[PATCH net-next 02/19] net: tcp: add skb drop reasons to tcp_v4_rcv()

From: menglong8 . dong
Date: Tue Feb 15 2022 - 06:30:49 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

Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
---
net/ipv4/tcp_ipv4.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6873f46fc8ba..a93921fb498f 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;
@@ -2137,8 +2141,10 @@ int tcp_v4_rcv(struct sk_buff *skb)

no_tcp_socket:
drop_reason = SKB_DROP_REASON_NO_SOCKET;
- if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+ if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
goto discard_it;
+ }

tcp_v4_fill_cb(skb, iph, th);

@@ -2166,6 +2172,7 @@ 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;
}
--
2.34.1