Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Packet matching code. |
| 3 | * |
| 4 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| 5 | * Copyright (C) 2000-2004 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 | */ |
| 15 | #include <linux/config.h> |
| 16 | #include <linux/cache.h> |
| 17 | #include <linux/skbuff.h> |
| 18 | #include <linux/kmod.h> |
| 19 | #include <linux/vmalloc.h> |
| 20 | #include <linux/netdevice.h> |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/tcp.h> |
| 23 | #include <linux/udp.h> |
| 24 | #include <linux/icmp.h> |
| 25 | #include <net/ip.h> |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/semaphore.h> |
| 28 | #include <linux/proc_fs.h> |
| 29 | #include <linux/err.h> |
| 30 | |
| 31 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 32 | |
| 33 | MODULE_LICENSE("GPL"); |
| 34 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 35 | MODULE_DESCRIPTION("IPv4 packet filter"); |
| 36 | |
| 37 | /*#define DEBUG_IP_FIREWALL*/ |
| 38 | /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */ |
| 39 | /*#define DEBUG_IP_FIREWALL_USER*/ |
| 40 | |
| 41 | #ifdef DEBUG_IP_FIREWALL |
| 42 | #define dprintf(format, args...) printk(format , ## args) |
| 43 | #else |
| 44 | #define dprintf(format, args...) |
| 45 | #endif |
| 46 | |
| 47 | #ifdef DEBUG_IP_FIREWALL_USER |
| 48 | #define duprintf(format, args...) printk(format , ## args) |
| 49 | #else |
| 50 | #define duprintf(format, args...) |
| 51 | #endif |
| 52 | |
| 53 | #ifdef CONFIG_NETFILTER_DEBUG |
| 54 | #define IP_NF_ASSERT(x) \ |
| 55 | do { \ |
| 56 | if (!(x)) \ |
| 57 | printk("IP_NF_ASSERT: %s:%s:%u\n", \ |
| 58 | __FUNCTION__, __FILE__, __LINE__); \ |
| 59 | } while(0) |
| 60 | #else |
| 61 | #define IP_NF_ASSERT(x) |
| 62 | #endif |
| 63 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) |
| 64 | |
| 65 | static DECLARE_MUTEX(ipt_mutex); |
| 66 | |
| 67 | /* Must have mutex */ |
| 68 | #define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0) |
| 69 | #define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0) |
| 70 | #include <linux/netfilter_ipv4/lockhelp.h> |
| 71 | #include <linux/netfilter_ipv4/listhelp.h> |
| 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 | To be cache friendly on SMP, we arrange them like so: |
| 87 | [ n-entries ] |
| 88 | ... cache-align padding ... |
| 89 | [ n-entries ] |
| 90 | |
| 91 | Hence the start of any table is given by get_table() below. */ |
| 92 | |
| 93 | /* The table itself */ |
| 94 | struct ipt_table_info |
| 95 | { |
| 96 | /* Size per table */ |
| 97 | unsigned int size; |
| 98 | /* Number of entries: FIXME. --RR */ |
| 99 | unsigned int number; |
| 100 | /* Initial number of entries. Needed for module usage count */ |
| 101 | unsigned int initial_entries; |
| 102 | |
| 103 | /* Entry points and underflows */ |
| 104 | unsigned int hook_entry[NF_IP_NUMHOOKS]; |
| 105 | unsigned int underflow[NF_IP_NUMHOOKS]; |
| 106 | |
| 107 | /* ipt_entry tables: one per CPU */ |
| 108 | char entries[0] ____cacheline_aligned; |
| 109 | }; |
| 110 | |
| 111 | static LIST_HEAD(ipt_target); |
| 112 | static LIST_HEAD(ipt_match); |
| 113 | static LIST_HEAD(ipt_tables); |
| 114 | #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0) |
| 115 | |
| 116 | #ifdef CONFIG_SMP |
| 117 | #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p)) |
| 118 | #else |
| 119 | #define TABLE_OFFSET(t,p) 0 |
| 120 | #endif |
| 121 | |
| 122 | #if 0 |
| 123 | #define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0) |
| 124 | #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; }) |
| 125 | #define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0) |
| 126 | #endif |
| 127 | |
| 128 | /* Returns whether matches rule or not. */ |
| 129 | static inline int |
| 130 | ip_packet_match(const struct iphdr *ip, |
| 131 | const char *indev, |
| 132 | const char *outdev, |
| 133 | const struct ipt_ip *ipinfo, |
| 134 | int isfrag) |
| 135 | { |
| 136 | size_t i; |
| 137 | unsigned long ret; |
| 138 | |
| 139 | #define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg)) |
| 140 | |
| 141 | if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr, |
| 142 | IPT_INV_SRCIP) |
| 143 | || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr, |
| 144 | IPT_INV_DSTIP)) { |
| 145 | dprintf("Source or dest mismatch.\n"); |
| 146 | |
| 147 | dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n", |
| 148 | NIPQUAD(ip->saddr), |
| 149 | NIPQUAD(ipinfo->smsk.s_addr), |
| 150 | NIPQUAD(ipinfo->src.s_addr), |
| 151 | ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : ""); |
| 152 | dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n", |
| 153 | NIPQUAD(ip->daddr), |
| 154 | NIPQUAD(ipinfo->dmsk.s_addr), |
| 155 | NIPQUAD(ipinfo->dst.s_addr), |
| 156 | ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : ""); |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | /* Look for ifname matches; this should unroll nicely. */ |
| 161 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| 162 | ret |= (((const unsigned long *)indev)[i] |
| 163 | ^ ((const unsigned long *)ipinfo->iniface)[i]) |
| 164 | & ((const unsigned long *)ipinfo->iniface_mask)[i]; |
| 165 | } |
| 166 | |
| 167 | if (FWINV(ret != 0, IPT_INV_VIA_IN)) { |
| 168 | dprintf("VIA in mismatch (%s vs %s).%s\n", |
| 169 | indev, ipinfo->iniface, |
| 170 | ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":""); |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { |
| 175 | ret |= (((const unsigned long *)outdev)[i] |
| 176 | ^ ((const unsigned long *)ipinfo->outiface)[i]) |
| 177 | & ((const unsigned long *)ipinfo->outiface_mask)[i]; |
| 178 | } |
| 179 | |
| 180 | if (FWINV(ret != 0, IPT_INV_VIA_OUT)) { |
| 181 | dprintf("VIA out mismatch (%s vs %s).%s\n", |
| 182 | outdev, ipinfo->outiface, |
| 183 | ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":""); |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | /* Check specific protocol */ |
| 188 | if (ipinfo->proto |
| 189 | && FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) { |
| 190 | dprintf("Packet protocol %hi does not match %hi.%s\n", |
| 191 | ip->protocol, ipinfo->proto, |
| 192 | ipinfo->invflags&IPT_INV_PROTO ? " (INV)":""); |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | /* If we have a fragment rule but the packet is not a fragment |
| 197 | * then we return zero */ |
| 198 | if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) { |
| 199 | dprintf("Fragment rule but not fragment.%s\n", |
| 200 | ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : ""); |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | return 1; |
| 205 | } |
| 206 | |
| 207 | static inline int |
| 208 | ip_checkentry(const struct ipt_ip *ip) |
| 209 | { |
| 210 | if (ip->flags & ~IPT_F_MASK) { |
| 211 | duprintf("Unknown flag bits set: %08X\n", |
| 212 | ip->flags & ~IPT_F_MASK); |
| 213 | return 0; |
| 214 | } |
| 215 | if (ip->invflags & ~IPT_INV_MASK) { |
| 216 | duprintf("Unknown invflag bits set: %08X\n", |
| 217 | ip->invflags & ~IPT_INV_MASK); |
| 218 | return 0; |
| 219 | } |
| 220 | return 1; |
| 221 | } |
| 222 | |
| 223 | static unsigned int |
| 224 | ipt_error(struct sk_buff **pskb, |
| 225 | const struct net_device *in, |
| 226 | const struct net_device *out, |
| 227 | unsigned int hooknum, |
| 228 | const void *targinfo, |
| 229 | void *userinfo) |
| 230 | { |
| 231 | if (net_ratelimit()) |
| 232 | printk("ip_tables: error: `%s'\n", (char *)targinfo); |
| 233 | |
| 234 | return NF_DROP; |
| 235 | } |
| 236 | |
| 237 | static inline |
| 238 | int do_match(struct ipt_entry_match *m, |
| 239 | const struct sk_buff *skb, |
| 240 | const struct net_device *in, |
| 241 | const struct net_device *out, |
| 242 | int offset, |
| 243 | int *hotdrop) |
| 244 | { |
| 245 | /* Stop iteration if it doesn't match */ |
| 246 | if (!m->u.kernel.match->match(skb, in, out, m->data, offset, hotdrop)) |
