batman-adv: Use only queued fragments when merging
The fragment queueing code now validates the total_size of each fragment,
checks when enough fragments are queued to allow to merge them into a
single packet and if the fragments have the correct size. Therefore, it is
not required to have any other parameter for the merging function than a
list of queued fragments.
This change should avoid problems like in the past when the different skb
from the list and the function parameter were mixed incorrectly.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index a9fc653..6ce3c84 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -231,19 +231,13 @@
* Returns the merged skb or NULL on error.
*/
static struct sk_buff *
-batadv_frag_merge_packets(struct hlist_head *chain, struct sk_buff *skb)
+batadv_frag_merge_packets(struct hlist_head *chain)
{
struct batadv_frag_packet *packet;
struct batadv_frag_list_entry *entry;
struct sk_buff *skb_out = NULL;
int size, hdr_size = sizeof(struct batadv_frag_packet);
- /* Make sure incoming skb has non-bogus data. */
- packet = (struct batadv_frag_packet *)skb->data;
- size = ntohs(packet->total_size);
- if (size > batadv_frag_size_limit())
- goto free;
-
/* Remove first entry, as this is the destination for the rest of the
* fragments.
*/
@@ -252,6 +246,9 @@
skb_out = entry->skb;
kfree(entry);
+ packet = (struct batadv_frag_packet *)skb_out->data;
+ size = ntohs(packet->total_size);
+
/* Make room for the rest of the fragments. */
if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) {
kfree_skb(skb_out);
@@ -307,7 +304,7 @@
if (hlist_empty(&head))
goto out;
- skb_out = batadv_frag_merge_packets(&head, *skb);
+ skb_out = batadv_frag_merge_packets(&head);
if (!skb_out)
goto out_err;