lkml.org 
[lkml]   [2022]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 374/779] inet: add READ_ONCE(sk->sk_bound_dev_if) in INET_MATCH()
    Date
    From: Eric Dumazet <edumazet@google.com>

    [ Upstream commit 4915d50e300e96929d2462041d6f6c6f061167fd ]

    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 <edumazet@google.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    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 749bb1e46087..825ad1d06d05 100644
    --- a/include/net/inet_hashtables.h
    +++ b/include/net/inet_hashtables.h
    @@ -295,7 +295,6 @@ 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) ( \
    @@ -307,24 +306,22 @@ 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 e0a88bb0a58c..49a6315d521f 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 342f3df77835..7c502c4a160b 100644
    --- a/net/ipv4/inet_hashtables.c
    +++ b/net/ipv4/inet_hashtables.c
    @@ -410,13 +410,11 @@ struct sock *__inet_lookup_established(struct net *net,
    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;
    }
    @@ -465,8 +463,7 @@ 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))
    @@ -532,9 +529,7 @@ 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 4ad4daa16cce..efef7ba44e1d 100644
    --- a/net/ipv4/udp.c
    +++ b/net/ipv4/udp.c
    @@ -2554,8 +2554,7 @@ 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;
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-08-15 21:05    [W:4.053 / U:0.100 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site