xml.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*****************************************************************************
   3  *
   4  *   XML parsing helpers
   5  *
   6  *   Copyright (C) 2006,2007 Nedko Arnaudov <nedko@arnaudov.name>
   7  *
   8  *   This program is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU General Public License as published by
  10  *   the Free Software Foundation; version 2 of the License
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  *****************************************************************************/
  22
  23 #include <libxml/parser.h>
  24 #include <libxml/xpath.h>
  25 #include <string.h>
  26
  27 #define DISABLE_DEBUG_OUTPUT
  28
  29 #include "xml.h"
  30 #include "log.h"
  31
  32 int
  33 xml_get_content(
  34   xmlDocPtr doc_ptr,
  35   const char * xpath,
  36   xmlBufferPtr content_buffer_ptr)
  37 {
  38   int ret;
  39   xmlXPathContextPtr xpath_ctx;
  40   xmlXPathObjectPtr xpath_obj;
  41
  42   /* Create xpath evaluation context */
  43   xpath_ctx = xmlXPathNewContext(doc_ptr);
  44   if (xpath_ctx == NULL)
  45   {
  46     ERROR_OUT("Unable to create new XPath context");
  47     ret = -1;
  48     goto exit;
  49   }
  50
  51   /* Evaluate xpath expression */
  52   xpath_obj = xmlXPathEvalExpression((const xmlChar *)xpath, xpath_ctx);
  53   if (xpath_obj == NULL)
  54   {
  55     ERROR_OUT("Unable to evaluate XPath expression \"%s\"", xpath);
  56     ret = -1;
  57     goto free_xpath_ctx;
  58   }
  59
  60   if (xpath_obj->nodesetval == NULL || xpath_obj->nodesetval->nodeNr == 0)
  61   {
  62     ERROR_OUT("XPath \"%s\" evaluation returned no data", xpath);
  63     ret = -1;
  64     goto free_xpath_obj;
  65   }
  66
  67   if (xpath_obj->nodesetval->nodeNr != 1)
  68   {
  69     ERROR_OUT("XPath \"%s\" evaluation returned multiple entries (%d)", xpath, xpath_obj->nodesetval->nodeNr);
  70     ret = -1;
  71     goto free_xpath_obj;
  72   }
  73
  74   ret = xmlNodeBufGetContent(content_buffer_ptr, xpath_obj->nodesetval->nodeTab[0]);
  75   if (ret != 0)
  76   {
  77     ERROR_OUT("xmlNodeBufGetContent() failed. (%d)", ret);
  78     ret = -1;
  79     goto free_xpath_obj;
  80   }
  81
  82   ret = 0;
  83
  84 free_xpath_obj:
  85   xmlXPathFreeObject(xpath_obj);
  86
  87 free_xpath_ctx:
  88   xmlXPathFreeContext(xpath_ctx);
  89
  90 exit:
  91   return ret;
  92 }
  93
  94 int
  95 xml_check_path(
  96   xmlDocPtr doc_ptr,
  97   const char * xpath)
  98 {
  99   int ret;
 100   xmlXPathContextPtr xpath_ctx;
 101   xmlXPathObjectPtr xpath_obj;
 102
 103   /* Create xpath evaluation context */
 104   xpath_ctx = xmlXPathNewContext(doc_ptr);
 105   if (xpath_ctx == NULL)
 106   {
 107     ERROR_OUT("Unable to create new XPath context");
 108     ret = -1;
 109     goto exit;
 110   }
 111
 112   /* Evaluate xpath expression */
 113   xpath_obj = xmlXPathEvalExpression((const xmlChar *)xpath, xpath_ctx);
 114   if (xpath_obj == NULL)
 115   {
 116     ERROR_OUT("Unable to evaluate XPath expression \"%s\"", xpath);
 117     ret = -1;
 118     goto free_xpath_ctx;
 119   }
 120
 121   if (xpath_obj->nodesetval == NULL || xpath_obj->nodesetval->nodeNr == 0)
 122   {
 123     DEBUG_OUT("XPath \"%s\" evaluation returned no data", xpath);
 124     ret = 0;
 125     goto free_xpath_obj;
 126   }
 127
 128   if (xpath_obj->nodesetval->nodeNr != 1)
 129   {
 130     DEBUG_OUT("XPath \"%s\" evaluation returned multiple entries (%d)", xpath, xpath_obj->nodesetval->nodeNr);
 131     ret = 2;
 132     goto free_xpath_obj;
 133   }
 134
 135   DEBUG_OUT("XPath \"%s\" evaluation returned one entry", xpath);
 136   ret = 1;
 137
 138 free_xpath_obj:
 139   xmlXPathFreeObject(xpath_obj);
 140
 141 free_xpath_ctx:
 142   xmlXPathFreeContext(xpath_ctx);
 143
 144 exit:
 145   return ret;
 146 }
 147
 148 int
 149 xml_get_string(
 150   xmlDocPtr doc_ptr,
 151   const char * xpath,
 152   char * buffer_ptr,
 153   size_t buffer_size)
 154 {
 155   int ret;
 156   xmlBufferPtr content_buffer_ptr;
 157
 158   content_buffer_ptr = xmlBufferCreate();
 159   if (content_buffer_ptr == NULL)
 160   {
 161     ERROR_OUT("xmlBufferCreate() failed.");
