cpl.c

用来作为linux中SIP SERVER,完成VOIP网络电话中服务器的功能

		for( i=cpl_env.realm_prefix.len-1 ; i>=0 ; i-- )
			if ( cpl_env.realm_prefix.s[i]!=((uri->host.s[i])|(0x20)) )
				break;
		if (i==-1)
			do_strip = 1;
	}

	/* calculate the len (without terminating \0) */
	uh->len = 4*((flg&BUILD_UH_ADDSIP)!=0) + uri->user.len + 1 +
		uri->host.len - do_strip*cpl_env.realm_prefix.len;
	if (flg&BUILD_UH_SHM) {
		uh->s = (char*)shm_malloc( uh->len + 1 );
		if (!uh->s) {
			LOG(L_ERR,"ERROR:cpl-c:build_userhost: no more shm memory.\n");
			return -1;
		}
	} else {
		uh->s = buf;
		if ( uh->len > MAX_USERHOST_LEN ) {
			LOG(L_ERR,"ERROR:cpl-c:build_userhost: user+host longer than %d\n",
				MAX_USERHOST_LEN);
			return -1;
		}
	}

	/* build user@host */
	p = uh->s;
	if (flg&BUILD_UH_ADDSIP) {
		memcpy( uh->s, "sip:", 4);
		p += 4;
	}
	/* user part */
	if (cpl_env.case_sensitive) {
		memcpy( p, uri->user.s, uri->user.len);
		p += uri->user.len;
	} else {
		for(i=0;i<uri->user.len;i++)
			*(p++) = (0x20)|(uri->user.s[i]);
	}
	*(p++) = '@';
	/* host part in lower cases */
	for( i=do_strip*cpl_env.realm_prefix.len ; i< uri->host.len ; i++ )
		*(p++) = (0x20)|(uri->host.s[i]);
	*(p++) = 0;

	/* sanity check */
	if (p-uh->s!=uh->len+1) {
		LOG(L_CRIT,"BUG:cpl-c:build_userhost: buffer overflow l=%d,w=%ld\n",
			uh->len,(long)(p-uh->s));
		return -1;
	}
	return 0;
}



static inline int get_dest_user(struct sip_msg *msg, str *uh, int flg)
{
	struct sip_uri uri;

	/*  get the user_name from new_uri/RURI/To */
	DBG("DEBUG:cpl-c:get_dest_user: trying to get user from new_uri\n");
	if ( !msg->new_uri.s || parse_uri( msg->new_uri.s,msg->new_uri.len,&uri)==-1
	|| !uri.user.len )
	{
		DBG("DEBUG:cpl-c:get_dest_user: trying to get user from R_uri\n");
		if ( parse_uri( msg->first_line.u.request.uri.s,
		msg->first_line.u.request.uri.len ,&uri)==-1 || !uri.user.len )
		{
			DBG("DEBUG:cpl-c:get_dest_user: trying to get user from To\n");
			if ( (!msg->to&&( (parse_headers(msg,HDR_TO,0)==-1) || !msg->to))||
			parse_uri( get_to(msg)->uri.s, get_to(msg)->uri.len, &uri)==-1
			|| !uri.user.len)
			{
				LOG(L_ERR,"ERROR:cpl-c:get_dest_user: unable to extract user"
					" name from RURI or To header!\n");
				return -1;
			}
		}
	}
	return build_userhost( &uri, uh, flg);
}



static inline int get_orig_user(struct sip_msg *msg, str *uh, int flg)
{
	struct to_body *from;
	struct sip_uri uri;
	
	/* if it's outgoing -> get the user_name from From */
	/* parsing from header */
	DBG("DEBUG:cpl-c:get_orig_user: trying to get user from From\n");
	if ( parse_from_header( msg )==-1 ) {
		LOG(L_ERR,"ERROR:cpl-c:get_orig_user: unable to extract URI "
			"from FROM header\n");
		return -1;
	}
	from = (struct to_body*)msg->from->parsed;
	/* parse the extracted uri from From */
	if (parse_uri( from->uri.s, from->uri.len, &uri)||!uri.user.len) {
		LOG(L_ERR,"ERROR:cpl-c:get_orig_user: unable to extract user name "
			"from URI (From header)\n");
		return -1;
	}
	return build_userhost( &uri, uh, flg);
}



