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 void __ovs_ct_free_action(struct ovs_conntrack_info
*ct_info
);
58 static u16
key_to_nfproto(const struct sw_flow_key
*key
)
60 switch (ntohs(key
->eth
.type
)) {
66 return NFPROTO_UNSPEC
;
70 /* Map SKB connection state into the values used by flow definition. */
71 static u8
ovs_ct_get_state(enum ip_conntrack_info ctinfo
)
73 u8 ct_state
= OVS_CS_F_TRACKED
;
76 case IP_CT_ESTABLISHED_REPLY
:
77 case IP_CT_RELATED_REPLY
:
79 ct_state
|= OVS_CS_F_REPLY_DIR
;
86 case IP_CT_ESTABLISHED
:
87 case IP_CT_ESTABLISHED_REPLY
:
88 ct_state
|= OVS_CS_F_ESTABLISHED
;
91 case IP_CT_RELATED_REPLY
:
92 ct_state
|= OVS_CS_F_RELATED
;
96 ct_state
|= OVS_CS_F_NEW
;
105 static u32
ovs_ct_get_mark(const struct nf_conn
*ct
)
107 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
108 return ct
? ct
->mark
: 0;
114 static void ovs_ct_get_labels(const struct nf_conn
*ct
,
115 struct ovs_key_ct_labels
*labels
)
117 struct nf_conn_labels
*cl
= ct
? nf_ct_labels_find(ct
) : NULL
;
120 size_t len
= cl
->words
* sizeof(long);
122 if (len
> OVS_CT_LABELS_LEN
)
123 len
= OVS_CT_LABELS_LEN
;
124 else if (len
< OVS_CT_LABELS_LEN
)
125 memset(labels
, 0, OVS_CT_LABELS_LEN
);
126 memcpy(labels
, cl
->bits
, len
);
128 memset(labels
, 0, OVS_CT_LABELS_LEN
);
132 static void __ovs_ct_update_key(struct sw_flow_key
*key
, u8 state
,
133 const struct nf_conntrack_zone
*zone
,
134 const struct nf_conn
*ct
)
136 key
->ct
.state
= state
;
137 key
->ct
.zone
= zone
->id
;
138 key
->ct
.mark
= ovs_ct_get_mark(ct
);
139 ovs_ct_get_labels(ct
, &key
->ct
.labels
);
142 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
143 * previously sent the packet to conntrack via the ct action.
145 static void ovs_ct_update_key(const struct sk_buff
*skb
,
146 const struct ovs_conntrack_info
*info
,
147 struct sw_flow_key
*key
, bool post_ct
)
149 const struct nf_conntrack_zone
*zone
= &nf_ct_zone_dflt
;
150 enum ip_conntrack_info ctinfo
;
154 ct
= nf_ct_get(skb
, &ctinfo
);
156 state
= ovs_ct_get_state(ctinfo
);
157 if (!nf_ct_is_confirmed(ct
))
158 state
|= OVS_CS_F_NEW
;
160 state
|= OVS_CS_F_RELATED
;
161 zone
= nf_ct_zone(ct
);
162 } else if (post_ct
) {
163 state
= OVS_CS_F_TRACKED
| OVS_CS_F_INVALID
;
167 __ovs_ct_update_key(key
, state
, zone
, ct
);
170 void ovs_ct_fill_key(const struct sk_buff
*skb
, struct sw_flow_key
*key
)
172 ovs_ct_update_key(skb
, NULL
, key
, false);
175 int ovs_ct_put_key(const struct sw_flow_key
*key
, struct sk_buff
*skb
)
177 if (nla_put_u32(skb
, OVS_KEY_ATTR_CT_STATE
, key
->ct
.state
))
180 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES
) &&
181 nla_put_u16(skb
, OVS_KEY_ATTR_CT_ZONE
, key
->ct
.zone
))
184 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK
) &&
185 nla_put_u32(skb
, OVS_KEY_ATTR_CT_MARK
, key
->ct
.mark
))
188 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS
) &&
189 nla_put(skb
, OVS_KEY_ATTR_CT_LABELS
