| 1 | /* |
| 2 | * Packet matching code. |
| 3 | * |
| 4 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| 5 | * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> |
| 6 | * Copyright (C) 2006-2010 Patrick McHardy <kaber@trash.net> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 13 | #include <linux/cache.h> |
| 14 | #include <linux/capability.h> |
| 15 | #include <linux/skbuff.h> |
| 16 | #include <linux/kmod.h> |
| 17 | #include <linux/vmalloc.h> |
| 18 | #include <linux/netdevice.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/icmp.h> |
| 21 | #include <net/ip.h> |
| 22 | #include <net/compat.h> |
| 23 | #include <linux/uaccess.h> |
| 24 | #include <linux/mutex.h> |
| 25 | #include <linux/proc_fs.h> |
| 26 | #include <linux/err.h> |
| 27 | #include <linux/cpumask.h> |
| 28 | |
| 29 | #include <linux/netfilter/x_tables.h> |
| 30 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 31 | #include <net/netfilter/nf_log.h> |
| 32 | #include "../../netfilter/xt_repldata.h" |
| 33 | |
| 34 | MODULE_LICENSE("GPL"); |
| 35 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 36 | MODULE_DESCRIPTION("IPv4 packet filter"); |
| 37 | |
| 38 | void *ipt_alloc_initial_table(const struct xt_table *info) |
| 39 | { |
| 40 | return xt_alloc_initial_table(ipt, IPT); |
| 41 | } |
| 42 | EXPORT_SYMBOL_GPL(ipt_alloc_initial_table); |
| 43 | |
| 44 | /* Returns whether matches rule or not. */ |
| 45 | /* Performance critical - called for every packet */ |
| 46 | static inline bool |
| 47 | ip_packet_match(const struct iphdr *ip, |
| 48 | const char *indev, |
| 49 | const char *outdev, |
| 50 | const struct ipt_ip *ipinfo, |
| 51 | int isfrag) |
| 52 | { |
| 53 | unsigned long ret; |
| 54 | |
| 55 | if (NF_INVF(ipinfo, IPT_INV_SRCIP, |
| 56 | (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) || |
| 57 | NF_INVF(ipinfo, IPT_INV_DSTIP, |
| 58 | (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr)) |
| 59 | return false; |
| 60 | |
| 61 | ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask); |
| 62 | |
| 63 | if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0)) |
| 64 | return false; |
| 65 | |
| 66 | ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask); |
| 67 | |
| 68 | if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0)) |
| 69 | return false; |
| 70 | |
| 71 | /* Check specific protocol */ |
| 72 | if (ipinfo->proto && |
| 73 | NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto)) |
| 74 | return false; |
| 75 | |
| 76 | /* If we have a fragment rule but the packet is not a fragment |
| 77 | * then we return zero */ |
| 78 | if (NF_INVF(ipinfo, IPT_INV_FRAG, |
| 79 | (ipinfo->flags & IPT_F_FRAG) && !isfrag)) |
| 80 | return false; |
| 81 | |
| 82 | return true; |
| 83 | } |
| 84 | |
| 85 | static bool |
| 86 | ip_checkentry(const struct ipt_ip *ip) |
| 87 | { |
| 88 | if (ip->flags & ~IPT_F_MASK) |
| 89 | return false; |
| 90 | if (ip->invflags & ~IPT_INV_MASK) |
| 91 | return false; |
| 92 | return true; |
| 93 | } |
| 94 | |
| 95 | static unsigned int |
| 96 | ipt_error(struct sk_buff *skb, const struct xt_action_param *par) |
| 97 | { |
| 98 | net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); |
| 99 | |
| 100 | return NF_DROP; |
| 101 | } |
| 102 | |
| 103 | /* Performance critical */ |
| 104 | static inline struct ipt_entry * |
| 105 | get_entry(const void *base, unsigned int offset) |
| 106 | { |
| 107 | return (struct ipt_entry *)(base + offset); |
| 108 | } |
| 109 | |
| 110 | /* All zeroes == unconditional rule. */ |
| 111 | /* Mildly perf critical (only if packet tracing is on) */ |
| 112 | static inline bool unconditional(const struct ipt_entry *e) |
| 113 | { |
| 114 | static const struct ipt_ip uncond; |
| 115 | |
| 116 | return e->target_offset == sizeof(struct ipt_entry) && |
| 117 | memcmp(&e->ip, &uncond, sizeof(uncond)) == 0; |
| 118 | } |
| 119 | |
| 120 | /* for const-correctness */ |
| 121 | static inline const struct xt_entry_target * |
| 122 | ipt_get_target_c(const struct ipt_entry *e) |
| 123 | { |
| 124 | return ipt_get_target((struct ipt_entry *)e); |
| 125 | } |
| 126 | |
| 127 | #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) |
| 128 | static const char *const hooknames[] = { |
| 129 | [NF_INET_PRE_ROUTING] = "PREROUTING", |
| 130 | [NF_INET_LOCAL_IN] = "INPUT", |
| 131 | [NF_INET_FORWARD] = "FORWARD", |
| 132 | [NF_INET_LOCAL_OUT] = "OUTPUT", |
| 133 | [NF_INET_POST_ROUTING] = "POSTROUTING", |
| 134 | }; |
| 135 | |
| 136 | enum nf_ip_trace_comments { |
| 137 | NF_IP_TRACE_COMMENT_RULE, |
| 138 | NF_IP_TRACE_COMMENT_RETURN, |
| 139 | NF_IP_TRACE_COMMENT_POLICY, |
| 140 | }; |
| 141 | |
| 142 | static const char *const comments[] = { |
| 143 | [NF_IP_TRACE_COMMENT_RULE] = "rule", |
| 144 | [NF_IP_TRACE_COMMENT_RETURN] = "return", |
| 145 | [NF_IP_TRACE_COMMENT_POLICY] = "policy", |
| 146 | }; |
| 147 | |
| 148 | static const struct nf_loginfo trace_loginfo = { |
| 149 | .type = NF_LOG_TYPE_LOG, |
| 150 | .u = { |
| 151 | .log = { |
| 152 | .level = 4, |
| 153 | .logflags = NF_LOG_DEFAULT_MASK, |
| 154 | }, |
| 155 | }, |
| 156 | }; |
| 157 | |
| 158 | /* Mildly perf critical (only if packet tracing is on) */ |
| 159 | static inline int |
| 160 | get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e, |
| 161 | const char *hookname, const char **chainname, |
| 162 | const char **comment, unsigned int *rulenum) |
| 163 | { |
| 164 | const struct xt_standard_target *t = (void *)ipt_get_target_c(s); |
| 165 | |
| 166 | if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { |
| 167 | /* Head of user chain: ERROR target with chainname */ |
| 168 | *chainname = t->target.data; |
| 169 | (*rulenum) = 0; |
| 170 | } else if (s == e) { |
| 171 | (*rulenum)++; |
| 172 | |
| 173 | if (unconditional(s) && |
| 174 | strcmp(t->target.u.kernel.target->name, |
| 175 | XT_STANDARD_TARGET) == 0 && |
| 176 | t->verdict < 0) { |
| 177 | /* Tail of chains: STANDARD target (return/policy) */ |
| 178 | *comment = *chainname == hookname |
| 179 | ? comments[NF_IP_TRACE_COMMENT_POLICY] |
| 180 | : comments[NF_IP_TRACE_COMMENT_RETURN]; |
| 181 | } |
| 182 | return 1; |
| 183 | } else |
| 184 | (*rulenum)++; |
| 185 | |
| 186 | return 0; |
| 187 | } |
| 188 | |
| 189 | static void trace_packet(struct net *net, |
| 190 | const struct sk_buff *skb, |
| 191 | unsigned int hook, |
| 192 | const struct net_device *in, |
| 193 | const struct net_device *out, |
| 194 | const char *tablename, |
| 195 | const struct xt_table_info *private, |
| 196 | const struct ipt_entry *e) |
| 197 | { |
| 198 | const struct ipt_entry *root; |
| 199 | const char *hookname, *chainname, *comment; |
| 200 | const struct ipt_entry *iter; |
| 201 | unsigned int rulenum = 0; |
| 202 | |
| 203 | root = get_entry(private->entries, private->hook_entry[hook]); |
| 204 | |
| 205 | hookname = chainname = hooknames[hook]; |
| 206 | comment = comments[NF_IP_TRACE_COMMENT_RULE]; |
| 207 | |
| 208 | xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) |
| 209 | if (get_chainname_rulenum(iter, e, hookname, |
| 210 | &chainname, &comment, &rulenum) != 0) |
| 211 | break; |
| 212 | |
| 213 | nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo, |
| 214 | "TRACE: %s:%s:%s:%u ", |
| 215 | tablename, chainname, comment, rulenum); |
| 216 | } |
| 217 | #endif |
| 218 | |
| 219 | static inline |
| 220 | struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry) |
| 221 | { |
| 222 | return (void *)entry + entry->next_offset; |
| 223 | } |
| 224 | |
| 225 | /* Returns one of the generic firewall policies, like NF_ACCEPT. */ |
| 226 | unsigned int |
| 227 | ipt_do_table(struct sk_buff *skb, |
| 228 | const struct nf_hook_state *state, |
| 229 | struct xt_table *table) |
| 230 | { |
| 231 | unsigned int hook = state->hook; |
| 232 | static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); |
| 233 | const struct iphdr *ip; |
| 234 | /* Initializing verdict to NF_DROP keeps gcc happy. */ |
| 235 | unsigned int verdict = NF_DROP; |
| 236 | const char *indev, *outdev; |
| 237 | const void *table_base; |
| 238 | struct ipt_entry *e, **jumpstack; |
| 239 | unsigned int stackidx, cpu; |
| 240 | const struct xt_table_info *private; |
| 241 | struct xt_action_param acpar; |
| 242 | unsigned int addend; |
| 243 | |
| 244 | /* Initialization */ |
| 245 | stackidx = 0; |
| 246 | ip = ip_hdr(skb); |
| 247 | indev = state->in ? state->in->name : nulldevname; |
| 248 | outdev = state->out ? state->out->name : nulldevname; |
| 249 | /* We handle fragments by dealing with the first fragment as |
| 250 | * if it was a normal packet. All other fragments are treated |
| 251 | * normally, except that they will NEVER match rules that ask |
| 252 | * things we don't know, ie. tcp syn flag or ports). If the |
| 253 | * rule is also a fragment-specific rule, non-fragments won't |
| 254 | * match it. */ |
| 255 | acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET; |
| 256 | acpar.thoff = ip_hdrlen(skb); |
| 257 | acpar.hotdrop = false; |
| 258 | acpar.state = state; |
| 259 | |
| 260 | WARN_ON(!(table->valid_hooks & (1 << hook))); |
| 261 | local_bh_disable(); |
| 262 | addend = xt_write_recseq_begin(); |
| 263 | private = table->private; |
| 264 | cpu = smp_processor_id(); |
| 265 | /* |
| 266 | * Ensure we load private-> members after we've fetched the base |
| 267 | * pointer. |
| 268 | */ |
| 269 | smp_read_barrier_depends(); |
| 270 | table_base = private->entries; |
| 271 | jumpstack = (struct ipt_entry **)private->jumpstack[cpu]; |
| 272 | |
| 273 | /* Switch to alternate jumpstack if we're being invoked via TEE. |
| 274 | * TEE issues XT_CONTINUE verdict on original skb so we must not |
| 275 | * clobber the jumpstack. |
| 276 | * |
| 277 | * For recursion via REJECT or SYNPROXY the stack will be clobbered |
| 278 | * but it is no problem since absolute verdict is issued by these. |
| 279 | */ |
| 280 | if (static_key_false(&xt_tee_enabled)) |
| 281 | jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); |
| 282 | |
| 283 | e = get_entry(table_base, private->hook_entry[hook]); |
| 284 | |
| 285 | do { |
| 286 | const struct xt_entry_target *t; |
| 287 | const struct xt_entry_match *ematch; |
| 288 | struct xt_counters *counter; |
| 289 | |
| 290 | WARN_ON(!e); |
| 291 | if (!ip_packet_match(ip, indev, outdev, |
| 292 | &e->ip, acpar.fragoff)) { |
| 293 | no_match: |
| 294 | e = ipt_next_entry(e); |
| 295 | continue; |
| 296 | } |
| 297 | |
| 298 | xt_ematch_foreach(ematch, e) { |
| 299 | acpar.match = ematch->u.kernel.match; |
| 300 | acpar.matchinfo = ematch->data; |
| 301 | if (!acpar.match->match(skb, &acpar)) |
| 302 | goto no_match; |
| 303 | } |
| 304 | |
| 305 | counter = xt_get_this_cpu_counter(&e->counters); |
| 306 | ADD_COUNTER(*counter, skb->len, 1); |
| 307 | |
| 308 | t = ipt_get_target(e); |
| 309 | WARN_ON(!t->u.kernel.target); |
| 310 | |
| 311 | #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) |
| 312 | /* The packet is traced: log it */ |
| 313 | if (unlikely(skb->nf_trace)) |
| 314 | trace_packet(state->net, skb, hook, state->in, |
| 315 | state->out, table->name, private, e); |
| 316 | #endif |
| 317 | /* Standard target? */ |
| 318 | if (!t->u.kernel.target->target) { |
| 319 | int v; |
| 320 | |
| 321 | v = ((struct xt_standard_target *)t)->verdict; |
| 322 | if (v < 0) { |
| 323 | /* Pop from stack? */ |
| 324 | if (v != XT_RETURN) { |
| 325 | verdict = (unsigned int)(-v) - 1; |
| 326 | break; |
| 327 | } |
| 328 | if (stackidx == 0) { |
| 329 | e = get_entry(table_base, |
| 330 | private->underflow[hook]); |
| 331 | } else { |
| 332 | e = jumpstack[--stackidx]; |
| 333 | e = ipt_next_entry(e); |
| 334 | } |
| 335 | continue; |
| 336 | } |
| 337 | if (table_base + v != ipt_next_entry(e) && |
| 338 | !(e->ip.flags & IPT_F_GOTO)) { |
| 339 | if (unlikely(stackidx >= private->stacksize)) { |
| 340 | verdict = NF_DROP; |
| 341 | break; |
| 342 | } |
| 343 | jumpstack[stackidx++] = e; |
| 344 | } |
| 345 | |
| 346 | e = get_entry(table_base, v); |
| 347 | continue; |
| 348 | } |
| 349 | |
| 350 | acpar.target = t->u.kernel.target; |
| 351 | acpar.targinfo = t->data; |
| 352 | |
| 353 | verdict = t->u.kernel.target->target(skb, &acpar); |
| 354 | if (verdict == XT_CONTINUE) { |
| 355 | /* Target might have changed stuff. */ |
| 356 | ip = ip_hdr(skb); |
| 357 | e = ipt_next_entry(e); |
| 358 | } else { |
| 359 | /* Verdict */ |
| 360 | break; |
| 361 | } |
| 362 | } while (!acpar.hotdrop); |
| 363 | |
| 364 | xt_write_recseq_end(addend); |
| 365 | local_bh_enable(); |
| 366 | |
| 367 | if (acpar.hotdrop) |
| 368 | return NF_DROP; |
| 369 | else return verdict; |
| 370 | } |
| 371 | |
| 372 | /* Figures out from what hook each rule can be called: returns 0 if |
| 373 | there are loops. Puts hook bitmask in comefrom. */ |
| 374 | static int |
| 375 | mark_source_chains(const struct xt_table_info *newinfo, |
| 376 | unsigned int valid_hooks, void *entry0, |
| 377 | unsigned int *offsets) |
| 378 | { |
| 379 | unsigned int hook; |
| 380 | |
| 381 | /* No recursion; use packet counter to save back ptrs (reset |
| 382 | to 0 as we leave), and comefrom to save source hook bitmask */ |
| 383 | for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { |
| 384 | unsigned int pos = newinfo->hook_entry[hook]; |
| 385 | struct ipt_entry *e = entry0 + pos; |
| 386 | |
| 387 | if (!(valid_hooks & (1 << hook))) |
| 388 | continue; |
| 389 | |
| 390 | /* Set initial back pointer. */ |
| 391 | e->counters.pcnt = pos; |
| 392 | |
| 393 | for (;;) { |
| 394 | const struct xt_standard_target *t |
| 395 | = (void *)ipt_get_target_c(e); |
| 396 | int visited = e->comefrom & (1 << hook); |
| 397 | |
| 398 | if (e->comefrom & (1 << NF_INET_NUMHOOKS)) |
| 399 | return 0; |
| 400 | |
| 401 | e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); |
| 402 | |
| 403 | /* Unconditional return/END. */ |
| 404 | if ((unconditional(e) && |
| 405 | (strcmp(t->target.u.user.name, |
| 406 | XT_STANDARD_TARGET) == 0) && |
| 407 | t->verdict < 0) || visited) { |
| 408 | unsigned int oldpos, size; |
| 409 | |
| 410 | if ((strcmp(t->target.u.user.name, |
| 411 | XT_STANDARD_TARGET) == 0) && |
| 412 | t->verdict < -NF_MAX_VERDICT - 1) |
| 413 | return 0; |
| 414 | |
| 415 | /* Return: backtrack through the last |
| 416 | big jump. */ |
| 417 | do { |
| 418 | e->comefrom ^= (1<<NF_INET_NUMHOOKS); |
| 419 | oldpos = pos; |
| 420 | pos = e->counters.pcnt; |
| 421 | e->counters.pcnt = 0; |
| 422 | |
