diff -ru linux-2.6.18/include/linux/sysctl.h linux-2.6.18.new/include/linux/sysctl.h --- linux-2.6.18/include/linux/sysctl.h 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/include/linux/sysctl.h 2006-10-11 10:27:52.000000000 -0700 @@ -411,6 +411,8 @@ NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS=115, NET_TCP_DMA_COPYBREAK=116, NET_TCP_SLOW_START_AFTER_IDLE=117, + NET_TCP_RTO_MAX=118, + NET_TCP_RTO_INIT=119, }; enum { diff -ru linux-2.6.18/include/linux/tcp.h linux-2.6.18.new/include/linux/tcp.h --- linux-2.6.18/include/linux/tcp.h 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/include/linux/tcp.h 2006-10-11 10:41:40.000000000 -0700 @@ -94,6 +94,8 @@ #define TCP_INFO 11 /* Information about this connection. */ #define TCP_QUICKACK 12 /* Block/reenable quick acks */ #define TCP_CONGESTION 13 /* Congestion control algorithm */ +#define TCP_BACKOFF_MAX 14 /* Maximum backoff value */ +#define TCP_BACKOFF_INIT 15 /* Initial backoff value */ #define TCPI_OPT_TIMESTAMPS 1 #define TCPI_OPT_SACK 2 @@ -257,6 +259,8 @@ __u8 frto_counter; /* Number of new acks after RTO */ __u8 nonagle; /* Disable Nagle algorithm? */ __u8 keepalive_probes; /* num of allowed keep alive probes */ + __u16 rto_max; /* Maximum backoff value in ms */ + __u16 rto_init; /* Initial backoff value in ms */ /* RTT measurement */ __u32 srtt; /* smoothed round trip time << 3 */ diff -ru linux-2.6.18/include/net/tcp.h linux-2.6.18.new/include/net/tcp.h --- linux-2.6.18/include/net/tcp.h 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/include/net/tcp.h 2006-10-11 17:43:23.091431000 -0700 @@ -227,11 +227,23 @@ extern int sysctl_tcp_base_mss; extern int sysctl_tcp_workaround_signed_windows; extern int sysctl_tcp_slow_start_after_idle; +extern unsigned long sysctl_tcp_rto_max; +extern unsigned long sysctl_tcp_rto_init; extern atomic_t tcp_memory_allocated; extern atomic_t tcp_sockets_allocated; extern int tcp_memory_pressure; +static inline unsigned long tcp_rto_max(struct tcp_sock *tp) +{ + return tp->rto_max ? msecs_to_jiffies(tp->rto_max) : sysctl_tcp_rto_max; +} + +static inline unsigned long tcp_rto_init(struct tcp_sock *tp) +{ + return tp->rto_init ? msecs_to_jiffies(tp->rto_init) : sysctl_tcp_rto_init; +} + /* * The next routines deal with comparing 32 bit unsigned ints * and worry about wraparound (automatic with unsigned arithmetic). Only in linux-2.6.18.new/include/net: tcp.h~ diff -ru linux-2.6.18/net/ipv4/sysctl_net_ipv4.c linux-2.6.18.new/net/ipv4/sysctl_net_ipv4.c --- linux-2.6.18/net/ipv4/sysctl_net_ipv4.c 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/net/ipv4/sysctl_net_ipv4.c 2006-10-11 16:00:37.000000000 -0700 @@ -128,6 +128,8 @@ return ret; } +static unsigned long tcp_rto_min=0; +static unsigned long tcp_rto_max=65535; ctl_table ipv4_table[] = { { @@ -697,6 +699,26 @@ .mode = 0644, .proc_handler = &proc_dointvec }, + { + .ctl_name = NET_TCP_RTO_MAX, + .procname = "tcp_rto_max", + .data = &sysctl_tcp_rto_max, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_doulongvec_ms_jiffies_minmax, + .extra1 = &tcp_rto_min_constant, + .extra2 = &tcp_rto_max_constant, + }, + { + .ctl_name = NET_TCP_RTO_INIT, + .procname = "tcp_rto_init", + .data = &sysctl_tcp_rto_init, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = &proc_doulongvec_ms_jiffies_minmax, + .extra1 = &tcp_rto_min_constant, + .extra2 = &tcp_rto_max_constant, + }, { .ctl_name = 0 } }; diff -ru linux-2.6.18/net/ipv4/tcp.c linux-2.6.18.new/net/ipv4/tcp.c --- linux-2.6.18/net/ipv4/tcp.c 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/net/ipv4/tcp.c 2006-10-11 16:00:37.000000000 -0700 @@ -1764,6 +1764,8 @@ return err; } +#define TCP_BACKOFF_MAXVAL 65535 + /* * Socket option code for TCP. */ @@ -1939,6 +1941,20 @@ } break; + case TCP_BACKOFF_MAX: + if (val < 1 || val > TCP_BACKOFF_MAXVAL) + err = -EINVAL; + else + tp->rto_max = val; + break; + + case TCP_BACKOFF_INIT: + if (val < 1 || val > TCP_BACKOFF_MAXVAL) + err = -EINVAL; + else + tp->rto_init = val; + break; + default: err = -ENOPROTOOPT; break; @@ -2110,6 +2126,12 @@ if (copy_to_user(optval, icsk->icsk_ca_ops->name, len)) return -EFAULT; return 0; + case TCP_BACKOFF_MAX: + val = jiffies_to_msecs(tcp_rto_max(tp)); + break; + case TCP_BACKOFF_INIT: + val = jiffies_to_msecs(tcp_rto_init(tp)); + break; default: return -ENOPROTOOPT; }; diff -ru linux-2.6.18/net/ipv4/tcp_timer.c linux-2.6.18.new/net/ipv4/tcp_timer.c --- linux-2.6.18/net/ipv4/tcp_timer.c 2006-09-19 20:42:06.000000000 -0700 +++ linux-2.6.18.new/net/ipv4/tcp_timer.c 2006-10-11 10:41:39.000000000 -0700 @@ -31,6 +31,8 @@ int sysctl_tcp_retries1 = TCP_RETR1; int sysctl_tcp_retries2 = TCP_RETR2; int sysctl_tcp_orphan_retries; +unsigned long sysctl_tcp_rto_max = TCP_RTO_MAX; +unsigned long sysctl_tcp_rto_init = TCP_TIMEOUT_INIT; static void tcp_write_timer(unsigned long); static void tcp_delack_timer(unsigned long); @@ -71,7 +73,8 @@ /* If peer does not open window for long time, or did not transmit * anything for long time, penalize it. */ - if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset) + if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*tcp_rto_max(tp) || + !do_reset) orphans <<= 1; /* If some dubious ICMP arrived, penalize even more. */ @@ -256,8 +259,8 @@ max_probes = sysctl_tcp_retries2; if (sock_flag(sk, SOCK_DEAD)) { - const int alive = ((icsk->icsk_rto << icsk->icsk_backoff) < TCP_RTO_MAX); - + const int alive = ((icsk->icsk_rto << icsk->icsk_backoff) < + tcp_rto_max(tp)); max_probes = tcp_orphan_retries(sk, alive); if (tcp_out_of_resources(sk, alive || icsk->icsk_probes_out <= max_probes)) @@ -301,7 +304,7 @@ inet->num, tp->snd_una, tp->snd_nxt); } #endif - if (tcp_time_stamp - tp->rcv_tstamp > TCP_RTO_MAX) { + if (tcp_time_stamp - tp->rcv_tstamp > tcp_rto_max(tp)) { tcp_write_err(sk); goto out; } @@ -373,7 +376,8 @@ out_reset_timer: icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX); - inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, + tcp_rto_max(tp)); if (icsk->icsk_retransmits > sysctl_tcp_retries1) __sk_dst_reset(sk); @@ -427,8 +431,8 @@ static void tcp_synack_timer(struct sock *sk) { - inet_csk_reqsk_queue_prune(sk, TCP_SYNQ_INTERVAL, - TCP_TIMEOUT_INIT, TCP_RTO_MAX); + inet_csk_reqsk_queue_prune(sk, TCP_SYNQ_INTERVAL, TCP_TIMEOUT_INIT, + tcp_rto_max(tcp_sk(sk))); } void tcp_set_keepalive(struct sock *sk, int val)