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TOMOYO Linux Cross Reference
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 <linux/static_key.h>
 20 #include <net/ip.h>
 21 #include <net/genetlink.h>
 22 #include <net/netfilter/nf_conntrack_core.h>
 23 #include <net/netfilter/nf_conntrack_count.h>
 24 #include <net/netfilter/nf_conntrack_helper.h>
 25 #include <net/netfilter/nf_conntrack_labels.h>
 26 #include <net/netfilter/nf_conntrack_seqadj.h>
 27 #include <net/netfilter/nf_conntrack_zones.h>
 28 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 29 #include <net/ipv6_frag.h>
 30 
 31 #ifdef CONFIG_NF_NAT_NEEDED
 32 #include <linux/netfilter/nf_nat.h>
 33 #include <net/netfilter/nf_nat_core.h>
 34 #include <net/netfilter/nf_nat_l3proto.h>
 35 #endif
 36 
 37 #include "datapath.h"
 38 #include "conntrack.h"
 39 #include "flow.h"
 40 #include "flow_netlink.h"
 41 
 42 struct ovs_ct_len_tbl {
 43         int maxlen;
 44         int minlen;
 45 };
 46 
 47 /* Metadata mark for masked write to conntrack mark */
 48 struct md_mark {
 49         u32 value;
 50         u32 mask;
 51 };
 52 
 53 /* Metadata label for masked write to conntrack label. */
 54 struct md_labels {
 55         struct ovs_key_ct_labels value;
 56         struct ovs_key_ct_labels mask;
 57 };
 58 
 59 enum ovs_ct_nat {
 60         OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
 61         OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
 62         OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
 63 };
 64 
 65 /* Conntrack action context for execution. */
 66 struct ovs_conntrack_info {
 67         struct nf_conntrack_helper *helper;
 68         struct nf_conntrack_zone zone;
 69         struct nf_conn *ct;
 70         u8 commit : 1;
 71         u8 nat : 3;                 /* enum ovs_ct_nat */
 72         u8 force : 1;
 73         u8 have_eventmask : 1;
 74         u16 family;
 75         u32 eventmask;              /* Mask of 1 << IPCT_*. */
 76         struct md_mark mark;
 77         struct md_labels labels;
 78 #ifdef CONFIG_NF_NAT_NEEDED
 79         struct nf_nat_range2 range;  /* Only present for SRC NAT and DST NAT. */
 80 #endif
 81 };
 82 
 83 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
 84 #define OVS_CT_LIMIT_UNLIMITED  0
 85 #define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
 86 #define CT_LIMIT_HASH_BUCKETS 512
 87 static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
 88 
 89 struct ovs_ct_limit {
 90         /* Elements in ovs_ct_limit_info->limits hash table */
 91         struct hlist_node hlist_node;
 92         struct rcu_head rcu;
 93         u16 zone;
 94         u32 limit;
 95 };
 96 
 97 struct ovs_ct_limit_info {
 98         u32 default_limit;
 99         struct hlist_head *limits;
100         struct nf_conncount_data *data;
101 };
102 
103 static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
104         [OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
105 };
106 #endif
107 
108 static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
109 
110 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
111 
112 static u16 key_to_nfproto(const struct sw_flow_key *key)
113 {
114         switch (ntohs(key->eth.type)) {
115         case ETH_P_IP:
116                 return NFPROTO_IPV4;
117         case ETH_P_IPV6:
118                 return NFPROTO_IPV6;
119         default:
120                 return NFPROTO_UNSPEC;
121         }
122 }
123 
124 /* Map SKB connection state into the values used by flow definition. */
125 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
126 {
127         u8 ct_state = OVS_CS_F_TRACKED;
128 
129         switch (ctinfo) {
130         case IP_CT_ESTABLISHED_REPLY:
131         case IP_CT_RELATED_REPLY:
132                 ct_state |= OVS_CS_F_REPLY_DIR;
133                 break;
134         default:
135                 break;
136         }
137 
138         switch (ctinfo) {
139         case IP_CT_ESTABLISHED:
140         case IP_CT_ESTABLISHED_REPLY:
141                 ct_state |= OVS_CS_F_ESTABLISHED;
142                 break;
143         case IP_CT_RELATED:
144         case IP_CT_RELATED_REPLY:
145                 ct_state |= OVS_CS_F_RELATED;
146                 break;
147         case IP_CT_NEW:
148                 ct_state |= OVS_CS_F_NEW;
149                 break;
150         default:
151                 break;
152         }
153 
154         return ct_state;
155 }
156 
157 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
158 {
159 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
160         return ct ? ct->mark : 0;
161 #else
162         return 0;
163 #endif
164 }
165 
166 /* Guard against conntrack labels max size shrinking below 128 bits. */
167 #if NF_CT_LABELS_MAX_SIZE < 16
168 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
169 #endif
170 
171 static void ovs_ct_get_labels(const struct nf_conn *ct,
172                               struct ovs_key_ct_labels *labels)
173 {
174         struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
175 
176         if (cl)
177                 memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
178         else
179                 memset(labels, 0, OVS_CT_LABELS_LEN);
180 }
181 
182 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
183                                         const struct nf_conntrack_tuple *orig,
184                                         u8 icmp_proto)
185 {
186         key->ct_orig_proto = orig->dst.protonum;
187         if (orig->dst.protonum == icmp_proto) {
188                 key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
189                 key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
190         } else {
191                 key->ct.orig_tp.src = orig->src.u.all;
192                 key->ct.orig_tp.dst = orig->dst.u.all;
193         }
194 }
195 
196 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
197                                 const struct nf_conntrack_zone *zone,
198                                 const struct nf_conn *ct)
199 {
200         key->ct_state = state;
201         key->ct_zone = zone->id;
202         key->ct.mark = ovs_ct_get_mark(ct);
203         ovs_ct_get_labels(ct, &key->ct.labels);
204 
205         if (ct) {
206                 const struct nf_conntrack_tuple *orig;
207 
208                 /* Use the master if we have one. */
209                 if (ct->master)
210                         ct = ct->master;
211                 orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
212 
213                 /* IP version must match with the master connection. */
214                 if (key->eth.type == htons(ETH_P_IP) &&
215                     nf_ct_l3num(ct) == NFPROTO_IPV4) {
216                         key->ipv4.ct_orig.src = orig->src.u3.ip;
217                         key->ipv4.ct_orig.dst = orig->dst.u3.ip;
218                         __ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
219                         return;
220                 } else if (key->eth.type == htons(ETH_P_IPV6) &&
221                            !sw_flow_key_is_nd(key) &&
222                            nf_ct_l3num(ct) == NFPROTO_IPV6) {
223                         key->ipv6.ct_orig.src = orig->src.u3.in6;
224                         key->ipv6.ct_orig.dst = orig->dst.u3.in6;
225                         __ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
226                         return;
227                 }
228         }
229         /* Clear 'ct_orig_proto' to mark the non-existence of conntrack
230          * original direction key fields.
231          */
232         key->ct_orig_proto = 0;
233 }
234 
235 /* Update 'key' based on skb->_nfct.  If 'post_ct' is true, then OVS has
236  * previously sent the packet to conntrack via the ct action.  If
237  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
238  * initialized from the connection status.
239  */
240 static void ovs_ct_update_key(const struct sk_buff *skb,
241                               const struct ovs_conntrack_info *info,
242                               struct sw_flow_key *key, bool post_ct,
243                               bool keep_nat_flags)
244 {
245         const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
246         enum ip_conntrack_info ctinfo;
247         struct nf_conn *ct;
248         u8 state = 0;
249 
250         ct = nf_ct_get(skb, &ctinfo);
251         if (ct) {
252                 state = ovs_ct_get_state(ctinfo);
253                 /* All unconfirmed entries are NEW connections. */
254                 if (!nf_ct_is_confirmed(ct))
255                         state |= OVS_CS_F_NEW;
256                 /* OVS persists the related flag for the duration of the
257                  * connection.
258                  */
259                 if (ct->master)
260                         state |= OVS_CS_F_RELATED;
261                 if (keep_nat_flags) {
262                         state |= key->ct_state & OVS_CS_F_NAT_MASK;
263                 } else {
264                         if (ct->status & IPS_SRC_NAT)
265                                 state |= OVS_CS_F_SRC_NAT;
266                         if (ct->status & IPS_DST_NAT)
267                                 state |= OVS_CS_F_DST_NAT;
268                 }
269                 zone = nf_ct_zone(ct);
270         } else if (post_ct) {
271                 state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
272                 if (info)
273                         zone = &info->zone;
274         }
275         __ovs_ct_update_key(key, state, zone, ct);
276 }
277 
278 /* This is called to initialize CT key fields possibly coming in from the local
279  * stack.
