wireshark/packet-rtsp.c

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/* packet-rtsp.c
* Routines for RTSP packet disassembly (RFC 2326)
*
* Jason Lango <jal@netapp.com>
* Liberally copied from packet-http.c, by Guy Harris <guy@alum.mit.edu>
*
* $Id: packet-rtsp.c,v 1.50 2002/08/28 21:00:30 jmayer Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <glib.h>
#include <epan/packet.h>
#include "packet-rtp.h"
#include "packet-rtcp.h"
#include <epan/conversation.h>
#include <epan/strutil.h>
static int proto_rtsp = -1;
static gint ett_rtsp = -1;
static gint ett_rtspframe = -1;
static int hf_rtsp_method = -1;
static int hf_rtsp_url = -1;
static int hf_rtsp_status = -1;
static dissector_handle_t sdp_handle;
static dissector_handle_t rtp_handle;
static dissector_handle_t rtcp_handle;
static GMemChunk *rtsp_vals = NULL;
#define rtsp_hash_init_count 20
#define TCP_PORT_RTSP 554
/*
* Takes an array of bytes, assumed to contain a null-terminated
* string, as an argument, and returns the length of the string -
* i.e., the size of the array, minus 1 for the null terminator.
*/
#define STRLEN_CONST(str) (sizeof (str) - 1)
#define RTSP_FRAMEHDR ('$')
typedef struct {
dissector_handle_t dissector;
} rtsp_interleaved_t;
#define RTSP_MAX_INTERLEAVED (8)
/*
* Careful about dynamically allocating memory in this structure (say
* for dynamically increasing the size of the 'interleaved' array) -
* the containing structure is garbage collected and contained
* pointers will not be freed.
*/
typedef struct {
rtsp_interleaved_t interleaved[RTSP_MAX_INTERLEAVED];
} rtsp_conversation_data_t;
static int
dissect_rtspinterleaved(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree)
{
proto_tree *rtspframe_tree;
proto_item *ti;
int orig_offset;
guint8 rf_start; /* always RTSP_FRAMEHDR */
guint8 rf_chan; /* interleaved channel id */
guint16 rf_len; /* packet length */
gint framelen;
tvbuff_t *next_tvb;
conversation_t *conv;
rtsp_conversation_data_t *data;
dissector_handle_t dissector;
orig_offset = offset;
rf_start = tvb_get_guint8(tvb, offset);
rf_chan = tvb_get_guint8(tvb, offset+1);
rf_len = tvb_get_ntohs(tvb, offset+2);
if (check_col(pinfo->cinfo, COL_INFO))
col_add_fstr(pinfo->cinfo, COL_INFO,
"Interleaved channel 0x%02x, %u bytes",
rf_chan, rf_len);
if (tree == NULL) {
/*
* We're not building a full protocol tree; all we care
* about is setting the column info.
*/
return -1;
}
ti = proto_tree_add_protocol_format(tree, proto_rtsp, tvb, offset, 4,
"RTSP Interleaved Frame, Channel: 0x%02x, %u bytes",
rf_chan, rf_len);
rtspframe_tree = proto_item_add_subtree(ti, ett_rtspframe);
proto_tree_add_text(rtspframe_tree, tvb, offset, 1,
"Magic: 0x%02x",
rf_start);
offset += 1;
proto_tree_add_text(rtspframe_tree, tvb, offset, 1,
"Channel: 0x%02x",
rf_chan);
offset += 1;
proto_tree_add_text(rtspframe_tree, tvb, offset, 2,
"Length: %u bytes",
rf_len);
offset += 2;
/*
* We set the actual length of the tvbuff for the interleaved
* stuff to the minimum of what's left in the tvbuff and the
* length in the header.
*
* XXX - what if there's nothing left in the tvbuff?
* We'd want a BoundsError exception to be thrown, so
* that a Short Frame would be reported.
