/*
* 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
*
*/
/**@CFILE sip_util.c
*
* SIP utility functions.
*
* @author Pekka Pessi <Pekka.Pessi@nokia.com>.
*
* @date Created: Tue Jun 13 02:57:51 2000 ppessi
*/
#include "config.h"
/* Avoid casting sip_t to msg_pub_t and sip_header_t to msg_header_t */
#define MSG_PUB_T struct sip_s
#define MSG_HDR_T union sip_header_u
#include <sofia-sip/su_alloc.h>
#include <sofia-sip/su_strlst.h>
#include <sofia-sip/string0.h>
#include "sofia-sip/sip_parser.h"
#include <sofia-sip/sip_header.h>
#include <sofia-sip/sip_util.h>
#include <sofia-sip/sip_status.h>
#include <sofia-sip/bnf.h>
#include <sofia-sip/hostdomain.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <float.h>
#include <limits.h>
#include <ctype.h>
/**
* Compare two SIP addresses ( @From or @To headers).
*
* @retval nonzero if matching.
* @retval zero if not matching.
*/
int sip_addr_match(sip_addr_t const *a, sip_addr_t const *b)
{
return
(a->a_tag == NULL || b->a_tag == NULL ||
strcmp(a->a_tag, b->a_tag) == 0)
&&
str0casecmp(a->a_host, b->a_host) == 0
&&
str0cmp(a->a_user, b->a_user) == 0
&&
str0cmp(a->a_url->url_scheme, b->a_url->url_scheme);
}
/**@ingroup sip_contact
*
* Create a contact header.
*
* Create a @Contact header object with the given URL and list of parameters.
*
* @param home memory home
* @param url URL (string or pointer to url_t)
* @param p,... NULL-terminated list of @Contact parameters
*
* @return
* A pointer to newly created @Contact header object when successful or NULL
* upon an error.
*
*/
sip_contact_t * sip_contact_create(su_home_t *home,
url_string_t const *url,
char const *p, ...)
{
su_strlst_t *l;
su_home_t *lhome;
sip_contact_t *m;
if (url == NULL)
return NULL;
l = su_strlst_create_with(NULL, "<", NULL), lhome = su_strlst_home(l);
if (l == NULL)
return NULL;
if (url_is_string(url))
su_strlst_append(l, (char const *)url);
else
su_strlst_append(l, url_as_string(lhome, url->us_url));
su_strlst_append(l, ">");
if (p) {
va_list ap;
va_start(ap, p);
for (; p; p = va_arg(ap, char const *)) {
su_strlst_append(l, ";");
su_strlst_append(l, p);
}
va_end(ap);
}
m = sip_contact_make(home, su_strlst_join(l, lhome, ""));
su_strlst_destroy(l);
return m;
}
/** Convert a @Via header to @Contact header.
*
* The @Contact URI will contain the port number if needed. If transport
* protocol name starts with "TLS", "SIPS:" URI schema is used. Transport
* parameter is included in the URI unless the transport protocol is UDP.
*
* @param home memory home
* @param v @Via header field structure
* (with <sent-protocol> and <sent-by> parameters)
* @param user username for @Contact URI (may be NULL)
*
* @retval contact header structure
* @retval NULL upon an error
*
* @sa sip_contact_create_from_via_with_transport(),
* sip_contact_string_from_via()
*/
sip_contact_t *
sip_contact_create_from_via(su_home_t *home,
sip_via_t const *v,
char const *user)
{
const char *tp;
if (!v) return NULL;
tp = v->v_protocol;
if (tp == sip_transport_udp ||
strcasecmp(tp, sip_transport_udp) == 0) /* Default is UDP */
tp = NULL;
return sip_contact_create_from_via_with_transport(home, v, user, tp);
}
/** Convert a @Via header to @Contact header.
*
* The @Contact URI will contain the port number and transport parameters if
* needed. If transport protocol name starts with "TLS", "SIPS:" URI schema
* is used.
*
* @param home memory home
* @param v @Via header field structure
* (with <sent-by> parameter containing host and port)
* @param user username for @Contact URI (may be NULL)
* @param transport transport name for @Contact URI (may be NULL)
*
* @retval contact header structure
* @retval NULL upon an error
*
* @sa sip_contact_create_from_via(), sip_contact_string_from_via()
*/
sip_contact_t *
sip_contact_create_from_via_with_transport(su_home_t *home,
sip_via_t const *v,
char const *user,
char const *transport)
{
char *s = sip_contact_string_from_via(NULL, v, user, transport);
sip_contact_t *m = sip_contact_make(home, s);
su_free(NULL, s);
return m;
}
/** Convert a @Via header to @Contact URL string.
*
* The @Contact URI will contain the port number and transport parameters if
* needed. If transport protocol name starts with "TLS", "SIPS:" URI schema
* is used.