| 247 | return 1; |
| 248 | else |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | static inline struct ipt_entry * |
| 253 | get_entry(void *base, unsigned int offset) |
| 254 | { |
| 255 | return (struct ipt_entry *)(base + offset); |
| 256 | } |
| 257 | |
| 258 | /* Returns one of the generic firewall policies, like NF_ACCEPT. */ |
| 259 | unsigned int |
| 260 | ipt_do_table(struct sk_buff **pskb, |
| 261 | unsigned int hook, |
| 262 | const struct net_device *in, |
| 263 | const struct net_device *out, |
| 264 | struct ipt_table *table, |
| 265 | void *userdata) |
| 266 | { |
| 267 | static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); |
| 268 | u_int16_t offset; |
| 269 | struct iphdr *ip; |
| 270 | u_int16_t datalen; |
| 271 | int hotdrop = 0; |
| 272 | /* Initializing verdict to NF_DROP keeps gcc happy. */ |
| 273 | unsigned int verdict = NF_DROP; |
| 274 | const char *indev, *outdev; |
| 275 | void *table_base; |
| 276 | struct ipt_entry *e, *back; |
| 277 | |
| 278 | /* Initialization */ |
| 279 | ip = (*pskb)->nh.iph; |
| 280 | datalen = (*pskb)->len - ip->ihl * 4; |
| 281 | indev = in ? in->name : nulldevname; |
| 282 | outdev = out ? out->name : nulldevname; |
| 283 | /* We handle fragments by dealing with the first fragment as |
| 284 | * if it was a normal packet. All other fragments are treated |
| 285 | * normally, except that they will NEVER match rules that ask |
| 286 | * things we don't know, ie. tcp syn flag or ports). If the |
| 287 | * rule is also a fragment-specific rule, non-fragments won't |
| 288 | * match it. */ |
| 289 | offset = ntohs(ip->frag_off) & IP_OFFSET; |
| 290 | |
| 291 | read_lock_bh(&table->lock); |
| 292 | IP_NF_ASSERT(table->valid_hooks & (1 << hook)); |
| 293 | table_base = (void *)table->private->entries |
| 294 | + TABLE_OFFSET(table->private, smp_processor_id()); |
| 295 | e = get_entry(table_base, table->private->hook_entry[hook]); |
| 296 | |
| 297 | #ifdef CONFIG_NETFILTER_DEBUG |
| 298 | /* Check noone else using our table */ |
| 299 | if (((struct ipt_entry *)table_base)->comefrom != 0xdead57ac |
| 300 | && ((struct ipt_entry *)table_base)->comefrom != 0xeeeeeeec) { |
| 301 | printk("ASSERT: CPU #%u, %s comefrom(%p) = %X\n", |
| 302 | smp_processor_id(), |
| 303 | table->name, |
| 304 | &((struct ipt_entry *)table_base)->comefrom, |
| 305 | ((struct ipt_entry *)table_base)->comefrom); |
| 306 | } |
| 307 | ((struct ipt_entry *)table_base)->comefrom = 0x57acc001; |
| 308 | #endif |
| 309 | |
| 310 | /* For return from builtin chain */ |
| 311 | back = get_entry(table_base, table->private->underflow[hook]); |
| 312 | |
| 313 | do { |
| 314 | IP_NF_ASSERT(e); |
| 315 | IP_NF_ASSERT(back); |
| 316 | (*pskb)->nfcache |= e->nfcache; |
| 317 | if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) { |
| 318 | struct ipt_entry_target *t; |
| 319 | |
| 320 | if (IPT_MATCH_ITERATE(e, do_match, |
| 321 | *pskb, in, out, |
| 322 | offset, &hotdrop) != 0) |
| 323 | goto no_match; |
| 324 | |
| 325 | ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1); |
| 326 | |
| 327 | t = ipt_get_target(e); |
| 328 | IP_NF_ASSERT(t->u.kernel.target); |
| 329 | /* Standard target? */ |
| 330 | if (!t->u.kernel.target->target) { |
| 331 | int v; |
| 332 | |
| 333 | v = ((struct ipt_standard_target *)t)->verdict; |
| 334 | if (v < 0) { |
| 335 | /* Pop from stack? */ |
| 336 | if (v != IPT_RETURN) { |
| 337 | verdict = (unsigned)(-v) - 1; |
| 338 | break; |
| 339 | } |
| 340 | e = back; |
| 341 | back = get_entry(table_base, |
| 342 | back->comefrom); |
| 343 | continue; |
| 344 | } |
| 345 | if (table_base + v |
| 346 | != (void *)e + e->next_offset) { |
| 347 | /* Save old back ptr in next entry */ |
| 348 | struct ipt_entry *next |
| 349 | = (void *)e + e->next_offset; |
| 350 | next->comefrom |
| 351 | = (void *)back - table_base; |
| 352 | /* set back pointer to next entry */ |
| 353 | back = next; |
| 354 | } |
| 355 | |
| 356 | e = get_entry(table_base, v); |
| 357 | } else { |
| 358 | /* Targets which reenter must return |
| 359 | abs. verdicts */ |
| 360 | #ifdef CONFIG_NETFILTER_DEBUG |
| 361 | ((struct ipt_entry *)table_base)->comefrom |
| 362 | = 0xeeeeeeec; |
| 363 | #endif |
| 364 | verdict = t->u.kernel.target->target(pskb, |
| 365 | in, out, |
| 366 | hook, |
| 367 | t->data, |
| 368 | userdata); |
| 369 | |
| 370 | #ifdef CONFIG_NETFILTER_DEBUG |
| 371 | if (((struct ipt_entry *)table_base)->comefrom |
| 372 | != 0xeeeeeeec |
| 373 | && verdict == IPT_CONTINUE) { |
| 374 | printk("Target %s reentered!\n", |
| 375 | t->u.kernel.target->name); |
| 376 | verdict = NF_DROP; |
| 377 | } |
| 378 | ((struct ipt_entry *)table_base)->comefrom |
| 379 | = 0x57acc001; |
| 380 | #endif |
| 381 | /* Target might have changed stuff. */ |
| 382 | ip = (*pskb)->nh.iph; |
| 383 | datalen = (*pskb)->len - ip->ihl * 4; |
| 384 | |
| 385 | if (verdict == IPT_CONTINUE) |
| 386 | e = (void *)e + e->next_offset; |
| 387 | else |
| 388 | /* Verdict */ |
| 389 | break; |
| 390 | } |
| 391 | } else { |
| 392 | |
| 393 | no_match: |
| 394 | e = (void *)e + e->next_offset; |
| 395 | } |
| 396 | } while (!hotdrop); |
| 397 | |
| 398 | #ifdef CONFIG_NETFILTER_DEBUG |
| 399 | ((struct ipt_entry *)table_base)->comefrom = 0xdead57ac; |
| 400 | #endif |
| 401 | read_unlock_bh(&table->lock); |
| 402 | |
| 403 | #ifdef DEBUG_ALLOW_ALL |
| 404 | return NF_ACCEPT; |
| 405 | #else |
| 406 | if (hotdrop) |
| 407 | return NF_DROP; |
| 408 | else return verdict; |
| 409 | #endif |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * These are weird, but module loading must not be done with mutex |
| 414 | * held (since they will register), and we have to have a single |
| 415 | * function to use try_then_request_module(). |
| 416 | */ |
| 417 | |
| 418 | /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */ |
| 419 | static inline struct ipt_table *find_table_lock(const char *name) |
| 420 | { |
| 421 | struct ipt_table *t; |
| 422 | |
| 423 | if (down_interruptible(&ipt_mutex) != 0) |
| 424 | return ERR_PTR(-EINTR); |
| 425 | |
| 426 | list_for_each_entry(t, &ipt_tables, list) |
| 427 | if (strcmp(t->name, name) == 0 && try_module_get(t->me)) |
| 428 | return t; |
| 429 | up(&ipt_mutex); |
| 430 | return NULL; |
| 431 | } |
| 432 | |
| 433 | /* Find match, grabs ref. Returns ERR_PTR() on error. */ |
| 434 | static inline struct ipt_match *find_match(const char *name, u8 revision) |
| 435 | { |
| 436 | struct ipt_match *m; |
| 437 | int err = 0; |
| 438 | |
| 439 | if (down_interruptible(&ipt_mutex) != 0) |
| 440 | return ERR_PTR(-EINTR); |
| 441 | |
| 442 | list_for_each_entry(m, &ipt_match, list) { |
| 443 | if (strcmp(m->name, name) == 0) { |
| 444 | if (m->revision == revision) { |
| 445 | if (try_module_get(m->me)) { |
| 446 | up(&ipt_mutex); |
| 447 | return m; |
| 448 | } |
| 449 | } else |
| 450 | err = -EPROTOTYPE; /* Found something. */ |
| 451 | } |
| 452 | } |
| 453 | up(&ipt_mutex); |
| 454 | return ERR_PTR(err); |
| 455 | } |
| 456 | |
| 457 | /* Find target, grabs ref. Returns ERR_PTR() on error. */ |
| 458 | static inline struct ipt_target *find_target(const char *name, u8 revision) |
| 459 | { |
| 460 | struct ipt_target *t; |
| 461 | int err = 0; |
| 462 | |
| 463 | if (down_interruptible(&ipt_mutex) != 0) |
| 464 | return ERR_PTR(-EINTR); |
| 465 | |
| 466 | list_for_each_entry(t, &ipt_target, list) { |
| 467 | if (strcmp(t->name, name) == 0) { |
| 468 | if (t->revision == revision) { |
| 469 | if (try_module_get(t->me)) { |
| 470 | up(&ipt_mutex); |
| 471 | return t; |
| 472 | } |
| 473 | } else |
| 474 | err = -EPROTOTYPE; /* Found something. */ |
| 475 | } |
| 476 | } |
| 477 | up(&ipt_mutex); |
| 478 | return ERR_PTR(err); |
| 479 | } |
| 480 | |
| 481 | struct ipt_target *ipt_find_target(const char *name, u8 revision) |
| 482 | { |
| 483 | struct ipt_target *target; |
| 484 | |