| 423 | /* We're at the start. */ |
| 424 | if (pos == oldpos) |
| 425 | goto next; |
| 426 | |
| 427 | e = entry0 + pos; |
| 428 | } while (oldpos == pos + e->next_offset); |
| 429 | |
| 430 | /* Move along one */ |
| 431 | size = e->next_offset; |
| 432 | e = entry0 + pos + size; |
| 433 | if (pos + size >= newinfo->size) |
| 434 | return 0; |
| 435 | e->counters.pcnt = pos; |
| 436 | pos += size; |
| 437 | } else { |
| 438 | int newpos = t->verdict; |
| 439 | |
| 440 | if (strcmp(t->target.u.user.name, |
| 441 | XT_STANDARD_TARGET) == 0 && |
| 442 | newpos >= 0) { |
| 443 | /* This a jump; chase it. */ |
| 444 | if (!xt_find_jump_offset(offsets, newpos, |
| 445 | newinfo->number)) |
| 446 | return 0; |
| 447 | e = entry0 + newpos; |
| 448 | } else { |
| 449 | /* ... this is a fallthru */ |
| 450 | newpos = pos + e->next_offset; |
| 451 | if (newpos >= newinfo->size) |
| 452 | return 0; |
| 453 | } |
| 454 | e = entry0 + newpos; |
| 455 | e->counters.pcnt = pos; |
| 456 | pos = newpos; |
| 457 | } |
| 458 | } |
| 459 | next: ; |
| 460 | } |
| 461 | return 1; |
| 462 | } |
| 463 | |
| 464 | static void cleanup_match(struct xt_entry_match *m, struct net *net) |
| 465 | { |
| 466 | struct xt_mtdtor_param par; |
| 467 | |
| 468 | par.net = net; |
| 469 | par.match = m->u.kernel.match; |
| 470 | par.matchinfo = m->data; |
| 471 | par.family = NFPROTO_IPV4; |
| 472 | if (par.match->destroy != NULL) |
| 473 | par.match->destroy(&par); |
| 474 | module_put(par.match->me); |
| 475 | } |
| 476 | |
| 477 | static int |
| 478 | check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) |
| 479 | { |
| 480 | const struct ipt_ip *ip = par->entryinfo; |
| 481 | |
| 482 | par->match = m->u.kernel.match; |
| 483 | par->matchinfo = m->data; |
| 484 | |
| 485 | return xt_check_match(par, m->u.match_size - sizeof(*m), |
| 486 | ip->proto, ip->invflags & IPT_INV_PROTO); |
| 487 | } |
| 488 | |
| 489 | static int |
| 490 | find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) |
| 491 | { |
| 492 | struct xt_match *match; |
| 493 | int ret; |
| 494 | |
| 495 | match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, |
| 496 | m->u.user.revision); |
| 497 | if (IS_ERR(match)) |
| 498 | return PTR_ERR(match); |
| 499 | m->u.kernel.match = match; |
| 500 | |
| 501 | ret = check_match(m, par); |
| 502 | if (ret) |
| 503 | goto err; |
| 504 | |
| 505 | return 0; |
| 506 | err: |
| 507 | module_put(m->u.kernel.match->me); |
| 508 | return ret; |
| 509 | } |
| 510 | |
| 511 | static int check_target(struct ipt_entry *e, struct net *net, const char *name) |
| 512 | { |
| 513 | struct xt_entry_target *t = ipt_get_target(e); |
| 514 | struct xt_tgchk_param par = { |
| 515 | .net = net, |
| 516 | .table = name, |
| 517 | .entryinfo = e, |
| 518 | .target = t->u.kernel.target, |
| 519 | .targinfo = t->data, |
| 520 | .hook_mask = e->comefrom, |
| 521 | .family = NFPROTO_IPV4, |
| 522 | }; |
| 523 | |
| 524 | return xt_check_target(&par, t->u.target_size - sizeof(*t), |
| 525 | e->ip.proto, e->ip.invflags & IPT_INV_PROTO); |
| 526 | } |
| 527 | |
| 528 | static int |
| 529 | find_check_entry(struct ipt_entry *e, struct net *net, const char *name, |
| 530 | unsigned int size, |
| 531 | struct xt_percpu_counter_alloc_state *alloc_state) |
| 532 | { |
| 533 | struct xt_entry_target *t; |
| 534 | struct xt_target *target; |
| 535 | int ret; |
| 536 | unsigned int j; |
| 537 | struct xt_mtchk_param mtpar; |
| 538 | struct xt_entry_match *ematch; |
| 539 | |
| 540 | if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) |
| 541 | return -ENOMEM; |
| 542 | |
| 543 | j = 0; |
| 544 | memset(&mtpar, 0, sizeof(mtpar)); |
| 545 | mtpar.net = net; |
| 546 | mtpar.table = name; |
| 547 | mtpar.entryinfo = &e->ip; |
| 548 | mtpar.hook_mask = e->comefrom; |
| 549 | mtpar.family = NFPROTO_IPV4; |
| 550 | xt_ematch_foreach(ematch, e) { |
| 551 | ret = find_check_match(ematch, &mtpar); |
| 552 | if (ret != 0) |
| 553 | goto cleanup_matches; |
| 554 | ++j; |
| 555 | } |
| 556 | |
| 557 | t = ipt_get_target(e); |
| 558 | target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, |
| 559 | t->u.user.revision); |
| 560 | if (IS_ERR(target)) { |
| 561 | ret = PTR_ERR(target); |
| 562 | goto cleanup_matches; |
| 563 | } |
| 564 | t->u.kernel.target = target; |
| 565 | |
| 566 | ret = check_target(e, net, name); |
| 567 | if (ret) |
| 568 | goto err; |
| 569 | |
| 570 | return 0; |
| 571 | err: |
| 572 | module_put(t->u.kernel.target->me); |
| 573 | cleanup_matches: |
| 574 | xt_ematch_foreach(ematch, e) { |
| 575 | if (j-- == 0) |
| 576 | break; |
| 577 | cleanup_match(ematch, net); |
| 578 | } |
| 579 | |
| 580 | xt_percpu_counter_free(&e->counters); |
| 581 | |
| 582 | return ret; |
| 583 | } |
| 584 | |
| 585 | static bool check_underflow(const struct ipt_entry *e) |
| 586 | { |
| 587 | const struct xt_entry_target *t; |
| 588 | unsigned int verdict; |
| 589 | |
| 590 | if (!unconditional(e)) |
| 591 | return false; |
| 592 | t = ipt_get_target_c(e); |
| 593 | if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) |
| 594 | return false; |
| 595 | verdict = ((struct xt_standard_target *)t)->verdict; |
| 596 | verdict = -verdict - 1; |
| 597 | return verdict == NF_DROP || verdict == NF_ACCEPT; |
| 598 | } |
| 599 | |
| 600 | static int |
| 601 | check_entry_size_and_hooks(struct ipt_entry *e, |
| 602 | struct xt_table_info *newinfo, |
| 603 | const unsigned char *base, |
| 604 | const unsigned char *limit, |
| 605 | const unsigned int *hook_entries, |
| 606 | const unsigned int *underflows, |
| 607 | unsigned int valid_hooks) |
| 608 | { |
| 609 | unsigned int h; |
| 610 | int err; |
| 611 | |
| 612 | if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 || |
| 613 | (unsigned char *)e + sizeof(struct ipt_entry) >= limit || |
| 614 | (unsigned char *)e + e->next_offset > limit) |
| 615 | return -EINVAL; |
| 616 | |
| 617 | if (e->next_offset |
| 618 | < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) |
| 619 | return -EINVAL; |
| 620 | |
| 621 | if (!ip_checkentry(&e->ip)) |
| 622 | return -EINVAL; |
| 623 | |
| 624 | err = xt_check_entry_offsets(e, e->elems, e->target_offset, |
| 625 | e->next_offset); |
| 626 | if (err) |
| 627 | return err; |
| 628 | |
| 629 | /* Check hooks & underflows */ |
| 630 | for (h = 0; h < NF_INET_NUMHOOKS; h++) { |
| 631 | if (!(valid_hooks & (1 << h))) |
| 632 | continue; |
| 633 | if ((unsigned char *)e - base == hook_entries[h]) |
| 634 | newinfo->hook_entry[h] = hook_entries[h]; |
| 635 | if ((unsigned char *)e - base == underflows[h]) { |
| 636 | if (!check_underflow(e)) |
| 637 | return -EINVAL; |
| 638 | |
| 639 | newinfo->underflow[h] = underflows[h]; |
| 640 | } |
| 641 | } |
| 642 | |
| 643 | /* Clear counters and comefrom */ |
| 644 | e->counters = ((struct xt_counters) { 0, 0 }); |
| 645 | e->comefrom = 0; |
| 646 | return 0; |
| 647 | } |
| 648 | |
| 649 | static void |
| 650 | cleanup_entry(struct ipt_entry *e, struct net *net) |
| 651 | { |
| 652 | struct xt_tgdtor_param par; |
| 653 | struct xt_entry_target *t; |
| 654 | struct xt_entry_match *ematch; |
| 655 | |
| 656 | /* Cleanup all matches */ |
| 657 | xt_ematch_foreach(ematch, e) |
| 658 | cleanup_match(ematch, net); |