*/
framelen = tvb_length_remaining(tvb, offset);
if (framelen > rf_len)
framelen = rf_len;
next_tvb = tvb_new_subset(tvb, offset, framelen, rf_len);
conv = find_conversation(&pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
if (conv &&
(data = conversation_get_proto_data(conv, proto_rtsp)) &&
rf_chan < RTSP_MAX_INTERLEAVED &&
(dissector = data->interleaved[rf_chan].dissector)) {
call_dissector(dissector, next_tvb, pinfo, tree);
} else {
proto_tree_add_text(rtspframe_tree, tvb, offset, rf_len,
"Data (%u bytes)", rf_len);
}
offset += rf_len;
return offset - orig_offset;
}
static void process_rtsp_request(tvbuff_t *tvb, int offset, const guchar *data,
size_t linelen, proto_tree *tree);
static void process_rtsp_reply(tvbuff_t *tvb, int offset, const guchar *data,
size_t linelen, proto_tree *tree);
typedef enum {
RTSP_REQUEST,
RTSP_REPLY,
NOT_RTSP
} rtsp_type_t;
static const char *rtsp_methods[] = {
"DESCRIBE", "ANNOUNCE", "GET_PARAMETER", "OPTIONS",
"PAUSE", "PLAY", "RECORD", "REDIRECT", "SETUP",
"SET_PARAMETER", "TEARDOWN"
};
#define RTSP_NMETHODS (sizeof rtsp_methods / sizeof rtsp_methods[0])
static rtsp_type_t
is_rtsp_request_or_reply(const guchar *line, size_t linelen)
{
unsigned ii;
/* Is this an RTSP reply? */
if (linelen >= 5 && strncasecmp("RTSP/", line, 5) == 0) {
/*
* Yes.
*/
return RTSP_REPLY;
}
/*
* Is this an RTSP request?
* Check whether the line begins with one of the RTSP request
* methods.
*/
for (ii = 0; ii < RTSP_NMETHODS; ii++) {
size_t len = strlen(rtsp_methods[ii]);
if (linelen >= len &&
strncasecmp(rtsp_methods[ii], line, len) == 0)
return RTSP_REQUEST;
}
return NOT_RTSP;
}
static const char rtsp_content_type[] = "Content-Type:";
static int
is_content_sdp(const guchar *line, size_t linelen)
{
static const char type[] = "application/sdp";
size_t typelen = STRLEN_CONST(type);
line += STRLEN_CONST(rtsp_content_type);
linelen -= STRLEN_CONST(rtsp_content_type);
while (linelen > 0 && (*line == ' ' || *line == '\t')) {
line++;
linelen--;
}
if (linelen < typelen || strncasecmp(type, line, typelen))
return FALSE;
line += typelen;
linelen -= typelen;
if (linelen > 0 && !isspace(*line))
return FALSE;
return TRUE;
}
static const char rtsp_transport[] = "Transport:";
static const char rtsp_sps[] = "server_port=";
static const char rtsp_cps[] = "client_port=";
static const char rtsp_rtp[] = "rtp/";
static const char rtsp_inter[] = "interleaved=";
static void
rtsp_create_conversation(packet_info *pinfo, const guchar *line_begin,
size_t line_len)
{
conversation_t *conv;
guchar buf[256];
guchar *tmp;
guint c_data_port, c_mon_port;
guint s_data_port, s_mon_port;
address null_addr;
if (line_len > sizeof(buf) - 1) {
/*
* Don't overflow the buffer.
*/
line_len = sizeof(buf) - 1;
}
memcpy(buf, line_begin, line_len);
buf[line_len] = '\0';
tmp = buf + STRLEN_CONST(rtsp_transport);
while (*tmp && isspace(*tmp))
tmp++;
if (strncasecmp(tmp, rtsp_rtp, strlen(rtsp_rtp)) != 0) {
g_warning("Frame %u: rtsp: unknown transport", pinfo->fd->num);
return;
}
c_data_port = c_mon_port = 0;
s_data_port = s_mon_port = 0;
if ((tmp = strstr(buf, rtsp_sps))) {
tmp += strlen(rtsp_sps);
if (sscanf(tmp, "%u-%u", &s_data_port, &s_mon_port) < 1) {
g_warning("Frame %u: rtsp: bad server_port",
pinfo->fd->num);
return;
}
}
if ((tmp = strstr(buf, rtsp_cps))) {
tmp += strlen(rtsp_cps);
if (sscanf(tmp, "%u-%u", &c_data_port, &c_mon_port) < 1) {
g_warning("Frame %u: rtsp: bad client_port",
pinfo->fd->num);
return;
}
}
if (!c_data_port) {
rtsp_conversation_data_t *data;
guint s_data_chan, s_mon_chan;
int i;
/*
* Deal with RTSP TCP-interleaved conversations.
