/*
* This file is part of the Sofia-SIP package
*
* Copyright (C) 2005 Nokia Corporation.
*
* Contact: Pekka Pessi <pekka.pessi@nokia.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
/**@ingroup sdp_parser
* @CFILE sdp_parse.c
* @brief Simple SDP parser interface.
*
* @author Pekka Pessi <Pekka.Pessi@nokia.com>
* @author Kai Vehmanen <kai.vehmanen@nokia.com>
*
* @date Created: Fri Feb 18 10:25:08 2000 ppessi
*
* @sa @RFC4566, @RFC2327.
*/
#include "config.h"
#include <sofia-sip/su_alloc.h>
#include <sofia-sip/su_string.h>
#include "sofia-sip/sdp.h"
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <limits.h>
#include <assert.h>
/** @typedef struct sdp_parser_s sdp_parser_t;
*
* SDP parser handle.
*
* The SDP parser handle returned by sdp_parse() contains either
* a successfully parsed SDP session #sdp_session_t or an error message.
* If sdp_session() returns non-NULL, parsing was successful.
*
* @sa #sdp_session_t, sdp_parse(), sdp_session(), sdp_parsing_error(),
* sdp_sanity_check(), sdp_parser_home(), sdp_parser_free(), @RFC4566,
* @RFC2327.
*/
struct sdp_parser_s {
su_home_t pr_home[1];
union {
char pru_error[128];
sdp_session_t pru_session[1];
} pr_output;
char *pr_message;
sdp_mode_t pr_session_mode;
unsigned pr_ok : 1;
unsigned pr_strict : 1;
unsigned pr_anynet : 1;
unsigned pr_mode_0000 : 1;
unsigned pr_mode_manual : 1;
unsigned pr_insane : 1;
unsigned pr_c_missing : 1;
unsigned pr_config : 1;
};
#define is_posdigit(c) ((c) >= '1' && (c) <= '9')
#define is_digit(c) ((c) >= '0' && (c) <= '9')
#define is_space(c) ((c) == ' ')
#define is_tab(c) ((c) == '\t')
#define pr_error pr_output.pru_error
#define pr_session pr_output.pru_session
#ifdef _MSC_VER
#undef STRICT
#endif
#define STRICT(pr) (pr->pr_strict)
/* Static parser object used when running out of memory */
static const struct sdp_parser_s no_mem_error =
{
{ SU_HOME_INIT(no_mem_error) },
{ "sdp: not enough memory" }
};
/* Internal prototypes */
static void parse_message(sdp_parser_t *p);
static int parsing_error(sdp_parser_t *p, char const *fmt, ...);
/** Parse an SDP message.
*
* The function sdp_parse() parses an SDP message @a msg of size @a
* msgsize. Parsing is done according to the given @a flags. The SDP message
* may not contain a NUL.
*
* The parsing result is stored to an #sdp_session_t structure.
*
* @param home memory home
* @param msg pointer to message
* @param msgsize size of the message (excluding final NUL, if any)
* @param flags flags affecting the parsing.
*
* The following flags are used by parser:
*
* @li #sdp_f_strict Parser should accept only messages conforming strictly
* to the specification.
* @li #sdp_f_anynet Parser accepts unknown network or address types.
* @li #sdp_f_insane Do not run sanity check.
* @li #sdp_f_c_missing Sanity check does not require c= for each m= line
* @li #sdp_f_mode_0000 Parser regards "c=IN IP4 0.0.0.0" as "a=inactive"
* (likewise with c=IN IP6 ::)
* @li #sdp_f_mode_manual Do not generate or parse SDP mode
* @li #sdp_f_config Parse config files (any line can be missing)
*
* @return
* Always a valid parser handle.
*
* @todo Parser accepts some non-conforming SDP even with #sdp_f_strict.
*
* @sa sdp_session(), sdp_parsing_error(), sdp_sanity_check(),
* sdp_parser_home(), sdp_parser_free(), @RFC4566, @RFC2327.
*/
sdp_parser_t *
sdp_parse(su_home_t *home, char const msg[], issize_t msgsize, int flags)
{
sdp_parser_t *p;
char *b;
size_t len;
if (msgsize == -1 || msg == NULL) {
p = su_home_clone(home, sizeof(*p));
if (p)
parsing_error(p, "invalid input message");
else
p = (sdp_parser_t*)&no_mem_error;
return p;
}
if (msgsize == -1 && msg)
len = strlen(msg);
else
len = msgsize;
if (len > ISSIZE_MAX)
len = ISSIZE_MAX;
p = su_home_clone(home, sizeof(*p) + len + 1);
if (p) {
b = strncpy((void *)(p + 1), msg, len);
b[len] = 0;
p->pr_message = b;
p->pr_strict = (flags & sdp_f_strict) != 0;
p->pr_anynet = (flags & sdp_f_anynet) != 0;
p->pr_mode_0000 = (flags & sdp_f_mode_0000) != 0;
p->pr_insane = (flags & sdp_f_insane) != 0;
p->pr_c_missing = (flags & sdp_f_c_missing) != 0;
if (flags & sdp_f_config)
p->pr_c_missing = 1, p->pr_config = 1;
p->pr_mode_manual = (flags & sdp_f_mode_manual) != 0;
p->pr_session_mode = sdp_sendrecv;
parse_message(p);
return p;
}
if (p)
sdp_parser_free(p);
return (sdp_parser_t*)&no_mem_error;
}
/** Obtain memory home used by parser */
su_home_t *sdp_parser_home(sdp_parser_t *parser)
{
if (parser != &no_mem_error)
return parser->pr_home;
else
return NULL;
}
/** Retrieve an SDP session structure.
*
* The function sdp_session() returns a pointer to the SDP session
* structure associated with the SDP parser @a p. The pointer and all the
* data in the structure are valid until sdp_parser_free() is called.
*
* @param p SDP parser
*
* @return
* The function sdp_session() returns a pointer to an parsed SDP message
* or NULL, if an error has occurred. */
sdp_session_t *
sdp_session(sdp_parser_t *p)
{
return p && p->pr_ok ? p->pr_session : NULL;
}
/** Get a parsing error message.
*
* The function sdp_parsing_error() returns the error message associated
* with an SDP parser @a p.
*
* @param p SDP parser
*
* @return
* The function sdp_parsing_error() returns a C string describing parsing
* error, or NULL if no error occurred.
*/
char const *sdp_parsing_error(sdp_parser_t *p)
{
return !p->pr_ok ? p->pr_error : NULL;
}
/** Free an SDP parser.