, sizeof(key
->ct
.labels
),
196 static int ovs_ct_set_mark(struct sk_buff
*skb
, struct sw_flow_key
*key
,
197 u32 ct_mark
, u32 mask
)
199 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
200 enum ip_conntrack_info ctinfo
;
205 /* The connection could be invalid, in which case set_mark is no-op. */
206 ct
= nf_ct_get(skb
, &ctinfo
);
210 new_mark
= ct_mark
| (ct
->mark
& ~(mask
));
211 if (ct
->mark
!= new_mark
) {
213 nf_conntrack_event_cache(IPCT_MARK
, ct
);
214 key
->ct
.mark
= new_mark
;
223 static int ovs_ct_set_labels(struct sk_buff
*skb
, struct sw_flow_key
*key
,
224 const struct ovs_key_ct_labels
*labels
,
225 const struct ovs_key_ct_labels
*mask
)
227 enum ip_conntrack_info ctinfo
;
228 struct nf_conn_labels
*cl
;
232 /* The connection could be invalid, in which case set_label is no-op.*/
233 ct
= nf_ct_get(skb
, &ctinfo
);
237 cl
= nf_ct_labels_find(ct
);
239 nf_ct_labels_ext_add(ct
);
240 cl
= nf_ct_labels_find(ct
);
242 if (!cl
|| cl
->words
* sizeof(long) < OVS_CT_LABELS_LEN
)
245 err
= nf_connlabels_replace(ct
, (u32
*)labels
, (u32
*)mask
,
246 OVS_CT_LABELS_LEN
/ sizeof(u32
));
250 ovs_ct_get_labels(ct
, &key
->ct
.labels
);
254 /* 'skb' should already be pulled to nh_ofs. */
255 static int ovs_ct_helper(struct sk_buff
*skb
, u16 proto
)
257 const struct nf_conntrack_helper
*helper
;
258 const struct nf_conn_help
*help
;
259 enum ip_conntrack_info ctinfo
;
260 unsigned int protoff
;
263 ct
= nf_ct_get(skb
, &ctinfo
);
264 if (!ct
|| ctinfo
== IP_CT_RELATED_REPLY
)
267 help
= nfct_help(ct
);
271 helper
= rcu_dereference(help
->helper
);
277 protoff
= ip_hdrlen(skb
);
280 u8 nexthdr
= ipv6_hdr(skb
)->nexthdr
;
284 ofs
= ipv6_skip_exthdr(skb
, sizeof(struct ipv6hdr
), &nexthdr
,
286 if (ofs
< 0 || (frag_off
& htons(~0x7)) != 0) {
287 pr_debug("proto header not found\n");
294 WARN_ONCE(1, "helper invoked on non-IP family!");
298 return helper
->help(skb
, protoff
, ct
, ctinfo
);
301 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
302 * value if 'skb' is freed.
304 static int handle_fragments(struct net
*net
, struct sw_flow_key
*key
,
305 u16 zone
, struct sk_buff
*skb
)
307 struct ovs_skb_cb ovs_cb
= *OVS_CB(skb
);
310 if (key
->eth
.type
== htons(ETH_P_IP
)) {
311 enum ip_defrag_users user
= IP_DEFRAG_CONNTRACK_IN
+ zone
;
313 memset(IPCB(skb
), 0, sizeof(struct inet_skb_parm
));
314 err
= ip_defrag(net
, skb
, user
);
318 ovs_cb
.mru
= IPCB(skb
)->frag_max_size
;
319 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
320 } else if (key
->eth
.type
== htons(ETH_P_IPV6
)) {
321 enum ip6_defrag_users user
= IP6_DEFRAG_CONNTRACK_IN
+ zone
;
323 memset(IP6CB(skb
), 0, sizeof(struct inet6_skb_parm
));
324 err
= nf_ct_frag6_gather(net
, skb
, user
);
328 key
->ip
.proto
= ipv6_hdr(skb
)->nexthdr
;
329 ovs_cb
.mru
= IP6CB(skb
)->frag_max_size
;
333 return -EPFNOSUPPORT
;
336 key
->ip
.frag
= OVS_FRAG_TYPE_NONE
;
339 *OVS_CB(skb
) = ovs_cb
;
