| 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 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * 19 Jan 2002 Harald Welte <laforge@gnumonks.org> |
| 12 | * - increase module usage count as soon as we have rules inside |
| 13 | * a table |
| 14 | * 06 Jun 2002 Andras Kis-Szabo <kisza@sch.bme.hu> |
| 15 | * - new extension header parser code |
| 16 | * 15 Oct 2005 Harald Welte <laforge@netfilter.org> |
| 17 | * - Unification of {ip,ip6}_tables into x_tables |
| 18 | * - Removed tcp and udp code, since it's not ipv6 specific |
| 19 | */ |
| 20 | |
| 21 | #include <linux/capability.h> |
| 22 | #include <linux/in.h> |
| 23 | #include <linux/skbuff.h> |
| 24 | #include <linux/kmod.h> |
| 25 | #include <linux/vmalloc.h> |
| 26 | #include <linux/netdevice.h> |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/poison.h> |
| 29 | #include <linux/icmpv6.h> |
| 30 | #include <net/ipv6.h> |
| 31 | #include <asm/uaccess.h> |
| 32 | #include <linux/mutex.h> |
| 33 | #include <linux/proc_fs.h> |
| 34 | #include <linux/cpumask.h> |
| 35 | |
| 36 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 37 | #include <linux/netfilter/x_tables.h> |
| 38 | |
| 39 | MODULE_LICENSE("GPL"); |
| 40 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 41 | MODULE_DESCRIPTION("IPv6 packet filter"); |
| 42 | |
| 43 | #define IPV6_HDR_LEN (sizeof(struct ipv6hdr)) |
| 44 | #define IPV6_OPTHDR_LEN (sizeof(struct ipv6_opt_hdr)) |
| 45 | |
| 46 | /*#define DEBUG_IP_FIREWALL*/ |
| 47 | /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */ |
| 48 | /*#define DEBUG_IP_FIREWALL_USER*/ |
| 49 | |
| 50 | #ifdef DEBUG_IP_FIREWALL |
| 51 | #define dprintf(format, args...) printk(format , ## args) |
| 52 | #else |
| 53 | #define dprintf(format, args...) |
| 54 | #endif |
| 55 | |
| 56 | #ifdef DEBUG_IP_FIREWALL_USER |
| 57 | #define duprintf(format, args...) printk(format , ## args) |
| 58 | #else |
| 59 | #define duprintf(format, args...) |
| 60 | #endif |
| 61 | |
| 62 | #ifdef CONFIG_NETFILTER_DEBUG |
| 63 | #define IP_NF_ASSERT(x) \ |
| 64 | do { \ |
| 65 | if (!(x)) \ |
| 66 | printk("IP_NF_ASSERT: %s:%s:%u\n", \ |
| 67 | __FUNCTION__, __FILE__, __LINE__); \ |
| 68 | } while(0) |
| 69 | #else |
| 70 | #define IP_NF_ASSERT(x) |
| 71 | #endif |
| 72 | |
| 73 | #if 0 |
| 74 | /* All the better to debug you with... */ |
| 75 | #define static |
| 76 | #define inline |
| 77 | #endif |
| 78 | |
| 79 | /* |
| 80 | We keep a set of rules for each CPU, so we can avoid write-locking |
| 81 | them in the softirq when updating the counters and therefore |
| 82 | only need to read-lock in the softirq; doing a write_lock_bh() in user |
| 83 | context stops packets coming through and allows user context to read |
| 84 | the counters or update the rules. |
| 85 | |
| 86 | Hence the start of any table is given by get_table() below. */ |
| 87 | |
| 88 | #if 0 |
| 89 | #define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0) |
| 90 | #define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; }) |
| 91 | #define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0) |
| 92 | #endif |
| 93 | |
| 94 | /* Check for an extension */ |
| 95 | int |
| 96 | ip6t_ext_hdr(u8 nexthdr) |
| 97 | { |
| 98 | return ( (nexthdr == IPPROTO_HOPOPTS) || |
| 99 | (nexthdr == IPPROTO_ROUTING) || |
| 100 | (nexthdr == IPPROTO_FRAGMENT) || |
| 101 | (nexthdr == IPPROTO_ESP) || |
| 102 | (nexthdr == IPPROTO_AH) || |
| 103 | (nexthdr == IPPROTO_NONE) || |
| 104 | (nexthdr == IPPROTO_DSTOPTS) ); |
| 105 | } |
| 106 | |
| 107 | /* Returns whether matches rule or not. */ |
| 108 | static inline int |
| 109 | ip6_packet_match(const struct sk_buff *skb, |
| 110 | const char *indev, |
| 111 | const char *outdev, |
| 112 | const struct ip6t_ip6 *ip6info, |
| 113 | unsigned int *protoff, |
| 114 | int *fragoff, int *hotdrop) |
| 115 | { |
| 116 | size_t i; |
| 117 | unsigned long ret; |
| 118 | const struct ipv6hdr *ipv6 = skb->nh.ipv6h; |
| 119 | |
| 120 | #define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg)) |
| 121 | |
| 122 | if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, |
| 123 | &ip6info->src), IP6T_INV_SRCIP) |
| 124 | || FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, |
| 125 | &ip6info->dst), IP6T_INV_DSTIP)) { |
| 126 | dprintf("Source or dest mismatch.\n"); |
| 127 | /* |
| 128 | dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr, |
| 129 | ipinfo->smsk.s_addr, ipinfo->src.s_addr, |
| 130 | ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : ""); |
| 131 | dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr, |
| 132 | ipinfo->dmsk.s_addr, ipinfo->dst.s_addr, |
| 133 | ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/ |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | /* Look for ifname matches; this should unroll nicely. */ |
| 138 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| 139 | ret |= (((const unsigned long *)indev)[i] |
| 140 | ^ ((const unsigned long *)ip6info->iniface)[i]) |
| 141 | & ((const unsigned long *)ip6info->iniface_mask)[i]; |
| 142 | } |
| 143 | |
| 144 | if (FWINV(ret != 0, IP6T_INV_VIA_IN)) { |
| 145 | dprintf("VIA in mismatch (%s vs %s).%s\n", |
| 146 | indev, ip6info->iniface, |
| 147 | ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":""); |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| 152 | ret |= (((const unsigned long *)outdev)[i] |
| 153 | ^ ((const unsigned long *)ip6info->outiface)[i]) |
| 154 | & ((const unsigned long *)ip6info->outiface_mask)[i]; |
| 155 | } |
| 156 | |
| 157 | if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) { |
| 158 | dprintf("VIA out mismatch (%s vs %s).%s\n", |
| 159 | outdev, ip6info->outiface, |
| 160 | ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":""); |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | /* ... might want to do something with class and flowlabel here ... */ |
| 165 | |
| 166 | /* look for the desired protocol header */ |
| 167 | if((ip6info->flags & IP6T_F_PROTO)) { |
| 168 | int protohdr; |
| 169 | unsigned short _frag_off; |
| 170 | |
| 171 | protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off); |
| 172 | if (protohdr < 0) { |
| 173 | if (_frag_off == 0) |
| 174 | *hotdrop = 1; |
| 175 | return 0; |
| 176 | } |
| 177 | *fragoff = _frag_off; |
| 178 | |
| 179 | dprintf("Packet protocol %hi ?= %s%hi.\n", |
| 180 | protohdr, |
| 181 | ip6info->invflags & IP6T_INV_PROTO ? "!":"", |
| 182 | ip6info->proto); |
| 183 | |
| 184 | if (ip6info->proto == protohdr) { |
| 185 | if(ip6info->invflags & IP6T_INV_PROTO) { |
| 186 | return 0; |
| 187 | } |
| 188 | return 1; |
| 189 | } |
| 190 | |
| 191 | /* We need match for the '-p all', too! */ |
| 192 | if ((ip6info->proto != 0) && |
| 193 | !(ip6info->invflags & IP6T_INV_PROTO)) |
| 194 | return 0; |
| 195 | } |
| 196 | return 1; |
| 197 | } |
| 198 | |
| 199 | /* should be ip6 safe */ |
| 200 | static inline int |
| 201 | ip6_checkentry(const struct ip6t_ip6 *ipv6) |
| 202 | { |
| 203 | if (ipv6->flags & ~IP6T_F_MASK) { |
| 204 | duprintf("Unknown flag bits set: %08X\n", |
| 205 | ipv6->flags & ~IP6T_F_MASK); |
| 206 | return 0; |
| 207 | } |
| 208 | if (ipv6->invflags & ~IP6T_INV_MASK) { |
| 209 | duprintf("Unknown invflag bits set: %08X\n", |
| 210 | ipv6->invflags & ~IP6T_INV_MASK); |
| 211 | return 0; |
| 212 | } |
| 213 | return 1; |
| 214 | } |
| 215 | |
| 216 | static unsigned int |
| 217 | ip6t_error(struct sk_buff **pskb, |
| 218 | const struct net_device *in, |
| 219 | const struct net_device *out, |
| 220 | unsigned int hooknum, |
| 221 | const struct xt_target *target, |
| 222 | const void *targinfo) |
| 223 | { |
| 224 | if (net_ratelimit()) |
| 225 | printk("ip6_tables: error: `%s'\n", (char *)targinfo); |
| 226 | |
| 227 | return NF_DROP; |
| 228 | } |
| 229 | |
| 230 | static inline |
| 231 | int do_match(struct ip6t_entry_match *m, |
| 232 | const struct sk_buff *skb, |
| 233 | const struct net_device *in, |
| 234 | const struct net_device *out, |
| 235 | int offset, |
| 236 | unsigned int protoff, |
| 237 | int *hotdrop) |
| 238 | { |
| 239 | /* Stop iteration if it doesn't match */ |
| 240 | if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data, |
| 241 | offset, protoff, hotdrop)) |
| 242 | return 1; |
| 243 | else |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | static inline struct ip6t_entry * |
| 248 | get_entry(void *base, unsigned int offset) |
| 249 | { |
| 250 | return (struct ip6t_entry *)(base + offset); |
| 251 | } |
| 252 | |
| 253 | /* Returns one of the generic firewall policies, like NF_ACCEPT. */ |
| 254 | unsigned int |
| 255 | ip6t_do_table(struct sk_buff **pskb, |
| 256 | unsigned int hook, |
| 257 | const struct net_device *in, |
| 258 | const struct net_device *out, |
| 259 | struct xt_table *table) |
| 260 | { |
| 261 | static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); |
| 262 | int offset = 0; |
| 263 | unsigned int protoff = 0; |
| 264 | int hotdrop = 0; |
| 265 | /* Initializing verdict to NF_DROP keeps gcc happy. */ |
| 266 | unsigned int verdict = NF_DROP; |
| 267 | const char *indev, *outdev; |
| 268 | void *table_base; |
| 269 | struct ip6t_entry *e, *back; |
| 270 | struct xt_table_info *private; |
| 271 | |
| 272 | /* Initialization */ |
| 273 | indev = in ? in->name : nulldevname; |
| 274 | outdev = out ? out->name : nulldevname; |
| 275 | /* We handle fragments by dealing with the first fragment as |
| 276 | * if it was a normal packet. All other fragments are treated |
| 277 | * normally, except that they will NEVER match rules that ask |
| 278 | * things we don't know, ie. tcp syn flag or ports). If the |
| 279 | * rule is also a fragment-specific rule, non-fragments won't |
| 280 | * match it. */ |
| 281 | |
| 282 | read_lock_bh(&table->lock); |
| 283 | private = table->private; |
| 284 | IP_NF_ASSERT(table->valid_hooks & (1 << hook)); |
| 285 | table_base = (void *)private->entries[smp_processor_id()]; |
| 286 | e = get_entry(table_base, private->hook_entry[hook]); |
| 287 | |
| 288 | /* For return from builtin chain */ |
| 289 | back = get_entry(table_base, private->underflow[hook]); |
| 290 | |
| 291 | do { |
| 292 | IP_NF_ASSERT(e); |
| 293 | IP_NF_ASSERT(back); |
| 294 | if (ip6_packet_match(*pskb, indev, outdev, &e->ipv6, |
| 295 | &protoff, &offset, &hotdrop)) { |
| 296 | struct ip6t_entry_target *t; |
| 297 | |
| 298 | if (IP6T_MATCH_ITERATE(e, do_match, |
| 299 | *pskb, in, out, |
| 300 | offset, protoff, &hotdrop) != 0) |
| 301 | goto no_match; |
| 302 | |
| 303 | ADD_COUNTER(e->counters, |
| 304 | ntohs((*pskb)->nh.ipv6h->payload_len) |
| 305 | + IPV6_HDR_LEN, |
| 306 | 1); |
| 307 | |
| 308 | t = ip6t_get_target(e); |
| 309 | IP_NF_ASSERT(t->u.kernel.target); |
| 310 | /* Standard target? */ |
| 311 | if (!t->u.kernel.target->target) { |
| 312 | int v; |
| 313 | |
| 314 | v = ((struct ip6t_standard_target *)t)->verdict; |
| 315 | if (v < 0) { |
| 316 | /* Pop from stack? */ |
| 317 | if (v != IP6T_RETURN) { |
| 318 | verdict = (unsigned)(-v) - 1; |
| 319 | break; |
| 320 | } |
| 321 | e = back; |
| 322 | back = get_entry(table_base, |
| 323 | back->comefrom); |
| 324 | continue; |
| 325 | } |
| 326 | if (table_base + v != (void *)e + e->next_offset |
| 327 | && !(e->ipv6.flags & IP6T_F_GOTO)) { |
| 328 | /* Save old back ptr in next entry */ |
| 329 | struct ip6t_entry *next |
| 330 | = (void *)e + e->next_offset; |
| 331 | next->comefrom |
| 332 | = (void *)back - table_base; |
| 333 | /* set back pointer to next entry */ |
| 334 | back = next; |
| 335 | } |
| 336 | |
| 337 | e = get_entry(table_base, v); |
| 338 | } else { |
| 339 | /* Targets which reenter must return |
| 340 | abs. verdicts */ |
| 341 | #ifdef CONFIG_NETFILTER_DEBUG |
| 342 | ((struct ip6t_entry *)table_base)->comefrom |
| 343 | = 0xeeeeeeec; |
| 344 | #endif |
| 345 | verdict = t->u.kernel.target->target(pskb, |
| 346 | in, out, |
| 347 | hook, |
| 348 | t->u.kernel.target, |
| 349 | t->data); |
| 350 | |
| 351 | #ifdef CONFIG_NETFILTER_DEBUG |
| 352 | if (((struct ip6t_entry *)table_base)->comefrom |
| 353 | != 0xeeeeeeec |
| 354 | && verdict == IP6T_CONTINUE) { |
| 355 | printk("Target %s reentered!\n", |
| 356 | t->u.kernel.target->name); |
| 357 | verdict = NF_DROP; |
| 358 | } |
| 359 | ((struct ip6t_entry *)table_base)->comefrom |
| 360 | = 0x57acc001; |
| 361 | #endif |
| 362 | if (verdict == IP6T_CONTINUE) |
| 363 | e = (void *)e + e->next_offset; |
| 364 | else |
| 365 | /* Verdict */ |
| 366 | break; |
| 367 | } |
| 368 | } else { |
| 369 | |
| 370 | no_match: |
| 371 | e = (void *)e + e->next_offset; |
| 372 | } |
| 373 | } while (!hotdrop); |
| 374 | |
| 375 | #ifdef CONFIG_NETFILTER_DEBUG |
| 376 | ((struct ip6t_entry *)table_base)->comefrom = NETFILTER_LINK_POISON; |
| 377 | #endif |
| 378 | read_unlock_bh(&table->lock); |
| 379 | |
| 380 | #ifdef DEBUG_ALLOW_ALL |
| 381 | return NF_ACCEPT; |
| 382 | #else |
| 383 | if (hotdrop) |
| 384 | return NF_DROP; |
| 385 | else return verdict; |
| 386 | #endif |
| 387 | } |
| 388 | |
| 389 | /* All zeroes == unconditional rule. */ |
| 390 | static inline int |
| 391 | unconditional(const struct ip6t_ip6 *ipv6) |
| 392 | { |
| 393 | unsigned int i; |
| 394 | |
| 395 | for (i = 0; i < sizeof(*ipv6); i++) |
| 396 | if (((char *)ipv6)[i]) |
| 397 | break; |
| 398 | |
| 399 | return (i == sizeof(*ipv6)); |
| 400 | } |
| 401 | |
| 402 | /* Figures out from what hook each rule can be called: returns 0 if |
| 403 | there are loops. Puts hook bitmask in comefrom. */ |
| 404 | static int |
| 405 | mark_source_chains(struct xt_table_info *newinfo, |
| 406 | unsigned int valid_hooks, void *entry0) |
| 407 | { |
| 408 | unsigned int hook; |
| 409 | |
| 410 | /* No recursion; use packet counter to save back ptrs (reset |
| 411 | to 0 as we leave), and comefrom to save source hook bitmask */ |
| 412 | for (hook = 0; hook < NF_IP6_NUMHOOKS; hook++) { |
| 413 | unsigned int pos = newinfo->hook_entry[hook]; |
| 414 | struct ip6t_entry *e |
| 415 | = (struct ip6t_entry *)(entry0 + pos); |
| 416 | |
| 417 | if (!(valid_hooks & (1 << hook))) |
| 418 | continue; |
| 419 | |
| 420 | /* Set initial back pointer. */ |
| 421 | e->counters.pcnt = pos; |
| 422 | |
| 423 | for (;;) { |
| 424 | struct ip6t_standard_target *t |
| 425 | = (void *)ip6t_get_target(e); |
| 426 | |
| 427 | if (e->comefrom & (1 << NF_IP6_NUMHOOKS)) { |
| 428 | printk("iptables: loop hook %u pos %u %08X.\n", |
| 429 | hook, pos, e->comefrom); |
| 430 | return 0; |
| 431 | } |
| 432 | e->comefrom |
| 433 | |= ((1 << hook) | (1 << NF_IP6_NUMHOOKS)); |
| 434 | |
| 435 | /* Unconditional return/END. */ |
| 436 | if (e->target_offset == sizeof(struct ip6t_entry) |
| 437 | && (strcmp(t->target.u.user.name, |
| 438 | IP6T_STANDARD_TARGET) == 0) |
| 439 | && t->verdict < 0 |
| 440 | && unconditional(&e->ipv6)) { |
| 441 | unsigned int oldpos, size; |
| 442 | |
| 443 | /* Return: backtrack through the last |
| 444 | big jump. */ |
| 445 | do { |
| 446 | e->comefrom ^= (1<<NF_IP6_NUMHOOKS); |
| 447 | #ifdef DEBUG_IP_FIREWALL_USER |
| 448 | if (e->comefrom |
| 449 | & (1 << NF_IP6_NUMHOOKS)) { |
| 450 | duprintf("Back unset " |
| 451 | "on hook %u " |
| 452 | "rule %u\n", |
| 453 | hook, pos); |
| 454 | } |
| 455 | #endif |
| 456 | oldpos = pos; |
| 457 | pos = e->counters.pcnt; |
| 458 | e->counters.pcnt = 0; |
| 459 | |
| 460 | /* We're at the start. */ |
| 461 | if (pos == oldpos) |
| 462 | goto next; |
| 463 | |
| 464 | e = (struct ip6t_entry *) |
| 465 | (entry0 + pos); |
| 466 | } while (oldpos == pos + e->next_offset); |
| 467 | |
| 468 | /* Move along one */ |
| 469 | size = e->next_offset; |
| 470 | e = (struct ip6t_entry *) |
| 471 | (entry0 + pos + size); |
| 472 | e->counters.pcnt = pos; |
| 473 | pos += size; |
| 474 | } else { |
| 475 | int newpos = t->verdict; |
| 476 | |
| 477 | if (strcmp(t->target.u.user.name, |
| 478 | IP6T_STANDARD_TARGET) == 0 |
| 479 | && newpos >= 0) { |
| 480 | /* This a jump; chase it. */ |
| 481 | duprintf("Jump rule %u -> %u\n", |
| 482 | pos, newpos); |
| 483 | } else { |
| 484 | /* ... this is a fallthru */ |
| 485 | newpos = pos + e->next_offset; |
| 486 | } |
| 487 | e = (struct ip6t_entry *) |
| 488 | (entry0 + newpos); |
| 489 | e->counters.pcnt = pos; |
| 490 | pos = newpos; |
| 491 | } |
| 492 | } |
| 493 | next: |
| 494 | duprintf("Finished chain %u\n", hook); |
| 495 | } |
| 496 | return 1; |
| 497 | } |
| 498 | |
| 499 | static inline int |
| 500 | cleanup_match(struct ip6t_entry_match *m, unsigned int *i) |
| 501 | { |
| 502 | if (i && (*i)-- == 0) |
| 503 | return 1; |
| 504 | |
| 505 | if (m->u.kernel.match->destroy) |
| 506 | m->u.kernel.match->destroy(m->u.kernel.match, m->data); |
| 507 | module_put(m->u.kernel.match->me); |
| 508 | return 0; |
| 509 | } |
| 510 | |
| 511 | static inline int |
| 512 | standard_check(const struct ip6t_entry_target *t, |
| 513 | unsigned int max_offset) |
| 514 | { |
| 515 | struct ip6t_standard_target *targ = (void *)t; |
| 516 | |
| 517 | /* Check standard info. */ |
| 518 | if (targ->verdict >= 0 |
| 519 | && targ->verdict > max_offset - sizeof(struct ip6t_entry)) { |
| 520 | duprintf("ip6t_standard_check: bad verdict (%i)\n", |
| 521 | targ->verdict); |
| 522 | return 0; |
| 523 | } |
| 524 | if (targ->verdict < -NF_MAX_VERDICT - 1) { |
| 525 | duprintf("ip6t_standard_check: bad negative verdict (%i)\n", |
| 526 | targ->verdict); |
| 527 | return 0; |
| 528 | } |
| 529 | return 1; |
| 530 | } |
| 531 | |
| 532 | static inline int |
| 533 | check_match(struct ip6t_entry_match *m, |
| 534 | const char *name, |
| 535 | const struct ip6t_ip6 *ipv6, |
| 536 | unsigned int hookmask, |
| 537 | unsigned int *i) |
| 538 | { |
| 539 | struct ip6t_match *match; |
| 540 | int ret; |
| 541 | |
| 542 | match = try_then_request_module(xt_find_match(AF_INET6, m->u.user.name, |
| 543 | m->u.user.revision), |
| 544 | "ip6t_%s", m->u.user.name); |
| 545 | if (IS_ERR(match) || !match) { |
| 546 | duprintf("check_match: `%s' not found\n", m->u.user.name); |
| 547 | return match ? PTR_ERR(match) : -ENOENT; |
| 548 | } |
| 549 | m->u.kernel.match = match; |
| 550 | |
| 551 | ret = xt_check_match(match, AF_INET6, m->u.match_size - sizeof(*m), |
| 552 | name, hookmask, ipv6->proto, |
| 553 | ipv6->invflags & IP6T_INV_PROTO); |
| 554 | if (ret) |
| 555 | goto err; |
| 556 | |
| 557 | if (m->u.kernel.match->checkentry |
| 558 | && !m->u.kernel.match->checkentry(name, ipv6, match, m->data, |
| 559 | hookmask)) { |
| 560 | duprintf("ip_tables: check failed for `%s'.\n", |
| 561 | m->u.kernel.match->name); |
| 562 | ret = -EINVAL; |
| 563 | goto err; |
| 564 | } |
| 565 | |
| 566 | (*i)++; |
| 567 | return 0; |
| 568 | err: |
| 569 | module_put(m->u.kernel.match->me); |
| 570 | return ret; |
| 571 | } |
| 572 | |
| 573 | static struct ip6t_target ip6t_standard_target; |
| 574 | |
| 575 | static inline int |
| 576 | check_entry(struct ip6t_entry *e, const char *name, unsigned int size, |
| 577 | unsigned int *i) |
| 578 | { |
| 579 | struct ip6t_entry_target *t; |
| 580 | struct ip6t_target *target; |
| 581 | int ret; |
| 582 | unsigned int j; |
| 583 | |
| 584 | if (!ip6_checkentry(&e->ipv6)) { |
| 585 | duprintf("ip_tables: ip check failed %p %s.\n", e, name); |
| 586 | return -EINVAL; |
| 587 | } |
| 588 | |
| 589 | j = 0; |
| 590 | ret = IP6T_MATCH_ITERATE(e, check_match, name, &e->ipv6, e->comefrom, &j); |
| 591 | if (ret != 0) |
| 592 | goto cleanup_matches; |
| 593 | |
| 594 | t = ip6t_get_target(e); |
| 595 | target = try_then_request_module(xt_find_target(AF_INET6, |
| 596 | t->u.user.name, |
| 597 | t->u.user.revision), |
| 598 | "ip6t_%s", t->u.user.name); |
| 599 | if (IS_ERR(target) || !target) { |
| 600 | duprintf("check_entry: `%s' not found\n", t->u.user.name); |
| 601 | ret = target ? PTR_ERR(target) : -ENOENT; |
| 602 | goto cleanup_matches; |
| 603 | } |
| 604 | t->u.kernel.target = target; |
| 605 | |
| 606 | ret = xt_check_target(target, AF_INET6, t->u.target_size - sizeof(*t), |
| 607 | name, e->comefrom, e->ipv6.proto, |
| 608 | e->ipv6.invflags & IP6T_INV_PROTO); |
| 609 | if (ret) |
| 610 | goto err; |
| 611 | |
| 612 | if (t->u.kernel.target == &ip6t_standard_target) { |
| 613 | if (!standard_check(t, size)) { |
| 614 | ret = -EINVAL; |
| 615 | goto err; |
| 616 | } |
| 617 | } else if (t->u.kernel.target->checkentry |
| 618 | && !t->u.kernel.target->checkentry(name, e, target, t->data, |
| 619 | e->comefrom)) { |
| 620 | duprintf("ip_tables: check failed for `%s'.\n", |
| 621 | t->u.kernel.target->name); |
| 622 | ret = -EINVAL; |
| 623 | goto err; |
| 624 | } |
| 625 | |
| 626 | (*i)++; |
| 627 | return 0; |
| 628 | err: |
| 629 | module_put(t->u.kernel.target->me); |
| 630 | cleanup_matches: |
| 631 | IP6T_MATCH_ITERATE(e, cleanup_match, &j); |
| 632 | return ret; |
| 633 | } |
| 634 | |
| 635 | static inline int |
| 636 | check_entry_size_and_hooks(struct ip6t_entry *e, |
| 637 | struct xt_table_info *newinfo, |
| 638 | unsigned char *base, |
| 639 | unsigned char *limit, |
| 640 | const unsigned int *hook_entries, |
| 641 | const unsigned int *underflows, |
| 642 | unsigned int *i) |
| 643 | { |
| 644 | unsigned int h; |
| 645 | |
| 646 | if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 |
| 647 | || (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) { |
| 648 | duprintf("Bad offset %p\n", e); |
| 649 | return -EINVAL; |
| 650 | } |
| 651 | |
| 652 | if (e->next_offset |
| 653 | < sizeof(struct ip6t_entry) + sizeof(struct ip6t_entry_target)) { |
| 654 | duprintf("checking: element %p size %u\n", |
| 655 | e, e->next_offset); |
| 656 | return -EINVAL; |
| 657 | } |
| 658 | |
| 659 | /* Check hooks & underflows */ |
| 660 | for (h = 0; h < NF_IP6_NUMHOOKS; h++) { |
| 661 | if ((unsigned char *)e - base == hook_entries[h]) |
| 662 | newinfo->hook_entry[h] = hook_entries[h]; |
| 663 | if ((unsigned char *)e - base == underflows[h]) |
| 664 | newinfo->underflow[h] = underflows[h]; |
| 665 | } |
| 666 | |
| 667 | /* FIXME: underflows must be unconditional, standard verdicts |
| 668 | < 0 (not IP6T_RETURN). --RR */ |
| 669 | |
| 670 | /* Clear counters and comefrom */ |
| 671 | e->counters = ((struct xt_counters) { 0, 0 }); |
| 672 | e->comefrom = 0; |
| 673 | |
| 674 | (*i)++; |
| 675 | return 0; |
| 676 | } |
| 677 | |
| 678 | static inline int |
| 679 | cleanup_entry(struct ip6t_entry *e, unsigned int *i) |
| 680 | { |
| 681 | struct ip6t_entry_target *t; |
| 682 | |
| 683 | if (i && (*i)-- == 0) |
| 684 | return 1; |
| 685 | |
| 686 | /* Cleanup all matches */ |
| 687 | IP6T_MATCH_ITERATE(e, cleanup_match, NULL); |
| 688 | t = ip6t_get_target(e); |
| 689 | if (t->u.kernel.target->destroy) |
| 690 | t->u.kernel.target->destroy(t->u.kernel.target, t->data); |
| 691 | module_put(t->u.kernel.target->me); |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | /* Checks and translates the user-supplied table segment (held in |
| 696 | newinfo) */ |
| 697 | static int |
| 698 | translate_table(const char *name, |
| 699 | unsigned int valid_hooks, |
| 700 | struct xt_table_info *newinfo, |
| 701 | void *entry0, |
| 702 | unsigned int size, |
| 703 | unsigned int number, |
| 704 | const unsigned int *hook_entries, |
| 705 | const unsigned int *underflows) |
| 706 | { |
| 707 | unsigned int i; |
| 708 | int ret; |
| 709 | |
| 710 | newinfo->size = size; |
| 711 | newinfo->number = number; |
| 712 | |
| 713 | /* Init all hooks to impossible value. */ |
| 714 | for (i = 0; i < NF_IP6_NUMHOOKS; i++) { |
| 715 | newinfo->hook_entry[i] = 0xFFFFFFFF; |
| 716 | newinfo->underflow[i] = 0xFFFFFFFF; |
| 717 | } |
| 718 | |
| 719 | duprintf("translate_table: size %u\n", newinfo->size); |
| 720 | i = 0; |
| 721 | /* Walk through entries, checking offsets. */ |
| 722 | ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size, |
| 723 | check_entry_size_and_hooks, |
| 724 | newinfo, |
| 725 | entry0, |
| 726 | entry0 + size, |
| 727 | hook_entries, underflows, &i); |
| 728 | if (ret != 0) |
| 729 | return ret; |
| 730 | |
| 731 | if (i != number) { |
| 732 | duprintf("translate_table: %u not %u entries\n", |
| 733 | i, number); |
| 734 | return -EINVAL; |
| 735 | } |
| 736 | |
| 737 | /* Check hooks all assigned */ |
| 738 | for (i = 0; i < NF_IP6_NUMHOOKS; i++) { |
| 739 | /* Only hooks which are valid */ |
| 740 | if (!(valid_hooks & (1 << i))) |
| 741 | continue; |
| 742 | if (newinfo->hook_entry[i] == 0xFFFFFFFF) { |
| 743 | duprintf("Invalid hook entry %u %u\n", |
| 744 | i, hook_entries[i]); |
| 745 | return -EINVAL; |
| 746 | } |
| 747 | if (newinfo->underflow[i] == 0xFFFFFFFF) { |
| 748 | duprintf("Invalid underflow %u %u\n", |
| 749 | i, underflows[i]); |
| 750 | return -EINVAL; |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | if (!mark_source_chains(newinfo, valid_hooks, entry0)) |
| 755 | return -ELOOP; |
| 756 | |
| 757 | /* Finally, each sanity check must pass */ |
| 758 | i = 0; |
| 759 | ret = IP6T_ENTRY_ITERATE(entry0, newinfo->size, |
| 760 | check_entry, name, size, &i); |
| 761 | |
| 762 | if (ret != 0) { |
| 763 | IP6T_ENTRY_ITERATE(entry0, newinfo->size, |
| 764 | cleanup_entry, &i); |
| 765 | return ret; |
| 766 | } |
| 767 | |
| 768 | /* And one copy for every other CPU */ |
| 769 | for_each_possible_cpu(i) { |
| 770 | if (newinfo->entries[i] && newinfo->entries[i] != entry0) |
| 771 | memcpy(newinfo->entries[i], entry0, newinfo->size); |
| 772 | } |
| 773 | |
| 774 | return ret; |
| 775 | } |
| 776 | |
| 777 | /* Gets counters. */ |
| 778 | static inline int |
| 779 | add_entry_to_counter(const struct ip6t_entry *e, |
| 780 | struct xt_counters total[], |
| 781 | unsigned int *i) |
| 782 | { |
| 783 | ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); |
| 784 | |
| 785 | (*i)++; |
| 786 | return 0; |
| 787 | } |
| 788 | |
| 789 | static inline int |
| 790 | set_entry_to_counter(const struct ip6t_entry *e, |
| 791 | struct ip6t_counters total[], |
| 792 | unsigned int *i) |
| 793 | { |
| 794 | SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); |
| 795 | |
| 796 | (*i)++; |
| 797 | return 0; |
| 798 | } |
| 799 | |
| 800 | static void |
| 801 | get_counters(const struct xt_table_info *t, |
| 802 | struct xt_counters counters[]) |
| 803 | { |
| 804 | unsigned int cpu; |
| 805 | unsigned int i; |
| 806 | unsigned int curcpu; |
| 807 | |
| 808 | /* Instead of clearing (by a previous call to memset()) |
| 809 | * the counters and using adds, we set the counters |
| 810 | * with data used by 'current' CPU |
| 811 | * We dont care about preemption here. |
| 812 | */ |
| 813 | curcpu = raw_smp_processor_id(); |
| 814 | |
| 815 | i = 0; |
| 816 | IP6T_ENTRY_ITERATE(t->entries[curcpu], |
| 817 | t->size, |
| 818 | set_entry_to_counter, |
| 819 | counters, |
| 820 | &i); |
| 821 | |
| 822 | for_each_possible_cpu(cpu) { |
| 823 | if (cpu == curcpu) |
| 824 | continue; |
| 825 | i = 0; |
| 826 | IP6T_ENTRY_ITERATE(t->entries[cpu], |
| 827 | t->size, |
| 828 | add_entry_to_counter, |
| 829 | counters, |
| 830 | &i); |
| 831 | } |
| 832 | } |
| 833 | |
| 834 | static int |
| 835 | copy_entries_to_user(unsigned int total_size, |
| 836 | struct xt_table *table, |
| 837 | void __user *userptr) |
| 838 | { |
| 839 | unsigned int off, num, countersize; |
| 840 | struct ip6t_entry *e; |
| 841 | struct xt_counters *counters; |
| 842 | struct xt_table_info *private = table->private; |
| 843 | int ret = 0; |
| 844 | void *loc_cpu_entry; |
| 845 | |
| 846 | /* We need atomic snapshot of counters: rest doesn't change |
| 847 | (other than comefrom, which userspace doesn't care |
| 848 | about). */ |
| 849 | countersize = sizeof(struct xt_counters) * private->number; |
| 850 | counters = vmalloc(countersize); |
| 851 | |
| 852 | if (counters == NULL) |
| 853 | return -ENOMEM; |
| 854 | |
| 855 | /* First, sum counters... */ |
| 856 | write_lock_bh(&table->lock); |
| 857 | get_counters(private, counters); |
| 858 | write_unlock_bh(&table->lock); |
| 859 | |
| 860 | /* choose the copy that is on ourc node/cpu */ |
| 861 | loc_cpu_entry = private->entries[raw_smp_processor_id()]; |
| 862 | if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) { |
| 863 | ret = -EFAULT; |
| 864 | goto free_counters; |
| 865 | } |
| 866 | |
| 867 | /* FIXME: use iterator macros --RR */ |
| 868 | /* ... then go back and fix counters and names */ |
| 869 | for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ |
| 870 | unsigned int i; |
| 871 | struct ip6t_entry_match *m; |
| 872 | struct ip6t_entry_target *t; |
| 873 | |
| 874 | e = (struct ip6t_entry *)(loc_cpu_entry + off); |
| 875 | if (copy_to_user(userptr + off |
| 876 | + offsetof(struct ip6t_entry, counters), |
| 877 | &counters[num], |
| 878 | sizeof(counters[num])) != 0) { |
| 879 | ret = -EFAULT; |
| 880 | goto free_counters; |
| 881 | } |
| 882 | |
| 883 | for (i = sizeof(struct ip6t_entry); |
| 884 | i < e->target_offset; |
| 885 | i += m->u.match_size) { |
| 886 | m = (void *)e + i; |
| 887 | |
| 888 | if (copy_to_user(userptr + off + i |
| 889 | + offsetof(struct ip6t_entry_match, |
| 890 | u.user.name), |
| 891 | m->u.kernel.match->name, |
| 892 | strlen(m->u.kernel.match->name)+1) |
| 893 | != 0) { |
| 894 | ret = -EFAULT; |
| 895 | goto free_counters; |
| 896 | } |
| 897 | } |
| 898 | |
| 899 | t = ip6t_get_target(e); |
| 900 | if (copy_to_user(userptr + off + e->target_offset |
| 901 | + offsetof(struct ip6t_entry_target, |
| 902 | u.user.name), |
| 903 | t->u.kernel.target->name, |
| 904 | strlen(t->u.kernel.target->name)+1) != 0) { |
| 905 | ret = -EFAULT; |
| 906 | goto free_counters; |
| 907 | } |
| 908 | } |
| 909 | |
| 910 | free_counters: |
| 911 | vfree(counters); |
| 912 | return ret; |
| 913 | } |
| 914 | |
| 915 | static int |
| 916 | get_entries(const struct ip6t_get_entries *entries, |
| 917 | struct ip6t_get_entries __user *uptr) |
| 918 | { |
| 919 | int ret; |
| 920 | struct xt_table *t; |
| 921 | |
| 922 | t = xt_find_table_lock(AF_INET6, entries->name); |
| 923 | if (t && !IS_ERR(t)) { |
| 924 | struct xt_table_info *private = t->private; |
| 925 | duprintf("t->private->number = %u\n", private->number); |
| 926 | if (entries->size == private->size) |
| 927 | ret = copy_entries_to_user(private->size, |
| 928 | t, uptr->entrytable); |
| 929 | else { |
| 930 | duprintf("get_entries: I've got %u not %u!\n", |
| 931 | private->size, entries->size); |
| 932 | ret = -EINVAL; |
| 933 | } |
| 934 | module_put(t->me); |
| 935 | xt_table_unlock(t); |
| 936 | } else |
| 937 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 938 | |
| 939 | return ret; |
| 940 | } |
| 941 | |
| 942 | static int |
| 943 | do_replace(void __user *user, unsigned int len) |
| 944 | { |
| 945 | int ret; |
| 946 | struct ip6t_replace tmp; |
| 947 | struct xt_table *t; |
| 948 | struct xt_table_info *newinfo, *oldinfo; |
| 949 | struct xt_counters *counters; |
| 950 | void *loc_cpu_entry, *loc_cpu_old_entry; |
| 951 | |
| 952 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 953 | return -EFAULT; |
| 954 | |
| 955 | /* overflow check */ |
| 956 | if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS - |
| 957 | SMP_CACHE_BYTES) |
| 958 | return -ENOMEM; |
| 959 | if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) |
| 960 | return -ENOMEM; |
| 961 | |
| 962 | newinfo = xt_alloc_table_info(tmp.size); |
| 963 | if (!newinfo) |
| 964 | return -ENOMEM; |
| 965 | |
| 966 | /* choose the copy that is on our node/cpu */ |
| 967 | loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; |
| 968 | if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), |
| 969 | tmp.size) != 0) { |
| 970 | ret = -EFAULT; |
| 971 | goto free_newinfo; |
| 972 | } |
| 973 | |
| 974 | counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters)); |
| 975 | if (!counters) { |
| 976 | ret = -ENOMEM; |
| 977 | goto free_newinfo; |
| 978 | } |
| 979 | |
| 980 | ret = translate_table(tmp.name, tmp.valid_hooks, |
| 981 | newinfo, loc_cpu_entry, tmp.size, tmp.num_entries, |
| 982 | tmp.hook_entry, tmp.underflow); |
| 983 | if (ret != 0) |
| 984 | goto free_newinfo_counters; |
| 985 | |
| 986 | duprintf("ip_tables: Translated table\n"); |
| 987 | |
| 988 | t = try_then_request_module(xt_find_table_lock(AF_INET6, tmp.name), |
| 989 | "ip6table_%s", tmp.name); |
| 990 | if (!t || IS_ERR(t)) { |
| 991 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 992 | goto free_newinfo_counters_untrans; |
| 993 | } |
| 994 | |
| 995 | /* You lied! */ |
| 996 | if (tmp.valid_hooks != t->valid_hooks) { |
| 997 | duprintf("Valid hook crap: %08X vs %08X\n", |
| 998 | tmp.valid_hooks, t->valid_hooks); |
| 999 | ret = -EINVAL; |
| 1000 | goto put_module; |
| 1001 | } |
| 1002 | |
| 1003 | oldinfo = xt_replace_table(t, tmp.num_counters, newinfo, &ret); |
| 1004 | if (!oldinfo) |
| 1005 | goto put_module; |
| 1006 | |
| 1007 | /* Update module usage count based on number of rules */ |
| 1008 | duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n", |
| 1009 | oldinfo->number, oldinfo->initial_entries, newinfo->number); |
| 1010 | if ((oldinfo->number > oldinfo->initial_entries) || |
| 1011 | (newinfo->number <= oldinfo->initial_entries)) |
| 1012 | module_put(t->me); |
| 1013 | if ((oldinfo->number > oldinfo->initial_entries) && |
| 1014 | (newinfo->number <= oldinfo->initial_entries)) |
| 1015 | module_put(t->me); |
| 1016 | |
| 1017 | /* Get the old counters. */ |
| 1018 | get_counters(oldinfo, counters); |
| 1019 | /* Decrease module usage counts and free resource */ |
| 1020 | loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()]; |
| 1021 | IP6T_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL); |
| 1022 | xt_free_table_info(oldinfo); |
| 1023 | if (copy_to_user(tmp.counters, counters, |
| 1024 | sizeof(struct xt_counters) * tmp.num_counters) != 0) |
| 1025 | ret = -EFAULT; |
| 1026 | vfree(counters); |
| 1027 | xt_table_unlock(t); |
| 1028 | return ret; |
| 1029 | |
| 1030 | put_module: |
| 1031 | module_put(t->me); |
| 1032 | xt_table_unlock(t); |
| 1033 | free_newinfo_counters_untrans: |
| 1034 | IP6T_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL); |
| 1035 | free_newinfo_counters: |
| 1036 | vfree(counters); |
| 1037 | free_newinfo: |
| 1038 | xt_free_table_info(newinfo); |
| 1039 | return ret; |
| 1040 | } |
| 1041 | |
| 1042 | /* We're lazy, and add to the first CPU; overflow works its fey magic |
| 1043 | * and everything is OK. */ |
| 1044 | static inline int |
| 1045 | add_counter_to_entry(struct ip6t_entry *e, |
| 1046 | const struct xt_counters addme[], |
| 1047 | unsigned int *i) |
| 1048 | { |
| 1049 | #if 0 |
| 1050 | duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n", |
| 1051 | *i, |
| 1052 | (long unsigned int)e->counters.pcnt, |
| 1053 | (long unsigned int)e->counters.bcnt, |
| 1054 | (long unsigned int)addme[*i].pcnt, |
| 1055 | (long unsigned int)addme[*i].bcnt); |
| 1056 | #endif |
| 1057 | |
| 1058 | ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); |
| 1059 | |
| 1060 | (*i)++; |
| 1061 | return 0; |
| 1062 | } |
| 1063 | |
| 1064 | static int |
| 1065 | do_add_counters(void __user *user, unsigned int len) |
| 1066 | { |
| 1067 | unsigned int i; |
| 1068 | struct xt_counters_info tmp, *paddc; |
| 1069 | struct xt_table_info *private; |
| 1070 | struct xt_table *t; |
| 1071 | int ret = 0; |
| 1072 | void *loc_cpu_entry; |
| 1073 | |
| 1074 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 1075 | return -EFAULT; |
| 1076 | |
| 1077 | if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters)) |
| 1078 | return -EINVAL; |
| 1079 | |
| 1080 | paddc = vmalloc(len); |
| 1081 | if (!paddc) |
| 1082 | return -ENOMEM; |
| 1083 | |
| 1084 | if (copy_from_user(paddc, user, len) != 0) { |
| 1085 | ret = -EFAULT; |
| 1086 | goto free; |
| 1087 | } |
| 1088 | |
| 1089 | t = xt_find_table_lock(AF_INET6, tmp.name); |
| 1090 | if (!t || IS_ERR(t)) { |
| 1091 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1092 | goto free; |
| 1093 | } |
| 1094 | |
| 1095 | write_lock_bh(&t->lock); |
| 1096 | private = t->private; |
| 1097 | if (private->number != tmp.num_counters) { |
| 1098 | ret = -EINVAL; |
| 1099 | goto unlock_up_free; |
| 1100 | } |
| 1101 | |
| 1102 | i = 0; |
| 1103 | /* Choose the copy that is on our node */ |
| 1104 | loc_cpu_entry = private->entries[smp_processor_id()]; |
| 1105 | IP6T_ENTRY_ITERATE(loc_cpu_entry, |
| 1106 | private->size, |
| 1107 | add_counter_to_entry, |
| 1108 | paddc->counters, |
| 1109 | &i); |
| 1110 | unlock_up_free: |
| 1111 | write_unlock_bh(&t->lock); |
| 1112 | xt_table_unlock(t); |
| 1113 | module_put(t->me); |
| 1114 | free: |
| 1115 | vfree(paddc); |
| 1116 | |
| 1117 | return ret; |
| 1118 | } |
| 1119 | |
| 1120 | static int |
| 1121 | do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) |
| 1122 | { |
| 1123 | int ret; |
| 1124 | |
| 1125 | if (!capable(CAP_NET_ADMIN)) |
| 1126 | return -EPERM; |
| 1127 | |
| 1128 | switch (cmd) { |
| 1129 | case IP6T_SO_SET_REPLACE: |
| 1130 | ret = do_replace(user, len); |
| 1131 | break; |
| 1132 | |
| 1133 | case IP6T_SO_SET_ADD_COUNTERS: |
| 1134 | ret = do_add_counters(user, len); |
| 1135 | break; |
| 1136 | |
| 1137 | default: |
| 1138 | duprintf("do_ip6t_set_ctl: unknown request %i\n", cmd); |
| 1139 | ret = -EINVAL; |
| 1140 | } |
| 1141 | |
| 1142 | return ret; |
| 1143 | } |
| 1144 | |
| 1145 | static int |
| 1146 | do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| 1147 | { |
| 1148 | int ret; |
| 1149 | |
| 1150 | if (!capable(CAP_NET_ADMIN)) |
| 1151 | return -EPERM; |
| 1152 | |
| 1153 | switch (cmd) { |
| 1154 | case IP6T_SO_GET_INFO: { |
| 1155 | char name[IP6T_TABLE_MAXNAMELEN]; |
| 1156 | struct xt_table *t; |
| 1157 | |
| 1158 | if (*len != sizeof(struct ip6t_getinfo)) { |
| 1159 | duprintf("length %u != %u\n", *len, |
| 1160 | sizeof(struct ip6t_getinfo)); |
| 1161 | ret = -EINVAL; |
| 1162 | break; |
| 1163 | } |
| 1164 | |
| 1165 | if (copy_from_user(name, user, sizeof(name)) != 0) { |
| 1166 | ret = -EFAULT; |
| 1167 | break; |
| 1168 | } |
| 1169 | name[IP6T_TABLE_MAXNAMELEN-1] = '\0'; |
| 1170 | |
| 1171 | t = try_then_request_module(xt_find_table_lock(AF_INET6, name), |
| 1172 | "ip6table_%s", name); |
| 1173 | if (t && !IS_ERR(t)) { |
| 1174 | struct ip6t_getinfo info; |
| 1175 | struct xt_table_info *private = t->private; |
| 1176 | |
| 1177 | info.valid_hooks = t->valid_hooks; |
| 1178 | memcpy(info.hook_entry, private->hook_entry, |
| 1179 | sizeof(info.hook_entry)); |
| 1180 | memcpy(info.underflow, private->underflow, |
| 1181 | sizeof(info.underflow)); |
| 1182 | info.num_entries = private->number; |
| 1183 | info.size = private->size; |
| 1184 | memcpy(info.name, name, sizeof(info.name)); |
| 1185 | |
| 1186 | if (copy_to_user(user, &info, *len) != 0) |
| 1187 | ret = -EFAULT; |
| 1188 | else |
| 1189 | ret = 0; |
| 1190 | xt_table_unlock(t); |
| 1191 | module_put(t->me); |
| 1192 | } else |
| 1193 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1194 | } |
| 1195 | break; |
| 1196 | |
| 1197 | case IP6T_SO_GET_ENTRIES: { |
| 1198 | struct ip6t_get_entries get; |
| 1199 | |
| 1200 | if (*len < sizeof(get)) { |
| 1201 | duprintf("get_entries: %u < %u\n", *len, sizeof(get)); |
| 1202 | ret = -EINVAL; |
| 1203 | } else if (copy_from_user(&get, user, sizeof(get)) != 0) { |
| 1204 | ret = -EFAULT; |
| 1205 | } else if (*len != sizeof(struct ip6t_get_entries) + get.size) { |
| 1206 | duprintf("get_entries: %u != %u\n", *len, |
| 1207 | sizeof(struct ip6t_get_entries) + get.size); |
| 1208 | ret = -EINVAL; |
| 1209 | } else |
| 1210 | ret = get_entries(&get, user); |
| 1211 | break; |
| 1212 | } |
| 1213 | |
| 1214 | case IP6T_SO_GET_REVISION_MATCH: |
| 1215 | case IP6T_SO_GET_REVISION_TARGET: { |
| 1216 | struct ip6t_get_revision rev; |
| 1217 | int target; |
| 1218 | |
| 1219 | if (*len != sizeof(rev)) { |
| 1220 | ret = -EINVAL; |
| 1221 | break; |
| 1222 | } |
| 1223 | if (copy_from_user(&rev, user, sizeof(rev)) != 0) { |
| 1224 | ret = -EFAULT; |
| 1225 | break; |
| 1226 | } |
| 1227 | |
| 1228 | if (cmd == IP6T_SO_GET_REVISION_TARGET) |
| 1229 | target = 1; |
| 1230 | else |
| 1231 | target = 0; |
| 1232 | |
| 1233 | try_then_request_module(xt_find_revision(AF_INET6, rev.name, |
| 1234 | rev.revision, |
| 1235 | target, &ret), |
| 1236 | "ip6t_%s", rev.name); |
| 1237 | break; |
| 1238 | } |
| 1239 | |
| 1240 | default: |
| 1241 | duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd); |
| 1242 | ret = -EINVAL; |
| 1243 | } |
| 1244 | |
| 1245 | return ret; |
| 1246 | } |
| 1247 | |
| 1248 | int ip6t_register_table(struct xt_table *table, |
| 1249 | const struct ip6t_replace *repl) |
| 1250 | { |
| 1251 | int ret; |
| 1252 | struct xt_table_info *newinfo; |
| 1253 | static struct xt_table_info bootstrap |
| 1254 | = { 0, 0, 0, { 0 }, { 0 }, { } }; |
| 1255 | void *loc_cpu_entry; |
| 1256 | |
| 1257 | newinfo = xt_alloc_table_info(repl->size); |
| 1258 | if (!newinfo) |
| 1259 | return -ENOMEM; |
| 1260 | |
| 1261 | /* choose the copy on our node/cpu */ |
| 1262 | loc_cpu_entry = newinfo->entries[raw_smp_processor_id()]; |
| 1263 | memcpy(loc_cpu_entry, repl->entries, repl->size); |
| 1264 | |
| 1265 | ret = translate_table(table->name, table->valid_hooks, |
| 1266 | newinfo, loc_cpu_entry, repl->size, |
| 1267 | repl->num_entries, |
| 1268 | repl->hook_entry, |
| 1269 | repl->underflow); |
| 1270 | if (ret != 0) { |
| 1271 | xt_free_table_info(newinfo); |
| 1272 | return ret; |
| 1273 | } |
| 1274 | |
| 1275 | ret = xt_register_table(table, &bootstrap, newinfo); |
| 1276 | if (ret != 0) { |
| 1277 | xt_free_table_info(newinfo); |
| 1278 | return ret; |
| 1279 | } |
| 1280 | |
| 1281 | return 0; |
| 1282 | } |
| 1283 | |
| 1284 | void ip6t_unregister_table(struct xt_table *table) |
| 1285 | { |
| 1286 | struct xt_table_info *private; |
| 1287 | void *loc_cpu_entry; |
| 1288 | |
| 1289 | private = xt_unregister_table(table); |
| 1290 | |
| 1291 | /* Decrease module usage counts and free resources */ |
| 1292 | loc_cpu_entry = private->entries[raw_smp_processor_id()]; |
| 1293 | IP6T_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL); |
| 1294 | xt_free_table_info(private); |
| 1295 | } |
| 1296 | |
| 1297 | /* Returns 1 if the type and code is matched by the range, 0 otherwise */ |
| 1298 | static inline int |
| 1299 | icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, |
| 1300 | u_int8_t type, u_int8_t code, |
| 1301 | int invert) |
| 1302 | { |
| 1303 | return (type == test_type && code >= min_code && code <= max_code) |
| 1304 | ^ invert; |
| 1305 | } |
| 1306 | |
| 1307 | static int |
| 1308 | icmp6_match(const struct sk_buff *skb, |
| 1309 | const struct net_device *in, |
| 1310 | const struct net_device *out, |
| 1311 | const struct xt_match *match, |
| 1312 | const void *matchinfo, |
| 1313 | int offset, |
| 1314 | unsigned int protoff, |
| 1315 | int *hotdrop) |
| 1316 | { |
| 1317 | struct icmp6hdr _icmp, *ic; |
| 1318 | const struct ip6t_icmp *icmpinfo = matchinfo; |
| 1319 | |
| 1320 | /* Must not be a fragment. */ |
| 1321 | if (offset) |
| 1322 | return 0; |
| 1323 | |
| 1324 | ic = skb_header_pointer(skb, protoff, sizeof(_icmp), &_icmp); |
| 1325 | if (ic == NULL) { |
| 1326 | /* We've been asked to examine this packet, and we |
| 1327 | can't. Hence, no choice but to drop. */ |
| 1328 | duprintf("Dropping evil ICMP tinygram.\n"); |
| 1329 | *hotdrop = 1; |
| 1330 | return 0; |
| 1331 | } |
| 1332 | |
| 1333 | return icmp6_type_code_match(icmpinfo->type, |
| 1334 | icmpinfo->code[0], |
| 1335 | icmpinfo->code[1], |
| 1336 | ic->icmp6_type, ic->icmp6_code, |
| 1337 | !!(icmpinfo->invflags&IP6T_ICMP_INV)); |
| 1338 | } |
| 1339 | |
| 1340 | /* Called when user tries to insert an entry of this type. */ |
| 1341 | static int |
| 1342 | icmp6_checkentry(const char *tablename, |
| 1343 | const void *entry, |
| 1344 | const struct xt_match *match, |
| 1345 | void *matchinfo, |
| 1346 | unsigned int hook_mask) |
| 1347 | { |
| 1348 | const struct ip6t_icmp *icmpinfo = matchinfo; |
| 1349 | |
| 1350 | /* Must specify no unknown invflags */ |
| 1351 | return !(icmpinfo->invflags & ~IP6T_ICMP_INV); |
| 1352 | } |
| 1353 | |
| 1354 | /* The built-in targets: standard (NULL) and error. */ |
| 1355 | static struct ip6t_target ip6t_standard_target = { |
| 1356 | .name = IP6T_STANDARD_TARGET, |
| 1357 | .targetsize = sizeof(int), |
| 1358 | .family = AF_INET6, |
| 1359 | }; |
| 1360 | |
| 1361 | static struct ip6t_target ip6t_error_target = { |
| 1362 | .name = IP6T_ERROR_TARGET, |
| 1363 | .target = ip6t_error, |
| 1364 | .targetsize = IP6T_FUNCTION_MAXNAMELEN, |
| 1365 | .family = AF_INET6, |
| 1366 | }; |
| 1367 | |
| 1368 | static struct nf_sockopt_ops ip6t_sockopts = { |
| 1369 | .pf = PF_INET6, |
| 1370 | .set_optmin = IP6T_BASE_CTL, |
| 1371 | .set_optmax = IP6T_SO_SET_MAX+1, |
| 1372 | .set = do_ip6t_set_ctl, |
| 1373 | .get_optmin = IP6T_BASE_CTL, |
| 1374 | .get_optmax = IP6T_SO_GET_MAX+1, |
| 1375 | .get = do_ip6t_get_ctl, |
| 1376 | }; |
| 1377 | |
| 1378 | static struct ip6t_match icmp6_matchstruct = { |
| 1379 | .name = "icmp6", |
| 1380 | .match = &icmp6_match, |
| 1381 | .matchsize = sizeof(struct ip6t_icmp), |
| 1382 | .checkentry = icmp6_checkentry, |
| 1383 | .proto = IPPROTO_ICMPV6, |
| 1384 | .family = AF_INET6, |
| 1385 | }; |
| 1386 | |
| 1387 | static int __init ip6_tables_init(void) |
| 1388 | { |
| 1389 | int ret; |
| 1390 | |
| 1391 | ret = xt_proto_init(AF_INET6); |
| 1392 | if (ret < 0) |
| 1393 | goto err1; |
| 1394 | |
| 1395 | /* Noone else will be downing sem now, so we won't sleep */ |
| 1396 | ret = xt_register_target(&ip6t_standard_target); |
| 1397 | if (ret < 0) |
| 1398 | goto err2; |
| 1399 | ret = xt_register_target(&ip6t_error_target); |
| 1400 | if (ret < 0) |
| 1401 | goto err3; |
| 1402 | ret = xt_register_match(&icmp6_matchstruct); |
| 1403 | if (ret < 0) |
| 1404 | goto err4; |
| 1405 | |
| 1406 | /* Register setsockopt */ |
| 1407 | ret = nf_register_sockopt(&ip6t_sockopts); |
| 1408 | if (ret < 0) |
| 1409 | goto err5; |
| 1410 | |
| 1411 | printk("ip6_tables: (C) 2000-2006 Netfilter Core Team\n"); |
| 1412 | return 0; |
| 1413 | |
| 1414 | err5: |
| 1415 | xt_unregister_match(&icmp6_matchstruct); |
| 1416 | err4: |
| 1417 | xt_unregister_target(&ip6t_error_target); |
| 1418 | err3: |
| 1419 | xt_unregister_target(&ip6t_standard_target); |
| 1420 | err2: |
| 1421 | xt_proto_fini(AF_INET6); |
| 1422 | err1: |
| 1423 | return ret; |
| 1424 | } |
| 1425 | |
| 1426 | static void __exit ip6_tables_fini(void) |
| 1427 | { |
| 1428 | nf_unregister_sockopt(&ip6t_sockopts); |
| 1429 | xt_unregister_match(&icmp6_matchstruct); |
| 1430 | xt_unregister_target(&ip6t_error_target); |
| 1431 | xt_unregister_target(&ip6t_standard_target); |
| 1432 | xt_proto_fini(AF_INET6); |
| 1433 | } |
| 1434 | |
| 1435 | /* |
| 1436 | * find the offset to specified header or the protocol number of last header |
| 1437 | * if target < 0. "last header" is transport protocol header, ESP, or |
| 1438 | * "No next header". |
| 1439 | * |
| 1440 | * If target header is found, its offset is set in *offset and return protocol |
| 1441 | * number. Otherwise, return -1. |
| 1442 | * |
| 1443 | * If the first fragment doesn't contain the final protocol header or |
| 1444 | * NEXTHDR_NONE it is considered invalid. |
| 1445 | * |
| 1446 | * Note that non-1st fragment is special case that "the protocol number |
| 1447 | * of last header" is "next header" field in Fragment header. In this case, |
| 1448 | * *offset is meaningless and fragment offset is stored in *fragoff if fragoff |
| 1449 | * isn't NULL. |
| 1450 | * |
| 1451 | */ |
| 1452 | int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, |
| 1453 | int target, unsigned short *fragoff) |
| 1454 | { |
| 1455 | unsigned int start = (u8*)(skb->nh.ipv6h + 1) - skb->data; |
| 1456 | u8 nexthdr = skb->nh.ipv6h->nexthdr; |
| 1457 | unsigned int len = skb->len - start; |
| 1458 | |
| 1459 | if (fragoff) |
| 1460 | *fragoff = 0; |
| 1461 | |
| 1462 | while (nexthdr != target) { |
| 1463 | struct ipv6_opt_hdr _hdr, *hp; |
| 1464 | unsigned int hdrlen; |
| 1465 | |
| 1466 | if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) { |
| 1467 | if (target < 0) |
| 1468 | break; |
| 1469 | return -ENOENT; |
| 1470 | } |
| 1471 | |
| 1472 | hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); |
| 1473 | if (hp == NULL) |
| 1474 | return -EBADMSG; |
| 1475 | if (nexthdr == NEXTHDR_FRAGMENT) { |
| 1476 | unsigned short _frag_off, *fp; |
| 1477 | fp = skb_header_pointer(skb, |
| 1478 | start+offsetof(struct frag_hdr, |
| 1479 | frag_off), |
| 1480 | sizeof(_frag_off), |
| 1481 | &_frag_off); |
| 1482 | if (fp == NULL) |
| 1483 | return -EBADMSG; |
| 1484 | |
| 1485 | _frag_off = ntohs(*fp) & ~0x7; |
| 1486 | if (_frag_off) { |
| 1487 | if (target < 0 && |
| 1488 | ((!ipv6_ext_hdr(hp->nexthdr)) || |
| 1489 | nexthdr == NEXTHDR_NONE)) { |
| 1490 | if (fragoff) |
| 1491 | *fragoff = _frag_off; |
| 1492 | return hp->nexthdr; |
| 1493 | } |
| 1494 | return -ENOENT; |
| 1495 | } |
| 1496 | hdrlen = 8; |
| 1497 | } else if (nexthdr == NEXTHDR_AUTH) |
| 1498 | hdrlen = (hp->hdrlen + 2) << 2; |
| 1499 | else |
| 1500 | hdrlen = ipv6_optlen(hp); |
| 1501 | |
| 1502 | nexthdr = hp->nexthdr; |
| 1503 | len -= hdrlen; |
| 1504 | start += hdrlen; |
| 1505 | } |
| 1506 | |
| 1507 | *offset = start; |
| 1508 | return nexthdr; |
| 1509 | } |
| 1510 | |
| 1511 | EXPORT_SYMBOL(ip6t_register_table); |
| 1512 | EXPORT_SYMBOL(ip6t_unregister_table); |
| 1513 | EXPORT_SYMBOL(ip6t_do_table); |
| 1514 | EXPORT_SYMBOL(ip6t_ext_hdr); |
| 1515 | EXPORT_SYMBOL(ipv6_find_hdr); |
| 1516 | |
| 1517 | module_init(ip6_tables_init); |
| 1518 | module_exit(ip6_tables_fini); |