1 files changed, 98 insertions, 304 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index f730935b824a..5010f0c5a56e 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)
 #else
 # define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG)
 #endif
-
-#define BICTCP_BETA_SCALE    1024       /* Scale factor beta calculation
-                                         * max_cwnd = snd_cwnd * beta
-                                         */
-#define BICTCP_MAX_INCREMENT 32         /*
-                                         * Limit on the amount of
-                                         * increment allowed during
-                                         * binary search.
-                                         */
-#define BICTCP_FUNC_OF_MIN_INCR 11      /*
-                                         * log(B/Smin)/log(B/(B-1))+1,
-                                         * Smin:min increment
-                                         * B:log factor
-                                         */
-#define BICTCP_B                4        /*
-                                          * In binary search,
-                                          * go to point (max+min)/N
-                                          */
-
 /*
  *      TCP option
  */
@@ -596,16 +577,7 @@ extern int sysctl_tcp_adv_win_scale;
 extern int sysctl_tcp_tw_reuse;
 extern int sysctl_tcp_frto;
 extern int sysctl_tcp_low_latency;
-extern int sysctl_tcp_westwood;
-extern int sysctl_tcp_vegas_cong_avoid;
-extern int sysctl_tcp_vegas_alpha;
-extern int sysctl_tcp_vegas_beta;
-extern int sysctl_tcp_vegas_gamma;
 extern int sysctl_tcp_nometrics_save;
-extern int sysctl_tcp_bic;
-extern int sysctl_tcp_bic_fast_convergence;
-extern int sysctl_tcp_bic_low_window;
-extern int sysctl_tcp_bic_beta;
 extern int sysctl_tcp_moderate_rcvbuf;
 extern int sysctl_tcp_tso_win_divisor;
 
@@ -749,11 +721,16 @@ static inline int tcp_ack_scheduled(struct tcp_sock *tp)
         return tp->ack.pending&TCP_ACK_SCHED;
 }
 
-static __inline__ void tcp_dec_quickack_mode(struct tcp_sock *tp)
+static __inline__ void tcp_dec_quickack_mode(struct tcp_sock *tp, unsigned int pkts)
 {
-        if (tp->ack.quick && --tp->ack.quick == 0) {
-                /* Leaving quickack mode we deflate ATO. */
-                tp->ack.ato = TCP_ATO_MIN;
+        if (tp->ack.quick) {
+                if (pkts >= tp->ack.quick) {
+                        tp->ack.quick = 0;
+
+                        /* Leaving quickack mode we deflate ATO. */
+                        tp->ack.ato = TCP_ATO_MIN;
+                } else
+                        tp->ack.quick -= pkts;
         }
 }
 
@@ -871,7 +848,9 @@ extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
 
 /* tcp_output.c */
 
-extern int tcp_write_xmit(struct sock *, int nonagle);
+extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
+                                      unsigned int cur_mss, int nonagle);
+extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp);
 extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
 extern void tcp_xmit_retransmit_queue(struct sock *);
 extern void tcp_simple_retransmit(struct sock *);
@@ -881,12 +860,16 @@ extern void tcp_send_probe0(struct sock *);
 extern void tcp_send_partial(struct sock *);
 extern int  tcp_write_wakeup(struct sock *);
 extern void tcp_send_fin(struct sock *sk);
-extern void tcp_send_active_reset(struct sock *sk, int priority);
+extern void tcp_send_active_reset(struct sock *sk,
+                                  unsigned int __nocast priority);
 extern int  tcp_send_synack(struct sock *);
-extern void tcp_push_one(struct sock *, unsigned mss_now);
+extern void tcp_push_one(struct sock *, unsigned int mss_now);
 extern void tcp_send_ack(struct sock *sk);
 extern void tcp_send_delayed_ack(struct sock *sk);
 
