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

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