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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / openvswitch / conntrack.c
blobc5904f629091d71420645b9585bf1362b0f39de2
1 /*
2 * Copyright (c) 2015 Nicira, Inc.
3 *
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.
7 *
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.
12 */
13
14 #include <linux/module.h>
15 #include <linux/openvswitch.h>
16 #include <linux/tcp.h>
17 #include <linux/udp.h>
18 #include <linux/sctp.h>
19 #include <net/ip.h>
20 #include <net/netfilter/nf_conntrack_core.h>
21 #include <net/netfilter/nf_conntrack_helper.h>
22 #include <net/netfilter/nf_conntrack_labels.h>
23 #include <net/netfilter/nf_conntrack_seqadj.h>
24 #include <net/netfilter/nf_conntrack_zones.h>
25 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
26
27 #ifdef CONFIG_NF_NAT_NEEDED
28 #include <linux/netfilter/nf_nat.h>
29 #include <net/netfilter/nf_nat_core.h>
30 #include <net/netfilter/nf_nat_l3proto.h>
31 #endif
32
33 #include "datapath.h"
34 #include "conntrack.h"
35 #include "flow.h"
36 #include "flow_netlink.h"
37
38 struct ovs_ct_len_tbl {
39 int maxlen;
40 int minlen;
41 };
42
43 /* Metadata mark for masked write to conntrack mark */
44 struct md_mark {
45 u32 value;
46 u32 mask;
47 };
48
49 /* Metadata label for masked write to conntrack label. */
50 struct md_labels {
51 struct ovs_key_ct_labels value;
52 struct ovs_key_ct_labels mask;
53 };
54
55 enum ovs_ct_nat {
56 OVS_CT_NAT = 1 << 0, /* NAT for committed connections only. */
57 OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
58 OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
59 };
60
61 /* Conntrack action context for execution. */
62 struct ovs_conntrack_info {
63 struct nf_conntrack_helper *helper;
64 struct nf_conntrack_zone zone;
65 struct nf_conn *ct;
66 u8 commit : 1;
67 u8 nat : 3; /* enum ovs_ct_nat */
68 u8 force : 1;
69 u8 have_eventmask : 1;
70 u16 family;
71 u32 eventmask; /* Mask of 1 << IPCT_*. */
72 struct md_mark mark;
73 struct md_labels labels;
74 #ifdef CONFIG_NF_NAT_NEEDED
75 struct nf_nat_range range; /* Only present for SRC NAT and DST NAT. */
76 #endif
77 };
78
79 static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
80
81 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
82
83 static u16 key_to_nfproto(const struct sw_flow_key *key)
84 {
85 switch (ntohs(key->eth.type)) {
86 case ETH_P_IP:
87 return NFPROTO_IPV4;
88 case ETH_P_IPV6:
89 return NFPROTO_IPV6;
90 default:
91 return NFPROTO_UNSPEC;
92 }
93 }
94
95 /* Map SKB connection state into the values used by flow definition. */
96 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
97 {
98 u8 ct_state = OVS_CS_F_TRACKED;
99
100 switch (ctinfo) {
101 case IP_CT_ESTABLISHED_REPLY:
102 case IP_CT_RELATED_REPLY:
103 ct_state |= OVS_CS_F_REPLY_DIR;
104 break;
105 default:
106 break;
107 }
108
109 switch (ctinfo) {
110 case IP_CT_ESTABLISHED:
111 case IP_CT_ESTABLISHED_REPLY:
112 ct_state |= OVS_CS_F_ESTABLISHED;
113 break;
114 case IP_CT_RELATED:
115 case IP_CT_RELATED_REPLY:
116 ct_state |= OVS_CS_F_RELATED;
117 break;
118 case IP_CT_NEW:
119 ct_state |= OVS_CS_F_NEW;
120 break;
121 default:
122 break;
123 }
124
125 return ct_state;
126 }
127
128 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
129 {
130 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
131 return ct ? ct->mark : 0;
132 #else
133 return 0;
134 #endif
135 }
136
137 /* Guard against conntrack labels max size shrinking below 128 bits. */
138 #if NF_CT_LABELS_MAX_SIZE < 16
139 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
140 #endif
141
142 static void ovs_ct_get_labels(const struct nf_conn *ct,
143 struct ovs_key_ct_labels *labels)
144 {
145 struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
146
147 if (cl)
148 memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
149 else
150 memset(labels, 0, OVS_CT_LABELS_LEN);
151 }
152
153 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
154 const struct nf_conntrack_tuple *orig,
155 u8 icmp_proto)
156 {
157 key->ct_orig_proto = orig->dst.protonum;
158 if (orig->dst.protonum == icmp_proto) {
159 key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
160 key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
161 } else {
162 key->ct.orig_tp.src = orig->src.u.all;
163 key->ct.orig_tp.dst = orig->dst.u.all;
164 }
165 }
166
167 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
168 const struct nf_conntrack_zone *zone,
169 const struct nf_conn *ct)
170 {
171 key->ct_state = state;
172 key->ct_zone = zone->id;
173 key->ct.mark = ovs_ct_get_mark(ct);
174 ovs_ct_get_labels(ct, &key->ct.labels);
175
176 if (ct) {
177 const struct nf_conntrack_tuple *orig;
178
179 /* Use the master if we have one. */
180 if (ct->master)
181 ct = ct->master;
182 orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
183
184 /* IP version must match with the master connection. */
185 if (key->eth.type == htons(ETH_P_IP) &&
186 nf_ct_l3num(ct) == NFPROTO_IPV4) {
187 key->ipv4.ct_orig.src = orig->src.u3.ip;
188 key->ipv4.ct_orig.dst = orig->dst.u3.ip;
189 __ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
190 return;
191 } else if (key->eth.type == htons(ETH_P_IPV6) &&
192 !sw_flow_key_is_nd(key) &&
193 nf_ct_l3num(ct) == NFPROTO_IPV6) {
194 key->ipv6.ct_orig.src = orig->src.u3.in6;
195 key->ipv6.ct_orig.dst = orig->dst.u3.in6;
196 __ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
197 return;
198 }
199 }
200 /* Clear 'ct_orig_proto' to mark the non-existence of conntrack
201 * original direction key fields.
202 */
203 key->ct_orig_proto = 0;
204 }
205
206 /* Update 'key' based on skb->_nfct. If 'post_ct' is true, then OVS has
207 * previously sent the packet to conntrack via the ct action. If
208 * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
209 * initialized from the connection status.
