dbus/xml_expat.c

   1 /* -*- Mode: C ; c-basic-offset: 4 -*- */
   2 /*
   3     Copyright (C) 2007,2008,2011 Nedko Arnaudov
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #if defined(HAVE_CONFIG_H)
  21 #include "config.h"
  22 #endif
  23
  24 #include <stdbool.h>
  25 #include <stdint.h>
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29 #include <fcntl.h>
  30 #include <errno.h>
  31 #include <string.h>
  32 #include <assert.h>
  33 #include <expat.h>
  34 #include <dbus/dbus.h>
  35
  36 #include "controller_internal.h"
  37 #include "jackdbus.h"
  38
  39 bool
  40 jack_controller_settings_init()
  41 {
  42     return true;
  43 }
  44
  45 void
  46 jack_controller_settings_uninit()
  47 {
  48 }
  49
  50 struct parse_context
  51 {
  52     struct jack_controller *controller_ptr;
  53     XML_Bool error;
  54     bool option_value_capture;
  55     char option[JACK_PARAM_STRING_MAX+1];
  56     int option_used;
  57     const char * address[PARAM_ADDRESS_SIZE];
  58     int address_index;
  59     char * container;
  60     char *name;
  61 };
  62
  63 #define context_ptr ((struct parse_context *)data)
  64
  65 void
  66 jack_controller_settings_callback_chrdata(void *data, const XML_Char *s, int len)
  67 {
  68     if (context_ptr->error)
  69     {
  70         return;
  71     }
  72
  73     if (context_ptr->option_value_capture)
  74     {
  75         if (context_ptr->option_used + len >= JACK_PARAM_STRING_MAX)
  76         {
  77             jack_error("xml parse max char data length reached");
  78             context_ptr->error = XML_TRUE;
  79             return;
  80         }
  81
  82         memcpy(context_ptr->option + context_ptr->option_used, s, len);
  83         context_ptr->option_used += len;
  84     }
  85 }
  86
  87 void
  88 jack_controller_settings_callback_elstart(void *data, const char *el, const char **attr)
  89 {
  90     if (context_ptr->error)
  91     {
  92         return;
  93     }
  94
  95     if (context_ptr->address_index >= PARAM_ADDRESS_SIZE)
  96     {
  97         assert(context_ptr->address_index == PARAM_ADDRESS_SIZE);
  98         jack_error("xml param address max depth reached");
  99         context_ptr->error = XML_TRUE;
 100         return;
 101     }
 102
 103     //jack_info("<%s>", el);
 104
 105     if (strcmp(el, "jack") == 0)
 106     {
 107         return;
 108     }
 109
 110     if (strcmp(el, PTNODE_ENGINE) == 0)
 111     {
 112         context_ptr->address[context_ptr->address_index++] = PTNODE_ENGINE;
 113         return;
 114     }
 115
 116     if (strcmp(el, PTNODE_DRIVERS) == 0)
 117     {
 118         context_ptr->address[context_ptr->address_index++] = PTNODE_DRIVERS;
 119         return;
 120     }
 121
 122     if (strcmp(el, PTNODE_INTERNALS) == 0)
 123     {
 124         context_ptr->address[context_ptr->address_index++] = PTNODE_INTERNALS;
 125         return;
 126     }
 127
 128     if (strcmp(el, "driver") == 0 ||
 129         strcmp(el, "internal") == 0)
 130     {
 131         if ((attr[0] == NULL || attr[2] != NULL) || strcmp(attr[0], "name") != 0)
 132         {
 133             jack_error("<%s> XML element must contain exactly one attribute, named \"name\"", el);
 134             context_ptr->error = XML_TRUE;
 135             return;
 136         }
 137
 138         context_ptr->container = strdup(attr[1]);
 139         if (context_ptr->container == NULL)
 140         {
 141             jack_error("strdup() failed");
 142             context_ptr->error = XML_TRUE;
 143             return;
 144         }
 145
 146         context_ptr->address[context_ptr->address_index++] = context_ptr->container;
 147
 148         return;
 149     }
 150
 151     if (strcmp(el, "option") == 0)
 152     {
 153         if ((attr[0] == NULL || attr[2] != NULL) || strcmp(attr[0], "name") != 0)
 154         {
 155             jack_error("<option> XML element must contain exactly one attribute, named \"name\"");
 156             context_ptr->error = XML_TRUE;
 157             return;
 158         }
 159
 160         context_ptr->name = strdup(attr[1]);
 161         if (context_ptr->name == NULL)
 162         {
 163             jack_error("strdup() failed");
 164             context_ptr->error = XML_TRUE;
 165             return;
 166         }
 167
 168         context_ptr->address[context_ptr->address_index++] = context_ptr->name;
 169         context_ptr->option_value_capture = true;
 170         context_ptr->option_used = 0;
 171         return;
 172     }
 173
 174     jack_error("unknown element \"%s\"", el);
 175     context_ptr->error = XML_TRUE;
 176 }
 177
