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Linux/net/openvswitch/conntrack.c

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  1 /*
  2  * Copyright (c) 2015 Nicira, Inc.
  3  *
  4  * This program is free software; you can redistribute it and/or
  5  * modify it under the terms of version 2 of the GNU General Public
  6  * License as published by the Free Software Foundation.
  7  *
  8  * This program is distributed in the hope that it will be useful, but
  9  * WITHOUT ANY WARRANTY; without even the implied warranty of
 10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 11  * General Public License for more details.
 12  */
 13 
 14 #include <linux/module.h>
 15 #include <linux/openvswitch.h>
 16 #include <linux/tcp.h>
 17 #include <linux/udp.h>
 18 #include <linux/sctp.h>
 19 #include <net/ip.h>
 20 #include <net/netfilter/nf_conntrack_core.h>
 21 #include <net/netfilter/nf_conntrack_helper.h>
 22 #include <net/netfilter/nf_conntrack_labels.h>
 23 #include <net/netfilter/nf_conntrack_seqadj.h>
 24 #include <net/netfilter/nf_conntrack_zones.h>
 25 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 26 
 27 #ifdef CONFIG_NF_NAT_NEEDED
 28 #include <linux/netfilter/nf_nat.h>
 29 #include <net/netfilter/nf_nat_core.h>
 30 #include <net/netfilter/nf_nat_l3proto.h>
 31 #endif
 32 
 33 #include "datapath.h"
 34 #include "conntrack.h"
 35 #include "flow.h"
 36 #include "flow_netlink.h"
 37 
 38 struct ovs_ct_len_tbl {
 39         int maxlen;
 40         int minlen;
 41 };
 42 
 43 /* Metadata mark for masked write to conntrack mark */
 44 struct md_mark {
 45         u32 value;
 46         u32 mask;
 47 };
 48 
 49 /* Metadata label for masked write to conntrack label. */
 50 struct md_labels {
 51         struct ovs_key_ct_labels value;
 52         struct ovs_key_ct_labels mask;
 53 };
 54 
 55 enum ovs_ct_nat {
 56         OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
 57         OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
 58         OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
 59 };
 60 
 61 /* Conntrack action context for execution. */
 62 struct ovs_conntrack_info {
 63         struct nf_conntrack_helper *helper;
 64         struct nf_conntrack_zone zone;
 65         struct nf_conn *ct;
 66         u8 commit : 1;
 67         u8 nat : 3;                 /* enum ovs_ct_nat */
 68         u16 family;
 69         struct md_mark mark;
 70         struct md_labels labels;
 71 #ifdef CONFIG_NF_NAT_NEEDED
 72         struct nf_nat_range range;  /* Only present for SRC NAT and DST NAT. */
 73 #endif
 74 };
 75 
 76 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
 77 
 78 static u16 key_to_nfproto(const struct sw_flow_key *key)
 79 {
 80         switch (ntohs(key->eth.type)) {
 81         case ETH_P_IP:
 82                 return NFPROTO_IPV4;
 83         case ETH_P_IPV6:
 84                 return NFPROTO_IPV6;
 85         default:
 86                 return NFPROTO_UNSPEC;
 87         }
 88 }
 89 
 90 /* Map SKB connection state into the values used by flow definition. */
 91 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
 92 {
 93         u8 ct_state = OVS_CS_F_TRACKED;
 94 
 95         switch (ctinfo) {
 96         case IP_CT_ESTABLISHED_REPLY:
 97         case IP_CT_RELATED_REPLY:
 98                 ct_state |= OVS_CS_F_REPLY_DIR;
 99                 break;
100         default:
101                 break;
102         }
103 
104         switch (ctinfo) {
105         case IP_CT_ESTABLISHED:
106         case IP_CT_ESTABLISHED_REPLY:
107                 ct_state |= OVS_CS_F_ESTABLISHED;
108                 break;
109         case IP_CT_RELATED:
110         case IP_CT_RELATED_REPLY:
111                 ct_state |= OVS_CS_F_RELATED;
112                 break;
113         case IP_CT_NEW:
114                 ct_state |= OVS_CS_F_NEW;
115                 break;
116         default:
117                 break;
118         }
119 
120         return ct_state;
121 }
122 
123 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
124 {
125 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
126         return ct ? ct->mark : 0;
127 #else
128         return 0;
129 #endif
130 }
131 
132 static void ovs_ct_get_labels(const struct nf_conn *ct,
133                               struct ovs_key_ct_labels *labels)
134 {
135         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
136 
137         if (cl) {
138                 size_t len = cl->words * sizeof(long);
139 
140                 if (len > OVS_CT_LABELS_LEN)
141                         len = OVS_CT_LABELS_LEN;
142                 else if (len < OVS_CT_LABELS_LEN)
143                         memset(labels, 0, OVS_CT_LABELS_LEN);
144                 memcpy(labels, cl->bits, len);
145         } else {
146                 memset(labels, 0, OVS_CT_LABELS_LEN);
147         }
148 }
149 
150 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
151                                 const struct nf_conntrack_zone *zone,
152                                 const struct nf_conn *ct)
153 {
154         key->ct.state = state;
155         key->ct.zone = zone->id;
156         key->ct.mark = ovs_ct_get_mark(ct);
157         ovs_ct_get_labels(ct, &key->ct.labels);
158 }
159 
160 /* Update 'key' based on skb->nfct.  If 'post_ct' is true, then OVS has
161  * previously sent the packet to conntrack via the ct action.  If
162  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
163  * initialized from the connection status.