210 */
211 static void ovs_ct_update_key(const struct sk_buff *skb,
212 const struct ovs_conntrack_info *info,
213 struct sw_flow_key *key, bool post_ct,
214 bool keep_nat_flags)
215 {
216 const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
217 enum ip_conntrack_info ctinfo;
218 struct nf_conn *ct;
219 u8 state = 0;
220
221 ct = nf_ct_get(skb, &ctinfo);
222 if (ct) {
223 state = ovs_ct_get_state(ctinfo);
224 /* All unconfirmed entries are NEW connections. */
225 if (!nf_ct_is_confirmed(ct))
226 state |= OVS_CS_F_NEW;
227 /* OVS persists the related flag for the duration of the
228 * connection.
229 */
230 if (ct->master)
231 state |= OVS_CS_F_RELATED;
232 if (keep_nat_flags) {
233 state |= key->ct_state & OVS_CS_F_NAT_MASK;
234 } else {
235 if (ct->status & IPS_SRC_NAT)
236 state |= OVS_CS_F_SRC_NAT;
237 if (ct->status & IPS_DST_NAT)
238 state |= OVS_CS_F_DST_NAT;
239 }
240 zone = nf_ct_zone(ct);
241 } else if (post_ct) {
242 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
243 if (info)
244 zone = &info->zone;
245 }
246 __ovs_ct_update_key(key, state, zone, ct);
247 }
248
249 /* This is called to initialize CT key fields possibly coming in from the local
250 * stack.
251 */
252 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
253 {
254 ovs_ct_update_key(skb, NULL, key, false, false);
255 }
256
257 #define IN6_ADDR_INITIALIZER(ADDR) \
258 { (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
259 (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }
260
261 int ovs_ct_put_key(const struct sw_flow_key *swkey,
262 const struct sw_flow_key *output, struct sk_buff *skb)
263 {
264 if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
265 return -EMSGSIZE;
266
267 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
268 nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
269 return -EMSGSIZE;
270
271 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
272 nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
273 return -EMSGSIZE;
274
275 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
276 nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
277 &output->ct.labels))
278 return -EMSGSIZE;
279
280 if (swkey->ct_orig_proto) {
281 if (swkey->eth.type == htons(ETH_P_IP)) {
282 struct ovs_key_ct_tuple_ipv4 orig = {
283 output->ipv4.ct_orig.src,
284 output->ipv4.ct_orig.dst,
285 output->ct.orig_tp.src,
286 output->ct.orig_tp.dst,
287 output->ct_orig_proto,
288 };
289 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
290 sizeof(orig), &orig))
291 return -EMSGSIZE;
292 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
293 struct ovs_key_ct_tuple_ipv6 orig = {
294 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
295 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
296 output->ct.orig_tp.src,
297 output->ct.orig_tp.dst,
298 output->ct_orig_proto,
299 };
300 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
301 sizeof(orig), &orig))
302 return -EMSGSIZE;
303 }
304 }
305
306 return 0;
307 }
308
309 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
310 u32 ct_mark, u32 mask)
311 {
312 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
313 u32 new_mark;
314
315 new_mark = ct_mark | (ct->mark & ~(mask));
316 if (ct->mark != new_mark) {
317 ct->mark = new_mark;
318 if (nf_ct_is_confirmed(ct))
319 nf_conntrack_event_cache(IPCT_MARK, ct);
320 key->ct.mark = new_mark;
321 }
322
323 return 0;
324 #else
325 return -ENOTSUPP;
326 #endif
327 }
328
329 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
330 {
331 struct nf_conn_labels *cl;
332
333 cl = nf_ct_labels_find(ct);
334 if (!cl) {
335 nf_ct_labels_ext_add(ct);
336 cl = nf_ct_labels_find(ct);
337 }
338
339 return cl;
340 }
341
342 /* Initialize labels for a new, yet to be committed conntrack entry. Note that
343 * since the new connection is not yet confirmed, and thus no-one else has
344 * access to it's labels, we simply write them over.
345 */
346 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
347 const struct ovs_key_ct_labels *labels,
348 const struct ovs_key_ct_labels *mask)
349 {
350 struct nf_conn_labels *cl, *master_cl;
351 bool have_mask = labels_nonzero(mask);
352
353 /* Inherit master's labels to the related connection? */
354 master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
355
356 if (!master_cl && !have_mask)
357 return 0; /* Nothing to do. */
358
359 cl = ovs_ct_get_conn_labels(ct);
360 if (!cl)
361 return -ENOSPC;
362
363 /* Inherit the master's labels, if any. */
364 if (master_cl)
365 *cl = *master_cl;
366
367 if (have_mask) {
368 u32 *dst = (u32 *)cl->bits;
369 int i;
370
371 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
372 dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
373 (labels->ct_labels_32[i]
374 & mask->ct_labels_32[i]);
375 }
376
377 /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
378 * IPCT_LABEL bit is set in the event cache.
379 */
380 nf_conntrack_event_cache(IPCT_LABEL, ct);
381
382 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
383
384 return 0;
385 }
386
387 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
388 const struct ovs_key_ct_labels *labels,
389 const struct ovs_key_ct_labels *mask)
390 {
391 struct nf_conn_labels *cl;
392 int err;
393
394 cl = ovs_ct_get_conn_labels(ct);
395 if (!cl)
396 return -ENOSPC;
397
398 err = nf_connlabels_replace(ct, labels->ct_labels_32,
399 mask->ct_labels_32,
400 OVS_CT_LABELS_LEN_32);
401 if (err)
402 return err;
403
404 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
405
406 return 0;
407 }
408
409 /* 'skb' should already be pulled to nh_ofs. */
410 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
411 {
412 const struct nf_conntrack_helper *helper;
413 const struct nf_conn_help *help;
414 enum ip_conntrack_info ctinfo;
415 unsigned int protoff;
416 struct nf_conn *ct;
417 int err;
418
419 ct = nf_ct_get(skb, &ctinfo);
420 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
421 return NF_ACCEPT;
422
423 help = nfct_help(ct);
424 if (!help)
425 return NF_ACCEPT;
426
427 helper = rcu_dereference(help->helper);
428 if (!helper)
429 return NF_ACCEPT;
430
431 switch (proto) {
432 case NFPROTO_IPV4:
433 protoff = ip_hdrlen(skb);
434 break;
435 case NFPROTO_IPV6: {
436 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
437 __be16 frag_off;
438 int ofs;
439
440 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
441 &frag_off);
442 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
443 pr_debug("proto header not found\n");
444 return NF_ACCEPT;
445 }
446 protoff = ofs;
447 break;
448 }
449 default:
450 WARN_ONCE(1, "helper invoked on non-IP family!");
451 return NF_DROP;
452 }
453
454 err = helper->help(skb, protoff, ct, ctinfo);
455 if (err != NF_ACCEPT)
456 return err;
457
458 /* Adjust seqs after helper. This is needed due to some helpers (e.g.,
459 * FTP with NAT) adusting the TCP payload size when mangling IP
460 * addresses and/or port numbers in the text-based control connection.
