/
t_cancel.c
545 lines (487 loc) · 15.6 KB
/
t_cancel.c
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/*
* Copyright (C) 2001-2003 FhG Fokus
*
* This file is part of Kamailio, a free SIP server.
*
* Kamailio 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
*
* Kamailio 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
*
*/
#include <stdio.h> /* for FILE* in fifo_uac_cancel */
#ifdef EXTRA_DEBUG
#include <assert.h>
#endif /* EXTRA_DEBUG */
#include "config.h"
#include "t_funcs.h"
#include "../../core/dprint.h"
#include "../../core/ut.h"
#include "t_reply.h"
#include "t_cancel.h"
#include "t_msgbuilder.h"
#include "t_lookup.h" /* for t_lookup_callid in fifo_uac_cancel */
#include "t_hooks.h"
typedef struct cancel_reason_map {
int code;
str text;
} cancel_reason_map_t;
static cancel_reason_map_t _cancel_reason_map[] = {
{ 200, str_init("Call completed elsewhere") },
{ 0, {0, 0} }
};
/**
*
*/
void cancel_reason_text(struct cancel_info* cancel_data)
{
int i;
if(cancel_data->reason.cause<=0
|| cancel_data->reason.u.text.s!=NULL) return;
for(i=0; _cancel_reason_map[i].text.s!=0; i++) {
if(_cancel_reason_map[i].code==cancel_data->reason.cause) {
cancel_data->reason.u.text = _cancel_reason_map[i].text;
return;
}
}
return;
}
/** Prepare to cancel a transaction.
* Determine which branches should be canceled and prepare them (internally
* mark them as "cancel in progress", see prepare_cancel_branch()).
* Can be called without REPLY_LOCK, since prepare_cancel_branch() is atomic
* now * -- andrei
* WARNING: - has side effects, see prepare_cancel_branch()
* - one _must_ call cancel_uacs(cancel_bm) if *cancel_bm!=0 or
* you'll have some un-cancelable branches (because they remain
* "marked" internally)
* @param t - transaction whose branches will be canceled
* @param cancel_bm - pointer to a branch bitmap that will be filled with
* the branches that must be canceled (must be passed to cancel_uacs() if
* !=0).
* @param skip - branch bitmap of branches that should not be canceled
*/
void prepare_to_cancel(struct cell *t, branch_bm_t *cancel_bm,
branch_bm_t skip_branches)
{
int i;
int branches_no;
branch_bm_t mask;
*cancel_bm=0;
branches_no=t->nr_of_outgoings;
mask=~skip_branches;
membar_depends();
for( i=0 ; i<branches_no ; i++ ) {
*cancel_bm |= ((mask & (1<<i)) && prepare_cancel_branch(t, i, 1))<<i;
}
}
/* cancel branches scheduled for deletion
* params: t - transaction
* cancel_data - structure filled with the cancel bitmap (bitmap with
* the branches that are supposed to be canceled) and
* the cancel reason.
* flags - how_to_cancel flags, see cancel_branch()
* returns: bitmap with the still active branches (on fr timer)
* WARNING: always fill cancel_data->cancel_bitmap using prepare_to_cancel(),
* supplying values in any other way is a bug*/
int cancel_uacs( struct cell *t, struct cancel_info* cancel_data, int flags)
{
int i;
int ret;
int r;
ret=0;
cancel_reason_text(cancel_data);
/* cancel pending client transactions, if any */
for( i=0 ; i<t->nr_of_outgoings ; i++ )
if (cancel_data->cancel_bitmap & (1<<i)){
r=cancel_branch(
t,
i,
&cancel_data->reason,
flags | ((t->uac[i].request.buffer==NULL)?
F_CANCEL_B_FAKE_REPLY:0) /* blind UAC? */
);
ret|=(r!=0)<<i;
}
return ret;
}
int cancel_all_uacs(struct cell *trans, int how)
{
struct cancel_info cancel_data;
int i,j;
#ifdef EXTRA_DEBUG
assert(trans);
#endif
LM_DBG("Canceling T@%p [%u:%u]\n", trans, trans->hash_index, trans->label);
init_cancel_info(&cancel_data);
prepare_to_cancel(trans, &cancel_data.cancel_bitmap, 0);
/* tell tm to cancel the call */
i=cancel_uacs(trans, &cancel_data, how);
if (how & F_CANCEL_UNREF)
UNREF(trans);
/* count the still active branches */
if (! how) {
j=0;
while(i){
j++;
i&=i-1;
}
return j;
}
return 0;
}
/* should be called directly only if one of the condition below is true:
* - prepare_cancel_branch or prepare_to_cancel returned true for this branch
* - buffer value was 0 and then set to BUSY in an atomic op.:
* if (atomic_cmpxchg_long(&buffer, 0, BUSY_BUFFER)==0).
