@@ -115,6 +115,8 @@ struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp);
int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
gfp_t flags);
+int nf_ct_helper(struct sk_buff *skb, u16 proto);
+
void nf_ct_helper_destroy(struct nf_conn *ct);
static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
@@ -26,7 +26,9 @@
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_log.h>
+#include <net/ip.h>
static DEFINE_MUTEX(nf_ct_helper_mutex);
struct hlist_head *nf_ct_helper_hash __read_mostly;
@@ -240,6 +242,75 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
}
EXPORT_SYMBOL_GPL(__nf_ct_try_assign_helper);
+/* 'skb' should already be pulled to nh_ofs. */
+int nf_ct_helper(struct sk_buff *skb, u16 proto)
+{
+ const struct nf_conntrack_helper *helper;
+ const struct nf_conn_help *help;
+ enum ip_conntrack_info ctinfo;
+ unsigned int protoff;
+ struct nf_conn *ct;
+ int err;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
+
+ help = nfct_help(ct);
+ if (!help)
+ return NF_ACCEPT;
+
+ helper = rcu_dereference(help->helper);
+ if (!helper)
+ return NF_ACCEPT;
+
+ if (helper->tuple.src.l3num != NFPROTO_UNSPEC &&
+ helper->tuple.src.l3num != proto)
+ return NF_ACCEPT;
+
+ switch (proto) {
+ case NFPROTO_IPV4:
+ protoff = ip_hdrlen(skb);
+ proto = ip_hdr(skb)->protocol;
+ break;
+ case NFPROTO_IPV6: {
+ u8 nexthdr = ipv6_hdr(skb)->nexthdr;
+ __be16 frag_off;
+ int ofs;
+
+ ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
+ &frag_off);
+ if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
+ pr_debug("proto header not found\n");
+ return NF_ACCEPT;
+ }
+ protoff = ofs;
+ proto = nexthdr;
+ break;
+ }
+ default:
+ WARN_ONCE(1, "helper invoked on non-IP family!");
+ return NF_DROP;
+ }
+
+ if (helper->tuple.dst.protonum != proto)
+ return NF_ACCEPT;
+
+ err = helper->help(skb, protoff, ct, ctinfo);
+ if (err != NF_ACCEPT)
+ return err;
+
+ /* Adjust seqs after helper. This is needed due to some helpers (e.g.,
+ * FTP with NAT) adusting the TCP payload size when mangling IP
+ * addresses and/or port numbers in the text-based control connection.
+ */
+ if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
+ !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
+ return NF_DROP;
+ return NF_ACCEPT;
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper);
+
/* appropriate ct lock protecting must be taken by caller */
static int unhelp(struct nf_conn *ct, void *me)
{
@@ -434,65 +434,6 @@ static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
return 0;
}
-/* 'skb' should already be pulled to nh_ofs. */
-static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
-{
- const struct nf_conntrack_helper *helper;
- const struct nf_conn_help *help;
- enum ip_conntrack_info ctinfo;
- unsigned int protoff;
- struct nf_conn *ct;
- int err;
-
- ct = nf_ct_get(skb, &ctinfo);
- if (!ct || ctinfo == IP_CT_RELATED_REPLY)
- return NF_ACCEPT;
-
- help = nfct_help(ct);
- if (!help)
- return NF_ACCEPT;
-
- helper = rcu_dereference(help->helper);
- if (!helper)
- return NF_ACCEPT;
-
- switch (proto) {
- case NFPROTO_IPV4:
- protoff = ip_hdrlen(skb);
- break;
- case NFPROTO_IPV6: {
- u8 nexthdr = ipv6_hdr(skb)->nexthdr;
- __be16 frag_off;
- int ofs;
-
- ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
- &frag_off);
- if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
- pr_debug("proto header not found\n");
- return NF_ACCEPT;
- }
- protoff = ofs;
- break;
- }
- default:
- WARN_ONCE(1, "helper invoked on non-IP family!");
- return NF_DROP;
- }
-
- err = helper->help(skb, protoff, ct, ctinfo);
- if (err != NF_ACCEPT)
- return err;
-
- /* Adjust seqs after helper. This is needed due to some helpers (e.g.,
- * FTP with NAT) adusting the TCP payload size when mangling IP
- * addresses and/or port numbers in the text-based control connection.
- */
- if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
- !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
- return NF_DROP;
- return NF_ACCEPT;
-}
-
/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
* value if 'skb' is freed.
*/
@@ -1038,7 +979,7 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
*/
if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
info->commit) &&
- ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
+ nf_ct_helper(skb, info->family) != NF_ACCEPT) {
return -EINVAL;
}
Move ovs_ct_helper from openvswitch to nf_conntrack_helper and rename as nf_ct_helper so that it can be used in TC act_ct in the next patch. Note that it also adds the checks for the family and proto, as in TC act_ct, the packets with correct family and proto are not guaranteed. Signed-off-by: Xin Long <lucien.xin@gmail.com> --- include/net/netfilter/nf_conntrack_helper.h | 2 + net/netfilter/nf_conntrack_helper.c | 71 +++++++++++++++++++++ net/openvswitch/conntrack.c | 61 +----------------- 3 files changed, 74 insertions(+), 60 deletions(-)