461 */
462 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
463 !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
464 return NF_DROP;
465 return NF_ACCEPT;
466 }
467
468 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
469 * value if 'skb' is freed.
470 */
471 static int handle_fragments(struct net *net, struct sw_flow_key *key,
472 u16 zone, struct sk_buff *skb)
473 {
474 struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
475 int err;
476
477 if (key->eth.type == htons(ETH_P_IP)) {
478 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
479
480 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
481 err = ip_defrag(net, skb, user);
482 if (err)
483 return err;
484
485 ovs_cb.mru = IPCB(skb)->frag_max_size;
486 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
487 } else if (key->eth.type == htons(ETH_P_IPV6)) {
488 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
489
490 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
491 err = nf_ct_frag6_gather(net, skb, user);
492 if (err) {
493 if (err != -EINPROGRESS)
494 kfree_skb(skb);
495 return err;
496 }
497
498 key->ip.proto = ipv6_hdr(skb)->nexthdr;
499 ovs_cb.mru = IP6CB(skb)->frag_max_size;
500 #endif
501 } else {
502 kfree_skb(skb);
503 return -EPFNOSUPPORT;
504 }
505
506 key->ip.frag = OVS_FRAG_TYPE_NONE;
507 skb_clear_hash(skb);
508 skb->ignore_df = 1;
509 *OVS_CB(skb) = ovs_cb;
510
511 return 0;
512 }
513
514 static struct nf_conntrack_expect *
515 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
516 u16 proto, const struct sk_buff *skb)
517 {
518 struct nf_conntrack_tuple tuple;
519 struct nf_conntrack_expect *exp;
520
521 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
522 return NULL;
523
524 exp = __nf_ct_expect_find(net, zone, &tuple);
525 if (exp) {
526 struct nf_conntrack_tuple_hash *h;
527
528 /* Delete existing conntrack entry, if it clashes with the
529 * expectation. This can happen since conntrack ALGs do not
530 * check for clashes between (new) expectations and existing
531 * conntrack entries. nf_conntrack_in() will check the
532 * expectations only if a conntrack entry can not be found,
533 * which can lead to OVS finding the expectation (here) in the
534 * init direction, but which will not be removed by the
535 * nf_conntrack_in() call, if a matching conntrack entry is
536 * found instead. In this case all init direction packets
537 * would be reported as new related packets, while reply
538 * direction packets would be reported as un-related
539 * established packets.
540 */
541 h = nf_conntrack_find_get(net, zone, &tuple);
542 if (h) {
543 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
544
545 nf_ct_delete(ct, 0, 0);
546 nf_conntrack_put(&ct->ct_general);
547 }
548 }
549
550 return exp;
551 }
552
553 /* This replicates logic from nf_conntrack_core.c that is not exported. */
554 static enum ip_conntrack_info
555 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
556 {
557 const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
558
559 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
560 return IP_CT_ESTABLISHED_REPLY;
561 /* Once we've had two way comms, always ESTABLISHED. */
562 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
563 return IP_CT_ESTABLISHED;
564 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
565 return IP_CT_RELATED;
566 return IP_CT_NEW;
567 }
568
569 /* Find an existing connection which this packet belongs to without
570 * re-attributing statistics or modifying the connection state. This allows an
571 * skb->_nfct lost due to an upcall to be recovered during actions execution.
572 *
573 * Must be called with rcu_read_lock.
574 *
575 * On success, populates skb->_nfct and returns the connection. Returns NULL
576 * if there is no existing entry.
577 */
578 static struct nf_conn *
579 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
580 u8 l3num, struct sk_buff *skb, bool natted)
581 {
582 const struct nf_conntrack_l3proto *l3proto;
583 const struct nf_conntrack_l4proto *l4proto;
584 struct nf_conntrack_tuple tuple;
585 struct nf_conntrack_tuple_hash *h;
586 struct nf_conn *ct;
587 unsigned int dataoff;
588 u8 protonum;
589
590 l3proto = __nf_ct_l3proto_find(l3num);
591 if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
592 &protonum) <= 0) {
593 pr_debug("ovs_ct_find_existing: Can't get protonum\n");
594 return NULL;
595 }
596 l4proto = __nf_ct_l4proto_find(l3num, protonum);
597 if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
598 protonum, net, &tuple, l3proto, l4proto)) {
599 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
600 return NULL;
601 }
602
603 /* Must invert the tuple if skb has been transformed by NAT. */
604 if (natted) {
605 struct nf_conntrack_tuple inverse;
606
607 if (!nf_ct_invert_tuple(&inverse, &tuple, l3proto, l4proto)) {
608 pr_debug("ovs_ct_find_existing: Inversion failed!\n");
609 return NULL;
610 }
611 tuple = inverse;
612 }
613
614 /* look for tuple match */
615 h = nf_conntrack_find_get(net, zone, &tuple);
616 if (!h)
617 return NULL; /* Not found. */
618
619 ct = nf_ct_tuplehash_to_ctrack(h);
620
621 /* Inverted packet tuple matches the reverse direction conntrack tuple,
622 * select the other tuplehash to get the right 'ctinfo' bits for this
623 * packet.
624 */
625 if (natted)
626 h = &ct->tuplehash[!h->tuple.dst.dir];
627
628 nf_ct_set(skb, ct, ovs_ct_get_info(h));
629 return ct;
630 }
631
632 static
633 struct nf_conn *ovs_ct_executed(struct net *net,
634 const struct sw_flow_key *key,
635 const struct ovs_conntrack_info *info,
636 struct sk_buff *skb,
637 bool *ct_executed)
638 {
639 struct nf_conn *ct = NULL;
640
641 /* If no ct, check if we have evidence that an existing conntrack entry
642 * might be found for this skb. This happens when we lose a skb->_nfct
643 * due to an upcall, or if the direction is being forced. If the
644 * connection was not confirmed, it is not cached and needs to be run
645 * through conntrack again.
