netfilter: ipset: Support comments for ipset entries in the core.

This adds the core support for having comments on ipset entries.

The comments are stored as standard null-terminated strings in
dynamically allocated memory after being passed to the kernel. As a
result of this, code has been added to the generic destroy function to
iterate all extensions and call that extension's destroy task if the set
has that extension activated, and if such a task is defined.

Signed-off-by: Oliver Smith <oliver@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

1 files changed, 14 insertions, 0 deletions

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index f35afed3814f..3bf9a3d29dff 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -315,6 +315,7 @@ ip_set_get_ipaddr6(struct nlattr *nla, union nf_inet_addr *ipaddr)
 }
 EXPORT_SYMBOL_GPL(ip_set_get_ipaddr6);
 
+typedef void (*destroyer)(void *);
 /* ipset data extension types, in size order */
 
 const struct ip_set_ext_type ip_set_extensions[] = {
@@ -329,6 +330,13 @@ const struct ip_set_ext_type ip_set_extensions[] = {
                 .len    = sizeof(unsigned long),
                 .align  = __alignof__(unsigned long),
         },
+        [IPSET_EXT_ID_COMMENT] = {
+                .type    = IPSET_EXT_COMMENT | IPSET_EXT_DESTROY,
+                .flag    = IPSET_FLAG_WITH_COMMENT,
+                .len     = sizeof(struct ip_set_comment),
+                .align   = __alignof__(struct ip_set_comment),
+                .destroy = (destroyer) ip_set_comment_free,
+        },
 };
 EXPORT_SYMBOL_GPL(ip_set_extensions);
 
@@ -380,6 +388,12 @@ ip_set_get_extensions(struct ip_set *set, struct nlattr *tb[],
                         ext->packets = be64_to_cpu(nla_get_be64(
                                                    tb[IPSET_ATTR_PACKETS]));
         }
+        if (tb[IPSET_ATTR_COMMENT]) {
+                if (!(set->extensions & IPSET_EXT_COMMENT))
+                        return -IPSET_ERR_COMMENT;
+                ext->comment = ip_set_comment_uget(tb[IPSET_ATTR_COMMENT]);
+        }
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(ip_set_get_extensions);