modules_k/cpl-c/cpl_proxy.h

/*
 * $Id$
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 * -------
 * 2003-07-29: file created (bogdan)
 * 2004-06-14: flag CPL_IS_STATEFUL is set now immediately after the 
 *             transaction is created (bogdan)
 */

#include "../../modules/tm/h_table.h"
#include "../../parser/contact/parse_contact.h"


#define duplicate_str( _orig_ , _new_ ) \
        do {\
                (_new_) = (str*)shm_malloc(sizeof(str)+(_orig_)->len);\
                if (!(_new_)) goto mem_error;\
                (_new_)->len = (_orig_)->len;\
                (_new_)->s = (char*)((_new_))+sizeof(str);\
                memcpy((_new_)->s,(_orig_)->s,(_orig_)->len);\
        } while(0)

#define search_and_duplicate_hdr( _intr_ , _field_ , _name_ , _sfoo_ ) \
        do {\
                if (!(_intr_)->_field_) {\
                        if (!(_intr_)->msg->_field_) { \
                                if (parse_headers((_intr_)->msg,_name_,0)==-1) {\
                                        LM_ERR("bad %llx hdr\n",_name_);\
                                        goto runtime_error;\
                                } else if ( !(_intr_)->msg->_field_) {\
                                        (_intr_)->_field_ = STR_NOT_FOUND;\
                                } else {\
                                        (_sfoo_) = &((_intr_)->msg->_field_->body);\
                                        duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
                                }\
                        } else {\
                                (_sfoo_) = &((_intr_)->msg->_field_->body);\
                                duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
                        }\
                } else {\
                        (_sfoo_) = (_intr_)->_field_;\
                        duplicate_str( (_sfoo_) , (_intr_)->_field_ );\
                }\
        }while(0)



static inline int parse_q(str *q, unsigned int *prio)
{
        if (q->s[0]=='0')
                *prio=0;
        else if (q->s[0]=='1')
                *prio=10;
        else
                goto error;
        if (q->s[1]!='.')
                goto error;
        if (q->s[2]<'0' || q->s[2]>'9')
                goto error;
        *prio += q->s[2] - '0';
        if (*prio>10)
                goto error;

        return 0;
error:
        LM_ERR("bad q param <%.*s>\n",q->len,q->s);
        return -1;
}



static inline int add_contacts_to_loc_set(struct sip_msg* msg,
                                                                                                        struct location **loc_set)
{
        struct sip_uri uri;
        struct contact *contacts;
        unsigned int prio;

        /* we need to have the contact header */
        if (msg->contact==0) {
                /* find and parse the Contact header */
                if ((parse_headers(msg, HDR_CONTACT_F, 0)==-1) || (msg->contact==0)) {
                        LM_ERR("error parsing or no Contact hdr found!\n");
                        goto error;
                }
        }

        /* extract from contact header the all the addresses */
        if (parse_contact( msg->contact )!=0) {
                LM_ERR("unable to parse Contact hdr!\n");
                goto error;
        }

        /* in contact hdr, in parsed attr, we should have a list of contacts */
        if ( msg->contact->parsed ) {
                contacts = ((struct contact_body*)msg->contact->parsed)->contacts;
                for( ; contacts ; contacts=contacts->next) {
                        /* check if the contact is a valid sip uri */
                        if (parse_uri( contacts->uri.s, contacts->uri.len , &uri)!=0) {
                                continue;
                        }
                        /* convert the q param to int value (if any) */
                        if (contacts->q) {
                                if (parse_q( &(contacts->q->body), &prio )!=0)
                                        continue;
                        } else {
                                prio = 10; /* set default to minimum */
                        }
                        /* add the uri to location set */
                        if (add_location(loc_set,&contacts->uri,0,prio,CPL_LOC_DUPL)!=0) {
                                LM_ERR("unable to add <%.*s>\n",
                                        contacts->uri.len,contacts->uri.s);
                        }
                }
        }

