main: parse our own command line and the kernel command line

1 files changed, 207 insertions, 14 deletions

diff --git a/main.c b/main.c
index 86ccc72a16..acfa35fe6e 100644
--- a/main.c
+++ b/main.c
@@ -27,29 +27,226 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <getopt.h>
 
 #include "manager.h"
 #include "log.h"
 #include "mount-setup.h"
 
+static enum {
+        ACTION_RUN,
+        ACTION_HELP
+} action = ACTION_RUN;
+
+static char *default_unit = NULL;
+
+static int set_default_unit(const char *u) {
+        char *c;
+
+        assert(u);
+
+        if (!(c = strdup(u)))
+                return -ENOMEM;
+
+        free(default_unit);
+        default_unit = c;
+        return 0;
+}
+
+static int parse_proc_cmdline_word(const char *word) {
+
+        static const char * const rlmap[] = {
+                "single", SPECIAL_RUNLEVEL1_TARGET,
+                "-s",     SPECIAL_RUNLEVEL1_TARGET,
+                "s",      SPECIAL_RUNLEVEL1_TARGET,
+                "S",      SPECIAL_RUNLEVEL1_TARGET,
+                "1",      SPECIAL_RUNLEVEL1_TARGET,
+                "2",      SPECIAL_RUNLEVEL2_TARGET,
+                "3",      SPECIAL_RUNLEVEL3_TARGET,
+                "4",      SPECIAL_RUNLEVEL4_TARGET,
+                "5",      SPECIAL_RUNLEVEL5_TARGET
+        };
+
+        if (startswith(word, "systemd.default="))
+                return set_default_unit(word + 15);
+
+        else if (startswith(word, "systemd.log_target=")) {
+
+                if (log_set_target_from_string(word + 19) < 0)
+                        log_warning("Failed to parse log target %s. Ignoring.", word + 19);
+
+        } else if (startswith(word, "systemd.log_level=")) {
+
+                if (log_set_max_level_from_string(word + 18) < 0)
+                        log_warning("Failed to parse log level %s. Ignoring.", word + 18);
+
+        } else {
+                unsigned i;
+
+                /* SysV compatibility */
+
+                for (i = 0; i < ELEMENTSOF(rlmap); i += 2)
+                        if (streq(word, rlmap[i]))
+                                return set_default_unit(rlmap[i+1]);
+        }
+
+        return 0;
+}
+
+static int parse_proc_cmdline(void) {
+        char *line;
+        int r;
+        char *w;
+        size_t l;
+        char *state;
+
+        if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) {
+                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(errno));
+                return 0;
+        }
+
+        FOREACH_WORD_QUOTED(w, l, line, state) {
+                char *word;
+
+                if (!(word = strndup(w, l))) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                r = parse_proc_cmdline_word(word);
+                free(word);
+
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+
+finish:
+        free(line);
+        return r;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_LOG_LEVEL = 0x100,
+                ARG_LOG_TARGET,
+                ARG_DEFAULT
+        };
+
+        static const struct option options[] = {
+                { "log-level",  required_argument, NULL, ARG_LOG_LEVEL },
+                { "log-target", required_argument, NULL, ARG_LOG_TARGET },
+                { "default",    required_argument, NULL, ARG_DEFAULT },
+                { "help",       no_argument,       NULL, 'h' },
+                { NULL,         0,                 NULL, 0 }
+        };
+
+        int c, r;
+
+        assert(argc >= 1);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+
+                switch (c) {
+
+                case ARG_LOG_LEVEL:
+                        if ((r = log_set_max_level_from_string(optarg)) < 0) {
+                                log_error("Failed to parse log level %s.", optarg);
+                                return r;
+                        }
+
+                        break;
+
+                case ARG_LOG_TARGET:
+
+                        if ((r = log_set_target_from_string(optarg)) < 0) {
+                                log_error("Failed to parse log target %s.", optarg);
+                                return r;
+                        }
+
+                        break;
+
+                case ARG_DEFAULT:
+
+                        if ((r = set_default_unit(optarg)) < 0) {
+                                log_error("Failed to set default unit %s: %s", optarg, strerror(-r));
+                                return r;
+                        }
+
+                        break;
+
+                case 'h':
+                        action = ACTION_HELP;
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        return -EINVAL;
+                }
+
+        if (optind < argc) {
+                log_error("Too many arguments.");
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int help(void) {
+
+        printf("%s [options]\n\n"
+               "  -h --help               Show this help\n"
+               "     --default=UNIT       Set default unit\n"
+               "     --log-level=LEVEL    Set log level\n"
+               "     --log-target=TARGET  Set log target (console, syslog, kmsg)\n",
+               __progname);
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
         Manager *m = NULL;
         Unit *target = NULL;
         Job *job = NULL;
         int r, retval = 1;
-        const char *default_unit;
 
-        if (argc >= 2)
-                default_unit = argv[1];
-        else
-                default_unit = SPECIAL_DEFAULT_TARGET;
+        if (set_default_unit(SPECIAL_DEFAULT_TARGET) < 0)
+                goto finish;
 
-        /* Move out of the way, so that we won't block unmounts */
-        assert_se(chdir("/")  == 0);
+        /* Mount /proc, /sys and friends, so that /proc/cmdline and
+         * /proc/$PID/fd is available. */
+        mount_setup();
 
         /* Reset all signal handlers. */
         assert_se(reset_all_signal_handlers() == 0);
 
+        /* Close all open files */
+        assert_se(close_all_fds(NULL, 0) == 0);
+
+        if (parse_proc_cmdline() < 0)
+                goto finish;
+
+        log_parse_environment();
+
+        if (parse_argv(argc, argv) < 0)
+                goto finish;
+
+        if (action == ACTION_HELP) {
+                retval = help();
+                goto finish;
+        }
+
+        assert_se(action == ACTION_RUN);
+
+        /* Move out of the way, so that we won't block unmounts */
+        assert_se(chdir("/")  == 0);
+
         /* Become a session leader if we aren't one yet. */
         setsid();
 
@@ -59,12 +256,6 @@ int main(int argc, char *argv[]) {
         /* Make sure D-Bus doesn't fiddle with the SIGPIPE handlers */
         dbus_connection_set_change_sigpipe(FALSE);
 
-        /* Mount /dev, /sys and friends */
-        mount_setup();
-
-        /* Set up logging */
-        log_set_target(LOG_TARGET_CONSOLE);
-
         /* Open the logging devices, if possible and necessary*/
         log_open_syslog();
         log_open_kmsg();
@@ -104,11 +295,13 @@ int main(int argc, char *argv[]) {
 
         retval = 0;
 
+        log_debug("Exit.");
+
 finish:
         if (m)
                 manager_free(m);
 
-        log_debug("Exit.");
+        free(default_unit);
 
         dbus_shutdown();