mirror of
https://github.com/morgan9e/systemd
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1d84ad9445
This improves kernel command line parsing in a number of ways: a) An kernel option "foo_bar=xyz" is now considered equivalent to "foo-bar-xyz", i.e. when comparing kernel command line option names "-" and "_" are now considered equivalent (this only applies to the option names though, not the option values!). Most of our kernel options used "-" as word separator in kernel command line options so far, but some used "_". With this change, which was a source of confusion for users (well, at least of one user: myself, I just couldn't remember that it's systemd.debug-shell, not systemd.debug_shell). Considering both as equivalent is inspired how modern kernel module loading normalizes all kernel module names to use underscores now too. b) All options previously using a dash for separating words in kernel command line options now use an underscore instead, in all documentation and in code. Since a) has been implemented this should not create any compatibility problems, but normalizes our documentation and our code. c) All kernel command line options which take booleans (or are boolean-like) have been reworked so that "foobar" (without argument) is now equivalent to "foobar=1" (but not "foobar=0"), thus normalizing the handling of our boolean arguments. Specifically this means systemd.debug-shell and systemd_debug_shell=1 are now entirely equivalent. d) All kernel command line options which take an argument, and where no argument is specified will now result in a log message. e.g. passing just "systemd.unit" will no result in a complain that it needs an argument. This is implemented in the proc_cmdline_missing_value() function. e) There's now a call proc_cmdline_get_bool() similar to proc_cmdline_get_key() that parses booleans (following the logic explained in c). f) The proc_cmdline_parse() call's boolean argument has been replaced by a new flags argument that takes a common set of bits with proc_cmdline_get_key(). g) All kernel command line APIs now begin with the same "proc_cmdline_" prefix. h) There are now tests for much of this. Yay!
289 lines
8.3 KiB
C
289 lines
8.3 KiB
C
/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <stdbool.h>
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#include <stddef.h>
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#include <string.h>
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#include "alloc-util.h"
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#include "extract-word.h"
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#include "fileio.h"
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#include "macro.h"
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#include "parse-util.h"
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#include "proc-cmdline.h"
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#include "process-util.h"
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#include "special.h"
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#include "string-util.h"
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#include "util.h"
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#include "virt.h"
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int proc_cmdline(char **ret) {
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const char *e;
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assert(ret);
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/* For testing purposes it is sometimes useful to be able to override what we consider /proc/cmdline to be */
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e = secure_getenv("SYSTEMD_PROC_CMDLINE");
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if (e) {
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char *m;
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m = strdup(e);
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if (!m)
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return -ENOMEM;
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*ret = m;
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return 0;
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}
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if (detect_container() > 0)
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return get_process_cmdline(1, 0, false, ret);
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else
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return read_one_line_file("/proc/cmdline", ret);
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}
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int proc_cmdline_parse(proc_cmdline_parse_t parse_item, void *data, unsigned flags) {
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_cleanup_free_ char *line = NULL;
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const char *p;
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int r;
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assert(parse_item);
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r = proc_cmdline(&line);
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if (r < 0)
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return r;
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p = line;
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for (;;) {
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_cleanup_free_ char *word = NULL;
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char *value, *key, *q;
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r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
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if (r < 0)
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return r;
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if (r == 0)
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break;
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key = word;
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/* Filter out arguments that are intended only for the initrd */
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q = startswith(word, "rd.");
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if (q) {
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if (!in_initrd())
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continue;
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if (flags & PROC_CMDLINE_STRIP_RD_PREFIX)
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key = q;
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}
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value = strchr(key, '=');
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if (value)
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*(value++) = 0;
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r = parse_item(key, value, data);
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if (r < 0)
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return r;
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}
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return 0;
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}
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static bool relaxed_equal_char(char a, char b) {
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return a == b ||
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(a == '_' && b == '-') ||
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(a == '-' && b == '_');
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}
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char *proc_cmdline_key_startswith(const char *s, const char *prefix) {
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assert(s);
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assert(prefix);
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/* Much like startswith(), but considers "-" and "_" the same */
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for (; *prefix != 0; s++, prefix++)
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if (!relaxed_equal_char(*s, *prefix))
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return NULL;
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return (char*) s;
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}
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bool proc_cmdline_key_streq(const char *x, const char *y) {
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assert(x);
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assert(y);
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/* Much like streq(), but considers "-" and "_" the same */
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for (; *x != 0 || *y != 0; x++, y++)
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if (!relaxed_equal_char(*x, *y))
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return false;
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return true;
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}
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int proc_cmdline_get_key(const char *key, unsigned flags, char **value) {
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_cleanup_free_ char *line = NULL, *ret = NULL;
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bool found = false;
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const char *p;
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int r;
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/* Looks for a specific key on the kernel command line. Supports two modes:
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*
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* a) The "value" parameter is used. In this case a parameter beginning with the "key" string followed by "="
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* is searched, and the value following this is returned in "value".
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*
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* b) as above, but the PROC_CMDLINE_VALUE_OPTIONAL flag is set. In this case if the the key is found as a
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* separate word (i.e. not followed by "=" but instead by whitespace or the end of the command line), then
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* this is also accepted, and "value" is returned as NULL.
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*
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* c) The "value" parameter is NULL. In this case a search for the exact "key" parameter is performed.
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*
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* In all three cases, > 0 is returned if the key is found, 0 if not.*/
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if (isempty(key))
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return -EINVAL;
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if ((flags & PROC_CMDLINE_VALUE_OPTIONAL) && !value)
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return -EINVAL;
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r = proc_cmdline(&line);
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if (r < 0)
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return r;
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p = line;
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for (;;) {
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_cleanup_free_ char *word = NULL;
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const char *e;
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r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
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if (r < 0)
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return r;
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if (r == 0)
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break;
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/* Automatically filter out arguments that are intended only for the initrd, if we are not in the
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* initrd. */
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if (!in_initrd() && startswith(word, "rd."))
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continue;
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if (value) {
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e = proc_cmdline_key_startswith(word, key);
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if (!e)
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continue;
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if (*e == '=') {
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r = free_and_strdup(&ret, e+1);
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if (r < 0)
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return r;
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found = true;
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} else if (*e == 0 && (flags & PROC_CMDLINE_VALUE_OPTIONAL))
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found = true;
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} else {
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if (streq(word, key))
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found = true;
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}
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}
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if (value) {
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*value = ret;
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ret = NULL;
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}
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return found;
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}
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int proc_cmdline_get_bool(const char *key, bool *ret) {
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_cleanup_free_ char *v = NULL;
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int r;
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assert(ret);
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r = proc_cmdline_get_key(key, PROC_CMDLINE_VALUE_OPTIONAL, &v);
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if (r < 0)
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return r;
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if (r == 0) {
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*ret = false;
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return 0;
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}
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if (v) { /* parameter passed */
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r = parse_boolean(v);
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if (r < 0)
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return r;
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*ret = r;
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} else /* no parameter passed */
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*ret = true;
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return 1;
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}
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int shall_restore_state(void) {
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bool ret;
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int r;
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r = proc_cmdline_get_bool("systemd.restore_state", &ret);
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if (r < 0)
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return r;
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return r > 0 ? ret : true;
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}
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static const char * const rlmap[] = {
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"emergency", SPECIAL_EMERGENCY_TARGET,
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"-b", SPECIAL_EMERGENCY_TARGET,
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"rescue", SPECIAL_RESCUE_TARGET,
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"single", SPECIAL_RESCUE_TARGET,
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"-s", SPECIAL_RESCUE_TARGET,
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"s", SPECIAL_RESCUE_TARGET,
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"S", SPECIAL_RESCUE_TARGET,
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"1", SPECIAL_RESCUE_TARGET,
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"2", SPECIAL_MULTI_USER_TARGET,
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"3", SPECIAL_MULTI_USER_TARGET,
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"4", SPECIAL_MULTI_USER_TARGET,
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"5", SPECIAL_GRAPHICAL_TARGET,
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NULL
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};
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static const char * const rlmap_initrd[] = {
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"emergency", SPECIAL_EMERGENCY_TARGET,
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"rescue", SPECIAL_RESCUE_TARGET,
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NULL
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};
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const char* runlevel_to_target(const char *word) {
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size_t i;
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const char * const *rlmap_ptr = in_initrd() ? rlmap_initrd
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: rlmap;
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if (!word)
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return NULL;
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if (in_initrd() && (word = startswith(word, "rd.")) == NULL)
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return NULL;
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for (i = 0; rlmap_ptr[i] != NULL; i += 2)
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if (streq(word, rlmap_ptr[i]))
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return rlmap_ptr[i+1];
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return NULL;
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}
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