        return 0;
error:
        return -1;
}



static void reply_callback( struct cell* t, int type, struct tmcb_params* ps)
{
        struct cpl_interpreter *intr = (struct cpl_interpreter*)(*(ps->param));
        struct location        *loc  = 0;
        int rez;

        if (intr==0) {
                LM_WARN("param=0 for callback %d, transaction=%p \n",type,t);
                return;
        }

        if (type&TMCB_RESPONSE_OUT) {
                /* the purpose of the final reply is to trash down the interpreter
                 * structure! it's the safest place to do that, since this callback
                 * it's called only once per transaction for final codes (>=200) ;-) */
                if (ps->code>=200) {
                        LM_DBG("code=%d, final reply received\n", ps->code);
                        /* CPL interpretation done, call established -> destroy */
                        free_cpl_interpreter( intr );
                        /* set to zero the param callback*/
                        *(ps->param) = 0;
                }
                return;
        } else if (! (type&TMCB_ON_FAILURE)) {
                LM_ERR("unknown type %d\n",type);
                goto exit;
        }

        LM_DBG("negativ reply received\n");

        intr->flags |= CPL_PROXY_DONE;
        intr->msg = ps->req;

        /* is the negative reply triggered by a cancel from UAC side? */
        if (was_cancelled(t)) {
                /* stop whole interpretation */
                return;
        }

        /* if it's a redirect-> do I have to added to the location set ? */
        if (intr->proxy.recurse && (ps->code)/100==3) {
                LM_DBG("recurse level %d processing..\n",intr->proxy.recurse);
                intr->proxy.recurse--;
                /* get the locations from the Contact */
                add_contacts_to_loc_set( ps->rpl, &(intr->loc_set));
                switch (intr->proxy.ordering) {
                        case SEQUENTIAL_VAL:
                                /* update the last_to_proxy to last location from set */
                                if (intr->proxy.last_to_proxy==0) {
                                        /* the pointer went through entire old set -> set it to the
                                         * updated set, from the beginning  */
                                        if (intr->loc_set==0)
                                                /* the updated set is also empty -> proxy ended */
                                                break;
                                        intr->proxy.last_to_proxy = intr->loc_set;
                                }
                                while(intr->proxy.last_to_proxy->next)
                                        intr->proxy.last_to_proxy=intr->proxy.last_to_proxy->next;
                                break;
                        case PARALLEL_VAL:
                                /* push the whole new location set to be proxy */
                                intr->proxy.last_to_proxy = intr->loc_set;
                                break;
                        case FIRSTONLY_VAL:
                                intr->proxy.last_to_proxy = 0;
                                break;
                }
        }

        /* the current proxying failed -> do I have another location to try ?
         * This applies only for SERIAL forking or if RECURSE is set */
        if (intr->proxy.last_to_proxy && !(no_new_branches(t)) ) {
                /* continue proxying */
                LM_DBG("resuming proxying....\n");
                switch (intr->proxy.ordering) {
                        case PARALLEL_VAL:
                                /* I get here only if I got a 3xx and RECURSE in on ->
                                 * forward to all location from location set */
                                intr->proxy.last_to_proxy = 0;
                                cpl_proxy_to_loc_set(intr->msg,&(intr->loc_set),intr->flags );
                                break;
                        case SEQUENTIAL_VAL:
                                /* place a new branch to the next location from loc. set*/
                                loc = remove_first_location( &(intr->loc_set) );
                                /*print_location_set(intr->loc_set);*/
                                /* update (if necessary) the last_to_proxy location  */
                                if (intr->proxy.last_to_proxy==loc)
                                        intr->proxy.last_to_proxy = 0;
                                cpl_proxy_to_loc_set(intr->msg,&loc,intr->flags );
                                break;
                        default:
                                LM_CRIT("unexpected ordering found "
                                        "when continuing proxying (%d)\n",intr->proxy.ordering);
                                goto exit;
                }
                /* nothing more to be done */
                return;
        } else {
                /* done with proxying.... -> process the final response */
                LM_DBG("final_reply: got a final %d\n",ps->code);
                intr->ip = 0;
                if (ps->code==486 || ps->code==600) {
                        /* busy response */
                        intr->ip = intr->proxy.busy;
                } else if (ps->code==408) {
                        /* request timeout -> no response */
                        intr->ip = intr->proxy.noanswer;
                } else if (((ps->code)/100)==3) {
                        /* redirection */
                        /* add to the location list all the addresses from Contact */
                        add_contacts_to_loc_set( ps->rpl, &(intr->loc_set));
                        print_location_set( intr->loc_set );
                        intr->ip = intr->proxy.redirect;
                } else {
                        /* generic failure */
                        intr->ip = intr->proxy.failure;
                }

