lib/dpkg/dir.c

   1 /*
   2  * libdpkg - Debian packaging suite library routines
   3  * dir.c - directory handling functions
   4  *
   5  * Copyright © 2010 Guillem Jover <guillem@debian.org>
   6  *
   7  * This is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This 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, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <compat.h>
  23
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <dirent.h>
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <unistd.h>
  33
  34 #include <dpkg/dpkg.h>
  35 #include <dpkg/i18n.h>
  36 #include <dpkg/dir.h>
  37
  38 static int
  39 dir_make_path_noalloc(char *dirname, mode_t mode)
  40 {
  41         char *slash;
  42
  43         /* Find the first slash, and ignore it, as it will be either the
  44          * slash for the root directory, for the current directory in a
  45          * relative pathname or its parent. */
  46         slash = strchr(dirname, '/');
  47
  48         while (slash != NULL) {
  49                 slash = strchr(slash + 1, '/');
  50                 if (slash)
  51                         *slash = '\0';
  52
  53                 if (mkdir(dirname, mode) < 0 && errno != EEXIST)
  54                         return -1;
  55                 if (slash)
  56                         *slash = '/';
  57         }
  58
  59         return 0;
  60 }
  61
  62 /**
  63  * Create the directory and all its parents if necessary.
  64  *
  65  * @param path The pathname to create directories for.
  66  * @param mode The pathname mode.
  67  */
  68 int
  69 dir_make_path(const char *path, mode_t mode)
  70 {
  71         char *dirname;
  72         int rc;
  73
  74         dirname = m_strdup(path);
  75         rc = dir_make_path_noalloc(dirname, mode);
  76         free(dirname);
  77
  78         return rc;
  79 }
  80
  81 int
  82 dir_make_path_parent(const char *path, mode_t mode)
  83 {
  84         char *dirname, *slash;
  85         int rc;
  86
  87         dirname = m_strdup(path);
  88         slash = strrchr(dirname, '/');
  89         if (slash != NULL) {
  90                 *slash = '\0';
  91                 rc = dir_make_path_noalloc(dirname, mode);
  92         } else {
  93                 rc = -1;
  94         }
  95         free(dirname);
  96
  97         return rc;
  98 }
  99
 100 /**
 101  * Sync a directory to disk from a DIR structure.
 102  *
 103  * @param dir The directory to sync.
 104  * @param path The name of the directory to sync (for error messages).
 105  */
 106 static void
 107 dir_sync(DIR *dir, const char *path)
 108 {
 109 #ifdef HAVE_FSYNC_DIR
 110         int fd;
 111
 112         fd = dirfd(dir);
 113         if (fd < 0)
 114                 ohshite(_("unable to get file descriptor for directory '%s'"),
 115                         path);
 116
 117         if (fsync(fd))
 118                 ohshite(_("unable to sync directory '%s'"), path);
 119 #endif
 120 }
 121
 122 /**
 123  * Sync a directory to disk from a pathname.
 124  *
 125  * @param path The name of the directory to sync.
 126  */
 127 void
 128 dir_sync_path(const char *path)
 129 {
 130 #ifdef HAVE_FSYNC_DIR
 131         DIR *dir;
 132
 133         dir = opendir(path);
 134         if (!dir)
 135                 ohshite(_("unable to open directory '%s'"), path);
 136
 137         dir_sync(dir, path);
 138
 139         closedir(dir);
 140 #endif
 141 }
 142
 143 /**
 144  * Sync to disk the parent directory of a pathname.
 145  *
 146  * @param path The child pathname of the directory to sync.
 147  */
 148 void
 149 dir_sync_path_parent(const char *path)
 150 {
 151 #ifdef HAVE_FSYNC_DIR
 152         char *dirname, *slash;
 153
 154         dirname = m_strdup(path);
 155
 156         slash = strrchr(dirname, '/');
 157         if (slash != NULL) {
 158                 *slash = '\0';
 159                 dir_sync_path(dirname);
 160         }
 161
 162         free(dirname);
 163 #endif
 164 }
 165
 166 /* TODO: Ideally we'd use openat() here, to avoid the path mangling, but
 167  * it's not widely available yet, so this will do for now. */
 168 static void
 169 dir_file_sync(const char *dir, const char *filename)
 170 {
 171         char *path;
 172         int fd;
 173
 174         path = str_fmt("%s/%s", dir, filename);
 175
 176         fd = open(path, O_WRONLY);
 177         if (fd < 0)
 178                 ohshite(_("unable to open file '%s'"), path);
 179         if (fsync(fd))
 180                 ohshite(_("unable to sync file '%s'"), path);
 181         if (close(fd))
 182                 ohshite(_("unable to close file '%s'"), path);
 183
 184         free(path);
 185 }
 186
 187 /**
 188  * Sync to disk the contents and the directory specified.
 189  *
 190  * @param path The pathname to sync.
 191  */
 192 void
 193 dir_sync_contents(const char *path)
 194 {
 195         DIR *dir;
 196         struct dirent *dent;
 197
 198         dir = opendir(path);
 199         if (!dir)
 200                 ohshite(_("unable to open directory '%s'"), path);
 201
 202         while ((dent = readdir(dir)) != NULL) {
 203                 if (strcmp(dent->d_name, ".") == 0 ||
 204                     strcmp(dent->d_name, "..") == 0)
 205                         continue;
 206
 207                 dir_file_sync(path, dent->d_name);
 208         }
 209
 210         dir_sync(dir, path);
 211
 212         closedir(dir);
 213 }