164  */
165 static void ovs_ct_update_key(const struct sk_buff *skb,
166                               const struct ovs_conntrack_info *info,
167                               struct sw_flow_key *key, bool post_ct,
168                               bool keep_nat_flags)
169 {
170         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
171         enum ip_conntrack_info ctinfo;
172         struct nf_conn *ct;
173         u8 state = 0;
174 
175         ct = nf_ct_get(skb, &ctinfo);
176         if (ct) {
177                 state = ovs_ct_get_state(ctinfo);
178                 /* All unconfirmed entries are NEW connections. */
179                 if (!nf_ct_is_confirmed(ct))
180                         state |= OVS_CS_F_NEW;
181                 /* OVS persists the related flag for the duration of the
182                  * connection.
183                  */
184                 if (ct->master)
185                         state |= OVS_CS_F_RELATED;
186                 if (keep_nat_flags) {
187                         state |= key->ct.state & OVS_CS_F_NAT_MASK;
188                 } else {
189                         if (ct->status & IPS_SRC_NAT)
190                                 state |= OVS_CS_F_SRC_NAT;
191                         if (ct->status & IPS_DST_NAT)
192                                 state |= OVS_CS_F_DST_NAT;
193                 }
194                 zone = nf_ct_zone(ct);
195         } else if (post_ct) {
196                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
197                 if (info)
198                         zone = &info->zone;
199         }
200         __ovs_ct_update_key(key, state, zone, ct);
201 }
202 
203 /* This is called to initialize CT key fields possibly coming in from the local
204  * stack.
205  */
206 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
207 {
208         ovs_ct_update_key(skb, NULL, key, false, false);
209 }
210 
211 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
212 {
213         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
214                 return -EMSGSIZE;
215 
216         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
217             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
218                 return -EMSGSIZE;
219 
220         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
221             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
222                 return -EMSGSIZE;
223 
224         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
225             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
226                     &key->ct.labels))
227                 return -EMSGSIZE;
228 
229         return 0;
230 }
231 
232 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
233                            u32 ct_mark, u32 mask)
234 {
235 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
236         enum ip_conntrack_info ctinfo;
237         struct nf_conn *ct;
238         u32 new_mark;
239 
240         /* The connection could be invalid, in which case set_mark is no-op. */
241         ct = nf_ct_get(skb, &ctinfo);
242         if (!ct)
243                 return 0;
244 
245         new_mark = ct_mark | (ct->mark & ~(mask));
246         if (ct->mark != new_mark) {
247                 ct->mark = new_mark;
248                 nf_conntrack_event_cache(IPCT_MARK, ct);
249                 key->ct.mark = new_mark;
250         }
251 
252         return 0;
253 #else
254         return -ENOTSUPP;
255 #endif
256 }
257 
258 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
259                              const struct ovs_key_ct_labels *labels,
260                              const struct ovs_key_ct_labels *mask)
261 {
262         enum ip_conntrack_info ctinfo;
263         struct nf_conn_labels *cl;
264         struct nf_conn *ct;
265         int err;
266 
267         /* The connection could be invalid, in which case set_label is no-op.*/
268         ct = nf_ct_get(skb, &ctinfo);
269         if (!ct)
270                 return 0;
271 
272         cl = nf_ct_labels_find(ct);
273         if (!cl) {
274                 nf_ct_labels_ext_add(ct);
275                 cl = nf_ct_labels_find(ct);
276         }
277         if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
278                 return -ENOSPC;
279 
280         err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
281                                     OVS_CT_LABELS_LEN / sizeof(u32));
282         if (err)
283                 return err;
284 
285         ovs_ct_get_labels(ct, &key->ct.labels);
286         return 0;
287 }
288 
289 /* 'skb' should already be pulled to nh_ofs. */
290 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
291 {
292         const struct nf_conntrack_helper *helper;
293         const struct nf_conn_help *help;
294         enum ip_conntrack_info ctinfo;
295         unsigned int protoff;
296         struct nf_conn *ct;
297         int err;
298 
299         ct = nf_ct_get(skb, &ctinfo);
300         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
301                 return NF_ACCEPT;
302 
303         help = nfct_help(ct);
304         if (!help)
305                 return NF_ACCEPT;
306 
307         helper = rcu_dereference(help->helper);
308         if (!helper)
309                 return NF_ACCEPT;
310 
311         switch (proto) {
312         case NFPROTO_IPV4:
313                 protoff = ip_hdrlen(skb);
314                 break;
315         case NFPROTO_IPV6: {
316                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
317                 __be16 frag_off;
318                 int ofs;
319 
320                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
321                                        &frag_off);
322                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
323                         pr_debug("proto header not found\n");
324                         return NF_ACCEPT;
325                 }
326                 protoff = ofs;
327                 break;
328         }
329         default:
330                 WARN_ONCE(1, "helper invoked on non-IP family!");
331                 return NF_DROP;
332         }
333 
334         err = helper->help(skb, protoff, ct, ctinfo);
335         if (err != NF_ACCEPT)
336                 return err;
337 
338         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
339          * FTP with NAT) adusting the TCP payload size when mangling IP
340          * addresses and/or port numbers in the text-based control connection.
