/
t_reply.c
1832 lines (1613 loc) · 52.2 KB
/
t_reply.c
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/*
* Copyright (C) 2010-2014 OpenSIPS Solutions
* Copyright (C) 2001-2003 FhG Fokus
*
* This file is part of opensips, a free SIP server.
*
* opensips is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
*
* opensips is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* History:
* --------
* 2003-01-19 faked lump list created in on_reply handlers
* 2003-01-27 next baby-step to removing ZT - PRESERVE_ZT (jiri)
* 2003-02-13 updated to use rb->dst (andrei)
* 2003-02-18 replaced TOTAG_LEN w/ TOTAG_VALUE_LEN (TOTAG_LEN was defined
* twice with different values!) (andrei)
* 2003-02-28 scratchpad compatibility abandoned (jiri)
* 2003-03-01 kr set through a function now (jiri)
* 2003-03-06 saving of to-tags for ACK/200 matching introduced,
* voicemail changes accepted, updated to new callback
* names (jiri)
* 2003-03-10 fixed new to tag bug/typo (if w/o {}) (andrei)
* 2003-03-16 removed _TOTAG (jiri)
* 2003-03-31 200 for INVITE/UAS resent even for UDP (jiri)
* 2003-03-31 removed msg->repl_add_rm (andrei)
* 2003-04-05 s/reply_route/failure_route, onreply_route introduced (jiri)
* 2003-04-14 local acks generated before reply processing to avoid
* delays in length reply processing (like opening TCP
* connection to an unavailable destination) (jiri)
* 2003-09-11 updates to new build_res_buf_from_sip_req() interface (bogdan)
* 2003-09-11 t_reply_with_body() reshaped to use reply_lumps +
* build_res_buf_from_sip_req() instead of
* build_res_buf_with_body_from_sip_req() (bogdan)
* 2003-11-05 flag context updated from failure/reply handlers back
* to transaction context (jiri)
* 2003-11-11: build_lump_rpl() removed, add_lump_rpl() has flags (bogdan)
* 2003-12-04 global TM callbacks switched to per transaction callbacks
* (bogdan)
* 2004-02-06: support for user pref. added - destroy_avps (bogdan)
* 2003-11-05 flag context updated from failure/reply handlers back
* to transaction context (jiri)
* 2003-11-11: build_lump_rpl() removed, add_lump_rpl() has flags (bogdan)
* 2004-02-13: t->is_invite and t->local replaced with flags (bogdan)
* 2004-02-18 fifo_t_reply imported from vm module (bogdan)
* 2004-08-23 avp list is available from failure/on_reply routes (bogdan)
* 2004-10-01 added a new param.: restart_fr_on_each_reply (andrei)
* 2005-03-01 force for statefull replies the incoming interface of
* the request (bogdan)
* 2005-03-01 local ACK sent to same address as INVITE ->
* all [build|send]_[local]_ack functions merged into
* send_ack() (bogdan)
* 2007-01-25 DNS failover at transaction level added (bogdan)
*/
#include "../../hash_func.h"
#include "../../dprint.h"
#include "../../config.h"
#include "../../parser/parser_f.h"
#include "../../ut.h"
#include "../../timer.h"
#include "../../error.h"
#include "../../action.h"
#include "../../dset.h"
#include "../../tags.h"
#include "../../data_lump.h"
#include "../../data_lump_rpl.h"
#include "../../usr_avp.h"
#include "../../receive.h"
#include "../../msg_callbacks.h"
#include "h_table.h"
#include "t_hooks.h"
#include "t_funcs.h"
#include "t_reply.h"
#include "t_cancel.h"
#include "t_msgbuilder.h"
#include "t_lookup.h"
#include "t_fwd.h"
#include "fix_lumps.h"
#include "t_stats.h"
#include "uac.h"
/* restart fr timer on each provisional reply, default yes */
int restart_fr_on_each_reply=1;
int onreply_avp_mode = 0;
