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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 20:26:31 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 20:26:31 -0400
commita39451c17f53bbae053555670c7b678d46bcebba (patch)
tree8bb6106ec7812a421c3d3eb9c8c273580cc703fc
parentadb7ee3746b579a7fa7af7c4ec2c8164bc910ed4 (diff)
parent0e57976b6376f7fda6bef8b7dee2a3c8819ec9e9 (diff)
Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
Diffstat
-rw-r--r--Documentation/networking/ip-sysctl.txt56
-rw-r--r--Documentation/networking/tcp.txt69
-rw-r--r--include/linux/sysctl.h9
-rw-r--r--include/linux/tcp.h49
-rw-r--r--include/linux/tcp_diag.h4
-rw-r--r--include/net/tcp.h237
-rw-r--r--net/ipv4/Kconfig90
-rw-r--r--net/ipv4/Makefile10
-rw-r--r--net/ipv4/sysctl_net_ipv4.c114
-rw-r--r--net/ipv4/tcp.c2
-rw-r--r--net/ipv4/tcp_bic.c331
-rw-r--r--net/ipv4/tcp_cong.c195
-rw-r--r--net/ipv4/tcp_diag.c34
-rw-r--r--net/ipv4/tcp_highspeed.c181
-rw-r--r--net/ipv4/tcp_htcp.c289
-rw-r--r--net/ipv4/tcp_hybla.c187
-rw-r--r--net/ipv4/tcp_input.c737
-rw-r--r--net/ipv4/tcp_ipv4.c3
-rw-r--r--net/ipv4/tcp_minisocks.c4
-rw-r--r--net/ipv4/tcp_output.c23
-rw-r--r--net/ipv4/tcp_scalable.c68
-rw-r--r--net/ipv4/tcp_vegas.c411
-rw-r--r--net/ipv4/tcp_westwood.c259
-rw-r--r--net/ipv6/tcp_ipv6.c2
24 files changed, 2304 insertions, 1060 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index a2c893a7475d..ab65714d95fc 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -304,57 +304,6 @@ tcp_low_latency - BOOLEAN
304 changed would be a Beowulf compute cluster. 304 changed would be a Beowulf compute cluster.
305 Default: 0 305 Default: 0
306 306
307tcp_westwood - BOOLEAN
308 Enable TCP Westwood+ congestion control algorithm.
309 TCP Westwood+ is a sender-side only modification of the TCP Reno
310 protocol stack that optimizes the performance of TCP congestion
311 control. It is based on end-to-end bandwidth estimation to set
312 congestion window and slow start threshold after a congestion
313 episode. Using this estimation, TCP Westwood+ adaptively sets a
314 slow start threshold and a congestion window which takes into
315 account the bandwidth used at the time congestion is experienced.
316 TCP Westwood+ significantly increases fairness wrt TCP Reno in
317 wired networks and throughput over wireless links.
318 Default: 0
319
320tcp_vegas_cong_avoid - BOOLEAN
321 Enable TCP Vegas congestion avoidance algorithm.
322 TCP Vegas is a sender-side only change to TCP that anticipates
323 the onset of congestion by estimating the bandwidth. TCP Vegas
324 adjusts the sending rate by modifying the congestion
325 window. TCP Vegas should provide less packet loss, but it is
326 not as aggressive as TCP Reno.
327 Default:0
328
329tcp_bic - BOOLEAN
330 Enable BIC TCP congestion control algorithm.
331 BIC-TCP is a sender-side only change that ensures a linear RTT
332 fairness under large windows while offering both scalability and
333 bounded TCP-friendliness. The protocol combines two schemes
334 called additive increase and binary search increase. When the
335 congestion window is large, additive increase with a large
336 increment ensures linear RTT fairness as well as good
337 scalability. Under small congestion windows, binary search
338 increase provides TCP friendliness.
339 Default: 0
340
341tcp_bic_low_window - INTEGER
342 Sets the threshold window (in packets) where BIC TCP starts to
343 adjust the congestion window. Below this threshold BIC TCP behaves
344 the same as the default TCP Reno.
345 Default: 14
346
347tcp_bic_fast_convergence - BOOLEAN
348 Forces BIC TCP to more quickly respond to changes in congestion
349 window. Allows two flows sharing the same connection to converge
350 more rapidly.
351 Default: 1
352
353tcp_default_win_scale - INTEGER
354 Sets the minimum window scale TCP will negotiate for on all
355 conections.
356 Default: 7
357
358tcp_tso_win_divisor - INTEGER 307tcp_tso_win_divisor - INTEGER
359 This allows control over what percentage of the congestion window 308 This allows control over what percentage of the congestion window
360 can be consumed by a single TSO frame. 309 can be consumed by a single TSO frame.
@@ -368,6 +317,11 @@ tcp_frto - BOOLEAN
368 where packet loss is typically due to random radio interference 317 where packet loss is typically due to random radio interference
369 rather than intermediate router congestion. 318 rather than intermediate router congestion.
370 319
320tcp_congestion_control - STRING
321 Set the congestion control algorithm to be used for new
322 connections. The algorithm "reno" is always available, but
323 additional choices may be available based on kernel configuration.
324
371somaxconn - INTEGER 325somaxconn - INTEGER
372 Limit of socket listen() backlog, known in userspace as SOMAXCONN. 326 Limit of socket listen() backlog, known in userspace as SOMAXCONN.
373 Defaults to 128. See also tcp_max_syn_backlog for additional tuning 327 Defaults to 128. See also tcp_max_syn_backlog for additional tuning
diff --git a/Documentation/networking/tcp.txt b/Documentation/networking/tcp.txt
index 71749007091e..0fa300425575 100644
--- a/Documentation/networking/tcp.txt
+++ b/Documentation/networking/tcp.txt
@@ -1,5 +1,72 @@
1How the new TCP output machine [nyi] works. 1TCP protocol
2============
3
4Last updated: 21 June 2005
5
6Contents
7========
8
9- Congestion control
10- How the new TCP output machine [nyi] works
11
12Congestion control
13==================
14
15The following variables are used in the tcp_sock for congestion control:
16snd_cwnd The size of the congestion window
17snd_ssthresh Slow start threshold. We are in slow start if
18 snd_cwnd is less than this.
19snd_cwnd_cnt A counter used to slow down the rate of increase
20 once we exceed slow start threshold.
21snd_cwnd_clamp This is the maximum size that snd_cwnd can grow to.
22snd_cwnd_stamp Timestamp for when congestion window last validated.
23snd_cwnd_used Used as a highwater mark for how much of the
24 congestion window is in use. It is used to adjust
25 snd_cwnd down when the link is limited by the
26 application rather than the network.
27
28As of 2.6.13, Linux supports pluggable congestion control algorithms.
29A congestion control mechanism can be registered through functions in
30tcp_cong.c. The functions used by the congestion control mechanism are
31registered via passing a tcp_congestion_ops struct to
32tcp_register_congestion_control. As a minimum name, ssthresh,
33cong_avoid, min_cwnd must be valid.
2 34
35Private data for a congestion control mechanism is stored in tp->ca_priv.
36tcp_ca(tp) returns a pointer to this space. This is preallocated space - it
37is important to check the size of your private data will fit this space, or
38alternatively space could be allocated elsewhere and a pointer to it could
39be stored here.
40
41There are three kinds of congestion control algorithms currently: The
42simplest ones are derived from TCP reno (highspeed, scalable) and just
43provide an alternative the congestion window calculation. More complex
44ones like BIC try to look at other events to provide better
45heuristics. There are also round trip time based algorithms like
46Vegas and Westwood+.
47
48Good TCP congestion control is a complex problem because the algorithm
49needs to maintain fairness and performance. Please review current
50research and RFC's before developing new modules.
51
52The method that is used to determine which congestion control mechanism is
53determined by the setting of the sysctl net.ipv4.tcp_congestion_control.
54The default congestion control will be the last one registered (LIFO);
55so if you built everything as modules. the default will be reno. If you
56build with the default's from Kconfig, then BIC will be builtin (not a module)
57and it will end up the default.
58
59If you really want a particular default value then you will need
60to set it with the sysctl. If you use a sysctl, the module will be autoloaded
61if needed and you will get the expected protocol. If you ask for an
62unknown congestion method, then the sysctl attempt will fail.
63
64If you remove a tcp congestion control module, then you will get the next
65available one. Since reno can not be built as a module, and can not be
66deleted, it will always be available.
67
68How the new TCP output machine [nyi] works.
69===========================================
3 70
4Data is kept on a single queue. The skb->users flag tells us if the frame is 71Data is kept on a single queue. The skb->users flag tells us if the frame is
5one that has been queued already. To add a frame we throw it on the end. Ack 72one that has been queued already. To add a frame we throw it on the end. Ack
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 614e939c78a4..72965bfe6cfb 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -333,21 +333,14 @@ enum
333 NET_TCP_FRTO=92, 333 NET_TCP_FRTO=92,
334 NET_TCP_LOW_LATENCY=93, 334 NET_TCP_LOW_LATENCY=93,
335 NET_IPV4_IPFRAG_SECRET_INTERVAL=94, 335 NET_IPV4_IPFRAG_SECRET_INTERVAL=94,
336 NET_TCP_WESTWOOD=95,
337 NET_IPV4_IGMP_MAX_MSF=96, 336 NET_IPV4_IGMP_MAX_MSF=96,
338 NET_TCP_NO_METRICS_SAVE=97, 337 NET_TCP_NO_METRICS_SAVE=97,
339 NET_TCP_VEGAS=98,
340 NET_TCP_VEGAS_ALPHA=99,
341 NET_TCP_VEGAS_BETA=100,
342 NET_TCP_VEGAS_GAMMA=101,
343 NET_TCP_BIC=102,
344 NET_TCP_BIC_FAST_CONVERGENCE=103,
345 NET_TCP_BIC_LOW_WINDOW=104,
346 NET_TCP_DEFAULT_WIN_SCALE=105, 338 NET_TCP_DEFAULT_WIN_SCALE=105,
347 NET_TCP_MODERATE_RCVBUF=106, 339 NET_TCP_MODERATE_RCVBUF=106,
348 NET_TCP_TSO_WIN_DIVISOR=107, 340 NET_TCP_TSO_WIN_DIVISOR=107,
349 NET_TCP_BIC_BETA=108, 341 NET_TCP_BIC_BETA=108,
350 NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR=109, 342 NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR=109,
343 NET_TCP_CONG_CONTROL=110,
351}; 344};
352 345
353enum { 346enum {
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 97a7c9e03df5..3ea75dd6640a 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -203,13 +203,6 @@ struct tcp_sack_block {
203 __u32 end_seq; 203 __u32 end_seq;
204}; 204};
205 205
206enum tcp_congestion_algo {
207 TCP_RENO=0,
208 TCP_VEGAS,
209 TCP_WESTWOOD,
210 TCP_BIC,
211};
212
213struct tcp_options_received { 206struct tcp_options_received {
214/* PAWS/RTTM data */ 207/* PAWS/RTTM data */
215 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */ 208 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
@@ -305,7 +298,7 @@ struct tcp_sock {
305 __u8 reordering; /* Packet reordering metric. */ 298 __u8 reordering; /* Packet reordering metric. */
306 __u8 frto_counter; /* Number of new acks after RTO */ 299 __u8 frto_counter; /* Number of new acks after RTO */
307 300
308 __u8 adv_cong; /* Using Vegas, Westwood, or BIC */ 301 __u8 unused;
309 __u8 defer_accept; /* User waits for some data after accept() */ 302 __u8 defer_accept; /* User waits for some data after accept() */
310 303
311/* RTT measurement */ 304/* RTT measurement */
@@ -401,37 +394,10 @@ struct tcp_sock {
401 __u32 time; 394 __u32 time;
402 } rcvq_space; 395 } rcvq_space;
403 396
404/* TCP Westwood structure */ 397 /* Pluggable TCP congestion control hook */
405 struct { 398 struct tcp_congestion_ops *ca_ops;
406 __u32 bw_ns_est; /* first bandwidth estimation..not too smoothed 8) */ 399 u32 ca_priv[16];
407 __u32 bw_est; /* bandwidth estimate */ 400#define TCP_CA_PRIV_SIZE (16*sizeof(u32))
408 __u32 rtt_win_sx; /* here starts a new evaluation... */
409 __u32 bk;
410 __u32 snd_una; /* used for evaluating the number of acked bytes */
411 __u32 cumul_ack;
412 __u32 accounted;
413 __u32 rtt;
414 __u32 rtt_min; /* minimum observed RTT */
415 } westwood;
416
417/* Vegas variables */
418 struct {
419 __u32 beg_snd_nxt; /* right edge during last RTT */
420 __u32 beg_snd_una; /* left edge during last RTT */
421 __u32 beg_snd_cwnd; /* saves the size of the cwnd */
422 __u8 doing_vegas_now;/* if true, do vegas for this RTT */
423 __u16 cntRTT; /* # of RTTs measured within last RTT */
424 __u32 minRTT; /* min of RTTs measured within last RTT (in usec) */
425 __u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */
426 } vegas;
427
428 /* BI TCP Parameters */
429 struct {
430 __u32 cnt; /* increase cwnd by 1 after this number of ACKs */
431 __u32 last_max_cwnd; /* last maximium snd_cwnd */
432 __u32 last_cwnd; /* the last snd_cwnd */
433 __u32 last_stamp; /* time when updated last_cwnd */
434 } bictcp;
435}; 401};
436 402
437static inline struct tcp_sock *tcp_sk(const struct sock *sk) 403static inline struct tcp_sock *tcp_sk(const struct sock *sk)
@@ -439,6 +405,11 @@ static inline struct tcp_sock *tcp_sk(const struct sock *sk)
439 return (struct tcp_sock *)sk; 405 return (struct tcp_sock *)sk;
440} 406}
441 407
408static inline void *tcp_ca(const struct tcp_sock *tp)
409{
410 return (void *) tp->ca_priv;
411}
412
442#endif 413#endif
443 414
444#endif /* _LINUX_TCP_H */ 415#endif /* _LINUX_TCP_H */
diff --git a/include/linux/tcp_diag.h b/include/linux/tcp_diag.h
index ceee962e1d15..7a5996743946 100644
--- a/include/linux/tcp_diag.h
+++ b/include/linux/tcp_diag.h
@@ -99,9 +99,10 @@ enum
99 TCPDIAG_MEMINFO, 99 TCPDIAG_MEMINFO,
100 TCPDIAG_INFO, 100 TCPDIAG_INFO,
101 TCPDIAG_VEGASINFO, 101 TCPDIAG_VEGASINFO,
102 TCPDIAG_CONG,
102}; 103};
103 104
104#define TCPDIAG_MAX TCPDIAG_VEGASINFO 105#define TCPDIAG_MAX TCPDIAG_CONG
105 106
106 107
107/* TCPDIAG_MEM */ 108/* TCPDIAG_MEM */
@@ -123,5 +124,4 @@ struct tcpvegas_info {
123 __u32 tcpv_minrtt; 124 __u32 tcpv_minrtt;
124}; 125};
125 126
126
127#endif /* _TCP_DIAG_H_ */ 127#endif /* _TCP_DIAG_H_ */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index f730935b824a..e427cf35915c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -505,25 +505,6 @@ static __inline__ int tcp_sk_listen_hashfn(struct sock *sk)
505#else 505#else
506# define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG) 506# define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG)
507#endif 507#endif
508
509#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation
510 * max_cwnd = snd_cwnd * beta
511 */
512#define BICTCP_MAX_INCREMENT 32 /*
513 * Limit on the amount of
514 * increment allowed during
515 * binary search.
516 */
517#define BICTCP_FUNC_OF_MIN_INCR 11 /*
518 * log(B/Smin)/log(B/(B-1))+1,
519 * Smin:min increment
520 * B:log factor
521 */
522#define BICTCP_B 4 /*
523 * In binary search,
524 * go to point (max+min)/N
525 */
526
527/* 508/*
528 * TCP option 509 * TCP option
529 */ 510 */
@@ -596,16 +577,7 @@ extern int sysctl_tcp_adv_win_scale;
596extern int sysctl_tcp_tw_reuse; 577extern int sysctl_tcp_tw_reuse;
597extern int sysctl_tcp_frto; 578extern int sysctl_tcp_frto;
598extern int sysctl_tcp_low_latency; 579extern int sysctl_tcp_low_latency;
599extern int sysctl_tcp_westwood;
600extern int sysctl_tcp_vegas_cong_avoid;
601extern int sysctl_tcp_vegas_alpha;
602extern int sysctl_tcp_vegas_beta;
603extern int sysctl_tcp_vegas_gamma;
604extern int sysctl_tcp_nometrics_save; 580extern int sysctl_tcp_nometrics_save;
605extern int sysctl_tcp_bic;
606extern int sysctl_tcp_bic_fast_convergence;
607extern int sysctl_tcp_bic_low_window;
608extern int sysctl_tcp_bic_beta;
609extern int sysctl_tcp_moderate_rcvbuf; 581extern int sysctl_tcp_moderate_rcvbuf;
610extern int sysctl_tcp_tso_win_divisor; 582extern int sysctl_tcp_tso_win_divisor;
611 583
@@ -1136,6 +1108,80 @@ static inline void tcp_packets_out_dec(struct tcp_sock *tp,
1136 tp->packets_out -= tcp_skb_pcount(skb); 1108 tp->packets_out -= tcp_skb_pcount(skb);
1137} 1109}
1138 1110
1111/* Events passed to congestion control interface */
1112enum tcp_ca_event {
1113 CA_EVENT_TX_START, /* first transmit when no packets in flight */
1114 CA_EVENT_CWND_RESTART, /* congestion window restart */
1115 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
1116 CA_EVENT_FRTO, /* fast recovery timeout */
1117 CA_EVENT_LOSS, /* loss timeout */
1118 CA_EVENT_FAST_ACK, /* in sequence ack */
1119 CA_EVENT_SLOW_ACK, /* other ack */
1120};
1121
1122/*
1123 * Interface for adding new TCP congestion control handlers
1124 */
1125#define TCP_CA_NAME_MAX 16
1126struct tcp_congestion_ops {
1127 struct list_head list;
1128
1129 /* initialize private data (optional) */
1130 void (*init)(struct tcp_sock *tp);
1131 /* cleanup private data (optional) */
1132 void (*release)(struct tcp_sock *tp);
1133
1134 /* return slow start threshold (required) */
1135 u32 (*ssthresh)(struct tcp_sock *tp);
1136 /* lower bound for congestion window (optional) */
1137 u32 (*min_cwnd)(struct tcp_sock *tp);
1138 /* do new cwnd calculation (required) */
1139 void (*cong_avoid)(struct tcp_sock *tp, u32 ack,
1140 u32 rtt, u32 in_flight, int good_ack);
1141 /* round trip time sample per acked packet (optional) */
1142 void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt);
1143 /* call before changing ca_state (optional) */
1144 void (*set_state)(struct tcp_sock *tp, u8 new_state);
1145 /* call when cwnd event occurs (optional) */
1146 void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev);
1147 /* new value of cwnd after loss (optional) */
1148 u32 (*undo_cwnd)(struct tcp_sock *tp);
1149 /* hook for packet ack accounting (optional) */
1150 void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked);
1151 /* get info for tcp_diag (optional) */
1152 void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb);
1153
1154 char name[TCP_CA_NAME_MAX];
1155 struct module *owner;
1156};
1157
1158extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
1159extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
1160
1161extern void tcp_init_congestion_control(struct tcp_sock *tp);
1162extern void tcp_cleanup_congestion_control(struct tcp_sock *tp);
1163extern int tcp_set_default_congestion_control(const char *name);
1164extern void tcp_get_default_congestion_control(char *name);
1165
1166extern struct tcp_congestion_ops tcp_reno;
1167extern u32 tcp_reno_ssthresh(struct tcp_sock *tp);
1168extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack,
1169 u32 rtt, u32 in_flight, int flag);
1170extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp);
1171
1172static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
1173{
1174 if (tp->ca_ops->set_state)
1175 tp->ca_ops->set_state(tp, ca_state);
1176 tp->ca_state = ca_state;
1177}
1178
1179static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event)
1180{
1181 if (tp->ca_ops->cwnd_event)
1182 tp->ca_ops->cwnd_event(tp, event);
1183}
1184
1139/* This determines how many packets are "in the network" to the best 1185/* This determines how many packets are "in the network" to the best
1140 * of our knowledge. In many cases it is conservative, but where 1186 * of our knowledge. In many cases it is conservative, but where
1141 * detailed information is available from the receiver (via SACK 1187 * detailed information is available from the receiver (via SACK
@@ -1155,91 +1201,6 @@ static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
1155 return (tp->packets_out - tp->left_out + tp->retrans_out); 1201 return (tp->packets_out - tp->left_out + tp->retrans_out);
1156} 1202}
1157 1203
1158/*
1159 * Which congestion algorithim is in use on the connection.
