diff options
Diffstat (limited to 'src/grp-initprogs/systemd-sysctl/sysctl.c')
| -rw-r--r-- | src/grp-initprogs/systemd-sysctl/sysctl.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/src/grp-initprogs/systemd-sysctl/sysctl.c b/src/grp-initprogs/systemd-sysctl/sysctl.c new file mode 100644 index 0000000000..de047890f6 --- /dev/null +++ b/src/grp-initprogs/systemd-sysctl/sysctl.c @@ -0,0 +1,305 @@ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <getopt.h> +#include <limits.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "systemd-basic/conf-files.h" +#include "systemd-basic/def.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/hashmap.h" +#include "systemd-basic/log.h" +#include "systemd-basic/path-util.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/strv.h" +#include "systemd-basic/util.h" +#include "systemd-shared/sysctl-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 l[LINE_MAX], *p, *value, *new_value, *property, *existing; + void *v; + int k; + + if (!fgets(l, sizeof(l), f)) { + if (feof(f)) + break; + + return log_error_errno(errno, "Failed to read file '%s', ignoring: %m", path); + } + + c++; + + p = strstrip(l); + if (!*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 (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(&string_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, 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; +} |