*
* The contact URI string returned will always have angle brackets ("<" and
* ">") around it.
*
* @param home memory home
* @param v @Via header field structure
* (with <sent-by> parameter containing host and port)
* @param user username for @Contact URI (may be NULL)
* @param transport transport name for @Contact URI (may be NULL)
*
* @retval string containing Contact URI with angle brackets
* @retval NULL upon an error
*/
char *
sip_contact_string_from_via(su_home_t *home,
sip_via_t const *v,
char const *user,
char const *transport)
{
const char *host, *port, *maddr, *comp;
char const *scheme = "sip:";
int one = 1;
char _transport[16];
if (!v) return NULL;
host = v->v_host;
if (v->v_received)
host = v->v_received;
port = sip_via_port(v, &one);
maddr = v->v_maddr;
comp = v->v_comp;
if (host == NULL)
return NULL;
if (sip_transport_has_tls(v->v_protocol) ||
sip_transport_has_tls(transport)) {
scheme = "sips:";
if (port && strcmp(port, SIPS_DEFAULT_SERV) == 0)
port = NULL;
if (port || host_is_ip_address(host))
transport = NULL;
}
else if (port && strcmp(port, SIP_DEFAULT_SERV) == 0 &&
(host_is_ip_address(host) || host_has_domain_invalid(host))) {
port = NULL;
}
if (transport && strncasecmp(transport, "SIP/2.0/", 8) == 0)
transport += 8;
/* Make transport parameter lowercase */
if (transport && strlen(transport) < (sizeof _transport)) {
char *s = strcpy(_transport, transport);
short c;
for (s = _transport; (c = *s) && c != ';'; s++)
if (isupper(c))
*s = tolower(c);
transport = _transport;
}
return su_strcat_all(home,
"<",
scheme,
user ? user : "", user ? "@" : "",
host,
SIP_STRLOG(":", port),
SIP_STRLOG(";transport=", transport),
SIP_STRLOG(";maddr=", maddr),
SIP_STRLOG(";comp=", comp),
">",
NULL);
}
/** Check if tranport name refers to TLS */
int sip_transport_has_tls(char const *transport_name)
{
if (!transport_name)
return 0;
if (transport_name == sip_transport_tls)
return 1;
/* transport name starts with TLS or SIP/2.0/TLS */
return
strncasecmp(transport_name, "TLS", 3) == 0 ||
strncasecmp(transport_name, sip_transport_tls, 11) == 0;
}
/**Perform sanity check on a SIP message
*
* Check that the SIP message has all the mandatory fields.
*
* @param sip SIP message to be checked
*
* @return
* When the SIP message fulfills the minimum requirements, return zero,
* otherwise a negative status code.
*/
int
sip_sanity_check(sip_t const *sip)
{
if (!sip ||
!((sip->sip_request != NULL) ^ (sip->sip_status != NULL)) ||
!sip->sip_to ||
!sip->sip_from ||
!sip->sip_call_id ||
!sip->sip_cseq ||
!sip->sip_via ||
(sip->sip_flags & MSG_FLG_TRUNC))
return -1; /* Bad request */
if (sip->sip_request) {
url_t const *ruri = sip->sip_request->rq_url;
switch (ruri->url_type) {
case url_invalid:
return -1;
case url_sip: case url_sips: case url_im: case url_pres:
if (!ruri->url_host || strlen(ruri->url_host) == 0)
return -1;
break;
case url_tel:
if (!ruri->url_user || strlen(ruri->url_user) == 0)
return -1;
break;
}
if (sip->sip_request->rq_method != sip->sip_cseq->cs_method)
return -1;
if (sip->sip_request->rq_method == sip_method_unknown &&
str0casecmp(sip->sip_request->rq_method_name,
sip->sip_cseq->cs_method_name))
return -1;
}
return 0;
}
/** Decode a string containg header field.
*
* The header object is initialized with the contents of the string. The
* string is modified when parsing. The home is used to allocate extra
* memory required when parsing, e.g., for parameter list or when there
* string contains multiple header fields.
*
* @deprecated
* Use msg_header_make() or header-specific make functions, e.g.,
* sip_via_make().
*
* @retval 0 when successful
* @retval -1 upon an error.
*/
issize_t sip_header_field_d(su_home_t *home, sip_header_t *h, char *s, isize_t slen)
{
assert(SIP_HDR_TEST(h));
if (h && s && s[slen] == '\0') {
size_t n = span_lws(s);
s += n; slen -= n;
for (n = slen; n >= 1 && IS_LWS(s[n - 1]); n--)
;
s[n] = '\0';
return h->sh_class->hc_parse(home, h, s, slen);
}
else
return -1;
}
/** Encode a SIP header contents.
*
* @deprecated Use msg_header_field_e() instead.
