/*

 * Copyright (c) 2004 Juha Heinanen

 *

 *

 * This file is part of opensips, a free SIP server.

 *

 * opensips 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

 *

 * opensips 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

 *

 * History:

 * --------

 *  2005-07-05 - moved and merged method types in msg_parser.h (ramona)

 *             - changed and exported parse_method() to use it from other

 *               files (ramona)

 */

#include <strings.h>

#include "../dprint.h"

#include "../trim.h"

#include "../core_stats.h"

#include "parse_methods.h"

#include "msg_parser.h"

/*

 * Check if argument is valid RFC3261 token character.

 */

static inline int method_char(char _c)

{

  return (_c >= 65 && _c <= 90)    /* upper alpha */

    || (_c >= 97 && _c <= 122)   /* lower aplha */

    || (_c >= 48 && _c <= 57)    /* digits */

    || (_c == '-') || (_c == '.') || (_c == '!') || (_c == '%')

    || (_c == '*') || (_c == '_') || (_c == '+') || (_c == '`')

    || (_c == '\'') || (_c == '~');

}

/*

 * Parse a method pointed by start, end is the last character to check (if NULL

 * assume that start is a zero terminated string)

 * => assign enum bit to method.

 * Returns pointer to next char if parse succeeded

 * and NULL otherwise.

 */

char* parse_method(char* start, char* end, unsigned int* method)

{

  int len=0;

  int max=0;

   if (!start || !method) {

     LM_ERR("invalid parameter value\n");

     return NULL;

   }

   if(end)

     max = end - start;

   *method = METHOD_UNDEF;

   switch (start[0]) {

     case 'A':

     case 'a':

      if(end && max<3)

        goto unknown;

      if ((start[1]=='c' || start[1]=='C')

          && (start[2]=='k' || start[2]=='K'))

      {

        *method = METHOD_ACK;

        len = 3;

        goto done;

      }

      goto unknown;

    case 'B':

    case 'b':

      if(end && max<3)

        goto unknown;

      if ((start[1]=='y' || start[1]=='Y')

          && (start[2]=='e' || start[2]=='E'))

      {

        *method = METHOD_BYE;

        len = 3;

        goto done;

      }

      goto unknown;

    case 'C':

    case 'c':

      if(end && max<6)

        goto unknown;

      if ((start[1]=='a' || start[1]=='A')

          && (start[2]=='n' || start[2]=='N')

          && (start[3]=='c' || start[3]=='C')

          && (start[4]=='e' || start[4]=='E')

          && (start[5]=='l' || start[5]=='L'))

      {

        *method = METHOD_CANCEL;

        len = 6;

        goto done;

      }

      goto unknown;

    case 'I':

    case 'i':

      if(end && max<4)

        goto unknown;

      if(start[1]!='n' && start[1]!='N')

        goto unknown;

      if ((start[2]=='f' || start[2]=='F')

          && (start[3]=='o' || start[3]=='O'))

      {

        *method = METHOD_INFO;

        len = 4;

        goto done;

      }

      if(end && max<6)

        goto unknown;

      if ((start[2]=='v' || start[2]=='V')

          && (start[3]=='i' || start[3]=='I')

          && (start[4]=='t' || start[4]=='T')

          && (start[5]=='e' || start[5]=='E'))

      {

        *method = METHOD_INVITE;

        len = 6;

        goto done;

      }

      goto unknown;

    case 'M':

    case 'm':

      if(end && max<7)

        goto unknown;

      if ((start[1]=='e' || start[1]=='E')

          && (start[2]=='s' || start[2]=='S')

          && (start[3]=='s' || start[3]=='S')

          && (start[4]=='a' || start[4]=='A')

          && (start[5]=='g' || start[5]=='G')

          && (start[6]=='e' || start[6]=='E')) {

        *method = METHOD_MESSAGE;

        len = 7;

        goto done;

      }

      goto unknown;

    case 'N':

    case 'n':

      if(end && max<6)

        goto unknown;

      if ((start[1]=='o' || start[1]=='O')

          && (start[2]=='t' || start[2]=='T')

          && (start[3]=='i' || start[3]=='I')

          && (start[4]=='f' || start[4]=='F')

          && (start[5]=='y' || start[5]=='Y'))

      {

        *method = METHOD_NOTIFY;

        len = 6;

        goto done;

      }

      goto unknown;

    case 'O':

    case 'o':

      if(end && max<7)

        goto unknown;

      if((start[1]=='p' || start[1]=='P')

          && (start[2]=='t' || start[2]=='T')

          && (start[3]=='i' || start[3]=='I')

          && (start[4]=='o' || start[4]=='O')

          && (start[5]=='n' || start[5]=='N')

          && (start[6]=='s' || start[6]=='S'))

      {

        *method = METHOD_OPTIONS;

        len = 7;

        goto done;

      }

      goto unknown;

    case 'P':

    case 'p':

      if(end && max<5)

        goto unknown;

      if((start[1]=='r' || start[1]=='R')

          && (start[2]=='a' || start[2]=='A')

          && (start[3]=='c' || start[3]=='C')

