1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2015 Nicira, Inc.
4 */
5
6 #include <linux/module.h>
7 #include <linux/openvswitch.h>
8 #include <linux/tcp.h>
9 #include <linux/udp.h>
10 #include <linux/sctp.h>
11 #include <linux/static_key.h>
12 #include <net/ip.h>
13 #include <net/genetlink.h>
14 #include <net/netfilter/nf_conntrack_core.h>
15 #include <net/netfilter/nf_conntrack_count.h>
16 #include <net/netfilter/nf_conntrack_helper.h>
17 #include <net/netfilter/nf_conntrack_labels.h>
18 #include <net/netfilter/nf_conntrack_seqadj.h>
19 #include <net/netfilter/nf_conntrack_timeout.h>
20 #include <net/netfilter/nf_conntrack_zones.h>
21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
22 #include <net/ipv6_frag.h>
23
24 #if IS_ENABLED(CONFIG_NF_NAT)
25 #include <net/netfilter/nf_nat.h>
26 #endif
27
28 #include "datapath.h"
29 #include "conntrack.h"
30 #include "flow.h"
31 #include "flow_netlink.h"
32
33 struct ovs_ct_len_tbl {
34 int maxlen;
35 int minlen;
36 };
37
38 /* Metadata mark for masked write to conntrack mark */
39 struct md_mark {
40 u32 value;
41 u32 mask;
42 };
43
44 /* Metadata label for masked write to conntrack label. */
45 struct md_labels {
46 struct ovs_key_ct_labels value;
47 struct ovs_key_ct_labels mask;
48 };
49
50 enum ovs_ct_nat {
51 OVS_CT_NAT = 1 << 0, /* NAT for committed connections only. */
52 OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
53 OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
54 };
55
56 /* Conntrack action context for execution. */
57 struct ovs_conntrack_info {
58 struct nf_conntrack_helper *helper;
59 struct nf_conntrack_zone zone;
60 struct nf_conn *ct;
61 u8 commit : 1;
62 u8 nat : 3; /* enum ovs_ct_nat */
63 u8 force : 1;
64 u8 have_eventmask : 1;
65 u16 family;
66 u32 eventmask; /* Mask of 1 << IPCT_*. */
67 struct md_mark mark;
68 struct md_labels labels;
69 char timeout[CTNL_TIMEOUT_NAME_MAX];
70 struct nf_ct_timeout *nf_ct_timeout;
71 #if IS_ENABLED(CONFIG_NF_NAT)
72 struct nf_nat_range2 range; /* Only present for SRC NAT and DST NAT. */
73 #endif
74 };
75
76 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
77 #define OVS_CT_LIMIT_UNLIMITED 0
78 #define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
79 #define CT_LIMIT_HASH_BUCKETS 512
80 static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
81
82 struct ovs_ct_limit {
83 /* Elements in ovs_ct_limit_info->limits hash table */
84 struct hlist_node hlist_node;
85 struct rcu_head rcu;
86 u16 zone;
87 u32 limit;
88 };
89
90 struct ovs_ct_limit_info {
91 u32 default_limit;
92 struct hlist_head *limits;
93 struct nf_conncount_data *data;
94 };
95
96 static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
97 [OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
98 };
99 #endif
100
101 static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
102
103 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
104
key_to_nfproto(const struct sw_flow_key * key)105 static u16 key_to_nfproto(const struct sw_flow_key *key)
106 {
107 switch (ntohs(key->eth.type)) {
108 case ETH_P_IP:
109 return NFPROTO_IPV4;
110 case ETH_P_IPV6:
111 return NFPROTO_IPV6;
112 default:
113 return NFPROTO_UNSPEC;
114 }
115 }
116
117 /* Map SKB connection state into the values used by flow definition. */
ovs_ct_get_state(enum ip_conntrack_info ctinfo)118 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
119 {
120 u8 ct_state = OVS_CS_F_TRACKED;
121
122 switch (ctinfo) {
123 case IP_CT_ESTABLISHED_REPLY:
124 case IP_CT_RELATED_REPLY:
125 ct_state |= OVS_CS_F_REPLY_DIR;
126 break;
127 default:
128 break;
129 }
130
131 switch (ctinfo) {
132 case IP_CT_ESTABLISHED:
133 case IP_CT_ESTABLISHED_REPLY:
134 ct_state |= OVS_CS_F_ESTABLISHED;
135 break;
136 case IP_CT_RELATED:
137 case IP_CT_RELATED_REPLY:
138 ct_state |= OVS_CS_F_RELATED;
139 break;
140 case IP_CT_NEW:
141 ct_state |= OVS_CS_F_NEW;
142 break;
143 default:
144 break;
145 }
146
147 return ct_state;
148 }
149
ovs_ct_get_mark(const struct nf_conn * ct)150 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
151 {
152 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
153 return ct ? READ_ONCE(ct->mark) : 0;
154 #else
155 return 0;
156 #endif
157 }
158
159 /* Guard against conntrack labels max size shrinking below 128 bits. */
160 #if NF_CT_LABELS_MAX_SIZE < 16
161 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
162 #endif
163
ovs_ct_get_labels(const struct nf_conn * ct,struct ovs_key_ct_labels * labels)164 static void ovs_ct_get_labels(const struct nf_conn *ct,
165 struct ovs_key_ct_labels *labels)
166 {
167 struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
168
169 if (cl)
170 memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
171 else
172 memset(labels, 0, OVS_CT_LABELS_LEN);
173 }
174
__ovs_ct_update_key_orig_tp(struct sw_flow_key * key,const struct nf_conntrack_tuple * orig,u8 icmp_proto)175 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
176 const struct nf_conntrack_tuple *orig,
177 u8 icmp_proto)
178 {
179 key->ct_orig_proto = orig->dst.protonum;
180 if (orig->dst.protonum == icmp_proto) {
181 key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
182 key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
183 } else {
184 key->ct.orig_tp.src = orig->src.u.all;
185 key->ct.orig_tp.dst = orig->dst.u.all;
186 }
187 }
188
__ovs_ct_update_key(struct sw_flow_key * key,u8 state,const struct nf_conntrack_zone * zone,const struct nf_conn * ct)189 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
190 const struct nf_conntrack_zone *zone,
191 const struct nf_conn *ct)
192 {
193 key->ct_state = state;
194 key->ct_zone = zone->id;
195 key->ct.mark = ovs_ct_get_mark(ct);
196 ovs_ct_get_labels(ct, &key->ct.labels);
197
198 if (ct) {
199 const struct nf_conntrack_tuple *orig;
200
201 /* Use the master if we have one. */
202 if (ct->master)
203 ct = ct->master;
204 orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
205
206 /* IP version must match with the master connection. */
207 if (key->eth.type == htons(ETH_P_IP) &&
208 nf_ct_l3num(ct) == NFPROTO_IPV4) {
209 key->ipv4.ct_orig.src = orig->src.u3.ip;
210 key->ipv4.ct_orig.dst = orig->dst.u3.ip;
211 __ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
212 return;
213 } else if (key->eth.type == htons(ETH_P_IPV6) &&
214 !sw_flow_key_is_nd(key) &&
215 nf_ct_l3num(ct) == NFPROTO_IPV6) {
216 key->ipv6.ct_orig.src = orig->src.u3.in6;
217 key->ipv6.ct_orig.dst = orig->dst.u3.in6;
218 __ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
219 return;
220 }
221 }
222 /* Clear 'ct_orig_proto' to mark the non-existence of conntrack
223 * original direction key fields.
224 */
225 key->ct_orig_proto = 0;
226 }
227
228 /* Update 'key' based on skb->_nfct. If 'post_ct' is true, then OVS has
229 * previously sent the packet to conntrack via the ct action. If
230 * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
231 * initialized from the connection status.
232 */
ovs_ct_update_key(const struct sk_buff * skb,const struct ovs_conntrack_info * info,struct sw_flow_key * key,bool post_ct,bool keep_nat_flags)233 static void ovs_ct_update_key(const struct sk_buff *skb,
234 const struct ovs_conntrack_info *info,
235 struct sw_flow_key *key, bool post_ct,
236 bool keep_nat_flags)
237 {
238 const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
239 enum ip_conntrack_info ctinfo;
240 struct nf_conn *ct;
241 u8 state = 0;
242
243 ct = nf_ct_get(skb, &ctinfo);
244 if (ct) {
245 state = ovs_ct_get_state(ctinfo);
246 /* All unconfirmed entries are NEW connections. */
247 if (!nf_ct_is_confirmed(ct))
248 state |= OVS_CS_F_NEW;
249 /* OVS persists the related flag for the duration of the
250 * connection.
251 */
252 if (ct->master)
253 state |= OVS_CS_F_RELATED;
254 if (keep_nat_flags) {
255 state |= key->ct_state & OVS_CS_F_NAT_MASK;
256 } else {
257 if (ct->status & IPS_SRC_NAT)
258 state |= OVS_CS_F_SRC_NAT;
259 if (ct->status & IPS_DST_NAT)
260 state |= OVS_CS_F_DST_NAT;
261 }
262 zone = nf_ct_zone(ct);
263 } else if (post_ct) {
264 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
265 if (info)
266 zone = &info->zone;
267 }
268 __ovs_ct_update_key(key, state, zone, ct);
269 }
270
271 /* This is called to initialize CT key fields possibly coming in from the local
272 * stack.