341          */
342         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
343             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
344                 return NF_DROP;
345         return NF_ACCEPT;
346 }
347 
348 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
349  * value if 'skb' is freed.
350  */
351 static int handle_fragments(struct net *net, struct sw_flow_key *key,
352                             u16 zone, struct sk_buff *skb)
353 {
354         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
355         int err;
356 
357         if (key->eth.type == htons(ETH_P_IP)) {
358                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
359 
360                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
361                 err = ip_defrag(net, skb, user);
362                 if (err)
363                         return err;
364 
365                 ovs_cb.mru = IPCB(skb)->frag_max_size;
366 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
367         } else if (key->eth.type == htons(ETH_P_IPV6)) {
368                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
369 
370                 skb_orphan(skb);
371                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
372                 err = nf_ct_frag6_gather(net, skb, user);
373                 if (err)
374                         return err;
375 
376                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
377                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
378 #endif
379         } else {
380                 kfree_skb(skb);
381                 return -EPFNOSUPPORT;
382         }
383 
384         key->ip.frag = OVS_FRAG_TYPE_NONE;
385         skb_clear_hash(skb);
386         skb->ignore_df = 1;
387         *OVS_CB(skb) = ovs_cb;
388 
389         return 0;
390 }
391 
392 static struct nf_conntrack_expect *
393 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
394                    u16 proto, const struct sk_buff *skb)
395 {
396         struct nf_conntrack_tuple tuple;
397 
398         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
399                 return NULL;
400         return __nf_ct_expect_find(net, zone, &tuple);
401 }
402 
403 /* This replicates logic from nf_conntrack_core.c that is not exported. */
404 static enum ip_conntrack_info
405 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
406 {
407         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
408 
409         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
410                 return IP_CT_ESTABLISHED_REPLY;
411         /* Once we've had two way comms, always ESTABLISHED. */
412         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
413                 return IP_CT_ESTABLISHED;
414         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
415                 return IP_CT_RELATED;
416         return IP_CT_NEW;
417 }
418 
419 /* Find an existing connection which this packet belongs to without
420  * re-attributing statistics or modifying the connection state.  This allows an
421  * skb->nfct lost due to an upcall to be recovered during actions execution.
422  *
423  * Must be called with rcu_read_lock.
424  *
425  * On success, populates skb->nfct and skb->nfctinfo, and returns the
426  * connection.  Returns NULL if there is no existing entry.
427  */
428 static struct nf_conn *
429 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
430                      u8 l3num, struct sk_buff *skb)
431 {
432         struct nf_conntrack_l3proto *l3proto;
433         struct nf_conntrack_l4proto *l4proto;
434         struct nf_conntrack_tuple tuple;
435         struct nf_conntrack_tuple_hash *h;
436         enum ip_conntrack_info ctinfo;
437         struct nf_conn *ct;
438         unsigned int dataoff;
439         u8 protonum;
440 
441         l3proto = __nf_ct_l3proto_find(l3num);
442         if (!l3proto) {
443                 pr_debug("ovs_ct_find_existing: Can't get l3proto\n");
444                 return NULL;
445         }
446         if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
447                                  &protonum) <= 0) {
448                 pr_debug("ovs_ct_find_existing: Can't get protonum\n");
449                 return NULL;
450         }
451         l4proto = __nf_ct_l4proto_find(l3num, protonum);
452         if (!l4proto) {
453                 pr_debug("ovs_ct_find_existing: Can't get l4proto\n");
454                 return NULL;
455         }
456         if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
457                              protonum, net, &tuple, l3proto, l4proto)) {
458                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
459                 return NULL;
460         }
461 
462         /* look for tuple match */
463         h = nf_conntrack_find_get(net, zone, &tuple);
464         if (!h)
465                 return NULL;   /* Not found. */
466 
467         ct = nf_ct_tuplehash_to_ctrack(h);
468 
469         ctinfo = ovs_ct_get_info(h);
470         if (ctinfo == IP_CT_NEW) {
471                 /* This should not happen. */
472                 WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
473         }
474         skb->nfct = &ct->ct_general;
475         skb->nfctinfo = ctinfo;
476         return ct;
477 }
478 
479 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
480 static bool skb_nfct_cached(struct net *net,
481                             const struct sw_flow_key *key,
482                             const struct ovs_conntrack_info *info,
483                             struct sk_buff *skb)
484 {
485         enum ip_conntrack_info ctinfo;
486         struct nf_conn *ct;
487 
488         ct = nf_ct_get(skb, &ctinfo);
489         /* If no ct, check if we have evidence that an existing conntrack entry
490          * might be found for this skb.  This happens when we lose a skb->nfct
491          * due to an upcall.  If the connection was not confirmed, it is not
492          * cached and needs to be run through conntrack again.
493          */
494         if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
495             !(key->ct.state & OVS_CS_F_INVALID) &&
496             key->ct.zone == info->zone.id)
497                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
498         if (!ct)
499                 return false;
500         if (!net_eq(net, read_pnet(&ct->ct_net)))
501                 return false;
502         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
503                 return false;
504         if (info->helper) {
505                 struct nf_conn_help *help;
506 
507                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
508                 if (help && rcu_access_pointer(help->helper) != info->helper)
509                         return false;
510         }
511 
512         return true;
513 }
514 
515 #ifdef CONFIG_NF_NAT_NEEDED
516 /* Modelled after nf_nat_ipv[46]_fn().
