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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <unistd.h>
#include "alloc-util.h"
#include "dropin.h"
#include "generator.h"
#include "initrd-util.h"
#include "mkdir-label.h"
#include "parse-util.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "special.h"
#include "string-util.h"
#include "strv.h"
#include "unit-file.h"
#include "unit-name.h"
static const char *arg_dest = NULL;
static char *arg_default_unit = NULL;
static char **arg_mask = NULL;
static char **arg_wants = NULL;
static char *arg_debug_shell = NULL;
STATIC_DESTRUCTOR_REGISTER(arg_default_unit, freep);
STATIC_DESTRUCTOR_REGISTER(arg_mask, strv_freep);
STATIC_DESTRUCTOR_REGISTER(arg_wants, strv_freep);
STATIC_DESTRUCTOR_REGISTER(arg_debug_shell, freep);
static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
int r;
assert(key);
if (streq(key, "systemd.mask")) {
char *n;
if (proc_cmdline_value_missing(key, value))
return 0;
r = unit_name_mangle(value, UNIT_NAME_MANGLE_WARN, &n);
if (r < 0)
return log_error_errno(r, "Failed to glob unit name: %m");
r = strv_consume(&arg_mask, n);
if (r < 0)
return log_oom();
} else if (streq(key, "systemd.wants")) {
char *n;
if (proc_cmdline_value_missing(key, value))
return 0;
r = unit_name_mangle(value, UNIT_NAME_MANGLE_WARN, &n);
if (r < 0)
return log_error_errno(r, "Failed to glob unit name: %m");
r = strv_consume(&arg_wants, n);
if (r < 0)
return log_oom();
} else if (proc_cmdline_key_streq(key, "systemd.debug_shell")) {
const char *t = NULL;
r = value ? parse_boolean(value) : 1;
if (r < 0)
t = skip_dev_prefix(value);
else if (r > 0)
t = skip_dev_prefix(DEBUGTTY);
return free_and_strdup_warn(&arg_debug_shell, t);
} else if (streq(key, "systemd.unit")) {
if (proc_cmdline_value_missing(key, value))
return 0;
return free_and_strdup_warn(&arg_default_unit, value);
} else if (!value) {
const char *target;
target = runlevel_to_target(key);
if (target)
return free_and_strdup_warn(&arg_default_unit, target);
}
return 0;
}
static int generate_mask_symlinks(void) {
int r = 0;
STRV_FOREACH(u, arg_mask) {
_cleanup_free_ char *p = NULL;
p = path_join(empty_to_root(arg_dest), *u);
if (!p)
return log_oom();
if (symlink("/dev/null", p) < 0)
r = log_error_errno(errno,
"Failed to create mask symlink %s: %m",
p);
}
return r;
}
static int generate_wants_symlinks(void) {
int r = 0;
STRV_FOREACH(u, arg_wants) {
_cleanup_free_ char *f = NULL;
const char *target;
/* This should match what do_queue_default_job() in core/main.c does. */
if (arg_default_unit)
target = arg_default_unit;
else if (in_initrd())
target = SPECIAL_INITRD_TARGET;
else
target = SPECIAL_DEFAULT_TARGET;
f = path_join(SYSTEM_DATA_UNIT_DIR, *u);
if (!f)
return log_oom();
r = generator_add_symlink(arg_dest, target, "wants", f);
if (r < 0)
return r;
}
return r;
}
static void install_debug_shell_dropin(const char *dir) {
int r;
if (streq(arg_debug_shell, skip_dev_prefix(DEBUGTTY)))
return;
r = write_drop_in_format(dir, "debug-shell.service", 50, "tty",
"[Unit]\n"
"Description=Early root shell on /dev/%s FOR DEBUGGING ONLY\n"
"ConditionPathExists=\n"
"[Service]\n"
"TTYPath=/dev/%s",
arg_debug_shell, arg_debug_shell);
if (r < 0)
log_warning_errno(r, "Failed to write drop-in for debug-shell.service, ignoring: %m");
}
static int run(const char *dest, const char *dest_early, const char *dest_late) {
int r, q;
assert_se(arg_dest = dest_early);
r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_RD_STRICT | PROC_CMDLINE_STRIP_RD_PREFIX);
if (r < 0)
log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
if (arg_debug_shell) {
r = strv_extend(&arg_wants, "debug-shell.service");
if (r < 0)
return log_oom();
install_debug_shell_dropin(arg_dest);
}
r = generate_mask_symlinks();
q = generate_wants_symlinks();
return r < 0 ? r : q;
}
DEFINE_MAIN_GENERATOR_FUNCTION(run);
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