dbus-address.c

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-address.c  Server address parser.
 *
 * Copyright (C) 2003  CodeFactory AB
 * Copyright (C) 2004-2007  Red Hat, Inc.
 * Copyright (C) 2007  Ralf Habacker
 * Copyright (C) 2013  Chengwei Yang / Intel
 *
 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
 *
 * Licensed under the Academic Free License version 2.1
 *
 * This program 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.
 *
 * This program 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
 *
 */
 
#include <config.h>
#include "dbus-address.h"
#include "dbus-internals.h"
#include "dbus-list.h"
#include "dbus-string.h"
#include "dbus-protocol.h"
#include <dbus/dbus-test-tap.h>
 
struct DBusAddressEntry
{
  DBusString method; 
  DBusList *keys;    
  DBusList *values;  
};
 
 
void
_dbus_set_bad_address (DBusError  *error,
                       const char *address_problem_type,
                       const char *address_problem_field,
                       const char *address_problem_other)
{
  if (address_problem_type != NULL)
    dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                    "Server address of type %s was missing argument %s",
                    address_problem_type, address_problem_field);
  else
    dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                    "Could not parse server address: %s",
                    address_problem_other);
}
 
#define _DBUS_ADDRESS_OPTIONALLY_ESCAPED_BYTE(b)        \
         (((b) >= 'a' && (b) <= 'z') ||                 \
          ((b) >= 'A' && (b) <= 'Z') ||                 \
          ((b) >= '0' && (b) <= '9') ||                 \
          (b) == '-' ||                                 \
          (b) == '_' ||                                 \
          (b) == '/' ||                                 \
          (b) == '\\' ||                                \
          (b) == '*' ||                                \
          (b) == '.')
 
dbus_bool_t
_dbus_address_append_escaped (DBusString       *escaped,
                              const DBusString *unescaped)
{
  const unsigned char *p;
  const unsigned char *end;
  dbus_bool_t ret;
  int orig_len;
 
  ret = FALSE;
 
  orig_len = _dbus_string_get_length (escaped);
  p = _dbus_string_get_const_udata (unescaped);
  end = p + _dbus_string_get_length (unescaped);
  while (p != end)
    {
      if (_DBUS_ADDRESS_OPTIONALLY_ESCAPED_BYTE (*p))
        {
          if (!_dbus_string_append_byte (escaped, *p))
            goto out;
        }
      else
        {
          if (!_dbus_string_append_byte (escaped, '%'))
            goto out;
          if (!_dbus_string_append_byte_as_hex (escaped, *p))
            goto out;
        }
      
      ++p;
    }
 
  ret = TRUE;
  
 out:
  if (!ret)
    _dbus_string_set_length (escaped, orig_len);
  return ret;
}
 
 
static void
dbus_address_entry_free (DBusAddressEntry *entry)
{
  DBusList *link;
  
  _dbus_string_free (&entry->method);
 
  link = _dbus_list_get_first_link (&entry->keys);
  while (link != NULL)
    {
      _dbus_string_free (link->data);
      dbus_free (link->data);
      
      link = _dbus_list_get_next_link (&entry->keys, link);
    }
  _dbus_list_clear (&entry->keys);
  
  link = _dbus_list_get_first_link (&entry->values);
  while (link != NULL)
    {
      _dbus_string_free (link->data);
      dbus_free (link->data);
      
      link = _dbus_list_get_next_link (&entry->values, link);
    }
  _dbus_list_clear (&entry->values);
  
  dbus_free (entry);
}
 
void
dbus_address_entries_free (DBusAddressEntry **entries)
{
  int i;
  
  for (i = 0; entries[i] != NULL; i++)
    dbus_address_entry_free (entries[i]);
  dbus_free (entries);
}
 
static DBusAddressEntry *
create_entry (void)
{
  DBusAddressEntry *entry;
 
  entry = dbus_new0 (DBusAddressEntry, 1);
 
  if (entry == NULL)
    return NULL;
 
  if (!_dbus_string_init (&entry->method))
    {
      dbus_free (entry);
      return NULL;
    }
 
  return entry;
}
 
const char *
dbus_address_entry_get_method (DBusAddressEntry *entry)
{
  return _dbus_string_get_const_data (&entry->method);
}
 