517  * range is only used for new, uninitialized NAT state.
518  * Returns either NF_ACCEPT or NF_DROP.
519  */
520 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
521                               enum ip_conntrack_info ctinfo,
522                               const struct nf_nat_range *range,
523                               enum nf_nat_manip_type maniptype)
524 {
525         int hooknum, nh_off, err = NF_ACCEPT;
526 
527         nh_off = skb_network_offset(skb);
528         skb_pull(skb, nh_off);
529 
530         /* See HOOK2MANIP(). */
531         if (maniptype == NF_NAT_MANIP_SRC)
532                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
533         else
534                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
535 
536         switch (ctinfo) {
537         case IP_CT_RELATED:
538         case IP_CT_RELATED_REPLY:
539                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
540                     skb->protocol == htons(ETH_P_IP) &&
541                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
542                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
543                                                            hooknum))
544                                 err = NF_DROP;
545                         goto push;
546                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
547                            skb->protocol == htons(ETH_P_IPV6)) {
548                         __be16 frag_off;
549                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
550                         int hdrlen = ipv6_skip_exthdr(skb,
551                                                       sizeof(struct ipv6hdr),
552                                                       &nexthdr, &frag_off);
553 
554                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
555                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
556                                                                      ctinfo,
557                                                                      hooknum,
558                                                                      hdrlen))
559                                         err = NF_DROP;
560                                 goto push;
561                         }
562                 }
563                 /* Non-ICMP, fall thru to initialize if needed. */
564         case IP_CT_NEW:
565                 /* Seen it before?  This can happen for loopback, retrans,
566                  * or local packets.
567                  */
568                 if (!nf_nat_initialized(ct, maniptype)) {
569                         /* Initialize according to the NAT action. */
570                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
571                                 /* Action is set up to establish a new
572                                  * mapping.
573                                  */
574                                 ? nf_nat_setup_info(ct, range, maniptype)
575                                 : nf_nat_alloc_null_binding(ct, hooknum);
576                         if (err != NF_ACCEPT)
577                                 goto push;
578                 }
579                 break;
580 
581         case IP_CT_ESTABLISHED:
582         case IP_CT_ESTABLISHED_REPLY:
583                 break;
584 
585         default:
586                 err = NF_DROP;
587                 goto push;
588         }
589 
590         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
591 push:
592         skb_push(skb, nh_off);
593 
594         return err;
595 }
596 
597 static void ovs_nat_update_key(struct sw_flow_key *key,
598                                const struct sk_buff *skb,
599                                enum nf_nat_manip_type maniptype)
600 {
601         if (maniptype == NF_NAT_MANIP_SRC) {
602                 __be16 src;
603 
604                 key->ct.state |= OVS_CS_F_SRC_NAT;
605                 if (key->eth.type == htons(ETH_P_IP))
606                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
607                 else if (key->eth.type == htons(ETH_P_IPV6))
608                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
609                                sizeof(key->ipv6.addr.src));
610                 else
611                         return;
612 
613                 if (key->ip.proto == IPPROTO_UDP)
614                         src = udp_hdr(skb)->source;
615                 else if (key->ip.proto == IPPROTO_TCP)
616                         src = tcp_hdr(skb)->source;
617                 else if (key->ip.proto == IPPROTO_SCTP)
618                         src = sctp_hdr(skb)->source;
619                 else
620                         return;
621 
622                 key->tp.src = src;
623         } else {
624                 __be16 dst;
625 
626                 key->ct.state |= OVS_CS_F_DST_NAT;
627                 if (key->eth.type == htons(ETH_P_IP))
628                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
629                 else if (key->eth.type == htons(ETH_P_IPV6))
630                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
631                                sizeof(key->ipv6.addr.dst));
632                 else
633                         return;
634 
635                 if (key->ip.proto == IPPROTO_UDP)
636                         dst = udp_hdr(skb)->dest;
637                 else if (key->ip.proto == IPPROTO_TCP)
638                         dst = tcp_hdr(skb)->dest;
639                 else if (key->ip.proto == IPPROTO_SCTP)
640                         dst = sctp_hdr(skb)->dest;
641                 else
642                         return;
643 
644                 key->tp.dst = dst;
645         }
646 }
647 
648 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
649 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
650                       const struct ovs_conntrack_info *info,
651                       struct sk_buff *skb, struct nf_conn *ct,
652                       enum ip_conntrack_info ctinfo)
653 {
654         enum nf_nat_manip_type maniptype;
655         int err;
656 
657         if (nf_ct_is_untracked(ct)) {
658                 /* A NAT action may only be performed on tracked packets. */
659                 return NF_ACCEPT;
660         }
661 
662         /* Add NAT extension if not confirmed yet. */
663         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
664                 return NF_ACCEPT;   /* Can't NAT. */
665 
666         /* Determine NAT type.
667          * Check if the NAT type can be deduced from the tracked connection.
668          * Make sure new expected connections (IP_CT_RELATED) are NATted only
669          * when committing.
