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Linux/net/openvswitch/conntrack.c

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  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 
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. */
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 
150 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
151 {
152 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
153         return ct ? 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 
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 
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 
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  */
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  */
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 
279 #define IN6_ADDR_INITIALIZER(ADDR) \
280         { (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
281           (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }
282 
283 int ovs_ct_put_key(const struct sw_flow_key *swkey,
284                    const struct sw_flow_key *output, struct sk_buff *skb)
285 {
286         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
287                 return -EMSGSIZE;
288 
289         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
290             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
291                 return -EMSGSIZE;
292 
293         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
294             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
295                 return -EMSGSIZE;
296 
297         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
298             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
299                     &output->ct.labels))
300                 return -EMSGSIZE;
301 
302         if (swkey->ct_orig_proto) {
303                 if (swkey->eth.type == htons(ETH_P_IP)) {
304                         struct ovs_key_ct_tuple_ipv4 orig = {
305                                 output->ipv4.ct_orig.src,
306                                 output->ipv4.ct_orig.dst,
307                                 output->ct.orig_tp.src,
308                                 output->ct.orig_tp.dst,
309                                 output->ct_orig_proto,
310                         };
311                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
312                                     sizeof(orig), &orig))
313                                 return -EMSGSIZE;
314                 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
315                         struct ovs_key_ct_tuple_ipv6 orig = {
316                                 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
317                                 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
318                                 output->ct.orig_tp.src,
319                                 output->ct.orig_tp.dst,
320                                 output->ct_orig_proto,
321                         };
322                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
323                                     sizeof(orig), &orig))
324                                 return -EMSGSIZE;
325                 }
326         }
327 
328         return 0;
329 }
330 
331 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
332                            u32 ct_mark, u32 mask)
333 {
334 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
335         u32 new_mark;
336 
337         new_mark = ct_mark | (ct->mark & ~(mask));
338         if (ct->mark != new_mark) {
339                 ct->mark = new_mark;
340                 if (nf_ct_is_confirmed(ct))
341                         nf_conntrack_event_cache(IPCT_MARK, ct);
342                 key->ct.mark = new_mark;
343         }
344 
345         return 0;
346 #else
347         return -ENOTSUPP;
348 #endif
349 }
350 
351 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
352 {
353         struct nf_conn_labels *cl;
354 
355         cl = nf_ct_labels_find(ct);
356         if (!cl) {
357                 nf_ct_labels_ext_add(ct);
358                 cl = nf_ct_labels_find(ct);
359         }
360 
361         return cl;
362 }
363 
364 /* Initialize labels for a new, yet to be committed conntrack entry.  Note that
365  * since the new connection is not yet confirmed, and thus no-one else has
366  * access to it's labels, we simply write them over.
367  */
368 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
369                               const struct ovs_key_ct_labels *labels,
370                               const struct ovs_key_ct_labels *mask)
371 {
372         struct nf_conn_labels *cl, *master_cl;
373         bool have_mask = labels_nonzero(mask);
374 
375         /* Inherit master's labels to the related connection? */
376         master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
377 
378         if (!master_cl && !have_mask)
379                 return 0;   /* Nothing to do. */
380 
381         cl = ovs_ct_get_conn_labels(ct);
382         if (!cl)
383                 return -ENOSPC;
384 
385         /* Inherit the master's labels, if any. */
386         if (master_cl)
387                 *cl = *master_cl;
388 
389         if (have_mask) {
390                 u32 *dst = (u32 *)cl->bits;
391                 int i;
392 
393                 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
394                         dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
395                                 (labels->ct_labels_32[i]
396                                  & mask->ct_labels_32[i]);
397         }
398 
399         /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
400          * IPCT_LABEL bit is set in the event cache.
401          */
402         nf_conntrack_event_cache(IPCT_LABEL, ct);
403 
404         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
405 
406         return 0;
407 }
408 
409 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
410                              const struct ovs_key_ct_labels *labels,
411                              const struct ovs_key_ct_labels *mask)
412 {
413         struct nf_conn_labels *cl;
414         int err;
415 
416         cl = ovs_ct_get_conn_labels(ct);
417         if (!cl)
418                 return -ENOSPC;
419 
420         err = nf_connlabels_replace(ct, labels->ct_labels_32,
421                                     mask->ct_labels_32,
422                                     OVS_CT_LABELS_LEN_32);
423         if (err)
424                 return err;
425 
426         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
427 
428         return 0;
429 }
430 
431 /* 'skb' should already be pulled to nh_ofs. */
432 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
433 {
434         const struct nf_conntrack_helper *helper;
435         const struct nf_conn_help *help;
436         enum ip_conntrack_info ctinfo;
437         unsigned int protoff;
438         struct nf_conn *ct;
439         int err;
440 
441         ct = nf_ct_get(skb, &ctinfo);
442         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
443                 return NF_ACCEPT;
444 
445         help = nfct_help(ct);
446         if (!help)
447                 return NF_ACCEPT;
448 
449         helper = rcu_dereference(help->helper);
450         if (!helper)
451                 return NF_ACCEPT;
452 
453         switch (proto) {
454         case NFPROTO_IPV4:
455                 protoff = ip_hdrlen(skb);
456                 break;
457         case NFPROTO_IPV6: {
458                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
459                 __be16 frag_off;
460                 int ofs;
461 
462                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
463                                        &frag_off);
464                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
465                         pr_debug("proto header not found\n");
466                         return NF_ACCEPT;
467                 }
468                 protoff = ofs;
469                 break;
470         }
471         default:
472                 WARN_ONCE(1, "helper invoked on non-IP family!");
473                 return NF_DROP;
474         }
475 
476         err = helper->help(skb, protoff, ct, ctinfo);
477         if (err != NF_ACCEPT)
478                 return err;
479 
480         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
481          * FTP with NAT) adusting the TCP payload size when mangling IP
482          * addresses and/or port numbers in the text-based control connection.
483          */
484         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
485             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
486                 return NF_DROP;
487         return NF_ACCEPT;
488 }
489 
490 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
491  * value if 'skb' is freed.
492  */
493 static int handle_fragments(struct net *net, struct sw_flow_key *key,
494                             u16 zone, struct sk_buff *skb)
495 {
496         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
497         int err;
498 
499         if (key->eth.type == htons(ETH_P_IP)) {
500                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
501 
502                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
503                 err = ip_defrag(net, skb, user);
504                 if (err)
505                         return err;
506 
507                 ovs_cb.mru = IPCB(skb)->frag_max_size;
508 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
509         } else if (key->eth.type == htons(ETH_P_IPV6)) {
510                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
511 
512                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
513                 err = nf_ct_frag6_gather(net, skb, user);
514                 if (err) {
515                         if (err != -EINPROGRESS)
516                                 kfree_skb(skb);
517                         return err;
518                 }
519 
520                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
521                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
522 #endif
523         } else {
524                 kfree_skb(skb);
525                 return -EPFNOSUPPORT;
526         }
527 
528         /* The key extracted from the fragment that completed this datagram
529          * likely didn't have an L4 header, so regenerate it.
530          */
531         ovs_flow_key_update_l3l4(skb, key);
532 
533         key->ip.frag = OVS_FRAG_TYPE_NONE;
534         skb_clear_hash(skb);
535         skb->ignore_df = 1;
536         *OVS_CB(skb) = ovs_cb;
537 
538         return 0;
539 }
540 
541 static struct nf_conntrack_expect *
542 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
543                    u16 proto, const struct sk_buff *skb)
544 {
545         struct nf_conntrack_tuple tuple;
546         struct nf_conntrack_expect *exp;
547 
548         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
549                 return NULL;
550 
551         exp = __nf_ct_expect_find(net, zone, &tuple);
552         if (exp) {
553                 struct nf_conntrack_tuple_hash *h;
554 
555                 /* Delete existing conntrack entry, if it clashes with the
556                  * expectation.  This can happen since conntrack ALGs do not
557                  * check for clashes between (new) expectations and existing
558                  * conntrack entries.  nf_conntrack_in() will check the
559                  * expectations only if a conntrack entry can not be found,
560                  * which can lead to OVS finding the expectation (here) in the
561                  * init direction, but which will not be removed by the
562                  * nf_conntrack_in() call, if a matching conntrack entry is
563                  * found instead.  In this case all init direction packets
564                  * would be reported as new related packets, while reply
565                  * direction packets would be reported as un-related
566                  * established packets.
