~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/netfilter/nf_nat_core.c

Version: ~ [ linux-5.10-rc5 ] ~ [ linux-5.9.10 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.79 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.159 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.208 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.245 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.245 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * (C) 1999-2001 Paul `Rusty' Russell
  4  * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
  5  * (C) 2011 Patrick McHardy <kaber@trash.net>
  6  */
  7 
  8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  9 
 10 #include <linux/module.h>
 11 #include <linux/types.h>
 12 #include <linux/timer.h>
 13 #include <linux/skbuff.h>
 14 #include <linux/gfp.h>
 15 #include <net/xfrm.h>
 16 #include <linux/jhash.h>
 17 #include <linux/rtnetlink.h>
 18 
 19 #include <net/netfilter/nf_conntrack.h>
 20 #include <net/netfilter/nf_conntrack_core.h>
 21 #include <net/netfilter/nf_nat.h>
 22 #include <net/netfilter/nf_nat_helper.h>
 23 #include <net/netfilter/nf_conntrack_helper.h>
 24 #include <net/netfilter/nf_conntrack_seqadj.h>
 25 #include <net/netfilter/nf_conntrack_zones.h>
 26 #include <linux/netfilter/nf_nat.h>
 27 
 28 #include "nf_internals.h"
 29 
 30 static spinlock_t nf_nat_locks[CONNTRACK_LOCKS];
 31 
 32 static DEFINE_MUTEX(nf_nat_proto_mutex);
 33 static unsigned int nat_net_id __read_mostly;
 34 
 35 static struct hlist_head *nf_nat_bysource __read_mostly;
 36 static unsigned int nf_nat_htable_size __read_mostly;
 37 static unsigned int nf_nat_hash_rnd __read_mostly;
 38 
 39 struct nf_nat_lookup_hook_priv {
 40         struct nf_hook_entries __rcu *entries;
 41 
 42         struct rcu_head rcu_head;
 43 };
 44 
 45 struct nf_nat_hooks_net {
 46         struct nf_hook_ops *nat_hook_ops;
 47         unsigned int users;
 48 };
 49 
 50 struct nat_net {
 51         struct nf_nat_hooks_net nat_proto_net[NFPROTO_NUMPROTO];
 52 };
 53 
 54 #ifdef CONFIG_XFRM
 55 static void nf_nat_ipv4_decode_session(struct sk_buff *skb,
 56                                        const struct nf_conn *ct,
 57                                        enum ip_conntrack_dir dir,
 58                                        unsigned long statusbit,
 59                                        struct flowi *fl)
 60 {
 61         const struct nf_conntrack_tuple *t = &ct->tuplehash[dir].tuple;
 62         struct flowi4 *fl4 = &fl->u.ip4;
 63 
 64         if (ct->status & statusbit) {
 65                 fl4->daddr = t->dst.u3.ip;
 66                 if (t->dst.protonum == IPPROTO_TCP ||
 67                     t->dst.protonum == IPPROTO_UDP ||
 68                     t->dst.protonum == IPPROTO_UDPLITE ||
 69                     t->dst.protonum == IPPROTO_DCCP ||
 70                     t->dst.protonum == IPPROTO_SCTP)
 71                         fl4->fl4_dport = t->dst.u.all;
 72         }
 73 
 74         statusbit ^= IPS_NAT_MASK;
 75 
 76         if (ct->status & statusbit) {
 77                 fl4->saddr = t->src.u3.ip;
 78                 if (t->dst.protonum == IPPROTO_TCP ||
 79                     t->dst.protonum == IPPROTO_UDP ||
 80                     t->dst.protonum == IPPROTO_UDPLITE ||
 81                     t->dst.protonum == IPPROTO_DCCP ||
 82                     t->dst.protonum == IPPROTO_SCTP)
 83                         fl4->fl4_sport = t->src.u.all;
 84         }
 85 }
 86 
 87 static void nf_nat_ipv6_decode_session(struct sk_buff *skb,
 88                                        const struct nf_conn *ct,
 89                                        enum ip_conntrack_dir dir,
 90                                        unsigned long statusbit,
 91                                        struct flowi *fl)
 92 {
 93 #if IS_ENABLED(CONFIG_IPV6)
 94         const struct nf_conntrack_tuple *t = &ct->tuplehash[dir].tuple;
 95         struct flowi6 *fl6 = &fl->u.ip6;
 96 
 97         if (ct->status & statusbit) {
 98                 fl6->daddr = t->dst.u3.in6;
 99                 if (t->dst.protonum == IPPROTO_TCP ||
100                     t->dst.protonum == IPPROTO_UDP ||
101                     t->dst.protonum == IPPROTO_UDPLITE ||
102                     t->dst.protonum == IPPROTO_DCCP ||
103                     t->dst.protonum == IPPROTO_SCTP)
104                         fl6->fl6_dport = t->dst.u.all;
105         }
106 
107         statusbit ^= IPS_NAT_MASK;
108 
109         if (ct->status & statusbit) {
110                 fl6->saddr = t->src.u3.in6;
111                 if (t->dst.protonum == IPPROTO_TCP ||
112                     t->dst.protonum == IPPROTO_UDP ||
113                     t->dst.protonum == IPPROTO_UDPLITE ||
114                     t->dst.protonum == IPPROTO_DCCP ||
115                     t->dst.protonum == IPPROTO_SCTP)
116                         fl6->fl6_sport = t->src.u.all;
117         }
118 #endif
119 }
120 
121 static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
122 {
123         const struct nf_conn *ct;
124         enum ip_conntrack_info ctinfo;
125         enum ip_conntrack_dir dir;
126         unsigned  long statusbit;
127         u8 family;
128 
129         ct = nf_ct_get(skb, &ctinfo);
