From 61ca2800f3a1666478bdc01fc796d36c917a5032 Mon Sep 17 00:00:00 2001

From: Tom Gundersen <teg@jklm.no>

Date: Sun, 18 Aug 2013 14:59:00 +0800

Subject: [PATCH] cryptsetup-generator: allow specifying options in

 /proc/cmdline

MIME-Version: 1.0

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Content-Transfer-Encoding: 8bit

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.

Tested-by: Thomas Bächler <thomas@archlinux.org>

---

 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 215ac2d..d6b7e49 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 967c5e6..ba6efa6 100644

--- a/src/cryptsetup/cryptsetup-generator.c

+++ b/src/cryptsetup/cryptsetup-generator.c

@@ -240,7 +240,7 @@ 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;

@@ -307,7 +307,20 @@ 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();

@@ -337,6 +350,7 @@ 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;

@@ -357,7 +371,7 @@ 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)

@@ -412,6 +426,26 @@ 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

@@ -452,7 +486,7 @@ 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-"))

@@ -467,7 +501,44 @@ 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;

         }