src/basic/conf-files.c

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