1160 */
1161#define tcp_is_vegas(__tp) ((__tp)->adv_cong == TCP_VEGAS)
1162#define tcp_is_westwood(__tp) ((__tp)->adv_cong == TCP_WESTWOOD)
1163#define tcp_is_bic(__tp) ((__tp)->adv_cong == TCP_BIC)
1164
1165/* Recalculate snd_ssthresh, we want to set it to:
1166 *
1167 * Reno:
1168 * one half the current congestion window, but no
1169 * less than two segments
1170 *
1171 * BIC:
1172 * behave like Reno until low_window is reached,
1173 * then increase congestion window slowly
1174 */
1175static inline __u32 tcp_recalc_ssthresh(struct tcp_sock *tp)
1176{
1177 if (tcp_is_bic(tp)) {
1178 if (sysctl_tcp_bic_fast_convergence &&
1179 tp->snd_cwnd < tp->bictcp.last_max_cwnd)
1180 tp->bictcp.last_max_cwnd = (tp->snd_cwnd *
1181 (BICTCP_BETA_SCALE
1182 + sysctl_tcp_bic_beta))
1183 / (2 * BICTCP_BETA_SCALE);
1184 else
1185 tp->bictcp.last_max_cwnd = tp->snd_cwnd;
1186
1187 if (tp->snd_cwnd > sysctl_tcp_bic_low_window)
1188 return max((tp->snd_cwnd * sysctl_tcp_bic_beta)
1189 / BICTCP_BETA_SCALE, 2U);
1190 }
1191
1192 return max(tp->snd_cwnd >> 1U, 2U);
1193}
1194
1195/* Stop taking Vegas samples for now. */
1196#define tcp_vegas_disable(__tp) ((__tp)->vegas.doing_vegas_now = 0)
1197
1198static inline void tcp_vegas_enable(struct tcp_sock *tp)
1199{
1200 /* There are several situations when we must "re-start" Vegas:
1201 *
1202 * o when a connection is established
1203 * o after an RTO
1204 * o after fast recovery
1205 * o when we send a packet and there is no outstanding
1206 * unacknowledged data (restarting an idle connection)
1207 *
1208 * In these circumstances we cannot do a Vegas calculation at the
1209 * end of the first RTT, because any calculation we do is using
1210 * stale info -- both the saved cwnd and congestion feedback are
1211 * stale.
1212 *
1213 * Instead we must wait until the completion of an RTT during
1214 * which we actually receive ACKs.
1215 */
1216
1217 /* Begin taking Vegas samples next time we send something. */
1218 tp->vegas.doing_vegas_now = 1;
1219
1220 /* Set the beginning of the next send window. */
1221 tp->vegas.beg_snd_nxt = tp->snd_nxt;
1222
1223 tp->vegas.cntRTT = 0;
1224 tp->vegas.minRTT = 0x7fffffff;
1225}
1226
1227/* Should we be taking Vegas samples right now? */
1228#define tcp_vegas_enabled(__tp) ((__tp)->vegas.doing_vegas_now)
1229
1230extern void tcp_ca_init(struct tcp_sock *tp);
1231
1232static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
1233{
1234 if (tcp_is_vegas(tp)) {
1235 if (ca_state == TCP_CA_Open)
1236 tcp_vegas_enable(tp);
1237 else
1238 tcp_vegas_disable(tp);
1239 }
1240 tp->ca_state = ca_state;
1241}
1242
1243/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. 1204/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
1244 * The exception is rate halving phase, when cwnd is decreasing towards 1205 * The exception is rate halving phase, when cwnd is decreasing towards
1245 * ssthresh. 1206 * ssthresh.
@@ -1288,7 +1249,7 @@ static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
1288static inline void __tcp_enter_cwr(struct tcp_sock *tp) 1249static inline void __tcp_enter_cwr(struct tcp_sock *tp)
1289{ 1250{
1290 tp->undo_marker = 0; 1251 tp->undo_marker = 0;
1291 tp->snd_ssthresh = tcp_recalc_ssthresh(tp); 1252 tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
1292 tp->snd_cwnd = min(tp->snd_cwnd, 1253 tp->snd_cwnd = min(tp->snd_cwnd,
1293 tcp_packets_in_flight(tp) + 1U); 1254 tcp_packets_in_flight(tp) + 1U);
1294 tp->snd_cwnd_cnt = 0; 1255 tp->snd_cwnd_cnt = 0;
@@ -1876,52 +1837,4 @@ struct tcp_iter_state {
1876extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo); 1837extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
1877extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo); 1838extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
1878 1839
1879/* TCP Westwood functions and constants */
1880
1881#define TCP_WESTWOOD_INIT_RTT (20*HZ) /* maybe too conservative?! */
1882#define TCP_WESTWOOD_RTT_MIN (HZ/20) /* 50ms */
1883
1884static inline void tcp_westwood_update_rtt(struct tcp_sock *tp, __u32 rtt_seq)
1885{
1886 if (tcp_is_westwood(tp))
1887 tp->westwood.rtt = rtt_seq;
1888}
1889
1890static inline __u32 __tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
1891{
1892 return max((tp->westwood.bw_est) * (tp->westwood.rtt_min) /
1893 (__u32) (tp->mss_cache_std),
1894 2U);
1895}
1896
1897static inline __u32 tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
1898{
1899 return tcp_is_westwood(tp) ? __tcp_westwood_bw_rttmin(tp) : 0;
1900}
1901
1902static inline int tcp_westwood_ssthresh(struct tcp_sock *tp)
1903{
1904 __u32 ssthresh = 0;
1905
1906 if (tcp_is_westwood(tp)) {
1907 ssthresh = __tcp_westwood_bw_rttmin(tp);
1908 if (ssthresh)
1909 tp->snd_ssthresh = ssthresh;
1910 }
1911
1912 return (ssthresh != 0);
1913}
1914
1915static inline int tcp_westwood_cwnd(struct tcp_sock *tp)
1916{
1917 __u32 cwnd = 0;
1918
1919 if (tcp_is_westwood(tp)) {
1920 cwnd = __tcp_westwood_bw_rttmin(tp);
1921 if (cwnd)
1922 tp->snd_cwnd = cwnd;
1923 }
1924
1925 return (cwnd != 0);
1926}
1927#endif /* _TCP_H */ 1840#endif /* _TCP_H */
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 567b03b1c349..690e88ba2484 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -433,5 +433,95 @@ config IP_TCPDIAG
433config IP_TCPDIAG_IPV6 433config IP_TCPDIAG_IPV6
434 def_bool (IP_TCPDIAG=y && IPV6=y) || (IP_TCPDIAG=m && IPV6) 434 def_bool (IP_TCPDIAG=y && IPV6=y) || (IP_TCPDIAG=m && IPV6)
435 435
436# TCP Reno is builtin (required as fallback)
437menu "TCP congestion control"
438 depends on INET
439
440config TCP_CONG_BIC
441 tristate "Binary Increase Congestion (BIC) control"
442 depends on INET
443 default y
444 ---help---
445 BIC-TCP is a sender-side only change that ensures a linear RTT
446 fairness under large windows while offering both scalability and
447 bounded TCP-friendliness. The protocol combines two schemes
448 called additive increase and binary search increase. When the
449 congestion window is large, additive increase with a large
450 increment ensures linear RTT fairness as well as good
451 scalability. Under small congestion windows, binary search
452 increase provides TCP friendliness.
453 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
454
455config TCP_CONG_WESTWOOD
456 tristate "TCP Westwood+"
457 depends on INET
458 default m
459 ---help---
460 TCP Westwood+ is a sender-side only modification of the TCP Reno
461 protocol stack that optimizes the performance of TCP congestion
462 control. It is based on end-to-end bandwidth estimation to set
463 congestion window and slow start threshold after a congestion
464 episode. Using this estimation, TCP Westwood+ adaptively sets a
465 slow start threshold and a congestion window which takes into
466 account the bandwidth used at the time congestion is experienced.
467 TCP Westwood+ significantly increases fairness wrt TCP Reno in
468 wired networks and throughput over wireless links.
469
470config TCP_CONG_HTCP
471 tristate "H-TCP"
472 depends on INET
473 default m
474 ---help---
475 H-TCP is a send-side only modifications of the TCP Reno
476 protocol stack that optimizes the performance of TCP
477 congestion control for high speed network links. It uses a
478 modeswitch to change the alpha and beta parameters of TCP Reno
479 based on network conditions and in a way so as to be fair with
480 other Reno and H-TCP flows.
481
482config TCP_CONG_HSTCP
483 tristate "High Speed TCP"
484 depends on INET && EXPERIMENTAL
485 default n
486 ---help---
487 Sally Floyd's High Speed TCP (RFC 3649) congestion control.
488 A modification to TCP's congestion control mechanism for use
489 with large congestion windows. A table indicates how much to
490 increase the congestion window by when an ACK is received.
491 For more detail see http://www.icir.org/floyd/hstcp.html
492
493config TCP_CONG_HYBLA
494 tristate "TCP-Hybla congestion control algorithm"
495 depends on INET && EXPERIMENTAL
496 default n
497 ---help---
498 TCP-Hybla is a sender-side only change that eliminates penalization of
499 long-RTT, large-bandwidth connections, like when satellite legs are
500 involved, expecially when sharing a common bottleneck with normal
501 terrestrial connections.
502
503config TCP_CONG_VEGAS
504 tristate "TCP Vegas"
505 depends on INET && EXPERIMENTAL
506 default n
507 ---help---
508 TCP Vegas is a sender-side only change to TCP that anticipates
509 the onset of congestion by estimating the bandwidth. TCP Vegas
510 adjusts the sending rate by modifying the congestion
511 window. TCP Vegas should provide less packet loss, but it is
512 not as aggressive as TCP Reno.
513
514config TCP_CONG_SCALABLE
515 tristate "Scalable TCP"
516 depends on INET && EXPERIMENTAL
517 default n
518 ---help---
519 Scalable TCP is a sender-side only change to TCP which uses a
520 MIMD congestion control algorithm which has some nice scaling
521 properties, though is known to have fairness issues.
522 See http://www-lce.eng.cam.ac.uk/~ctk21/scalable/
523
524endmenu
525
436source "net/ipv4/ipvs/Kconfig" 526source "net/ipv4/ipvs/Kconfig"
437 527
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 65d57d8e1add..5718cdb3a61e 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -5,7 +5,8 @@
5obj-y := utils.o route.o inetpeer.o protocol.o \ 5obj-y := utils.o route.o inetpeer.o protocol.o \
6 ip_input.o ip_fragment.o ip_forward.o ip_options.o \ 6 ip_input.o ip_fragment.o ip_forward.o ip_options.o \
7 ip_output.o ip_sockglue.o \ 7 ip_output.o ip_sockglue.o \
8 tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o tcp_minisocks.o \ 8 tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
9 tcp_minisocks.o tcp_cong.o \
9 datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \ 10 datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \
10 sysctl_net_ipv4.o fib_frontend.o fib_semantics.o 11 sysctl_net_ipv4.o fib_frontend.o fib_semantics.o
11 12
@@ -30,6 +31,13 @@ obj-$(CONFIG_NETFILTER) += netfilter/
30obj-$(CONFIG_IP_VS) += ipvs/ 31obj-$(CONFIG_IP_VS) += ipvs/
31obj-$(CONFIG_IP_TCPDIAG) += tcp_diag.o 32obj-$(CONFIG_IP_TCPDIAG) += tcp_diag.o
32obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o 33obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o
34obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o
35obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o
36obj-$(CONFIG_TCP_CONG_HSTCP) += tcp_highspeed.o
37obj-$(CONFIG_TCP_CONG_HYBLA) += tcp_hybla.o
38obj-$(CONFIG_TCP_CONG_HTCP) += tcp_htcp.o
39obj-$(CONFIG_TCP_CONG_VEGAS) += tcp_vegas.o
40obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
33 41
34obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \ 42obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
35 xfrm4_output.o 43 xfrm4_output.o
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 23068bddbf0b..e32894532416 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -118,6 +118,45 @@ static int ipv4_sysctl_forward_strategy(ctl_table *table,
118 return 1; 118 return 1;
119} 119}
120 120
121static int proc_tcp_congestion_control(ctl_table *ctl, int write, struct file * filp,
122 void __user *buffer, size_t *lenp, loff_t *ppos)
123{
124 char val[TCP_CA_NAME_MAX];
125 ctl_table tbl = {
126 .data = val,
127 .maxlen = TCP_CA_NAME_MAX,
128 };
129 int ret;
130
131 tcp_get_default_congestion_control(val);
132
133 ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
134 if (write && ret == 0)
135 ret = tcp_set_default_congestion_control(val);
136 return ret;
137}
138
139int sysctl_tcp_congestion_control(ctl_table *table, int __user *name, int nlen,
140 void __user *oldval, size_t __user *oldlenp,
141 void __user *newval, size_t newlen,
142 void **context)
143{
144 char val[TCP_CA_NAME_MAX];
145 ctl_table tbl = {
146 .data = val,
147 .maxlen = TCP_CA_NAME_MAX,
148 };
149 int ret;
150
151 tcp_get_default_congestion_control(val);
152 ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen,
153 context);
154 if (ret == 0 && newval && newlen)
155 ret = tcp_set_default_congestion_control(val);
156 return ret;
157}
158
159
121ctl_table ipv4_table[] = { 160ctl_table ipv4_table[] = {
122 { 161 {
123 .ctl_name = NET_IPV4_TCP_TIMESTAMPS, 162 .ctl_name = NET_IPV4_TCP_TIMESTAMPS,
@@ -612,70 +651,6 @@ ctl_table ipv4_table[] = {
612 .proc_handler = &proc_dointvec, 651 .proc_handler = &proc_dointvec,
613 }, 652 },
614 { 653 {
615 .ctl_name = NET_TCP_WESTWOOD,
616 .procname = "tcp_westwood",
617 .data = &sysctl_tcp_westwood,
618 .maxlen = sizeof(int),
619 .mode = 0644,
620 .proc_handler = &proc_dointvec,
621 },
622 {
623 .ctl_name = NET_TCP_VEGAS,
624 .procname = "tcp_vegas_cong_avoid",
625 .data = &sysctl_tcp_vegas_cong_avoid,
626 .maxlen = sizeof(int),
627 .mode = 0644,
628 .proc_handler = &proc_dointvec,
629 },
630 {
631 .ctl_name = NET_TCP_VEGAS_ALPHA,
632 .procname = "tcp_vegas_alpha",
633 .data = &sysctl_tcp_vegas_alpha,
634 .maxlen = sizeof(int),
635 .mode = 0644,
636 .proc_handler = &proc_dointvec,
637 },
638 {
639 .ctl_name = NET_TCP_VEGAS_BETA,
640 .procname = "tcp_vegas_beta",
641 .data = &sysctl_tcp_vegas_beta,
642 .maxlen = sizeof(int),
643 .mode = 0644,
644 .proc_handler = &proc_dointvec,
645 },
646 {
647 .ctl_name = NET_TCP_VEGAS_GAMMA,
648 .procname = "tcp_vegas_gamma",
649 .data = &sysctl_tcp_vegas_gamma,
650 .maxlen = sizeof(int),
651 .mode = 0644,
652 .proc_handler = &proc_dointvec,
653 },
654 {
655 .ctl_name = NET_TCP_BIC,
656 .procname = "tcp_bic",
657 .data = &sysctl_tcp_bic,
658 .maxlen = sizeof(int),
659 .mode = 0644,
660 .proc_handler = &proc_dointvec,
661 },
662 {
663 .ctl_name = NET_TCP_BIC_FAST_CONVERGENCE,
664 .procname = "tcp_bic_fast_convergence",
665 .data = &sysctl_tcp_bic_fast_convergence,
666 .maxlen = sizeof(int),
667 .mode = 0644,
668 .proc_handler = &proc_dointvec,
669 },
670 {
671 .ctl_name = NET_TCP_BIC_LOW_WINDOW,
672 .procname = "tcp_bic_low_window",
673 .data = &sysctl_tcp_bic_low_window,
674 .maxlen = sizeof(int),
675 .mode = 0644,
676 .proc_handler = &proc_dointvec,
677 },
678 {
679 .ctl_name = NET_TCP_MODERATE_RCVBUF, 654 .ctl_name = NET_TCP_MODERATE_RCVBUF,
680 .procname = "tcp_moderate_rcvbuf", 655 .procname = "tcp_moderate_rcvbuf",
681 .data = &sysctl_tcp_moderate_rcvbuf, 656 .data = &sysctl_tcp_moderate_rcvbuf,
@@ -692,13 +667,14 @@ ctl_table ipv4_table[] = {
692 .proc_handler = &proc_dointvec, 667 .proc_handler = &proc_dointvec,
693 }, 668 },
694 { 669 {
695 .ctl_name = NET_TCP_BIC_BETA, 670 .ctl_name = NET_TCP_CONG_CONTROL,
696 .procname = "tcp_bic_beta", 671 .procname = "tcp_congestion_control",
697 .data = &sysctl_tcp_bic_beta,
698 .maxlen = sizeof(int),
699 .mode = 0644, 672 .mode = 0644,
700 .proc_handler = &proc_dointvec, 673 .maxlen = TCP_CA_NAME_MAX,
674 .proc_handler = &proc_tcp_congestion_control,
675 .strategy = &sysctl_tcp_congestion_control,
701 }, 676 },
677
702 { .ctl_name = 0 } 678 { .ctl_name = 0 }
703}; 679};
704 680
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 674bbd8cfd36..f3dbc8dc1263 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2333,6 +2333,8 @@ void __init tcp_init(void)
2333 printk(KERN_INFO "TCP: Hash tables configured " 2333 printk(KERN_INFO "TCP: Hash tables configured "
2334 "(established %d bind %d)\n", 2334 "(established %d bind %d)\n",
2335 tcp_ehash_size << 1, tcp_bhash_size); 2335 tcp_ehash_size << 1, tcp_bhash_size);
2336
2337 tcp_register_congestion_control(&tcp_reno);
2336} 2338}
2337 2339
2338EXPORT_SYMBOL(tcp_accept); 2340EXPORT_SYMBOL(tcp_accept);
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
new file mode 100644
index 000000000000..ec38d45d6649
--- /dev/null
+++ b/net/ipv4/tcp_bic.c
@@ -0,0 +1,331 @@
1/*
2 * Binary Increase Congestion control for TCP
3 *
4 * This is from the implementation of BICTCP in
5 * Lison-Xu, Kahaled Harfoush, and Injong Rhee.
6 * "Binary Increase Congestion Control for Fast, Long Distance
7 * Networks" in InfoComm 2004
8 * Available from:
9 * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp.pdf
10 *
11 * Unless BIC is enabled and congestion window is large
12 * this behaves the same as the original Reno.
13 */
14
15#include <linux/config.h>
16#include <linux/mm.h>
17#include <linux/module.h>
18#include <net/tcp.h>
19
20
21#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation
22 * max_cwnd = snd_cwnd * beta
23 */
24#define BICTCP_B 4 /*
25 * In binary search,
26 * go to point (max+min)/N
27 */
28
29static int fast_convergence = 1;
30static int max_increment = 32;
31static int low_window = 14;
32static int beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */
33static int low_utilization_threshold = 153;
34static int low_utilization_period = 2;
35static int initial_ssthresh = 100;
36static int smooth_part = 20;
37
38module_param(fast_convergence, int, 0644);
39MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence");
40module_param(max_increment, int, 0644);
41MODULE_PARM_DESC(max_increment, "Limit on increment allowed during binary search");
42module_param(low_window, int, 0644);
43MODULE_PARM_DESC(low_window, "lower bound on congestion window (for TCP friendliness)");
44module_param(beta, int, 0644);
45MODULE_PARM_DESC(beta, "beta for multiplicative increase");
46module_param(low_utilization_threshold, int, 0644);
47MODULE_PARM_DESC(low_utilization_threshold, "percent (scaled by 1024) for low utilization mode");
48module_param(low_utilization_period, int, 0644);
49MODULE_PARM_DESC(low_utilization_period, "if average delay exceeds then goto to low utilization mode (seconds)");
50module_param(initial_ssthresh, int, 0644);
51MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold");
52module_param(smooth_part, int, 0644);
53MODULE_PARM_DESC(smooth_part, "log(B/(B*Smin))/log(B/(B-1))+B, # of RTT from Wmax-B to Wmax");
54
55
56/* BIC TCP Parameters */
57struct bictcp {
58 u32 cnt; /* increase cwnd by 1 after ACKs */
59 u32 last_max_cwnd; /* last maximum snd_cwnd */
60 u32 loss_cwnd; /* congestion window at last loss */
61 u32 last_cwnd; /* the last snd_cwnd */
62 u32 last_time; /* time when updated last_cwnd */
63 u32 delay_min; /* min delay */
64 u32 delay_max; /* max delay */
65 u32 last_delay;
66 u8 low_utilization;/* 0: high; 1: low */
67 u32 low_utilization_start; /* starting time of low utilization detection*/
68 u32 epoch_start; /* beginning of an epoch */
69#define ACK_RATIO_SHIFT 4
70 u32 delayed_ack; /* estimate the ratio of Packets/ACKs << 4 */
71};
72
73static inline void bictcp_reset(struct bictcp *ca)
74{
75 ca->cnt = 0;
76 ca->last_max_cwnd = 0;
77 ca->loss_cwnd = 0;
78 ca->last_cwnd = 0;
79 ca->last_time = 0;
80 ca->delay_min = 0;
81 ca->delay_max = 0;
82 ca->last_delay = 0;
83 ca->low_utilization = 0;
84 ca->low_utilization_start = 0;
85 ca->epoch_start = 0;
86 ca->delayed_ack = 2 << ACK_RATIO_SHIFT;
87}
88
89static void bictcp_init(struct tcp_sock *tp)
90{
91 bictcp_reset(tcp_ca(tp));
92 if (initial_ssthresh)
93 tp->snd_ssthresh = initial_ssthresh;
94}
95
96/*
97 * Compute congestion window to use.