*
* params: t - transaction
* branch - branch number to be canceled
* reason - cancel reason structure
* flags - howto cancel:
* F_CANCEL_B_KILL - will completely stop the
* branch (stops the timers), use with care
* F_CANCEL_B_FAKE_REPLY - will send a fake 487
* to all branches that haven't received any response
* (>=100). It assumes the REPLY_LOCK is not held
* (if it is => deadlock)
* F_CANCEL_B_FORCE_C - will send a cancel (and create the
* corresp. local cancel rb) even if no reply was
* received; F_CANCEL_B_FAKE_REPLY will be ignored.
* F_CANCEL_B_FORCE_RETR - don't stop retransmission if no
* reply was received on the branch; incompatible
* with F_CANCEL_B_FAKE_REPLY, F_CANCEL_B_FORCE_C and
* F_CANCEL_B_KILL (all of them take precedence) a
* default: stop only the retransmissions for the branch
* and leave it to timeout if it doesn't receive any
* response to the CANCEL
* returns: 0 - branch inactive after running cancel_branch()
* 1 - branch still active (fr_timer)
* -1 - error
* WARNING:
* - F_CANCEL_B_KILL should be used only if the transaction is killed
* explicitly afterwards (since it might kill all the timers
* the transaction won't be able to "kill" itself => if not
* explicitly "put_on_wait" it might live forever)
* - F_CANCEL_B_FAKE_REPLY must be used only if the REPLY_LOCK is not
* held
* - checking for buffer==0 under REPLY_LOCK is no enough, an
* atomic_cmpxhcg or atomic_get_and_set _must_ be used.
*/
int cancel_branch( struct cell *t, int branch,
struct cancel_reason* reason,
int flags )
{
char *cancel;
unsigned int len;
struct retr_buf *crb, *irb;
int ret;
struct cancel_info tmp_cd;
void* pcbuf;
int reply_status;
crb=&t->uac[branch].local_cancel;
irb=&t->uac[branch].request;
irb->flags|=F_RB_CANCELED;
ret=1;
init_cancel_info(&tmp_cd);
# ifdef EXTRA_DEBUG
if (crb->buffer!=BUSY_BUFFER) {
LM_CRIT("attempt to rewrite cancel buffer: %p\n", crb->buffer);
abort();
}
# endif
if (flags & F_CANCEL_B_KILL){
stop_rb_timers( irb );
ret=0;
if ((t->uac[branch].last_received < 100) &&
!(flags & F_CANCEL_B_FORCE_C)) {
LM_DBG("no response ever received: giving up on cancel\n");
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
/* try to relay auto-generated 487 canceling response only when
* another one is not under relaying on the branch and there is
* no forced response per transaction from script */
if((flags & F_CANCEL_B_FAKE_REPLY)
&& !(irb->flags&F_RB_RELAYREPLY)
&& !(t->flags&T_ADMIN_REPLY)) {
LOCK_REPLIES(t);
reply_status = relay_reply(t, FAKED_REPLY, branch, 487,
&tmp_cd, 1);
if(reply_status == RPS_ERROR || reply_status == RPS_TGONE) {
return -1;
}
}
/* do nothing, hope that the caller will clean up */
return ret;
}
}else{
if (t->uac[branch].last_received < 100){
if (!(flags & F_CANCEL_B_FORCE_C)) {
/* no response received => don't send a cancel on this branch,
* just drop it */
if (!(flags & F_CANCEL_B_FORCE_RETR))
stop_rb_retr(irb); /* stop retransmissions */
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
if (flags & F_CANCEL_B_FAKE_REPLY){
stop_rb_timers( irb ); /* stop even the fr timer */
LOCK_REPLIES(t);
reply_status = relay_reply(t, FAKED_REPLY, branch, 487,
&tmp_cd, 1);
if(reply_status == RPS_ERROR || reply_status == RPS_TGONE) {
return -1;
}