567                  */
568                 h = nf_conntrack_find_get(net, zone, &tuple);
569                 if (h) {
570                         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
571 
572                         nf_ct_delete(ct, 0, 0);
573                         nf_conntrack_put(&ct->ct_general);
574                 }
575         }
576 
577         return exp;
578 }
579 
580 /* This replicates logic from nf_conntrack_core.c that is not exported. */
581 static enum ip_conntrack_info
582 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
583 {
584         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
585 
586         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
587                 return IP_CT_ESTABLISHED_REPLY;
588         /* Once we've had two way comms, always ESTABLISHED. */
589         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
590                 return IP_CT_ESTABLISHED;
591         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
592                 return IP_CT_RELATED;
593         return IP_CT_NEW;
594 }
595 
596 /* Find an existing connection which this packet belongs to without
597  * re-attributing statistics or modifying the connection state.  This allows an
598  * skb->_nfct lost due to an upcall to be recovered during actions execution.
599  *
600  * Must be called with rcu_read_lock.
601  *
602  * On success, populates skb->_nfct and returns the connection.  Returns NULL
603  * if there is no existing entry.
604  */
605 static struct nf_conn *
606 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
607                      u8 l3num, struct sk_buff *skb, bool natted)
608 {
609         struct nf_conntrack_tuple tuple;
610         struct nf_conntrack_tuple_hash *h;
611         struct nf_conn *ct;
612 
613         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
614                                net, &tuple)) {
615                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
616                 return NULL;
617         }
618 
619         /* Must invert the tuple if skb has been transformed by NAT. */
620         if (natted) {
621                 struct nf_conntrack_tuple inverse;
622 
623                 if (!nf_ct_invert_tuple(&inverse, &tuple)) {
624                         pr_debug("ovs_ct_find_existing: Inversion failed!\n");
625                         return NULL;
626                 }
627                 tuple = inverse;
628         }
629 
630         /* look for tuple match */
631         h = nf_conntrack_find_get(net, zone, &tuple);
632         if (!h)
633                 return NULL;   /* Not found. */
634 
635         ct = nf_ct_tuplehash_to_ctrack(h);
636 
637         /* Inverted packet tuple matches the reverse direction conntrack tuple,
638          * select the other tuplehash to get the right 'ctinfo' bits for this
639          * packet.
640          */
641         if (natted)
642                 h = &ct->tuplehash[!h->tuple.dst.dir];
643 
644         nf_ct_set(skb, ct, ovs_ct_get_info(h));
645         return ct;
646 }
647 
648 static
649 struct nf_conn *ovs_ct_executed(struct net *net,
650                                 const struct sw_flow_key *key,
651                                 const struct ovs_conntrack_info *info,
652                                 struct sk_buff *skb,
653                                 bool *ct_executed)
654 {
655         struct nf_conn *ct = NULL;
656 
657         /* If no ct, check if we have evidence that an existing conntrack entry
658          * might be found for this skb.  This happens when we lose a skb->_nfct
659          * due to an upcall, or if the direction is being forced.  If the
660          * connection was not confirmed, it is not cached and needs to be run
661          * through conntrack again.
662          */
663         *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
664                        !(key->ct_state & OVS_CS_F_INVALID) &&
665                        (key->ct_zone == info->zone.id);
666 
667         if (*ct_executed || (!key->ct_state && info->force)) {
668                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
669                                           !!(key->ct_state &
670                                           OVS_CS_F_NAT_MASK));
671         }
672 
673         return ct;
674 }
675 
676 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
677 static bool skb_nfct_cached(struct net *net,
678                             const struct sw_flow_key *key,
679                             const struct ovs_conntrack_info *info,
680                             struct sk_buff *skb)
681 {
682         enum ip_conntrack_info ctinfo;
683         struct nf_conn *ct;
684         bool ct_executed = true;
685 
686         ct = nf_ct_get(skb, &ctinfo);
687         if (!ct)
688                 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
689 
690         if (ct)
691                 nf_ct_get(skb, &ctinfo);
692         else
693                 return false;
694 
695         if (!net_eq(net, read_pnet(&ct->ct_net)))
696                 return false;
697         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
698                 return false;
699         if (info->helper) {
700                 struct nf_conn_help *help;
701 
702                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
703                 if (help && rcu_access_pointer(help->helper) != info->helper)
704                         return false;
705         }
706         if (info->nf_ct_timeout) {
707                 struct nf_conn_timeout *timeout_ext;
708 
709                 timeout_ext = nf_ct_timeout_find(ct);
710                 if (!timeout_ext || info->nf_ct_timeout !=
711                     rcu_dereference(timeout_ext->timeout))
712                         return false;
713         }
714         /* Force conntrack entry direction to the current packet? */
715         if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
716                 /* Delete the conntrack entry if confirmed, else just release
717                  * the reference.
718                  */
719                 if (nf_ct_is_confirmed(ct))
720                         nf_ct_delete(ct, 0, 0);
721 
722                 nf_conntrack_put(&ct->ct_general);
723                 nf_ct_set(skb, NULL, 0);
724                 return false;
725         }
726 
727         return ct_executed;
728 }
729 
730 #if IS_ENABLED(CONFIG_NF_NAT)
731 /* Modelled after nf_nat_ipv[46]_fn().
732  * range is only used for new, uninitialized NAT state.
733  * Returns either NF_ACCEPT or NF_DROP.
734  */
735 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
736                               enum ip_conntrack_info ctinfo,
737                               const struct nf_nat_range2 *range,
738                               enum nf_nat_manip_type maniptype)
739 {
740         int hooknum, nh_off, err = NF_ACCEPT;
741 
742         nh_off = skb_network_offset(skb);
743         skb_pull_rcsum(skb, nh_off);
744 
745         /* See HOOK2MANIP(). */
746         if (maniptype == NF_NAT_MANIP_SRC)
747                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
748         else
749                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
750 
751         switch (ctinfo) {
752         case IP_CT_RELATED:
753         case IP_CT_RELATED_REPLY:
754                 if (IS_ENABLED(CONFIG_NF_NAT) &&
755                     skb->protocol == htons(ETH_P_IP) &&
756                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
757                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
758                                                            hooknum))
759                                 err = NF_DROP;
760                         goto push;
761                 } else if (IS_ENABLED(CONFIG_IPV6) &&
762                            skb->protocol == htons(ETH_P_IPV6)) {
763                         __be16 frag_off;
764                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
765                         int hdrlen = ipv6_skip_exthdr(skb,
766                                                       sizeof(struct ipv6hdr),
767                                                       &nexthdr, &frag_off);
768 
769                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
770                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
771                                                                      ctinfo,
772                                                                      hooknum,
773                                                                      hdrlen))
774                                         err = NF_DROP;
775                                 goto push;
776                         }
777                 }
778                 /* Non-ICMP, fall thru to initialize if needed. */
779                 /* fall through */
780         case IP_CT_NEW:
781                 /* Seen it before?  This can happen for loopback, retrans,
782                  * or local packets.
783                  */
784                 if (!nf_nat_initialized(ct, maniptype)) {
785                         /* Initialize according to the NAT action. */
786                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
787                                 /* Action is set up to establish a new
788                                  * mapping.
