src/basic/conf-files.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <stdarg.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include "conf-files.h"
   9 #include "def.h"
  10 #include "dirent-util.h"
  11 #include "fd-util.h"
  12 #include "hashmap.h"
  13 #include "log.h"
  14 #include "macro.h"
  15 #include "path-util.h"
  16 #include "set.h"
  17 #include "sort-util.h"
  18 #include "stat-util.h"
  19 #include "string-util.h"
  20 #include "strv.h"
  21 #include "terminal-util.h"
  22
  23 static int files_add(
  24                 Hashmap *h,
  25                 Set *masked,
  26                 const char *suffix,
  27                 const char *root,
  28                 unsigned flags,
  29                 const char *path) {
  30
  31         _cleanup_closedir_ DIR *dir = NULL;
  32         const char *dirpath;
  33         struct dirent *de;
  34         int r;
  35
  36         assert(h);
  37         assert((flags & CONF_FILES_FILTER_MASKED) == 0 || masked);
  38         assert(path);
  39
  40         dirpath = prefix_roota(root, path);
  41
  42         dir = opendir(dirpath);
  43         if (!dir) {
  44                 if (errno == ENOENT)
  45                         return 0;
  46
  47                 return log_debug_errno(errno, "Failed to open directory '%s': %m", dirpath);
  48         }
  49
  50         FOREACH_DIRENT(de, dir, return -errno) {
  51                 struct stat st;
  52                 char *p, *key;
  53
  54                 /* Does this match the suffix? */
  55                 if (suffix && !endswith(de->d_name, suffix))
  56                         continue;
  57
  58                 /* Has this file already been found in an earlier directory? */
  59                 if (hashmap_contains(h, de->d_name)) {
  60                         log_debug("Skipping overridden file '%s/%s'.", dirpath, de->d_name);
  61                         continue;
  62                 }
  63
  64                 /* Has this been masked in an earlier directory? */
  65                 if ((flags & CONF_FILES_FILTER_MASKED) && set_contains(masked, de->d_name)) {
  66                         log_debug("File '%s/%s' is masked by previous entry.", dirpath, de->d_name);
  67                         continue;
  68                 }
  69
  70                 /* Read file metadata if we shall validate the check for file masks, for node types or whether the node is marked executable. */
  71                 if (flags & (CONF_FILES_FILTER_MASKED|CONF_FILES_REGULAR|CONF_FILES_DIRECTORY|CONF_FILES_EXECUTABLE))
  72                         if (fstatat(dirfd(dir), de->d_name, &st, 0) < 0) {
  73                                 log_debug_errno(errno, "Failed to stat '%s/%s', ignoring: %m", dirpath, de->d_name);
  74                                 continue;
  75                         }
  76
  77                 /* Is this a masking entry? */
  78                 if ((flags & CONF_FILES_FILTER_MASKED))
  79                         if (null_or_empty(&st)) {
  80                                 assert(masked);
  81
  82                                 /* Mark this one as masked */
  83                                 r = set_put_strdup(&masked, de->d_name);
  84                                 if (r < 0)
  85                                         return r;
  86
  87                                 log_debug("File '%s/%s' is a mask.", dirpath, de->d_name);
  88                                 continue;
  89                         }
  90
  91                 /* Does this node have the right type? */
  92                 if (flags & (CONF_FILES_REGULAR|CONF_FILES_DIRECTORY))
  93                         if (!((flags & CONF_FILES_DIRECTORY) && S_ISDIR(st.st_mode)) &&
  94                             !((flags & CONF_FILES_REGULAR) && S_ISREG(st.st_mode))) {
  95                                 log_debug("Ignoring '%s/%s', as it does not have the right type.", dirpath, de->d_name);
  96                                 continue;
  97                         }
  98
  99                 /* Does this node have the executable bit set? */
 100                 if (flags & CONF_FILES_EXECUTABLE)
 101                         /* As requested: check if the file is marked executable. Note that we don't check access(X_OK)
 102                          * here, as we care about whether the file is marked executable at all, and not whether it is
 103                          * executable for us, because if so, such errors are stuff we should log about. */
 104
 105                         if ((st.st_mode & 0111) == 0) { /* not executable */
 106                                 log_debug("Ignoring '%s/%s', as it is not marked executable.", dirpath, de->d_name);
 107                                 continue;
 108                         }
 109
 110                 if (flags & CONF_FILES_BASENAME) {
 111                         p = strdup(de->d_name);
 112                         if (!p)
 113                                 return -ENOMEM;
 114
 115                         key = p;
 116                 } else {
 117                         p = path_join(dirpath, de->d_name);
 118                         if (!p)
 119                                 return -ENOMEM;
 120
 121                         key = basename(p);
 122                 }
 123
 124                 r = hashmap_put(h, key, p);
 125                 if (r < 0) {
 126                         free(p);
 127                         return log_debug_errno(r, "Failed to add item to hashmap: %m");
 128                 }
 129
 130                 assert(r > 0);
 131         }
 132
 133         return 0;
 134 }
 135
 136 static int base_cmp(char * const *a, char * const *b) {
 137         return strcmp(basename(*a), basename(*b));
 138 }
 139
 140 static int conf_files_list_strv_internal(
 141                 char ***ret,
 142                 const char *suffix,
 143                 const char *root,
 144                 unsigned flags,
 145                 char **dirs) {
 146
 147         _cleanup_hashmap_free_ Hashmap *fh = NULL;
 148         _cleanup_set_free_free_ Set *masked = NULL;
 149         char **files, **p;
 150         int r;
 151
 152         assert(ret);
 153
 154         /* This alters the dirs string array */
 155         if (!path_strv_resolve_uniq(dirs, root))
 156                 return -ENOMEM;
 157
 158         fh = hashmap_new(&path_hash_ops);
 159         if (!fh)
 160                 return -ENOMEM;
 161
 162         if (flags & CONF_FILES_FILTER_MASKED) {
 163                 masked = set_new(&path_hash_ops);
 164                 if (!masked)
 165                         return -ENOMEM;
 166         }
 167
 168         STRV_FOREACH(p, dirs) {
 169                 r = files_add(fh, masked, suffix, root, flags, *p);
 170                 if (r == -ENOMEM)
 171                         return r;
 172                 if (r < 0)
 173                         log_debug_errno(r, "Failed to search for files in %s, ignoring: %m", *p);
 174         }
 175
 176         files = hashmap_get_strv(fh);
 177         if (!files)
 178                 return -ENOMEM;
 179
 180         typesafe_qsort(files, hashmap_size(fh), base_cmp);
 181         *ret = files;
 182
 183         return 0;
 184 }
 185
 186 int conf_files_insert(char ***strv, const char *root, char **dirs, const char *path) {
 187         /* Insert a path into strv, at the place honouring the usual sorting rules:
 188          * - we first compare by the basename
 189          * - and then we compare by dirname, allowing just one file with the given
 190          *   basename.