/* disable the 6xx fork-blocking - default no (as per RFC3261) */
int disable_6xx_block = 0;
/* flag for marching minor branches */
int minor_branch_flag = -1;
char *minor_branch_flag_str = 0;
/* private place where we create to-tags for replies */
char tm_tags[TOTAG_VALUE_LEN];
static str tm_tag = {tm_tags,TOTAG_VALUE_LEN};
char *tm_tag_suffix;
static int picked_branch=-1;
/* where to go if there is no positive reply */
static int goto_on_negative=0;
/* where to go on receipt of reply */
static int goto_on_reply=0;
/* currently processed branch */
extern int _tm_branch_index;
/* returns the picked branch */
int t_get_picked_branch(void)
{
return picked_branch;
}
/* we store the reply_route # in private memory which is
then processed during t_relay; we cannot set this value
before t_relay creates transaction context or after
t_relay when a reply may arrive after we set this
value; that's why we do it how we do it, i.e.,
*inside* t_relay using hints stored in private memory
before t_relay is called
*/
void t_on_negative( unsigned int go_to )
{
struct cell *t = get_t();
/* in MODE_REPLY and MODE_ONFAILURE T will be set to current transaction;
* in MODE_REQUEST T will be set only if the transaction was already
* created; if not -> use the static variable */
if (!t || t==T_UNDEFINED )
goto_on_negative=go_to;
else
t->on_negative = go_to;
}
void t_on_reply( unsigned int go_to )
{
struct cell *t = get_t();
/* in MODE_REPLY and MODE_ONFAILURE T will be set to current transaction;
* in MODE_REQUEST T will be set only if the transaction was already
* created; if not -> use the static variable */
if (!t || t==T_UNDEFINED ) {
goto_on_reply=go_to;
} else {
if (route_type==BRANCH_ROUTE) {
t->uac[_tm_branch_index].on_reply = go_to;
} else {
t->on_reply = go_to;
}
}
}
unsigned int get_on_negative(void)
{
return goto_on_negative;
}
unsigned int get_on_reply(void)
{
return goto_on_reply;
}
void tm_init_tags(void)
{
init_tags(tm_tags, &tm_tag_suffix,
"OpenSIPS-TM/tags", TM_TAG_SEPARATOR );
}
/* returns 0 if the message was previously acknowledged
* (i.e., no E2EACK callback is needed) and one if the
* callback shall be executed */
int unmatched_totag(struct cell *t, struct sip_msg *ack)
{
struct totag_elem *i;
str *tag;
if (parse_headers(ack, HDR_TO_F,0)==-1 ||
!ack->to ) {
LM_ERR("To invalid\n");
return 1;
}
tag=&get_to(ack)->tag_value;
for (i=t->fwded_totags; i; i=i->next) {
if (i->tag.len==tag->len
&& memcmp(i->tag.s, tag->s, tag->len)==0) {
LM_DBG("totag for e2e ACK found: %d\n", i->acked);
/* to-tag recorded, and an ACK has been received for it */
if (i->acked) return 0;
/* to-tag recorded, but this ACK came for the first time */
i->acked=1;
return 1;
}
}
/* surprising: to-tag never sighted before */
return 1;
}
static inline void update_local_tags(struct cell *trans,
struct bookmark *bm, char *dst_buffer,
char *src_buffer /* to which bm refers */)
{
if (bm->to_tag_val.s) {
trans->uas.local_totag.s=bm->to_tag_val.s-src_buffer+dst_buffer;
trans->uas.local_totag.len=bm->to_tag_val.len;
}
}
/* append a newly received tag from a 200/INVITE to
* transaction's set; (only safe if called from within
* a REPLY_LOCK); it returns 1 if such a to tag already
* exists
*/
inline static int update_totag_set(struct cell *t, struct sip_msg *ok)
{
struct totag_elem *i, *n;
str *tag;
char *s;
if (!ok->to || !ok->to->parsed) {
LM_ERR("to not parsed\n");
return 0;
}
tag=&get_to(ok)->tag_value;