646 */
647 *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
648 !(key->ct_state & OVS_CS_F_INVALID) &&
649 (key->ct_zone == info->zone.id);
650
651 if (*ct_executed || (!key->ct_state && info->force)) {
652 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
653 !!(key->ct_state &
654 OVS_CS_F_NAT_MASK));
655 }
656
657 return ct;
658 }
659
660 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
661 static bool skb_nfct_cached(struct net *net,
662 const struct sw_flow_key *key,
663 const struct ovs_conntrack_info *info,
664 struct sk_buff *skb)
665 {
666 enum ip_conntrack_info ctinfo;
667 struct nf_conn *ct;
668 bool ct_executed = true;
669
670 ct = nf_ct_get(skb, &ctinfo);
671 if (!ct)
672 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
673
674 if (ct)
675 nf_ct_get(skb, &ctinfo);
676 else
677 return false;
678
679 if (!net_eq(net, read_pnet(&ct->ct_net)))
680 return false;
681 if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
682 return false;
683 if (info->helper) {
684 struct nf_conn_help *help;
685
686 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
687 if (help && rcu_access_pointer(help->helper) != info->helper)
688 return false;
689 }
690 /* Force conntrack entry direction to the current packet? */
691 if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
692 /* Delete the conntrack entry if confirmed, else just release
693 * the reference.
694 */
695 if (nf_ct_is_confirmed(ct))
696 nf_ct_delete(ct, 0, 0);
697
698 nf_conntrack_put(&ct->ct_general);
699 nf_ct_set(skb, NULL, 0);
700 return false;
701 }
702
703 return ct_executed;
704 }
705
706 #ifdef CONFIG_NF_NAT_NEEDED
707 /* Modelled after nf_nat_ipv[46]_fn().
708 * range is only used for new, uninitialized NAT state.
709 * Returns either NF_ACCEPT or NF_DROP.
710 */
711 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
712 enum ip_conntrack_info ctinfo,
713 const struct nf_nat_range *range,
714 enum nf_nat_manip_type maniptype)
715 {
716 int hooknum, nh_off, err = NF_ACCEPT;
717
718 nh_off = skb_network_offset(skb);
719 skb_pull_rcsum(skb, nh_off);
720
721 /* See HOOK2MANIP(). */
722 if (maniptype == NF_NAT_MANIP_SRC)
723 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
724 else
725 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
726
727 switch (ctinfo) {
728 case IP_CT_RELATED:
729 case IP_CT_RELATED_REPLY:
730 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
731 skb->protocol == htons(ETH_P_IP) &&
732 ip_hdr(skb)->protocol == IPPROTO_ICMP) {
733 if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
734 hooknum))
735 err = NF_DROP;
736 goto push;
737 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
738 skb->protocol == htons(ETH_P_IPV6)) {
739 __be16 frag_off;
740 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
741 int hdrlen = ipv6_skip_exthdr(skb,
742 sizeof(struct ipv6hdr),
743 &nexthdr, &frag_off);
744
745 if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
746 if (!nf_nat_icmpv6_reply_translation(skb, ct,
747 ctinfo,
748 hooknum,
749 hdrlen))
750 err = NF_DROP;
751 goto push;
752 }
753 }
754 /* Non-ICMP, fall thru to initialize if needed. */
755 /* fall through */
756 case IP_CT_NEW:
757 /* Seen it before? This can happen for loopback, retrans,
758 * or local packets.
759 */
760 if (!nf_nat_initialized(ct, maniptype)) {
761 /* Initialize according to the NAT action. */
762 err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
763 /* Action is set up to establish a new
764 * mapping.
765 */
766 ? nf_nat_setup_info(ct, range, maniptype)
767 : nf_nat_alloc_null_binding(ct, hooknum);
768 if (err != NF_ACCEPT)
769 goto push;
770 }
771 break;
772
773 case IP_CT_ESTABLISHED:
774 case IP_CT_ESTABLISHED_REPLY:
775 break;
776
777 default:
778 err = NF_DROP;
779 goto push;
780 }
781
782 err = nf_nat_packet(ct, ctinfo, hooknum, skb);
783 push:
784 skb_push(skb, nh_off);
785 skb_postpush_rcsum(skb, skb->data, nh_off);
786
787 return err;
788 }
789
790 static void ovs_nat_update_key(struct sw_flow_key *key,
791 const struct sk_buff *skb,
792 enum nf_nat_manip_type maniptype)
793 {
794 if (maniptype == NF_NAT_MANIP_SRC) {
795 __be16 src;
796
797 key->ct_state |= OVS_CS_F_SRC_NAT;
798 if (key->eth.type == htons(ETH_P_IP))
799 key->ipv4.addr.src = ip_hdr(skb)->saddr;
800 else if (key->eth.type == htons(ETH_P_IPV6))
801 memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
802 sizeof(key->ipv6.addr.src));
803 else
804 return;
805
806 if (key->ip.proto == IPPROTO_UDP)
807 src = udp_hdr(skb)->source;
808 else if (key->ip.proto == IPPROTO_TCP)
809 src = tcp_hdr(skb)->source;
810 else if (key->ip.proto == IPPROTO_SCTP)
811 src = sctp_hdr(skb)->source;
812 else
813 return;
814
815 key->tp.src = src;
816 } else {
817 __be16 dst;
818
819 key->ct_state |= OVS_CS_F_DST_NAT;
820 if (key->eth.type == htons(ETH_P_IP))
821 key->ipv4.addr.dst = ip_hdr(skb)->daddr;
822 else if (key->eth.type == htons(ETH_P_IPV6))
823 memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
824 sizeof(key->ipv6.addr.dst));
825 else
826 return;
827
828 if (key->ip.proto == IPPROTO_UDP)
829 dst = udp_hdr(skb)->dest;
830 else if (key->ip.proto == IPPROTO_TCP)
831 dst = tcp_hdr(skb)->dest;
832 else if (key->ip.proto == IPPROTO_SCTP)
833 dst = sctp_hdr(skb)->dest;
834 else
835 return;
836
837 key->tp.dst = dst;
838 }
839 }
840
841 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
842 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
843 const struct ovs_conntrack_info *info,
844 struct sk_buff *skb, struct nf_conn *ct,
845 enum ip_conntrack_info ctinfo)
846 {
847 enum nf_nat_manip_type maniptype;
848 int err;
849
850 /* Add NAT extension if not confirmed yet. */
851 if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
852 return NF_ACCEPT; /* Can't NAT. */
853
854 /* Determine NAT type.