| 659 | t = ipt_get_target(e); |
| 660 | |
| 661 | par.net = net; |
| 662 | par.target = t->u.kernel.target; |
| 663 | par.targinfo = t->data; |
| 664 | par.family = NFPROTO_IPV4; |
| 665 | if (par.target->destroy != NULL) |
| 666 | par.target->destroy(&par); |
| 667 | module_put(par.target->me); |
| 668 | xt_percpu_counter_free(&e->counters); |
| 669 | } |
| 670 | |
| 671 | /* Checks and translates the user-supplied table segment (held in |
| 672 | newinfo) */ |
| 673 | static int |
| 674 | translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, |
| 675 | const struct ipt_replace *repl) |
| 676 | { |
| 677 | struct xt_percpu_counter_alloc_state alloc_state = { 0 }; |
| 678 | struct ipt_entry *iter; |
| 679 | unsigned int *offsets; |
| 680 | unsigned int i; |
| 681 | int ret = 0; |
| 682 | |
| 683 | newinfo->size = repl->size; |
| 684 | newinfo->number = repl->num_entries; |
| 685 | |
| 686 | /* Init all hooks to impossible value. */ |
| 687 | for (i = 0; i < NF_INET_NUMHOOKS; i++) { |
| 688 | newinfo->hook_entry[i] = 0xFFFFFFFF; |
| 689 | newinfo->underflow[i] = 0xFFFFFFFF; |
| 690 | } |
| 691 | |
| 692 | offsets = xt_alloc_entry_offsets(newinfo->number); |
| 693 | if (!offsets) |
| 694 | return -ENOMEM; |
| 695 | i = 0; |
| 696 | /* Walk through entries, checking offsets. */ |
| 697 | xt_entry_foreach(iter, entry0, newinfo->size) { |
| 698 | ret = check_entry_size_and_hooks(iter, newinfo, entry0, |
| 699 | entry0 + repl->size, |
| 700 | repl->hook_entry, |
| 701 | repl->underflow, |
| 702 | repl->valid_hooks); |
| 703 | if (ret != 0) |
| 704 | goto out_free; |
| 705 | if (i < repl->num_entries) |
| 706 | offsets[i] = (void *)iter - entry0; |
| 707 | ++i; |
| 708 | if (strcmp(ipt_get_target(iter)->u.user.name, |
| 709 | XT_ERROR_TARGET) == 0) |
| 710 | ++newinfo->stacksize; |
| 711 | } |
| 712 | |
| 713 | ret = -EINVAL; |
| 714 | if (i != repl->num_entries) |
| 715 | goto out_free; |
| 716 | |
| 717 | /* Check hooks all assigned */ |
| 718 | for (i = 0; i < NF_INET_NUMHOOKS; i++) { |
| 719 | /* Only hooks which are valid */ |
| 720 | if (!(repl->valid_hooks & (1 << i))) |
| 721 | continue; |
| 722 | if (newinfo->hook_entry[i] == 0xFFFFFFFF) |
| 723 | goto out_free; |
| 724 | if (newinfo->underflow[i] == 0xFFFFFFFF) |
| 725 | goto out_free; |
| 726 | } |
| 727 | |
| 728 | if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { |
| 729 | ret = -ELOOP; |
| 730 | goto out_free; |
| 731 | } |
| 732 | kvfree(offsets); |
| 733 | |
| 734 | /* Finally, each sanity check must pass */ |
| 735 | i = 0; |
| 736 | xt_entry_foreach(iter, entry0, newinfo->size) { |
| 737 | ret = find_check_entry(iter, net, repl->name, repl->size, |
| 738 | &alloc_state); |
| 739 | if (ret != 0) |
| 740 | break; |
| 741 | ++i; |
| 742 | } |
| 743 | |
| 744 | if (ret != 0) { |
| 745 | xt_entry_foreach(iter, entry0, newinfo->size) { |
| 746 | if (i-- == 0) |
| 747 | break; |
| 748 | cleanup_entry(iter, net); |
| 749 | } |
| 750 | return ret; |
| 751 | } |
| 752 | |
| 753 | return ret; |
| 754 | out_free: |
| 755 | kvfree(offsets); |
| 756 | return ret; |
| 757 | } |
| 758 | |
| 759 | static void |
| 760 | get_counters(const struct xt_table_info *t, |
| 761 | struct xt_counters counters[]) |
| 762 | { |
| 763 | struct ipt_entry *iter; |
| 764 | unsigned int cpu; |
| 765 | unsigned int i; |
| 766 | |
| 767 | for_each_possible_cpu(cpu) { |
| 768 | seqcount_t *s = &per_cpu(xt_recseq, cpu); |
| 769 | |
| 770 | i = 0; |
| 771 | xt_entry_foreach(iter, t->entries, t->size) { |
| 772 | struct xt_counters *tmp; |
| 773 | u64 bcnt, pcnt; |
| 774 | unsigned int start; |
| 775 | |
| 776 | tmp = xt_get_per_cpu_counter(&iter->counters, cpu); |
| 777 | do { |
| 778 | start = read_seqcount_begin(s); |
| 779 | bcnt = tmp->bcnt; |
| 780 | pcnt = tmp->pcnt; |
| 781 | } while (read_seqcount_retry(s, start)); |
| 782 | |
| 783 | ADD_COUNTER(counters[i], bcnt, pcnt); |
| 784 | ++i; /* macro does multi eval of i */ |
| 785 | cond_resched(); |
| 786 | } |
| 787 | } |
| 788 | } |
| 789 | |
| 790 | static struct xt_counters *alloc_counters(const struct xt_table *table) |
| 791 | { |
| 792 | unsigned int countersize; |
| 793 | struct xt_counters *counters; |
| 794 | const struct xt_table_info *private = table->private; |
| 795 | |
| 796 | /* We need atomic snapshot of counters: rest doesn't change |
| 797 | (other than comefrom, which userspace doesn't care |
| 798 | about). */ |
| 799 | countersize = sizeof(struct xt_counters) * private->number; |
| 800 | counters = vzalloc(countersize); |
| 801 | |
| 802 | if (counters == NULL) |
| 803 | return ERR_PTR(-ENOMEM); |
| 804 | |
| 805 | get_counters(private, counters); |
| 806 | |
| 807 | return counters; |
| 808 | } |
| 809 | |
| 810 | static int |
| 811 | copy_entries_to_user(unsigned int total_size, |
| 812 | const struct xt_table *table, |
| 813 | void __user *userptr) |
| 814 | { |
| 815 | unsigned int off, num; |
| 816 | const struct ipt_entry *e; |
| 817 | struct xt_counters *counters; |
| 818 | const struct xt_table_info *private = table->private; |
| 819 | int ret = 0; |
| 820 | const void *loc_cpu_entry; |
| 821 | |
| 822 | counters = alloc_counters(table); |
| 823 | if (IS_ERR(counters)) |
| 824 | return PTR_ERR(counters); |
| 825 | |
| 826 | loc_cpu_entry = private->entries; |
| 827 | |
| 828 | /* FIXME: use iterator macros --RR */ |
| 829 | /* ... then go back and fix counters and names */ |
| 830 | for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ |
| 831 | unsigned int i; |
| 832 | const struct xt_entry_match *m; |
| 833 | const struct xt_entry_target *t; |
| 834 | |
| 835 | e = loc_cpu_entry + off; |
| 836 | if (copy_to_user(userptr + off, e, sizeof(*e))) { |
| 837 | ret = -EFAULT; |
| 838 | goto free_counters; |
| 839 | } |
| 840 | if (copy_to_user(userptr + off |
| 841 | + offsetof(struct ipt_entry, counters), |
| 842 | &counters[num], |
| 843 | sizeof(counters[num])) != 0) { |
| 844 | ret = -EFAULT; |
| 845 | goto free_counters; |
| 846 | } |
| 847 | |
| 848 | for (i = sizeof(struct ipt_entry); |
| 849 | i < e->target_offset; |
| 850 | i += m->u.match_size) { |
| 851 | m = (void *)e + i; |
| 852 | |
| 853 | if (xt_match_to_user(m, userptr + off + i)) { |
| 854 | ret = -EFAULT; |
| 855 | goto free_counters; |
| 856 | } |
| 857 | } |
| 858 | |
| 859 | t = ipt_get_target_c(e); |
| 860 | if (xt_target_to_user(t, userptr + off + e->target_offset)) { |
| 861 | ret = -EFAULT; |
| 862 | goto free_counters; |
| 863 | } |
| 864 | } |
| 865 | |
| 866 | free_counters: |
| 867 | vfree(counters); |
| 868 | return ret; |
| 869 | } |
| 870 | |
| 871 | #ifdef CONFIG_COMPAT |
| 872 | static void compat_standard_from_user(void *dst, const void *src) |
| 873 | { |
| 874 | int v = *(compat_int_t *)src; |
| 875 | |
| 876 | if (v > 0) |
| 877 | v += xt_compat_calc_jump(AF_INET, v); |
| 878 | memcpy(dst, &v, sizeof(v)); |
| 879 | } |
| 880 | |
| 881 | static int compat_standard_to_user(void __user *dst, const void *src) |
| 882 | { |
| 883 | compat_int_t cv = *(int *)src; |
| 884 | |
| 885 | if (cv > 0) |
| 886 | cv -= xt_compat_calc_jump(AF_INET, cv); |
| 887 | return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; |
| 888 | } |
| 889 | |
| 890 | static int compat_calc_entry(const struct ipt_entry *e, |
