/*
* check if a given request (outbound -> inbound) shall its
* request URI get rewritten based upon our UA knowledge
*
* RETURNS
* STS_TRUE if to be rewritten
* STS_FALSE otherwise
*/
int check_rewrite_rq_uri (osip_message_t *sip) {
int i, j, sts;
int dflidx;
osip_header_t *ua_hdr;
/* get index of default entry */
dflidx=(sizeof(RQ_rewrite)/sizeof(RQ_rewrite[0])) - 1;
/* check fort existence of method */
if ((sip==NULL) ||
(sip->sip_method==NULL)) {
ERROR("check_rewrite_rq_uri: got NULL method");
return STS_FALSE;
}
/* extract UA string */
osip_message_get_user_agent (sip, 0, &ua_hdr);
if ((ua_hdr==NULL) || (ua_hdr->hvalue==NULL)) {
DEBUGC(DBCLASS_SIP, "check_rewrite_rq_uri: NULL UA in Header, "
"using default");
i=dflidx;
} else {
/* loop through the knowledge base */
for (i=0; RQ_rewrite[i].UAstring; i++) {
if (strncmp(RQ_rewrite[i].UAstring, ua_hdr->hvalue,
sizeof(RQ_rewrite[i].UAstring))==0) {
DEBUGC(DBCLASS_SIP, "got knowledge entry for [%s]",
ua_hdr->hvalue);
break;
}
} /* for i */
} /* if ua_hdr */
for (j=0; RQ_method[j].name; j++)
{
if (strncmp(RQ_method[j].name,
sip->sip_method, RQ_method[j].size)==0)
{
if (RQ_rewrite[i].action[j] >= 0)
{
sts = (RQ_rewrite[i].action[j])? STS_TRUE: STS_FALSE;
}
else
{
sts = (RQ_rewrite[dflidx].action[j])? STS_TRUE: STS_FALSE;
}
DEBUGC(DBCLASS_SIP, "check_rewrite_rq_uri: [%s:%s, i=%i, j=%i] "
"got action %s",
(sip && sip->sip_method) ?
sip->sip_method : "*NULL*",
(ua_hdr && ua_hdr->hvalue)? ua_hdr->hvalue:"*NULL*",
i, j, (sts==STS_TRUE)? "rewrite":"norewrite");
return sts;
}
} /* for j */
WARN("check_rewrite_rq_uri: didn't get a hit of the method [%s]",
sip->sip_method);
return STS_FALSE;
}
/*
* PROXY_RESPONSE
*
* RETURNS
* STS_SUCCESS on success
* STS_FAILURE on error
* RFC3261
* Section 16.7: Proxy Behavior - Response Processing
* 1. Find the appropriate response context
* 2. Update timer C for provisional responses
* 3. Remove the topmost Via
* 4. Add the response to the response context
* 5. Check to see if this response should be forwarded immediately
* 6. When necessary, choose the best final response from the
* response context
* 7. Aggregate authorization header field values if necessary
* 8. Optionally rewrite Record-Route header field values
* 9. Forward the response
* 10. Generate any necessary CANCEL requests
*
*/
int proxy_response (sip_ticket_t *ticket) {
int i;
int sts;
int type;
struct in_addr sendto_addr;
osip_via_t *via;
int port;
char *buffer;
int buflen;
osip_message_t *response;
struct sockaddr_in *from;
DEBUGC(DBCLASS_PROXY,"proxy_response");
if (ticket==NULL) {
ERROR("proxy_response: called with NULL ticket");
return STS_FAILURE;
}
response=ticket->sipmsg;
from=&ticket->from;
/*
* RFC 3261, Section 16.7 step 3
* Proxy Behavior - Response Processing - Remove my Via header field value
*/
/* remove my Via header line */
sts = sip_del_myvia(ticket);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_PROXY,"not addressed to my VIA, ignoring response");
return STS_FAILURE;
}
/*
* figure out if this is an request coming from the outside
* world to one of our registered clients
*/
/* Ahhrghh...... a response seems to have NO contact information...