*/
issize_t sip_header_field_e(char *b, isize_t bsiz, sip_header_t const *h, int flags)
{
return msg_header_field_e(b, bsiz, h, flags);
}
/** Convert the header @a h to a string allocated from @a home. */
char *sip_header_as_string(su_home_t *home, sip_header_t const *h)
{
ssize_t len;
char *rv, s[128];
if (h == NULL)
return NULL;
len = sip_header_field_e(s, sizeof(s), h, 0);
if (len >= 0 && (size_t)len < sizeof(s))
return su_strdup(home, s);
if (len == -1)
len = 2 * sizeof(s);
else
len += 1;
for (rv = su_alloc(home, len);
rv;
rv = su_realloc(home, rv, len)) {
ssize_t n = sip_header_field_e(rv, len, h, 0);
if (n > -1 && n + 1 <= len)
break;
if (n > -1) /* glibc >2.1 */
len = n + 1;
else /* glibc 2.0 */
len *= 2;
}
return rv;
}
/** Calculate size of a SIP header. */
isize_t sip_header_size(sip_header_t const *h)
{
assert(h == NULL || h == SIP_NONE || h->sh_class);
if (h == NULL || h == SIP_NONE)
return 0;
else
return h->sh_class->hc_dxtra(h, h->sh_class->hc_size);
}
/** Duplicate a url or make a url out of string.
* @deprecated Use url_hdup() instead.
*/
url_t *sip_url_dup(su_home_t *home, url_t const *o)
{
return url_hdup(home, o);
}
/**Calculate Q value.
*
* Convert q-value string @a q to numeric value
* in range (0..1000). Q values are used, for instance, to describe
* relative priorities of registered contacts.
*
* @param q q-value string <code>("1" | "." 1,3DIGIT)</code>
*
* @return An integer in range 0 .. 1000.
*/
unsigned sip_q_value(char const *q)
{
unsigned value = 0;
if (!q)
return 1000;
if (q[0] != '0' && q[0] != '.' && q[0] != '1')
return 500; /* Garbage... */
while (q[0] == '0')
q++;
if (q[0] >= '1' && q[0] <= '9')
return 1000;
if (q[0] == '\0')
return 0;
if (q[0] != '.')
return 500; /* Garbage... */
if (q[1] >= '0' && q[1] <= '9') {
value = (q[1] - '0') * 100;
if (q[2] >= '0' && q[2] <= '9') {
value += (q[2] - '0') * 10;
if (q[3] >= '0' && q[3] <= '9') {
value += (q[3] - '0');
if (q[4] > '5' && q[4] <= '9')
/* Round upwards */
value += 1;
else if (q[4] == '5')
value += value & 1; /* Round to even */
}
}
}
return value;
}
/**@ingroup sip_route
*
* Get first route header and remove it from its fragment chain.
*
*/
sip_route_t *sip_route_remove(msg_t *msg, sip_t *sip)
{
sip_route_t *r;
if ((r = sip->sip_route))
msg_header_remove(msg, (msg_pub_t *)sip, (msg_header_t *)r);
return r;
}
/**@ingroup sip_route
*
* Get last route header and remove it from its fragment chain.
*
*/
sip_route_t *sip_route_pop(msg_t *msg, sip_t *sip)
{
sip_route_t *r;
for (r = sip->sip_route; r; r = r->r_next)
if (r->r_next == NULL) {
msg_header_remove(msg, (msg_pub_t *)sip, (msg_header_t *)r);
return r;
}
return NULL;
}
/**@ingroup sip_route
*
* Get first route header and rewrite the RequestURI.
*/
sip_route_t *sip_route_follow(msg_t *msg, sip_t *sip)
{
if (sip->sip_route) {
/* XXX - in case of outbound proxy, route may contain our address */
sip_route_t *r = sip_route_remove(msg, sip);
sip_request_t *rq = sip->sip_request;
rq = sip_request_create(msg_home(msg), rq->rq_method, rq->rq_method_name,
(url_string_t const *)r->r_url, rq->rq_version);
url_strip_transport(rq->rq_url);
msg_header_insert(msg, (msg_pub_t *)sip, (msg_header_t *)rq);
return r;
}
return NULL;
}
/**@ingroup sip_route
*
* Check if route header has lr param.
*
* "lr" param can be either URL or header parameter.
*/
int
sip_route_is_loose(sip_route_t const *r)
{
if (!r)
return 0;
if (r->r_url->url_params)
return url_has_param(r->r_url, "lr");
else
return r->r_params && msg_params_find(r->r_params, "lr") != NULL;
}
/**@ingroup sip_route
*
* Reverse a route header (@Route, @RecordRoute, @Path, @ServiceRoute).