if (!tag->s) {
LM_DBG("no tag in to\n");
return 0;
}
for (i=t->fwded_totags; i; i=i->next) {
if (i->tag.len==tag->len
&& memcmp(i->tag.s, tag->s, tag->len) ==0 ){
/* to tag already recorded */
#ifdef XL_DEBUG
LM_CRIT("totag retransmission\n");
#else
LM_DBG("totag retransmission\n");
#endif
return 1;
}
}
/* that's a new to-tag -- record it */
#ifndef HP_MALLOC
shm_lock();
n=(struct totag_elem*) shm_malloc_unsafe(sizeof(struct totag_elem));
s=(char *)shm_malloc_unsafe(tag->len);
shm_unlock();
#else
n=(struct totag_elem*) shm_malloc(sizeof(struct totag_elem));
s=(char *)shm_malloc(tag->len);
#endif
if (!s || !n) {
LM_ERR("no more share memory \n");
if (n) shm_free(n);
if (s) shm_free(s);
return 0;
}
memset(n, 0, sizeof(struct totag_elem));
memcpy(s, tag->s, tag->len );
n->tag.s=s;n->tag.len=tag->len;
n->next=t->fwded_totags;
t->fwded_totags=n;
LM_DBG("new totag \n");
return 0;
}
/*
* Build and send an ACK to a negative reply
*/
static int send_ack(struct sip_msg* rpl, struct cell *trans, int branch)
{
str method = str_init(ACK);
str to;
str ack_buf;
if(parse_headers(rpl,is_local(trans)?HDR_EOH_F:(HDR_TO_F|HDR_FROM_F),0)==-1
|| !rpl->to || !rpl->from ) {
LM_ERR("failed to generate a HBH ACK if key HFs in reply missing\n");
goto error;
}
to.s=rpl->to->name.s;
to.len=rpl->to->len;
ack_buf.s = is_local(trans)?
build_dlg_ack(rpl, trans, branch, &to, (unsigned int*)&ack_buf.len):
build_local( trans, branch, &method, NULL, rpl, (unsigned int*)&ack_buf.len );
if (ack_buf.s==0) {
LM_ERR("failed to build ACK\n");
goto error;
}
if (trans->uac[branch].br_flags & tcp_no_new_conn_bflag)
tcp_no_new_conn = 1;
if(SEND_PR_BUFFER(&trans->uac[branch].request, ack_buf.s, ack_buf.len)==0){
/* successfully sent out */
if ( has_tran_tmcbs( trans, TMCB_MSG_SENT_OUT) ) {
set_extra_tmcb_params( &ack_buf, &trans->uac[branch].request.dst);
run_trans_callbacks( TMCB_MSG_SENT_OUT,
trans, trans->uas.request, 0, 0);
}
}
tcp_no_new_conn = 0;
shm_free(ack_buf.s);
return 0;
error:
return -1;
}
static int _reply_light( struct cell *trans, char* buf, unsigned int len,
unsigned int code, char *to_tag, unsigned int to_tag_len,
int lock, struct bookmark *bm)
{
struct retr_buf *rb;
unsigned int buf_len;
branch_bm_t cancel_bitmap = 0;
str cb_s;
if (!buf)
{
LM_DBG("response building failed\n");
/* determine if there are some branches to be canceled */
if ( is_invite(trans) ) {
if (lock) LOCK_REPLIES( trans );
which_cancel(trans, &cancel_bitmap );
if (lock) UNLOCK_REPLIES( trans );
}
/* and clean-up, including cancellations, if needed */
goto error;
}
if (lock) LOCK_REPLIES( trans );
if (trans->uas.status>=200) {
LM_ERR("failed to generate %d reply when a final %d was sent out\n",
code, trans->uas.status);
goto error2;
}
if ( is_invite(trans) && code>=200 )
which_cancel(trans, &cancel_bitmap );
rb = & trans->uas.response;
rb->activ_type=code;
trans->uas.status = code;
buf_len = rb->buffer.s ? len : len + REPLY_OVERBUFFER_LEN;
rb->buffer.s = shm_realloc( rb->buffer.s, buf_len );
/* puts the reply's buffer to uas.response */
if (! rb->buffer.s ) {
LM_ERR("failed to allocate shmem buffer\n");
goto error3;
}
update_local_tags(trans, bm, rb->buffer.s, buf);
rb->buffer.len = len ;
memcpy( rb->buffer.s , buf , len );
/* needs to be protected too because what timers are set depends
on current transactions status */
/* t_update_timers_after_sending_reply( rb ); */
trans->relaied_reply_branch=-2;
