Add new function to filter fstab options

This fixes parsing of options in shared/generator.c. Existing code
had some issues:

- it would treate whitespace and semicolons as seperators. fstab(5)
  is pretty clear that only commas matter. And the syntax does
  not allow for spaces to be inserted in the field in fstab.
  Whitespace might be escaped, but then it should not seperate
  options. Treat whitespace and semicolons as any other character.
- it assumed that x-systemd.device-timeout would always be followed
  by "=". But this is not guaranteed, hasmntopt will return this
  option even if there's no value. Uninitialized memory could be read.
- some error paths would log, and inconsistently, some would just
  return an error code.

Filtering is split out to a separate function and tests are added.

Similar code paths in other places are adjusted to use the new function.

1 files changed, 6 insertions, 36 deletions

diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
index 496657bdc1..64eed49523 100644
--- a/src/fstab-generator/fstab-generator.c
+++ b/src/fstab-generator/fstab-generator.c
@@ -29,6 +29,7 @@
 #include "util.h"
 #include "unit-name.h"
 #include "path-util.h"
+#include "fstab-util.h"
 #include "mount-setup.h"
 #include "special.h"
 #include "mkdir.h"
@@ -47,33 +48,6 @@ static char *arg_usr_what = NULL;
 static char *arg_usr_fstype = NULL;
 static char *arg_usr_options = NULL;
 
-static int mount_find_pri(struct mntent *me, int *ret) {
-        char *end, *opt;
-        unsigned long r;
-
-        assert(me);
-        assert(ret);
-
-        opt = hasmntopt(me, "pri");
-        if (!opt)
-                return 0;
-
-        opt += strlen("pri");
-        if (*opt != '=')
-                return -EINVAL;
-
-        errno = 0;
-        r = strtoul(opt + 1, &end, 10);
-        if (errno > 0)
-                return -errno;
-
-        if (end == opt + 1 || (*end != ',' && *end != 0))
-                return -EINVAL;
-
-        *ret = (int) r;
-        return 1;
-}
-
 static int add_swap(
                 const char *what,
                 struct mntent *me,
@@ -97,11 +71,9 @@ static int add_swap(
                 return 0;
         }
 
-        r = mount_find_pri(me, &pri);
-        if (r < 0) {
-                log_error("Failed to parse priority");
-                return r;
-        }
+        r = fstab_find_pri(me->mnt_opts, &pri);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse priority: %m");
 
         name = unit_name_from_path(what, ".swap");
         if (!name)
@@ -434,8 +406,7 @@ static int add_root_mount(void) {
         if (!arg_root_options)
                 opts = arg_root_rw > 0 ? "rw" : "ro";
         else if (arg_root_rw >= 0 ||
-                 (!mount_test_option(arg_root_options, "ro") &&
-                  !mount_test_option(arg_root_options, "rw")))
+                 !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
                 opts = strappenda(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
         else
                 opts = arg_root_options;
@@ -492,8 +463,7 @@ static int add_usr_mount(void) {
 
         if (!arg_usr_options)
                 opts = arg_root_rw > 0 ? "rw" : "ro";
-        else if (!mount_test_option(arg_usr_options, "ro") &&
-                 !mount_test_option(arg_usr_options, "rw"))
+        else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
                 opts = strappenda(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
         else
                 opts = arg_usr_options;