aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv4/tcp_timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv4/tcp_timer.c')
-rw-r--r--net/ipv4/tcp_timer.c41
1 files changed, 35 insertions, 6 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index cdb2ca7684d4..8816a20c2597 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -132,6 +132,35 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
132 } 132 }
133} 133}
134 134
135/* This function calculates a "timeout" which is equivalent to the timeout of a
136 * TCP connection after "boundary" unsucessful, exponentially backed-off
137 * retransmissions with an initial RTO of TCP_RTO_MIN.
138 */
139static bool retransmits_timed_out(struct sock *sk,
140 unsigned int boundary)
141{
142 unsigned int timeout, linear_backoff_thresh;
143 unsigned int start_ts;
144
145 if (!inet_csk(sk)->icsk_retransmits)
146 return false;
147
148 if (unlikely(!tcp_sk(sk)->retrans_stamp))
149 start_ts = TCP_SKB_CB(tcp_write_queue_head(sk))->when;
150 else
151 start_ts = tcp_sk(sk)->retrans_stamp;
152
153 linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN);
154
155 if (boundary <= linear_backoff_thresh)
156 timeout = ((2 << boundary) - 1) * TCP_RTO_MIN;
157 else
158 timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN +
159 (boundary - linear_backoff_thresh) * TCP_RTO_MAX;
160
161 return (tcp_time_stamp - start_ts) >= timeout;
162}
163
135/* A write timeout has occurred. Process the after effects. */ 164/* A write timeout has occurred. Process the after effects. */
136static int tcp_write_timeout(struct sock *sk) 165static int tcp_write_timeout(struct sock *sk)
137{ 166{
@@ -141,14 +170,14 @@ static int tcp_write_timeout(struct sock *sk)
141 170
142 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 171 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
143 if (icsk->icsk_retransmits) 172 if (icsk->icsk_retransmits)
144 dst_negative_advice(&sk->sk_dst_cache); 173 dst_negative_advice(&sk->sk_dst_cache, sk);
145 retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 174 retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
146 } else { 175 } else {
147 if (retransmits_timed_out(sk, sysctl_tcp_retries1)) { 176 if (retransmits_timed_out(sk, sysctl_tcp_retries1)) {
148 /* Black hole detection */ 177 /* Black hole detection */
149 tcp_mtu_probing(icsk, sk); 178 tcp_mtu_probing(icsk, sk);
150 179
151 dst_negative_advice(&sk->sk_dst_cache); 180 dst_negative_advice(&sk->sk_dst_cache, sk);
152 } 181 }
153 182
154 retry_until = sysctl_tcp_retries2; 183 retry_until = sysctl_tcp_retries2;
@@ -303,15 +332,15 @@ void tcp_retransmit_timer(struct sock *sk)
303 struct inet_sock *inet = inet_sk(sk); 332 struct inet_sock *inet = inet_sk(sk);
304 if (sk->sk_family == AF_INET) { 333 if (sk->sk_family == AF_INET) {
305 LIMIT_NETDEBUG(KERN_DEBUG "TCP: Peer %pI4:%u/%u unexpectedly shrunk window %u:%u (repaired)\n", 334 LIMIT_NETDEBUG(KERN_DEBUG "TCP: Peer %pI4:%u/%u unexpectedly shrunk window %u:%u (repaired)\n",
306 &inet->daddr, ntohs(inet->dport), 335 &inet->inet_daddr, ntohs(inet->inet_dport),
307 inet->num, tp->snd_una, tp->snd_nxt); 336 inet->inet_num, tp->snd_una, tp->snd_nxt);
308 } 337 }
309#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 338#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
310 else if (sk->sk_family == AF_INET6) { 339 else if (sk->sk_family == AF_INET6) {
311 struct ipv6_pinfo *np = inet6_sk(sk); 340 struct ipv6_pinfo *np = inet6_sk(sk);
312 LIMIT_NETDEBUG(KERN_DEBUG "TCP: Peer %pI6:%u/%u unexpectedly shrunk window %u:%u (repaired)\n", 341 LIMIT_NETDEBUG(KERN_DEBUG "TCP: Peer %pI6:%u/%u unexpectedly shrunk window %u:%u (repaired)\n",
313 &np->daddr, ntohs(inet->dport), 342 &np->daddr, ntohs(inet->inet_dport),
314 inet->num, tp->snd_una, tp->snd_nxt); 343 inet->inet_num, tp->snd_una, tp->snd_nxt);
315 } 344 }
316#endif 345#endif
317#endif 346#endif