* so let's take FROM instead...
* the TO and FROM headers are EQUAL to the request - that means
* they are swapped in their meaning for a response...
*/
#if _OLD_DIRECTION_EVALUATION
type = 0;
for (i=0; i<URLMAP_SIZE; i++) {
if (urlmap[i].active == 0) continue;
/* incoming response ('from' == 'masq') || ('from' == 'reg') */
if ((compare_url(response->from->url, urlmap[i].reg_url)==STS_SUCCESS) ||
(compare_url(response->from->url, urlmap[i].masq_url)==STS_SUCCESS)) {
type=RESTYP_INCOMING;
DEBUGC(DBCLASS_PROXY,"incoming response for %s@%s from outbound",
response->from->url->username? response->from->url->username:"******",
response->from->url->host? response->from->url->host : "*NULL*");
break;
}
/* outgoing response ('to' == 'reg') || ('to' == 'masq' ) */
if ((compare_url(response->to->url, urlmap[i].masq_url)==STS_SUCCESS) ||
(compare_url(response->to->url, urlmap[i].reg_url)==STS_SUCCESS)){
type=RESTYP_OUTGOING;
DEBUGC(DBCLASS_PROXY,"outgoing response for %s@%s from inbound",
response->from->url->username ?
response->from->url->username : "******",
response->from->url->host ?
response->from->url->host : "*NULL*");
break;
}
}
#else
type = 0;
/*
* did I receive the telegram from a REGISTERED host?
* -> it must be an OUTGOING response
*/
for (i=0; i<URLMAP_SIZE; i++) {
struct in_addr tmp_addr;
if (urlmap[i].active == 0) continue;
if (get_ip_by_host(urlmap[i].true_url->host, &tmp_addr) == STS_FAILURE) {
DEBUGC(DBCLASS_PROXY, "proxy_response: cannot resolve host [%s]",
urlmap[i].true_url);
} else {
DEBUGC(DBCLASS_PROXY, "proxy_response: reghost:%s ip:%s",
urlmap[i].true_url->host, utils_inet_ntoa(from->sin_addr));
if (memcmp(&tmp_addr, &from->sin_addr, sizeof(tmp_addr)) == 0) {
type=RESTYP_OUTGOING;
break;
}
}
}
/*
* is the telegram directed to an internal registered host?
* -> it must be an INCOMING response
*/
if (type == 0) {
for (i=0; i<URLMAP_SIZE; i++) {
if (urlmap[i].active == 0) continue;
/* incoming response ('from' == 'masq') || ('from' == 'reg') */
if ((compare_url(response->from->url, urlmap[i].reg_url)==STS_SUCCESS) ||
(compare_url(response->from->url, urlmap[i].masq_url)==STS_SUCCESS)) {
type=RESTYP_INCOMING;
break;
}
}
}
/* &&&& Open Issue &&&&
it has been seen with cross-provider calls that the FROM may be 'garbled'
(e.g [email protected] for calls made sipphone -> FWD)
How can we deal with this? Should I take into consideration the 'Via'
headers? This is the only clue I have, pointing to the *real* UA.
