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TOMOYO Linux Cross Reference
Linux/net/ipv4/netfilter/ip_tables.c

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  1 /*
  2  * Packet matching code.
  3  *
  4  * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
  5  * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
  6  * Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net>
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License version 2 as
 10  * published by the Free Software Foundation.
 11  */
 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13 #include <linux/cache.h>
 14 #include <linux/capability.h>
 15 #include <linux/skbuff.h>
 16 #include <linux/kmod.h>
 17 #include <linux/vmalloc.h>
 18 #include <linux/netdevice.h>
 19 #include <linux/module.h>
 20 #include <linux/icmp.h>
 21 #include <net/ip.h>
 22 #include <net/compat.h>
 23 #include <asm/uaccess.h>
 24 #include <linux/mutex.h>
 25 #include <linux/proc_fs.h>
 26 #include <linux/err.h>
 27 #include <linux/cpumask.h>
 28 
 29 #include <linux/netfilter/x_tables.h>
 30 #include <linux/netfilter_ipv4/ip_tables.h>
 31 #include <net/netfilter/nf_log.h>
 32 #include "../../netfilter/xt_repldata.h"
 33 
 34 MODULE_LICENSE("GPL");
 35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
 36 MODULE_DESCRIPTION("IPv4 packet filter");
 37 
 38 /*#define DEBUG_IP_FIREWALL*/
 39 /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
 40 /*#define DEBUG_IP_FIREWALL_USER*/
 41 
 42 #ifdef DEBUG_IP_FIREWALL
 43 #define dprintf(format, args...) pr_info(format , ## args)
 44 #else
 45 #define dprintf(format, args...)
 46 #endif
 47 
 48 #ifdef DEBUG_IP_FIREWALL_USER
 49 #define duprintf(format, args...) pr_info(format , ## args)
 50 #else
 51 #define duprintf(format, args...)
 52 #endif
 53 
 54 #ifdef CONFIG_NETFILTER_DEBUG
 55 #define IP_NF_ASSERT(x)         WARN_ON(!(x))
 56 #else
 57 #define IP_NF_ASSERT(x)
 58 #endif
 59 
 60 #if 0
 61 /* All the better to debug you with... */
 62 #define static
 63 #define inline
 64 #endif
 65 
 66 void *ipt_alloc_initial_table(const struct xt_table *info)
 67 {
 68         return xt_alloc_initial_table(ipt, IPT);
 69 }
 70 EXPORT_SYMBOL_GPL(ipt_alloc_initial_table);
 71 
 72 /* Returns whether matches rule or not. */
 73 /* Performance critical - called for every packet */
 74 static inline bool
 75 ip_packet_match(const struct iphdr *ip,
 76                 const char *indev,
 77                 const char *outdev,
 78                 const struct ipt_ip *ipinfo,
 79                 int isfrag)
 80 {
 81         unsigned long ret;
 82 
 83 #define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
 84 
 85         if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
 86                   IPT_INV_SRCIP) ||
 87             FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
 88                   IPT_INV_DSTIP)) {
 89                 dprintf("Source or dest mismatch.\n");
 90 
 91                 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
 92                         &ip->saddr, &ipinfo->smsk.s_addr, &ipinfo->src.s_addr,
 93                         ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
 94                 dprintf("DST: %pI4 Mask: %pI4 Target: %pI4.%s\n",
 95                         &ip->daddr, &ipinfo->dmsk.s_addr, &ipinfo->dst.s_addr,
 96                         ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
 97                 return false;
 98         }
 99 
100         ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
101 
102         if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
103                 dprintf("VIA in mismatch (%s vs %s).%s\n",
104                         indev, ipinfo->iniface,
105                         ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
106                 return false;
107         }
108 
109         ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
110 
111         if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
112                 dprintf("VIA out mismatch (%s vs %s).%s\n",
113                         outdev, ipinfo->outiface,
114                         ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
115                 return false;
116         }
117 
118         /* Check specific protocol */
119         if (ipinfo->proto &&
120             FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
121                 dprintf("Packet protocol %hi does not match %hi.%s\n",
122                         ip->protocol, ipinfo->proto,
123                         ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
124                 return false;
125         }
126 
127         /* If we have a fragment rule but the packet is not a fragment
128          * then we return zero */
129         if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
130                 dprintf("Fragment rule but not fragment.%s\n",
131                         ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
132                 return false;
133         }
134 
135         return true;
136 }
137 
138 static bool
139 ip_checkentry(const struct ipt_ip *ip)
140 {
141         if (ip->flags & ~IPT_F_MASK) {
142                 duprintf("Unknown flag bits set: %08X\n",
143                          ip->flags & ~IPT_F_MASK);
144                 return false;
145         }
146         if (ip->invflags & ~IPT_INV_MASK) {
147                 duprintf("Unknown invflag bits set: %08X\n",
148                          ip->invflags & ~IPT_INV_MASK);
149                 return false;
150         }
151         return true;
152 }
153 
154 static unsigned int
155 ipt_error(struct sk_buff *skb, const struct xt_action_param *par)
156 {
157         net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);
158 
159         return NF_DROP;
160 }
161 
162 /* Performance critical */
163 static inline struct ipt_entry *
164 get_entry(const void *base, unsigned int offset)
165 {
166         return (struct ipt_entry *)(base + offset);
167 }
168 
169 /* All zeroes == unconditional rule. */
170 /* Mildly perf critical (only if packet tracing is on) */
171 static inline bool unconditional(const struct ipt_ip *ip)
172 {
173         static const struct ipt_ip uncond;
174 
175         return memcmp(ip, &uncond, sizeof(uncond)) == 0;
176 #undef FWINV
177 }
178 
179 /* for const-correctness */
180 static inline const struct xt_entry_target *
181 ipt_get_target_c(const struct ipt_entry *e)
182 {
183         return ipt_get_target((struct ipt_entry *)e);
184 }
185 
186 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
187 static const char *const hooknames[] = {
188         [NF_INET_PRE_ROUTING]           = "PREROUTING",
189         [NF_INET_LOCAL_IN]              = "INPUT",
190         [NF_INET_FORWARD]               = "FORWARD",
191         [NF_INET_LOCAL_OUT]             = "OUTPUT",
192         [NF_INET_POST_ROUTING]          = "POSTROUTING",
193 };
194 
195 enum nf_ip_trace_comments {
196         NF_IP_TRACE_COMMENT_RULE,
197         NF_IP_TRACE_COMMENT_RETURN,
198         NF_IP_TRACE_COMMENT_POLICY,
199 };
200 
201 static const char *const comments[] = {
202         [NF_IP_TRACE_COMMENT_RULE]      = "rule",
203         [NF_IP_TRACE_COMMENT_RETURN]    = "return",
204         [NF_IP_TRACE_COMMENT_POLICY]    = "policy",
205 };
206 
207 static struct nf_loginfo trace_loginfo = {
208         .type = NF_LOG_TYPE_LOG,
209         .u = {
210                 .log = {
211                         .level = 4,
212                         .logflags = NF_LOG_MASK,
213                 },
214         },
215 };
216 
217 /* Mildly perf critical (only if packet tracing is on) */
218 static inline int
219 get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e,
220                       const char *hookname, const char **chainname,
221                       const char **comment, unsigned int *rulenum)
222 {
223         const struct xt_standard_target *t = (void *)ipt_get_target_c(s);
224 
225         if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
226                 /* Head of user chain: ERROR target with chainname */
227                 *chainname = t->target.data;
228                 (*rulenum) = 0;
229         } else if (s == e) {
230                 (*rulenum)++;
231 
232                 if (s->target_offset == sizeof(struct ipt_entry) &&
233                     strcmp(t->target.u.kernel.target->name,
234                            XT_STANDARD_TARGET) == 0 &&
235                    t->verdict < 0 &&
236                    unconditional(&s->ip)) {
237                         /* Tail of chains: STANDARD target (return/policy) */
238                         *comment = *chainname == hookname
239                                 ? comments[NF_IP_TRACE_COMMENT_POLICY]
240                                 : comments[NF_IP_TRACE_COMMENT_RETURN];
241                 }
242                 return 1;
243         } else
244                 (*rulenum)++;
245 
246         return 0;
247 }
248 
249 static void trace_packet(const struct sk_buff *skb,
250                          unsigned int hook,
251                          const struct net_device *in,
252                          const struct net_device *out,
253                          const char *tablename,
254                          const struct xt_table_info *private,
255                          const struct ipt_entry *e)
256 {
257         const void *table_base;
258         const struct ipt_entry *root;
259         const char *hookname, *chainname, *comment;
260         const struct ipt_entry *iter;
261         unsigned int rulenum = 0;
262         struct net *net = dev_net(in ? in : out);
263 
264         table_base = private->entries[smp_processor_id()];
265         root = get_entry(table_base, private->hook_entry[hook]);
266 
267         hookname = chainname = hooknames[hook];
268         comment = comments[NF_IP_TRACE_COMMENT_RULE];
269 
270         xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
271                 if (get_chainname_rulenum(iter, e, hookname,
272                     &chainname, &comment, &rulenum) != 0)
273                         break;
274 
275         nf_log_packet(net, AF_INET, hook, skb, in, out, &trace_loginfo,
276                       "TRACE: %s:%s:%s:%u ",
277                       tablename, chainname, comment, rulenum);
278 }
279 #endif
280 
281 static inline __pure
282 struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry)
283 {
284         return (void *)entry + entry->next_offset;
285 }
286 
287 /* Returns one of the generic firewall policies, like NF_ACCEPT. */
288 unsigned int
289 ipt_do_table(struct sk_buff *skb,
290              unsigned int hook,
291              const struct net_device *in,
292              const struct net_device *out,
293              struct xt_table *table)
294 {
295         static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
296         const struct iphdr *ip;
297         /* Initializing verdict to NF_DROP keeps gcc happy. */
298         unsigned int verdict = NF_DROP;
299         const char *indev, *outdev;
300         const void *table_base;
301         struct ipt_entry *e, **jumpstack;
302         unsigned int *stackptr, origptr, cpu;
303         const struct xt_table_info *private;
304         struct xt_action_param acpar;
305         unsigned int addend;
306 
307         /* Initialization */
308         ip = ip_hdr(skb);
309         indev = in ? in->name : nulldevname;
310         outdev = out ? out->name : nulldevname;
311         /* We handle fragments by dealing with the first fragment as
312          * if it was a normal packet.  All other fragments are treated
313          * normally, except that they will NEVER match rules that ask
314          * things we don't know, ie. tcp syn flag or ports).  If the
315          * rule is also a fragment-specific rule, non-fragments won't
316          * match it. */
317         acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
318         acpar.thoff   = ip_hdrlen(skb);
319         acpar.hotdrop = false;
320         acpar.in      = in;
321         acpar.out     = out;
322         acpar.family  = NFPROTO_IPV4;
323         acpar.hooknum = hook;
324 
325         IP_NF_ASSERT(table->valid_hooks & (1 << hook));
326         local_bh_disable();
327         addend = xt_write_recseq_begin();
328         private = table->private;
329         cpu        = smp_processor_id();
330         /*
331          * Ensure we load private-> members after we've fetched the base
332          * pointer.