98 */
99static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
100{
101 if (ca->last_cwnd == cwnd &&
102 (s32)(tcp_time_stamp - ca->last_time) <= HZ / 32)
103 return;
104
105 ca->last_cwnd = cwnd;
106 ca->last_time = tcp_time_stamp;
107
108 if (ca->epoch_start == 0) /* record the beginning of an epoch */
109 ca->epoch_start = tcp_time_stamp;
110
111 /* start off normal */
112 if (cwnd <= low_window) {
113 ca->cnt = cwnd;
114 return;
115 }
116
117 /* binary increase */
118 if (cwnd < ca->last_max_cwnd) {
119 __u32 dist = (ca->last_max_cwnd - cwnd)
120 / BICTCP_B;
121
122 if (dist > max_increment)
123 /* linear increase */
124 ca->cnt = cwnd / max_increment;
125 else if (dist <= 1U)
126 /* binary search increase */
127 ca->cnt = (cwnd * smooth_part) / BICTCP_B;
128 else
129 /* binary search increase */
130 ca->cnt = cwnd / dist;
131 } else {
132 /* slow start AMD linear increase */
133 if (cwnd < ca->last_max_cwnd + BICTCP_B)
134 /* slow start */
135 ca->cnt = (cwnd * smooth_part) / BICTCP_B;
136 else if (cwnd < ca->last_max_cwnd + max_increment*(BICTCP_B-1))
137 /* slow start */
138 ca->cnt = (cwnd * (BICTCP_B-1))
139 / cwnd-ca->last_max_cwnd;
140 else
141 /* linear increase */
142 ca->cnt = cwnd / max_increment;
143 }
144
145 /* if in slow start or link utilization is very low */
146 if ( ca->loss_cwnd == 0 ||
147 (cwnd > ca->loss_cwnd && ca->low_utilization)) {
148 if (ca->cnt > 20) /* increase cwnd 5% per RTT */
149 ca->cnt = 20;
150 }
151
152 ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack;
153 if (ca->cnt == 0) /* cannot be zero */
154 ca->cnt = 1;
155}
156
157
158/* Detect low utilization in congestion avoidance */
159static inline void bictcp_low_utilization(struct tcp_sock *tp, int flag)
160{
161 struct bictcp *ca = tcp_ca(tp);
162 u32 dist, delay;
163
164 /* No time stamp */
165 if (!(tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr) ||
166 /* Discard delay samples right after fast recovery */
167 tcp_time_stamp < ca->epoch_start + HZ ||
168 /* this delay samples may not be accurate */
169 flag == 0) {
170 ca->last_delay = 0;
171 goto notlow;
172 }
173
174 delay = ca->last_delay<<3; /* use the same scale as tp->srtt*/
175 ca->last_delay = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
176 if (delay == 0) /* no previous delay sample */
177 goto notlow;
178
179 /* first time call or link delay decreases */
180 if (ca->delay_min == 0 || ca->delay_min > delay) {
181 ca->delay_min = ca->delay_max = delay;
182 goto notlow;
183 }
184
185 if (ca->delay_max < delay)
186 ca->delay_max = delay;
187
188 /* utilization is low, if avg delay < dist*threshold
189 for checking_period time */
190 dist = ca->delay_max - ca->delay_min;
191 if (dist <= ca->delay_min>>6 ||
192 tp->srtt - ca->delay_min >= (dist*low_utilization_threshold)>>10)
193 goto notlow;
194
195 if (ca->low_utilization_start == 0) {
196 ca->low_utilization = 0;
197 ca->low_utilization_start = tcp_time_stamp;
198 } else if ((s32)(tcp_time_stamp - ca->low_utilization_start)
199 > low_utilization_period*HZ) {
200 ca->low_utilization = 1;
201 }
202
203 return;
204
205 notlow:
206 ca->low_utilization = 0;
207 ca->low_utilization_start = 0;
208
209}
210
211static void bictcp_cong_avoid(struct tcp_sock *tp, u32 ack,
212 u32 seq_rtt, u32 in_flight, int data_acked)
213{
214 struct bictcp *ca = tcp_ca(tp);
215
216 bictcp_low_utilization(tp, data_acked);
217
218 if (in_flight < tp->snd_cwnd)
219 return;
220
221 if (tp->snd_cwnd <= tp->snd_ssthresh) {
222 /* In "safe" area, increase. */
223 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
224 tp->snd_cwnd++;
225 } else {
226 bictcp_update(ca, tp->snd_cwnd);
227
228 /* In dangerous area, increase slowly.
229 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
230 */
231 if (tp->snd_cwnd_cnt >= ca->cnt) {
232 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
233 tp->snd_cwnd++;
234 tp->snd_cwnd_cnt = 0;
235 } else
236 tp->snd_cwnd_cnt++;
237 }
238
239}
240
241/*
242 * behave like Reno until low_window is reached,
243 * then increase congestion window slowly
244 */
245static u32 bictcp_recalc_ssthresh(struct tcp_sock *tp)
246{
247 struct bictcp *ca = tcp_ca(tp);
248
249 ca->epoch_start = 0; /* end of epoch */
250
251 /* in case of wrong delay_max*/
252 if (ca->delay_min > 0 && ca->delay_max > ca->delay_min)
253 ca->delay_max = ca->delay_min
254 + ((ca->delay_max - ca->delay_min)* 90) / 100;
255
256 /* Wmax and fast convergence */
257 if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence)
258 ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta))
259 / (2 * BICTCP_BETA_SCALE);
260 else
261 ca->last_max_cwnd = tp->snd_cwnd;
262
263 ca->loss_cwnd = tp->snd_cwnd;
264
265
266 if (tp->snd_cwnd <= low_window)
267 return max(tp->snd_cwnd >> 1U, 2U);
268 else
269 return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U);
270}
271
272static u32 bictcp_undo_cwnd(struct tcp_sock *tp)
273{
274 struct bictcp *ca = tcp_ca(tp);
275
276 return max(tp->snd_cwnd, ca->last_max_cwnd);
277}
278
279static u32 bictcp_min_cwnd(struct tcp_sock *tp)
280{
281 return tp->snd_ssthresh;
282}
283
284static void bictcp_state(struct tcp_sock *tp, u8 new_state)
285{
286 if (new_state == TCP_CA_Loss)
287 bictcp_reset(tcp_ca(tp));
288}
289
290/* Track delayed acknowledgement ratio using sliding window
291 * ratio = (15*ratio + sample) / 16
292 */
293static void bictcp_acked(struct tcp_sock *tp, u32 cnt)
294{
295 if (cnt > 0 && tp->ca_state == TCP_CA_Open) {
296 struct bictcp *ca = tcp_ca(tp);
297 cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
298 ca->delayed_ack += cnt;
299 }
300}
301
302
303static struct tcp_congestion_ops bictcp = {
304 .init = bictcp_init,
305 .ssthresh = bictcp_recalc_ssthresh,
306 .cong_avoid = bictcp_cong_avoid,
307 .set_state = bictcp_state,
308 .undo_cwnd = bictcp_undo_cwnd,
309 .min_cwnd = bictcp_min_cwnd,
310 .pkts_acked = bictcp_acked,
311 .owner = THIS_MODULE,
312 .name = "bic",
313};
314
315static int __init bictcp_register(void)
316{
317 BUG_ON(sizeof(struct bictcp) > TCP_CA_PRIV_SIZE);
318 return tcp_register_congestion_control(&bictcp);
319}
320
321static void __exit bictcp_unregister(void)
322{
323 tcp_unregister_congestion_control(&bictcp);
324}
325
326module_init(bictcp_register);
327module_exit(bictcp_unregister);
328
329MODULE_AUTHOR("Stephen Hemminger");
330MODULE_LICENSE("GPL");
331MODULE_DESCRIPTION("BIC TCP");
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
new file mode 100644
index 000000000000..665394a63ae4
--- /dev/null
+++ b/net/ipv4/tcp_cong.c
@@ -0,0 +1,195 @@
1/*
2 * Plugable TCP congestion control support and newReno
3 * congestion control.
4 * Based on ideas from I/O scheduler suport and Web100.
5 *
6 * Copyright (C) 2005 Stephen Hemminger <shemminger@osdl.org>
7 */
8
9#include <linux/config.h>
10#include <linux/module.h>
11#include <linux/mm.h>
12#include <linux/types.h>
13#include <linux/list.h>
14#include <net/tcp.h>
15
16static DEFINE_SPINLOCK(tcp_cong_list_lock);
17static LIST_HEAD(tcp_cong_list);
18
19/* Simple linear search, don't expect many entries! */
20static struct tcp_congestion_ops *tcp_ca_find(const char *name)
21{
22 struct tcp_congestion_ops *e;
23
24 list_for_each_entry(e, &tcp_cong_list, list) {
25 if (strcmp(e->name, name) == 0)
26 return e;
27 }
28
29 return NULL;
30}
31
32/*
33 * Attach new congestion control algorthim to the list
34 * of available options.
35 */
36int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
37{
38 int ret = 0;
39
40 /* all algorithms must implement ssthresh and cong_avoid ops */
41 if (!ca->ssthresh || !ca->cong_avoid || !ca->min_cwnd) {
42 printk(KERN_ERR "TCP %s does not implement required ops\n",
43 ca->name);
44 return -EINVAL;
45 }
46
47 spin_lock(&tcp_cong_list_lock);
48 if (tcp_ca_find(ca->name)) {
49 printk(KERN_NOTICE "TCP %s already registered\n", ca->name);
50 ret = -EEXIST;
51 } else {
52 list_add_rcu(&ca->list, &tcp_cong_list);
53 printk(KERN_INFO "TCP %s registered\n", ca->name);
54 }
55 spin_unlock(&tcp_cong_list_lock);
56
57 return ret;
58}
59EXPORT_SYMBOL_GPL(tcp_register_congestion_control);
60
61/*
62 * Remove congestion control algorithm, called from
63 * the module's remove function. Module ref counts are used
64 * to ensure that this can't be done till all sockets using
65 * that method are closed.
66 */
67void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
68{
69 spin_lock(&tcp_cong_list_lock);
70 list_del_rcu(&ca->list);
71 spin_unlock(&tcp_cong_list_lock);
72}
73EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
74
75/* Assign choice of congestion control. */
76void tcp_init_congestion_control(struct tcp_sock *tp)
77{
78 struct tcp_congestion_ops *ca;
79
80 rcu_read_lock();
81 list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
82 if (try_module_get(ca->owner)) {
83 tp->ca_ops = ca;
84 break;
85 }
86
87 }
88 rcu_read_unlock();
89
90 if (tp->ca_ops->init)
91 tp->ca_ops->init(tp);
92}
93
94/* Manage refcounts on socket close. */
95void tcp_cleanup_congestion_control(struct tcp_sock *tp)
96{
97 if (tp->ca_ops->release)
98 tp->ca_ops->release(tp);
99 module_put(tp->ca_ops->owner);
100}
101
102/* Used by sysctl to change default congestion control */
103int tcp_set_default_congestion_control(const char *name)
104{
105 struct tcp_congestion_ops *ca;
106 int ret = -ENOENT;
107
108 spin_lock(&tcp_cong_list_lock);
109 ca = tcp_ca_find(name);
110#ifdef CONFIG_KMOD
111 if (!ca) {
112 spin_unlock(&tcp_cong_list_lock);
113
114 request_module("tcp_%s", name);
115 spin_lock(&tcp_cong_list_lock);
116 ca = tcp_ca_find(name);
117 }
118#endif
119
120 if (ca) {
121 list_move(&ca->list, &tcp_cong_list);
122 ret = 0;
123 }
124 spin_unlock(&tcp_cong_list_lock);
125
126 return ret;
127}
128
129/* Get current default congestion control */
130void tcp_get_default_congestion_control(char *name)
131{
132 struct tcp_congestion_ops *ca;
133 /* We will always have reno... */
134 BUG_ON(list_empty(&tcp_cong_list));
135
136 rcu_read_lock();
137 ca = list_entry(tcp_cong_list.next, struct tcp_congestion_ops, list);
138 strncpy(name, ca->name, TCP_CA_NAME_MAX);
139 rcu_read_unlock();
140}
141
142/*
143 * TCP Reno congestion control
144 * This is special case used for fallback as well.
145 */
146/* This is Jacobson's slow start and congestion avoidance.
147 * SIGCOMM '88, p. 328.
148 */
149void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt, u32 in_flight,
150 int flag)
151{
152 if (in_flight < tp->snd_cwnd)
153 return;
154
155 if (tp->snd_cwnd <= tp->snd_ssthresh) {
156 /* In "safe" area, increase. */
157 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
158 tp->snd_cwnd++;
159 } else {
160 /* In dangerous area, increase slowly.
161 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
162 */
163 if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
164 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
165 tp->snd_cwnd++;
166 tp->snd_cwnd_cnt = 0;
167 } else
168 tp->snd_cwnd_cnt++;
169 }
170}
171EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
172
173/* Slow start threshold is half the congestion window (min 2) */
174u32 tcp_reno_ssthresh(struct tcp_sock *tp)
175{
176 return max(tp->snd_cwnd >> 1U, 2U);
177}
178EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
179
180/* Lower bound on congestion window. */
181u32 tcp_reno_min_cwnd(struct tcp_sock *tp)
182{
183 return tp->snd_ssthresh/2;
184}
185EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);
186
187struct tcp_congestion_ops tcp_reno = {
188 .name = "reno",
189 .owner = THIS_MODULE,
190 .ssthresh = tcp_reno_ssthresh,
191 .cong_avoid = tcp_reno_cong_avoid,
192 .min_cwnd = tcp_reno_min_cwnd,
193};
194
195EXPORT_SYMBOL_GPL(tcp_reno);
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 634befc07921..f66945cb158f 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -42,15 +42,8 @@ struct tcpdiag_entry
42 42
43static struct sock *tcpnl; 43static struct sock *tcpnl;
44 44
45
46#define TCPDIAG_PUT(skb, attrtype, attrlen) \ 45#define TCPDIAG_PUT(skb, attrtype, attrlen) \
47({ int rtalen = RTA_LENGTH(attrlen); \ 46 RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
48 struct rtattr *rta; \
49 if (skb_tailroom(skb) < RTA_ALIGN(rtalen)) goto nlmsg_failure; \
50 rta = (void*)__skb_put(skb, RTA_ALIGN(rtalen)); \
51 rta->rta_type = attrtype; \
52 rta->rta_len = rtalen; \
53 RTA_DATA(rta); })
54 47
55static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk, 48static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
56 int ext, u32 pid, u32 seq, u16 nlmsg_flags) 49 int ext, u32 pid, u32 seq, u16 nlmsg_flags)
@@ -61,7 +54,6 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
61 struct nlmsghdr *nlh; 54 struct nlmsghdr *nlh;
62 struct tcp_info *info = NULL; 55 struct tcp_info *info = NULL;
63 struct tcpdiag_meminfo *minfo = NULL; 56 struct tcpdiag_meminfo *minfo = NULL;
64 struct tcpvegas_info *vinfo = NULL;
65 unsigned char *b = skb->tail; 57 unsigned char *b = skb->tail;
66 58
67 nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r)); 59 nlh = NLMSG_PUT(skb, pid, seq, TCPDIAG_GETSOCK, sizeof(*r));
@@ -73,9 +65,11 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
73 if (ext & (1<<(TCPDIAG_INFO-1))) 65 if (ext & (1<<(TCPDIAG_INFO-1)))
74 info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info)); 66 info = TCPDIAG_PUT(skb, TCPDIAG_INFO, sizeof(*info));
75 67
76 if ((tcp_is_westwood(tp) || tcp_is_vegas(tp)) 68 if (ext & (1<<(TCPDIAG_CONG-1))) {
77 && (ext & (1<<(TCPDIAG_VEGASINFO-1)))) 69 size_t len = strlen(tp->ca_ops->name);
78 vinfo = TCPDIAG_PUT(skb, TCPDIAG_VEGASINFO, sizeof(*vinfo)); 70 strcpy(TCPDIAG_PUT(skb, TCPDIAG_CONG, len+1),
71 tp->ca_ops->name);
72 }
79 } 73 }
80 r->tcpdiag_family = sk->sk_family; 74 r->tcpdiag_family = sk->sk_family;
81 r->tcpdiag_state = sk->sk_state; 75 r->tcpdiag_state = sk->sk_state;
@@ -166,23 +160,13 @@ static int tcpdiag_fill(struct sk_buff *skb, struct sock *sk,
166 if (info) 160 if (info)
167 tcp_get_info(sk, info); 161 tcp_get_info(sk, info);
168 162
169 if (vinfo) { 163 if (sk->sk_state < TCP_TIME_WAIT && tp->ca_ops->get_info)
170 if (tcp_is_vegas(tp)) { 164 tp->ca_ops->get_info(tp, ext, skb);
171 vinfo->tcpv_enabled = tp->vegas.doing_vegas_now;
172 vinfo->tcpv_rttcnt = tp->vegas.cntRTT;
173 vinfo->tcpv_rtt = jiffies_to_usecs(tp->vegas.baseRTT);
174 vinfo->tcpv_minrtt = jiffies_to_usecs(tp->vegas.minRTT);
175 } else {
176 vinfo->tcpv_enabled = 0;
177 vinfo->tcpv_rttcnt = 0;
178 vinfo->tcpv_rtt = jiffies_to_usecs(tp->westwood.rtt);
179 vinfo->tcpv_minrtt = jiffies_to_usecs(tp->westwood.rtt_min);
180 }
181 }
182 165
183 nlh->nlmsg_len = skb->tail - b; 166 nlh->nlmsg_len = skb->tail - b;
184 return skb->len; 167 return skb->len;
185 168
169rtattr_failure:
186nlmsg_failure: 170nlmsg_failure:
187 skb_trim(skb, b - skb->data); 171 skb_trim(skb, b - skb->data);
188 return -1; 172 return -1;
diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
new file mode 100644
index 000000000000..36c51f8136bf
--- /dev/null
+++ b/net/ipv4/tcp_highspeed.c
@@ -0,0 +1,181 @@
1/*
2 * Sally Floyd's High Speed TCP (RFC 3649) congestion control
3 *
4 * See http://www.icir.org/floyd/hstcp.html
5 *
6 * John Heffner <jheffner@psc.edu>
7 */
8
9#include <linux/config.h>
10#include <linux/module.h>
11#include <net/tcp.h>
12
13
14/* From AIMD tables from RFC 3649 appendix B,
15 * with fixed-point MD scaled <<8.