*/
sip_route_t *sip_route_reverse_as(su_home_t *home,
msg_hclass_t *hc,
sip_route_t const *route)
{
sip_route_t *reverse = NULL;
sip_route_t r[1], *tmp;
sip_route_init(r);
r->r_common->h_class = hc;
for (reverse = NULL; route; route = route->r_next) {
*r->r_url = *route->r_url;
/* Fix broken (Record-)Routes without <> */
if (r->r_url->url_params == NULL
&& r->r_params
&& r->r_params[0]
&& (r->r_params[0][0] == 'l' || r->r_params[0][0] == 'L')
&& (r->r_params[0][1] == 'r' || r->r_params[0][1] == 'R')
&& (r->r_params[0][2] == '=' || r->r_params[0][2] == 0))
r->r_url->url_params = route->r_params[0],
r->r_params = route->r_params + 1;
else
r->r_params = route->r_params;
tmp = (sip_route_t *)msg_header_dup_as(home, hc, (msg_header_t *)r);
if (!tmp)
goto error;
tmp->r_next = reverse;
reverse = tmp;
}
return reverse;
error:
msg_header_free_all(home, (msg_header_t *)reverse);
return NULL;
}
/**@ingroup sip_route
*
* Reverse a @Route header.
*
* Reverse A route header like @RecordRoute or @Path.
*/
sip_route_t *sip_route_reverse(su_home_t *home, sip_route_t const *route)
{
return sip_route_reverse_as(home, sip_route_class, route);
}
/**@ingroup sip_route
*
* Fix and duplicate a route header (@Route, @RecordRoute, @Path, @ServiceRoute).
*
*/
sip_route_t *sip_route_fixdup_as(su_home_t *home,
msg_hclass_t *hc,
sip_route_t const *route)
{
sip_route_t *copy = NULL;
sip_route_t r[1], **rr;
sip_route_init(r);
/* Copy the record route as route */
for (rr = © route; route = route->r_next) {
*r->r_url = *route->r_url;
/* Fix broken (Record-)Routes without <> */
if (r->r_url->url_params == NULL
&& r->r_params
&& r->r_params[0]
&& (r->r_params[0][0] == 'l' || r->r_params[0][0] == 'L')
&& (r->r_params[0][1] == 'r' || r->r_params[0][1] == 'R')
&& (r->r_params[0][2] == '=' || r->r_params[0][2] == 0))
r->r_url->url_params = route->r_params[0],
r->r_params = route->r_params + 1;
else
r->r_params = route->r_params;
*rr = (sip_route_t *)msg_header_dup_as(home, hc, (msg_header_t *)r);
if (!*rr) goto error;
rr = &(*rr)->r_next;
}
return copy;
error:
msg_header_free_all(home, (msg_header_t *)copy);
return NULL;
}
/**@ingroup sip_route
*
* Fix and duplicate a @Route header.
*
* Copy a route header like @RecordRoute or @Path as @Route.
*
*/
sip_route_t *sip_route_fixdup(su_home_t *home, sip_route_t const *route)
{
return sip_route_fixdup_as(home, sip_route_class, route);
}
static void sip_fragment_clear_chain(sip_header_t *h)
{
void const *next;
for (h = h; h; h = h->sh_succ) {
next = (char *)h->sh_data + h->sh_len;
sip_fragment_clear(h->sh_common);
if (!next ||
!h->sh_succ ||
h->sh_next != h->sh_succ ||
h->sh_succ->sh_data != next ||
h->sh_succ->sh_len)
return;
}
}
/**@ingroup sip_route
*
* Fix @Route header.
*/
sip_route_t *sip_route_fix(sip_route_t *route)
{
sip_route_t *r;
sip_header_t *h = NULL;
size_t i;
for (r = route; r; r = r->r_next) {
/* Keep track of first header structure on this header line */
if (!h
|| (char *)h->sh_data + h->sh_len != r->r_common->h_data
|| r->r_common->h_len)
h = (sip_header_t *)r;
if (r->r_url->url_params == NULL
&& r->r_params
&& r->r_params[0]
&& (r->r_params[0][0] == 'l' || r->r_params[0][0] == 'L')
&& (r->r_params[0][1] == 'r' || r->r_params[0][1] == 'R')
&& (r->r_params[0][2] == '=' || r->r_params[0][2] == 0)) {
r->r_url->url_params = r->r_params[0];
for (i = 0; r->r_params[i]; i++)
((char const **)r->r_params)[i] = r->r_params[i + 1];
sip_fragment_clear_chain(h);
}
}
return route;
}
/**@ingroup sip_via
*
* Get first via header and remove it from its fragment chain.
*/
sip_via_t *sip_via_remove(msg_t *msg, sip_t *sip)
{
sip_via_t *v;
if (sip == NULL)
return NULL;
for (v = sip->sip_via; v; v = v->v_next) {
sip_fragment_clear(v->v_common);
if (v->v_next != (void *)v->v_common->h_succ)
break;
}
if ((v = sip->sip_via))
msg_header_remove(msg, (msg_pub_t *)sip, (msg_header_t *)v);
return v;
}
/** Serialize payload.