130         if (ct == NULL)
131                 return;
132 
133         family = nf_ct_l3num(ct);
134         dir = CTINFO2DIR(ctinfo);
135         if (dir == IP_CT_DIR_ORIGINAL)
136                 statusbit = IPS_DST_NAT;
137         else
138                 statusbit = IPS_SRC_NAT;
139 
140         switch (family) {
141         case NFPROTO_IPV4:
142                 nf_nat_ipv4_decode_session(skb, ct, dir, statusbit, fl);
143                 return;
144         case NFPROTO_IPV6:
145                 nf_nat_ipv6_decode_session(skb, ct, dir, statusbit, fl);
146                 return;
147         }
148 }
149 
150 int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
151 {
152         struct flowi fl;
153         unsigned int hh_len;
154         struct dst_entry *dst;
155         struct sock *sk = skb->sk;
156         int err;
157 
158         err = xfrm_decode_session(skb, &fl, family);
159         if (err < 0)
160                 return err;
161 
162         dst = skb_dst(skb);
163         if (dst->xfrm)
164                 dst = ((struct xfrm_dst *)dst)->route;
165         if (!dst_hold_safe(dst))
166                 return -EHOSTUNREACH;
167 
168         if (sk && !net_eq(net, sock_net(sk)))
169                 sk = NULL;
170 
171         dst = xfrm_lookup(net, dst, &fl, sk, 0);
172         if (IS_ERR(dst))
173                 return PTR_ERR(dst);
174 
175         skb_dst_drop(skb);
176         skb_dst_set(skb, dst);
177 
178         /* Change in oif may mean change in hh_len. */
179         hh_len = skb_dst(skb)->dev->hard_header_len;
180         if (skb_headroom(skb) < hh_len &&
181             pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
182                 return -ENOMEM;
183         return 0;
184 }
185 EXPORT_SYMBOL(nf_xfrm_me_harder);
186 #endif /* CONFIG_XFRM */
187 
188 /* We keep an extra hash for each conntrack, for fast searching. */
189 static unsigned int
190 hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
191 {
192         unsigned int hash;
193 
194         get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
195 
196         /* Original src, to ensure we map it consistently if poss. */
197         hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
198                       tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
199 
200         return reciprocal_scale(hash, nf_nat_htable_size);
201 }
202 
203 /* Is this tuple already taken? (not by us) */
204 static int
205 nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
206                   const struct nf_conn *ignored_conntrack)
207 {
208         /* Conntrack tracking doesn't keep track of outgoing tuples; only
209          * incoming ones.  NAT means they don't have a fixed mapping,
210          * so we invert the tuple and look for the incoming reply.
211          *
212          * We could keep a separate hash if this proves too slow.
213          */
214         struct nf_conntrack_tuple reply;
215 
216         nf_ct_invert_tuple(&reply, tuple);
217         return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
218 }
219 
220 static bool nf_nat_inet_in_range(const struct nf_conntrack_tuple *t,
221                                  const struct nf_nat_range2 *range)
222 {
223         if (t->src.l3num == NFPROTO_IPV4)
224                 return ntohl(t->src.u3.ip) >= ntohl(range->min_addr.ip) &&
225                        ntohl(t->src.u3.ip) <= ntohl(range->max_addr.ip);
226 
227         return ipv6_addr_cmp(&t->src.u3.in6, &range->min_addr.in6) >= 0 &&
228                ipv6_addr_cmp(&t->src.u3.in6, &range->max_addr.in6) <= 0;
229 }
230 
231 /* Is the manipable part of the tuple between min and max incl? */
232 static bool l4proto_in_range(const struct nf_conntrack_tuple *tuple,
233                              enum nf_nat_manip_type maniptype,
234                              const union nf_conntrack_man_proto *min,
235                              const union nf_conntrack_man_proto *max)
236 {
237         __be16 port;
238 
239         switch (tuple->dst.protonum) {
240         case IPPROTO_ICMP:
241         case IPPROTO_ICMPV6:
242                 return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
243                        ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
244         case IPPROTO_GRE: /* all fall though */
245         case IPPROTO_TCP:
246         case IPPROTO_UDP:
247         case IPPROTO_UDPLITE:
248         case IPPROTO_DCCP:
249         case IPPROTO_SCTP:
250                 if (maniptype == NF_NAT_MANIP_SRC)
251                         port = tuple->src.u.all;
252                 else
253                         port = tuple->dst.u.all;
254 
255                 return ntohs(port) >= ntohs(min->all) &&
256                        ntohs(port) <= ntohs(max->all);
257         default:
258                 return true;
259         }
260 }
261 
262 /* If we source map this tuple so reply looks like reply_tuple, will
263  * that meet the constraints of range.
264  */
265 static int in_range(const struct nf_conntrack_tuple *tuple,
266                     const struct nf_nat_range2 *range)
267 {
268         /* If we are supposed to map IPs, then we must be in the
269          * range specified, otherwise let this drag us onto a new src IP.