Maybe I should put in a 'siproxd' ftag value to recognize it as a header
inserted by myself
*/
if ((type == 0) && (!osip_list_eol(response->vias, 0))) {
osip_via_t *via;
struct in_addr addr_via, addr_myself;
int port_via, port_ua;
/* get the via address */
via = (osip_via_t *) osip_list_get (response->vias, 0);
DEBUGC(DBCLASS_PROXY, "proxy_response: check via [%s] for "
"registered UA",via->host);
sts=get_ip_by_host(via->host, &addr_via);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_DNS, "proxy_response: cannot resolve VIA [%s]",
via->host);
} else {
for (i=0; i<URLMAP_SIZE; i++) {
if (urlmap[i].active == 0) continue;
/* incoming response (1st via in list points to a registered UA) */
sts=get_ip_by_host(urlmap[i].true_url->host, &addr_myself);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_DNS, "proxy_response: cannot resolve "
"true_url [%s]", via->host);
continue;
}
port_via=0;
if (via->port) port_via=atoi(via->port);
if (port_via <= 0) port_via=SIP_PORT;
port_ua=0;
if (urlmap[i].true_url->port)
port_ua=atoi(urlmap[i].true_url->port);
if (port_ua <= 0) port_ua=SIP_PORT;
DEBUGC(DBCLASS_BABBLE, "proxy_response: checking for registered "
"host [%s:%i] <-> [%s:%i]",
urlmap[i].true_url->host, port_ua,
via->host, port_via);
if ((memcmp(&addr_myself, &addr_via, sizeof(addr_myself))==0) &&
(port_via == port_ua)) {
type=RESTYP_INCOMING;
break;
}
}
}
}
#endif
ticket->direction=type;
/*
* ok, we got a response that we are allowed to process.
*/
switch (type) {
/*
* from an external host to the internal masqueraded host
*/
case RESTYP_INCOMING:
DEBUGC(DBCLASS_PROXY,"incoming response for %s@%s from outbound",
response->from->url->username? response->from->url->username:"******",
response->from->url->host? response->from->url->host : "*NULL*");
/*
* Response for INVITE - deal with RTP data in body and
* start RTP proxy stream(s). In case
* of a negative answer, stop RTP stream
*/
if (MSG_IS_RESPONSE_FOR(response,"INVITE")) {
/* positive response, start RTP stream */
if ((MSG_IS_STATUS_1XX(response)) ||
(MSG_IS_STATUS_2XX(response))) {
if (configuration.rtp_proxy_enable == 1) {
sts = proxy_rewrite_invitation_body(response, DIR_INCOMING);
}
/* negative - stop a possibly started RTP stream */
} else if ((MSG_IS_STATUS_4XX(response)) ||
(MSG_IS_STATUS_5XX(response)) ||
(MSG_IS_STATUS_6XX(response))) {
rtp_stop_fwd(osip_message_get_call_id(response), DIR_INCOMING);
rtp_stop_fwd(osip_message_get_call_id(response), DIR_OUTGOING);
}
} /* if INVITE */
/*
* Response for REGISTER - special handling of Contact header
*/
if (MSG_IS_RESPONSE_FOR(response,"REGISTER")) {
/*
* REGISTER returns *my* Contact header information.
* Rewrite Contact header back to represent the true address.
* Other responses do return the Contact header of the sender.
*/
sip_rewrite_contact(ticket, DIR_INCOMING);
}
/*
* Response for SUBSCRIBE
*
* HACK for Grandstream SIP phones (with newer firmware like 1.0.4.40):
* They send a SUBSCRIBE request to the registration server. In
* case of beeing registering directly to siproxd, this request of
* course will eventually be forwarded back to the same UA.
* Grandstream then does reply with an '202' response (A 202
* response merely indicates that the subscription has been
* understood, and that authorization may or may not have been
* granted), which then of course is forwarded back to the phone.
* Ans it seems that the Grandstream can *not* *handle* this
* response, as it immediately sends another SUBSCRIBE request.
* And this games goes on and on and on...
*
* As a workaround we will transform any 202 response to a
* '404 unknown destination'
*
*/
{
osip_header_t *ua_hdr=NULL;
osip_message_get_user_agent(response, 0, &ua_hdr);
if (ua_hdr && ua_hdr->hvalue &&
(osip_strncasecmp(ua_hdr->hvalue,"grandstream", 11)==0) &&
(MSG_IS_RESPONSE_FOR(response,"SUBSCRIBE")) &&
(MSG_TEST_CODE(response, 202))) {
DEBUGC(DBCLASS_PROXY, "proxy_response: Grandstream hack 202->404");
response->status_code=404;
}
}
break;
/*
* from the internal masqueraded host to an external host
*/
case RESTYP_OUTGOING:
DEBUGC(DBCLASS_PROXY,"outgoing response for %s@%s from inbound",
response->from->url->username ?
