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: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2013-06-04 22:22:15 +00:00 committed by Pablo Neira Ayuso
parent 4e7dba99c9
commit 9cefbbc9c8
1 changed files with 12 additions and 10 deletions

View File

@ -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;