 178 void
 179 jack_controller_settings_callback_elend(void *data, const char *el)
 180 {
 181     int i;
 182
 183     if (context_ptr->error)
 184     {
 185         return;
 186     }
 187
 188     //jack_info("</%s> (depth = %d)", el, context_ptr->address_index);
 189
 190     if (strcmp(el, "option") == 0)
 191     {
 192         assert(context_ptr->option_value_capture);
 193         context_ptr->option[context_ptr->option_used] = 0;
 194
 195         for (i = context_ptr->address_index; i < PARAM_ADDRESS_SIZE; i++)
 196         {
 197             context_ptr->address[context_ptr->address_index] = NULL;
 198         }
 199
 200         jack_controller_deserialize_parameter_value(context_ptr->controller_ptr, context_ptr->address, context_ptr->option);
 201
 202         free(context_ptr->name);
 203         context_ptr->name = NULL;
 204         context_ptr->option_value_capture = false;
 205         context_ptr->address_index--;
 206     }
 207     else if (context_ptr->container != NULL)
 208     {
 209         //jack_info("'%s'", context_ptr->container);
 210         free(context_ptr->container);
 211         context_ptr->container = NULL;
 212         context_ptr->address_index--;
 213     }
 214     else if (strcmp(el, PTNODE_ENGINE) == 0 ||
 215              strcmp(el, PTNODE_DRIVERS) == 0 ||
 216              strcmp(el, PTNODE_INTERNALS) == 0)
 217     {
 218         context_ptr->address_index--;
 219     }
 220     else
 221     {
 222         //jack_info("no depth decrement");
 223     }
 224 }
 225
 226 #undef context_ptr
 227
 228 void
 229 jack_controller_settings_load(
 230     struct jack_controller * controller_ptr)
 231 {
 232     XML_Parser parser;
 233     int bytes_read;
 234     void *buffer;
 235     char *filename;
 236     size_t conf_len;
 237     struct stat st;
 238     int fd;
 239     enum XML_Status xmls;
 240     struct parse_context context;
 241
 242     conf_len = strlen(JACKDBUS_CONF);
 243
 244     filename = malloc(g_jackdbus_config_dir_len + conf_len + 1);
 245     if (filename == NULL)
 246     {
 247         jack_error("Out of memory.");
 248         goto exit;
 249     }
 250
 251     memcpy(filename, g_jackdbus_config_dir, g_jackdbus_config_dir_len);
 252     memcpy(filename + g_jackdbus_config_dir_len, JACKDBUS_CONF, conf_len);
 253     filename[g_jackdbus_config_dir_len + conf_len] = 0;
 254
 255     jack_info("Loading settings from \"%s\" using %s ...", filename, XML_ExpatVersion());
 256
 257     if (stat(filename, &st) != 0)
 258     {
 259         jack_error("failed to stat \"%s\", error is %d (%s)", filename, errno, strerror(errno));
 260     }
 261
 262     fd = open(filename, O_RDONLY);
 263     if (fd == -1)
 264     {
 265         jack_error("open() failed to open conf filename.");
 266         goto exit_free_filename;
 267     }
 268
 269     parser = XML_ParserCreate(NULL);
 270     if (parser == NULL)
 271     {
 272         jack_error("XML_ParserCreate() failed to create parser object.");
 273         goto exit_close_file;
 274     }
 275
 276     //jack_info("conf file size is %llu bytes", (unsigned long long)st.st_size);
 277
 278     /* we are expecting that conf file has small enough size to fit in memory */
 279
 280     buffer = XML_GetBuffer(parser, st.st_size);
 281     if (buffer == NULL)
 282     {
 283         jack_error("XML_GetBuffer() failed.");
 284         goto exit_free_parser;
 285     }
 286
 287     bytes_read = read(fd, buffer, st.st_size);
 288     if (bytes_read != st.st_size)
 289     {
 290         jack_error("read() returned unexpected result.");
 291         goto exit_free_parser;
 292     }
 293
 294     context.controller_ptr = controller_ptr;
 295     context.error = XML_FALSE;
 296     context.option_value_capture = false;
 297     context.address_index = 0;
 298     context.name = NULL;
 299     context.container = NULL;
 300
 301     XML_SetElementHandler(parser, jack_controller_settings_callback_elstart, jack_controller_settings_callback_elend);
 302     XML_SetCharacterDataHandler(parser, jack_controller_settings_callback_chrdata);
 303     XML_SetUserData(parser, &context);
 304
 305     xmls = XML_ParseBuffer(parser, bytes_read, XML_TRUE);
 306
 307     free(context.name);
 308     free(context.container);
 309
 310     if (xmls == XML_STATUS_ERROR)
 311     {
 312         jack_error("XML_ParseBuffer() failed.");
 313         goto exit_free_parser;
 314     }
 315
 316 exit_free_parser:
 317     XML_ParserFree(parser);
 318
 319 exit_close_file:
 320     close(fd);
 321
 322 exit_free_filename:
 323     free(filename);
 324
 325 exit:
 326     return;
 327 }