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 "chase.h"
   9 #include "conf-files.h"
  10 #include "constants.h"
  11 #include "dirent-util.h"
  12 #include "fd-util.h"
  13 #include "hashmap.h"
  14 #include "log.h"
  15 #include "macro.h"
  16 #include "nulstr-util.h"
  17 #include "path-util.h"
  18 #include "set.h"
  19 #include "sort-util.h"
  20 #include "stat-util.h"
  21 #include "string-util.h"
  22 #include "strv.h"
  23 #include "terminal-util.h"
  24
  25 static int files_add(
  26                 DIR *dir,
  27                 const char *dirpath,
  28                 Hashmap **files,
  29                 Set **masked,
  30                 const char *suffix,
  31                 unsigned flags) {
  32
  33         int r;
  34
  35         assert(dir);
  36         assert(dirpath);
  37         assert(files);
  38         assert(masked);
  39
  40         FOREACH_DIRENT(de, dir, return -errno) {
  41                 _cleanup_free_ char *n = NULL, *p = NULL;
  42                 struct stat st;
  43
  44                 /* Does this match the suffix? */
  45                 if (suffix && !endswith(de->d_name, suffix))
  46                         continue;
  47
  48                 /* Has this file already been found in an earlier directory? */
  49                 if (hashmap_contains(*files, de->d_name)) {
  50                         log_debug("Skipping overridden file '%s/%s'.", dirpath, de->d_name);
  51                         continue;
  52                 }
  53
  54                 /* Has this been masked in an earlier directory? */
  55                 if ((flags & CONF_FILES_FILTER_MASKED) && set_contains(*masked, de->d_name)) {
  56                         log_debug("File '%s/%s' is masked by previous entry.", dirpath, de->d_name);
  57                         continue;
  58                 }
  59
  60                 /* Read file metadata if we shall validate the check for file masks, for node types or whether the node is marked executable. */
  61                 if (flags & (CONF_FILES_FILTER_MASKED|CONF_FILES_REGULAR|CONF_FILES_DIRECTORY|CONF_FILES_EXECUTABLE))
  62                         if (fstatat(dirfd(dir), de->d_name, &st, 0) < 0) {
  63                                 log_debug_errno(errno, "Failed to stat '%s/%s', ignoring: %m", dirpath, de->d_name);
  64                                 continue;
  65                         }
  66
  67                 /* Is this a masking entry? */
  68                 if ((flags & CONF_FILES_FILTER_MASKED))
  69                         if (null_or_empty(&st)) {
  70                                 /* Mark this one as masked */
  71                                 r = set_put_strdup(masked, de->d_name);
  72                                 if (r < 0)
  73                                         return r;
  74
  75                                 log_debug("File '%s/%s' is a mask.", dirpath, de->d_name);
  76                                 continue;
  77                         }
  78
  79                 /* Does this node have the right type? */
  80                 if (flags & (CONF_FILES_REGULAR|CONF_FILES_DIRECTORY))
  81                         if (!((flags & CONF_FILES_DIRECTORY) && S_ISDIR(st.st_mode)) &&
  82                             !((flags & CONF_FILES_REGULAR) && S_ISREG(st.st_mode))) {
  83                                 log_debug("Ignoring '%s/%s', as it does not have the right type.", dirpath, de->d_name);
  84                                 continue;
  85                         }
  86
  87                 /* Does this node have the executable bit set? */
  88                 if (flags & CONF_FILES_EXECUTABLE)
  89                         /* As requested: check if the file is marked executable. Note that we don't check access(X_OK)
  90                          * here, as we care about whether the file is marked executable at all, and not whether it is
  91                          * executable for us, because if so, such errors are stuff we should log about. */
  92
  93                         if ((st.st_mode & 0111) == 0) { /* not executable */
  94                                 log_debug("Ignoring '%s/%s', as it is not marked executable.", dirpath, de->d_name);
  95                                 continue;
  96                         }
  97
  98                 n = strdup(de->d_name);
  99                 if (!n)
 100                         return -ENOMEM;
 101
 102                 if ((flags & CONF_FILES_BASENAME))
 103                         r = hashmap_ensure_put(files, &string_hash_ops_free, n, n);
 104                 else {