333          */
334         smp_read_barrier_depends();
335         table_base = private->entries[cpu];
336         jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
337         stackptr   = per_cpu_ptr(private->stackptr, cpu);
338         origptr    = *stackptr;
339 
340         e = get_entry(table_base, private->hook_entry[hook]);
341 
342         pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n",
343                  table->name, hook, origptr,
344                  get_entry(table_base, private->underflow[hook]));
345 
346         do {
347                 const struct xt_entry_target *t;
348                 const struct xt_entry_match *ematch;
349 
350                 IP_NF_ASSERT(e);
351                 if (!ip_packet_match(ip, indev, outdev,
352                     &e->ip, acpar.fragoff)) {
353  no_match:
354                         e = ipt_next_entry(e);
355                         continue;
356                 }
357 
358                 xt_ematch_foreach(ematch, e) {
359                         acpar.match     = ematch->u.kernel.match;
360                         acpar.matchinfo = ematch->data;
361                         if (!acpar.match->match(skb, &acpar))
362                                 goto no_match;
363                 }
364 
365                 ADD_COUNTER(e->counters, skb->len, 1);
366 
367                 t = ipt_get_target(e);
368                 IP_NF_ASSERT(t->u.kernel.target);
369 
370 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
371                 /* The packet is traced: log it */
372                 if (unlikely(skb->nf_trace))
373                         trace_packet(skb, hook, in, out,
374                                      table->name, private, e);
375 #endif
376                 /* Standard target? */
377                 if (!t->u.kernel.target->target) {
378                         int v;
379 
380                         v = ((struct xt_standard_target *)t)->verdict;
381                         if (v < 0) {
382                                 /* Pop from stack? */
383                                 if (v != XT_RETURN) {
384                                         verdict = (unsigned int)(-v) - 1;
385                                         break;
386                                 }
387                                 if (*stackptr <= origptr) {
388                                         e = get_entry(table_base,
389                                             private->underflow[hook]);
390                                         pr_debug("Underflow (this is normal) "
391                                                  "to %p\n", e);
392                                 } else {
393                                         e = jumpstack[--*stackptr];
394                                         pr_debug("Pulled %p out from pos %u\n",
395                                                  e, *stackptr);
396                                         e = ipt_next_entry(e);
397                                 }
398                                 continue;
399                         }
400                         if (table_base + v != ipt_next_entry(e) &&
401                             !(e->ip.flags & IPT_F_GOTO)) {
402                                 if (*stackptr >= private->stacksize) {
403                                         verdict = NF_DROP;
404                                         break;
405                                 }
406                                 jumpstack[(*stackptr)++] = e;
407                                 pr_debug("Pushed %p into pos %u\n",
408                                          e, *stackptr - 1);
409                         }
410 
411                         e = get_entry(table_base, v);
412                         continue;
413                 }
414 
415                 acpar.target   = t->u.kernel.target;
416                 acpar.targinfo = t->data;
417 
418                 verdict = t->u.kernel.target->target(skb, &acpar);
419                 /* Target might have changed stuff. */
420                 ip = ip_hdr(skb);
421                 if (verdict == XT_CONTINUE)
422                         e = ipt_next_entry(e);
423                 else
424                         /* Verdict */
425                         break;
426         } while (!acpar.hotdrop);
427         pr_debug("Exiting %s; resetting sp from %u to %u\n",
428                  __func__, *stackptr, origptr);
429         *stackptr = origptr;
430         xt_write_recseq_end(addend);
431         local_bh_enable();
432 
433 #ifdef DEBUG_ALLOW_ALL
434         return NF_ACCEPT;
435 #else
436         if (acpar.hotdrop)
437                 return NF_DROP;
438         else return verdict;
439 #endif
440 }
441 
442 /* Figures out from what hook each rule can be called: returns 0 if
443    there are loops.  Puts hook bitmask in comefrom. */
444 static int
445 mark_source_chains(const struct xt_table_info *newinfo,
446                    unsigned int valid_hooks, void *entry0)
447 {
448         unsigned int hook;
449 
450         /* No recursion; use packet counter to save back ptrs (reset
451            to 0 as we leave), and comefrom to save source hook bitmask */
452         for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
453                 unsigned int pos = newinfo->hook_entry[hook];
454                 struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
455 
456                 if (!(valid_hooks & (1 << hook)))
457                         continue;
458 
459                 /* Set initial back pointer. */
460                 e->counters.pcnt = pos;
461 
462                 for (;;) {
463                         const struct xt_standard_target *t
464                                 = (void *)ipt_get_target_c(e);
465                         int visited = e->comefrom & (1 << hook);
466 
467                         if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
468                                 pr_err("iptables: loop hook %u pos %u %08X.\n",
469                                        hook, pos, e->comefrom);
470                                 return 0;
471                         }
472                         e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
473 
474                         /* Unconditional return/END. */
475                         if ((e->target_offset == sizeof(struct ipt_entry) &&
476                              (strcmp(t->target.u.user.name,
477                                      XT_STANDARD_TARGET) == 0) &&
478                              t->verdict < 0 && unconditional(&e->ip)) ||
479                             visited) {
480                                 unsigned int oldpos, size;
481 
482                                 if ((strcmp(t->target.u.user.name,
483                                             XT_STANDARD_TARGET) == 0) &&
484                                     t->verdict < -NF_MAX_VERDICT - 1) {
485                                         duprintf("mark_source_chains: bad "
486                                                 "negative verdict (%i)\n",
487                                                                 t->verdict);
488                                         return 0;
489                                 }
490 
491                                 /* Return: backtrack through the last
492                                    big jump. */
493                                 do {
494                                         e->comefrom ^= (1<<NF_INET_NUMHOOKS);
495 #ifdef DEBUG_IP_FIREWALL_USER
496                                         if (e->comefrom
497                                             & (1 << NF_INET_NUMHOOKS)) {
498                                                 duprintf("Back unset "
499                                                          "on hook %u "
500                                                          "rule %u\n",
501                                                          hook, pos);
502                                         }
503 #endif
504                                         oldpos = pos;
505                                         pos = e->counters.pcnt;
506                                         e->counters.pcnt = 0;
507 
508                                         /* We're at the start. */
509                                         if (pos == oldpos)
510                                                 goto next;
511 
512                                         e = (struct ipt_entry *)
513                                                 (entry0 + pos);
514                                 } while (oldpos == pos + e->next_offset);
515 
516                                 /* Move along one */
517                                 size = e->next_offset;
518                                 e = (struct ipt_entry *)
519                                         (entry0 + pos + size);
520                                 e->counters.pcnt = pos;
521                                 pos += size;
522                         } else {
523                                 int newpos = t->verdict;
524 
525                                 if (strcmp(t->target.u.user.name,
526                                            XT_STANDARD_TARGET) == 0 &&
527                                     newpos >= 0) {
528                                         if (newpos > newinfo->size -
529                                                 sizeof(struct ipt_entry)) {
530                                                 duprintf("mark_source_chains: "
531                                                         "bad verdict (%i)\n",
532                                                                 newpos);
533                                                 return 0;
534                                         }
535                                         /* This a jump; chase it. */
536                                         duprintf("Jump rule %u -> %u\n",
537                                                  pos, newpos);
538                                 } else {
539                                         /* ... this is a fallthru */
540                                         newpos = pos + e->next_offset;
541                                 }
542                                 e = (struct ipt_entry *)
543                                         (entry0 + newpos);
544                                 e->counters.pcnt = pos;
545                                 pos = newpos;
546                         }
547                 }
548                 next:
549                 duprintf("Finished chain %u\n", hook);
550         }
551         return 1;
552 }
553 
554 static void cleanup_match(struct xt_entry_match *m, struct net *net)
555 {
556         struct xt_mtdtor_param par;
557 
558         par.net       = net;
559         par.match     = m->u.kernel.match;
560         par.matchinfo = m->data;
561         par.family    = NFPROTO_IPV4;
562         if (par.match->destroy != NULL)
563                 par.match->destroy(&par);
564         module_put(par.match->me);
565 }
566 
567 static int
568 check_entry(const struct ipt_entry *e, const char *name)
569 {
570         const struct xt_entry_target *t;
571 
572         if (!ip_checkentry(&e->ip)) {
573                 duprintf("ip check failed %p %s.\n", e, name);
574                 return -EINVAL;
575         }
576 
577         if (e->target_offset + sizeof(struct xt_entry_target) >
578             e->next_offset)
579                 return -EINVAL;
580 
581         t = ipt_get_target_c(e);
582         if (e->target_offset + t->u.target_size > e->next_offset)
583                 return -EINVAL;
584 
585         return 0;
586 }
587 
588 static int
589 check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
590 {
591         const struct ipt_ip *ip = par->entryinfo;
592         int ret;
593 
594         par->match     = m->u.kernel.match;
595         par->matchinfo = m->data;
596 
597         ret = xt_check_match(par, m->u.match_size - sizeof(*m),
598               ip->proto, ip->invflags & IPT_INV_PROTO);
599         if (ret < 0) {
600                 duprintf("check failed for `%s'.\n", par->match->name);
601                 return ret;
602         }
603         return 0;
604 }
605 
606 static int
607 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
