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authorDamian Lukowski <damian@tvk.rwth-aachen.de>2010-09-28 16:08:32 -0400
committerDavid S. Miller <davem@davemloft.net>2010-09-28 16:08:32 -0400
commit4d22f7d372f5769c6c0149e427ed6353e2dcfe61 (patch)
tree7f4ff499d171f4d9b78975300aedd6c9d527073f /net
parent01db403cf99f739f86903314a489fb420e0e254f (diff)
net-2.6: SYN retransmits: Add new parameter to retransmits_timed_out()
Fixes kernel Bugzilla Bug 18952 This patch adds a syn_set parameter to the retransmits_timed_out() routine and updates its callers. If not set, TCP_RTO_MIN is taken as the calculation basis as before. If set, TCP_TIMEOUT_INIT is used instead, so that sysctl_syn_retries represents the actual amount of SYN retransmissions in case no SYNACKs are received when establishing a new connection. Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_timer.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index c35b469e851c..74c54b30600f 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -135,13 +135,16 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
135 135
136/* This function calculates a "timeout" which is equivalent to the timeout of a 136/* This function calculates a "timeout" which is equivalent to the timeout of a
137 * TCP connection after "boundary" unsuccessful, exponentially backed-off 137 * TCP connection after "boundary" unsuccessful, exponentially backed-off
138 * retransmissions with an initial RTO of TCP_RTO_MIN. 138 * retransmissions with an initial RTO of TCP_RTO_MIN or TCP_TIMEOUT_INIT if
139 * syn_set flag is set.
139 */ 140 */
140static bool retransmits_timed_out(struct sock *sk, 141static bool retransmits_timed_out(struct sock *sk,
141 unsigned int boundary) 142 unsigned int boundary,
143 bool syn_set)
142{ 144{
143 unsigned int timeout, linear_backoff_thresh; 145 unsigned int timeout, linear_backoff_thresh;
144 unsigned int start_ts; 146 unsigned int start_ts;
147 unsigned int rto_base = syn_set ? TCP_TIMEOUT_INIT : TCP_RTO_MIN;
145 148
146 if (!inet_csk(sk)->icsk_retransmits) 149 if (!inet_csk(sk)->icsk_retransmits)
147 return false; 150 return false;
@@ -151,12 +154,12 @@ static bool retransmits_timed_out(struct sock *sk,
151 else 154 else
152 start_ts = tcp_sk(sk)->retrans_stamp; 155 start_ts = tcp_sk(sk)->retrans_stamp;
153 156
154 linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN); 157 linear_backoff_thresh = ilog2(TCP_RTO_MAX/rto_base);
155 158
156 if (boundary <= linear_backoff_thresh) 159 if (boundary <= linear_backoff_thresh)
157 timeout = ((2 << boundary) - 1) * TCP_RTO_MIN; 160 timeout = ((2 << boundary) - 1) * rto_base;
158 else 161 else
159 timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN + 162 timeout = ((2 << linear_backoff_thresh) - 1) * rto_base +
160 (boundary - linear_backoff_thresh) * TCP_RTO_MAX; 163 (boundary - linear_backoff_thresh) * TCP_RTO_MAX;
161 164
162 return (tcp_time_stamp - start_ts) >= timeout; 165 return (tcp_time_stamp - start_ts) >= timeout;
@@ -167,14 +170,15 @@ static int tcp_write_timeout(struct sock *sk)
167{ 170{
168 struct inet_connection_sock *icsk = inet_csk(sk); 171 struct inet_connection_sock *icsk = inet_csk(sk);
169 int retry_until; 172 int retry_until;
170 bool do_reset; 173 bool do_reset, syn_set = 0;
171 174
172 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 175 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
173 if (icsk->icsk_retransmits) 176 if (icsk->icsk_retransmits)
174 dst_negative_advice(sk); 177 dst_negative_advice(sk);
175 retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries; 178 retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
179 syn_set = 1;
176 } else { 180 } else {
177 if (retransmits_timed_out(sk, sysctl_tcp_retries1)) { 181 if (retransmits_timed_out(sk, sysctl_tcp_retries1, 0)) {
178 /* Black hole detection */ 182 /* Black hole detection */
179 tcp_mtu_probing(icsk, sk); 183 tcp_mtu_probing(icsk, sk);
180 184
@@ -187,14 +191,14 @@ static int tcp_write_timeout(struct sock *sk)
187 191
188 retry_until = tcp_orphan_retries(sk, alive); 192 retry_until = tcp_orphan_retries(sk, alive);
189 do_reset = alive || 193 do_reset = alive ||
190 !retransmits_timed_out(sk, retry_until); 194 !retransmits_timed_out(sk, retry_until, 0);
191 195
192 if (tcp_out_of_resources(sk, do_reset)) 196 if (tcp_out_of_resources(sk, do_reset))
193 return 1; 197 return 1;
194 } 198 }
195 } 199 }
196 200
197 if (retransmits_timed_out(sk, retry_until)) { 201 if (retransmits_timed_out(sk, retry_until, syn_set)) {
198 /* Has it gone just too far? */ 202 /* Has it gone just too far? */
199 tcp_write_err(sk); 203 tcp_write_err(sk);
200 return 1; 204 return 1;
@@ -436,7 +440,7 @@ out_reset_timer:
436 icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX); 440 icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
437 } 441 }
438 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX); 442 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX);
439 if (retransmits_timed_out(sk, sysctl_tcp_retries1 + 1)) 443 if (retransmits_timed_out(sk, sysctl_tcp_retries1 + 1, 0))
440 __sk_dst_reset(sk); 444 __sk_dst_reset(sk);
441 445
442out:; 446out:;