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authorMenglong Dong <imagedong@tencent.com>2022-01-09 14:36:27 +0800
committerJakub Kicinski <kuba@kernel.org>2022-01-09 16:30:34 -0800
commit85125597419aec3aa7b8f3b8713e415f997796f2 (patch)
tree10a76ff72bf482d9e89e41fcf4d12ca5f0194d36
parentc504e5c2f9648a1e5c2be01e8c3f59d394192bd3 (diff)
downloadmac80211-next-85125597419aec3aa7b8f3b8713e415f997796f2.tar.gz
net: skb: use kfree_skb_reason() in tcp_v4_rcv()
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> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--include/linux/skbuff.h4
-rw-r--r--include/trace/events/skb.h4
-rw-r--r--net/ipv4/tcp_ipv4.c14
3 files changed, 19 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index ef0870abc791c9..c9c97b0d0fe9ef 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 294c61bbe44b6e..faa7d068a7bc0e 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 9861786b833653..b3f34e366b27f7 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 @@ process:
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 @@ put_and_return:
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 @@ no_tcp_socket:
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 @@ bad_packet:
discard_it:
/* Discard frame. */
- kfree_skb(skb);
+ kfree_skb_reason(skb, drop_reason);
return 0;
discard_and_relse: