1 /* SPDX-License-Identifier: LGPL-2.1+ */
10 #include <sys/types.h>
12 #include "conf-files.h"
14 #include "errno-util.h"
17 #include "glob-util.h"
20 #include "main-func.h"
22 #include "path-util.h"
23 #include "pretty-print.h"
24 #include "string-util.h"
26 #include "sysctl-util.h"
28 static char **arg_prefixes
= NULL
;
29 static bool arg_cat_config
= false;
30 static PagerFlags arg_pager_flags
= 0;
32 STATIC_DESTRUCTOR_REGISTER(arg_prefixes
, strv_freep
);
34 typedef struct Option
{
40 static Option
*option_free(Option
*o
) {
50 DEFINE_TRIVIAL_CLEANUP_FUNC(Option
*, option_free
);
51 DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(option_hash_ops
, char, string_hash_func
, string_compare_func
, Option
, option_free
);
53 static bool test_prefix(const char *p
) {
56 if (strv_isempty(arg_prefixes
))
59 STRV_FOREACH(i
, arg_prefixes
) {
62 t
= path_startswith(*i
, "/proc/sys/");
66 if (path_startswith(p
, t
))
73 static Option
*option_new(
76 bool ignore_failure
) {
78 _cleanup_(option_freep
) Option
*o
= NULL
;
88 .value
= value
? strdup(value
) : NULL
,
89 .ignore_failure
= ignore_failure
,
94 if (value
&& !o
->value
)
100 static int sysctl_write_or_warn(const char *key
, const char *value
, bool ignore_failure
) {
103 r
= sysctl_write(key
, value
);
105 /* If the sysctl is not available in the kernel or we are running with reduced privileges and
106 * cannot write it, then log about the issue, and proceed without failing. (EROFS is treated
107 * as a permission problem here, since that's how container managers usually protected their
108 * sysctls.) In all other cases log an error and make the tool fail. */
109 if (ignore_failure
|| r
== -EROFS
|| ERRNO_IS_PRIVILEGE(r
))
110 log_debug_errno(r
, "Couldn't write '%s' to '%s', ignoring: %m", value
, key
);
111 else if (r
== -ENOENT
)
112 log_info_errno(r
, "Couldn't write '%s' to '%s', ignoring: %m", value
, key
);
114 return log_error_errno(r
, "Couldn't write '%s' to '%s': %m", value
, key
);
120 static int apply_all(OrderedHashmap
*sysctl_options
) {
125 ORDERED_HASHMAP_FOREACH(option
, sysctl_options
, i
) {
128 /* Ignore "negative match" options, they are there only to exclude stuff from globs. */
132 if (string_is_glob(option
->key
)) {
133 _cleanup_strv_free_
char **paths
= NULL
;
134 _cleanup_free_
char *pattern
= NULL
;
137 pattern
= path_join("/proc/sys", option
->key
);
141 k
= glob_extend(&paths
, pattern
, GLOB_NOCHECK
);
143 if (option
->ignore_failure
|| ERRNO_IS_PRIVILEGE(k
))
144 log_debug_errno(k
, "Failed to resolve glob '%s', ignoring: %m",
147 log_error_errno(k
, "Couldn't resolve glob '%s': %m",
153 } else if (strv_isempty(paths
))
154 log_debug("No match for glob: %s", option
->key
);
156 STRV_FOREACH(s
, paths
) {
159 assert_se(key
= path_startswith(*s
, "/proc/sys"));
161 if (!test_prefix(key
))
164 if (ordered_hashmap_contains(sysctl_options
, key
)) {
165 log_info("Not setting %s (explicit setting exists).", key
);
169 k
= sysctl_write_or_warn(key
, option
->value
, option
->ignore_failure
);
175 k
= sysctl_write_or_warn(option
->key
, option
->value
, option
->ignore_failure
);
184 static int parse_file(OrderedHashmap
**sysctl_options
, const char *path
, bool ignore_enoent
) {
185 _cleanup_fclose_
FILE *f
= NULL
;
191 r
= search_and_fopen(path
, "re", NULL
, (const char**) CONF_PATHS_STRV("sysctl.d"), &f
);
193 if (ignore_enoent
&& r
== -ENOENT
)
196 return log_error_errno(r
, "Failed to open file '%s', ignoring: %m", path
);
199 log_debug("Parsing %s", path
);
201 _cleanup_(option_freep
) Option
*new_option
= NULL
;
202 _cleanup_free_
char *l
= NULL
;
