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Commit 9cefbbc9 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: nfnetlink_queue: cleanup copy_range usage 



For every packet queued, we check if configured copy_range
is 0, and treat that as 'copy entire packet'.

We can move this check to the queue configuration, and can
set copy_range appropriately.

Also, convert repetitive '0xffff - NLA_HDRLEN' to a macro.

[ queue initialization still used 0xffff, although its harmless
  since the initial setting is overwritten on queue config ]

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 4e7dba99

net/netfilter/nfnetlink_queue_core.c

+12 −10
Original line number Diff line number Diff line
@@ -41,6 +41,14 @@ 


#define NFQNL_QMAX_DEFAULT 1024



/* We're using struct nlattr which has 16bit nla_len. Note that nla_len

 * includes the header length. Thus, the maximum packet length that we

 * support is 65531 bytes. We send truncated packets if the specified length

 * is larger than that.  Userspace can check for presence of NFQA_CAP_LEN

 * attribute to detect truncation.

 */

#define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN)



struct nfqnl_instance {

	struct hlist_node hlist;		/* global list of queues */

	struct rcu_head rcu;
@@ -122,7 +130,7 @@ instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, 
	inst->queue_num = queue_num;

	inst->peer_portid = portid;

	inst->queue_maxlen = NFQNL_QMAX_DEFAULT;

	inst->copy_range = 0xffff;

	inst->copy_range = NFQNL_MAX_COPY_RANGE;

	inst->copy_mode = NFQNL_COPY_NONE;

	spin_lock_init(&inst->lock);

	INIT_LIST_HEAD(&inst->queue_list);
@@ -333,10 +341,9 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue, 
			return NULL;



		data_len = ACCESS_ONCE(queue->copy_range);

		if (data_len == 0 || data_len > entskb->len)

		if (data_len > entskb->len)

			data_len = entskb->len;





		if (!entskb->head_frag ||

		    skb_headlen(entskb) < L1_CACHE_BYTES ||

		    skb_shinfo(entskb)->nr_frags >= MAX_SKB_FRAGS)
@@ -727,13 +734,8 @@ nfqnl_set_mode(struct nfqnl_instance *queue, 


	case NFQNL_COPY_PACKET:

		queue->copy_mode = mode;

		/* We're using struct nlattr which has 16bit nla_len. Note that

		 * nla_len includes the header length. Thus, the maximum packet

		 * length that we support is 65531 bytes. We send truncated

		 * packets if the specified length is larger than that.

		 */

		if (range > 0xffff - NLA_HDRLEN)

			queue->copy_range = 0xffff - NLA_HDRLEN;

		if (range == 0 || range > NFQNL_MAX_COPY_RANGE)

			queue->copy_range = NFQNL_MAX_COPY_RANGE;

		else

			queue->copy_range = range;

		break;