16 */
17static const struct hstcp_aimd_val {
18 unsigned int cwnd;
19 unsigned int md;
20} hstcp_aimd_vals[] = {
21 { 38, 128, /* 0.50 */ },
22 { 118, 112, /* 0.44 */ },
23 { 221, 104, /* 0.41 */ },
24 { 347, 98, /* 0.38 */ },
25 { 495, 93, /* 0.37 */ },
26 { 663, 89, /* 0.35 */ },
27 { 851, 86, /* 0.34 */ },
28 { 1058, 83, /* 0.33 */ },
29 { 1284, 81, /* 0.32 */ },
30 { 1529, 78, /* 0.31 */ },
31 { 1793, 76, /* 0.30 */ },
32 { 2076, 74, /* 0.29 */ },
33 { 2378, 72, /* 0.28 */ },
34 { 2699, 71, /* 0.28 */ },
35 { 3039, 69, /* 0.27 */ },
36 { 3399, 68, /* 0.27 */ },
37 { 3778, 66, /* 0.26 */ },
38 { 4177, 65, /* 0.26 */ },
39 { 4596, 64, /* 0.25 */ },
40 { 5036, 62, /* 0.25 */ },
41 { 5497, 61, /* 0.24 */ },
42 { 5979, 60, /* 0.24 */ },
43 { 6483, 59, /* 0.23 */ },
44 { 7009, 58, /* 0.23 */ },
45 { 7558, 57, /* 0.22 */ },
46 { 8130, 56, /* 0.22 */ },
47 { 8726, 55, /* 0.22 */ },
48 { 9346, 54, /* 0.21 */ },
49 { 9991, 53, /* 0.21 */ },
50 { 10661, 52, /* 0.21 */ },
51 { 11358, 52, /* 0.20 */ },
52 { 12082, 51, /* 0.20 */ },
53 { 12834, 50, /* 0.20 */ },
54 { 13614, 49, /* 0.19 */ },
55 { 14424, 48, /* 0.19 */ },
56 { 15265, 48, /* 0.19 */ },
57 { 16137, 47, /* 0.19 */ },
58 { 17042, 46, /* 0.18 */ },
59 { 17981, 45, /* 0.18 */ },
60 { 18955, 45, /* 0.18 */ },
61 { 19965, 44, /* 0.17 */ },
62 { 21013, 43, /* 0.17 */ },
63 { 22101, 43, /* 0.17 */ },
64 { 23230, 42, /* 0.17 */ },
65 { 24402, 41, /* 0.16 */ },
66 { 25618, 41, /* 0.16 */ },
67 { 26881, 40, /* 0.16 */ },
68 { 28193, 39, /* 0.16 */ },
69 { 29557, 39, /* 0.15 */ },
70 { 30975, 38, /* 0.15 */ },
71 { 32450, 38, /* 0.15 */ },
72 { 33986, 37, /* 0.15 */ },
73 { 35586, 36, /* 0.14 */ },
74 { 37253, 36, /* 0.14 */ },
75 { 38992, 35, /* 0.14 */ },
76 { 40808, 35, /* 0.14 */ },
77 { 42707, 34, /* 0.13 */ },
78 { 44694, 33, /* 0.13 */ },
79 { 46776, 33, /* 0.13 */ },
80 { 48961, 32, /* 0.13 */ },
81 { 51258, 32, /* 0.13 */ },
82 { 53677, 31, /* 0.12 */ },
83 { 56230, 30, /* 0.12 */ },
84 { 58932, 30, /* 0.12 */ },
85 { 61799, 29, /* 0.12 */ },
86 { 64851, 28, /* 0.11 */ },
87 { 68113, 28, /* 0.11 */ },
88 { 71617, 27, /* 0.11 */ },
89 { 75401, 26, /* 0.10 */ },
90 { 79517, 26, /* 0.10 */ },
91 { 84035, 25, /* 0.10 */ },
92 { 89053, 24, /* 0.10 */ },
93};
94
95#define HSTCP_AIMD_MAX ARRAY_SIZE(hstcp_aimd_vals)
96
97struct hstcp {
98 u32 ai;
99};
100
101static void hstcp_init(struct tcp_sock *tp)
102{
103 struct hstcp *ca = tcp_ca(tp);
104
105 ca->ai = 0;
106
107 /* Ensure the MD arithmetic works. This is somewhat pedantic,
108 * since I don't think we will see a cwnd this large. :) */
109 tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
110}
111
112static void hstcp_cong_avoid(struct tcp_sock *tp, u32 adk, u32 rtt,
113 u32 in_flight, int good)
114{
115 struct hstcp *ca = tcp_ca(tp);
116
117 if (in_flight < tp->snd_cwnd)
118 return;
119
120 if (tp->snd_cwnd <= tp->snd_ssthresh) {
121 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
122 tp->snd_cwnd++;
123 } else {
124 /* Update AIMD parameters */
125 if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
126 while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
127 ca->ai < HSTCP_AIMD_MAX)
128 ca->ai++;
129 } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
130 while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
131 ca->ai > 0)
132 ca->ai--;
133 }
134
135 /* Do additive increase */
136 if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
137 tp->snd_cwnd_cnt += ca->ai;
138 if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
139 tp->snd_cwnd++;
140 tp->snd_cwnd_cnt -= tp->snd_cwnd;
141 }
142 }
143 }
144}
145
146static u32 hstcp_ssthresh(struct tcp_sock *tp)
147{
148 struct hstcp *ca = tcp_ca(tp);
149
150 /* Do multiplicative decrease */
151 return max(tp->snd_cwnd - ((tp->snd_cwnd * hstcp_aimd_vals[ca->ai].md) >> 8), 2U);
152}
153
154
155static struct tcp_congestion_ops tcp_highspeed = {
156 .init = hstcp_init,
157 .ssthresh = hstcp_ssthresh,
158 .cong_avoid = hstcp_cong_avoid,
159 .min_cwnd = tcp_reno_min_cwnd,
160
161 .owner = THIS_MODULE,
162 .name = "highspeed"
163};
164
165static int __init hstcp_register(void)
166{
167 BUG_ON(sizeof(struct hstcp) > TCP_CA_PRIV_SIZE);
168 return tcp_register_congestion_control(&tcp_highspeed);
169}
170
171static void __exit hstcp_unregister(void)
172{
173 tcp_unregister_congestion_control(&tcp_highspeed);
174}
175
176module_init(hstcp_register);
177module_exit(hstcp_unregister);
178
179MODULE_AUTHOR("John Heffner");
180MODULE_LICENSE("GPL");
181MODULE_DESCRIPTION("High Speed TCP");
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
new file mode 100644
index 000000000000..40168275acf9
--- /dev/null
+++ b/net/ipv4/tcp_htcp.c
@@ -0,0 +1,289 @@
1/*
2 * H-TCP congestion control. The algorithm is detailed in:
3 * R.N.Shorten, D.J.Leith:
4 * "H-TCP: TCP for high-speed and long-distance networks"
5 * Proc. PFLDnet, Argonne, 2004.
6 * http://www.hamilton.ie/net/htcp3.pdf
7 */
8
9#include <linux/config.h>
10#include <linux/mm.h>
11#include <linux/module.h>
12#include <net/tcp.h>
13
14#define ALPHA_BASE (1<<7) /* 1.0 with shift << 7 */
15#define BETA_MIN (1<<6) /* 0.5 with shift << 7 */
16#define BETA_MAX 102 /* 0.8 with shift << 7 */
17
18static int use_rtt_scaling = 1;
19module_param(use_rtt_scaling, int, 0644);
20MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");
21
22static int use_bandwidth_switch = 1;
23module_param(use_bandwidth_switch, int, 0644);
24MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");
25
26struct htcp {
27 u16 alpha; /* Fixed point arith, << 7 */
28 u8 beta; /* Fixed point arith, << 7 */
29 u8 modeswitch; /* Delay modeswitch until we had at least one congestion event */
30 u8 ccount; /* Number of RTTs since last congestion event */
31 u8 undo_ccount;
32 u16 packetcount;
33 u32 minRTT;
34 u32 maxRTT;
35 u32 snd_cwnd_cnt2;
36
37 u32 undo_maxRTT;
38 u32 undo_old_maxB;
39
40 /* Bandwidth estimation */
41 u32 minB;
42 u32 maxB;
43 u32 old_maxB;
44 u32 Bi;
45 u32 lasttime;
46};
47
48static inline void htcp_reset(struct htcp *ca)
49{
50 ca->undo_ccount = ca->ccount;
51 ca->undo_maxRTT = ca->maxRTT;
52 ca->undo_old_maxB = ca->old_maxB;
53
54 ca->ccount = 0;
55 ca->snd_cwnd_cnt2 = 0;
56}
57
58static u32 htcp_cwnd_undo(struct tcp_sock *tp)
59{
60 struct htcp *ca = tcp_ca(tp);
61 ca->ccount = ca->undo_ccount;
62 ca->maxRTT = ca->undo_maxRTT;
63 ca->old_maxB = ca->undo_old_maxB;
64 return max(tp->snd_cwnd, (tp->snd_ssthresh<<7)/ca->beta);
65}
66
67static inline void measure_rtt(struct tcp_sock *tp)
68{
69 struct htcp *ca = tcp_ca(tp);
70 u32 srtt = tp->srtt>>3;
71
72 /* keep track of minimum RTT seen so far, minRTT is zero at first */
73 if (ca->minRTT > srtt || !ca->minRTT)
74 ca->minRTT = srtt;
75
76 /* max RTT */
77 if (tp->ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && ca->ccount > 3) {
78 if (ca->maxRTT < ca->minRTT)
79 ca->maxRTT = ca->minRTT;
80 if (ca->maxRTT < srtt && srtt <= ca->maxRTT+HZ/50)
81 ca->maxRTT = srtt;
82 }
83}
84
85static void measure_achieved_throughput(struct tcp_sock *tp, u32 pkts_acked)
86{
87 struct htcp *ca = tcp_ca(tp);
88 u32 now = tcp_time_stamp;
89
90 /* achieved throughput calculations */
91 if (tp->ca_state != TCP_CA_Open && tp->ca_state != TCP_CA_Disorder) {
92 ca->packetcount = 0;
93 ca->lasttime = now;
94 return;
95 }
96
97 ca->packetcount += pkts_acked;
98
99 if (ca->packetcount >= tp->snd_cwnd - (ca->alpha>>7? : 1)
100 && now - ca->lasttime >= ca->minRTT
101 && ca->minRTT > 0) {
102 __u32 cur_Bi = ca->packetcount*HZ/(now - ca->lasttime);
103 if (ca->ccount <= 3) {
104 /* just after backoff */
105 ca->minB = ca->maxB = ca->Bi = cur_Bi;
106 } else {
107 ca->Bi = (3*ca->Bi + cur_Bi)/4;
108 if (ca->Bi > ca->maxB)
109 ca->maxB = ca->Bi;
110 if (ca->minB > ca->maxB)
111 ca->minB = ca->maxB;
112 }
113 ca->packetcount = 0;
114 ca->lasttime = now;
115 }
116}
117
118static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
119{
120 if (use_bandwidth_switch) {
121 u32 maxB = ca->maxB;
122 u32 old_maxB = ca->old_maxB;
123 ca->old_maxB = ca->maxB;
124
125 if (!between(5*maxB, 4*old_maxB, 6*old_maxB)) {
126 ca->beta = BETA_MIN;
127 ca->modeswitch = 0;
128 return;
129 }
130 }
131
132 if (ca->modeswitch && minRTT > max(HZ/100, 1) && maxRTT) {
133 ca->beta = (minRTT<<7)/maxRTT;
134 if (ca->beta < BETA_MIN)
135 ca->beta = BETA_MIN;
136 else if (ca->beta > BETA_MAX)
137 ca->beta = BETA_MAX;
138 } else {
139 ca->beta = BETA_MIN;
140 ca->modeswitch = 1;
141 }
142}
143
144static inline void htcp_alpha_update(struct htcp *ca)
145{
146 u32 minRTT = ca->minRTT;
147 u32 factor = 1;
148 u32 diff = ca->ccount * minRTT; /* time since last backoff */
149
150 if (diff > HZ) {
151 diff -= HZ;
152 factor = 1+ ( 10*diff + ((diff/2)*(diff/2)/HZ) )/HZ;
153 }
154
155 if (use_rtt_scaling && minRTT) {
156 u32 scale = (HZ<<3)/(10*minRTT);
157 scale = min(max(scale, 1U<<2), 10U<<3); /* clamping ratio to interval [0.5,10]<<3 */
158 factor = (factor<<3)/scale;
159 if (!factor)
160 factor = 1;
161 }
162
163 ca->alpha = 2*factor*((1<<7)-ca->beta);
164 if (!ca->alpha)
165 ca->alpha = ALPHA_BASE;
166}
167
168/* After we have the rtt data to calculate beta, we'd still prefer to wait one
169 * rtt before we adjust our beta to ensure we are working from a consistent
170 * data.
171 *
172 * This function should be called when we hit a congestion event since only at
173 * that point do we really have a real sense of maxRTT (the queues en route
174 * were getting just too full now).
175 */
176static void htcp_param_update(struct tcp_sock *tp)
177{
178 struct htcp *ca = tcp_ca(tp);
179 u32 minRTT = ca->minRTT;
180 u32 maxRTT = ca->maxRTT;
181
182 htcp_beta_update(ca, minRTT, maxRTT);
183 htcp_alpha_update(ca);
184
185 /* add slowly fading memory for maxRTT to accommodate routing changes etc */
186 if (minRTT > 0 && maxRTT > minRTT)
187 ca->maxRTT = minRTT + ((maxRTT-minRTT)*95)/100;
188}
189
190static u32 htcp_recalc_ssthresh(struct tcp_sock *tp)
191{
192 struct htcp *ca = tcp_ca(tp);
193 htcp_param_update(tp);
194 return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
195}
196
197static void htcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
198 u32 in_flight, int data_acked)
199{
200 struct htcp *ca = tcp_ca(tp);
201
202 if (in_flight < tp->snd_cwnd)
203 return;
204
205 if (tp->snd_cwnd <= tp->snd_ssthresh) {
206 /* In "safe" area, increase. */
207 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
208 tp->snd_cwnd++;
209 } else {
210 measure_rtt(tp);
211
212 /* keep track of number of round-trip times since last backoff event */
213 if (ca->snd_cwnd_cnt2++ > tp->snd_cwnd) {
214 ca->ccount++;
215 ca->snd_cwnd_cnt2 = 0;
216 htcp_alpha_update(ca);
217 }
218
219 /* In dangerous area, increase slowly.
220 * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
221 */
222 if ((tp->snd_cwnd_cnt++ * ca->alpha)>>7 >= tp->snd_cwnd) {
223 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
224 tp->snd_cwnd++;
225 tp->snd_cwnd_cnt = 0;
226 ca->ccount++;
227 }
228 }
229}
230
231/* Lower bound on congestion window. */
232static u32 htcp_min_cwnd(struct tcp_sock *tp)
233{
234 return tp->snd_ssthresh;
235}
236
237
238static void htcp_init(struct tcp_sock *tp)
239{
240 struct htcp *ca = tcp_ca(tp);
241
242 memset(ca, 0, sizeof(struct htcp));
243 ca->alpha = ALPHA_BASE;
244 ca->beta = BETA_MIN;
245}
246
247static void htcp_state(struct tcp_sock *tp, u8 new_state)
248{
249 switch (new_state) {
250 case TCP_CA_CWR:
251 case TCP_CA_Recovery:
252 case TCP_CA_Loss:
253 htcp_reset(tcp_ca(tp));
254 break;
255 }
256}
257
258static struct tcp_congestion_ops htcp = {
259 .init = htcp_init,
260 .ssthresh = htcp_recalc_ssthresh,
261 .min_cwnd = htcp_min_cwnd,
262 .cong_avoid = htcp_cong_avoid,
263 .set_state = htcp_state,
264 .undo_cwnd = htcp_cwnd_undo,
265 .pkts_acked = measure_achieved_throughput,
266 .owner = THIS_MODULE,
267 .name = "htcp",
268};
269
270static int __init htcp_register(void)
271{
272 BUG_ON(sizeof(struct htcp) > TCP_CA_PRIV_SIZE);
273 BUILD_BUG_ON(BETA_MIN >= BETA_MAX);
274 if (!use_bandwidth_switch)
275 htcp.pkts_acked = NULL;
276 return tcp_register_congestion_control(&htcp);
277}
278
279static void __exit htcp_unregister(void)
280{
281 tcp_unregister_congestion_control(&htcp);
282}
283
284module_init(htcp_register);
285module_exit(htcp_unregister);
286
287MODULE_AUTHOR("Baruch Even");
288MODULE_LICENSE("GPL");
289MODULE_DESCRIPTION("H-TCP");
diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c
new file mode 100644
index 000000000000..13a66342c304
--- /dev/null
+++ b/net/ipv4/tcp_hybla.c
@@ -0,0 +1,187 @@
1/*
2 * TCP HYBLA
3 *
4 * TCP-HYBLA Congestion control algorithm, based on:
5 * C.Caini, R.Firrincieli, "TCP-Hybla: A TCP Enhancement
6 * for Heterogeneous Networks",
7 * International Journal on satellite Communications,
8 * September 2004
9 * Daniele Lacamera
10 * root at danielinux.net
11 */
12
13#include <linux/config.h>
14#include <linux/module.h>
15#include <net/tcp.h>
16
17/* Tcp Hybla structure. */
18struct hybla {
19 u8 hybla_en;
20 u32 snd_cwnd_cents; /* Keeps increment values when it is <1, <<7 */
21 u32 rho; /* Rho parameter, integer part */
22 u32 rho2; /* Rho * Rho, integer part */
23 u32 rho_3ls; /* Rho parameter, <<3 */
24 u32 rho2_7ls; /* Rho^2, <<7 */
25 u32 minrtt; /* Minimum smoothed round trip time value seen */
26};
27
28/* Hybla reference round trip time (default= 1/40 sec = 25 ms),
29 expressed in jiffies */
30static int rtt0 = 25;
31module_param(rtt0, int, 0644);
32MODULE_PARM_DESC(rtt0, "reference rout trip time (ms)");
33
34
35/* This is called to refresh values for hybla parameters */
36static inline void hybla_recalc_param (struct tcp_sock *tp)
37{
38 struct hybla *ca = tcp_ca(tp);
39
40 ca->rho_3ls = max_t(u32, tp->srtt / msecs_to_jiffies(rtt0), 8);
41 ca->rho = ca->rho_3ls >> 3;
42 ca->rho2_7ls = (ca->rho_3ls * ca->rho_3ls) << 1;
43 ca->rho2 = ca->rho2_7ls >>7;
44}
45
46static void hybla_init(struct tcp_sock *tp)
47{
48 struct hybla *ca = tcp_ca(tp);
49
50 ca->rho = 0;
51 ca->rho2 = 0;
52 ca->rho_3ls = 0;
53 ca->rho2_7ls = 0;
54 ca->snd_cwnd_cents = 0;
55 ca->hybla_en = 1;
56 tp->snd_cwnd = 2;
57 tp->snd_cwnd_clamp = 65535;
58
59 /* 1st Rho measurement based on initial srtt */
60 hybla_recalc_param(tp);
61
62 /* set minimum rtt as this is the 1st ever seen */
63 ca->minrtt = tp->srtt;
64 tp->snd_cwnd = ca->rho;
65}
66
67static void hybla_state(struct tcp_sock *tp, u8 ca_state)
68{
69 struct hybla *ca = tcp_ca(tp);
70
71 ca->hybla_en = (ca_state == TCP_CA_Open);
72}
73
74static inline u32 hybla_fraction(u32 odds)
75{
76 static const u32 fractions[] = {
77 128, 139, 152, 165, 181, 197, 215, 234,
78 };
79
80 return (odds < ARRAY_SIZE(fractions)) ? fractions[odds] : 128;
81}
82
83/* TCP Hybla main routine.
84 * This is the algorithm behavior:
85 * o Recalc Hybla parameters if min_rtt has changed
86 * o Give cwnd a new value based on the model proposed
87 * o remember increments <1
88 */
89static void hybla_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
90 u32 in_flight, int flag)
91{
92 struct hybla *ca = tcp_ca(tp);
93 u32 increment, odd, rho_fractions;
94 int is_slowstart = 0;
95
96 /* Recalculate rho only if this srtt is the lowest */
97 if (tp->srtt < ca->minrtt){
98 hybla_recalc_param(tp);
99 ca->minrtt = tp->srtt;
100 }
101
102 if (!ca->hybla_en)
103 return tcp_reno_cong_avoid(tp, ack, rtt, in_flight, flag);
104
105 if (in_flight < tp->snd_cwnd)
106 return;
107
108 if (ca->rho == 0)
109 hybla_recalc_param(tp);
110
111 rho_fractions = ca->rho_3ls - (ca->rho << 3);
112
113 if (tp->snd_cwnd < tp->snd_ssthresh) {
114 /*
115 * slow start
116 * INC = 2^RHO - 1
117 * This is done by splitting the rho parameter
118 * into 2 parts: an integer part and a fraction part.
119 * Inrement<<7 is estimated by doing:
120 * [2^(int+fract)]<<7
121 * that is equal to:
122 * (2^int) * [(2^fract) <<7]
123 * 2^int is straightly computed as 1<<int,
124 * while we will use hybla_slowstart_fraction_increment() to
125 * calculate 2^fract in a <<7 value.
126 */
127 is_slowstart = 1;
128 increment = ((1 << ca->rho) * hybla_fraction(rho_fractions))
129 - 128;
130 } else {
131 /*
132 * congestion avoidance
133 * INC = RHO^2 / W
134 * as long as increment is estimated as (rho<<7)/window
135 * it already is <<7 and we can easily count its fractions.
136 */
137 increment = ca->rho2_7ls / tp->snd_cwnd;
138 if (increment < 128)
139 tp->snd_cwnd_cnt++;
140 }
141
142 odd = increment % 128;
143 tp->snd_cwnd += increment >> 7;
144 ca->snd_cwnd_cents += odd;
145
146 /* check when fractions goes >=128 and increase cwnd by 1. */
147 while(ca->snd_cwnd_cents >= 128) {
148 tp->snd_cwnd++;
149 ca->snd_cwnd_cents -= 128;
150 tp->snd_cwnd_cnt = 0;
151 }
152
153 /* clamp down slowstart cwnd to ssthresh value. */
154 if (is_slowstart)
155 tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
156
157 tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
158}
159
160static struct tcp_congestion_ops tcp_hybla = {
161 .init = hybla_init,
162 .ssthresh = tcp_reno_ssthresh,
163 .min_cwnd = tcp_reno_min_cwnd,
164 .cong_avoid = hybla_cong_avoid,
165 .set_state = hybla_state,
166
167 .owner = THIS_MODULE,
168 .name = "hybla"
169};
170
171static int __init hybla_register(void)
172{
173 BUG_ON(sizeof(struct hybla) > TCP_CA_PRIV_SIZE);
174 return tcp_register_congestion_control(&tcp_hybla);
175}
176
177static void __exit hybla_unregister(void)
178{
179 tcp_unregister_congestion_control(&tcp_hybla);
180}
181
182module_init(hybla_register);
183module_exit(hybla_unregister);
184
185MODULE_AUTHOR("Daniele Lacamera");
186MODULE_LICENSE("GPL");
187MODULE_DESCRIPTION("TCP Hybla");
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 5bad504630a3..7bbbbc33eb4b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -61,7 +61,6 @@
61 * Panu Kuhlberg: Experimental audit of TCP (re)transmission 61 * Panu Kuhlberg: Experimental audit of TCP (re)transmission
62 * engine. Lots of bugs are found. 62 * engine. Lots of bugs are found.
