[PATCH net-next 2/2] net: skb: use kfree_skb_with_reason() in tcp_v4_rcv()
flat view
STALE1747d
SUPERSEDED
From: <hidden>
Date: 2021-12-29 14:32:43
Also in:
lkml
Subsystem:
networking [general], networking [tcp], the rest, tracing · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision v1 of 3 in this series.
Revisions (3)
- v1 current
- v3 [diff vs current]
- v4 [diff vs current]
From: Menglong Dong <redacted>
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 <redacted>
---
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