From dca43c75e7e545694a9dd6288553f55c53e2a3a3 Mon Sep 17 00:00:00 2001 From: Jerry Chu Date: Fri, 27 Aug 2010 19:13:28 +0000 Subject: tcp: Add TCP_USER_TIMEOUT socket option. This patch provides a "user timeout" support as described in RFC793. The socket option is also needed for the the local half of RFC5482 "TCP User Timeout Option". TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int, when > 0, to specify the maximum amount of time in ms that transmitted data may remain unacknowledged before TCP will forcefully close the corresponding connection and return ETIMEDOUT to the application. If 0 is given, TCP will continue to use the system default. Increasing the user timeouts allows a TCP connection to survive extended periods without end-to-end connectivity. Decreasing the user timeouts allows applications to "fail fast" if so desired. Otherwise it may take upto 20 minutes with the current system defaults in a normal WAN environment. The socket option can be made during any state of a TCP connection, but is only effective during the synchronized states of a connection (ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, or LAST-ACK). Moreover, when used with the TCP keepalive (SO_KEEPALIVE) option, TCP_USER_TIMEOUT will overtake keepalive to determine when to close a connection due to keepalive failure. The option does not change in anyway when TCP retransmits a packet, nor when a keepalive probe will be sent. This option, like many others, will be inherited by an acceptor from its listener. Signed-off-by: H.K. Jerry Chu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 176e11aaea77..cf3254528753 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2391,7 +2391,12 @@ static int do_tcp_setsockopt(struct sock *sk, int level, err = tp->af_specific->md5_parse(sk, optval, optlen); break; #endif - + case TCP_USER_TIMEOUT: + /* Cap the max timeout in ms TCP will retry/retrans + * before giving up and aborting (ETIMEDOUT) a connection. + */ + icsk->icsk_user_timeout = msecs_to_jiffies(val); + break; default: err = -ENOPROTOOPT; break; @@ -2610,6 +2615,10 @@ static int do_tcp_getsockopt(struct sock *sk, int level, case TCP_THIN_DUPACK: val = tp->thin_dupack; break; + + case TCP_USER_TIMEOUT: + val = jiffies_to_msecs(icsk->icsk_user_timeout); + break; default: return -ENOPROTOOPT; } -- cgit v1.2.2 From 8d987e5c75107ca7515fa19e857cfa24aab6ec8f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 9 Nov 2010 23:24:26 +0000 Subject: net: avoid limits overflow Robin Holt tried to boot a 16TB machine and found some limits were reached : sysctl_tcp_mem[2], sysctl_udp_mem[2] We can switch infrastructure to use long "instead" of "int", now atomic_long_t primitives are available for free. Signed-off-by: Eric Dumazet Reported-by: Robin Holt Reviewed-by: Robin Holt Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 1664a0590bb8..245603c4ad48 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -282,7 +282,7 @@ int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; struct percpu_counter tcp_orphan_count; EXPORT_SYMBOL_GPL(tcp_orphan_count); -int sysctl_tcp_mem[3] __read_mostly; +long sysctl_tcp_mem[3] __read_mostly; int sysctl_tcp_wmem[3] __read_mostly; int sysctl_tcp_rmem[3] __read_mostly; @@ -290,7 +290,7 @@ EXPORT_SYMBOL(sysctl_tcp_mem); EXPORT_SYMBOL(sysctl_tcp_rmem); EXPORT_SYMBOL(sysctl_tcp_wmem); -atomic_t tcp_memory_allocated; /* Current allocated memory. */ +atomic_long_t tcp_memory_allocated; /* Current allocated memory. */ EXPORT_SYMBOL(tcp_memory_allocated); /* -- cgit v1.2.2 From 7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 10 Nov 2010 21:35:37 -0800 Subject: tcp: Increase TCP_MAXSEG socket option minimum. As noted by Steve Chen, since commit f5fff5dc8a7a3f395b0525c02ba92c95d42b7390 ("tcp: advertise MSS requested by user") we can end up with a situation where tcp_select_initial_window() does a divide by a zero (or even negative) mss value. The problem is that sometimes we effectively subtract TCPOLEN_TSTAMP_ALIGNED and/or TCPOLEN_MD5SIG_ALIGNED from the mss. Fix this by increasing the minimum from 8 to 64. Reported-by: Steve Chen Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 245603c4ad48..081419969485 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2246,7 +2246,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, /* Values greater than interface MTU won't take effect. However * at the point when this call is done we typically don't yet * know which interface is going to be used */ - if (val < 8 || val > MAX_TCP_WINDOW) { + if (val < 64 || val > MAX_TCP_WINDOW) { err = -EINVAL; break; } -- cgit v1.2.2