*
* The function sdp_parser_free() frees an SDP parser object along with
* the memory blocks associated with it.
*
* @param p pointer to the SDP parser to be freed
*/
void sdp_parser_free(sdp_parser_t *p)
{
if (p && p != &no_mem_error)
su_home_unref(p->pr_home);
}
/* ========================================================================= */
/* =========================================================================
* Private part
*/
/* Parsing tokens */
#define SPACE " "
#define TAB "\011"
#define CRLF "\015\012"
#define ALPHA "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define DIGIT "0123456789"
#define TOKEN ALPHA DIGIT "-!#$%&'*+.^_`{|}~"
/* ========================================================================= */
/* Parsing functions */
static void post_session(sdp_parser_t *p, sdp_session_t *sdp);
static void parse_origin(sdp_parser_t *p, char *r, sdp_origin_t **result);
static void parse_subject(sdp_parser_t *p, char *r, sdp_text_t **result);
static void parse_information(sdp_parser_t *p, char *r, sdp_text_t **result);
static void parse_uri(sdp_parser_t *p, char *r, sdp_text_t **result);
static void parse_email(sdp_parser_t *p, char *r, sdp_list_t **result);
static void parse_phone(sdp_parser_t *p, char *r, sdp_list_t **result);
static void parse_connection(sdp_parser_t *p, char *r, sdp_connection_t **result);
static void parse_bandwidth(sdp_parser_t *p, char *r, sdp_bandwidth_t **result);
static void parse_time(sdp_parser_t *p, char *r, sdp_time_t **result);
static void parse_repeat(sdp_parser_t *p, char *r, sdp_repeat_t **result);
static void parse_zone(sdp_parser_t *p, char *r, sdp_zone_t **result);
static void parse_key(sdp_parser_t *p, char *r, sdp_key_t **result);
static void parse_session_attr(sdp_parser_t *p, char *r, sdp_attribute_t **result);
static void parse_media(sdp_parser_t *p, char *r, sdp_media_t **result);
static void parse_payload(sdp_parser_t *p, char *r, sdp_rtpmap_t **result);
static void parse_media_attr(sdp_parser_t *p, char *r, sdp_media_t *m,
sdp_attribute_t **result);
static int parse_rtpmap(sdp_parser_t *p, char *r, sdp_media_t *m);
static int parse_fmtp(sdp_parser_t *p, char *r, sdp_media_t *m);
static void parse_text_list(sdp_parser_t *p, char *r, sdp_list_t **result);
static void parse_descs(sdp_parser_t *p, char *r, char *m, sdp_media_t **result);
static int parse_ul(sdp_parser_t *p, char **r, unsigned long *result,
unsigned long max_value);
static int parse_ull(sdp_parser_t *p, char **r, uint64_t *result,
uint64_t max_value);
static void parse_alloc_error(sdp_parser_t *p, const char *typename);
static char *next(char **message, const char *sep, const char *strip);
static char *token(char **message, const char *sep, const char *legal,
const char *strip);
#if 0
static void check_mandatory(sdp_parser_t *p, sdp_session_t *sdp);
#endif
/* -------------------------------------------------------------------------
* Macro PARSE_ALLOC
*
* Description:
* This macro declares a pointer (v) of given type (t). It then allocates
* an structure of given type (t). If allocation was succesful, it assigns
* the XX_size member with appropriate value.
*/
#define PARSE_ALLOC(p, t, v) \
t *v = su_salloc(p->pr_home, sizeof(*v)); \
if (!v && (parse_alloc_error(p, #t), 1)) return;
/* -------------------------------------------------------------------------
* Macro PARSE_CHECK_REST
*
* Description:
* This macro check if there is extra data at the end of field.
*/
#define PARSE_CHECK_REST(p, s, n)\
if (*s && (parsing_error(p, "extra data after %s (\"%.04s\")", n, s), 1)) \
return
/* -------------------------------------------------------------------------
* Function parse_message() - parse an SDP message
*
* Description:
* This function parses an SDP message, which is copied into the
* p->pr_message. The p->pr_message is modified during the parsing,
* and parts of it are returned in p->pr_session.
*
* Parameters:
* p - pointer to SDP parser object
*/
static void parse_message(sdp_parser_t *p)
{
/*
announcement = proto-version
origin-field
session-name-field
information-field
uri-field
email-fields
phone-fields
connection-field
bandwidth-fields
time-fields
key-field
attribute-fields
media-descriptions
*/
sdp_session_t *sdp = p->pr_session;
char *record, *rest;
char const *strip;
char *message = p->pr_message;
char field = '\0';
sdp_list_t **emails = &sdp->sdp_emails;
sdp_list_t **phones = &sdp->sdp_phones;
sdp_bandwidth_t **bandwidths = &sdp->sdp_bandwidths;
sdp_time_t **times = &sdp->sdp_time;
sdp_repeat_t **repeats = NULL;
sdp_zone_t **zones = NULL;
sdp_attribute_t **attributes = &sdp->sdp_attributes;
if (!STRICT(p))
strip = SPACE TAB; /* skip initial whitespace */
else
strip = "";
p->pr_ok = 1;
p->pr_session->sdp_size = sizeof(p->pr_session);
/* Require that version comes first */
record = next(&message, CRLF, strip);
if (!su_strmatch(record, "v=0")) {
if (!p->pr_config || !record || record[1] != '=') {
parsing_error(p, "bad SDP message");
return;
}
}
else {
record = next(&message, CRLF, strip);
}
/*
XXX - the lines in SDP are in certain order, which we don't check here.
For stricter parsing we might want to parse o= and s= next.
