[IPV{4,6}]: Fixing a bug that reading /proc/net/{udp,udp6} may drop some data.

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 08c3a40a4bd2d1d0b921acf9a69e4152e7436bcb..1746eae040b3d343793422dfc53fe22d1e35b997 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1349,64 +1349,65 @@ struct proto udp_prot = {
 /* ------------------------------------------------------------------------ */
 #ifdef CONFIG_PROC_FS
 
-static __inline__ struct sock *udp_get_bucket(struct seq_file *seq, loff_t *pos)
+static struct sock *udp_get_first(struct seq_file *seq)
 {
-       int i;
        struct sock *sk;
-       struct hlist_node *node;
-       loff_t l = *pos;
        struct udp_iter_state *state = seq->private;
 
-       for (; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
-               i = 0;
+       for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
+               struct hlist_node *node;
                sk_for_each(sk, node, &udp_hash[state->bucket]) {
-                       if (sk->sk_family != state->family) {
-                               ++i;
-                               continue;
-                       }
-                       if (l--) {
-                               ++i;
-                               continue;
-                       }
-                       *pos = i;
-                       goto out;
+                       if (sk->sk_family == state->family)
+                               goto found;
                }
        }
        sk = NULL;
-out:
+found:
        return sk;
 }
 
+static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
+{
+       struct udp_iter_state *state = seq->private;
+
+       do {
+               sk = sk_next(sk);
+try_again:
+               ;
+       } while (sk && sk->sk_family != state->family);
+
+       if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
+               sk = sk_head(&udp_hash[state->bucket]);
+               goto try_again;
+       }
+       return sk;
+}
+
+static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
+{
+       struct sock *sk = udp_get_first(seq);
+
+       if (sk)
+               while(pos && (sk = udp_get_next(seq, sk)) != NULL)
+                       --pos;
+       return pos ? NULL : sk;
+}
+
 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
 {
        read_lock(&udp_hash_lock);
-       return *pos ? udp_get_bucket(seq, pos) : (void *)1;
+       return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
 }
 
 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
        struct sock *sk;
-       struct hlist_node *node;
-       struct udp_iter_state *state;
-
-       if (v == (void *)1) {
-               sk = udp_get_bucket(seq, pos);
-               goto out;
-       }
-
-       state = seq->private;
-
-       sk = v;
-       sk_for_each_continue(sk, node)
-               if (sk->sk_family == state->family)
-                       goto out;
 
-       if (++state->bucket >= UDP_HTABLE_SIZE) 
-               goto out;
+       if (v == (void *)1)
+               sk = udp_get_idx(seq, 0);
+       else
+               sk = udp_get_next(seq, v);
 
-       *pos = 0;
-       sk = udp_get_bucket(seq, pos);
-out:
        ++*pos;
        return sk;
 }