270          */
271         if (range->flags & NF_NAT_RANGE_MAP_IPS &&
272             !nf_nat_inet_in_range(tuple, range))
273                 return 0;
274 
275         if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
276                 return 1;
277 
278         return l4proto_in_range(tuple, NF_NAT_MANIP_SRC,
279                                 &range->min_proto, &range->max_proto);
280 }
281 
282 static inline int
283 same_src(const struct nf_conn *ct,
284          const struct nf_conntrack_tuple *tuple)
285 {
286         const struct nf_conntrack_tuple *t;
287 
288         t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
289         return (t->dst.protonum == tuple->dst.protonum &&
290                 nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
291                 t->src.u.all == tuple->src.u.all);
292 }
293 
294 /* Only called for SRC manip */
295 static int
296 find_appropriate_src(struct net *net,
297                      const struct nf_conntrack_zone *zone,
298                      const struct nf_conntrack_tuple *tuple,
299                      struct nf_conntrack_tuple *result,
300                      const struct nf_nat_range2 *range)
301 {
302         unsigned int h = hash_by_src(net, tuple);
303         const struct nf_conn *ct;
304 
305         hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
306                 if (same_src(ct, tuple) &&
307                     net_eq(net, nf_ct_net(ct)) &&
308                     nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
309                         /* Copy source part from reply tuple. */
310                         nf_ct_invert_tuple(result,
311                                        &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
312                         result->dst = tuple->dst;
313 
314                         if (in_range(result, range))
315                                 return 1;
316                 }
317         }
318         return 0;
319 }
320 
321 /* For [FUTURE] fragmentation handling, we want the least-used
322  * src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
323  * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
324  * 1-65535, we don't do pro-rata allocation based on ports; we choose
325  * the ip with the lowest src-ip/dst-ip/proto usage.
326  */
327 static void
328 find_best_ips_proto(const struct nf_conntrack_zone *zone,
329                     struct nf_conntrack_tuple *tuple,
330                     const struct nf_nat_range2 *range,
331                     const struct nf_conn *ct,
332                     enum nf_nat_manip_type maniptype)
333 {
334         union nf_inet_addr *var_ipp;
335         unsigned int i, max;
336         /* Host order */
337         u32 minip, maxip, j, dist;
338         bool full_range;
339 
340         /* No IP mapping?  Do nothing. */
341         if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
342                 return;
343 
344         if (maniptype == NF_NAT_MANIP_SRC)
345                 var_ipp = &tuple->src.u3;
346         else
347                 var_ipp = &tuple->dst.u3;
348 
349         /* Fast path: only one choice. */
350         if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
351                 *var_ipp = range->min_addr;
352                 return;
353         }
354 
355         if (nf_ct_l3num(ct) == NFPROTO_IPV4)
356                 max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
357         else
358                 max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
359 
360         /* Hashing source and destination IPs gives a fairly even
361          * spread in practice (if there are a small number of IPs
362          * involved, there usually aren't that many connections
363          * anyway).  The consistency means that servers see the same
364          * client coming from the same IP (some Internet Banking sites
365          * like this), even across reboots.
366          */
367         j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
368                    range->flags & NF_NAT_RANGE_PERSISTENT ?
369                         0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
370 
371         full_range = false;
372         for (i = 0; i <= max; i++) {
373                 /* If first bytes of the address are at the maximum, use the
374                  * distance. Otherwise use the full range.
375                  */
376                 if (!full_range) {
377                         minip = ntohl((__force __be32)range->min_addr.all[i]);
378                         maxip = ntohl((__force __be32)range->max_addr.all[i]);
379                         dist  = maxip - minip + 1;
380                 } else {
381                         minip = 0;
382                         dist  = ~0;
383                 }
384 
385                 var_ipp->all[i] = (__force __u32)
386                         htonl(minip + reciprocal_scale(j, dist));
387                 if (var_ipp->all[i] != range->max_addr.all[i])
388                         full_range = true;
389 
390                 if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
391                         j ^= (__force u32)tuple->dst.u3.all[i];
392         }
393 }
394 
395 /* Alter the per-proto part of the tuple (depending on maniptype), to
396  * give a unique tuple in the given range if possible.
397  *
398  * Per-protocol part of tuple is initialized to the incoming packet.
