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[RTPproxy] Simplify positive reply parsing and minor cleanups 

* Merge both 'positive reply' and 'version ack' processing into one block.
* Also use realsize where possible instead of recalculating packet's size
again.
* Add a bit more comments.
* Remove some 'magic' numbers. Use actual string sizes instead.
* Skip trailing zeroes inserted by some old SIP-servers.

Change-Id: Ie66aa4d6e807a1f351b62d36333301fdec1550fa
Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>
Reviewed-on: https://code.wireshark.org/review/8738
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>
This commit is contained in:
Peter Lemenkov 2015-05-22 18:49:55 +03:00 committed by Anders Broman
parent 8ccf65bfb2
commit 305960174d
1 changed files with 33 additions and 14 deletions
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47
epan/dissectors/packet-rtpproxy.c
View File

@ -279,8 +279,8 @@ static gint ett_rtpproxy_ng_bencode = -1;
static guint rtpproxy_tcp_port = 22222;
static guint rtpproxy_udp_port = 22222;
static gboolean rtpproxy_establish_conversation = TRUE;
/* See - http://www.opensips.org/html/docs/modules/devel/rtpproxy.html#id250016 */
/* See - http://www.kamailio.org/docs/modules/devel/modules/rtpproxy.html#idm448 */
/* See - https://www.opensips.org/html/docs/modules/1.10.x/rtpproxy.html#id293555 */
/* See - http://www.kamailio.org/docs/modules/4.3.x/modules/rtpproxy.html#idp15794952 */
static guint rtpproxy_timeout = 1000;
static nstime_t rtpproxy_timeout_ns = {1, 0};
@ -462,7 +462,7 @@ rtpproxy_add_tid(gboolean is_request, tvbuff_t *tvb, packet_info *pinfo, proto_t
pi = proto_tree_add_uint(rtpproxy_tree, is_request ? hf_rtpproxy_response_in : hf_rtpproxy_request_in, tvb, 0, 0, is_request ? rtpproxy_info->resp_frame : rtpproxy_info->req_frame);
PROTO_ITEM_SET_GENERATED(pi);
/* If reply then calculate response time */
/* If not a request (so it's a reply) then calculate response time */
if (!is_request){
nstime_delta(&ns, &pinfo->fd->abs_ts, &rtpproxy_info->req_time);
pi = proto_tree_add_time(rtpproxy_tree, hf_rtpproxy_response_time, tvb, 0, 0, &ns);
@ -575,6 +575,11 @@ dissect_rtpproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
/* Calculate size to prevent recalculation in the future */
realsize = tvb_reported_length(tvb);
/* Don't count trailing zeroes (inserted by some SIP-servers sometimes) */
while (tvb_get_guint8(tvb, realsize - 1) == 0){
realsize -= 1;
}
/* Check for LF (required for TCP connection, optional for UDP) */
if (tvb_get_guint8(tvb, realsize - 1) == '\n'){
/* Don't count trailing LF */
@ -636,9 +641,14 @@ dissect_rtpproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
ti = proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_request, tvb, offset, -1, ENC_NA);
rtpproxy_tree = proto_item_add_subtree(ti, ett_rtpproxy_request);
/* A specific case - version request */
if ((tmp == 'v') && (offset + (gint)strlen("VF YYYMMDD") + 1 == realsize)){
/* Skip whitespace */
/* A specific case - version request:
* https://github.com/sippy/rtpproxy/wiki/RTPP-%28RTPproxy-protocol%29-technical-specification#get-list-of-veatures
*
* In this case a command size must be bigger or equal to a "VF YYYYMMDD" string size.
* It's bigger if there is more than one space inserted between "VF" and "YYYYMMDD" tokens.
*/
if ((tmp == 'v') && (offset + (gint)strlen("VF YYYYMMDD") <= realsize)){
/* Skip whitespace between "VF" and "YYYYMMDD" tokens */
new_offset = tvb_skip_wsp(tvb, offset + ((guint)strlen("VF") + 1), -1);
ti = proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_version_request, tvb, new_offset, (gint)strlen("YYYYMMDD"), ENC_ASCII | ENC_NA);
tmpstr = tvb_get_string_enc(wmem_packet_scope(), tvb, new_offset, (gint)strlen("YYYYMMDD"), ENC_ASCII);
@ -803,16 +813,25 @@ dissect_rtpproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
break;
}
if ((tmp == '0')&& ((tvb_reported_length(tvb) == (guint)(offset+1))||(tvb_reported_length(tvb) == (guint)(offset+2)))){
/* Check for a single '0' or '1' character followed by the end-of-line.
* These both are positive replies - either a 'positive reply' or a 'version ack'.
*
* https://github.com/sippy/rtpproxy/wiki/RTPP-%28RTPproxy-protocol%29-technical-specification#positive-reply
* https://github.com/sippy/rtpproxy/wiki/RTPP-%28RTPproxy-protocol%29-technical-specification#version-reply
*/
if (((tmp == '0') || (tmp == '1')) && (realsize == offset + (gint)strlen("X"))){
proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_ok, tvb, offset, 1, ENC_ASCII | ENC_NA);
break;
}
if ((tmp == '1') && ((tvb_reported_length(tvb) == (guint)(offset+1))||(tvb_reported_length(tvb) == (guint)(offset+2)))){
proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_ok, tvb, offset, 1, ENC_ASCII | ENC_NA);
break;
}
if (tvb_reported_length(tvb) == (guint)(offset+9)){
proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_version_supported, tvb, offset, 8, ENC_ASCII | ENC_NA);
/* Check for the VERSION_NUMBER string reply:
* https://github.com/sippy/rtpproxy/wiki/RTPP-%28RTPproxy-protocol%29-technical-specification#version-reply
*
* If a total size equals to a current offset + size of "YYYYMMDD" string
* then it's a version reply.
*/
if (realsize == offset + (gint)strlen("YYYYMMDD")){
proto_tree_add_item(rtpproxy_tree, hf_rtpproxy_version_supported, tvb, offset, strlen("YYYYMMDD"), ENC_ASCII | ENC_NA);
break;
}
@ -829,7 +848,7 @@ dissect_rtpproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
/* Try rtpengine bogus extension first. It appends 4 or
* 6 depending on type of the IP. See
* https://github.com/sipwise/rtpengine/blob/master/daemon/call_interfaces.c#L66
* https://github.com/sipwise/rtpengine/blob/eea3256/daemon/call_interfaces.c#L74
* for further details */
tmp = tvb_find_guint8(tvb, offset, -1, ' ');
if(tmp == (guint)(-1)){