*/
for (;
record && p->pr_ok;
record = next(&message, CRLF, strip)) {
field = record[0];
rest = record + 2; rest += strspn(rest, strip);
if (record[1] != '=') {
parsing_error(p, "bad line \"%s\"", record);
return;
}
switch (field) {
case 'o':
parse_origin(p, rest, &sdp->sdp_origin);
break;
case 's':
parse_subject(p, rest, &sdp->sdp_subject);
break;
case 'i':
parse_information(p, rest, &sdp->sdp_information);
break;
case 'u':
parse_uri(p, rest, &sdp->sdp_uri);
break;
case 'e':
parse_email(p, rest, emails);
emails = &(*emails)->l_next;
break;
case 'p':
parse_phone(p, rest, phones);
phones = &(*phones)->l_next;
break;
case 'c':
parse_connection(p, rest, &sdp->sdp_connection);
break;
case 'b':
parse_bandwidth(p, rest, bandwidths);
bandwidths = &(*bandwidths)->b_next;
break;
case 't':
parse_time(p, rest, times);
repeats = &(*times)->t_repeat;
zones = &(*times)->t_zone;
times = &(*times)->t_next;
break;
case 'r':
if (repeats)
parse_repeat(p, rest, repeats);
else
parsing_error(p, "repeat field without time field");
break;
case 'z':
if (zones)
parse_zone(p, rest, zones), zones = NULL;
else
parsing_error(p, "zone field without time field");
break;
case 'k':
parse_key(p, rest, &sdp->sdp_key);
break;
case 'a':
parse_session_attr(p, rest, attributes);
if (*attributes)
attributes = &(*attributes)->a_next;
break;
case 'm':
parse_descs(p, record, message, &sdp->sdp_media);
post_session(p, sdp);
return;
default:
parsing_error(p, "unknown field \"%s\"", record);
return;
}
}
post_session(p, sdp);
}
int sdp_connection_is_inaddr_any(sdp_connection_t const *c)
{
return
c &&
c->c_nettype == sdp_net_in &&
((c->c_addrtype == sdp_addr_ip4 && su_strmatch(c->c_address, "0.0.0.0")) ||
(c->c_addrtype == sdp_addr_ip6 && su_strmatch(c->c_address, "::")));
}
/**Postprocess session description.
*
* Postprocessing includes setting the session backpointer for each media,
* doing sanity checks and setting rejected and mode flags.
*/
static void post_session(sdp_parser_t *p, sdp_session_t *sdp)
{
sdp_media_t *m;
sdp_connection_t const *c;
if (!p->pr_ok)
return;
/* Set session back-pointer */
for (m = sdp->sdp_media; m; m = m->m_next) {
m->m_session = sdp;
}
if (p->pr_config) {
if (sdp->sdp_version[0] != 0)
parsing_error(p, "Incorrect version");
return;
}
/* Go through all media and set mode */
for (m = sdp->sdp_media; m; m = m->m_next) {
if (m->m_port == 0) {
m->m_mode = sdp_inactive;
m->m_rejected = 1;
continue;
}
c = sdp_media_connections(m);
if (p->pr_mode_0000 && sdp_connection_is_inaddr_any(c)) {
/* Reset recvonly flag */
m->m_mode &= ~sdp_recvonly;
}
}
if (p->pr_insane)
return;
/* Verify that all mandatory fields are present */
if (sdp_sanity_check(p) < 0)
return;
}
/** Validates that all mandatory fields exist
*
* Checks that all necessary fields (v=, o=) exists in the parsed sdp. If
* strict, check that all mandatory fields (c=, o=, s=, t=) are present.
* This function also goes through all media, marks rejected media as such,
* and updates the mode accordingly.
*
* @retval 0 if parsed SDP description is valid
* @retval -1 if some SDP line is missing
* @retval -2 if c= line is missing
*/
int sdp_sanity_check(sdp_parser_t *p)
{
sdp_session_t *sdp = p->pr_session;
sdp_media_t *m;
if (!p || !p->pr_ok)
return -1;
else if (sdp->sdp_version[0] != 0)
return parsing_error(p, "Incorrect version");
else if (!sdp->sdp_origin)
return parsing_error(p, "No o= present");
else if (p->pr_strict && !sdp->sdp_subject)
return parsing_error(p, "No s= present");
else if (p->pr_strict && !sdp->sdp_time)
return parsing_error(p, "No t= present");
/* If there is no session level c= check that one exists for all media */
/* c= line may be missing if this is a RTSP description */
if (!p->pr_c_missing && !sdp->sdp_connection) {
for (m = sdp->sdp_media ; m ; m = m->m_next) {
if (!m->m_connections && !m->m_rejected) {
parsing_error(p, "No c= on either session level or all mediums");
return -2;
}
}
}
return 0;
}
#if 0
/**
* Parse a "v=" field
*
* The function parser_version() parses the SDP version field.
*
* @param p pointer to SDP parser object
* @param r pointer to record data
* @param result pointer to which parsed record is assigned
*/
static void parse_version(sdp_parser_t *p, char *r, sdp_version_t *result)
{
/*
proto-version = "v=" 1*DIGIT CRLF
;[RFC2327] describes version 0
*/
if (parse_ul(p, &r, result, 0))
parsing_error(p, "version \"%s\" is invalid", r);
else if (*result > 0)
parsing_error(p, "unknown version v=%s", r);
}
#endif
/* -------------------------------------------------------------------------
* Function parse_origin() - parse an "o=" field
*
* Description:
* This function parses an SDP origin field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_origin(sdp_parser_t *p, char *r, sdp_origin_t **result)
{
/*
origin-field = "o=" username space
sess-id space sess-version space
nettype space addrtype space
addr CRLF
username = safe
;pretty wide definition, but doesn't include space
sess-id = 1*(DIGIT)
;should be unique for this originating username/host
sess-version = 1*(DIGIT)
;0 is a new session
*/
PARSE_ALLOC(p, sdp_origin_t, o);
*result = o;
o->o_username = token(&r, SPACE TAB, NULL, SPACE TAB);
if (!o->o_username) {
parsing_error(p, "invalid username");
return;
}
if (parse_ull(p, &r, &o->o_id, 0)) {
parsing_error(p, "invalid session id");
return;
}
if (parse_ull(p, &r, &o->o_version, 0)) {
parsing_error(p, "invalid session version");
return;
}
parse_connection(p, r, &o->o_address);
}
/* -------------------------------------------------------------------------
* Function parse_subject() - parse an "s=" field
*
* Description:
* This function parses an SDP subject field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_subject(sdp_parser_t *p, char *r, sdp_text_t **result)
{
/*
session-name-field = "s=" text CRLF
text = byte-string
*/
*result = r;
}
/* -------------------------------------------------------------------------
* Function parse_information() - parse an "i=" field
*
* Description:
* This function parses an SDP information field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_information(sdp_parser_t *p, char *r, sdp_text_t **result)
{
/*
information-field = ["i=" text CRLF]
*/
*result = r;
}
/* -------------------------------------------------------------------------
* Function parse_uri() - parse an "u=" field
*
* Description:
* This function parses an SDP URI field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_uri(sdp_parser_t *p, char *r, sdp_text_t **result)
{
/*
uri-field = ["u=" uri CRLF]
uri= ;defined in RFC1630
*/
/* XXX - no syntax checking here */
*result = r;
}
/* -------------------------------------------------------------------------
* Function parse_email() - parse an "e=" field
*
* Description:
* This function parses an SDP email field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_email(sdp_parser_t *p, char *r, sdp_list_t **result)
{
/*
email-fields = *("e=" email-address CRLF)
email-address = email | email "(" email-safe ")" |
email-safe "<" email ">"
email = ;defined in RFC822 */
parse_text_list(p, r, result);
}
/* -------------------------------------------------------------------------
* Function parse_phone() - parse an "p=" field
*
* Description:
* This function parses an SDP phone field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_phone(sdp_parser_t *p, char *r, sdp_list_t **result)
{
/*
phone-fields = *("p=" phone-number CRLF)
phone-number = phone | phone "(" email-safe ")" |
email-safe "<" phone ">"
phone = "+" POS-DIGIT 1*(space | "-" | DIGIT)
;there must be a space or hyphen between the
;international code and the rest of the number.