344 static struct nf_conntrack_expect
*
345 ovs_ct_expect_find(struct net
*net
, const struct nf_conntrack_zone
*zone
,
346 u16 proto
, const struct sk_buff
*skb
)
348 struct nf_conntrack_tuple tuple
;
350 if (!nf_ct_get_tuplepr(skb
, skb_network_offset(skb
), proto
, net
, &tuple
))
352 return __nf_ct_expect_find(net
, zone
, &tuple
);
355 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
356 static bool skb_nfct_cached(const struct net
*net
, const struct sk_buff
*skb
,
357 const struct ovs_conntrack_info
*info
)
359 enum ip_conntrack_info ctinfo
;
362 ct
= nf_ct_get(skb
, &ctinfo
);
365 if (!net_eq(net
, read_pnet(&ct
->ct_net
)))
367 if (!nf_ct_zone_equal_any(info
->ct
, nf_ct_zone(ct
)))
370 struct nf_conn_help
*help
;
372 help
= nf_ct_ext_find(ct
, NF_CT_EXT_HELPER
);
373 if (help
&& rcu_access_pointer(help
->helper
) != info
->helper
)
380 static int __ovs_ct_lookup(struct net
*net
, struct sw_flow_key
*key
,
381 const struct ovs_conntrack_info
*info
,
384 /* If we are recirculating packets to match on conntrack fields and
385 * committing with a separate conntrack action, then we don't need to
386 * actually run the packet through conntrack twice unless it's for a
389 if (!skb_nfct_cached(net
, skb
, info
)) {
390 struct nf_conn
*tmpl
= info
->ct
;
392 /* Associate skb with specified zone. */
395 nf_conntrack_put(skb
->nfct
);
396 nf_conntrack_get(&tmpl
->ct_general
);
397 skb
->nfct
= &tmpl
->ct_general
;
398 skb
->nfctinfo
= IP_CT_NEW
;
401 if (nf_conntrack_in(net
, info
->family
, NF_INET_PRE_ROUTING
,
405 if (ovs_ct_helper(skb
, info
->family
) != NF_ACCEPT
) {
406 WARN_ONCE(1, "helper rejected packet");
411 ovs_ct_update_key(skb
, info
, key
, true);
416 /* Lookup connection and read fields into key. */
417 static int ovs_ct_lookup(struct net
*net
, struct sw_flow_key
*key
,
418 const struct ovs_conntrack_info
*info
,
421 struct nf_conntrack_expect
*exp
;
423 exp
= ovs_ct_expect_find(net
, &info
->zone
, info
->family
, skb
);
427 state
= OVS_CS_F_TRACKED
| OVS_CS_F_NEW
| OVS_CS_F_RELATED
;
428 __ovs_ct_update_key(key
, state
, &info
->zone
, exp
->master
);
432 err
= __ovs_ct_lookup(net
, key
, info
, skb
);
440 /* Lookup connection and confirm if unconfirmed. */
441 static int ovs_ct_commit(struct net
*net
, struct sw_flow_key
*key
,
442 const struct ovs_conntrack_info
*info
,
448 state
= key
->ct
.state
;
449 if (key
->ct
.zone
== info
->zone
.id
&&
450 ((state
& OVS_CS_F_TRACKED
) && !(state
& OVS_CS_F_NEW
))) {
451 /* Previous lookup has shown that this connection is already
452 * tracked and committed. Skip committing.
457 err
= __ovs_ct_lookup(net
, key
, info
, skb
);
460 if (nf_conntrack_confirm(skb
) != NF_ACCEPT
)
466 static bool labels_nonzero(const struct ovs_key_ct_labels
*labels
)
470 for (i
= 0; i
< sizeof(*labels
); i
++)
471 if (labels
->ct_labels
[i
])
477 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
478 * value if 'skb' is freed.