789                                  */
790                                 ? nf_nat_setup_info(ct, range, maniptype)
791                                 : nf_nat_alloc_null_binding(ct, hooknum);
792                         if (err != NF_ACCEPT)
793                                 goto push;
794                 }
795                 break;
796 
797         case IP_CT_ESTABLISHED:
798         case IP_CT_ESTABLISHED_REPLY:
799                 break;
800 
801         default:
802                 err = NF_DROP;
803                 goto push;
804         }
805 
806         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
807 push:
808         skb_push(skb, nh_off);
809         skb_postpush_rcsum(skb, skb->data, nh_off);
810 
811         return err;
812 }
813 
814 static void ovs_nat_update_key(struct sw_flow_key *key,
815                                const struct sk_buff *skb,
816                                enum nf_nat_manip_type maniptype)
817 {
818         if (maniptype == NF_NAT_MANIP_SRC) {
819                 __be16 src;
820 
821                 key->ct_state |= OVS_CS_F_SRC_NAT;
822                 if (key->eth.type == htons(ETH_P_IP))
823                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
824                 else if (key->eth.type == htons(ETH_P_IPV6))
825                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
826                                sizeof(key->ipv6.addr.src));
827                 else
828                         return;
829 
830                 if (key->ip.proto == IPPROTO_UDP)
831                         src = udp_hdr(skb)->source;
832                 else if (key->ip.proto == IPPROTO_TCP)
833                         src = tcp_hdr(skb)->source;
834                 else if (key->ip.proto == IPPROTO_SCTP)
835                         src = sctp_hdr(skb)->source;
836                 else
837                         return;
838 
839                 key->tp.src = src;
840         } else {
841                 __be16 dst;
842 
843                 key->ct_state |= OVS_CS_F_DST_NAT;
844                 if (key->eth.type == htons(ETH_P_IP))
845                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
846                 else if (key->eth.type == htons(ETH_P_IPV6))
847                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
848                                sizeof(key->ipv6.addr.dst));
849                 else
850                         return;
851 
852                 if (key->ip.proto == IPPROTO_UDP)
853                         dst = udp_hdr(skb)->dest;
854                 else if (key->ip.proto == IPPROTO_TCP)
855                         dst = tcp_hdr(skb)->dest;
856                 else if (key->ip.proto == IPPROTO_SCTP)
857                         dst = sctp_hdr(skb)->dest;
858                 else
859                         return;
860 
861                 key->tp.dst = dst;
862         }
863 }
864 
865 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
866 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
867                       const struct ovs_conntrack_info *info,
868                       struct sk_buff *skb, struct nf_conn *ct,
869                       enum ip_conntrack_info ctinfo)
870 {
871         enum nf_nat_manip_type maniptype;
872         int err;
873 
874         /* Add NAT extension if not confirmed yet. */
875         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
876                 return NF_ACCEPT;   /* Can't NAT. */
877 
878         /* Determine NAT type.
879          * Check if the NAT type can be deduced from the tracked connection.
880          * Make sure new expected connections (IP_CT_RELATED) are NATted only
881          * when committing.
882          */
883         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
884             ct->status & IPS_NAT_MASK &&
885             (ctinfo != IP_CT_RELATED || info->commit)) {
886                 /* NAT an established or related connection like before. */
887                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
888                         /* This is the REPLY direction for a connection
889                          * for which NAT was applied in the forward
890                          * direction.  Do the reverse NAT.
891                          */
892                         maniptype = ct->status & IPS_SRC_NAT
893                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
894                 else
895                         maniptype = ct->status & IPS_SRC_NAT
896                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
897         } else if (info->nat & OVS_CT_SRC_NAT) {
898                 maniptype = NF_NAT_MANIP_SRC;
899         } else if (info->nat & OVS_CT_DST_NAT) {
900                 maniptype = NF_NAT_MANIP_DST;
901         } else {
902                 return NF_ACCEPT; /* Connection is not NATed. */
903         }
904         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
905 
906         if (err == NF_ACCEPT &&
907             ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
908                 if (maniptype == NF_NAT_MANIP_SRC)
909                         maniptype = NF_NAT_MANIP_DST;
910                 else
911                         maniptype = NF_NAT_MANIP_SRC;
912 
913                 err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
914                                          maniptype);
915         }
916 
917         /* Mark NAT done if successful and update the flow key. */
918         if (err == NF_ACCEPT)
919                 ovs_nat_update_key(key, skb, maniptype);
920 
921         return err;
922 }
923 #else /* !CONFIG_NF_NAT */
924 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
925                       const struct ovs_conntrack_info *info,
926                       struct sk_buff *skb, struct nf_conn *ct,
927                       enum ip_conntrack_info ctinfo)
928 {
929         return NF_ACCEPT;
930 }
931 #endif
932 
933 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
934  * not done already.  Update key with new CT state after passing the packet
935  * through conntrack.
936  * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
937  * set to NULL and 0 will be returned.
938  */
939 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
940                            const struct ovs_conntrack_info *info,
941                            struct sk_buff *skb)
942 {
943         /* If we are recirculating packets to match on conntrack fields and
944          * committing with a separate conntrack action,  then we don't need to
945          * actually run the packet through conntrack twice unless it's for a
946          * different zone.
947          */
948         bool cached = skb_nfct_cached(net, key, info, skb);
949         enum ip_conntrack_info ctinfo;
950         struct nf_conn *ct;
951 
952         if (!cached) {
953                 struct nf_hook_state state = {
954                         .hook = NF_INET_PRE_ROUTING,
955                         .pf = info->family,
956                         .net = net,
957                 };
958                 struct nf_conn *tmpl = info->ct;
959                 int err;
960 
961                 /* Associate skb with specified zone. */
962                 if (tmpl) {
963                         if (skb_nfct(skb))
964                                 nf_conntrack_put(skb_nfct(skb));
965                         nf_conntrack_get(&tmpl->ct_general);
966                         nf_ct_set(skb, tmpl, IP_CT_NEW);
967                 }
968 
969                 err = nf_conntrack_in(skb, &state);
970                 if (err != NF_ACCEPT)
971                         return -ENOENT;
972 
973                 /* Clear CT state NAT flags to mark that we have not yet done
974                  * NAT after the nf_conntrack_in() call.  We can actually clear
975                  * the whole state, as it will be re-initialized below.
976                  */
977                 key->ct_state = 0;
978 
979                 /* Update the key, but keep the NAT flags. */
980                 ovs_ct_update_key(skb, info, key, true, true);
981         }
982 
983         ct = nf_ct_get(skb, &ctinfo);
984         if (ct) {
985                 bool add_helper = false;
986 
987                 /* Packets starting a new connection must be NATted before the
988                  * helper, so that the helper knows about the NAT.  We enforce
989                  * this by delaying both NAT and helper calls for unconfirmed
990                  * connections until the committing CT action.  For later
991                  * packets NAT and Helper may be called in either order.
992                  *
993                  * NAT will be done only if the CT action has NAT, and only
994                  * once per packet (per zone), as guarded by the NAT bits in
995                  * the key->ct_state.
996                  */
997                 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
998                     (nf_ct_is_confirmed(ct) || info->commit) &&
999                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
1000                         return -EINVAL;
1001                 }
1002 
1003                 /* Userspace may decide to perform a ct lookup without a helper
1004                  * specified followed by a (recirculate and) commit with one,
1005                  * or attach a helper in a later commit.  Therefore, for
1006                  * connections which we will commit, we may need to attach
1007                  * the helper here.