*/
parse_text_list(p, r, result);
}
/* -------------------------------------------------------------------------
* Function parse_connection() - parse an "c=" field
*
* Description:
* This function parses an SDP connection field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_connection(sdp_parser_t *p, char *r, sdp_connection_t **result)
{
/*
connection-field = ["c=" nettype space addrtype space
connection-address CRLF]
;a connection field must be present
;in every media description or at the
;session-level
nettype = "IN"
;list to be extended
addrtype = "IP4" | "IP6"
;list to be extended
connection-address = multicast-address
| addr
multicast-address = 3*(decimal-uchar ".") decimal-uchar "/" ttl
[ "/" integer ]
;multicast addresses may be in the range
;224.0.0.0 to 239.255.255.255
ttl = decimal-uchar
addr = FQDN | unicast-address
FQDN = 4*(alpha-numeric|"-"|".")
;fully qualified domain name as specified in RFC1035
unicast-address = IP4-address | IP6-address
IP4-address = b1 "." decimal-uchar "." decimal-uchar "." b4
b1 = decimal-uchar
;less than "224"; not "0" or "127"
b4 = decimal-uchar
;not "0"
IP6-address = ;to be defined
*/
PARSE_ALLOC(p, sdp_connection_t, c);
*result = c;
if (su_casenmatch(r, "IN", 2)) {
char *s;
/* nettype is internet */
c->c_nettype = sdp_net_in;
s = token(&r, SPACE TAB, NULL, NULL);
/* addrtype */
s = token(&r, SPACE TAB, NULL, NULL);
if (su_casematch(s, "IP4"))
c->c_addrtype = sdp_addr_ip4;
else if (su_casematch(s, "IP6"))
c->c_addrtype = sdp_addr_ip6;
else {
parsing_error(p, "unknown IN address type: %s", s);
return;
}
/* address */
s = next(&r, SPACE TAB, SPACE TAB);
c->c_address = s;
if (!s || !*s) {
parsing_error(p, "invalid address");
return;
}
/* ttl */
s = strchr(s, '/');
if (s) {
unsigned long value;
*s++ = 0;
if (parse_ul(p, &s, &value, 256) ||
(*s && *s != '/')) {
parsing_error(p, "invalid ttl");
return;
}
c->c_ttl = value;
c->c_mcast = 1;
/* multiple groups */
value = 1;
if (*s++ == '/')
if (parse_ul(p, &s, &value, 0) || *s) {
parsing_error(p, "invalid number of multicast groups");
return;
}
c->c_groups = value;
}
else
c->c_groups = 1;
}
else if (p->pr_anynet) {
c->c_nettype = sdp_net_x;
c->c_addrtype = sdp_addr_x;
c->c_address = r;
c->c_ttl = 0;
c->c_groups = 1;
}
else
parsing_error(p, "invalid address");
}
/* -------------------------------------------------------------------------
* Function parse_bandwidth() - parse an "b=" field
*
* Description:
* This function parses an SDP bandwidth field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_bandwidth(sdp_parser_t *p, char *r, sdp_bandwidth_t **result)
{
/*
bandwidth-fields = *("b=" bwtype ":" bandwidth CRLF)
bwtype = token
bandwidth = 1*(DIGIT)
*/
/* NOTE: bwtype can also be like X-barf */
sdp_bandwidth_e modifier;
char *name;
unsigned long value;
name = token(&r, ":", TOKEN, SPACE TAB);
if (name == NULL || parse_ul(p, &r, &value, 0)) {
parsing_error(p, "invalid bandwidth");
return;
}
if (su_casematch(name, "CT"))
modifier = sdp_bw_ct, name = NULL;
else if (su_casematch(name, "AS") == 0)
modifier = sdp_bw_as, name = NULL;
else
modifier = sdp_bw_x;
if (STRICT(p))
PARSE_CHECK_REST(p, r, "b");
{
PARSE_ALLOC(p, sdp_bandwidth_t, b);
*result = b;
b->b_modifier = modifier;
b->b_modifier_name = name;
b->b_value = value;
}
}
/* -------------------------------------------------------------------------
* Function parse_time() - parse an "t=" field
*
* Description:
* This function parses an SDP time field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_time(sdp_parser_t *p, char *r, sdp_time_t **result)
{
/*
time-fields = 1*( "t=" start-time SP stop-time
*(CRLF repeat-fields) CRLF)
[zone-adjustments CRLF]
start-time = time / "0"
stop-time = time / "0"
time = POS-DIGIT 9*DIGIT
; Decimal representation of NTP time in
; seconds since 1900. The representation
; of NTP time is an unbounded length field
; containing at least 10 digits. Unlike the
; 64-bit representation used elsewhere, time
; in SDP does not wrap in the year 2036.
*/
PARSE_ALLOC(p, sdp_time_t, t);
*result = t;
if (parse_ul(p, &r, &t->t_start, 0) ||
parse_ul(p, &r, &t->t_stop, 0))
parsing_error(p, "invalid time");
else if (STRICT(p)) {
PARSE_CHECK_REST(p, r, "t");
}
}
/**
* Parse an "r=" field
*
* The function parse_repeat() parses an SDP repeat field.