273 */
ovs_ct_fill_key(const struct sk_buff * skb,struct sw_flow_key * key)274 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
275 {
276 ovs_ct_update_key(skb, NULL, key, false, false);
277 }
278
ovs_ct_put_key(const struct sw_flow_key * swkey,const struct sw_flow_key * output,struct sk_buff * skb)279 int ovs_ct_put_key(const struct sw_flow_key *swkey,
280 const struct sw_flow_key *output, struct sk_buff *skb)
281 {
282 if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
283 return -EMSGSIZE;
284
285 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
286 nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
287 return -EMSGSIZE;
288
289 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
290 nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
291 return -EMSGSIZE;
292
293 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
294 nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
295 &output->ct.labels))
296 return -EMSGSIZE;
297
298 if (swkey->ct_orig_proto) {
299 if (swkey->eth.type == htons(ETH_P_IP)) {
300 struct ovs_key_ct_tuple_ipv4 orig;
301
302 memset(&orig, 0, sizeof(orig));
303 orig.ipv4_src = output->ipv4.ct_orig.src;
304 orig.ipv4_dst = output->ipv4.ct_orig.dst;
305 orig.src_port = output->ct.orig_tp.src;
306 orig.dst_port = output->ct.orig_tp.dst;
307 orig.ipv4_proto = output->ct_orig_proto;
308
309 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
310 sizeof(orig), &orig))
311 return -EMSGSIZE;
312 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
313 struct ovs_key_ct_tuple_ipv6 orig;
314
315 memset(&orig, 0, sizeof(orig));
316 memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
317 sizeof(orig.ipv6_src));
318 memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
319 sizeof(orig.ipv6_dst));
320 orig.src_port = output->ct.orig_tp.src;
321 orig.dst_port = output->ct.orig_tp.dst;
322 orig.ipv6_proto = output->ct_orig_proto;
323
324 if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
325 sizeof(orig), &orig))
326 return -EMSGSIZE;
327 }
328 }
329
330 return 0;
331 }
332
ovs_ct_set_mark(struct nf_conn * ct,struct sw_flow_key * key,u32 ct_mark,u32 mask)333 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
334 u32 ct_mark, u32 mask)
335 {
336 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
337 u32 new_mark;
338
339 new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
340 if (READ_ONCE(ct->mark) != new_mark) {
341 WRITE_ONCE(ct->mark, new_mark);
342 if (nf_ct_is_confirmed(ct))
343 nf_conntrack_event_cache(IPCT_MARK, ct);
344 key->ct.mark = new_mark;
345 }
346
347 return 0;
348 #else
349 return -ENOTSUPP;
350 #endif
351 }
352
ovs_ct_get_conn_labels(struct nf_conn * ct)353 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
354 {
355 struct nf_conn_labels *cl;
356
357 cl = nf_ct_labels_find(ct);
358 if (!cl) {
359 nf_ct_labels_ext_add(ct);
360 cl = nf_ct_labels_find(ct);
361 }
362
363 return cl;
364 }
365
366 /* Initialize labels for a new, yet to be committed conntrack entry. Note that
367 * since the new connection is not yet confirmed, and thus no-one else has
368 * access to it's labels, we simply write them over.
369 */
ovs_ct_init_labels(struct nf_conn * ct,struct sw_flow_key * key,const struct ovs_key_ct_labels * labels,const struct ovs_key_ct_labels * mask)370 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
371 const struct ovs_key_ct_labels *labels,
372 const struct ovs_key_ct_labels *mask)
373 {
374 struct nf_conn_labels *cl, *master_cl;
375 bool have_mask = labels_nonzero(mask);
376
377 /* Inherit master's labels to the related connection? */
378 master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
379
380 if (!master_cl && !have_mask)
381 return 0; /* Nothing to do. */
382
383 cl = ovs_ct_get_conn_labels(ct);
384 if (!cl)
385 return -ENOSPC;
386
387 /* Inherit the master's labels, if any. */
388 if (master_cl)
389 *cl = *master_cl;
390
391 if (have_mask) {
392 u32 *dst = (u32 *)cl->bits;
393 int i;
394
395 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
396 dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
397 (labels->ct_labels_32[i]
398 & mask->ct_labels_32[i]);
399 }
400
401 /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
402 * IPCT_LABEL bit is set in the event cache.
403 */
404 nf_conntrack_event_cache(IPCT_LABEL, ct);
405
406 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
407
408 return 0;
409 }
410
ovs_ct_set_labels(struct nf_conn * ct,struct sw_flow_key * key,const struct ovs_key_ct_labels * labels,const struct ovs_key_ct_labels * mask)411 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
412 const struct ovs_key_ct_labels *labels,
413 const struct ovs_key_ct_labels *mask)
414 {
415 struct nf_conn_labels *cl;
416 int err;
417
418 cl = ovs_ct_get_conn_labels(ct);
419 if (!cl)
420 return -ENOSPC;
421
422 err = nf_connlabels_replace(ct, labels->ct_labels_32,
423 mask->ct_labels_32,
424 OVS_CT_LABELS_LEN_32);
425 if (err)
426 return err;
427
428 memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
429
430 return 0;
431 }
432
433 /* 'skb' should already be pulled to nh_ofs. */
ovs_ct_helper(struct sk_buff * skb,u16 proto)434 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
435 {
436 const struct nf_conntrack_helper *helper;
437 const struct nf_conn_help *help;
438 enum ip_conntrack_info ctinfo;
439 unsigned int protoff;
440 struct nf_conn *ct;
441 int err;
442
443 ct = nf_ct_get(skb, &ctinfo);
444 if (!ct || ctinfo == IP_CT_RELATED_REPLY)
445 return NF_ACCEPT;
446
447 help = nfct_help(ct);
448 if (!help)
449 return NF_ACCEPT;
450
451 helper = rcu_dereference(help->helper);
452 if (!helper)
453 return NF_ACCEPT;
454
455 switch (proto) {
456 case NFPROTO_IPV4:
457 protoff = ip_hdrlen(skb);
458 break;
459 case NFPROTO_IPV6: {
460 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
461 __be16 frag_off;
462 int ofs;
463
464 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
465 &frag_off);
466 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
467 pr_debug("proto header not found\n");
468 return NF_ACCEPT;
469 }
470 protoff = ofs;
471 break;
472 }
473 default:
474 WARN_ONCE(1, "helper invoked on non-IP family!");
475 return NF_DROP;
476 }
477
478 err = helper->help(skb, protoff, ct, ctinfo);
479 if (err != NF_ACCEPT)
480 return err;
481
482 /* Adjust seqs after helper. This is needed due to some helpers (e.g.,
483 * FTP with NAT) adusting the TCP payload size when mangling IP
484 * addresses and/or port numbers in the text-based control connection.
485 */
486 if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
487 !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
488 return NF_DROP;
489 return NF_ACCEPT;
490 }
491
492 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
493 * value if 'skb' is freed.
494 */
handle_fragments(struct net * net,struct sw_flow_key * key,u16 zone,struct sk_buff * skb)495 static int handle_fragments(struct net *net, struct sw_flow_key *key,
496 u16 zone, struct sk_buff *skb)
497 {
498 struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
499 int err;
500
501 if (key->eth.type == htons(ETH_P_IP)) {
502 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
503
504 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
505 err = ip_defrag(net, skb, user);
506 if (err)
507 return err;
508
509 ovs_cb.mru = IPCB(skb)->frag_max_size;
510 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
511 } else if (key->eth.type == htons(ETH_P_IPV6)) {
512 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
513
514 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
515 err = nf_ct_frag6_gather(net, skb, user);
516 if (err) {
517 if (err != -EINPROGRESS)
518 kfree_skb(skb);
519 return err;
520 }
521
522 key->ip.proto = ipv6_hdr(skb)->nexthdr;
523 ovs_cb.mru = IP6CB(skb)->frag_max_size;
524 #endif
525 } else {
526 kfree_skb(skb);
527 return -EPFNOSUPPORT;
528 }
529
530 /* The key extracted from the fragment that completed this datagram
531 * likely didn't have an L4 header, so regenerate it.
532 */
533 ovs_flow_key_update_l3l4(skb, key);
534
535 key->ip.frag = OVS_FRAG_TYPE_NONE;
536 skb_clear_hash(skb);
537 skb->ignore_df = 1;
538 *OVS_CB(skb) = ovs_cb;
539
540 return 0;
541 }
542
543 static struct nf_conntrack_expect *
ovs_ct_expect_find(struct net * net,const struct nf_conntrack_zone * zone,u16 proto,const struct sk_buff * skb)544 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
545 u16 proto, const struct sk_buff *skb)
546 {
547 struct nf_conntrack_tuple tuple;
548 struct nf_conntrack_expect *exp;
549
550 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
551 return NULL;
552
553 exp = __nf_ct_expect_find(net, zone, &tuple);
554 if (exp) {
555 struct nf_conntrack_tuple_hash *h;
556
557 /* Delete existing conntrack entry, if it clashes with the
558 * expectation. This can happen since conntrack ALGs do not
559 * check for clashes between (new) expectations and existing
560 * conntrack entries. nf_conntrack_in() will check the
561 * expectations only if a conntrack entry can not be found,
562 * which can lead to OVS finding the expectation (here) in the
563 * init direction, but which will not be removed by the
564 * nf_conntrack_in() call, if a matching conntrack entry is
565 * found instead. In this case all init direction packets
566 * would be reported as new related packets, while reply
567 * direction packets would be reported as un-related
568 * established packets.