855 * Check if the NAT type can be deduced from the tracked connection.
856 * Make sure new expected connections (IP_CT_RELATED) are NATted only
857 * when committing.
858 */
859 if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
860 ct->status & IPS_NAT_MASK &&
861 (ctinfo != IP_CT_RELATED || info->commit)) {
862 /* NAT an established or related connection like before. */
863 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
864 /* This is the REPLY direction for a connection
865 * for which NAT was applied in the forward
866 * direction. Do the reverse NAT.
867 */
868 maniptype = ct->status & IPS_SRC_NAT
869 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
870 else
871 maniptype = ct->status & IPS_SRC_NAT
872 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
873 } else if (info->nat & OVS_CT_SRC_NAT) {
874 maniptype = NF_NAT_MANIP_SRC;
875 } else if (info->nat & OVS_CT_DST_NAT) {
876 maniptype = NF_NAT_MANIP_DST;
877 } else {
878 return NF_ACCEPT; /* Connection is not NATed. */
879 }
880 err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
881
882 /* Mark NAT done if successful and update the flow key. */
883 if (err == NF_ACCEPT)
884 ovs_nat_update_key(key, skb, maniptype);
885
886 return err;
887 }
888 #else /* !CONFIG_NF_NAT_NEEDED */
889 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
890 const struct ovs_conntrack_info *info,
891 struct sk_buff *skb, struct nf_conn *ct,
892 enum ip_conntrack_info ctinfo)
893 {
894 return NF_ACCEPT;
895 }
896 #endif
897
898 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
899 * not done already. Update key with new CT state after passing the packet
900 * through conntrack.
901 * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
902 * set to NULL and 0 will be returned.
903 */
904 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
905 const struct ovs_conntrack_info *info,
906 struct sk_buff *skb)
907 {
908 /* If we are recirculating packets to match on conntrack fields and
909 * committing with a separate conntrack action, then we don't need to
910 * actually run the packet through conntrack twice unless it's for a
911 * different zone.
912 */
913 bool cached = skb_nfct_cached(net, key, info, skb);
914 enum ip_conntrack_info ctinfo;
915 struct nf_conn *ct;
916
917 if (!cached) {
918 struct nf_conn *tmpl = info->ct;
919 int err;
920
921 /* Associate skb with specified zone. */
922 if (tmpl) {
923 if (skb_nfct(skb))
924 nf_conntrack_put(skb_nfct(skb));
925 nf_conntrack_get(&tmpl->ct_general);
926 nf_ct_set(skb, tmpl, IP_CT_NEW);
927 }
928
929 err = nf_conntrack_in(net, info->family,
930 NF_INET_PRE_ROUTING, skb);
931 if (err != NF_ACCEPT)
932 return -ENOENT;
933
934 /* Clear CT state NAT flags to mark that we have not yet done
935 * NAT after the nf_conntrack_in() call. We can actually clear
936 * the whole state, as it will be re-initialized below.
937 */
938 key->ct_state = 0;
939
940 /* Update the key, but keep the NAT flags. */
941 ovs_ct_update_key(skb, info, key, true, true);
942 }
943
944 ct = nf_ct_get(skb, &ctinfo);
945 if (ct) {
946 /* Packets starting a new connection must be NATted before the
947 * helper, so that the helper knows about the NAT. We enforce
948 * this by delaying both NAT and helper calls for unconfirmed
949 * connections until the committing CT action. For later
950 * packets NAT and Helper may be called in either order.
951 *
952 * NAT will be done only if the CT action has NAT, and only
953 * once per packet (per zone), as guarded by the NAT bits in
954 * the key->ct_state.
955 */
956 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
957 (nf_ct_is_confirmed(ct) || info->commit) &&
958 ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
959 return -EINVAL;
960 }
961
962 /* Userspace may decide to perform a ct lookup without a helper
963 * specified followed by a (recirculate and) commit with one.
964 * Therefore, for unconfirmed connections which we will commit,
965 * we need to attach the helper here.
966 */
967 if (!nf_ct_is_confirmed(ct) && info->commit &&
968 info->helper && !nfct_help(ct)) {
969 int err = __nf_ct_try_assign_helper(ct, info->ct,
970 GFP_ATOMIC);
971 if (err)
972 return err;
973 }
974
975 /* Call the helper only if:
976 * - nf_conntrack_in() was executed above ("!cached") for a
977 * confirmed connection, or
978 * - When committing an unconfirmed connection.
979 */
980 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
981 ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
982 return -EINVAL;
983 }
984 }
985
986 return 0;
987 }
988
989 /* Lookup connection and read fields into key. */
990 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
991 const struct ovs_conntrack_info *info,
992 struct sk_buff *skb)
993 {
994 struct nf_conntrack_expect *exp;
995
996 /* If we pass an expected packet through nf_conntrack_in() the
997 * expectation is typically removed, but the packet could still be
998 * lost in upcall processing. To prevent this from happening we
999 * perform an explicit expectation lookup. Expected connections are
1000 * always new, and will be passed through conntrack only when they are
1001 * committed, as it is OK to remove the expectation at that time.
1002 */
1003 exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1004 if (exp) {
1005 u8 state;
1006
1007 /* NOTE: New connections are NATted and Helped only when
1008 * committed, so we are not calling into NAT here.
