From: Jesse Gross <jesse@nicira.com>
Date: Wed, 11 Feb 2015 01:00:45 +0000 (-0800)
Subject: Check offloaded vlans are from the outermost part of the packet.
X-Git-Tag: libpcap-1.7.2^2~19
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/44ef59e3e254156a7afa7c7aff614887eee23be9

Check offloaded vlans are from the outermost part of the packet.

VLAN acceleration doesn't apply to any tags that are inside of
any type of encapsulation.
---

diff --git a/gencode.c b/gencode.c
index 277015e3..af0f3017 100644
--- a/gencode.c
+++ b/gencode.c
@@ -7955,7 +7955,11 @@ gen_vlan(vlan_num)
 	case DLT_NETANALYZER:
 	case DLT_NETANALYZER_TRANSPARENT:
 #if defined(SKF_AD_VLAN_TAG) && defined(SKF_AD_VLAN_TAG_PRESENT)
-		if (vlan_stack_depth == 0) {
+		/* Verify that this is the outer part of the packet and
+		 * not encapsulated somehow. */
+		if (vlan_stack_depth == 0 && !off_linkhdr.is_variable &&
+		    off_linkhdr.constant_part ==
+		    off_outermostlinkhdr.constant_part) {
 			/*
 			 * Do we need special VLAN handling?
 			 */