return 0; /* should be inactive after the 487 */
}
/* do nothing, just wait for the final timeout */
return 1;
}
}
stop_rb_retr(irb); /* stop retransmissions */
}
if (cfg_get(tm, tm_cfg, reparse_invite) ||
(t->uas.request && t->uas.request->msg_flags&(FL_USE_UAC_FROM|FL_USE_UAC_TO))) {
/* build the CANCEL from the INVITE which was sent out */
cancel = build_local_reparse(t, branch, &len, CANCEL, CANCEL_LEN,
(t->uas.request && t->uas.request->msg_flags&FL_USE_UAC_TO)?0:&t->to
, reason
);
} else {
/* build the CANCEL from the received INVITE */
cancel = build_local(t, branch, &len, CANCEL, CANCEL_LEN, &t->to
, reason
);
}
if (!cancel || len<=0) {
LM_ERR("attempt to build a CANCEL failed\n");
if(cancel) {
shm_free(cancel);
cancel = NULL;
}
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
return -1;
}
/* install cancel now */
crb->dst = irb->dst;
crb->branch = branch;
/* label it as cancel so that FR timer can better know how to
deal with it */
crb->rbtype = TYPE_LOCAL_CANCEL;
/* be extra carefully and check for bugs (the below if could be replaced
* by an atomic_set((void*)&crb->buffer, cancel) */
if (unlikely(atomic_cmpxchg_long((void*)&crb->buffer, (long)BUSY_BUFFER,
(long)cancel)!= (long)BUSY_BUFFER)){
LM_BUG("local_cancel buffer=%p != BUSY_BUFFER"
" (trying to continue)\n", crb->buffer);
shm_free(cancel);
return -1;
}
membar_write_atomic_op(); /* cancel retr. can be called from
reply_received w/o the reply lock held =>
they check for buffer_len to
see if a valid reply exists */
crb->buffer_len = len;
LM_DBG("sending cancel...\n");
if (SEND_BUFFER( crb )>=0){
if (unlikely (has_tran_tmcbs(t, TMCB_REQUEST_OUT)))
run_trans_callbacks_with_buf(TMCB_REQUEST_OUT, crb, t->uas.request, 0, TMCB_LOCAL_F);
if (unlikely (has_tran_tmcbs(t, TMCB_REQUEST_SENT)))
run_trans_callbacks_with_buf(TMCB_REQUEST_SENT, crb, t->uas.request, 0, TMCB_LOCAL_F);
}
/*sets and starts the FINAL RESPONSE timer */
if (start_retr( crb )!=0)
LM_CRIT("failed to start retransmission for %p\n", crb);
return ret;
}
/* fifo command to cancel a pending call (Uli)
* Syntax:
*
* ":uac_cancel:[response file]\n
* callid\n
* cseq\n
*/
void rpc_cancel(rpc_t* rpc, void* c)
{
struct cell *trans;
static char cseq[128], callid[128];
struct cancel_info cancel_data;
int i,j;
str cseq_s; /* cseq */
str callid_s; /* callid */
cseq_s.s=cseq;
callid_s.s=callid;
init_cancel_info(&cancel_data);
if (rpc->scan(c, "SS", &callid_s, &cseq_s) < 2) {
rpc->fault(c, 400, "Callid and CSeq expected as parameters");
return;
}
if( t_lookup_callid(&trans, callid_s, cseq_s) < 0 ) {
LM_DBG("Lookup failed\n");
rpc->fault(c, 400, "Transaction not found");
return;
}
/* find the branches that need cancel-ing */
prepare_to_cancel(trans, &cancel_data.cancel_bitmap, 0);
/* tell tm to cancel the call */
DBG("Now calling cancel_uacs\n");
i=cancel_uacs(trans, &cancel_data, 0); /* don't fake 487s,
just wait for timeout */
/* t_lookup_callid REF`d the transaction for us, we must UNREF here! */
UNREF(trans);
j=0;
while(i){
j++;
i&=i-1;
}
rpc->add(c, "ds", j, "branches remaining (waiting for timeout)");
}
/* returns <0 on error */
int cancel_b_flags_get(unsigned int* f, int m)
{
int ret;
ret=0;
switch(m){
case 1:
*f=F_CANCEL_B_FORCE_RETR;
break;
case 0:
*f=F_CANCEL_B_FAKE_REPLY;
