/* * This file is part of the Sofia-SIP package * * Copyright (C) 2005 Nokia Corporation. * * Contact: Pekka Pessi * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * */ /**@CFILE nta_check.c * @brief Checks for features, MIME types, session timer. * * @author Pekka Pessi * * @date Created: Wed Mar 8 16:35:05 EET 2006 ppessi */ #include "config.h" #include #include #include #include #include /* ======================================================================== */ /* Request validation */ /**Check that we support all features which UAC requires. * * The list of supported features is compared with the list of features * required by the UAC. If some features are not listed as supported, return * 420. If @a irq is non-NULL, the 420 response message is sent to the * client along with list of unsupported features in the @Unsupported * header, too. * * @param irq incoming transaction object (may be NULL). * @param sip contents of the SIP message * @param supported list of protocol features supported * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 0 if successful. * 420 if any of the required features is not supported. */ int nta_check_required(nta_incoming_t *irq, sip_t const *sip, sip_supported_t const *supported, tag_type_t tag, tag_value_t value, ...) { int status = 0; if (sip->sip_require) { su_home_t home[SU_HOME_AUTO_SIZE(512)]; sip_unsupported_t *us; su_home_auto(home, sizeof home); us = sip_has_unsupported(home, supported, sip->sip_require); if (us) { status = 420; if (irq) { ta_list ta; ta_start(ta, tag, value); nta_incoming_treply(irq, SIP_420_BAD_EXTENSION, SIPTAG_UNSUPPORTED(us), SIPTAG_SUPPORTED(supported), ta_tags(ta)); ta_end(ta); } } su_home_deinit(home); } return status; } /** Check that UAC supports all the required features. * * The list of required features is compared with the features supported by * the UAC. If some features are not supported, return 421. If @a irq is * non-NULL, the 421 response message is sent to the client, too. * * @param irq incoming transaction object (may be NULL). * @param sip contents of the SIP message * @param require list of required protocol features * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 0 if successful. * 421 if any of the required features is not supported. */ int nta_check_supported(nta_incoming_t *irq, sip_t const *sip, sip_require_t *require, tag_type_t tag, tag_value_t value, ...) { if (!sip_has_unsupported(NULL, sip->sip_supported, require)) return 0; if (irq) { ta_list ta; ta_start(ta, tag, value); nta_incoming_treply(irq, SIP_421_EXTENSION_REQUIRED, SIPTAG_REQUIRE(require), ta_tags(ta)); ta_end(ta); } return 421; } /** Check that we allow the request method. * * The request-method is compared with the list of supported methods in @a * allow. If match is found, 0 is is returned. Otherwise, if the * request-method is well-known, 405 is returned. If the request-method is * unknown, 501 is returned. If @a irq is non-NULL, the 405 or 501 response * message is sent to the client, too. * * @param irq incoming transaction object (may be NULL). * @param sip contents of the SIP message * @param allow list of allowed methods * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 0 if successful, 405 is request-method is not allowed, 501 if * request-method is unknown. */ int nta_check_method(nta_incoming_t *irq, sip_t const *sip, sip_allow_t const *allow, tag_type_t tag, tag_value_t value, ...) { /* Check extensions */ sip_method_t method = sip->sip_request->rq_method; char const *name = sip->sip_request->rq_method_name; if (sip_is_allowed(allow, method, name)) return 0; if (irq) { ta_list ta; ta_start(ta, tag, value); if (method != sip_method_unknown) /* Well-known method */ nta_incoming_treply(irq, SIP_405_METHOD_NOT_ALLOWED, SIPTAG_ALLOW(allow), ta_tags(ta)); else /* Completeley unknown method */ nta_incoming_treply(irq, SIP_501_NOT_IMPLEMENTED, SIPTAG_ALLOW(allow), ta_tags(ta)); ta_end(ta); } return method != sip_method_unknown ? 405 : 501; } static char const application_sdp[] = "application/sdp"; /** Check that we understand session content in the request. * * If there is no @ContentDisposition header or the @ContentDisposition * header indicated "session", the message body and content-type is compared * with the acceptable session content-types listed in @a session_accepts. * (typically, @c "application/sdp"). If no match is found, a 415 is * returned. If @a irq is non-NULL, the 415 response message is sent to the * client, too. * * If the @ContentDisposition header indicates something else but "session", * and it does not contain "handling=optional" parameter, a 415 response is * returned, too. * * Also, the @ContentEncoding header is checked. If it is not empty * (indicating no content-encoding), a 415 response is returned, too. * * @param irq incoming (server) transaction object (may be NULL). * @param sip contents of the SIP message * @param session_accepts list of acceptable content-types for "session" * content disposition * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 0 if successful, 415 if content-type is not acceptable. */ int nta_check_session_content(nta_incoming_t *irq, sip_t const *sip, sip_accept_t const *session_accepts, tag_type_t tag, tag_value_t value, ...) { sip_content_type_t const *c = sip->sip_content_type; sip_content_disposition_t const *cd = sip->sip_content_disposition; int acceptable_type = 0, acceptable_encoding = 0; if (sip->sip_payload == NULL) return 0; if (cd == NULL || strcasecmp(cd->cd_type, "session") == 0) { sip_accept_t const *ab = session_accepts; char const *c_type; if (c) c_type = c->c_type; else if (sip->sip_payload->pl_len > 3 && strncasecmp(sip->sip_payload->pl_data, "v=0", 3) == 0) /* Missing Content-Type, but it looks like SDP */ c_type = application_sdp; else /* No chance */ ab = NULL, c_type = NULL; for (; ab; ab = ab->ac_next) { if (strcasecmp(c_type, ab->ac_type) == 0) break; } if (ab) acceptable_type = 1; } else if (cd->cd_optional) acceptable_type = 1; /* Empty or missing Content-Encoding */ if (!sip->sip_content_encoding || !sip->sip_content_encoding->k_items || !sip->sip_content_encoding->k_items[0] || !sip->sip_content_encoding->k_items[0][0]) acceptable_encoding = 1; if (acceptable_type && acceptable_encoding) return 0; if (irq) { ta_list ta; ta_start(ta, tag, value); nta_incoming_treply(irq, SIP_415_UNSUPPORTED_MEDIA, SIPTAG_ACCEPT(session_accepts), ta_tags(ta)); ta_end(ta); } return 415; } /**Check that UAC accepts one of listed MIME content-types. * * The list of acceptable content-types are compared with the acceptable * content-types. If match is found, it is returned in @a return_acceptable. * If no match is found, a 406 is returned. If @a irq is non-NULL, the 406 * response message is sent to the client, too. * * @param irq incoming transaction object (may be NULL). * @param sip contents of the SIP message * @param acceptable list of acceptable content types * @param return_acceptable optional return-value parameter for * matched content-type * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 406 if no content-type is acceptable by client, 0 if successful. */ int nta_check_accept(nta_incoming_t *irq, sip_t const *sip, sip_accept_t const *acceptable, sip_accept_t const **return_acceptable, tag_type_t tag, tag_value_t value, ...) { ta_list ta; sip_accept_t const *ac, *ab; sip_method_t method; if (!acceptable) return 0; if (sip->sip_request) method = sip->sip_request->rq_method; else /* if (sip->sip_cseq) */ method = sip->sip_cseq->cs_method; /* Missing Accept header implies support for SDP in INVITE and OPTIONS * (and PRACK and UPDATE?) */ if (!sip->sip_accept && (method == sip_method_invite || method == sip_method_options || method == sip_method_prack || method == sip_method_update)) { for (ab = acceptable; ab; ab = ab->ac_next) if (strcasecmp(application_sdp, ab->ac_type) == 0) { if (return_acceptable) *return_acceptable = ab; return 0; } } for (ac = sip->sip_accept; ac; ac = ac->ac_next) { if (sip_q_value(ac->ac_q) == 0 || !ac->ac_type) continue; for (ab = acceptable; ab; ab = ab->ac_next) if (strcasecmp(ac->ac_type, ab->ac_type) == 0) { if (return_acceptable) *return_acceptable = ab; return 0; } } if (irq) { ta_start(ta, tag, value); nta_incoming_treply(irq, SIP_406_NOT_ACCEPTABLE, SIPTAG_ACCEPT(acceptable), ta_tags(ta)); ta_end(ta); } return 406; } /**Check @SessionExpires header. * * If the proposed session-expiration time is smaller than @MinSE or our * minimal session expiration time, respond with 422 containing shortest * acceptable session expiration time in @MinSE header. * * @param irq incoming transaction object (may be NULL). * @param sip contents of the SIP message * @param my_min_se minimal session expiration time in seconds * @param tag, value, ... optional list of tagged arguments used * when responding to the transaction * * @return 422 if session expiration time is too small, 0 when successful. */ int nta_check_session_expires(nta_incoming_t *irq, sip_t const *sip, sip_time_t my_min_se, tag_type_t tag, tag_value_t value, ...) { unsigned long min_se = my_min_se; if (sip->sip_min_se && min_se < sip->sip_min_se->min_delta) min_se = sip->sip_min_se->min_delta; if (sip->sip_session_expires->x_delta >= min_se) return 0; if (irq) { ta_list ta; sip_min_se_t min_se0[1]; ta_start(ta, tag, value); sip_min_se_init(min_se0)->min_delta = min_se; nta_incoming_treply(irq, SIP_422_SESSION_TIMER_TOO_SMALL, SIPTAG_MIN_SE(min_se0), ta_tags(ta)); ta_end(ta); } return 422; }