 105                         p = path_join(dirpath, de->d_name);
 106                         if (!p)
 107                                 return -ENOMEM;
 108
 109                         r = hashmap_ensure_put(files, &string_hash_ops_free_free, n, p);
 110                 }
 111                 if (r < 0)
 112                         return r;
 113                 assert(r > 0);
 114
 115                 TAKE_PTR(n);
 116                 TAKE_PTR(p);
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int base_cmp(char * const *a, char * const *b) {
 123         assert(a);
 124         assert(b);
 125         return path_compare_filename(*a, *b);
 126 }
 127
 128 static int copy_and_sort_files_from_hashmap(Hashmap *fh, char ***ret) {
 129         _cleanup_free_ char **sv = NULL;
 130         char **files;
 131
 132         assert(ret);
 133
 134         sv = hashmap_get_strv(fh);
 135         if (!sv)
 136                 return -ENOMEM;
 137
 138         /* The entries in the array given by hashmap_get_strv() are still owned by the hashmap. */
 139         files = strv_copy(sv);
 140         if (!files)
 141                 return -ENOMEM;
 142
 143         typesafe_qsort(files, strv_length(files), base_cmp);
 144
 145         *ret = files;
 146         return 0;
 147 }
 148
 149 int conf_files_list_strv(
 150                 char ***ret,
 151                 const char *suffix,
 152                 const char *root,
 153                 unsigned flags,
 154                 const char * const *dirs) {
 155
 156         _cleanup_hashmap_free_ Hashmap *fh = NULL;
 157         _cleanup_set_free_ Set *masked = NULL;
 158         int r;
 159
 160         assert(ret);
 161
 162         STRV_FOREACH(p, dirs) {
 163                 _cleanup_closedir_ DIR *dir = NULL;
 164                 _cleanup_free_ char *path = NULL;
 165
 166                 r = chase_and_opendir(*p, root, CHASE_PREFIX_ROOT, &path, &dir);
 167                 if (r < 0) {
 168                         if (r != -ENOENT)
 169                                 log_debug_errno(r, "Failed to chase and open directory '%s', ignoring: %m", *p);
 170                         continue;
 171                 }
 172
 173                 r = files_add(dir, path, &fh, &masked, suffix, flags);
 174                 if (r == -ENOMEM)
 175                         return r;
 176                 if (r < 0)
 177                         log_debug_errno(r, "Failed to search for files in '%s', ignoring: %m", path);
 178         }
 179
 180         return copy_and_sort_files_from_hashmap(fh, ret);
 181 }
 182
 183 int conf_files_list_strv_at(
 184                 char ***ret,
 185                 const char *suffix,
 186                 int rfd,
 187                 unsigned flags,
 188                 const char * const *dirs) {
 189
 190         _cleanup_hashmap_free_ Hashmap *fh = NULL;
 191         _cleanup_set_free_ Set *masked = NULL;
 192         int r;
 193
 194         assert(rfd >= 0 || rfd == AT_FDCWD);
 195         assert(ret);
 196
 197         STRV_FOREACH(p, dirs) {
 198                 _cleanup_closedir_ DIR *dir = NULL;
 199                 _cleanup_free_ char *path = NULL;
 200
 201                 r = chase_and_opendirat(rfd, *p, CHASE_AT_RESOLVE_IN_ROOT, &path, &dir);
 202                 if (r < 0) {
 203                         if (r != -ENOENT)
 204                                 log_debug_errno(r, "Failed to chase and open directory '%s', ignoring: %m", *p);
 205                         continue;
 206                 }
 207
 208                 r = files_add(dir, path, &fh, &masked, suffix, flags);
 209                 if (r == -ENOMEM)
 210                         return r;
 211                 if (r < 0)
 212                         log_debug_errno(r, "Failed to search for files in '%s', ignoring: %m", path);
 213         }
 214
 215         return copy_and_sort_files_from_hashmap(fh, ret);
 216 }
 217
 218 int conf_files_insert(char ***strv, const char *root, char **dirs, const char *path) {
 219         /* Insert a path into strv, at the place honouring the usual sorting rules:
 220          * - we first compare by the basename
 221          * - and then we compare by dirname, allowing just one file with the given
 222          *   basename.
 223          * This means that we will
 224          * - add a new entry if basename(path) was not on the list,
 225          * - do nothing if an entry with higher priority was already present,
 226          * - do nothing if our new entry matches the existing entry,
 227          * - replace the existing entry if our new entry has higher priority.
