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