diff options
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 71 |
1 files changed, 42 insertions, 29 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 0b5ab04d3c5..6728772a943 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -69,6 +69,7 @@ #include <net/transp_v6.h> #include <net/ipv6.h> #include <net/inet_common.h> +#include <net/timewait_sock.h> #include <net/xfrm.h> #include <linux/inet.h> @@ -118,6 +119,39 @@ static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb) skb->h.th->source); } +int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) +{ + const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); + struct tcp_sock *tp = tcp_sk(sk); + + /* With PAWS, it is safe from the viewpoint + of data integrity. Even without PAWS it is safe provided sequence + spaces do not overlap i.e. at data rates <= 80Mbit/sec. + + Actually, the idea is close to VJ's one, only timestamp cache is + held not per host, but per port pair and TW bucket is used as state + holder. + + If TW bucket has been already destroyed we fall back to VJ's scheme + and use initial timestamp retrieved from peer table. + */ + if (tcptw->tw_ts_recent_stamp && + (twp == NULL || (sysctl_tcp_tw_reuse && + xtime.tv_sec - tcptw->tw_ts_recent_stamp > 1))) { + tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; + if (tp->write_seq == 0) + tp->write_seq = 1; + tp->rx_opt.ts_recent = tcptw->tw_ts_recent; + tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; + sock_hold(sktw); + return 1; + } + + return 0; +} + +EXPORT_SYMBOL_GPL(tcp_twsk_unique); + /* called with local bh disabled */ static int __tcp_v4_check_established(struct sock *sk, __u16 lport, struct inet_timewait_sock **twp) @@ -142,35 +176,9 @@ static int __tcp_v4_check_established(struct sock *sk, __u16 lport, tw = inet_twsk(sk2); if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) { - const struct tcp_timewait_sock *tcptw = tcp_twsk(sk2); - struct tcp_sock *tp = tcp_sk(sk); - - /* With PAWS, it is safe from the viewpoint - of data integrity. Even without PAWS it - is safe provided sequence spaces do not - overlap i.e. at data rates <= 80Mbit/sec. - - Actually, the idea is close to VJ's one, - only timestamp cache is held not per host, - but per port pair and TW bucket is used - as state holder. - - If TW bucket has been already destroyed we - fall back to VJ's scheme and use initial - timestamp retrieved from peer table. - */ - if (tcptw->tw_ts_recent_stamp && - (!twp || (sysctl_tcp_tw_reuse && - xtime.tv_sec - - tcptw->tw_ts_recent_stamp > 1))) { - tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; - if (tp->write_seq == 0) - tp->write_seq = 1; - tp->rx_opt.ts_recent = tcptw->tw_ts_recent; - tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; - sock_hold(sk2); + if (twsk_unique(sk, sk2, twp)) goto unique; - } else + else goto not_unique; } } @@ -869,6 +877,11 @@ struct request_sock_ops tcp_request_sock_ops = { .send_reset = tcp_v4_send_reset, }; +static struct timewait_sock_ops tcp_timewait_sock_ops = { + .twsk_obj_size = sizeof(struct tcp_timewait_sock), + .twsk_unique = tcp_twsk_unique, +}; + int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) { struct inet_request_sock *ireq; @@ -1979,7 +1992,7 @@ struct proto tcp_prot = { .sysctl_rmem = sysctl_tcp_rmem, .max_header = MAX_TCP_HEADER, .obj_size = sizeof(struct tcp_sock), - .twsk_obj_size = sizeof(struct tcp_timewait_sock), + .twsk_prot = &tcp_timewait_sock_ops, .rsk_prot = &tcp_request_sock_ops, }; |