1 files changed, 95 insertions, 85 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 28e029632493..2549b29b062d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -62,6 +62,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/sysctl.h>
 #include <linux/kernel.h>
@@ -77,10 +78,13 @@ int sysctl_tcp_window_scaling __read_mostly = 1;
 int sysctl_tcp_sack __read_mostly = 1;
 int sysctl_tcp_fack __read_mostly = 1;
 int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH;
+EXPORT_SYMBOL(sysctl_tcp_reordering);
 int sysctl_tcp_ecn __read_mostly = 2;
+EXPORT_SYMBOL(sysctl_tcp_ecn);
 int sysctl_tcp_dsack __read_mostly = 1;
 int sysctl_tcp_app_win __read_mostly = 31;
 int sysctl_tcp_adv_win_scale __read_mostly = 2;
+EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
 
 int sysctl_tcp_stdurg __read_mostly;
 int sysctl_tcp_rfc1337 __read_mostly;
@@ -89,6 +93,8 @@ int sysctl_tcp_frto __read_mostly = 2;
 int sysctl_tcp_frto_response __read_mostly;
 int sysctl_tcp_nometrics_save __read_mostly;
 
+int sysctl_tcp_thin_dupack __read_mostly;
+
 int sysctl_tcp_moderate_rcvbuf __read_mostly = 1;
 int sysctl_tcp_abc __read_mostly;
 
@@ -176,7 +182,7 @@ static void tcp_incr_quickack(struct sock *sk)
                 icsk->icsk_ack.quick = min(quickacks, TCP_MAX_QUICKACKS);
 }
 
-void tcp_enter_quickack_mode(struct sock *sk)
+static void tcp_enter_quickack_mode(struct sock *sk)
 {
         struct inet_connection_sock *icsk = inet_csk(sk);
         tcp_incr_quickack(sk);
@@ -253,8 +259,11 @@ static void tcp_fixup_sndbuf(struct sock *sk)
         int sndmem = tcp_sk(sk)->rx_opt.mss_clamp + MAX_TCP_HEADER + 16 +
                      sizeof(struct sk_buff);
 
-        if (sk->sk_sndbuf < 3 * sndmem)
-                sk->sk_sndbuf = min(3 * sndmem, sysctl_tcp_wmem[2]);
+        if (sk->sk_sndbuf < 3 * sndmem) {
+                sk->sk_sndbuf = 3 * sndmem;
+                if (sk->sk_sndbuf > sysctl_tcp_wmem[2])
+                        sk->sk_sndbuf = sysctl_tcp_wmem[2];
+        }
 }
 
 /* 2. Tuning advertised window (window_clamp, rcv_ssthresh)
@@ -390,7 +399,7 @@ static void tcp_clamp_window(struct sock *sk)
         if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
             !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
             !tcp_memory_pressure &&
-            atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
+            atomic_long_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
                 sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
                                     sysctl_tcp_rmem[2]);
         }
@@ -416,15 +425,16 @@ void tcp_initialize_rcv_mss(struct sock *sk)
 
         inet_csk(sk)->icsk_ack.rcv_mss = hint;
 }
+EXPORT_SYMBOL(tcp_initialize_rcv_mss);
 
 /* Receiver "autotuning" code.
  *
  * The algorithm for RTT estimation w/o timestamps is based on
  * Dynamic Right-Sizing (DRS) by Wu Feng and Mike Fisk of LANL.
- * <http://www.lanl.gov/radiant/website/pubs/drs/lacsi2001.ps>
+ * <http://public.lanl.gov/radiant/pubs.html#DRS>
  *
  * More detail on this code can be found at
- * <http://www.psc.edu/~jheffner/senior_thesis.ps>,
+ * <http://staff.psc.edu/jheffner/>,
  * though this reference is out of date.  A new paper
  * is pending.
  */
@@ -724,7 +734,7 @@ void tcp_update_metrics(struct sock *sk)
                          * Reset our results.
                          */
                         if (!(dst_metric_locked(dst, RTAX_RTT)))
-                                dst->metrics[RTAX_RTT - 1] = 0;
+                                dst_metric_set(dst, RTAX_RTT, 0);
                         return;
                 }
 