*
* The sip_payload_serialize() adds missing headers to MIME multiparty payload,
* encodes them and orders them in header chain. It also calculates the total
* length of the payload.
*/
unsigned long sip_payload_serialize(msg_t *msg, sip_payload_t *pl)
{
unsigned long total;
for (total = 0; pl; pl = (sip_payload_t *)pl->pl_next) {
total += (unsigned)pl->pl_common->h_len;
}
return total;
}
/**
* Remove extra parameters from an AOR URL.
*
* The extra parameters listed in the @RFC3261 table 1 include port number,
* method, maddr, ttl, transport, lr and headers.
*
* @note The funtion modifies the @a url and the strings attached to it.
*
* @retval 0 when successful
* @retval -1 upon an error
*/
int sip_aor_strip(url_t *url)
{
if (url == NULL)
return -1;
url->url_port = NULL;
url->url_headers = NULL;
if (url->url_params)
url_strip_transport(url);
if (url->url_params)
url->url_params =
url_strip_param_string((char *)url->url_params, "lr");
return 0;
}
/** Compare @SecurityVerify header with @SecurityServer header. */
int sip_security_verify_compare(sip_security_server_t const *s,
sip_security_verify_t const *v,
msg_param_t *return_d_ver)
{
size_t i, j;
int retval, digest;
msg_param_t const *s_params, *v_params, empty[] = { NULL };
if (return_d_ver)
*return_d_ver = NULL;
if (s == NULL)
return 0;
for (;;s = s->sa_next, v = v->sa_next) {
if (s == NULL || v == NULL)
return (s == NULL) - (v == NULL);
if ((retval = str0cmp(s->sa_mec, v->sa_mec)))
return retval;
digest = strcasecmp(s->sa_mec, "Digest") == 0;
s_params = s->sa_params, v_params = v->sa_params;
if (digest && s_params == NULL && v_params != NULL)
s_params = empty;
if (s_params == NULL || v_params == NULL) {
if ((retval = (s_params == NULL) - (v_params == NULL)))
return retval;
continue;
}
for (i = 0, j = 0;; i++, j++) {
if (digest && v_params[j] &&
strncasecmp(v_params[j], "d-ver=", 6) == 0) {
if (return_d_ver)
*return_d_ver = v_params[j] + strlen("d-ver=");
j++;
}
retval = str0cmp(s_params[i], v_params[j]);
if (retval || s_params[i] == NULL || v_params[j] == NULL)
break;
}
if (retval)
return retval;
}
}
/** Select best mechanism from @SecurityClient header.
*
* @note We assume that @SecurityServer header in @a s is sorted by
* preference.
*/
sip_security_client_t const *
sip_security_client_select(sip_security_client_t const *client,
sip_security_server_t const *server)
{
sip_security_server_t const *c, *s;
if (server == NULL || client == NULL)
return NULL;
for (s = server; s; s = s->sa_next) {
for (c = client; c; c = c->sa_next) {
if (str0cmp(s->sa_mec, c->sa_mec) == 0)
return c;
}
}
return NULL;
}
/**Checks if the response with given response code terminates dialog or
* dialog usage.
*
* @return -1 if the response with given code terminates whole dialog.
* @return 1 if the response terminates the dialog usage.
* @return 0 if the response does not terminate dialog or dialog usage.
*
* @return
* The @a *return_graceful_terminate_usage is set to 1, if application
* should gracefully terminate its dialog usage. It is set to 0, if no
* graceful terminate is required. If it is up to application policy to
* decide whether to gracefully terminate or not, the
* @a *return_graceful_terminate_usage is left unmodified.
*
* @RFC5057
*/
int sip_response_terminates_dialog(int response_code,
sip_method_t method,
int *return_graceful_terminate_usage)
{
enum { no_effect, terminate_usage = 1, terminate_dialog = -1 };
int dummy;
if (!return_graceful_terminate_usage)
return_graceful_terminate_usage = &dummy;
if (response_code < 300)
return *return_graceful_terminate_usage = 0;
/*
3xx responses: Redirection mid-dialog is not well understood in SIP,
but whatever effect it has impacts the entire dialog and all of
its usages equally. In our example scenario, both the
subscription and the invite usage would be redirected by this
single response.