+/* tcp_input.c */
+extern void tcp_cwnd_application_limited(struct sock *sk);
+
 /* tcp_timer.c */
 extern void tcp_init_xmit_timers(struct sock *);
 extern void tcp_clear_xmit_timers(struct sock *);
@@ -986,7 +969,7 @@ static inline void tcp_reset_xmit_timer(struct sock *sk, int what, unsigned long
 static inline void tcp_initialize_rcv_mss(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
-        unsigned int hint = min(tp->advmss, tp->mss_cache_std);
+        unsigned int hint = min_t(unsigned int, tp->advmss, tp->mss_cache);
 
         hint = min(hint, tp->rcv_wnd/2);
         hint = min(hint, TCP_MIN_RCVMSS);
@@ -1009,7 +992,7 @@ static __inline__ void tcp_fast_path_on(struct tcp_sock *tp)
 
 static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp)
 {
-        if (skb_queue_len(&tp->out_of_order_queue) == 0 &&
+        if (skb_queue_empty(&tp->out_of_order_queue) &&
             tp->rcv_wnd &&
             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
             !tp->urg_data)
@@ -1136,6 +1119,82 @@ static inline void tcp_packets_out_dec(struct tcp_sock *tp,
         tp->packets_out -= tcp_skb_pcount(skb);
 }
 
+/* Events passed to congestion control interface */
+enum tcp_ca_event {
+        CA_EVENT_TX_START,      /* first transmit when no packets in flight */
+        CA_EVENT_CWND_RESTART,  /* congestion window restart */
+        CA_EVENT_COMPLETE_CWR,  /* end of congestion recovery */
+        CA_EVENT_FRTO,          /* fast recovery timeout */
+        CA_EVENT_LOSS,          /* loss timeout */
+        CA_EVENT_FAST_ACK,      /* in sequence ack */
+        CA_EVENT_SLOW_ACK,      /* other ack */
+};
+
+/*
+ * Interface for adding new TCP congestion control handlers
+ */
+#define TCP_CA_NAME_MAX 16
+struct tcp_congestion_ops {
+        struct list_head        list;
+
+        /* initialize private data (optional) */
+        void (*init)(struct tcp_sock *tp);
+        /* cleanup private data  (optional) */
+        void (*release)(struct tcp_sock *tp);
+
+        /* return slow start threshold (required) */
+        u32 (*ssthresh)(struct tcp_sock *tp);
+        /* lower bound for congestion window (optional) */
+        u32 (*min_cwnd)(struct tcp_sock *tp);
+        /* do new cwnd calculation (required) */
+        void (*cong_avoid)(struct tcp_sock *tp, u32 ack,
+                           u32 rtt, u32 in_flight, int good_ack);
+        /* round trip time sample per acked packet (optional) */
+        void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt);
+        /* call before changing ca_state (optional) */
+        void (*set_state)(struct tcp_sock *tp, u8 new_state);
+        /* call when cwnd event occurs (optional) */
+        void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev);
+        /* new value of cwnd after loss (optional) */
+        u32  (*undo_cwnd)(struct tcp_sock *tp);
+        /* hook for packet ack accounting (optional) */
+        void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked);
+        /* get info for tcp_diag (optional) */
+        void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb);
+
+        char            name[TCP_CA_NAME_MAX];
+        struct module   *owner;
+};
+
+extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
+extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
+
+extern void tcp_init_congestion_control(struct tcp_sock *tp);
+extern void tcp_cleanup_congestion_control(struct tcp_sock *tp);
+extern int tcp_set_default_congestion_control(const char *name);
+extern void tcp_get_default_congestion_control(char *name);
+extern int tcp_set_congestion_control(struct tcp_sock *tp, const char *name);
+
+extern struct tcp_congestion_ops tcp_init_congestion_ops;
+extern u32 tcp_reno_ssthresh(struct tcp_sock *tp);
+extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack,
+                                u32 rtt, u32 in_flight, int flag);
+extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp);
+extern struct tcp_congestion_ops tcp_reno;
+
+static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
+{
+        if (tp->ca_ops->set_state)
+                tp->ca_ops->set_state(tp, ca_state);
+        tp->ca_state = ca_state;
+}
+
+static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event)
+{
+        if (tp->ca_ops->cwnd_event)
+                tp->ca_ops->cwnd_event(tp, event);
+}
+
 /* This determines how many packets are "in the network" to the best
  * of our knowledge.  In many cases it is conservative, but where
  * detailed information is available from the receiver (via SACK
@@ -1155,91 +1214,6 @@ static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
         return (tp->packets_out - tp->left_out + tp->retrans_out);
 }
 
