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