response->from->url->username : "******",
response->from->url->host ?
response->from->url->host : "*NULL*");
/* rewrite Contact header to represent the masqued address */
sip_rewrite_contact(ticket, DIR_OUTGOING);
/*
* If an 2xx OK or 1xx response, answer to an INVITE request,
* rewrite body
*
* In case of a negative answer, stop RTP stream
*/
if (MSG_IS_RESPONSE_FOR(response,"INVITE")) {
/* positive response, start RTP stream */
if ((MSG_IS_STATUS_1XX(response)) ||
(MSG_IS_STATUS_2XX(response))) {
/* This is an outgoing response, therefore an outgoing stream */
sts = proxy_rewrite_invitation_body(response, DIR_OUTGOING);
/* megative - stop a possibly started RTP stream */
} else if ((MSG_IS_STATUS_4XX(response)) ||
(MSG_IS_STATUS_5XX(response)) ||
(MSG_IS_STATUS_6XX(response))) {
rtp_stop_fwd(osip_message_get_call_id(response), DIR_INCOMING);
rtp_stop_fwd(osip_message_get_call_id(response), DIR_OUTGOING);
}
} /* if INVITE */
break;
default:
DEBUGC(DBCLASS_PROXY, "response from/to unregistered UA (%s@%s)",
response->from->url->username? response->from->url->username:"******",
response->from->url->host? response->from->url->host : "*NULL*");
return STS_FAILURE;
}
/*
* for ALL incoming response include my Record-Route header.
* The local UA will probably send its answer to the topmost
* Route Header (8.1.2 of RFC3261)
*/
if (type == RESTYP_INCOMING) {
DEBUGC(DBCLASS_PROXY,"Adding my Record-Route");
route_add_recordroute(ticket);
} else {
/*
* outgoing packets must not have my record route header, as
* this likely will contain a private IP address (my inbound).
*/
DEBUGC(DBCLASS_PROXY,"Purging Record-Routes (outgoing packet)");
route_purge_recordroute(ticket);
}
/*
* Determine Next-Hop Address
*/
/*&&&& priority probably should be:
* 1) Route header
* 2) fixed outbound proxy
* 3) SIP URI
*/
/*
* check if we need to send to an outbound proxy
*/
if ((type == RESTYP_OUTGOING) &&
(sip_find_outbound_proxy(ticket, &sendto_addr, &port) == STS_SUCCESS)) {
DEBUGC(DBCLASS_PROXY, "proxy_response: have outbound proxy %s:%i",
utils_inet_ntoa(sendto_addr), port);
/*
* Route present?
* If so, fetch address from topmost Route: header and remove it.
*/
} else if ((type == RESTYP_OUTGOING) &&
(response->routes && !osip_list_eol(response->routes, 0))) {
sts=route_determine_nexthop(ticket, &sendto_addr, &port);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_PROXY, "proxy_response: route_determine_nexthop failed");
return STS_FAILURE;
}
DEBUGC(DBCLASS_PROXY, "proxy_response: have Route header to %s:%i",
utils_inet_ntoa(sendto_addr), port);
} else {
/* get target address and port from VIA header */
via = (osip_via_t *) osip_list_get (response->vias, 0);
if (via == NULL) {
ERROR("proxy_response: list_get via failed");
return STS_FAILURE;
}
sts = get_ip_by_host(via->host, &sendto_addr);
if (sts == STS_FAILURE) {
DEBUGC(DBCLASS_PROXY, "proxy_response: cannot resolve VIA [%s]",
via->host);
return STS_FAILURE;
}
if (via->port) {
port=atoi(via->port);
} else {
port=SIP_PORT;
}
}
sts = sip_message_to_str(response, &buffer, &buflen);
if (sts != 0) {
ERROR("proxy_response: sip_message_to_str failed");
return STS_FAILURE;
}
sipsock_send(sendto_addr, port, ticket->protocol,
buffer, buflen);
osip_free (buffer);
return STS_SUCCESS;
}