63 * Pasi Sarolahti: F-RTO for dealing with spurious RTOs 63 * Pasi Sarolahti: F-RTO for dealing with spurious RTOs
64 * Angelo Dell'Aera: TCP Westwood+ support
65 */ 64 */
66 65
67#include <linux/config.h> 66#include <linux/config.h>
@@ -88,23 +87,9 @@ int sysctl_tcp_rfc1337;
88int sysctl_tcp_max_orphans = NR_FILE; 87int sysctl_tcp_max_orphans = NR_FILE;
89int sysctl_tcp_frto; 88int sysctl_tcp_frto;
90int sysctl_tcp_nometrics_save; 89int sysctl_tcp_nometrics_save;
91int sysctl_tcp_westwood;
92int sysctl_tcp_vegas_cong_avoid;
93 90
94int sysctl_tcp_moderate_rcvbuf = 1; 91int sysctl_tcp_moderate_rcvbuf = 1;
95 92
96/* Default values of the Vegas variables, in fixed-point representation
97 * with V_PARAM_SHIFT bits to the right of the binary point.
98 */
99#define V_PARAM_SHIFT 1
100int sysctl_tcp_vegas_alpha = 1<<V_PARAM_SHIFT;
101int sysctl_tcp_vegas_beta = 3<<V_PARAM_SHIFT;
102int sysctl_tcp_vegas_gamma = 1<<V_PARAM_SHIFT;
103int sysctl_tcp_bic = 1;
104int sysctl_tcp_bic_fast_convergence = 1;
105int sysctl_tcp_bic_low_window = 14;
106int sysctl_tcp_bic_beta = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */
107
108#define FLAG_DATA 0x01 /* Incoming frame contained data. */ 93#define FLAG_DATA 0x01 /* Incoming frame contained data. */
109#define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */ 94#define FLAG_WIN_UPDATE 0x02 /* Incoming ACK was a window update. */
110#define FLAG_DATA_ACKED 0x04 /* This ACK acknowledged new data. */ 95#define FLAG_DATA_ACKED 0x04 /* This ACK acknowledged new data. */
@@ -333,15 +318,6 @@ static void tcp_init_buffer_space(struct sock *sk)
333 tp->snd_cwnd_stamp = tcp_time_stamp; 318 tp->snd_cwnd_stamp = tcp_time_stamp;
334} 319}
335 320
336static void init_bictcp(struct tcp_sock *tp)
337{
338 tp->bictcp.cnt = 0;
339
340 tp->bictcp.last_max_cwnd = 0;
341 tp->bictcp.last_cwnd = 0;
342 tp->bictcp.last_stamp = 0;
343}
344
345/* 5. Recalculate window clamp after socket hit its memory bounds. */ 321/* 5. Recalculate window clamp after socket hit its memory bounds. */
346static void tcp_clamp_window(struct sock *sk, struct tcp_sock *tp) 322static void tcp_clamp_window(struct sock *sk, struct tcp_sock *tp)
347{ 323{
@@ -558,45 +534,6 @@ static void tcp_event_data_recv(struct sock *sk, struct tcp_sock *tp, struct sk_
558 tcp_grow_window(sk, tp, skb); 534 tcp_grow_window(sk, tp, skb);
559} 535}
560 536
561/* When starting a new connection, pin down the current choice of
562 * congestion algorithm.
563 */
564void tcp_ca_init(struct tcp_sock *tp)
565{
566 if (sysctl_tcp_westwood)
567 tp->adv_cong = TCP_WESTWOOD;
568 else if (sysctl_tcp_bic)
569 tp->adv_cong = TCP_BIC;
570 else if (sysctl_tcp_vegas_cong_avoid) {
571 tp->adv_cong = TCP_VEGAS;
572 tp->vegas.baseRTT = 0x7fffffff;
573 tcp_vegas_enable(tp);
574 }
575}
576
577/* Do RTT sampling needed for Vegas.
578 * Basically we:
579 * o min-filter RTT samples from within an RTT to get the current
580 * propagation delay + queuing delay (we are min-filtering to try to
581 * avoid the effects of delayed ACKs)
582 * o min-filter RTT samples from a much longer window (forever for now)
583 * to find the propagation delay (baseRTT)
584 */
585static inline void vegas_rtt_calc(struct tcp_sock *tp, __u32 rtt)
586{
587 __u32 vrtt = rtt + 1; /* Never allow zero rtt or baseRTT */
588
589 /* Filter to find propagation delay: */
590 if (vrtt < tp->vegas.baseRTT)
591 tp->vegas.baseRTT = vrtt;
592
593 /* Find the min RTT during the last RTT to find
594 * the current prop. delay + queuing delay:
595 */
596 tp->vegas.minRTT = min(tp->vegas.minRTT, vrtt);
597 tp->vegas.cntRTT++;
598}
599
600/* Called to compute a smoothed rtt estimate. The data fed to this 537/* Called to compute a smoothed rtt estimate. The data fed to this
601 * routine either comes from timestamps, or from segments that were 538 * routine either comes from timestamps, or from segments that were
602 * known _not_ to have been retransmitted [see Karn/Partridge 539 * known _not_ to have been retransmitted [see Karn/Partridge
@@ -606,13 +543,10 @@ static inline void vegas_rtt_calc(struct tcp_sock *tp, __u32 rtt)
606 * To save cycles in the RFC 1323 implementation it was better to break 543 * To save cycles in the RFC 1323 implementation it was better to break
607 * it up into three procedures. -- erics 544 * it up into three procedures. -- erics
608 */ 545 */
609static void tcp_rtt_estimator(struct tcp_sock *tp, __u32 mrtt) 546static void tcp_rtt_estimator(struct tcp_sock *tp, __u32 mrtt, u32 *usrtt)
610{ 547{
611 long m = mrtt; /* RTT */ 548 long m = mrtt; /* RTT */
612 549
613 if (tcp_vegas_enabled(tp))
614 vegas_rtt_calc(tp, mrtt);
615
616 /* The following amusing code comes from Jacobson's 550 /* The following amusing code comes from Jacobson's
617 * article in SIGCOMM '88. Note that rtt and mdev 551 * article in SIGCOMM '88. Note that rtt and mdev
618 * are scaled versions of rtt and mean deviation. 552 * are scaled versions of rtt and mean deviation.
@@ -670,7 +604,8 @@ static void tcp_rtt_estimator(struct tcp_sock *tp, __u32 mrtt)
670 tp->rtt_seq = tp->snd_nxt; 604 tp->rtt_seq = tp->snd_nxt;
671 } 605 }
672 606
673 tcp_westwood_update_rtt(tp, tp->srtt >> 3); 607 if (tp->ca_ops->rtt_sample)
608 tp->ca_ops->rtt_sample(tp, *usrtt);
674} 609}
675 610
676/* Calculate rto without backoff. This is the second half of Van Jacobson's 611/* Calculate rto without backoff. This is the second half of Van Jacobson's
@@ -1185,8 +1120,8 @@ void tcp_enter_frto(struct sock *sk)
1185 tp->snd_una == tp->high_seq || 1120 tp->snd_una == tp->high_seq ||
1186 (tp->ca_state == TCP_CA_Loss && !tp->retransmits)) { 1121 (tp->ca_state == TCP_CA_Loss && !tp->retransmits)) {
1187 tp->prior_ssthresh = tcp_current_ssthresh(tp); 1122 tp->prior_ssthresh = tcp_current_ssthresh(tp);
1188 if (!tcp_westwood_ssthresh(tp)) 1123 tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
1189 tp->snd_ssthresh = tcp_recalc_ssthresh(tp); 1124 tcp_ca_event(tp, CA_EVENT_FRTO);
1190 } 1125 }
1191 1126
1192 /* Have to clear retransmission markers here to keep the bookkeeping 1127 /* Have to clear retransmission markers here to keep the bookkeeping
@@ -1252,8 +1187,6 @@ static void tcp_enter_frto_loss(struct sock *sk)
1252 tcp_set_ca_state(tp, TCP_CA_Loss); 1187 tcp_set_ca_state(tp, TCP_CA_Loss);
1253 tp->high_seq = tp->frto_highmark; 1188 tp->high_seq = tp->frto_highmark;
1254 TCP_ECN_queue_cwr(tp); 1189 TCP_ECN_queue_cwr(tp);
1255
1256 init_bictcp(tp);
1257} 1190}
1258 1191
1259void tcp_clear_retrans(struct tcp_sock *tp) 1192void tcp_clear_retrans(struct tcp_sock *tp)
@@ -1283,7 +1216,8 @@ void tcp_enter_loss(struct sock *sk, int how)
1283 if (tp->ca_state <= TCP_CA_Disorder || tp->snd_una == tp->high_seq || 1216 if (tp->ca_state <= TCP_CA_Disorder || tp->snd_una == tp->high_seq ||
1284 (tp->ca_state == TCP_CA_Loss && !tp->retransmits)) { 1217 (tp->ca_state == TCP_CA_Loss && !tp->retransmits)) {
1285 tp->prior_ssthresh = tcp_current_ssthresh(tp); 1218 tp->prior_ssthresh = tcp_current_ssthresh(tp);
1286 tp->snd_ssthresh = tcp_recalc_ssthresh(tp); 1219 tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
1220 tcp_ca_event(tp, CA_EVENT_LOSS);
1287 } 1221 }
1288 tp->snd_cwnd = 1; 1222 tp->snd_cwnd = 1;
1289 tp->snd_cwnd_cnt = 0; 1223 tp->snd_cwnd_cnt = 0;
@@ -1596,28 +1530,14 @@ static inline void tcp_moderate_cwnd(struct tcp_sock *tp)
1596} 1530}
1597 1531
1598/* Decrease cwnd each second ack. */ 1532/* Decrease cwnd each second ack. */
1599
1600static void tcp_cwnd_down(struct tcp_sock *tp) 1533static void tcp_cwnd_down(struct tcp_sock *tp)
1601{ 1534{
1602 int decr = tp->snd_cwnd_cnt + 1; 1535 int decr = tp->snd_cwnd_cnt + 1;
1603 __u32 limit;
1604
1605 /*
1606 * TCP Westwood
1607 * Here limit is evaluated as BWestimation*RTTmin (for obtaining it
1608 * in packets we use mss_cache). If sysctl_tcp_westwood is off
1609 * tcp_westwood_bw_rttmin() returns 0. In such case snd_ssthresh is
1610 * still used as usual. It prevents other strange cases in which
1611 * BWE*RTTmin could assume value 0. It should not happen but...
1612 */
1613
1614 if (!(limit = tcp_westwood_bw_rttmin(tp)))
1615 limit = tp->snd_ssthresh/2;
1616 1536
1617 tp->snd_cwnd_cnt = decr&1; 1537 tp->snd_cwnd_cnt = decr&1;
1618 decr >>= 1; 1538 decr >>= 1;
1619 1539
1620 if (decr && tp->snd_cwnd > limit) 1540 if (decr && tp->snd_cwnd > tp->ca_ops->min_cwnd(tp))
1621 tp->snd_cwnd -= decr; 1541 tp->snd_cwnd -= decr;
1622 1542
1623 tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp)+1); 1543 tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp)+1);
@@ -1654,8 +1574,8 @@ static void DBGUNDO(struct sock *sk, struct tcp_sock *tp, const char *msg)
1654static void tcp_undo_cwr(struct tcp_sock *tp, int undo) 1574static void tcp_undo_cwr(struct tcp_sock *tp, int undo)
1655{ 1575{
1656 if (tp->prior_ssthresh) { 1576 if (tp->prior_ssthresh) {
1657 if (tcp_is_bic(tp)) 1577 if (tp->ca_ops->undo_cwnd)
1658 tp->snd_cwnd = max(tp->snd_cwnd, tp->bictcp.last_max_cwnd); 1578 tp->snd_cwnd = tp->ca_ops->undo_cwnd(tp);
1659 else 1579 else
1660 tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh<<1); 1580 tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh<<1);
1661 1581
@@ -1767,11 +1687,9 @@ static int tcp_try_undo_loss(struct sock *sk, struct tcp_sock *tp)
1767 1687
1768static inline void tcp_complete_cwr(struct tcp_sock *tp) 1688static inline void tcp_complete_cwr(struct tcp_sock *tp)
1769{ 1689{
1770 if (tcp_westwood_cwnd(tp)) 1690 tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
1771 tp->snd_ssthresh = tp->snd_cwnd;
1772 else
1773 tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
1774 tp->snd_cwnd_stamp = tcp_time_stamp; 1691 tp->snd_cwnd_stamp = tcp_time_stamp;
1692 tcp_ca_event(tp, CA_EVENT_COMPLETE_CWR);
1775} 1693}
1776 1694
1777static void tcp_try_to_open(struct sock *sk, struct tcp_sock *tp, int flag) 1695static void tcp_try_to_open(struct sock *sk, struct tcp_sock *tp, int flag)
@@ -1946,7 +1864,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
1946 if (tp->ca_state < TCP_CA_CWR) { 1864 if (tp->ca_state < TCP_CA_CWR) {
1947 if (!(flag&FLAG_ECE)) 1865 if (!(flag&FLAG_ECE))
1948 tp->prior_ssthresh = tcp_current_ssthresh(tp); 1866 tp->prior_ssthresh = tcp_current_ssthresh(tp);
1949 tp->snd_ssthresh = tcp_recalc_ssthresh(tp); 1867 tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
1950 TCP_ECN_queue_cwr(tp); 1868 TCP_ECN_queue_cwr(tp);
1951 } 1869 }
1952 1870
@@ -1963,7 +1881,7 @@ tcp_fastretrans_alert(struct sock *sk, u32 prior_snd_una,
1963/* Read draft-ietf-tcplw-high-performance before mucking 1881/* Read draft-ietf-tcplw-high-performance before mucking
1964 * with this code. (Superceeds RFC1323) 1882 * with this code. (Superceeds RFC1323)
1965 */ 1883 */
1966static void tcp_ack_saw_tstamp(struct tcp_sock *tp, int flag) 1884static void tcp_ack_saw_tstamp(struct tcp_sock *tp, u32 *usrtt, int flag)
1967{ 1885{
1968 __u32 seq_rtt; 1886 __u32 seq_rtt;
1969 1887
@@ -1983,13 +1901,13 @@ static void tcp_ack_saw_tstamp(struct tcp_sock *tp, int flag)
1983 * in window is lost... Voila. --ANK (010210) 1901 * in window is lost... Voila. --ANK (010210)
1984 */ 1902 */
1985 seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr; 1903 seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
1986 tcp_rtt_estimator(tp, seq_rtt); 1904 tcp_rtt_estimator(tp, seq_rtt, usrtt);
1987 tcp_set_rto(tp); 1905 tcp_set_rto(tp);
1988 tp->backoff = 0; 1906 tp->backoff = 0;
1989 tcp_bound_rto(tp); 1907 tcp_bound_rto(tp);
1990} 1908}
1991 1909
1992static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, int flag) 1910static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, u32 *usrtt, int flag)
1993{ 1911{
1994 /* We don't have a timestamp. Can only use 1912 /* We don't have a timestamp. Can only use
1995 * packets that are not retransmitted to determine 1913 * packets that are not retransmitted to determine
@@ -2003,338 +1921,29 @@ static void tcp_ack_no_tstamp(struct tcp_sock *tp, u32 seq_rtt, int flag)
2003 if (flag & FLAG_RETRANS_DATA_ACKED) 1921 if (flag & FLAG_RETRANS_DATA_ACKED)
2004 return; 1922 return;
2005 1923
2006 tcp_rtt_estimator(tp, seq_rtt); 1924 tcp_rtt_estimator(tp, seq_rtt, usrtt);
2007 tcp_set_rto(tp); 1925 tcp_set_rto(tp);
2008 tp->backoff = 0; 1926 tp->backoff = 0;
2009 tcp_bound_rto(tp); 1927 tcp_bound_rto(tp);
2010} 1928}
2011 1929
2012static inline void tcp_ack_update_rtt(struct tcp_sock *tp, 1930static inline void tcp_ack_update_rtt(struct tcp_sock *tp,
2013 int flag, s32 seq_rtt) 1931 int flag, s32 seq_rtt, u32 *usrtt)
2014{ 1932{
2015 /* Note that peer MAY send zero echo. In this case it is ignored. (rfc1323) */ 1933 /* Note that peer MAY send zero echo. In this case it is ignored. (rfc1323) */
2016 if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr) 1934 if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
2017 tcp_ack_saw_tstamp(tp, flag); 1935 tcp_ack_saw_tstamp(tp, usrtt, flag);
2018 else if (seq_rtt >= 0) 1936 else if (seq_rtt >= 0)
2019 tcp_ack_no_tstamp(tp, seq_rtt, flag); 1937 tcp_ack_no_tstamp(tp, seq_rtt, usrtt, flag);
2020} 1938}
2021 1939
2022/* 1940static inline void tcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
2023 * Compute congestion window to use. 1941 u32 in_flight, int good)
2024 *
2025 * This is from the implementation of BICTCP in
2026 * Lison-Xu, Kahaled Harfoush, and Injog Rhee.
2027 * "Binary Increase Congestion Control for Fast, Long Distance
2028 * Networks" in InfoComm 2004
2029 * Available from:
2030 * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp.pdf
2031 *
2032 * Unless BIC is enabled and congestion window is large
2033 * this behaves the same as the original Reno.
2034 */
2035static inline __u32 bictcp_cwnd(struct tcp_sock *tp)
2036{
2037 /* orignal Reno behaviour */
2038 if (!tcp_is_bic(tp))
2039 return tp->snd_cwnd;
2040
2041 if (tp->bictcp.last_cwnd == tp->snd_cwnd &&
2042 (s32)(tcp_time_stamp - tp->bictcp.last_stamp) <= (HZ>>5))
2043 return tp->bictcp.cnt;
2044
2045 tp->bictcp.last_cwnd = tp->snd_cwnd;
2046 tp->bictcp.last_stamp = tcp_time_stamp;
2047
2048 /* start off normal */
2049 if (tp->snd_cwnd <= sysctl_tcp_bic_low_window)
2050 tp->bictcp.cnt = tp->snd_cwnd;
2051
2052 /* binary increase */
2053 else if (tp->snd_cwnd < tp->bictcp.last_max_cwnd) {
2054 __u32 dist = (tp->bictcp.last_max_cwnd - tp->snd_cwnd)
2055 / BICTCP_B;
2056
2057 if (dist > BICTCP_MAX_INCREMENT)
2058 /* linear increase */
2059 tp->bictcp.cnt = tp->snd_cwnd / BICTCP_MAX_INCREMENT;
2060 else if (dist <= 1U)
2061 /* binary search increase */
2062 tp->bictcp.cnt = tp->snd_cwnd * BICTCP_FUNC_OF_MIN_INCR
2063 / BICTCP_B;
2064 else
2065 /* binary search increase */
2066 tp->bictcp.cnt = tp->snd_cwnd / dist;
2067 } else {
2068 /* slow start amd linear increase */
2069 if (tp->snd_cwnd < tp->bictcp.last_max_cwnd + BICTCP_B)
2070 /* slow start */
2071 tp->bictcp.cnt = tp->snd_cwnd * BICTCP_FUNC_OF_MIN_INCR
2072 / BICTCP_B;
2073 else if (tp->snd_cwnd < tp->bictcp.last_max_cwnd
2074 + BICTCP_MAX_INCREMENT*(BICTCP_B-1))
2075 /* slow start */
2076 tp->bictcp.cnt = tp->snd_cwnd * (BICTCP_B-1)
2077 / (tp->snd_cwnd-tp->bictcp.last_max_cwnd);
2078 else
2079 /* linear increase */
2080 tp->bictcp.cnt = tp->snd_cwnd / BICTCP_MAX_INCREMENT;
2081 }
2082 return tp->bictcp.cnt;
2083}
2084
2085/* This is Jacobson's slow start and congestion avoidance.
2086 * SIGCOMM '88, p. 328.
2087 */
2088static inline void reno_cong_avoid(struct tcp_sock *tp)
2089{ 1942{
2090 if (tp->snd_cwnd <= tp->snd_ssthresh) { 1943 tp->ca_ops->cong_avoid(tp, ack, rtt, in_flight, good);
2091 /* In "safe" area, increase. */
2092 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
2093 tp->snd_cwnd++;
2094 } else {
2095 /* In dangerous area, increase slowly.
2096 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
2097 */
2098 if (tp->snd_cwnd_cnt >= bictcp_cwnd(tp)) {
2099 if (tp->snd_cwnd < tp->snd_cwnd_clamp)
2100 tp->snd_cwnd++;
2101 tp->snd_cwnd_cnt=0;
2102 } else
2103 tp->snd_cwnd_cnt++;
2104 }
2105 tp->snd_cwnd_stamp = tcp_time_stamp; 1944 tp->snd_cwnd_stamp = tcp_time_stamp;
2106} 1945}
2107 1946
2108/* This is based on the congestion detection/avoidance scheme described in
2109 * Lawrence S. Brakmo and Larry L. Peterson.