280  */
281 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
282 {
283         ovs_ct_update_key(skb, NULL, key, false, false);
284 }
285 
286 #define IN6_ADDR_INITIALIZER(ADDR) \
287         { (ADDR).s6_addr32[0], (ADDR).s6_addr32[1], \
288           (ADDR).s6_addr32[2], (ADDR).s6_addr32[3] }
289 
290 int ovs_ct_put_key(const struct sw_flow_key *swkey,
291                    const struct sw_flow_key *output, struct sk_buff *skb)
292 {
293         if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
294                 return -EMSGSIZE;
295 
296         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
297             nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
298                 return -EMSGSIZE;
299 
300         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
301             nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
302                 return -EMSGSIZE;
303 
304         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
305             nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
306                     &output->ct.labels))
307                 return -EMSGSIZE;
308 
309         if (swkey->ct_orig_proto) {
310                 if (swkey->eth.type == htons(ETH_P_IP)) {
311                         struct ovs_key_ct_tuple_ipv4 orig = {
312                                 output->ipv4.ct_orig.src,
313                                 output->ipv4.ct_orig.dst,
314                                 output->ct.orig_tp.src,
315                                 output->ct.orig_tp.dst,
316                                 output->ct_orig_proto,
317                         };
318                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
319                                     sizeof(orig), &orig))
320                                 return -EMSGSIZE;
321                 } else if (swkey->eth.type == htons(ETH_P_IPV6)) {
322                         struct ovs_key_ct_tuple_ipv6 orig = {
323                                 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.src),
324                                 IN6_ADDR_INITIALIZER(output->ipv6.ct_orig.dst),
325                                 output->ct.orig_tp.src,
326                                 output->ct.orig_tp.dst,
327                                 output->ct_orig_proto,
328                         };
329                         if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
330                                     sizeof(orig), &orig))
331                                 return -EMSGSIZE;
332                 }
333         }
334 
335         return 0;
336 }
337 
338 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
339                            u32 ct_mark, u32 mask)
340 {
341 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
342         u32 new_mark;
343 
344         new_mark = ct_mark | (ct->mark & ~(mask));
345         if (ct->mark != new_mark) {
346                 ct->mark = new_mark;
347                 if (nf_ct_is_confirmed(ct))
348                         nf_conntrack_event_cache(IPCT_MARK, ct);
349                 key->ct.mark = new_mark;
350         }
351 
352         return 0;
353 #else
354         return -ENOTSUPP;
355 #endif
356 }
357 
358 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
359 {
360         struct nf_conn_labels *cl;
361 
362         cl = nf_ct_labels_find(ct);
363         if (!cl) {
364                 nf_ct_labels_ext_add(ct);
365                 cl = nf_ct_labels_find(ct);
366         }
367 
368         return cl;
369 }
370 
371 /* Initialize labels for a new, yet to be committed conntrack entry.  Note that
372  * since the new connection is not yet confirmed, and thus no-one else has
373  * access to it's labels, we simply write them over.
374  */
375 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
376                               const struct ovs_key_ct_labels *labels,
377                               const struct ovs_key_ct_labels *mask)
378 {
379         struct nf_conn_labels *cl, *master_cl;
380         bool have_mask = labels_nonzero(mask);
381 
382         /* Inherit master's labels to the related connection? */
383         master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
384 
385         if (!master_cl && !have_mask)
386                 return 0;   /* Nothing to do. */
387 
388         cl = ovs_ct_get_conn_labels(ct);
389         if (!cl)
390                 return -ENOSPC;
391 
392         /* Inherit the master's labels, if any. */
393         if (master_cl)
394                 *cl = *master_cl;
395 
396         if (have_mask) {
397                 u32 *dst = (u32 *)cl->bits;
398                 int i;
399 
400                 for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
401                         dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
402                                 (labels->ct_labels_32[i]
403                                  & mask->ct_labels_32[i]);
404         }
405 
406         /* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
407          * IPCT_LABEL bit is set in the event cache.
408          */
409         nf_conntrack_event_cache(IPCT_LABEL, ct);
410 
411         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
412 
413         return 0;
414 }
415 
416 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
417                              const struct ovs_key_ct_labels *labels,
418                              const struct ovs_key_ct_labels *mask)
419 {
420         struct nf_conn_labels *cl;
421         int err;
422 
423         cl = ovs_ct_get_conn_labels(ct);
424         if (!cl)
425                 return -ENOSPC;
426 
427         err = nf_connlabels_replace(ct, labels->ct_labels_32,
428                                     mask->ct_labels_32,
429                                     OVS_CT_LABELS_LEN_32);
430         if (err)
431                 return err;
432 
433         memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
434 
435         return 0;
436 }
437 
438 /* 'skb' should already be pulled to nh_ofs. */
439 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
440 {
441         const struct nf_conntrack_helper *helper;
442         const struct nf_conn_help *help;
443         enum ip_conntrack_info ctinfo;
444         unsigned int protoff;
445         struct nf_conn *ct;
446         int err;
447 
448         ct = nf_ct_get(skb, &ctinfo);
449         if (!ct || ctinfo == IP_CT_RELATED_REPLY)
450                 return NF_ACCEPT;
451 
452         help = nfct_help(ct);
453         if (!help)
454                 return NF_ACCEPT;
455 
456         helper = rcu_dereference(help->helper);
457         if (!helper)
458                 return NF_ACCEPT;
459 
460         switch (proto) {
461         case NFPROTO_IPV4:
462                 protoff = ip_hdrlen(skb);
463                 break;
464         case NFPROTO_IPV6: {
465                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
466                 __be16 frag_off;
467                 int ofs;
468 
469                 ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
470                                        &frag_off);
471                 if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
472                         pr_debug("proto header not found\n");
473                         return NF_ACCEPT;
474                 }
475                 protoff = ofs;
476                 break;
477         }
478         default:
479                 WARN_ONCE(1, "helper invoked on non-IP family!");
480                 return NF_DROP;
481         }
482 
483         err = helper->help(skb, protoff, ct, ctinfo);
484         if (err != NF_ACCEPT)
485                 return err;
486 
487         /* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
488          * FTP with NAT) adusting the TCP payload size when mangling IP
489          * addresses and/or port numbers in the text-based control connection.
490          */
491         if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
492             !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
493                 return NF_DROP;
494         return NF_ACCEPT;
495 }
496 
497 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
498  * value if 'skb' is freed.
499  */
500 static int handle_fragments(struct net *net, struct sw_flow_key *key,
501                             u16 zone, struct sk_buff *skb)
502 {
503         struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
504         int err;
505 
506         if (key->eth.type == htons(ETH_P_IP)) {
507                 enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
508 
509                 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
510                 err = ip_defrag(net, skb, user);
511                 if (err)
512                         return err;
513 
514                 ovs_cb.mru = IPCB(skb)->frag_max_size;
515 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
516         } else if (key->eth.type == htons(ETH_P_IPV6)) {
517                 enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
518 
519                 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
520                 err = nf_ct_frag6_gather(net, skb, user);
521                 if (err) {
522                         if (err != -EINPROGRESS)
523                                 kfree_skb(skb);
524                         return err;
525                 }
526 
527                 key->ip.proto = ipv6_hdr(skb)->nexthdr;
528                 ovs_cb.mru = IP6CB(skb)->frag_max_size;
529 #endif
530         } else {
531                 kfree_skb(skb);
532                 return -EPFNOSUPPORT;
533         }
534 
535         key->ip.frag = OVS_FRAG_TYPE_NONE;
536         skb_clear_hash(skb);
537         skb->ignore_df = 1;
538         *OVS_CB(skb) = ovs_cb;
539 
540         return 0;
541 }
542 
543 static struct nf_conntrack_expect *
544 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
545                    u16 proto, const struct sk_buff *skb)
546 {
547         struct nf_conntrack_tuple tuple;
548         struct nf_conntrack_expect *exp;
549 
550         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
551                 return NULL;
552 
553         exp = __nf_ct_expect_find(net, zone, &tuple);
554         if (exp) {
555                 struct nf_conntrack_tuple_hash *h;
556 
557                 /* Delete existing conntrack entry, if it clashes with the
558                  * expectation.  This can happen since conntrack ALGs do not
559                  * check for clashes between (new) expectations and existing
560                  * conntrack entries.  nf_conntrack_in() will check the
561                  * expectations only if a conntrack entry can not be found,
562                  * which can lead to OVS finding the expectation (here) in the
563                  * init direction, but which will not be removed by the
564                  * nf_conntrack_in() call, if a matching conntrack entry is
565                  * found instead.  In this case all init direction packets
566                  * would be reported as new related packets, while reply
567                  * direction packets would be reported as un-related
568                  * established packets.