1009 */
1010 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1011 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1012 } else {
1013 struct nf_conn *ct;
1014 int err;
1015
1016 err = __ovs_ct_lookup(net, key, info, skb);
1017 if (err)
1018 return err;
1019
1020 ct = (struct nf_conn *)skb_nfct(skb);
1021 if (ct)
1022 nf_ct_deliver_cached_events(ct);
1023 }
1024
1025 return 0;
1026 }
1027
1028 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1029 {
1030 size_t i;
1031
1032 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1033 if (labels->ct_labels_32[i])
1034 return true;
1035
1036 return false;
1037 }
1038
1039 /* Lookup connection and confirm if unconfirmed. */
1040 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1041 const struct ovs_conntrack_info *info,
1042 struct sk_buff *skb)
1043 {
1044 enum ip_conntrack_info ctinfo;
1045 struct nf_conn *ct;
1046 int err;
1047
1048 err = __ovs_ct_lookup(net, key, info, skb);
1049 if (err)
1050 return err;
1051
1052 /* The connection could be invalid, in which case this is a no-op.*/
1053 ct = nf_ct_get(skb, &ctinfo);
1054 if (!ct)
1055 return 0;
1056
1057 /* Set the conntrack event mask if given. NEW and DELETE events have
1058 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1059 * typically would receive many kinds of updates. Setting the event
1060 * mask allows those events to be filtered. The set event mask will
1061 * remain in effect for the lifetime of the connection unless changed
1062 * by a further CT action with both the commit flag and the eventmask
1063 * option. */
1064 if (info->have_eventmask) {
1065 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1066
1067 if (cache)
1068 cache->ctmask = info->eventmask;
1069 }
1070
1071 /* Apply changes before confirming the connection so that the initial
1072 * conntrack NEW netlink event carries the values given in the CT
1073 * action.
1074 */
1075 if (info->mark.mask) {
1076 err = ovs_ct_set_mark(ct, key, info->mark.value,
1077 info->mark.mask);
1078 if (err)
1079 return err;
1080 }
1081 if (!nf_ct_is_confirmed(ct)) {
1082 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1083 &info->labels.mask);
1084 if (err)
1085 return err;
1086 } else if (labels_nonzero(&info->labels.mask)) {
1087 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1088 &info->labels.mask);
1089 if (err)
1090 return err;
1091 }
1092 /* This will take care of sending queued events even if the connection
1093 * is already confirmed.
1094 */
1095 if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1096 return -EINVAL;
1097
1098 return 0;
1099 }
1100
1101 /* Trim the skb to the length specified by the IP/IPv6 header,
1102 * removing any trailing lower-layer padding. This prepares the skb
1103 * for higher-layer processing that assumes skb->len excludes padding
1104 * (such as nf_ip_checksum). The caller needs to pull the skb to the
1105 * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1106 */
1107 static int ovs_skb_network_trim(struct sk_buff *skb)
1108 {
1109 unsigned int len;
1110 int err;
1111
1112 switch (skb->protocol) {
1113 case htons(ETH_P_IP):
1114 len = ntohs(ip_hdr(skb)->tot_len);
1115 break;
1116 case htons(ETH_P_IPV6):
1117 len = sizeof(struct ipv6hdr)
1118 + ntohs(ipv6_hdr(skb)->payload_len);
1119 break;
1120 default:
1121 len = skb->len;
1122 }
1123
1124 err = pskb_trim_rcsum(skb, len);
1125 if (err)
1126 kfree_skb(skb);
1127
1128 return err;
1129 }
1130
1131 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1132 * value if 'skb' is freed.
1133 */
1134 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1135 struct sw_flow_key *key,
1136 const struct ovs_conntrack_info *info)
1137 {
1138 int nh_ofs;
1139 int err;
1140
1141 /* The conntrack module expects to be working at L3. */
1142 nh_ofs = skb_network_offset(skb);
1143 skb_pull_rcsum(skb, nh_ofs);
1144
1145 err = ovs_skb_network_trim(skb);
1146 if (err)
1147 return err;
1148
1149 if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1150 err = handle_fragments(net, key, info->zone.id, skb);
1151 if (err)
1152 return err;
1153 }
1154
1155 if (info->commit)
1156 err = ovs_ct_commit(net, key, info, skb);
1157 else
1158 err = ovs_ct_lookup(net, key, info, skb);
1159
1160 skb_push(skb, nh_ofs);
1161 skb_postpush_rcsum(skb, skb->data, nh_ofs);
1162 if (err)
1163 kfree_skb(skb);
1164 return err;
1165 }
1166
1167 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1168 {
1169 if (skb_nfct(skb)) {
1170 nf_conntrack_put(skb_nfct(skb));
1171 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1172 ovs_ct_fill_key(skb, key);
1173 }
1174
1175 return 0;
1176 }
1177
1178 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1179 const struct sw_flow_key *key, bool log)
1180 {
1181 struct nf_conntrack_helper *helper;
1182 struct nf_conn_help *help;
1183
1184 helper = nf_conntrack_helper_try_module_get(name, info->family,
1185 key->ip.proto);
1186 if (!helper) {
1187 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1188 return -EINVAL;
1189 }
1190
1191 help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
1192 if (!help) {
1193 nf_conntrack_helper_put(helper);
1194 return -ENOMEM;
1195 }
1196
1197 rcu_assign_pointer(help->helper, helper);
1198 info->helper = helper;
1199 return 0;
1200 }
1201
1202 #ifdef CONFIG_NF_NAT_NEEDED
1203 static int parse_nat(const struct nlattr *attr,
1204 struct ovs_conntrack_info *info, bool log)
1205 {
1206 struct nlattr *a;
1207 int rem;
1208 bool have_ip_max = false;
1209 bool have_proto_max = false;
1210 bool ip_vers = (info->family == NFPROTO_IPV6);
1211
1212 nla_for_each_nested(a, attr, rem) {
1213 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1214 [OVS_NAT_ATTR_SRC] = {0, 0},
1215 [OVS_NAT_ATTR_DST] = {0, 0},
1216 [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1217 sizeof(struct in6_addr)},
1218 [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1219 sizeof(struct in6_addr)},
1220 [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1221 [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1222 [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1223 [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1224 [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1225 };
1226 int type = nla_type(a);
1227
1228 if (type > OVS_NAT_ATTR_MAX) {
1229 OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1230 type, OVS_NAT_ATTR_MAX);
1231 return -EINVAL;
1232 }
1233
1234 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1235 OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1236 type, nla_len(a),
1237 ovs_nat_attr_lens[type][ip_vers]);
1238 return -EINVAL;
1239 }
1240
1241 switch (type) {
1242 case OVS_NAT_ATTR_SRC:
1243 case OVS_NAT_ATTR_DST:
1244 if (info->nat) {
1245 OVS_NLERR(log, "Only one type of NAT may be specified");
1246 return -ERANGE;
1247 }
1248 info->nat |= OVS_CT_NAT;
1249 info->nat |= ((type == OVS_NAT_ATTR_SRC)
1250 ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1251 break;
1252
1253 case OVS_NAT_ATTR_IP_MIN:
1254 nla_memcpy(&info->range.min_addr, a,
1255 sizeof(info->range.min_addr));
1256 info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1257 break;
1258
1259 case OVS_NAT_ATTR_IP_MAX:
1260 have_ip_max = true;
1261 nla_memcpy(&info->range.max_addr, a,
1262 sizeof(info->range.max_addr));
1263 info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1264 break;
1265
1266 case OVS_NAT_ATTR_PROTO_MIN:
1267 info->range.min_proto.all = htons(nla_get_u16(a));
1268 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1269 break;
1270
1271 case OVS_NAT_ATTR_PROTO_MAX:
1272 have_proto_max = true;
1273 info->range.max_proto.all = htons(nla_get_u16(a));
1274 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1275 break;
1276
1277 case OVS_NAT_ATTR_PERSISTENT:
1278 info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1279 break;
1280
1281 case OVS_NAT_ATTR_PROTO_HASH:
1282 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1283 break;
1284
1285 case OVS_NAT_ATTR_PROTO_RANDOM:
1286 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1287 break;
1288
1289 default:
1290 OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1291 return -EINVAL;
1292 }
1293 }
1294
1295 if (rem > 0) {
1296 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1297 return -EINVAL;
1298 }
1299 if (!info->nat) {
1300 /* Do not allow flags if no type is given. */
1301 if (info->range.flags) {
1302 OVS_NLERR(log,
1303 "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1304 );
1305 return -EINVAL;
1306 }
1307 info->nat = OVS_CT_NAT; /* NAT existing connections. */
1308 } else if (!info->commit) {
1309 OVS_NLERR(log,
1310 "NAT attributes may be specified only when CT COMMIT flag is also specified."