670          */
671         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
672             ct->status & IPS_NAT_MASK &&
673             (ctinfo != IP_CT_RELATED || info->commit)) {
674                 /* NAT an established or related connection like before. */
675                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
676                         /* This is the REPLY direction for a connection
677                          * for which NAT was applied in the forward
678                          * direction.  Do the reverse NAT.
679                          */
680                         maniptype = ct->status & IPS_SRC_NAT
681                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
682                 else
683                         maniptype = ct->status & IPS_SRC_NAT
684                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
685         } else if (info->nat & OVS_CT_SRC_NAT) {
686                 maniptype = NF_NAT_MANIP_SRC;
687         } else if (info->nat & OVS_CT_DST_NAT) {
688                 maniptype = NF_NAT_MANIP_DST;
689         } else {
690                 return NF_ACCEPT; /* Connection is not NATed. */
691         }
692         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
693 
694         /* Mark NAT done if successful and update the flow key. */
695         if (err == NF_ACCEPT)
696                 ovs_nat_update_key(key, skb, maniptype);
697 
698         return err;
699 }
700 #else /* !CONFIG_NF_NAT_NEEDED */
701 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
702                       const struct ovs_conntrack_info *info,
703                       struct sk_buff *skb, struct nf_conn *ct,
704                       enum ip_conntrack_info ctinfo)
705 {
706         return NF_ACCEPT;
707 }
708 #endif
709 
710 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
711  * not done already.  Update key with new CT state after passing the packet
712  * through conntrack.
713  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
714  * set to NULL and 0 will be returned.
715  */
716 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
717                            const struct ovs_conntrack_info *info,
718                            struct sk_buff *skb)
719 {
720         /* If we are recirculating packets to match on conntrack fields and
721          * committing with a separate conntrack action,  then we don't need to
722          * actually run the packet through conntrack twice unless it's for a
723          * different zone.
724          */
725         bool cached = skb_nfct_cached(net, key, info, skb);
726         enum ip_conntrack_info ctinfo;
727         struct nf_conn *ct;
728 
729         if (!cached) {
730                 struct nf_conn *tmpl = info->ct;
731                 int err;
732 
733                 /* Associate skb with specified zone. */
734                 if (tmpl) {
735                         if (skb->nfct)
736                                 nf_conntrack_put(skb->nfct);
737                         nf_conntrack_get(&tmpl->ct_general);
738                         skb->nfct = &tmpl->ct_general;
739                         skb->nfctinfo = IP_CT_NEW;
740                 }
741 
742                 /* Repeat if requested, see nf_iterate(). */
743                 do {
744                         err = nf_conntrack_in(net, info->family,
745                                               NF_INET_PRE_ROUTING, skb);
746                 } while (err == NF_REPEAT);
747 
748                 if (err != NF_ACCEPT)
749                         return -ENOENT;
750 
751                 /* Clear CT state NAT flags to mark that we have not yet done
752                  * NAT after the nf_conntrack_in() call.  We can actually clear
753                  * the whole state, as it will be re-initialized below.
754                  */
755                 key->ct.state = 0;
756 
757                 /* Update the key, but keep the NAT flags. */
758                 ovs_ct_update_key(skb, info, key, true, true);
759         }
760 
761         ct = nf_ct_get(skb, &ctinfo);
762         if (ct) {
763                 /* Packets starting a new connection must be NATted before the
764                  * helper, so that the helper knows about the NAT.  We enforce
765                  * this by delaying both NAT and helper calls for unconfirmed
766                  * connections until the committing CT action.  For later
767                  * packets NAT and Helper may be called in either order.
768                  *
769                  * NAT will be done only if the CT action has NAT, and only
770                  * once per packet (per zone), as guarded by the NAT bits in
771                  * the key->ct.state.
772                  */
773                 if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
774                     (nf_ct_is_confirmed(ct) || info->commit) &&
775                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
776                         return -EINVAL;
777                 }
778 
779                 /* Userspace may decide to perform a ct lookup without a helper
780                  * specified followed by a (recirculate and) commit with one.
781                  * Therefore, for unconfirmed connections which we will commit,
782                  * we need to attach the helper here.
783                  */
784                 if (!nf_ct_is_confirmed(ct) && info->commit &&
785                     info->helper && !nfct_help(ct)) {
786                         int err = __nf_ct_try_assign_helper(ct, info->ct,
787                                                             GFP_ATOMIC);
788                         if (err)
789                                 return err;
790                 }
791 
792                 /* Call the helper only if:
793                  * - nf_conntrack_in() was executed above ("!cached") for a
794                  *   confirmed connection, or
795                  * - When committing an unconfirmed connection.
796                  */
797                 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
798                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
799                         return -EINVAL;
800                 }
801         }
802 
803         return 0;
804 }
805 
806 /* Lookup connection and read fields into key. */
807 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
808                          const struct ovs_conntrack_info *info,
809                          struct sk_buff *skb)
810 {
811         struct nf_conntrack_expect *exp;
812 
813         /* If we pass an expected packet through nf_conntrack_in() the
814          * expectation is typically removed, but the packet could still be
815          * lost in upcall processing.  To prevent this from happening we
816          * perform an explicit expectation lookup.  Expected connections are
817          * always new, and will be passed through conntrack only when they are
818          * committed, as it is OK to remove the expectation at that time.