const char *
dbus_address_entry_get_value (DBusAddressEntry *entry,
                              const char       *key)
{
  DBusList *values, *keys;
 
  keys = _dbus_list_get_first_link (&entry->keys);
  values = _dbus_list_get_first_link (&entry->values);
 
  while (keys != NULL)
    {
      _dbus_assert (values != NULL);
 
      if (_dbus_string_equal_c_str (keys->data, key))
        return _dbus_string_get_const_data (values->data);
 
      keys = _dbus_list_get_next_link (&entry->keys, keys);
      values = _dbus_list_get_next_link (&entry->values, values);
    }
  
  return NULL;
}
 
static dbus_bool_t
append_unescaped_value (DBusString       *unescaped,
                        const DBusString *escaped,
                        int               escaped_start,
                        int               escaped_len,
                        DBusError        *error)
{
  const char *p;
  const char *end;
  dbus_bool_t ret;
  
  ret = FALSE;
 
  p = _dbus_string_get_const_data (escaped) + escaped_start;
  end = p + escaped_len;
  while (p != end)
    {
      if (_DBUS_ADDRESS_OPTIONALLY_ESCAPED_BYTE (*p))
        {
          if (!_dbus_string_append_byte (unescaped, *p))
            goto out;
        }
      else if (*p == '%')
        {
          /* Efficiency is king */
          char buf[3];
          DBusString hex;
          int hex_end;
          
          ++p;
 
          if ((p + 2) > end)
            {
              dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                              "In D-Bus address, percent character was not followed by two hex digits");
              goto out;
            }
            
          buf[0] = *p;
          ++p;
          buf[1] = *p;
          buf[2] = '\0';
 
          _dbus_string_init_const (&hex, buf);
 
          if (!_dbus_string_hex_decode (&hex, 0, &hex_end,
                                        unescaped,
                                        _dbus_string_get_length (unescaped)))
            goto out;
 
          if (hex_end != 2)
            {
              dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                              "In D-Bus address, percent character was followed by characters other than hex digits");
              goto out;
            }
        }
      else
        {
          /* Error, should have been escaped */
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                          "In D-Bus address, character '%c' should have been escaped\n",
                          *p);
          goto out;
        }
      
      ++p;
    }
 
  ret = TRUE;
  
 out:
  if (!ret && error && !dbus_error_is_set (error))
    _DBUS_SET_OOM (error);
 
  _dbus_assert (ret || error == NULL || dbus_error_is_set (error));
  
  return ret;
}
 
dbus_bool_t
dbus_parse_address (const char         *address,
                    DBusAddressEntry ***entry_result,
                    int                *array_len,
                    DBusError          *error)
{
  DBusString str;
  int pos, end_pos, len, i;
  DBusList *entries, *link;
  DBusAddressEntry **entry_array;
 
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  _dbus_string_init_const (&str, address);
 
  entries = NULL;
  pos = 0;
  len = _dbus_string_get_length (&str);
 
  if (len == 0)
  {
    dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                    "Empty address '%s'", address);
    goto error;
  }
  
  while (pos < len)
    {
      DBusAddressEntry *entry;
 
      int found_pos;
 
      entry = create_entry ();
      if (!entry)
        {
          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
 
          goto error;
        }
      
      /* Append the entry */
      if (!_dbus_list_append (&entries, entry))
        {
          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
          dbus_address_entry_free (entry);
          goto error;
        }
      
      /* Look for a semi-colon */
      if (!_dbus_string_find (&str, pos, ";", &end_pos))
        end_pos = len;
      
      /* Look for the colon : */
      if (!_dbus_string_find_to (&str, pos, end_pos, ":", &found_pos))
        {
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS, "Address does not contain a colon");
          goto error;
        }
 
      if (!_dbus_string_copy_len (&str, pos, found_pos - pos, &entry->method, 0))
        {
          dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
          goto error;
        }
          
      pos = found_pos + 1;
 
      while (pos < end_pos)
        {
          int comma_pos, equals_pos;
 
          if (!_dbus_string_find_to (&str, pos, end_pos, ",", &comma_pos))
            comma_pos = end_pos;
          