2110 * "TCP Vegas: End to end congestion avoidance on a global internet."
2111 * IEEE Journal on Selected Areas in Communication, 13(8):1465--1480,
2112 * October 1995. Available from:
2113 * ftp://ftp.cs.arizona.edu/xkernel/Papers/jsac.ps
2114 *
2115 * See http://www.cs.arizona.edu/xkernel/ for their implementation.
2116 * The main aspects that distinguish this implementation from the
2117 * Arizona Vegas implementation are:
2118 * o We do not change the loss detection or recovery mechanisms of
2119 * Linux in any way. Linux already recovers from losses quite well,
2120 * using fine-grained timers, NewReno, and FACK.
2121 * o To avoid the performance penalty imposed by increasing cwnd
2122 * only every-other RTT during slow start, we increase during
2123 * every RTT during slow start, just like Reno.
2124 * o Largely to allow continuous cwnd growth during slow start,
2125 * we use the rate at which ACKs come back as the "actual"
2126 * rate, rather than the rate at which data is sent.
2127 * o To speed convergence to the right rate, we set the cwnd
2128 * to achieve the right ("actual") rate when we exit slow start.
2129 * o To filter out the noise caused by delayed ACKs, we use the
2130 * minimum RTT sample observed during the last RTT to calculate
2131 * the actual rate.
2132 * o When the sender re-starts from idle, it waits until it has
2133 * received ACKs for an entire flight of new data before making
2134 * a cwnd adjustment decision. The original Vegas implementation
2135 * assumed senders never went idle.
2136 */
2137static void vegas_cong_avoid(struct tcp_sock *tp, u32 ack, u32 seq_rtt)
2138{
2139 /* The key players are v_beg_snd_una and v_beg_snd_nxt.
2140 *
2141 * These are so named because they represent the approximate values
2142 * of snd_una and snd_nxt at the beginning of the current RTT. More
2143 * precisely, they represent the amount of data sent during the RTT.
2144 * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
2145 * we will calculate that (v_beg_snd_nxt - v_beg_snd_una) outstanding
2146 * bytes of data have been ACKed during the course of the RTT, giving
2147 * an "actual" rate of:
2148 *
2149 * (v_beg_snd_nxt - v_beg_snd_una) / (rtt duration)
2150 *
2151 * Unfortunately, v_beg_snd_una is not exactly equal to snd_una,
2152 * because delayed ACKs can cover more than one segment, so they
2153 * don't line up nicely with the boundaries of RTTs.
2154 *
2155 * Another unfortunate fact of life is that delayed ACKs delay the
2156 * advance of the left edge of our send window, so that the number
2157 * of bytes we send in an RTT is often less than our cwnd will allow.
2158 * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
2159 */
2160
2161 if (after(ack, tp->vegas.beg_snd_nxt)) {
2162 /* Do the Vegas once-per-RTT cwnd adjustment. */
2163 u32 old_wnd, old_snd_cwnd;
2164
2165
2166 /* Here old_wnd is essentially the window of data that was
2167 * sent during the previous RTT, and has all
2168 * been acknowledged in the course of the RTT that ended
2169 * with the ACK we just received. Likewise, old_snd_cwnd
2170 * is the cwnd during the previous RTT.
2171 */
2172 old_wnd = (tp->vegas.beg_snd_nxt - tp->vegas.beg_snd_una) /
2173 tp->mss_cache_std;
2174 old_snd_cwnd = tp->vegas.beg_snd_cwnd;
2175
2176 /* Save the extent of the current window so we can use this
2177 * at the end of the next RTT.
2178 */
2179 tp->vegas.beg_snd_una = tp->vegas.beg_snd_nxt;
2180 tp->vegas.beg_snd_nxt = tp->snd_nxt;
2181 tp->vegas.beg_snd_cwnd = tp->snd_cwnd;
2182
2183 /* Take into account the current RTT sample too, to
2184 * decrease the impact of delayed acks. This double counts
2185 * this sample since we count it for the next window as well,
2186 * but that's not too awful, since we're taking the min,
2187 * rather than averaging.
2188 */
2189 vegas_rtt_calc(tp, seq_rtt);
2190
2191 /* We do the Vegas calculations only if we got enough RTT
2192 * samples that we can be reasonably sure that we got
2193 * at least one RTT sample that wasn't from a delayed ACK.
2194 * If we only had 2 samples total,
2195 * then that means we're getting only 1 ACK per RTT, which
2196 * means they're almost certainly delayed ACKs.
2197 * If we have 3 samples, we should be OK.
2198 */
2199
2200 if (tp->vegas.cntRTT <= 2) {
2201 /* We don't have enough RTT samples to do the Vegas
2202 * calculation, so we'll behave like Reno.
2203 */
2204 if (tp->snd_cwnd > tp->snd_ssthresh)
2205 tp->snd_cwnd++;
2206 } else {
2207 u32 rtt, target_cwnd, diff;
2208
2209 /* We have enough RTT samples, so, using the Vegas
2210 * algorithm, we determine if we should increase or
2211 * decrease cwnd, and by how much.
2212 */
2213
2214 /* Pluck out the RTT we are using for the Vegas
2215 * calculations. This is the min RTT seen during the
2216 * last RTT. Taking the min filters out the effects
2217 * of delayed ACKs, at the cost of noticing congestion
2218 * a bit later.
2219 */
2220 rtt = tp->vegas.minRTT;
2221
2222 /* Calculate the cwnd we should have, if we weren't
2223 * going too fast.
2224 *
2225 * This is:
2226 * (actual rate in segments) * baseRTT
2227 * We keep it as a fixed point number with
2228 * V_PARAM_SHIFT bits to the right of the binary point.
2229 */
2230 target_cwnd = ((old_wnd * tp->vegas.baseRTT)
2231 << V_PARAM_SHIFT) / rtt;
2232
2233 /* Calculate the difference between the window we had,
2234 * and the window we would like to have. This quantity
2235 * is the "Diff" from the Arizona Vegas papers.
2236 *
2237 * Again, this is a fixed point number with
2238 * V_PARAM_SHIFT bits to the right of the binary
2239 * point.
2240 */
2241 diff = (old_wnd << V_PARAM_SHIFT) - target_cwnd;
2242
2243 if (tp->snd_cwnd < tp->snd_ssthresh) {
2244 /* Slow start. */
2245 if (diff > sysctl_tcp_vegas_gamma) {
2246 /* Going too fast. Time to slow down
2247 * and switch to congestion avoidance.
2248 */
2249 tp->snd_ssthresh = 2;
2250
2251 /* Set cwnd to match the actual rate
2252 * exactly:
2253 * cwnd = (actual rate) * baseRTT
2254 * Then we add 1 because the integer
2255 * truncation robs us of full link
2256 * utilization.
2257 */
2258 tp->snd_cwnd = min(tp->snd_cwnd,
2259 (target_cwnd >>
2260 V_PARAM_SHIFT)+1);
2261
2262 }
2263 } else {
2264 /* Congestion avoidance. */
2265 u32 next_snd_cwnd;
2266
2267 /* Figure out where we would like cwnd
2268 * to be.
2269 */
2270 if (diff > sysctl_tcp_vegas_beta) {
2271 /* The old window was too fast, so
2272 * we slow down.
2273 */
2274 next_snd_cwnd = old_snd_cwnd - 1;
2275 } else if (diff < sysctl_tcp_vegas_alpha) {
2276 /* We don't have enough extra packets
2277 * in the network, so speed up.
2278 */
2279 next_snd_cwnd = old_snd_cwnd + 1;
2280 } else {
2281 /* Sending just as fast as we
2282 * should be.
2283 */
2284 next_snd_cwnd = old_snd_cwnd;
2285 }
2286
2287 /* Adjust cwnd upward or downward, toward the
2288 * desired value.
2289 */
2290 if (next_snd_cwnd > tp->snd_cwnd)
2291 tp->snd_cwnd++;
2292 else if (next_snd_cwnd < tp->snd_cwnd)
2293 tp->snd_cwnd--;
2294 }
2295 }
2296
2297 /* Wipe the slate clean for the next RTT. */
2298 tp->vegas.cntRTT = 0;
2299 tp->vegas.minRTT = 0x7fffffff;
2300 }
2301
2302 /* The following code is executed for every ack we receive,
2303 * except for conditions checked in should_advance_cwnd()
2304 * before the call to tcp_cong_avoid(). Mainly this means that
2305 * we only execute this code if the ack actually acked some
2306 * data.
2307 */
2308
2309 /* If we are in slow start, increase our cwnd in response to this ACK.
2310 * (If we are not in slow start then we are in congestion avoidance,
2311 * and adjust our congestion window only once per RTT. See the code
2312 * above.)
2313 */
2314 if (tp->snd_cwnd <= tp->snd_ssthresh)
2315 tp->snd_cwnd++;
2316
2317 /* to keep cwnd from growing without bound */
2318 tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
2319
2320 /* Make sure that we are never so timid as to reduce our cwnd below
2321 * 2 MSS.
2322 *
2323 * Going below 2 MSS would risk huge delayed ACKs from our receiver.
2324 */
2325 tp->snd_cwnd = max(tp->snd_cwnd, 2U);
2326
2327 tp->snd_cwnd_stamp = tcp_time_stamp;
2328}
2329
2330static inline void tcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 seq_rtt)
2331{
2332 if (tcp_vegas_enabled(tp))
2333 vegas_cong_avoid(tp, ack, seq_rtt);
2334 else
2335 reno_cong_avoid(tp);
2336}
2337
2338/* Restart timer after forward progress on connection. 1947/* Restart timer after forward progress on connection.
2339 * RFC2988 recommends to restart timer to now+rto. 1948 * RFC2988 recommends to restart timer to now+rto.
2340 */ 1949 */
@@ -2415,13 +2024,18 @@ static int tcp_tso_acked(struct sock *sk, struct sk_buff *skb,
2415 2024
2416 2025
2417/* Remove acknowledged frames from the retransmission queue. */ 2026/* Remove acknowledged frames from the retransmission queue. */
2418static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) 2027static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p, s32 *seq_usrtt)
2419{ 2028{
2420 struct tcp_sock *tp = tcp_sk(sk); 2029 struct tcp_sock *tp = tcp_sk(sk);
2421 struct sk_buff *skb; 2030 struct sk_buff *skb;
2422 __u32 now = tcp_time_stamp; 2031 __u32 now = tcp_time_stamp;
2423 int acked = 0; 2032 int acked = 0;
2424 __s32 seq_rtt = -1; 2033 __s32 seq_rtt = -1;
2034 struct timeval usnow;
2035 u32 pkts_acked = 0;
2036
2037 if (seq_usrtt)
2038 do_gettimeofday(&usnow);
2425 2039
2426 while ((skb = skb_peek(&sk->sk_write_queue)) && 2040 while ((skb = skb_peek(&sk->sk_write_queue)) &&
2427 skb != sk->sk_send_head) { 2041 skb != sk->sk_send_head) {
@@ -2448,6 +2062,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
2448 */ 2062 */
2449 if (!(scb->flags & TCPCB_FLAG_SYN)) { 2063 if (!(scb->flags & TCPCB_FLAG_SYN)) {
2450 acked |= FLAG_DATA_ACKED; 2064 acked |= FLAG_DATA_ACKED;
2065 ++pkts_acked;
2451 } else { 2066 } else {
2452 acked |= FLAG_SYN_ACKED; 2067 acked |= FLAG_SYN_ACKED;
2453 tp->retrans_stamp = 0; 2068 tp->retrans_stamp = 0;
@@ -2461,6 +2076,10 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
2461 seq_rtt = -1; 2076 seq_rtt = -1;
2462 } else if (seq_rtt < 0) 2077 } else if (seq_rtt < 0)
2463 seq_rtt = now - scb->when; 2078 seq_rtt = now - scb->when;
2079 if (seq_usrtt)
2080 *seq_usrtt = (usnow.tv_sec - skb->stamp.tv_sec) * 1000000
2081 + (usnow.tv_usec - skb->stamp.tv_usec);
2082
2464 if (sacked & TCPCB_SACKED_ACKED) 2083 if (sacked & TCPCB_SACKED_ACKED)
2465 tp->sacked_out -= tcp_skb_pcount(skb); 2084 tp->sacked_out -= tcp_skb_pcount(skb);
2466 if (sacked & TCPCB_LOST) 2085 if (sacked & TCPCB_LOST)
@@ -2479,8 +2098,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p)
2479 } 2098 }
2480 2099
2481 if (acked&FLAG_ACKED) { 2100 if (acked&FLAG_ACKED) {
2482 tcp_ack_update_rtt(tp, acked, seq_rtt); 2101 tcp_ack_update_rtt(tp, acked, seq_rtt, seq_usrtt);
2483 tcp_ack_packets_out(sk, tp); 2102 tcp_ack_packets_out(sk, tp);
2103
2104 if (tp->ca_ops->pkts_acked)
2105 tp->ca_ops->pkts_acked(tp, pkts_acked);
2484 } 2106 }
2485 2107
2486#if FASTRETRANS_DEBUG > 0 2108#if FASTRETRANS_DEBUG > 0
@@ -2624,257 +2246,6 @@ static void tcp_process_frto(struct sock *sk, u32 prior_snd_una)
2624 tp->frto_counter = (tp->frto_counter + 1) % 3; 2246 tp->frto_counter = (tp->frto_counter + 1) % 3;
2625} 2247}
2626 2248
2627/*
2628 * TCP Westwood+
2629 */
2630
2631/*
2632 * @init_westwood
2633 * This function initializes fields used in TCP Westwood+. We can't
2634 * get no information about RTTmin at this time so we simply set it to
2635 * TCP_WESTWOOD_INIT_RTT. This value was chosen to be too conservative
2636 * since in this way we're sure it will be updated in a consistent
2637 * way as soon as possible. It will reasonably happen within the first
2638 * RTT period of the connection lifetime.
2639 */
2640
2641static void init_westwood(struct sock *sk)
2642{
2643 struct tcp_sock *tp = tcp_sk(sk);
2644
2645 tp->westwood.bw_ns_est = 0;
2646 tp->westwood.bw_est = 0;
2647 tp->westwood.accounted = 0;
2648 tp->westwood.cumul_ack = 0;
2649 tp->westwood.rtt_win_sx = tcp_time_stamp;
2650 tp->westwood.rtt = TCP_WESTWOOD_INIT_RTT;
2651 tp->westwood.rtt_min = TCP_WESTWOOD_INIT_RTT;
2652 tp->westwood.snd_una = tp->snd_una;
2653}
2654
2655/*
2656 * @westwood_do_filter
2657 * Low-pass filter. Implemented using constant coeffients.
2658 */
2659
2660static inline __u32 westwood_do_filter(__u32 a, __u32 b)
2661{
2662 return (((7 * a) + b) >> 3);
2663}
2664
2665static void westwood_filter(struct sock *sk, __u32 delta)
2666{
2667 struct tcp_sock *tp = tcp_sk(sk);
2668
2669 tp->westwood.bw_ns_est =
2670 westwood_do_filter(tp->westwood.bw_ns_est,
2671 tp->westwood.bk / delta);
2672 tp->westwood.bw_est =
2673 westwood_do_filter(tp->westwood.bw_est,
2674 tp->westwood.bw_ns_est);
2675}
2676
2677/*
2678 * @westwood_update_rttmin
2679 * It is used to update RTTmin. In this case we MUST NOT use
2680 * WESTWOOD_RTT_MIN minimum bound since we could be on a LAN!
2681 */
2682
2683static inline __u32 westwood_update_rttmin(const struct sock *sk)
2684{
2685 const struct tcp_sock *tp = tcp_sk(sk);
2686 __u32 rttmin = tp->westwood.rtt_min;
2687
2688 if (tp->westwood.rtt != 0 &&
2689 (tp->westwood.rtt < tp->westwood.rtt_min || !rttmin))
2690 rttmin = tp->westwood.rtt;
2691
2692 return rttmin;
2693}
2694
2695/*
2696 * @westwood_acked
2697 * Evaluate increases for dk.
2698 */
2699
2700static inline __u32 westwood_acked(const struct sock *sk)
2701{
2702 const struct tcp_sock *tp = tcp_sk(sk);
2703
2704 return tp->snd_una - tp->westwood.snd_una;
2705}
2706
2707/*
2708 * @westwood_new_window
2709 * It evaluates if we are receiving data inside the same RTT window as
2710 * when we started.
2711 * Return value:
2712 * It returns 0 if we are still evaluating samples in the same RTT
2713 * window, 1 if the sample has to be considered in the next window.
2714 */
2715
2716static int westwood_new_window(const struct sock *sk)
2717{
2718 const struct tcp_sock *tp = tcp_sk(sk);
2719 __u32 left_bound;
2720 __u32 rtt;
2721 int ret = 0;
2722
2723 left_bound = tp->westwood.rtt_win_sx;
2724 rtt = max(tp->westwood.rtt, (u32) TCP_WESTWOOD_RTT_MIN);
2725
2726 /*
2727 * A RTT-window has passed. Be careful since if RTT is less than
2728 * 50ms we don't filter but we continue 'building the sample'.
2729 * This minimum limit was choosen since an estimation on small
2730 * time intervals is better to avoid...
2731 * Obvioulsy on a LAN we reasonably will always have
2732 * right_bound = left_bound + WESTWOOD_RTT_MIN
2733 */
2734
2735 if ((left_bound + rtt) < tcp_time_stamp)
2736 ret = 1;
2737
2738 return ret;
2739}
2740
2741/*
2742 * @westwood_update_window
2743 * It updates RTT evaluation window if it is the right moment to do
2744 * it. If so it calls filter for evaluating bandwidth.
2745 */
2746
2747static void __westwood_update_window(struct sock *sk, __u32 now)
2748{
2749 struct tcp_sock *tp = tcp_sk(sk);
2750 __u32 delta = now - tp->westwood.rtt_win_sx;
2751
2752 if (delta) {
2753 if (tp->westwood.rtt)
2754 westwood_filter(sk, delta);
2755
2756 tp->westwood.bk = 0;
2757 tp->westwood.rtt_win_sx = tcp_time_stamp;
2758 }
2759}
2760
2761
2762static void westwood_update_window(struct sock *sk, __u32 now)
2763{
2764 if (westwood_new_window(sk))
2765 __westwood_update_window(sk, now);
2766}
2767
2768/*
2769 * @__tcp_westwood_fast_bw
2770 * It is called when we are in fast path. In particular it is called when
2771 * header prediction is successfull. In such case infact update is
2772 * straight forward and doesn't need any particular care.
2773 */
2774
2775static void __tcp_westwood_fast_bw(struct sock *sk, struct sk_buff *skb)
2776{
2777 struct tcp_sock *tp = tcp_sk(sk);
2778
2779 westwood_update_window(sk, tcp_time_stamp);
2780
2781 tp->westwood.bk += westwood_acked(sk);
2782 tp->westwood.snd_una = tp->snd_una;
2783 tp->westwood.rtt_min = westwood_update_rttmin(sk);
2784}
2785
2786static inline void tcp_westwood_fast_bw(struct sock *sk, struct sk_buff *skb)
2787{
2788 if (tcp_is_westwood(tcp_sk(sk)))
2789 __tcp_westwood_fast_bw(sk, skb);
2790}
2791
2792
2793/*
2794 * @westwood_dupack_update
2795 * It updates accounted and cumul_ack when receiving a dupack.
2796 */
2797
2798static void westwood_dupack_update(struct sock *sk)
2799{
2800 struct tcp_sock *tp = tcp_sk(sk);
2801
2802 tp->westwood.accounted += tp->mss_cache_std;
2803 tp->westwood.cumul_ack = tp->mss_cache_std;
2804}
2805
2806static inline int westwood_may_change_cumul(struct tcp_sock *tp)
2807{
2808 return (tp->westwood.cumul_ack > tp->mss_cache_std);
2809}
2810
2811static inline void westwood_partial_update(struct tcp_sock *tp)
2812{
2813 tp->westwood.accounted -= tp->westwood.cumul_ack;
2814 tp->westwood.cumul_ack = tp->mss_cache_std;
2815}
2816
2817static inline void westwood_complete_update(struct tcp_sock *tp)
2818{
2819 tp->westwood.cumul_ack -= tp->westwood.accounted;
2820 tp->westwood.accounted = 0;
2821}
2822
2823/*
2824 * @westwood_acked_count
2825 * This function evaluates cumul_ack for evaluating dk in case of
2826 * delayed or partial acks.
2827 */
2828
2829static inline __u32 westwood_acked_count(struct sock *sk)
2830{
2831 struct tcp_sock *tp = tcp_sk(sk);
2832
2833 tp->westwood.cumul_ack = westwood_acked(sk);
2834
2835 /* If cumul_ack is 0 this is a dupack since it's not moving
2836 * tp->snd_una.