| 891 | const struct xt_table_info *info, |
| 892 | const void *base, struct xt_table_info *newinfo) |
| 893 | { |
| 894 | const struct xt_entry_match *ematch; |
| 895 | const struct xt_entry_target *t; |
| 896 | unsigned int entry_offset; |
| 897 | int off, i, ret; |
| 898 | |
| 899 | off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); |
| 900 | entry_offset = (void *)e - base; |
| 901 | xt_ematch_foreach(ematch, e) |
| 902 | off += xt_compat_match_offset(ematch->u.kernel.match); |
| 903 | t = ipt_get_target_c(e); |
| 904 | off += xt_compat_target_offset(t->u.kernel.target); |
| 905 | newinfo->size -= off; |
| 906 | ret = xt_compat_add_offset(AF_INET, entry_offset, off); |
| 907 | if (ret) |
| 908 | return ret; |
| 909 | |
| 910 | for (i = 0; i < NF_INET_NUMHOOKS; i++) { |
| 911 | if (info->hook_entry[i] && |
| 912 | (e < (struct ipt_entry *)(base + info->hook_entry[i]))) |
| 913 | newinfo->hook_entry[i] -= off; |
| 914 | if (info->underflow[i] && |
| 915 | (e < (struct ipt_entry *)(base + info->underflow[i]))) |
| 916 | newinfo->underflow[i] -= off; |
| 917 | } |
| 918 | return 0; |
| 919 | } |
| 920 | |
| 921 | static int compat_table_info(const struct xt_table_info *info, |
| 922 | struct xt_table_info *newinfo) |
| 923 | { |
| 924 | struct ipt_entry *iter; |
| 925 | const void *loc_cpu_entry; |
| 926 | int ret; |
| 927 | |
| 928 | if (!newinfo || !info) |
| 929 | return -EINVAL; |
| 930 | |
| 931 | /* we dont care about newinfo->entries */ |
| 932 | memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); |
| 933 | newinfo->initial_entries = 0; |
| 934 | loc_cpu_entry = info->entries; |
| 935 | ret = xt_compat_init_offsets(AF_INET, info->number); |
| 936 | if (ret) |
| 937 | return ret; |
| 938 | xt_entry_foreach(iter, loc_cpu_entry, info->size) { |
| 939 | ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); |
| 940 | if (ret != 0) |
| 941 | return ret; |
| 942 | } |
| 943 | return 0; |
| 944 | } |
| 945 | #endif |
| 946 | |
| 947 | static int get_info(struct net *net, void __user *user, |
| 948 | const int *len, int compat) |
| 949 | { |
| 950 | char name[XT_TABLE_MAXNAMELEN]; |
| 951 | struct xt_table *t; |
| 952 | int ret; |
| 953 | |
| 954 | if (*len != sizeof(struct ipt_getinfo)) |
| 955 | return -EINVAL; |
| 956 | |
| 957 | if (copy_from_user(name, user, sizeof(name)) != 0) |
| 958 | return -EFAULT; |
| 959 | |
| 960 | name[XT_TABLE_MAXNAMELEN-1] = '\0'; |
| 961 | #ifdef CONFIG_COMPAT |
| 962 | if (compat) |
| 963 | xt_compat_lock(AF_INET); |
| 964 | #endif |
| 965 | t = try_then_request_module(xt_find_table_lock(net, AF_INET, name), |
| 966 | "iptable_%s", name); |
| 967 | if (t) { |
| 968 | struct ipt_getinfo info; |
| 969 | const struct xt_table_info *private = t->private; |
| 970 | #ifdef CONFIG_COMPAT |
| 971 | struct xt_table_info tmp; |
| 972 | |
| 973 | if (compat) { |
| 974 | ret = compat_table_info(private, &tmp); |
| 975 | xt_compat_flush_offsets(AF_INET); |
| 976 | private = &tmp; |
| 977 | } |
| 978 | #endif |
| 979 | memset(&info, 0, sizeof(info)); |
| 980 | info.valid_hooks = t->valid_hooks; |
| 981 | memcpy(info.hook_entry, private->hook_entry, |
| 982 | sizeof(info.hook_entry)); |
| 983 | memcpy(info.underflow, private->underflow, |
| 984 | sizeof(info.underflow)); |
| 985 | info.num_entries = private->number; |
| 986 | info.size = private->size; |
| 987 | strcpy(info.name, name); |
| 988 | |
| 989 | if (copy_to_user(user, &info, *len) != 0) |
| 990 | ret = -EFAULT; |
| 991 | else |
| 992 | ret = 0; |
| 993 | |
| 994 | xt_table_unlock(t); |
| 995 | module_put(t->me); |
| 996 | } else |
| 997 | ret = -ENOENT; |
| 998 | #ifdef CONFIG_COMPAT |
| 999 | if (compat) |
| 1000 | xt_compat_unlock(AF_INET); |
| 1001 | #endif |
| 1002 | return ret; |
| 1003 | } |
| 1004 | |
| 1005 | static int |
| 1006 | get_entries(struct net *net, struct ipt_get_entries __user *uptr, |
| 1007 | const int *len) |
| 1008 | { |
| 1009 | int ret; |
| 1010 | struct ipt_get_entries get; |
| 1011 | struct xt_table *t; |
| 1012 | |
| 1013 | if (*len < sizeof(get)) |
| 1014 | return -EINVAL; |
| 1015 | if (copy_from_user(&get, uptr, sizeof(get)) != 0) |
| 1016 | return -EFAULT; |
| 1017 | if (*len != sizeof(struct ipt_get_entries) + get.size) |
| 1018 | return -EINVAL; |
| 1019 | get.name[sizeof(get.name) - 1] = '\0'; |
| 1020 | |
| 1021 | t = xt_find_table_lock(net, AF_INET, get.name); |
| 1022 | if (t) { |
| 1023 | const struct xt_table_info *private = t->private; |
| 1024 | if (get.size == private->size) |
| 1025 | ret = copy_entries_to_user(private->size, |
| 1026 | t, uptr->entrytable); |
| 1027 | else |
| 1028 | ret = -EAGAIN; |
| 1029 | |
| 1030 | module_put(t->me); |
| 1031 | xt_table_unlock(t); |
| 1032 | } else |
| 1033 | ret = -ENOENT; |
| 1034 | |
| 1035 | return ret; |
| 1036 | } |
| 1037 | |
| 1038 | static int |
| 1039 | __do_replace(struct net *net, const char *name, unsigned int valid_hooks, |
| 1040 | struct xt_table_info *newinfo, unsigned int num_counters, |
| 1041 | void __user *counters_ptr) |
| 1042 | { |
| 1043 | int ret; |
| 1044 | struct xt_table *t; |
| 1045 | struct xt_table_info *oldinfo; |
| 1046 | struct xt_counters *counters; |
| 1047 | struct ipt_entry *iter; |
| 1048 | |
| 1049 | ret = 0; |
| 1050 | counters = xt_counters_alloc(num_counters); |
| 1051 | if (!counters) { |
| 1052 | ret = -ENOMEM; |
| 1053 | goto out; |
| 1054 | } |
| 1055 | |
| 1056 | t = try_then_request_module(xt_find_table_lock(net, AF_INET, name), |
| 1057 | "iptable_%s", name); |
| 1058 | if (!t) { |
| 1059 | ret = -ENOENT; |
| 1060 | goto free_newinfo_counters_untrans; |
| 1061 | } |
| 1062 | |
| 1063 | /* You lied! */ |
| 1064 | if (valid_hooks != t->valid_hooks) { |
| 1065 | ret = -EINVAL; |
| 1066 | goto put_module; |
| 1067 | } |
| 1068 | |
| 1069 | oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); |
| 1070 | if (!oldinfo) |
| 1071 | goto put_module; |
| 1072 | |
| 1073 | /* Update module usage count based on number of rules */ |
| 1074 | if ((oldinfo->number > oldinfo->initial_entries) || |
| 1075 | (newinfo->number <= oldinfo->initial_entries)) |
| 1076 | module_put(t->me); |
| 1077 | if ((oldinfo->number > oldinfo->initial_entries) && |
| 1078 | (newinfo->number <= oldinfo->initial_entries)) |
| 1079 | module_put(t->me); |
| 1080 | |
| 1081 | /* Get the old counters, and synchronize with replace */ |
| 1082 | get_counters(oldinfo, counters); |
| 1083 | |
| 1084 | /* Decrease module usage counts and free resource */ |
| 1085 | xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) |
| 1086 | cleanup_entry(iter, net); |
| 1087 | |
| 1088 | xt_free_table_info(oldinfo); |
| 1089 | if (copy_to_user(counters_ptr, counters, |
| 1090 | sizeof(struct xt_counters) * num_counters) != 0) { |
| 1091 | /* Silent error, can't fail, new table is already in place */ |
| 1092 | net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n"); |
| 1093 | } |
| 1094 | vfree(counters); |
| 1095 | xt_table_unlock(t); |
| 1096 | return ret; |
| 1097 | |
| 1098 | put_module: |
| 1099 | module_put(t->me); |
| 1100 | xt_table_unlock(t); |
| 1101 | free_newinfo_counters_untrans: |
| 1102 | vfree(counters); |
| 1103 | out: |
| 1104 | return ret; |
| 1105 | } |
| 1106 | |
| 1107 | static int |
