int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
u32 group, int allocation)
{
struct sock *sk;
struct sk_buff *skb2 = NULL;
int protocol = ssk->protocol;
int failure = 0, delivered = 0;
/* While we sleep in clone, do not allow to change socket list */
netlink_lock_table();
for (sk = nl_table[protocol]; sk; sk = sk->next) {
if (ssk == sk)
continue;
if (sk->protinfo.af_netlink->pid == pid ||
!(sk->protinfo.af_netlink->groups&group))
continue;
if (failure) {
netlink_overrun(sk);
continue;
}
sock_hold(sk);
if (skb2 == NULL) {
if (atomic_read(&skb->users) != 1) {
skb2 = skb_clone(skb, allocation);
} else {
skb2 = skb;
atomic_inc(&skb->users);
}
}
if (skb2 == NULL) {
netlink_overrun(sk);
/* Clone failed. Notify ALL listeners. */
failure = 1;
} else if (netlink_broadcast_deliver(sk, skb2)) {
netlink_overrun(sk);
} else {
delivered = 1;
skb2 = NULL;
}
sock_put(sk);
}
netlink_unlock_table();
if (skb2)
kfree_skb(skb2);
kfree_skb(skb);
if (delivered)
return 0;
if (failure)
return -ENOBUFS;
return -ESRCH;
}
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
u32 group, int allocation)
{
struct netlink_broadcast_data info;
struct hlist_node *node;
struct sock *sk;
info.exclude_sk = ssk;
info.pid = pid;
info.group = group;
info.failure = 0;
info.congested = 0;
info.delivered = 0;
info.allocation = allocation;
info.skb = skb;
info.skb2 = NULL;
netlink_trim(skb, allocation);
/* While we sleep in clone, do not allow to change socket list */
netlink_lock_table();
sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
do_one_broadcast(sk, &info);
netlink_unlock_table();
if (info.skb2)
kfree_skb(info.skb2);
kfree_skb(skb);
if (info.delivered) {
if (info.congested && (allocation & __GFP_WAIT))
yield();
return 0;
}
if (info.failure)
return -ENOBUFS;
return -ESRCH;
}