2837 */
2838 if (!(tp->westwood.cumul_ack))
2839 westwood_dupack_update(sk);
2840
2841 if (westwood_may_change_cumul(tp)) {
2842 /* Partial or delayed ack */
2843 if (tp->westwood.accounted >= tp->westwood.cumul_ack)
2844 westwood_partial_update(tp);
2845 else
2846 westwood_complete_update(tp);
2847 }
2848
2849 tp->westwood.snd_una = tp->snd_una;
2850
2851 return tp->westwood.cumul_ack;
2852}
2853
2854
2855/*
2856 * @__tcp_westwood_slow_bw
2857 * It is called when something is going wrong..even if there could
2858 * be no problems! Infact a simple delayed packet may trigger a
2859 * dupack. But we need to be careful in such case.
2860 */
2861
2862static void __tcp_westwood_slow_bw(struct sock *sk, struct sk_buff *skb)
2863{
2864 struct tcp_sock *tp = tcp_sk(sk);
2865
2866 westwood_update_window(sk, tcp_time_stamp);
2867
2868 tp->westwood.bk += westwood_acked_count(sk);
2869 tp->westwood.rtt_min = westwood_update_rttmin(sk);
2870}
2871
2872static inline void tcp_westwood_slow_bw(struct sock *sk, struct sk_buff *skb)
2873{
2874 if (tcp_is_westwood(tcp_sk(sk)))
2875 __tcp_westwood_slow_bw(sk, skb);
2876}
2877
2878/* This routine deals with incoming acks, but not outgoing ones. */ 2249/* This routine deals with incoming acks, but not outgoing ones. */
2879static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag) 2250static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
2880{ 2251{
@@ -2884,6 +2255,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
2884 u32 ack = TCP_SKB_CB(skb)->ack_seq; 2255 u32 ack = TCP_SKB_CB(skb)->ack_seq;
2885 u32 prior_in_flight; 2256 u32 prior_in_flight;
2886 s32 seq_rtt; 2257 s32 seq_rtt;
2258 s32 seq_usrtt = 0;
2887 int prior_packets; 2259 int prior_packets;
2888 2260
2889 /* If the ack is newer than sent or older than previous acks 2261 /* If the ack is newer than sent or older than previous acks
@@ -2902,9 +2274,10 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
2902 */ 2274 */
2903 tcp_update_wl(tp, ack, ack_seq); 2275 tcp_update_wl(tp, ack, ack_seq);
2904 tp->snd_una = ack; 2276 tp->snd_una = ack;
2905 tcp_westwood_fast_bw(sk, skb);
2906 flag |= FLAG_WIN_UPDATE; 2277 flag |= FLAG_WIN_UPDATE;
2907 2278
2279 tcp_ca_event(tp, CA_EVENT_FAST_ACK);
2280
2908 NET_INC_STATS_BH(LINUX_MIB_TCPHPACKS); 2281 NET_INC_STATS_BH(LINUX_MIB_TCPHPACKS);
2909 } else { 2282 } else {
2910 if (ack_seq != TCP_SKB_CB(skb)->end_seq) 2283 if (ack_seq != TCP_SKB_CB(skb)->end_seq)
@@ -2920,7 +2293,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
2920 if (TCP_ECN_rcv_ecn_echo(tp, skb->h.th)) 2293 if (TCP_ECN_rcv_ecn_echo(tp, skb->h.th))
2921 flag |= FLAG_ECE; 2294 flag |= FLAG_ECE;
2922 2295
2923 tcp_westwood_slow_bw(sk,skb); 2296 tcp_ca_event(tp, CA_EVENT_SLOW_ACK);
2924 } 2297 }
2925 2298
2926 /* We passed data and got it acked, remove any soft error 2299 /* We passed data and got it acked, remove any soft error
@@ -2935,22 +2308,20 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
2935 prior_in_flight = tcp_packets_in_flight(tp); 2308 prior_in_flight = tcp_packets_in_flight(tp);
2936 2309
2937 /* See if we can take anything off of the retransmit queue. */ 2310 /* See if we can take anything off of the retransmit queue. */
2938 flag |= tcp_clean_rtx_queue(sk, &seq_rtt); 2311 flag |= tcp_clean_rtx_queue(sk, &seq_rtt,
2312 tp->ca_ops->rtt_sample ? &seq_usrtt : NULL);
2939 2313
2940 if (tp->frto_counter) 2314 if (tp->frto_counter)
2941 tcp_process_frto(sk, prior_snd_una); 2315 tcp_process_frto(sk, prior_snd_una);
2942 2316
2943 if (tcp_ack_is_dubious(tp, flag)) { 2317 if (tcp_ack_is_dubious(tp, flag)) {
2944 /* Advanve CWND, if state allows this. */ 2318 /* Advanve CWND, if state allows this. */
2945 if ((flag & FLAG_DATA_ACKED) && 2319 if ((flag & FLAG_DATA_ACKED) && tcp_may_raise_cwnd(tp, flag))
2946 (tcp_vegas_enabled(tp) || prior_in_flight >= tp->snd_cwnd) && 2320 tcp_cong_avoid(tp, ack, seq_rtt, prior_in_flight, 0);
2947 tcp_may_raise_cwnd(tp, flag))
2948 tcp_cong_avoid(tp, ack, seq_rtt);
2949 tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag); 2321 tcp_fastretrans_alert(sk, prior_snd_una, prior_packets, flag);
2950 } else { 2322 } else {
2951 if ((flag & FLAG_DATA_ACKED) && 2323 if ((flag & FLAG_DATA_ACKED))
2952 (tcp_vegas_enabled(tp) || prior_in_flight >= tp->snd_cwnd)) 2324 tcp_cong_avoid(tp, ack, seq_rtt, prior_in_flight, 1);
2953 tcp_cong_avoid(tp, ack, seq_rtt);
2954 } 2325 }
2955 2326
2956 if ((flag & FLAG_FORWARD_PROGRESS) || !(flag&FLAG_NOT_DUP)) 2327 if ((flag & FLAG_FORWARD_PROGRESS) || !(flag&FLAG_NOT_DUP))
@@ -4552,6 +3923,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
4552 3923
4553 tcp_init_metrics(sk); 3924 tcp_init_metrics(sk);
4554 3925
3926 tcp_init_congestion_control(tp);
3927
4555 /* Prevent spurious tcp_cwnd_restart() on first data 3928 /* Prevent spurious tcp_cwnd_restart() on first data
4556 * packet. 3929 * packet.
4557 */ 3930 */
@@ -4708,9 +4081,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
4708 if(tp->af_specific->conn_request(sk, skb) < 0) 4081 if(tp->af_specific->conn_request(sk, skb) < 0)
4709 return 1; 4082 return 1;
4710 4083
4711 init_westwood(sk);
4712 init_bictcp(tp);
4713
4714 /* Now we have several options: In theory there is 4084 /* Now we have several options: In theory there is
4715 * nothing else in the frame. KA9Q has an option to 4085 * nothing else in the frame. KA9Q has an option to
4716 * send data with the syn, BSD accepts data with the 4086 * send data with the syn, BSD accepts data with the
@@ -4732,9 +4102,6 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
4732 goto discard; 4102 goto discard;
4733 4103
4734 case TCP_SYN_SENT: 4104 case TCP_SYN_SENT:
4735 init_westwood(sk);
4736 init_bictcp(tp);
4737
4738 queued = tcp_rcv_synsent_state_process(sk, skb, th, len); 4105 queued = tcp_rcv_synsent_state_process(sk, skb, th, len);
4739 if (queued >= 0) 4106 if (queued >= 0)
4740 return queued; 4107 return queued;
@@ -4816,7 +4183,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
4816 */ 4183 */
4817 if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && 4184 if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
4818 !tp->srtt) 4185 !tp->srtt)
4819 tcp_ack_saw_tstamp(tp, 0); 4186 tcp_ack_saw_tstamp(tp, 0, 0);
4820 4187
4821 if (tp->rx_opt.tstamp_ok) 4188 if (tp->rx_opt.tstamp_ok)
4822 tp->advmss -= TCPOLEN_TSTAMP_ALIGNED; 4189 tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
@@ -4828,6 +4195,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
4828 4195
4829 tcp_init_metrics(sk); 4196 tcp_init_metrics(sk);
4830 4197
4198 tcp_init_congestion_control(tp);
4199
4831 /* Prevent spurious tcp_cwnd_restart() on 4200 /* Prevent spurious tcp_cwnd_restart() on
4832 * first data packet. 4201 * first data packet.
4833 */ 4202 */
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2d41d5d6ad19..9122814c13ad 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2048,6 +2048,7 @@ static int tcp_v4_init_sock(struct sock *sk)
2048 tp->mss_cache_std = tp->mss_cache = 536; 2048 tp->mss_cache_std = tp->mss_cache = 536;
2049 2049
2050 tp->reordering = sysctl_tcp_reordering; 2050 tp->reordering = sysctl_tcp_reordering;
2051 tp->ca_ops = &tcp_reno;
2051 2052
2052 sk->sk_state = TCP_CLOSE; 2053 sk->sk_state = TCP_CLOSE;
2053 2054
@@ -2070,6 +2071,8 @@ int tcp_v4_destroy_sock(struct sock *sk)
2070 2071
2071 tcp_clear_xmit_timers(sk); 2072 tcp_clear_xmit_timers(sk);
2072 2073
2074 tcp_cleanup_congestion_control(tp);
2075
2073 /* Cleanup up the write buffer. */ 2076 /* Cleanup up the write buffer. */
2074 sk_stream_writequeue_purge(sk); 2077 sk_stream_writequeue_purge(sk);
2075 2078
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index b3943e7562f3..f42a284164b7 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -774,6 +774,8 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
774 newtp->frto_counter = 0; 774 newtp->frto_counter = 0;
775 newtp->frto_highmark = 0; 775 newtp->frto_highmark = 0;
776 776
777 newtp->ca_ops = &tcp_reno;
778
777 tcp_set_ca_state(newtp, TCP_CA_Open); 779 tcp_set_ca_state(newtp, TCP_CA_Open);
778 tcp_init_xmit_timers(newsk); 780 tcp_init_xmit_timers(newsk);
779 skb_queue_head_init(&newtp->out_of_order_queue); 781 skb_queue_head_init(&newtp->out_of_order_queue);
@@ -842,8 +844,6 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
842 if (newtp->ecn_flags&TCP_ECN_OK) 844 if (newtp->ecn_flags&TCP_ECN_OK)
843 sock_set_flag(newsk, SOCK_NO_LARGESEND); 845 sock_set_flag(newsk, SOCK_NO_LARGESEND);
844 846
845 tcp_ca_init(newtp);
846
847 TCP_INC_STATS_BH(TCP_MIB_PASSIVEOPENS); 847 TCP_INC_STATS_BH(TCP_MIB_PASSIVEOPENS);
848 } 848 }
849 return newsk; 849 return newsk;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f17c6577e337..0e17c244875c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -111,8 +111,7 @@ static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
111 u32 restart_cwnd = tcp_init_cwnd(tp, dst); 111 u32 restart_cwnd = tcp_init_cwnd(tp, dst);
112 u32 cwnd = tp->snd_cwnd; 112 u32 cwnd = tp->snd_cwnd;
113 113
114 if (tcp_is_vegas(tp)) 114 tcp_ca_event(tp, CA_EVENT_CWND_RESTART);
115 tcp_vegas_enable(tp);
116 115
117 tp->snd_ssthresh = tcp_current_ssthresh(tp); 116 tp->snd_ssthresh = tcp_current_ssthresh(tp);
118 restart_cwnd = min(restart_cwnd, cwnd); 117 restart_cwnd = min(restart_cwnd, cwnd);
@@ -280,6 +279,10 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
280#define SYSCTL_FLAG_WSCALE 0x2 279#define SYSCTL_FLAG_WSCALE 0x2
281#define SYSCTL_FLAG_SACK 0x4 280#define SYSCTL_FLAG_SACK 0x4
282 281
282 /* If congestion control is doing timestamping */
283 if (tp->ca_ops->rtt_sample)
284 do_gettimeofday(&skb->stamp);
285
283 sysctl_flags = 0; 286 sysctl_flags = 0;
284 if (tcb->flags & TCPCB_FLAG_SYN) { 287 if (tcb->flags & TCPCB_FLAG_SYN) {
285 tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS; 288 tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
@@ -304,17 +307,8 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
304 (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK)); 307 (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
305 } 308 }
306 309
307 /* 310 if (tcp_packets_in_flight(tp) == 0)
308 * If the connection is idle and we are restarting, 311 tcp_ca_event(tp, CA_EVENT_TX_START);
309 * then we don't want to do any Vegas calculations
310 * until we get fresh RTT samples. So when we
311 * restart, we reset our Vegas state to a clean
312 * slate. After we get acks for this flight of
313 * packets, _then_ we can make Vegas calculations
314 * again.
315 */
316 if (tcp_is_vegas(tp) && tcp_packets_in_flight(tp) == 0)
317 tcp_vegas_enable(tp);
318 312
319 th = (struct tcphdr *) skb_push(skb, tcp_header_size); 313 th = (struct tcphdr *) skb_push(skb, tcp_header_size);
320 skb->h.th = th; 314 skb->h.th = th;
@@ -521,6 +515,7 @@ static int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len)
521 * skbs, which it never sent before. --ANK 515 * skbs, which it never sent before. --ANK
522 */ 516 */
523 TCP_SKB_CB(buff)->when = TCP_SKB_CB(skb)->when; 517 TCP_SKB_CB(buff)->when = TCP_SKB_CB(skb)->when;
518 buff->stamp = skb->stamp;
524 519
525 if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) { 520 if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
526 tp->lost_out -= tcp_skb_pcount(skb); 521 tp->lost_out -= tcp_skb_pcount(skb);
@@ -1449,7 +1444,6 @@ static inline void tcp_connect_init(struct sock *sk)
1449 tp->window_clamp = dst_metric(dst, RTAX_WINDOW); 1444 tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
1450 tp->advmss = dst_metric(dst, RTAX_ADVMSS); 1445 tp->advmss = dst_metric(dst, RTAX_ADVMSS);
1451 tcp_initialize_rcv_mss(sk); 1446 tcp_initialize_rcv_mss(sk);
1452 tcp_ca_init(tp);
1453 1447
1454 tcp_select_initial_window(tcp_full_space(sk), 1448 tcp_select_initial_window(tcp_full_space(sk),
1455 tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0), 1449 tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
@@ -1503,7 +1497,6 @@ int tcp_connect(struct sock *sk)
1503 TCP_SKB_CB(buff)->end_seq = tp->write_seq; 1497 TCP_SKB_CB(buff)->end_seq = tp->write_seq;
1504 tp->snd_nxt = tp->write_seq; 1498 tp->snd_nxt = tp->write_seq;
1505 tp->pushed_seq = tp->write_seq; 1499 tp->pushed_seq = tp->write_seq;
1506 tcp_ca_init(tp);
1507 1500
1508 /* Send it off. */ 1501 /* Send it off. */
1509 TCP_SKB_CB(buff)->when = tcp_time_stamp; 1502 TCP_SKB_CB(buff)->when = tcp_time_stamp;
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
new file mode 100644
index 000000000000..70e108e15c71
--- /dev/null
+++ b/net/ipv4/tcp_scalable.c
@@ -0,0 +1,68 @@
1/* Tom Kelly's Scalable TCP
2 *
3 * See htt://www-lce.eng.cam.ac.uk/~ctk21/scalable/
4 *
5 * John Heffner <jheffner@sc.edu>
6 */
7
8#include <linux/config.h>
9#include <linux/module.h>
10#include <net/tcp.h>
11
12/* These factors derived from the recommended values in the aer:
13 * .01 and and 7/8. We use 50 instead of 100 to account for
14 * delayed ack.
15 */
16#define TCP_SCALABLE_AI_CNT 50U
17#define TCP_SCALABLE_MD_SCALE 3
18
19static void tcp_scalable_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
20 u32 in_flight, int flag)
21{
22 if (in_flight < tp->snd_cwnd)
23 return;
24
25 if (tp->snd_cwnd <= tp->snd_ssthresh) {
26 tp->snd_cwnd++;
27 } else {
28 tp->snd_cwnd_cnt++;
29 if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
30 tp->snd_cwnd++;
31 tp->snd_cwnd_cnt = 0;
32 }
33 }
34 tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
35 tp->snd_cwnd_stamp = tcp_time_stamp;
36}
37
38static u32 tcp_scalable_ssthresh(struct tcp_sock *tp)
39{
40 return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U);
41}
42
43
44static struct tcp_congestion_ops tcp_scalable = {
45 .ssthresh = tcp_scalable_ssthresh,
46 .cong_avoid = tcp_scalable_cong_avoid,
47 .min_cwnd = tcp_reno_min_cwnd,
48
49 .owner = THIS_MODULE,
50 .name = "scalable",
51};
52
53static int __init tcp_scalable_register(void)
54{
55 return tcp_register_congestion_control(&tcp_scalable);
56}
57
58static void __exit tcp_scalable_unregister(void)
59{
60 tcp_unregister_congestion_control(&tcp_scalable);
61}
62
63module_init(tcp_scalable_register);
64module_exit(tcp_scalable_unregister);
65
66MODULE_AUTHOR("John Heffner");
67MODULE_LICENSE("GPL");
68MODULE_DESCRIPTION("Scalable TCP");
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
new file mode 100644
index 000000000000..9bd443db5193
--- /dev/null
+++ b/net/ipv4/tcp_vegas.c
@@ -0,0 +1,411 @@
1/*
2 * TCP Vegas congestion control
3 *
4 * This is based on the congestion detection/avoidance scheme described in
5 * Lawrence S. Brakmo and Larry L. Peterson.
6 * "TCP Vegas: End to end congestion avoidance on a global internet."
7 * IEEE Journal on Selected Areas in Communication, 13(8):1465--1480,
8 * October 1995. Available from:
9 * ftp://ftp.cs.arizona.edu/xkernel/Papers/jsac.ps
10 *
11 * See http://www.cs.arizona.edu/xkernel/ for their implementation.
12 * The main aspects that distinguish this implementation from the
13 * Arizona Vegas implementation are:
14 * o We do not change the loss detection or recovery mechanisms of
15 * Linux in any way. Linux already recovers from losses quite well,
16 * using fine-grained timers, NewReno, and FACK.
17 * o To avoid the performance penalty imposed by increasing cwnd
18 * only every-other RTT during slow start, we increase during
19 * every RTT during slow start, just like Reno.
20 * o Largely to allow continuous cwnd growth during slow start,
21 * we use the rate at which ACKs come back as the "actual"
22 * rate, rather than the rate at which data is sent.
23 * o To speed convergence to the right rate, we set the cwnd
24 * to achieve the right ("actual") rate when we exit slow start.
25 * o To filter out the noise caused by delayed ACKs, we use the
26 * minimum RTT sample observed during the last RTT to calculate
27 * the actual rate.
28 * o When the sender re-starts from idle, it waits until it has
29 * received ACKs for an entire flight of new data before making
30 * a cwnd adjustment decision. The original Vegas implementation
31 * assumed senders never went idle.
32 */
33
34#include <linux/config.h>
35#include <linux/mm.h>
36#include <linux/module.h>
37#include <linux/skbuff.h>
38#include <linux/tcp_diag.h>
39
40#include <net/tcp.h>
41
42/* Default values of the Vegas variables, in fixed-point representation
43 * with V_PARAM_SHIFT bits to the right of the binary point.
44 */
45#define V_PARAM_SHIFT 1
46static int alpha = 1<<V_PARAM_SHIFT;
47static int beta = 3<<V_PARAM_SHIFT;
48static int gamma = 1<<V_PARAM_SHIFT;
49
50module_param(alpha, int, 0644);
51MODULE_PARM_DESC(alpha, "lower bound of packets in network (scale by 2)");
52module_param(beta, int, 0644);
53MODULE_PARM_DESC(beta, "upper bound of packets in network (scale by 2)");
54module_param(gamma, int, 0644);
55MODULE_PARM_DESC(gamma, "limit on increase (scale by 2)");
56
57
58/* Vegas variables */
59struct vegas {
60 u32 beg_snd_nxt; /* right edge during last RTT */
61 u32 beg_snd_una; /* left edge during last RTT */
62 u32 beg_snd_cwnd; /* saves the size of the cwnd */
63 u8 doing_vegas_now;/* if true, do vegas for this RTT */
64 u16 cntRTT; /* # of RTTs measured within last RTT */
65 u32 minRTT; /* min of RTTs measured within last RTT (in usec) */
66 u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */
67};
68
69/* There are several situations when we must "re-start" Vegas:
70 *
71 * o when a connection is established
72 * o after an RTO
73 * o after fast recovery
74 * o when we send a packet and there is no outstanding
75 * unacknowledged data (restarting an idle connection)
76 *
77 * In these circumstances we cannot do a Vegas calculation at the
78 * end of the first RTT, because any calculation we do is using
79 * stale info -- both the saved cwnd and congestion feedback are
80 * stale.
81 *
82 * Instead we must wait until the completion of an RTT during
83 * which we actually receive ACKs.
