[systemd-devel] [PATCH] cryptsetup-generator: allow specifying options in /proc/cmdline
Tom Gundersen
teg at jklm.no
Sun Aug 18 09:15:14 PDT 2013
The main usecase for this is to make it possible to use cryptsetup in
the initrd without it having to include a host-specific /etc/crypttab.
Cc: Harald Hoyer <harald at redhat.com>
Tested-by: Thomas Bächler <thomas at archlinux.org>
---
Hi guys,
This allows us to use systemd in the initrd for encrypted root in Arch. I
didn't look much into how this is done in dracut, so comments on whether
or not this will work for you would be welcome.
Cheers,
Tom
man/systemd-cryptsetup-generator.xml | 23 ++++++++++
src/cryptsetup/cryptsetup-generator.c | 79 +++++++++++++++++++++++++++++++++--
2 files changed, 98 insertions(+), 4 deletions(-)
diff --git a/man/systemd-cryptsetup-generator.xml b/man/systemd-cryptsetup-generator.xml
index 7950032..3fab17b 100644
--- a/man/systemd-cryptsetup-generator.xml
+++ b/man/systemd-cryptsetup-generator.xml
@@ -137,6 +137,29 @@
will be activated in the initrd or the real root.</para>
</listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.options=</varname></term>
+ <term><varname>rd.luks.options=</varname></term>
+
+ <listitem><para>Takes a LUKS super
+ block UUID followed by an '=' and a string
+ of options separated by commas as argument.
+ This will override the options for the given
+ UUID.</para>
+ <para>If only a list of options, without an
+ UUID, is specified, they apply to any UUIDs not
+ specified elsewhere, and without an entry in
+ /etc/crypttab.</para><para>
+ <varname>rd.luks.options=</varname>
+ is honored only by initial RAM disk
+ (initrd) while
+ <varname>luks.options=</varname> is
+ honored by both the main system and
+ the initrd.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>luks.key=</varname></term>
<term><varname>rd.luks.key=</varname></term>
diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
index 81b7708..b140f0d 100644
--- a/src/cryptsetup/cryptsetup-generator.c
+++ b/src/cryptsetup/cryptsetup-generator.c
@@ -233,7 +233,7 @@ static int create_disk(
return 0;
}
-static int parse_proc_cmdline(char ***arg_proc_cmdline_disks, char **arg_proc_cmdline_keyfile) {
+static int parse_proc_cmdline(char ***arg_proc_cmdline_disks, char ***arg_proc_cmdline_options, char **arg_proc_cmdline_keyfile) {
_cleanup_free_ char *line = NULL;
char *w = NULL, *state = NULL;
int r;
@@ -300,7 +300,20 @@ static int parse_proc_cmdline(char ***arg_proc_cmdline_disks, char **arg_proc_cm
return log_oom();
}
+ } else if (startswith(word, "luks.options=")) {
+ if (strv_extend(arg_proc_cmdline_options, word + 13) < 0)
+ return log_oom();
+
+ } else if (startswith(word, "rd.luks.options=")) {
+
+ if (in_initrd()) {
+ if (strv_extend(arg_proc_cmdline_options, word + 16) < 0)
+ return log_oom();
+ }
+
} else if (startswith(word, "luks.key=")) {
+ if (*arg_proc_cmdline_keyfile)
+ free(*arg_proc_cmdline_keyfile);
*arg_proc_cmdline_keyfile = strdup(word + 9);
if (!*arg_proc_cmdline_keyfile)
return log_oom();
@@ -330,6 +343,7 @@ static int parse_proc_cmdline(char ***arg_proc_cmdline_disks, char **arg_proc_cm
int main(int argc, char *argv[]) {
_cleanup_strv_free_ char **arg_proc_cmdline_disks_done = NULL;
_cleanup_strv_free_ char **arg_proc_cmdline_disks = NULL;
+ _cleanup_strv_free_ char **arg_proc_cmdline_options = NULL;
_cleanup_free_ char *arg_proc_cmdline_keyfile = NULL;
_cleanup_fclose_ FILE *f = NULL;
unsigned n = 0;
@@ -350,7 +364,7 @@ int main(int argc, char *argv[]) {
umask(0022);
- if (parse_proc_cmdline(&arg_proc_cmdline_disks, &arg_proc_cmdline_keyfile) < 0)
+ if (parse_proc_cmdline(&arg_proc_cmdline_disks, &arg_proc_cmdline_options, &arg_proc_cmdline_keyfile) < 0)
return EXIT_FAILURE;
if (!arg_enabled)
@@ -405,6 +419,26 @@ int main(int argc, char *argv[]) {
continue;
}
+ if (arg_proc_cmdline_options) {
+ /*
+ If options are specified on the kernel commandline, let them override
+ the ones from crypttab.
+ */
+ STRV_FOREACH(i, arg_proc_cmdline_options) {
+ _cleanup_free_ char *proc_uuid = NULL, *proc_options = NULL;
+ const char *p = *i;
+
+ k = sscanf(p, "%m[0-9a-fA-F-]=%ms", &proc_uuid, &proc_options);
+ if (k == 2 && streq(proc_uuid, device + 5)) {
+ if (options)
+ free(options);
+ options = strdup(p);
+ if (!proc_options)
+ return log_oom();
+ }
+ }
+ }
+
if (arg_proc_cmdline_disks) {
/*
If luks UUIDs are specified on the kernel command line, use them as a filter
@@ -445,7 +479,7 @@ next:
on the kernel command line and not yet written.
*/
- _cleanup_free_ char *name = NULL, *device = NULL;
+ _cleanup_free_ char *name = NULL, *device = NULL, *options = NULL;
const char *p = *i;
if (startswith(p, "luks-"))
@@ -460,7 +494,44 @@ next:
if (!name || !device)
return log_oom();
- if (create_disk(name, device, arg_proc_cmdline_keyfile, "timeout=0") < 0)
+ if (arg_proc_cmdline_options) {
+ /*
+ If options are specified on the kernel commandline, use them.
+ */
+ char **j;
+
+ STRV_FOREACH(j, arg_proc_cmdline_options) {
+ _cleanup_free_ char *proc_uuid = NULL, *proc_options = NULL;
+ const char *s = *j;
+ int k;
+
+ k = sscanf(s, "%m[0-9a-fA-F-]=%ms", &proc_uuid, &proc_options);
+ if (k == 2) {
+ if (streq(proc_uuid, device + 5)) {
+ if (options)
+ free(options);
+ options = strdup(proc_options);
+ if (!options)
+ return log_oom();
+ }
+ } else if (!options) {
+ /*
+ Fall back to options without a specified UUID
+ */
+ options = strdup(s);
+ if (!options)
+ return log_oom();
+ }
+ }
+ }
+
+ if (!options) {
+ options = strdup("timeout=0");
+ if (!options)
+ return log_oom();
+ }
+
+ if (create_disk(name, device, arg_proc_cmdline_keyfile, options) < 0)
r = EXIT_FAILURE;
}
--
1.8.3.4
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