1008                  */
1009                 if (info->commit && info->helper && !nfct_help(ct)) {
1010                         int err = __nf_ct_try_assign_helper(ct, info->ct,
1011                                                             GFP_ATOMIC);
1012                         if (err)
1013                                 return err;
1014                         add_helper = true;
1015 
1016                         /* helper installed, add seqadj if NAT is required */
1017                         if (info->nat && !nfct_seqadj(ct)) {
1018                                 if (!nfct_seqadj_ext_add(ct))
1019                                         return -EINVAL;
1020                         }
1021                 }
1022 
1023                 /* Call the helper only if:
1024                  * - nf_conntrack_in() was executed above ("!cached") or a
1025                  *   helper was just attached ("add_helper") for a confirmed
1026                  *   connection, or
1027                  * - When committing an unconfirmed connection.
1028                  */
1029                 if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
1030                                               info->commit) &&
1031                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
1032                         return -EINVAL;
1033                 }
1034         }
1035 
1036         return 0;
1037 }
1038 
1039 /* Lookup connection and read fields into key. */
1040 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
1041                          const struct ovs_conntrack_info *info,
1042                          struct sk_buff *skb)
1043 {
1044         struct nf_conntrack_expect *exp;
1045 
1046         /* If we pass an expected packet through nf_conntrack_in() the
1047          * expectation is typically removed, but the packet could still be
1048          * lost in upcall processing.  To prevent this from happening we
1049          * perform an explicit expectation lookup.  Expected connections are
1050          * always new, and will be passed through conntrack only when they are
1051          * committed, as it is OK to remove the expectation at that time.
1052          */
1053         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1054         if (exp) {
1055                 u8 state;
1056 
1057                 /* NOTE: New connections are NATted and Helped only when
1058                  * committed, so we are not calling into NAT here.
1059                  */
1060                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1061                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1062         } else {
1063                 struct nf_conn *ct;
1064                 int err;
1065 
1066                 err = __ovs_ct_lookup(net, key, info, skb);
1067                 if (err)
1068                         return err;
1069 
1070                 ct = (struct nf_conn *)skb_nfct(skb);
1071                 if (ct)
1072                         nf_ct_deliver_cached_events(ct);
1073         }
1074 
1075         return 0;
1076 }
1077 
1078 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1079 {
1080         size_t i;
1081 
1082         for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1083                 if (labels->ct_labels_32[i])
1084                         return true;
1085 
1086         return false;
1087 }
1088 
1089 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1090 static struct hlist_head *ct_limit_hash_bucket(
1091         const struct ovs_ct_limit_info *info, u16 zone)
1092 {
1093         return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
1094 }
1095 
1096 /* Call with ovs_mutex */
1097 static void ct_limit_set(const struct ovs_ct_limit_info *info,
1098                          struct ovs_ct_limit *new_ct_limit)
1099 {
1100         struct ovs_ct_limit *ct_limit;
1101         struct hlist_head *head;
1102 
1103         head = ct_limit_hash_bucket(info, new_ct_limit->zone);
1104         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1105                 if (ct_limit->zone == new_ct_limit->zone) {
1106                         hlist_replace_rcu(&ct_limit->hlist_node,
1107                                           &new_ct_limit->hlist_node);
1108                         kfree_rcu(ct_limit, rcu);
1109                         return;
1110                 }
1111         }
1112 
1113         hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
1114 }
1115 
1116 /* Call with ovs_mutex */
1117 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
1118 {
1119         struct ovs_ct_limit *ct_limit;
1120         struct hlist_head *head;
1121         struct hlist_node *n;
1122 
1123         head = ct_limit_hash_bucket(info, zone);
1124         hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
1125                 if (ct_limit->zone == zone) {
1126                         hlist_del_rcu(&ct_limit->hlist_node);
1127                         kfree_rcu(ct_limit, rcu);
1128                         return;
1129                 }
1130         }
1131 }
1132 
1133 /* Call with RCU read lock */
1134 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
1135 {
1136         struct ovs_ct_limit *ct_limit;
1137         struct hlist_head *head;
1138 
1139         head = ct_limit_hash_bucket(info, zone);
1140         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1141                 if (ct_limit->zone == zone)
1142                         return ct_limit->limit;
1143         }
1144 
1145         return info->default_limit;
1146 }
1147 
1148 static int ovs_ct_check_limit(struct net *net,
1149                               const struct ovs_conntrack_info *info,
1150                               const struct nf_conntrack_tuple *tuple)
1151 {
1152         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1153         const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1154         u32 per_zone_limit, connections;
1155         u32 conncount_key;
1156 
1157         conncount_key = info->zone.id;
1158 
1159         per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1160         if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1161                 return 0;
1162 
1163         connections = nf_conncount_count(net, ct_limit_info->data,
1164                                          &conncount_key, tuple, &info->zone);
1165         if (connections > per_zone_limit)
1166                 return -ENOMEM;
1167 
1168         return 0;
1169 }
1170 #endif
1171 
1172 /* Lookup connection and confirm if unconfirmed. */
1173 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1174                          const struct ovs_conntrack_info *info,
1175                          struct sk_buff *skb)
1176 {
1177         enum ip_conntrack_info ctinfo;
1178         struct nf_conn *ct;
1179         int err;
1180 
1181         err = __ovs_ct_lookup(net, key, info, skb);
1182         if (err)
1183                 return err;
1184 
1185         /* The connection could be invalid, in which case this is a no-op.*/
1186         ct = nf_ct_get(skb, &ctinfo);
1187         if (!ct)
1188                 return 0;
1189 
1190 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1191         if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1192                 if (!nf_ct_is_confirmed(ct)) {
1193                         err = ovs_ct_check_limit(net, info,
1194                                 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1195                         if (err) {
1196                                 net_warn_ratelimited("openvswitch: zone: %u "
1197                                         "exceeds conntrack limit\n",
1198                                         info->zone.id);
1199                                 return err;
1200                         }
1201                 }
1202         }
1203 #endif
1204 
1205         /* Set the conntrack event mask if given.  NEW and DELETE events have
1206          * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1207          * typically would receive many kinds of updates.  Setting the event
1208          * mask allows those events to be filtered.  The set event mask will
1209          * remain in effect for the lifetime of the connection unless changed
1210          * by a further CT action with both the commit flag and the eventmask
1211          * option. */
1212         if (info->have_eventmask) {
1213                 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1214 
1215                 if (cache)
1216                         cache->ctmask = info->eventmask;
1217         }
1218 
1219         /* Apply changes before confirming the connection so that the initial
1220          * conntrack NEW netlink event carries the values given in the CT
1221          * action.
1222          */
1223         if (info->mark.mask) {
1224                 err = ovs_ct_set_mark(ct, key, info->mark.value,
1225                                       info->mark.mask);
1226                 if (err)
1227                         return err;
1228         }
1229         if (!nf_ct_is_confirmed(ct)) {
1230                 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1231                                          &info->labels.mask);
1232                 if (err)
1233                         return err;
1234         } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1235                    labels_nonzero(&info->labels.mask)) {
1236                 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1237                                         &info->labels.mask);
1238                 if (err)
1239                         return err;
1240         }
1241         /* This will take care of sending queued events even if the connection
1242          * is already confirmed.
1243          */
1244         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1245                 return -EINVAL;
1246 
1247         return 0;
1248 }
1249 
1250 /* Trim the skb to the length specified by the IP/IPv6 header,
1251  * removing any trailing lower-layer padding. This prepares the skb
1252  * for higher-layer processing that assumes skb->len excludes padding
1253  * (such as nf_ip_checksum). The caller needs to pull the skb to the
1254  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1255  */
1256 static int ovs_skb_network_trim(struct sk_buff *skb)
1257 {
1258         unsigned int len;
1259         int err;
1260 
1261         switch (skb->protocol) {
1262         case htons(ETH_P_IP):
1263                 len = ntohs(ip_hdr(skb)->tot_len);
1264                 break;
1265         case htons(ETH_P_IPV6):
1266                 len = sizeof(struct ipv6hdr)
1267                         + ntohs(ipv6_hdr(skb)->payload_len);
1268                 break;
1269         default:
1270                 len = skb->len;
1271         }
1272 
1273         err = pskb_trim_rcsum(skb, len);
1274         if (err)
1275                 kfree_skb(skb);
1276 
1277         return err;
1278 }
1279 
1280 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1281  * value if 'skb' is freed.