*/
if ((tmp = strstr(buf, rtsp_inter)) == NULL) {
/*
* No interleaved or server_port - probably a
* SETUP request, rather than reply.
*/
return;
}
tmp += strlen(rtsp_inter);
i = sscanf(tmp, "%u-%u", &s_data_chan, &s_mon_chan);
if (i < 1) {
g_warning("Frame %u: rtsp: bad interleaved",
pinfo->fd->num);
return;
}
conv = find_conversation(&pinfo->src, &pinfo->dst, pinfo->ptype,
pinfo->srcport, pinfo->destport, 0);
if (!conv) {
conv = conversation_new(&pinfo->src, &pinfo->dst,
pinfo->ptype, pinfo->srcport, pinfo->destport,
0);
}
data = conversation_get_proto_data(conv, proto_rtsp);
if (!data) {
data = g_mem_chunk_alloc(rtsp_vals);
conversation_add_proto_data(conv, proto_rtsp, data);
}
if (s_data_chan < RTSP_MAX_INTERLEAVED) {
data->interleaved[s_data_chan].dissector =
rtp_handle;
}
if (i > 1 && s_mon_chan < RTSP_MAX_INTERLEAVED) {
data->interleaved[s_mon_chan].dissector =
rtcp_handle;
}
return;
}
/*
* We only want to match on the destination address, not the
* source address, because the server might send back a packet
* from an address other than the address to which its client
* sent the packet, so we construct a conversation with no
* second address.
*/
SET_ADDRESS(&null_addr, pinfo->src.type, 0, NULL);
conv = conversation_new(&pinfo->dst, &null_addr, PT_UDP, c_data_port,
s_data_port, NO_ADDR2 | (!s_data_port ? NO_PORT2 : 0));
conversation_set_dissector(conv, rtp_handle);
if (!c_mon_port)
return;
conv = conversation_new(&pinfo->dst, &null_addr, PT_UDP, c_mon_port,
s_mon_port, NO_ADDR2 | (!s_mon_port ? NO_PORT2 : 0));
conversation_set_dissector(conv, rtcp_handle);
}
static const char rtsp_content_length[] = "Content-Length:";
static int
rtsp_get_content_length(const guchar *line_begin, size_t line_len)
{
guchar buf[256];
guchar *tmp;
long content_length;
char *p;
guchar *up;
if (line_len > sizeof(buf) - 1) {
/*
* Don't overflow the buffer.