569 */
570 h = nf_conntrack_find_get(net, zone, &tuple);
571 if (h) {
572 struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
573
574 nf_ct_delete(ct, 0, 0);
575 nf_conntrack_put(&ct->ct_general);
576 }
577 }
578
579 return exp;
580 }
581
582 /* This replicates logic from nf_conntrack_core.c that is not exported. */
583 static enum ip_conntrack_info
ovs_ct_get_info(const struct nf_conntrack_tuple_hash * h)584 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
585 {
586 const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
587
588 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
589 return IP_CT_ESTABLISHED_REPLY;
590 /* Once we've had two way comms, always ESTABLISHED. */
591 if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
592 return IP_CT_ESTABLISHED;
593 if (test_bit(IPS_EXPECTED_BIT, &ct->status))
594 return IP_CT_RELATED;
595 return IP_CT_NEW;
596 }
597
598 /* Find an existing connection which this packet belongs to without
599 * re-attributing statistics or modifying the connection state. This allows an
600 * skb->_nfct lost due to an upcall to be recovered during actions execution.
601 *
602 * Must be called with rcu_read_lock.
603 *
604 * On success, populates skb->_nfct and returns the connection. Returns NULL
605 * if there is no existing entry.
606 */
607 static struct nf_conn *
ovs_ct_find_existing(struct net * net,const struct nf_conntrack_zone * zone,u8 l3num,struct sk_buff * skb,bool natted)608 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
609 u8 l3num, struct sk_buff *skb, bool natted)
610 {
611 struct nf_conntrack_tuple tuple;
612 struct nf_conntrack_tuple_hash *h;
613 struct nf_conn *ct;
614
615 if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
616 net, &tuple)) {
617 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
618 return NULL;
619 }
620
621 /* Must invert the tuple if skb has been transformed by NAT. */
622 if (natted) {
623 struct nf_conntrack_tuple inverse;
624
625 if (!nf_ct_invert_tuple(&inverse, &tuple)) {
626 pr_debug("ovs_ct_find_existing: Inversion failed!\n");
627 return NULL;
628 }
629 tuple = inverse;
630 }
631
632 /* look for tuple match */
633 h = nf_conntrack_find_get(net, zone, &tuple);
634 if (!h)
635 return NULL; /* Not found. */
636
637 ct = nf_ct_tuplehash_to_ctrack(h);
638
639 /* Inverted packet tuple matches the reverse direction conntrack tuple,
640 * select the other tuplehash to get the right 'ctinfo' bits for this
641 * packet.
642 */
643 if (natted)
644 h = &ct->tuplehash[!h->tuple.dst.dir];
645
646 nf_ct_set(skb, ct, ovs_ct_get_info(h));
647 return ct;
648 }
649
650 static
ovs_ct_executed(struct net * net,const struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb,bool * ct_executed)651 struct nf_conn *ovs_ct_executed(struct net *net,
652 const struct sw_flow_key *key,
653 const struct ovs_conntrack_info *info,
654 struct sk_buff *skb,
655 bool *ct_executed)
656 {
657 struct nf_conn *ct = NULL;
658
659 /* If no ct, check if we have evidence that an existing conntrack entry
660 * might be found for this skb. This happens when we lose a skb->_nfct
661 * due to an upcall, or if the direction is being forced. If the
662 * connection was not confirmed, it is not cached and needs to be run
663 * through conntrack again.
664 */
665 *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
666 !(key->ct_state & OVS_CS_F_INVALID) &&
667 (key->ct_zone == info->zone.id);
668
669 if (*ct_executed || (!key->ct_state && info->force)) {
670 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
671 !!(key->ct_state &
672 OVS_CS_F_NAT_MASK));
673 }
674
675 return ct;
676 }
677
678 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
skb_nfct_cached(struct net * net,const struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb)679 static bool skb_nfct_cached(struct net *net,
680 const struct sw_flow_key *key,
681 const struct ovs_conntrack_info *info,
682 struct sk_buff *skb)
683 {
684 enum ip_conntrack_info ctinfo;
685 struct nf_conn *ct;
686 bool ct_executed = true;
687
688 ct = nf_ct_get(skb, &ctinfo);
689 if (!ct)
690 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
691
692 if (ct)
693 nf_ct_get(skb, &ctinfo);
694 else
695 return false;
696
697 if (!net_eq(net, read_pnet(&ct->ct_net)))
698 return false;
699 if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
700 return false;
701 if (info->helper) {
702 struct nf_conn_help *help;
703
704 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
705 if (help && rcu_access_pointer(help->helper) != info->helper)
706 return false;
707 }
708 if (info->nf_ct_timeout) {
709 struct nf_conn_timeout *timeout_ext;
710
711 timeout_ext = nf_ct_timeout_find(ct);
712 if (!timeout_ext || info->nf_ct_timeout !=
713 rcu_dereference(timeout_ext->timeout))
714 return false;
715 }
716 /* Force conntrack entry direction to the current packet? */
717 if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
718 /* Delete the conntrack entry if confirmed, else just release
719 * the reference.
720 */
721 if (nf_ct_is_confirmed(ct))
722 nf_ct_delete(ct, 0, 0);
723
724 nf_conntrack_put(&ct->ct_general);
725 nf_ct_set(skb, NULL, 0);
726 return false;
727 }
728
729 return ct_executed;
730 }
731
732 #if IS_ENABLED(CONFIG_NF_NAT)
ovs_nat_update_key(struct sw_flow_key * key,const struct sk_buff * skb,enum nf_nat_manip_type maniptype)733 static void ovs_nat_update_key(struct sw_flow_key *key,
734 const struct sk_buff *skb,
735 enum nf_nat_manip_type maniptype)
736 {
737 if (maniptype == NF_NAT_MANIP_SRC) {
738 __be16 src;
739
740 key->ct_state |= OVS_CS_F_SRC_NAT;
741 if (key->eth.type == htons(ETH_P_IP))
742 key->ipv4.addr.src = ip_hdr(skb)->saddr;
743 else if (key->eth.type == htons(ETH_P_IPV6))
744 memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
745 sizeof(key->ipv6.addr.src));
746 else
747 return;
748
749 if (key->ip.proto == IPPROTO_UDP)
750 src = udp_hdr(skb)->source;
751 else if (key->ip.proto == IPPROTO_TCP)
752 src = tcp_hdr(skb)->source;
753 else if (key->ip.proto == IPPROTO_SCTP)
754 src = sctp_hdr(skb)->source;
755 else
756 return;
757
758 key->tp.src = src;
759 } else {
760 __be16 dst;
761
762 key->ct_state |= OVS_CS_F_DST_NAT;
763 if (key->eth.type == htons(ETH_P_IP))
764 key->ipv4.addr.dst = ip_hdr(skb)->daddr;
765 else if (key->eth.type == htons(ETH_P_IPV6))
766 memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
767 sizeof(key->ipv6.addr.dst));
768 else
769 return;
770
771 if (key->ip.proto == IPPROTO_UDP)
772 dst = udp_hdr(skb)->dest;
773 else if (key->ip.proto == IPPROTO_TCP)
774 dst = tcp_hdr(skb)->dest;
775 else if (key->ip.proto == IPPROTO_SCTP)
776 dst = sctp_hdr(skb)->dest;
777 else
778 return;
779
780 key->tp.dst = dst;
781 }
782 }
783
784 /* Modelled after nf_nat_ipv[46]_fn().
785 * range is only used for new, uninitialized NAT state.
786 * Returns either NF_ACCEPT or NF_DROP.
787 */
ovs_ct_nat_execute(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,const struct nf_nat_range2 * range,enum nf_nat_manip_type maniptype,struct sw_flow_key * key)788 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
789 enum ip_conntrack_info ctinfo,
790 const struct nf_nat_range2 *range,
791 enum nf_nat_manip_type maniptype, struct sw_flow_key *key)
792 {
793 int hooknum, nh_off, err = NF_ACCEPT;
794
795 nh_off = skb_network_offset(skb);
796 skb_pull_rcsum(skb, nh_off);
797
798 /* See HOOK2MANIP(). */
799 if (maniptype == NF_NAT_MANIP_SRC)
800 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
801 else
802 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
803
804 switch (ctinfo) {
805 case IP_CT_RELATED:
806 case IP_CT_RELATED_REPLY:
807 if (IS_ENABLED(CONFIG_NF_NAT) &&
808 skb->protocol == htons(ETH_P_IP) &&
809 ip_hdr(skb)->protocol == IPPROTO_ICMP) {
810 if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
811 hooknum))
812 err = NF_DROP;
813 goto push;
814 } else if (IS_ENABLED(CONFIG_IPV6) &&
815 skb->protocol == htons(ETH_P_IPV6)) {
816 __be16 frag_off;
817 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
818 int hdrlen = ipv6_skip_exthdr(skb,
819 sizeof(struct ipv6hdr),
820 &nexthdr, &frag_off);
821
822 if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
823 if (!nf_nat_icmpv6_reply_translation(skb, ct,
824 ctinfo,
825 hooknum,
826 hdrlen))
827 err = NF_DROP;
828 goto push;
829 }
830 }
831 /* Non-ICMP, fall thru to initialize if needed. */
832 fallthrough;
833 case IP_CT_NEW:
834 /* Seen it before? This can happen for loopback, retrans,
835 * or local packets.
836 */
837 if (!nf_nat_initialized(ct, maniptype)) {
838 /* Initialize according to the NAT action. */
839 err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
840 /* Action is set up to establish a new
841 * mapping.
