From 4915d50e300e96929d2462041d6f6c6f061167fd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 12 May 2022 09:56:01 -0700 Subject: [PATCH] inet: add READ_ONCE(sk->sk_bound_dev_if) in INET_MATCH() INET_MATCH() runs without holding a lock on the socket. We probably need to annotate most reads. This patch makes INET_MATCH() an inline function to ease our changes. v2: We remove the 32bit version of it, as modern compilers should generate the same code really, no need to try to be smarter. Also make 'struct net *net' the first argument. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/inet_hashtables.h | 35 ++++++++++++++++------------------- include/net/sock.h | 3 --- net/ipv4/inet_hashtables.c | 15 +++++---------- net/ipv4/udp.c | 3 +-- 4 files changed, 22 insertions(+), 34 deletions(-) diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index 1b87067..59d7202 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -255,7 +255,6 @@ static inline struct sock *inet_lookup_listener(struct net *net, ((__force __portpair)(((__u32)(__dport) << 16) | (__force __u32)(__be16)(__sport))) #endif -#if (BITS_PER_LONG == 64) #ifdef __BIG_ENDIAN #define INET_ADDR_COOKIE(__name, __saddr, __daddr) \ const __addrpair __name = (__force __addrpair) ( \ @@ -267,24 +266,22 @@ static inline struct sock *inet_lookup_listener(struct net *net, (((__force __u64)(__be32)(__daddr)) << 32) | \ ((__force __u64)(__be32)(__saddr))) #endif /* __BIG_ENDIAN */ -#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \ - (((__sk)->sk_portpair == (__ports)) && \ - ((__sk)->sk_addrpair == (__cookie)) && \ - (((__sk)->sk_bound_dev_if == (__dif)) || \ - ((__sk)->sk_bound_dev_if == (__sdif))) && \ - net_eq(sock_net(__sk), (__net))) -#else /* 32-bit arch */ -#define INET_ADDR_COOKIE(__name, __saddr, __daddr) \ - const int __name __deprecated __attribute__((unused)) - -#define INET_MATCH(__sk, __net, __cookie, __saddr, __daddr, __ports, __dif, __sdif) \ - (((__sk)->sk_portpair == (__ports)) && \ - ((__sk)->sk_daddr == (__saddr)) && \ - ((__sk)->sk_rcv_saddr == (__daddr)) && \ - (((__sk)->sk_bound_dev_if == (__dif)) || \ - ((__sk)->sk_bound_dev_if == (__sdif))) && \ - net_eq(sock_net(__sk), (__net))) -#endif /* 64-bit arch */ + +static inline bool INET_MATCH(struct net *net, const struct sock *sk, + const __addrpair cookie, const __portpair ports, + int dif, int sdif) +{ + int bound_dev_if; + + if (!net_eq(sock_net(sk), net) || + sk->sk_portpair != ports || + sk->sk_addrpair != cookie) + return false; + + /* Paired with WRITE_ONCE() from sock_bindtoindex_locked() */ + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + return bound_dev_if == dif || bound_dev_if == sdif; +} /* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need * not check it for lookups anymore, thanks Alexey. -DaveM diff --git a/include/net/sock.h b/include/net/sock.h index 73063c8..01edfde 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -161,9 +161,6 @@ typedef __u64 __bitwise __addrpair; * for struct sock and struct inet_timewait_sock. */ struct sock_common { - /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned - * address on 64bit arches : cf INET_MATCH() - */ union { __addrpair skc_addrpair; struct { diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 0b8235f..5257a75 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -373,13 +373,11 @@ begin: sk_nulls_for_each_rcu(sk, node, &head->chain) { if (sk->sk_hash != hash) continue; - if (likely(INET_MATCH(sk, net, acookie, - saddr, daddr, ports, dif, sdif))) { + if (likely(INET_MATCH(net, sk, acookie, ports, dif, sdif))) { if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) goto out; - if (unlikely(!INET_MATCH(sk, net, acookie, - saddr, daddr, ports, - dif, sdif))) { + if (unlikely(!INET_MATCH(net, sk, acookie, + ports, dif, sdif))) { sock_gen_put(sk); goto begin; } @@ -428,8 +426,7 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row, if (sk2->sk_hash != hash) continue; - if (likely(INET_MATCH(sk2, net, acookie, - saddr, daddr, ports, dif, sdif))) { + if (likely(INET_MATCH(net, sk2, acookie, ports, dif, sdif))) { if (sk2->sk_state == TCP_TIME_WAIT) { tw = inet_twsk(sk2); if (twsk_unique(sk, sk2, twp)) @@ -495,9 +492,7 @@ static bool inet_ehash_lookup_by_sk(struct sock *sk, if (esk->sk_hash != sk->sk_hash) continue; if (sk->sk_family == AF_INET) { - if (unlikely(INET_MATCH(esk, net, acookie, - sk->sk_daddr, - sk->sk_rcv_saddr, + if (unlikely(INET_MATCH(net, esk, acookie, ports, dif, sdif))) { return true; } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 9d5071c..53342ce 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2563,8 +2563,7 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net, struct sock *sk; udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { - if (INET_MATCH(sk, net, acookie, rmt_addr, - loc_addr, ports, dif, sdif)) + if (INET_MATCH(net, sk, acookie, ports, dif, sdif)) return sk; /* Only check first socket in chain */ break; -- 2.7.4