*/
line_len = sizeof(buf) - 1;
}
memcpy(buf, line_begin, line_len);
buf[line_len] = '\0';
tmp = buf + STRLEN_CONST(rtsp_content_length);
while (*tmp && isspace(*tmp))
tmp++;
content_length = strtol(tmp, &p, 10);
up = p;
if (up == tmp || (*up != '\0' && !isspace(*up)))
return -1; /* not a valid number */
return content_length;
}
static int
dissect_rtspmessage(tvbuff_t *tvb, int offset, packet_info *pinfo,
proto_tree *tree)
{
proto_tree *rtsp_tree;
proto_item *ti = NULL;
const guchar *line;
gint next_offset;
const guchar *linep, *lineend;
int orig_offset;
size_t linelen;
guchar c;
gboolean is_mime_header;
int is_sdp = FALSE;
int datalen;
int content_length;
int reported_datalen;
orig_offset = offset;
rtsp_tree = NULL;
if (tree) {
Allow a length of -1 to be specified when adding FT_NONE and FT_PROTOCOL items to the protocol tree; it's interpreted as "the rest of the data in the tvbuff". This can be used if 1) the item covers the entire packet or the remaining payload in the packet or 2) the item's length won't be known until it's dissected, and will be then set with "proto_item_set_len()" - if an exception is thrown in the dissection, it means the item ran *past* the end of the tvbuff, so saying it runs to the end of the tvbuff is reasonable. Convert a number of "proto_tree_add_XXX()" calls using "tvb_length_remaining()", values derived from the result of "tvb_length()", or 0 (in the case of items whose length is unknown) to use -1 instead (using 0 means that if an exception is thrown, selecting the item highlights nothing; using -1 means it highlights all the data for that item that's available). In some places where "tvb_length()" or "tvb_length_remaining()" was used to determine how large a packet is, use "tvb_reported_length()" or "tvb_reported_length_remaining()", instead - the first two calls indicate how much captured data was in the packet, the latter two calls indicate how large the packet actually was (and the fact that using the latter could cause BoundsError exceptions to be thrown is a feature - if such an exception is thrown, the frame really *was* short, and it should be tagged as such). Replace some "proto_tree_add_XXX()" calls with equivalent "proto_tree_add_item()" calls. Fix some indentation. svn path=/trunk/; revision=4578
2002-01-20 22:12:39 +00:00
ti = proto_tree_add_item(tree, proto_rtsp, tvb, offset, -1,
FALSE);
rtsp_tree = proto_item_add_subtree(ti, ett_rtsp);
}
if (check_col(pinfo->cinfo, COL_INFO)) {
/*
* Put the first line from the buffer into the summary
* if it's an RTSP request or reply (but leave out the
* line terminator).
* Otherwise, just call it a continuation.
*/
linelen = tvb_find_line_end(tvb, offset, -1, &next_offset,
FALSE);
line = tvb_get_ptr(tvb, offset, linelen);
switch (is_rtsp_request_or_reply(line, linelen)) {
case RTSP_REQUEST:
case RTSP_REPLY:
col_add_str(pinfo->cinfo, COL_INFO,
format_text(line, linelen));
break;
default:
col_set_str(pinfo->cinfo, COL_INFO, "Continuation");
break;
}
}
/*
* We haven't yet seen a Content-Length header.
*/
content_length = -1;
/*
* Process the packet data, a line at a time.
*/
while (tvb_offset_exists(tvb, offset)) {
/*
* We haven't yet concluded that this is a MIME header.
*/
is_mime_header = FALSE;
/*
* Find the end of the line.
*/
linelen = tvb_find_line_end(tvb, offset, -1, &next_offset,
FALSE);
/*
* Get a buffer that refers to the line.
*/
line = tvb_get_ptr(tvb, offset, linelen);
lineend = line + linelen;
/*
* OK, does it look like an RTSP request or
* response?
*/
switch (is_rtsp_request_or_reply(line, linelen)) {
case RTSP_REQUEST:
if (rtsp_tree != NULL)
process_rtsp_request(tvb, offset, line, linelen,
rtsp_tree);
goto is_rtsp;
case RTSP_REPLY:
if (rtsp_tree != NULL)
process_rtsp_reply(tvb, offset, line, linelen,
rtsp_tree);
goto is_rtsp;
case NOT_RTSP:
break;
}
/*
* No. Does it look like a blank line (as would
* appear at the end of an RTSP request)?
*/
if (linelen == 0)
goto is_rtsp; /* Yes. */
/*
* No. Does it look like a MIME header?
*/
linep = line;
while (linep < lineend) {
c = *linep++;
if (!isprint(c))
break; /* not printable, not a MIME header */
switch (c) {
case '(':
case ')':
case '<':
case '>':
case '@':
case ',':
case ';':
case '\\':
case '"':
case '/':
case '[':
case ']':
case '?':
case '=':
case '{':
case '}':
/*
* It's a tspecial, so it's not
* part of a token, so it's not
* a field name for the beginning
* of a MIME header.
*/
goto not_rtsp;
case ':':
/*
* This ends the token; we consider
* this to be a MIME header.