*
* @param p pointer to SDP parser object
* @param r pointer to record data
* @param result pointer to which parsed record is assigned
*
*/
static void parse_repeat(sdp_parser_t *p, char *d, sdp_repeat_t **result)
{
/*
repeat-fields = %x72 "=" repeat-interval 2*(SP typed-time)
repeat-interval = POS-DIGIT *DIGIT [fixed-len-time-unit]
typed-time = 1*DIGIT [fixed-len-time-unit]
fixed-len-time-unit = %x64 / %x68 / %x6d / %x73 ; "d" | "h" | "m" | "s"
*/
unsigned long tt, *interval;
size_t i;
int n, N;
char *s;
sdp_repeat_t *r;
int strict = STRICT(p);
/** Count number of intervals */
for (N = 0, s = d; *s; ) {
if (!(is_posdigit(*s) || (!strict && (*s) == '0')))
break;
do { s++; } while (is_digit(*s));
if (*s && strchr(strict ? "dhms" : "dhmsDHMS", *s))
s++;
N++;
if (!(i = strict ? is_space(*s) : strspn(s, SPACE TAB)))
break;
s += i;
}
PARSE_CHECK_REST(p, s, "r");
if (N < 2) {
parsing_error(p, "invalid repeat");
return;
}
if (!(r = su_salloc(p->pr_home, offsetof(sdp_repeat_t, r_offsets[N - 1])))) {
parse_alloc_error(p, "sdp_repeat_t");
return;
}
r->r_number_of_offsets = N - 2;
r->r_offsets[N - 2] = 0;
for (n = 0, interval = &r->r_interval; n < N; n++) {
tt = strtoul(d, &d, 10);
switch (*d) {
case 'd': case 'D': tt *= 24;
case 'h': case 'H': tt *= 60;
case 'm': case 'M': tt *= 60;
case 's': case 'S': d++;
break;
}
interval[n] = tt;
while (is_space(*d))
d++;
}
*result = r;
}
/* -------------------------------------------------------------------------
* Function parse_zone() - parse an "z=" field
*
* Description:
* This function parses an SDP time zone field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*
*/
static void parse_zone(sdp_parser_t *p, char *r, sdp_zone_t **result)
{
char *s;
size_t i;
int n, N;
sdp_zone_t *z;
/*
zone-adjustments = time space ["-"] typed-time
*(space time space ["-"] typed-time)
*/
/** Count number of timezones, check syntax */
for (N = 0, s = r; *s;) {
if (!(is_posdigit(*s) || (!STRICT(p) && (*s) == '0')))
break;
do { s++; } while (is_digit(*s));
if (!(i = STRICT(p) ? is_space(*s) : strspn(s, SPACE TAB)))
break;
s += i;
if (!(*s == '-' || is_posdigit(*s) || (!STRICT(p) && (*s) == '0')))
break;
do { s++; } while (is_digit(*s));
if (*s && strchr("dhms", *s))
s++;
N++;
if (!(i = STRICT(p) ? is_space(*s) : strspn(s, SPACE TAB)))
break;
s += i;
}
PARSE_CHECK_REST(p, s, "z");
if (N < 1) {
parsing_error(p, "invalid timezone");
return;
}
if (!(z = su_salloc(p->pr_home, offsetof(sdp_zone_t, z_adjustments[N])))) {
parse_alloc_error(p, "sdp_zone_t");
return;
}
z->z_number_of_adjustments = N;
for (n = 0; n < N; n++) {
unsigned long at = strtoul(r, &r, 10);
long offset = strtol(r, &r, 10);
switch (*r) {
case 'd': offset *= 24;
case 'h': offset *= 60;
case 'm': offset *= 60;
case 's': r++;
break;
}
z->z_adjustments[n].z_at = at;
z->z_adjustments[n].z_offset = offset;
}
*result = z;
}
/* -------------------------------------------------------------------------
* Function parse_key() - parse an "k=" field
*
* Description:
* This function parses an SDP key field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*
*/
static void parse_key(sdp_parser_t *p, char *r, sdp_key_t **result)
{
char *s;
/*
key-field = ["k=" key-type CRLF]
key-type = "prompt" |
"clear:" key-data |
"base64:" key-data |
"uri:" uri
key-data = email-safe | "~" | "
*/
s = token(&r, ":", TOKEN, SPACE TAB);
if (!s) {
parsing_error(p, "invalid key method");
return;
}
{
PARSE_ALLOC(p, sdp_key_t, k);
*result = k;
/* These are defined as key-sensitive in RFC 4566 */
#define MATCH(s, tok) \
(STRICT(p) ? su_strmatch((s), (tok)) : su_casematch((s), (tok)))
if (MATCH(s, "clear"))
k->k_method = sdp_key_clear, k->k_method_name = "clear";
else if (MATCH(s, "base64"))
k->k_method = sdp_key_base64, k->k_method_name = "base64";
else if (MATCH(s, "uri"))
k->k_method = sdp_key_uri, k->k_method_name = "uri";
else if (MATCH(s, "prompt"))
k->k_method = sdp_key_prompt, k->k_method_name = "prompt";
else if (!STRICT(p))
k->k_method = sdp_key_x, k->k_method_name = s;
else {
parsing_error(p, "invalid key method");
return;
}
k->k_material = r;
}
}
/* -------------------------------------------------------------------------
* Function parse_session_attr() - parse a session "a=" field
*
* Description:
* This function parses an SDP attribute field regarding whole session.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_session_attr(sdp_parser_t *p, char *r, sdp_attribute_t **result)
{
/*
attribute-fields = *("a=" attribute CRLF)
attribute = (att-field ":" att-value) / att-field
att-field = token
att-value = byte-string
*/
char *name = NULL, *value = NULL;
if (!(name = token(&r, ":", TOKEN, SPACE TAB))) {
parsing_error(p,"invalid attribute name");
return;
}
if (*r)
value = r;
else
PARSE_CHECK_REST(p, r, "a");
if (su_casematch(name, "charset")) {
p->pr_session->sdp_charset = value;
return;
}
if (p->pr_mode_manual)
;
else if (su_casematch(name, "inactive"))
p->pr_session_mode = sdp_inactive;
else if (su_casematch(name, "sendonly"))
p->pr_session_mode = sdp_sendonly;
else if (su_casematch(name, "recvonly"))
p->pr_session_mode = sdp_recvonly;
else if (su_casematch(name, "sendrecv"))
p->pr_session_mode = sdp_sendrecv;
{
PARSE_ALLOC(p, sdp_attribute_t, a);
*result = a;
a->a_name = name;
a->a_value = value;
}
}
/* -------------------------------------------------------------------------
* Function parse_media() - parse an "m=" field
*
* Description:
* This function parses an SDP media field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_media(sdp_parser_t *p, char *r, sdp_media_t **result)
{
/*
media-descriptions = *( media-field
information-field
*(connection-field)
bandwidth-fields
key-field
attribute-fields )
