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 <songliubrav...@fb.com>
---
include/trace/events/tcp.h | 11 +++++++++++
net/core/net-traces.c | 2 ++
net/ipv4/tcp_ipv4.c | 6 +++++-
net/ipv4/tcp_output.c | 5 +++++
net/ipv6/tcp_ipv6.c | 10 ++++++++--
5 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 2b6fe72..3e57e1a 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -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 */
diff --git a/net/core/net-traces.c b/net/core/net-traces.c
index f4e4fa2..8dcd9b0 100644
--- a/net/core/net-traces.c
+++ b/net/core/net-traces.c
@@ -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);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e22439f..eb3f3b8 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -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));
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 988733f..1f01f4c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -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.
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index ae83615..0e25299 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -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
--
2.9.5
