sip_parser.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2005 Nokia Corporation.
 *
 * Contact: Pekka Pessi <[e-mail]>
 *
 * 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
 *
 */

/**@ingroup sip_parser
 * @CFILE sip_parser.c
 *
 * SIP parser.
 *
 * @author Pekka Pessi <[e-mail]>.
 *
 * @date Created: Thu Oct  5 14:01:24 2000 ppessi
 */

#include "config.h"

/* Avoid casting sip_t to msg_pub_t and sip_header_t to msg_header_t */
#define MSG_PUB_T       struct sip_s
#define MSG_HDR_T       union sip_header_u

#include <sofia-sip/su_tagarg.h>
#include "sofia-sip/sip_parser.h"
#include <sofia-sip/msg_mclass.h>

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>

#ifndef UINT32_MAX
#define UINT32_MAX (0xffffffffU)
#endif

/** Version of the SIP module */
char const sip_parser_version[] = VERSION;

/** SIP version 2.0. */
char const sip_version_2_0[] = "SIP/2.0";

/** Default message class */
extern msg_mclass_t sip_mclass[];

static msg_mclass_t const *_default = sip_mclass;

/** Return a built-in SIP parser object. */
msg_mclass_t const *sip_default_mclass(void)
{
  return _default;
}

/** Update the default SIP parser.
 *
 * Use the extended SIP parser as default one.
 *
 * If the applications want to use headers added after @VERSION_1_12_5,
 * they should call this function before doing any other initialization, e.g.,
 * @code
 *   su_init();
 *   if (sip_update_default_mclass(sip_extend_mclass(NULL)) < 0) {
 *     su_deinit();
 *     exit(2);
 *   }
 * @endcode
 *
 * The default parser is not extended because it may break the old
 * applications looking for extension headers from sip_unknown list.
 *
 * @retval 0 when successful
 * @retval -1 upon an error
 *
 * @sa sip_extend_mclass()
 *
 * @NEW_1_12_7.
 */
int sip_update_default_mclass(msg_mclass_t const *mclass)
{
  if (mclass == NULL)
    return -1;
  _default = mclass;
  return 0;
}

/**Extend SIP parser class with extension headers.
 *
 * Extend given SIP parser class with extension headers. If the given parser
 * (message class) is the default one or NULL, make a clone of default
 * parser before extending it.
 *
 * @param input pointer to a SIP message class (may be NULL)
 *
 * @return Pointer to extended mclass, or NULL upon an error.
 *
 * @sa
 * @AlertInfo,
 * @ReplyTo,
 * @RemotePartyId,
 * @PAssertedIdentity,
 * @PPreferredIdentity,
 * @SuppressBodyIfMatch,
 * @SuppressNotifyIfMatch
 *
 * @NEW_1_12_7.
 */
msg_mclass_t *sip_extend_mclass(msg_mclass_t *input)
{
  msg_mclass_t *mclass;

  if (input == NULL || input == _default)
    mclass = msg_mclass_clone(_default, 0, 0);
  else
    mclass = input;

  if (mclass) {
    extern msg_hclass_t * const sip_extensions[];
    int i;

    for (i = 0; sip_extensions[i]; i++) {
      msg_hclass_t *hclass = sip_extensions[i];
      if (mclass->mc_unknown != msg_find_hclass(mclass, hclass->hc_name, NULL))
	continue;

      if (msg_mclass_insert_header(mclass, hclass, 0) < 0) {
	if (input != mclass)
	  free(mclass);
	return mclass = NULL;
      }
    }
  }

  return mclass;
}

/** Extract the SIP message body, including separator line. 
 *
 * @param msg  message object [IN]
 * @param sip  public SIP message structure [IN/OUT]
 * @param b    buffer containing unparsed data [IN]
 * @param bsiz buffer size [IN]
 * @param eos  true if buffer contains whole message [IN]
 *
 * @retval -1 error
 * @retval 0  cannot proceed
 * @retval m 
 */
issize_t sip_extract_body(msg_t *msg, sip_t *sip, char b[], isize_t bsiz, int eos)
{
  ssize_t m = 0;
  size_t body_len;
  
  if (!(sip->sip_flags & MSG_FLG_BODY)) {
    /* We are looking at a potential empty line */
    m = msg_extract_separator(msg, (msg_pub_t *)sip, b, bsiz, eos);
    if (m <= 0)
      return m;
    sip->sip_flags |= MSG_FLG_BODY;
    b += m;
    bsiz -= m;
  }