if (lock) UNLOCK_REPLIES( trans );
/* do UAC cleanup procedures in case we generated
a final answer whereas there are pending UACs */
if (code>=200) {
if ( is_local(trans) ) {
LM_DBG("local transaction completed\n");
if ( has_tran_tmcbs(trans, TMCB_LOCAL_COMPLETED) ) {
run_trans_callbacks( TMCB_LOCAL_COMPLETED, trans,
0, FAKED_REPLY, code);
}
} else {
/* run the PRE send callbacks */
if ( has_tran_tmcbs(trans, TMCB_RESPONSE_PRE_OUT) ) {
cb_s.s = buf;
cb_s.len = len;
set_extra_tmcb_params( &cb_s, &rb->dst);
if (lock)
run_trans_callbacks_locked( TMCB_RESPONSE_PRE_OUT, trans,
trans->uas.request, FAKED_REPLY, code);
else
run_trans_callbacks( TMCB_RESPONSE_PRE_OUT, trans,
trans->uas.request, FAKED_REPLY, code);
}
}
if (!is_hopbyhop_cancel(trans)) {
cleanup_uac_timers( trans );
if (is_invite(trans)) cancel_uacs( trans, cancel_bitmap );
/* for auth related replies, we do not do retransmission
(via set_final_timer()), but only wait for a final
reply (put_on_wait() ) - see RFC 3261 (26.3.2.4 DoS Protection) */
if ((code != 401) && (code != 407))
set_final_timer( trans );
else
put_on_wait(trans);
}
}
/* send it out : response.dst.send_sock is valid all the time now,
* as it's taken from original request -bogdan */
if (!trans->uas.response.dst.send_sock) {
LM_CRIT("send_sock is NULL\n");
}
if(trans->uas.request && trans->uas.request->flags&tcp_no_new_conn_rplflag)
tcp_no_new_conn = 1;
if ( SEND_PR_BUFFER( rb, buf, len )==0 ) {
LM_DBG("reply sent out. buf=%p: %.9s..., "
"shmem=%p: %.9s\n", buf, buf, rb->buffer.s, rb->buffer.s );
if (has_tran_tmcbs(trans, TMCB_MSG_SENT_OUT) ) {
cb_s.s = buf;
cb_s.len = len;
set_extra_tmcb_params( &cb_s, &rb->dst);
run_trans_callbacks( TMCB_MSG_SENT_OUT, trans,
NULL, FAKED_REPLY, code);
}
stats_trans_rpl( code, 1 /*local*/ );
}
tcp_no_new_conn = 0;
/* run the POST send callbacks */
if (code>=200&&!is_local(trans)&&has_tran_tmcbs(trans,TMCB_RESPONSE_OUT)){
cb_s.s = buf;
cb_s.len = len;
set_extra_tmcb_params( &cb_s, &rb->dst);
if (lock)
run_trans_callbacks_locked( TMCB_RESPONSE_OUT, trans,
trans->uas.request, FAKED_REPLY, code);
else
run_trans_callbacks( TMCB_RESPONSE_OUT, trans,
trans->uas.request, FAKED_REPLY, code);
}
pkg_free( buf ) ;
LM_DBG("finished\n");
return 1;
error3:
error2:
if (lock) UNLOCK_REPLIES( trans );
pkg_free ( buf );
error:
/* do UAC cleanup */
cleanup_uac_timers( trans );
if ( is_invite(trans) ) cancel_uacs( trans, cancel_bitmap );
/* we did not succeed -- put the transaction on wait */
put_on_wait(trans);
return -1;
}
/* send a UAS reply
* returns 1 if everything was OK or -1 for error
*/
static int _reply( struct cell *trans, struct sip_msg* p_msg,
unsigned int code, str *text, int lock )
{
unsigned int len;
char * buf, *dset;
struct bookmark bm;
int dset_len;
if (code>=200) set_kr(REQ_RPLD);
/* compute the buffer in private memory prior to entering lock;
* create to-tag if needed */
/* if that is a redirection message, dump current message set to it */
if (code>=300 && code<400) {
dset=print_dset(p_msg, &dset_len);
if (dset) {
add_lump_rpl(p_msg, dset, dset_len, LUMP_RPL_HDR);
}
}
/* check if the UAS retranmission port needs to be updated */
if ( (p_msg->msg_flags ^ trans->uas.request->msg_flags) & FL_FORCE_RPORT )
su_setport( &trans->uas.response.dst.to, p_msg->rcv.src_port );
if (code>=180 && p_msg->to
&& (get_to(p_msg)->tag_value.s==0
|| get_to(p_msg)->tag_value.len==0)) {
calc_crc_suffix( p_msg, tm_tag_suffix );