842 */
843 ? nf_nat_setup_info(ct, range, maniptype)
844 : nf_nat_alloc_null_binding(ct, hooknum);
845 if (err != NF_ACCEPT)
846 goto push;
847 }
848 break;
849
850 case IP_CT_ESTABLISHED:
851 case IP_CT_ESTABLISHED_REPLY:
852 break;
853
854 default:
855 err = NF_DROP;
856 goto push;
857 }
858
859 err = nf_nat_packet(ct, ctinfo, hooknum, skb);
860 push:
861 skb_push(skb, nh_off);
862 skb_postpush_rcsum(skb, skb->data, nh_off);
863
864 /* Update the flow key if NAT successful. */
865 if (err == NF_ACCEPT)
866 ovs_nat_update_key(key, skb, maniptype);
867
868 return err;
869 }
870
871 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
ovs_ct_nat(struct net * net,struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo)872 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
873 const struct ovs_conntrack_info *info,
874 struct sk_buff *skb, struct nf_conn *ct,
875 enum ip_conntrack_info ctinfo)
876 {
877 enum nf_nat_manip_type maniptype;
878 int err;
879
880 /* Add NAT extension if not confirmed yet. */
881 if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
882 return NF_ACCEPT; /* Can't NAT. */
883
884 /* Determine NAT type.
885 * Check if the NAT type can be deduced from the tracked connection.
886 * Make sure new expected connections (IP_CT_RELATED) are NATted only
887 * when committing.
888 */
889 if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
890 ct->status & IPS_NAT_MASK &&
891 (ctinfo != IP_CT_RELATED || info->commit)) {
892 /* NAT an established or related connection like before. */
893 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
894 /* This is the REPLY direction for a connection
895 * for which NAT was applied in the forward
896 * direction. Do the reverse NAT.
897 */
898 maniptype = ct->status & IPS_SRC_NAT
899 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
900 else
901 maniptype = ct->status & IPS_SRC_NAT
902 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
903 } else if (info->nat & OVS_CT_SRC_NAT) {
904 maniptype = NF_NAT_MANIP_SRC;
905 } else if (info->nat & OVS_CT_DST_NAT) {
906 maniptype = NF_NAT_MANIP_DST;
907 } else {
908 return NF_ACCEPT; /* Connection is not NATed. */
909 }
910 err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype, key);
911
912 if (err == NF_ACCEPT && ct->status & IPS_DST_NAT) {
913 if (ct->status & IPS_SRC_NAT) {
914 if (maniptype == NF_NAT_MANIP_SRC)
915 maniptype = NF_NAT_MANIP_DST;
916 else
917 maniptype = NF_NAT_MANIP_SRC;
918
919 err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
920 maniptype, key);
921 } else if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) {
922 err = ovs_ct_nat_execute(skb, ct, ctinfo, NULL,
923 NF_NAT_MANIP_SRC, key);
924 }
925 }
926
927 return err;
928 }
929 #else /* !CONFIG_NF_NAT */
ovs_ct_nat(struct net * net,struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo)930 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
931 const struct ovs_conntrack_info *info,
932 struct sk_buff *skb, struct nf_conn *ct,
933 enum ip_conntrack_info ctinfo)
934 {
935 return NF_ACCEPT;
936 }
937 #endif
938
939 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
940 * not done already. Update key with new CT state after passing the packet
941 * through conntrack.
942 * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
943 * set to NULL and 0 will be returned.
944 */
__ovs_ct_lookup(struct net * net,struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb)945 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
946 const struct ovs_conntrack_info *info,
947 struct sk_buff *skb)
948 {
949 /* If we are recirculating packets to match on conntrack fields and
950 * committing with a separate conntrack action, then we don't need to
951 * actually run the packet through conntrack twice unless it's for a
952 * different zone.
953 */
954 bool cached = skb_nfct_cached(net, key, info, skb);
955 enum ip_conntrack_info ctinfo;
956 struct nf_conn *ct;
957
958 if (!cached) {
959 struct nf_hook_state state = {
960 .hook = NF_INET_PRE_ROUTING,
961 .pf = info->family,
962 .net = net,
963 };
964 struct nf_conn *tmpl = info->ct;
965 int err;
966
967 /* Associate skb with specified zone. */
968 if (tmpl) {
969 if (skb_nfct(skb))
970 nf_conntrack_put(skb_nfct(skb));
971 nf_conntrack_get(&tmpl->ct_general);
972 nf_ct_set(skb, tmpl, IP_CT_NEW);
973 }
974
975 err = nf_conntrack_in(skb, &state);
976 if (err != NF_ACCEPT)
977 return -ENOENT;
978
979 /* Clear CT state NAT flags to mark that we have not yet done
980 * NAT after the nf_conntrack_in() call. We can actually clear
981 * the whole state, as it will be re-initialized below.
982 */
983 key->ct_state = 0;
984
985 /* Update the key, but keep the NAT flags. */
986 ovs_ct_update_key(skb, info, key, true, true);
987 }
988
989 ct = nf_ct_get(skb, &ctinfo);
990 if (ct) {
991 bool add_helper = false;
992
993 /* Packets starting a new connection must be NATted before the
994 * helper, so that the helper knows about the NAT. We enforce
995 * this by delaying both NAT and helper calls for unconfirmed
996 * connections until the committing CT action. For later
997 * packets NAT and Helper may be called in either order.
998 *
999 * NAT will be done only if the CT action has NAT, and only
1000 * once per packet (per zone), as guarded by the NAT bits in
1001 * the key->ct_state.
1002 */
1003 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
1004 (nf_ct_is_confirmed(ct) || info->commit) &&
1005 ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
1006 return -EINVAL;
1007 }
1008
1009 /* Userspace may decide to perform a ct lookup without a helper
1010 * specified followed by a (recirculate and) commit with one,
1011 * or attach a helper in a later commit. Therefore, for
1012 * connections which we will commit, we may need to attach
1013 * the helper here.
1014 */
1015 if (info->commit && info->helper && !nfct_help(ct)) {
1016 int err = __nf_ct_try_assign_helper(ct, info->ct,
1017 GFP_ATOMIC);
1018 if (err)
1019 return err;
1020 add_helper = true;
1021
1022 /* helper installed, add seqadj if NAT is required */
1023 if (info->nat && !nfct_seqadj(ct)) {
1024 if (!nfct_seqadj_ext_add(ct))
1025 return -EINVAL;
1026 }
1027 }
1028
1029 /* Call the helper only if:
1030 * - nf_conntrack_in() was executed above ("!cached") or a
1031 * helper was just attached ("add_helper") for a confirmed
1032 * connection, or
1033 * - When committing an unconfirmed connection.
1034 */
1035 if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
1036 info->commit) &&
1037 ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
1038 return -EINVAL;
1039 }
1040 }
1041
1042 return 0;
1043 }
1044
1045 /* Lookup connection and read fields into key. */
ovs_ct_lookup(struct net * net,struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb)1046 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
1047 const struct ovs_conntrack_info *info,
1048 struct sk_buff *skb)
1049 {
1050 struct nf_conntrack_expect *exp;
1051
1052 /* If we pass an expected packet through nf_conntrack_in() the
1053 * expectation is typically removed, but the packet could still be
1054 * lost in upcall processing. To prevent this from happening we
1055 * perform an explicit expectation lookup. Expected connections are
1056 * always new, and will be passed through conntrack only when they are
1057 * committed, as it is OK to remove the expectation at that time.
1058 */
1059 exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1060 if (exp) {
1061 u8 state;
1062
1063 /* NOTE: New connections are NATted and Helped only when
1064 * committed, so we are not calling into NAT here.