/* Params: 
 *   str1 - as unsigned int - can be CPL_RUN_INCOMING or CPL_RUN_OUTGOING 
 *   str2 - as unsigned int - flags regarding state(less)|(ful) 
 */
static int cpl_invoke_script(struct sip_msg* msg, char* str1, char* str2)
{
	struct cpl_interpreter  *cpl_intr;
	str  user;
	str  loc;
	str  script;

	/* get the user_name */
	if ( ((unsigned long)str1)&CPL_RUN_INCOMING ) {
		/* if it's incoming -> get the destination user name */
		if (get_dest_user( msg, &user, BUILD_UH_SHM)==-1)
			goto error0;
	} else {
		/* if it's outgoing -> get the origin user name */
		if (get_orig_user( msg, &user, BUILD_UH_SHM)==-1)
			goto error0;
	}

	/* get the script for this user */
	if (get_user_script(&user, &script, "cpl_bin")==-1)
		goto error1;

	/* has the user a non-empty script? if not, return normally, allowing ser to
	 * continue its script */
	if ( !script.s || !script.len ) {
		shm_free(user.s);
		return 1;
	}

	/* build a new script interpreter */
	if ( (cpl_intr=new_cpl_interpreter(msg,&script))==0 )
		goto error2;
	/* set the flags */
	cpl_intr->flags =(unsigned int)((unsigned long)str1)|((unsigned long)str2);
	/* attache the user */
	cpl_intr->user = user;
	/* for OUTGOING we need also the destination user for init. with him
	 * the location set */
	if ( ((unsigned long)str1)&CPL_RUN_OUTGOING ) {
		if (get_dest_user( msg, &loc,BUILD_UH_ADDSIP)==-1)
			goto error3;
		if (add_location( &(cpl_intr->loc_set), &loc,10,CPL_LOC_DUPL)==-1)
			goto error3;
	}

	/* since the script interpretation can take some time, it will be better to
	 * send a 100 back to prevent the UAC to retransmit
	if ( cpl_tmb.t_reply( msg, (int)100, "Running cpl script" )!=1 ) {
		LOG(L_ERR,"ERROR:cpl_invoke_script: unable to send 100 reply!\n");
		goto error3;
	}
	* this should be done from script - it's much sooner ;-) */

	/* run the script */
	switch (cpl_run_script( cpl_intr )) {
		case SCRIPT_DEFAULT:
			free_cpl_interpreter( cpl_intr );
			return 1; /* execution of ser's script will continue */
		case SCRIPT_END:
			free_cpl_interpreter( cpl_intr );
		case SCRIPT_TO_BE_CONTINUED:
			return 0; /* break the SER script */
		case SCRIPT_RUN_ERROR:
		case SCRIPT_FORMAT_ERROR:
			goto error3;
	}

	return 1;
error3:
	free_cpl_interpreter( cpl_intr );
	return -1;
error2:
	shm_free(script.s);
error1:
	shm_free(user.s);
error0:
	return -1;
}



#define CPL_SCRIPT          "script"
#define CPL_SCRIPT_LEN      (sizeof(CPL_SCRIPT)-1)
#define ACTION_PARAM        "action"
#define ACTION_PARAM_LEN    (sizeof(ACTION_PARAM)-1)
#define STORE_ACTION        "store"
#define STORE_ACTION_LEN    (sizeof(STORE_ACTION)-1)
#define REMOVE_ACTION       "remove"
#define REMOVE_ACTION_LEN   (sizeof(REMOVE_ACTION)-1)

#define REMOVE_SCRIPT       0xcaca
#define STORE_SCRIPT        0xbebe

#define CONTENT_TYPE_HDR      ("Content-Type: application/cpl-xml"CRLF)
#define CONTENT_TYPE_HDR_LEN  (sizeof(CONTENT_TYPE_HDR)-1)

struct cpl_error {
	int   err_code;
	char *err_msg;
};

static struct cpl_error bad_req = {400,"Bad request"};
static struct cpl_error intern_err = {500,"Internal server error"};
static struct cpl_error bad_cpl = {400,"Bad CPL script"};

static struct cpl_error *cpl_err = &bad_req;


static inline int do_script_action(struct sip_msg *msg, int action)
{
	str  body = {0,0};
	str  user = {0,0};
	str  bin  = {0,0};
	str  log  = {0,0};

