/* this is the code which decides what and when shall be relayed
upstream; note well -- it assumes it is entered locked with
REPLY_LOCK and it returns unlocked!
*/
enum rps relay_reply( struct cell *t, struct sip_msg *p_msg, int branch,
unsigned int msg_status, branch_bm_t *cancel_bitmap )
{
int relay;
int save_clone;
char *buf;
/* length of outbound reply */
unsigned int res_len;
int relayed_code;
struct sip_msg *relayed_msg;
struct bookmark bm;
int totag_retr;
enum rps reply_status;
/* retransmission structure of outbound reply and request */
struct retr_buf *uas_rb;
str cb_s;
str text;
/* keep compiler warnings about use of uninit vars silent */
res_len=0;
buf=0;
relayed_msg=0;
relayed_code=0;
totag_retr=0;
/* remember, what was sent upstream to know whether we are
* forwarding a first final reply or not */
/* *** store and relay message as needed *** */
reply_status = t_should_relay_response(t, msg_status, branch,
&save_clone, &relay, cancel_bitmap, p_msg );
LM_DBG("branch=%d, save=%d, relay=%d\n",
branch, save_clone, relay );
/* store the message if needed */
if (save_clone) /* save for later use, typically branch picking */
{
if (!store_reply( t, branch, p_msg ))
goto error01;
}
uas_rb = & t->uas.response;
if (relay >= 0 ) {
/* initialize sockets for outbound reply */
uas_rb->activ_type=msg_status;
t->relaied_reply_branch = relay;
/* try building the outbound reply from either the current
* or a stored message */
relayed_msg = branch==relay ? p_msg : t->uac[relay].reply;
if (relayed_msg==FAKED_REPLY) {
relayed_code = branch==relay
? msg_status : t->uac[relay].last_received;
text.s = error_text(relayed_code);
text.len = strlen(text.s); /* FIXME - bogdan*/
if (relayed_code>=180 && t->uas.request->to
&& (get_to(t->uas.request)->tag_value.s==0
|| get_to(t->uas.request)->tag_value.len==0)) {
calc_crc_suffix( t->uas.request, tm_tag_suffix );
buf = build_res_buf_from_sip_req(
relayed_code,
&text,
&tm_tag,
t->uas.request, &res_len, &bm );
} else {
buf = build_res_buf_from_sip_req( relayed_code,
&text, 0/* no to-tag */,
t->uas.request, &res_len, &bm );
}
} else {
/* run callbacks for all types of responses -
* even if they are shmem-ed or not */
if (has_tran_tmcbs(t,TMCB_RESPONSE_FWDED) ) {
run_trans_callbacks( TMCB_RESPONSE_FWDED, t, t->uas.request,
relayed_msg, msg_status );
}
relayed_code=relayed_msg->REPLY_STATUS;
buf = build_res_buf_from_sip_res( relayed_msg, &res_len,
uas_rb->dst.send_sock);
/* remove all lumps which are not in shm
* added either by build_res_buf_from_sip_res, or by
* the callbacks that have been called with shmem-ed messages - vlad */
if (branch!=relay) {
del_notflaged_lumps( &(relayed_msg->add_rm), LUMPFLAG_SHMEM);
del_notflaged_lumps( &(relayed_msg->body_lumps), LUMPFLAG_SHMEM);
}
}
if (!buf) {
LM_ERR("no mem for outbound reply buffer\n");
goto error02;
}
/* attempt to copy the message to UAS's shmem:
- copy to-tag for ACK matching as well
- allocate little a bit more for provisional as
larger messages are likely to follow and we will be
able to reuse the memory frag
*/
uas_rb->buffer.s = (char*)shm_resize( uas_rb->buffer.s, res_len +
(msg_status<200 ? REPLY_OVERBUFFER_LEN : 0));
if (!uas_rb->buffer.s) {
LM_ERR("no more share memory\n");
goto error03;
}
uas_rb->buffer.len = res_len;
memcpy( uas_rb->buffer.s, buf, res_len );
if (relayed_msg==FAKED_REPLY) { /* to-tags for local replies */
update_local_tags(t, &bm, uas_rb->buffer.s, buf);
}
stats_trans_rpl( relayed_code, (relayed_msg==FAKED_REPLY)?1:0 );
/* update the status ... */
t->uas.status = relayed_code;
if (is_invite(t) && relayed_msg!=FAKED_REPLY
&& relayed_code>=200 && relayed_code < 300
&& has_tran_tmcbs( t,
TMCB_RESPONSE_OUT|TMCB_RESPONSE_PRE_OUT)) {