| 1108 | do_replace(struct net *net, const void __user *user, unsigned int len) |
| 1109 | { |
| 1110 | int ret; |
| 1111 | struct ipt_replace tmp; |
| 1112 | struct xt_table_info *newinfo; |
| 1113 | void *loc_cpu_entry; |
| 1114 | struct ipt_entry *iter; |
| 1115 | |
| 1116 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 1117 | return -EFAULT; |
| 1118 | |
| 1119 | /* overflow check */ |
| 1120 | if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) |
| 1121 | return -ENOMEM; |
| 1122 | if (tmp.num_counters == 0) |
| 1123 | return -EINVAL; |
| 1124 | |
| 1125 | tmp.name[sizeof(tmp.name)-1] = 0; |
| 1126 | |
| 1127 | newinfo = xt_alloc_table_info(tmp.size); |
| 1128 | if (!newinfo) |
| 1129 | return -ENOMEM; |
| 1130 | |
| 1131 | loc_cpu_entry = newinfo->entries; |
| 1132 | if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), |
| 1133 | tmp.size) != 0) { |
| 1134 | ret = -EFAULT; |
| 1135 | goto free_newinfo; |
| 1136 | } |
| 1137 | |
| 1138 | ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); |
| 1139 | if (ret != 0) |
| 1140 | goto free_newinfo; |
| 1141 | |
| 1142 | ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, |
| 1143 | tmp.num_counters, tmp.counters); |
| 1144 | if (ret) |
| 1145 | goto free_newinfo_untrans; |
| 1146 | return 0; |
| 1147 | |
| 1148 | free_newinfo_untrans: |
| 1149 | xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) |
| 1150 | cleanup_entry(iter, net); |
| 1151 | free_newinfo: |
| 1152 | xt_free_table_info(newinfo); |
| 1153 | return ret; |
| 1154 | } |
| 1155 | |
| 1156 | static int |
| 1157 | do_add_counters(struct net *net, const void __user *user, |
| 1158 | unsigned int len, int compat) |
| 1159 | { |
| 1160 | unsigned int i; |
| 1161 | struct xt_counters_info tmp; |
| 1162 | struct xt_counters *paddc; |
| 1163 | struct xt_table *t; |
| 1164 | const struct xt_table_info *private; |
| 1165 | int ret = 0; |
| 1166 | struct ipt_entry *iter; |
| 1167 | unsigned int addend; |
| 1168 | |
| 1169 | paddc = xt_copy_counters_from_user(user, len, &tmp, compat); |
| 1170 | if (IS_ERR(paddc)) |
| 1171 | return PTR_ERR(paddc); |
| 1172 | |
| 1173 | t = xt_find_table_lock(net, AF_INET, tmp.name); |
| 1174 | if (!t) { |
| 1175 | ret = -ENOENT; |
| 1176 | goto free; |
| 1177 | } |
| 1178 | |
| 1179 | local_bh_disable(); |
| 1180 | private = t->private; |
| 1181 | if (private->number != tmp.num_counters) { |
| 1182 | ret = -EINVAL; |
| 1183 | goto unlock_up_free; |
| 1184 | } |
| 1185 | |
| 1186 | i = 0; |
| 1187 | addend = xt_write_recseq_begin(); |
| 1188 | xt_entry_foreach(iter, private->entries, private->size) { |
| 1189 | struct xt_counters *tmp; |
| 1190 | |
| 1191 | tmp = xt_get_this_cpu_counter(&iter->counters); |
| 1192 | ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); |
| 1193 | ++i; |
| 1194 | } |
| 1195 | xt_write_recseq_end(addend); |
| 1196 | unlock_up_free: |
| 1197 | local_bh_enable(); |
| 1198 | xt_table_unlock(t); |
| 1199 | module_put(t->me); |
| 1200 | free: |
| 1201 | vfree(paddc); |
| 1202 | |
| 1203 | return ret; |
| 1204 | } |
| 1205 | |
| 1206 | #ifdef CONFIG_COMPAT |
| 1207 | struct compat_ipt_replace { |
| 1208 | char name[XT_TABLE_MAXNAMELEN]; |
| 1209 | u32 valid_hooks; |
| 1210 | u32 num_entries; |
| 1211 | u32 size; |
| 1212 | u32 hook_entry[NF_INET_NUMHOOKS]; |
| 1213 | u32 underflow[NF_INET_NUMHOOKS]; |
| 1214 | u32 num_counters; |
| 1215 | compat_uptr_t counters; /* struct xt_counters * */ |
| 1216 | struct compat_ipt_entry entries[0]; |
| 1217 | }; |
| 1218 | |
| 1219 | static int |
| 1220 | compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr, |
| 1221 | unsigned int *size, struct xt_counters *counters, |
| 1222 | unsigned int i) |
| 1223 | { |
| 1224 | struct xt_entry_target *t; |
| 1225 | struct compat_ipt_entry __user *ce; |
| 1226 | u_int16_t target_offset, next_offset; |
| 1227 | compat_uint_t origsize; |
| 1228 | const struct xt_entry_match *ematch; |
| 1229 | int ret = 0; |
| 1230 | |
| 1231 | origsize = *size; |
| 1232 | ce = *dstptr; |
| 1233 | if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 || |
| 1234 | copy_to_user(&ce->counters, &counters[i], |
| 1235 | sizeof(counters[i])) != 0) |
| 1236 | return -EFAULT; |
| 1237 | |
| 1238 | *dstptr += sizeof(struct compat_ipt_entry); |
| 1239 | *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); |
| 1240 | |
| 1241 | xt_ematch_foreach(ematch, e) { |
| 1242 | ret = xt_compat_match_to_user(ematch, dstptr, size); |
| 1243 | if (ret != 0) |
| 1244 | return ret; |
| 1245 | } |
| 1246 | target_offset = e->target_offset - (origsize - *size); |
| 1247 | t = ipt_get_target(e); |
| 1248 | ret = xt_compat_target_to_user(t, dstptr, size); |
| 1249 | if (ret) |
| 1250 | return ret; |
| 1251 | next_offset = e->next_offset - (origsize - *size); |
| 1252 | if (put_user(target_offset, &ce->target_offset) != 0 || |
| 1253 | put_user(next_offset, &ce->next_offset) != 0) |
| 1254 | return -EFAULT; |
| 1255 | return 0; |
| 1256 | } |
| 1257 | |
| 1258 | static int |
| 1259 | compat_find_calc_match(struct xt_entry_match *m, |
| 1260 | const struct ipt_ip *ip, |
| 1261 | int *size) |
| 1262 | { |
| 1263 | struct xt_match *match; |
| 1264 | |
| 1265 | match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, |
| 1266 | m->u.user.revision); |
| 1267 | if (IS_ERR(match)) |
| 1268 | return PTR_ERR(match); |
| 1269 | |
| 1270 | m->u.kernel.match = match; |
| 1271 | *size += xt_compat_match_offset(match); |
| 1272 | return 0; |
| 1273 | } |
| 1274 | |
| 1275 | static void compat_release_entry(struct compat_ipt_entry *e) |
| 1276 | { |
| 1277 | struct xt_entry_target *t; |
| 1278 | struct xt_entry_match *ematch; |
| 1279 | |
| 1280 | /* Cleanup all matches */ |
| 1281 | xt_ematch_foreach(ematch, e) |
| 1282 | module_put(ematch->u.kernel.match->me); |
| 1283 | t = compat_ipt_get_target(e); |
| 1284 | module_put(t->u.kernel.target->me); |
| 1285 | } |
| 1286 | |
| 1287 | static int |
| 1288 | check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, |
| 1289 | struct xt_table_info *newinfo, |
| 1290 | unsigned int *size, |
| 1291 | const unsigned char *base, |
| 1292 | const unsigned char *limit) |
| 1293 | { |
| 1294 | struct xt_entry_match *ematch; |
| 1295 | struct xt_entry_target *t; |
| 1296 | struct xt_target *target; |
| 1297 | unsigned int entry_offset; |
| 1298 | unsigned int j; |
| 1299 | int ret, off; |
| 1300 | |
| 1301 | if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 || |
| 1302 | (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit || |
| 1303 | (unsigned char *)e + e->next_offset > limit) |
| 1304 | return -EINVAL; |
| 1305 | |
| 1306 | if (e->next_offset < sizeof(struct compat_ipt_entry) + |
| 1307 | sizeof(struct compat_xt_entry_target)) |
| 1308 | return -EINVAL; |
| 1309 | |
| 1310 | if (!ip_checkentry(&e->ip)) |
| 1311 | return -EINVAL; |
| 1312 | |
| 1313 | ret = xt_compat_check_entry_offsets(e, e->elems, |
| 1314 | e->target_offset, e->next_offset); |
| 1315 | if (ret) |
| 1316 | return ret; |
| 1317 | |
| 1318 | off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); |
| 1319 | entry_offset = (void *)e - (void *)base; |
| 1320 | j = 0; |
| 1321 | xt_ematch_foreach(ematch, e) { |
| 1322 | ret = compat_find_calc_match(ematch, &e->ip, &off); |