	/* content-length (if present) */
	if ( !msg->content_length && ((parse_headers(msg,HDR_CONTENTLENGTH,0)==-1)
	|| !msg->content_length) ) {
		LOG(L_ERR,"ERROR:cpl-c:do_script_action: no Content-Length "
			"hdr found!\n");
		goto error;
	}
	body.len = get_content_length( msg );

	/* get the user name */
	if (get_dest_user( msg, &user, 0)==-1)
		goto error;

	/* we have the script and the user */
	switch (action) {
		case STORE_SCRIPT :
			/* check the len -> it must not be 0 */
			if (body.len==0) {
				LOG(L_ERR,"ERROR:cpl-c:do_script_action: 0 content-len found "
					"for store\n");
				goto error_1;
			}
			/* get the message's body */
			body.s = get_body( msg );
			if (body.s==0) {
				LOG(L_ERR,"ERROR:cpl-c:do_script_action: cannot extract "
					"body from msg!\n");
				goto error_1;
			}
			/* now compile the script and place it into database */
			/* get the binary coding for the XML file */
			if ( encodeCPL( &body, &bin, &log)!=1) {
				cpl_err = &bad_cpl;
				goto error_1;
			}

			/* write both the XML and binary formats into database */
			if (write_to_db(user.s, &body, &bin)!=1) {
				cpl_err = &intern_err;
				goto error_1;
			}
			break;
		case REMOVE_SCRIPT:
			/* check the len -> it must be 0 */
			if (body.len!=0) {
				LOG(L_ERR,"ERROR:cpl-c:do_script_action: non-0 content-len "
					"found for remove\n");
				goto error_1;
			}
			/* remove the script for the user */
			if (rmv_from_db(user.s)!=1) {
				cpl_err = &intern_err;
				goto error_1;
			}
			break;
	}

	if (log.s) pkg_free( log.s );
	return 0;
error_1:
	if (log.s) pkg_free( log.s );
error:
	return -1;
}



static inline int do_script_download(struct sip_msg *msg)
{
	str  user  = {0,0};
	str script = {0,0};

	/* get the destination user name */
	if (get_dest_user( msg, &user, 0)==-1)
		goto error;

	/* get the user's xml script from the database */
	if (get_user_script(&user, &script, "cpl_xml")==-1)
		goto error;

	/* add a lump with content-type hdr */
	if (add_lump_rpl( msg, CONTENT_TYPE_HDR, CONTENT_TYPE_HDR_LEN,
	LUMP_RPL_HDR)==0) {
		LOG(L_ERR,"ERROR:cpl-c:do_script_download: cannot build hdr lump\n");
		cpl_err = &intern_err;
		goto error;
	}

	if (script.s!=0) {
		/*DBG("script len=%d\n--------\n%.*s\n--------\n",
			script.len, script.len, script.s);*/
		/* user has a script -> add a body lump */
		if ( add_lump_rpl( msg, script.s, script.len, LUMP_RPL_BODY)==0) {
			LOG(L_ERR,"ERROR:cpl-c:do_script_download: cannot build "
				"body lump\n");
			cpl_err = &intern_err;
			goto error;
		}
		/* build_lump_rpl duplicates the added text, so free the original */
		shm_free( script.s );
	}

	return 0;
error:
	if (script.s)
		shm_free(script.s);
	return -1;
}



static int w_process_register(struct sip_msg* msg, char* str, char* str2)
{
	return cpl_process_register( msg, 0);
}



static int w_process_register_norpl(struct sip_msg* msg, char* str,char* str2)
{
	return cpl_process_register( msg, 1);
}



static int cpl_process_register(struct sip_msg* msg, int no_rpl)
{
	struct disposition *disp;
	struct disposition_param *param;
	int  ret;
	int  mime;
	int  *mimes;

	/* make sure that is a REGISTER ??? */

	/* here should be the CONTACT- hack */

	/* is there a CONTENT-TYPE hdr ? */
	mime = parse_content_type_hdr( msg );
	if (mime==-1)
		goto error;

