netfilter: ctnetlink: add and use a helper for mark parsing

ctnetlink dumps can be filtered based on the connmark.

Prepare for status bit filtering by using a named structure and by
moving the mark parsing code to a helper.

Else ctnetlink_alloc_filter size grows a bit too big for my taste
when status handling is added.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index e81af33b233b1831d8c753028542792b11192f4b..e8368e66b0f525a99b1a500a9025b81a93772d44 100644 (file)
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -852,6 +852,11 @@ static int ctnetlink_done(struct netlink_callback *cb)
        return 0;
 }
 
+struct ctnetlink_filter_u32 {
+       u32 val;
+       u32 mask;
+};
+
 struct ctnetlink_filter {
        u8 family;
 
@@ -862,10 +867,7 @@ struct ctnetlink_filter {
        struct nf_conntrack_tuple reply;
        struct nf_conntrack_zone zone;
 
-       struct {
-               u_int32_t val;
-               u_int32_t mask;
-       } mark;
+       struct ctnetlink_filter_u32 mark;
 };
 
 static const struct nla_policy cta_filter_nla_policy[CTA_FILTER_MAX + 1] = {
@@ -907,6 +909,24 @@ static int ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
                                         struct nf_conntrack_zone *zone,
                                         u_int32_t flags);
 
+static int ctnetlink_filter_parse_mark(struct ctnetlink_filter_u32 *mark,
+                                      const struct nlattr * const cda[])
+{
+#ifdef CONFIG_NF_CONNTRACK_MARK
+       if (cda[CTA_MARK]) {
+               mark->val = ntohl(nla_get_be32(cda[CTA_MARK]));
+
+               if (cda[CTA_MARK_MASK])
+                       mark->mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
+               else
+                       mark->mask = 0xffffffff;
+       } else if (cda[CTA_MARK_MASK]) {
+               return -EINVAL;
+       }
+#endif
+       return 0;
+}
+
 static struct ctnetlink_filter *
 ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
 {
@@ -924,18 +944,10 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
 
        filter->family = family;
 
-#ifdef CONFIG_NF_CONNTRACK_MARK
-       if (cda[CTA_MARK]) {
-               filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK]));
-               if (cda[CTA_MARK_MASK])
-                       filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
-               else
-                       filter->mark.mask = 0xffffffff;
-       } else if (cda[CTA_MARK_MASK]) {
-               err = -EINVAL;
+       err = ctnetlink_filter_parse_mark(&filter->mark, cda);
+       if (err)
                goto err_filter;
-       }
-#endif
+
        if (!cda[CTA_FILTER])
                return filter;