1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 
3 #include <errno.h>
4 #include <sys/stat.h>
5 #include <unistd.h>
6 
7 #include "efi-loader.h"
8 #include "generator.h"
9 #include "log.h"
10 #include "mkdir.h"
11 #include "special.h"
12 #include "string-util.h"
13 #include "util.h"
14 #include "virt.h"
15 
16 /* This generator pulls systemd-bless-boot.service into the initial transaction if the "LoaderBootCountPath" EFI
17  * variable is set, i.e. the system boots up with boot counting in effect, which means we should mark the boot as
18  * "good" if we manage to boot up far enough. */
19 
20 static const char *arg_dest = "/tmp";
21 
main(int argc,char * argv[])22 int main(int argc, char *argv[]) {
23         const char *p;
24 
25         log_setup_generator();
26 
27         if (argc > 1 && argc != 4) {
28                 log_error("This program takes three or no arguments.");
29                 return EXIT_FAILURE;
30         }
31 
32         if (argc > 1)
33                 arg_dest = argv[2];
34 
35         if (in_initrd() > 0) {
36                 log_debug("Skipping generator, running in the initrd.");
37                 return EXIT_SUCCESS;
38         }
39 
40         if (detect_container() > 0) {
41                 log_debug("Skipping generator, running in a container.");
42                 return EXIT_SUCCESS;
43         }
44 
45         if (!is_efi_boot()) {
46                 log_debug("Skipping generator, not an EFI boot.");
47                 return EXIT_SUCCESS;
48         }
49 
50         if (access(EFIVAR_PATH(EFI_LOADER_VARIABLE(LoaderBootCountPath)), F_OK) < 0) {
51 
52                 if (errno == ENOENT) {
53                         log_debug_errno(errno, "Skipping generator, not booted with boot counting in effect.");
54                         return EXIT_SUCCESS;
55                 }
56 
57                 log_error_errno(errno, "Failed to check if LoaderBootCountPath EFI variable exists: %m");
58                 return EXIT_FAILURE;
59         }
60 
61         /* We pull this in from basic.target so that it ends up in all "regular" boot ups, but not in rescue.target or
62          * even emergency.target. */
63         p = strjoina(arg_dest, "/" SPECIAL_BASIC_TARGET ".wants/systemd-bless-boot.service");
64         (void) mkdir_parents(p, 0755);
65         if (symlink(SYSTEM_DATA_UNIT_DIR "/systemd-bless-boot.service", p) < 0) {
66                 log_error_errno(errno, "Failed to create symlink '%s': %m", p);
67                 return EXIT_FAILURE;
68         }
69 
70         return EXIT_SUCCESS;
71 }
72