1282  */
1283 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1284                    struct sw_flow_key *key,
1285                    const struct ovs_conntrack_info *info)
1286 {
1287         int nh_ofs;
1288         int err;
1289 
1290         /* The conntrack module expects to be working at L3. */
1291         nh_ofs = skb_network_offset(skb);
1292         skb_pull_rcsum(skb, nh_ofs);
1293 
1294         err = ovs_skb_network_trim(skb);
1295         if (err)
1296                 return err;
1297 
1298         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1299                 err = handle_fragments(net, key, info->zone.id, skb);
1300                 if (err)
1301                         return err;
1302         }
1303 
1304         if (info->commit)
1305                 err = ovs_ct_commit(net, key, info, skb);
1306         else
1307                 err = ovs_ct_lookup(net, key, info, skb);
1308 
1309         skb_push(skb, nh_ofs);
1310         skb_postpush_rcsum(skb, skb->data, nh_ofs);
1311         if (err)
1312                 kfree_skb(skb);
1313         return err;
1314 }
1315 
1316 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1317 {
1318         if (skb_nfct(skb)) {
1319                 nf_conntrack_put(skb_nfct(skb));
1320                 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1321                 ovs_ct_fill_key(skb, key);
1322         }
1323 
1324         return 0;
1325 }
1326 
1327 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1328                              const struct sw_flow_key *key, bool log)
1329 {
1330         struct nf_conntrack_helper *helper;
1331         struct nf_conn_help *help;
1332         int ret = 0;
1333 
1334         helper = nf_conntrack_helper_try_module_get(name, info->family,
1335                                                     key->ip.proto);
1336         if (!helper) {
1337                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1338                 return -EINVAL;
1339         }
1340 
1341         help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
1342         if (!help) {
1343                 nf_conntrack_helper_put(helper);
1344                 return -ENOMEM;
1345         }
1346 
1347 #if IS_ENABLED(CONFIG_NF_NAT)
1348         if (info->nat) {
1349                 ret = nf_nat_helper_try_module_get(name, info->family,
1350                                                    key->ip.proto);
1351                 if (ret) {
1352                         nf_conntrack_helper_put(helper);
1353                         OVS_NLERR(log, "Failed to load \"%s\" NAT helper, error: %d",
1354                                   name, ret);
1355                         return ret;
1356                 }
1357         }
1358 #endif
1359         rcu_assign_pointer(help->helper, helper);
1360         info->helper = helper;
1361         return ret;
1362 }
1363 
1364 #if IS_ENABLED(CONFIG_NF_NAT)
1365 static int parse_nat(const struct nlattr *attr,
1366                      struct ovs_conntrack_info *info, bool log)
1367 {
1368         struct nlattr *a;
1369         int rem;
1370         bool have_ip_max = false;
1371         bool have_proto_max = false;
1372         bool ip_vers = (info->family == NFPROTO_IPV6);
1373 
1374         nla_for_each_nested(a, attr, rem) {
1375                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1376                         [OVS_NAT_ATTR_SRC] = {0, 0},
1377                         [OVS_NAT_ATTR_DST] = {0, 0},
1378                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1379                                                  sizeof(struct in6_addr)},
1380                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1381                                                  sizeof(struct in6_addr)},
1382                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1383                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1384                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1385                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1386                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1387                 };
1388                 int type = nla_type(a);
1389 
1390                 if (type > OVS_NAT_ATTR_MAX) {
1391                         OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1392                                   type, OVS_NAT_ATTR_MAX);
1393                         return -EINVAL;
1394                 }
1395 
1396                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1397                         OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1398                                   type, nla_len(a),
1399                                   ovs_nat_attr_lens[type][ip_vers]);
1400                         return -EINVAL;
1401                 }
1402 
1403                 switch (type) {
1404                 case OVS_NAT_ATTR_SRC:
1405                 case OVS_NAT_ATTR_DST:
1406                         if (info->nat) {
1407                                 OVS_NLERR(log, "Only one type of NAT may be specified");
1408                                 return -ERANGE;
1409                         }
1410                         info->nat |= OVS_CT_NAT;
1411                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
1412                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1413                         break;
1414 
1415                 case OVS_NAT_ATTR_IP_MIN:
1416                         nla_memcpy(&info->range.min_addr, a,
1417                                    sizeof(info->range.min_addr));
1418                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1419                         break;
1420 
1421                 case OVS_NAT_ATTR_IP_MAX:
1422                         have_ip_max = true;
1423                         nla_memcpy(&info->range.max_addr, a,
1424                                    sizeof(info->range.max_addr));
1425                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1426                         break;
1427 
1428                 case OVS_NAT_ATTR_PROTO_MIN:
1429                         info->range.min_proto.all = htons(nla_get_u16(a));
1430                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1431                         break;
1432 
1433                 case OVS_NAT_ATTR_PROTO_MAX:
1434                         have_proto_max = true;
1435                         info->range.max_proto.all = htons(nla_get_u16(a));
1436                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1437                         break;
1438 
1439                 case OVS_NAT_ATTR_PERSISTENT:
1440                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1441                         break;
1442 
1443                 case OVS_NAT_ATTR_PROTO_HASH:
1444                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1445                         break;
1446 
1447                 case OVS_NAT_ATTR_PROTO_RANDOM:
1448                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1449                         break;
1450 
1451                 default:
1452                         OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1453                         return -EINVAL;
1454                 }
1455         }
1456 
1457         if (rem > 0) {
1458                 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1459                 return -EINVAL;
1460         }
1461         if (!info->nat) {
1462                 /* Do not allow flags if no type is given. */
1463                 if (info->range.flags) {
1464                         OVS_NLERR(log,
1465                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1466                                   );
1467                         return -EINVAL;
1468                 }
1469                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1470         } else if (!info->commit) {
1471                 OVS_NLERR(log,
1472                           "NAT attributes may be specified only when CT COMMIT flag is also specified."