@@ -766,57 +776,48 @@ void tcp_update_metrics(struct sock *sk)
                         if (dst_metric(dst, RTAX_SSTHRESH) &&
                             !dst_metric_locked(dst, RTAX_SSTHRESH) &&
                             (tp->snd_cwnd >> 1) > dst_metric(dst, RTAX_SSTHRESH))
-                                dst->metrics[RTAX_SSTHRESH-1] = tp->snd_cwnd >> 1;
+                                dst_metric_set(dst, RTAX_SSTHRESH, tp->snd_cwnd >> 1);
                         if (!dst_metric_locked(dst, RTAX_CWND) &&
                             tp->snd_cwnd > dst_metric(dst, RTAX_CWND))
-                                dst->metrics[RTAX_CWND - 1] = tp->snd_cwnd;
+                                dst_metric_set(dst, RTAX_CWND, tp->snd_cwnd);
                 } else if (tp->snd_cwnd > tp->snd_ssthresh &&
                            icsk->icsk_ca_state == TCP_CA_Open) {
                         /* Cong. avoidance phase, cwnd is reliable. */
                         if (!dst_metric_locked(dst, RTAX_SSTHRESH))
-                                dst->metrics[RTAX_SSTHRESH-1] =
-                                        max(tp->snd_cwnd >> 1, tp->snd_ssthresh);
+                                dst_metric_set(dst, RTAX_SSTHRESH,
+                                               max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
                         if (!dst_metric_locked(dst, RTAX_CWND))
-                                dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_cwnd) >> 1;
+                                dst_metric_set(dst, RTAX_CWND,
+                                               (dst_metric(dst, RTAX_CWND) +
+                                                tp->snd_cwnd) >> 1);
                 } else {
                         /* Else slow start did not finish, cwnd is non-sense,
                            ssthresh may be also invalid.
                          */
                         if (!dst_metric_locked(dst, RTAX_CWND))
-                                dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_ssthresh) >> 1;
+                                dst_metric_set(dst, RTAX_CWND,
+                                               (dst_metric(dst, RTAX_CWND) +
+                                                tp->snd_ssthresh) >> 1);
                         if (dst_metric(dst, RTAX_SSTHRESH) &&
                             !dst_metric_locked(dst, RTAX_SSTHRESH) &&
                             tp->snd_ssthresh > dst_metric(dst, RTAX_SSTHRESH))
-                                dst->metrics[RTAX_SSTHRESH-1] = tp->snd_ssthresh;
+                                dst_metric_set(dst, RTAX_SSTHRESH, tp->snd_ssthresh);
                 }
 
                 if (!dst_metric_locked(dst, RTAX_REORDERING)) {
                         if (dst_metric(dst, RTAX_REORDERING) < tp->reordering &&
                             tp->reordering != sysctl_tcp_reordering)
-                                dst->metrics[RTAX_REORDERING-1] = tp->reordering;
+                                dst_metric_set(dst, RTAX_REORDERING, tp->reordering);
                 }
         }
 }
 
-/* Numbers are taken from RFC3390.
- *
- * John Heffner states:
- *
- *      The RFC specifies a window of no more than 4380 bytes
- *      unless 2*MSS > 4380.  Reading the pseudocode in the RFC
- *      is a bit misleading because they use a clamp at 4380 bytes
- *      rather than use a multiplier in the relevant range.
- */
 __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst)
 {
         __u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0);
 
-        if (!cwnd) {
-                if (tp->mss_cache > 1460)
-                        cwnd = 2;
-                else
-                        cwnd = (tp->mss_cache > 1095) ? 3 : 4;
-        }
+        if (!cwnd)
+                cwnd = rfc3390_bytes_to_packets(tp->mss_cache);
         return min_t(__u32, cwnd, tp->snd_cwnd_clamp);
 }
 