  if (sip->sip_content_length)
    body_len = sip->sip_content_length->l_length;
  else if (MSG_IS_MAILBOX(sip->sip_flags)) /* message fragments */
    body_len = 0;
  else if (eos)
    body_len = bsiz;
  else if (bsiz == 0)
    return m;
  else
    return -1;

  if (body_len == 0) {
    sip->sip_flags |= MSG_FLG_COMPLETE;
    return m;
  }

  if (m)
    return m;

  if (eos && body_len > bsiz) {
    sip->sip_flags |= MSG_FLG_TRUNC | MSG_FLG_ERROR;
    return bsiz;
  }

  if ((m = msg_extract_payload(msg, (msg_pub_t *)sip, 
			       NULL, body_len, b, bsiz, eos)) == -1)
    return -1;
  
  sip->sip_flags |= MSG_FLG_FRAGS;
  if (bsiz >= body_len)
    sip->sip_flags |= MSG_FLG_COMPLETE;

  return m;
}

/** Parse SIP version.
 *
 * Parse a SIP version string. Update the 
 * pointer at @a ss to first non-LWS character after the version string.
 *
 * @param ss   string to be parsed [IN/OUT]
 * @param ver  value result for version [OUT]
 *
 * @retval 0 when successful,
 * @retval -1 upon an error.
 */
int sip_version_d(char **ss, char const **ver)
{
  char *s = *ss;
  char const *result;
  size_t const version_size = sizeof(sip_version_2_0) - 1;

  if (strncasecmp(s, sip_version_2_0, version_size) == 0 && 
      !IS_TOKEN(s[version_size])) {
    result = sip_version_2_0;
    s += version_size;
  }
  else {
    /* Version consists of two tokens, separated by / */
    size_t l1 = 0, l2 = 0, n;

    result = s;

    l1 = span_token(s);
    for (n = l1; IS_LWS(s[n]); n++);
    if (s[n] == '/') {
      for (n++; IS_LWS(s[n]); n++);
      l2 = span_token(s + n);
      n += l2;
    }

    if (l1 == 0 || l2 == 0)
      return -1;

    /* If there is extra ws between tokens, compact version */
    if (n > l1 + 1 + l2) {
      s[l1] = '/';
      memmove(s + l1 + 1, s + n - l2, l2);
      s[l1 + 1 + l2] = 0;

      /* Compare again with compacted version */ 
      if (strcasecmp(s, sip_version_2_0) == 0)
	result = sip_version_2_0;
    }

    s += n;
  }

  while (IS_WS(*s)) *s++ = '\0';
  
  *ss = s;

  if (ver) 
    *ver = result;

  return 0;
}

/** Calculate extra space required by version string */
isize_t sip_version_xtra(char const *version)
{
  if (version == SIP_VERSION_CURRENT)
    return 0;
  return MSG_STRING_SIZE(version);
}

/** Duplicate a transport string */
void sip_version_dup(char **pp, char const **dd, char const *s)
{
  if (s == SIP_VERSION_CURRENT)
    *dd = s;
  else
    MSG_STRING_DUP(*pp, *dd, s);
}

char const sip_method_name_invite[] =  	 "INVITE";
char const sip_method_name_ack[] =     	 "ACK";
char const sip_method_name_cancel[] =  	 "CANCEL";
char const sip_method_name_bye[] =     	 "BYE";
char const sip_method_name_options[] = 	 "OPTIONS";
char const sip_method_name_register[] =  "REGISTER";
char const sip_method_name_info[] =      "INFO";
char const sip_method_name_prack[] =     "PRACK";
char const sip_method_name_update[] =    "UPDATE";
char const sip_method_name_message[] =   "MESSAGE";
char const sip_method_name_subscribe[] = "SUBSCRIBE";
char const sip_method_name_notify[] =    "NOTIFY";
char const sip_method_name_refer[] =     "REFER";
char const sip_method_name_publish[] =   "PUBLISH";

/** Well-known SIP method names. */
char const * const sip_method_names[] = {
  "<UNKNOWN>",
  sip_method_name_invite,
  sip_method_name_ack,
  sip_method_name_cancel,
  sip_method_name_bye,
  sip_method_name_options,
  sip_method_name_register,
  sip_method_name_info,
  sip_method_name_prack,
  sip_method_name_update,
  sip_method_name_message,
  sip_method_name_subscribe,
  sip_method_name_notify,
  sip_method_name_refer,