-/*
- * Which congestion algorithim is in use on the connection.
- */
-#define tcp_is_vegas(__tp)      ((__tp)->adv_cong == TCP_VEGAS)
-#define tcp_is_westwood(__tp)   ((__tp)->adv_cong == TCP_WESTWOOD)
-#define tcp_is_bic(__tp)        ((__tp)->adv_cong == TCP_BIC)
-
-/* Recalculate snd_ssthresh, we want to set it to:
- *
- * Reno:
- *      one half the current congestion window, but no
- *      less than two segments
- *
- * BIC:
- *      behave like Reno until low_window is reached,
- *      then increase congestion window slowly
- */
-static inline __u32 tcp_recalc_ssthresh(struct tcp_sock *tp)
-{
-        if (tcp_is_bic(tp)) {
-                if (sysctl_tcp_bic_fast_convergence &&
-                    tp->snd_cwnd < tp->bictcp.last_max_cwnd)
-                        tp->bictcp.last_max_cwnd = (tp->snd_cwnd * 
-                                                    (BICTCP_BETA_SCALE
-                                                     + sysctl_tcp_bic_beta))
-                                / (2 * BICTCP_BETA_SCALE);
-                else
-                        tp->bictcp.last_max_cwnd = tp->snd_cwnd;
-
-                if (tp->snd_cwnd > sysctl_tcp_bic_low_window)
-                        return max((tp->snd_cwnd * sysctl_tcp_bic_beta)
-                                   / BICTCP_BETA_SCALE, 2U);
-        }
-
-        return max(tp->snd_cwnd >> 1U, 2U);
-}
-
-/* Stop taking Vegas samples for now. */
-#define tcp_vegas_disable(__tp) ((__tp)->vegas.doing_vegas_now = 0)
-    
-static inline void tcp_vegas_enable(struct tcp_sock *tp)
-{
-        /* There are several situations when we must "re-start" Vegas:
-         *
-         *  o when a connection is established
-         *  o after an RTO
-         *  o after fast recovery
-         *  o when we send a packet and there is no outstanding
-         *    unacknowledged data (restarting an idle connection)
-         *
-         * In these circumstances we cannot do a Vegas calculation at the
-         * end of the first RTT, because any calculation we do is using
-         * stale info -- both the saved cwnd and congestion feedback are
-         * stale.
-         *
-         * Instead we must wait until the completion of an RTT during
-         * which we actually receive ACKs.
-         */
-    
-        /* Begin taking Vegas samples next time we send something. */
-        tp->vegas.doing_vegas_now = 1;
-     
-        /* Set the beginning of the next send window. */
-        tp->vegas.beg_snd_nxt = tp->snd_nxt;
-
-        tp->vegas.cntRTT = 0;
-        tp->vegas.minRTT = 0x7fffffff;
-}
-
-/* Should we be taking Vegas samples right now? */
-#define tcp_vegas_enabled(__tp) ((__tp)->vegas.doing_vegas_now)
-
-extern void tcp_ca_init(struct tcp_sock *tp);
-
-static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
-{
-        if (tcp_is_vegas(tp)) {
-                if (ca_state == TCP_CA_Open) 
-                        tcp_vegas_enable(tp);
-                else
-                        tcp_vegas_disable(tp);
-        }
-        tp->ca_state = ca_state;
-}
-
 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
  * The exception is rate halving phase, when cwnd is decreasing towards
  * ssthresh.
@@ -1262,33 +1236,11 @@ static inline void tcp_sync_left_out(struct tcp_sock *tp)
         tp->left_out = tp->sacked_out + tp->lost_out;
 }
 
