2 * Copyright (c) 2015 Nicira, Inc.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
14 #include <linux/module.h>
15 #include <linux/openvswitch.h>
17 #include <net/netfilter/nf_conntrack_core.h>
18 #include <net/netfilter/nf_conntrack_helper.h>
19 #include <net/netfilter/nf_conntrack_labels.h>
20 #include <net/netfilter/nf_conntrack_zones.h>
21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
24 #include "conntrack.h"
26 #include "flow_netlink.h"
28 struct ovs_ct_len_tbl {
33 /* Metadata mark for masked write to conntrack mark */
39 /* Metadata label for masked write to conntrack label. */
41 struct ovs_key_ct_labels value;
42 struct ovs_key_ct_labels mask;
45 /* Conntrack action context for execution. */
46 struct ovs_conntrack_info {
47 struct nf_conntrack_helper *helper;
48 struct nf_conntrack_zone zone;
53 struct md_labels labels;
56 static u16 key_to_nfproto(const struct sw_flow_key *key)
58 switch (ntohs(key->eth.type)) {
64 return NFPROTO_UNSPEC;
68 /* Map SKB connection state into the values used by flow definition. */
69 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
71 u8 ct_state = OVS_CS_F_TRACKED;
74 case IP_CT_ESTABLISHED_REPLY:
75 case IP_CT_RELATED_REPLY:
77 ct_state |= OVS_CS_F_REPLY_DIR;
84 case IP_CT_ESTABLISHED:
85 case IP_CT_ESTABLISHED_REPLY:
86 ct_state |= OVS_CS_F_ESTABLISHED;
89 case IP_CT_RELATED_REPLY:
90 ct_state |= OVS_CS_F_RELATED;
94 ct_state |= OVS_CS_F_NEW;
103 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
105 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
106 return ct ? ct->mark : 0;
112 static void ovs_ct_get_labels(const struct nf_conn *ct,
113 struct ovs_key_ct_labels *labels)
115 struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
118 size_t len = cl->words * sizeof(long);
120 if (len > OVS_CT_LABELS_LEN)
121 len = OVS_CT_LABELS_LEN;
122 else if (len < OVS_CT_LABELS_LEN)
123 memset(labels, 0, OVS_CT_LABELS_LEN);
124 memcpy(labels, cl->bits, len);
126 memset(labels, 0, OVS_CT_LABELS_LEN);
130 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
131 const struct nf_conntrack_zone *zone,
132 const struct nf_conn *ct)
134 key->ct.state = state;
135 key->ct.zone = zone->id;
136 key->ct.mark = ovs_ct_get_mark(ct);
137 ovs_ct_get_labels(ct, &key->ct.labels);
140 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
141 * previously sent the packet to conntrack via the ct action.
143 static void ovs_ct_update_key(const struct sk_buff *skb,
144 struct sw_flow_key *key, bool post_ct)
146 const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
147 enum ip_conntrack_info ctinfo;
151 ct = nf_ct_get(skb, &ctinfo);
153 state = ovs_ct_get_state(ctinfo);
154 if (!nf_ct_is_confirmed(ct))
155 state |= OVS_CS_F_NEW;
157 state |= OVS_CS_F_RELATED;
158 zone = nf_ct_zone(ct);
159 } else if (post_ct) {
160 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
162 __ovs_ct_update_key(key, state, zone, ct);
165 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
167 ovs_ct_update_key(skb, key, false);
170 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
172 if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
175 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
176 nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
179 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
180 nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
183 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
184 nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
191 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
192 u32 ct_mark, u32 mask)
194 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
195 enum ip_conntrack_info ctinfo;
200 /* The connection could be invalid, in which case set_mark is no-op. */
201 ct = nf_ct_get(skb, &ctinfo);
205 new_mark = ct_mark | (ct->mark & ~(mask));
206 if (ct->mark != new_mark) {
208 nf_conntrack_event_cache(IPCT_MARK, ct);
209 key->ct.mark = new_mark;
218 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
219 const struct ovs_key_ct_labels *labels,
220 const struct ovs_key_ct_labels *mask)
222 enum ip_conntrack_info ctinfo;
223 struct nf_conn_labels *cl;
227 /* The connection could be invalid, in which case set_label is no-op.*/
228 ct = nf_ct_get(skb, &ctinfo);
232 cl = nf_ct_labels_find(ct);
234 nf_ct_labels_ext_add(ct);
