parse_supported.c

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/*
 * $Id: parse_supported.c 4720 2008-08-23 10:56:15Z henningw $
 *
 * Copyright (C) 2006 Andreas Granig <agranig@linguin.org>
 *
 * 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
 */

/*!
 * \file
 * \brief Supported parser
 * \ingroup parser
 */

#include "../mem/mem.h"
#include "keys.h"
#include "parse_supported.h"

#define IS_DELIM(c) (*(c) == ' ' || *(c) == '\t' || *(c) == '\r' || *(c) == '\n' || *(c) == ',')

/* from parser/parse_hname2.c: */
#define LOWER_BYTE(b) ((b) | 0x20)
#define LOWER_DWORD(d) ((d) | 0x20202020)
#define READ(val) \
   (*(val + 0) + (*(val + 1) << 8) + (*(val + 2) << 16) + (*(val + 3) << 24))


/*!
 * Parse Supported HF body.
 */
static inline int parse_supported_body(str *body, unsigned int *sup)
{
   register char* p;
   register unsigned int val;
   int len, pos = 0;

   *sup = 0;

   p = body->s;
   len = body->len;

   while (pos < len) {
      /* skip spaces and commas */
      for (; pos < len && IS_DELIM(p); ++pos, ++p);

      val = LOWER_DWORD(READ(p));
      switch (val) {

         /* "path" */
         case _path_:
            if(pos + 4 <= len && IS_DELIM(p+4)) {
               *sup |= F_SUPPORTED_PATH;
               pos += 5; p += 5;
            }
            break;

         /* "100rel" */
         case _100r_:
            if ( pos+6 <= len
                && LOWER_BYTE(*(p+4))=='e' && LOWER_BYTE(*(p+5))=='l'
                && IS_DELIM(p+6)) {
               *sup |= F_SUPPORTED_100REL;
               pos += SUPPORTED_100REL_LEN + 1;
               p   += SUPPORTED_100REL_LEN + 1;
            }
            break;

         /* "timer" */
         case _time_:
            if ( pos+5 <= len && LOWER_BYTE(*(p+4))=='r'
                && IS_DELIM(p+5) ) {
               *sup |= F_SUPPORTED_TIMER;
               pos += SUPPORTED_TIMER_LEN + 1;
               p   += SUPPORTED_TIMER_LEN + 1;
            }
            break;

         /* unknown */
         default:
            /* skip element */
            for (; pos < len && !IS_DELIM(p); ++pos, ++p);
            break;
      }
   }
   
   return 0;
}

/*!
 * Parse all Supported headers
 */
int parse_supported( struct sip_msg *msg)
{
   unsigned int supported;
   struct hdr_field  *hdr;
   struct supported_body *sb;

   /* maybe the header is already parsed! */
   if (msg->supported && msg->supported->parsed)
      return 0;

   /* parse to the end in order to get all SUPPORTED headers */
   if (parse_headers(msg,HDR_EOH_F,0)==-1 || !msg->supported)
      return -1;

   /* bad luck! :-( - we have to parse them */
   supported = 0;
   for( hdr=msg->supported ; hdr ; hdr=hdr->sibling) {
      if (hdr->parsed) {
         supported |= ((struct supported_body*)hdr->parsed)->supported;
         continue;
      }

      sb = (struct supported_body*)pkg_malloc(sizeof(struct supported_body));
      if (sb == 0) {
         LM_ERR("out of pkg_memory\n");
         return -1;
      }

      parse_supported_body(&(hdr->body), &(sb->supported));
      sb->supported_all = 0;
      hdr->parsed = (void*)sb;
      supported |= sb->supported;
   }

   ((struct supported_body*)msg->supported->parsed)->supported_all = 
      supported;
   return 0;
}