*/
if (response_code < 400)
return *return_graceful_terminate_usage = 0;
if (response_code < 500) switch (response_code) {
default:
case 400: /** @par 400 and unrecognized 4xx responses
These responses affect only the NOTIFY transaction, not the
subscription, the dialog it resides in (beyond affecting the local
CSeq), or any other usage of that dialog. In general, the response
is a complaint about this transaction, not the usage or dialog the
transaction occurs in.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 401:
case 407: /** @par 401 Unauthorized and 407 Proxy Authentication Required
This request, not the subscription or dialog, is being challenged. The
usages and dialog are not terminated.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 402: /** @par 402 Payment Required
This is a reserved response code. If encountered, it should be
treated as an unrecognized 4xx.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 403: /** @par 403 Forbidden
This response terminates the subscription, but has no effect on
any other usages of the dialog. In our example scenario, the
invite usage continues to exist. Similarly, if the 403 came in
response to a re-INVITE, the invite usage would be terminated, but
not the subscription.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 404: /** @par 404 Not Found
This response destroys the dialog and all usages sharing it. The
Request-URI that is being 404ed is the remote target set by the
@Contact provided by the peer. Getting this response means
something has gone fundamentally wrong with the dialog state.
*/
return terminate_dialog;
case 405: /** @par 405 Method Not Allowed
In our example scenario, this response destroys the subscription,
but not the invite usage or the dialog. It's an aberrant case for
NOTIFYs to receive a 405 since they only come as a result to
something that creates subscription. In general, a 405 within a
given usage affects only that usage, but does not affect other
usages of the dialog.
*/
switch (method) {
case sip_method_notify:
case sip_method_subscribe:
case sip_method_invite:
return terminate_usage;
default:
*return_graceful_terminate_usage = 0;
return 0;
}
case 406: /** @par 406 Not Acceptable
These responses concern details of the message in the transaction.
Subsequent requests in this same usage may succeed. Neither the
usage nor dialog is terminated, other usages sharing this dialog
are unaffected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 408: /** @par 408 Request Timeout
Receiving a 408 will have the same effect on
usages and dialogs as a real transaction timeout as described in
Section 3.2.
*/
return terminate_usage;
case 410: /** @par 410 Gone
This response destroys the dialog and all usages sharing
it. The Request-URI that is being rejected is the remote target
set by the @Contact provided by the peer. Similar to 404, getting
this response means something has gone fundamentally wrong with
the dialog state, its slightly less aberrant in that the other
endpoint recognizes that this was once a valid URI that it isn't
willing to respond to anymore.
*/
return terminate_dialog;
case 412: /* Conditional Request Failed: */
case 413: /* Request Entity Too Large: */
case 414: /* Request-URI Too Long: */
case 415: /* Unsupported Media Type: */
/** @par 412, 413, 414 and 415
These responses concern details of the message in the transaction.
Subsequent requests in this same usage may succeed. Neither the usage
nor dialog is terminated, other usages sharing this dialog are
unaffected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 416: /** @par 416 Unsupported URI Scheme
Similar to 404 and 410, this response
came to a request whose Request-URI was provided by the peer in a
@Contact header field. Something has gone fundamentally wrong, and
the dialog and all of its usages are destroyed.
*/
return terminate_dialog;
case 417:
/** @par 417 Uknown Resource-Priority
The effect of this response on usages
and dialogs is analgous to that for 420 and 488. The usage is not
affected. The dialog is only affected by a change in its local
@CSeq. No other usages of the dialog are affected.
*/
case 420: /* Bad Extension */
case 421: /* Extension Required */
/** @par 420 Bad Extension and 421 Extension Required
These responses are objecting to the request, not the usage. The
usage is not affected. The dialog is only affected by a change in
its local @CSeq. No other usages of the dialog are affected.
*/
case 422: /** @par 422 Session Interval Too Small
This response will not be returned to
a NOTIFY in our example scenario. This response is non-sensical
for any mid-usage request. If it is received, an element in the
path of the request is violating protocol, and the recipient
should treat this as it would an unknown 4xx response. If the
response came to a request that was attempting to establish a new
usage in an existing dialog, no new usage is created and existing
usages are unaffected.
*/
case 423: /** @par 423 Interval Too Brief
This response won't happen in our example
scenario, but if it came in response to a re-SUBSCRIBE, the
subscribe usage is not destroyed (or otherwise affected). No
other usages of the dialog are affected.
*/
case 428: /** @par 428 Use Identity Header
This response objects to the request, not
the usage. The usage is not affected. The dialog is only
affected by a change in its local @CSeq. No other usages of the
dialog are affected. */
case 429: /** @par 429 Provide Referrer Identity
This response won't be returned to a NOTIFY as in our example
scenario, but when it is returned to a REFER, it is objecting to
the REFER request itself, not any usage the REFER occurs within.
The usage is unaffected. Any other usages sharing this dialog are
unaffected. The dialog is only affected by a change in its local
@CSeq.
*/
case 436: case 437: case 438:
/** @par 436 Bad Identity-Info, 437 Unsupported Certificate, 438 Invalid \
* Identity Header
*
* These responses object to the request, not the usage.
