From 1330b6ef3313fcec577d2b020c290dc8b9f11f1a Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 7 Mar 2022 16:44:21 -0800 Subject: [PATCH] skb: make drop reason booleanable We have a number of cases where function returns drop/no drop decision as a boolean. Now that we want to report the reason code as well we have to pass extra output arguments. We can make the reason code evaluate correctly as bool. I believe we're good to reorder the reasons as they are reported to user space as strings. Signed-off-by: Jakub Kicinski Reviewed-by: David Ahern Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + include/net/tcp.h | 21 +++++++++++---------- net/ipv4/tcp.c | 21 +++++++++------------ net/ipv4/tcp_ipv4.c | 12 +++++++----- net/ipv6/tcp_ipv6.c | 11 +++++++---- 5 files changed, 35 insertions(+), 31 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 34f572271c0c..26538ceb4b01 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -314,6 +314,7 @@ struct sk_buff; * used to translate the reason to string. */ enum skb_drop_reason { + SKB_NOT_DROPPED_YET = 0, SKB_DROP_REASON_NOT_SPECIFIED, /* drop reason is not specified */ SKB_DROP_REASON_NO_SOCKET, /* socket not found */ SKB_DROP_REASON_PKT_TOO_SMALL, /* packet size is too small */ diff --git a/include/net/tcp.h b/include/net/tcp.h index d486d7b6112d..ee8237b58e1d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1674,10 +1674,11 @@ tcp_md5_do_lookup(const struct sock *sk, int l3index, return NULL; return __tcp_md5_do_lookup(sk, l3index, addr, family); } -bool tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, - enum skb_drop_reason *reason, - const void *saddr, const void *daddr, - int family, int dif, int sdif); + +enum skb_drop_reason +tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, + const void *saddr, const void *daddr, + int family, int dif, int sdif); #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) @@ -1688,13 +1689,13 @@ tcp_md5_do_lookup(const struct sock *sk, int l3index, { return NULL; } -static inline bool tcp_inbound_md5_hash(const struct sock *sk, - const struct sk_buff *skb, - enum skb_drop_reason *reason, - const void *saddr, const void *daddr, - int family, int dif, int sdif) + +static inline enum skb_drop_reason +tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, + const void *saddr, const void *daddr, + int family, int dif, int sdif); { - return false; + return SKB_NOT_DROPPED_YET; } #define tcp_twsk_md5_key(twsk) NULL #endif diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 33f20134e3f1..b5f032958b2c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4434,10 +4434,10 @@ int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *ke EXPORT_SYMBOL(tcp_md5_hash_key); /* Called with rcu_read_lock() */ -bool tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, - enum skb_drop_reason *reason, - const void *saddr, const void *daddr, - int family, int dif, int sdif) +enum skb_drop_reason +tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, + const void *saddr, const void *daddr, + int family, int dif, int sdif) { /* * This gets called for each TCP segment that arrives @@ -4464,18 +4464,16 @@ bool tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, /* We've parsed the options - do we have a hash? */ if (!hash_expected && !hash_location) - return false; + return SKB_NOT_DROPPED_YET; if (hash_expected && !hash_location) { - *reason = SKB_DROP_REASON_TCP_MD5NOTFOUND; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); - return true; + return SKB_DROP_REASON_TCP_MD5NOTFOUND; } if (!hash_expected && hash_location) { - *reason = SKB_DROP_REASON_TCP_MD5UNEXPECTED; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); - return true; + return SKB_DROP_REASON_TCP_MD5UNEXPECTED; } /* check the signature */ @@ -4483,7 +4481,6 @@ bool tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, 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); if (family == AF_INET) { net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n", @@ -4497,9 +4494,9 @@ bool tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, saddr, ntohs(th->source), daddr, ntohs(th->dest), l3index); } - return true; + return SKB_DROP_REASON_TCP_MD5FAILURE; } - return false; + return SKB_NOT_DROPPED_YET; } EXPORT_SYMBOL(tcp_inbound_md5_hash); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 411357ad9757..81694a354110 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1965,9 +1965,10 @@ int tcp_v4_rcv(struct sk_buff *skb) struct sock *nsk; sk = req->rsk_listener; - if (unlikely(tcp_inbound_md5_hash(sk, skb, &drop_reason, - &iph->saddr, &iph->daddr, - AF_INET, dif, sdif))) { + drop_reason = tcp_inbound_md5_hash(sk, skb, + &iph->saddr, &iph->daddr, + AF_INET, dif, sdif); + if (unlikely(drop_reason)) { sk_drops_add(sk, skb); reqsk_put(req); goto discard_it; @@ -2041,8 +2042,9 @@ int tcp_v4_rcv(struct sk_buff *skb) goto discard_and_relse; } - if (tcp_inbound_md5_hash(sk, skb, &drop_reason, &iph->saddr, - &iph->daddr, AF_INET, dif, sdif)) + drop_reason = tcp_inbound_md5_hash(sk, skb, &iph->saddr, + &iph->daddr, AF_INET, dif, sdif); + if (drop_reason) goto discard_and_relse; nf_reset_ct(skb); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index cb2bb7d2e907..13678d3908fa 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1632,8 +1632,10 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) struct sock *nsk; sk = req->rsk_listener; - if (tcp_inbound_md5_hash(sk, skb, &drop_reason, &hdr->saddr, - &hdr->daddr, AF_INET6, dif, sdif)) { + drop_reason = tcp_inbound_md5_hash(sk, skb, + &hdr->saddr, &hdr->daddr, + AF_INET6, dif, sdif); + if (drop_reason) { sk_drops_add(sk, skb); reqsk_put(req); goto discard_it; @@ -1704,8 +1706,9 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) goto discard_and_relse; } - if (tcp_inbound_md5_hash(sk, skb, &drop_reason, &hdr->saddr, - &hdr->daddr, AF_INET6, dif, sdif)) + drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr, + AF_INET6, dif, sdif); + if (drop_reason) goto discard_and_relse; if (tcp_filter(sk, skb)) {