84 */
85static inline void vegas_enable(struct tcp_sock *tp)
86{
87 struct vegas *vegas = tcp_ca(tp);
88
89 /* Begin taking Vegas samples next time we send something. */
90 vegas->doing_vegas_now = 1;
91
92 /* Set the beginning of the next send window. */
93 vegas->beg_snd_nxt = tp->snd_nxt;
94
95 vegas->cntRTT = 0;
96 vegas->minRTT = 0x7fffffff;
97}
98
99/* Stop taking Vegas samples for now. */
100static inline void vegas_disable(struct tcp_sock *tp)
101{
102 struct vegas *vegas = tcp_ca(tp);
103
104 vegas->doing_vegas_now = 0;
105}
106
107static void tcp_vegas_init(struct tcp_sock *tp)
108{
109 struct vegas *vegas = tcp_ca(tp);
110
111 vegas->baseRTT = 0x7fffffff;
112 vegas_enable(tp);
113}
114
115/* Do RTT sampling needed for Vegas.
116 * Basically we:
117 * o min-filter RTT samples from within an RTT to get the current
118 * propagation delay + queuing delay (we are min-filtering to try to
119 * avoid the effects of delayed ACKs)
120 * o min-filter RTT samples from a much longer window (forever for now)
121 * to find the propagation delay (baseRTT)
122 */
123static void tcp_vegas_rtt_calc(struct tcp_sock *tp, u32 usrtt)
124{
125 struct vegas *vegas = tcp_ca(tp);
126 u32 vrtt = usrtt + 1; /* Never allow zero rtt or baseRTT */
127
128 /* Filter to find propagation delay: */
129 if (vrtt < vegas->baseRTT)
130 vegas->baseRTT = vrtt;
131
132 /* Find the min RTT during the last RTT to find
133 * the current prop. delay + queuing delay:
134 */
135 vegas->minRTT = min(vegas->minRTT, vrtt);
136 vegas->cntRTT++;
137}
138
139static void tcp_vegas_state(struct tcp_sock *tp, u8 ca_state)
140{
141
142 if (ca_state == TCP_CA_Open)
143 vegas_enable(tp);
144 else
145 vegas_disable(tp);
146}
147
148/*
149 * If the connection is idle and we are restarting,
150 * then we don't want to do any Vegas calculations
151 * until we get fresh RTT samples. So when we
152 * restart, we reset our Vegas state to a clean
153 * slate. After we get acks for this flight of
154 * packets, _then_ we can make Vegas calculations
155 * again.
156 */
157static void tcp_vegas_cwnd_event(struct tcp_sock *tp, enum tcp_ca_event event)
158{
159 if (event == CA_EVENT_CWND_RESTART ||
160 event == CA_EVENT_TX_START)
161 tcp_vegas_init(tp);
162}
163
164static void tcp_vegas_cong_avoid(struct tcp_sock *tp, u32 ack,
165 u32 seq_rtt, u32 in_flight, int flag)
166{
167 struct vegas *vegas = tcp_ca(tp);
168
169 if (!vegas->doing_vegas_now)
170 return tcp_reno_cong_avoid(tp, ack, seq_rtt, in_flight, flag);
171
172 /* The key players are v_beg_snd_una and v_beg_snd_nxt.
173 *
174 * These are so named because they represent the approximate values
175 * of snd_una and snd_nxt at the beginning of the current RTT. More
176 * precisely, they represent the amount of data sent during the RTT.
177 * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
178 * we will calculate that (v_beg_snd_nxt - v_beg_snd_una) outstanding
179 * bytes of data have been ACKed during the course of the RTT, giving
180 * an "actual" rate of:
181 *
182 * (v_beg_snd_nxt - v_beg_snd_una) / (rtt duration)
183 *
184 * Unfortunately, v_beg_snd_una is not exactly equal to snd_una,
185 * because delayed ACKs can cover more than one segment, so they
186 * don't line up nicely with the boundaries of RTTs.
187 *
188 * Another unfortunate fact of life is that delayed ACKs delay the
189 * advance of the left edge of our send window, so that the number
190 * of bytes we send in an RTT is often less than our cwnd will allow.
191 * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
192 */
193
194 if (after(ack, vegas->beg_snd_nxt)) {
195 /* Do the Vegas once-per-RTT cwnd adjustment. */
196 u32 old_wnd, old_snd_cwnd;
197
198
199 /* Here old_wnd is essentially the window of data that was
200 * sent during the previous RTT, and has all
201 * been acknowledged in the course of the RTT that ended
202 * with the ACK we just received. Likewise, old_snd_cwnd
203 * is the cwnd during the previous RTT.
204 */
205 old_wnd = (vegas->beg_snd_nxt - vegas->beg_snd_una) /
206 tp->mss_cache;
207 old_snd_cwnd = vegas->beg_snd_cwnd;
208
209 /* Save the extent of the current window so we can use this
210 * at the end of the next RTT.
211 */
212 vegas->beg_snd_una = vegas->beg_snd_nxt;
213 vegas->beg_snd_nxt = tp->snd_nxt;
214 vegas->beg_snd_cwnd = tp->snd_cwnd;
215
216 /* Take into account the current RTT sample too, to
217 * decrease the impact of delayed acks. This double counts
218 * this sample since we count it for the next window as well,
219 * but that's not too awful, since we're taking the min,
220 * rather than averaging.
221 */
222 tcp_vegas_rtt_calc(tp, seq_rtt*1000);
223
224 /* We do the Vegas calculations only if we got enough RTT
225 * samples that we can be reasonably sure that we got
226 * at least one RTT sample that wasn't from a delayed ACK.
227 * If we only had 2 samples total,
228 * then that means we're getting only 1 ACK per RTT, which
229 * means they're almost certainly delayed ACKs.
230 * If we have 3 samples, we should be OK.
231 */
232
233 if (vegas->cntRTT <= 2) {
234 /* We don't have enough RTT samples to do the Vegas
235 * calculation, so we'll behave like Reno.
236 */
237 if (tp->snd_cwnd > tp->snd_ssthresh)
238 tp->snd_cwnd++;
239 } else {
240 u32 rtt, target_cwnd, diff;
241
242 /* We have enough RTT samples, so, using the Vegas
243 * algorithm, we determine if we should increase or
244 * decrease cwnd, and by how much.
245 */
246
247 /* Pluck out the RTT we are using for the Vegas
248 * calculations. This is the min RTT seen during the
249 * last RTT. Taking the min filters out the effects
250 * of delayed ACKs, at the cost of noticing congestion
251 * a bit later.
252 */
253 rtt = vegas->minRTT;
254
255 /* Calculate the cwnd we should have, if we weren't
256 * going too fast.
257 *
258 * This is:
259 * (actual rate in segments) * baseRTT
260 * We keep it as a fixed point number with
261 * V_PARAM_SHIFT bits to the right of the binary point.
262 */
263 target_cwnd = ((old_wnd * vegas->baseRTT)
264 << V_PARAM_SHIFT) / rtt;
265
266 /* Calculate the difference between the window we had,
267 * and the window we would like to have. This quantity
268 * is the "Diff" from the Arizona Vegas papers.
269 *
270 * Again, this is a fixed point number with
271 * V_PARAM_SHIFT bits to the right of the binary
272 * point.
273 */
274 diff = (old_wnd << V_PARAM_SHIFT) - target_cwnd;
275
276 if (tp->snd_cwnd < tp->snd_ssthresh) {
277 /* Slow start. */
278 if (diff > gamma) {
279 /* Going too fast. Time to slow down
280 * and switch to congestion avoidance.
281 */
282 tp->snd_ssthresh = 2;
283
284 /* Set cwnd to match the actual rate
285 * exactly:
286 * cwnd = (actual rate) * baseRTT
287 * Then we add 1 because the integer
288 * truncation robs us of full link
289 * utilization.
290 */
291 tp->snd_cwnd = min(tp->snd_cwnd,
292 (target_cwnd >>
293 V_PARAM_SHIFT)+1);
294
295 }
296 } else {
297 /* Congestion avoidance. */
298 u32 next_snd_cwnd;
299
300 /* Figure out where we would like cwnd
301 * to be.
302 */
303 if (diff > beta) {
304 /* The old window was too fast, so
305 * we slow down.
306 */
307 next_snd_cwnd = old_snd_cwnd - 1;
308 } else if (diff < alpha) {
309 /* We don't have enough extra packets
310 * in the network, so speed up.
311 */
312 next_snd_cwnd = old_snd_cwnd + 1;
313 } else {
314 /* Sending just as fast as we
315 * should be.
316 */
317 next_snd_cwnd = old_snd_cwnd;
318 }
319
320 /* Adjust cwnd upward or downward, toward the
321 * desired value.
322 */
323 if (next_snd_cwnd > tp->snd_cwnd)
324 tp->snd_cwnd++;
325 else if (next_snd_cwnd < tp->snd_cwnd)
326 tp->snd_cwnd--;
327 }
328 }
329
330 /* Wipe the slate clean for the next RTT. */
331 vegas->cntRTT = 0;
332 vegas->minRTT = 0x7fffffff;
333 }
334
335 /* The following code is executed for every ack we receive,
336 * except for conditions checked in should_advance_cwnd()
337 * before the call to tcp_cong_avoid(). Mainly this means that
338 * we only execute this code if the ack actually acked some
339 * data.
340 */
341
342 /* If we are in slow start, increase our cwnd in response to this ACK.
343 * (If we are not in slow start then we are in congestion avoidance,
344 * and adjust our congestion window only once per RTT. See the code
345 * above.)
346 */
347 if (tp->snd_cwnd <= tp->snd_ssthresh)
348 tp->snd_cwnd++;
349
350 /* to keep cwnd from growing without bound */
351 tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
352
353 /* Make sure that we are never so timid as to reduce our cwnd below
354 * 2 MSS.
355 *
356 * Going below 2 MSS would risk huge delayed ACKs from our receiver.
357 */
358 tp->snd_cwnd = max(tp->snd_cwnd, 2U);
359}
360
361/* Extract info for Tcp socket info provided via netlink. */
362static void tcp_vegas_get_info(struct tcp_sock *tp, u32 ext,
363 struct sk_buff *skb)
364{
365 const struct vegas *ca = tcp_ca(tp);
366 if (ext & (1<<(TCPDIAG_VEGASINFO-1))) {
367 struct tcpvegas_info *info;
368
369 info = RTA_DATA(__RTA_PUT(skb, TCPDIAG_VEGASINFO,
370 sizeof(*info)));
371
372 info->tcpv_enabled = ca->doing_vegas_now;
373 info->tcpv_rttcnt = ca->cntRTT;
374 info->tcpv_rtt = ca->baseRTT;
375 info->tcpv_minrtt = ca->minRTT;
376 rtattr_failure: ;
377 }
378}
379
380static struct tcp_congestion_ops tcp_vegas = {
381 .init = tcp_vegas_init,
382 .ssthresh = tcp_reno_ssthresh,
383 .cong_avoid = tcp_vegas_cong_avoid,
384 .min_cwnd = tcp_reno_min_cwnd,
385 .rtt_sample = tcp_vegas_rtt_calc,
386 .set_state = tcp_vegas_state,
387 .cwnd_event = tcp_vegas_cwnd_event,
388 .get_info = tcp_vegas_get_info,
389
390 .owner = THIS_MODULE,
391 .name = "vegas",
392};
393
394static int __init tcp_vegas_register(void)
395{
396 BUG_ON(sizeof(struct vegas) > TCP_CA_PRIV_SIZE);
397 tcp_register_congestion_control(&tcp_vegas);
398 return 0;
399}
400
401static void __exit tcp_vegas_unregister(void)
402{
403 tcp_unregister_congestion_control(&tcp_vegas);
404}
405
406module_init(tcp_vegas_register);
407module_exit(tcp_vegas_unregister);
408
409MODULE_AUTHOR("Stephen Hemminger");
410MODULE_LICENSE("GPL");
411MODULE_DESCRIPTION("TCP Vegas");
diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
new file mode 100644
index 000000000000..ef827242c940
--- /dev/null
+++ b/net/ipv4/tcp_westwood.c
@@ -0,0 +1,259 @@
1/*
2 * TCP Westwood+
3 *
4 * Angelo Dell'Aera: TCP Westwood+ support
5 */
6
7#include <linux/config.h>
8#include <linux/mm.h>
9#include <linux/module.h>
10#include <linux/skbuff.h>
11#include <linux/tcp_diag.h>
12#include <net/tcp.h>
13
14/* TCP Westwood structure */
15struct westwood {
16 u32 bw_ns_est; /* first bandwidth estimation..not too smoothed 8) */
17 u32 bw_est; /* bandwidth estimate */
18 u32 rtt_win_sx; /* here starts a new evaluation... */
19 u32 bk;
20 u32 snd_una; /* used for evaluating the number of acked bytes */
21 u32 cumul_ack;
22 u32 accounted;
23 u32 rtt;
24 u32 rtt_min; /* minimum observed RTT */
25};
26
27
28/* TCP Westwood functions and constants */
29#define TCP_WESTWOOD_RTT_MIN (HZ/20) /* 50ms */
30#define TCP_WESTWOOD_INIT_RTT (20*HZ) /* maybe too conservative?! */
31
32/*
33 * @tcp_westwood_create
34 * This function initializes fields used in TCP Westwood+,
35 * it is called after the initial SYN, so the sequence numbers
36 * are correct but new passive connections we have no
37 * information about RTTmin at this time so we simply set it to
38 * TCP_WESTWOOD_INIT_RTT. This value was chosen to be too conservative
39 * since in this way we're sure it will be updated in a consistent
40 * way as soon as possible. It will reasonably happen within the first
41 * RTT period of the connection lifetime.
42 */
43static void tcp_westwood_init(struct tcp_sock *tp)
44{
45 struct westwood *w = tcp_ca(tp);
46
47 w->bk = 0;
48 w->bw_ns_est = 0;
49 w->bw_est = 0;
50 w->accounted = 0;
51 w->cumul_ack = 0;
52 w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT;
53 w->rtt_win_sx = tcp_time_stamp;
54 w->snd_una = tp->snd_una;
55}
56
57/*
58 * @westwood_do_filter
59 * Low-pass filter. Implemented using constant coefficients.
60 */
61static inline u32 westwood_do_filter(u32 a, u32 b)
62{
63 return (((7 * a) + b) >> 3);
64}
65
66static inline void westwood_filter(struct westwood *w, u32 delta)
67{
68 w->bw_ns_est = westwood_do_filter(w->bw_ns_est, w->bk / delta);
69 w->bw_est = westwood_do_filter(w->bw_est, w->bw_ns_est);
70}
71
72/*
73 * @westwood_pkts_acked
74 * Called after processing group of packets.
75 * but all westwood needs is the last sample of srtt.
76 */
77static void tcp_westwood_pkts_acked(struct tcp_sock *tp, u32 cnt)
78{
79 struct westwood *w = tcp_ca(tp);
80 if (cnt > 0)
81 w->rtt = tp->srtt >> 3;
82}
83
84/*
85 * @westwood_update_window
86 * It updates RTT evaluation window if it is the right moment to do
87 * it. If so it calls filter for evaluating bandwidth.
88 */
89static void westwood_update_window(struct tcp_sock *tp)
90{
91 struct westwood *w = tcp_ca(tp);
92 s32 delta = tcp_time_stamp - w->rtt_win_sx;
93
94 /*
95 * See if a RTT-window has passed.
96 * Be careful since if RTT is less than
97 * 50ms we don't filter but we continue 'building the sample'.
98 * This minimum limit was chosen since an estimation on small
99 * time intervals is better to avoid...
100 * Obviously on a LAN we reasonably will always have
101 * right_bound = left_bound + WESTWOOD_RTT_MIN
102 */
103 if (w->rtt && delta > max_t(u32, w->rtt, TCP_WESTWOOD_RTT_MIN)) {
104 westwood_filter(w, delta);
105
106 w->bk = 0;
107 w->rtt_win_sx = tcp_time_stamp;
108 }
109}
110
111/*
112 * @westwood_fast_bw
113 * It is called when we are in fast path. In particular it is called when
114 * header prediction is successful. In such case in fact update is
115 * straight forward and doesn't need any particular care.
116 */
117static inline void westwood_fast_bw(struct tcp_sock *tp)
118{
119 struct westwood *w = tcp_ca(tp);
120
121 westwood_update_window(tp);
122
123 w->bk += tp->snd_una - w->snd_una;
124 w->snd_una = tp->snd_una;
125 w->rtt_min = min(w->rtt, w->rtt_min);
126}
127
128/*
129 * @westwood_acked_count
130 * This function evaluates cumul_ack for evaluating bk in case of
131 * delayed or partial acks.
132 */
133static inline u32 westwood_acked_count(struct tcp_sock *tp)
134{
135 struct westwood *w = tcp_ca(tp);
136
137 w->cumul_ack = tp->snd_una - w->snd_una;
138
139 /* If cumul_ack is 0 this is a dupack since it's not moving
140 * tp->snd_una.
141 */
142 if (!w->cumul_ack) {
143 w->accounted += tp->mss_cache;
144 w->cumul_ack = tp->mss_cache;
145 }
146
147 if (w->cumul_ack > tp->mss_cache) {
148 /* Partial or delayed ack */
149 if (w->accounted >= w->cumul_ack) {
150 w->accounted -= w->cumul_ack;
151 w->cumul_ack = tp->mss_cache;
152 } else {
153 w->cumul_ack -= w->accounted;
154 w->accounted = 0;
155 }
156 }
157
158 w->snd_una = tp->snd_una;
159
160 return w->cumul_ack;
161}
162
163static inline u32 westwood_bw_rttmin(const struct tcp_sock *tp)
164{
165 struct westwood *w = tcp_ca(tp);
166 return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2);
167}
168
169/*
170 * TCP Westwood
171 * Here limit is evaluated as Bw estimation*RTTmin (for obtaining it
172 * in packets we use mss_cache). Rttmin is guaranteed to be >= 2
173 * so avoids ever returning 0.
174 */
175static u32 tcp_westwood_cwnd_min(struct tcp_sock *tp)
176{
177 return westwood_bw_rttmin(tp);
178}
179
180static void tcp_westwood_event(struct tcp_sock *tp, enum tcp_ca_event event)
181{
182 struct westwood *w = tcp_ca(tp);
183
184 switch(event) {
185 case CA_EVENT_FAST_ACK:
186 westwood_fast_bw(tp);
187 break;
188
189 case CA_EVENT_COMPLETE_CWR:
190 tp->snd_cwnd = tp->snd_ssthresh = westwood_bw_rttmin(tp);
191 break;
192
193 case CA_EVENT_FRTO:
194 tp->snd_ssthresh = westwood_bw_rttmin(tp);
195 break;
196
197 case CA_EVENT_SLOW_ACK:
198 westwood_update_window(tp);
199 w->bk += westwood_acked_count(tp);
200 w->rtt_min = min(w->rtt, w->rtt_min);
201 break;
202
203 default:
204 /* don't care */
205 break;
206 }
207}
208
209
210/* Extract info for Tcp socket info provided via netlink. */
211static void tcp_westwood_info(struct tcp_sock *tp, u32 ext,
212 struct sk_buff *skb)
213{
214 const struct westwood *ca = tcp_ca(tp);
215 if (ext & (1<<(TCPDIAG_VEGASINFO-1))) {
216 struct rtattr *rta;
217 struct tcpvegas_info *info;
218
219 rta = __RTA_PUT(skb, TCPDIAG_VEGASINFO, sizeof(*info));
220 info = RTA_DATA(rta);
221 info->tcpv_enabled = 1;
222 info->tcpv_rttcnt = 0;
223 info->tcpv_rtt = jiffies_to_usecs(ca->rtt);
224 info->tcpv_minrtt = jiffies_to_usecs(ca->rtt_min);
225 rtattr_failure: ;
226 }
227}
228
229
230static struct tcp_congestion_ops tcp_westwood = {
231 .init = tcp_westwood_init,
232 .ssthresh = tcp_reno_ssthresh,
233 .cong_avoid = tcp_reno_cong_avoid,
234 .min_cwnd = tcp_westwood_cwnd_min,
235 .cwnd_event = tcp_westwood_event,
236 .get_info = tcp_westwood_info,
237 .pkts_acked = tcp_westwood_pkts_acked,
238
239 .owner = THIS_MODULE,
240 .name = "westwood"
241};
242
243static int __init tcp_westwood_register(void)
244{
245 BUG_ON(sizeof(struct westwood) > TCP_CA_PRIV_SIZE);
246 return tcp_register_congestion_control(&tcp_westwood);
247}
248
249static void __exit tcp_westwood_unregister(void)
250{
251 tcp_unregister_congestion_control(&tcp_westwood);
252}
253
254module_init(tcp_westwood_register);
255module_exit(tcp_westwood_unregister);
256
257MODULE_AUTHOR("Stephen Hemminger, Angelo Dell'Aera");
258MODULE_LICENSE("GPL");
259MODULE_DESCRIPTION("TCP Westwood+");
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2414937f2a83..fce56039b0e9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2025,7 +2025,7 @@ static int tcp_v6_init_sock(struct sock *sk)
2025 sk->sk_state = TCP_CLOSE; 2025 sk->sk_state = TCP_CLOSE;
2026 2026
2027 tp->af_specific = &ipv6_specific; 2027 tp->af_specific = &ipv6_specific;
2028 2028 tp->ca_ops = &tcp_reno;
2029 sk->sk_write_space = sk_stream_write_space; 2029 sk->sk_write_space = sk_stream_write_space;
2030 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); 2030 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
2031 2031
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-12 15:51:28 -0500