569                  */
570                 h = nf_conntrack_find_get(net, zone, &tuple);
571                 if (h) {
572                         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
573 
574                         nf_ct_delete(ct, 0, 0);
575                         nf_conntrack_put(&ct->ct_general);
576                 }
577         }
578 
579         return exp;
580 }
581 
582 /* This replicates logic from nf_conntrack_core.c that is not exported. */
583 static enum ip_conntrack_info
584 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
585 {
586         const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
587 
588         if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
589                 return IP_CT_ESTABLISHED_REPLY;
590         /* Once we've had two way comms, always ESTABLISHED. */
591         if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
592                 return IP_CT_ESTABLISHED;
593         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
594                 return IP_CT_RELATED;
595         return IP_CT_NEW;
596 }
597 
598 /* Find an existing connection which this packet belongs to without
599  * re-attributing statistics or modifying the connection state.  This allows an
600  * skb->_nfct lost due to an upcall to be recovered during actions execution.
601  *
602  * Must be called with rcu_read_lock.
603  *
604  * On success, populates skb->_nfct and returns the connection.  Returns NULL
605  * if there is no existing entry.
606  */
607 static struct nf_conn *
608 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
609                      u8 l3num, struct sk_buff *skb, bool natted)
610 {
611         struct nf_conntrack_tuple tuple;
612         struct nf_conntrack_tuple_hash *h;
613         struct nf_conn *ct;
614 
615         if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
616                                net, &tuple)) {
617                 pr_debug("ovs_ct_find_existing: Can't get tuple\n");
618                 return NULL;
619         }
620 
621         /* Must invert the tuple if skb has been transformed by NAT. */
622         if (natted) {
623                 struct nf_conntrack_tuple inverse;
624 
625                 if (!nf_ct_invert_tuplepr(&inverse, &tuple)) {
626                         pr_debug("ovs_ct_find_existing: Inversion failed!\n");
627                         return NULL;
628                 }
629                 tuple = inverse;
630         }
631 
632         /* look for tuple match */
633         h = nf_conntrack_find_get(net, zone, &tuple);
634         if (!h)
635                 return NULL;   /* Not found. */
636 
637         ct = nf_ct_tuplehash_to_ctrack(h);
638 
639         /* Inverted packet tuple matches the reverse direction conntrack tuple,
640          * select the other tuplehash to get the right 'ctinfo' bits for this
641          * packet.
642          */
643         if (natted)
644                 h = &ct->tuplehash[!h->tuple.dst.dir];
645 
646         nf_ct_set(skb, ct, ovs_ct_get_info(h));
647         return ct;
648 }
649 
650 static
651 struct nf_conn *ovs_ct_executed(struct net *net,
652                                 const struct sw_flow_key *key,
653                                 const struct ovs_conntrack_info *info,
654                                 struct sk_buff *skb,
655                                 bool *ct_executed)
656 {
657         struct nf_conn *ct = NULL;
658 
659         /* If no ct, check if we have evidence that an existing conntrack entry
660          * might be found for this skb.  This happens when we lose a skb->_nfct
661          * due to an upcall, or if the direction is being forced.  If the
662          * connection was not confirmed, it is not cached and needs to be run
663          * through conntrack again.
664          */
665         *ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
666                        !(key->ct_state & OVS_CS_F_INVALID) &&
667                        (key->ct_zone == info->zone.id);
668 
669         if (*ct_executed || (!key->ct_state && info->force)) {
670                 ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
671                                           !!(key->ct_state &
672                                           OVS_CS_F_NAT_MASK));
673         }
674 
675         return ct;
676 }
677 
678 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
679 static bool skb_nfct_cached(struct net *net,
680                             const struct sw_flow_key *key,
681                             const struct ovs_conntrack_info *info,
682                             struct sk_buff *skb)
683 {
684         enum ip_conntrack_info ctinfo;
685         struct nf_conn *ct;
686         bool ct_executed = true;
687 
688         ct = nf_ct_get(skb, &ctinfo);
689         if (!ct)
690                 ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
691 
692         if (ct)
693                 nf_ct_get(skb, &ctinfo);
694         else
695                 return false;
696 
697         if (!net_eq(net, read_pnet(&ct->ct_net)))
698                 return false;
699         if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
700                 return false;
701         if (info->helper) {
702                 struct nf_conn_help *help;
703 
704                 help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
705                 if (help && rcu_access_pointer(help->helper) != info->helper)
706                         return false;
707         }
708         /* Force conntrack entry direction to the current packet? */
709         if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
710                 /* Delete the conntrack entry if confirmed, else just release
711                  * the reference.
712                  */
713                 if (nf_ct_is_confirmed(ct))
714                         nf_ct_delete(ct, 0, 0);
715 
716                 nf_conntrack_put(&ct->ct_general);
717                 nf_ct_set(skb, NULL, 0);
718                 return false;
719         }
720 
721         return ct_executed;
722 }
723 
724 #ifdef CONFIG_NF_NAT_NEEDED
725 /* Modelled after nf_nat_ipv[46]_fn().
726  * range is only used for new, uninitialized NAT state.
727  * Returns either NF_ACCEPT or NF_DROP.
728  */
729 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
730                               enum ip_conntrack_info ctinfo,
731                               const struct nf_nat_range2 *range,
732                               enum nf_nat_manip_type maniptype)
733 {
734         int hooknum, nh_off, err = NF_ACCEPT;
735 
736         nh_off = skb_network_offset(skb);
737         skb_pull_rcsum(skb, nh_off);
738 
739         /* See HOOK2MANIP(). */
740         if (maniptype == NF_NAT_MANIP_SRC)
741                 hooknum = NF_INET_LOCAL_IN; /* Source NAT */
742         else
743                 hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
744 
745         switch (ctinfo) {
746         case IP_CT_RELATED:
747         case IP_CT_RELATED_REPLY:
748                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
749                     skb->protocol == htons(ETH_P_IP) &&
750                     ip_hdr(skb)->protocol == IPPROTO_ICMP) {
751                         if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
752                                                            hooknum))
753                                 err = NF_DROP;
754                         goto push;
755                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
756                            skb->protocol == htons(ETH_P_IPV6)) {
757                         __be16 frag_off;
758                         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
759                         int hdrlen = ipv6_skip_exthdr(skb,
760                                                       sizeof(struct ipv6hdr),
761                                                       &nexthdr, &frag_off);
762 
763                         if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
764                                 if (!nf_nat_icmpv6_reply_translation(skb, ct,
765                                                                      ctinfo,
766                                                                      hooknum,
767                                                                      hdrlen))
768                                         err = NF_DROP;
769                                 goto push;
770                         }
771                 }
772                 /* Non-ICMP, fall thru to initialize if needed. */
773                 /* fall through */
774         case IP_CT_NEW:
775                 /* Seen it before?  This can happen for loopback, retrans,
776                  * or local packets.
777                  */
778                 if (!nf_nat_initialized(ct, maniptype)) {
779                         /* Initialize according to the NAT action. */
780                         err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
781                                 /* Action is set up to establish a new
782                                  * mapping.
783                                  */
784                                 ? nf_nat_setup_info(ct, range, maniptype)
785                                 : nf_nat_alloc_null_binding(ct, hooknum);
786                         if (err != NF_ACCEPT)
787                                 goto push;
788                 }
789                 break;
790 
791         case IP_CT_ESTABLISHED:
792         case IP_CT_ESTABLISHED_REPLY:
793                 break;
794 
795         default:
796                 err = NF_DROP;
797                 goto push;
798         }
799 
800         err = nf_nat_packet(ct, ctinfo, hooknum, skb);
801 push:
802         skb_push(skb, nh_off);
803         skb_postpush_rcsum(skb, skb->data, nh_off);
804 
805         return err;
806 }
807 
808 static void ovs_nat_update_key(struct sw_flow_key *key,
809                                const struct sk_buff *skb,
810                                enum nf_nat_manip_type maniptype)
811 {
812         if (maniptype == NF_NAT_MANIP_SRC) {
813                 __be16 src;
814 
815                 key->ct_state |= OVS_CS_F_SRC_NAT;
816                 if (key->eth.type == htons(ETH_P_IP))
817                         key->ipv4.addr.src = ip_hdr(skb)->saddr;
818                 else if (key->eth.type == htons(ETH_P_IPV6))
819                         memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
820                                sizeof(key->ipv6.addr.src));
821                 else
822                         return;
823 
824                 if (key->ip.proto == IPPROTO_UDP)
825                         src = udp_hdr(skb)->source;
826                 else if (key->ip.proto == IPPROTO_TCP)
827                         src = tcp_hdr(skb)->source;
828                 else if (key->ip.proto == IPPROTO_SCTP)
829                         src = sctp_hdr(skb)->source;
830                 else
831                         return;
832 
833                 key->tp.src = src;
834         } else {
835                 __be16 dst;
836 
837                 key->ct_state |= OVS_CS_F_DST_NAT;
838                 if (key->eth.type == htons(ETH_P_IP))
839                         key->ipv4.addr.dst = ip_hdr(skb)->daddr;
840                 else if (key->eth.type == htons(ETH_P_IPV6))
841                         memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
842                                sizeof(key->ipv6.addr.dst));
843                 else
844                         return;
845 
846                 if (key->ip.proto == IPPROTO_UDP)
847                         dst = udp_hdr(skb)->dest;
848                 else if (key->ip.proto == IPPROTO_TCP)
849                         dst = tcp_hdr(skb)->dest;
850                 else if (key->ip.proto == IPPROTO_SCTP)
851                         dst = sctp_hdr(skb)->dest;
852                 else
853                         return;
854 
855                 key->tp.dst = dst;
856         }
857 }
858 
859 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
860 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
861                       const struct ovs_conntrack_info *info,
862                       struct sk_buff *skb, struct nf_conn *ct,
863                       enum ip_conntrack_info ctinfo)
864 {
865         enum nf_nat_manip_type maniptype;
866         int err;
867 
868         /* Add NAT extension if not confirmed yet. */
869         if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
870                 return NF_ACCEPT;   /* Can't NAT. */
871 
872         /* Determine NAT type.
873          * Check if the NAT type can be deduced from the tracked connection.
874          * Make sure new expected connections (IP_CT_RELATED) are NATted only
875          * when committing.
876          */
877         if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
878             ct->status & IPS_NAT_MASK &&
879             (ctinfo != IP_CT_RELATED || info->commit)) {
880                 /* NAT an established or related connection like before. */
881                 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
882                         /* This is the REPLY direction for a connection
883                          * for which NAT was applied in the forward
884                          * direction.  Do the reverse NAT.
885                          */
886                         maniptype = ct->status & IPS_SRC_NAT
887                                 ? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
888                 else
889                         maniptype = ct->status & IPS_SRC_NAT
890                                 ? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
891         } else if (info->nat & OVS_CT_SRC_NAT) {
892                 maniptype = NF_NAT_MANIP_SRC;
893         } else if (info->nat & OVS_CT_DST_NAT) {
894                 maniptype = NF_NAT_MANIP_DST;
895         } else {
896                 return NF_ACCEPT; /* Connection is not NATed. */
897         }
898         err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
899 
900         /* Mark NAT done if successful and update the flow key. */
901         if (err == NF_ACCEPT)
902                 ovs_nat_update_key(key, skb, maniptype);
903 
904         return err;
905 }
906 #else /* !CONFIG_NF_NAT_NEEDED */
907 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
908                       const struct ovs_conntrack_info *info,
909                       struct sk_buff *skb, struct nf_conn *ct,
910                       enum ip_conntrack_info ctinfo)
911 {
912         return NF_ACCEPT;
913 }
914 #endif
915 
916 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
917  * not done already.  Update key with new CT state after passing the packet
918  * through conntrack.
919  * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
920  * set to NULL and 0 will be returned.
921  */
922 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
923                            const struct ovs_conntrack_info *info,
924                            struct sk_buff *skb)
925 {
926         /* If we are recirculating packets to match on conntrack fields and
927          * committing with a separate conntrack action,  then we don't need to
928          * actually run the packet through conntrack twice unless it's for a
929          * different zone.
930          */
931         bool cached = skb_nfct_cached(net, key, info, skb);
932         enum ip_conntrack_info ctinfo;
933         struct nf_conn *ct;
934 
935         if (!cached) {
936                 struct nf_hook_state state = {
937                         .hook = NF_INET_PRE_ROUTING,
938                         .pf = info->family,
939                         .net = net,
940                 };
941                 struct nf_conn *tmpl = info->ct;
942                 int err;
943 
944                 /* Associate skb with specified zone. */
945                 if (tmpl) {
946                         if (skb_nfct(skb))
947                                 nf_conntrack_put(skb_nfct(skb));
948                         nf_conntrack_get(&tmpl->ct_general);
949                         nf_ct_set(skb, tmpl, IP_CT_NEW);
950                 }
951 
952                 err = nf_conntrack_in(skb, &state);
953                 if (err != NF_ACCEPT)
954                         return -ENOENT;
955 
956                 /* Clear CT state NAT flags to mark that we have not yet done
957                  * NAT after the nf_conntrack_in() call.  We can actually clear
958                  * the whole state, as it will be re-initialized below.
959                  */
960                 key->ct_state = 0;
961 
962                 /* Update the key, but keep the NAT flags. */
963                 ovs_ct_update_key(skb, info, key, true, true);
964         }
965 
966         ct = nf_ct_get(skb, &ctinfo);
967         if (ct) {
968                 /* Packets starting a new connection must be NATted before the
969                  * helper, so that the helper knows about the NAT.  We enforce
970                  * this by delaying both NAT and helper calls for unconfirmed
971                  * connections until the committing CT action.  For later
972                  * packets NAT and Helper may be called in either order.
973                  *
974                  * NAT will be done only if the CT action has NAT, and only
975                  * once per packet (per zone), as guarded by the NAT bits in
976                  * the key->ct_state.
977                  */
978                 if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
979                     (nf_ct_is_confirmed(ct) || info->commit) &&
980                     ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
981                         return -EINVAL;
982                 }
983 
984                 /* Userspace may decide to perform a ct lookup without a helper
985                  * specified followed by a (recirculate and) commit with one.
986                  * Therefore, for unconfirmed connections which we will commit,
987                  * we need to attach the helper here.
988                  */
989                 if (!nf_ct_is_confirmed(ct) && info->commit &&
990                     info->helper && !nfct_help(ct)) {
991                         int err = __nf_ct_try_assign_helper(ct, info->ct,
992                                                             GFP_ATOMIC);
993                         if (err)
994                                 return err;
995                 }
996 
997                 /* Call the helper only if:
998                  * - nf_conntrack_in() was executed above ("!cached") for a
999                  *   confirmed connection, or
1000                  * - When committing an unconfirmed connection.
1001                  */
1002                 if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
1003                     ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
1004                         return -EINVAL;
1005                 }
1006         }
1007 
1008         return 0;
1009 }
1010 
1011 /* Lookup connection and read fields into key. */
1012 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
1013                          const struct ovs_conntrack_info *info,
1014                          struct sk_buff *skb)
1015 {
1016         struct nf_conntrack_expect *exp;
1017 
1018         /* If we pass an expected packet through nf_conntrack_in() the
1019          * expectation is typically removed, but the packet could still be
1020          * lost in upcall processing.  To prevent this from happening we
1021          * perform an explicit expectation lookup.  Expected connections are
1022          * always new, and will be passed through conntrack only when they are
1023          * committed, as it is OK to remove the expectation at that time.
1024          */
1025         exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
1026         if (exp) {
1027                 u8 state;
1028 
1029                 /* NOTE: New connections are NATted and Helped only when
1030                  * committed, so we are not calling into NAT here.
