static inline void frag_push(struct sfm_frag** head, struct sfm_frag* frag)
{
register struct sfm_frag* old;
register struct sfm_frag* crt;
crt=(void*)atomic_get_long(head);
do{
frag->u.nxt_free=crt;
old=crt;
membar_write_atomic_op();
crt=(void*)atomic_cmpxchg_long((void*)head, (long)old, (long)frag);
}while(crt!=old);
}
/* lockless insert: should be always safe */
int insert_tmcb(struct tmcb_head_list *cb_list, int types,
transaction_cb f, void *param,
release_tmcb_param rel_func)
{
struct tm_callback *cbp;
struct tm_callback *old;
/* build a new callback structure */
if (!(cbp=shm_malloc( sizeof( struct tm_callback)))) {
LOG(L_ERR, "ERROR:tm:insert_tmcb: out of shm. mem\n");
return E_OUT_OF_MEM;
}
atomic_or_int(&cb_list->reg_types, types);
/* ... and fill it up */
cbp->callback = f;
cbp->param = param;
cbp->release = rel_func;
cbp->types = types;
cbp->id=0;
old=(struct tm_callback*)cb_list->first;
/* link it into the proper place... */
do{
cbp->next = old;
/*
if (cbp->next)
cbp->id = cbp->next->id+1;
else
cbp->id = 0;
-- callback ids are useless -- andrei */
membar_write_atomic_op();
old=(void*)atomic_cmpxchg_long((void*)&cb_list->first,
(long)old, (long)cbp);
}while(old!=cbp->next);
return 1;
}
/* should be called directly only if one of the condition bellow 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,
#ifdef CANCEL_REASON_SUPPORT
struct cancel_reason* reason,
#endif /* CANCEL_REASON_SUPPORT */
int flags )
{
char *cancel;
unsigned int len;
struct retr_buf *crb, *irb;
int ret;
struct cancel_info tmp_cd;
void* pcbuf;
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) {
LOG(L_CRIT, "ERROR: 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)) {
DBG("DEBUG: cancel_branch: 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);
if (relay_reply(t, FAKED_REPLY, branch, 487, &tmp_cd, 1) ==
RPS_ERROR){
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);
if (relay_reply(t, FAKED_REPLY, branch, 487, &tmp_cd, 1)==
RPS_ERROR){
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
#ifdef CANCEL_REASON_SUPPORT
, reason
#endif /* CANCEL_REASON_SUPPORT */
);
} else {
/* build the CANCEL from the received INVITE */
cancel = build_local(t, branch, &len, CANCEL, CANCEL_LEN, &t->to
#ifdef CANCEL_REASON_SUPPORT
, reason
#endif /* CANCEL_REASON_SUPPORT */
);
}
if (!cancel) {
LOG(L_ERR, "ERROR: attempt to build a CANCEL failed\n");
/* 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->activ_type = 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)){
BUG("tm: cancel_branch: 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;
DBG("DEBUG: cancel_branch: 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)
LOG(L_CRIT, "BUG: cancel_branch: failed to start retransmission"
" for %p\n", crb);
return ret;
}