| 1323 | if (ret != 0) |
| 1324 | goto release_matches; |
| 1325 | ++j; |
| 1326 | } |
| 1327 | |
| 1328 | t = compat_ipt_get_target(e); |
| 1329 | target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, |
| 1330 | t->u.user.revision); |
| 1331 | if (IS_ERR(target)) { |
| 1332 | ret = PTR_ERR(target); |
| 1333 | goto release_matches; |
| 1334 | } |
| 1335 | t->u.kernel.target = target; |
| 1336 | |
| 1337 | off += xt_compat_target_offset(target); |
| 1338 | *size += off; |
| 1339 | ret = xt_compat_add_offset(AF_INET, entry_offset, off); |
| 1340 | if (ret) |
| 1341 | goto out; |
| 1342 | |
| 1343 | return 0; |
| 1344 | |
| 1345 | out: |
| 1346 | module_put(t->u.kernel.target->me); |
| 1347 | release_matches: |
| 1348 | xt_ematch_foreach(ematch, e) { |
| 1349 | if (j-- == 0) |
| 1350 | break; |
| 1351 | module_put(ematch->u.kernel.match->me); |
| 1352 | } |
| 1353 | return ret; |
| 1354 | } |
| 1355 | |
| 1356 | static void |
| 1357 | compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, |
| 1358 | unsigned int *size, |
| 1359 | struct xt_table_info *newinfo, unsigned char *base) |
| 1360 | { |
| 1361 | struct xt_entry_target *t; |
| 1362 | struct ipt_entry *de; |
| 1363 | unsigned int origsize; |
| 1364 | int h; |
| 1365 | struct xt_entry_match *ematch; |
| 1366 | |
| 1367 | origsize = *size; |
| 1368 | de = *dstptr; |
| 1369 | memcpy(de, e, sizeof(struct ipt_entry)); |
| 1370 | memcpy(&de->counters, &e->counters, sizeof(e->counters)); |
| 1371 | |
| 1372 | *dstptr += sizeof(struct ipt_entry); |
| 1373 | *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); |
| 1374 | |
| 1375 | xt_ematch_foreach(ematch, e) |
| 1376 | xt_compat_match_from_user(ematch, dstptr, size); |
| 1377 | |
| 1378 | de->target_offset = e->target_offset - (origsize - *size); |
| 1379 | t = compat_ipt_get_target(e); |
| 1380 | xt_compat_target_from_user(t, dstptr, size); |
| 1381 | |
| 1382 | de->next_offset = e->next_offset - (origsize - *size); |
| 1383 | |
| 1384 | for (h = 0; h < NF_INET_NUMHOOKS; h++) { |
| 1385 | if ((unsigned char *)de - base < newinfo->hook_entry[h]) |
| 1386 | newinfo->hook_entry[h] -= origsize - *size; |
| 1387 | if ((unsigned char *)de - base < newinfo->underflow[h]) |
| 1388 | newinfo->underflow[h] -= origsize - *size; |
| 1389 | } |
| 1390 | } |
| 1391 | |
| 1392 | static int |
| 1393 | translate_compat_table(struct net *net, |
| 1394 | struct xt_table_info **pinfo, |
| 1395 | void **pentry0, |
| 1396 | const struct compat_ipt_replace *compatr) |
| 1397 | { |
| 1398 | unsigned int i, j; |
| 1399 | struct xt_table_info *newinfo, *info; |
| 1400 | void *pos, *entry0, *entry1; |
| 1401 | struct compat_ipt_entry *iter0; |
| 1402 | struct ipt_replace repl; |
| 1403 | unsigned int size; |
| 1404 | int ret; |
| 1405 | |
| 1406 | info = *pinfo; |
| 1407 | entry0 = *pentry0; |
| 1408 | size = compatr->size; |
| 1409 | info->number = compatr->num_entries; |
| 1410 | |
| 1411 | j = 0; |
| 1412 | xt_compat_lock(AF_INET); |
| 1413 | ret = xt_compat_init_offsets(AF_INET, compatr->num_entries); |
| 1414 | if (ret) |
| 1415 | goto out_unlock; |
| 1416 | /* Walk through entries, checking offsets. */ |
| 1417 | xt_entry_foreach(iter0, entry0, compatr->size) { |
| 1418 | ret = check_compat_entry_size_and_hooks(iter0, info, &size, |
| 1419 | entry0, |
| 1420 | entry0 + compatr->size); |
| 1421 | if (ret != 0) |
| 1422 | goto out_unlock; |
| 1423 | ++j; |
| 1424 | } |
| 1425 | |
| 1426 | ret = -EINVAL; |
| 1427 | if (j != compatr->num_entries) |
| 1428 | goto out_unlock; |
| 1429 | |
| 1430 | ret = -ENOMEM; |
| 1431 | newinfo = xt_alloc_table_info(size); |
| 1432 | if (!newinfo) |
| 1433 | goto out_unlock; |
| 1434 | |
| 1435 | newinfo->number = compatr->num_entries; |
| 1436 | for (i = 0; i < NF_INET_NUMHOOKS; i++) { |
| 1437 | newinfo->hook_entry[i] = compatr->hook_entry[i]; |
| 1438 | newinfo->underflow[i] = compatr->underflow[i]; |
| 1439 | } |
| 1440 | entry1 = newinfo->entries; |
| 1441 | pos = entry1; |
| 1442 | size = compatr->size; |
| 1443 | xt_entry_foreach(iter0, entry0, compatr->size) |
| 1444 | compat_copy_entry_from_user(iter0, &pos, &size, |
| 1445 | newinfo, entry1); |
| 1446 | |
| 1447 | /* all module references in entry0 are now gone. |
| 1448 | * entry1/newinfo contains a 64bit ruleset that looks exactly as |
| 1449 | * generated by 64bit userspace. |
| 1450 | * |
| 1451 | * Call standard translate_table() to validate all hook_entrys, |
| 1452 | * underflows, check for loops, etc. |
| 1453 | */ |
| 1454 | xt_compat_flush_offsets(AF_INET); |
| 1455 | xt_compat_unlock(AF_INET); |
| 1456 | |
| 1457 | memcpy(&repl, compatr, sizeof(*compatr)); |
| 1458 | |
| 1459 | for (i = 0; i < NF_INET_NUMHOOKS; i++) { |
| 1460 | repl.hook_entry[i] = newinfo->hook_entry[i]; |
| 1461 | repl.underflow[i] = newinfo->underflow[i]; |
| 1462 | } |
| 1463 | |
| 1464 | repl.num_counters = 0; |
| 1465 | repl.counters = NULL; |
| 1466 | repl.size = newinfo->size; |
| 1467 | ret = translate_table(net, newinfo, entry1, &repl); |
| 1468 | if (ret) |
| 1469 | goto free_newinfo; |
| 1470 | |
| 1471 | *pinfo = newinfo; |
| 1472 | *pentry0 = entry1; |
| 1473 | xt_free_table_info(info); |
| 1474 | return 0; |
| 1475 | |
| 1476 | free_newinfo: |
| 1477 | xt_free_table_info(newinfo); |
| 1478 | return ret; |
| 1479 | out_unlock: |
| 1480 | xt_compat_flush_offsets(AF_INET); |
| 1481 | xt_compat_unlock(AF_INET); |
| 1482 | xt_entry_foreach(iter0, entry0, compatr->size) { |
| 1483 | if (j-- == 0) |
| 1484 | break; |
| 1485 | compat_release_entry(iter0); |
| 1486 | } |
| 1487 | return ret; |
| 1488 | } |
| 1489 | |
| 1490 | static int |
| 1491 | compat_do_replace(struct net *net, void __user *user, unsigned int len) |
| 1492 | { |
| 1493 | int ret; |
| 1494 | struct compat_ipt_replace tmp; |
| 1495 | struct xt_table_info *newinfo; |
| 1496 | void *loc_cpu_entry; |
| 1497 | struct ipt_entry *iter; |
| 1498 | |
| 1499 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) |
| 1500 | return -EFAULT; |
| 1501 | |
| 1502 | /* overflow check */ |
| 1503 | if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) |
| 1504 | return -ENOMEM; |
| 1505 | if (tmp.num_counters == 0) |
| 1506 | return -EINVAL; |
| 1507 | |
| 1508 | tmp.name[sizeof(tmp.name)-1] = 0; |
| 1509 | |
| 1510 | newinfo = xt_alloc_table_info(tmp.size); |
| 1511 | if (!newinfo) |
| 1512 | return -ENOMEM; |
| 1513 | |
| 1514 | loc_cpu_entry = newinfo->entries; |
| 1515 | if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), |
| 1516 | tmp.size) != 0) { |
| 1517 | ret = -EFAULT; |
| 1518 | goto free_newinfo; |
| 1519 | } |
| 1520 | |
| 1521 | ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); |
| 1522 | if (ret != 0) |
| 1523 | goto free_newinfo; |
| 1524 | |
| 1525 | ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, |
| 1526 | tmp.num_counters, compat_ptr(tmp.counters)); |
| 1527 | if (ret) |
| 1528 | goto free_newinfo_untrans; |
| 1529 | return 0; |
| 1530 | |
| 1531 | free_newinfo_untrans: |
| 1532 | xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) |
| 1533 | cleanup_entry(iter, net); |
| 1534 | free_newinfo: |
| 1535 | xt_free_table_info(newinfo); |
| 1536 | return ret; |
| 1537 | } |
| 1538 | |
| 1539 | static int |