@@ -915,25 +916,20 @@ static void tcp_init_metrics(struct sock *sk)
                 tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
         }
         tcp_set_rto(sk);
-        if (inet_csk(sk)->icsk_rto < TCP_TIMEOUT_INIT && !tp->rx_opt.saw_tstamp)
-                goto reset;
-
-cwnd:
-        tp->snd_cwnd = tcp_init_cwnd(tp, dst);
-        tp->snd_cwnd_stamp = tcp_time_stamp;
-        return;
-
+        if (inet_csk(sk)->icsk_rto < TCP_TIMEOUT_INIT && !tp->rx_opt.saw_tstamp) {
 reset:
-        /* Play conservative. If timestamps are not
-         * supported, TCP will fail to recalculate correct
-         * rtt, if initial rto is too small. FORGET ALL AND RESET!
-         */
-        if (!tp->rx_opt.saw_tstamp && tp->srtt) {
-                tp->srtt = 0;
-                tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_INIT;
-                inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+                /* Play conservative. If timestamps are not
+                 * supported, TCP will fail to recalculate correct
+                 * rtt, if initial rto is too small. FORGET ALL AND RESET!
+                 */
+                if (!tp->rx_opt.saw_tstamp && tp->srtt) {
+                        tp->srtt = 0;
+                        tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_INIT;
+                        inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+                }
         }
-        goto cwnd;
+        tp->snd_cwnd = tcp_init_cwnd(tp, dst);
+        tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
 static void tcp_update_reordering(struct sock *sk, const int metric,
@@ -2307,7 +2303,7 @@ static inline int tcp_dupack_heuristics(struct tcp_sock *tp)
 
 static inline int tcp_skb_timedout(struct sock *sk, struct sk_buff *skb)
 {
-        return (tcp_time_stamp - TCP_SKB_CB(skb)->when > inet_csk(sk)->icsk_rto);
+        return tcp_time_stamp - TCP_SKB_CB(skb)->when > inet_csk(sk)->icsk_rto;
 }
 
 static inline int tcp_head_timedout(struct sock *sk)
@@ -2447,6 +2443,16 @@ static int tcp_time_to_recover(struct sock *sk)
                 return 1;
         }
 
+        /* If a thin stream is detected, retransmit after first
+         * received dupack. Employ only if SACK is supported in order
+         * to avoid possible corner-case series of spurious retransmissions
+         * Use only if there are no unsent data.
+         */
+        if ((tp->thin_dupack || sysctl_tcp_thin_dupack) &&
+            tcp_stream_is_thin(tp) && tcp_dupack_heuristics(tp) > 1 &&
+            tcp_is_sack(tp) && !tcp_send_head(sk))
+                return 1;
+
         return 0;
 }
 
@@ -2491,7 +2497,7 @@ static void tcp_timeout_skbs(struct sock *sk)
 /* Mark head of queue up as lost. With RFC3517 SACK, the packets is
  * is against sacked "cnt", otherwise it's against facked "cnt"
  */
-static void tcp_mark_head_lost(struct sock *sk, int packets)
+static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct sk_buff *skb;
@@ -2503,6 +2509,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
         if (tp->lost_skb_hint) {
                 skb = tp->lost_skb_hint;
                 cnt = tp->lost_cnt_hint;
+                /* Head already handled? */
+                if (mark_head && skb != tcp_write_queue_head(sk))
+                        return;
         } else {
                 skb = tcp_write_queue_head(sk);
                 cnt = 0;
@@ -2525,7 +2534,8 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
                         cnt += tcp_skb_pcount(skb);
 
                 if (cnt > packets) {
-                        if (tcp_is_sack(tp) || (oldcnt >= packets))
+                        if ((tcp_is_sack(tp) && !tcp_is_fack(tp)) ||
+                            (oldcnt >= packets))
                                 break;
 
                         mss = skb_shinfo(skb)->gso_size;
@@ -2536,6 +2546,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
                 }
 
                 tcp_skb_mark_lost(tp, skb);
+
+                if (mark_head)
+                        break;
         }
         tcp_verify_left_out(tp);
 }
@@ -2547,17 +2560,18 @@ static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit)
         struct tcp_sock *tp = tcp_sk(sk);
 
         if (tcp_is_reno(tp)) {
-                tcp_mark_head_lost(sk, 1);
+                tcp_mark_head_lost(sk, 1, 1);
         } else if (tcp_is_fack(tp)) {
                 int lost = tp->fackets_out - tp->reordering;
                 if (lost <= 0)
                         lost = 1;
-                tcp_mark_head_lost(sk, lost);
+                tcp_mark_head_lost(sk, lost, 0);
         } else {
                 int sacked_upto = tp->sacked_out - tp->reordering;
-                if (sacked_upto < fast_rexmit)
-                        sacked_upto = fast_rexmit;
-                tcp_mark_head_lost(sk, sacked_upto);
+                if (sacked_upto >= 0)
+                        tcp_mark_head_lost(sk, sacked_upto, 0);
+                else if (fast_rexmit)
+                        tcp_mark_head_lost(sk, 1, 1);
         }
 