399  */
400 static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
401                                         const struct nf_nat_range2 *range,
402                                         enum nf_nat_manip_type maniptype,
403                                         const struct nf_conn *ct)
404 {
405         unsigned int range_size, min, max, i, attempts;
406         __be16 *keyptr;
407         u16 off;
408         static const unsigned int max_attempts = 128;
409 
410         switch (tuple->dst.protonum) {
411         case IPPROTO_ICMP: /* fallthrough */
412         case IPPROTO_ICMPV6:
413                 /* id is same for either direction... */
414                 keyptr = &tuple->src.u.icmp.id;
415                 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
416                         min = 0;
417                         range_size = 65536;
418                 } else {
419                         min = ntohs(range->min_proto.icmp.id);
420                         range_size = ntohs(range->max_proto.icmp.id) -
421                                      ntohs(range->min_proto.icmp.id) + 1;
422                 }
423                 goto find_free_id;
424 #if IS_ENABLED(CONFIG_NF_CT_PROTO_GRE)
425         case IPPROTO_GRE:
426                 /* If there is no master conntrack we are not PPTP,
427                    do not change tuples */
428                 if (!ct->master)
429                         return;
430 
431                 if (maniptype == NF_NAT_MANIP_SRC)
432                         keyptr = &tuple->src.u.gre.key;
433                 else
434                         keyptr = &tuple->dst.u.gre.key;
435 
436                 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
437                         min = 1;
438                         range_size = 65535;
439                 } else {
440                         min = ntohs(range->min_proto.gre.key);
441                         range_size = ntohs(range->max_proto.gre.key) - min + 1;
442                 }
443                 goto find_free_id;
444 #endif
445         case IPPROTO_UDP:       /* fallthrough */
446         case IPPROTO_UDPLITE:   /* fallthrough */
447         case IPPROTO_TCP:       /* fallthrough */
448         case IPPROTO_SCTP:      /* fallthrough */
449         case IPPROTO_DCCP:      /* fallthrough */
450                 if (maniptype == NF_NAT_MANIP_SRC)
451                         keyptr = &tuple->src.u.all;
452                 else
453                         keyptr = &tuple->dst.u.all;
454 
455                 break;
456         default:
457                 return;
458         }
459 
460         /* If no range specified... */
461         if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
462                 /* If it's dst rewrite, can't change port */
463                 if (maniptype == NF_NAT_MANIP_DST)
464                         return;
465 
466                 if (ntohs(*keyptr) < 1024) {
467                         /* Loose convention: >> 512 is credential passing */
468                         if (ntohs(*keyptr) < 512) {
469                                 min = 1;
470                                 range_size = 511 - min + 1;
471                         } else {
472                                 min = 600;
473                                 range_size = 1023 - min + 1;
474                         }
475                 } else {
476                         min = 1024;
477                         range_size = 65535 - 1024 + 1;
478                 }
479         } else {
480                 min = ntohs(range->min_proto.all);
481                 max = ntohs(range->max_proto.all);
482                 if (unlikely(max < min))
483                         swap(max, min);
484                 range_size = max - min + 1;
485         }
486 
487 find_free_id:
488         if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
489                 off = (ntohs(*keyptr) - ntohs(range->base_proto.all));
490         else
491                 off = prandom_u32();
492 
493         attempts = range_size;
494         if (attempts > max_attempts)
495                 attempts = max_attempts;
496 
497         /* We are in softirq; doing a search of the entire range risks
498          * soft lockup when all tuples are already used.
499          *
500          * If we can't find any free port from first offset, pick a new
501          * one and try again, with ever smaller search window.
502          */
503 another_round:
504         for (i = 0; i < attempts; i++, off++) {
505                 *keyptr = htons(min + off % range_size);
506                 if (!nf_nat_used_tuple(tuple, ct))
507                         return;
508         }
509 
510         if (attempts >= range_size || attempts < 16)
511                 return;
512         attempts /= 2;
513         off = prandom_u32();
514         goto another_round;
515 }
516 
517 /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
518  * we change the source to map into the range. For NF_INET_PRE_ROUTING
519  * and NF_INET_LOCAL_OUT, we change the destination to map into the
520  * range. It might not be possible to get a unique tuple, but we try.
521  * At worst (or if we race), we will end up with a final duplicate in
522  * __nf_conntrack_confirm and drop the packet. */
523 static void
524 get_unique_tuple(struct nf_conntrack_tuple *tuple,
525                  const struct nf_conntrack_tuple *orig_tuple,
526                  const struct nf_nat_range2 *range,
527                  struct nf_conn *ct,
528                  enum nf_nat_manip_type maniptype)
529 {
530         const struct nf_conntrack_zone *zone;
531         struct net *net = nf_ct_net(ct);
532 
533         zone = nf_ct_zone(ct);
534 
535         /* 1) If this srcip/proto/src-proto-part is currently mapped,
536          * and that same mapping gives a unique tuple within the given
537          * range, use that.
538          *
539          * This is only required for source (ie. NAT/masq) mappings.
540          * So far, we don't do local source mappings, so multiple
541          * manips not an issue.
542          */
543         if (maniptype == NF_NAT_MANIP_SRC &&
544             !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
545                 /* try the original tuple first */
546                 if (in_range(orig_tuple, range)) {
547                         if (!nf_nat_used_tuple(orig_tuple, ct)) {
548                                 *tuple = *orig_tuple;
549                                 return;
550                         }
551                 } else if (find_appropriate_src(net, zone,
552                                                 orig_tuple, tuple, range)) {
553                         pr_debug("get_unique_tuple: Found current src map\n");
554                         if (!nf_nat_used_tuple(tuple, ct))
555                                 return;
556                 }
557         }
558 
559         /* 2) Select the least-used IP/proto combination in the given range */
560         *tuple = *orig_tuple;
561         find_best_ips_proto(zone, tuple, range, ct, maniptype);
562 
563         /* 3) The per-protocol part of the manip is made to map into
564          * the range to make a unique tuple.