*/
is_mime_header = TRUE;
goto is_rtsp;
case ' ':
case '\t':
/*
* LWS (RFC-2616, 4.2); continue the previous
* header.
*/
goto is_rtsp;
}
}
not_rtsp:
/*
* We don't consider this part of an RTSP request or
* reply, so we don't display it.
*/
break;
is_rtsp:
/*
* Put this line.
*/
if (rtsp_tree) {
proto_tree_add_text(rtsp_tree, tvb, offset,
next_offset - offset, "%s",
tvb_format_text(tvb, offset, next_offset - offset));
}
if (is_mime_header) {
/*
* Process some MIME headers specially.
*/
#define MIME_HDR_MATCHES(header) \
(linelen > STRLEN_CONST(header) && \
strncasecmp(line, (header), STRLEN_CONST(header)) == 0)
if (MIME_HDR_MATCHES(rtsp_transport)) {
/*
* Based on the port numbers specified
* in the Transport: header, set up
* a conversation that will be dissected
* with the appropriate dissector.
*/
rtsp_create_conversation(pinfo, line, linelen);
} else if (MIME_HDR_MATCHES(rtsp_content_type)) {
/*
* If the Content-Type: header says this
* is SDP, dissect the payload as SDP.
*/
if (is_content_sdp(line, linelen))
is_sdp = TRUE;
} else if (MIME_HDR_MATCHES(rtsp_content_length)) {
/*
* Only the amount specified by the
* Content-Length: header should be treated
* as payload.
*/
content_length = rtsp_get_content_length(line,
linelen);
}
}
offset = next_offset;
}
/*
* If a content length was supplied, the amount of data to be
* processed as RTSP payload is the minimum of the content
* length and the amount of data remaining in the frame.
*
* If no content length was supplied, the amount of data to be
* processed is the amount of data remaining in the frame.
*/
datalen = tvb_length_remaining(tvb, offset);
if (content_length != -1) {
if (datalen > content_length)
datalen = content_length;
/*
* XXX - for now, if the content length is greater
* than the amount of data left in this frame (not
* the amount of *captured* data left in the frame
* minus the current offset, but the amount of *actual*
* data that was reported to be in the frame minus
* the current offset), limit it to the amount
* of data left in this frame.
*
* If we ever handle data that crosses frame
* boundaries, we'll need to remember the actual
* content length.
*/
reported_datalen = tvb_reported_length_remaining(tvb, offset);
if (content_length > reported_datalen)
content_length = reported_datalen;
}
if (datalen > 0) {
/*
* There's stuff left over; process it.
*/
if (is_sdp) {
tvbuff_t *new_tvb;
/*
* Fix up the top-level item so that it doesn't
* include the SDP stuff.
*/
if (ti != NULL)
proto_item_set_len(ti, offset);
/*
* Now create a tvbuff for the SDP stuff and
* dissect it.
*
* The amount of data to be processed that's
* available in the tvbuff is "datalen", which
* is the minimum of the amount of data left in
* the tvbuff and any specified content length.
*
* The amount of data to be processed that's in
* this frame, regardless of whether it was
* captured or not, is "content_length",
* which, if no content length was specified,
* is -1, i.e. "to the end of the frame.