         tcp_timeout_skbs(sk);
@@ -2623,7 +2637,7 @@ static void DBGUNDO(struct sock *sk, const char *msg)
         if (sk->sk_family == AF_INET) {
                 printk(KERN_DEBUG "Undo %s %pI4/%u c%u l%u ss%u/%u p%u\n",
                        msg,
-                       &inet->daddr, ntohs(inet->dport),
+                       &inet->inet_daddr, ntohs(inet->inet_dport),
                        tp->snd_cwnd, tcp_left_out(tp),
                        tp->snd_ssthresh, tp->prior_ssthresh,
                        tp->packets_out);
@@ -2633,7 +2647,7 @@ static void DBGUNDO(struct sock *sk, const char *msg)
                 struct ipv6_pinfo *np = inet6_sk(sk);
                 printk(KERN_DEBUG "Undo %s %pI6/%u c%u l%u ss%u/%u p%u\n",
                        msg,
-                       &np->daddr, ntohs(inet->dport),
+                       &np->daddr, ntohs(inet->inet_dport),
                        tp->snd_cwnd, tcp_left_out(tp),
                        tp->snd_ssthresh, tp->prior_ssthresh,
                        tp->packets_out);
@@ -2866,7 +2880,7 @@ static void tcp_mtup_probe_success(struct sock *sk)
                        icsk->icsk_mtup.probe_size;
         tp->snd_cwnd_cnt = 0;
         tp->snd_cwnd_stamp = tcp_time_stamp;
-        tp->rcv_ssthresh = tcp_current_ssthresh(sk);
+        tp->snd_ssthresh = tcp_current_ssthresh(sk);
 
         icsk->icsk_mtup.search_low = icsk->icsk_mtup.probe_size;
         icsk->icsk_mtup.probe_size = 0;
@@ -2922,6 +2936,7 @@ void tcp_simple_retransmit(struct sock *sk)
         }
         tcp_xmit_retransmit_queue(sk);
 }
+EXPORT_SYMBOL(tcp_simple_retransmit);
 
 /* Process an event, which can update packets-in-flight not trivially.
  * Main goal of this function is to calculate new estimate for left_out,
@@ -2962,7 +2977,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag)
             before(tp->snd_una, tp->high_seq) &&
             icsk->icsk_ca_state != TCP_CA_Open &&
             tp->fackets_out > tp->reordering) {
-                tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering);
+                tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering, 0);
                 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSS);
         }
 
@@ -3270,7 +3285,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
                  * connection startup slow start one packet too
                  * quickly.  This is severely frowned upon behavior.
                  */
-                if (!(scb->flags & TCPCB_FLAG_SYN)) {
+                if (!(scb->flags & TCPHDR_SYN)) {
                         flag |= FLAG_DATA_ACKED;
                 } else {
                         flag |= FLAG_SYN_ACKED;
@@ -3390,8 +3405,8 @@ static void tcp_ack_probe(struct sock *sk)
 
 static inline int tcp_ack_is_dubious(const struct sock *sk, const int flag)
 {
-        return (!(flag & FLAG_NOT_DUP) || (flag & FLAG_CA_ALERT) ||
-                inet_csk(sk)->icsk_ca_state != TCP_CA_Open);
+        return !(flag & FLAG_NOT_DUP) || (flag & FLAG_CA_ALERT) ||
+                inet_csk(sk)->icsk_ca_state != TCP_CA_Open;
 }
 
 static inline int tcp_may_raise_cwnd(const struct sock *sk, const int flag)
@@ -3408,9 +3423,9 @@ static inline int tcp_may_update_window(const struct tcp_sock *tp,
                                         const u32 ack, const u32 ack_seq,
                                         const u32 nwin)
 {
-        return (after(ack, tp->snd_una) ||
+        return  after(ack, tp->snd_una) ||
                 after(ack_seq, tp->snd_wl1) ||
-                (ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd));
+                (ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd);
 }
 
 /* Update our send window.
@@ -3694,7 +3709,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
         }
 
         if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP))
-                dst_confirm(sk->sk_dst_cache);
+                dst_confirm(__sk_dst_get(sk));
 
         return 1;
 
@@ -3829,18 +3844,20 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
                                         /* 16-bit multiple */
                                         opt_rx->cookie_plus = opsize;
                                         *hvpp = ptr;
+                                        break;
                                 default:
                                         /* ignore option */
                                         break;
-                                };
+                                }
                                 break;
-                        };
+                        }
 
