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Commit 1a50307b authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso Committed by David S. Miller
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netlink: fix NETLINK_RECV_NO_ENOBUFS in netlink_set_err() 



Currently, ENOBUFS errors are reported to the socket via
netlink_set_err() even if NETLINK_RECV_NO_ENOBUFS is set. However,
that should not happen. This fixes this problem and it changes the
prototype of netlink_set_err() to return the number of sockets that
have set the NETLINK_RECV_NO_ENOBUFS socket option. This return
value is used in the next patch in these bugfix series.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 73852e81

include/linux/netlink.h

+1 −1
Original line number Diff line number Diff line
@@ -188,7 +188,7 @@ extern int netlink_has_listeners(struct sock *sk, unsigned int group); 
extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);

extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,

			     __u32 group, gfp_t allocation);

extern void netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);

extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);

extern int netlink_register_notifier(struct notifier_block *nb);

extern int netlink_unregister_notifier(struct notifier_block *nb);

net/netlink/af_netlink.c

+14 −3
Original line number Diff line number Diff line
@@ -1093,6 +1093,7 @@ static inline int do_one_set_err(struct sock *sk, 
				 struct netlink_set_err_data *p)

{

	struct netlink_sock *nlk = nlk_sk(sk);

	int ret = 0;



	if (sk == p->exclude_sk)

		goto out;
@@ -1104,10 +1105,15 @@ static inline int do_one_set_err(struct sock *sk, 
	    !test_bit(p->group - 1, nlk->groups))

		goto out;



	if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {

		ret = 1;

		goto out;

	}



	sk->sk_err = p->code;

	sk->sk_error_report(sk);

out:

	return 0;

	return ret;

}



/**
@@ -1116,12 +1122,16 @@ static inline int do_one_set_err(struct sock *sk, 
 * @pid: the PID of a process that we want to skip (if any)

 * @groups: the broadcast group that will notice the error

 * @code: error code, must be negative (as usual in kernelspace)

 *

 * This function returns the number of broadcast listeners that have set the

 * NETLINK_RECV_NO_ENOBUFS socket option.

 */

void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)

int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)

{

	struct netlink_set_err_data info;

	struct hlist_node *node;

	struct sock *sk;

	int ret = 0;



	info.exclude_sk = ssk;

	info.pid = pid;
@@ -1132,9 +1142,10 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) 
	read_lock(&nl_table_lock);



	sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)

		do_one_set_err(sk, &info);

		ret += do_one_set_err(sk, &info);



	read_unlock(&nl_table_lock);

	return ret;

}

EXPORT_SYMBOL(netlink_set_err);