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author | Peter Oskolkov <posk@google.com> | 2018-12-12 13:15:34 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-12-14 15:55:20 -0800 |
commit | 23b0269e58aee1165133b9696e43992f969b5088 (patch) | |
tree | 0f35b0e22da71c251ee338e0d00b80b8c1c62e7d /net/ipv6/udp.c | |
parent | 4cdeeee9252af1ba50482f91d615f326365306bd (diff) | |
download | linux-23b0269e58aee1165133b9696e43992f969b5088.tar.gz linux-23b0269e58aee1165133b9696e43992f969b5088.tar.bz2 linux-23b0269e58aee1165133b9696e43992f969b5088.zip |
net: udp6: prefer listeners bound to an address
A relatively common use case is to have several IPs configured
on a host, and have different listeners for each of them. We would
like to add a "catch all" listener on addr_any, to match incoming
connections not served by any of the listeners bound to a specific
address.
However, port-only lookups can match addr_any sockets when sockets
listening on specific addresses are present if so_reuseport flag
is set. This patch eliminates lookups into port-only hashtable,
as lookups by (addr,port) tuple are easily available.
In addition, compute_score() is tweaked to _not_ match
addr_any sockets to specific addresses, as hash collisions
could result in the unwanted behavior described above.
Tested: the patch compiles; full test in the last patch in this
patchset. Existing reuseport_* selftests also pass.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/udp.c')
-rw-r--r-- | net/ipv6/udp.c | 79 |
1 files changed, 21 insertions, 58 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 09cba4cfe31f..9cbf363172bd 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -125,6 +125,9 @@ static int compute_score(struct sock *sk, struct net *net, sk->sk_family != PF_INET6) return -1; + if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) + return -1; + score = 0; inet = inet_sk(sk); @@ -134,12 +137,6 @@ static int compute_score(struct sock *sk, struct net *net, score++; } - if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) { - if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) - return -1; - score++; - } - if (!ipv6_addr_any(&sk->sk_v6_daddr)) { if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) return -1; @@ -197,66 +194,32 @@ struct sock *__udp6_lib_lookup(struct net *net, int dif, int sdif, struct udp_table *udptable, struct sk_buff *skb) { - struct sock *sk, *result; unsigned short hnum = ntohs(dport); - unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); - struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; + unsigned int hash2, slot2; + struct udp_hslot *hslot2; + struct sock *result; bool exact_dif = udp6_lib_exact_dif_match(net, skb); - int score, badness; - u32 hash = 0; - if (hslot->count > 10) { - hash2 = ipv6_portaddr_hash(net, daddr, hnum); + hash2 = ipv6_portaddr_hash(net, daddr, hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + result = udp6_lib_lookup2(net, saddr, sport, + daddr, hnum, dif, sdif, exact_dif, + hslot2, skb); + if (!result) { + hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum); slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; - if (hslot->count < hslot2->count) - goto begin; result = udp6_lib_lookup2(net, saddr, sport, - daddr, hnum, dif, sdif, exact_dif, - hslot2, skb); - if (!result) { - unsigned int old_slot2 = slot2; - hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum); - slot2 = hash2 & udptable->mask; - /* avoid searching the same slot again. */ - if (unlikely(slot2 == old_slot2)) - return result; - - hslot2 = &udptable->hash2[slot2]; - if (hslot->count < hslot2->count) - goto begin; - - result = udp6_lib_lookup2(net, saddr, sport, - daddr, hnum, dif, sdif, - exact_dif, hslot2, - skb); - } - if (unlikely(IS_ERR(result))) - return NULL; - return result; - } -begin: - result = NULL; - badness = -1; - sk_for_each_rcu(sk, &hslot->head) { - score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, - sdif, exact_dif); - if (score > badness) { - if (sk->sk_reuseport) { - hash = udp6_ehashfn(net, daddr, hnum, - saddr, sport); - result = reuseport_select_sock(sk, hash, skb, - sizeof(struct udphdr)); - if (unlikely(IS_ERR(result))) - return NULL; - if (result) - return result; - } - result = sk; - badness = score; - } + &in6addr_any, hnum, dif, sdif, + exact_dif, hslot2, + skb); } + if (unlikely(IS_ERR(result))) + return NULL; return result; } EXPORT_SYMBOL_GPL(__udp6_lib_lookup); |