203 bool ignore_failure
= false;
208 k
= read_line(f
, LONG_LINE_MAX
, &l
);
212 return log_error_errno(k
, "Failed to read file '%s', ignoring: %m", path
);
220 if (strchr(COMMENTS
"\n", *p
))
223 value
= strchr(p
, '=');
226 ignore_failure
= true;
232 value
= strstrip(value
);
236 /* We have a "negative match" option. Let's continue with value==NULL. */
239 log_syntax(NULL
, LOG_WARNING
, path
, c
, 0,
240 "Line is not an assignment, ignoring: %s", p
);
248 p
= sysctl_normalize(p
);
250 /* We can't filter out globs at this point, we'll need to do that later. */
251 if (!string_is_glob(p
) &&
255 if (ordered_hashmap_ensure_allocated(sysctl_options
, &option_hash_ops
) < 0)
258 existing
= ordered_hashmap_get(*sysctl_options
, p
);
260 if (streq_ptr(value
, existing
->value
)) {
261 existing
->ignore_failure
= existing
->ignore_failure
|| ignore_failure
;
265 log_debug("Overwriting earlier assignment of %s at '%s:%u'.", p
, path
, c
);
266 option_free(ordered_hashmap_remove(*sysctl_options
, p
));
269 new_option
= option_new(p
, value
, ignore_failure
);
273 k
= ordered_hashmap_put(*sysctl_options
, new_option
->key
, new_option
);
275 return log_error_errno(k
, "Failed to add sysctl variable %s to hashmap: %m", p
);
277 TAKE_PTR(new_option
);
283 static int help(void) {
284 _cleanup_free_
char *link
= NULL
;
287 r
= terminal_urlify_man("systemd-sysctl.service", "8", &link
);
291 printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n"
292 "Applies kernel sysctl settings.\n\n"
293 " -h --help Show this help\n"
294 " --version Show package version\n"
295 " --cat-config Show configuration files\n"
296 " --prefix=PATH Only apply rules with the specified prefix\n"
297 " --no-pager Do not pipe output into a pager\n"
298 "\nSee the %s for details.\n"
299 , program_invocation_short_name
306 static int parse_argv(int argc
, char *argv
[]) {
315 static const struct option options
[] = {
316 { "help", no_argument
, NULL
, 'h' },
317 { "version", no_argument
, NULL
, ARG_VERSION
},
318 { "cat-config", no_argument
, NULL
, ARG_CAT_CONFIG
},
319 { "prefix", required_argument
, NULL
, ARG_PREFIX
},
320 { "no-pager", no_argument
, NULL
, ARG_NO_PAGER
},
329 while ((c
= getopt_long(argc
, argv
, "h", options
, NULL
)) >= 0)
340 arg_cat_config
= true;
346 /* We used to require people to specify absolute paths
347 * in /proc/sys in the past. This is kinda useless, but
348 * we need to keep compatibility. We now support any
349 * sysctl name available. */
350 sysctl_normalize(optarg
);
352 if (path_startswith(optarg
, "/proc/sys"))
355 p
= path_join("/proc/sys", optarg
);
359 if (strv_consume(&arg_prefixes
, p
) < 0)
366 arg_pager_flags
|= PAGER_DISABLE
;
373 assert_not_reached("Unhandled option");
376 if (arg_cat_config
&& argc
> optind
)
377 return log_error_errno(SYNTHETIC_ERRNO(EINVAL
),
378 "Positional arguments are not allowed with --cat-config");
383 static int run(int argc
, char *argv
[]) {
384 _cleanup_(ordered_hashmap_freep
) OrderedHashmap
*sysctl_options
= NULL
;
387 r
= parse_argv(argc
, argv
);
400 for (i
= optind
; i
< argc
; i
++) {
401 k
= parse_file(&sysctl_options
, argv
[i
], false);
406 _cleanup_strv_free_
char **files
= NULL
;
409 r
= conf_files_list_strv(&files
, ".conf", NULL
, 0, (const char**) CONF_PATHS_STRV("sysctl.d"));
411 return log_error_errno(r
, "Failed to enumerate sysctl.d files: %m");
413 if (arg_cat_config
) {
414 (void) pager_open(arg_pager_flags
);
416 return cat_files(NULL
, files
, 0);
419 STRV_FOREACH(f
, files
) {
420 k
= parse_file(&sysctl_options
, *f
, true);
426 k
= apply_all(sysctl_options
);
433 DEFINE_MAIN_FUNCTION(run
);