 228          */
 229         size_t i, n;
 230         char *t;
 231         int r;
 232
 233         n = strv_length(*strv);
 234         for (i = 0; i < n; i++) {
 235                 int c;
 236
 237                 c = base_cmp((char* const*) *strv + i, (char* const*) &path);
 238                 if (c == 0)
 239                         /* Oh, there already is an entry with a matching name (the last component). */
 240                         STRV_FOREACH(dir, dirs) {
 241                                 _cleanup_free_ char *rdir = NULL;
 242                                 char *p1, *p2;
 243
 244                                 rdir = path_join(root, *dir);
 245                                 if (!rdir)
 246                                         return -ENOMEM;
 247
 248                                 p1 = path_startswith((*strv)[i], rdir);
 249                                 if (p1)
 250                                         /* Existing entry with higher priority
 251                                          * or same priority, no need to do anything. */
 252                                         return 0;
 253
 254                                 p2 = path_startswith(path, *dir);
 255                                 if (p2) {
 256                                         /* Our new entry has higher priority */
 257
 258                                         t = path_join(root, path);
 259                                         if (!t)
 260                                                 return log_oom();
 261
 262                                         return free_and_replace((*strv)[i], t);
 263                                 }
 264                         }
 265
 266                 else if (c > 0)
 267                         /* Following files have lower priority, let's go insert our
 268                          * new entry. */
 269                         break;
 270
 271                 /* … we are not there yet, let's continue */
 272         }
 273
 274         /* The new file has lower priority than all the existing entries */
 275         t = path_join(root, path);
 276         if (!t)
 277                 return -ENOMEM;
 278
 279         r = strv_insert(strv, i, t);
 280         if (r < 0)
 281                 free(t);
 282
 283         return r;
 284 }
 285
 286 int conf_files_list(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dir) {
 287         return conf_files_list_strv(ret, suffix, root, flags, STRV_MAKE_CONST(dir));
 288 }
 289
 290 int conf_files_list_at(char ***ret, const char *suffix, int rfd, unsigned flags, const char *dir) {
 291         return conf_files_list_strv_at(ret, suffix, rfd, flags, STRV_MAKE_CONST(dir));
 292 }
 293
 294 int conf_files_list_nulstr(char ***ret, const char *suffix, const char *root, unsigned flags, const char *dirs) {
 295         _cleanup_strv_free_ char **d = NULL;
 296
 297         assert(ret);
 298
 299         d = strv_split_nulstr(dirs);
 300         if (!d)
 301                 return -ENOMEM;
 302
 303         return conf_files_list_strv(ret, suffix, root, flags, (const char**) d);
 304 }
 305
 306 int conf_files_list_nulstr_at(char ***ret, const char *suffix, int rfd, unsigned flags, const char *dirs) {
 307         _cleanup_strv_free_ char **d = NULL;
 308
 309         assert(ret);
 310
 311         d = strv_split_nulstr(dirs);
 312         if (!d)
 313                 return -ENOMEM;
 314
 315         return conf_files_list_strv_at(ret, suffix, rfd, flags, (const char**) d);
 316 }
 317
 318 int conf_files_list_with_replacement(
 319                 const char *root,
 320                 char **config_dirs,
 321                 const char *replacement,
 322                 char ***ret_files,
 323                 char **ret_replace_file) {
 324
 325         _cleanup_strv_free_ char **f = NULL;
 326         _cleanup_free_ char *p = NULL;
 327         int r;
 328
 329         assert(config_dirs);
 330         assert(ret_files);
 331         assert(ret_replace_file || !replacement);
 332
 333         r = conf_files_list_strv(&f, ".conf", root, 0, (const char* const*) config_dirs);
 334         if (r < 0)
 335                 return log_error_errno(r, "Failed to enumerate config files: %m");
 336
 337         if (replacement) {
 338                 r = conf_files_insert(&f, root, config_dirs, replacement);
 339                 if (r < 0)
 340                         return log_error_errno(r, "Failed to extend config file list: %m");
 341
 342                 p = path_join(root, replacement);
 343                 if (!p)
 344                         return log_oom();
 345         }
 346
 347         *ret_files = TAKE_PTR(f);
 348         if (ret_replace_file)
 349                 *ret_replace_file = TAKE_PTR(p);
 350
 351         return 0;
 352 }
 353
 354 int conf_files_list_dropins(
 355                 char ***ret,
 356                 const char *dropin_dirname,
 357                 const char *root,
 358                 const char * const *dirs) {
 359
 360         _cleanup_strv_free_ char **dropin_dirs = NULL;
 361         const char *suffix;
 362         int r;
 363
 364         assert(ret);
 365         assert(dropin_dirname);
 366         assert(dirs);
 367
 368         suffix = strjoina("/", dropin_dirname);
 369         r = strv_extend_strv_concat(&dropin_dirs, (char**) dirs, suffix);
 370         if (r < 0)
 371                 return r;
 372
 373         return conf_files_list_strv(ret, ".conf", root, 0, (const char* const*) dropin_dirs);
 374 }