db_id.c

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/* 
 * $Id: db_id.c 5413 2009-01-05 12:27:49Z henningw $
 *
 * Copyright (C) 2001-2005 iptel.org
 * Copyright (C) 2007-2008 1&1 Internet AG
 *
 * 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 db/db_id.c
 * \ingroup db
 * \brief Functions for parsing a database URL and work with db identifier.
 */

#include "db_id.h"
#include "../dprint.h"
#include "../mem/mem.h"
#include "../ut.h"
#include <stdlib.h>
#include <string.h>


/**
 * Duplicate a string
 * \param dst destination
 * \param begin start of the string
 * \param end end of the string
 */
static int dupl_string(char** dst, const char* begin, const char* end)
{
   if (*dst) pkg_free(*dst);

   *dst = pkg_malloc(end - begin + 1);
   if ((*dst) == NULL) {
      return -1;
   }

   memcpy(*dst, begin, end - begin);
   (*dst)[end - begin] = '\0';
   return 0;
}


/**
 * Parse a database URL of form 
 * scheme://[username[:password]@]hostname[:port]/database
 *
 * \param id filled id struct
 * \param url parsed URL
 * \return 0 if parsing was successful and -1 otherwise
 */
static int parse_db_url(struct db_id* id, const str* url)
{
#define SHORTEST_DB_URL "s://a/b"
#define SHORTEST_DB_URL_LEN (sizeof(SHORTEST_DB_URL) - 1)

   enum state {
      ST_SCHEME,     /* Scheme part */
      ST_SLASH1,     /* First slash */
      ST_SLASH2,     /* Second slash */
      ST_USER_HOST,  /* Username or hostname */
      ST_PASS_PORT,  /* Password or port part */
      ST_HOST,       /* Hostname part */
      ST_PORT,       /* Port part */
      ST_DB          /* Database part */
   };

   enum state st;
   unsigned int len, i;
   const char* begin;
   char* prev_token;

   prev_token = 0;

   if (!id || !url || !url->s) {
      goto err;
   }
   
   len = url->len;
   if (len < SHORTEST_DB_URL_LEN) {
      goto err;
   }
   
   /* Initialize all attributes to 0 */
   memset(id, 0, sizeof(struct db_id));
   st = ST_SCHEME;
   begin = url->s;

   for(i = 0; i < len; i++) {
      switch(st) {
      case ST_SCHEME:
         switch(url->s[i]) {
         case ':':
            st = ST_SLASH1;
            if (dupl_string(&id->scheme, begin, url->s + i) < 0) goto err;
            break;
         }
         break;

      case ST_SLASH1:
         switch(url->s[i]) {
         case '/':
            st = ST_SLASH2;
            break;

         default:
            goto err;
         }
         break;

      case ST_SLASH2:
         switch(url->s[i]) {
         case '/':
            st = ST_USER_HOST;
            begin = url->s + i + 1;
            break;
            
         default:
            goto err;
         }
         break;

      case ST_USER_HOST:
         switch(url->s[i]) {
         case '@':
            st = ST_HOST;
            if (dupl_string(&id->username, begin, url->s + i) < 0) goto err;
            begin = url->s + i + 1;
            break;

         case ':':
            st = ST_PASS_PORT;
            if (dupl_string(&prev_token, begin, url->s + i) < 0) goto err;
            begin = url->s + i + 1;
            break;

         case '/':
            if (dupl_string(&id->host, begin, url->s + i) < 0) goto err;
            if (dupl_string(&id->database, url->s + i + 1, url->s + len) < 0) goto err;
            return 0;
         }
         break;

      case ST_PASS_PORT:
         switch(url->s[i]) {
         case '@':
            st = ST_HOST;
            id->username = prev_token;
            if (dupl_string(&id->password, begin, url->s + i) < 0) goto err;
            begin = url->s + i + 1;
            break;

         case '/':
            id->host = prev_token;
            id->port = str2s(begin, url->s + i - begin, 0);
            if (dupl_string(&id->database, url->s + i + 1, url->s + len) < 0) goto err;
            return 0;
         }
         break;

      case ST_HOST:
         switch(url->s[i]) {
         case ':':
            st = ST_PORT;
            if (dupl_string(&id->host, begin, url->s + i) < 0) goto err;
            begin = url->s + i + 1;
            break;

         case '/':
            if (dupl_string(&id->host, begin, url->s + i) < 0) goto err;
            if (dupl_string(&id->database, url->s + i + 1, url->s + len) < 0) goto err;
            return 0;
         }
         break;

      case ST_PORT:
         switch(url->s[i]) {
         case '/':
            id->port = str2s(begin, url->s + i - begin, 0);
            if (dupl_string(&id->database, url->s + i + 1, url->s + len) < 0) goto err;
            return 0;
         }
         break;
         
      case ST_DB:
         break;
      }
   }

   if (st != ST_DB) goto err;
   return 0;

 err:
   if (id->scheme) pkg_free(id->scheme);
   if (id->username) pkg_free(id->username);
   if (id->password) pkg_free(id->password);
   if (id->host) pkg_free(id->host);
   if (id->database) pkg_free(id->database);
   if (prev_token) pkg_free(prev_token);
   return -1;
}


/**
 * Create a new connection identifier
 * \param url database URL
 * \return connection identifier, or zero on error
 */
struct db_id* new_db_id(const str* url)
{
   struct db_id* ptr;

   if (!url || !url->s) {
      LM_ERR("invalid parameter\n");
      return 0;
   }

   ptr = (struct db_id*)pkg_malloc(sizeof(struct db_id));
   if (!ptr) {
      LM_ERR("no private memory left\n");
      goto err;
   }
   memset(ptr, 0, sizeof(struct db_id));

   if (parse_db_url(ptr, url) < 0) {
      LM_ERR("error while parsing database URL: '%.*s' \n", url->len, url->s);
      goto err;
   }

   return ptr;

 err:
   if (ptr) pkg_free(ptr);
   return 0;
}


/**
 * Compare two connection identifiers
 * \param id1 first identifier
 * \param id2 second identifier
 * \return one if both are equal, zero otherwise
 */
unsigned char cmp_db_id(const struct db_id* id1, const struct db_id* id2)
{
   if (!id1 || !id2) return 0;
   if (id1->port != id2->port) return 0;

   if (strcmp(id1->scheme, id2->scheme)) return 0;
   if (id1->username!=0 && id2->username!=0) {
      if (strcmp(id1->username, id2->username)) return 0;
   } else {
      if (id1->username!=0 || id2->username!=0) return 0;
   }
   if (id1->password!=0 && id2->password!=0) {
      if(strcmp(id1->password, id2->password)) return 0;
   } else {
      if (id1->password!=0 || id2->password!=0) return 0;
   }
   if (strcasecmp(id1->host, id2->host)) return 0;
   if (strcmp(id1->database, id2->database)) return 0;
   return 1;
}


/**
 * Free a connection identifier
 * \param id identifier
 */
void free_db_id(struct db_id* id)
{
   if (!id) return;

   if (id->scheme) pkg_free(id->scheme);
   if (id->username) pkg_free(id->username);
   if (id->password) pkg_free(id->password);
   if (id->host) pkg_free(id->host);
   if (id->database) pkg_free(id->database);
   pkg_free(id);
}