608 {
609         struct xt_match *match;
610         int ret;
611 
612         match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
613                                       m->u.user.revision);
614         if (IS_ERR(match)) {
615                 duprintf("find_check_match: `%s' not found\n", m->u.user.name);
616                 return PTR_ERR(match);
617         }
618         m->u.kernel.match = match;
619 
620         ret = check_match(m, par);
621         if (ret)
622                 goto err;
623 
624         return 0;
625 err:
626         module_put(m->u.kernel.match->me);
627         return ret;
628 }
629 
630 static int check_target(struct ipt_entry *e, struct net *net, const char *name)
631 {
632         struct xt_entry_target *t = ipt_get_target(e);
633         struct xt_tgchk_param par = {
634                 .net       = net,
635                 .table     = name,
636                 .entryinfo = e,
637                 .target    = t->u.kernel.target,
638                 .targinfo  = t->data,
639                 .hook_mask = e->comefrom,
640                 .family    = NFPROTO_IPV4,
641         };
642         int ret;
643 
644         ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
645               e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
646         if (ret < 0) {
647                 duprintf("check failed for `%s'.\n",
648                          t->u.kernel.target->name);
649                 return ret;
650         }
651         return 0;
652 }
653 
654 static int
655 find_check_entry(struct ipt_entry *e, struct net *net, const char *name,
656                  unsigned int size)
657 {
658         struct xt_entry_target *t;
659         struct xt_target *target;
660         int ret;
661         unsigned int j;
662         struct xt_mtchk_param mtpar;
663         struct xt_entry_match *ematch;
664 
665         ret = check_entry(e, name);
666         if (ret)
667                 return ret;
668 
669         j = 0;
670         mtpar.net       = net;
671         mtpar.table     = name;
672         mtpar.entryinfo = &e->ip;
673         mtpar.hook_mask = e->comefrom;
674         mtpar.family    = NFPROTO_IPV4;
675         xt_ematch_foreach(ematch, e) {
676                 ret = find_check_match(ematch, &mtpar);
677                 if (ret != 0)
678                         goto cleanup_matches;
679                 ++j;
680         }
681 
682         t = ipt_get_target(e);
683         target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
684                                         t->u.user.revision);
685         if (IS_ERR(target)) {
686                 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
687                 ret = PTR_ERR(target);
688                 goto cleanup_matches;
689         }
690         t->u.kernel.target = target;
691 
692         ret = check_target(e, net, name);
693         if (ret)
694                 goto err;
695         return 0;
696  err:
697         module_put(t->u.kernel.target->me);
698  cleanup_matches:
699         xt_ematch_foreach(ematch, e) {
700                 if (j-- == 0)
701                         break;
702                 cleanup_match(ematch, net);
703         }
704         return ret;
705 }
706 
707 static bool check_underflow(const struct ipt_entry *e)
708 {
709         const struct xt_entry_target *t;
710         unsigned int verdict;
711 
712         if (!unconditional(&e->ip))
713                 return false;
714         t = ipt_get_target_c(e);
715         if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
716                 return false;
717         verdict = ((struct xt_standard_target *)t)->verdict;
718         verdict = -verdict - 1;
719         return verdict == NF_DROP || verdict == NF_ACCEPT;
720 }
721 
722 static int
723 check_entry_size_and_hooks(struct ipt_entry *e,
724                            struct xt_table_info *newinfo,
725                            const unsigned char *base,
726                            const unsigned char *limit,
727                            const unsigned int *hook_entries,
728                            const unsigned int *underflows,
729                            unsigned int valid_hooks)
730 {
731         unsigned int h;
732 
733         if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 ||
734             (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
735                 duprintf("Bad offset %p\n", e);
736                 return -EINVAL;
737         }
738 
739         if (e->next_offset
740             < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) {
741                 duprintf("checking: element %p size %u\n",
742                          e, e->next_offset);
743                 return -EINVAL;
744         }
745 
746         /* Check hooks & underflows */
747         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
748                 if (!(valid_hooks & (1 << h)))
749                         continue;
750                 if ((unsigned char *)e - base == hook_entries[h])
751                         newinfo->hook_entry[h] = hook_entries[h];
752                 if ((unsigned char *)e - base == underflows[h]) {
753                         if (!check_underflow(e)) {
754                                 pr_err("Underflows must be unconditional and "
755                                        "use the STANDARD target with "
756                                        "ACCEPT/DROP\n");
757                                 return -EINVAL;
758                         }
759                         newinfo->underflow[h] = underflows[h];
760                 }
761         }
762 
763         /* Clear counters and comefrom */
764         e->counters = ((struct xt_counters) { 0, 0 });
765         e->comefrom = 0;
766         return 0;
767 }
768 
769 static void
770 cleanup_entry(struct ipt_entry *e, struct net *net)
771 {
772         struct xt_tgdtor_param par;
773         struct xt_entry_target *t;
774         struct xt_entry_match *ematch;
775 
776         /* Cleanup all matches */
777         xt_ematch_foreach(ematch, e)
778                 cleanup_match(ematch, net);
779         t = ipt_get_target(e);
780 
781         par.net      = net;
782         par.target   = t->u.kernel.target;
783         par.targinfo = t->data;
784         par.family   = NFPROTO_IPV4;
785         if (par.target->destroy != NULL)
786                 par.target->destroy(&par);
787         module_put(par.target->me);
788 }
789 
790 /* Checks and translates the user-supplied table segment (held in
791    newinfo) */
792 static int
793 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
794                 const struct ipt_replace *repl)
795 {
796         struct ipt_entry *iter;
797         unsigned int i;
798         int ret = 0;
799 
800         newinfo->size = repl->size;
801         newinfo->number = repl->num_entries;
802 
803         /* Init all hooks to impossible value. */
804         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
805                 newinfo->hook_entry[i] = 0xFFFFFFFF;
806                 newinfo->underflow[i] = 0xFFFFFFFF;
807         }
808 
809         duprintf("translate_table: size %u\n", newinfo->size);
810         i = 0;
811         /* Walk through entries, checking offsets. */
812         xt_entry_foreach(iter, entry0, newinfo->size) {
813                 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
814                                                  entry0 + repl->size,
815                                                  repl->hook_entry,
816                                                  repl->underflow,
817                                                  repl->valid_hooks);
818                 if (ret != 0)
819                         return ret;
820                 ++i;
821                 if (strcmp(ipt_get_target(iter)->u.user.name,
822                     XT_ERROR_TARGET) == 0)
823                         ++newinfo->stacksize;
824         }
825 
826         if (i != repl->num_entries) {
827                 duprintf("translate_table: %u not %u entries\n",
828                          i, repl->num_entries);
829                 return -EINVAL;
830         }
831 
832         /* Check hooks all assigned */
833         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
834                 /* Only hooks which are valid */
835                 if (!(repl->valid_hooks & (1 << i)))
836                         continue;
837                 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
838                         duprintf("Invalid hook entry %u %u\n",
839                                  i, repl->hook_entry[i]);
840                         return -EINVAL;
841                 }
842                 if (newinfo->underflow[i] == 0xFFFFFFFF) {
843                         duprintf("Invalid underflow %u %u\n",
844                                  i, repl->underflow[i]);
845                         return -EINVAL;
846                 }
847         }
848 
849         if (!mark_source_chains(newinfo, repl->valid_hooks, entry0))
850                 return -ELOOP;
851 
852         /* Finally, each sanity check must pass */
853         i = 0;
854         xt_entry_foreach(iter, entry0, newinfo->size) {
855                 ret = find_check_entry(iter, net, repl->name, repl->size);
856                 if (ret != 0)
857                         break;
858                 ++i;
859         }
860 
861         if (ret != 0) {
862                 xt_entry_foreach(iter, entry0, newinfo->size) {
863                         if (i-- == 0)
864                                 break;
865                         cleanup_entry(iter, net);
866                 }
867                 return ret;
868         }
869 
870         /* And one copy for every other CPU */
871         for_each_possible_cpu(i) {
872                 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
873                         memcpy(newinfo->entries[i], entry0, newinfo->size);
874         }
875 
876         return ret;
877 }
878 
879 static void
880 get_counters(const struct xt_table_info *t,
881              struct xt_counters counters[])
882 {
883         struct ipt_entry *iter;
884         unsigned int cpu;
885         unsigned int i;
886 
887         for_each_possible_cpu(cpu) {
888                 seqcount_t *s = &per_cpu(xt_recseq, cpu);
889 
890                 i = 0;
891                 xt_entry_foreach(iter, t->entries[cpu], t->size) {
892                         u64 bcnt, pcnt;
893                         unsigned int start;
894 
895                         do {
896                                 start = read_seqcount_begin(s);
897                                 bcnt = iter->counters.bcnt;
898                                 pcnt = iter->counters.pcnt;
899                         } while (read_seqcount_retry(s, start));
900 
901                         ADD_COUNTER(counters[i], bcnt, pcnt);
902                         ++i; /* macro does multi eval of i */
903                 }
904         }
905 }
906 
907 static struct xt_counters *alloc_counters(const struct xt_table *table)
908 {
909         unsigned int countersize;
910         struct xt_counters *counters;
911         const struct xt_table_info *private = table->private;
912 
913         /* We need atomic snapshot of counters: rest doesn't change
914            (other than comefrom, which userspace doesn't care
915            about). */
916         countersize = sizeof(struct xt_counters) * private->number;
917         counters = vzalloc(countersize);
918 
919         if (counters == NULL)
920                 return ERR_PTR(-ENOMEM);
921 
922         get_counters(private, counters);
923 
924         return counters;
925 }
926 
927 static int
928 copy_entries_to_user(unsigned int total_size,
929                      const struct xt_table *table,
930                      void __user *userptr)
931 {
932         unsigned int off, num;
933         const struct ipt_entry *e;
934         struct xt_counters *counters;
935         const struct xt_table_info *private = table->private;
936         int ret = 0;
937         const void *loc_cpu_entry;
938 
939         counters = alloc_counters(table);
940         if (IS_ERR(counters))
941                 return PTR_ERR(counters);
942 
943         /* choose the copy that is on our node/cpu, ...