| 485 | target = try_then_request_module(find_target(name, revision), |
| 486 | "ipt_%s", name); |
| 487 | if (IS_ERR(target) || !target) |
| 488 | return NULL; |
| 489 | return target; |
| 490 | } |
| 491 | |
| 492 | static int match_revfn(const char *name, u8 revision, int *bestp) |
| 493 | { |
| 494 | struct ipt_match *m; |
| 495 | int have_rev = 0; |
| 496 | |
| 497 | list_for_each_entry(m, &ipt_match, list) { |
| 498 | if (strcmp(m->name, name) == 0) { |
| 499 | if (m->revision > *bestp) |
| 500 | *bestp = m->revision; |
| 501 | if (m->revision == revision) |
| 502 | have_rev = 1; |
| 503 | } |
| 504 | } |
| 505 | return have_rev; |
| 506 | } |
| 507 | |
| 508 | static int target_revfn(const char *name, u8 revision, int *bestp) |
| 509 | { |
| 510 | struct ipt_target *t; |
| 511 | int have_rev = 0; |
| 512 | |
| 513 | list_for_each_entry(t, &ipt_target, list) { |
| 514 | if (strcmp(t->name, name) == 0) { |
| 515 | if (t->revision > *bestp) |
| 516 | *bestp = t->revision; |
| 517 | if (t->revision == revision) |
| 518 | have_rev = 1; |
| 519 | } |
| 520 | } |
| 521 | return have_rev; |
| 522 | } |
| 523 | |
| 524 | /* Returns true or false (if no such extension at all) */ |
| 525 | static inline int find_revision(const char *name, u8 revision, |
| 526 | int (*revfn)(const char *, u8, int *), |
| 527 | int *err) |
| 528 | { |
| 529 | int have_rev, best = -1; |
| 530 | |
| 531 | if (down_interruptible(&ipt_mutex) != 0) { |
| 532 | *err = -EINTR; |
| 533 | return 1; |
| 534 | } |
| 535 | have_rev = revfn(name, revision, &best); |
| 536 | up(&ipt_mutex); |
| 537 | |
| 538 | /* Nothing at all? Return 0 to try loading module. */ |
| 539 | if (best == -1) { |
| 540 | *err = -ENOENT; |
| 541 | return 0; |
| 542 | } |
| 543 | |
| 544 | *err = best; |
| 545 | if (!have_rev) |
| 546 | *err = -EPROTONOSUPPORT; |
| 547 | return 1; |
| 548 | } |
| 549 | |
| 550 | |
| 551 | /* All zeroes == unconditional rule. */ |
| 552 | static inline int |
| 553 | unconditional(const struct ipt_ip *ip) |
| 554 | { |
| 555 | unsigned int i; |
| 556 | |
| 557 | for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++) |
| 558 | if (((__u32 *)ip)[i]) |
| 559 | return 0; |
| 560 | |
| 561 | return 1; |
| 562 | } |
| 563 | |
| 564 | /* Figures out from what hook each rule can be called: returns 0 if |
| 565 | there are loops. Puts hook bitmask in comefrom. */ |
| 566 | static int |
| 567 | mark_source_chains(struct ipt_table_info *newinfo, unsigned int valid_hooks) |
| 568 | { |
| 569 | unsigned int hook; |
| 570 | |
| 571 | /* No recursion; use packet counter to save back ptrs (reset |
| 572 | to 0 as we leave), and comefrom to save source hook bitmask */ |
| 573 | for (hook = 0; hook < NF_IP_NUMHOOKS; hook++) { |
| 574 | unsigned int pos = newinfo->hook_entry[hook]; |
| 575 | struct ipt_entry *e |
| 576 | = (struct ipt_entry *)(newinfo->entries + pos); |
| 577 | |
| 578 | if (!(valid_hooks & (1 << hook))) |
| 579 | continue; |
| 580 | |
| 581 | /* Set initial back pointer. */ |
| 582 | e->counters.pcnt = pos; |
| 583 | |
| 584 | for (;;) { |
| 585 | struct ipt_standard_target *t |
| 586 | = (void *)ipt_get_target(e); |
| 587 | |
| 588 | if (e->comefrom & (1 << NF_IP_NUMHOOKS)) { |
| 589 | printk("iptables: loop hook %u pos %u %08X.\n", |
| 590 | hook, pos, e->comefrom); |
| 591 | return 0; |
| 592 | } |
| 593 | e->comefrom |
| 594 | |= ((1 << hook) | (1 << NF_IP_NUMHOOKS)); |
| 595 | |
| 596 | /* Unconditional return/END. */ |
| 597 | if (e->target_offset == sizeof(struct ipt_entry) |
| 598 | && (strcmp(t->target.u.user.name, |
| 599 | IPT_STANDARD_TARGET) == 0) |
| 600 | && t->verdict < 0 |
| 601 | && unconditional(&e->ip)) { |
| 602 | unsigned int oldpos, size; |
| 603 | |
| 604 | /* Return: backtrack through the last |
| 605 | big jump. */ |
| 606 | do { |
| 607 | e->comefrom ^= (1<<NF_IP_NUMHOOKS); |
| 608 | #ifdef DEBUG_IP_FIREWALL_USER |
| 609 | if (e->comefrom |
| 610 | & (1 << NF_IP_NUMHOOKS)) { |
| 611 | duprintf("Back unset " |
| 612 | "on hook %u " |
| 613 | "rule %u\n", |
| 614 | hook, pos); |
| 615 | } |
| 616 | #endif |
| 617 | oldpos = pos; |
| 618 | pos = e->counters.pcnt; |
| 619 | e->counters.pcnt = 0; |
| 620 | |
| 621 | /* We're at the start. */ |
| 622 | if (pos == oldpos) |
| 623 | goto next; |
| 624 | |
| 625 | e = (struct ipt_entry *) |
| 626 | (newinfo->entries + pos); |
| 627 | } while (oldpos == pos + e->next_offset); |
| 628 | |
| 629 | /* Move along one */ |
| 630 | size = e->next_offset; |
| 631 | e = (struct ipt_entry *) |
| 632 | (newinfo->entries + pos + size); |
| 633 | e->counters.pcnt = pos; |
| 634 | pos += size; |
| 635 | } else { |
| 636 | int newpos = t->verdict; |
| 637 | |
| 638 | if (strcmp(t->target.u.user.name, |
| 639 | IPT_STANDARD_TARGET) == 0 |
| 640 | && newpos >= 0) { |
| 641 | /* This a jump; chase it. */ |
| 642 | duprintf("Jump rule %u -> %u\n", |
| 643 | pos, newpos); |
| 644 | } else { |
| 645 | /* ... this is a fallthru */ |
| 646 | newpos = pos + e->next_offset; |
| 647 | } |
| 648 | e = (struct ipt_entry *) |
| 649 | (newinfo->entries + newpos); |
| 650 | e->counters.pcnt = pos; |
| 651 | pos = newpos; |
| 652 | } |
| 653 | } |
| 654 | next: |
| 655 | duprintf("Finished chain %u\n", hook); |
| 656 | } |
| 657 | return 1; |
| 658 | } |
| 659 | |
| 660 | static inline int |
| 661 | cleanup_match(struct ipt_entry_match *m, unsigned int *i) |
| 662 | { |
| 663 | if (i && (*i)-- == 0) |
| 664 | return 1; |
| 665 | |
| 666 | if (m->u.kernel.match->destroy) |
| 667 | m->u.kernel.match->destroy(m->data, |
| 668 | m->u.match_size - sizeof(*m)); |
| 669 | module_put(m->u.kernel.match->me); |
| 670 | return 0; |
| 671 | } |
| 672 | |
| 673 | static inline int |
| 674 | standard_check(const struct ipt_entry_target *t, |
| 675 | unsigned int max_offset) |
| 676 | { |
| 677 | struct ipt_standard_target *targ = (void *)t; |
| 678 | |
| 679 | /* Check standard info. */ |
| 680 | if (t->u.target_size |
| 681 | != IPT_ALIGN(sizeof(struct ipt_standard_target))) { |
| 682 | duprintf("standard_check: target size %u != %u\n", |
| 683 | t->u.target_size, |
| 684 | IPT_ALIGN(sizeof(struct ipt_standard_target))); |
| 685 | return 0; |
| 686 | } |
| 687 | |
| 688 | if (targ->verdict >= 0 |
| 689 | && targ->verdict > max_offset - sizeof(struct ipt_entry)) { |
| 690 | duprintf("ipt_standard_check: bad verdict (%i)\n", |
| 691 | targ->verdict); |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | if (targ->verdict < -NF_MAX_VERDICT - 1) { |
| 696 | duprintf("ipt_standard_check: bad negative verdict (%i)\n", |
| 697 | targ->verdict); |
| 698 | return 0; |
| 699 | } |
| 700 | return 1; |
| 701 | } |
| 702 | |
| 703 | static inline int |
| 704 | check_match(struct ipt_entry_match *m, |
| 705 | const char *name, |
| 706 | const struct ipt_ip *ip, |
| 707 | unsigned int hookmask, |
| 708 | unsigned int *i) |
| 709 | { |
| 710 | struct ipt_match *match; |
| 711 | |
| 712 | match = try_then_request_module(find_match(m->u.user.name, |
| 713 | m->u.user.revision), |
| 714 | "ipt_%s", m->u.user.name); |
| 715 | if (IS_ERR(match) || !match) { |
| 716 | duprintf("check_match: `%s' not found\n", m->u.user.name); |
| 717 | return match ? PTR_ERR(match) : -ENOENT; |
| 718 | } |
| 719 | m->u.kernel.match = match; |
| 720 | |
| 721 | if (m->u.kernel.match->checkentry |
| 722 | && !m->u.kernel.match->checkentry(name, ip, m->data, |
| 723 | m->u.match_size - sizeof(*m), |
| 724 | hookmask)) { |
| 725 | module_put(m->u.kernel.match->me); |
| 726 | duprintf("ip_tables: check failed for `%s'.\n", |
| 727 | m->u.kernel.match->name); |
| 728 | return -EINVAL; |
| 729 | } |
| 730 | |
| 731 | (*i)++; |
| 732 | return 0; |
| 733 | } |
| 734 | |
| 735 | static struct ipt_target ipt_standard_target; |
| 736 | |
| 737 | static inline int |
| 738 | check_entry(struct ipt_entry *e, const char *name, unsigned int size, |
| 739 | unsigned int *i) |
| 740 | { |
| 741 | struct ipt_entry_target *t; |
| 742 | struct ipt_target *target; |