 191          * This means that we will
 192          * - add a new entry if basename(path) was not on the list,
 193          * - do nothing if an entry with higher priority was already present,
 194          * - do nothing if our new entry matches the existing entry,
 195          * - replace the existing entry if our new entry has higher priority.
 196          */
 197         size_t i, n;
 198         char *t;
 199         int r;
 200
 201         n = strv_length(*strv);
 202         for (i = 0; i < n; i++) {
 203                 int c;
 204
 205                 c = base_cmp((char* const*) *strv + i, (char* const*) &path);
 206                 if (c == 0) {
 207                         char **dir;
 208
 209                         /* Oh, there already is an entry with a matching name (the last component). */
 210
 211                         STRV_FOREACH(dir, dirs) {
 212                                 _cleanup_free_ char *rdir = NULL;
 213                                 char *p1, *p2;
 214
 215                                 rdir = path_join(root, *dir);
 216                                 if (!rdir)
 217                                         return -ENOMEM;
 218
 219                                 p1 = path_startswith((*strv)[i], rdir);
 220                                 if (p1)
 221                                         /* Existing entry with higher priority
 222                                          * or same priority, no need to do anything. */
 223                                         return 0;
 224
 225                                 p2 = path_startswith(path, *dir);
 226                                 if (p2) {
 227                                         /* Our new entry has higher priority */
 228
 229                                         t = path_join(root, path);
 230                                         if (!t)
 231                                                 return log_oom();
 232
 233                                         return free_and_replace((*strv)[i], t);
 234                                 }
 235                         }
 236
 237                 } else if (c > 0)
 238                         /* Following files have lower priority, let's go insert our
 239                          * new entry. */
 240                         break;
 241
 242                 /* … we are not there yet, let's continue */
 243         }
 244
 245         /* The new file has lower priority than all the existing entries */
 246         t = path_join(root, path);
 247         if (!t)
 248                 return -ENOMEM;
 249
 250         r = strv_insert(strv, i, t);
 251         if (r < 0)
 252                 free(t);
 253
 254         return r;
 255 }
 256
 257 int conf_files_list_strv(char ***ret, const char *suffix, const char *root, unsigned flags, const char* const* dirs) {
 258         _cleanup_strv_free_ char **copy = NULL;
 259
 260         assert(ret);
 261
 262         copy = strv_copy((char**) dirs);
 263         if (!copy)
 264                 return -ENOMEM;
 265
 266         return conf_files_list_strv_internal(ret, suffix, root, flags, copy);
 267 }
 268
 269 int conf_files_list(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dir) {
 270         _cleanup_strv_free_ char **dirs = NULL;
 271
 272         assert(ret);
 273
 274         dirs = strv_new(dir);
 275         if (!dirs)
 276                 return -ENOMEM;
 277
 278         return conf_files_list_strv_internal(ret, suffix, root, flags, dirs);
 279 }
 280
 281 int conf_files_list_nulstr(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dirs) {
 282         _cleanup_strv_free_ char **d = NULL;
 283
 284         assert(ret);
 285
 286         d = strv_split_nulstr(dirs);
 287         if (!d)
 288                 return -ENOMEM;
 289
 290         return conf_files_list_strv_internal(ret, suffix, root, flags, d);
 291 }
 292
 293 int conf_files_list_with_replacement(
 294                 const char *root,
 295                 char **config_dirs,
 296                 const char *replacement,
 297                 char ***ret_files,
 298                 char **ret_replace_file) {
 299
 300         _cleanup_strv_free_ char **f = NULL;
 301         _cleanup_free_ char *p = NULL;
 302         int r;
 303
 304         assert(config_dirs);
 305         assert(ret_files);
 306         assert(ret_replace_file || !replacement);
 307
 308         r = conf_files_list_strv(&f, ".conf", root, 0, (const char* const*) config_dirs);
 309         if (r < 0)
 310                 return log_error_errno(r, "Failed to enumerate config files: %m");
 311
 312         if (replacement) {
 313                 r = conf_files_insert(&f, root, config_dirs, replacement);
 314                 if (r < 0)
 315                         return log_error_errno(r, "Failed to extend config file list: %m");
 316
 317                 p = path_join(root, replacement);
 318                 if (!p)
 319                         return log_oom();
 320         }
 321
 322         *ret_files = TAKE_PTR(f);
 323         if (ret_replace_file)
 324                 *ret_replace_file = TAKE_PTR(p);
 325
 326         return 0;
 327 }