main,log: parse the log related kernel command line parameters at one place only, and for all tools

Previously, we ended up parsing some of them three times: in main.c when
processing the kernel cmdline, in main.c when processing the process
cmdline (only for containers), and in log.c again.

Let's streamline this, and only parse them in log.c

In PID 1 also make sure we parse "quiet" first, and then override this
with the more specific checks in log.c

1 files changed, 37 insertions, 17 deletions

diff --git a/src/shared/log.c b/src/shared/log.c
index 2bac998bc..b730ac921 100644
--- a/src/shared/log.c
+++ b/src/shared/log.c
@@ -871,27 +871,47 @@ int log_set_max_level_from_string(const char *e) {
         return 0;
 }
 
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+
+        /*
+         * The systemd.log_xyz= settings are parsed by all tools, and
+         * so is "debug".
+         *
+         * However, "quiet" is only parsed by PID 1!
+         */
+
+        if (streq(key, "debug") && !value)
+                log_set_max_level(LOG_DEBUG);
+
+        else if (streq(key, "systemd.log_target") && value) {
+
+                if (log_set_target_from_string(value) < 0)
+                        log_warning("Failed to parse log target '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_level") && value) {
+
+                if (log_set_max_level_from_string(value) < 0)
+                        log_warning("Failed to parse log level '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_color") && value) {
+
+                if (log_show_color_from_string(value) < 0)
+                        log_warning("Failed to parse log color setting '%s'. Ignoring.", value);
+
+        } else if (streq(key, "systemd.log_location") && value) {
+
+                if (log_show_location_from_string(value) < 0)
+                        log_warning("Failed to parse log location setting '%s'. Ignoring.", value);
+        }
+
+        return 0;
+}
+
 void log_parse_environment(void) {
         _cleanup_free_ char *line = NULL;
         const char *e;
-        int r;
 
-        r = proc_cmdline(&line);
-        if (r < 0)
-                log_warning("Failed to read /proc/cmdline. Ignoring: %s", strerror(-r));
-        else if (r > 0) {
-                const char *word, *state;
-                size_t l;
-
-                FOREACH_WORD_QUOTED(word, l, line, state) {
-                        if (l == 5 && startswith(word, "debug")) {
-                                log_set_max_level(LOG_DEBUG);
-                                break;
-                        }
-                }
-                if (!isempty(state))
-                        log_warning("Trailing garbage and the end of kernel commandline, ignoring.");
-        }
+        parse_proc_cmdline(parse_proc_cmdline_item);
 
         e = secure_getenv("SYSTEMD_LOG_TARGET");
         if (e && log_set_target_from_string(e) < 0)