buf = build_res_buf_from_sip_req(code,text, &tm_tag, p_msg, &len, &bm);
return _reply_light( trans, buf, len, code,
tm_tag.s, TOTAG_VALUE_LEN, lock, &bm);
} else {
buf = build_res_buf_from_sip_req(code,text, 0 /*no to-tag*/,
p_msg, &len, &bm);
return _reply_light(trans,buf,len,code, 0, 0 /* no to-tag */,
lock, &bm);
}
}
/*if msg is set -> it will fake the env. vars conforming with the msg; if NULL
* the env. will be restore to original */
static inline void faked_env( struct cell *t,struct sip_msg *msg)
{
static struct cell *backup_t;
static struct usr_avp **backup_list;
static struct socket_info* backup_si;
static int backup_route_type;
if (msg) {
swap_route_type( backup_route_type, FAILURE_ROUTE);
/* tm actions look in beginning whether transaction is
* set -- whether we are called from a reply-processing
* or a timer process, we need to set current transaction;
* otherwise the actions would attempt to look the transaction
* up (unnecessary overhead, refcounting)
*/
/* backup */
backup_t = get_t();
/* fake transaction */
set_t(t);
/* make available the avp list from transaction */
backup_list = set_avp_list( &t->user_avps );
/* set default send address to the saved value */
backup_si = bind_address;
bind_address = t->uac[0].request.dst.send_sock;
} else {
/* restore original environment */
set_t(backup_t);
set_route_type( backup_route_type );
/* restore original avp list */
set_avp_list( backup_list );
bind_address = backup_si;
}
}
/* return 1 if a failure_route processes */
static inline int run_failure_handlers(struct cell *t)
{
static struct sip_msg faked_req;
struct sip_msg *shmem_msg;
struct ua_client *uac;
int on_failure;
shmem_msg = t->uas.request;
uac = &t->uac[picked_branch];
/* failure_route for a local UAC? */
if (!shmem_msg || REQ_LINE(shmem_msg).method_value==METHOD_CANCEL ) {
LM_WARN("no UAC or CANCEL support (%d, %d) \n",
t->on_negative, t->tmcb_hl.reg_types);
return 0;
}
/* don't start faking anything if we don't have to */
if ( !has_tran_tmcbs( t, TMCB_ON_FAILURE) && !t->on_negative ) {
LM_WARN("no negative handler (%d, %d)\n",t->on_negative,
t->tmcb_hl.reg_types);
return 1;
}
if (!fake_req(&faked_req, shmem_msg, &t->uas, uac, 0/*no dst_uri*/)) {
LM_ERR("fake_req failed\n");
return 0;
}
/* fake also the env. conforming to the fake msg */
faked_env( t, &faked_req);
/* DONE with faking ;-) -> run the failure handlers */
if ( has_tran_tmcbs( t, TMCB_ON_FAILURE) ) {
run_trans_callbacks( TMCB_ON_FAILURE, t, &faked_req,
uac->reply, uac->last_received);
}
if (t->on_negative) {
/* update flags in transaction if changed by callbacks */
shmem_msg->flags = faked_req.flags;
/* avoid recursion -- if failure_route forwards, and does not
* set next failure route, failure_route will not be reentered
* on failure */
on_failure = t->on_negative;
t->on_negative=0;
/* run a reply_route action if some was marked */
run_top_route(failure_rlist[on_failure].a, &faked_req);
}
/* restore original environment and free the fake msg */
faked_env( t, 0);
free_faked_req(&faked_req,t);
/* if failure handler changed flag, update transaction context */
shmem_msg->flags = faked_req.flags;
/* branch flags do not need to be updated as this branch will be never
* used again */
return 1;
}
static inline int is_3263_failure(struct cell *t)
{
/* is is a DNS failover scenario? - according to RFC 3263
* and RFC 3261, this means 503 reply with Retr-After hdr
* or timeout with no reply */