                if (intr->ip==0)
                        intr->ip = (intr->proxy.default_)?
                                intr->proxy.default_:DEFAULT_ACTION;
                if (intr->ip!=DEFAULT_ACTION)
                        intr->ip = get_first_child( intr->ip );

                if( intr->ip==DEFAULT_ACTION)
                        rez = run_default(intr);
                else
                        rez = cpl_run_script(intr);
                switch ( rez ) {
                        case SCRIPT_END:
                                /* we don't need to free the interpreter here since it will 
                                 * be freed in the final_reply callback */
                        case SCRIPT_TO_BE_CONTINUED:
                                return;
                        case SCRIPT_RUN_ERROR:
                        case SCRIPT_FORMAT_ERROR:
                                goto exit;
                        default:
                                LM_CRIT("improper result %d\n",
                                        rez);
                                goto exit;
                }
        }

exit:
        /* in case of error the default response chosen by ser at the last
         * proxying will be forwarded to the UAC */
        free_cpl_interpreter( intr );
        /* set to zero the param callback*/
        *(ps->param) = 0;
        return;
}



static inline char *run_proxy( struct cpl_interpreter *intr )
{
        unsigned short attr_name;
        unsigned short n;
        int_str is_val;
        char *kid;
        char *p;
        int i;
        str *s;
        struct location *loc;

        intr->proxy.ordering = PARALLEL_VAL;
        intr->proxy.recurse = (unsigned short)cpl_env.proxy_recurse;

        /* identify the attributes */
        for( i=NR_OF_ATTR(intr->ip),p=ATTR_PTR(intr->ip) ; i>0 ; i-- ) {
                get_basic_attr( p, attr_name, n, intr, script_error);
                switch (attr_name) {
                        case TIMEOUT_ATTR:
                                if (cpl_env.timer_avp.n || cpl_env.timer_avp.s.s) {
                                        is_val.n = n;
                                        if ( add_avp( cpl_env.timer_avp_type,
                                        cpl_env.timer_avp, is_val)<0) {
                                                LM_ERR("unable to set timer AVP\n");
                                                /* continue */
                                        }
                                }
                                break;
                        case RECURSE_ATTR:
                                switch (n) {
                                        case NO_VAL:
                                                intr->proxy.recurse = 0;
                                                break;
                                        case YES_VAL:
                                                /* already set as default */
                                                break;
                                        default:
                                                LM_ERR("invalid value (%u) found"
                                                        " for attr. RECURSE in PROXY node!\n",n);
                                                goto script_error;
                                }
                                break;
                        case ORDERING_ATTR:
                                if (n!=PARALLEL_VAL && n!=SEQUENTIAL_VAL && n!=FIRSTONLY_VAL){
                                        LM_ERR("invalid value (%u) found"
                                                " for attr. ORDERING in PROXY node!\n",n);
                                        goto script_error;
                                }
                                intr->proxy.ordering = n;
                                break;
                        default:
                                LM_ERR("unknown attribute (%d) in"
                                        "PROXY node\n",attr_name);
                                goto script_error;
                }
        }

        intr->proxy.busy = intr->proxy.noanswer = 0;
        intr->proxy.redirect = intr->proxy.failure = intr->proxy.default_ = 0;