1031                  */
1032                 state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
1033                 __ovs_ct_update_key(key, state, &info->zone, exp->master);
1034         } else {
1035                 struct nf_conn *ct;
1036                 int err;
1037 
1038                 err = __ovs_ct_lookup(net, key, info, skb);
1039                 if (err)
1040                         return err;
1041 
1042                 ct = (struct nf_conn *)skb_nfct(skb);
1043                 if (ct)
1044                         nf_ct_deliver_cached_events(ct);
1045         }
1046 
1047         return 0;
1048 }
1049 
1050 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
1051 {
1052         size_t i;
1053 
1054         for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
1055                 if (labels->ct_labels_32[i])
1056                         return true;
1057 
1058         return false;
1059 }
1060 
1061 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1062 static struct hlist_head *ct_limit_hash_bucket(
1063         const struct ovs_ct_limit_info *info, u16 zone)
1064 {
1065         return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
1066 }
1067 
1068 /* Call with ovs_mutex */
1069 static void ct_limit_set(const struct ovs_ct_limit_info *info,
1070                          struct ovs_ct_limit *new_ct_limit)
1071 {
1072         struct ovs_ct_limit *ct_limit;
1073         struct hlist_head *head;
1074 
1075         head = ct_limit_hash_bucket(info, new_ct_limit->zone);
1076         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1077                 if (ct_limit->zone == new_ct_limit->zone) {
1078                         hlist_replace_rcu(&ct_limit->hlist_node,
1079                                           &new_ct_limit->hlist_node);
1080                         kfree_rcu(ct_limit, rcu);
1081                         return;
1082                 }
1083         }
1084 
1085         hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
1086 }
1087 
1088 /* Call with ovs_mutex */
1089 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
1090 {
1091         struct ovs_ct_limit *ct_limit;
1092         struct hlist_head *head;
1093         struct hlist_node *n;
1094 
1095         head = ct_limit_hash_bucket(info, zone);
1096         hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
1097                 if (ct_limit->zone == zone) {
1098                         hlist_del_rcu(&ct_limit->hlist_node);
1099                         kfree_rcu(ct_limit, rcu);
1100                         return;
1101                 }
1102         }
1103 }
1104 
1105 /* Call with RCU read lock */
1106 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
1107 {
1108         struct ovs_ct_limit *ct_limit;
1109         struct hlist_head *head;
1110 
1111         head = ct_limit_hash_bucket(info, zone);
1112         hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1113                 if (ct_limit->zone == zone)
1114                         return ct_limit->limit;
1115         }
1116 
1117         return info->default_limit;
1118 }
1119 
1120 static int ovs_ct_check_limit(struct net *net,
1121                               const struct ovs_conntrack_info *info,
1122                               const struct nf_conntrack_tuple *tuple)
1123 {
1124         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1125         const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1126         u32 per_zone_limit, connections;
1127         u32 conncount_key;
1128 
1129         conncount_key = info->zone.id;
1130 
1131         per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1132         if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1133                 return 0;
1134 
1135         connections = nf_conncount_count(net, ct_limit_info->data,
1136                                          &conncount_key, tuple, &info->zone);
1137         if (connections > per_zone_limit)
1138                 return -ENOMEM;
1139 
1140         return 0;
1141 }
1142 #endif
1143 
1144 /* Lookup connection and confirm if unconfirmed. */
1145 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1146                          const struct ovs_conntrack_info *info,
1147                          struct sk_buff *skb)
1148 {
1149         enum ip_conntrack_info ctinfo;
1150         struct nf_conn *ct;
1151         int err;
1152 
1153         err = __ovs_ct_lookup(net, key, info, skb);
1154         if (err)
1155                 return err;
1156 
1157         /* The connection could be invalid, in which case this is a no-op.*/
1158         ct = nf_ct_get(skb, &ctinfo);
1159         if (!ct)
1160                 return 0;
1161 
1162 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1163         if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1164                 if (!nf_ct_is_confirmed(ct)) {
1165                         err = ovs_ct_check_limit(net, info,
1166                                 &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1167                         if (err) {
1168                                 net_warn_ratelimited("openvswitch: zone: %u "
1169                                         "exceeds conntrack limit\n",
1170                                         info->zone.id);
1171                                 return err;
1172                         }
1173                 }
1174         }
1175 #endif
1176 
1177         /* Set the conntrack event mask if given.  NEW and DELETE events have
1178          * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1179          * typically would receive many kinds of updates.  Setting the event
1180          * mask allows those events to be filtered.  The set event mask will
1181          * remain in effect for the lifetime of the connection unless changed
1182          * by a further CT action with both the commit flag and the eventmask
1183          * option. */
1184         if (info->have_eventmask) {
1185                 struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1186 
1187                 if (cache)
1188                         cache->ctmask = info->eventmask;
1189         }
1190 
1191         /* Apply changes before confirming the connection so that the initial
1192          * conntrack NEW netlink event carries the values given in the CT
1193          * action.
1194          */
1195         if (info->mark.mask) {
1196                 err = ovs_ct_set_mark(ct, key, info->mark.value,
1197                                       info->mark.mask);
1198                 if (err)
1199                         return err;
1200         }
1201         if (!nf_ct_is_confirmed(ct)) {
1202                 err = ovs_ct_init_labels(ct, key, &info->labels.value,
1203                                          &info->labels.mask);
1204                 if (err)
1205                         return err;
1206         } else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1207                    labels_nonzero(&info->labels.mask)) {
1208                 err = ovs_ct_set_labels(ct, key, &info->labels.value,
1209                                         &info->labels.mask);
1210                 if (err)
1211                         return err;
1212         }
1213         /* This will take care of sending queued events even if the connection
1214          * is already confirmed.
1215          */
1216         if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1217                 return -EINVAL;
1218 
1219         return 0;
1220 }
1221 
1222 /* Trim the skb to the length specified by the IP/IPv6 header,
1223  * removing any trailing lower-layer padding. This prepares the skb
1224  * for higher-layer processing that assumes skb->len excludes padding
1225  * (such as nf_ip_checksum). The caller needs to pull the skb to the
1226  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1227  */
1228 static int ovs_skb_network_trim(struct sk_buff *skb)
1229 {
1230         unsigned int len;
1231         int err;
1232 
1233         switch (skb->protocol) {
1234         case htons(ETH_P_IP):
1235                 len = ntohs(ip_hdr(skb)->tot_len);
1236                 break;
1237         case htons(ETH_P_IPV6):
1238                 len = sizeof(struct ipv6hdr)
1239                         + ntohs(ipv6_hdr(skb)->payload_len);
1240                 break;
1241         default:
1242                 len = skb->len;
1243         }
1244 
1245         err = pskb_trim_rcsum(skb, len);
1246         if (err)
1247                 kfree_skb(skb);
1248 
1249         return err;
1250 }
1251 
1252 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1253  * value if 'skb' is freed.
1254  */
1255 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1256                    struct sw_flow_key *key,
1257                    const struct ovs_conntrack_info *info)
1258 {
1259         int nh_ofs;
1260         int err;
1261 
1262         /* The conntrack module expects to be working at L3. */
1263         nh_ofs = skb_network_offset(skb);
1264         skb_pull_rcsum(skb, nh_ofs);
1265 
1266         err = ovs_skb_network_trim(skb);
1267         if (err)
1268                 return err;
1269 
1270         if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1271                 err = handle_fragments(net, key, info->zone.id, skb);
1272                 if (err)
1273                         return err;
1274         }
1275 
1276         if (info->commit)
1277                 err = ovs_ct_commit(net, key, info, skb);
1278         else
1279                 err = ovs_ct_lookup(net, key, info, skb);
1280 
1281         skb_push(skb, nh_ofs);
1282         skb_postpush_rcsum(skb, skb->data, nh_ofs);
1283         if (err)
1284                 kfree_skb(skb);
1285         return err;
1286 }
1287 
1288 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1289 {
1290         if (skb_nfct(skb)) {
1291                 nf_conntrack_put(skb_nfct(skb));
1292                 nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1293                 ovs_ct_fill_key(skb, key);
1294         }
1295 
1296         return 0;
1297 }
1298 
1299 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
1300                              const struct sw_flow_key *key, bool log)
1301 {
1302         struct nf_conntrack_helper *helper;
1303         struct nf_conn_help *help;
1304 
1305         helper = nf_conntrack_helper_try_module_get(name, info->family,
1306                                                     key->ip.proto);
1307         if (!helper) {
1308                 OVS_NLERR(log, "Unknown helper \"%s\"", name);
1309                 return -EINVAL;
1310         }
1311 
1312         help = nf_ct_helper_ext_add(info->ct, GFP_KERNEL);
1313         if (!help) {
1314                 nf_conntrack_helper_put(helper);
1315                 return -ENOMEM;
1316         }
1317 
1318         rcu_assign_pointer(help->helper, helper);
1319         info->helper = helper;
1320 
1321         if (info->nat)
1322                 request_module("ip_nat_%s", name);
1323 
1324         return 0;
1325 }
1326 
1327 #ifdef CONFIG_NF_NAT_NEEDED
1328 static int parse_nat(const struct nlattr *attr,
1329                      struct ovs_conntrack_info *info, bool log)
1330 {
1331         struct nlattr *a;
1332         int rem;
1333         bool have_ip_max = false;
1334         bool have_proto_max = false;
1335         bool ip_vers = (info->family == NFPROTO_IPV6);
1336 
1337         nla_for_each_nested(a, attr, rem) {
1338                 static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1339                         [OVS_NAT_ATTR_SRC] = {0, 0},
1340                         [OVS_NAT_ATTR_DST] = {0, 0},
1341                         [OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1342                                                  sizeof(struct in6_addr)},
1343                         [OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1344                                                  sizeof(struct in6_addr)},
1345                         [OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1346                         [OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1347                         [OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1348                         [OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1349                         [OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1350                 };
1351                 int type = nla_type(a);
1352 
1353                 if (type > OVS_NAT_ATTR_MAX) {
1354                         OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1355                                   type, OVS_NAT_ATTR_MAX);
1356                         return -EINVAL;
1357                 }
1358 
1359                 if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1360                         OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1361                                   type, nla_len(a),
1362                                   ovs_nat_attr_lens[type][ip_vers]);
1363                         return -EINVAL;
1364                 }
1365 
1366                 switch (type) {
1367                 case OVS_NAT_ATTR_SRC:
1368                 case OVS_NAT_ATTR_DST:
1369                         if (info->nat) {
1370                                 OVS_NLERR(log, "Only one type of NAT may be specified");
1371                                 return -ERANGE;
1372                         }
1373                         info->nat |= OVS_CT_NAT;
1374                         info->nat |= ((type == OVS_NAT_ATTR_SRC)
1375                                         ? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1376                         break;
1377 
1378                 case OVS_NAT_ATTR_IP_MIN:
1379                         nla_memcpy(&info->range.min_addr, a,
1380                                    sizeof(info->range.min_addr));
1381                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1382                         break;
1383 
1384                 case OVS_NAT_ATTR_IP_MAX:
1385                         have_ip_max = true;
1386                         nla_memcpy(&info->range.max_addr, a,
1387                                    sizeof(info->range.max_addr));
1388                         info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1389                         break;
1390 
1391                 case OVS_NAT_ATTR_PROTO_MIN:
1392                         info->range.min_proto.all = htons(nla_get_u16(a));
1393                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1394                         break;
1395 
1396                 case OVS_NAT_ATTR_PROTO_MAX:
1397                         have_proto_max = true;
1398                         info->range.max_proto.all = htons(nla_get_u16(a));
1399                         info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1400                         break;
1401 
1402                 case OVS_NAT_ATTR_PERSISTENT:
1403                         info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1404                         break;
1405 
1406                 case OVS_NAT_ATTR_PROTO_HASH:
1407                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1408                         break;
1409 
1410                 case OVS_NAT_ATTR_PROTO_RANDOM:
1411                         info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1412                         break;
1413 
1414                 default:
1415                         OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1416                         return -EINVAL;
1417                 }
1418         }
1419 
1420         if (rem > 0) {
1421                 OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1422                 return -EINVAL;
1423         }
1424         if (!info->nat) {
1425                 /* Do not allow flags if no type is given. */
1426                 if (info->range.flags) {
1427                         OVS_NLERR(log,
1428                                   "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1429                                   );
1430                         return -EINVAL;
1431                 }
1432                 info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1433         } else if (!info->commit) {
1434                 OVS_NLERR(log,
1435                           "NAT attributes may be specified only when CT COMMIT flag is also specified."
