From 643b622b51f1f0015e0a80f90b4ef9032e6ddb1b Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Sun, 20 Feb 2022 15:06:32 +0800 Subject: net: tcp: add skb drop reasons to tcp_v{4,6}_inbound_md5_hash() Pass the address of drop reason to tcp_v4_inbound_md5_hash() and tcp_v6_inbound_md5_hash() to store the reasons for skb drops when this function fails. Therefore, the drop reason can be passed to kfree_skb_reason() when the skb needs to be freed. Following drop reasons are added: SKB_DROP_REASON_TCP_MD5NOTFOUND SKB_DROP_REASON_TCP_MD5UNEXPECTED SKB_DROP_REASON_TCP_MD5FAILURE SKB_DROP_REASON_TCP_MD5* above correspond to LINUX_MIB_TCPMD5* Reviewed-by: Mengen Sun Reviewed-by: Hao Peng Signed-off-by: Menglong Dong Reviewed-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/tcp_ipv6.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 0aa17073df1a..1262b790b146 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -775,7 +775,8 @@ clear_hash_noput: static bool tcp_v6_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, - int dif, int sdif) + int dif, int sdif, + enum skb_drop_reason *reason) { #ifdef CONFIG_TCP_MD5SIG const __u8 *hash_location = NULL; @@ -798,11 +799,13 @@ static bool tcp_v6_inbound_md5_hash(const struct sock *sk, return false; if (hash_expected && !hash_location) { + *reason = SKB_DROP_REASON_TCP_MD5NOTFOUND; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); return true; } if (!hash_expected && hash_location) { + *reason = SKB_DROP_REASON_TCP_MD5UNEXPECTED; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); return true; } @@ -813,6 +816,7 @@ static bool tcp_v6_inbound_md5_hash(const struct sock *sk, NULL, skb); if (genhash || memcmp(hash_location, newhash, 16) != 0) { + *reason = SKB_DROP_REASON_TCP_MD5FAILURE; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n", genhash ? "failed" : "mismatch", @@ -1681,7 +1685,8 @@ process: struct sock *nsk; sk = req->rsk_listener; - if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) { + if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif, + &drop_reason)) { sk_drops_add(sk, skb); reqsk_put(req); goto discard_it; @@ -1752,7 +1757,7 @@ process: goto discard_and_relse; } - if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) + if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif, &drop_reason)) goto discard_and_relse; if (tcp_filter(sk, skb)) { -- cgit v1.2.3