media-field = "m=" media space port ["/" integer]
space proto 1*(space fmt) CRLF
media = token
;typically "audio", "video", "application"
;or "data"
fmt = token
;typically an RTP payload type for audio
;and video media
proto = token *("/" token)
;typically "RTP/AVP" or "udp" for IP4
port = 1*(DIGIT)
;should in the range "1024" to "65535" inclusive
*/
char *s;
unsigned long value;
PARSE_ALLOC(p, sdp_media_t, m);
*result = m;
m->m_mode = sdp_sendrecv;
s = token(&r, SPACE, TOKEN, NULL);
if (!s) {
parsing_error(p, "m= invalid media field");
return;
}
sdp_media_type(m, s);
/* Accept m=* in configuration file */
if (p->pr_config && m->m_type == sdp_media_any) {
r += strspn(r, SPACE TAB);
if (r[0] == '\0') {
m->m_proto = sdp_proto_any, m->m_proto_name = "*";
return;
}
}
if (parse_ul(p, &r, &value, 0)) {
parsing_error(p, "m= invalid port number");
return;
}
m->m_port = value;
if (*r == '/') {
r++;
if (parse_ul(p, &r, &value, 0)) {
parsing_error(p, "m= invalid port specification");
return;
}
m->m_number_of_ports = value;
}
s = token(&r, SPACE, "/" TOKEN, SPACE);
if (s == NULL) {
parsing_error(p, "m= missing protocol");
return;
}
if (!STRICT(p) && su_casematch(s, "RTP"))
m->m_proto = sdp_proto_rtp, m->m_proto_name = "RTP/AVP";
else
sdp_media_transport(m, s);
/* RTP format list */
if (*r && sdp_media_has_rtp(m)) {
parse_payload(p, r, &m->m_rtpmaps);
return;
}
/* "normal" format list */
if (*r) {
sdp_list_t **fmt = &m->m_format;
while (r && *r) {
PARSE_ALLOC(p, sdp_list_t, l);
*fmt = l;
l->l_text = token(&r, SPACE TAB, TOKEN, SPACE TAB);
fmt = &l->l_next;
}
}
}
/** Set media type */
void sdp_media_type(sdp_media_t *m, char const *s)
{
if (su_strmatch(s, "*"))
m->m_type = sdp_media_any, m->m_type_name = "*";
else if (su_casematch(s, "audio"))
m->m_type = sdp_media_audio, m->m_type_name = "audio";
else if (su_casematch(s, "video"))
m->m_type = sdp_media_video, m->m_type_name = "video";
else if (su_casematch(s, "application"))
m->m_type = sdp_media_application, m->m_type_name = "application";
else if (su_casematch(s, "data"))
m->m_type = sdp_media_data, m->m_type_name = "data";
else if (su_casematch(s, "control"))
m->m_type = sdp_media_control, m->m_type_name = "control";
else if (su_casematch(s, "message"))
m->m_type = sdp_media_message, m->m_type_name = "message";
else if (su_casematch(s, "image"))
m->m_type = sdp_media_image, m->m_type_name = "image";
else if (su_casematch(s, "red"))
m->m_type = sdp_media_red, m->m_type_name = "red";
else
m->m_type = sdp_media_x, m->m_type_name = s;
}
/** Set transport protocol.
*
* Set the @m->m_proto to a well-known protocol type as
* well as canonize case of @a m_proto_name.
*/
void sdp_media_transport(sdp_media_t *m, char const *s)
{
if (m == NULL || s == NULL)
;
else if (su_strmatch(s, "*"))
m->m_proto = sdp_proto_any, m->m_proto_name = "*";
else if (su_casematch(s, "RTP/AVP"))
m->m_proto = sdp_proto_rtp, m->m_proto_name = "RTP/AVP";
else if (su_casematch(s, "RTP/SAVP"))
m->m_proto = sdp_proto_srtp, m->m_proto_name = "RTP/SAVP";
else if (su_casematch(s, "RTP/SAVPF"))
m->m_proto = sdp_proto_extended_srtp, m->m_proto_name = "RTP/SAVPF";
else if (su_casematch(s, "UDP/TLS/RTP/SAVPF"))
m->m_proto = sdp_proto_extended_srtp, m->m_proto_name = "UDP/TLS/RTP/SAVPF";
else if (su_casematch(s, "udptl"))
/* Lower case - be compatible with people living by T.38 examples */
m->m_proto = sdp_proto_udptl, m->m_proto_name = "udptl";
else if (su_casematch(s, "TCP/MSRP"))
m->m_proto = sdp_proto_msrp, m->m_proto_name = "TCP/MSRP";
else if (su_casematch(s, "TCP/TLS/MSRP"))
m->m_proto = sdp_proto_msrps, m->m_proto_name = "TCP/TLS/MSRP";
else if (su_casematch(s, "UDP"))
m->m_proto = sdp_proto_udp, m->m_proto_name = "UDP";
else if (su_casematch(s, "TCP"))
m->m_proto = sdp_proto_tcp, m->m_proto_name = "TCP";
else if (su_casematch(s, "TLS"))
m->m_proto = sdp_proto_tls, m->m_proto_name = "TLS";
else
m->m_proto = sdp_proto_x, m->m_proto_name = s;
}
/** Check if media uses RTP as its transport protocol. */
int sdp_media_has_rtp(sdp_media_t const *m)
{
return m && (m->m_proto == sdp_proto_rtp || m->m_proto == sdp_proto_srtp || m->m_proto == sdp_proto_extended_srtp);
}
#define RTPMAP(pt, encoding, rate, params) \
{ sizeof(sdp_rtpmap_t), NULL, encoding, rate, (char *)params, NULL, 1, pt, 0 }
/* rtpmaps for well-known codecs */
static sdp_rtpmap_t const
sdp_rtpmap_pcmu = RTPMAP(0, "PCMU", 8000, 0),
sdp_rtpmap_1016 = RTPMAP(1, "1016", 8000, 0),
sdp_rtpmap_g721 = RTPMAP(2, "G721", 8000, 0),
sdp_rtpmap_gsm = RTPMAP(3, "GSM", 8000, 0),
sdp_rtpmap_g723 = RTPMAP(4, "G723", 8000, 0),
sdp_rtpmap_dvi4_8000 = RTPMAP(5, "DVI4", 8000, 0),
sdp_rtpmap_dvi4_16000 = RTPMAP(6, "DVI4", 16000, 0),
sdp_rtpmap_lpc = RTPMAP(7, "LPC", 8000, 0),
sdp_rtpmap_pcma = RTPMAP(8, "PCMA", 8000, 0),
sdp_rtpmap_g722 = RTPMAP(9, "G722", 8000, 0),
sdp_rtpmap_l16_2 = RTPMAP(10, "L16", 44100, "2"),
sdp_rtpmap_l16 = RTPMAP(11, "L16", 44100, 0),
sdp_rtpmap_qcelp = RTPMAP(12, "QCELP", 8000, 0),
sdp_rtpmap_cn = RTPMAP(13, "CN", 8000, 0),
sdp_rtpmap_mpa = RTPMAP(14, "MPA", 90000, 0),
sdp_rtpmap_g728 = RTPMAP(15, "G728", 8000, 0),
sdp_rtpmap_dvi4_11025 = RTPMAP(16, "DVI4", 11025, 0),
sdp_rtpmap_dvi4_22050 = RTPMAP(17, "DVI4", 22050, 0),
sdp_rtpmap_g729 = RTPMAP(18, "G729", 8000, 0),
sdp_rtpmap_reserved_cn = RTPMAP(19, "CN", 8000, 0),
/* video codecs */
sdp_rtpmap_celb = RTPMAP(25, "CelB", 90000, 0),
sdp_rtpmap_jpeg = RTPMAP(26, "JPEG", 90000, 0),
sdp_rtpmap_nv = RTPMAP(28, "nv", 90000, 0),
sdp_rtpmap_h261 = RTPMAP(31, "H261", 90000, 0),
sdp_rtpmap_mpv = RTPMAP(32, "MPV", 90000, 0),
sdp_rtpmap_mp2t = RTPMAP(33, "MP2T", 90000, 0),
sdp_rtpmap_h263 = RTPMAP(34, "H263", 90000, 0);
/** Table of rtpmap structures by payload type numbers.