*/
new_tvb = tvb_new_subset(tvb, offset, datalen,
content_length);
Add a mechanism by which a dissector can be registered by name, another dissector can get a "handle" for that dissector by name and then call that dissector through the handle. This allows dissectors that can't be called through a port table or a heuristic table to be called from other dissectors without directly referring to the dissector function - dynamically-loaded modules, under Windows, cannot directly call functions in the main program, and non-plugin dissectors are in the main program and thus cannot be called from plugin dissectors unless either 1) a pointer to the dissector is put in the Big Transfer Vector or 2) some other mechanism for getting a pointer to the dissector is provided. This mechanism could also support registering old-style dissectors and calling them from new-style dissectors without the new-style dissector having to do the argument translation itself (I didn't add support for registering old-style dissectors because I'd prefer to have people tvbuffify their code if they have to register a dissector...). It could also, in the future, perhaps support disabling of protocols; setting "pinfo->current_proto"; inside "call_dissector()" - and inside "{old_}dissector_try_port()" and "{old_"dissector_try_heuristic()" - allowing a pile of stuff that currently has to be done in every dissector be done by common code. (I have some ideas about how to do this, by having "proto_register_protocol()" take an abbreviation - of the sort that would be put in, for example, "pinfo->current_proto" - as an argument; having the calls to register dissectors take an index returned by "proto_register_protocol()" as an argument. The abbreviation could be used elsewhere as well, e.g. in the "Decoding" tab of the "Edit->Protocols" dialog box, and in a GUI for constructing protocol filters. Watch this space.) Make "dissect_sdp()" the first client of this mechanism; it's now static to "packet-sdp.c", and all dissectors that call it - including the MGCP plugin - now call it through a dissector handle fetched by "find_dissector()". (Next step - see if Ethereal can now compile on Windows as a result of this.) svn path=/trunk/; revision=2647
2000-11-15 07:07:52 +00:00
call_dissector(sdp_handle, new_tvb, pinfo, tree);
} else {
if (tvb_get_guint8(tvb, offset) == RTSP_FRAMEHDR) {
/*
* This is interleaved stuff; don't
* treat it as raw data - set "datalen"
* to 0, so we won't skip the offset
* past it, which will cause our
* caller to process that stuff itself.
*/
datalen = 0;
} else {
proto_tree_add_text(rtsp_tree, tvb, offset,
datalen, "Data (%d bytes)", datalen);
}
}
/*
* We've processed "datalen" bytes worth of data
* (which may be no data at all); advance the
* offset past whatever data we've processed, so they
* don't process it.
*/
offset += datalen;
}
return offset - orig_offset;
}
static void
process_rtsp_request(tvbuff_t *tvb, int offset, const guchar *data,
size_t linelen, proto_tree *tree)
{
const guchar *lineend = data + linelen;
unsigned ii;
const guchar *url;
const guchar *url_start;
guchar *tmp_url;
/* Request Methods */
for (ii = 0; ii < RTSP_NMETHODS; ii++) {
size_t len = strlen(rtsp_methods[ii]);
if (linelen >= len && !strncasecmp(rtsp_methods[ii], data, len))
break;
}
if (ii == RTSP_NMETHODS) {
/*
* We got here because "is_rtsp_request_or_reply()" returned
* RTSP_REQUEST, so we know one of the request methods
* matched, so we "can't get here".
*/
g_assert_not_reached();
}
/* Method name */
proto_tree_add_string_hidden(tree, hf_rtsp_method, tvb, offset,
strlen(rtsp_methods[ii]), rtsp_methods[ii]);
/* URL */
url = data;
while (url < lineend && !isspace(*url))
url++;
while (url < lineend && isspace(*url))
url++;
url_start = url;
while (url < lineend && !isspace(*url))
url++;
tmp_url = g_malloc(url - url_start + 1);
memcpy(tmp_url, url_start, url - url_start);
tmp_url[url - url_start] = 0;
proto_tree_add_string_hidden(tree, hf_rtsp_url, tvb,
offset + (url_start - data), url - url_start, tmp_url);
g_free(tmp_url);
}
static void
process_rtsp_reply(tvbuff_t *tvb, int offset, const guchar *data,
size_t linelen, proto_tree *tree)
{
const guchar *lineend = data + linelen;
const guchar *status = data;
const guchar *status_start;
unsigned int status_i;
/* status code */
while (status < lineend && !isspace(*status))
status++;
while (status < lineend && isspace(*status))
status++;
status_start = status;
status_i = 0;
while (status < lineend && isdigit(*status))
status_i = status_i * 10 + *status++ - '0';
proto_tree_add_uint_hidden(tree, hf_rtsp_status, tvb,
offset + (status_start - data),
status - status_start, status_i);
}
static void
dissect_rtsp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset = 0;
int len;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RTSP");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
while (tvb_offset_exists(tvb, offset)) {
len = (tvb_get_guint8(tvb, offset) == RTSP_FRAMEHDR)
? dissect_rtspinterleaved(tvb, offset, pinfo, tree)
: dissect_rtspmessage(tvb, offset, pinfo, tree);
if (len == -1)
break;
offset += len;
/*
* OK, we've set the Protocol and Info columns for the
* first RTSP message; make the columns non-writable,
* so that we don't change it for subsequent RTSP messages.