1436                           );
1437                 return -EINVAL;
1438         }
1439         /* Allow missing IP_MAX. */
1440         if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1441                 memcpy(&info->range.max_addr, &info->range.min_addr,
1442                        sizeof(info->range.max_addr));
1443         }
1444         /* Allow missing PROTO_MAX. */
1445         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1446             !have_proto_max) {
1447                 info->range.max_proto.all = info->range.min_proto.all;
1448         }
1449         return 0;
1450 }
1451 #endif
1452 
1453 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1454         [OVS_CT_ATTR_COMMIT]    = { .minlen = 0, .maxlen = 0 },
1455         [OVS_CT_ATTR_FORCE_COMMIT]      = { .minlen = 0, .maxlen = 0 },
1456         [OVS_CT_ATTR_ZONE]      = { .minlen = sizeof(u16),
1457                                     .maxlen = sizeof(u16) },
1458         [OVS_CT_ATTR_MARK]      = { .minlen = sizeof(struct md_mark),
1459                                     .maxlen = sizeof(struct md_mark) },
1460         [OVS_CT_ATTR_LABELS]    = { .minlen = sizeof(struct md_labels),
1461                                     .maxlen = sizeof(struct md_labels) },
1462         [OVS_CT_ATTR_HELPER]    = { .minlen = 1,
1463                                     .maxlen = NF_CT_HELPER_NAME_LEN },
1464 #ifdef CONFIG_NF_NAT_NEEDED
1465         /* NAT length is checked when parsing the nested attributes. */
1466         [OVS_CT_ATTR_NAT]       = { .minlen = 0, .maxlen = INT_MAX },
1467 #endif
1468         [OVS_CT_ATTR_EVENTMASK] = { .minlen = sizeof(u32),
1469                                     .maxlen = sizeof(u32) },
1470 };
1471 
1472 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1473                     const char **helper, bool log)
1474 {
1475         struct nlattr *a;
1476         int rem;
1477 
1478         nla_for_each_nested(a, attr, rem) {
1479                 int type = nla_type(a);
1480                 int maxlen;
1481                 int minlen;
1482 
1483                 if (type > OVS_CT_ATTR_MAX) {
1484                         OVS_NLERR(log,
1485                                   "Unknown conntrack attr (type=%d, max=%d)",
1486                                   type, OVS_CT_ATTR_MAX);
1487                         return -EINVAL;
1488                 }
1489 
1490                 maxlen = ovs_ct_attr_lens[type].maxlen;
1491                 minlen = ovs_ct_attr_lens[type].minlen;
1492                 if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1493                         OVS_NLERR(log,
1494                                   "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1495                                   type, nla_len(a), maxlen);
1496                         return -EINVAL;
1497                 }
1498 
1499                 switch (type) {
1500                 case OVS_CT_ATTR_FORCE_COMMIT:
1501                         info->force = true;
1502                         /* fall through. */
1503                 case OVS_CT_ATTR_COMMIT:
1504                         info->commit = true;
1505                         break;
1506 #ifdef CONFIG_NF_CONNTRACK_ZONES
1507                 case OVS_CT_ATTR_ZONE:
1508                         info->zone.id = nla_get_u16(a);
1509                         break;
1510 #endif
1511 #ifdef CONFIG_NF_CONNTRACK_MARK
1512                 case OVS_CT_ATTR_MARK: {
1513                         struct md_mark *mark = nla_data(a);
1514 
1515                         if (!mark->mask) {
1516                                 OVS_NLERR(log, "ct_mark mask cannot be 0");
1517                                 return -EINVAL;
1518                         }
1519                         info->mark = *mark;
1520                         break;
1521                 }
1522 #endif
1523 #ifdef CONFIG_NF_CONNTRACK_LABELS
1524                 case OVS_CT_ATTR_LABELS: {
1525                         struct md_labels *labels = nla_data(a);
1526 
1527                         if (!labels_nonzero(&labels->mask)) {
1528                                 OVS_NLERR(log, "ct_labels mask cannot be 0");
1529                                 return -EINVAL;
1530                         }
1531                         info->labels = *labels;
1532                         break;
1533                 }
1534 #endif
1535                 case OVS_CT_ATTR_HELPER:
1536                         *helper = nla_data(a);
1537                         if (!memchr(*helper, '\0', nla_len(a))) {
1538                                 OVS_NLERR(log, "Invalid conntrack helper");
1539                                 return -EINVAL;
1540                         }
1541                         break;
1542 #ifdef CONFIG_NF_NAT_NEEDED
1543                 case OVS_CT_ATTR_NAT: {
1544                         int err = parse_nat(a, info, log);
1545 
1546                         if (err)
1547                                 return err;
1548                         break;
1549                 }
1550 #endif
1551                 case OVS_CT_ATTR_EVENTMASK:
1552                         info->have_eventmask = true;
1553                         info->eventmask = nla_get_u32(a);
1554                         break;
1555 
1556                 default:
1557                         OVS_NLERR(log, "Unknown conntrack attr (%d)",
1558                                   type);
1559                         return -EINVAL;
1560                 }
1561         }
1562 
1563 #ifdef CONFIG_NF_CONNTRACK_MARK
1564         if (!info->commit && info->mark.mask) {
1565                 OVS_NLERR(log,
1566                           "Setting conntrack mark requires 'commit' flag.");
1567                 return -EINVAL;
1568         }
1569 #endif
1570 #ifdef CONFIG_NF_CONNTRACK_LABELS
1571         if (!info->commit && labels_nonzero(&info->labels.mask)) {
1572                 OVS_NLERR(log,
1573                           "Setting conntrack labels requires 'commit' flag.");
1574                 return -EINVAL;
1575         }
1576 #endif
1577         if (rem > 0) {
1578                 OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1579                 return -EINVAL;
1580         }
1581 
1582         return 0;
1583 }
1584 
1585 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1586 {
1587         if (attr == OVS_KEY_ATTR_CT_STATE)
1588                 return true;
1589         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1590             attr == OVS_KEY_ATTR_CT_ZONE)
1591                 return true;
1592         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1593             attr == OVS_KEY_ATTR_CT_MARK)
1594                 return true;
1595         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1596             attr == OVS_KEY_ATTR_CT_LABELS) {
1597                 struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1598 
1599                 return ovs_net->xt_label;
1600         }
1601 
1602         return false;
1603 }
1604 
1605 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1606                        const struct sw_flow_key *key,
1607                        struct sw_flow_actions **sfa,  bool log)
1608 {
1609         struct ovs_conntrack_info ct_info;
1610         const char *helper = NULL;
1611         u16 family;
1612         int err;
1613 
1614         family = key_to_nfproto(key);
1615         if (family == NFPROTO_UNSPEC) {
1616                 OVS_NLERR(log, "ct family unspecified");
1617                 return -EINVAL;
1618         }
1619 
1620         memset(&ct_info, 0, sizeof(ct_info));
1621         ct_info.family = family;
1622 
1623         nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1624                         NF_CT_DEFAULT_ZONE_DIR, 0);
1625 
1626         err = parse_ct(attr, &ct_info, &helper, log);
1627         if (err)
1628                 return err;
1629 
1630         /* Set up template for tracking connections in specific zones. */
1631         ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1632         if (!ct_info.ct) {
1633                 OVS_NLERR(log, "Failed to allocate conntrack template");
1634                 return -ENOMEM;
1635         }
1636         if (helper) {
1637                 err = ovs_ct_add_helper(&ct_info, helper, key, log);
1638                 if (err)
1639                         goto err_free_ct;
1640         }
1641 
1642         err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1643                                  sizeof(ct_info), log);
1644         if (err)
1645                 goto err_free_ct;
1646 
1647         __set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1648         nf_conntrack_get(&ct_info.ct->ct_general);
1649         return 0;
1650 err_free_ct:
1651         __ovs_ct_free_action(&ct_info);
1652         return err;
1653 }
1654 
1655 #ifdef CONFIG_NF_NAT_NEEDED
1656 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1657                                struct sk_buff *skb)
1658 {
1659         struct nlattr *start;
1660 
1661         start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1662         if (!start)
1663                 return false;
1664 
1665         if (info->nat & OVS_CT_SRC_NAT) {
1666                 if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1667                         return false;
1668         } else if (info->nat & OVS_CT_DST_NAT) {
1669                 if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1670                         return false;
1671         } else {
1672                 goto out;
1673         }
1674 
1675         if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1676                 if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1677                     info->family == NFPROTO_IPV4) {
1678                         if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1679                                             info->range.min_addr.ip) ||
1680                             (info->range.max_addr.ip
1681                              != info->range.min_addr.ip &&
1682                              (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1683                                               info->range.max_addr.ip))))
1684                                 return false;
1685                 } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1686                            info->family == NFPROTO_IPV6) {
1687                         if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1688                                              &info->range.min_addr.in6) ||