235 cl = nf_ct_labels_find(ct);
237 if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
240 err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
241 OVS_CT_LABELS_LEN / sizeof(u32));
245 ovs_ct_get_labels(ct, &key->ct.labels);
249 /* 'skb' should already be pulled to nh_ofs. */
250 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
252 const struct nf_conntrack_helper *helper;
253 const struct nf_conn_help *help;
254 enum ip_conntrack_info ctinfo;
255 unsigned int protoff;
258 ct = nf_ct_get(skb, &ctinfo);
259 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
262 help = nfct_help(ct);
266 helper = rcu_dereference(help->helper);
272 protoff = ip_hdrlen(skb);
275 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
279 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
281 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
282 pr_debug("proto header not found\n");
289 WARN_ONCE(1, "helper invoked on non-IP family!");
293 return helper->help(skb, protoff, ct, ctinfo);
296 static int handle_fragments(struct net *net, struct sw_flow_key *key,
297 u16 zone, struct sk_buff *skb)
299 struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
301 if (key->eth.type == htons(ETH_P_IP)) {
302 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
305 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
306 err = ip_defrag(net, skb, user);
310 ovs_cb.mru = IPCB(skb)->frag_max_size;
311 } else if (key->eth.type == htons(ETH_P_IPV6)) {
312 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
313 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
314 struct sk_buff *reasm;
316 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
317 reasm = nf_ct_frag6_gather(net, skb, user);
324 key->ip.proto = ipv6_hdr(reasm)->nexthdr;
325 skb_morph(skb, reasm);
327 ovs_cb.mru = IP6CB(skb)->frag_max_size;
329 return -EPFNOSUPPORT;
332 return -EPFNOSUPPORT;
335 key->ip.frag = OVS_FRAG_TYPE_NONE;
338 *OVS_CB(skb) = ovs_cb;
343 static struct nf_conntrack_expect *
344 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
345 u16 proto, const struct sk_buff *skb)
347 struct nf_conntrack_tuple tuple;
349 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
351 return __nf_ct_expect_find(net, zone, &tuple);
354 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
355 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
356 const struct ovs_conntrack_info *info)
358 enum ip_conntrack_info ctinfo;
361 ct = nf_ct_get(skb, &ctinfo);
364 if (!net_eq(net, read_pnet(&ct->ct_net)))
366 if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
369 struct nf_conn_help *help;
371 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
372 if (help && rcu_access_pointer(help->helper) != info->helper)
379 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
380 const struct ovs_conntrack_info *info,
383 /* If we are recirculating packets to match on conntrack fields and
384 * committing with a separate conntrack action, then we don't need to
385 * actually run the packet through conntrack twice unless it's for a
388 if (!skb_nfct_cached(net, skb, info)) {
389 struct nf_conn *tmpl = info->ct;
391 /* Associate skb with specified zone. */
394 nf_conntrack_put(skb->nfct);
395 nf_conntrack_get(&tmpl->ct_general);
396 skb->nfct = &tmpl->ct_general;
397 skb->nfctinfo = IP_CT_NEW;
400 if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
404 if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
405 WARN_ONCE(1, "helper rejected packet");
410 ovs_ct_update_key(skb, key, true);
415 /* Lookup connection and read fields into key. */
416 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
417 const struct ovs_conntrack_info *info,
420 struct nf_conntrack_expect *exp;
422 exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
426 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
427 __ovs_ct_update_key(key, state, &info->zone, exp->master);
431 err = __ovs_ct_lookup(net, key, info, skb);
439 /* Lookup connection and confirm if unconfirmed. */
440 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
441 const struct ovs_conntrack_info *info,
447 state = key->ct.state;
448 if (key->ct.zone == info->zone.id &&
449 ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
450 /* Previous lookup has shown that this connection is already
451 * tracked and committed. Skip committing.