1311 );
1312 return -EINVAL;
1313 }
1314 /* Allow missing IP_MAX. */
1315 if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1316 memcpy(&info->range.max_addr, &info->range.min_addr,
1317 sizeof(info->range.max_addr));
1318 }
1319 /* Allow missing PROTO_MAX. */
1320 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1321 !have_proto_max) {
1322 info->range.max_proto.all = info->range.min_proto.all;
1323 }
1324 return 0;
1325 }
1326 #endif
1327
1328 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1329 [OVS_CT_ATTR_COMMIT] = { .minlen = 0, .maxlen = 0 },
1330 [OVS_CT_ATTR_FORCE_COMMIT] = { .minlen = 0, .maxlen = 0 },
1331 [OVS_CT_ATTR_ZONE] = { .minlen = sizeof(u16),
1332 .maxlen = sizeof(u16) },
1333 [OVS_CT_ATTR_MARK] = { .minlen = sizeof(struct md_mark),
1334 .maxlen = sizeof(struct md_mark) },
1335 [OVS_CT_ATTR_LABELS] = { .minlen = sizeof(struct md_labels),
1336 .maxlen = sizeof(struct md_labels) },
1337 [OVS_CT_ATTR_HELPER] = { .minlen = 1,
1338 .maxlen = NF_CT_HELPER_NAME_LEN },
1339 #ifdef CONFIG_NF_NAT_NEEDED
1340 /* NAT length is checked when parsing the nested attributes. */
1341 [OVS_CT_ATTR_NAT] = { .minlen = 0, .maxlen = INT_MAX },
1342 #endif
1343 [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1344 .maxlen = sizeof(u32) },
1345 };
1346
1347 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1348 const char **helper, bool log)
1349 {
1350 struct nlattr *a;
1351 int rem;
1352
1353 nla_for_each_nested(a, attr, rem) {
1354 int type = nla_type(a);
1355 int maxlen;
1356 int minlen;
1357
1358 if (type > OVS_CT_ATTR_MAX) {
1359 OVS_NLERR(log,
1360 "Unknown conntrack attr (type=%d, max=%d)",
1361 type, OVS_CT_ATTR_MAX);
1362 return -EINVAL;
1363 }
1364
1365 maxlen = ovs_ct_attr_lens[type].maxlen;
1366 minlen = ovs_ct_attr_lens[type].minlen;
1367 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1368 OVS_NLERR(log,
1369 "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1370 type, nla_len(a), maxlen);
1371 return -EINVAL;
1372 }
1373
1374 switch (type) {
1375 case OVS_CT_ATTR_FORCE_COMMIT:
1376 info->force = true;
1377 /* fall through. */
1378 case OVS_CT_ATTR_COMMIT:
1379 info->commit = true;
1380 break;
1381 #ifdef CONFIG_NF_CONNTRACK_ZONES
1382 case OVS_CT_ATTR_ZONE:
1383 info->zone.id = nla_get_u16(a);
1384 break;
1385 #endif
1386 #ifdef CONFIG_NF_CONNTRACK_MARK
1387 case OVS_CT_ATTR_MARK: {
1388 struct md_mark *mark = nla_data(a);
1389
1390 if (!mark->mask) {
1391 OVS_NLERR(log, "ct_mark mask cannot be 0");
1392 return -EINVAL;
1393 }
1394 info->mark = *mark;
1395 break;
1396 }
1397 #endif
1398 #ifdef CONFIG_NF_CONNTRACK_LABELS
1399 case OVS_CT_ATTR_LABELS: {
1400 struct md_labels *labels = nla_data(a);
1401
1402 if (!labels_nonzero(&labels->mask)) {
1403 OVS_NLERR(log, "ct_labels mask cannot be 0");
1404 return -EINVAL;
1405 }
1406 info->labels = *labels;
1407 break;
1408 }
1409 #endif
1410 case OVS_CT_ATTR_HELPER:
1411 *helper = nla_data(a);
1412 if (!memchr(*helper, '\0', nla_len(a))) {
1413 OVS_NLERR(log, "Invalid conntrack helper");
1414 return -EINVAL;
1415 }
1416 break;
1417 #ifdef CONFIG_NF_NAT_NEEDED
1418 case OVS_CT_ATTR_NAT: {
1419 int err = parse_nat(a, info, log);
1420
1421 if (err)
1422 return err;
1423 break;
1424 }
1425 #endif
1426 case OVS_CT_ATTR_EVENTMASK:
1427 info->have_eventmask = true;
1428 info->eventmask = nla_get_u32(a);
1429 break;
1430
1431 default:
1432 OVS_NLERR(log, "Unknown conntrack attr (%d)",
1433 type);
1434 return -EINVAL;
1435 }
1436 }
1437
1438 #ifdef CONFIG_NF_CONNTRACK_MARK
1439 if (!info->commit && info->mark.mask) {
1440 OVS_NLERR(log,
1441 "Setting conntrack mark requires 'commit' flag.");
1442 return -EINVAL;
1443 }
1444 #endif
1445 #ifdef CONFIG_NF_CONNTRACK_LABELS
1446 if (!info->commit && labels_nonzero(&info->labels.mask)) {
1447 OVS_NLERR(log,
1448 "Setting conntrack labels requires 'commit' flag.");
1449 return -EINVAL;
1450 }
1451 #endif
1452 if (rem > 0) {
1453 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1454 return -EINVAL;
1455 }
1456
1457 return 0;
1458 }
1459
1460 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1461 {
1462 if (attr == OVS_KEY_ATTR_CT_STATE)
1463 return true;
1464 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1465 attr == OVS_KEY_ATTR_CT_ZONE)
1466 return true;
1467 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1468 attr == OVS_KEY_ATTR_CT_MARK)
1469 return true;
1470 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1471 attr == OVS_KEY_ATTR_CT_LABELS) {
1472 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1473
1474 return ovs_net->xt_label;
1475 }
1476
1477 return false;
1478 }
1479
1480 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1481 const struct sw_flow_key *key,
1482 struct sw_flow_actions **sfa, bool log)
1483 {
1484 struct ovs_conntrack_info ct_info;
1485 const char *helper = NULL;
1486 u16 family;
1487 int err;
1488
1489 family = key_to_nfproto(key);
1490 if (family == NFPROTO_UNSPEC) {
1491 OVS_NLERR(log, "ct family unspecified");
1492 return -EINVAL;
1493 }
1494
1495 memset(&ct_info, 0, sizeof(ct_info));
1496 ct_info.family = family;
1497
1498 nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1499 NF_CT_DEFAULT_ZONE_DIR, 0);
1500
1501 err = parse_ct(attr, &ct_info, &helper, log);
1502 if (err)
1503 return err;
1504