1065 */
1066 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1067 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1068 } else {
1069 struct nf_conn *ct;
1070 int err;
1071
1072 err = __ovs_ct_lookup(net, key, info, skb);
1073 if (err)
1074 return err;
1075
1076 ct = (struct nf_conn *)skb_nfct(skb);
1077 if (ct)
1078 nf_ct_deliver_cached_events(ct);
1079 }
1080
1081 return 0;
1082 }
1083
labels_nonzero(const struct ovs_key_ct_labels * labels)1084 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1085 {
1086 size_t i;
1087
1088 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1089 if (labels->ct_labels_32[i])
1090 return true;
1091
1092 return false;
1093 }
1094
1095 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
ct_limit_hash_bucket(const struct ovs_ct_limit_info * info,u16 zone)1096 static struct hlist_head *ct_limit_hash_bucket(
1097 const struct ovs_ct_limit_info *info, u16 zone)
1098 {
1099 return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
1100 }
1101
1102 /* Call with ovs_mutex */
ct_limit_set(const struct ovs_ct_limit_info * info,struct ovs_ct_limit * new_ct_limit)1103 static void ct_limit_set(const struct ovs_ct_limit_info *info,
1104 struct ovs_ct_limit *new_ct_limit)
1105 {
1106 struct ovs_ct_limit *ct_limit;
1107 struct hlist_head *head;
1108
1109 head = ct_limit_hash_bucket(info, new_ct_limit->zone);
1110 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1111 if (ct_limit->zone == new_ct_limit->zone) {
1112 hlist_replace_rcu(&ct_limit->hlist_node,
1113 &new_ct_limit->hlist_node);
1114 kfree_rcu(ct_limit, rcu);
1115 return;
1116 }
1117 }
1118
1119 hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
1120 }
1121
1122 /* Call with ovs_mutex */
ct_limit_del(const struct ovs_ct_limit_info * info,u16 zone)1123 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
1124 {
1125 struct ovs_ct_limit *ct_limit;
1126 struct hlist_head *head;
1127 struct hlist_node *n;
1128
1129 head = ct_limit_hash_bucket(info, zone);
1130 hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
1131 if (ct_limit->zone == zone) {
1132 hlist_del_rcu(&ct_limit->hlist_node);
1133 kfree_rcu(ct_limit, rcu);
1134 return;
1135 }
1136 }
1137 }
1138
1139 /* Call with RCU read lock */
ct_limit_get(const struct ovs_ct_limit_info * info,u16 zone)1140 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
1141 {
1142 struct ovs_ct_limit *ct_limit;
1143 struct hlist_head *head;
1144
1145 head = ct_limit_hash_bucket(info, zone);
1146 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1147 if (ct_limit->zone == zone)
1148 return ct_limit->limit;
1149 }
1150
1151 return info->default_limit;
1152 }
1153
ovs_ct_check_limit(struct net * net,const struct ovs_conntrack_info * info,const struct nf_conntrack_tuple * tuple)1154 static int ovs_ct_check_limit(struct net *net,
1155 const struct ovs_conntrack_info *info,
1156 const struct nf_conntrack_tuple *tuple)
1157 {
1158 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1159 const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1160 u32 per_zone_limit, connections;
1161 u32 conncount_key;
1162
1163 conncount_key = info->zone.id;
1164
1165 per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1166 if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1167 return 0;
1168
1169 connections = nf_conncount_count(net, ct_limit_info->data,
1170 &conncount_key, tuple, &info->zone);
1171 if (connections > per_zone_limit)
1172 return -ENOMEM;
1173
1174 return 0;
1175 }
1176 #endif
1177
1178 /* Lookup connection and confirm if unconfirmed. */
ovs_ct_commit(struct net * net,struct sw_flow_key * key,const struct ovs_conntrack_info * info,struct sk_buff * skb)1179 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1180 const struct ovs_conntrack_info *info,
1181 struct sk_buff *skb)
1182 {
1183 enum ip_conntrack_info ctinfo;
1184 struct nf_conn *ct;
1185 int err;
1186
1187 err = __ovs_ct_lookup(net, key, info, skb);
1188 if (err)
1189 return err;
1190
1191 /* The connection could be invalid, in which case this is a no-op.*/
1192 ct = nf_ct_get(skb, &ctinfo);
1193 if (!ct)
1194 return 0;
1195
1196 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1197 if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1198 if (!nf_ct_is_confirmed(ct)) {
1199 err = ovs_ct_check_limit(net, info,
1200 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1201 if (err) {
1202 net_warn_ratelimited("openvswitch: zone: %u "
1203 "exceeds conntrack limit\n",
1204 info->zone.id);
1205 return err;
1206 }
1207 }
1208 }
1209 #endif
1210
1211 /* Set the conntrack event mask if given. NEW and DELETE events have
1212 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1213 * typically would receive many kinds of updates. Setting the event
1214 * mask allows those events to be filtered. The set event mask will
1215 * remain in effect for the lifetime of the connection unless changed
1216 * by a further CT action with both the commit flag and the eventmask
1217 * option. */
1218 if (info->have_eventmask) {
1219 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1220
1221 if (cache)
1222 cache->ctmask = info->eventmask;
1223 }
1224
1225 /* Apply changes before confirming the connection so that the initial
1226 * conntrack NEW netlink event carries the values given in the CT
1227 * action.
1228 */
1229 if (info->mark.mask) {
1230 err = ovs_ct_set_mark(ct, key, info->mark.value,
1231 info->mark.mask);
1232 if (err)
1233 return err;
1234 }
1235 if (!nf_ct_is_confirmed(ct)) {
1236 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1237 &info->labels.mask);
1238 if (err)
1239 return err;
1240 } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1241 labels_nonzero(&info->labels.mask)) {
1242 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1243 &info->labels.mask);
1244 if (err)
1245 return err;
1246 }
1247 /* This will take care of sending queued events even if the connection
1248 * is already confirmed.
1249 */
1250 if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1251 return -EINVAL;
1252
1253 return 0;
1254 }
1255
1256 /* Trim the skb to the length specified by the IP/IPv6 header,
1257 * removing any trailing lower-layer padding. This prepares the skb
1258 * for higher-layer processing that assumes skb->len excludes padding
1259 * (such as nf_ip_checksum). The caller needs to pull the skb to the
1260 * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1261 */
ovs_skb_network_trim(struct sk_buff * skb)1262 static int ovs_skb_network_trim(struct sk_buff *skb)
1263 {
1264 unsigned int len;
1265 int err;
1266
1267 switch (skb->protocol) {
1268 case htons(ETH_P_IP):
1269 len = ntohs(ip_hdr(skb)->tot_len);
1270 break;
1271 case htons(ETH_P_IPV6):
1272 len = sizeof(struct ipv6hdr)
1273 + ntohs(ipv6_hdr(skb)->payload_len);
1274 break;
1275 default:
1276 len = skb->len;
1277 }
1278
1279 err = pskb_trim_rcsum(skb, len);
1280 if (err)
1281 kfree_skb(skb);
1282
1283 return err;
1284 }
1285
1286 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1287 * value if 'skb' is freed.
1288 */
ovs_ct_execute(struct net * net,struct sk_buff * skb,struct sw_flow_key * key,const struct ovs_conntrack_info * info)1289 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1290 struct sw_flow_key *key,
1291 const struct ovs_conntrack_info *info)
1292 {
1293 int nh_ofs;
1294 int err;
1295
1296 /* The conntrack module expects to be working at L3. */
1297 nh_ofs = skb_network_offset(skb);
1298 skb_pull_rcsum(skb, nh_ofs);
1299
1300 err = ovs_skb_network_trim(skb);
1301 if (err)
1302 return err;
1303
1304 if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1305 err = handle_fragments(net, key, info->zone.id, skb);
1306 if (err)
1307 return err;
1308 }
1309
1310 if (info->commit)
1311 err = ovs_ct_commit(net, key, info, skb);
1312 else
1313 err = ovs_ct_lookup(net, key, info, skb);
1314
1315 skb_push(skb, nh_ofs);
1316 skb_postpush_rcsum(skb, skb->data, nh_ofs);
1317 if (err)
1318 kfree_skb(skb);
1319 return err;
1320 }
1321
ovs_ct_clear(struct sk_buff * skb,struct sw_flow_key * key)1322 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1323 {
1324 if (skb_nfct(skb)) {
1325 nf_conntrack_put(skb_nfct(skb));
1326 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1327 if (key)
1328 ovs_ct_fill_key(skb, key);
1329 }
1330
1331 return 0;
1332 }
1333
ovs_ct_add_helper(struct ovs_conntrack_info * info,const char * name,const struct sw_flow_key * key,bool log)1334 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1335 const struct sw_flow_key *key, bool log)
1336 {
1337 struct nf_conntrack_helper *helper;
1338 struct nf_conn_help *help;
1339 int ret = 0;
1340
1341 helper = nf_conntrack_helper_try_module_get(name, info->family,
1342 key->ip.proto);
1343 if (!helper) {
1344 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1345 return -EINVAL;
1346 }
1347
1348 help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
1349 if (!help) {
1350 nf_conntrack_helper_put(helper);
1351 return -ENOMEM;
1352 }
1353
1354 #if IS_ENABLED(CONFIG_NF_NAT)
1355 if (info->nat) {
1356 ret = nf_nat_helper_try_module_get(name, info->family,
1357 key->ip.proto);
1358 if (ret) {
1359 nf_conntrack_helper_put(helper);
1360 OVS_NLERR(log, "Failed to load \"%s\" NAT helper, error: %d",
1361 name, ret);
1362 return ret;
1363 }
1364 }
1365 #endif
1366 rcu_assign_pointer(help->helper, helper);
1367 info->helper = helper;
1368 return ret;
1369 }
1370
1371 #if IS_ENABLED(CONFIG_NF_NAT)
parse_nat(const struct nlattr * attr,struct ovs_conntrack_info * info,bool log)1372 static int parse_nat(const struct nlattr *attr,
1373 struct ovs_conntrack_info *info, bool log)
1374 {
1375 struct nlattr *a;
1376 int rem;
1377 bool have_ip_max = false;
1378 bool have_proto_max = false;
1379 bool ip_vers = (info->family == NFPROTO_IPV6);
1380
1381 nla_for_each_nested(a, attr, rem) {
1382 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1383 [OVS_NAT_ATTR_SRC] = {0, 0},
1384 [OVS_NAT_ATTR_DST] = {0, 0},
1385 [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1386 sizeof(struct in6_addr)},
1387 [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1388 sizeof(struct in6_addr)},
1389 [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1390 [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1391 [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1392 [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1393 [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1394 };
1395 int type = nla_type(a);
1396
1397 if (type > OVS_NAT_ATTR_MAX) {
1398 OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1399 type, OVS_NAT_ATTR_MAX);
1400 return -EINVAL;
1401 }
1402
1403 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1404 OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1405 type, nla_len(a),
1406 ovs_nat_attr_lens[type][ip_vers]);
1407 return -EINVAL;
1408 }
1409
1410 switch (type) {
1411 case OVS_NAT_ATTR_SRC:
1412 case OVS_NAT_ATTR_DST:
1413 if (info->nat) {
1414 OVS_NLERR(log, "Only one type of NAT may be specified");
1415 return -ERANGE;
1416 }
1417 info->nat |= OVS_CT_NAT;
1418 info->nat |= ((type == OVS_NAT_ATTR_SRC)
1419 ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1420 break;
1421
1422 case OVS_NAT_ATTR_IP_MIN:
1423 nla_memcpy(&info->range.min_addr, a,
1424 sizeof(info->range.min_addr));
1425 info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1426 break;
1427
1428 case OVS_NAT_ATTR_IP_MAX:
1429 have_ip_max = true;
1430 nla_memcpy(&info->range.max_addr, a,
1431 sizeof(info->range.max_addr));
1432 info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1433 break;
1434
1435 case OVS_NAT_ATTR_PROTO_MIN:
1436 info->range.min_proto.all = htons(nla_get_u16(a));
1437 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1438 break;
1439
1440 case OVS_NAT_ATTR_PROTO_MAX:
1441 have_proto_max = true;
1442 info->range.max_proto.all = htons(nla_get_u16(a));
1443 info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1444 break;
1445
1446 case OVS_NAT_ATTR_PERSISTENT:
1447 info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1448 break;
1449
1450 case OVS_NAT_ATTR_PROTO_HASH:
1451 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1452 break;
1453
1454 case OVS_NAT_ATTR_PROTO_RANDOM:
1455 info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1456 break;
1457
1458 default:
1459 OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1460 return -EINVAL;
1461 }
1462 }
1463
1464 if (rem > 0) {
1465 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1466 return -EINVAL;
1467 }
1468 if (!info->nat) {
1469 /* Do not allow flags if no type is given. */
1470 if (info->range.flags) {
1471 OVS_NLERR(log,
1472 "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1473 );
1474 return -EINVAL;
1475 }
1476 info->nat = OVS_CT_NAT; /* NAT existing connections. */
1477 } else if (!info->commit) {
1478 OVS_NLERR(log,
1479 "NAT attributes may be specified only when CT COMMIT flag is also specified."
