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, 4 insertions, 67 deletions

diff --git a/src/core/swap.c b/src/core/swap.c
index cb19d0f123..b2ebed4b72 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -41,6 +41,7 @@
 #include "path-util.h"
 #include "virt.h"
 #include "udev-util.h"
+#include "fstab-util.h"
 
 static const UnitActiveState state_translation_table[_SWAP_STATE_MAX] = {
         [SWAP_DEAD] = UNIT_INACTIVE,
@@ -704,71 +705,6 @@ fail:
         swap_enter_dead(s, SWAP_FAILURE_RESOURCES);
 }
 
-static int mount_find_pri(const char *options, int *ret) {
-        const char *opt;
-        char *end;
-        unsigned long r;
-
-        assert(ret);
-
-        if (!options)
-                return 0;
-
-        opt = mount_test_option(options, "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 mount_find_discard(const char *options, char **ret) {
-        const char *opt;
-        char *ans;
-        size_t len;
-
-        assert(ret);
-
-        if (!options)
-                return 0;
-
-        opt = mount_test_option(options, "discard");
-        if (!opt)
-                return 0;
-
-        opt += strlen("discard");
-        if (*opt == ',' || *opt == '\0')
-                ans = strdup("all");
-        else {
-                if (*opt != '=')
-                        return -EINVAL;
-
-                len = strcspn(opt + 1, ",");
-                if (len == 0)
-                        return -EINVAL;
-
-                ans = strndup(opt + 1, len);
-        }
-
-        if (!ans)
-                return -ENOMEM;
-
-        *ret = ans;
-        return 1;
-}
-
 static void swap_enter_activating(Swap *s) {
         _cleanup_free_ char *discard = NULL;
         int r, priority = -1;
@@ -779,11 +715,12 @@ static void swap_enter_activating(Swap *s) {
         s->control_command = s->exec_command + SWAP_EXEC_ACTIVATE;
 
         if (s->from_fragment) {
-                mount_find_discard(s->parameters_fragment.options, &discard);
+                fstab_filter_options(s->parameters_fragment.options, "discard\0",
+                                     NULL, &discard, NULL);
 
                 priority = s->parameters_fragment.priority;
                 if (priority < 0)
-                        mount_find_pri(s->parameters_fragment.options, &priority);
+                        fstab_find_pri(s->parameters_fragment.options, &priority);
         }
 
         r = exec_command_set(s->control_command, "/sbin/swapon", NULL);