565          */
566 
567         /* Only bother mapping if it's not already in range and unique */
568         if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
569                 if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
570                         if (!(range->flags & NF_NAT_RANGE_PROTO_OFFSET) &&
571                             l4proto_in_range(tuple, maniptype,
572                                   &range->min_proto,
573                                   &range->max_proto) &&
574                             (range->min_proto.all == range->max_proto.all ||
575                              !nf_nat_used_tuple(tuple, ct)))
576                                 return;
577                 } else if (!nf_nat_used_tuple(tuple, ct)) {
578                         return;
579                 }
580         }
581 
582         /* Last chance: get protocol to try to obtain unique tuple. */
583         nf_nat_l4proto_unique_tuple(tuple, range, maniptype, ct);
584 }
585 
586 struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
587 {
588         struct nf_conn_nat *nat = nfct_nat(ct);
589         if (nat)
590                 return nat;
591 
592         if (!nf_ct_is_confirmed(ct))
593                 nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
594 
595         return nat;
596 }
597 EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
598 
599 unsigned int
600 nf_nat_setup_info(struct nf_conn *ct,
601                   const struct nf_nat_range2 *range,
602                   enum nf_nat_manip_type maniptype)
603 {
604         struct net *net = nf_ct_net(ct);
605         struct nf_conntrack_tuple curr_tuple, new_tuple;
606 
607         /* Can't setup nat info for confirmed ct. */
608         if (nf_ct_is_confirmed(ct))
609                 return NF_ACCEPT;
610 
611         WARN_ON(maniptype != NF_NAT_MANIP_SRC &&
612                 maniptype != NF_NAT_MANIP_DST);
613 
614         if (WARN_ON(nf_nat_initialized(ct, maniptype)))
615                 return NF_DROP;
616 
617         /* What we've got will look like inverse of reply. Normally
618          * this is what is in the conntrack, except for prior
619          * manipulations (future optimization: if num_manips == 0,
620          * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
621          */
622         nf_ct_invert_tuple(&curr_tuple,
623                            &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
624 
625         get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
626 
627         if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
628                 struct nf_conntrack_tuple reply;
629 
630                 /* Alter conntrack table so will recognize replies. */
631                 nf_ct_invert_tuple(&reply, &new_tuple);
632                 nf_conntrack_alter_reply(ct, &reply);
633 
634                 /* Non-atomic: we own this at the moment. */
635                 if (maniptype == NF_NAT_MANIP_SRC)
636                         ct->status |= IPS_SRC_NAT;
637                 else
638                         ct->status |= IPS_DST_NAT;
639 
640                 if (nfct_help(ct) && !nfct_seqadj(ct))
641                         if (!nfct_seqadj_ext_add(ct))
642                                 return NF_DROP;
643         }
644 
645         if (maniptype == NF_NAT_MANIP_SRC) {
646                 unsigned int srchash;
647                 spinlock_t *lock;
648 
649                 srchash = hash_by_src(net,
650                                       &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
651                 lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS];
652                 spin_lock_bh(lock);
653                 hlist_add_head_rcu(&ct->nat_bysource,
654                                    &nf_nat_bysource[srchash]);
655                 spin_unlock_bh(lock);
656         }
657 
658         /* It's done. */
659         if (maniptype == NF_NAT_MANIP_DST)
660                 ct->status |= IPS_DST_NAT_DONE;
661         else
662                 ct->status |= IPS_SRC_NAT_DONE;
663 
664         return NF_ACCEPT;
665 }
666 EXPORT_SYMBOL(nf_nat_setup_info);
667 
668 static unsigned int
669 __nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
670 {
671         /* Force range to this IP; let proto decide mapping for
672          * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
673          * Use reply in case it's already been mangled (eg local packet).
674          */
675         union nf_inet_addr ip =
676                 (manip == NF_NAT_MANIP_SRC ?
677                 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
678                 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
679         struct nf_nat_range2 range = {
680                 .flags          = NF_NAT_RANGE_MAP_IPS,
681                 .min_addr       = ip,
682                 .max_addr       = ip,
683         };
684         return nf_nat_setup_info(ct, &range, manip);
685 }
686 
687 unsigned int
688 nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
689 {
690         return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
691 }
692 EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
693 
694 /* Do packet manipulations according to nf_nat_setup_info. */
695 unsigned int nf_nat_packet(struct nf_conn *ct,
696                            enum ip_conntrack_info ctinfo,
697                            unsigned int hooknum,
698                            struct sk_buff *skb)
699 {
700         enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
701         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
702         unsigned int verdict = NF_ACCEPT;
703         unsigned long statusbit;
704 
705         if (mtype == NF_NAT_MANIP_SRC)
706                 statusbit = IPS_SRC_NAT;
707         else
708                 statusbit = IPS_DST_NAT;
709 
710         /* Invert if this is reply dir. */
711         if (dir == IP_CT_DIR_REPLY)
712                 statusbit ^= IPS_NAT_MASK;
713 
714         /* Non-atomic: these bits don't change. */
715         if (ct->status & statusbit)
716                 verdict = nf_nat_manip_pkt(skb, ct, mtype, dir);
717 
718         return verdict;
719 }
720 EXPORT_SYMBOL_GPL(nf_nat_packet);
721 
722 unsigned int
723 nf_nat_inet_fn(void *priv, struct sk_buff *skb,
724                const struct nf_hook_state *state)
725 {
726         struct nf_conn *ct;
727         enum ip_conntrack_info ctinfo;
728         struct nf_conn_nat *nat;
729         /* maniptype == SRC for postrouting. */
730         enum nf_nat_manip_type maniptype = HOOK2MANIP(state->hook);
731 
732         ct = nf_ct_get(skb, &ctinfo);
733         /* Can't track?  It's not due to stress, or conntrack would
734          * have dropped it.  Hence it's the user's responsibilty to
735          * packet filter it out, or implement conntrack/NAT for that
736          * protocol. 8) --RR
737          */
738         if (!ct)
739                 return NF_ACCEPT;
740 
741         nat = nfct_nat(ct);
742 
743         switch (ctinfo) {
744         case IP_CT_RELATED:
745         case IP_CT_RELATED_REPLY:
746                 /* Only ICMPs can be IP_CT_IS_REPLY.  Fallthrough */
747         case IP_CT_NEW:
748                 /* Seen it before?  This can happen for loopback, retrans,
749                  * or local packets.