LM_DBG("dns-failover test: branch=%d, last_recv=%d, flags=%X\n",
picked_branch, t->uac[picked_branch].last_received,
t->uac[picked_branch].flags);
switch (t->uac[picked_branch].last_received) {
case 408:
return ((t->uac[picked_branch].flags&T_UAC_HAS_RECV_REPLY)==0);
case 503:
if (t->uac[picked_branch].reply==NULL ||
t->uac[picked_branch].reply==FAKED_REPLY)
return 0;
/* we do not care about the Retry-After header in 503
* as following discussion on sip-implementers list :
* with or without a RA header, a 503 should fire DNS
* based failover - bogdan
*/
return 1;
}
return 0;
}
static inline int do_dns_failover(struct cell *t)
{
static struct sip_msg faked_req;
struct sip_msg *shmem_msg;
struct sip_msg *req;
struct ua_client *uac;
dlg_t dialog;
int ret, sip_msg_len;
uac = &t->uac[picked_branch];
/* check if the DNS resolver can get at least one new IP */
if ( get_next_su( uac->proxy, &uac->request.dst.to, 1)!=0 )
return -1;
LM_DBG("new destination available\n");
if (t->uas.request==NULL) {
if (!is_local(t)) {
LM_CRIT("BUG: proxy transaction without UAS request :-/\n");
return -1;
}
/* create the cloned SIP msg -> first create a new SIP msg */
memset( &dialog, 0, sizeof(dialog));
dialog.send_sock = uac->request.dst.send_sock;
dialog.hooks.next_hop = &uac->uri;
req = buf_to_sip_msg(uac->request.buffer.s, uac->request.buffer.len,
&dialog);
if (req==NULL) {
LM_ERR("failed to generate SIP msg from previous buffer\n");
return -1;
}
/* now do the actual cloning of the SIP message */
t->uas.request = sip_msg_cloner( req, &sip_msg_len, 1);
if (t->uas.request==NULL) {
LM_ERR("cloning failed\n");
free_sip_msg(req);
pkg_free(req);
return -1;
}
t->uas.end_request = ((char*)t->uas.request) + sip_msg_len;
/* free the actual SIP message, keep the clone only */
free_sip_msg(req);
pkg_free(req);
}
shmem_msg = t->uas.request;
if (!fake_req(&faked_req, shmem_msg, &t->uas, uac, 1/*with dst_uri*/)) {
LM_ERR("fake_req failed\n");
return -1;
}
/* fake also the env. conforming to the fake msg */
faked_env( t, &faked_req);
ret = -1;
/* set info as current destination */
if ( set_ruri( &faked_req, &uac->uri)!= 0)
goto done;
setb0flags( &faked_req, uac->br_flags );
faked_req.force_send_socket = shmem_msg->force_send_socket;
/* send it out */
if (t_forward_nonack( t, &faked_req, uac->proxy,1/*reset*/,1/*locked*/)==1)
ret = 0;
done:
/* restore original environment and free the fake msg */
faked_env( t, 0);
free_faked_req(&faked_req,t);
return ret;
}
static inline int branch_prio( short ret_code, unsigned int is_cancelled)
{
int first_digit;
first_digit = ret_code / 100;
switch(first_digit){
case 1: /* 100 - 199 */
case 2: /* 200 - 299 */
return ret_code;
case 6:
return ret_code - 300; /* 300 - 399 */
case 3:
return ret_code + 100; /* 400 - 499 */
case 5:
if (ret_code==503)
return 801; /* 801 */
return ret_code + 200; /* 700 - 799 */
case 4:
switch(ret_code){
case 401:
return 500; /* 500 - 599 */
case 407:
return 501;
case 415:
return 502;
case 420:
return 503;
case 484:
return 504;
case 408:
return 800; /* 800 */
case 487:
if(is_cancelled)
return 0;
default: /* the rest of ret codes in the 4xx class */
return ret_code + 200; /* 600 - 699 */
}
default:
return ret_code + 200; /* > 900 */
}
}
/* select a branch for forwarding; returns:
* 0..X ... branch number
* -1 ... error
* -2 ... can't decide yet -- incomplete branches present
*/
static inline int t_pick_branch( struct cell *t, int *res_code, int *do_cancel)
