1 files changed, 52 insertions, 71 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 57e26fa66185..eacf4cfef146 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -108,9 +108,6 @@
  *      Snmp MIB for the UDP layer
  */
 
-DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
-EXPORT_SYMBOL(udp_stats_in6);
-
 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
 DEFINE_RWLOCK(udp_hash_lock);
 
@@ -125,14 +122,23 @@ EXPORT_SYMBOL(sysctl_udp_wmem_min);
 atomic_t udp_memory_allocated;
 EXPORT_SYMBOL(udp_memory_allocated);
 
-static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
-                                        const struct hlist_head udptable[])
+static int udp_lib_lport_inuse(struct net *net, __u16 num,
+                               const struct hlist_head udptable[],
+                               struct sock *sk,
+                               int (*saddr_comp)(const struct sock *sk1,
+                                                 const struct sock *sk2))
 {
-        struct sock *sk;
+        struct sock *sk2;
         struct hlist_node *node;
 
-        sk_for_each(sk, node, &udptable[udp_hashfn(net, num)])
-                if (net_eq(sock_net(sk), net) && sk->sk_hash == num)
+        sk_for_each(sk2, node, &udptable[udp_hashfn(net, num)])
+                if (net_eq(sock_net(sk2), net)                  &&
+                    sk2 != sk                                   &&
+                    sk2->sk_hash == num                         &&
+                    (!sk2->sk_reuse || !sk->sk_reuse)           &&
+                    (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
+                        || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+                    (*saddr_comp)(sk, sk2))
                         return 1;
         return 0;
 }
@@ -149,83 +155,37 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
                                          const struct sock *sk2 )    )
 {
         struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
-        struct hlist_node *node;
-        struct hlist_head *head;
-        struct sock *sk2;
         int    error = 1;
         struct net *net = sock_net(sk);
 
         write_lock_bh(&udp_hash_lock);
 
         if (!snum) {
-                int i, low, high, remaining;
-                unsigned rover, best, best_size_so_far;
+                int low, high, remaining;
+                unsigned rand;
+                unsigned short first;
 
                 inet_get_local_port_range(&low, &high);
                 remaining = (high - low) + 1;
 
-                best_size_so_far = UINT_MAX;
-                best = rover = net_random() % remaining + low;
-
-                /* 1st pass: look for empty (or shortest) hash chain */
-                for (i = 0; i < UDP_HTABLE_SIZE; i++) {
-                        int size = 0;
-
-                        head = &udptable[udp_hashfn(net, rover)];
-                        if (hlist_empty(head))
-                                goto gotit;
-
-                        sk_for_each(sk2, node, head) {
-                                if (++size >= best_size_so_far)
-                                        goto next;
-                        }
-                        best_size_so_far = size;
-                        best = rover;
-                next:
-                        /* fold back if end of range */
-                        if (++rover > high)
-                                rover = low + ((rover - low)
-                                               & (UDP_HTABLE_SIZE - 1));
-
-
-                }
-
-                /* 2nd pass: find hole in shortest hash chain */
-                rover = best;
-                for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
-                        if (! __udp_lib_lport_inuse(net, rover, udptable))
-                                goto gotit;
-                        rover += UDP_HTABLE_SIZE;
-                        if (rover > high)
-                                rover = low + ((rover - low)
-                                               & (UDP_HTABLE_SIZE - 1));
+                rand = net_random();
+                snum = first = rand % remaining + low;
+                rand |= 1;
+                while (udp_lib_lport_inuse(net, snum, udptable, sk,
+                                           saddr_comp)) {
+                        do {
+                                snum = snum + rand;
+                        } while (snum < low || snum > high);
+                        if (snum == first)
+                                goto fail;
                 }
-
-
-                /* All ports in use! */
+        } else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
                 goto fail;
 
-gotit:
-                snum = rover;
-        } else {
-                head = &udptable[udp_hashfn(net, snum)];
-
-                sk_for_each(sk2, node, head)
-                        if (sk2->sk_hash == snum                             &&
-                            sk2 != sk                                        &&
-                            net_eq(sock_net(sk2), net)                       &&
-                            (!sk2->sk_reuse        || !sk->sk_reuse)         &&
-                            (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
-                             || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
-                            (*saddr_comp)(sk, sk2)                             )
-                                goto fail;
-        }
-
         inet_sk(sk)->num = snum;
         sk->sk_hash = snum;
         if (sk_unhashed(sk)) {
-                head = &udptable[udp_hashfn(net, snum)];
-                sk_add_node(sk, head);
+                sk_add_node(sk, &udptable[udp_hashfn(net, snum)]);
                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
         }
         error = 0;
@@ -302,6 +262,28 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
         return result;
 }
 
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+                                                 __be16 sport, __be16 dport,
+                                                 struct hlist_head udptable[])
+{
+        struct sock *sk;
+        const struct iphdr *iph = ip_hdr(skb);
+
+        if (unlikely(sk = skb_steal_sock(skb)))
+                return sk;
+        else
+                return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
+                                         iph->daddr, dport, inet_iif(skb),
+                                         udptable);
+}
+
+struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+                             __be32 daddr, __be16 dport, int dif)
+{
+        return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, udp_hash);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+
 static inline struct sock *udp_v4_mcast_next(struct sock *sk,
                                              __be16 loc_port, __be32 loc_addr,
                                              __be16 rmt_port, __be32 rmt_addr,
@@ -1201,8 +1183,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
                 return __udp4_lib_mcast_deliver(net, skb, uh,
                                 saddr, daddr, udptable);
 
-        sk = __udp4_lib_lookup(net, saddr, uh->source, daddr,
-                        uh->dest, inet_iif(skb), udptable);
+        sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 
         if (sk != NULL) {
                 int ret = udp_queue_rcv_skb(sk, skb);