944          * This choice is lazy (because current thread is
945          * allowed to migrate to another cpu)
946          */
947         loc_cpu_entry = private->entries[raw_smp_processor_id()];
948         if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
949                 ret = -EFAULT;
950                 goto free_counters;
951         }
952 
953         /* FIXME: use iterator macros --RR */
954         /* ... then go back and fix counters and names */
955         for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
956                 unsigned int i;
957                 const struct xt_entry_match *m;
958                 const struct xt_entry_target *t;
959 
960                 e = (struct ipt_entry *)(loc_cpu_entry + off);
961                 if (copy_to_user(userptr + off
962                                  + offsetof(struct ipt_entry, counters),
963                                  &counters[num],
964                                  sizeof(counters[num])) != 0) {
965                         ret = -EFAULT;
966                         goto free_counters;
967                 }
968 
969                 for (i = sizeof(struct ipt_entry);
970                      i < e->target_offset;
971                      i += m->u.match_size) {
972                         m = (void *)e + i;
973 
974                         if (copy_to_user(userptr + off + i
975                                          + offsetof(struct xt_entry_match,
976                                                     u.user.name),
977                                          m->u.kernel.match->name,
978                                          strlen(m->u.kernel.match->name)+1)
979                             != 0) {
980                                 ret = -EFAULT;
981                                 goto free_counters;
982                         }
983                 }
984 
985                 t = ipt_get_target_c(e);
986                 if (copy_to_user(userptr + off + e->target_offset
987                                  + offsetof(struct xt_entry_target,
988                                             u.user.name),
989                                  t->u.kernel.target->name,
990                                  strlen(t->u.kernel.target->name)+1) != 0) {
991                         ret = -EFAULT;
992                         goto free_counters;
993                 }
994         }
995 
996  free_counters:
997         vfree(counters);
998         return ret;
999 }
1000 
1001 #ifdef CONFIG_COMPAT
1002 static void compat_standard_from_user(void *dst, const void *src)
1003 {
1004         int v = *(compat_int_t *)src;
1005 
1006         if (v > 0)
1007                 v += xt_compat_calc_jump(AF_INET, v);
1008         memcpy(dst, &v, sizeof(v));
1009 }
1010 
1011 static int compat_standard_to_user(void __user *dst, const void *src)
1012 {
1013         compat_int_t cv = *(int *)src;
1014 
1015         if (cv > 0)
1016                 cv -= xt_compat_calc_jump(AF_INET, cv);
1017         return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
1018 }
1019 
1020 static int compat_calc_entry(const struct ipt_entry *e,
1021                              const struct xt_table_info *info,
1022                              const void *base, struct xt_table_info *newinfo)
1023 {
1024         const struct xt_entry_match *ematch;
1025         const struct xt_entry_target *t;
1026         unsigned int entry_offset;
1027         int off, i, ret;
1028 
1029         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1030         entry_offset = (void *)e - base;
1031         xt_ematch_foreach(ematch, e)
1032                 off += xt_compat_match_offset(ematch->u.kernel.match);
1033         t = ipt_get_target_c(e);
1034         off += xt_compat_target_offset(t->u.kernel.target);
1035         newinfo->size -= off;
1036         ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1037         if (ret)
1038                 return ret;
1039 
1040         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1041                 if (info->hook_entry[i] &&
1042                     (e < (struct ipt_entry *)(base + info->hook_entry[i])))
1043                         newinfo->hook_entry[i] -= off;
1044                 if (info->underflow[i] &&
1045                     (e < (struct ipt_entry *)(base + info->underflow[i])))
1046                         newinfo->underflow[i] -= off;
1047         }
1048         return 0;
1049 }
1050 
1051 static int compat_table_info(const struct xt_table_info *info,
1052                              struct xt_table_info *newinfo)
1053 {
1054         struct ipt_entry *iter;
1055         void *loc_cpu_entry;
1056         int ret;
1057 
1058         if (!newinfo || !info)
1059                 return -EINVAL;
1060 
1061         /* we dont care about newinfo->entries[] */
1062         memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
1063         newinfo->initial_entries = 0;
1064         loc_cpu_entry = info->entries[raw_smp_processor_id()];
1065         xt_compat_init_offsets(AF_INET, info->number);
1066         xt_entry_foreach(iter, loc_cpu_entry, info->size) {
1067                 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
1068                 if (ret != 0)
1069                         return ret;
1070         }
1071         return 0;
1072 }
1073 #endif
1074 
1075 static int get_info(struct net *net, void __user *user,
1076                     const int *len, int compat)
1077 {
1078         char name[XT_TABLE_MAXNAMELEN];
1079         struct xt_table *t;
1080         int ret;
1081 
1082         if (*len != sizeof(struct ipt_getinfo)) {
1083                 duprintf("length %u != %zu\n", *len,
1084                          sizeof(struct ipt_getinfo));
1085                 return -EINVAL;
1086         }
1087 
1088         if (copy_from_user(name, user, sizeof(name)) != 0)
1089                 return -EFAULT;
1090 
1091         name[XT_TABLE_MAXNAMELEN-1] = '\0';
1092 #ifdef CONFIG_COMPAT
1093         if (compat)
1094                 xt_compat_lock(AF_INET);
1095 #endif
1096         t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1097                                     "iptable_%s", name);
1098         if (!IS_ERR_OR_NULL(t)) {
1099                 struct ipt_getinfo info;
1100                 const struct xt_table_info *private = t->private;
1101 #ifdef CONFIG_COMPAT
1102                 struct xt_table_info tmp;
1103 
1104                 if (compat) {
1105                         ret = compat_table_info(private, &tmp);
1106                         xt_compat_flush_offsets(AF_INET);
1107                         private = &tmp;
1108                 }
1109 #endif
1110                 memset(&info, 0, sizeof(info));
1111                 info.valid_hooks = t->valid_hooks;
1112                 memcpy(info.hook_entry, private->hook_entry,
1113                        sizeof(info.hook_entry));
1114                 memcpy(info.underflow, private->underflow,
1115                        sizeof(info.underflow));
1116                 info.num_entries = private->number;
1117                 info.size = private->size;
1118                 strcpy(info.name, name);
1119 
1120                 if (copy_to_user(user, &info, *len) != 0)
1121                         ret = -EFAULT;
1122                 else
1123                         ret = 0;
1124 
1125                 xt_table_unlock(t);
1126                 module_put(t->me);
1127         } else
1128                 ret = t ? PTR_ERR(t) : -ENOENT;
1129 #ifdef CONFIG_COMPAT
1130         if (compat)
1131                 xt_compat_unlock(AF_INET);
1132 #endif
1133         return ret;
1134 }
1135 
1136 static int
1137 get_entries(struct net *net, struct ipt_get_entries __user *uptr,
1138             const int *len)
1139 {
1140         int ret;
1141         struct ipt_get_entries get;
1142         struct xt_table *t;
1143 
1144         if (*len < sizeof(get)) {
1145                 duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
1146                 return -EINVAL;
1147         }
1148         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1149                 return -EFAULT;
1150         if (*len != sizeof(struct ipt_get_entries) + get.size) {
1151                 duprintf("get_entries: %u != %zu\n",
1152                          *len, sizeof(get) + get.size);
1153                 return -EINVAL;
1154         }
1155 
1156         t = xt_find_table_lock(net, AF_INET, get.name);
1157         if (!IS_ERR_OR_NULL(t)) {
1158                 const struct xt_table_info *private = t->private;
1159                 duprintf("t->private->number = %u\n", private->number);
1160                 if (get.size == private->size)
1161                         ret = copy_entries_to_user(private->size,
1162                                                    t, uptr->entrytable);
1163                 else {
1164                         duprintf("get_entries: I've got %u not %u!\n",
1165                                  private->size, get.size);
1166                         ret = -EAGAIN;
1167                 }
1168                 module_put(t->me);
1169                 xt_table_unlock(t);
1170         } else
1171                 ret = t ? PTR_ERR(t) : -ENOENT;
1172 
1173         return ret;
1174 }
1175 
1176 static int
1177 __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
1178              struct xt_table_info *newinfo, unsigned int num_counters,
1179              void __user *counters_ptr)
1180 {
1181         int ret;
1182         struct xt_table *t;
1183         struct xt_table_info *oldinfo;
1184         struct xt_counters *counters;
1185         void *loc_cpu_old_entry;
1186         struct ipt_entry *iter;
1187 
1188         ret = 0;
1189         counters = vzalloc(num_counters * sizeof(struct xt_counters));
1190         if (!counters) {
1191                 ret = -ENOMEM;
1192                 goto out;
1193         }
1194 
1195         t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
1196                                     "iptable_%s", name);
1197         if (IS_ERR_OR_NULL(t)) {
1198                 ret = t ? PTR_ERR(t) : -ENOENT;
1199                 goto free_newinfo_counters_untrans;
1200         }
1201 
1202         /* You lied! */
1203         if (valid_hooks != t->valid_hooks) {
1204                 duprintf("Valid hook crap: %08X vs %08X\n",
1205                          valid_hooks, t->valid_hooks);
1206                 ret = -EINVAL;
1207                 goto put_module;