819          */
820         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
821         if (exp) {
822                 u8 state;
823 
824                 /* NOTE: New connections are NATted and Helped only when
825                  * committed, so we are not calling into NAT here.
826                  */
827                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
828                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
829         } else
830                 return __ovs_ct_lookup(net, key, info, skb);
831 
832         return 0;
833 }
834 
835 /* Lookup connection and confirm if unconfirmed. */
836 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
837                          const struct ovs_conntrack_info *info,
838                          struct sk_buff *skb)
839 {
840         int err;
841 
842         err = __ovs_ct_lookup(net, key, info, skb);
843         if (err)
844                 return err;
845         /* This is a no-op if the connection has already been confirmed. */
846         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
847                 return -EINVAL;
848 
849         return 0;
850 }
851 
852 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
853 {
854         size_t i;
855 
856         for (i = 0; i < sizeof(*labels); i++)
857                 if (labels->ct_labels[i])
858                         return true;
859 
860         return false;
861 }
862 
863 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
864  * value if 'skb' is freed.
865  */
866 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
867                    struct sw_flow_key *key,
868                    const struct ovs_conntrack_info *info)
869 {
870         int nh_ofs;
871         int err;
872 
873         /* The conntrack module expects to be working at L3. */
874         nh_ofs = skb_network_offset(skb);
875         skb_pull(skb, nh_ofs);
876 
877         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
878                 err = handle_fragments(net, key, info->zone.id, skb);
879                 if (err)
880                         return err;
881         }
882 
883         if (info->commit)
884                 err = ovs_ct_commit(net, key, info, skb);
885         else
886                 err = ovs_ct_lookup(net, key, info, skb);
887         if (err)
888                 goto err;
889 
890         if (info->mark.mask) {
891                 err = ovs_ct_set_mark(skb, key, info->mark.value,
892                                       info->mark.mask);
893                 if (err)
894                         goto err;
895         }
896         if (labels_nonzero(&info->labels.mask))
897                 err = ovs_ct_set_labels(skb, key, &info->labels.value,
898                                         &info->labels.mask);
899 err:
900         skb_push(skb, nh_ofs);
901         if (err)
902                 kfree_skb(skb);
903         return err;
904 }
905 
906 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
907                              const struct sw_flow_key *key, bool log)
908 {
909         struct nf_conntrack_helper *helper;
910         struct nf_conn_help *help;
911 
912         helper = nf_conntrack_helper_try_module_get(name, info->family,
913                                                     key->ip.proto);
914         if (!helper) {
915                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
916                 return -EINVAL;
917         }
918 
919         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
920         if (!help) {
921                 module_put(helper->me);
922                 return -ENOMEM;
923         }
924 
925         rcu_assign_pointer(help->helper, helper);
926         info->helper = helper;
927         return 0;
928 }
929 
930 #ifdef CONFIG_NF_NAT_NEEDED
931 static int parse_nat(const struct nlattr *attr,
932                      struct ovs_conntrack_info *info, bool log)
933 {
934         struct nlattr *a;
935         int rem;
936         bool have_ip_max = false;
937         bool have_proto_max = false;
938         bool ip_vers = (info->family == NFPROTO_IPV6);
939 
940         nla_for_each_nested(a, attr, rem) {
941                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
942                         [OVS_NAT_ATTR_SRC] = {0, 0},
943                         [OVS_NAT_ATTR_DST] = {0, 0},
944                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
945                                                  sizeof(struct in6_addr)},
946                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
947                                                  sizeof(struct in6_addr)},
948                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
949                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
950                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
951                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
952                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
953                 };
954                 int type = nla_type(a);
955 
956                 if (type > OVS_NAT_ATTR_MAX) {
957                         OVS_NLERR(log,
958                                   "Unknown NAT attribute (type=%d, max=%d).\n",
959                                   type, OVS_NAT_ATTR_MAX);
960                         return -EINVAL;
961                 }
962 
963                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
964                         OVS_NLERR(log,
965                                   "NAT attribute type %d has unexpected length (%d != %d).\n",
966                                   type, nla_len(a),
967                                   ovs_nat_attr_lens[type][ip_vers]);
968                         return -EINVAL;
969                 }
970 
971                 switch (type) {
972                 case OVS_NAT_ATTR_SRC:
973                 case OVS_NAT_ATTR_DST:
974                         if (info->nat) {
975                                 OVS_NLERR(log,
976                                           "Only one type of NAT may be specified.\n"
977                                           );
978                                 return -ERANGE;
979                         }
980                         info->nat |= OVS_CT_NAT;
981                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
982                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
983                         break;
984 
985                 case OVS_NAT_ATTR_IP_MIN:
986                         nla_memcpy(&info->range.min_addr, a,
987                                    sizeof(info->range.min_addr));
988                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
989                         break;
990 
991                 case OVS_NAT_ATTR_IP_MAX:
992                         have_ip_max = true;
993                         nla_memcpy(&info->range.max_addr, a,
994                                    sizeof(info->range.max_addr));
995                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
996                         break;
997 
998                 case OVS_NAT_ATTR_PROTO_MIN:
999                         info->range.min_proto.all = htons(nla_get_u16(a));
1000                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1001                         break;
1002 
1003                 case OVS_NAT_ATTR_PROTO_MAX:
1004                         have_proto_max = true;
1005                         info->range.max_proto.all = htons(nla_get_u16(a));