*/
col_set_writable(pinfo->cinfo, FALSE);
}
}
static void
rtsp_init(void)
{
/* Routine to initialize rtsp protocol before each capture or filter pass. */
/* Release any memory if needed. Then setup the memory chunks. */
if (rtsp_vals)
g_mem_chunk_destroy(rtsp_vals);
rtsp_vals = g_mem_chunk_new("rtsp_vals",
sizeof(rtsp_conversation_data_t),
rtsp_hash_init_count * sizeof(rtsp_conversation_data_t),
G_ALLOC_AND_FREE);
}
void
proto_register_rtsp(void)
{
static gint *ett[] = {
&ett_rtspframe,
&ett_rtsp,
};
static hf_register_info hf[] = {
{ &hf_rtsp_method,
{ "Method", "rtsp.method", FT_STRING, BASE_NONE, NULL, 0, "", HFILL }},
{ &hf_rtsp_url,
{ "URL", "rtsp.url", FT_STRING, BASE_NONE, NULL, 0, "", HFILL }},
{ &hf_rtsp_status,
{ "Status", "rtsp.status", FT_UINT32, BASE_DEC, NULL, 0, "", HFILL }},
};
proto_rtsp = proto_register_protocol("Real Time Streaming Protocol",
"RTSP", "rtsp");
proto_register_field_array(proto_rtsp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_init_routine(rtsp_init); /* register re-init routine */
}
void
proto_reg_handoff_rtsp(void)
{
dissector_handle_t rtsp_handle;
rtsp_handle = create_dissector_handle(dissect_rtsp, proto_rtsp);
dissector_add("tcp.port", TCP_PORT_RTSP, rtsp_handle);
Add a mechanism by which a dissector can be registered by name, another dissector can get a "handle" for that dissector by name and then call that dissector through the handle. This allows dissectors that can't be called through a port table or a heuristic table to be called from other dissectors without directly referring to the dissector function - dynamically-loaded modules, under Windows, cannot directly call functions in the main program, and non-plugin dissectors are in the main program and thus cannot be called from plugin dissectors unless either 1) a pointer to the dissector is put in the Big Transfer Vector or 2) some other mechanism for getting a pointer to the dissector is provided. This mechanism could also support registering old-style dissectors and calling them from new-style dissectors without the new-style dissector having to do the argument translation itself (I didn't add support for registering old-style dissectors because I'd prefer to have people tvbuffify their code if they have to register a dissector...). It could also, in the future, perhaps support disabling of protocols; setting "pinfo->current_proto"; inside "call_dissector()" - and inside "{old_}dissector_try_port()" and "{old_"dissector_try_heuristic()" - allowing a pile of stuff that currently has to be done in every dissector be done by common code. (I have some ideas about how to do this, by having "proto_register_protocol()" take an abbreviation - of the sort that would be put in, for example, "pinfo->current_proto" - as an argument; having the calls to register dissectors take an index returned by "proto_register_protocol()" as an argument. The abbreviation could be used elsewhere as well, e.g. in the "Decoding" tab of the "Edit->Protocols" dialog box, and in a GUI for constructing protocol filters. Watch this space.) Make "dissect_sdp()" the first client of this mechanism; it's now static to "packet-sdp.c", and all dissectors that call it - including the MGCP plugin - now call it through a dissector handle fetched by "find_dissector()". (Next step - see if Ethereal can now compile on Windows as a result of this.) svn path=/trunk/; revision=2647
2000-11-15 07:07:52 +00:00
sdp_handle = find_dissector("sdp");
rtp_handle = find_dissector("rtp");
rtcp_handle = find_dissector("rtcp");
}