{
int lowest_b, lowest_s, b, prio;
unsigned int cancelled;
lowest_b=-1; lowest_s=999;
cancelled = was_cancelled(t);
*do_cancel = 0;
for ( b=t->first_branch; b<t->nr_of_outgoings ; b++ ) {
/* skip PHONY branches if the transaction was canceled by UAC;
* a phony branch is used just to force the transaction to wait for
* more branches, but if canceled, it makes no sense to wait anymore */
if ( (t->uac[b].flags & T_UAC_IS_PHONY) &&
(t->flags & T_WAS_CANCELLED_FLAG) )
continue;
/* skip 'empty branches' */
if (!t->uac[b].request.buffer.s) continue;
/* there is still an unfinished UAC transaction; wait now! */
if ( t->uac[b].last_received<200 ) {
if (t->uac[b].br_flags & minor_branch_flag) {
*do_cancel = 1;
continue; /* if last branch, lowest_b remains -1 */
}
return -2;
}
/* compare against the priority of the current branch */
prio = branch_prio(t->uac[b].last_received,cancelled);
if ( (lowest_b==-1) || (prio<lowest_s) ) {
lowest_b = b;
lowest_s = prio;
}
} /* find lowest branch */
LM_DBG("picked branch %d, code %d (prio=%d)\n",
lowest_b,lowest_b==-1 ? -1 : t->uac[lowest_b].last_received,lowest_s);
*res_code=lowest_s;
return lowest_b;
}
/* Quick and harmless test to see if the transaction still has
pending branches */
static inline int tran_is_completed( struct cell *t )
{
int i;
for( i=t->first_branch ; i<t->nr_of_outgoings ; i++ )
if ( t->uac[i].last_received<200 )
return 0;
return 1;
}
/* This is the neurological point of reply processing -- called
* from within a REPLY_LOCK, t_should_relay_response decides
* how a reply shall be processed and how transaction state is
* affected.
*
* Checks if the new reply (with new_code status) should be sent or not
* based on the current
* transaction status.
* Returns - branch number (0,1,...) which should be relayed
* -1 if nothing to be relayed
*/
static enum rps t_should_relay_response( struct cell *Trans , int new_code,
int branch , int *should_store, int *should_relay,
branch_bm_t *cancel_bitmap, struct sip_msg *reply )
{
int branch_cnt;
int picked_code;
int inv_through;
int do_cancel;
/* note: this code never lets replies to CANCEL go through;
we generate always a local 200 for CANCEL; 200s are
not relayed because it's not an INVITE transaction;
>= 300 are not relayed because 200 was already sent
out
*/
LM_DBG("T_code=%d, new_code=%d\n", Trans->uas.status,new_code);
/* a final reply after 200 OK on a transaction with multi branch 200 OK */
if ( is_invite(Trans) && new_code>=200
&& Trans->flags&T_MULTI_200OK_FLAG
&& Trans->uas.status>=200 && Trans->uas.status<300) {
*should_store=0;
picked_branch=-1;
Trans->uac[branch].last_received=new_code;
if (new_code>=300) {
/* negative reply, we simply discard (no relay, no save) */
*should_relay = -1;
return RPS_DISCARDED;
}
/* 2xx reply - is this the last branch to complete?? */
if (tran_is_completed(Trans)) {
/* last branch gets also a 200OK, no more pending branches */
*should_relay = branch;
return RPS_COMPLETED;
} else {
/* 200 OK, but still having ongoing branches */
*should_relay = branch;
return RPS_RELAY;
}
}
inv_through=new_code>=200 && new_code<300 && is_invite(Trans);
/* if final response sent out, allow only INVITE 2xx */
if ( Trans->uas.status >= 200 ) {
if (inv_through) {
LM_DBG("200 OK for INVITE after final sent\n");
*should_store=0;
Trans->uac[branch].last_received=new_code;
*should_relay=branch;
return RPS_PUSHED_AFTER_COMPLETION;
}