456 err = __ovs_ct_lookup(net, key, info, skb);
459 if (nf_conntrack_confirm(skb) != NF_ACCEPT)
465 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
469 for (i = 0; i < sizeof(*labels); i++)
470 if (labels->ct_labels[i])
476 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
477 struct sw_flow_key *key,
478 const struct ovs_conntrack_info *info)
483 /* The conntrack module expects to be working at L3. */
484 nh_ofs = skb_network_offset(skb);
485 skb_pull(skb, nh_ofs);
487 if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
488 err = handle_fragments(net, key, info->zone.id, skb);
494 err = ovs_ct_commit(net, key, info, skb);
496 err = ovs_ct_lookup(net, key, info, skb);
500 if (info->mark.mask) {
501 err = ovs_ct_set_mark(skb, key, info->mark.value,
506 if (labels_nonzero(&info->labels.mask))
507 err = ovs_ct_set_labels(skb, key, &info->labels.value,
510 skb_push(skb, nh_ofs);
514 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
515 const struct sw_flow_key *key, bool log)
517 struct nf_conntrack_helper *helper;
518 struct nf_conn_help *help;
520 helper = nf_conntrack_helper_try_module_get(name, info->family,
523 OVS_NLERR(log, "Unknown helper \"%s\"", name);
527 help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
529 module_put(helper->me);
533 rcu_assign_pointer(help->helper, helper);
534 info->helper = helper;
538 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
539 [OVS_CT_ATTR_COMMIT] = { .minlen = 0, .maxlen = 0 },
540 [OVS_CT_ATTR_ZONE] = { .minlen = sizeof(u16),
541 .maxlen = sizeof(u16) },
542 [OVS_CT_ATTR_MARK] = { .minlen = sizeof(struct md_mark),
543 .maxlen = sizeof(struct md_mark) },
544 [OVS_CT_ATTR_LABELS] = { .minlen = sizeof(struct md_labels),
545 .maxlen = sizeof(struct md_labels) },
546 [OVS_CT_ATTR_HELPER] = { .minlen = 1,
547 .maxlen = NF_CT_HELPER_NAME_LEN }
550 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
551 const char **helper, bool log)
556 nla_for_each_nested(a, attr, rem) {
557 int type = nla_type(a);
558 int maxlen = ovs_ct_attr_lens[type].maxlen;
559 int minlen = ovs_ct_attr_lens[type].minlen;
561 if (type > OVS_CT_ATTR_MAX) {
563 "Unknown conntrack attr (type=%d, max=%d)",
564 type, OVS_CT_ATTR_MAX);
567 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
569 "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
570 type, nla_len(a), maxlen);
575 case OVS_CT_ATTR_COMMIT:
578 #ifdef CONFIG_NF_CONNTRACK_ZONES
579 case OVS_CT_ATTR_ZONE:
580 info->zone.id = nla_get_u16(a);
583 #ifdef CONFIG_NF_CONNTRACK_MARK
584 case OVS_CT_ATTR_MARK: {
585 struct md_mark *mark = nla_data(a);
588 OVS_NLERR(log, "ct_mark mask cannot be 0");
595 #ifdef CONFIG_NF_CONNTRACK_LABELS
596 case OVS_CT_ATTR_LABELS: {
597 struct md_labels *labels = nla_data(a);
599 if (!labels_nonzero(&labels->mask)) {
600 OVS_NLERR(log, "ct_labels mask cannot be 0");
603 info->labels = *labels;
607 case OVS_CT_ATTR_HELPER:
608 *helper = nla_data(a);
609 if (!memchr(*helper, '\0', nla_len(a))) {
610 OVS_NLERR(log, "Invalid conntrack helper");
615 OVS_NLERR(log, "Unknown conntrack attr (%d)",
622 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
629 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
631 if (attr == OVS_KEY_ATTR_CT_STATE)
633 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
634 attr == OVS_KEY_ATTR_CT_ZONE)
636 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
637 attr == OVS_KEY_ATTR_CT_MARK)
639 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
640 attr == OVS_KEY_ATTR_CT_LABELS) {
641 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
643 return ovs_net->xt_label;
649 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
650 const struct sw_flow_key *key,
651 struct sw_flow_actions **sfa, bool log)
653 struct ovs_conntrack_info ct_info;
654 const char *helper = NULL;
658 family = key_to_nfproto(key);
659 if (family == NFPROTO_UNSPEC) {
660 OVS_NLERR(log, "ct family unspecified");
664 memset(&ct_info, 0, sizeof(ct_info));
665 ct_info.family = family;
667 nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
668 NF_CT_DEFAULT_ZONE_DIR, 0);
670 err = parse_ct(attr, &ct_info, &helper, log);
674 /* Set up template for tracking connections in specific zones. */
675 ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
677 OVS_NLERR(log, "Failed to allocate conntrack template");
681 err = ovs_ct_add_helper(&ct_info, helper, key, log);
686 err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
687 sizeof(ct_info), log);
691 __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
692 nf_conntrack_get(&ct_info.ct->ct_general);
695 nf_conntrack_free(ct_info.ct);
699 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
702 struct nlattr *start;
704 start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
708 if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
710 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
711 nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
713 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
714 nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
717 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
718 labels_nonzero(&ct_info->labels.mask) &&
719 nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
722 if (ct_info->helper) {
723 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
724 ct_info->helper->name))
728 nla_nest_end(skb, start);
733 void ovs_ct_free_action(const struct nlattr *a)
735 struct ovs_conntrack_info *ct_info = nla_data(a);
738 module_put(ct_info->helper->me);
740 nf_ct_put(ct_info->ct);
743 void ovs_ct_init(struct net *net)
745 unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
746 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
748 if (nf_connlabels_get(net, n_bits)) {
749 ovs_net->xt_label = false;
750 OVS_NLERR(true, "Failed to set connlabel length");
752 ovs_net->xt_label = true;
756 void ovs_ct_exit(struct net *net)
758 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
760 if (ovs_net->xt_label)
761 nf_connlabels_put(net);