mi_parser.c

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/*
 * $Id: mi_parser.c 5514 2009-01-26 12:33:24Z henningw $
 *
 * Copyright (C) 2006 Voice Sistem SRL
 *
 * 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.
 *
 *
 * History:
 * ---------
 *  2006-09-25  first version (bogdan)
 */

/*!
 * \file
 * \brief MI Fifo :: Parser
 * \ingroup mi
 */


#include <stdio.h>
#include <string.h>
#include <ctype.h>

#include "../../str.h"
#include "../../dprint.h"
#include "../../mi/mi.h"
#include "../../mem/mem.h"
#include "fifo_fnc.h"
#include "mi_fifo.h"
#include "mi_parser.h"

static char *mi_parse_buffer = 0;
static unsigned int mi_parse_buffer_len = 0;


int mi_parser_init( unsigned int size )
{
   mi_parse_buffer_len = size;
   mi_parse_buffer = pkg_malloc(size);

   if(!mi_parse_buffer){
      LM_ERR("pkg_malloc cannot allocate any more memory!\n");
      return -1;
   }

   return 0;
}



/* returns -1 = error
 *          0 = ok
 *          1 = end of stream
 */
static inline int mi_parse_node( FILE *stream, str *buf, str *name, str *value)
{
   char *p, *pmax;
   char *start;
   char *mark_nsp;
   int line_len;

   /* read one line */
   do {
      if (mi_read_line( buf->s, buf->len, stream, &line_len)<0) {
         LM_ERR("failed to read from fifo\n");
         return -1;
      }
      if (line_len == 1){
         LM_DBG("end of fifo input tree\n");
         return 1;
      }

      start = buf->s;
      pmax = buf->s + line_len - 1;

      /* remove leading spaces */
      for( ; start<pmax && isspace((int)*start) ; start++ );
   } while ( start==pmax );

   /* init */
   name->s = value->s = 0;
   name->len = value->len = 0;

   mark_nsp = 0;

   /* start parsing */
   if (*start!='"') {
      /* look for the atribute name */
      p = mark_nsp = start;
      while ( p!=pmax && ( (p[0]!=MI_ATTR_VAL_SEP1) || (p+1==pmax)
      || p[1]!=MI_ATTR_VAL_SEP2) ) {
         if (!isspace((int)*p)) {
            if (*p=='"')
               goto parse_err;
            mark_nsp = p;
         }
         p++;
      }

      if (p!=pmax) {
         /* we have found the separator */
         if (p==start) {
            /* empty attr name */
         } else {
            name->s = start;
            name->len = mark_nsp - start + 1;
         }

         p += 2; /* for separator */

         LM_DBG("attr name <%.*s> found\n",
            name->len, name->s);

         /* consume the trailing spaces */
         for( ; p!=pmax && isspace((int)*p) ; p++);

         if (p==pmax) {
            /* empty value.....we are done */
            goto done;
         }

         /* value (only if not quoted ) */
         if (*p!='"') {
            for( start=p ; p!=pmax ; p++ ) {
               if (!isspace((int)*p)) {
                  if (*p=='"')
                     goto parse_err;
                  mark_nsp = p;
               }
            }
            value->s = start;
            value->len = mark_nsp + 1  - start;
            goto done;
         }
         /* quoted value....continue */
      } else {
         /* we have an empty name ... and we read a non-quoted value */
         value->s = start;
         value->len = mark_nsp + 1 - start;
         goto done;
      }
   } else {
      p = start;
   }

   start = p+1;
   value->s = start;

   do {
      p = start;
      /* parse the buffer and look for " */
      while (p<pmax) {
         if (*p=='"') {
            if (start+1!=p && *(p-1)=='\\') {
               /* skip current char */
               memmove( p-1, p, pmax-p);
               pmax--;
            } else {
               /* end of value */
               value->len = p - value->s;
               /* is the line ending propely (only spaces) ? */
               for( p++ ; p!=pmax && isspace((int)*p) ; p++);
               if (p!=pmax)
                  goto parse_err;
               /* found! */
               goto done;
            }
         } else {
            p++;
         }
      }

      /* adjust input buffer */
      p++;
      buf->len -= p - buf->s;
      buf->s = p;

      /*read one more line */
      if (mi_read_line( buf->s, buf->len, stream, &line_len)<0) {
         LM_ERR("failed to re-read from fifo\n");
         return -1;
      }
      if (line_len == 1) {
         LM_DBG("end of fifo input tree\n");
         return -2;
      }

      start = buf->s;
      pmax = buf->s + line_len - 1;
   } while(1);

done:
   buf->len -= p - buf->s;
   buf->s = p;
   return 0;
parse_err:
   LM_ERR("parse error around %c\n",*p);
   return -1;
}



struct mi_root * mi_parse_tree(FILE *stream) {
   struct mi_root *root;
   struct mi_node *node;
   str name;
   str value;
   str buf;
   int ret;

   buf.s = mi_parse_buffer;
   buf.len= mi_parse_buffer_len;

   root = init_mi_tree(0,0,0);
   if (!root) {
      LM_ERR("the MI tree cannot be initialized!\n");
      goto error;
   }
   node = &root->node;

   name.s = value.s = 0;
   name.len = value.len = 0;

   /* every tree for a command ends with a \n that is alone on its line */
   while ( (ret=mi_parse_node(stream, &buf, &name, &value))>=0 ) {
      if (ret==1)
         return root;

      LM_DBG("adding node <%.*s> ; val <%.*s>\n",
         name.len,name.s, value.len,value.s);

      if(!add_mi_node_child(node,0,name.s,name.len,value.s,value.len)){
         LM_ERR("cannot add the child node to the MI tree\n");
         goto error;
      }
   }

   LM_ERR("Parse error!\n");
   if (ret==-1) {
      /* consume the rest of the fifo request */
      do {
         mi_read_line(mi_parse_buffer,mi_parse_buffer_len,stream,&ret);
      }while(ret>1);
   }

error:
   if (root)
      free_mi_tree(root);
   return 0;
}