1006                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1007                         break;
1008 
1009                 case OVS_NAT_ATTR_PERSISTENT:
1010                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1011                         break;
1012 
1013                 case OVS_NAT_ATTR_PROTO_HASH:
1014                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1015                         break;
1016 
1017                 case OVS_NAT_ATTR_PROTO_RANDOM:
1018                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1019                         break;
1020 
1021                 default:
1022                         OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1023                         return -EINVAL;
1024                 }
1025         }
1026 
1027         if (rem > 0) {
1028                 OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1029                 return -EINVAL;
1030         }
1031         if (!info->nat) {
1032                 /* Do not allow flags if no type is given. */
1033                 if (info->range.flags) {
1034                         OVS_NLERR(log,
1035                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1036                                   );
1037                         return -EINVAL;
1038                 }
1039                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1040         } else if (!info->commit) {
1041                 OVS_NLERR(log,
1042                           "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1043                           );
1044                 return -EINVAL;
1045         }
1046         /* Allow missing IP_MAX. */
1047         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1048                 memcpy(&info->range.max_addr, &info->range.min_addr,
1049                        sizeof(info->range.max_addr));
1050         }
1051         /* Allow missing PROTO_MAX. */
1052         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1053             !have_proto_max) {
1054                 info->range.max_proto.all = info->range.min_proto.all;
1055         }
1056         return 0;
1057 }
1058 #endif
1059 
1060 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1061         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1062         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1063                                     .maxlen = sizeof(u16) },
1064         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1065                                     .maxlen = sizeof(struct md_mark) },
1066         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1067                                     .maxlen = sizeof(struct md_labels) },
1068         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1069                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1070 #ifdef CONFIG_NF_NAT_NEEDED
1071         /* NAT length is checked when parsing the nested attributes. */
1072         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1073 #endif
1074 };
1075 
1076 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1077                     const char **helper, bool log)
1078 {
1079         struct nlattr *a;
1080         int rem;
1081 
1082         nla_for_each_nested(a, attr, rem) {
1083                 int type = nla_type(a);
1084                 int maxlen = ovs_ct_attr_lens[type].maxlen;
1085                 int minlen = ovs_ct_attr_lens[type].minlen;
1086 
1087                 if (type > OVS_CT_ATTR_MAX) {
1088                         OVS_NLERR(log,
1089                                   "Unknown conntrack attr (type=%d, max=%d)",
1090                                   type, OVS_CT_ATTR_MAX);
1091                         return -EINVAL;
1092                 }
1093                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1094                         OVS_NLERR(log,
1095                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1096                                   type, nla_len(a), maxlen);
1097                         return -EINVAL;
1098                 }
1099 
1100                 switch (type) {
1101                 case OVS_CT_ATTR_COMMIT:
1102                         info->commit = true;
1103                         break;
1104 #ifdef CONFIG_NF_CONNTRACK_ZONES
1105                 case OVS_CT_ATTR_ZONE:
1106                         info->zone.id = nla_get_u16(a);
1107                         break;
1108 #endif
1109 #ifdef CONFIG_NF_CONNTRACK_MARK
1110                 case OVS_CT_ATTR_MARK: {
1111                         struct md_mark *mark = nla_data(a);
1112 
1113                         if (!mark->mask) {
1114                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1115                                 return -EINVAL;
1116                         }
1117                         info->mark = *mark;
1118                         break;
1119                 }
1120 #endif
1121 #ifdef CONFIG_NF_CONNTRACK_LABELS
1122                 case OVS_CT_ATTR_LABELS: {
1123                         struct md_labels *labels = nla_data(a);
1124 
1125                         if (!labels_nonzero(&labels->mask)) {
1126                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1127                                 return -EINVAL;
1128                         }
1129                         info->labels = *labels;
1130                         break;
1131                 }
1132 #endif
1133                 case OVS_CT_ATTR_HELPER:
1134                         *helper = nla_data(a);
1135                         if (!memchr(*helper, '\0', nla_len(a))) {
1136                                 OVS_NLERR(log, "Invalid conntrack helper");
1137                                 return -EINVAL;
1138                         }
1139                         break;
1140 #ifdef CONFIG_NF_NAT_NEEDED
1141                 case OVS_CT_ATTR_NAT: {
1142                         int err = parse_nat(a, info, log);
1143 
1144                         if (err)
1145                                 return err;
1146                         break;
1147                 }
1148 #endif
1149                 default:
1150                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1151                                   type);
1152                         return -EINVAL;
1153                 }
1154         }
1155 
1156         if (rem > 0) {
1157                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1158                 return -EINVAL;
1159         }
1160 
1161         return 0;
1162 }
1163 
1164 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1165 {
1166         if (attr == OVS_KEY_ATTR_CT_STATE)
1167                 return true;
1168         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1169             attr == OVS_KEY_ATTR_CT_ZONE)
1170                 return true;
1171         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1172             attr == OVS_KEY_ATTR_CT_MARK)
1173                 return true;
1174         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1175             attr == OVS_KEY_ATTR_CT_LABELS) {
1176                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1177 
1178                 return ovs_net->xt_label;
1179         }
1180 
1181         return false;
1182 }
1183 
1184 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1185                        const struct sw_flow_key *key,
1186                        struct sw_flow_actions **sfa,  bool log)
1187 {
1188         struct ovs_conntrack_info ct_info;