 162     ret = -1;
 163     goto exit;
 164   }
 165
 166   ret = xml_get_content(doc_ptr, xpath, content_buffer_ptr);
 167   if (ret != 0)
 168   {
 169     goto free_buffer;
 170   }
 171
 172   DEBUG_OUT(
 173     "XPath \"%s\" execution returned content \"%s\" (%u bytes)",
 174     xpath,
 175     xmlBufferContent(content_buffer_ptr),
 176     xmlBufferLength(content_buffer_ptr));
 177
 178   if (buffer_size < xmlBufferLength(content_buffer_ptr) + 1)
 179   {
 180     ERROR_OUT(
 181       "%u chars are requires to store \"%s\" but only %u are available",
 182       xmlBufferLength(content_buffer_ptr) + 1,
 183       xmlBufferContent(content_buffer_ptr),
 184       buffer_size);
 185     ret = -1;
 186     goto free_buffer;
 187   }
 188
 189   memcpy(buffer_ptr, xmlBufferContent(content_buffer_ptr), xmlBufferLength(content_buffer_ptr) + 1);
 190   ret = 0;
 191
 192 free_buffer:
 193   xmlBufferFree(content_buffer_ptr);
 194
 195 exit:
 196   return ret;
 197 }
 198
 199 int
 200 xml_get_string_dup(
 201   xmlDocPtr doc_ptr,
 202   const char * xpath,
 203   char ** buffer_ptr_ptr)
 204 {
 205   int ret;
 206   xmlBufferPtr content_buffer_ptr;
 207   char * buffer_ptr;
 208
 209   content_buffer_ptr = xmlBufferCreate();
 210   if (content_buffer_ptr == NULL)
 211   {
 212     ERROR_OUT("xmlBufferCreate() failed.");
 213     ret = -1;
 214     goto exit;
 215   }
 216
 217   ret = xml_get_content(doc_ptr, xpath, content_buffer_ptr);
 218   if (ret != 0)
 219   {
 220     goto free_buffer;
 221   }
 222
 223   DEBUG_OUT(
 224     "XPath \"%s\" execution returned content \"%s\" (%u bytes)",
 225     xpath,
 226     xmlBufferContent(content_buffer_ptr),
 227     xmlBufferLength(content_buffer_ptr));
 228
 229   buffer_ptr = strdup((const char *)xmlBufferContent(content_buffer_ptr));
 230   if (buffer_ptr == NULL)
 231   {
 232     ERROR_OUT("strdup failed.");
 233     ret = -1;
 234     goto free_buffer;
 235   }
 236
 237   *buffer_ptr_ptr = buffer_ptr;
 238   ret = 0;
 239
 240 free_buffer:
 241   xmlBufferFree(content_buffer_ptr);
 242
 243 exit:
 244   return ret;
 245 }
 246
 247 int
 248 xml_get_int(
 249   xmlDocPtr doc_ptr,
 250   const char * xpath,
 251   int * value_ptr)
 252 {
 253   int ret;
 254   xmlBufferPtr content_buffer_ptr;
 255
 256   content_buffer_ptr = xmlBufferCreate();
 257   if (content_buffer_ptr == NULL)
 258   {
 259     ERROR_OUT("xmlBufferCreate() failed.");
 260     ret = -1;
 261     goto exit;
 262   }
 263
 264   ret = xml_get_content(doc_ptr, xpath, content_buffer_ptr);
 265   if (ret != 0)
 266   {
 267     goto free_buffer;
 268   }
 269
 270   DEBUG_OUT(
 271     "XPath \"%s\" execution returned content \"%s\" (%u bytes)",
 272     xpath,
 273     xmlBufferContent(content_buffer_ptr),
 274     xmlBufferLength(content_buffer_ptr));
 275
 276   *value_ptr = atoi((const char *)xmlBufferContent(content_buffer_ptr));
 277   ret = 0;
 278
 279 free_buffer:
 280   xmlBufferFree(content_buffer_ptr);
 281
 282 exit:
 283   return ret;
 284 }
 285
 286 int
 287 xml_get_uint(
 288   xmlDocPtr doc_ptr,
 289   const char * xpath,
 290   unsigned int * value_ptr)
 291 {
 292   int ret;
 293   xmlBufferPtr content_buffer_ptr;
 294   int value;
 295
 296   content_buffer_ptr = xmlBufferCreate();
 297   if (content_buffer_ptr == NULL)
 298   {
 299     ERROR_OUT("xmlBufferCreate() failed.");
 300     ret = -1;
 301     goto exit;
 302   }
 303
 304   ret = xml_get_content(doc_ptr, xpath, content_buffer_ptr);
 305   if (ret != 0)
 306   {
 307     goto free_buffer;
 308   }
 309
 310   DEBUG_OUT(
 311     "XPath \"%s\" execution returned content \"%s\" (%u bytes)",
 312     xpath,
 313     xmlBufferContent(content_buffer_ptr),
 314     xmlBufferLength(content_buffer_ptr));
 315
 316   value = atoi((const char *)xmlBufferContent(content_buffer_ptr));
 317   if (value < 0)
 318   {
 319     ERROR_OUT("\"%s\" cannot be converted to unsigned int", xmlBufferContent(content_buffer_ptr));
 320     return -1;
 321   }
 322
 323   *value_ptr = (unsigned int)value;
 324   ret = 0;
 325
 326 free_buffer:
 327   xmlBufferFree(content_buffer_ptr);
 328
 329 exit:
 330   return ret;
 331 }