From: Florian Westphal <fw@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nfnetlink_queue_core.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c
index cff4449..3c42181 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -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;
--
1.7.10.4
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