totag_retr=update_totag_set(t, relayed_msg);
}
}; /* if relay ... */
UNLOCK_REPLIES( t );
/* Setup retransmission timer _before_ the reply is sent
* to avoid race conditions
*/
if (reply_status == RPS_COMPLETED) {
/* 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 ((relayed_code != 401) && (relayed_code != 407))
set_final_timer(t);
else
put_on_wait(t);
}
/* send it now (from the private buffer) */
if (relay >= 0) {
/* run the PRE sending out callback */
if (!totag_retr && has_tran_tmcbs(t, TMCB_RESPONSE_PRE_OUT) ) {
cb_s.s = buf;
cb_s.len = res_len;
set_extra_tmcb_params( &cb_s, &uas_rb->dst);
run_trans_callbacks_locked(TMCB_RESPONSE_PRE_OUT,t,t->uas.request,
relayed_msg, relayed_code);
}
SEND_PR_BUFFER( uas_rb, buf, res_len );
LM_DBG("sent buf=%p: %.9s..., shmem=%p: %.9s\n",
buf, buf, uas_rb->buffer.s, uas_rb->buffer.s );
/* run the POST sending out callback */
if (!totag_retr && has_tran_tmcbs(t, TMCB_RESPONSE_OUT) ) {
cb_s.s = buf;
cb_s.len = res_len;
set_extra_tmcb_params( &cb_s, &uas_rb->dst);
run_trans_callbacks_locked( TMCB_RESPONSE_OUT, t, t->uas.request,
relayed_msg, relayed_code);
}
pkg_free( buf );
}
/* success */
return reply_status;
error03:
pkg_free( buf );
error02:
if (save_clone) {
if (t->uac[branch].reply!=FAKED_REPLY)
sip_msg_free( t->uac[branch].reply );
t->uac[branch].reply = NULL;
}
error01:
text.s = "Reply processing error";
text.len = sizeof("Reply processing error")-1;
t_reply_unsafe( t, t->uas.request, 500, &text );
UNLOCK_REPLIES(t);
if (is_invite(t)) cancel_uacs( t, *cancel_bitmap );
/* a serious error occurred -- attempt to send an error reply;
it will take care of clean-ups */
/* failure */
return RPS_ERROR;
}
/* Continues the SIP request processing previously saved by
* t_suspend(). The script does not continue from the same
* point, but a separate route block is executed instead.
*
* Return value:
* 0 - success
* <0 - failure
*/
int t_continue(unsigned int hash_index, unsigned int label,
struct action *route)
{
struct cell *t;
struct sip_msg faked_req;
struct cancel_info cancel_data;
int branch;
struct ua_client *uac =NULL;
int ret;
int cb_type;
int msg_status;
int last_uac_status;
int reply_status;
int do_put_on_wait;
struct hdr_field *hdr, *prev = 0, *tmp = 0;
if (t_lookup_ident(&t, hash_index, label) < 0) {
LM_ERR("transaction not found\n");
return -1;
}
if (!(t->flags & T_ASYNC_SUSPENDED)) {
LM_WARN("transaction is not suspended [%u:%u]\n", hash_index, label);
return -2;
}
if (t->flags & T_CANCELED) {
t->flags &= ~T_ASYNC_SUSPENDED;
/* The transaction has already been canceled,
* needless to continue */
UNREF(t); /* t_unref would kill the transaction */
/* reset T as we have no working T anymore */
set_t(T_UNDEFINED, T_BR_UNDEFINED);
return 1;
}
/* The transaction has to be locked to protect it
* form calling t_continue() multiple times simultaneously */
LOCK_ASYNC_CONTINUE(t);
t->flags |= T_ASYNC_CONTINUE; /* we can now know anywhere in kamailio
* that we are executing post a suspend */
/* which route block type were we in when we were suspended */
cb_type = FAILURE_CB_TYPE;;
switch (t->async_backup.backup_route) {
case REQUEST_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
case FAILURE_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
case TM_ONREPLY_ROUTE:
cb_type = ONREPLY_CB_TYPE;
break;
case BRANCH_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
}
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
branch = t->async_backup.blind_uac; /* get the branch of the blind UAC setup
* during suspend */
if (branch >= 0) {
stop_rb_timers(&t->uac[branch].request);
if (t->uac[branch].last_received != 0) {
/* Either t_continue() has already been
* called or the branch has already timed out.
