ipv6/udp: Add 4-tuple hash for connected socket

Implement ipv6 udp hash4 like that in ipv4. The major difference is that
the hash value should be calculated with udp6_ehashfn(). Besides,
ipv4-mapped ipv6 address is handled before hash() and rehash(). Export
udp_ehashfn because now we use it in udpv6 rehash.

Core procedures of hash/unhash/rehash are same as ipv4, and udpv4 and
udpv6 share the same udptable, so some functions in ipv4 hash4 can also
be shared.

Co-developed-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Co-developed-by: Fred Chen <fred.cc@alibaba-inc.com>
Signed-off-by: Fred Chen <fred.cc@alibaba-inc.com>
Co-developed-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Yubing Qiu <yubing.qiuyubing@alibaba-inc.com>
Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/udp.h b/include/net/udp.h
index feb06c0e48fbaf40c38dda5b6b3e9ae43de80280..6e89520e100dcb5df7b68ea7856d7a08aca7c6cc 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -303,6 +303,8 @@ static inline int udp_lib_hash(struct sock *sk)
 
 void udp_lib_unhash(struct sock *sk);
 void udp_lib_rehash(struct sock *sk, u16 new_hash, u16 new_hash4);
+u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
+               const __be32 faddr, const __be16 fport);
 
 static inline void udp_lib_close(struct sock *sk, long timeout)
 {

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index b6c5edd7ff48f927da5929d833e9a4562cd229c3..6a01905d379fdd5c1815c3a71694071f6e5e06d3 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -410,7 +410,6 @@ static int compute_score(struct sock *sk, const struct net *net,
        return score;
 }
 
-INDIRECT_CALLABLE_SCOPE
 u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
                const __be32 faddr, const __be16 fport)
 {
@@ -419,6 +418,7 @@ u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
        return __inet_ehashfn(laddr, lport, faddr, fport,
                              udp_ehash_secret + net_hash_mix(net));
 }
+EXPORT_SYMBOL(udp_ehashfn);
 
 /* called with rcu_read_lock() */
 static struct sock *udp4_lib_lookup2(const struct net *net,

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 1ea99d704e31a680506da016f5878aa8b953d3ca..d766fd798ecf9916f4581a39aaea609ee7e864a6 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -110,8 +110,19 @@ void udp_v6_rehash(struct sock *sk)
        u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
                                          &sk->sk_v6_rcv_saddr,
                                          inet_sk(sk)->inet_num);
+       u16 new_hash4;
 
-       udp_lib_rehash(sk, new_hash, 0); /* 4-tuple hash not implemented */
+       if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
+               new_hash4 = udp_ehashfn(sock_net(sk),
+                                       sk->sk_rcv_saddr, sk->sk_num,
+                                       sk->sk_daddr, sk->sk_dport);
+       } else {
+               new_hash4 = udp6_ehashfn(sock_net(sk),
+                                        &sk->sk_v6_rcv_saddr, sk->sk_num,
+                                        &sk->sk_v6_daddr, sk->sk_dport);
+       }
+
+       udp_lib_rehash(sk, new_hash, new_hash4);
 }
 
 static int compute_score(struct sock *sk, const struct net *net,
@@ -216,6 +227,74 @@ rescore:
        return result;
 }
 
+#if IS_ENABLED(CONFIG_BASE_SMALL)
+static struct sock *udp6_lib_lookup4(const struct net *net,
+                                    const struct in6_addr *saddr, __be16 sport,
+                                    const struct in6_addr *daddr,
+                                    unsigned int hnum, int dif, int sdif,
+                                    struct udp_table *udptable)
+{
+       return NULL;
+}
+
+static void udp6_hash4(struct sock *sk)
+{
+}
+#else /* !CONFIG_BASE_SMALL */
+static struct sock *udp6_lib_lookup4(const struct net *net,
+                                    const struct in6_addr *saddr, __be16 sport,
+                                    const struct in6_addr *daddr,
+                                    unsigned int hnum, int dif, int sdif,
+                                    struct udp_table *udptable)
+{
+       const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
+       const struct hlist_nulls_node *node;
+       struct udp_hslot *hslot4;
+       unsigned int hash4, slot;
+       struct udp_sock *up;
+       struct sock *sk;
+
+       hash4 = udp6_ehashfn(net, daddr, hnum, saddr, sport);
+       slot = hash4 & udptable->mask;
+       hslot4 = &udptable->hash4[slot];
+
+begin:
+       udp_lrpa_for_each_entry_rcu(up, node, &hslot4->nulls_head) {
+               sk = (struct sock *)up;
+               if (inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
+                       return sk;
+       }
+
+       /* if the nulls value we got at the end of this lookup is not the
+        * expected one, we must restart lookup. We probably met an item that
+        * was moved to another chain due to rehash.
+        */
+       if (get_nulls_value(node) != slot)
+               goto begin;
+
+       return NULL;
+}
+
+static void udp6_hash4(struct sock *sk)
+{
+       struct net *net = sock_net(sk);
+       unsigned int hash;
+
+       if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
+               udp4_hash4(sk);
+               return;
+       }
+
+       if (sk_unhashed(sk) || ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+               return;
+
+       hash = udp6_ehashfn(net, &sk->sk_v6_rcv_saddr, sk->sk_num,
+                           &sk->sk_v6_daddr, sk->sk_dport);
+
+       udp_lib_hash4(sk, hash);
+}
+#endif /* CONFIG_BASE_SMALL */
+
 /* rcu_read_lock() must be held */
 struct sock *__udp6_lib_lookup(const struct net *net,
                               const struct in6_addr *saddr, __be16 sport,
@@ -231,6 +310,13 @@ struct sock *__udp6_lib_lookup(const struct net *net,
        hash2 = ipv6_portaddr_hash(net, daddr, hnum);
        hslot2 = udp_hashslot2(udptable, hash2);
 
+       if (udp_has_hash4(hslot2)) {
+               result = udp6_lib_lookup4(net, saddr, sport, daddr, hnum,
+                                         dif, sdif, udptable);
+               if (result) /* udp6_lib_lookup4 return sk or NULL */
+                       return result;
+       }
+
        /* Lookup connected or non-wildcard sockets */
        result = udp6_lib_lookup2(net, saddr, sport,
                                  daddr, hnum, dif, sdif,
@@ -1166,6 +1252,18 @@ static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
        return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
 }
 
+static int udpv6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+       int res;
+
+       lock_sock(sk);
+       res = __ip6_datagram_connect(sk, uaddr, addr_len);
+       if (!res)
+               udp6_hash4(sk);
+       release_sock(sk);
+       return res;
+}
+
 /**
  *     udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
  *     @sk:    socket we are sending on
@@ -1761,7 +1859,7 @@ struct proto udpv6_prot = {
        .owner                  = THIS_MODULE,
        .close                  = udp_lib_close,
        .pre_connect            = udpv6_pre_connect,
-       .connect                = ip6_datagram_connect,
+       .connect                = udpv6_connect,
        .disconnect             = udp_disconnect,
        .ioctl                  = udp_ioctl,
        .init                   = udpv6_init_sock,