750                  */
751                 if (!nf_nat_initialized(ct, maniptype)) {
752                         struct nf_nat_lookup_hook_priv *lpriv = priv;
753                         struct nf_hook_entries *e = rcu_dereference(lpriv->entries);
754                         unsigned int ret;
755                         int i;
756 
757                         if (!e)
758                                 goto null_bind;
759 
760                         for (i = 0; i < e->num_hook_entries; i++) {
761                                 ret = e->hooks[i].hook(e->hooks[i].priv, skb,
762                                                        state);
763                                 if (ret != NF_ACCEPT)
764                                         return ret;
765                                 if (nf_nat_initialized(ct, maniptype))
766                                         goto do_nat;
767                         }
768 null_bind:
769                         ret = nf_nat_alloc_null_binding(ct, state->hook);
770                         if (ret != NF_ACCEPT)
771                                 return ret;
772                 } else {
773                         pr_debug("Already setup manip %s for ct %p (status bits 0x%lx)\n",
774                                  maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST",
775                                  ct, ct->status);
776                         if (nf_nat_oif_changed(state->hook, ctinfo, nat,
777                                                state->out))
778                                 goto oif_changed;
779                 }
780                 break;
781         default:
782                 /* ESTABLISHED */
783                 WARN_ON(ctinfo != IP_CT_ESTABLISHED &&
784                         ctinfo != IP_CT_ESTABLISHED_REPLY);
785                 if (nf_nat_oif_changed(state->hook, ctinfo, nat, state->out))
786                         goto oif_changed;
787         }
788 do_nat:
789         return nf_nat_packet(ct, ctinfo, state->hook, skb);
790 
791 oif_changed:
792         nf_ct_kill_acct(ct, ctinfo, skb);
793         return NF_DROP;
794 }
795 EXPORT_SYMBOL_GPL(nf_nat_inet_fn);
796 
797 struct nf_nat_proto_clean {
798         u8      l3proto;
799         u8      l4proto;
800 };
801 
802 /* kill conntracks with affected NAT section */
803 static int nf_nat_proto_remove(struct nf_conn *i, void *data)
804 {
805         const struct nf_nat_proto_clean *clean = data;
806 
807         if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
808             (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
809                 return 0;
810 
811         return i->status & IPS_NAT_MASK ? 1 : 0;
812 }
813 
814 static void __nf_nat_cleanup_conntrack(struct nf_conn *ct)
815 {
816         unsigned int h;
817 
818         h = hash_by_src(nf_ct_net(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
819         spin_lock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
820         hlist_del_rcu(&ct->nat_bysource);
821         spin_unlock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
822 }
823 
824 static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
825 {
826         if (nf_nat_proto_remove(ct, data))
827                 return 1;
828 
829         /* This module is being removed and conntrack has nat null binding.
830          * Remove it from bysource hash, as the table will be freed soon.
831          *
832          * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
833          * will delete entry from already-freed table.
834          */
835         if (test_and_clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status))
836                 __nf_nat_cleanup_conntrack(ct);
837 
838         /* don't delete conntrack.  Although that would make things a lot
839          * simpler, we'd end up flushing all conntracks on nat rmmod.
840          */
841         return 0;
842 }
843 
844 /* No one using conntrack by the time this called. */
845 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
846 {
847         if (ct->status & IPS_SRC_NAT_DONE)
848                 __nf_nat_cleanup_conntrack(ct);
849 }
850 
851 static struct nf_ct_ext_type nat_extend __read_mostly = {
852         .len            = sizeof(struct nf_conn_nat),
853         .align          = __alignof__(struct nf_conn_nat),
854         .destroy        = nf_nat_cleanup_conntrack,
855         .id             = NF_CT_EXT_NAT,
856 };
857 
858 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
859 
860 #include <linux/netfilter/nfnetlink.h>
861 #include <linux/netfilter/nfnetlink_conntrack.h>
862 
863 static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
864         [CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
865         [CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
866 };
867 
868 static int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
869                                           struct nf_nat_range2 *range)
870 {
871         if (tb[CTA_PROTONAT_PORT_MIN]) {
872                 range->min_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]);
873                 range->max_proto.all = range->min_proto.all;
874                 range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
875         }
876         if (tb[CTA_PROTONAT_PORT_MAX]) {
877                 range->max_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]);
878                 range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
879         }
880         return 0;
881 }
882 
883 static int nfnetlink_parse_nat_proto(struct nlattr *attr,
884                                      const struct nf_conn *ct,
885                                      struct nf_nat_range2 *range)
886 {