1689                             (memcmp(&info->range.max_addr.in6,
1690                                     &info->range.min_addr.in6,
1691                                     sizeof(info->range.max_addr.in6)) &&
1692                              (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1693                                                &info->range.max_addr.in6))))
1694                                 return false;
1695                 } else {
1696                         return false;
1697                 }
1698         }
1699         if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1700             (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1701                          ntohs(info->range.min_proto.all)) ||
1702              (info->range.max_proto.all != info->range.min_proto.all &&
1703               nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1704                           ntohs(info->range.max_proto.all)))))
1705                 return false;
1706 
1707         if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1708             nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1709                 return false;
1710         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1711             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1712                 return false;
1713         if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1714             nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1715                 return false;
1716 out:
1717         nla_nest_end(skb, start);
1718 
1719         return true;
1720 }
1721 #endif
1722 
1723 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1724                           struct sk_buff *skb)
1725 {
1726         struct nlattr *start;
1727 
1728         start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1729         if (!start)
1730                 return -EMSGSIZE;
1731 
1732         if (ct_info->commit && nla_put_flag(skb, ct_info->force
1733                                             ? OVS_CT_ATTR_FORCE_COMMIT
1734                                             : OVS_CT_ATTR_COMMIT))
1735                 return -EMSGSIZE;
1736         if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1737             nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1738                 return -EMSGSIZE;
1739         if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1740             nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1741                     &ct_info->mark))
1742                 return -EMSGSIZE;
1743         if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1744             labels_nonzero(&ct_info->labels.mask) &&
1745             nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1746                     &ct_info->labels))
1747                 return -EMSGSIZE;
1748         if (ct_info->helper) {
1749                 if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1750                                    ct_info->helper->name))
1751                         return -EMSGSIZE;
1752         }
1753         if (ct_info->have_eventmask &&
1754             nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1755                 return -EMSGSIZE;
1756 
1757 #ifdef CONFIG_NF_NAT_NEEDED
1758         if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1759                 return -EMSGSIZE;
1760 #endif
1761         nla_nest_end(skb, start);
1762 
1763         return 0;
1764 }
1765 
1766 void ovs_ct_free_action(const struct nlattr *a)
1767 {
1768         struct ovs_conntrack_info *ct_info = nla_data(a);
1769 
1770         __ovs_ct_free_action(ct_info);
1771 }
1772 
1773 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1774 {
1775         if (ct_info->helper)
1776                 nf_conntrack_helper_put(ct_info->helper);
1777         if (ct_info->ct)
1778                 nf_ct_tmpl_free(ct_info->ct);
1779 }
1780 
1781 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1782 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1783 {
1784         int i, err;
1785 
1786         ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1787                                          GFP_KERNEL);
1788         if (!ovs_net->ct_limit_info)
1789                 return -ENOMEM;
1790 
1791         ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1792         ovs_net->ct_limit_info->limits =
1793                 kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1794                               GFP_KERNEL);
1795         if (!ovs_net->ct_limit_info->limits) {
1796                 kfree(ovs_net->ct_limit_info);
1797                 return -ENOMEM;
1798         }
1799 
1800         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1801                 INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1802 
1803         ovs_net->ct_limit_info->data =
1804                 nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1805 
1806         if (IS_ERR(ovs_net->ct_limit_info->data)) {
1807                 err = PTR_ERR(ovs_net->ct_limit_info->data);
1808                 kfree(ovs_net->ct_limit_info->limits);
1809                 kfree(ovs_net->ct_limit_info);
1810                 pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1811                 return err;
1812         }
1813         return 0;
1814 }
1815 
1816 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1817 {
1818         const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1819         int i;
1820 
1821         nf_conncount_destroy(net, NFPROTO_INET, info->data);
1822         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1823                 struct hlist_head *head = &info->limits[i];
1824                 struct ovs_ct_limit *ct_limit;
1825 
1826                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node)
1827                         kfree_rcu(ct_limit, rcu);
1828         }
1829         kfree(ovs_net->ct_limit_info->limits);
1830         kfree(ovs_net->ct_limit_info);
1831 }
1832 
1833 static struct sk_buff *
1834 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1835                              struct ovs_header **ovs_reply_header)
1836 {
1837         struct ovs_header *ovs_header = info->userhdr;
1838         struct sk_buff *skb;
1839 
1840         skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1841         if (!skb)
1842                 return ERR_PTR(-ENOMEM);
1843 
1844         *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1845                                         info->snd_seq,
1846                                         &dp_ct_limit_genl_family, 0, cmd);
1847 
1848         if (!*ovs_reply_header) {
1849                 nlmsg_free(skb);
1850                 return ERR_PTR(-EMSGSIZE);
1851         }
1852         (*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1853 
1854         return skb;
1855 }
1856 
1857 static bool check_zone_id(int zone_id, u16 *pzone)
1858 {
1859         if (zone_id >= 0 && zone_id <= 65535) {
1860                 *pzone = (u16)zone_id;
1861                 return true;
1862         }
1863         return false;
1864 }
1865 
1866 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1867                                        struct ovs_ct_limit_info *info)
1868 {
1869         struct ovs_zone_limit *zone_limit;
1870         int rem;
1871         u16 zone;
1872 
1873         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1874         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1875 
1876         while (rem >= sizeof(*zone_limit)) {
1877                 if (unlikely(zone_limit->zone_id ==
1878                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1879                         ovs_lock();
1880                         info->default_limit = zone_limit->limit;
1881                         ovs_unlock();
1882                 } else if (unlikely(!check_zone_id(
1883                                 zone_limit->zone_id, &zone))) {
1884                         OVS_NLERR(true, "zone id is out of range");
1885                 } else {
1886                         struct ovs_ct_limit *ct_limit;
1887 
1888                         ct_limit = kmalloc(sizeof(*ct_limit), GFP_KERNEL);
1889                         if (!ct_limit)
1890                                 return -ENOMEM;
1891 
1892                         ct_limit->zone = zone;
1893                         ct_limit->limit = zone_limit->limit;
1894 
1895                         ovs_lock();
1896                         ct_limit_set(info, ct_limit);
1897                         ovs_unlock();
1898                 }
1899                 rem -= NLA_ALIGN(sizeof(*zone_limit));
1900                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1901                                 NLA_ALIGN(sizeof(*zone_limit)));
1902         }
1903 
1904         if (rem)
1905                 OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1906 
1907         return 0;
1908 }
1909 
1910 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1911                                        struct ovs_ct_limit_info *info)
1912 {
1913         struct ovs_zone_limit *zone_limit;
1914         int rem;
1915         u16 zone;
1916 
1917         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1918         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1919 
1920         while (rem >= sizeof(*zone_limit)) {
1921                 if (unlikely(zone_limit->zone_id ==
1922                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1923                         ovs_lock();
1924                         info->default_limit = OVS_CT_LIMIT_DEFAULT;
1925                         ovs_unlock();
1926                 } else if (unlikely(!check_zone_id(
1927                                 zone_limit->zone_id, &zone))) {
1928                         OVS_NLERR(true, "zone id is out of range");
1929                 } else {
1930                         ovs_lock();
1931                         ct_limit_del(info, zone);
1932                         ovs_unlock();
1933                 }
1934                 rem -= NLA_ALIGN(sizeof(*zone_limit));
1935                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1936                                 NLA_ALIGN(sizeof(*zone_limit)));
1937         }
1938 
1939         if (rem)
1940                 OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
1941 
1942         return 0;
1943 }
1944 
1945 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
1946                                           struct sk_buff *reply)
1947 {
