[B.A.T.M.A.N.] [PATCHv2] batman-adv: Return reason for failure in batadv_check_unicast_packet()

* [B.A.T.M.A.N.] [PATCHv2] batman-adv: Return reason for failure in batadv_check_unicast_packet()
@ 2013-01-13 23:12 Martin Hundebøll
  2013-01-13 23:20 ` [B.A.T.M.A.N.] [PATCHv3] " Martin Hundebøll
  0 siblings, 1 reply; 4+ messages in thread
From: Martin Hundebøll @ 2013-01-13 23:12 UTC (permalink / raw)
  To: b.a.t.m.a.n; +Cc: Martin Hundebøll

batadv_check_unicast_packet() is changed to return a value based on the
reason to drop the packet, which will be useful information for
future users of batadv_check_unicast_packet().

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
---
v2:
 * Changed return values to defined error codes.
 * Send as separate patch

 routing.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/routing.c b/routing.c
index 1aa1722..a3ee5be 100644
--- a/routing.c
+++ b/routing.c
@@ -552,27 +552,37 @@ batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
 	return router;
 }
 
+/**
+ * batadv_check_unicast_packet - Check for malformed unicast packets
+ * @skb: packet to check
+ * @hdr_size: size of header to pull
+ *
+ * Check for short header and bad addresses in given packet. Returns negative
+ * value when check fails and 0 otherwise. The negative value depends on the
+ * reason: -ENODATA for bad header, -EBADR for broadcast destination or source
+ * source, and -EREMOTE for non-local (other host) destination.
+ */
 static int batadv_check_unicast_packet(struct sk_buff *skb, int hdr_size)
 {
 	struct ethhdr *ethhdr;
 
 	/* drop packet if it has not necessary minimum size */
 	if (unlikely(!pskb_may_pull(skb, hdr_size)))
-		return -1;
+		return -ENODATA;
 
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with unicast indication but broadcast recipient */
 	if (is_broadcast_ether_addr(ethhdr->h_dest))
-		return -1;
+		return -EBADR;
 
 	/* packet with broadcast sender address */
 	if (is_broadcast_ether_addr(ethhdr->h_source))
-		return -1;
+		return -EBADR;
 
 	/* not for me */
 	if (!batadv_is_my_mac(ethhdr->h_dest))
-		return -1;
+		return -EREMOTE;
 
 	return 0;
 }
-- 
1.8.1


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