	/* check the mime type */
	DBG("DEBUG:cpl_process_register: Content-Type mime found %u, %u\n",
		mime>>16,mime&0x00ff);
	if ( mime && mime==(TYPE_APPLICATION<<16)+SUBTYPE_CPLXML ) {
		/* can be an upload or remove -> check for the content-purpose and
		 * content-action headers */
		DBG("DEBUG:cpl_process_register: carrying CPL -> look at "
			"Content-Disposition\n");
		if (parse_content_disposition( msg )!=0) {
			LOG(L_ERR,"ERROR:cpl_process_register: Content-Disposition missing "
				"or corrupted\n");
			goto error;
		}
		disp = get_content_disposition(msg);
		print_disposition( disp ); /* just for DEBUG */
		/* check if the type of disposition is SCRIPT */
		if (disp->type.len!=CPL_SCRIPT_LEN ||
		strncasecmp(disp->type.s,CPL_SCRIPT,CPL_SCRIPT_LEN) ) {
			LOG(L_ERR,"ERROR:cpl_process_register: bogus message - Content-Type"
				"says CPL_SCRIPT, but Content-Disposition something else\n");
			goto error;
		}
		/* disposition type is OK -> look for action parameter */
		for(param=disp->params;param;param=param->next) {
			if (param->name.len==ACTION_PARAM_LEN &&
			!strncasecmp(param->name.s,ACTION_PARAM,ACTION_PARAM_LEN))
				break;
		}
		if (param==0) {
			LOG(L_ERR,"ERROR:cpl_process_register: bogus message - "
				"Content-Disposition has no action param\n");
			goto error;
		}
		/* action param found -> check its value: store or remove */
		if (param->body.len==STORE_ACTION_LEN &&
		!strncasecmp( param->body.s, STORE_ACTION, STORE_ACTION_LEN)) {
			/* it's a store action -> get the script from body message and store
			 * it into database (CPL and BINARY format) */
			if (do_script_action( msg, STORE_SCRIPT)==-1)
				goto error;
		} else
		if (param->body.len==REMOVE_ACTION_LEN &&
		!strncasecmp( param->body.s, REMOVE_ACTION, REMOVE_ACTION_LEN)) {
			/* it's a remove action -> remove the script from database */
			if (do_script_action( msg, REMOVE_SCRIPT)==-1)
				goto error;
		} else {
			LOG(L_ERR,"ERROR:cpl_process_register: unknown action <%.*s>\n",
				param->body.len,param->body.s);
			goto error;
		}

		/* do I have to send to reply? */
		if (no_rpl)
			goto resume_script;

		/* send a 200 OK reply back */
		cpl_fct.sl_reply( msg, (char*)200, "OK");
		/* I send the reply and I don't want to return to script execution, so
		 * I return 0 to do break */
		goto stop_script;
	}

	/* is there an ACCEPT hdr ? */
	if ( (ret=parse_accept_hdr(msg))==-1)
		goto error;
	if (ret==0 || (mimes=get_accept(msg))==0 )
		/* accept header not present or no mimes found */
		goto resume_script;

	/* looks if the REGISTER accepts cpl-xml or * */
	while (*mimes) {
		DBG("DEBUG: accept mime found %u, %u\n",
			(*mimes)>>16,(*mimes)&0x00ff);
		if (*mimes==(TYPE_ALL<<16)+SUBTYPE_ALL ||
		*mimes==(TYPE_APPLICATION<<16)+SUBTYPE_CPLXML )
			break;
		mimes++;
	}
	if (*mimes==0)
		/* no accept mime that matched cpl */
		goto resume_script;

	/* get the user name from msg, retrieve the script from db
	 * and appended to reply */
	if (do_script_download( msg )==-1)
		goto error;

	/* do I have to send to reply? */
	if (no_rpl)
		goto resume_script;

	/* send a 200 OK reply back */
	cpl_fct.sl_reply( msg, (char*)200, "OK");

stop_script:
	return 0;
resume_script:
	return 1;
error:
	/* send a error reply back */
	cpl_fct.sl_reply( msg, (char*)(long)cpl_err->err_code, cpl_err->err_msg);
	/* I don't want to return to script execution, so I return 0 to do break */
	return 0;
}