887         struct nlattr *tb[CTA_PROTONAT_MAX+1];
888         int err;
889 
890         err = nla_parse_nested_deprecated(tb, CTA_PROTONAT_MAX, attr,
891                                           protonat_nla_policy, NULL);
892         if (err < 0)
893                 return err;
894 
895         return nf_nat_l4proto_nlattr_to_range(tb, range);
896 }
897 
898 static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
899         [CTA_NAT_V4_MINIP]      = { .type = NLA_U32 },
900         [CTA_NAT_V4_MAXIP]      = { .type = NLA_U32 },
901         [CTA_NAT_V6_MINIP]      = { .len = sizeof(struct in6_addr) },
902         [CTA_NAT_V6_MAXIP]      = { .len = sizeof(struct in6_addr) },
903         [CTA_NAT_PROTO]         = { .type = NLA_NESTED },
904 };
905 
906 static int nf_nat_ipv4_nlattr_to_range(struct nlattr *tb[],
907                                        struct nf_nat_range2 *range)
908 {
909         if (tb[CTA_NAT_V4_MINIP]) {
910                 range->min_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MINIP]);
911                 range->flags |= NF_NAT_RANGE_MAP_IPS;
912         }
913 
914         if (tb[CTA_NAT_V4_MAXIP])
915                 range->max_addr.ip = nla_get_be32(tb[CTA_NAT_V4_MAXIP]);
916         else
917                 range->max_addr.ip = range->min_addr.ip;
918 
919         return 0;
920 }
921 
922 static int nf_nat_ipv6_nlattr_to_range(struct nlattr *tb[],
923                                        struct nf_nat_range2 *range)
924 {
925         if (tb[CTA_NAT_V6_MINIP]) {
926                 nla_memcpy(&range->min_addr.ip6, tb[CTA_NAT_V6_MINIP],
927                            sizeof(struct in6_addr));
928                 range->flags |= NF_NAT_RANGE_MAP_IPS;
929         }
930 
931         if (tb[CTA_NAT_V6_MAXIP])
932                 nla_memcpy(&range->max_addr.ip6, tb[CTA_NAT_V6_MAXIP],
933                            sizeof(struct in6_addr));
934         else
935                 range->max_addr = range->min_addr;
936 
937         return 0;
938 }
939 
940 static int
941 nfnetlink_parse_nat(const struct nlattr *nat,
942                     const struct nf_conn *ct, struct nf_nat_range2 *range)
943 {
944         struct nlattr *tb[CTA_NAT_MAX+1];
945         int err;
946 
947         memset(range, 0, sizeof(*range));
948 
949         err = nla_parse_nested_deprecated(tb, CTA_NAT_MAX, nat,
950                                           nat_nla_policy, NULL);
951         if (err < 0)
952                 return err;
953 
954         switch (nf_ct_l3num(ct)) {
955         case NFPROTO_IPV4:
956                 err = nf_nat_ipv4_nlattr_to_range(tb, range);
957                 break;
958         case NFPROTO_IPV6:
959                 err = nf_nat_ipv6_nlattr_to_range(tb, range);
960                 break;
961         default:
962                 err = -EPROTONOSUPPORT;
963                 break;
964         }
965 
966         if (err)
967                 return err;
968 
969         if (!tb[CTA_NAT_PROTO])
970                 return 0;
971 
972         return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
973 }
974 
975 /* This function is called under rcu_read_lock() */
976 static int
977 nfnetlink_parse_nat_setup(struct nf_conn *ct,
978                           enum nf_nat_manip_type manip,
979                           const struct nlattr *attr)
980 {
981         struct nf_nat_range2 range;
982         int err;
983 
984         /* Should not happen, restricted to creating new conntracks
985          * via ctnetlink.
986          */
987         if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
988                 return -EEXIST;
989 
990         /* No NAT information has been passed, allocate the null-binding */
991         if (attr == NULL)
992                 return __nf_nat_alloc_null_binding(ct, manip) == NF_DROP ? -ENOMEM : 0;
993 
994         err = nfnetlink_parse_nat(attr, ct, &range);
995         if (err < 0)
996                 return err;
997 
998         return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0;
999 }
1000 #else
1001 static int
1002 nfnetlink_parse_nat_setup(struct nf_conn *ct,
1003                           enum nf_nat_manip_type manip,
1004                           const struct nlattr *attr)
1005 {
1006         return -EOPNOTSUPP;
1007 }
1008 #endif
1009 
1010 static struct nf_ct_helper_expectfn follow_master_nat = {
1011         .name           = "nat-follow-master",
1012         .expectfn       = nf_nat_follow_master,
1013 };
1014 
1015 int nf_nat_register_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops,
1016                        const struct nf_hook_ops *orig_nat_ops, unsigned int ops_count)
1017 {
1018         struct nat_net *nat_net = net_generic(net, nat_net_id);
1019         struct nf_nat_hooks_net *nat_proto_net;
1020         struct nf_nat_lookup_hook_priv *priv;
1021         unsigned int hooknum = ops->hooknum;
1022         struct nf_hook_ops *nat_ops;
1023         int i, ret;
1024 
1025         if (WARN_ON_ONCE(pf >= ARRAY_SIZE(nat_net->nat_proto_net)))
1026                 return -EINVAL;
1027 
1028         nat_proto_net = &nat_net->nat_proto_net[pf];
1029 
1030         for (i = 0; i < ops_count; i++) {
1031                 if (orig_nat_ops[i].hooknum == hooknum) {
1032                         hooknum = i;
1033                         break;
1034                 }
1035         }
1036 
1037         if (WARN_ON_ONCE(i == ops_count))
1038                 return -EINVAL;
1039 
1040         mutex_lock(&nf_nat_proto_mutex);
1041         if (!nat_proto_net->nat_hook_ops) {
1042                 WARN_ON(nat_proto_net->users != 0);
1043 
1044                 nat_ops = kmemdup(orig_nat_ops, sizeof(*orig_nat_ops) * ops_count, GFP_KERNEL);
1045                 if (!nat_ops) {