*
* The table of reserved payload numbers is constructed from @RFC3551
* and @RFC1890. Note the clock rate of G722.
*
* Use sdp_rtpmap_dup() to copy these structures.
*/
sdp_rtpmap_t const * const sdp_rtpmap_well_known[128] =
{
&sdp_rtpmap_pcmu, /* 0 */
&sdp_rtpmap_1016, /* 1 */
&sdp_rtpmap_g721, /* 2 */
&sdp_rtpmap_gsm, /* 3 */
&sdp_rtpmap_g723, /* 4 */
&sdp_rtpmap_dvi4_8000, /* 5 */
&sdp_rtpmap_dvi4_16000, /* 6 */
&sdp_rtpmap_lpc, /* 7 */
&sdp_rtpmap_pcma, /* 8 */
&sdp_rtpmap_g722, /* 9 */
&sdp_rtpmap_l16_2, /* 10 */
&sdp_rtpmap_l16, /* 11 */
&sdp_rtpmap_qcelp, /* 12 */
&sdp_rtpmap_cn, /* 13 */
&sdp_rtpmap_mpa, /* 14 */
&sdp_rtpmap_g728, /* 15 */
&sdp_rtpmap_dvi4_11025, /* 16 */
&sdp_rtpmap_dvi4_22050, /* 17 */
&sdp_rtpmap_g729, /* 18 */
&sdp_rtpmap_reserved_cn, /* 19 */
NULL, /* 20 */
NULL, /* 21 */
NULL, /* 22 */
NULL, /* 23 */
NULL, /* 24 */
&sdp_rtpmap_celb, /* 25 */
&sdp_rtpmap_jpeg, /* 26 */
NULL, /* 27 */
&sdp_rtpmap_nv, /* 28 */
NULL, /* 29 */
NULL, /* 30 */
&sdp_rtpmap_h261, /* 31 */
&sdp_rtpmap_mpv, /* 32 */
&sdp_rtpmap_mp2t, /* 33 */
&sdp_rtpmap_h263, /* 34 */
NULL,
};
/**
* The function parse_payload() parses an RTP payload type list, and
* creates an rtpmap structure for each payload type.
*
* @param p pointer to SDP parser object
* @param r pointer to record data
* @param result pointer to which parsed record is assigned
*/
static void parse_payload(sdp_parser_t *p, char *r, sdp_rtpmap_t **result)
{
while (*r) {
unsigned long value;
if (parse_ul(p, &r, &value, 128) == 0) {
PARSE_ALLOC(p, sdp_rtpmap_t, rm);
assert(0 <= value && value < 128);
*result = rm; result = &rm->rm_next;
if (sdp_rtpmap_well_known[value]) {
*rm = *sdp_rtpmap_well_known[value];
}
else {
rm->rm_predef = 1;
rm->rm_pt = value;
rm->rm_encoding = "";
rm->rm_rate = 0;
}
}
else if (p->pr_config && r[0] == '*' && (r[1] == ' ' || r[1] == '\0')) {
PARSE_ALLOC(p, sdp_rtpmap_t, rm);
*result = rm; result = &rm->rm_next;
rm->rm_predef = 1;
rm->rm_any = 1;
rm->rm_encoding = "*";
rm->rm_rate = 0;
return;
}
else {
parsing_error(p, "m= invalid format for RTP/AVT");
return;
}
}
}
/* -------------------------------------------------------------------------
* Function parse_media_attr() - parse a media-specific "a=" field
*
* Description:
* This function parses a media-specific attribute field.
*
* Parameters:
* p - pointer to SDP parser object
* r - pointer to record data
* result - pointer to which parsed record is assigned
*/
static void parse_media_attr(sdp_parser_t *p, char *r, sdp_media_t *m,
sdp_attribute_t **result)
{
/*
attribute-fields = *("a=" attribute CRLF)
attribute = (att-field ":" att-value) / att-field
att-field = token
att-value = byte-string
a=rtpmap:<payload type> <encoding name>/<clock rate>[/<encoding parameters>]
a=fmtp:<payload type> <parameters>
*/
int rtp = sdp_media_has_rtp(m);
char *name = NULL, *value = NULL;
int n;
if (!(name = token(&r, ":", TOKEN, SPACE TAB))) {
parsing_error(p,"invalid attribute name");
return;
}
if (*r)
value = r;
else
PARSE_CHECK_REST(p, r, "a");
if (p->pr_mode_manual)
;
else if (m->m_port == 0 || su_casematch(name, "inactive")) {
m->m_mode = sdp_inactive;
return;
}
else if (su_casematch(name, "sendonly")) {
m->m_mode = sdp_sendonly;
return;
}
else if (su_casematch(name, "recvonly")) {
m->m_mode = sdp_recvonly;
return;
}
else if (su_casematch(name, "sendrecv")) {
m->m_mode = sdp_sendrecv;
return;
}
if (rtp && su_casematch(name, "rtpmap")) {
if ((n = parse_rtpmap(p, r, m)) == 0 || n < -1)
return;
}
else if (rtp && su_casematch(name, "fmtp")) {
if ((n = parse_fmtp(p, r, m)) == 0 || n < -1)
return;
}
else {
PARSE_ALLOC(p, sdp_attribute_t, a);
*result = a;
a->a_name = name;
a->a_value = value;
}
}
/** Parse rtpmap attribute.