          && (start[4]=='k' || start[4]=='K'))

      {

        *method = METHOD_PRACK;

        len = 5;

        goto done;

      }

      if(end && max<7)

        goto unknown;

      if ((start[1]=='u' || start[1]=='U')

           && (start[2]=='b' || start[2]=='B')

           && (start[3]=='l' || start[3]=='L')

           && (start[4]=='i' || start[4]=='I')

           && (start[5]=='s' || start[5]=='S')

           && (start[6]=='h' || start[6]=='H'))

      {

        *method = METHOD_PUBLISH;

        len = 7;

        goto done;

      }

      goto unknown;

    case 'R':

    case 'r':

      if(end && max<5)

        goto unknown;

      if(start[1]!='e' && start[1]!='E')

        goto unknown;

      if((start[2]=='f' || start[2]=='F')

           && (start[3]=='e' || start[3]=='E')

           && (start[4]=='r' || start[4]=='R'))

      {

        *method = METHOD_REFER;

        len = 5;

        goto done;

      }

      if(end && max<8)

        goto unknown;

      if ((start[2]=='g' || start[2]=='G')

           && (start[3]=='i' || start[3]=='I')

           && (start[4]=='s' || start[4]=='S')

           && (start[5]=='t' || start[5]=='T')

           && (start[6]=='e' || start[6]=='E')

           && (start[7]=='r' || start[7]=='R'))

      {

        *method = METHOD_REGISTER;

        len = 8;

        goto done;

      }

      goto unknown;

    case 'S':

    case 's':

      if(end && max<9)

        goto unknown;

      if ((start[1]=='u' || start[1]=='U')

           && (start[2]=='b' || start[2]=='B')

           && (start[3]=='s' || start[3]=='S')

           && (start[4]=='c' || start[4]=='C')

           && (start[5]=='r' || start[5]=='R')

           && (start[6]=='i' || start[6]=='I')

           && (start[7]=='b' || start[7]=='B')

           && (start[8]=='e' || start[8]=='E'))

      {

        *method = METHOD_SUBSCRIBE;

        len = 9;

        goto done;

      }

      goto unknown;

    case 'U':

    case 'u':

      if(end && max<6)

        goto unknown;

      if ((start[1]=='p' || start[1]=='P')

          && (start[2]=='d' || start[2]=='D')

          && (start[3]=='a' || start[3]=='A')

          && (start[4]=='t' || start[4]=='T')

          && (start[5]=='e' || start[5]=='E')) {

        *method = METHOD_UPDATE;

        len = 6;

        goto done;

      }

      goto unknown;

    default:

      goto unknown;

    }

done:

  if(!end || (end && len < max))

  {

    if(start[len]!='\0' && start[len]!=',' && start[len]!=' '

        && start[len]!='\t' && start[len]!='\r' && start[len]!='\n')

      goto unknown;

  }

  return (start+len);

unknown:

  *method = METHOD_OTHER;

  if(end)

  {

    while(len < max)

    {

      if((start[len]=='\0' || start[len]==',' || start[len]==' '

            || start[len]=='\t' || start[len]=='\r'

            || start[len]=='\n'))

        return (start+len);

      if(!method_char(start[len]))

      {

        LM_ERR("invalid character %c\n", start[len]);

        return NULL;

      }

      len++;

    }

    return end;

  }

  while(start[len]!='\0' && start[len]!=',' && start[len]!=' '

      && start[len]!='\t' && start[len]!='\r' && start[len]!='\n')

  {

    if(!method_char(start[len]))

    {

      LM_ERR("invalid character %c!\n", start[len]);

      return NULL;

    }

    len++;

  }

  return (start+len);

}

/*

 * Parse comma separated list of methods pointed by _body and assign their

 * enum bits to _methods.  Returns 0 on success and -1 on failure.

 */

int parse_methods(str* _body, unsigned int* _methods)

{

  str next;

  char *p;

  char *p0;

  unsigned int method;

  if (!_body || !_methods) {

    LM_ERR("invalid parameter value\n");

    return -1;

  }

  next.len = _body->len;

  next.s = _body->s;

  trim_leading(&next);

  *_methods = 0;

  if (next.len == 0) {

    goto done;

  }

  method = 0;

  p = next.s;

  while (p<next.s+next.len) {

    if((p0=parse_method(p, next.s+next.len, &method))!=NULL) {

      *_methods |= method;

      p = p0;

    } else {

      LM_ERR("invalid method [%.*s]\n", next.len, next.s);

      return -1;

    }

    while(p<next.s+next.len && (*p==' ' || *p=='\t'

          || *p=='\r' || *p=='\n'))

      p++;

    if(p>=next.s+next.len || *p == '\0')

      goto done;

    if (*p == ',')

    {

      p++;

      while(p<next.s+next.len && (*p==' ' || *p=='\t'

          || *p=='\r' || *p=='\n'))

        p++;

      if(p>=next.s+next.len)

        goto done;

    } else {

      LM_ERR("comma expected\n");

      return -1;

    }

  }

done:

  LM_DBG("methods 0x%X\n", *_methods);

  return 0;

}