1480 );
1481 return -EINVAL;
1482 }
1483 /* Allow missing IP_MAX. */
1484 if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1485 memcpy(&info->range.max_addr, &info->range.min_addr,
1486 sizeof(info->range.max_addr));
1487 }
1488 /* Allow missing PROTO_MAX. */
1489 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1490 !have_proto_max) {
1491 info->range.max_proto.all = info->range.min_proto.all;
1492 }
1493 return 0;
1494 }
1495 #endif
1496
1497 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1498 [OVS_CT_ATTR_COMMIT] = { .minlen = 0, .maxlen = 0 },
1499 [OVS_CT_ATTR_FORCE_COMMIT] = { .minlen = 0, .maxlen = 0 },
1500 [OVS_CT_ATTR_ZONE] = { .minlen = sizeof(u16),
1501 .maxlen = sizeof(u16) },
1502 [OVS_CT_ATTR_MARK] = { .minlen = sizeof(struct md_mark),
1503 .maxlen = sizeof(struct md_mark) },
1504 [OVS_CT_ATTR_LABELS] = { .minlen = sizeof(struct md_labels),
1505 .maxlen = sizeof(struct md_labels) },
1506 [OVS_CT_ATTR_HELPER] = { .minlen = 1,
1507 .maxlen = NF_CT_HELPER_NAME_LEN },
1508 #if IS_ENABLED(CONFIG_NF_NAT)
1509 /* NAT length is checked when parsing the nested attributes. */
1510 [OVS_CT_ATTR_NAT] = { .minlen = 0, .maxlen = INT_MAX },
1511 #endif
1512 [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1513 .maxlen = sizeof(u32) },
1514 [OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
1515 .maxlen = CTNL_TIMEOUT_NAME_MAX },
1516 };
1517
parse_ct(const struct nlattr * attr,struct ovs_conntrack_info * info,const char ** helper,bool log)1518 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1519 const char **helper, bool log)
1520 {
1521 struct nlattr *a;
1522 int rem;
1523
1524 nla_for_each_nested(a, attr, rem) {
1525 int type = nla_type(a);
1526 int maxlen;
1527 int minlen;
1528
1529 if (type > OVS_CT_ATTR_MAX) {
1530 OVS_NLERR(log,
1531 "Unknown conntrack attr (type=%d, max=%d)",
1532 type, OVS_CT_ATTR_MAX);
1533 return -EINVAL;
1534 }
1535
1536 maxlen = ovs_ct_attr_lens[type].maxlen;
1537 minlen = ovs_ct_attr_lens[type].minlen;
1538 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1539 OVS_NLERR(log,
1540 "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1541 type, nla_len(a), maxlen);
1542 return -EINVAL;
1543 }
1544
1545 switch (type) {
1546 case OVS_CT_ATTR_FORCE_COMMIT:
1547 info->force = true;
1548 fallthrough;
1549 case OVS_CT_ATTR_COMMIT:
1550 info->commit = true;
1551 break;
1552 #ifdef CONFIG_NF_CONNTRACK_ZONES
1553 case OVS_CT_ATTR_ZONE:
1554 info->zone.id = nla_get_u16(a);
1555 break;
1556 #endif
1557 #ifdef CONFIG_NF_CONNTRACK_MARK
1558 case OVS_CT_ATTR_MARK: {
1559 struct md_mark *mark = nla_data(a);
1560
1561 if (!mark->mask) {
1562 OVS_NLERR(log, "ct_mark mask cannot be 0");
1563 return -EINVAL;
1564 }
1565 info->mark = *mark;
1566 break;
1567 }
1568 #endif
1569 #ifdef CONFIG_NF_CONNTRACK_LABELS
1570 case OVS_CT_ATTR_LABELS: {
1571 struct md_labels *labels = nla_data(a);
1572
1573 if (!labels_nonzero(&labels->mask)) {
1574 OVS_NLERR(log, "ct_labels mask cannot be 0");
1575 return -EINVAL;
1576 }
1577 info->labels = *labels;
1578 break;
1579 }
1580 #endif
1581 case OVS_CT_ATTR_HELPER:
1582 *helper = nla_data(a);
1583 if (!memchr(*helper, '\0', nla_len(a))) {
1584 OVS_NLERR(log, "Invalid conntrack helper");
1585 return -EINVAL;
1586 }
1587 break;
1588 #if IS_ENABLED(CONFIG_NF_NAT)
1589 case OVS_CT_ATTR_NAT: {
1590 int err = parse_nat(a, info, log);
1591
1592 if (err)
1593 return err;
1594 break;
1595 }
1596 #endif
1597 case OVS_CT_ATTR_EVENTMASK:
1598 info->have_eventmask = true;
1599 info->eventmask = nla_get_u32(a);
1600 break;
1601 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1602 case OVS_CT_ATTR_TIMEOUT:
1603 memcpy(info->timeout, nla_data(a), nla_len(a));
1604 if (!memchr(info->timeout, '\0', nla_len(a))) {
1605 OVS_NLERR(log, "Invalid conntrack timeout");
1606 return -EINVAL;
1607 }
1608 break;
1609 #endif
1610
1611 default:
1612 OVS_NLERR(log, "Unknown conntrack attr (%d)",
1613 type);
1614 return -EINVAL;
1615 }
1616 }
1617
1618 #ifdef CONFIG_NF_CONNTRACK_MARK
1619 if (!info->commit && info->mark.mask) {
1620 OVS_NLERR(log,
1621 "Setting conntrack mark requires 'commit' flag.");
1622 return -EINVAL;
1623 }
1624 #endif
1625 #ifdef CONFIG_NF_CONNTRACK_LABELS
1626 if (!info->commit && labels_nonzero(&info->labels.mask)) {
1627 OVS_NLERR(log,
1628 "Setting conntrack labels requires 'commit' flag.");
1629 return -EINVAL;
1630 }
1631 #endif
1632 if (rem > 0) {
1633 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1634 return -EINVAL;
1635 }
1636
1637 return 0;
1638 }
1639
ovs_ct_verify(struct net * net,enum ovs_key_attr attr)1640 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1641 {
1642 if (attr == OVS_KEY_ATTR_CT_STATE)
1643 return true;
1644 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1645 attr == OVS_KEY_ATTR_CT_ZONE)
1646 return true;
1647 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1648 attr == OVS_KEY_ATTR_CT_MARK)
1649 return true;
1650 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1651 attr == OVS_KEY_ATTR_CT_LABELS) {
1652 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1653
1654 return ovs_net->xt_label;
1655 }
1656
1657 return false;
1658 }
1659
ovs_ct_copy_action(struct net * net,const struct nlattr * attr,const struct sw_flow_key * key,struct sw_flow_actions ** sfa,bool log)1660 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1661 const struct sw_flow_key *key,
1662 struct sw_flow_actions **sfa, bool log)
1663 {
1664 struct ovs_conntrack_info ct_info;
1665 const char *helper = NULL;
1666 u16 family;
1667 int err;
1668
1669 family = key_to_nfproto(key);
1670 if (family == NFPROTO_UNSPEC) {
1671 OVS_NLERR(log, "ct family unspecified");
1672 return -EINVAL;
1673 }
1674
1675 memset(&ct_info, 0, sizeof(ct_info));
1676 ct_info.family = family;
1677
1678 nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1679 NF_CT_DEFAULT_ZONE_DIR, 0);
1680
1681 err = parse_ct(attr, &ct_info, &helper, log);
1682 if (err)
1683 return err;
1684
1685 /* Set up template for tracking connections in specific zones. */
1686 ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1687 if (!ct_info.ct) {
1688 OVS_NLERR(log, "Failed to allocate conntrack template");
1689 return -ENOMEM;
1690 }
1691
1692 if (ct_info.timeout[0]) {
1693 if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
1694 ct_info.timeout))
1695 pr_info_ratelimited("Failed to associated timeout "
1696 "policy `%s'\n", ct_info.timeout);
1697 else
1698 ct_info.nf_ct_timeout = rcu_dereference(
1699 nf_ct_timeout_find(ct_info.ct)->timeout);
1700
1701 }
1702
1703 if (helper) {
1704 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1705 if (err)
1706 goto err_free_ct;
1707 }
1708
1709 err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1710 sizeof(ct_info), log);
1711 if (err)
1712 goto err_free_ct;
1713
1714 __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1715 nf_conntrack_get(&ct_info.ct->ct_general);
1716 return 0;
1717 err_free_ct:
1718 __ovs_ct_free_action(&ct_info);
1719 return err;
1720 }
1721
1722 #if IS_ENABLED(CONFIG_NF_NAT)
ovs_ct_nat_to_attr(const struct ovs_conntrack_info * info,struct sk_buff * skb)1723 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1724 struct sk_buff *skb)
1725 {
1726 struct nlattr *start;
1727
1728 start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
1729 if (!start)
1730 return false;
1731
1732 if (info->nat & OVS_CT_SRC_NAT) {
1733 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1734 return false;
1735 } else if (info->nat & OVS_CT_DST_NAT) {
1736 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1737 return false;
1738 } else {
1739 goto out;
1740 }
1741
1742 if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1743 if (IS_ENABLED(CONFIG_NF_NAT) &&
1744 info->family == NFPROTO_IPV4) {
1745 if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1746 info->range.min_addr.ip) ||
1747 (info->range.max_addr.ip
1748 != info->range.min_addr.ip &&
1749 (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1750 info->range.max_addr.ip))))
1751 return false;
1752 } else if (IS_ENABLED(CONFIG_IPV6) &&
1753 info->family == NFPROTO_IPV6) {
1754 if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1755 &info->range.min_addr.in6) ||
1756 (memcmp(&info->range.max_addr.in6,
1757 &info->range.min_addr.in6,
1758 sizeof(info->range.max_addr.in6)) &&
1759 (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1760 &info->range.max_addr.in6))))
