tcp: add tracepoint trace_tcp_send_reset

New tracepoint trace_tcp_send_reset is added and called from
tcp_v4_send_reset(), tcp_v6_send_reset() and tcp_send_active_reset().

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Song Liu 2017-10-23 09:20:24 -07:00 committed by David S. Miller
parent 7344e29f28
commit c24b14c46b
5 changed files with 31 additions and 3 deletions

View file

@ -77,6 +77,17 @@ DEFINE_EVENT(tcp_event_sk_skb, tcp_retransmit_skb,
TP_ARGS(sk, skb)
);
/*
* skb of trace_tcp_send_reset is the skb that caused RST. In case of
* active reset, skb should be NULL
*/
DEFINE_EVENT(tcp_event_sk_skb, tcp_send_reset,
TP_PROTO(const struct sock *sk, const struct sk_buff *skb),
TP_ARGS(sk, skb)
);
#endif /* _TRACE_TCP_H */
/* This part must be outside protection */

View file

@ -49,3 +49,5 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_update);
EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
EXPORT_TRACEPOINT_SYMBOL_GPL(napi_poll);
EXPORT_TRACEPOINT_SYMBOL_GPL(tcp_send_reset);

View file

@ -85,6 +85,8 @@
#include <crypto/hash.h>
#include <linux/scatterlist.h>
#include <trace/events/tcp.h>
#ifdef CONFIG_TCP_MD5SIG
static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th);
@ -701,8 +703,10 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
* routing might fail in this case. No choice here, if we choose to force
* input interface, we will misroute in case of asymmetric route.
*/
if (sk)
if (sk) {
arg.bound_dev_if = sk->sk_bound_dev_if;
trace_tcp_send_reset(sk, skb);
}
BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) !=
offsetof(struct inet_timewait_sock, tw_bound_dev_if));

View file

@ -3084,6 +3084,11 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority)
/* Send it off. */
if (tcp_transmit_skb(sk, skb, 0, priority))
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
/* skb of trace_tcp_send_reset() keeps the skb that caused RST,
* skb here is different to the troublesome skb, so use NULL
*/
trace_tcp_send_reset(sk, NULL);
}
/* Send a crossed SYN-ACK during socket establishment.

View file

@ -69,6 +69,8 @@
#include <crypto/hash.h>
#include <linux/scatterlist.h>
#include <trace/events/tcp.h>
static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req);
@ -890,7 +892,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
int genhash;
struct sock *sk1 = NULL;
#endif
int oif;
int oif = 0;
if (th->rst)
return;
@ -939,7 +941,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
(th->doff << 2);
oif = sk ? sk->sk_bound_dev_if : 0;
if (sk) {
oif = sk->sk_bound_dev_if;
trace_tcp_send_reset(sk, skb);
}
tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
#ifdef CONFIG_TCP_MD5SIG