        /* this is quite an "expensive" node to run, so let's make some checking
         * before getting deeply into it */
        for( i=0 ; i<NR_OF_KIDS(intr->ip) ; i++ ) {
                kid = intr->ip + KID_OFFSET(intr->ip,i);
                check_overflow_by_ptr( kid+SIMPLE_NODE_SIZE(kid), intr, script_error);
                switch ( NODE_TYPE(kid) ) {
                        case BUSY_NODE :
                                intr->proxy.busy = kid;
                                break;
                        case NOANSWER_NODE:
                                intr->proxy.noanswer = kid;
                                break;
                        case REDIRECTION_NODE:
                                intr->proxy.redirect = kid;
                                break;
                        case FAILURE_NODE:
                                intr->proxy.failure = kid;
                                break;
                        case DEFAULT_NODE:
                                intr->proxy.default_ = kid;
                                break;
                        default:
                                LM_ERR("unknown output node type"
                                        " (%d) for PROXY node\n",NODE_TYPE(kid));
                                goto script_error;
                }
        }

        /* if the location set if empty, I will go directly on failure/default */
        if (intr->loc_set==0) {
                LM_DBG("location set found empty -> going on "
                        "failure/default branch\n");
                        if (intr->proxy.failure)
                                return get_first_child(intr->proxy.failure);
                        else if (intr->proxy.default_)
                                return get_first_child(intr->proxy.default_);
                        else return DEFAULT_ACTION;
        }

        /* if it's the first execution of a proxy node, force parsing of the needed
         * headers and duplicate them in shared memory */
        if (!(intr->flags&CPL_PROXY_DONE)) {
                /* user name is already in shared memory */
                /* requested URI - mandatory in SIP msg (cannot be STR_NOT_FOUND) */
                s = GET_RURI( intr->msg );
                duplicate_str( s , intr->ruri );
                intr->flags |= CPL_RURI_DUPLICATED;
                /* TO header - mandatory in SIP msg (cannot be STR_NOT_FOUND) */
                if (!intr->to) {
                        if (!intr->msg->to &&
                        (parse_headers(intr->msg,HDR_TO_F,0)==-1 || !intr->msg->to)) {
                                LM_ERR("bad msg or missing TO header\n");
                                goto runtime_error;
                        }
                        s = &(get_to(intr->msg)->uri);
                } else {
                        s = intr->to;
                }
                duplicate_str( s , intr->to );
                intr->flags |= CPL_TO_DUPLICATED;
                /* FROM header - mandatory in SIP msg (cannot be STR_NOT_FOUND) */
                if (!intr->from) {
                        if (parse_from_header( intr->msg )<0)
                                goto runtime_error;
                        s = &(get_from(intr->msg)->uri);
                } else {
                        s = intr->from;
                }
                duplicate_str( s , intr->from );
                intr->flags |= CPL_FROM_DUPLICATED;
                /* SUBJECT header - optional in SIP msg (can be STR_NOT_FOUND) */
                if (intr->subject!=STR_NOT_FOUND) {
                        search_and_duplicate_hdr(intr,subject,HDR_SUBJECT_F,s);
                        if (intr->subject!=STR_NOT_FOUND)
                                intr->flags |= CPL_SUBJECT_DUPLICATED;
                }
                /* ORGANIZATION header - optional in SIP msg (can be STR_NOT_FOUND) */
                if ( intr->organization!=STR_NOT_FOUND) {
                        search_and_duplicate_hdr(intr,organization,HDR_ORGANIZATION_F,s);
                        if ( intr->organization!=STR_NOT_FOUND)
                                intr->flags |= CPL_ORGANIZATION_DUPLICATED;
                }
                /* USER_AGENT header - optional in SIP msg (can be STR_NOT_FOUND) */
                if (intr->user_agent!=STR_NOT_FOUND) {
                        search_and_duplicate_hdr(intr,user_agent,HDR_USERAGENT_F,s);
                        if (intr->user_agent!=STR_NOT_FOUND)
                                intr->flags |= CPL_USERAGENT_DUPLICATED;
                }
                /* ACCEPT_LANGUAGE header - optional in SIP msg
                 * (can be STR_NOT_FOUND) */
                if (intr->accept_language!=STR_NOT_FOUND) {
                        search_and_duplicate_hdr(intr,accept_language,
                                HDR_ACCEPTLANGUAGE_F,s);
                        if (intr->accept_language!=STR_NOT_FOUND)
                                intr->flags |= CPL_ACCEPTLANG_DUPLICATED;
                }
                /* PRIORITY header - optional in SIP msg (can be STR_NOT_FOUND) */
                if (intr->priority!=STR_NOT_FOUND) {
                        search_and_duplicate_hdr(intr,priority,HDR_PRIORITY_F,s);
                        if (intr->priority!=STR_NOT_FOUND)
                                intr->flags |= CPL_PRIORITY_DUPLICATED;
                }

