[PATCH net-next v3 2/9] net: tcp: add skb drop reasons to tcp_v4_rcv()

From: menglong8 . dong
Date: Sun Feb 20 2022 - 02:08:15 EST


From: Menglong Dong <imagedong@xxxxxxxxxxx>

Use kfree_skb_reason() for some path in tcp_v4_rcv() that missed before,
including:

SKB_DROP_REASON_SOCKET_FILTER
SKB_DROP_REASON_XFRM_POLICY

Reviewed-by: Mengen Sun <mengensun@xxxxxxxxxxx>
Reviewed-by: Hao Peng <flyingpeng@xxxxxxxxxxx>
Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
---
v2:
- let NO_SOCKET trump the XFRM failure
---
net/ipv4/tcp_ipv4.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6873f46fc8ba..a3beab01e9a7 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2057,6 +2057,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
iph = ip_hdr(skb);
tcp_v4_fill_cb(skb, iph, th);
nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+ } else {
+ drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
}
if (!nsk) {
reqsk_put(req);
@@ -2092,8 +2094,10 @@ int tcp_v4_rcv(struct sk_buff *skb)
}
}

- if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+ if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
goto discard_and_relse;
+ }

if (tcp_v4_inbound_md5_hash(sk, skb, dif, sdif))
goto discard_and_relse;
@@ -2166,6 +2170,7 @@ int tcp_v4_rcv(struct sk_buff *skb)

do_time_wait:
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
inet_twsk_put(inet_twsk(sk));
goto discard_it;
}
--
2.35.1