* Needless to continue. */
t->flags &= ~T_ASYNC_SUSPENDED;
UNLOCK_ASYNC_CONTINUE(t);
UNREF(t); /* t_unref would kill the transaction */
return 1;
}
/* Set last_received to something >= 200,
* the actual value does not matter, the branch
* will never be picked up for response forwarding.
* If last_received is lower than 200,
* then the branch may tried to be cancelled later,
* for example when t_reply() is called from
* a failure route => deadlock, because both
* of them need the reply lock to be held. */
t->uac[branch].last_received=500;
uac = &t->uac[branch];
}
/* else
Not a huge problem, fr timer will fire, but CANCEL
will not be sent. last_received will be set to 408. */
/* We should not reset kr here to 0 as it's quite possible before continuing the dev. has correctly set the
* kr by, for example, sending a transactional reply in code - resetting here will cause a dirty log message
* "WARNING: script writer didn't release transaction" to appear in log files. TODO: maybe we need to add
* a special kr for async?
* reset_kr();
*/
/* fake the request and the environment, like in failure_route */
if (!fake_req(&faked_req, t->uas.request, 0 /* extra flags */, uac)) {
LM_ERR("building fake_req failed\n");
ret = -1;
goto kill_trans;
}
faked_env( t, &faked_req, 1);
/* execute the pre/post -script callbacks based on original route block */
if (exec_pre_script_cb(&faked_req, cb_type)>0) {
if (run_top_route(route, &faked_req, 0)<0)
LM_ERR("failure inside run_top_route\n");
exec_post_script_cb(&faked_req, cb_type);
}
/* TODO: save_msg_lumps should clone the lumps to shm mem */
/* restore original environment and free the fake msg */
faked_env( t, 0, 1);
free_faked_req(&faked_req, t);
/* update the flags */
t->uas.request->flags = faked_req.flags;
if (t->uas.status < 200) {
/* No final reply has been sent yet.
* Check whether or not there is any pending branch.
*/
for ( branch = 0;
branch < t->nr_of_outgoings;
branch++
) {
if (t->uac[branch].last_received < 200)
break;
}
if (branch == t->nr_of_outgoings) {
/* There is not any open branch so there is
* no chance that a final response will be received. */
ret = 0;
goto kill_trans;
}
}
} else {
branch = t->async_backup.backup_branch;
init_cancel_info(&cancel_data);
LM_DBG("continuing from a suspended reply"
" - resetting the suspend branch flag\n");
if (t->uac[branch].reply) {
t->uac[branch].reply->msg_flags &= ~FL_RPL_SUSPENDED;
} else {
LM_WARN("no reply in t_continue for branch. not much we can do\n");
return 0;
}
if (t->uas.request) t->uas.request->msg_flags&= ~FL_RPL_SUSPENDED;
faked_env( t, t->uac[branch].reply, 1);
if (exec_pre_script_cb(t->uac[branch].reply, cb_type)>0) {
if (run_top_route(route, t->uac[branch].reply, 0)<0){
LOG(L_ERR, "ERROR: t_continue_reply: Error in run_top_route\n");
}
exec_post_script_cb(t->uac[branch].reply, cb_type);
}
LM_DBG("restoring previous environment");
faked_env( t, 0, 1);
/*lock transaction replies - will be unlocked when reply is relayed*/
LOCK_REPLIES( t );
if ( is_local(t) ) {
LM_DBG("t is local - sending reply with status code: [%d]\n",
t->uac[branch].reply->first_line.u.reply.statuscode);
reply_status = local_reply( t, t->uac[branch].reply, branch,
t->uac[branch].reply->first_line.u.reply.statuscode,
&cancel_data );
if (reply_status == RPS_COMPLETED) {
/* no more UAC FR/RETR (if I received a 2xx, there may
* be still pending branches ...
*/
cleanup_uac_timers( t );
if (is_invite(t)) cancel_uacs(t, &cancel_data, F_CANCEL_B_KILL);
/* There is no need to call set_final_timer because we know
* that the transaction is local */
put_on_wait(t);
}else if (unlikely(cancel_data.cancel_bitmap)){
/* cancel everything, even non-INVITEs (e.g in case of 6xx), use
* cancel_b_method for canceling unreplied branches */
cancel_uacs(t, &cancel_data, cfg_get(tm,tm_cfg, cancel_b_flags));
}
} else {
LM_DBG("t is not local - relaying reply with status code: [%d]\n",
t->uac[branch].reply->first_line.u.reply.statuscode);
do_put_on_wait = 0;
if(t->uac[branch].reply->first_line.u.reply.statuscode>=200){
do_put_on_wait = 1;
}
reply_status=relay_reply( t, t->uac[branch].reply, branch,
t->uac[branch].reply->first_line.u.reply.statuscode,
&cancel_data, do_put_on_wait );
if (reply_status == RPS_COMPLETED) {
/* no more UAC FR/RETR (if I received a 2xx, there may
be still pending branches ...