1473                           );
1474                 return -EINVAL;
1475         }
1476         /* Allow missing IP_MAX. */
1477         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1478                 memcpy(&info->range.max_addr, &info->range.min_addr,
1479                        sizeof(info->range.max_addr));
1480         }
1481         /* Allow missing PROTO_MAX. */
1482         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1483             !have_proto_max) {
1484                 info->range.max_proto.all = info->range.min_proto.all;
1485         }
1486         return 0;
1487 }
1488 #endif
1489 
1490 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1491         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1492         [OVS_CT_ATTR_FORCE_COMMIT]      = { .minlen = 0, .maxlen = 0 },
1493         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1494                                     .maxlen = sizeof(u16) },
1495         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1496                                     .maxlen = sizeof(struct md_mark) },
1497         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1498                                     .maxlen = sizeof(struct md_labels) },
1499         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1500                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1501 #if IS_ENABLED(CONFIG_NF_NAT)
1502         /* NAT length is checked when parsing the nested attributes. */
1503         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1504 #endif
1505         [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1506                                     .maxlen = sizeof(u32) },
1507         [OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
1508                                   .maxlen = CTNL_TIMEOUT_NAME_MAX },
1509 };
1510 
1511 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1512                     const char **helper, bool log)
1513 {
1514         struct nlattr *a;
1515         int rem;
1516 
1517         nla_for_each_nested(a, attr, rem) {
1518                 int type = nla_type(a);
1519                 int maxlen;
1520                 int minlen;
1521 
1522                 if (type > OVS_CT_ATTR_MAX) {
1523                         OVS_NLERR(log,
1524                                   "Unknown conntrack attr (type=%d, max=%d)",
1525                                   type, OVS_CT_ATTR_MAX);
1526                         return -EINVAL;
1527                 }
1528 
1529                 maxlen = ovs_ct_attr_lens[type].maxlen;
1530                 minlen = ovs_ct_attr_lens[type].minlen;
1531                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1532                         OVS_NLERR(log,
1533                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1534                                   type, nla_len(a), maxlen);
1535                         return -EINVAL;
1536                 }
1537 
1538                 switch (type) {
1539                 case OVS_CT_ATTR_FORCE_COMMIT:
1540                         info->force = true;
1541                         /* fall through. */
1542                 case OVS_CT_ATTR_COMMIT:
1543                         info->commit = true;
1544                         break;
1545 #ifdef CONFIG_NF_CONNTRACK_ZONES
1546                 case OVS_CT_ATTR_ZONE:
1547                         info->zone.id = nla_get_u16(a);
1548                         break;
1549 #endif
1550 #ifdef CONFIG_NF_CONNTRACK_MARK
1551                 case OVS_CT_ATTR_MARK: {
1552                         struct md_mark *mark = nla_data(a);
1553 
1554                         if (!mark->mask) {
1555                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1556                                 return -EINVAL;
1557                         }
1558                         info->mark = *mark;
1559                         break;
1560                 }
1561 #endif
1562 #ifdef CONFIG_NF_CONNTRACK_LABELS
1563                 case OVS_CT_ATTR_LABELS: {
1564                         struct md_labels *labels = nla_data(a);
1565 
1566                         if (!labels_nonzero(&labels->mask)) {
1567                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1568                                 return -EINVAL;
1569                         }
1570                         info->labels = *labels;
1571                         break;
1572                 }
1573 #endif
1574                 case OVS_CT_ATTR_HELPER:
1575                         *helper = nla_data(a);
1576                         if (!memchr(*helper, '\0', nla_len(a))) {
1577                                 OVS_NLERR(log, "Invalid conntrack helper");
1578                                 return -EINVAL;
1579                         }
1580                         break;
1581 #if IS_ENABLED(CONFIG_NF_NAT)
1582                 case OVS_CT_ATTR_NAT: {
1583                         int err = parse_nat(a, info, log);
1584 
1585                         if (err)
1586                                 return err;
1587                         break;
1588                 }
1589 #endif
1590                 case OVS_CT_ATTR_EVENTMASK:
1591                         info->have_eventmask = true;
1592                         info->eventmask = nla_get_u32(a);
1593                         break;
1594 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1595                 case OVS_CT_ATTR_TIMEOUT:
1596                         memcpy(info->timeout, nla_data(a), nla_len(a));
1597                         if (!memchr(info->timeout, '\0', nla_len(a))) {
1598                                 OVS_NLERR(log, "Invalid conntrack timeout");
1599                                 return -EINVAL;
1600                         }
1601                         break;
1602 #endif
1603 
1604                 default:
1605                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1606                                   type);
1607                         return -EINVAL;
1608                 }
1609         }
1610 
1611 #ifdef CONFIG_NF_CONNTRACK_MARK
1612         if (!info->commit && info->mark.mask) {
1613                 OVS_NLERR(log,
1614                           "Setting conntrack mark requires 'commit' flag.");
1615                 return -EINVAL;
1616         }
1617 #endif
1618 #ifdef CONFIG_NF_CONNTRACK_LABELS
1619         if (!info->commit && labels_nonzero(&info->labels.mask)) {
1620                 OVS_NLERR(log,
1621                           "Setting conntrack labels requires 'commit' flag.");
1622                 return -EINVAL;
1623         }
1624 #endif
1625         if (rem > 0) {
1626                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1627                 return -EINVAL;
1628         }
1629 
1630         return 0;
1631 }
1632 
1633 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1634 {
1635         if (attr == OVS_KEY_ATTR_CT_STATE)
1636                 return true;
1637         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1638             attr == OVS_KEY_ATTR_CT_ZONE)
1639                 return true;
1640         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1641             attr == OVS_KEY_ATTR_CT_MARK)
1642                 return true;
1643         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1644             attr == OVS_KEY_ATTR_CT_LABELS) {
1645                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1646 
1647                 return ovs_net->xt_label;
1648         }
1649 
1650         return false;
1651 }
1652 
1653 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1654                        const struct sw_flow_key *key,
1655                        struct sw_flow_actions **sfa,  bool log)
1656 {
1657         struct ovs_conntrack_info ct_info;
1658         const char *helper = NULL;
1659         u16 family;
1660         int err;
1661 
1662         family = key_to_nfproto(key);
1663         if (family == NFPROTO_UNSPEC) {
1664                 OVS_NLERR(log, "ct family unspecified");
1665                 return -EINVAL;
1666         }
1667 
1668         memset(&ct_info, 0, sizeof(ct_info));
1669         ct_info.family = family;
1670 
1671         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1672                         NF_CT_DEFAULT_ZONE_DIR, 0);
1673 
1674         err = parse_ct(attr, &ct_info, &helper, log);
1675         if (err)
1676                 return err;
1677 
1678         /* Set up template for tracking connections in specific zones. */
1679         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1680         if (!ct_info.ct) {
1681                 OVS_NLERR(log, "Failed to allocate conntrack template");
1682                 return -ENOMEM;
1683         }
1684 
1685         if (ct_info.timeout[0]) {
1686                 if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
1687                                       ct_info.timeout))
1688                         pr_info_ratelimited("Failed to associated timeout "
1689                                             "policy `%s'\n", ct_info.timeout);
1690                 else
1691                         ct_info.nf_ct_timeout = rcu_dereference(
1692                                 nf_ct_timeout_find(ct_info.ct)->timeout);
1693 
1694         }
1695 
1696         if (helper) {
1697                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1698                 if (err)
1699                         goto err_free_ct;
1700         }
1701 
1702         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1703                                  sizeof(ct_info), log);
1704         if (err)
1705                 goto err_free_ct;
1706 
1707         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1708         nf_conntrack_get(&ct_info.ct->ct_general);
1709         return 0;
1710 err_free_ct:
1711         __ovs_ct_free_action(&ct_info);
1712         return err;
1713 }
1714 
1715 #if IS_ENABLED(CONFIG_NF_NAT)
1716 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1717                                struct sk_buff *skb)
1718 {
1719         struct nlattr *start;
1720 
1721         start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
1722         if (!start)
1723                 return false;
1724 
1725         if (info->nat & OVS_CT_SRC_NAT) {
1726                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1727                         return false;
1728         } else if (info->nat & OVS_CT_DST_NAT) {
1729                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1730                         return false;
1731         } else {
1732                 goto out;
1733         }
1734 
1735         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1736                 if (IS_ENABLED(CONFIG_NF_NAT) &&
1737                     info->family == NFPROTO_IPV4) {
1738                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1739                                             info->range.min_addr.ip) ||
1740                             (info->range.max_addr.ip
1741                              != info->range.min_addr.ip &&