480 int ovs_ct_execute(struct net
*net
, struct sk_buff
*skb
,
481 struct sw_flow_key
*key
,
482 const struct ovs_conntrack_info
*info
)
487 /* The conntrack module expects to be working at L3. */
488 nh_ofs
= skb_network_offset(skb
);
489 skb_pull(skb
, nh_ofs
);
491 if (key
->ip
.frag
!= OVS_FRAG_TYPE_NONE
) {
492 err
= handle_fragments(net
, key
, info
->zone
.id
, skb
);
498 err
= ovs_ct_commit(net
, key
, info
, skb
);
500 err
= ovs_ct_lookup(net
, key
, info
, skb
);
504 if (info
->mark
.mask
) {
505 err
= ovs_ct_set_mark(skb
, key
, info
->mark
.value
,
510 if (labels_nonzero(&info
->labels
.mask
))
511 err
= ovs_ct_set_labels(skb
, key
, &info
->labels
.value
,
514 skb_push(skb
, nh_ofs
);
520 static int ovs_ct_add_helper(struct ovs_conntrack_info
*info
, const char *name
,
521 const struct sw_flow_key
*key
, bool log
)
523 struct nf_conntrack_helper
*helper
;
524 struct nf_conn_help
*help
;
526 helper
= nf_conntrack_helper_try_module_get(name
, info
->family
,
529 OVS_NLERR(log
, "Unknown helper \"%s\"", name
);
533 help
= nf_ct_helper_ext_add(info
->ct
, helper
, GFP_KERNEL
);
535 module_put(helper
->me
);
539 rcu_assign_pointer(help
->helper
, helper
);
540 info
->helper
= helper
;
544 static const struct ovs_ct_len_tbl ovs_ct_attr_lens
[OVS_CT_ATTR_MAX
+ 1] = {
545 [OVS_CT_ATTR_COMMIT
] = { .minlen
= 0, .maxlen
= 0 },
546 [OVS_CT_ATTR_ZONE
] = { .minlen
= sizeof(u16
),
547 .maxlen
= sizeof(u16
) },
548 [OVS_CT_ATTR_MARK
] = { .minlen
= sizeof(struct md_mark
),
549 .maxlen
= sizeof(struct md_mark
) },
550 [OVS_CT_ATTR_LABELS
] = { .minlen
= sizeof(struct md_labels
),
551 .maxlen
= sizeof(struct md_labels
) },
552 [OVS_CT_ATTR_HELPER
] = { .minlen
= 1,
553 .maxlen
= NF_CT_HELPER_NAME_LEN
}
556 static int parse_ct(const struct nlattr
*attr
, struct ovs_conntrack_info
*info
,
557 const char **helper
, bool log
)
562 nla_for_each_nested(a
, attr
, rem
) {
563 int type
= nla_type(a
);
564 int maxlen
= ovs_ct_attr_lens
[type
].maxlen
;
565 int minlen
= ovs_ct_attr_lens
[type
].minlen
;
567 if (type
> OVS_CT_ATTR_MAX
) {
569 "Unknown conntrack attr (type=%d, max=%d)",
570 type
, OVS_CT_ATTR_MAX
);
573 if (nla_len(a
) < minlen
|| nla_len(a
) > maxlen
) {
575 "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
576 type
, nla_len(a
), maxlen
);
581 case OVS_CT_ATTR_COMMIT
:
584 #ifdef CONFIG_NF_CONNTRACK_ZONES
585 case OVS_CT_ATTR_ZONE
:
586 info
->zone
.id
= nla_get_u16(a
);
589 #ifdef CONFIG_NF_CONNTRACK_MARK
590 case OVS_CT_ATTR_MARK
: {
591 struct md_mark
*mark
= nla_data(a
);
594 OVS_NLERR(log
, "ct_mark mask cannot be 0");
601 #ifdef CONFIG_NF_CONNTRACK_LABELS
602 case OVS_CT_ATTR_LABELS
: {
603 struct md_labels
*labels
= nla_data(a
);
605 if (!labels_nonzero(&labels
->mask
)) {
606 OVS_NLERR(log
, "ct_labels mask cannot be 0");
609 info
->labels
= *labels
;
613 case OVS_CT_ATTR_HELPER
:
614 *helper
= nla_data(a
);
615 if (!memchr(*helper
, '\0', nla_len(a
))) {
616 OVS_NLERR(log
, "Invalid conntrack helper");
621 OVS_NLERR(log
, "Unknown conntrack attr (%d)",
628 OVS_NLERR(log
, "Conntrack attr has %d unknown bytes", rem
);
635 bool ovs_ct_verify(struct net
*net