* The usage is not affected. The dialog is only affected by a
* change in its local @CSeq. No other usages of the dialog are
* affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 480: /** @par 480 Temporarily Unavailable
@RFC3261 is unclear on what this response means for mid-usage
requests. Clarifications will be made to show that this response
affects only the usage in which the request occurs. No other usages
are affected. If the response included a @RetryAfter header field,
further requests in that usage should not be sent until the indicated
time has past. Requests in other usages may still be sent at any time.
*/
return terminate_usage;
case 481: /** @par 481 Call/Transaction Does Not Exist
This response indicates that the peer has lost its copy of the dialog
state. The dialog and any usages sharing it are destroyed.
The dialog
itself should not be destroyed unless this was the last usage.
The effects of a 481 on a dialog and its usages are the most
ambiguous of any final response. There are implementations that
have chosen the meaning recommended here, and others that destroy
the entire dialog without regard to the number of outstanding
usages. Going forward with this clarification will allow those
deployed implementations that assumed only the usage was destroyed
to work with a wider number of implementations. Those that made
the other choice will continue to function as they do now,
suffering at most the same extra messages needed for a peer to
discover that that other usages have gone away that they currently
do. However, the necessary clarification to @RFC3261 needs to
make it very clear that the ability to terminate usages
independently from the overall dialog using a 481 is not
justification for designing new applications that count on
multiple usages in a dialog.
*/
return terminate_usage;
case 482: /** @par 482 Loop Detected
This response is aberrant mid-dialog. It will
only occur if the @RecordRoute header field was improperly
constructed by the proxies involved in setting up the dialog's
initial usage, or if a mid-dialog request forks and merges (which
should never happen). Future requests using this dialog state
will also fail. The dialog and any usages sharing it are
destroyed.
*/
return terminate_dialog;
case 483: /** @par 483 Too Many Hops
Similar to 482, receiving this mid-dialog is
aberrant. Unlike 482, recovery may be possible by increasing
@MaxForwards (assuming that the requester did something strange
like using a smaller value for @MaxForwards in mid-dialog requests
than it used for an initial request). If the request isn't tried
with an increased @MaxForwards, then the agent should attempt to
gracefully terminate this usage and all other usages that share
its dialog.
*/
*return_graceful_terminate_usage = 1;
return 0;
case 484: /* Address Incomplete */
case 485: /* Ambiguous */
/** @par 484 Address Incomplete and 485 Ambiguous
Similar to 404 and 410, these
responses came to a request whose Request-URI was provided by the
peer in a @Contact header field. Something has gone fundamentally
wrong, and the dialog and all of its usages are destroyed.
*/
return terminate_dialog;
case 486: /** @par 486 Busy Here
This response is non-sensical in our example scenario,
or in any scenario where this response comes inside an established
usage. If it occurs in that context, it should be treated as an
unknown 4xx response. The usage, and any other usages sharing its
dialog are unaffected. The dialog is only affected by the change
in its local @CSeq. If this response is to a request that is
attempting to establish a new usage within an existing dialog
(such as an INVITE sent within a dialog established by a
subscription), the request fails, no new usage is created, and no
other usages are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 487: /** @par 487 Request Terminated
This response speaks to the disposition of a
particular request (transaction). The usage in which that request
occurs is not affected by this response (it may be affected by
another associated request within that usage). No other usages
sharing this dialog are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 488: /** @par 488 Not Acceptable Here
This response is objecting to the request,
not the usage. The usage is not affected. The dialog is only
affected by a change in its local @CSeq. No other usages of the
dialog are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 489: /** @par 489 Bad Event
In our example scenario, @RFC3265 declares that the
subscription usage in which the NOTIFY is sent is terminated. The
invite usage is unaffected and the dialog continues to exist.
This response is only valid in the context of SUBSCRIBE and
NOTIFY. UAC behavior for receiving this response to other methods
is not specified, but treating it as an unknown 4xx is a
reasonable practice.
*/
*return_graceful_terminate_usage = 0;
return method == sip_method_notify ? terminate_usage : no_effect;
case 491: /** @par 491 Request Pending
This response addresses in-dialog request glare.
Its affect is scoped to the request. The usage in which the
request occurs is not affected. The dialog is only affected by
the change in its local @CSeq. No other usages sharing this dialog
are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 493: /** @par 493 Undecipherable
This response objects to the request, not the
usage. The usage is not affected. The dialog is only affected by
a change in its local @CSeq. No other usages of the dialog are
affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 494: /** @par 494 Security Agreement Required
This response is objecting to the
request, not the usage. The usage is not affected. The dialog is
only affected by a change in its local @CSeq. No other usages of
the dialog are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
}
if (response_code < 600) switch (response_code) {
case 500: /* 500 and 5xx unrecognized responses */
default:
/** @par 500 and 5xx unrecognized responses
These responses are complaints against the request (transaction),
not the usage. If the response contains a @RetryAfter header field
value, the server thinks the condition is temporary and the
request can be retried after the indicated interval. This usage,
and any other usages sharing the dialog are unaffected. If the
response does not contain a @RetryAfter header field value, the UA
may decide to retry after an interval of its choosing or attempt
to gracefully terminate the usage. Whether or not to terminate
other usages depends on the application. If the UA receives a 500
(or unrecognized 5xx) in response to an attempt to gracefully
terminate this usage, it can treat this usage as terminated. If
this is the last usage sharing the dialog, the dialog is also
terminated.