1761 return false;
1762 } else {
1763 return false;
1764 }
1765 }
1766 if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1767 (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1768 ntohs(info->range.min_proto.all)) ||
1769 (info->range.max_proto.all != info->range.min_proto.all &&
1770 nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1771 ntohs(info->range.max_proto.all)))))
1772 return false;
1773
1774 if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1775 nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1776 return false;
1777 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1778 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1779 return false;
1780 if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1781 nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1782 return false;
1783 out:
1784 nla_nest_end(skb, start);
1785
1786 return true;
1787 }
1788 #endif
1789
ovs_ct_action_to_attr(const struct ovs_conntrack_info * ct_info,struct sk_buff * skb)1790 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1791 struct sk_buff *skb)
1792 {
1793 struct nlattr *start;
1794
1795 start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
1796 if (!start)
1797 return -EMSGSIZE;
1798
1799 if (ct_info->commit && nla_put_flag(skb, ct_info->force
1800 ? OVS_CT_ATTR_FORCE_COMMIT
1801 : OVS_CT_ATTR_COMMIT))
1802 return -EMSGSIZE;
1803 if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1804 nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1805 return -EMSGSIZE;
1806 if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1807 nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1808 &ct_info->mark))
1809 return -EMSGSIZE;
1810 if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1811 labels_nonzero(&ct_info->labels.mask) &&
1812 nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1813 &ct_info->labels))
1814 return -EMSGSIZE;
1815 if (ct_info->helper) {
1816 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1817 ct_info->helper->name))
1818 return -EMSGSIZE;
1819 }
1820 if (ct_info->have_eventmask &&
1821 nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1822 return -EMSGSIZE;
1823 if (ct_info->timeout[0]) {
1824 if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
1825 return -EMSGSIZE;
1826 }
1827
1828 #if IS_ENABLED(CONFIG_NF_NAT)
1829 if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1830 return -EMSGSIZE;
1831 #endif
1832 nla_nest_end(skb, start);
1833
1834 return 0;
1835 }
1836
ovs_ct_free_action(const struct nlattr * a)1837 void ovs_ct_free_action(const struct nlattr *a)
1838 {
1839 struct ovs_conntrack_info *ct_info = nla_data(a);
1840
1841 __ovs_ct_free_action(ct_info);
1842 }
1843
__ovs_ct_free_action(struct ovs_conntrack_info * ct_info)1844 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1845 {
1846 if (ct_info->helper) {
1847 #if IS_ENABLED(CONFIG_NF_NAT)
1848 if (ct_info->nat)
1849 nf_nat_helper_put(ct_info->helper);
1850 #endif
1851 nf_conntrack_helper_put(ct_info->helper);
1852 }
1853 if (ct_info->ct) {
1854 if (ct_info->timeout[0])
1855 nf_ct_destroy_timeout(ct_info->ct);
1856 nf_ct_tmpl_free(ct_info->ct);
1857 }
1858 }
1859
1860 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
ovs_ct_limit_init(struct net * net,struct ovs_net * ovs_net)1861 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1862 {
1863 int i, err;
1864
1865 ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1866 GFP_KERNEL);
1867 if (!ovs_net->ct_limit_info)
1868 return -ENOMEM;
1869
1870 ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1871 ovs_net->ct_limit_info->limits =
1872 kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1873 GFP_KERNEL);
1874 if (!ovs_net->ct_limit_info->limits) {
1875 kfree(ovs_net->ct_limit_info);
1876 return -ENOMEM;
1877 }
1878
1879 for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1880 INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1881
1882 ovs_net->ct_limit_info->data =
1883 nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1884
1885 if (IS_ERR(ovs_net->ct_limit_info->data)) {
1886 err = PTR_ERR(ovs_net->ct_limit_info->data);
1887 kfree(ovs_net->ct_limit_info->limits);
1888 kfree(ovs_net->ct_limit_info);
1889 pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1890 return err;
1891 }
1892 return 0;
1893 }
1894
ovs_ct_limit_exit(struct net * net,struct ovs_net * ovs_net)1895 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1896 {
1897 const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1898 int i;
1899
1900 nf_conncount_destroy(net, NFPROTO_INET, info->data);
1901 for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1902 struct hlist_head *head = &info->limits[i];
1903 struct ovs_ct_limit *ct_limit;
1904
1905 hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
1906 lockdep_ovsl_is_held())
1907 kfree_rcu(ct_limit, rcu);
1908 }
1909 kfree(info->limits);
1910 kfree(info);
1911 }
1912
1913 static struct sk_buff *
ovs_ct_limit_cmd_reply_start(struct genl_info * info,u8 cmd,struct ovs_header ** ovs_reply_header)1914 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1915 struct ovs_header **ovs_reply_header)
1916 {
1917 struct ovs_header *ovs_header = info->userhdr;
1918 struct sk_buff *skb;
1919
1920 skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1921 if (!skb)
1922 return ERR_PTR(-ENOMEM);
1923
1924 *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1925 info->snd_seq,
1926 &dp_ct_limit_genl_family, 0, cmd);
1927
1928 if (!*ovs_reply_header) {
1929 nlmsg_free(skb);
1930 return ERR_PTR(-EMSGSIZE);
1931 }
1932 (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1933
1934 return skb;
1935 }
1936
check_zone_id(int zone_id,u16 * pzone)1937 static bool check_zone_id(int zone_id, u16 *pzone)
1938 {
1939 if (zone_id >= 0 && zone_id <= 65535) {
1940 *pzone = (u16)zone_id;
1941 return true;
1942 }
1943 return false;
1944 }
1945
ovs_ct_limit_set_zone_limit(struct nlattr * nla_zone_limit,struct ovs_ct_limit_info * info)1946 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1947 struct ovs_ct_limit_info *info)
1948 {
1949 struct ovs_zone_limit *zone_limit;
1950 int rem;
1951 u16 zone;
1952
1953 rem = NLA_ALIGN(nla_len(nla_zone_limit));
1954 zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1955
1956 while (rem >= sizeof(*zone_limit)) {
1957 if (unlikely(zone_limit->zone_id ==
1958 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1959 ovs_lock();
1960 info->default_limit = zone_limit->limit;
1961 ovs_unlock();
1962 } else if (unlikely(!check_zone_id(
1963 zone_limit->zone_id, &zone))) {
1964 OVS_NLERR(true, "zone id is out of range");
1965 } else {
1966 struct ovs_ct_limit *ct_limit;
1967
1968 ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
1969 if (!ct_limit)
1970 return -ENOMEM;
1971
1972 ct_limit->zone = zone;
1973 ct_limit->limit = zone_limit->limit;
1974
1975 ovs_lock();
1976 ct_limit_set(info, ct_limit);
1977 ovs_unlock();
1978 }
1979 rem -= NLA_ALIGN(sizeof(*zone_limit));
1980 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1981 NLA_ALIGN(sizeof(*zone_limit)));
1982 }
1983
1984 if (rem)
1985 OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1986
1987 return 0;
1988 }
1989
ovs_ct_limit_del_zone_limit(struct nlattr * nla_zone_limit,struct ovs_ct_limit_info * info)1990 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1991 struct ovs_ct_limit_info *info)
1992 {
1993 struct ovs_zone_limit *zone_limit;
1994 int rem;
1995 u16 zone;
1996
1997 rem = NLA_ALIGN(nla_len(nla_zone_limit));
1998 zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1999
2000 while (rem >= sizeof(*zone_limit)) {
2001 if (unlikely(zone_limit->zone_id ==
2002 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2003 ovs_lock();
2004 info->default_limit = OVS_CT_LIMIT_DEFAULT;
2005 ovs_unlock();
2006 } else if (unlikely(!check_zone_id(
2007 zone_limit->zone_id, &zone))) {
2008 OVS_NLERR(true, "zone id is out of range");
2009 } else {
2010 ovs_lock();
2011 ct_limit_del(info, zone);
2012 ovs_unlock();
2013 }
2014 rem -= NLA_ALIGN(sizeof(*zone_limit));
2015 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2016 NLA_ALIGN(sizeof(*zone_limit)));
2017 }
2018
2019 if (rem)
2020 OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
2021
2022 return 0;
2023 }
2024
ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info * info,struct sk_buff * reply)2025 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
2026 struct sk_buff *reply)
