/* forwards a request to dst
* parameters:
* msg - sip msg
* dst - destination name, if non-null it will be resolved and
* send_info updated with the ip/port. Even if dst is non
* null send_info must contain the protocol and if a non
* default port or non srv. lookup is desired, the port must
* be !=0
* port - used only if dst!=0 (else the port in send_info->to is used)
* send_info - value/result partially filled dest_info structure:
* - send_info->proto and comp are used
* - send_info->to will be filled (dns)
* - send_info->send_flags is filled from the message
* - if the send_socket member is null, a send_socket will be
* chosen automatically
* WARNING: don't forget to zero-fill all the unused members (a non-zero
* random id along with proto==PROTO_TCP can have bad consequences, same for
* a bogus send_socket value)
*/
int forward_request(struct sip_msg* msg, str* dst, unsigned short port,
struct dest_info* send_info)
{
unsigned int len;
char* buf;
char md5[MD5_LEN];
struct socket_info* orig_send_sock; /* initial send_sock */
int ret;
struct ip_addr ip; /* debugging only */
char proto;
#ifdef USE_DNS_FAILOVER
struct socket_info* prev_send_sock;
int err;
struct dns_srv_handle dns_srv_h;
prev_send_sock=0;
err=0;
#endif
buf=0;
orig_send_sock=send_info->send_sock;
proto=send_info->proto;
ret=0;
if(dst){
#ifdef USE_DNS_FAILOVER
if (cfg_get(core, core_cfg, use_dns_failover)){
dns_srv_handle_init(&dns_srv_h);
err=dns_sip_resolve2su(&dns_srv_h, &send_info->to, dst, port,
&proto, dns_flags);
if (err!=0){
LOG(L_ERR, "ERROR: forward_request: resolving \"%.*s\""
" failed: %s [%d]\n", dst->len, ZSW(dst->s),
dns_strerror(err), err);
ret=E_BAD_ADDRESS;
goto error;
}
}else
#endif
if (sip_hostport2su(&send_info->to, dst, port, &proto)<0){
LOG(L_ERR, "ERROR: forward_request: bad host name %.*s,"
" dropping packet\n", dst->len, ZSW(dst->s));
ret=E_BAD_ADDRESS;
goto error;
}
}/* dst */
send_info->send_flags=msg->fwd_send_flags;
/* calculate branch for outbound request; if syn_branch is turned off,
calculate is from transaction key, i.e., as an md5 of From/To/CallID/
CSeq exactly the same way as TM does; good for reboot -- than messages
belonging to transaction lost due to reboot will still be forwarded
with the same branch parameter and will be match-able downstream
if it is turned on, we don't care about reboot; we simply put a simple
value in there; better for performance
*/
if (syn_branch ) {
memcpy(msg->add_to_branch_s, "z9hG4bKcydzigwkX", 16);
msg->add_to_branch_len=16;
} else {
if (!char_msg_val( msg, md5 )) { /* parses transaction key */
LOG(L_ERR, "ERROR: forward_request: char_msg_val failed\n");
ret=E_UNSPEC;
goto error;
}
msg->hash_index=hash( msg->callid->body, get_cseq(msg)->number);
if (!branch_builder( msg->hash_index, 0, md5, 0 /* 0-th branch */,
msg->add_to_branch_s, &msg->add_to_branch_len )) {
LOG(L_ERR, "ERROR: forward_request: branch_builder failed\n");
ret=E_UNSPEC;
goto error;
}
}
/* try to send the message until success or all the ips are exhausted
