From 900f65d361d333c949ef76a828343075f4fdf523 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Thu, 19 Apr 2012 09:55:21 +0000 Subject: [PATCH] tcp: move duplicate code from tcp_v4_init_sock()/tcp_v6_init_sock() This commit moves the (substantial) common code shared between tcp_v4_init_sock() and tcp_v6_init_sock() to a new address-family independent function, tcp_init_sock(). Centralizing this functionality should help avoid drift issues, e.g. where the IPv4 side is updated without a corresponding update to IPv6. There was already some drift: IPv4 initialized snd_cwnd to TCP_INIT_CWND, while the IPv6 side was still initializing snd_cwnd to 2 (in this case it should not matter, since snd_cwnd is also initialized in tcp_init_metrics(), but the general risks and maintenance overhead remain). When diffing the old and new code, note that new tcp_init_sock() function uses the order of steps from the tcp_v4_init_sock() implementation (the order is slightly different in tcp_v6_init_sock()). Signed-off-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/tcp.h | 1 + net/ipv4/tcp.c | 64 +++++++++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_ipv4.c | 52 ++---------------------------------- net/ipv6/tcp_ipv6.c | 50 +---------------------------------- 4 files changed, 68 insertions(+), 99 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index b4ccb8a6c9c1..fc880e92164a 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -395,6 +395,7 @@ extern void tcp_enter_loss(struct sock *sk, int how); extern void tcp_clear_retrans(struct tcp_sock *tp); extern void tcp_update_metrics(struct sock *sk); extern void tcp_close(struct sock *sk, long timeout); +extern void tcp_init_sock(struct sock *sk); extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait); extern int tcp_getsockopt(struct sock *sk, int level, int optname, diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 3ce3bd031f33..bcc4eab5f251 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -363,6 +363,70 @@ static int retrans_to_secs(u8 retrans, int timeout, int rto_max) return period; } +/* Address-family independent initialization for a tcp_sock. + * + * NOTE: A lot of things set to zero explicitly by call to + * sk_alloc() so need not be done here. + */ +void tcp_init_sock(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct tcp_sock *tp = tcp_sk(sk); + + skb_queue_head_init(&tp->out_of_order_queue); + tcp_init_xmit_timers(sk); + tcp_prequeue_init(tp); + + icsk->icsk_rto = TCP_TIMEOUT_INIT; + tp->mdev = TCP_TIMEOUT_INIT; + + /* So many TCP implementations out there (incorrectly) count the + * initial SYN frame in their delayed-ACK and congestion control + * algorithms that we must have the following bandaid to talk + * efficiently to them. -DaveM + */ + tp->snd_cwnd = TCP_INIT_CWND; + + /* See draft-stevens-tcpca-spec-01 for discussion of the + * initialization of these values. + */ + tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; + tp->snd_cwnd_clamp = ~0; + tp->mss_cache = TCP_MSS_DEFAULT; + + tp->reordering = sysctl_tcp_reordering; + icsk->icsk_ca_ops = &tcp_init_congestion_ops; + + sk->sk_state = TCP_CLOSE; + + sk->sk_write_space = sk_stream_write_space; + sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + + icsk->icsk_sync_mss = tcp_sync_mss; + + /* TCP Cookie Transactions */ + if (sysctl_tcp_cookie_size > 0) { + /* Default, cookies without s_data_payload. */ + tp->cookie_values = + kzalloc(sizeof(*tp->cookie_values), + sk->sk_allocation); + if (tp->cookie_values != NULL) + kref_init(&tp->cookie_values->kref); + } + /* Presumed zeroed, in order of appearance: + * cookie_in_always, cookie_out_never, + * s_data_constant, s_data_in, s_data_out + */ + sk->sk_sndbuf = sysctl_tcp_wmem[1]; + sk->sk_rcvbuf = sysctl_tcp_rmem[1]; + + local_bh_disable(); + sock_update_memcg(sk); + sk_sockets_allocated_inc(sk); + local_bh_enable(); +} +EXPORT_SYMBOL(tcp_init_sock); + /* * Wait