tcp: account SYN-ACK timeouts & retransmissions

Currently we don't increment SYN-ACK timeouts & retransmissions
although we do increment the same stats for SYN. We seem to have lost
the SYN-ACK accounting with the introduction of tcp_syn_recv_timer
(commit 2248761e in the netdev-vger-cvs tree).

This patch fixes this issue. In the process we also rename the v4/v6
syn/ack retransmit functions for clarity. We also add a new
request_socket operations (syn_ack_timeout) so we can keep code in
inet_connection_sock.c protocol agnostic.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Octavian Purdila 2010-01-17 19:09:39 -08:00 committed by David S. Miller
parent 0ec00f0392
commit 72659ecce6
6 changed files with 32 additions and 10 deletions

View file

@ -45,6 +45,8 @@ struct request_sock_ops {
void (*send_reset)(struct sock *sk,
struct sk_buff *skb);
void (*destructor)(struct request_sock *req);
void (*syn_ack_timeout)(struct sock *sk,
struct request_sock *req);
};
/* struct request_sock - mini sock to represent a connection request

View file

@ -400,6 +400,8 @@ extern int compat_tcp_setsockopt(struct sock *sk,
int level, int optname,
char __user *optval, unsigned int optlen);
extern void tcp_set_keepalive(struct sock *sk, int val);
extern void tcp_syn_ack_timeout(struct sock *sk,
struct request_sock *req);
extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
struct msghdr *msg,
size_t len, int nonblock,

View file

@ -529,6 +529,8 @@ void inet_csk_reqsk_queue_prune(struct sock *parent,
syn_ack_recalc(req, thresh, max_retries,
queue->rskq_defer_accept,
&expire, &resend);
if (req->rsk_ops->syn_ack_timeout)
req->rsk_ops->syn_ack_timeout(parent, req);
if (!expire &&
(!resend ||
!req->rsk_ops->rtx_syn_ack(parent, req, NULL) ||

View file

@ -742,9 +742,9 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
* This still operates on a request_sock only, not on a big
* socket.
*/
static int __tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
struct request_values *rvp)
static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
struct request_values *rvp)
{
const struct inet_request_sock *ireq = inet_rsk(req);
int err = -1;
@ -775,10 +775,11 @@ static int __tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
return err;
}
static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req,
struct request_values *rvp)
{
return __tcp_v4_send_synack(sk, NULL, req, rvp);
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
return tcp_v4_send_synack(sk, NULL, req, rvp);
}
/*
@ -1192,10 +1193,11 @@ static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
struct request_sock_ops tcp_request_sock_ops __read_mostly = {
.family = PF_INET,
.obj_size = sizeof(struct tcp_request_sock),
.rtx_syn_ack = tcp_v4_send_synack,
.rtx_syn_ack = tcp_v4_rtx_synack,
.send_ack = tcp_v4_reqsk_send_ack,
.destructor = tcp_v4_reqsk_destructor,
.send_reset = tcp_v4_send_reset,
.syn_ack_timeout = tcp_syn_ack_timeout,
};
#ifdef CONFIG_TCP_MD5SIG
@ -1373,8 +1375,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
}
tcp_rsk(req)->snt_isn = isn;
if (__tcp_v4_send_synack(sk, dst, req,
(struct request_values *)&tmp_ext) ||
if (tcp_v4_send_synack(sk, dst, req,
(struct request_values *)&tmp_ext) ||
want_cookie)
goto drop_and_free;

View file

@ -474,6 +474,12 @@ static void tcp_synack_timer(struct sock *sk)
TCP_TIMEOUT_INIT, TCP_RTO_MAX);
}
void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req)
{
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPTIMEOUTS);
}
EXPORT_SYMBOL(tcp_syn_ack_timeout);
void tcp_set_keepalive(struct sock *sk, int val)
{
if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))

View file

@ -520,6 +520,13 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
return err;
}
static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
struct request_values *rvp)
{
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
return tcp_v6_send_synack(sk, req, rvp);
}
static inline void syn_flood_warning(struct sk_buff *skb)
{
#ifdef CONFIG_SYN_COOKIES
@ -890,10 +897,11 @@ static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
.family = AF_INET6,
.obj_size = sizeof(struct tcp6_request_sock),
.rtx_syn_ack = tcp_v6_send_synack,
.rtx_syn_ack = tcp_v6_rtx_synack,
.send_ack = tcp_v6_reqsk_send_ack,
.destructor = tcp_v6_reqsk_destructor,
.send_reset = tcp_v6_send_reset
.send_reset = tcp_v6_send_reset,
.syn_ack_timeout = tcp_syn_ack_timeout,
};
#ifdef CONFIG_TCP_MD5SIG