udp: complete port availability checking
While looking at UDP port randomization, I noticed it
was litle bit pessimistic, not looking at type of sockets
(IPV6/IPV4) and not looking at bound addresses if any.
We should perform same tests than when binding to a
specific port.
This permits a cleanup of udp_lib_get_port()
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 67d8430..eacf4cf 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -122,14 +122,23 @@
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;
}
@@ -146,9 +155,6 @@
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);
@@ -165,32 +171,21 @@
rand = net_random();
snum = first = rand % remaining + low;
rand |= 1;
- while (__udp_lib_lport_inuse(net, snum, udptable)) {
+ 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;
}
- } 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;
- }
+ } else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
+ 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;