          if (!_dbus_string_find_to (&str, pos, comma_pos, "=", &equals_pos) ||
              equals_pos == pos || equals_pos + 1 == comma_pos)
            {
              dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                              "'=' character not found or has no value following it");
              goto error;
            }
          else
            {
              DBusString *key;
              DBusString *value;
 
              key = dbus_new0 (DBusString, 1);
 
              if (!key)
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);             
                  goto error;
                }
 
              value = dbus_new0 (DBusString, 1);
              if (!value)
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
                  dbus_free (key);
                  goto error;
                }
              
              if (!_dbus_string_init (key))
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
                  dbus_free (key);
                  dbus_free (value);
                  
                  goto error;
                }
              
              if (!_dbus_string_init (value))
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
                  _dbus_string_free (key);
 
                  dbus_free (key);
                  dbus_free (value);              
                  goto error;
                }
 
              if (!_dbus_string_copy_len (&str, pos, equals_pos - pos, key, 0))
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
                  _dbus_string_free (key);
                  _dbus_string_free (value);
 
                  dbus_free (key);
                  dbus_free (value);              
                  goto error;
                }
 
              if (!append_unescaped_value (value, &str, equals_pos + 1,
                                           comma_pos - equals_pos - 1, error))
                {
                  _dbus_assert (error == NULL || dbus_error_is_set (error));
                  _dbus_string_free (key);
                  _dbus_string_free (value);
 
                  dbus_free (key);
                  dbus_free (value);              
                  goto error;
                }
 
              if (!_dbus_list_append (&entry->keys, key))
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);             
                  _dbus_string_free (key);
                  _dbus_string_free (value);
 
                  dbus_free (key);
                  dbus_free (value);              
                  goto error;
                }
 
              if (!_dbus_list_append (&entry->values, value))
                {
                  dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);             
                  _dbus_string_free (value);
 
                  dbus_free (value);
                  goto error;             
                }
            }
 
          pos = comma_pos + 1;
        }
 
      pos = end_pos + 1;
    }
 
  *array_len = _dbus_list_get_length (&entries);
  
  entry_array = dbus_new (DBusAddressEntry *, *array_len + 1);
 
  if (!entry_array)
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      
      goto error;
    }
  
  entry_array [*array_len] = NULL;
 
  link = _dbus_list_get_first_link (&entries);
  i = 0;
  while (link != NULL)
    {
      entry_array[i] = link->data;
      i++;
      link = _dbus_list_get_next_link (&entries, link);
    }
 
  _dbus_list_clear (&entries);
  *entry_result = entry_array;
 
  return TRUE;
 
 error:
  
  link = _dbus_list_get_first_link (&entries);
  while (link != NULL)
    {
      dbus_address_entry_free (link->data);
      link = _dbus_list_get_next_link (&entries, link);
    }
 
  _dbus_list_clear (&entries);
  
  return FALSE;
  
}
 
char*
dbus_address_escape_value (const char *value)
{
  DBusString escaped;
  DBusString unescaped;
  char *ret;
 
  ret = NULL;
 
  _dbus_string_init_const (&unescaped, value);
  
  if (!_dbus_string_init (&escaped))
    return NULL;
 
  if (!_dbus_address_append_escaped (&escaped, &unescaped))
    goto out;
  
  if (!_dbus_string_steal_data (&escaped, &ret))
    goto out;
 
 out:
  _dbus_string_free (&escaped);
  return ret;
}
 
char*
dbus_address_unescape_value (const char *value,
                             DBusError  *error)
{
  DBusString unescaped;
  DBusString escaped;
  char *ret;
  
  ret = NULL;
 
  _dbus_string_init_const (&escaped, value);
  
  if (!_dbus_string_init (&unescaped))
    return NULL;
 
  if (!append_unescaped_value (&unescaped, &escaped,
                               0, _dbus_string_get_length (&escaped),
                               error))
    goto out;
  
  if (!_dbus_string_steal_data (&unescaped, &ret))
    goto out;
 
 out:
  if (ret == NULL && error && !dbus_error_is_set (error))
    _DBUS_SET_OOM (error);
 
  _dbus_assert (ret != NULL || error == NULL || dbus_error_is_set (error));
  
  _dbus_string_free (&unescaped);
  return ret;
}