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authorJakub Sitnicki <jakub@cloudflare.com>2020-07-17 12:35:31 +0200
committerAlexei Starovoitov <ast@kernel.org>2020-07-18 05:18:17 +0200
commit6d4201b1386b335bb53628a04ad63e547872dc5a (patch)
tree0e70f7b235112512b6e9a2774e82899252550f4e /net/ipv6/udp.c
parentudp6: Extract helper for selecting socket from reuseport group (diff)
downloadlinux-6d4201b1386b335bb53628a04ad63e547872dc5a.tar.xz
linux-6d4201b1386b335bb53628a04ad63e547872dc5a.zip
udp6: Run SK_LOOKUP BPF program on socket lookup
Same as for udp4, let BPF program override the socket lookup result, by selecting a receiving socket of its choice or failing the lookup, if no connected UDP socket matched packet 4-tuple. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200717103536.397595-11-jakub@cloudflare.com
Diffstat (limited to 'net/ipv6/udp.c')
-rw-r--r--net/ipv6/udp.c60
1 files changed, 51 insertions, 9 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 084205c18a33..ff8be202726a 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -190,6 +190,31 @@ static struct sock *udp6_lib_lookup2(struct net *net,
return result;
}
+static inline struct sock *udp6_lookup_run_bpf(struct net *net,
+ struct udp_table *udptable,
+ struct sk_buff *skb,
+ const struct in6_addr *saddr,
+ __be16 sport,
+ const struct in6_addr *daddr,
+ u16 hnum)
+{
+ struct sock *sk, *reuse_sk;
+ bool no_reuseport;
+
+ if (udptable != &udp_table)
+ return NULL; /* only UDP is supported */
+
+ no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP,
+ saddr, sport, daddr, hnum, &sk);
+ if (no_reuseport || IS_ERR_OR_NULL(sk))
+ return sk;
+
+ reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
+ if (reuse_sk)
+ sk = reuse_sk;
+ return sk;
+}
+
/* rcu_read_lock() must be held */
struct sock *__udp6_lib_lookup(struct net *net,
const struct in6_addr *saddr, __be16 sport,
@@ -200,25 +225,42 @@ struct sock *__udp6_lib_lookup(struct net *net,
unsigned short hnum = ntohs(dport);
unsigned int hash2, slot2;
struct udp_hslot *hslot2;
- struct sock *result;
+ struct sock *result, *sk;
hash2 = ipv6_portaddr_hash(net, daddr, hnum);
slot2 = hash2 & udptable->mask;
hslot2 = &udptable->hash2[slot2];
+ /* Lookup connected or non-wildcard sockets */
result = udp6_lib_lookup2(net, saddr, sport,
daddr, hnum, dif, sdif,
hslot2, skb);
- if (!result) {
- hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
- slot2 = hash2 & udptable->mask;
+ if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
+ goto done;
+
+ /* Lookup redirect from BPF */
+ if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
+ sk = udp6_lookup_run_bpf(net, udptable, skb,
+ saddr, sport, daddr, hnum);
+ if (sk) {
+ result = sk;
+ goto done;
+ }
+ }
- hslot2 = &udptable->hash2[slot2];
+ /* Got non-wildcard socket or error on first lookup */
+ if (result)
+ goto done;
- result = udp6_lib_lookup2(net, saddr, sport,
- &in6addr_any, hnum, dif, sdif,
- hslot2, skb);
- }
+ /* Lookup wildcard sockets */
+ hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
+ slot2 = hash2 & udptable->mask;
+ hslot2 = &udptable->hash2[slot2];
+
+ result = udp6_lib_lookup2(net, saddr, sport,
+ &in6addr_any, hnum, dif, sdif,
+ hslot2, skb);
+done:
if (IS_ERR(result))
return NULL;
return result;