                /* now is the first time doing proxy, so I can still be stateless;
                 * as proxy is done all the time stateful, I have to switch from
                 * stateless to stateful if necessary.  */
                if ( !(intr->flags&CPL_IS_STATEFUL) ) {
                        i = cpl_fct.tmb.t_newtran( intr->msg );
                        if (i<0) {
                                LM_ERR("failed to build new transaction!\n");
                                goto runtime_error;
                        } else if (i==0) {
                                LM_ERR("processed INVITE is a retransmission!\n");
                                /* instead of generating an error is better just to break the
                                 * script by returning EO_SCRIPT */
                                return EO_SCRIPT;
                        }
                        intr->flags |= CPL_IS_STATEFUL;
                }

                /* as I am interested in getting the responses back - I need to install
                 * some callback functions for replies  */
                if (cpl_fct.tmb.register_tmcb(intr->msg,0,
                TMCB_ON_FAILURE|TMCB_RESPONSE_OUT,reply_callback,(void*)intr,0) <= 0 ) {
                        LM_ERR("failed to register TMCB_RESPONSE_OUT callback\n");
                        goto runtime_error;
                }
        }

        switch (intr->proxy.ordering) {
                case FIRSTONLY_VAL:
                        /* forward the request only to the first address from loc. set */
                        /* location set cannot be empty -> was checked before */
                        loc = remove_first_location( &(intr->loc_set) );
                        intr->proxy.last_to_proxy = 0;
                        /* set the new ip before proxy -> otherwise race cond with rpls */
                        intr->ip = CPL_TO_CONTINUE;
                        if (cpl_proxy_to_loc_set(intr->msg,&loc,intr->flags )==-1)
                                goto runtime_error;
                        break;
                case PARALLEL_VAL:
                        /* forward to all location from location set */
                        intr->proxy.last_to_proxy = 0;
                        /* set the new ip before proxy -> otherwise race cond with rpls */
                        intr->ip = CPL_TO_CONTINUE;
                        if (cpl_proxy_to_loc_set(intr->msg,&(intr->loc_set),intr->flags)
                        ==-1)
                                goto runtime_error;
                        break;
                case SEQUENTIAL_VAL:
                        /* forward the request one at the time to all addresses from
                         * loc. set; location set cannot be empty -> was checked before */
                        /* use the first location from set */
                        loc = remove_first_location( &(intr->loc_set) );
                        /* set as the last_to_proxy the last location from set */
                        intr->proxy.last_to_proxy = intr->loc_set;
                        while (intr->proxy.last_to_proxy&&intr->proxy.last_to_proxy->next)
                                intr->proxy.last_to_proxy = intr->proxy.last_to_proxy->next;
                        /* set the new ip before proxy -> otherwise race cond with rpls */
                        intr->ip = CPL_TO_CONTINUE;
                        if (cpl_proxy_to_loc_set(intr->msg,&loc,intr->flags)==-1)
                                goto runtime_error;
                        break;
        }

        return CPL_TO_CONTINUE;
script_error:
        return CPL_SCRIPT_ERROR;
mem_error:
        LM_ERR("no more free shm memory\n");
runtime_error:
        return CPL_RUNTIME_ERROR;
}