if ( is_hopbyhop_cancel(Trans) && new_code>=200) {
*should_store=0;
*should_relay=-1;
picked_branch=-1;
return RPS_COMPLETED;
}
/* except the exception above, too late messages will
be discarded */
goto discard;
}
/* if final response received at this branch, allow only INVITE 2xx */
if (Trans->uac[branch].last_received>=200
&& !(inv_through && Trans->uac[branch].last_received<300)) {
#ifdef EXTRA_DEBUG
/* don't report on retransmissions */
if (Trans->uac[branch].last_received==new_code) {
LM_DBG("final rely retransmission\n");
} else
/* if you FR-timed-out, faked a local 408 and 487 came, don't
* report on it either */
if (Trans->uac[branch].last_received==408 && new_code==487) {
LM_DBG("487 reply came for a timed-out branch\n");
} else {
/* this looks however how a very strange status rewrite attempt;
* report on it */
LM_DBG("status rewrite by UAS: stored: %d, received: %d\n",
Trans->uac[branch].last_received, new_code );
}
#endif
goto discard;
}
/* no final response sent yet */
/* negative replies subject to fork picking */
if (new_code >=300 ) {
Trans->uac[branch].last_received=new_code;
/* also append the current reply to the transaction to
* make it available in failure routes - a kind of "fake"
* save of the final reply per branch */
Trans->uac[branch].reply = reply;
if (new_code>=600 && !disable_6xx_block) {
/* this is a winner and close all branches */
which_cancel( Trans, cancel_bitmap );
picked_branch=branch;
/* no more new branches should be added to this transaction */
Trans->flags |= T_NO_NEW_BRANCHES_FLAG;
} else {
/* if all_final return lowest */
picked_branch = t_pick_branch( Trans, &picked_code, &do_cancel);
if (picked_branch==-2) { /* branches open yet */
*should_store=1;
*should_relay=-1;
picked_branch=-1;
Trans->uac[branch].reply = 0;
return RPS_STORE;
}
if (picked_branch==-1) {
LM_CRIT("pick_branch failed (lowest==-1) for code %d\n",new_code);
Trans->uac[branch].reply = 0;
goto discard;
}
if (do_cancel) {
branch_bm_t cb = 0;
which_cancel( Trans, &cb );
cleanup_uac_timers(Trans);
cancel_uacs( Trans, cb);
}
}
/* no more pending branches -- try if that changes after
* a callback; save branch count to be able to determine
* later if new branches were initiated */
branch_cnt=Trans->nr_of_outgoings;
reset_kr();
if ( !(Trans->flags&T_NO_DNS_FAILOVER_FLAG) &&
Trans->uac[picked_branch].proxy!=NULL ) {
/* is is a DNS failover scenario, according to RFC 3263 ? */
if (is_3263_failure(Trans)) {
LM_DBG("trying DNS-based failover\n");
/* do DNS failover -> add new branches */
if (do_dns_failover( Trans )!=0) {
/* skip the failed added branches */
branch_cnt = Trans->nr_of_outgoings;
}
}
}
/* run ON_FAILURE handlers ( route and callbacks) */
if ( branch_cnt==Trans->nr_of_outgoings &&
(has_tran_tmcbs( Trans, TMCB_ON_FAILURE) || Trans->on_negative) ) {
run_failure_handlers( Trans );
}
/* now reset it; after the failure logic, the reply may
* not be stored any more and we don't want to keep into
* transaction some broken reference */
Trans->uac[branch].reply = 0;
/* look if the callback perhaps replied transaction; it also
covers the case in which a transaction is replied localy
on CANCEL -- then it would make no sense to proceed to
new branches bellow
*/
if (Trans->uas.status >= 200) {
*should_store=0;
*should_relay=-1;
/* this might deserve an improvement -- if something
was already replied, it was put on wait and then,
returning RPS_COMPLETED will make t_on_reply