*/
cleanup_uac_timers( t );
/* 2xx is a special case: we can have a COMPLETED request
* with branches still open => we have to cancel them */
if (is_invite(t) && cancel_data.cancel_bitmap)
cancel_uacs( t, &cancel_data, F_CANCEL_B_KILL);
/* FR for negative INVITES, WAIT anything else */
/* Call to set_final_timer is embedded in relay_reply to avoid
* race conditions when reply is sent out and an ACK to stop
* retransmissions comes before retransmission timer is set.*/
}else if (unlikely(cancel_data.cancel_bitmap)){
/* cancel everything, even non-INVITEs (e.g in case of 6xx), use
* cancel_b_method for canceling unreplied branches */
cancel_uacs(t, &cancel_data, cfg_get(tm,tm_cfg, cancel_b_flags));
}
}
t->uac[branch].request.flags|=F_RB_REPLIED;
if (reply_status==RPS_ERROR){
goto done;
}
/* update FR/RETR timers on provisional replies */
msg_status=t->uac[branch].reply->REPLY_STATUS;
last_uac_status=t->uac[branch].last_received;
if (is_invite(t) && msg_status<200 &&
( cfg_get(tm, tm_cfg, restart_fr_on_each_reply) ||
( (last_uac_status<msg_status) &&
((msg_status>=180) || (last_uac_status==0)) )
) ) { /* provisional now */
restart_rb_fr(& t->uac[branch].request, t->fr_inv_timeout);
t->uac[branch].request.flags|=F_RB_FR_INV; /* mark fr_inv */
}
}
done:
UNLOCK_ASYNC_CONTINUE(t);
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
/* unref the transaction */
t_unref(t->uas.request);
} else {
tm_ctx_set_branch_index(T_BR_UNDEFINED);
/* unref the transaction */
t_unref(t->uac[branch].reply);
LOG(L_DBG,"DEBUG: t_continue_reply: Freeing earlier cloned reply\n");
/* free lumps that were added during reply processing */
del_nonshm_lump( &(t->uac[branch].reply->add_rm) );
del_nonshm_lump( &(t->uac[branch].reply->body_lumps) );
del_nonshm_lump_rpl( &(t->uac[branch].reply->reply_lump) );
/* free header's parsed structures that were added */
for( hdr=t->uac[branch].reply->headers ; hdr ; hdr=hdr->next ) {
if ( hdr->parsed && hdr_allocs_parse(hdr) &&
(hdr->parsed<(void*)t->uac[branch].reply ||
hdr->parsed>=(void*)t->uac[branch].end_reply)) {
clean_hdr_field(hdr);
hdr->parsed = 0;
}
}
/* now go through hdr_fields themselves and remove the pkg allocated space */
hdr = t->uac[branch].reply->headers;
while (hdr) {
if ( hdr && ((void*)hdr<(void*)t->uac[branch].reply ||
(void*)hdr>=(void*)t->uac[branch].end_reply)) {
//this header needs to be freed and removed form the list.
if (!prev) {
t->uac[branch].reply->headers = hdr->next;
} else {
prev->next = hdr->next;
}
tmp = hdr;
hdr = hdr->next;
pkg_free(tmp);
} else {
prev = hdr;
hdr = hdr->next;
}
}
sip_msg_free(t->uac[branch].reply);
t->uac[branch].reply = 0;
}
/*This transaction is no longer suspended so unsetting the SUSPEND flag*/
t->flags &= ~T_ASYNC_SUSPENDED;
return 0;
kill_trans:
t->flags &= ~T_ASYNC_SUSPENDED;
/* The script has hopefully set the error code. If not,
* let us reply with a default error. */
if ((kill_transaction_unsafe(t,
tm_error ? tm_error : E_UNSPEC)) <=0
) {
LOG(L_ERR, "ERROR: t_continue: "
"reply generation failed\n");
/* The transaction must be explicitely released,
* no more timer is running */
UNLOCK_ASYNC_CONTINUE(t);
t_release_transaction(t);
} else {
UNLOCK_ASYNC_CONTINUE(t);
}
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
t_unref(t->uas.request);
} else {
/* unref the transaction */
t_unref(t->uac[branch].reply);
}
return ret;
}
