udp: Simplify __udp*_lib_mcast_deliver.

Switch to using sk_nulls_for_each which shortens the code and makes it
easier to update.

Signed-off-by: David Held <drheld@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 53 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index b4481df3d5fa..7d3bd80085be 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -702,43 +702,26 @@ drop:
         return -1;
 }
 
-static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
-                                      __be16 loc_port, const struct in6_addr *loc_addr,
-                                      __be16 rmt_port, const struct in6_addr *rmt_addr,
-                                      int dif)
+static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
+                                   __be16 loc_port, const struct in6_addr *loc_addr,
+                                   __be16 rmt_port, const struct in6_addr *rmt_addr,
+                                   int dif, unsigned short hnum)
 {
-        struct hlist_nulls_node *node;
-        unsigned short num = ntohs(loc_port);
-
-        sk_nulls_for_each_from(sk, node) {
-                struct inet_sock *inet = inet_sk(sk);
-
-                if (!net_eq(sock_net(sk), net))
-                        continue;
-
-                if (udp_sk(sk)->udp_port_hash == num &&
-                    sk->sk_family == PF_INET6) {
-                        if (inet->inet_dport) {
-                                if (inet->inet_dport != rmt_port)
-                                        continue;
-                        }
-                        if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
-                            !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr))
-                                continue;
-
-                        if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
-                                continue;
+        struct inet_sock *inet = inet_sk(sk);
 
-                        if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
-                                if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))
-                                        continue;
-                        }
-                        if (!inet6_mc_check(sk, loc_addr, rmt_addr))
-                                continue;
-                        return sk;
-                }
-        }
-        return NULL;
+        if (!net_eq(sock_net(sk), net))
+                return false;
+
+        if (udp_sk(sk)->udp_port_hash != hnum ||
+            sk->sk_family != PF_INET6 ||
+            (inet->inet_dport && inet->inet_dport != rmt_port) ||
+            (!ipv6_addr_any(&sk->sk_v6_daddr) &&
+                    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
+            (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
+                return false;
+        if (!inet6_mc_check(sk, loc_addr, rmt_addr))
+                return false;
+        return true;
 }
 
 static void flush_stack(struct sock **stack, unsigned int count,
@@ -787,28 +770,27 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 {
         struct sock *sk, *stack[256 / sizeof(struct sock *)];
         const struct udphdr *uh = udp_hdr(skb);
-        struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
-        int dif;
+        struct hlist_nulls_node *node;
+        unsigned short hnum = ntohs(uh->dest);
+        struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
+        int dif = inet6_iif(skb);
         unsigned int i, count = 0;
 
         spin_lock(&hslot->lock);
-        sk = sk_nulls_head(&hslot->head);
-        dif = inet6_iif(skb);
-        sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
-        while (sk) {
-                /* If zero checksum and no_check is not on for
-                 * the socket then skip it.
-                 */
-                if (uh->check || udp_sk(sk)->no_check6_rx)
+        sk_nulls_for_each(sk, node, &hslot->head) {
+                if (__udp_v6_is_mcast_sock(net, sk,
+                                           uh->dest, daddr,
+                                           uh->source, saddr,
+                                           dif, hnum) &&
+                    /* If zero checksum and no_check is not on for
+                     * the socket then skip it.
+                     */
+                    (uh->check || udp_sk(sk)->no_check6_rx)) {
+                        if (unlikely(count == ARRAY_SIZE(stack))) {
+                                flush_stack(stack, count, skb, ~0);
+                                count = 0;
+                        }
                         stack[count++] = sk;
-
-                sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
-                                       uh->source, saddr, dif);
-                if (unlikely(count == ARRAY_SIZE(stack))) {
-                        if (!sk)
-                                break;
-                        flush_stack(stack, count, skb, ~0);
-                        count = 0;
                 }
         }
         /*