| 743 | int ret; |
| 744 | unsigned int j; |
| 745 | |
| 746 | if (!ip_checkentry(&e->ip)) { |
| 747 | duprintf("ip_tables: ip check failed %p %s.\n", e, name); |
| 748 | return -EINVAL; |
| 749 | } |
| 750 | |
| 751 | j = 0; |
| 752 | ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j); |
| 753 | if (ret != 0) |
| 754 | goto cleanup_matches; |
| 755 | |
| 756 | t = ipt_get_target(e); |
| 757 | target = try_then_request_module(find_target(t->u.user.name, |
| 758 | t->u.user.revision), |
| 759 | "ipt_%s", t->u.user.name); |
| 760 | if (IS_ERR(target) || !target) { |
| 761 | duprintf("check_entry: `%s' not found\n", t->u.user.name); |
| 762 | ret = target ? PTR_ERR(target) : -ENOENT; |
| 763 | goto cleanup_matches; |
| 764 | } |
| 765 | t->u.kernel.target = target; |
| 766 | |
| 767 | if (t->u.kernel.target == &ipt_standard_target) { |
| 768 | if (!standard_check(t, size)) { |
| 769 | ret = -EINVAL; |
| 770 | goto cleanup_matches; |
| 771 | } |
| 772 | } else if (t->u.kernel.target->checkentry |
| 773 | && !t->u.kernel.target->checkentry(name, e, t->data, |
| 774 | t->u.target_size |
| 775 | - sizeof(*t), |
| 776 | e->comefrom)) { |
| 777 | module_put(t->u.kernel.target->me); |
| 778 | duprintf("ip_tables: check failed for `%s'.\n", |
| 779 | t->u.kernel.target->name); |
| 780 | ret = -EINVAL; |
| 781 | goto cleanup_matches; |
| 782 | } |
| 783 | |
| 784 | (*i)++; |
| 785 | return 0; |
| 786 | |
| 787 | cleanup_matches: |
| 788 | IPT_MATCH_ITERATE(e, cleanup_match, &j); |
| 789 | return ret; |
| 790 | } |
| 791 | |
| 792 | static inline int |
| 793 | check_entry_size_and_hooks(struct ipt_entry *e, |
| 794 | struct ipt_table_info *newinfo, |
| 795 | unsigned char *base, |
| 796 | unsigned char *limit, |
| 797 | const unsigned int *hook_entries, |
| 798 | const unsigned int *underflows, |
| 799 | unsigned int *i) |
| 800 | { |
| 801 | unsigned int h; |
| 802 | |
| 803 | if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 |
| 804 | || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) { |
| 805 | duprintf("Bad offset %p\n", e); |
| 806 | return -EINVAL; |
| 807 | } |
| 808 | |
| 809 | if (e->next_offset |
| 810 | < sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) { |
| 811 | duprintf("checking: element %p size %u\n", |
| 812 | e, e->next_offset); |
| 813 | return -EINVAL; |
| 814 | } |
| 815 | |
| 816 | /* Check hooks & underflows */ |
| 817 | for (h = 0; h < NF_IP_NUMHOOKS; h++) { |
| 818 | if ((unsigned char *)e - base == hook_entries[h]) |
| 819 | newinfo->hook_entry[h] = hook_entries[h]; |
| 820 | if ((unsigned char *)e - base == underflows[h]) |
| 821 | newinfo->underflow[h] = underflows[h]; |
| 822 | } |
| 823 | |
| 824 | /* FIXME: underflows must be unconditional, standard verdicts |
| 825 | < 0 (not IPT_RETURN). --RR */ |
| 826 | |
| 827 | /* Clear counters and comefrom */ |
| 828 | e->counters = ((struct ipt_counters) { 0, 0 }); |
| 829 | e->comefrom = 0; |
| 830 | |
| 831 | (*i)++; |
| 832 | return 0; |
| 833 | } |
| 834 | |
| 835 | static inline int |
| 836 | cleanup_entry(struct ipt_entry *e, unsigned int *i) |
| 837 | { |
| 838 | struct ipt_entry_target *t; |
| 839 | |
| 840 | if (i && (*i)-- == 0) |
| 841 | return 1; |
| 842 | |
| 843 | /* Cleanup all matches */ |
| 844 | IPT_MATCH_ITERATE(e, cleanup_match, NULL); |
| 845 | t = ipt_get_target(e); |
| 846 | if (t->u.kernel.target->destroy) |
| 847 | t->u.kernel.target->destroy(t->data, |
| 848 | t->u.target_size - sizeof(*t)); |
| 849 | module_put(t->u.kernel.target->me); |
| 850 | return 0; |
| 851 | } |
| 852 | |
| 853 | /* Checks and translates the user-supplied table segment (held in |
| 854 | newinfo) */ |
| 855 | static int |
| 856 | translate_table(const char *name, |
| 857 | unsigned int valid_hooks, |
| 858 | struct ipt_table_info *newinfo, |
| 859 | unsigned int size, |
| 860 | unsigned int number, |
| 861 | const unsigned int *hook_entries, |
| 862 | const unsigned int *underflows) |
| 863 | { |
| 864 | unsigned int i; |
| 865 | int ret; |
| 866 | |
| 867 | newinfo->size = size; |
| 868 | newinfo->number = number; |
| 869 | |
| 870 | /* Init all hooks to impossible value. */ |
| 871 | for (i = 0; i < NF_IP_NUMHOOKS; i++) { |
| 872 | newinfo->hook_entry[i] = 0xFFFFFFFF; |
| 873 | newinfo->underflow[i] = 0xFFFFFFFF; |
| 874 | } |
| 875 | |
| 876 | duprintf("translate_table: size %u\n", newinfo->size); |
| 877 | i = 0; |
| 878 | /* Walk through entries, checking offsets. */ |
| 879 | ret = IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| 880 | check_entry_size_and_hooks, |
| 881 | newinfo, |
| 882 | newinfo->entries, |
| 883 | newinfo->entries + size, |
| 884 | hook_entries, underflows, &i); |
| 885 | if (ret != 0) |
| 886 | return ret; |
| 887 | |
| 888 | if (i != number) { |
| 889 | duprintf("translate_table: %u not %u entries\n", |
| 890 | i, number); |
| 891 | return -EINVAL; |
| 892 | } |
| 893 | |
| 894 | /* Check hooks all assigned */ |
| 895 | for (i = 0; i < NF_IP_NUMHOOKS; i++) { |
| 896 | /* Only hooks which are valid */ |
| 897 | if (!(valid_hooks & (1 << i))) |
| 898 | continue; |
| 899 | if (newinfo->hook_entry[i] == 0xFFFFFFFF) { |
| 900 | duprintf("Invalid hook entry %u %u\n", |
| 901 | i, hook_entries[i]); |
| 902 | return -EINVAL; |
| 903 | } |
| 904 | if (newinfo->underflow[i] == 0xFFFFFFFF) { |
| 905 | duprintf("Invalid underflow %u %u\n", |
| 906 | i, underflows[i]); |
| 907 | return -EINVAL; |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | if (!mark_source_chains(newinfo, valid_hooks)) |
| 912 | return -ELOOP; |
| 913 | |
| 914 | /* Finally, each sanity check must pass */ |
| 915 | i = 0; |
| 916 | ret = IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| 917 | check_entry, name, size, &i); |
| 918 | |
| 919 | if (ret != 0) { |
| 920 | IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, |
| 921 | cleanup_entry, &i); |
| 922 | return ret; |
| 923 | } |
| 924 | |
| 925 | /* And one copy for every other CPU */ |
| 926 | for (i = 1; i < num_possible_cpus(); i++) { |
| 927 | memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i, |
| 928 | newinfo->entries, |
| 929 | SMP_ALIGN(newinfo->size)); |
| 930 | } |
| 931 | |
| 932 | return ret; |
| 933 | } |
| 934 | |
| 935 | static struct ipt_table_info * |
| 936 | replace_table(struct ipt_table *table, |
| 937 | unsigned int num_counters, |
| 938 | struct ipt_table_info *newinfo, |
| 939 | int *error) |
| 940 | { |
| 941 | struct ipt_table_info *oldinfo; |
| 942 | |
| 943 | #ifdef CONFIG_NETFILTER_DEBUG |
| 944 | { |
| 945 | struct ipt_entry *table_base; |
| 946 | unsigned int i; |
| 947 | |
| 948 | for (i = 0; i < num_possible_cpus(); i++) { |
| 949 | table_base = |
| 950 | (void *)newinfo->entries |
| 951 | + TABLE_OFFSET(newinfo, i); |
| 952 | |
| 953 | table_base->comefrom = 0xdead57ac; |
| 954 | } |
| 955 | } |
| 956 | #endif |
| 957 | |
| 958 | /* Do the substitution. */ |
| 959 | write_lock_bh(&table->lock); |
| 960 | /* Check inside lock: is the old number correct? */ |
| 961 | if (num_counters != table->private->number) { |
| 962 | duprintf("num_counters != table->private->number (%u/%u)\n", |
| 963 | num_counters, table->private->number); |
| 964 | write_unlock_bh(&table->lock); |
| 965 | *error = -EAGAIN; |
| 966 | return NULL; |
| 967 | } |
| 968 | oldinfo = table->private; |
| 969 | table->private = newinfo; |
| 970 | newinfo->initial_entries = oldinfo->initial_entries; |
| 971 | write_unlock_bh(&table->lock); |
| 972 | |
| 973 | return oldinfo; |
| 974 | } |
| 975 | |
| 976 | /* Gets counters. */ |
| 977 | static inline int |
| 978 | add_entry_to_counter(const struct ipt_entry *e, |
| 979 | struct ipt_counters total[], |
| 980 | unsigned int *i) |
| 981 | { |
| 982 | ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); |
| 983 | |
| 984 | (*i)++; |
| 985 | return 0; |
| 986 | } |
| 987 | |
| 988 | static void |
| 989 | get_counters(const struct ipt_table_info *t, |