* (if dns lookup is performed && the dns cache used ) */
#ifdef USE_DNS_FAILOVER
do{
#endif
if (orig_send_sock==0) /* no forced send_sock => find it **/
send_info->send_sock=get_send_socket(msg, &send_info->to, proto);
if (send_info->send_sock==0){
LOG(L_ERR, "forward_req: ERROR: cannot forward to af %d, proto %d "
"no corresponding listening socket\n",
send_info->to.s.sa_family, proto);
ret=ser_error=E_NO_SOCKET;
#ifdef USE_DNS_FAILOVER
/* continue, maybe we find a socket for some other ip */
continue;
#else
goto error;
#endif
}
#ifdef USE_DNS_FAILOVER
if (prev_send_sock!=send_info->send_sock){
/* rebuild the message only if the send_sock changed */
prev_send_sock=send_info->send_sock;
#endif
if (buf) pkg_free(buf);
send_info->proto=proto;
buf = build_req_buf_from_sip_req(msg, &len, send_info, 0);
if (!buf){
LOG(L_ERR, "ERROR: forward_request: building failed\n");
ret=E_OUT_OF_MEM; /* most probable */
goto error;
}
#ifdef USE_DNS_FAILOVER
}
#endif
/* send it! */
DBG("Sending:\n%.*s.\n", (int)len, buf);
DBG("orig. len=%d, new_len=%d, proto=%d\n",
msg->len, len, send_info->proto );
if (run_onsend(msg, send_info, buf, len)==0){
su2ip_addr(&ip, &send_info->to);
LOG(L_INFO, "forward_request: request to %s:%d(%d) dropped"
" (onsend_route)\n", ip_addr2a(&ip),
su_getport(&send_info->to), send_info->proto);
ser_error=E_OK; /* no error */
ret=E_ADM_PROHIBITED;
#ifdef USE_DNS_FAILOVER
continue; /* try another ip */
#else
goto error; /* error ? */
#endif
}
#ifdef USE_DST_BLACKLIST
if (cfg_get(core, core_cfg, use_dst_blacklist)){
if (dst_is_blacklisted(send_info, msg)){
su2ip_addr(&ip, &send_info->to);
LOG(L_DBG, "DEBUG: blacklisted destination:%s:%d (%d)\n",
ip_addr2a(&ip), su_getport(&send_info->to),
send_info->proto);
ret=ser_error=E_SEND;
#ifdef USE_DNS_FAILOVER
continue; /* try another ip */
#else
goto error;
#endif
}
}
#endif
if (msg_send(send_info, buf, len)<0){
ret=ser_error=E_SEND;
#ifdef USE_DST_BLACKLIST
(void)dst_blacklist_add(BLST_ERR_SEND, send_info, msg);
#endif
#ifdef USE_DNS_FAILOVER
continue; /* try another ip */
#else
goto error;
#endif
}else{
ret=ser_error=E_OK;
/* sent requests stats */
STATS_TX_REQUEST( msg->first_line.u.request.method_value );
/* exit succcesfully */
goto end;
}
#ifdef USE_DNS_FAILOVER
}while(dst && cfg_get(core, core_cfg, use_dns_failover) &&
dns_srv_handle_next(&dns_srv_h, err) &&
((err=dns_sip_resolve2su(&dns_srv_h, &send_info->to, dst, port,
&proto, dns_flags))==0));
if ((err!=0) && (err!=-E_DNS_EOR)){
LOG(L_ERR, "ERROR: resolving %.*s host name in uri"
" failed: %s [%d] (dropping packet)\n",
dst->len, ZSW(dst->s),
dns_strerror(err), err);
ret=ser_error=E_BAD_ADDRESS;
goto error;
}
#endif
error:
STATS_TX_DROPS;
end:
#ifdef USE_DNS_FAILOVER
if (dst && cfg_get(core, core_cfg, use_dns_failover)){
dns_srv_handle_put(&dns_srv_h);
}
#endif
if (buf) pkg_free(buf);
/* received_buf & line_buf will be freed in receive_msg by free_lump_list*/
#if defined STATS_REQ_FWD_OK || defined STATS_REQ_FWD_DROP
if(ret==0)
STATS_REQ_FWD_OK();
else
STATS_REQ_FWD_DROP();
#endif /* STATS_REQ_FWD_* */