for a TCP event. * diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ba6dad81908e..5b07ea109300 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1890,62 +1890,14 @@ static int tcp_v4_init_sock(struct sock *sk) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); - skb_queue_head_init(&tp->out_of_order_queue); - tcp_init_xmit_timers(sk); - tcp_prequeue_init(tp); - - icsk->icsk_rto = TCP_TIMEOUT_INIT; - tp->mdev = TCP_TIMEOUT_INIT; - - /* So many TCP implementations out there (incorrectly) count the - * initial SYN frame in their delayed-ACK and congestion control - * algorithms that we must have the following bandaid to talk - * efficiently to them. -DaveM - */ - tp->snd_cwnd = TCP_INIT_CWND; - - /* See draft-stevens-tcpca-spec-01 for discussion of the - * initialization of these values. - */ - tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; - tp->snd_cwnd_clamp = ~0; - tp->mss_cache = TCP_MSS_DEFAULT; - - tp->reordering = sysctl_tcp_reordering; - icsk->icsk_ca_ops = &tcp_init_congestion_ops; - - sk->sk_state = TCP_CLOSE; - - sk->sk_write_space = sk_stream_write_space; - sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); + tcp_init_sock(sk); icsk->icsk_af_ops = &ipv4_specific; - icsk->icsk_sync_mss = tcp_sync_mss; + #ifdef CONFIG_TCP_MD5SIG tp->af_specific = &tcp_sock_ipv4_specific; #endif - /* TCP Cookie Transactions */ - if (sysctl_tcp_cookie_size > 0) { - /* Default, cookies without s_data_payload. */ - tp->cookie_values = - kzalloc(sizeof(*tp->cookie_values), - sk->sk_allocation); - if (tp->cookie_values != NULL) - kref_init(&tp->cookie_values->kref); - } - /* Presumed zeroed, in order of appearance: - * cookie_in_always, cookie_out_never, - * s_data_constant, s_data_in, s_data_out - */ - sk->sk_sndbuf = sysctl_tcp_wmem[1]; - sk->sk_rcvbuf = sysctl_tcp_rmem[1]; - - local_bh_disable(); - sock_update_memcg(sk); - sk_sockets_allocated_inc(sk); - local_bh_enable(); - return 0; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 050c55186bc4..24dac6b83fb9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1831,62 +1831,14 @@ static int tcp_v6_init_sock(struct sock *sk) struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); - skb_queue_head_init(&tp->out_of_order_queue); - tcp_init_xmit_timers(sk); - tcp_prequeue_init(tp); - - icsk->icsk_rto = TCP_TIMEOUT_INIT; - tp->mdev = TCP_TIMEOUT_INIT; - - /* So many TCP implementations out there (incorrectly) count the - * initial SYN frame in their delayed-ACK and congestion control - * algorithms that we must have the following bandaid to talk - * efficiently to them. -DaveM - */ - tp->snd_cwnd = 2; - - /* See draft-stevens-tcpca-spec-01 for discussion of the - * initialization of these values. - */ - tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; - tp->snd_cwnd_clamp = ~0; - tp->mss_cache = TCP_MSS_DEFAULT; - - tp->reordering = sysctl_tcp_reordering; - - sk->sk_state = TCP_CLOSE; + tcp_init_sock(sk); icsk->icsk_af_ops = &ipv6_specific; - icsk->icsk_ca_ops = &tcp_init_congestion_ops; - icsk->icsk_sync_mss = tcp_sync_mss; - sk->sk_write_space = sk_stream_write_space; - sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); #ifdef CONFIG_TCP_MD5SIG tp->af_specific = &tcp_sock_ipv6_specific; #endif - /* TCP Cookie Transactions */ - if (sysctl_tcp_cookie_size > 0) { - /* Default, cookies without s_data_payload. */ - tp->cookie_values = - kzalloc(sizeof(*tp->cookie_values), - sk->sk_allocation); - if (tp->cookie_values != NULL) - kref_init(&tp->cookie_values->kref); - } - /* Presumed zeroed, in order of appearance: - * cookie_in_always, cookie_out_never, - * s_data_constant, s_data_in, s_data_out - */ - sk->sk_sndbuf = sysctl_tcp_wmem[1]; - sk->sk_rcvbuf = sysctl_tcp_rmem[1]; - - local_bh_disable(); - sock_update_memcg(sk); - sk_sockets_allocated_inc(sk); - local_bh_enable(); - return 0; } -- 2.39.5