1742                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1743                                               info->range.max_addr.ip))))
1744                                 return false;
1745                 } else if (IS_ENABLED(CONFIG_IPV6) &&
1746                            info->family == NFPROTO_IPV6) {
1747                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1748                                              &info->range.min_addr.in6) ||
1749                             (memcmp(&info->range.max_addr.in6,
1750                                     &info->range.min_addr.in6,
1751                                     sizeof(info->range.max_addr.in6)) &&
1752                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1753                                                &info->range.max_addr.in6))))
1754                                 return false;
1755                 } else {
1756                         return false;
1757                 }
1758         }
1759         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1760             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1761                          ntohs(info->range.min_proto.all)) ||
1762              (info->range.max_proto.all != info->range.min_proto.all &&
1763               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1764                           ntohs(info->range.max_proto.all)))))
1765                 return false;
1766 
1767         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1768             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1769                 return false;
1770         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1771             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1772                 return false;
1773         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1774             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1775                 return false;
1776 out:
1777         nla_nest_end(skb, start);
1778 
1779         return true;
1780 }
1781 #endif
1782 
1783 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1784                           struct sk_buff *skb)
1785 {
1786         struct nlattr *start;
1787 
1788         start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
1789         if (!start)
1790                 return -EMSGSIZE;
1791 
1792         if (ct_info->commit && nla_put_flag(skb, ct_info->force
1793                                             ? OVS_CT_ATTR_FORCE_COMMIT
1794                                             : OVS_CT_ATTR_COMMIT))
1795                 return -EMSGSIZE;
1796         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1797             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1798                 return -EMSGSIZE;
1799         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1800             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1801                     &ct_info->mark))
1802                 return -EMSGSIZE;
1803         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1804             labels_nonzero(&ct_info->labels.mask) &&
1805             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1806                     &ct_info->labels))
1807                 return -EMSGSIZE;
1808         if (ct_info->helper) {
1809                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1810                                    ct_info->helper->name))
1811                         return -EMSGSIZE;
1812         }
1813         if (ct_info->have_eventmask &&
1814             nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1815                 return -EMSGSIZE;
1816         if (ct_info->timeout[0]) {
1817                 if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
1818                         return -EMSGSIZE;
1819         }
1820 
1821 #if IS_ENABLED(CONFIG_NF_NAT)
1822         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1823                 return -EMSGSIZE;
1824 #endif
1825         nla_nest_end(skb, start);
1826 
1827         return 0;
1828 }
1829 
1830 void ovs_ct_free_action(const struct nlattr *a)
1831 {
1832         struct ovs_conntrack_info *ct_info = nla_data(a);
1833 
1834         __ovs_ct_free_action(ct_info);
1835 }
1836 
1837 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1838 {
1839         if (ct_info->helper) {
1840 #if IS_ENABLED(CONFIG_NF_NAT)
1841                 if (ct_info->nat)
1842                         nf_nat_helper_put(ct_info->helper);
1843 #endif
1844                 nf_conntrack_helper_put(ct_info->helper);
1845         }
1846         if (ct_info->ct) {
1847                 if (ct_info->timeout[0])
1848                         nf_ct_destroy_timeout(ct_info->ct);
1849                 nf_ct_tmpl_free(ct_info->ct);
1850         }
1851 }
1852 
1853 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1854 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1855 {
1856         int i, err;
1857 
1858         ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1859                                          GFP_KERNEL);
1860         if (!ovs_net->ct_limit_info)
1861                 return -ENOMEM;
1862 
1863         ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1864         ovs_net->ct_limit_info->limits =
1865                 kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1866                               GFP_KERNEL);
1867         if (!ovs_net->ct_limit_info->limits) {
1868                 kfree(ovs_net->ct_limit_info);
1869                 return -ENOMEM;
1870         }
1871 
1872         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1873                 INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1874 
1875         ovs_net->ct_limit_info->data =
1876                 nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1877 
1878         if (IS_ERR(ovs_net->ct_limit_info->data)) {
1879                 err = PTR_ERR(ovs_net->ct_limit_info->data);
1880                 kfree(ovs_net->ct_limit_info->limits);
1881                 kfree(ovs_net->ct_limit_info);
1882                 pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1883                 return err;
1884         }
1885         return 0;
1886 }
1887 
1888 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1889 {
1890         const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1891         int i;
1892 
1893         nf_conncount_destroy(net, NFPROTO_INET, info->data);
1894         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1895                 struct hlist_head *head = &info->limits[i];
1896                 struct ovs_ct_limit *ct_limit;
1897 
1898                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
1899                                          lockdep_ovsl_is_held())
1900                         kfree_rcu(ct_limit, rcu);
1901         }
1902         kfree(ovs_net->ct_limit_info->limits);
1903         kfree(ovs_net->ct_limit_info);
1904 }
1905 
1906 static struct sk_buff *
1907 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1908                              struct ovs_header **ovs_reply_header)
1909 {
1910         struct ovs_header *ovs_header = info->userhdr;
1911         struct sk_buff *skb;
1912 
1913         skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1914         if (!skb)
1915                 return ERR_PTR(-ENOMEM);
1916 
1917         *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1918                                         info->snd_seq,
1919                                         &dp_ct_limit_genl_family, 0, cmd);
1920 
1921         if (!*ovs_reply_header) {
1922                 nlmsg_free(skb);
1923                 return ERR_PTR(-EMSGSIZE);
1924         }
1925         (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1926 
1927         return skb;
1928 }
1929 
1930 static bool check_zone_id(int zone_id, u16 *pzone)
1931 {
1932         if (zone_id >= 0 && zone_id <= 65535) {
1933                 *pzone = (u16)zone_id;
1934                 return true;
1935         }
1936         return false;
1937 }
1938 
1939 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1940                                        struct ovs_ct_limit_info *info)
1941 {
1942         struct ovs_zone_limit *zone_limit;
1943         int rem;
1944         u16 zone;
1945 
1946         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1947         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1948 
1949         while (rem >= sizeof(*zone_limit)) {
1950                 if (unlikely(zone_limit->zone_id ==
1951                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1952                         ovs_lock();
1953                         info->default_limit = zone_limit->limit;
1954                         ovs_unlock();
1955                 } else if (unlikely(!check_zone_id(
1956                                 zone_limit->zone_id, &zone))) {
1957                         OVS_NLERR(true, "zone id is out of range");
1958                 } else {
1959                         struct ovs_ct_limit *ct_limit;
1960 
1961                         ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
1962                         if (!ct_limit)
1963                                 return -ENOMEM;
1964 
1965                         ct_limit->zone = zone;
1966                         ct_limit->limit = zone_limit->limit;
1967 
1968                         ovs_lock();
1969                         ct_limit_set(info, ct_limit);
1970                         ovs_unlock();
1971                 }
1972                 rem -= NLA_ALIGN(sizeof(*zone_limit));
1973                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1974                                 NLA_ALIGN(sizeof(*zone_limit)));
1975         }
1976 
1977         if (rem)
1978                 OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1979 
1980         return 0;
1981 }
1982 
1983 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1984                                        struct ovs_ct_limit_info *info)
1985 {
1986         struct ovs_zone_limit *zone_limit;
1987         int rem;
1988         u16 zone;
1989 
1990         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1991         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1992 
1993         while (rem >= sizeof(*zone_limit)) {
1994                 if (unlikely(zone_limit->zone_id ==
1995                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1996                         ovs_lock();
1997                         info->default_limit = OVS_CT_LIMIT_DEFAULT;
1998                         ovs_unlock();
1999                 } else if (unlikely(!check_zone_id(
2000                                 zone_limit->zone_id, &zone))) {
2001                         OVS_NLERR(true, "zone id is out of range");
2002                 } else {
2003                         ovs_lock();
2004                         ct_limit_del(info, zone);
2005                         ovs_unlock();
2006                 }
2007                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2008                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2009                                 NLA_ALIGN(sizeof(*zone_limit)));