-extern void tcp_cwnd_application_limited(struct sock *sk);
-
-/* Congestion window validation. (RFC2861) */
-
-static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
-{
-        __u32 packets_out = tp->packets_out;
-
-        if (packets_out >= tp->snd_cwnd) {
-                /* Network is feed fully. */
-                tp->snd_cwnd_used = 0;
-                tp->snd_cwnd_stamp = tcp_time_stamp;
-        } else {
-                /* Network starves. */
-                if (tp->packets_out > tp->snd_cwnd_used)
-                        tp->snd_cwnd_used = tp->packets_out;
-
-                if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto)
-                        tcp_cwnd_application_limited(sk);
-        }
-}
-
-/* Set slow start threshould and cwnd not falling to slow start */
+/* Set slow start threshold and cwnd not falling to slow start */
 static inline void __tcp_enter_cwr(struct tcp_sock *tp)
 {
         tp->undo_marker = 0;
-        tp->snd_ssthresh = tcp_recalc_ssthresh(tp);
+        tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
         tp->snd_cwnd = min(tp->snd_cwnd,
                            tcp_packets_in_flight(tp) + 1U);
         tp->snd_cwnd_cnt = 0;
@@ -1316,12 +1268,6 @@ static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
         return 3;
 }
 
-static __inline__ int tcp_minshall_check(const struct tcp_sock *tp)
-{
-        return after(tp->snd_sml,tp->snd_una) &&
-                !after(tp->snd_sml, tp->snd_nxt);
-}
-
 static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, 
                                            const struct sk_buff *skb)
 {
@@ -1329,122 +1275,18 @@ static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss,
                 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
 }
 
-/* Return 0, if packet can be sent now without violation Nagle's rules:
-   1. It is full sized.
-   2. Or it contains FIN.
-   3. Or TCP_NODELAY was set.
-   4. Or TCP_CORK is not set, and all sent packets are ACKed.
-      With Minshall's modification: all sent small packets are ACKed.
- */
-
-static __inline__ int
-tcp_nagle_check(const struct tcp_sock *tp, const struct sk_buff *skb, 
-                unsigned mss_now, int nonagle)
-{
-        return (skb->len < mss_now &&
-                !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
-                ((nonagle&TCP_NAGLE_CORK) ||
-                 (!nonagle &&
-                  tp->packets_out &&
-                  tcp_minshall_check(tp))));
-}
-
-extern void tcp_set_skb_tso_segs(struct sock *, struct sk_buff *);
-
-/* This checks if the data bearing packet SKB (usually sk->sk_send_head)
- * should be put on the wire right now.
- */
-static __inline__ int tcp_snd_test(struct sock *sk,
-                                   struct sk_buff *skb,
-                                   unsigned cur_mss, int nonagle)
-{
-        struct tcp_sock *tp = tcp_sk(sk);
-        int pkts = tcp_skb_pcount(skb);
-
-        if (!pkts) {
-                tcp_set_skb_tso_segs(sk, skb);
-                pkts = tcp_skb_pcount(skb);
-        }
-
-        /*      RFC 1122 - section 4.2.3.4
-         *
-         *      We must queue if
-         *
-         *      a) The right edge of this frame exceeds the window
-         *      b) There are packets in flight and we have a small segment
-         *         [SWS avoidance and Nagle algorithm]
-         *         (part of SWS is done on packetization)
-         *         Minshall version sounds: there are no _small_
-         *         segments in flight. (tcp_nagle_check)
-         *      c) We have too many packets 'in flight'
-         *
-         *      Don't use the nagle rule for urgent data (or
-         *      for the final FIN -DaveM).
-         *
-         *      Also, Nagle rule does not apply to frames, which
-         *      sit in the middle of queue (they have no chances
-         *      to get new data) and if room at tail of skb is
-         *      not enough to save something seriously (<32 for now).
-         */
-
-        /* Don't be strict about the congestion window for the
-         * final FIN frame.  -DaveM
-         */
-        return (((nonagle&TCP_NAGLE_PUSH) || tp->urg_mode
-                 || !tcp_nagle_check(tp, skb, cur_mss, nonagle)) &&
-                (((tcp_packets_in_flight(tp) + (pkts-1)) < tp->snd_cwnd) ||
-                 (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) &&
-                !after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd));
-}
-
 static __inline__ void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp)
 {
         if (!tp->packets_out && !tp->pending)
                 tcp_reset_xmit_timer(sk, TCP_TIME_PROBE0, tp->rto);
 }
 