1189         const char *helper = NULL;
1190         u16 family;
1191         int err;
1192 
1193         family = key_to_nfproto(key);
1194         if (family == NFPROTO_UNSPEC) {
1195                 OVS_NLERR(log, "ct family unspecified");
1196                 return -EINVAL;
1197         }
1198 
1199         memset(&ct_info, 0, sizeof(ct_info));
1200         ct_info.family = family;
1201 
1202         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1203                         NF_CT_DEFAULT_ZONE_DIR, 0);
1204 
1205         err = parse_ct(attr, &ct_info, &helper, log);
1206         if (err)
1207                 return err;
1208 
1209         /* Set up template for tracking connections in specific zones. */
1210         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1211         if (!ct_info.ct) {
1212                 OVS_NLERR(log, "Failed to allocate conntrack template");
1213                 return -ENOMEM;
1214         }
1215 
1216         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1217         nf_conntrack_get(&ct_info.ct->ct_general);
1218 
1219         if (helper) {
1220                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1221                 if (err)
1222                         goto err_free_ct;
1223         }
1224 
1225         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1226                                  sizeof(ct_info), log);
1227         if (err)
1228                 goto err_free_ct;
1229 
1230         return 0;
1231 err_free_ct:
1232         __ovs_ct_free_action(&ct_info);
1233         return err;
1234 }
1235 
1236 #ifdef CONFIG_NF_NAT_NEEDED
1237 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1238                                struct sk_buff *skb)
1239 {
1240         struct nlattr *start;
1241 
1242         start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1243         if (!start)
1244                 return false;
1245 
1246         if (info->nat & OVS_CT_SRC_NAT) {
1247                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1248                         return false;
1249         } else if (info->nat & OVS_CT_DST_NAT) {
1250                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1251                         return false;
1252         } else {
1253                 goto out;
1254         }
1255 
1256         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1257                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1258                     info->family == NFPROTO_IPV4) {
1259                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1260                                             info->range.min_addr.ip) ||
1261                             (info->range.max_addr.ip
1262                              != info->range.min_addr.ip &&
1263                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1264                                               info->range.max_addr.ip))))
1265                                 return false;
1266                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1267                            info->family == NFPROTO_IPV6) {
1268                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1269                                              &info->range.min_addr.in6) ||
1270                             (memcmp(&info->range.max_addr.in6,
1271                                     &info->range.min_addr.in6,
1272                                     sizeof(info->range.max_addr.in6)) &&
1273                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1274                                                &info->range.max_addr.in6))))
1275                                 return false;
1276                 } else {
1277                         return false;
1278                 }
1279         }
1280         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1281             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1282                          ntohs(info->range.min_proto.all)) ||
1283              (info->range.max_proto.all != info->range.min_proto.all &&
1284               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1285                           ntohs(info->range.max_proto.all)))))
1286                 return false;
1287 
1288         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1289             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1290                 return false;
1291         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1292             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1293                 return false;
1294         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1295             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1296                 return false;
1297 out:
1298         nla_nest_end(skb, start);
1299 
1300         return true;
1301 }
1302 #endif
1303 
1304 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1305                           struct sk_buff *skb)
1306 {
1307         struct nlattr *start;
1308 
1309         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1310         if (!start)
1311                 return -EMSGSIZE;
1312 
1313         if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1314                 return -EMSGSIZE;
1315         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1316             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1317                 return -EMSGSIZE;
1318         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1319             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1320                     &ct_info->mark))
1321                 return -EMSGSIZE;
1322         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1323             labels_nonzero(&ct_info->labels.mask) &&
1324             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1325                     &ct_info->labels))
1326                 return -EMSGSIZE;
1327         if (ct_info->helper) {
1328                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1329                                    ct_info->helper->name))
1330                         return -EMSGSIZE;
1331         }
1332 #ifdef CONFIG_NF_NAT_NEEDED
1333         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1334                 return -EMSGSIZE;
1335 #endif
1336         nla_nest_end(skb, start);
1337 
1338         return 0;
1339 }
1340 
1341 void ovs_ct_free_action(const struct nlattr *a)
1342 {
1343         struct ovs_conntrack_info *ct_info = nla_data(a);
1344 
1345         __ovs_ct_free_action(ct_info);
1346 }
1347 
1348 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1349 {
1350         if (ct_info->helper)
1351                 module_put(ct_info->helper->me);
1352         if (ct_info->ct)
1353                 nf_ct_put(ct_info->ct);
1354 }
1355 
1356 void ovs_ct_init(struct net *net)
1357 {
1358         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1359         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1360 
1361         if (nf_connlabels_get(net, n_bits)) {
1362                 ovs_net->xt_label = false;
1363                 OVS_NLERR(true, "Failed to set connlabel length");
1364         } else {
1365                 ovs_net->xt_label = true;
1366         }
1367 }
1368 
1369 void ovs_ct_exit(struct net *net)
1370 {
1371         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1372 
1373         if (ovs_net->xt_label)
1374                 nf_connlabels_put(net);
1375 }
1376 

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