1046                         mutex_unlock(&nf_nat_proto_mutex);
1047                         return -ENOMEM;
1048                 }
1049 
1050                 for (i = 0; i < ops_count; i++) {
1051                         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1052                         if (priv) {
1053                                 nat_ops[i].priv = priv;
1054                                 continue;
1055                         }
1056                         mutex_unlock(&nf_nat_proto_mutex);
1057                         while (i)
1058                                 kfree(nat_ops[--i].priv);
1059                         kfree(nat_ops);
1060                         return -ENOMEM;
1061                 }
1062 
1063                 ret = nf_register_net_hooks(net, nat_ops, ops_count);
1064                 if (ret < 0) {
1065                         mutex_unlock(&nf_nat_proto_mutex);
1066                         for (i = 0; i < ops_count; i++)
1067                                 kfree(nat_ops[i].priv);
1068                         kfree(nat_ops);
1069                         return ret;
1070                 }
1071 
1072                 nat_proto_net->nat_hook_ops = nat_ops;
1073         }
1074 
1075         nat_ops = nat_proto_net->nat_hook_ops;
1076         priv = nat_ops[hooknum].priv;
1077         if (WARN_ON_ONCE(!priv)) {
1078                 mutex_unlock(&nf_nat_proto_mutex);
1079                 return -EOPNOTSUPP;
1080         }
1081 
1082         ret = nf_hook_entries_insert_raw(&priv->entries, ops);
1083         if (ret == 0)
1084                 nat_proto_net->users++;
1085 
1086         mutex_unlock(&nf_nat_proto_mutex);
1087         return ret;
1088 }
1089 
1090 void nf_nat_unregister_fn(struct net *net, u8 pf, const struct nf_hook_ops *ops,
1091                           unsigned int ops_count)
1092 {
1093         struct nat_net *nat_net = net_generic(net, nat_net_id);
1094         struct nf_nat_hooks_net *nat_proto_net;
1095         struct nf_nat_lookup_hook_priv *priv;
1096         struct nf_hook_ops *nat_ops;
1097         int hooknum = ops->hooknum;
1098         int i;
1099 
1100         if (pf >= ARRAY_SIZE(nat_net->nat_proto_net))
1101                 return;
1102 
1103         nat_proto_net = &nat_net->nat_proto_net[pf];
1104 
1105         mutex_lock(&nf_nat_proto_mutex);
1106         if (WARN_ON(nat_proto_net->users == 0))
1107                 goto unlock;
1108 
1109         nat_proto_net->users--;
1110 
1111         nat_ops = nat_proto_net->nat_hook_ops;
1112         for (i = 0; i < ops_count; i++) {
1113                 if (nat_ops[i].hooknum == hooknum) {
1114                         hooknum = i;
1115                         break;
1116                 }
1117         }
1118         if (WARN_ON_ONCE(i == ops_count))
1119                 goto unlock;
1120         priv = nat_ops[hooknum].priv;
1121         nf_hook_entries_delete_raw(&priv->entries, ops);
1122 
1123         if (nat_proto_net->users == 0) {
1124                 nf_unregister_net_hooks(net, nat_ops, ops_count);
1125 
1126                 for (i = 0; i < ops_count; i++) {
1127                         priv = nat_ops[i].priv;
1128                         kfree_rcu(priv, rcu_head);
1129                 }
1130 
1131                 nat_proto_net->nat_hook_ops = NULL;
1132                 kfree(nat_ops);
1133         }
1134 unlock:
1135         mutex_unlock(&nf_nat_proto_mutex);
1136 }
1137 
1138 static struct pernet_operations nat_net_ops = {
1139         .id = &nat_net_id,
1140         .size = sizeof(struct nat_net),
1141 };
1142 
1143 static struct nf_nat_hook nat_hook = {
1144         .parse_nat_setup        = nfnetlink_parse_nat_setup,
1145 #ifdef CONFIG_XFRM
1146         .decode_session         = __nf_nat_decode_session,
1147 #endif
1148         .manip_pkt              = nf_nat_manip_pkt,
1149 };
1150 
1151 static int __init nf_nat_init(void)
1152 {
1153         int ret, i;
1154 
1155         /* Leave them the same for the moment. */
1156         nf_nat_htable_size = nf_conntrack_htable_size;
1157         if (nf_nat_htable_size < CONNTRACK_LOCKS)
1158                 nf_nat_htable_size = CONNTRACK_LOCKS;
1159 
1160         nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
1161         if (!nf_nat_bysource)
1162                 return -ENOMEM;
1163 
1164         ret = nf_ct_extend_register(&nat_extend);
1165         if (ret < 0) {
1166                 kvfree(nf_nat_bysource);
1167                 pr_err("Unable to register extension\n");
1168                 return ret;
1169         }
1170 
1171         for (i = 0; i < CONNTRACK_LOCKS; i++)
1172                 spin_lock_init(&nf_nat_locks[i]);
1173 
1174         ret = register_pernet_subsys(&nat_net_ops);
1175         if (ret < 0) {
1176                 nf_ct_extend_unregister(&nat_extend);
1177                 return ret;
1178         }
1179 
1180         nf_ct_helper_expectfn_register(&follow_master_nat);
1181 
1182         WARN_ON(nf_nat_hook != NULL);
1183         RCU_INIT_POINTER(nf_nat_hook, &nat_hook);
1184 
1185         return 0;
1186 }
1187 
1188 static void __exit nf_nat_cleanup(void)
1189 {
1190         struct nf_nat_proto_clean clean = {};
1191 
1192         nf_ct_iterate_destroy(nf_nat_proto_clean, &clean);
1193 
1194         nf_ct_extend_unregister(&nat_extend);
1195         nf_ct_helper_expectfn_unregister(&follow_master_nat);
1196         RCU_INIT_POINTER(nf_nat_hook, NULL);
1197 
1198         synchronize_net();
1199         kvfree(nf_nat_bysource);
1200         unregister_pernet_subsys(&nat_net_ops);
1201 }
1202 
1203 MODULE_LICENSE("GPL");
1204 
1205 module_init(nf_nat_init);
1206 module_exit(nf_nat_cleanup);
1207 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp