summaryrefslogtreecommitdiffstats
path: root/src/sysctl/sysctl.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/sysctl/sysctl.c')
-rw-r--r--src/sysctl/sysctl.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/src/sysctl/sysctl.c b/src/sysctl/sysctl.c
new file mode 100644
index 0000000..c67d790
--- /dev/null
+++ b/src/sysctl/sysctl.c
@@ -0,0 +1,320 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#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 "main-func.h"
+#include "pager.h"
+#include "path-util.h"
+#include "pretty-print.h"
+#include "string-util.h"
+#include "strv.h"
+#include "sysctl-util.h"
+#include "util.h"
+
+static char **arg_prefixes = NULL;
+static bool arg_cat_config = false;
+static PagerFlags arg_pager_flags = 0;
+
+STATIC_DESTRUCTOR_REGISTER(arg_prefixes, strv_freep);
+
+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(path, "re", NULL, (const char**) CONF_PATHS_STRV("sysctl.d"), &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, p);
+
+ 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 int help(void) {
+ _cleanup_free_ char *link = NULL;
+ int r;
+
+ r = terminal_urlify_man("systemd-sysctl.service", "8", &link);
+ if (r < 0)
+ return log_oom();
+
+ printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n"
+ "Applies kernel sysctl settings.\n\n"
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ " --cat-config Show configuration files\n"
+ " --prefix=PATH Only apply rules with the specified prefix\n"
+ " --no-pager Do not pipe output into a pager\n"
+ "\nSee the %s for details.\n"
+ , program_invocation_short_name
+ , link
+ );
+
+ return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+ enum {
+ ARG_VERSION = 0x100,
+ ARG_CAT_CONFIG,
+ ARG_PREFIX,
+ ARG_NO_PAGER,
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "cat-config", no_argument, NULL, ARG_CAT_CONFIG },
+ { "prefix", required_argument, NULL, ARG_PREFIX },
+ { "no-pager", no_argument, NULL, ARG_NO_PAGER },
+ {}
+ };
+
+ int c;
+
+ assert(argc >= 0);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+
+ switch (c) {
+
+ case 'h':
+ return help();
+
+ case ARG_VERSION:
+ return version();
+
+ case ARG_CAT_CONFIG:
+ arg_cat_config = true;
+ break;
+
+ 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 ARG_NO_PAGER:
+ arg_pager_flags |= PAGER_DISABLE;
+ break;
+
+ case '?':
+ return -EINVAL;
+
+ default:
+ assert_not_reached("Unhandled option");
+ }
+
+ if (arg_cat_config && argc > optind)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Positional arguments are not allowed with --cat-config");
+
+ return 1;
+}
+
+static int run(int argc, char *argv[]) {
+ _cleanup_(ordered_hashmap_free_free_freep) OrderedHashmap *sysctl_options = NULL;
+ int r, k;
+
+ r = parse_argv(argc, argv);
+ if (r <= 0)
+ return r;
+
+ log_setup_service();
+
+ umask(0022);
+
+ sysctl_options = ordered_hashmap_new(&path_hash_ops);
+ if (!sysctl_options)
+ return log_oom();
+
+ 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_strv(&files, ".conf", NULL, 0, (const char**) CONF_PATHS_STRV("sysctl.d"));
+ if (r < 0)
+ return log_error_errno(r, "Failed to enumerate sysctl.d files: %m");
+
+ if (arg_cat_config) {
+ (void) pager_open(arg_pager_flags);
+
+ return cat_files(NULL, files, 0);
+ }
+
+ 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;
+
+ return r;
+}
+
+DEFINE_MAIN_FUNCTION(run);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 02:29:06 +0000