Commit 0f158b32 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: selectively purge error queue in IP_RECVERR / IPV6_RECVERR 



Setting IP_RECVERR and IPV6_RECVERR options to zero currently
purges the socket error queue, which was probably not expected
for zerocopy and tx_timestamp users.

I discovered this issue while preparing commit 6b5f43ea
("inet: move inet->recverr to inet->inet_flags"), I presume this
change does not need to be backported to stable kernels.

Add skb_errqueue_purge() helper to purge error messages only.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 412a75dc

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -3180,6 +3180,7 @@ static inline void skb_queue_purge(struct sk_buff_head *list) 
}



unsigned int skb_rbtree_purge(struct rb_root *root);

void skb_errqueue_purge(struct sk_buff_head *list);



void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);

net/core/skbuff.c

+21 −0
Original line number Diff line number Diff line
@@ -3745,6 +3745,27 @@ unsigned int skb_rbtree_purge(struct rb_root *root) 
	return sum;

}



void skb_errqueue_purge(struct sk_buff_head *list)

{

	struct sk_buff *skb, *next;

	struct sk_buff_head kill;

	unsigned long flags;



	__skb_queue_head_init(&kill);



	spin_lock_irqsave(&list->lock, flags);

	skb_queue_walk_safe(list, skb, next) {

		if (SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_ZEROCOPY ||

		    SKB_EXT_ERR(skb)->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING)

			continue;

		__skb_unlink(skb, list);

		__skb_queue_tail(&kill, skb);

	}

	spin_unlock_irqrestore(&list->lock, flags);

	__skb_queue_purge(&kill);

}

EXPORT_SYMBOL(skb_errqueue_purge);



/**

 *	skb_queue_head - queue a buffer at the list head

 *	@list: list to use

net/ipv4/ip_sockglue.c

+1 −1
Original line number Diff line number Diff line
@@ -976,7 +976,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname, 
	case IP_RECVERR:

		inet_assign_bit(RECVERR, sk, val);

		if (!val)

			skb_queue_purge(&sk->sk_error_queue);

			skb_errqueue_purge(&sk->sk_error_queue);

		return 0;

	case IP_RECVERR_RFC4884:

		if (val < 0 || val > 1)

net/ipv6/ipv6_sockglue.c

+1 −1
Original line number Diff line number Diff line
@@ -923,7 +923,7 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, 
			goto e_inval;

		np->recverr = valbool;

		if (!val)

			skb_queue_purge(&sk->sk_error_queue);

			skb_errqueue_purge(&sk->sk_error_queue);

		retv = 0;

		break;

	case IPV6_FLOWINFO_SEND: