#include <stdlib.h>

#include <stdbool.h>

#include <errno.h>

#include <string.h>

#include <stdio.h>

#include <limits.h>

#include <getopt.h>

#include "log.h"

#include "strv.h"

#include "util.h"

#include "hashmap.h"

#include "path-util.h"

#include "conf-files.h"

#include "fileio.h"

#include "build.h"

static char **arg_prefixes = NULL;

static const char conf_file_dirs[] = CONF_DIRS_NULSTR("sysctl");

static char* normalize_sysctl(char *s) {

char *n;

n = strpbrk(s, "/.");

/* If the first separator is a slash, the path is

if (!n || *n == '/')

return s;

/* Otherwise, dots become slashes and slashes become

while (n) {

if (*n == '.')

*n = '/';

else

*n = '.';

n = strpbrk(n + 1, "/.");

}

return s;

}

static int apply_sysctl(const char *property, const char *value) {

_cleanup_free_ char *p = NULL;

char *n;

int r = 0, k;

log_debug("Setting '%s' to '%s'", property, value);

p = new(char, strlen("/proc/sys/") + strlen(property) + 1);

if (!p)

return log_oom();

n = stpcpy(p, "/proc/sys/");

strcpy(n, property);

if (!strv_isempty(arg_prefixes)) {

char **i;

bool good = false;

STRV_FOREACH(i, arg_prefixes)

if (path_startswith(p, *i)) {

good = true;

break;

}

if (!good) {

log_debug("Skipping %s", p);

return 0;

}

}

k = write_string_file(p, value);

if (k < 0) {

log_full(k == -ENOENT ? LOG_DEBUG : LOG_WARNING,

"Failed to write '%s' to '%s': %s", value, p, strerror(-k));

if (k != -ENOENT && r == 0)

r = k;

}

return r;

}

static int apply_all(Hashmap *sysctl_options) {

int r = 0;

char *property, *value;

Iterator i;

assert(sysctl_options);

HASHMAP_FOREACH_KEY(value, property, sysctl_options, i) {

int k;

k = apply_sysctl(property, value);

if (k < 0 && r == 0)

r = k;

}

return r;

}

static int parse_file(Hashmap *sysctl_options, const char *path, bool ignore_enoent) {

_cleanup_fclose_ FILE *f = NULL;

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;

log_error("Failed to open file '%s', ignoring: %s", path, strerror(-r));

return r;

}

log_debug("parse: %s", path);

while (!feof(f)) {

char l[LINE_MAX], *p, *value, *new_value, *property, *existing;

void *v;

int k;

if (!fgets(l, sizeof(l), f)) {

if (feof(f))

break;

log_error("Failed to read file '%s', ignoring: %m", path);

return -errno;

}

p = strstrip(l);

if (!*p)

continue;

if (strchr(COMMENTS "\n", *p))

continue;

value = strchr(p, '=');

if (!value) {

log_error("Line is not an assignment in file '%s': %s", path, value);

if (r == 0)

r = -EINVAL;

continue;

}

*value = 0;

value++;

p = normalize_sysctl(strstrip(p));

value = strstrip(value);

existing = hashmap_get2(sysctl_options, p, &v);

if (existing) {

if (streq(value, existing))

continue;

log_info("Overwriting earlier assignment of %s in file '%s'.", p, path);

free(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 = hashmap_put(sysctl_options, property, new_value);

if (k < 0) {

log_error("Failed to add sysctl variable %s to hashmap: %s", property, strerror(-k));

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:

puts(PACKAGE_STRING);

puts(SYSTEMD_FEATURES);

return 0;

case ARG_PREFIX: {

char *p;

/* We used to require people to specify absolute paths

normalize_sysctl(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[]) {

int r = 0, k;

Hashmap *sysctl_options;

r = parse_argv(argc, argv);

if (r <= 0)

return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;

log_set_target(LOG_TARGET_AUTO);

log_parse_environment();

log_open();

umask(0022);

sysctl_options = 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("Failed to enumerate sysctl.d files: %s", strerror(-r));

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:

hashmap_free_free_free(sysctl_options);

strv_free(arg_prefixes);

return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;

}