| 990 | struct ipt_counters counters[]) |
| 991 | { |
| 992 | unsigned int cpu; |
| 993 | unsigned int i; |
| 994 | |
| 995 | for (cpu = 0; cpu < num_possible_cpus(); cpu++) { |
| 996 | i = 0; |
| 997 | IPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu), |
| 998 | t->size, |
| 999 | add_entry_to_counter, |
| 1000 | counters, |
| 1001 | &i); |
| 1002 | } |
| 1003 | } |
| 1004 | |
| 1005 | static int |
| 1006 | copy_entries_to_user(unsigned int total_size, |
| 1007 | struct ipt_table *table, |
| 1008 | void __user *userptr) |
| 1009 | { |
| 1010 | unsigned int off, num, countersize; |
| 1011 | struct ipt_entry *e; |
| 1012 | struct ipt_counters *counters; |
| 1013 | int ret = 0; |
| 1014 | |
| 1015 | /* We need atomic snapshot of counters: rest doesn't change |
| 1016 | (other than comefrom, which userspace doesn't care |
| 1017 | about). */ |
| 1018 | countersize = sizeof(struct ipt_counters) * table->private->number; |
| 1019 | counters = vmalloc(countersize); |
| 1020 | |
| 1021 | if (counters == NULL) |
| 1022 | return -ENOMEM; |
| 1023 | |
| 1024 | /* First, sum counters... */ |
| 1025 | memset(counters, 0, countersize); |
| 1026 | write_lock_bh(&table->lock); |
| 1027 | get_counters(table->private, counters); |
| 1028 | write_unlock_bh(&table->lock); |
| 1029 | |
| 1030 | /* ... then copy entire thing from CPU 0... */ |
| 1031 | if (copy_to_user(userptr, table->private->entries, total_size) != 0) { |
| 1032 | ret = -EFAULT; |
| 1033 | goto free_counters; |
| 1034 | } |
| 1035 | |
| 1036 | /* FIXME: use iterator macros --RR */ |
| 1037 | /* ... then go back and fix counters and names */ |
| 1038 | for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ |
| 1039 | unsigned int i; |
| 1040 | struct ipt_entry_match *m; |
| 1041 | struct ipt_entry_target *t; |
| 1042 | |
| 1043 | e = (struct ipt_entry *)(table->private->entries + off); |
| 1044 | if (copy_to_user(userptr + off |
| 1045 | + offsetof(struct ipt_entry, counters), |
| 1046 | &counters[num], |
| 1047 | sizeof(counters[num])) != 0) { |
| 1048 | ret = -EFAULT; |
| 1049 | goto free_counters; |
| 1050 | } |
| 1051 | |
| 1052 | for (i = sizeof(struct ipt_entry); |
| 1053 | i < e->target_offset; |
| 1054 | i += m->u.match_size) { |
| 1055 | m = (void *)e + i; |
| 1056 | |
| 1057 | if (copy_to_user(userptr + off + i |
| 1058 | + offsetof(struct ipt_entry_match, |
| 1059 | u.user.name), |
| 1060 | m->u.kernel.match->name, |
| 1061 | strlen(m->u.kernel.match->name)+1) |
| 1062 | != 0) { |
| 1063 | ret = -EFAULT; |
| 1064 | goto free_counters; |
| 1065 | } |
| 1066 | } |
| 1067 | |
| 1068 | t = ipt_get_target(e); |
| 1069 | if (copy_to_user(userptr + off + e->target_offset |
| 1070 | + offsetof(struct ipt_entry_target, |
| 1071 | u.user.name), |
| 1072 | t->u.kernel.target->name, |
| 1073 | strlen(t->u.kernel.target->name)+1) != 0) { |
| 1074 | ret = -EFAULT; |
| 1075 | goto free_counters; |
| 1076 | } |
| 1077 | } |
| 1078 | |
| 1079 | free_counters: |
| 1080 | vfree(counters); |
| 1081 | return ret; |
| 1082 | } |
| 1083 | |
| 1084 | static int |
| 1085 | get_entries(const struct ipt_get_entries *entries, |
| 1086 | struct ipt_get_entries __user *uptr) |
| 1087 | { |
| 1088 | int ret; |
| 1089 | struct ipt_table *t; |
| 1090 | |
| 1091 | t = find_table_lock(entries->name); |
| 1092 | if (t && !IS_ERR(t)) { |
| 1093 | duprintf("t->private->number = %u\n", |
| 1094 | t->private->number); |
| 1095 | if (entries->size == t->private->size) |
| 1096 | ret = copy_entries_to_user(t->private->size, |
| 1097 | t, uptr->entrytable); |
| 1098 | else { |
| 1099 | duprintf("get_entries: I've got %u not %u!\n", |
| 1100 | t->private->size, |
| 1101 | entries->size); |
| 1102 | ret = -EINVAL; |
| 1103 | } |
| 1104 | module_put(t->me); |
| 1105 | up(&ipt_mutex); |
| 1106 | } else |
| 1107 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1108 | |
| 1109 | return ret; |
| 1110 | } |
| 1111 | |
| 1112 | static int |
| 1113 | do_replace(void __user *user, unsigned int len) |
| 1114 | { |
| 1115 | int ret; |
| 1116 | struct ipt_replace tmp; |
| 1117 | struct ipt_table *t; |
| 1118 | struct ipt_table_info *newinfo, *oldinfo; |
| 1119 | struct ipt_counters *counters; |
| 1120 | |
| 1121 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 1122 | return -EFAULT; |
| 1123 | |
| 1124 | /* Hack: Causes ipchains to give correct error msg --RR */ |
| 1125 | if (len != sizeof(tmp) + tmp.size) |
| 1126 | return -ENOPROTOOPT; |
| 1127 | |
| 1128 | /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ |
| 1129 | if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages) |
| 1130 | return -ENOMEM; |
| 1131 | |
| 1132 | newinfo = vmalloc(sizeof(struct ipt_table_info) |
| 1133 | + SMP_ALIGN(tmp.size) * num_possible_cpus()); |
| 1134 | if (!newinfo) |
| 1135 | return -ENOMEM; |
| 1136 | |
| 1137 | if (copy_from_user(newinfo->entries, user + sizeof(tmp), |
| 1138 | tmp.size) != 0) { |
| 1139 | ret = -EFAULT; |
| 1140 | goto free_newinfo; |
| 1141 | } |
| 1142 | |
| 1143 | counters = vmalloc(tmp.num_counters * sizeof(struct ipt_counters)); |
| 1144 | if (!counters) { |
| 1145 | ret = -ENOMEM; |
| 1146 | goto free_newinfo; |
| 1147 | } |
| 1148 | memset(counters, 0, tmp.num_counters * sizeof(struct ipt_counters)); |
| 1149 | |
| 1150 | ret = translate_table(tmp.name, tmp.valid_hooks, |
| 1151 | newinfo, tmp.size, tmp.num_entries, |
| 1152 | tmp.hook_entry, tmp.underflow); |
| 1153 | if (ret != 0) |
| 1154 | goto free_newinfo_counters; |
| 1155 | |
| 1156 | duprintf("ip_tables: Translated table\n"); |
| 1157 | |
| 1158 | t = try_then_request_module(find_table_lock(tmp.name), |
| 1159 | "iptable_%s", tmp.name); |
| 1160 | if (!t || IS_ERR(t)) { |
| 1161 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1162 | goto free_newinfo_counters_untrans; |
| 1163 | } |
| 1164 | |
| 1165 | /* You lied! */ |
| 1166 | if (tmp.valid_hooks != t->valid_hooks) { |
| 1167 | duprintf("Valid hook crap: %08X vs %08X\n", |
| 1168 | tmp.valid_hooks, t->valid_hooks); |
| 1169 | ret = -EINVAL; |
| 1170 | goto put_module; |
| 1171 | } |
| 1172 | |
| 1173 | oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret); |
| 1174 | if (!oldinfo) |
| 1175 | goto put_module; |
| 1176 | |
| 1177 | /* Update module usage count based on number of rules */ |
| 1178 | duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n", |
| 1179 | oldinfo->number, oldinfo->initial_entries, newinfo->number); |
| 1180 | if ((oldinfo->number > oldinfo->initial_entries) || |
| 1181 | (newinfo->number <= oldinfo->initial_entries)) |
| 1182 | module_put(t->me); |
| 1183 | if ((oldinfo->number > oldinfo->initial_entries) && |
| 1184 | (newinfo->number <= oldinfo->initial_entries)) |
| 1185 | module_put(t->me); |
| 1186 | |
| 1187 | /* Get the old counters. */ |
| 1188 | get_counters(oldinfo, counters); |
| 1189 | /* Decrease module usage counts and free resource */ |
| 1190 | IPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL); |
| 1191 | vfree(oldinfo); |
| 1192 | if (copy_to_user(tmp.counters, counters, |
| 1193 | sizeof(struct ipt_counters) * tmp.num_counters) != 0) |
| 1194 | ret = -EFAULT; |
| 1195 | vfree(counters); |
| 1196 | up(&ipt_mutex); |
| 1197 | return ret; |
| 1198 | |
| 1199 | put_module: |
| 1200 | module_put(t->me); |
| 1201 | up(&ipt_mutex); |
| 1202 | free_newinfo_counters_untrans: |
| 1203 | IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL); |
| 1204 | free_newinfo_counters: |
| 1205 | vfree(counters); |
| 1206 | free_newinfo: |
| 1207 | vfree(newinfo); |
| 1208 | return ret; |
| 1209 | } |
| 1210 | |
| 1211 | /* We're lazy, and add to the first CPU; overflow works its fey magic |
| 1212 | * and everything is OK. */ |
| 1213 | static inline int |
| 1214 | add_counter_to_entry(struct ipt_entry *e, |
| 1215 | const struct ipt_counters addme[], |
| 1216 | unsigned int *i) |
| 1217 | { |
| 1218 | #if 0 |
| 1219 | duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n", |
