tree-wide: make parse_proc_cmdline() strip "rd." prefix automatically

This stripping is contolled by a new boolean parameter. When the parameter
is true, it means that the caller does not care about the distinction between
initrd and real root, and wants to act on both rd-dot-prefixed and unprefixed
parameters in the initramfs, and only on the unprefixed parameters in real
root. If the parameter is false, behaviour is the same as before.

Changes by caller:
log.c (systemd.log_*):      changed to accept rd-dot-prefix params
pid1:                       no change, custom logic
cryptsetup-generator:       no change, still accepts rd-dot-prefix params
debug-generator:            no change, does not accept rd-dot-prefix params
fsck:                       changed to accept rd-dot-prefix params
fstab-generator:            no change, custom logic
gpt-auto-generator:         no change, custom logic
hibernate-resume-generator: no change, does not accept rd-dot-prefix params
journald:                   changed to accept rd-dot-prefix params
modules-load:               no change, still accepts rd-dot-prefix params
quote-check:                no change, does not accept rd-dot-prefix params
udevd:                      no change, still accepts rd-dot-prefix params

I added support for "rd." params in the three cases where I think it's
useful: logging, fsck options, journald forwarding options.

3 files changed, 11 insertions, 6 deletions

diff --git a/src/basic/log.c b/src/basic/log.c
index 40f342ca72..2ff70be255 100644
--- a/src/basic/log.c
+++ b/src/basic/log.c
@@ -1012,7 +1012,7 @@ void log_parse_environment(void) {
                 /* Only try to read the command line in daemons.
                    We assume that anything that has a controlling
                    tty is user stuff. */
-                (void) parse_proc_cmdline(parse_proc_cmdline_item, NULL);
+                (void) parse_proc_cmdline(parse_proc_cmdline_item, NULL, true);
 
         e = secure_getenv("SYSTEMD_LOG_TARGET");
         if (e && log_set_target_from_string(e) < 0)
diff --git a/src/basic/proc-cmdline.c b/src/basic/proc-cmdline.c
index 951db34d1a..8297a222b7 100644
--- a/src/basic/proc-cmdline.c
+++ b/src/basic/proc-cmdline.c
@@ -42,7 +42,9 @@ int proc_cmdline(char **ret) {
                 return read_one_line_file("/proc/cmdline", ret);
 }
 
-int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value, void *data), void *data) {
+int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value, void *data),
+                       void *data,
+                       bool strip_prefix) {
         _cleanup_free_ char *line = NULL;
         const char *p;
         int r;
@@ -56,7 +58,7 @@ int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value, voi
         p = line;
         for (;;) {
                 _cleanup_free_ char *word = NULL;
-                char *value = NULL;
+                char *value = NULL, *unprefixed;
 
                 r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
                 if (r < 0)
@@ -66,14 +68,15 @@ int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value, voi
 
                 /* Filter out arguments that are intended only for the
                  * initrd */
-                if (!in_initrd() && startswith(word, "rd."))
+                unprefixed = startswith(word, "rd.");
+                if (unprefixed && !in_initrd())
                         continue;
 
                 value = strchr(word, '=');
                 if (value)
                         *(value++) = 0;
 
-                r = parse_item(word, value, data);
+                r = parse_item(strip_prefix && unprefixed ? unprefixed : word, value, data);
                 if (r < 0)
                         return r;
         }
diff --git a/src/basic/proc-cmdline.h b/src/basic/proc-cmdline.h
index a8832d8419..6d6ee95c11 100644
--- a/src/basic/proc-cmdline.h
+++ b/src/basic/proc-cmdline.h
@@ -20,7 +20,9 @@
 ***/
 
 int proc_cmdline(char **ret);
-int parse_proc_cmdline(int (*parse_word)(const char *key, const char *value, void *data), void *data);
+int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value, void *data),
+                       void *data,
+                       bool strip_prefix);
 int get_proc_cmdline_key(const char *parameter, char **value);
 
 int shall_restore_state(void);