1948         struct ovs_zone_limit zone_limit;
1949         int err;
1950 
1951         zone_limit.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE;
1952         zone_limit.limit = info->default_limit;
1953         err = nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
1954         if (err)
1955                 return err;
1956 
1957         return 0;
1958 }
1959 
1960 static int __ovs_ct_limit_get_zone_limit(struct net *net,
1961                                          struct nf_conncount_data *data,
1962                                          u16 zone_id, u32 limit,
1963                                          struct sk_buff *reply)
1964 {
1965         struct nf_conntrack_zone ct_zone;
1966         struct ovs_zone_limit zone_limit;
1967         u32 conncount_key = zone_id;
1968 
1969         zone_limit.zone_id = zone_id;
1970         zone_limit.limit = limit;
1971         nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
1972 
1973         zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
1974                                               &ct_zone);
1975         return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
1976 }
1977 
1978 static int ovs_ct_limit_get_zone_limit(struct net *net,
1979                                        struct nlattr *nla_zone_limit,
1980                                        struct ovs_ct_limit_info *info,
1981                                        struct sk_buff *reply)
1982 {
1983         struct ovs_zone_limit *zone_limit;
1984         int rem, err;
1985         u32 limit;
1986         u16 zone;
1987 
1988         rem = NLA_ALIGN(nla_len(nla_zone_limit));
1989         zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1990 
1991         while (rem >= sizeof(*zone_limit)) {
1992                 if (unlikely(zone_limit->zone_id ==
1993                                 OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1994                         err = ovs_ct_limit_get_default_limit(info, reply);
1995                         if (err)
1996                                 return err;
1997                 } else if (unlikely(!check_zone_id(zone_limit->zone_id,
1998                                                         &zone))) {
1999                         OVS_NLERR(true, "zone id is out of range");
2000                 } else {
2001                         rcu_read_lock();
2002                         limit = ct_limit_get(info, zone);
2003                         rcu_read_unlock();
2004 
2005                         err = __ovs_ct_limit_get_zone_limit(
2006                                 net, info->data, zone, limit, reply);
2007                         if (err)
2008                                 return err;
2009                 }
2010                 rem -= NLA_ALIGN(sizeof(*zone_limit));
2011                 zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
2012                                 NLA_ALIGN(sizeof(*zone_limit)));
2013         }
2014 
2015         if (rem)
2016                 OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
2017 
2018         return 0;
2019 }
2020 
2021 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
2022                                            struct ovs_ct_limit_info *info,
2023                                            struct sk_buff *reply)
2024 {
2025         struct ovs_ct_limit *ct_limit;
2026         struct hlist_head *head;
2027         int i, err = 0;
2028 
2029         err = ovs_ct_limit_get_default_limit(info, reply);
2030         if (err)
2031                 return err;
2032 
2033         rcu_read_lock();
2034         for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
2035                 head = &info->limits[i];
2036                 hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
2037                         err = __ovs_ct_limit_get_zone_limit(net, info->data,
2038                                 ct_limit->zone, ct_limit->limit, reply);
2039                         if (err)
2040                                 goto exit_err;
2041                 }
2042         }
2043 
2044 exit_err:
2045         rcu_read_unlock();
2046         return err;
2047 }
2048 
2049 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
2050 {
2051         struct nlattr **a = info->attrs;
2052         struct sk_buff *reply;
2053         struct ovs_header *ovs_reply_header;
2054         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2055         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2056         int err;
2057 
2058         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
2059                                              &ovs_reply_header);
2060         if (IS_ERR(reply))
2061                 return PTR_ERR(reply);
2062 
2063         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2064                 err = -EINVAL;
2065                 goto exit_err;
2066         }
2067 
2068         err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2069                                           ct_limit_info);
2070         if (err)
2071                 goto exit_err;
2072 
2073         static_branch_enable(&ovs_ct_limit_enabled);
2074 
2075         genlmsg_end(reply, ovs_reply_header);
2076         return genlmsg_reply(reply, info);
2077 
2078 exit_err:
2079         nlmsg_free(reply);
2080         return err;
2081 }
2082 
2083 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
2084 {
2085         struct nlattr **a = info->attrs;
2086         struct sk_buff *reply;
2087         struct ovs_header *ovs_reply_header;
2088         struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
2089         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2090         int err;
2091 
2092         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
2093                                              &ovs_reply_header);
2094         if (IS_ERR(reply))
2095                 return PTR_ERR(reply);
2096 
2097         if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2098                 err = -EINVAL;
2099                 goto exit_err;
2100         }
2101 
2102         err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
2103                                           ct_limit_info);
2104         if (err)
2105                 goto exit_err;
2106 
2107         genlmsg_end(reply, ovs_reply_header);
2108         return genlmsg_reply(reply, info);
2109 
2110 exit_err:
2111         nlmsg_free(reply);
2112         return err;
2113 }
2114 
2115 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
2116 {
2117         struct nlattr **a = info->attrs;
2118         struct nlattr *nla_reply;
2119         struct sk_buff *reply;
2120         struct ovs_header *ovs_reply_header;
2121         struct net *net = sock_net(skb->sk);
2122         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2123         struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2124         int err;
2125 
2126         reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2127                                              &ovs_reply_header);
2128         if (IS_ERR(reply))
2129                 return PTR_ERR(reply);
2130 
2131         nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2132 
2133         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2134                 err = ovs_ct_limit_get_zone_limit(
2135                         net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2136                         reply);
2137                 if (err)
2138                         goto exit_err;
2139         } else {
2140                 err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2141                                                       reply);
2142                 if (err)
2143                         goto exit_err;
2144         }
2145 
2146         nla_nest_end(reply, nla_reply);
2147         genlmsg_end(reply, ovs_reply_header);
2148         return genlmsg_reply(reply, info);
2149 
2150 exit_err:
2151         nlmsg_free(reply);
2152         return err;
2153 }
2154 
2155 static struct genl_ops ct_limit_genl_ops[] = {
2156         { .cmd = OVS_CT_LIMIT_CMD_SET,
2157                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2158                                            * privilege. */
2159                 .policy = ct_limit_policy,
2160                 .doit = ovs_ct_limit_cmd_set,
2161         },
2162         { .cmd = OVS_CT_LIMIT_CMD_DEL,
2163                 .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2164                                            * privilege. */
2165                 .policy = ct_limit_policy,
2166                 .doit = ovs_ct_limit_cmd_del,
2167         },
2168         { .cmd = OVS_CT_LIMIT_CMD_GET,
2169                 .flags = 0,               /* OK for unprivileged users. */
2170                 .policy = ct_limit_policy,
2171                 .doit = ovs_ct_limit_cmd_get,
2172         },
2173 };
2174 
2175 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2176         .name = OVS_CT_LIMIT_MCGROUP,
2177 };
2178 
2179 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2180         .hdrsize = sizeof(struct ovs_header),
2181         .name = OVS_CT_LIMIT_FAMILY,
2182         .version = OVS_CT_LIMIT_VERSION,
2183         .maxattr = OVS_CT_LIMIT_ATTR_MAX,
2184         .netnsok = true,
2185         .parallel_ops = true,
2186         .ops = ct_limit_genl_ops,
2187         .n_ops = ARRAY_SIZE(ct_limit_genl_ops),
2188         .mcgrps = &ovs_ct_limit_multicast_group,
2189         .n_mcgrps = 1,
2190         .module = THIS_MODULE,
2191 };
2192 #endif
2193 
2194 int ovs_ct_init(struct net *net)
2195 {
2196         unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2197         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2198 
2199         if (nf_connlabels_get(net, n_bits - 1)) {
2200                 ovs_net->xt_label = false;
2201                 OVS_NLERR(true, "Failed to set connlabel length");
2202         } else {
2203                 ovs_net->xt_label = true;
2204         }
2205 
2206 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2207         return ovs_ct_limit_init(net, ovs_net);
2208 #else
2209         return 0;
2210 #endif
2211 }
2212 
2213 void ovs_ct_exit(struct net *net)
2214 {
2215         struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2216 
2217 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2218         ovs_ct_limit_exit(net, ovs_net);
2219 #endif
2220 
2221         if (ovs_net->xt_label)
2222                 nf_connlabels_put(net);
2223 }
2224 

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