1208         }
1209 
1210         oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1211         if (!oldinfo)
1212                 goto put_module;
1213 
1214         /* Update module usage count based on number of rules */
1215         duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1216                 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1217         if ((oldinfo->number > oldinfo->initial_entries) ||
1218             (newinfo->number <= oldinfo->initial_entries))
1219                 module_put(t->me);
1220         if ((oldinfo->number > oldinfo->initial_entries) &&
1221             (newinfo->number <= oldinfo->initial_entries))
1222                 module_put(t->me);
1223 
1224         /* Get the old counters, and synchronize with replace */
1225         get_counters(oldinfo, counters);
1226 
1227         /* Decrease module usage counts and free resource */
1228         loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1229         xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1230                 cleanup_entry(iter, net);
1231 
1232         xt_free_table_info(oldinfo);
1233         if (copy_to_user(counters_ptr, counters,
1234                          sizeof(struct xt_counters) * num_counters) != 0) {
1235                 /* Silent error, can't fail, new table is already in place */
1236                 net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n");
1237         }
1238         vfree(counters);
1239         xt_table_unlock(t);
1240         return ret;
1241 
1242  put_module:
1243         module_put(t->me);
1244         xt_table_unlock(t);
1245  free_newinfo_counters_untrans:
1246         vfree(counters);
1247  out:
1248         return ret;
1249 }
1250 
1251 static int
1252 do_replace(struct net *net, const void __user *user, unsigned int len)
1253 {
1254         int ret;
1255         struct ipt_replace tmp;
1256         struct xt_table_info *newinfo;
1257         void *loc_cpu_entry;
1258         struct ipt_entry *iter;
1259 
1260         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1261                 return -EFAULT;
1262 
1263         /* overflow check */
1264         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1265                 return -ENOMEM;
1266         tmp.name[sizeof(tmp.name)-1] = 0;
1267 
1268         newinfo = xt_alloc_table_info(tmp.size);
1269         if (!newinfo)
1270                 return -ENOMEM;
1271 
1272         /* choose the copy that is on our node/cpu */
1273         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1274         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1275                            tmp.size) != 0) {
1276                 ret = -EFAULT;
1277                 goto free_newinfo;
1278         }
1279 
1280         ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
1281         if (ret != 0)
1282                 goto free_newinfo;
1283 
1284         duprintf("Translated table\n");
1285 
1286         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1287                            tmp.num_counters, tmp.counters);
1288         if (ret)
1289                 goto free_newinfo_untrans;
1290         return 0;
1291 
1292  free_newinfo_untrans:
1293         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1294                 cleanup_entry(iter, net);
1295  free_newinfo:
1296         xt_free_table_info(newinfo);
1297         return ret;
1298 }
1299 
1300 static int
1301 do_add_counters(struct net *net, const void __user *user,
1302                 unsigned int len, int compat)
1303 {
1304         unsigned int i, curcpu;
1305         struct xt_counters_info tmp;
1306         struct xt_counters *paddc;
1307         unsigned int num_counters;
1308         const char *name;
1309         int size;
1310         void *ptmp;
1311         struct xt_table *t;
1312         const struct xt_table_info *private;
1313         int ret = 0;
1314         void *loc_cpu_entry;
1315         struct ipt_entry *iter;
1316         unsigned int addend;
1317 #ifdef CONFIG_COMPAT
1318         struct compat_xt_counters_info compat_tmp;
1319 
1320         if (compat) {
1321                 ptmp = &compat_tmp;
1322                 size = sizeof(struct compat_xt_counters_info);
1323         } else
1324 #endif
1325         {
1326                 ptmp = &tmp;
1327                 size = sizeof(struct xt_counters_info);
1328         }
1329 
1330         if (copy_from_user(ptmp, user, size) != 0)
1331                 return -EFAULT;
1332 
1333 #ifdef CONFIG_COMPAT
1334         if (compat) {
1335                 num_counters = compat_tmp.num_counters;
1336                 name = compat_tmp.name;
1337         } else
1338 #endif
1339         {
1340                 num_counters = tmp.num_counters;
1341                 name = tmp.name;
1342         }
1343 
1344         if (len != size + num_counters * sizeof(struct xt_counters))
1345                 return -EINVAL;
1346 
1347         paddc = vmalloc(len - size);
1348         if (!paddc)
1349                 return -ENOMEM;
1350 
1351         if (copy_from_user(paddc, user + size, len - size) != 0) {
1352                 ret = -EFAULT;
1353                 goto free;
1354         }
1355 
1356         t = xt_find_table_lock(net, AF_INET, name);
1357         if (IS_ERR_OR_NULL(t)) {
1358                 ret = t ? PTR_ERR(t) : -ENOENT;
1359                 goto free;
1360         }
1361 
1362         local_bh_disable();
1363         private = t->private;
1364         if (private->number != num_counters) {
1365                 ret = -EINVAL;
1366                 goto unlock_up_free;
1367         }
1368 
1369         i = 0;
1370         /* Choose the copy that is on our node */
1371         curcpu = smp_processor_id();
1372         loc_cpu_entry = private->entries[curcpu];
1373         addend = xt_write_recseq_begin();
1374         xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1375                 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1376                 ++i;
1377         }
1378         xt_write_recseq_end(addend);
1379  unlock_up_free:
1380         local_bh_enable();
1381         xt_table_unlock(t);
1382         module_put(t->me);
1383  free:
1384         vfree(paddc);
1385 
1386         return ret;
1387 }
1388 
1389 #ifdef CONFIG_COMPAT
1390 struct compat_ipt_replace {
1391         char                    name[XT_TABLE_MAXNAMELEN];
1392         u32                     valid_hooks;
1393         u32                     num_entries;
1394         u32                     size;
1395         u32                     hook_entry[NF_INET_NUMHOOKS];
1396         u32                     underflow[NF_INET_NUMHOOKS];
1397         u32                     num_counters;
1398         compat_uptr_t           counters;       /* struct xt_counters * */
1399         struct compat_ipt_entry entries[0];
1400 };
1401 
1402 static int
1403 compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
1404                           unsigned int *size, struct xt_counters *counters,
1405                           unsigned int i)
1406 {
1407         struct xt_entry_target *t;
1408         struct compat_ipt_entry __user *ce;
1409         u_int16_t target_offset, next_offset;
1410         compat_uint_t origsize;
1411         const struct xt_entry_match *ematch;
1412         int ret = 0;
1413 
1414         origsize = *size;
1415         ce = (struct compat_ipt_entry __user *)*dstptr;
1416         if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 ||
1417             copy_to_user(&ce->counters, &counters[i],
1418             sizeof(counters[i])) != 0)
1419                 return -EFAULT;
1420 
1421         *dstptr += sizeof(struct compat_ipt_entry);
1422         *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1423 
1424         xt_ematch_foreach(ematch, e) {
1425                 ret = xt_compat_match_to_user(ematch, dstptr, size);
1426                 if (ret != 0)
1427                         return ret;
1428         }
1429         target_offset = e->target_offset - (origsize - *size);
1430         t = ipt_get_target(e);
1431         ret = xt_compat_target_to_user(t, dstptr, size);
1432         if (ret)
1433                 return ret;
1434         next_offset = e->next_offset - (origsize - *size);
1435         if (put_user(target_offset, &ce->target_offset) != 0 ||
1436             put_user(next_offset, &ce->next_offset) != 0)
1437                 return -EFAULT;
1438         return 0;
1439 }
1440 
1441 static int
1442 compat_find_calc_match(struct xt_entry_match *m,
1443                        const char *name,
1444                        const struct ipt_ip *ip,
1445                        unsigned int hookmask,
1446                        int *size)
1447 {
1448         struct xt_match *match;
1449 
1450         match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name,
1451                                       m->u.user.revision);
1452         if (IS_ERR(match)) {
1453                 duprintf("compat_check_calc_match: `%s' not found\n",
1454                          m->u.user.name);
1455                 return PTR_ERR(match);
1456         }
1457         m->u.kernel.match = match;
1458         *size += xt_compat_match_offset(match);
1459         return 0;
1460 }
1461 
1462 static void compat_release_entry(struct compat_ipt_entry *e)
1463 {
1464         struct xt_entry_target *t;
1465         struct xt_entry_match *ematch;
1466 
1467         /* Cleanup all matches */
1468         xt_ematch_foreach(ematch, e)
1469                 module_put(ematch->u.kernel.match->me);
1470         t = compat_ipt_get_target(e);
1471         module_put(t->u.kernel.target->me);
1472 }
1473 
1474 static int
1475 check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
1476                                   struct xt_table_info *newinfo,
1477                                   unsigned int *size,
1478                                   const unsigned char *base,
1479                                   const unsigned char *limit,
1480                                   const unsigned int *hook_entries,
1481                                   const unsigned int *underflows,
1482                                   const char *name)
1483 {
1484         struct xt_entry_match *ematch;
1485         struct xt_entry_target *t;
1486         struct xt_target *target;
1487         unsigned int entry_offset;
1488         unsigned int j;
1489         int ret, off, h;
1490 
1491         duprintf("check_compat_entry_size_and_hooks %p\n", e);
1492         if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 ||
1493             (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
1494                 duprintf("Bad offset %p, limit = %p\n", e, limit);
1495                 return -EINVAL;
1496         }
1497 
1498         if (e->next_offset < sizeof(struct compat_ipt_entry) +
1499                              sizeof(struct compat_xt_entry_target)) {
1500                 duprintf("checking: element %p size %u\n",
1501                          e, e->next_offset);
1502                 return -EINVAL;
1503         }
1504 
1505         /* For purposes of check_entry casting the compat entry is fine */
1506         ret = check_entry((struct ipt_entry *)e, name);
1507         if (ret)
1508                 return ret;
1509 
1510         off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1511         entry_offset = (void *)e - (void *)base;
1512         j = 0;
1513         xt_ematch_foreach(ematch, e) {
1514                 ret = compat_find_calc_match(ematch, name,
1515                                              &e->ip, e->comefrom, &off);
1516                 if (ret != 0)
1517                         goto release_matches;
1518                 ++j;
1519         }
1520 
1521         t = compat_ipt_get_target(e);
1522         target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name,
1523                                         t->u.user.revision);
1524         if (IS_ERR(target)) {
1525                 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1526                          t->u.user.name);
1527                 ret = PTR_ERR(target);
1528                 goto release_matches;
1529         }
1530         t->u.kernel.target = target;
1531 
1532         off += xt_compat_target_offset(target);
1533         *size += off;
1534         ret = xt_compat_add_offset(AF_INET, entry_offset, off);
1535         if (ret)
1536                 goto out;
1537 
1538         /* Check hooks & underflows */
1539         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1540                 if ((unsigned char *)e - base == hook_entries[h])
1541                         newinfo->hook_entry[h] = hook_entries[h];
1542                 if ((unsigned char *)e - base == underflows[h])
1543                         newinfo->underflow[h] = underflows[h];
1544         }
1545 
1546         /* Clear counters and comefrom */
1547         memset(&e->counters, 0, sizeof(e->counters));
1548         e->comefrom = 0;
1549         return 0;
1550 
1551 out:
1552         module_put(t->u.kernel.target->me);
1553 release_matches:
1554         xt_ematch_foreach(ematch, e) {
1555                 if (j-- == 0)
1556                         break;
1557                 module_put(ematch->u.kernel.match->me);
1558         }
1559         return ret;
1560 }
1561 
1562 static int
1563 compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
1564                             unsigned int *size, const char *name,
1565                             struct xt_table_info *newinfo, unsigned char *base)
1566 {
1567         struct xt_entry_target *t;
1568         struct xt_target *target;
1569         struct ipt_entry *de;
1570         unsigned int origsize;
1571         int ret, h;
1572         struct xt_entry_match *ematch;
1573 
1574         ret = 0;
1575         origsize = *size;
1576         de = (struct ipt_entry *)*dstptr;
1577         memcpy(de, e, sizeof(struct ipt_entry));
1578         memcpy(&de->counters, &e->counters, sizeof(e->counters));
1579 
1580         *dstptr += sizeof(struct ipt_entry);
1581         *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
1582 
1583         xt_ematch_foreach(ematch, e) {
1584                 ret = xt_compat_match_from_user(ematch, dstptr, size);
1585                 if (ret != 0)
1586                         return ret;
1587         }
1588         de->target_offset = e->target_offset - (origsize - *size);
1589         t = compat_ipt_get_target(e);
1590         target = t->u.kernel.target;
1591         xt_compat_target_from_user(t, dstptr, size);
1592 
1593         de->next_offset = e->next_offset - (origsize - *size);
1594         for (h = 0; h < NF_INET_NUMHOOKS; h++) {
1595                 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1596                         newinfo->hook_entry[h] -= origsize - *size;
1597                 if ((unsigned char *)de - base < newinfo->underflow[h])
1598                         newinfo->underflow[h] -= origsize - *size;
1599         }
1600         return ret;
1601 }
1602 
1603 static int
1604 compat_check_entry(struct ipt_entry *e, struct net *net, const char *name)
1605 {
1606         struct xt_entry_match *ematch;
1607         struct xt_mtchk_param mtpar;
1608         unsigned int j;
1609         int ret = 0;
1610 
1611         j = 0;
1612         mtpar.net       = net;
1613         mtpar.table     = name;
1614         mtpar.entryinfo = &e->ip;
1615         mtpar.hook_mask = e->comefrom;
1616         mtpar.family    = NFPROTO_IPV4;
1617         xt_ematch_foreach(ematch, e) {
1618                 ret = check_match(ematch, &mtpar);
1619                 if (ret != 0)
1620                         goto cleanup_matches;
1621                 ++j;
1622         }
1623 
1624         ret = check_target(e, net, name);
1625         if (ret)
1626                 goto cleanup_matches;
1627         return 0;
1628 
1629  cleanup_matches:
1630         xt_ematch_foreach(ematch, e) {
1631                 if (j-- == 0)
1632                         break;
1633                 cleanup_match(ematch, net);
1634         }
1635         return ret;
1636 }
1637 
1638 static int
1639 translate_compat_table(struct net *net,
1640                        const char *name,
1641                        unsigned int valid_hooks,
1642                        struct xt_table_info **pinfo,
1643                        void **pentry0,
1644                        unsigned int total_size,
1645                        unsigned int number,
1646                        unsigned int *hook_entries,
1647                        unsigned int *underflows)
1648 {
1649         unsigned int i, j;
1650         struct xt_table_info *newinfo, *info;
1651         void *pos, *entry0, *entry1;
1652         struct compat_ipt_entry *iter0;
1653         struct ipt_entry *iter1;
1654         unsigned int size;
1655         int ret;
1656 
1657         info = *pinfo;
1658         entry0 = *pentry0;
1659         size = total_size;
1660         info->number = number;
1661 
1662         /* Init all hooks to impossible value. */
1663         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1664                 info->hook_entry[i] = 0xFFFFFFFF;
1665                 info->underflow[i] = 0xFFFFFFFF;
1666         }
1667 
1668         duprintf("translate_compat_table: size %u\n", info->size);
1669         j = 0;
1670         xt_compat_lock(AF_INET);
1671         xt_compat_init_offsets(AF_INET, number);
1672         /* Walk through entries, checking offsets. */
1673         xt_entry_foreach(iter0, entry0, total_size) {
1674                 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1675                                                         entry0,
1676                                                         entry0 + total_size,
1677                                                         hook_entries,
1678                                                         underflows,
1679                                                         name);
1680                 if (ret != 0)
1681                         goto out_unlock;
1682                 ++j;
1683         }
1684 
1685         ret = -EINVAL;
1686         if (j != number) {
1687                 duprintf("translate_compat_table: %u not %u entries\n",
1688                          j, number);
1689                 goto out_unlock;
1690         }
1691 
1692         /* Check hooks all assigned */
1693         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1694                 /* Only hooks which are valid */
1695                 if (!(valid_hooks & (1 << i)))
1696                         continue;
1697                 if (info->hook_entry[i] == 0xFFFFFFFF) {
1698                         duprintf("Invalid hook entry %u %u\n",
1699                                  i, hook_entries[i]);
1700                         goto out_unlock;
1701                 }
1702                 if (info->underflow[i] == 0xFFFFFFFF) {
1703                         duprintf("Invalid underflow %u %u\n",
1704                                  i, underflows[i]);
1705                         goto out_unlock;
1706                 }
1707         }
1708 
1709         ret = -ENOMEM;
1710         newinfo = xt_alloc_table_info(size);
1711         if (!newinfo)
1712                 goto out_unlock;
1713 
1714         newinfo->number = number;
1715         for (i = 0; i < NF_INET_NUMHOOKS; i++) {
1716                 newinfo->hook_entry[i] = info->hook_entry[i];
1717                 newinfo->underflow[i] = info->underflow[i];
1718         }
1719         entry1 = newinfo->entries[raw_smp_processor_id()];
1720         pos = entry1;
1721         size = total_size;
1722         xt_entry_foreach(iter0, entry0, total_size) {
1723                 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1724                                                   name, newinfo, entry1);
1725                 if (ret != 0)
1726                         break;
1727         }
1728         xt_compat_flush_offsets(AF_INET);
1729         xt_compat_unlock(AF_INET);
1730         if (ret)
1731                 goto free_newinfo;
1732 
1733         ret = -ELOOP;
1734         if (!mark_source_chains(newinfo, valid_hooks, entry1))
1735                 goto free_newinfo;
1736 
1737         i = 0;
1738         xt_entry_foreach(iter1, entry1, newinfo->size) {
1739                 ret = compat_check_entry(iter1, net, name);
1740                 if (ret != 0)
1741                         break;
1742                 ++i;
1743                 if (strcmp(ipt_get_target(iter1)->u.user.name,
1744                     XT_ERROR_TARGET) == 0)
1745                         ++newinfo->stacksize;
1746         }
1747         if (ret) {
1748                 /*
1749                  * The first i matches need cleanup_entry (calls ->destroy)
1750                  * because they had called ->check already. The other j-i
1751                  * entries need only release.
1752                  */
1753                 int skip = i;
1754                 j -= i;
1755                 xt_entry_foreach(iter0, entry0, newinfo->size) {
1756                         if (skip-- > 0)
1757                                 continue;
1758                         if (j-- == 0)
1759                                 break;
1760                         compat_release_entry(iter0);
1761                 }
1762                 xt_entry_foreach(iter1, entry1, newinfo->size) {
1763                         if (i-- == 0)
1764                                 break;
1765                         cleanup_entry(iter1, net);
1766                 }
1767                 xt_free_table_info(newinfo);
1768                 return ret;
1769         }
1770 
1771         /* And one copy for every other CPU */
1772         for_each_possible_cpu(i)
1773                 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1774                         memcpy(newinfo->entries[i], entry1, newinfo->size);
1775 
1776         *pinfo = newinfo;
1777         *pentry0 = entry1;
1778         xt_free_table_info(info);
1779         return 0;
1780 
1781 free_newinfo:
1782         xt_free_table_info(newinfo);
1783 out:
1784         xt_entry_foreach(iter0, entry0, total_size) {
1785                 if (j-- == 0)
1786                         break;
1787                 compat_release_entry(iter0);
1788         }
1789         return ret;
1790 out_unlock:
1791         xt_compat_flush_offsets(AF_INET);
1792         xt_compat_unlock(AF_INET);
1793         goto out;
1794 }
1795 
1796 static int
1797 compat_do_replace(struct net *net, void __user *user, unsigned int len)
1798 {
1799         int ret;
1800         struct compat_ipt_replace tmp;
1801         struct xt_table_info *newinfo;
1802         void *loc_cpu_entry;
1803         struct ipt_entry *iter;
1804 
1805         if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1806                 return -EFAULT;
1807 
1808         /* overflow check */
1809         if (tmp.size >= INT_MAX / num_possible_cpus())
1810                 return -ENOMEM;
1811         if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1812                 return -ENOMEM;
1813         tmp.name[sizeof(tmp.name)-1] = 0;
1814 
1815         newinfo = xt_alloc_table_info(tmp.size);
1816         if (!newinfo)
1817                 return -ENOMEM;
1818 
1819         /* choose the copy that is on our node/cpu */
1820         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1821         if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1822                            tmp.size) != 0) {
1823                 ret = -EFAULT;
1824                 goto free_newinfo;
1825         }
1826 
1827         ret = translate_compat_table(net, tmp.name, tmp.valid_hooks,
1828                                      &newinfo, &loc_cpu_entry, tmp.size,
1829                                      tmp.num_entries, tmp.hook_entry,
1830                                      tmp.underflow);
1831         if (ret != 0)
1832                 goto free_newinfo;
1833 
1834         duprintf("compat_do_replace: Translated table\n");
1835 
1836         ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1837                            tmp.num_counters, compat_ptr(tmp.counters));
1838         if (ret)
1839                 goto free_newinfo_untrans;
1840         return 0;
1841 
1842  free_newinfo_untrans:
1843         xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1844                 cleanup_entry(iter, net);
1845  free_newinfo:
1846         xt_free_table_info(newinfo);
1847         return ret;
1848 }
1849 
1850 static int
1851 compat_do_ipt_set_ctl(struct sock *sk,  int cmd, void __user *user,
1852                       unsigned int len)
1853 {
1854         int ret;
1855 
1856         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1857                 return -EPERM;
1858 
1859         switch (cmd) {
1860         case IPT_SO_SET_REPLACE:
1861                 ret = compat_do_replace(sock_net(sk), user, len);
1862                 break;
1863 
1864         case IPT_SO_SET_ADD_COUNTERS:
1865                 ret = do_add_counters(sock_net(sk), user, len, 1);
1866                 break;
1867 
1868         default:
1869                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
1870                 ret = -EINVAL;
1871         }
1872 
1873         return ret;
1874 }
1875 
1876 struct compat_ipt_get_entries {
1877         char name[XT_TABLE_MAXNAMELEN];
1878         compat_uint_t size;
1879         struct compat_ipt_entry entrytable[0];
1880 };
1881 
1882 static int
1883 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
1884                             void __user *userptr)
1885 {
1886         struct xt_counters *counters;
1887         const struct xt_table_info *private = table->private;
1888         void __user *pos;
1889         unsigned int size;
1890         int ret = 0;
1891         const void *loc_cpu_entry;
1892         unsigned int i = 0;
1893         struct ipt_entry *iter;
1894 
1895         counters = alloc_counters(table);
1896         if (IS_ERR(counters))
1897                 return PTR_ERR(counters);
1898 
1899         /* choose the copy that is on our node/cpu, ...
1900          * This choice is lazy (because current thread is
1901          * allowed to migrate to another cpu)
1902          */
1903         loc_cpu_entry = private->entries[raw_smp_processor_id()];
1904         pos = userptr;
1905         size = total_size;
1906         xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1907                 ret = compat_copy_entry_to_user(iter, &pos,
1908                                                 &size, counters, i++);
1909                 if (ret != 0)
1910                         break;
1911         }
1912 
1913         vfree(counters);
1914         return ret;
1915 }
1916 
1917 static int
1918 compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
1919                    int *len)
1920 {
1921         int ret;
1922         struct compat_ipt_get_entries get;
1923         struct xt_table *t;
1924 
1925         if (*len < sizeof(get)) {
1926                 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1927                 return -EINVAL;
1928         }
1929 
1930         if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1931                 return -EFAULT;
1932 
1933         if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
1934                 duprintf("compat_get_entries: %u != %zu\n",
1935                          *len, sizeof(get) + get.size);
1936                 return -EINVAL;
1937         }
1938 
1939         xt_compat_lock(AF_INET);
1940         t = xt_find_table_lock(net, AF_INET, get.name);
1941         if (!IS_ERR_OR_NULL(t)) {
1942                 const struct xt_table_info *private = t->private;
1943                 struct xt_table_info info;
1944                 duprintf("t->private->number = %u\n", private->number);
1945                 ret = compat_table_info(private, &info);
1946                 if (!ret && get.size == info.size) {
1947                         ret = compat_copy_entries_to_user(private->size,
1948                                                           t, uptr->entrytable);
1949                 } else if (!ret) {
1950                         duprintf("compat_get_entries: I've got %u not %u!\n",
1951                                  private->size, get.size);
1952                         ret = -EAGAIN;
1953                 }
1954                 xt_compat_flush_offsets(AF_INET);
1955                 module_put(t->me);
1956                 xt_table_unlock(t);
1957         } else
1958                 ret = t ? PTR_ERR(t) : -ENOENT;
1959 
1960         xt_compat_unlock(AF_INET);
1961         return ret;
1962 }
1963 
1964 static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
1965 
1966 static int
1967 compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1968 {
1969         int ret;
1970 
1971         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1972                 return -EPERM;
1973 
1974         switch (cmd) {
1975         case IPT_SO_GET_INFO:
1976                 ret = get_info(sock_net(sk), user, len, 1);
1977                 break;
1978         case IPT_SO_GET_ENTRIES:
1979                 ret = compat_get_entries(sock_net(sk), user, len);
1980                 break;
1981         default:
1982                 ret = do_ipt_get_ctl(sk, cmd, user, len);
1983         }
1984         return ret;
1985 }
1986 #endif
1987 
1988 static int
1989 do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1990 {
1991         int ret;
1992 
1993         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1994                 return -EPERM;
1995 
1996         switch (cmd) {
1997         case IPT_SO_SET_REPLACE:
1998                 ret = do_replace(sock_net(sk), user, len);
1999                 break;
2000 
2001         case IPT_SO_SET_ADD_COUNTERS:
2002                 ret = do_add_counters(sock_net(sk), user, len, 0);
2003                 break;
2004 
2005         default:
2006                 duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
2007                 ret = -EINVAL;
2008         }
2009 
2010         return ret;
2011 }
2012 
2013 static int
2014 do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
2015 {
2016         int ret;
2017 