, enum ovs_key_attr attr
)
637 if (attr
== OVS_KEY_ATTR_CT_STATE
)
639 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES
) &&
640 attr
== OVS_KEY_ATTR_CT_ZONE
)
642 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK
) &&
643 attr
== OVS_KEY_ATTR_CT_MARK
)
645 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS
) &&
646 attr
== OVS_KEY_ATTR_CT_LABELS
) {
647 struct ovs_net
*ovs_net
= net_generic(net
, ovs_net_id
);
649 return ovs_net
->xt_label
;
655 int ovs_ct_copy_action(struct net
*net
, const struct nlattr
*attr
,
656 const struct sw_flow_key
*key
,
657 struct sw_flow_actions
**sfa
, bool log
)
659 struct ovs_conntrack_info ct_info
;
660 const char *helper
= NULL
;
664 family
= key_to_nfproto(key
);
665 if (family
== NFPROTO_UNSPEC
) {
666 OVS_NLERR(log
, "ct family unspecified");
670 memset(&ct_info
, 0, sizeof(ct_info
));
671 ct_info
.family
= family
;
673 nf_ct_zone_init(&ct_info
.zone
, NF_CT_DEFAULT_ZONE_ID
,
674 NF_CT_DEFAULT_ZONE_DIR
, 0);
676 err
= parse_ct(attr
, &ct_info
, &helper
, log
);
680 /* Set up template for tracking connections in specific zones. */
681 ct_info
.ct
= nf_ct_tmpl_alloc(net
, &ct_info
.zone
, GFP_KERNEL
);
683 OVS_NLERR(log
, "Failed to allocate conntrack template");
687 __set_bit(IPS_CONFIRMED_BIT
, &ct_info
.ct
->status
);
688 nf_conntrack_get(&ct_info
.ct
->ct_general
);
691 err
= ovs_ct_add_helper(&ct_info
, helper
, key
, log
);
696 err
= ovs_nla_add_action(sfa
, OVS_ACTION_ATTR_CT
, &ct_info
,
697 sizeof(ct_info
), log
);
703 __ovs_ct_free_action(&ct_info
);
707 int ovs_ct_action_to_attr(const struct ovs_conntrack_info
*ct_info
,
710 struct nlattr
*start
;
712 start
= nla_nest_start(skb
, OVS_ACTION_ATTR_CT
);
716 if (ct_info
->commit
&& nla_put_flag(skb
, OVS_CT_ATTR_COMMIT
))
718 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES
) &&
719 nla_put_u16(skb
, OVS_CT_ATTR_ZONE
, ct_info
->zone
.id
))
721 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK
) && ct_info
->mark
.mask
&&
722 nla_put(skb
, OVS_CT_ATTR_MARK
, sizeof(ct_info
->mark
),
725 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS
) &&
726 labels_nonzero(&ct_info
->labels
.mask
) &&
727 nla_put(skb
, OVS_CT_ATTR_LABELS
, sizeof(ct_info
->labels
),
730 if (ct_info
->helper
) {
731 if (nla_put_string(skb
, OVS_CT_ATTR_HELPER
,
732 ct_info
->helper
->name
))
736 nla_nest_end(skb
, start
);
741 void ovs_ct_free_action(const struct nlattr
*a
)
743 struct ovs_conntrack_info
*ct_info
= nla_data(a
);
745 __ovs_ct_free_action(ct_info
);
748 static void __ovs_ct_free_action(struct ovs_conntrack_info
*ct_info
)
751 module_put(ct_info
->helper
->me
);
753 nf_ct_put(ct_info
->ct
);
756 void ovs_ct_init(struct net
*net
)
758 unsigned int n_bits
= sizeof(struct ovs_key_ct_labels
) * BITS_PER_BYTE
;
759 struct ovs_net
*ovs_net
= net_generic(net
, ovs_net_id
);
761 if (nf_connlabels_get(net
, n_bits
)) {
762 ovs_net
->xt_label
= false;
763 OVS_NLERR(true, "Failed to set connlabel length");
765 ovs_net
->xt_label
= true;
769 void ovs_ct_exit(struct net
*net
)
771 struct ovs_net
*ovs_net
= net_generic(net
, ovs_net_id
);
773 if (ovs_net
->xt_label
)
774 nf_connlabels_put(net
);