| 1220 | *i, |
| 1221 | (long unsigned int)e->counters.pcnt, |
| 1222 | (long unsigned int)e->counters.bcnt, |
| 1223 | (long unsigned int)addme[*i].pcnt, |
| 1224 | (long unsigned int)addme[*i].bcnt); |
| 1225 | #endif |
| 1226 | |
| 1227 | ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); |
| 1228 | |
| 1229 | (*i)++; |
| 1230 | return 0; |
| 1231 | } |
| 1232 | |
| 1233 | static int |
| 1234 | do_add_counters(void __user *user, unsigned int len) |
| 1235 | { |
| 1236 | unsigned int i; |
| 1237 | struct ipt_counters_info tmp, *paddc; |
| 1238 | struct ipt_table *t; |
| 1239 | int ret = 0; |
| 1240 | |
| 1241 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 1242 | return -EFAULT; |
| 1243 | |
| 1244 | if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct ipt_counters)) |
| 1245 | return -EINVAL; |
| 1246 | |
| 1247 | paddc = vmalloc(len); |
| 1248 | if (!paddc) |
| 1249 | return -ENOMEM; |
| 1250 | |
| 1251 | if (copy_from_user(paddc, user, len) != 0) { |
| 1252 | ret = -EFAULT; |
| 1253 | goto free; |
| 1254 | } |
| 1255 | |
| 1256 | t = find_table_lock(tmp.name); |
| 1257 | if (!t || IS_ERR(t)) { |
| 1258 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1259 | goto free; |
| 1260 | } |
| 1261 | |
| 1262 | write_lock_bh(&t->lock); |
| 1263 | if (t->private->number != paddc->num_counters) { |
| 1264 | ret = -EINVAL; |
| 1265 | goto unlock_up_free; |
| 1266 | } |
| 1267 | |
| 1268 | i = 0; |
| 1269 | IPT_ENTRY_ITERATE(t->private->entries, |
| 1270 | t->private->size, |
| 1271 | add_counter_to_entry, |
| 1272 | paddc->counters, |
| 1273 | &i); |
| 1274 | unlock_up_free: |
| 1275 | write_unlock_bh(&t->lock); |
| 1276 | up(&ipt_mutex); |
| 1277 | module_put(t->me); |
| 1278 | free: |
| 1279 | vfree(paddc); |
| 1280 | |
| 1281 | return ret; |
| 1282 | } |
| 1283 | |
| 1284 | static int |
| 1285 | do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) |
| 1286 | { |
| 1287 | int ret; |
| 1288 | |
| 1289 | if (!capable(CAP_NET_ADMIN)) |
| 1290 | return -EPERM; |
| 1291 | |
| 1292 | switch (cmd) { |
| 1293 | case IPT_SO_SET_REPLACE: |
| 1294 | ret = do_replace(user, len); |
| 1295 | break; |
| 1296 | |
| 1297 | case IPT_SO_SET_ADD_COUNTERS: |
| 1298 | ret = do_add_counters(user, len); |
| 1299 | break; |
| 1300 | |
| 1301 | default: |
| 1302 | duprintf("do_ipt_set_ctl: unknown request %i\n", cmd); |
| 1303 | ret = -EINVAL; |
| 1304 | } |
| 1305 | |
| 1306 | return ret; |
| 1307 | } |
| 1308 | |
| 1309 | static int |
| 1310 | do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| 1311 | { |
| 1312 | int ret; |
| 1313 | |
| 1314 | if (!capable(CAP_NET_ADMIN)) |
| 1315 | return -EPERM; |
| 1316 | |
| 1317 | switch (cmd) { |
| 1318 | case IPT_SO_GET_INFO: { |
| 1319 | char name[IPT_TABLE_MAXNAMELEN]; |
| 1320 | struct ipt_table *t; |
| 1321 | |
| 1322 | if (*len != sizeof(struct ipt_getinfo)) { |
| 1323 | duprintf("length %u != %u\n", *len, |
| 1324 | sizeof(struct ipt_getinfo)); |
| 1325 | ret = -EINVAL; |
| 1326 | break; |
| 1327 | } |
| 1328 | |
| 1329 | if (copy_from_user(name, user, sizeof(name)) != 0) { |
| 1330 | ret = -EFAULT; |
| 1331 | break; |
| 1332 | } |
| 1333 | name[IPT_TABLE_MAXNAMELEN-1] = '\0'; |
| 1334 | |
| 1335 | t = try_then_request_module(find_table_lock(name), |
| 1336 | "iptable_%s", name); |
| 1337 | if (t && !IS_ERR(t)) { |
| 1338 | struct ipt_getinfo info; |
| 1339 | |
| 1340 | info.valid_hooks = t->valid_hooks; |
| 1341 | memcpy(info.hook_entry, t->private->hook_entry, |
| 1342 | sizeof(info.hook_entry)); |
| 1343 | memcpy(info.underflow, t->private->underflow, |
| 1344 | sizeof(info.underflow)); |
| 1345 | info.num_entries = t->private->number; |
| 1346 | info.size = t->private->size; |
| 1347 | memcpy(info.name, name, sizeof(info.name)); |
| 1348 | |
| 1349 | if (copy_to_user(user, &info, *len) != 0) |
| 1350 | ret = -EFAULT; |
| 1351 | else |
| 1352 | ret = 0; |
| 1353 | up(&ipt_mutex); |
| 1354 | module_put(t->me); |
| 1355 | } else |
| 1356 | ret = t ? PTR_ERR(t) : -ENOENT; |
| 1357 | } |
| 1358 | break; |
| 1359 | |
| 1360 | case IPT_SO_GET_ENTRIES: { |
| 1361 | struct ipt_get_entries get; |
| 1362 | |
| 1363 | if (*len < sizeof(get)) { |
| 1364 | duprintf("get_entries: %u < %u\n", *len, sizeof(get)); |
| 1365 | ret = -EINVAL; |
| 1366 | } else if (copy_from_user(&get, user, sizeof(get)) != 0) { |
| 1367 | ret = -EFAULT; |
| 1368 | } else if (*len != sizeof(struct ipt_get_entries) + get.size) { |
| 1369 | duprintf("get_entries: %u != %u\n", *len, |
| 1370 | sizeof(struct ipt_get_entries) + get.size); |
| 1371 | ret = -EINVAL; |
| 1372 | } else |
| 1373 | ret = get_entries(&get, user); |
| 1374 | break; |
| 1375 | } |
| 1376 | |
| 1377 | case IPT_SO_GET_REVISION_MATCH: |
| 1378 | case IPT_SO_GET_REVISION_TARGET: { |
| 1379 | struct ipt_get_revision rev; |
| 1380 | int (*revfn)(const char *, u8, int *); |
| 1381 | |
| 1382 | if (*len != sizeof(rev)) { |
| 1383 | ret = -EINVAL; |
| 1384 | break; |
| 1385 | } |
| 1386 | if (copy_from_user(&rev, user, sizeof(rev)) != 0) { |
| 1387 | ret = -EFAULT; |
| 1388 | break; |
| 1389 | } |
| 1390 | |
| 1391 | if (cmd == IPT_SO_GET_REVISION_TARGET) |
| 1392 | revfn = target_revfn; |
| 1393 | else |
| 1394 | revfn = match_revfn; |
| 1395 | |
| 1396 | try_then_request_module(find_revision(rev.name, rev.revision, |
| 1397 | revfn, &ret), |
| 1398 | "ipt_%s", rev.name); |
| 1399 | break; |
| 1400 | } |
| 1401 | |
| 1402 | default: |
| 1403 | duprintf("do_ipt_get_ctl: unknown request %i\n", cmd); |
| 1404 | ret = -EINVAL; |
| 1405 | } |
| 1406 | |
| 1407 | return ret; |
| 1408 | } |
| 1409 | |
| 1410 | /* Registration hooks for targets. */ |
| 1411 | int |
| 1412 | ipt_register_target(struct ipt_target *target) |
| 1413 | { |
| 1414 | int ret; |
| 1415 | |
| 1416 | ret = down_interruptible(&ipt_mutex); |
| 1417 | if (ret != 0) |
| 1418 | return ret; |
| 1419 | list_add(&target->list, &ipt_target); |
| 1420 | up(&ipt_mutex); |
| 1421 | return ret; |
| 1422 | } |
| 1423 | |
| 1424 | void |
| 1425 | ipt_unregister_target(struct ipt_target *target) |
| 1426 | { |
| 1427 | down(&ipt_mutex); |
| 1428 | LIST_DELETE(&ipt_target, target); |
| 1429 | up(&ipt_mutex); |
| 1430 | } |
| 1431 | |
| 1432 | int |
| 1433 | ipt_register_match(struct ipt_match *match) |
| 1434 | { |
| 1435 | int ret; |
| 1436 | |
| 1437 | ret = down_interruptible(&ipt_mutex); |
| 1438 | if (ret != 0) |
| 1439 | return ret; |
| 1440 | |
| 1441 | list_add(&match->list, &ipt_match); |
| 1442 | up(&ipt_mutex); |
| 1443 | |
| 1444 | return ret; |
| 1445 | } |
| 1446 | |
| 1447 | void |
| 1448 | ipt_unregister_match(struct ipt_match *match) |
| 1449 | { |
| 1450 | down(&ipt_mutex); |
| 1451 | LIST_DELETE(&ipt_match, match); |
| 1452 | up(&ipt_mutex); |
| 1453 | } |
| 1454 | |
| 1455 | int ipt_register_table(struct ipt_table *table, const struct ipt_replace *repl) |
| 1456 | { |
| 1457 | int ret; |
| 1458 | struct ipt_table_info *newinfo; |
| 1459 | static struct ipt_table_info bootstrap |
| 1460 | = { 0, 0, 0, { 0 }, { 0 }, { } }; |
| 1461 | |
| 1462 | newinfo = vmalloc(sizeof(struct ipt_table_info) |
| 1463 | + SMP_ALIGN(repl->size) * num_possible_cpus()); |
| 1464 | if (!newinfo) |
| 1465 | return -ENOMEM; |
| 1466 | |
| 1467 | memcpy(newinfo->entries, repl->entries, repl->size); |
| 1468 | |
| 1469 | ret = translate_table(table->name, table->valid_hooks, |
| 1470 | newinfo, repl->size, |
| 1471 | repl->num_entries, |
| 1472 | repl->hook_entry, |
| 1473 | repl->underflow); |
| 1474 | if (ret != 0) { |
| 1475 | vfree(newinfo); |
| 1476 | return ret; |
| 1477 | } |
| 1478 | |
| 1479 | ret = down_interruptible(&ipt_mutex); |
| 1480 | if (ret != 0) { |
| 1481 | vfree(newinfo); |
| 1482 | return ret; |
| 1483 | } |
| 1484 | |
| 1485 | /* Don't autoload: we'd eat our tail... */ |
| 1486 | if (list_named_find(&ipt_tables, table->name)) { |
| 1487 | ret = -EEXIST; |
| 1488 | goto free_unlock; |
| 1489 | } |
| 1490 | |
