Messages in this thread Patch in this message | | | From | menglong8.dong@gmail ... | Subject | [PATCH net-next 2/2] net: skb: use kfree_skb_with_reason() in tcp_v4_rcv() | Date | Wed, 29 Dec 2021 22:32:05 +0800 |
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From: Menglong Dong <imagedong@tencent.com>
Replace kfree_skb() with kfree_skb_with_reason() in tcp_v4_rcv(). Following drop reason are added:
SKB_DROP_REASON_NO_SOCK SKB_DROP_REASON_BAD_PACKET SKB_DROP_REASON_TCP_CSUM
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_SOCK
The reason of skb drop is printed too.
Signed-off-by: Menglong Dong <imagedong@tencent.com> --- include/linux/skbuff.h | 3 +++ include/trace/events/skb.h | 3 +++ net/ipv4/tcp_ipv4.c | 10 ++++++++-- 3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 3620b3ff2154..f85db6c035d1 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -313,6 +313,9 @@ struct sk_buff; */ enum skb_drop_reason { SKB_DROP_REASON_NOT_SPECIFIED, + SKB_DROP_REASON_NO_SOCK, + SKB_DROP_REASON_BAD_PACKET, + SKB_DROP_REASON_TCP_CSUM, SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index cab1c08a30cd..b9ea6b4ed7ec 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -11,6 +11,9 @@ #define TRACE_SKB_DROP_REASON \ EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ + EM(SKB_DROP_REASON_NO_SOCK, NO_SOCK) \ + EM(SKB_DROP_REASON_BAD_PACKET, BAD_PACKET) \ + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ EMe(SKB_DROP_REASON_MAX, HAHA_MAX) #undef EM diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ac10e4cdd8d0..03dc4c79b84b 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 = 0; 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_BAD_PACKET; goto bad_packet; + } if (!pskb_may_pull(skb, th->doff * 4)) goto discard_it; @@ -2124,6 +2128,7 @@ int tcp_v4_rcv(struct sk_buff *skb) return ret; no_tcp_socket: + drop_reason = SKB_DROP_REASON_NO_SOCK; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard_it; @@ -2131,6 +2136,7 @@ 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 +2147,7 @@ int tcp_v4_rcv(struct sk_buff *skb) discard_it: /* Discard frame. */ - kfree_skb(skb); + kfree_skb_with_reason(skb, drop_reason); return 0; discard_and_relse: -- 2.30.2
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