return ret;
}
inline static void final_response_handler(
struct retr_buf *r_buf, struct cell *t)
{
int silent;
#ifdef USE_DNS_FAILOVER
/*int i;
int added_branches;
*/
int branch_ret;
int prev_branch;
ticks_t now;
#endif
#ifdef EXTRA_DEBUG
if(t->flags & T_IN_AGONY) {
LM_ERR("transaction %p scheduled for deletion and"
" called from FR timer (flags %x)\n",
t, t->flags);
abort();
}
#endif
/* FR for local cancels.... */
if(r_buf->rbtype == TYPE_LOCAL_CANCEL) {
#ifdef TIMER_DEBUG
LM_DBG("stop retr for local cancel\n");
#endif
return;
}
/* FR for replies (negative INVITE replies) */
if(r_buf->rbtype > 0) {
#ifdef EXTRA_DEBUG
if(t->uas.request->REQ_METHOD != METHOD_INVITE || t->uas.status < 200) {
LM_CRIT("BUG - unknown type reply buffer\n");
abort();
}
#endif
put_on_wait(t);
return;
};
/* lock reply processing to determine how to proceed reliably */
LOCK_REPLIES(t);
/* now it can be only a request retransmission buffer;
try if you can simply discard the local transaction
state without compellingly removing it from the
world */
silent =
/* don't go silent if disallowed globally ... */
cfg_get(tm, tm_cfg, noisy_ctimer) == 0
/* ... or for this particular transaction */
&& has_noisy_ctimer(t) == 0
/* not for UACs */
&& !is_local(t)
/* invites only */
&& is_invite(t)
/* parallel forking does not allow silent state discarding */
&& t->nr_of_outgoings == 1
/* on_negativ reply handler not installed -- serial forking
* could occur otherwise */
&& t->on_failure == 0
/* the same for FAILURE callbacks */
&& !has_tran_tmcbs(t, TMCB_ON_FAILURE_RO | TMCB_ON_FAILURE)
/* something received -- we will not be silent on error */
&& t->uac[r_buf->branch].last_received == 0;
if(silent) {
UNLOCK_REPLIES(t);
#ifdef EXTRA_DEBUG
LM_DBG("transaction silently dropped (%p), branch %d, last_received %d\n",
t, r_buf->branch, t->uac[r_buf->branch].last_received);
#endif
put_on_wait(t);
return;
}
#ifdef EXTRA_DEBUG
LM_DBG("stop retr. and send CANCEL (%p)\n", t);
#endif
if((r_buf->branch < sr_dst_max_branches)
&& /* r_buf->branch is always >=0 */
(t->uac[r_buf->branch].last_received == 0)
&& (t->uac[r_buf->branch].request.buffer
!= NULL) /* not a blind UAC */
) {
/* no reply received */
#ifdef USE_DST_BLACKLIST
if(r_buf->my_T && r_buf->my_T->uas.request
&& (r_buf->my_T->uas.request->REQ_METHOD
& cfg_get(tm, tm_cfg, tm_blst_methods_add)))
dst_blacklist_add(
BLST_ERR_TIMEOUT, &r_buf->dst, r_buf->my_T->uas.request);
#endif
#ifdef USE_DNS_FAILOVER
/* if this is an invite, the destination resolves to more ips, and
* it still hasn't passed more than fr_inv_timeout since we
* started, add another branch/uac */
if(cfg_get(core, core_cfg, use_dns_failover)) {
now = get_ticks_raw();
if((s_ticks_t)(t->end_of_life - now) > 0) {
branch_ret = add_uac_dns_fallback(
t, t->uas.request, &t->uac[r_buf->branch], 0);
prev_branch = -1;
while((branch_ret >= 0) && (branch_ret != prev_branch)) {
prev_branch = branch_ret;
branch_ret =
t_send_branch(t, branch_ret, t->uas.request, 0, 0);
}
}
}
#endif
}
fake_reply(t, r_buf->branch, 408);
}
