From: menglong8.dong@gmail.com
To: rostedt@goodmis.org, dsahern@kernel.org
Cc: mingo@redhat.com, davem@davemloft.net, kuba@kernel.org,
nhorman@tuxdriver.com, edumazet@google.com,
yoshfuji@linux-ipv6.org, alobakin@pm.me, willemb@google.com,
cong.wang@bytedance.com, keescook@chromium.org,
pabeni@redhat.com, talalahmad@google.com, haokexin@gmail.com,
ilias.apalodimas@linaro.org, memxor@gmail.com,
atenart@kernel.org, bigeasy@linutronix.de, weiwan@google.com,
arnd@arndb.de, vvs@virtuozzo.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, jonathan.lemon@gmail.com,
imagedong@tencent.com
Subject: [PATCH v4 net-next 2/3] net: skb: use kfree_skb_reason() in tcp_v4_rcv()
Date: Sun, 9 Jan 2022 14:36:27 +0800 [thread overview]
Message-ID: <20220109063628.526990-3-imagedong@tencent.com> (raw)
In-Reply-To: <20220109063628.526990-1-imagedong@tencent.com>
From: Menglong Dong <imagedong@tencent.com>
Replace kfree_skb() with kfree_skb_reason() in tcp_v4_rcv(). Following
drop reasons are added:
SKB_DROP_REASON_NO_SOCKET
SKB_DROP_REASON_PKT_TOO_SMALL
SKB_DROP_REASON_TCP_CSUM
SKB_DROP_REASON_TCP_FILTER
After this patch, 'kfree_skb' event will print message like this:
$ TASK-PID CPU# ||||| TIMESTAMP FUNCTION
$ | | | ||||| | |
<idle>-0 [000] ..s1. 36.113438: kfree_skb: skbaddr=(____ptrval____) protocol=2048 location=(____ptrval____) reason: NO_SOCKET
The reason of skb drop is printed too.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
---
v3:
- rename kfree_skb_with_reason() to kfree_skb_reason()
v2:
- rename some reason name as David suggested
- add the new reason: SKB_DROP_REASON_TCP_FILTER
---
include/linux/skbuff.h | 4 ++++
include/trace/events/skb.h | 4 ++++
net/ipv4/tcp_ipv4.c | 14 +++++++++++---
3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index ef0870abc791..c9c97b0d0fe9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -313,6 +313,10 @@ struct sk_buff;
*/
enum skb_drop_reason {
SKB_DROP_REASON_NOT_SPECIFIED,
+ SKB_DROP_REASON_NO_SOCKET,
+ SKB_DROP_REASON_PKT_TOO_SMALL,
+ SKB_DROP_REASON_TCP_CSUM,
+ SKB_DROP_REASON_TCP_FILTER,
SKB_DROP_REASON_MAX,
};
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index b5ef652e5a93..c16febea9f62 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -11,6 +11,10 @@
#define TRACE_SKB_DROP_REASON \
EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \
+ EM(SKB_DROP_REASON_NO_SOCKET, NO_SOCKET) \
+ EM(SKB_DROP_REASON_PKT_TOO_SMALL, PKT_TOO_SMALL) \
+ EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \
+ EM(SKB_DROP_REASON_TCP_FILTER, TCP_FILTER) \
EMe(SKB_DROP_REASON_MAX, MAX)
#undef EM
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ac10e4cdd8d0..f83efcc6e76e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
const struct tcphdr *th;
bool refcounted;
struct sock *sk;
+ int drop_reason;
int ret;
+ drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (skb->pkt_type != PACKET_HOST)
goto discard_it;
@@ -1984,8 +1986,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
th = (const struct tcphdr *)skb->data;
- if (unlikely(th->doff < sizeof(struct tcphdr) / 4))
+ if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
+ drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
goto bad_packet;
+ }
if (!pskb_may_pull(skb, th->doff * 4))
goto discard_it;
@@ -2090,8 +2094,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
nf_reset_ct(skb);
- if (tcp_filter(sk, skb))
+ if (tcp_filter(sk, skb)) {
+ drop_reason = SKB_DROP_REASON_TCP_FILTER;
goto discard_and_relse;
+ }
th = (const struct tcphdr *)skb->data;
iph = ip_hdr(skb);
tcp_v4_fill_cb(skb, iph, th);
@@ -2124,6 +2130,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
return ret;
no_tcp_socket:
+ drop_reason = SKB_DROP_REASON_NO_SOCKET;
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard_it;
@@ -2131,6 +2138,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
if (tcp_checksum_complete(skb)) {
csum_error:
+ drop_reason = SKB_DROP_REASON_TCP_CSUM;
trace_tcp_bad_csum(skb);
__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
bad_packet:
@@ -2141,7 +2149,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
discard_it:
/* Discard frame. */
- kfree_skb(skb);
+ kfree_skb_reason(skb, drop_reason);
return 0;
discard_and_relse:
--
2.30.2
next prev parent reply other threads:[~2022-01-09 6:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-09 6:36 [PATCH v4 net-next 0/3] net: skb: introduce kfree_skb_with_reason() menglong8.dong
2022-01-09 6:36 ` [PATCH v4 net-next 1/3] net: skb: introduce kfree_skb_reason() menglong8.dong
2022-01-09 6:36 ` menglong8.dong [this message]
2022-01-09 6:36 ` [PATCH v4 net-next 3/3] net: skb: use kfree_skb_reason() in __udp4_lib_rcv() menglong8.dong
2022-01-10 0:50 ` [PATCH v4 net-next 0/3] net: skb: introduce kfree_skb_with_reason() patchwork-bot+netdevbpf
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