| 1491 | /* Simplifies replace_table code. */ |
| 1492 | table->private = &bootstrap; |
| 1493 | if (!replace_table(table, 0, newinfo, &ret)) |
| 1494 | goto free_unlock; |
| 1495 | |
| 1496 | duprintf("table->private->number = %u\n", |
| 1497 | table->private->number); |
| 1498 | |
| 1499 | /* save number of initial entries */ |
| 1500 | table->private->initial_entries = table->private->number; |
| 1501 | |
| 1502 | rwlock_init(&table->lock); |
| 1503 | list_prepend(&ipt_tables, table); |
| 1504 | |
| 1505 | unlock: |
| 1506 | up(&ipt_mutex); |
| 1507 | return ret; |
| 1508 | |
| 1509 | free_unlock: |
| 1510 | vfree(newinfo); |
| 1511 | goto unlock; |
| 1512 | } |
| 1513 | |
| 1514 | void ipt_unregister_table(struct ipt_table *table) |
| 1515 | { |
| 1516 | down(&ipt_mutex); |
| 1517 | LIST_DELETE(&ipt_tables, table); |
| 1518 | up(&ipt_mutex); |
| 1519 | |
| 1520 | /* Decrease module usage counts and free resources */ |
| 1521 | IPT_ENTRY_ITERATE(table->private->entries, table->private->size, |
| 1522 | cleanup_entry, NULL); |
| 1523 | vfree(table->private); |
| 1524 | } |
| 1525 | |
| 1526 | /* Returns 1 if the port is matched by the range, 0 otherwise */ |
| 1527 | static inline int |
| 1528 | port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert) |
| 1529 | { |
| 1530 | int ret; |
| 1531 | |
| 1532 | ret = (port >= min && port <= max) ^ invert; |
| 1533 | return ret; |
| 1534 | } |
| 1535 | |
| 1536 | static int |
| 1537 | tcp_find_option(u_int8_t option, |
| 1538 | const struct sk_buff *skb, |
| 1539 | unsigned int optlen, |
| 1540 | int invert, |
| 1541 | int *hotdrop) |
| 1542 | { |
| 1543 | /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */ |
| 1544 | u_int8_t _opt[60 - sizeof(struct tcphdr)], *op; |
| 1545 | unsigned int i; |
| 1546 | |
| 1547 | duprintf("tcp_match: finding option\n"); |
| 1548 | |
| 1549 | if (!optlen) |
| 1550 | return invert; |
| 1551 | |
| 1552 | /* If we don't have the whole header, drop packet. */ |
| 1553 | op = skb_header_pointer(skb, |
| 1554 | skb->nh.iph->ihl*4 + sizeof(struct tcphdr), |
| 1555 | optlen, _opt); |
| 1556 | if (op == NULL) { |
| 1557 | *hotdrop = 1; |
| 1558 | return 0; |
| 1559 | } |
| 1560 | |
| 1561 | for (i = 0; i < optlen; ) { |
| 1562 | if (op[i] == option) return !invert; |
| 1563 | if (op[i] < 2) i++; |
| 1564 | else i += op[i+1]?:1; |
| 1565 | } |
| 1566 | |
| 1567 | return invert; |
| 1568 | } |
| 1569 | |
| 1570 | static int |
| 1571 | tcp_match(const struct sk_buff *skb, |
| 1572 | const struct net_device *in, |
| 1573 | const struct net_device *out, |
| 1574 | const void *matchinfo, |
| 1575 | int offset, |
| 1576 | int *hotdrop) |
| 1577 | { |
| 1578 | struct tcphdr _tcph, *th; |
| 1579 | const struct ipt_tcp *tcpinfo = matchinfo; |
| 1580 | |
| 1581 | if (offset) { |
| 1582 | /* To quote Alan: |
| 1583 | |
| 1584 | Don't allow a fragment of TCP 8 bytes in. Nobody normal |
| 1585 | causes this. Its a cracker trying to break in by doing a |
| 1586 | flag overwrite to pass the direction checks. |
| 1587 | */ |
| 1588 | if (offset == 1) { |
| 1589 | duprintf("Dropping evil TCP offset=1 frag.\n"); |
| 1590 | *hotdrop = 1; |
| 1591 | } |
| 1592 | /* Must not be a fragment. */ |
| 1593 | return 0; |
| 1594 | } |
| 1595 | |
| 1596 | #define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg)) |
| 1597 | |
| 1598 | th = skb_header_pointer(skb, skb->nh.iph->ihl*4, |
| 1599 | sizeof(_tcph), &_tcph); |
| 1600 | if (th == NULL) { |
| 1601 | /* We've been asked to examine this packet, and we |
| 1602 | can't. Hence, no choice but to drop. */ |
| 1603 | duprintf("Dropping evil TCP offset=0 tinygram.\n"); |
| 1604 | *hotdrop = 1; |
| 1605 | return 0; |
| 1606 | } |
| 1607 | |
| 1608 | if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1], |
| 1609 | ntohs(th->source), |
| 1610 | !!(tcpinfo->invflags & IPT_TCP_INV_SRCPT))) |
| 1611 | return 0; |
| 1612 | if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1], |
| 1613 | ntohs(th->dest), |
| 1614 | !!(tcpinfo->invflags & IPT_TCP_INV_DSTPT))) |
| 1615 | return 0; |
| 1616 | if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask) |
| 1617 | == tcpinfo->flg_cmp, |
| 1618 | IPT_TCP_INV_FLAGS)) |
| 1619 | return 0; |
| 1620 | if (tcpinfo->option) { |
| 1621 | if (th->doff * 4 < sizeof(_tcph)) { |
| 1622 | *hotdrop = 1; |
| 1623 | return 0; |
| 1624 | } |
| 1625 | if (!tcp_find_option(tcpinfo->option, skb, |
| 1626 | th->doff*4 - sizeof(_tcph), |
| 1627 | tcpinfo->invflags & IPT_TCP_INV_OPTION, |
| 1628 | hotdrop)) |
| 1629 | return 0; |
| 1630 | } |
| 1631 | return 1; |
| 1632 | } |
| 1633 | |
| 1634 | /* Called when user tries to insert an entry of this type. */ |
| 1635 | static int |
| 1636 | tcp_checkentry(const char *tablename, |
| 1637 | const struct ipt_ip *ip, |
| 1638 | void *matchinfo, |
| 1639 | unsigned int matchsize, |
| 1640 | unsigned int hook_mask) |
| 1641 | { |
| 1642 | const struct ipt_tcp *tcpinfo = matchinfo; |
| 1643 | |
| 1644 | /* Must specify proto == TCP, and no unknown invflags */ |
| 1645 | return ip->proto == IPPROTO_TCP |
| 1646 | && !(ip->invflags & IPT_INV_PROTO) |
| 1647 | && matchsize == IPT_ALIGN(sizeof(struct ipt_tcp)) |
| 1648 | && !(tcpinfo->invflags & ~IPT_TCP_INV_MASK); |
| 1649 | } |
| 1650 | |
| 1651 | static int |
| 1652 | udp_match(const struct sk_buff *skb, |
| 1653 | const struct net_device *in, |
| 1654 | const struct net_device *out, |
| 1655 | const void *matchinfo, |
| 1656 | int offset, |
| 1657 | int *hotdrop) |
| 1658 | { |
| 1659 | struct udphdr _udph, *uh; |
| 1660 | const struct ipt_udp *udpinfo = matchinfo; |
| 1661 | |
| 1662 | /* Must not be a fragment. */ |
| 1663 | if (offset) |
| 1664 | return 0; |
| 1665 | |
| 1666 | uh = skb_header_pointer(skb, skb->nh.iph->ihl*4, |
| 1667 | sizeof(_udph), &_udph); |
| 1668 | if (uh == NULL) { |
| 1669 | /* We've been asked to examine this packet, and we |
| 1670 | can't. Hence, no choice but to drop. */ |
| 1671 | duprintf("Dropping evil UDP tinygram.\n"); |
| 1672 | *hotdrop = 1; |
| 1673 | return 0; |
| 1674 | } |
| 1675 | |
| 1676 | return port_match(udpinfo->spts[0], udpinfo->spts[1], |
| 1677 | ntohs(uh->source), |
| 1678 | !!(udpinfo->invflags & IPT_UDP_INV_SRCPT)) |
| 1679 | && port_match(udpinfo->dpts[0], udpinfo->dpts[1], |
| 1680 | ntohs(uh->dest), |
| 1681 | !!(udpinfo->invflags & IPT_UDP_INV_DSTPT)); |
| 1682 | } |
| 1683 | |
| 1684 | /* Called when user tries to insert an entry of this type. */ |
| 1685 | static int |
| 1686 | udp_checkentry(const char *tablename, |
| 1687 | const struct ipt_ip *ip, |
| 1688 | void *matchinfo, |
| 1689 | unsigned int matchinfosize, |
| 1690 | unsigned int hook_mask) |
| 1691 | { |
| 1692 | const struct ipt_udp *udpinfo = matchinfo; |
| 1693 | |
| 1694 | /* Must specify proto == UDP, and no unknown invflags */ |
| 1695 | if (ip->proto != IPPROTO_UDP || (ip->invflags & IPT_INV_PROTO)) { |
| 1696 | duprintf("ipt_udp: Protocol %u != %u\n", ip->proto, |
| 1697 | IPPROTO_UDP); |
| 1698 | return 0; |
| 1699 | } |
| 1700 | if (matchinfosize != IPT_ALIGN(sizeof(struct ipt_udp))) { |
| 1701 | duprintf("ipt_udp: matchsize %u != %u\n", |
| 1702 | matchinfosize, IPT_ALIGN(sizeof(struct ipt_udp))); |
| 1703 | return 0; |
| 1704 | } |
| 1705 | if (udpinfo->invflags & ~IPT_UDP_INV_MASK) { |
| 1706 | duprintf("ipt_udp: unknown flags %X\n", |
| 1707 | udpinfo->invflags); |
| 1708 | return 0; |
| 1709 | } |
| 1710 | |
| 1711 | return 1; |
| 1712 | } |
| 1713 | |
| 1714 | /* Returns 1 if the type and code is matched by the range, 0 otherwise */ |
| 1715 | static inline int |
| 1716 | icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, |
| 1717 | u_int8_t type, u_int8_t code, |
| 1718 | int invert) |
| 1719 | { |
| 1720 | return ((test_type == 0xFF) || (type == test_type && code >= min_code && code <= max_code)) |
| 1721 | ^ invert; |
| 1722 | } |
| 1723 | |
| 1724 | static int |
| 1725 | icmp_match(const struct sk_buff *skb, |