break;
case 2:
*f=F_CANCEL_B_FORCE_C;
break;
default:
*f=F_CANCEL_B_FAKE_REPLY;
ret=-1;
}
return ret;
}
/* fixup function for the default cancel branch method/flags
* (called by the configuration framework) */
int cancel_b_flags_fixup(void* handle, str* gname, str* name, void** val)
{
unsigned int m,f;
int ret;
m=(unsigned int)(long)(*val);
ret=cancel_b_flags_get(&f, m);
if (ret<0)
LM_ERR("invalid value for %.*s; %d\n", name->len, name->s, m);
*val=(void*)(long)f;
return ret;
}
/**
* This function cancels a previously created local invite
* transaction. The cancel parameter should NOT have any via (CANCEL is
* hop by hop). returns 0 if error return >0 if OK (returns the LABEL of
* the cancel).*/
unsigned int t_uac_cancel( str *headers, str *body,
unsigned int cancelled_hashIdx, unsigned int cancelled_label,
transaction_cb cb, void* cbp)
{
struct cell *t_invite,*cancel_cell;
struct retr_buf *cancel,*invite;
unsigned int len,ret;
char *buf;
ret=0;
if(t_lookup_ident(&t_invite,cancelled_hashIdx,cancelled_label)<0){
LM_ERR("failed to t_lookup_ident hash_idx=%d,"
"label=%d\n", cancelled_hashIdx,cancelled_label);
return 0;
}
/* <sanity_checks> */
if(! is_local(t_invite))
{
LM_ERR("tried to cancel a non-local transaction\n");
goto error3;
}
if(t_invite->uac[0].last_received < 100)
{
LM_WARN("trying to cancel a transaction not in "
"Proceeding state !\n");
goto error3;
}
if(t_invite->uac[0].last_received > 200)
{
LM_WARN("trying to cancel a completed transaction !\n");
goto error3;
}
/* </sanity_checks*/
/* <build_cell> */
if(!(cancel_cell = build_cell(0))){
ret=0;
LM_ERR("no more shm memory!\n");
goto error3;
}
reset_avps();
if(cb && insert_tmcb(&(cancel_cell->tmcb_hl),
TMCB_RESPONSE_IN|TMCB_LOCAL_COMPLETED,cb,cbp,0)!=1){
ret=0;
LM_ERR("short of tmcb shmem !\n");
goto error2;
}
/* </build_cell> */
/* <insert_into_hashtable> */
cancel_cell->flags |= T_IS_LOCAL_FLAG;
cancel_cell->hash_index=t_invite->hash_index;
LOCK_HASH(cancel_cell->hash_index);
insert_into_hash_table_unsafe(cancel_cell,cancel_cell->hash_index);
ret=cancel_cell->label;
cancel_cell->label=t_invite->label;
UNLOCK_HASH(cancel_cell->hash_index);
/* </insert_into_hashtable> */
/* <prepare_cancel> */
cancel=&cancel_cell->uac[0].request;
invite=&t_invite->uac[0].request;
cancel->dst.to = invite->dst.to;
cancel->dst.send_sock = invite->dst.send_sock;
cancel->dst.proto = invite->dst.proto;
//cancel->dst.proto_reserved1 = invite->dst.proto_reserved1;
buf = build_uac_cancel(headers, body, t_invite, 0, &len, &(cancel->dst));
if(!buf || len<=0) {
if(buf) {
shm_free(buf);
buf = NULL;
}
ret=0;
LM_ERR("attempt to build a CANCEL failed\n");
goto error1;
}
cancel->buffer=buf;
cancel->buffer_len=len;
cancel_cell->method.s = buf;
cancel_cell->method.len = 6 /*c-a-n-c-e-l*/;
/* </prepare_cancel> */
/* <strart_sending> */
cancel_cell->nr_of_outgoings++;
if (SEND_BUFFER(cancel)==-1) {
ret=0;
LM_ERR("send failed\n");
goto error1;
}
if(start_retr(cancel)!=0) {
LM_CRIT("failed to start retransmission for cancel %p\n", cancel);
}
/* </start_sending> */
return ret;
error1:
LOCK_HASH(cancel_cell->hash_index);
remove_from_hash_table_unsafe(cancel_cell);
UNLOCK_HASH(cancel_cell->hash_index);
error2:
free_cell(cancel_cell);
error3:
return ret;
}