*
* a=rtpmap:<payload type> <encoding name>/<clock rate>[/<encoding parameters>]
*/
static int parse_rtpmap(sdp_parser_t *p, char *r, sdp_media_t *m)
{
unsigned long pt, rate;
char *encoding, *params;
sdp_rtpmap_t *rm;
int strict = STRICT(p);
if (parse_ul(p, &r, &pt, 128)) {
if (strict)
parsing_error(p, "a=rtpmap: invalid payload type");
return -1;
}
for (rm = m->m_rtpmaps; rm; rm = rm->rm_next)
if (rm->rm_pt == pt)
break;
if (!rm) {
if (strict)
parsing_error(p, "a=rtpmap:%lu: unknown payload type", pt);
return -1;
}
encoding = token(&r, "/", TOKEN, NULL);
if (!r) {
parsing_error(p, "a=rtpmap:%lu: missing <clock rate>", pt);
return -2;
}
if (parse_ul(p, &r, &rate, 0)) {
parsing_error(p, "a=rtpmap:%lu %s: invalid <clock rate>", pt, encoding);
return -2;
}
if (*r == '/')
params = ++r;
else
params = 0;
rm->rm_predef = 0;
rm->rm_encoding = encoding;
rm->rm_rate = rate;
rm->rm_params = params;
return 0;
}
/** Parse fmtp attribute.
*
* a=fmtp:<payload type> <parameters>
*/
static int parse_fmtp(sdp_parser_t *p, char *r, sdp_media_t *m)
{
unsigned long pt;
sdp_rtpmap_t *rm;
int strict = STRICT(p);
if (parse_ul(p, &r, &pt, 128)) {
if (strict)
parsing_error(p, "a=rtpmap: invalid payload type");
return -1;
}
for (rm = m->m_rtpmaps; rm; rm = rm->rm_next)
if (rm->rm_pt == pt)
break;
if (!rm) {
if (strict)
parsing_error(p, "a=fmtp:%lu: unknown payload type", pt);
return -1;
}
rm->rm_fmtp = r;
return 0;
}
/* -------------------------------------------------------------------------
* Function parse_descs() - parse media descriptors
*
* Description:
* This function parses media descriptors at the end of SDP message.
*
* Parameters:
* p - pointer to SDP parser object
* record - pointer to first media field
* message - pointer to rest
* medias - pointer to which parsed media structures are assigned
*/
static void parse_descs(sdp_parser_t *p,
char *record,
char *message,
sdp_media_t **medias)
{
char *rest;
const char *strip;
sdp_media_t *m = NULL;
sdp_connection_t **connections = NULL;
sdp_bandwidth_t **bandwidths = NULL;
sdp_attribute_t **attributes = NULL;
if (!STRICT(p))
strip = SPACE TAB; /* skip initial whitespace */
else
strip = "";
for (;
record && p->pr_ok;
record = next(&message, CRLF, strip)) {
char field = record[0];
rest = record + 2; rest += strspn(rest, strip);
if (record[1] == '=') switch (field) {
case 'c':
assert(connections);
parse_connection(p, rest, connections);
connections = &(*connections)->c_next;
break;
case 'b':
assert(bandwidths);
parse_bandwidth(p, rest, bandwidths);
bandwidths = &(*bandwidths)->b_next;
break;
case 'k':
parse_key(p, rest, &m->m_key);
break;
case 'a':
assert(attributes);
parse_media_attr(p, rest, m, attributes);
if (*attributes)
attributes = &(*attributes)->a_next;
break;
case 'm':
parse_media(p, rest, medias);
m = *medias;
if (m) {
m->m_mode = p->pr_session_mode;
medias = &m->m_next;
connections = &m->m_connections;
bandwidths = &m->m_bandwidths;
attributes = &m->m_attributes;
}
}
}
}
static void parse_text_list(sdp_parser_t *p, char *r, sdp_list_t **result)
{
PARSE_ALLOC(p, sdp_list_t, l);
*result = l;
l->l_text = r;
}
/*
* parse_ul: parse an unsigned long
*/
static int parse_ul(sdp_parser_t *p, char **r,
unsigned long *result, unsigned long max)
{
char *ul = *r;
ul += strspn(ul, SPACE TAB);
*result = strtoul(ul, r, 10);
if (ul != *r && !(max && max <= *result)) {
*r += strspn(*r, SPACE TAB);
return 0;
}
return -1;
}
#if !HAVE_STRTOULL
#if !((defined(WIN32) || defined(_WIN32)) && (_MSC_VER >= 1800))
unsigned long long strtoull(char const *string, char **return_end, int base);
#endif
#endif
/*
* parse_ull: parse an unsigned long long
*/
static int parse_ull(sdp_parser_t *p, char **r,
uint64_t *result, uint64_t max)
{
unsigned long long ull;
char *s = *r;
s += strspn(s, SPACE TAB);
ull = strtoull(s, r, 10);
if (s != *r && !(max && max <= ull)) {
*result = (uint64_t)ull;
*r += strspn(*r, SPACE TAB);
return 0;
}
return -1;
}
static char *token(char **message,
const char *sep,
const char *legal,
const char *strip)
{
size_t n;
char *retval = *message;
if (strip)
retval += strspn(retval, strip);
if (legal)
n = strspn(retval, legal);
else
n = strcspn(retval, sep);
if (n == 0)
return NULL;
if (retval[n]) {
retval[n++] = '\0';
n += strspn(retval + n, sep);
}
*message = retval + n;
if (*retval == '\0')
return NULL;
return retval;
}
static char *next(char **message, const char *sep, const char *strip)
{
size_t n;
char *retval = *message;
if (strip[0])
retval += strspn(retval, strip);
n = strcspn(retval, sep);
if (n == 0)
return NULL;
if (retval[n]) {
retval[n++] = '\0';
n += strspn(retval + n, sep);
}
*message = retval + n;
if (*retval == '\0')
return NULL;
return retval;
}
static int parsing_error(sdp_parser_t *p, char const *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
memset(p->pr_error, 0, sizeof(p->pr_error));
vsnprintf(p->pr_error, sizeof(p->pr_error), fmt, ap);
va_end(ap);
p->pr_ok = 0;
return -1;
}
static void parse_alloc_error(sdp_parser_t *p, const char *typename)
{
parsing_error(p, "memory exhausted (while allocating memory for %s)",
typename);
}