src/notify/notify.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <getopt.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <unistd.h>
   8
   9 #include "sd-daemon.h"
  10
  11 #include "alloc-util.h"
  12 #include "env-util.h"
  13 #include "format-util.h"
  14 #include "log.h"
  15 #include "parse-util.h"
  16 #include "string-util.h"
  17 #include "strv.h"
  18 #include "terminal-util.h"
  19 #include "user-util.h"
  20 #include "util.h"
  21
  22 static bool arg_ready = false;
  23 static pid_t arg_pid = 0;
  24 static const char *arg_status = NULL;
  25 static bool arg_booted = false;
  26 static uid_t arg_uid = UID_INVALID;
  27 static gid_t arg_gid = GID_INVALID;
  28
  29 static int help(void) {
  30         _cleanup_free_ char *link = NULL;
  31         int r;
  32
  33         r = terminal_urlify_man("systemd-notify", "1", &link);
  34         if (r < 0)
  35                 return log_oom();
  36
  37         printf("%s [OPTIONS...] [VARIABLE=VALUE...]\n\n"
  38                "Notify the init system about service status updates.\n\n"
  39                "  -h --help            Show this help\n"
  40                "     --version         Show package version\n"
  41                "     --ready           Inform the init system about service start-up completion\n"
  42                "     --pid[=PID]       Set main PID of daemon\n"
  43                "     --uid=USER        Set user to send from\n"
  44                "     --status=TEXT     Set status text\n"
  45                "     --booted          Check if the system was booted up with systemd\n"
  46                "\nSee the %s for details.\n"
  47                , program_invocation_short_name
  48                , link
  49         );
  50
  51         return 0;
  52 }
  53
  54 static int parse_argv(int argc, char *argv[]) {
  55
  56         enum {
  57                 ARG_READY = 0x100,
  58                 ARG_VERSION,
  59                 ARG_PID,
  60                 ARG_STATUS,
  61                 ARG_BOOTED,
  62                 ARG_UID,
  63         };
  64
  65         static const struct option options[] = {
  66                 { "help",      no_argument,       NULL, 'h'           },
  67                 { "version",   no_argument,       NULL, ARG_VERSION   },
  68                 { "ready",     no_argument,       NULL, ARG_READY     },
  69                 { "pid",       optional_argument, NULL, ARG_PID       },
  70                 { "status",    required_argument, NULL, ARG_STATUS    },
  71                 { "booted",    no_argument,       NULL, ARG_BOOTED    },
  72                 { "uid",       required_argument, NULL, ARG_UID       },
  73                 {}
  74         };
  75
  76         int c, r;
  77
  78         assert(argc >= 0);
  79         assert(argv);
  80
  81         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
  82
  83                 switch (c) {
  84
  85                 case 'h':
  86                         return help();
  87
  88                 case ARG_VERSION:
  89                         return version();
  90
  91                 case ARG_READY:
  92                         arg_ready = true;
  93                         break;
  94
  95                 case ARG_PID:
  96
  97                         if (optarg) {
  98                                 if (parse_pid(optarg, &arg_pid) < 0) {
  99                                         log_error("Failed to parse PID %s.", optarg);
 100                                         return -EINVAL;
 101                                 }
 102                         } else
 103                                 arg_pid = getppid();
 104
 105                         break;
 106
 107                 case ARG_STATUS:
 108                         arg_status = optarg;
 109                         break;
 110
 111                 case ARG_BOOTED:
 112                         arg_booted = true;
 113                         break;
 114
 115                 case ARG_UID: {
 116                         const char *u = optarg;
 117
 118                         r = get_user_creds(&u, &arg_uid, &arg_gid, NULL, NULL, 0);
 119                         if (r == -ESRCH) /* If the user doesn't exist, then accept it anyway as numeric */
 120                                 r = parse_uid(u, &arg_uid);
 121                         if (r < 0)
 122                                 return log_error_errno(r, "Can't resolve user %s: %m", optarg);
 123
 124                         break;
 125                 }
 126
 127                 case '?':
 128                         return -EINVAL;
 129
 130                 default:
 131                         assert_not_reached("Unhandled option");
 132                 }
 133         }
 134
 135         if (optind >= argc &&
 136             !arg_ready &&
 137             !arg_status &&
 138             !arg_pid &&
 139             !arg_booted) {
 140                 help();
 141                 return -EINVAL;
 142         }
 143
 144         return 1;
 145 }
 146
 147 int main(int argc, char* argv[]) {
 148         _cleanup_free_ char *status = NULL, *cpid = NULL, *n = NULL;
 149         _cleanup_strv_free_ char **final_env = NULL;
 150         char* our_env[4];
 151         unsigned i = 0;
 152         int r;
 153
 154         log_parse_environment();
 155         log_open();
 156
 157         r = parse_argv(argc, argv);
 158         if (r <= 0)
 159                 goto finish;
 160
 161         if (arg_booted)
 162                 return sd_booted() <= 0;
 163
 164         if (arg_ready)
 165                 our_env[i++] = (char*) "READY=1";
 166
 167         if (arg_status) {
 168                 status = strappend("STATUS=", arg_status);
 169                 if (!status) {
 170                         r = log_oom();
 171                         goto finish;
 172                 }
 173
 174                 our_env[i++] = status;
 175         }
 176
 177         if (arg_pid > 0) {
 178                 if (asprintf(&cpid, "MAINPID="PID_FMT, arg_pid) < 0) {
 179                         r = log_oom();
 180                         goto finish;
 181                 }
 182
 183                 our_env[i++] = cpid;
 184         }
 185
 186         our_env[i++] = NULL;
 187
 188         final_env = strv_env_merge(2, our_env, argv + optind);
 189         if (!final_env) {
 190                 r = log_oom();
 191                 goto finish;
 192         }
 193
 194         if (strv_isempty(final_env)) {
 195                 r = 0;
 196                 goto finish;
 197         }
 198
 199         n = strv_join(final_env, "\n");
 200         if (!n) {
 201                 r = log_oom();
 202                 goto finish;
 203         }
 204
 205         /* If this is requested change to the requested UID/GID. Note thta we only change the real UID here, and leave
 206            the effective UID in effect (which is 0 for this to work). That's because we want the privileges to fake the
 207            ucred data, and sd_pid_notify() uses the real UID for filling in ucred. */
 208
 209         if (arg_gid != GID_INVALID)
 210                 if (setregid(arg_gid, (gid_t) -1) < 0) {
 211                         r = log_error_errno(errno, "Failed to change GID: %m");
 212                         goto finish;
 213                 }
 214
 215         if (arg_uid != UID_INVALID)
 216                 if (setreuid(arg_uid, (uid_t) -1) < 0) {
 217                         r = log_error_errno(errno, "Failed to change UID: %m");
 218                         goto finish;
 219                 }
 220
 221         r = sd_pid_notify(arg_pid ? arg_pid : getppid(), false, n);
 222         if (r < 0) {
 223                 log_error_errno(r, "Failed to notify init system: %m");
 224                 goto finish;
 225         } else if (r == 0) {
 226                 log_error("No status data could be sent: $NOTIFY_SOCKET was not set");
 227                 r = -EOPNOTSUPP;
 228         }
 229
 230 finish:
 231         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 232 }