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authorJan Engelhardt <jengelh@inai.de>2012-09-04 05:24:47 +0200
committerJan Engelhardt <jengelh@inai.de>2012-09-27 23:36:58 +0200
commitcd2f9bdbb7f9b737e5d640aafeb78bcd8e3a7adf (patch)
treefb1ab73ce71c44406051d024b2fba40b88dd97b5 /libxtables
parent954b76c317f641b7faf33cc26931d45585cc0dea (diff)
iptables: support for target aliases
This patch allows for target names listed on the command line to be rewritten to new names and revisions. As before, we will pick a revision that is supported by the kernel - now including real_name in the search. This gives us the possibility to test for many action names. Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Diffstat (limited to 'libxtables')
-rw-r--r--libxtables/xtables.c32
1 files changed, 25 insertions, 7 deletions
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 7f0d3ccb..a2b24c5a 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -872,9 +872,18 @@ void xtables_register_match(struct xtables_match *me)
* preferred.
*/
static int
-xtables_mt_prefer(unsigned int a_rev, unsigned int a_fam,
- unsigned int b_rev, unsigned int b_fam)
+xtables_mt_prefer(bool a_alias, unsigned int a_rev, unsigned int a_fam,
+ bool b_alias, unsigned int b_rev, unsigned int b_fam)
{
+ /*
+ * Alias ranks higher than no alias.
+ * (We want the new action to be used whenever possible.)
+ */
+ if (!a_alias && b_alias)
+ return -1;
+ if (a_alias && !b_alias)
+ return 1;
+
/* Higher revision ranks higher. */
if (a_rev < b_rev)
return -1;
@@ -894,14 +903,21 @@ xtables_mt_prefer(unsigned int a_rev, unsigned int a_fam,
static int xtables_match_prefer(const struct xtables_match *a,
const struct xtables_match *b)
{
- return xtables_mt_prefer(a->revision, a->family,
- b->revision, b->family);
+ return xtables_mt_prefer(false, a->revision, a->family,
+ false, b->revision, b->family);
}
static int xtables_target_prefer(const struct xtables_target *a,
const struct xtables_target *b)
{
- return xtables_mt_prefer(a->revision, a->family,
+ /*
+ * Note that if x->real_name==NULL, it will be set to x->name in
+ * xtables_register_*; the direct pointer comparison here is therefore
+ * legitimate to detect an alias.
+ */
+ return xtables_mt_prefer(a->name != a->real_name,
+ a->revision, a->family,
+ b->name != b->real_name,
b->revision, b->family);
}
@@ -985,6 +1001,8 @@ void xtables_register_target(struct xtables_target *me)
exit(1);
}
+ if (me->real_name == NULL)
+ me->real_name = me->name;
if (me->x6_options != NULL)
xtables_option_metavalidate(me->name, me->x6_options);
if (me->extra_opts != NULL)
@@ -1018,11 +1036,11 @@ static void xtables_fully_register_pending_target(struct xtables_target *me)
/* Now we have two (or more) options, check compatibility. */
if (compare > 0 &&
- compatible_target_revision(old->name, old->revision))
+ compatible_target_revision(old->real_name, old->revision))
return;
/* See if new target can be used. */
- if (!compatible_target_revision(me->name, me->revision))
+ if (!compatible_target_revision(me->real_name, me->revision))
return;
/* Delete old one. */