-static __inline__ int tcp_skb_is_last(const struct sock *sk, 
-                                      const struct sk_buff *skb)
-{
-        return skb->next == (struct sk_buff *)&sk->sk_write_queue;
-}
-
-/* Push out any pending frames which were held back due to
- * TCP_CORK or attempt at coalescing tiny packets.
- * The socket must be locked by the caller.
- */
-static __inline__ void __tcp_push_pending_frames(struct sock *sk,
-                                                 struct tcp_sock *tp,
-                                                 unsigned cur_mss,
-                                                 int nonagle)
-{
-        struct sk_buff *skb = sk->sk_send_head;
-
-        if (skb) {
-                if (!tcp_skb_is_last(sk, skb))
-                        nonagle = TCP_NAGLE_PUSH;
-                if (!tcp_snd_test(sk, skb, cur_mss, nonagle) ||
-                    tcp_write_xmit(sk, nonagle))
-                        tcp_check_probe_timer(sk, tp);
-        }
-        tcp_cwnd_validate(sk, tp);
-}
-
 static __inline__ void tcp_push_pending_frames(struct sock *sk,
                                                struct tcp_sock *tp)
 {
         __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle);
 }
 
-static __inline__ int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp)
-{
-        struct sk_buff *skb = sk->sk_send_head;
-
-        return (skb &&
-                tcp_snd_test(sk, skb, tcp_current_mss(sk, 1),
-                             tcp_skb_is_last(sk, skb) ? TCP_NAGLE_PUSH : tp->nonagle));
-}
-
 static __inline__ void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
 {
         tp->snd_wl1 = seq;
@@ -1876,52 +1718,4 @@ struct tcp_iter_state {
 extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
 extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
 
-/* TCP Westwood functions and constants */
-
-#define TCP_WESTWOOD_INIT_RTT  (20*HZ)           /* maybe too conservative?! */
-#define TCP_WESTWOOD_RTT_MIN   (HZ/20)           /* 50ms */
-
-static inline void tcp_westwood_update_rtt(struct tcp_sock *tp, __u32 rtt_seq)
-{
-        if (tcp_is_westwood(tp))
-                tp->westwood.rtt = rtt_seq;
-}
-
-static inline __u32 __tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
-{
-        return max((tp->westwood.bw_est) * (tp->westwood.rtt_min) /
-                   (__u32) (tp->mss_cache_std),
-                   2U);
-}
-
-static inline __u32 tcp_westwood_bw_rttmin(const struct tcp_sock *tp)
-{
-        return tcp_is_westwood(tp) ? __tcp_westwood_bw_rttmin(tp) : 0;
-}
-
-static inline int tcp_westwood_ssthresh(struct tcp_sock *tp)
-{
-        __u32 ssthresh = 0;
-
-        if (tcp_is_westwood(tp)) {
-                ssthresh = __tcp_westwood_bw_rttmin(tp);
-                if (ssthresh)
-                        tp->snd_ssthresh = ssthresh;  
-        }
-
-        return (ssthresh != 0);
-}
-
-static inline int tcp_westwood_cwnd(struct tcp_sock *tp)
-{
-        __u32 cwnd = 0;
-
-        if (tcp_is_westwood(tp)) {
-                cwnd = __tcp_westwood_bw_rttmin(tp);
-                if (cwnd)
-                        tp->snd_cwnd = cwnd;
-        }
-
-        return (cwnd != 0);
-}
 #endif  /* _TCP_H */