2027 {
2028 struct ovs_zone_limit zone_limit = {
2029 .zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
2030 .limit = info->default_limit,
2031 };
2032
2033 return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2034 }
2035
__ovs_ct_limit_get_zone_limit(struct net * net,struct nf_conncount_data * data,u16 zone_id,u32 limit,struct sk_buff * reply)2036 static int __ovs_ct_limit_get_zone_limit(struct net *net,
2037 struct nf_conncount_data *data,
2038 u16 zone_id, u32 limit,
2039 struct sk_buff *reply)
2040 {
2041 struct nf_conntrack_zone ct_zone;
2042 struct ovs_zone_limit zone_limit;
2043 u32 conncount_key = zone_id;
2044
2045 zone_limit.zone_id = zone_id;
2046 zone_limit.limit = limit;
2047 nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
2048
2049 zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
2050 &ct_zone);
2051 return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2052 }
2053
ovs_ct_limit_get_zone_limit(struct net * net,struct nlattr * nla_zone_limit,struct ovs_ct_limit_info * info,struct sk_buff * reply)2054 static int ovs_ct_limit_get_zone_limit(struct net *net,
2055 struct nlattr *nla_zone_limit,
2056 struct ovs_ct_limit_info *info,
2057 struct sk_buff *reply)
2058 {
2059 struct ovs_zone_limit *zone_limit;
2060 int rem, err;
2061 u32 limit;
2062 u16 zone;
2063
2064 rem = NLA_ALIGN(nla_len(nla_zone_limit));
2065 zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
2066
2067 while (rem >= sizeof(*zone_limit)) {
2068 if (unlikely(zone_limit->zone_id ==
2069 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2070 err = ovs_ct_limit_get_default_limit(info, reply);
2071 if (err)
2072 return err;
2073 } else if (unlikely(!check_zone_id(zone_limit->zone_id,
2074 &zone))) {
2075 OVS_NLERR(true, "zone id is out of range");
2076 } else {
2077 rcu_read_lock();
2078 limit = ct_limit_get(info, zone);
2079 rcu_read_unlock();
2080
2081 err = __ovs_ct_limit_get_zone_limit(
2082 net, info->data, zone, limit, reply);
2083 if (err)
2084 return err;
2085 }
2086 rem -= NLA_ALIGN(sizeof(*zone_limit));
2087 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2088 NLA_ALIGN(sizeof(*zone_limit)));
2089 }
2090
2091 if (rem)
2092 OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
2093
2094 return 0;
2095 }
2096
ovs_ct_limit_get_all_zone_limit(struct net * net,struct ovs_ct_limit_info * info,struct sk_buff * reply)2097 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
2098 struct ovs_ct_limit_info *info,
2099 struct sk_buff *reply)
2100 {
2101 struct ovs_ct_limit *ct_limit;
2102 struct hlist_head *head;
2103 int i, err = 0;
2104
2105 err = ovs_ct_limit_get_default_limit(info, reply);
2106 if (err)
2107 return err;
2108
2109 rcu_read_lock();
2110 for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
2111 head = &info->limits[i];
2112 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
2113 err = __ovs_ct_limit_get_zone_limit(net, info->data,
2114 ct_limit->zone, ct_limit->limit, reply);
2115 if (err)
2116 goto exit_err;
2117 }
2118 }
2119
2120 exit_err:
2121 rcu_read_unlock();
2122 return err;
2123 }
2124
ovs_ct_limit_cmd_set(struct sk_buff * skb,struct genl_info * info)2125 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
2126 {
2127 struct nlattr **a = info->attrs;
2128 struct sk_buff *reply;
2129 struct ovs_header *ovs_reply_header;
2130 struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2131 struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2132 int err;
2133
2134 reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
2135 &ovs_reply_header);
2136 if (IS_ERR(reply))
2137 return PTR_ERR(reply);
2138
2139 if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2140 err = -EINVAL;
2141 goto exit_err;
2142 }
2143
2144 err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2145 ct_limit_info);
2146 if (err)
2147 goto exit_err;
2148
2149 static_branch_enable(&ovs_ct_limit_enabled);
2150
2151 genlmsg_end(reply, ovs_reply_header);
2152 return genlmsg_reply(reply, info);
2153
2154 exit_err:
2155 nlmsg_free(reply);
2156 return err;
2157 }
2158
ovs_ct_limit_cmd_del(struct sk_buff * skb,struct genl_info * info)2159 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
2160 {
2161 struct nlattr **a = info->attrs;
2162 struct sk_buff *reply;
2163 struct ovs_header *ovs_reply_header;
2164 struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2165 struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2166 int err;
2167
2168 reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
2169 &ovs_reply_header);
2170 if (IS_ERR(reply))
2171 return PTR_ERR(reply);
2172
2173 if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2174 err = -EINVAL;
2175 goto exit_err;
2176 }
2177
2178 err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2179 ct_limit_info);
2180 if (err)
2181 goto exit_err;
2182
2183 genlmsg_end(reply, ovs_reply_header);
2184 return genlmsg_reply(reply, info);
2185
2186 exit_err:
2187 nlmsg_free(reply);
2188 return err;
2189 }
2190
ovs_ct_limit_cmd_get(struct sk_buff * skb,struct genl_info * info)2191 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
2192 {
2193 struct nlattr **a = info->attrs;
2194 struct nlattr *nla_reply;
2195 struct sk_buff *reply;
2196 struct ovs_header *ovs_reply_header;
2197 struct net *net = sock_net(skb->sk);
2198 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2199 struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2200 int err;
2201
2202 reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2203 &ovs_reply_header);
2204 if (IS_ERR(reply))
2205 return PTR_ERR(reply);
2206
2207 nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2208 if (!nla_reply) {
2209 err = -EMSGSIZE;
2210 goto exit_err;
2211 }
2212
2213 if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2214 err = ovs_ct_limit_get_zone_limit(
2215 net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2216 reply);
2217 if (err)
2218 goto exit_err;
2219 } else {
2220 err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2221 reply);
2222 if (err)
2223 goto exit_err;
2224 }
2225
2226 nla_nest_end(reply, nla_reply);
2227 genlmsg_end(reply, ovs_reply_header);
2228 return genlmsg_reply(reply, info);
2229
2230 exit_err:
2231 nlmsg_free(reply);
2232 return err;
2233 }
2234
2235 static const struct genl_small_ops ct_limit_genl_ops[] = {
2236 { .cmd = OVS_CT_LIMIT_CMD_SET,
2237 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2238 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2239 * privilege. */
2240 .doit = ovs_ct_limit_cmd_set,
2241 },
2242 { .cmd = OVS_CT_LIMIT_CMD_DEL,
2243 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2244 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2245 * privilege. */
2246 .doit = ovs_ct_limit_cmd_del,
2247 },
2248 { .cmd = OVS_CT_LIMIT_CMD_GET,
2249 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2250 .flags = 0, /* OK for unprivileged users. */
2251 .doit = ovs_ct_limit_cmd_get,
2252 },
2253 };
2254
2255 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2256 .name = OVS_CT_LIMIT_MCGROUP,
2257 };
2258
2259 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2260 .hdrsize = sizeof(struct ovs_header),
2261 .name = OVS_CT_LIMIT_FAMILY,
2262 .version = OVS_CT_LIMIT_VERSION,
2263 .maxattr = OVS_CT_LIMIT_ATTR_MAX,
2264 .policy = ct_limit_policy,
2265 .netnsok = true,
2266 .parallel_ops = true,
2267 .small_ops = ct_limit_genl_ops,
2268 .n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
2269 .mcgrps = &ovs_ct_limit_multicast_group,
2270 .n_mcgrps = 1,
2271 .module = THIS_MODULE,
2272 };
2273 #endif
2274
ovs_ct_init(struct net * net)2275 int ovs_ct_init(struct net *net)
2276 {
2277 unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2278 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2279
2280 if (nf_connlabels_get(net, n_bits - 1)) {
2281 ovs_net->xt_label = false;
2282 OVS_NLERR(true, "Failed to set connlabel length");
2283 } else {
2284 ovs_net->xt_label = true;
2285 }
2286
2287 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2288 return ovs_ct_limit_init(net, ovs_net);
2289 #else
2290 return 0;
2291 #endif
2292 }
2293
ovs_ct_exit(struct net * net)2294 void ovs_ct_exit(struct net *net)
2295 {
2296 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2297
2298 #if IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2299 ovs_ct_limit_exit(net, ovs_net);
2300 #endif
2301
2302 if (ovs_net->xt_label)
2303 nf_connlabels_put(net);
2304 }
2305