[PATCH v4 net-next 2/3] net: skb: use kfree_skb_reason() in tcp_v4_rcv()
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STALE1738d
From: <hidden>
Date: 2022-01-09 06:38:36
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 v4 of 3 in this series.
Revisions (3)
- v1 [diff vs current]
- v3 [diff vs current]
- v4 current
From: Menglong Dong <redacted>
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 <redacted>
---
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