2010         }
2011 
2012         if (rem)
2013                 OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
2014 
2015         return 0;
2016 }
2017 
2018 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
2019                                           struct sk_buff *reply)
2020 {
2021         struct ovs_zone_limit zone_limit;
2022         int err;
2023 
2024         zone_limit.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE;
2025         zone_limit.limit = info->default_limit;
2026         err = nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2027         if (err)
2028                 return err;
2029 
2030         return 0;
2031 }
2032 
2033 static int __ovs_ct_limit_get_zone_limit(struct net *net,
2034                                          struct nf_conncount_data *data,
2035                                          u16 zone_id, u32 limit,
2036                                          struct sk_buff *reply)
2037 {
2038         struct nf_conntrack_zone ct_zone;
2039         struct ovs_zone_limit zone_limit;
2040         u32 conncount_key = zone_id;
2041 
2042         zone_limit.zone_id = zone_id;
2043         zone_limit.limit = limit;
2044         nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
2045 
2046         zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
2047                                               &ct_zone);
2048         return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
2049 }
2050 
2051 static int ovs_ct_limit_get_zone_limit(struct net *net,
2052                                        struct nlattr *nla_zone_limit,
2053                                        struct ovs_ct_limit_info *info,
2054                                        struct sk_buff *reply)
2055 {
2056         struct ovs_zone_limit *zone_limit;
2057         int rem, err;
2058         u32 limit;
2059         u16 zone;
2060 
2061         rem = NLA_ALIGN(nla_len(nla_zone_limit));
2062         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
2063 
2064         while (rem >= sizeof(*zone_limit)) {
2065                 if (unlikely(zone_limit->zone_id ==
2066                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
2067                         err = ovs_ct_limit_get_default_limit(info, reply);
2068                         if (err)
2069                                 return err;
2070                 } else if (unlikely(!check_zone_id(zone_limit->zone_id,
2071                                                         &zone))) {
2072                         OVS_NLERR(true, "zone id is out of range");
2073                 } else {
2074                         rcu_read_lock();
2075                         limit = ct_limit_get(info, zone);
2076                         rcu_read_unlock();
2077 
2078                         err = __ovs_ct_limit_get_zone_limit(
2079                                 net, info->data, zone, limit, reply);
2080                         if (err)
2081                                 return err;
2082                 }
2083                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2084                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2085                                 NLA_ALIGN(sizeof(*zone_limit)));
2086         }
2087 
2088         if (rem)
2089                 OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
2090 
2091         return 0;
2092 }
2093 
2094 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
2095                                            struct ovs_ct_limit_info *info,
2096                                            struct sk_buff *reply)
2097 {
2098         struct ovs_ct_limit *ct_limit;
2099         struct hlist_head *head;
2100         int i, err = 0;
2101 
2102         err = ovs_ct_limit_get_default_limit(info, reply);
2103         if (err)
2104                 return err;
2105 
2106         rcu_read_lock();
2107         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
2108                 head = &info->limits[i];
2109                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
2110                         err = __ovs_ct_limit_get_zone_limit(net, info->data,
2111                                 ct_limit->zone, ct_limit->limit, reply);
2112                         if (err)
2113                                 goto exit_err;
2114                 }
2115         }
2116 
2117 exit_err:
2118         rcu_read_unlock();
2119         return err;
2120 }
2121 
2122 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
2123 {
2124         struct nlattr **a = info->attrs;
2125         struct sk_buff *reply;
2126         struct ovs_header *ovs_reply_header;
2127         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2128         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2129         int err;
2130 
2131         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
2132                                              &ovs_reply_header);
2133         if (IS_ERR(reply))
2134                 return PTR_ERR(reply);
2135 
2136         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2137                 err = -EINVAL;
2138                 goto exit_err;
2139         }
2140 
2141         err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2142                                           ct_limit_info);
2143         if (err)
2144                 goto exit_err;
2145 
2146         static_branch_enable(&ovs_ct_limit_enabled);
2147 
2148         genlmsg_end(reply, ovs_reply_header);
2149         return genlmsg_reply(reply, info);
2150 
2151 exit_err:
2152         nlmsg_free(reply);
2153         return err;
2154 }
2155 
2156 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
2157 {
2158         struct nlattr **a = info->attrs;
2159         struct sk_buff *reply;
2160         struct ovs_header *ovs_reply_header;
2161         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2162         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2163         int err;
2164 
2165         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
2166                                              &ovs_reply_header);
2167         if (IS_ERR(reply))
2168                 return PTR_ERR(reply);
2169 
2170         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2171                 err = -EINVAL;
2172                 goto exit_err;
2173         }
2174 
2175         err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2176                                           ct_limit_info);
2177         if (err)
2178                 goto exit_err;
2179 
2180         genlmsg_end(reply, ovs_reply_header);
2181         return genlmsg_reply(reply, info);
2182 
2183 exit_err:
2184         nlmsg_free(reply);
2185         return err;
2186 }
2187 
2188 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
2189 {
2190         struct nlattr **a = info->attrs;
2191         struct nlattr *nla_reply;
2192         struct sk_buff *reply;
2193         struct ovs_header *ovs_reply_header;
2194         struct net *net = sock_net(skb->sk);
2195         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2196         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2197         int err;
2198 
2199         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2200                                              &ovs_reply_header);
2201         if (IS_ERR(reply))
2202                 return PTR_ERR(reply);
2203 
2204         nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2205         if (!nla_reply) {
2206                 err = -EMSGSIZE;
2207                 goto exit_err;
2208         }
2209 
2210         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2211                 err = ovs_ct_limit_get_zone_limit(
2212                         net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2213                         reply);
2214                 if (err)
2215                         goto exit_err;
2216         } else {
2217                 err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2218                                                       reply);
2219                 if (err)
2220                         goto exit_err;
2221         }
2222 
2223         nla_nest_end(reply, nla_reply);
2224         genlmsg_end(reply, ovs_reply_header);
2225         return genlmsg_reply(reply, info);
2226 
2227 exit_err:
2228         nlmsg_free(reply);
2229         return err;
2230 }
2231 
2232 static struct genl_ops ct_limit_genl_ops[] = {
2233         { .cmd = OVS_CT_LIMIT_CMD_SET,
2234                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2235                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2236                                            * privilege. */
2237                 .doit = ovs_ct_limit_cmd_set,
2238         },
2239         { .cmd = OVS_CT_LIMIT_CMD_DEL,
2240                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2241                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2242                                            * privilege. */
2243                 .doit = ovs_ct_limit_cmd_del,
2244         },
2245         { .cmd = OVS_CT_LIMIT_CMD_GET,
2246                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2247                 .flags = 0,               /* OK for unprivileged users. */
2248                 .doit = ovs_ct_limit_cmd_get,
2249         },
2250 };
2251 
2252 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2253         .name = OVS_CT_LIMIT_MCGROUP,
2254 };
2255 
2256 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2257         .hdrsize = sizeof(struct ovs_header),
2258         .name = OVS_CT_LIMIT_FAMILY,
2259         .version = OVS_CT_LIMIT_VERSION,
2260         .maxattr = OVS_CT_LIMIT_ATTR_MAX,
2261         .policy = ct_limit_policy,
2262         .netnsok = true,
2263         .parallel_ops = true,
2264         .ops = ct_limit_genl_ops,
2265         .n_ops = ARRAY_SIZE(ct_limit_genl_ops),
2266         .mcgrps = &ovs_ct_limit_multicast_group,
2267         .n_mcgrps = 1,
2268         .module = THIS_MODULE,
2269 };
2270 #endif
2271 
2272 int ovs_ct_init(struct net *net)
2273 {
2274         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2275         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2276 
2277         if (nf_connlabels_get(net, n_bits - 1)) {
2278                 ovs_net->xt_label = false;
2279                 OVS_NLERR(true, "Failed to set connlabel length");
2280         } else {
2281                 ovs_net->xt_label = true;
2282         }
2283 
2284 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2285         return ovs_ct_limit_init(net, ovs_net);
2286 #else
2287         return 0;
2288 #endif
2289 }
2290 
2291 void ovs_ct_exit(struct net *net)
2292 {
2293         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2294 
2295 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2296         ovs_ct_limit_exit(net, ovs_net);
2297 #endif
2298 
2299         if (ovs_net->xt_label)
2300                 nf_connlabels_put(net);
2301 }
2302 

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