common/dirhelpers.c

   1 /* -*- Mode: C ; c-basic-offset: 2 -*- */
   2 /*
   3  * LADI Session Handler (ladish)
   4  *
   5  * Copyright (C) 2009,2010 Nedko Arnaudov <nedko@arnaudov.name>
   6  *
   7  **************************************************************************
   8  * This file contains implementation of the directory helper functions
   9  **************************************************************************
  10  *
  11  * LADI Session Handler is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * LADI Session Handler is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with LADI Session Handler. If not, see <http://www.gnu.org/licenses/>
  23  * or write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 #include "../common.h"
  28
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <stdarg.h>
  34
  35 /* ret=true, err=0 - directory was created successfully */
  36 /* ret=true, err=EEXIST - directory already exists */
  37 /* ret=true, err=ENOENT -  A directory component in dirname does not exist or is a dangling symbolic link */
  38 /* ret=true, err=error - directory creation failed in a bad way */
  39 /* ret=false, err=error - dirname is not valid directory path */
  40 static bool safe_mkdir(const char * dirname, int mode, int * err)
  41 {
  42   struct stat st;
  43
  44   ASSERT(*dirname);             /* empty string? */
  45
  46   if (mkdir(dirname, mode) == 0)
  47   {
  48     *err = 0;
  49     return true;
  50   }
  51
  52   if (errno != EEXIST)
  53   {
  54     *err = errno;
  55     return true;
  56   }
  57
  58   /* dirname path exists, not necessarily as a directory.
  59      This includes the case where pathname is a symbolic link,
  60      dangling or not. */
  61
  62   if (stat(dirname, &st) != 0)
  63   {
  64     *err = errno;
  65     log_error("Failed to stat \"%s\": %d (%s)", dirname, errno, strerror(errno));
  66     return false;
  67   }
  68   else if (!S_ISDIR(st.st_mode))
  69   {
  70     *err = ENOTDIR;
  71     log_error("\"%s\" exists but is not directory.", dirname);
  72     return false;
  73   }
  74
  75   *err = EEXIST;
  76   return true;
  77 }
  78
  79 static bool rmkdir(char * buffer, int mode)
  80 {
  81   int err;
  82   char * p;
  83   size_t len;
  84   bool last;
  85
  86   len = 0;
  87   p = buffer;
  88 loop:
  89   last = *p == 0;
  90   if (!last)
  91   {
  92     if (*p != '/')
  93     {
  94       len++;
  95       p++;
  96       goto loop;
  97     }
  98
  99     if (len == 0)
 100     {
 101       /* skip extra '/' chars */
 102       p++;
 103       goto loop;
 104     }
 105
 106     *p = 0;
 107   }
 108   else if (len == 0)
 109   {
 110     return true;
 111   }
 112
 113   if (!safe_mkdir(buffer, mode, &err))
 114   {
 115     return false;
 116   }
 117
 118   switch (err)
 119   {
 120   case 0:
 121     log_info("Directory \"%s\" created", buffer);
 122     /* fall through */
 123   case EEXIST:
 124     break;
 125   default:
 126     log_error("Failed to create \"%s\" directory: %d (%s)", buffer, errno, strerror(errno));
 127     return false;
 128   }
 129
 130   if (!last)
 131   {
 132     *p = '/';
 133     len = 0;
 134     p++;
 135     goto loop;
 136   }
 137
 138   return true;
 139 }
 140
 141 bool ensure_dir_exist(const char * dirname, int mode)
 142 {
 143   size_t len;
 144   char * buffer;
 145   int err;
 146   bool ret;
 147
 148   if (!safe_mkdir(dirname, mode, &err))
 149   {
 150     return false;
 151   }
 152
 153   if (err == 0 || err == EEXIST)
 154   {
 155     return true;
 156   }
 157
 158   if (errno != ENOENT)
 159   {
 160     log_error("Failed to create \"%s\" directory: %d (%s)", dirname, errno, strerror(errno));
 161     return false;
 162   }
 163
 164   /* A directory component in dirname does not exist or is a dangling symbolic link */
 165
 166   len = strlen(dirname);
 167
 168   buffer = malloc(len + 1);
 169   if (buffer == NULL)
 170   {
 171     log_error("malloc(%zu) failed.", len);
 172     return false;
 173   }
 174
 175   memcpy(buffer, dirname, len);
 176   buffer[len] = 0;
 177
 178   ret = rmkdir(buffer, mode);
 179
 180   free(buffer);
 181
 182   return ret;
 183 }
 184
 185 bool ensure_dir_exist_varg(int mode, ...)
 186 {
 187   va_list ap;
 188   const char * str;
 189   size_t len;
 190   char * buffer;
 191   char * p;
 192   int ret;
 193
 194   len = 0;
 195   va_start(ap, mode);
 196   while ((str = va_arg(ap, const char *)) != NULL)
 197   {
 198     len += strlen(str);
 199   }
 200   va_end(ap);
 201   ASSERT(len > 0);
 202   len++;
 203
 204   buffer = malloc(len);
 205   if (buffer == NULL)
 206   {
 207     log_error("malloc(%zu) failed.", len);
 208     return false;
 209   }
 210
 211   p = buffer;
 212   va_start(ap, mode);
 213   while ((str = va_arg(ap, const char *)) != NULL)
 214   {
 215     len = strlen(str);
 216     memcpy(buffer, str, len);
 217     p += len;
 218   }
 219   va_end(ap);
 220   ASSERT(p != buffer);
 221   *p = 0;
 222
 223   ret = rmkdir(buffer, mode);
 224
 225   free(buffer);
 226
 227   return ret;
 228 }