2018         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2019                 return -EPERM;
2020 
2021         switch (cmd) {
2022         case IPT_SO_GET_INFO:
2023                 ret = get_info(sock_net(sk), user, len, 0);
2024                 break;
2025 
2026         case IPT_SO_GET_ENTRIES:
2027                 ret = get_entries(sock_net(sk), user, len);
2028                 break;
2029 
2030         case IPT_SO_GET_REVISION_MATCH:
2031         case IPT_SO_GET_REVISION_TARGET: {
2032                 struct xt_get_revision rev;
2033                 int target;
2034 
2035                 if (*len != sizeof(rev)) {
2036                         ret = -EINVAL;
2037                         break;
2038                 }
2039                 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
2040                         ret = -EFAULT;
2041                         break;
2042                 }
2043                 rev.name[sizeof(rev.name)-1] = 0;
2044 
2045                 if (cmd == IPT_SO_GET_REVISION_TARGET)
2046                         target = 1;
2047                 else
2048                         target = 0;
2049 
2050                 try_then_request_module(xt_find_revision(AF_INET, rev.name,
2051                                                          rev.revision,
2052                                                          target, &ret),
2053                                         "ipt_%s", rev.name);
2054                 break;
2055         }
2056 
2057         default:
2058                 duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
2059                 ret = -EINVAL;
2060         }
2061 
2062         return ret;
2063 }
2064 
2065 struct xt_table *ipt_register_table(struct net *net,
2066                                     const struct xt_table *table,
2067                                     const struct ipt_replace *repl)
2068 {
2069         int ret;
2070         struct xt_table_info *newinfo;
2071         struct xt_table_info bootstrap = {0};
2072         void *loc_cpu_entry;
2073         struct xt_table *new_table;
2074 
2075         newinfo = xt_alloc_table_info(repl->size);
2076         if (!newinfo) {
2077                 ret = -ENOMEM;
2078                 goto out;
2079         }
2080 
2081         /* choose the copy on our node/cpu, but dont care about preemption */
2082         loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
2083         memcpy(loc_cpu_entry, repl->entries, repl->size);
2084 
2085         ret = translate_table(net, newinfo, loc_cpu_entry, repl);
2086         if (ret != 0)
2087                 goto out_free;
2088 
2089         new_table = xt_register_table(net, table, &bootstrap, newinfo);
2090         if (IS_ERR(new_table)) {
2091                 ret = PTR_ERR(new_table);
2092                 goto out_free;
2093         }
2094 
2095         return new_table;
2096 
2097 out_free:
2098         xt_free_table_info(newinfo);
2099 out:
2100         return ERR_PTR(ret);
2101 }
2102 
2103 void ipt_unregister_table(struct net *net, struct xt_table *table)
2104 {
2105         struct xt_table_info *private;
2106         void *loc_cpu_entry;
2107         struct module *table_owner = table->me;
2108         struct ipt_entry *iter;
2109 
2110         private = xt_unregister_table(table);
2111 
2112         /* Decrease module usage counts and free resources */
2113         loc_cpu_entry = private->entries[raw_smp_processor_id()];
2114         xt_entry_foreach(iter, loc_cpu_entry, private->size)
2115                 cleanup_entry(iter, net);
2116         if (private->number > private->initial_entries)
2117                 module_put(table_owner);
2118         xt_free_table_info(private);
2119 }
2120 
2121 /* Returns 1 if the type and code is matched by the range, 0 otherwise */
2122 static inline bool
2123 icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
2124                      u_int8_t type, u_int8_t code,
2125                      bool invert)
2126 {
2127         return ((test_type == 0xFF) ||
2128                 (type == test_type && code >= min_code && code <= max_code))
2129                 ^ invert;
2130 }
2131 
2132 static bool
2133 icmp_match(const struct sk_buff *skb, struct xt_action_param *par)
2134 {
2135         const struct icmphdr *ic;
2136         struct icmphdr _icmph;
2137         const struct ipt_icmp *icmpinfo = par->matchinfo;
2138 
2139         /* Must not be a fragment. */
2140         if (par->fragoff != 0)
2141                 return false;
2142 
2143         ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
2144         if (ic == NULL) {
2145                 /* We've been asked to examine this packet, and we
2146                  * can't.  Hence, no choice but to drop.
2147                  */
2148                 duprintf("Dropping evil ICMP tinygram.\n");
2149                 par->hotdrop = true;
2150                 return false;
2151         }
2152 
2153         return icmp_type_code_match(icmpinfo->type,
2154                                     icmpinfo->code[0],
2155                                     icmpinfo->code[1],
2156                                     ic->type, ic->code,
2157                                     !!(icmpinfo->invflags&IPT_ICMP_INV));
2158 }
2159 
2160 static int icmp_checkentry(const struct xt_mtchk_param *par)
2161 {
2162         const struct ipt_icmp *icmpinfo = par->matchinfo;
2163 
2164         /* Must specify no unknown invflags */
2165         return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0;
2166 }
2167 
2168 static struct xt_target ipt_builtin_tg[] __read_mostly = {
2169         {
2170                 .name             = XT_STANDARD_TARGET,
2171                 .targetsize       = sizeof(int),
2172                 .family           = NFPROTO_IPV4,
2173 #ifdef CONFIG_COMPAT
2174                 .compatsize       = sizeof(compat_int_t),
2175                 .compat_from_user = compat_standard_from_user,
2176                 .compat_to_user   = compat_standard_to_user,
2177 #endif
2178         },
2179         {
2180                 .name             = XT_ERROR_TARGET,
2181                 .target           = ipt_error,
2182                 .targetsize       = XT_FUNCTION_MAXNAMELEN,
2183                 .family           = NFPROTO_IPV4,
2184         },
2185 };
2186 
2187 static struct nf_sockopt_ops ipt_sockopts = {
2188         .pf             = PF_INET,
2189         .set_optmin     = IPT_BASE_CTL,
2190         .set_optmax     = IPT_SO_SET_MAX+1,
2191         .set            = do_ipt_set_ctl,
2192 #ifdef CONFIG_COMPAT
2193         .compat_set     = compat_do_ipt_set_ctl,
2194 #endif
2195         .get_optmin     = IPT_BASE_CTL,
2196         .get_optmax     = IPT_SO_GET_MAX+1,
2197         .get            = do_ipt_get_ctl,
2198 #ifdef CONFIG_COMPAT
2199         .compat_get     = compat_do_ipt_get_ctl,
2200 #endif
2201         .owner          = THIS_MODULE,
2202 };
2203 
2204 static struct xt_match ipt_builtin_mt[] __read_mostly = {
2205         {
2206                 .name       = "icmp",
2207                 .match      = icmp_match,
2208                 .matchsize  = sizeof(struct ipt_icmp),
2209                 .checkentry = icmp_checkentry,
2210                 .proto      = IPPROTO_ICMP,
2211                 .family     = NFPROTO_IPV4,
2212         },
2213 };
2214 
2215 static int __net_init ip_tables_net_init(struct net *net)
2216 {
2217         return xt_proto_init(net, NFPROTO_IPV4);
2218 }
2219 
2220 static void __net_exit ip_tables_net_exit(struct net *net)
2221 {
2222         xt_proto_fini(net, NFPROTO_IPV4);
2223 }
2224 
2225 static struct pernet_operations ip_tables_net_ops = {
2226         .init = ip_tables_net_init,
2227         .exit = ip_tables_net_exit,
2228 };
2229 
2230 static int __init ip_tables_init(void)
2231 {
2232         int ret;
2233 
2234         ret = register_pernet_subsys(&ip_tables_net_ops);
2235         if (ret < 0)
2236                 goto err1;
2237 
2238         /* No one else will be downing sem now, so we won't sleep */
2239         ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2240         if (ret < 0)
2241                 goto err2;
2242         ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2243         if (ret < 0)
2244                 goto err4;
2245 
2246         /* Register setsockopt */
2247         ret = nf_register_sockopt(&ipt_sockopts);
2248         if (ret < 0)
2249                 goto err5;
2250 
2251         pr_info("(C) 2000-2006 Netfilter Core Team\n");
2252         return 0;
2253 
2254 err5:
2255         xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2256 err4:
2257         xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2258 err2:
2259         unregister_pernet_subsys(&ip_tables_net_ops);
2260 err1:
2261         return ret;
2262 }
2263 
2264 static void __exit ip_tables_fini(void)
2265 {
2266         nf_unregister_sockopt(&ipt_sockopts);
2267 
2268         xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt));
2269         xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg));
2270         unregister_pernet_subsys(&ip_tables_net_ops);
2271 }
2272 
2273 EXPORT_SYMBOL(ipt_register_table);
2274 EXPORT_SYMBOL(ipt_unregister_table);
2275 EXPORT_SYMBOL(ipt_do_table);
2276 module_init(ip_tables_init);
2277 module_exit(ip_tables_fini);
2278 

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