1505 /* Set up template for tracking connections in specific zones. */
1506 ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1507 if (!ct_info.ct) {
1508 OVS_NLERR(log, "Failed to allocate conntrack template");
1509 return -ENOMEM;
1510 }
1511
1512 __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1513 nf_conntrack_get(&ct_info.ct->ct_general);
1514
1515 if (helper) {
1516 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1517 if (err)
1518 goto err_free_ct;
1519 }
1520
1521 err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1522 sizeof(ct_info), log);
1523 if (err)
1524 goto err_free_ct;
1525
1526 return 0;
1527 err_free_ct:
1528 __ovs_ct_free_action(&ct_info);
1529 return err;
1530 }
1531
1532 #ifdef CONFIG_NF_NAT_NEEDED
1533 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1534 struct sk_buff *skb)
1535 {
1536 struct nlattr *start;
1537
1538 start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1539 if (!start)
1540 return false;
1541
1542 if (info->nat & OVS_CT_SRC_NAT) {
1543 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1544 return false;
1545 } else if (info->nat & OVS_CT_DST_NAT) {
1546 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1547 return false;
1548 } else {
1549 goto out;
1550 }
1551
1552 if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1553 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1554 info->family == NFPROTO_IPV4) {
1555 if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1556 info->range.min_addr.ip) ||
1557 (info->range.max_addr.ip
1558 != info->range.min_addr.ip &&
1559 (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1560 info->range.max_addr.ip))))
1561 return false;
1562 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1563 info->family == NFPROTO_IPV6) {
1564 if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1565 &info->range.min_addr.in6) ||
1566 (memcmp(&info->range.max_addr.in6,
1567 &info->range.min_addr.in6,
1568 sizeof(info->range.max_addr.in6)) &&
1569 (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1570 &info->range.max_addr.in6))))
1571 return false;
1572 } else {
1573 return false;
1574 }
1575 }
1576 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1577 (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1578 ntohs(info->range.min_proto.all)) ||
1579 (info->range.max_proto.all != info->range.min_proto.all &&
1580 nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1581 ntohs(info->range.max_proto.all)))))
1582 return false;
1583
1584 if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1585 nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1586 return false;
1587 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1588 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1589 return false;
1590 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1591 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1592 return false;
1593 out:
1594 nla_nest_end(skb, start);
1595
1596 return true;
1597 }
1598 #endif
1599
1600 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1601 struct sk_buff *skb)
1602 {
1603 struct nlattr *start;
1604
1605 start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1606 if (!start)
1607 return -EMSGSIZE;
1608
1609 if (ct_info->commit && nla_put_flag(skb, ct_info->force
1610 ? OVS_CT_ATTR_FORCE_COMMIT
1611 : OVS_CT_ATTR_COMMIT))
1612 return -EMSGSIZE;
1613 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1614 nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1615 return -EMSGSIZE;
1616 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1617 nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1618 &ct_info->mark))
1619 return -EMSGSIZE;
1620 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1621 labels_nonzero(&ct_info->labels.mask) &&
1622 nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1623 &ct_info->labels))
1624 return -EMSGSIZE;
1625 if (ct_info->helper) {
1626 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1627 ct_info->helper->name))
1628 return -EMSGSIZE;
1629 }
1630 if (ct_info->have_eventmask &&
1631 nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1632 return -EMSGSIZE;
1633
1634 #ifdef CONFIG_NF_NAT_NEEDED
1635 if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1636 return -EMSGSIZE;
1637 #endif
1638 nla_nest_end(skb, start);
1639
1640 return 0;
1641 }
1642
1643 void ovs_ct_free_action(const struct nlattr *a)
1644 {
1645 struct ovs_conntrack_info *ct_info = nla_data(a);
1646
1647 __ovs_ct_free_action(ct_info);
1648 }
1649
1650 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1651 {
1652 if (ct_info->helper)
1653 nf_conntrack_helper_put(ct_info->helper);
1654 if (ct_info->ct)
1655 nf_ct_tmpl_free(ct_info->ct);
1656 }
1657
1658 void ovs_ct_init(struct net *net)
1659 {
1660 unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1661 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1662
1663 if (nf_connlabels_get(net, n_bits - 1)) {
1664 ovs_net->xt_label = false;
1665 OVS_NLERR(true, "Failed to set connlabel length");
1666 } else {
1667 ovs_net->xt_label = true;
1668 }
1669 }
1670
1671 void ovs_ct_exit(struct net *net)
1672 {
1673 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1674
1675 if (ovs_net->xt_label)
1676 nf_connlabels_put(net);
1677 }
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