*/
/* Do not change *return_graceful_terminate_usage */
return 0;
case 501: /** @par 501 Not Implemented
This would be a degenerate response in our
example scenario since the NOTIFY is being sent as part of an
established subscribe usage. In this case, the UA knows the
condition is unrecoverable and should stop attempting to send
NOTIFYs on this usage. (It may or may not destroy the usage. If
it remembers the bad behavior, it can reject any refresh
subscription). In general, this response may or may not affect
the usage (a 501 to an unknown method or an INFO will not end an
invite usage). It will never affect other usages sharing this
usage's dialog.
*/
/* Do not change *return_graceful_terminate_usage */
return 0;
case 502: /** @par 502 Bad Gateway
This response is aberrant mid-dialog. It will only occur if the
@RecordRoute header field was improperly constructed by the
proxies involved in setting up the dialog's initial usage. Future
requests using this dialog state will also fail. The dialog and
any usages sharing it are destroyed.
*/
return terminate_dialog;
case 503: /** @par 503 Service Unavailable
As per @RFC3263, the logic handling locating SIP servers for
transactions may handle 503 requests (effectively sequentially
forking at the endpoint based on DNS results). If this process
does not yield a better response, a 503 may be returned to the
transaction user. Like a 500 response, the error is a complaint
about this transaction, not the usage. Because this response
occurred in the context of an established usage (hence an existing
dialog), the route-set has already been formed and any opportunity
to try alternate servers (as recommended in @RFC3261) has been exhausted
by the @RFC3263 logic. The response should be handled as described
for 500 earlier in this memo.
*/
/* Do not change *return_graceful_terminate_usage */
return 0;
case 504: /** @par 504 Server Time-out
It is not obvious under what circumstances this
response would be returned to a request in an existing dialog. If
it occurs it should have the same affect on the dialog and its
usages as described for unknown 5xx responses.
*/
/* Do not change *return_graceful_terminate_usage */
return 0;
case 505: /* Version Not Supported */
case 513: /* Message Too Large */
/** @par 505 Version Not Supported and 513 Message Too Large
These responses are objecting to the request, not the usage. The
usage is not affected. The dialog is only affected by a change in
its local @CSeq. No other usages of the dialog are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 580: /** @par 580 Precondition Failure
This response is objecting to the request,
not the usage. The usage is not affected. The dialog is only
affected by a change in its local @CSeq. No other usages of the
dialog are affected.
*/
*return_graceful_terminate_usage = 0;
return 0;
}
if (response_code < 700) switch (response_code) {
case 600: /* 600 and 6xx unrecognized responses */
default:
/** @par 600 and 6xx unrecognized responses
Unlike 400 Bad Request, a 600 response code says something about
the recipient user, not the request that was made. This end user
is stating an unwillingness to communicate.
If the response contains a @RetryAfter header field value, the
user is indicating willingness to communicate later and the
request can be retried after the indicated interval. This usage,
and any other usages sharing the dialog are unaffected. If the
response does not contain a @RetryAfter header field value, the UA
may decide to retry after an interval of its choosing or attempt
to gracefully terminate the usage. Whether or not to terminate
other usages depends on the application. If the UA receives a 600
(or unrecognized 6xx) in response to an attempt to gracefully
terminate this usage, it can treat this usage as terminated. If
this is the last usage sharing the dialog, the dialog is also
terminated.
*/
/* Do not change graceful_terminate */
return 0;
case 603: /** @par 603 Decline
This response declines the action indicated by the
associated request. It can be used, for example, to decline a
hold or transfer attempt. Receiving this response does NOT
terminate the usage it occurs in. Other usages sharing the dialog
are unaffected.
*/
*return_graceful_terminate_usage = 0;
return 0;
case 604: /** @par 604 Does Not Exist Anywhere
Like 404, this response destroys the
dialog and all usages sharing it. The Request-URI that is being
604ed is the remote target set by the @Contact provided by the
peer. Getting this response means something has gone
fundamentally wrong with the dialog state.
*/
return terminate_dialog;
case 606: /** @par 606 Not Acceptable
This response is objecting to aspects of the
associated request, not the usage the request appears in. The
usage is unaffected. Any other usages sharing the dialog are
unaffected. The only affect on the dialog is the change in the
local @CSeq.
*/
*return_graceful_terminate_usage = 0;
return 0;
}
/* Do not change graceful_terminate */
return 0;
}