                         ptr += opsize-2;
                         length -= opsize;
                 }
         }
 }
+EXPORT_SYMBOL(tcp_parse_options);
 
 static int tcp_parse_aligned_timestamp(struct tcp_sock *tp, struct tcphdr *th)
 {
@@ -3907,13 +3924,14 @@ u8 *tcp_parse_md5sig_option(struct tcphdr *th)
                         if (opsize < 2 || opsize > length)
                                 return NULL;
                         if (opcode == TCPOPT_MD5SIG)
-                                return ptr;
+                                return opsize == TCPOLEN_MD5SIG ? ptr : NULL;
                 }
                 ptr += opsize - 2;
                 length -= opsize;
         }
         return NULL;
 }
+EXPORT_SYMBOL(tcp_parse_md5sig_option);
 #endif
 
 static inline void tcp_store_ts_recent(struct tcp_sock *tp)
@@ -4024,6 +4042,8 @@ static void tcp_reset(struct sock *sk)
         default:
                 sk->sk_err = ECONNRESET;
         }
+        /* This barrier is coupled with smp_rmb() in tcp_poll() */
+        smp_wmb();
 
         if (!sock_flag(sk, SOCK_DEAD))
                 sk->sk_error_report(sk);
@@ -4303,7 +4323,7 @@ static void tcp_ofo_queue(struct sock *sk)
                 }
 
                 if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
-                        SOCK_DEBUG(sk, "ofo packet was already received \n");
+                        SOCK_DEBUG(sk, "ofo packet was already received\n");
                         __skb_unlink(skb, &tp->out_of_order_queue);
                         __kfree_skb(skb);
                         continue;
@@ -4351,6 +4371,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
         if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
                 goto drop;
 
+        skb_dst_drop(skb);
         __skb_pull(skb, th->doff * 4);
 
         TCP_ECN_accept_cwr(tp, skb);
@@ -4842,7 +4863,7 @@ static int tcp_should_expand_sndbuf(struct sock *sk)
                 return 0;
 
         /* If we are under soft global TCP memory pressure, do not expand.  */
-        if (atomic_read(&tcp_memory_allocated) >= sysctl_tcp_mem[0])
+        if (atomic_long_read(&tcp_memory_allocated) >= sysctl_tcp_mem[0])
                 return 0;
 
         /* If we filled the congestion window, do not expand.  */
@@ -5414,6 +5435,7 @@ discard:
         __kfree_skb(skb);
         return 0;
 }
+EXPORT_SYMBOL(tcp_rcv_established);
 
 static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                                          struct tcphdr *th, unsigned len)
@@ -5783,11 +5805,9 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 
                                 /* tcp_ack considers this ACK as duplicate
                                  * and does not calculate rtt.
-                                 * Fix it at least with timestamps.
+                                 * Force it here.
                                  */
-                                if (tp->rx_opt.saw_tstamp &&
-                                    tp->rx_opt.rcv_tsecr && !tp->srtt)
-                                        tcp_ack_saw_tstamp(sk, 0);
+                                tcp_ack_update_rtt(sk, 0, 0);
 
                                 if (tp->rx_opt.tstamp_ok)
                                         tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
@@ -5819,7 +5839,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                         if (tp->snd_una == tp->write_seq) {
                                 tcp_set_state(sk, TCP_FIN_WAIT2);
                                 sk->sk_shutdown |= SEND_SHUTDOWN;
-                                dst_confirm(sk->sk_dst_cache);
+                                dst_confirm(__sk_dst_get(sk));
 
                                 if (!sock_flag(sk, SOCK_DEAD))
                                         /* Wake up lingering close() */
@@ -5915,14 +5935,4 @@ discard:
         }
         return 0;
 }
-
-EXPORT_SYMBOL(sysctl_tcp_ecn);
-EXPORT_SYMBOL(sysctl_tcp_reordering);
-EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
-EXPORT_SYMBOL(tcp_parse_options);
-#ifdef CONFIG_TCP_MD5SIG
-EXPORT_SYMBOL(tcp_parse_md5sig_option);
-#endif
-EXPORT_SYMBOL(tcp_rcv_established);
 EXPORT_SYMBOL(tcp_rcv_state_process);
-EXPORT_SYMBOL(tcp_initialize_rcv_mss);