| 1726 | const struct net_device *in, |
| 1727 | const struct net_device *out, |
| 1728 | const void *matchinfo, |
| 1729 | int offset, |
| 1730 | int *hotdrop) |
| 1731 | { |
| 1732 | struct icmphdr _icmph, *ic; |
| 1733 | const struct ipt_icmp *icmpinfo = matchinfo; |
| 1734 | |
| 1735 | /* Must not be a fragment. */ |
| 1736 | if (offset) |
| 1737 | return 0; |
| 1738 | |
| 1739 | ic = skb_header_pointer(skb, skb->nh.iph->ihl*4, |
| 1740 | sizeof(_icmph), &_icmph); |
| 1741 | if (ic == NULL) { |
| 1742 | /* We've been asked to examine this packet, and we |
| 1743 | * can't. Hence, no choice but to drop. |
| 1744 | */ |
| 1745 | duprintf("Dropping evil ICMP tinygram.\n"); |
| 1746 | *hotdrop = 1; |
| 1747 | return 0; |
| 1748 | } |
| 1749 | |
| 1750 | return icmp_type_code_match(icmpinfo->type, |
| 1751 | icmpinfo->code[0], |
| 1752 | icmpinfo->code[1], |
| 1753 | ic->type, ic->code, |
| 1754 | !!(icmpinfo->invflags&IPT_ICMP_INV)); |
| 1755 | } |
| 1756 | |
| 1757 | /* Called when user tries to insert an entry of this type. */ |
| 1758 | static int |
| 1759 | icmp_checkentry(const char *tablename, |
| 1760 | const struct ipt_ip *ip, |
| 1761 | void *matchinfo, |
| 1762 | unsigned int matchsize, |
| 1763 | unsigned int hook_mask) |
| 1764 | { |
| 1765 | const struct ipt_icmp *icmpinfo = matchinfo; |
| 1766 | |
| 1767 | /* Must specify proto == ICMP, and no unknown invflags */ |
| 1768 | return ip->proto == IPPROTO_ICMP |
| 1769 | && !(ip->invflags & IPT_INV_PROTO) |
| 1770 | && matchsize == IPT_ALIGN(sizeof(struct ipt_icmp)) |
| 1771 | && !(icmpinfo->invflags & ~IPT_ICMP_INV); |
| 1772 | } |
| 1773 | |
| 1774 | /* The built-in targets: standard (NULL) and error. */ |
| 1775 | static struct ipt_target ipt_standard_target = { |
| 1776 | .name = IPT_STANDARD_TARGET, |
| 1777 | }; |
| 1778 | |
| 1779 | static struct ipt_target ipt_error_target = { |
| 1780 | .name = IPT_ERROR_TARGET, |
| 1781 | .target = ipt_error, |
| 1782 | }; |
| 1783 | |
| 1784 | static struct nf_sockopt_ops ipt_sockopts = { |
| 1785 | .pf = PF_INET, |
| 1786 | .set_optmin = IPT_BASE_CTL, |
| 1787 | .set_optmax = IPT_SO_SET_MAX+1, |
| 1788 | .set = do_ipt_set_ctl, |
| 1789 | .get_optmin = IPT_BASE_CTL, |
| 1790 | .get_optmax = IPT_SO_GET_MAX+1, |
| 1791 | .get = do_ipt_get_ctl, |
| 1792 | }; |
| 1793 | |
| 1794 | static struct ipt_match tcp_matchstruct = { |
| 1795 | .name = "tcp", |
| 1796 | .match = &tcp_match, |
| 1797 | .checkentry = &tcp_checkentry, |
| 1798 | }; |
| 1799 | |
| 1800 | static struct ipt_match udp_matchstruct = { |
| 1801 | .name = "udp", |
| 1802 | .match = &udp_match, |
| 1803 | .checkentry = &udp_checkentry, |
| 1804 | }; |
| 1805 | |
| 1806 | static struct ipt_match icmp_matchstruct = { |
| 1807 | .name = "icmp", |
| 1808 | .match = &icmp_match, |
| 1809 | .checkentry = &icmp_checkentry, |
| 1810 | }; |
| 1811 | |
| 1812 | #ifdef CONFIG_PROC_FS |
| 1813 | static inline int print_name(const char *i, |
| 1814 | off_t start_offset, char *buffer, int length, |
| 1815 | off_t *pos, unsigned int *count) |
| 1816 | { |
| 1817 | if ((*count)++ >= start_offset) { |
| 1818 | unsigned int namelen; |
| 1819 | |
| 1820 | namelen = sprintf(buffer + *pos, "%s\n", |
| 1821 | i + sizeof(struct list_head)); |
| 1822 | if (*pos + namelen > length) { |
| 1823 | /* Stop iterating */ |
| 1824 | return 1; |
| 1825 | } |
| 1826 | *pos += namelen; |
| 1827 | } |
| 1828 | return 0; |
| 1829 | } |
| 1830 | |
| 1831 | static inline int print_target(const struct ipt_target *t, |
| 1832 | off_t start_offset, char *buffer, int length, |
| 1833 | off_t *pos, unsigned int *count) |
| 1834 | { |
| 1835 | if (t == &ipt_standard_target || t == &ipt_error_target) |
| 1836 | return 0; |
| 1837 | return print_name((char *)t, start_offset, buffer, length, pos, count); |
| 1838 | } |
| 1839 | |
| 1840 | static int ipt_get_tables(char *buffer, char **start, off_t offset, int length) |
| 1841 | { |
| 1842 | off_t pos = 0; |
| 1843 | unsigned int count = 0; |
| 1844 | |
| 1845 | if (down_interruptible(&ipt_mutex) != 0) |
| 1846 | return 0; |
| 1847 | |
| 1848 | LIST_FIND(&ipt_tables, print_name, void *, |
| 1849 | offset, buffer, length, &pos, &count); |
| 1850 | |
| 1851 | up(&ipt_mutex); |
| 1852 | |
| 1853 | /* `start' hack - see fs/proc/generic.c line ~105 */ |
| 1854 | *start=(char *)((unsigned long)count-offset); |
| 1855 | return pos; |
| 1856 | } |
| 1857 | |
| 1858 | static int ipt_get_targets(char *buffer, char **start, off_t offset, int length) |
| 1859 | { |
| 1860 | off_t pos = 0; |
| 1861 | unsigned int count = 0; |
| 1862 | |
| 1863 | if (down_interruptible(&ipt_mutex) != 0) |
| 1864 | return 0; |
| 1865 | |
| 1866 | LIST_FIND(&ipt_target, print_target, struct ipt_target *, |
| 1867 | offset, buffer, length, &pos, &count); |
| 1868 | |
| 1869 | up(&ipt_mutex); |
| 1870 | |
| 1871 | *start = (char *)((unsigned long)count - offset); |
| 1872 | return pos; |
| 1873 | } |
| 1874 | |
| 1875 | static int ipt_get_matches(char *buffer, char **start, off_t offset, int length) |
| 1876 | { |
| 1877 | off_t pos = 0; |
| 1878 | unsigned int count = 0; |
| 1879 | |
| 1880 | if (down_interruptible(&ipt_mutex) != 0) |
| 1881 | return 0; |
| 1882 | |
| 1883 | LIST_FIND(&ipt_match, print_name, void *, |
| 1884 | offset, buffer, length, &pos, &count); |
| 1885 | |
| 1886 | up(&ipt_mutex); |
| 1887 | |
| 1888 | *start = (char *)((unsigned long)count - offset); |
| 1889 | return pos; |
| 1890 | } |
| 1891 | |
| 1892 | static struct { char *name; get_info_t *get_info; } ipt_proc_entry[] = |
| 1893 | { { "ip_tables_names", ipt_get_tables }, |
| 1894 | { "ip_tables_targets", ipt_get_targets }, |
| 1895 | { "ip_tables_matches", ipt_get_matches }, |
| 1896 | { NULL, NULL} }; |
| 1897 | #endif /*CONFIG_PROC_FS*/ |
| 1898 | |
| 1899 | static int __init init(void) |
| 1900 | { |
| 1901 | int ret; |
| 1902 | |
| 1903 | /* Noone else will be downing sem now, so we won't sleep */ |
| 1904 | down(&ipt_mutex); |
| 1905 | list_append(&ipt_target, &ipt_standard_target); |
| 1906 | list_append(&ipt_target, &ipt_error_target); |
| 1907 | list_append(&ipt_match, &tcp_matchstruct); |
| 1908 | list_append(&ipt_match, &udp_matchstruct); |
| 1909 | list_append(&ipt_match, &icmp_matchstruct); |
| 1910 | up(&ipt_mutex); |
| 1911 | |
| 1912 | /* Register setsockopt */ |
| 1913 | ret = nf_register_sockopt(&ipt_sockopts); |
| 1914 | if (ret < 0) { |
| 1915 | duprintf("Unable to register sockopts.\n"); |
| 1916 | return ret; |
| 1917 | } |
| 1918 | |
| 1919 | #ifdef CONFIG_PROC_FS |
| 1920 | { |
| 1921 | struct proc_dir_entry *proc; |
| 1922 | int i; |
| 1923 | |
| 1924 | for (i = 0; ipt_proc_entry[i].name; i++) { |
| 1925 | proc = proc_net_create(ipt_proc_entry[i].name, 0, |
| 1926 | ipt_proc_entry[i].get_info); |
| 1927 | if (!proc) { |
| 1928 | while (--i >= 0) |
| 1929 | proc_net_remove(ipt_proc_entry[i].name); |
| 1930 | nf_unregister_sockopt(&ipt_sockopts); |
| 1931 | return -ENOMEM; |
| 1932 | } |
| 1933 | proc->owner = THIS_MODULE; |
| 1934 | } |
| 1935 | } |
| 1936 | #endif |
| 1937 | |
| 1938 | printk("ip_tables: (C) 2000-2002 Netfilter core team\n"); |
| 1939 | return 0; |
| 1940 | } |
| 1941 | |
| 1942 | static void __exit fini(void) |
| 1943 | { |
| 1944 | nf_unregister_sockopt(&ipt_sockopts); |
| 1945 | #ifdef CONFIG_PROC_FS |
| 1946 | { |
| 1947 | int i; |
| 1948 | for (i = 0; ipt_proc_entry[i].name; i++) |
| 1949 | proc_net_remove(ipt_proc_entry[i].name); |
| 1950 | } |
| 1951 | #endif |
| 1952 | } |
| 1953 | |
| 1954 | EXPORT_SYMBOL(ipt_register_table); |
| 1955 | EXPORT_SYMBOL(ipt_unregister_table); |
| 1956 | EXPORT_SYMBOL(ipt_register_match); |
| 1957 | EXPORT_SYMBOL(ipt_unregister_match); |
| 1958 | EXPORT_SYMBOL(ipt_do_table); |
| 1959 | EXPORT_SYMBOL(ipt_register_target); |
| 1960 | EXPORT_SYMBOL(ipt_unregister_target); |
| 1961 | EXPORT_SYMBOL(ipt_find_target); |
| 1962 | |
| 1963 | module_init(init); |
| 1964 | module_exit(fini); |