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Have per-queued-packet flags, including "is a packet in error". 

The contents of the packet_info structure change during the dissection
process, so you can't rely on its contents when running tap listeners.

Bug: 11184
Change-Id: I52fc45774add56ee2bcb5faef2af7c731b4304fd
Reviewed-on: https://code.wireshark.org/review/8486
Reviewed-by: Guy Harris <guy@alum.mit.edu>
This commit is contained in:
Guy Harris 2015-05-16 11:37:28 -07:00
parent 63295df655
commit cfc5a2e05f
1 changed files with 31 additions and 2 deletions
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33
epan/tap.c
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@ -51,13 +51,39 @@ static tap_dissector_t *tap_dissector_list=NULL;
* in order to be as fast as possible as we need to build and tear down the
* queued list at least once for each packet we see and thus we must be able
* to build and tear it down as fast as possible.
*
* XXX - some fields in packet_info get overwritten in the dissection
* process, such as the addresses and the "this is an error packet" flag.
* A packet may be queued at multiple protocol layers, but the packet_info
* structure will, when the tap listeners are run, contain the values as
* set by the topmost protocol layers.
*
* This means that the tap listener code can't rely on pinfo->flags.in_error_pkt
* to determine whether the packet should be handed to the listener, as, for
* a protocol with error report packets that include a copy of the
* packet in error (ICMP, ICMPv6, CLNP), that flag changes during the
* processing of the packet depending on whether we're currently dissecting
* the packet in error or not.
*
*
* It also means that a tap listener can't depend on the source and destination
* addresses being the correct ones for the packet being processed if, for
* example, you have some tunneling that causes multiple layers of the same
* protocol.
*
* For now, we handle the error packet flag by setting a bit in the flags
* field of the tap_packet_t structure. We may ultimately want stacks of
* addresses for this and other reasons.
*/
typedef struct _tap_packet_t {
int tap_id;
guint32 flags;
packet_info *pinfo;
const void *tap_specific_data;
} tap_packet_t;
#define TAP_PACKET_IS_ERROR_PACKET 0x00000001 /* packet being queued is an error packet */
#define TAP_PACKET_QUEUE_LEN 5000
static tap_packet_t tap_packet_array[TAP_PACKET_QUEUE_LEN];
static guint tap_packet_index;
@ -245,6 +271,9 @@ tap_queue_packet(int tap_id, packet_info *pinfo, const void *tap_specific_data)
tpt=&tap_packet_array[tap_packet_index];
tpt->tap_id=tap_id;
tpt->flags = 0;
if (pinfo->flags.in_error_pkt)
tpt->flags |= TAP_PACKET_IS_ERROR_PACKET;
tpt->pinfo=pinfo;
tpt->tap_specific_data=tap_specific_data;
tap_packet_index++;
@ -322,8 +351,8 @@ tap_push_tapped_queue(epan_dissect_t *edt)
for(i=0;i<tap_packet_index;i++){
for(tl=(tap_listener_t *)tap_listener_queue;tl;tl=tl->next){
tp=&tap_packet_array[i];
/* Don't tap the packet if its an "error" unless the listener tells us to */
if ((!tp->pinfo->flags.in_error_pkt) || (tl->flags & TL_REQUIRES_ERROR_PACKETS))
/* Don't tap the packet if it's an "error" unless the listener tells us to */
if ((!tp->flags & TAP_PACKET_IS_ERROR_PACKET) || (tl->flags & TL_REQUIRES_ERROR_PACKETS))
{
if(tp->tap_id==tl->tap_id){
gboolean passed=TRUE;