netfilter: ctnetlink: allow to dump expectation per master conntrack

This patch adds the ability to dump all existing expectations
per master conntrack.

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 9904b15f600e96f6d0285cff241339a364dc6200..6d0f8a17c5b77d6c02b4df99ceddb02f48954b3e 100644 (file)
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2409,6 +2409,92 @@ out:
        return skb->len;
 }
 
+static int
+ctnetlink_exp_ct_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct nf_conntrack_expect *exp, *last;
+       struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
+       struct nf_conn *ct = cb->data;
+       struct nf_conn_help *help = nfct_help(ct);
+       u_int8_t l3proto = nfmsg->nfgen_family;
+
+       if (cb->args[0])
+               return 0;
+
+       rcu_read_lock();
+       last = (struct nf_conntrack_expect *)cb->args[1];
+restart:
+       hlist_for_each_entry(exp, &help->expectations, lnode) {
+               if (l3proto && exp->tuple.src.l3num != l3proto)
+                       continue;
+               if (cb->args[1]) {
+                       if (exp != last)
+                               continue;
+                       cb->args[1] = 0;
+               }
+               if (ctnetlink_exp_fill_info(skb, NETLINK_CB(cb->skb).portid,
+                                           cb->nlh->nlmsg_seq,
+                                           IPCTNL_MSG_EXP_NEW,
+                                           exp) < 0) {
+                       if (!atomic_inc_not_zero(&exp->use))
+                               continue;
+                       cb->args[1] = (unsigned long)exp;
+                       goto out;
+               }
+       }
+       if (cb->args[1]) {
+               cb->args[1] = 0;
+               goto restart;
+       }
+       cb->args[0] = 1;
+out:
+       rcu_read_unlock();
+       if (last)
+               nf_ct_expect_put(last);
+
+       return skb->len;
+}
+
+static int ctnetlink_dump_exp_ct(struct sock *ctnl, struct sk_buff *skb,
+                                const struct nlmsghdr *nlh,
+                                const struct nlattr * const cda[])
+{
+       int err;
+       struct net *net = sock_net(ctnl);
+       struct nfgenmsg *nfmsg = nlmsg_data(nlh);
+       u_int8_t u3 = nfmsg->nfgen_family;
+       struct nf_conntrack_tuple tuple;
+       struct nf_conntrack_tuple_hash *h;
+       struct nf_conn *ct;
+       u16 zone = 0;
+       struct netlink_dump_control c = {
+               .dump = ctnetlink_exp_ct_dump_table,
+               .done = ctnetlink_exp_done,
+       };
+
+       err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER, u3);
+       if (err < 0)
+               return err;
+
+       if (cda[CTA_EXPECT_ZONE]) {
+               err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+               if (err < 0)
+                       return err;
+       }
+
+       h = nf_conntrack_find_get(net, zone, &tuple);
+       if (!h)
+               return -ENOENT;
+
+       ct = nf_ct_tuplehash_to_ctrack(h);
+       c.data = ct;
+
+       err = netlink_dump_start(ctnl, skb, nlh, &c);
+       nf_ct_put(ct);
+
+       return err;
+}
+
 static const struct nla_policy exp_nla_policy[CTA_EXPECT_MAX+1] = {
        [CTA_EXPECT_MASTER]     = { .type = NLA_NESTED },
        [CTA_EXPECT_TUPLE]      = { .type = NLA_NESTED },
@@ -2439,11 +2525,15 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
        int err;
 
        if (nlh->nlmsg_flags & NLM_F_DUMP) {
-               struct netlink_dump_control c = {
-                       .dump = ctnetlink_exp_dump_table,
-                       .done = ctnetlink_exp_done,
-               };
-               return netlink_dump_start(ctnl, skb, nlh, &c);
+               if (cda[CTA_EXPECT_MASTER])
+                       return ctnetlink_dump_exp_ct(ctnl, skb, nlh, cda);
+               else {
+                       struct netlink_dump_control c = {
+                               .dump = ctnetlink_exp_dump_table,
+                               .done = ctnetlink_exp_done,
+                       };
+                       return netlink_dump_start(ctnl, skb, nlh, &c);
+               }
        }
 
        err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);