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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
***/
#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "conf-files.h"
#include "def.h"
#include "fd-util.h"
#include "fileio.h"
#include "hashmap.h"
#include "log.h"
#include "path-util.h"
#include "string-util.h"
#include "strv.h"
#include "sysctl-util.h"
#include "util.h"
static char **arg_prefixes = NULL;
static const char conf_file_dirs[] = CONF_PATHS_NULSTR("sysctl.d");
static int apply_all(OrderedHashmap *sysctl_options) {
char *property, *value;
Iterator i;
int r = 0;
ORDERED_HASHMAP_FOREACH_KEY(value, property, sysctl_options, i) {
int k;
k = sysctl_write(property, value);
if (k < 0) {
/* If the sysctl is not available in the kernel or we are running with reduced privileges and
* cannot write it, then log about the issue at LOG_NOTICE level, and proceed without
* failing. (EROFS is treated as a permission problem here, since that's how container managers
* usually protected their sysctls.) In all other cases log an error and make the tool fail. */
if (IN_SET(k, -EPERM, -EACCES, -EROFS, -ENOENT))
log_notice_errno(k, "Couldn't write '%s' to '%s', ignoring: %m", value, property);
else {
log_error_errno(k, "Couldn't write '%s' to '%s': %m", value, property);
if (r == 0)
r = k;
}
}
}
return r;
}
static bool test_prefix(const char *p) {
char **i;
if (strv_isempty(arg_prefixes))
return true;
STRV_FOREACH(i, arg_prefixes) {
const char *t;
t = path_startswith(*i, "/proc/sys/");
if (!t)
t = *i;
if (path_startswith(p, t))
return true;
}
return false;
}
static int parse_file(OrderedHashmap *sysctl_options, const char *path, bool ignore_enoent) {
_cleanup_fclose_ FILE *f = NULL;
unsigned c = 0;
int r;
assert(path);
r = search_and_fopen_nulstr(path, "re", NULL, conf_file_dirs, &f);
if (r < 0) {
if (ignore_enoent && r == -ENOENT)
return 0;
return log_error_errno(r, "Failed to open file '%s', ignoring: %m", path);
}
log_debug("Parsing %s", path);
for (;;) {
char *p, *value, *new_value, *property, *existing;
_cleanup_free_ char *l = NULL;
void *v;
int k;
k = read_line(f, LONG_LINE_MAX, &l);
if (k == 0)
break;
if (k < 0)
return log_error_errno(k, "Failed to read file '%s', ignoring: %m", path);
c++;
p = strstrip(l);
if (isempty(p))
continue;
if (strchr(COMMENTS "\n", *p))
continue;
value = strchr(p, '=');
if (!value) {
log_error("Line is not an assignment at '%s:%u': %s", path, c, value);
if (r == 0)
r = -EINVAL;
continue;
}
*value = 0;
value++;
p = sysctl_normalize(strstrip(p));
value = strstrip(value);
if (!test_prefix(p))
continue;
existing = ordered_hashmap_get2(sysctl_options, p, &v);
if (existing) {
if (streq(value, existing))
continue;
log_debug("Overwriting earlier assignment of %s at '%s:%u'.", p, path, c);
free(ordered_hashmap_remove(sysctl_options, p));
free(v);
}
property = strdup(p);
if (!property)
return log_oom();
new_value = strdup(value);
if (!new_value) {
free(property);
return log_oom();
}
k = ordered_hashmap_put(sysctl_options, property, new_value);
if (k < 0) {
log_error_errno(k, "Failed to add sysctl variable %s to hashmap: %m", property);
free(property);
free(new_value);
return k;
}
}
return r;
}
static void help(void) {
printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n"
"Applies kernel sysctl settings.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
" --prefix=PATH Only apply rules with the specified prefix\n"
, program_invocation_short_name);
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_PREFIX
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "prefix", required_argument, NULL, ARG_PREFIX },
{}
};
int c;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
switch (c) {
case 'h':
help();
return 0;
case ARG_VERSION:
return version();
case ARG_PREFIX: {
char *p;
/* We used to require people to specify absolute paths
* in /proc/sys in the past. This is kinda useless, but
* we need to keep compatibility. We now support any
* sysctl name available. */
sysctl_normalize(optarg);
if (path_startswith(optarg, "/proc/sys"))
p = strdup(optarg);
else
p = strappend("/proc/sys/", optarg);
if (!p)
return log_oom();
if (strv_consume(&arg_prefixes, p) < 0)
return log_oom();
break;
}
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
return 1;
}
int main(int argc, char *argv[]) {
OrderedHashmap *sysctl_options = NULL;
int r = 0, k;
r = parse_argv(argc, argv);
if (r <= 0)
goto finish;
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
umask(0022);
sysctl_options = ordered_hashmap_new(&path_hash_ops);
if (!sysctl_options) {
r = log_oom();
goto finish;
}
r = 0;
if (argc > optind) {
int i;
for (i = optind; i < argc; i++) {
k = parse_file(sysctl_options, argv[i], false);
if (k < 0 && r == 0)
r = k;
}
} else {
_cleanup_strv_free_ char **files = NULL;
char **f;
r = conf_files_list_nulstr(&files, ".conf", NULL, 0, conf_file_dirs);
if (r < 0) {
log_error_errno(r, "Failed to enumerate sysctl.d files: %m");
goto finish;
}
STRV_FOREACH(f, files) {
k = parse_file(sysctl_options, *f, true);
if (k < 0 && r == 0)
r = k;
}
}
k = apply_all(sysctl_options);
if (k < 0 && r == 0)
r = k;
finish:
ordered_hashmap_free_free_free(sysctl_options);
strv_free(arg_prefixes);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
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