| 1540 | compat_do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, |
| 1541 | unsigned int len) |
| 1542 | { |
| 1543 | int ret; |
| 1544 | |
| 1545 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) |
| 1546 | return -EPERM; |
| 1547 | |
| 1548 | switch (cmd) { |
| 1549 | case IPT_SO_SET_REPLACE: |
| 1550 | ret = compat_do_replace(sock_net(sk), user, len); |
| 1551 | break; |
| 1552 | |
| 1553 | case IPT_SO_SET_ADD_COUNTERS: |
| 1554 | ret = do_add_counters(sock_net(sk), user, len, 1); |
| 1555 | break; |
| 1556 | |
| 1557 | default: |
| 1558 | ret = -EINVAL; |
| 1559 | } |
| 1560 | |
| 1561 | return ret; |
| 1562 | } |
| 1563 | |
| 1564 | struct compat_ipt_get_entries { |
| 1565 | char name[XT_TABLE_MAXNAMELEN]; |
| 1566 | compat_uint_t size; |
| 1567 | struct compat_ipt_entry entrytable[0]; |
| 1568 | }; |
| 1569 | |
| 1570 | static int |
| 1571 | compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, |
| 1572 | void __user *userptr) |
| 1573 | { |
| 1574 | struct xt_counters *counters; |
| 1575 | const struct xt_table_info *private = table->private; |
| 1576 | void __user *pos; |
| 1577 | unsigned int size; |
| 1578 | int ret = 0; |
| 1579 | unsigned int i = 0; |
| 1580 | struct ipt_entry *iter; |
| 1581 | |
| 1582 | counters = alloc_counters(table); |
| 1583 | if (IS_ERR(counters)) |
| 1584 | return PTR_ERR(counters); |
| 1585 | |
| 1586 | pos = userptr; |
| 1587 | size = total_size; |
| 1588 | xt_entry_foreach(iter, private->entries, total_size) { |
| 1589 | ret = compat_copy_entry_to_user(iter, &pos, |
| 1590 | &size, counters, i++); |
| 1591 | if (ret != 0) |
| 1592 | break; |
| 1593 | } |
| 1594 | |
| 1595 | vfree(counters); |
| 1596 | return ret; |
| 1597 | } |
| 1598 | |
| 1599 | static int |
| 1600 | compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr, |
| 1601 | int *len) |
| 1602 | { |
| 1603 | int ret; |
| 1604 | struct compat_ipt_get_entries get; |
| 1605 | struct xt_table *t; |
| 1606 | |
| 1607 | if (*len < sizeof(get)) |
| 1608 | return -EINVAL; |
| 1609 | |
| 1610 | if (copy_from_user(&get, uptr, sizeof(get)) != 0) |
| 1611 | return -EFAULT; |
| 1612 | |
| 1613 | if (*len != sizeof(struct compat_ipt_get_entries) + get.size) |
| 1614 | return -EINVAL; |
| 1615 | |
| 1616 | get.name[sizeof(get.name) - 1] = '\0'; |
| 1617 | |
| 1618 | xt_compat_lock(AF_INET); |
| 1619 | t = xt_find_table_lock(net, AF_INET, get.name); |
| 1620 | if (t) { |
| 1621 | const struct xt_table_info *private = t->private; |
| 1622 | struct xt_table_info info; |
| 1623 | ret = compat_table_info(private, &info); |
| 1624 | if (!ret && get.size == info.size) |
| 1625 | ret = compat_copy_entries_to_user(private->size, |
| 1626 | t, uptr->entrytable); |
| 1627 | else if (!ret) |
| 1628 | ret = -EAGAIN; |
| 1629 | |
| 1630 | xt_compat_flush_offsets(AF_INET); |
| 1631 | module_put(t->me); |
| 1632 | xt_table_unlock(t); |
| 1633 | } else |
| 1634 | ret = -ENOENT; |
| 1635 | |
| 1636 | xt_compat_unlock(AF_INET); |
| 1637 | return ret; |
| 1638 | } |
| 1639 | |
| 1640 | static int do_ipt_get_ctl(struct sock *, int, void __user *, int *); |
| 1641 | |
| 1642 | static int |
| 1643 | compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| 1644 | { |
| 1645 | int ret; |
| 1646 | |
| 1647 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) |
| 1648 | return -EPERM; |
| 1649 | |
| 1650 | switch (cmd) { |
| 1651 | case IPT_SO_GET_INFO: |
| 1652 | ret = get_info(sock_net(sk), user, len, 1); |
| 1653 | break; |
| 1654 | case IPT_SO_GET_ENTRIES: |
| 1655 | ret = compat_get_entries(sock_net(sk), user, len); |
| 1656 | break; |
| 1657 | default: |
| 1658 | ret = do_ipt_get_ctl(sk, cmd, user, len); |
| 1659 | } |
| 1660 | return ret; |
| 1661 | } |
| 1662 | #endif |
| 1663 | |
| 1664 | static int |
| 1665 | do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) |
| 1666 | { |
| 1667 | int ret; |
| 1668 | |
| 1669 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) |
| 1670 | return -EPERM; |
| 1671 | |
| 1672 | switch (cmd) { |
| 1673 | case IPT_SO_SET_REPLACE: |
| 1674 | ret = do_replace(sock_net(sk), user, len); |
| 1675 | break; |
| 1676 | |
| 1677 | case IPT_SO_SET_ADD_COUNTERS: |
| 1678 | ret = do_add_counters(sock_net(sk), user, len, 0); |
| 1679 | break; |
| 1680 | |
| 1681 | default: |
| 1682 | ret = -EINVAL; |
| 1683 | } |
| 1684 | |
| 1685 | return ret; |
| 1686 | } |
| 1687 | |
| 1688 | static int |
| 1689 | do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) |
| 1690 | { |
| 1691 | int ret; |
| 1692 | |
| 1693 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) |
| 1694 | return -EPERM; |
| 1695 | |
| 1696 | switch (cmd) { |
| 1697 | case IPT_SO_GET_INFO: |
| 1698 | ret = get_info(sock_net(sk), user, len, 0); |
| 1699 | break; |
| 1700 | |
| 1701 | case IPT_SO_GET_ENTRIES: |
| 1702 | ret = get_entries(sock_net(sk), user, len); |
| 1703 | break; |
| 1704 | |
| 1705 | case IPT_SO_GET_REVISION_MATCH: |
| 1706 | case IPT_SO_GET_REVISION_TARGET: { |
| 1707 | struct xt_get_revision rev; |
| 1708 | int target; |
| 1709 | |
| 1710 | if (*len != sizeof(rev)) { |
| 1711 | ret = -EINVAL; |
| 1712 | break; |
| 1713 | } |
| 1714 | if (copy_from_user(&rev, user, sizeof(rev)) != 0) { |
| 1715 | ret = -EFAULT; |
| 1716 | break; |
| 1717 | } |
| 1718 | rev.name[sizeof(rev.name)-1] = 0; |
| 1719 | |
| 1720 | if (cmd == IPT_SO_GET_REVISION_TARGET) |
| 1721 | target = 1; |
| 1722 | else |
| 1723 | target = 0; |
| 1724 | |
| 1725 | try_then_request_module(xt_find_revision(AF_INET, rev.name, |
| 1726 | rev.revision, |
| 1727 | target, &ret), |
| 1728 | "ipt_%s", rev.name); |
| 1729 | break; |
| 1730 | } |
| 1731 | |
| 1732 | default: |
| 1733 | ret = -EINVAL; |
| 1734 | } |
| 1735 | |
| 1736 | return ret; |
| 1737 | } |
| 1738 | |
| 1739 | static void __ipt_unregister_table(struct net *net, struct xt_table *table) |
| 1740 | { |
| 1741 | struct xt_table_info *private; |
| 1742 | void *loc_cpu_entry; |
| 1743 | struct module *table_owner = table->me; |
| 1744 | struct ipt_entry *iter; |
| 1745 | |
| 1746 | private = xt_unregister_table(table); |
| 1747 | |
| 1748 | /* Decrease module usage counts and free resources */ |
| 1749 | loc_cpu_entry = private->entries; |
| 1750 | xt_entry_foreach(iter, loc_cpu_entry, private->size) |
| 1751 | cleanup_entry(iter, net); |
| 1752 | if (private->number > private->initial_entries) |
| 1753 | module_put(table_owner); |
| 1754 | xt_free_table_info(private); |
| 1755 | } |
| 1756 | |
| 1757 | int ipt_register_table(struct net *net, const struct xt_table *table, |
| 1758 | const struct ipt_replace *repl, |
| 1759 | const struct nf_hook_ops *ops, struct xt_table **res) |
| 1760 | { |
| 1761 | int ret; |
| 1762 | struct xt_table_info *newinfo; |
| 1763 | struct xt_table_info bootstrap = {0}; |
| 1764 | void *loc_cpu_entry; |
| 1765 | struct xt_table *new_table; |
| 1766 | |
| 1767 | newinfo = xt_alloc_table_info(repl->size); |
| 1768 | if (!newinfo) |
| 1769 | return -ENOMEM; |
| 1770 | |
| 1771 | loc_cpu_entry = newinfo->entries; |
| 1772 | memcpy(loc_cpu_entry, repl->entries, repl->size); |
| 1773 | |
| 1774 | ret = translate_table(net, newinfo, loc_cpu_entry, repl); |
| 1775 | if (ret != 0) |
| 1776 | goto out_free; |
| 1777 | |
| 1778 | new_table = xt_register_table(net, table, &bootstrap, newinfo); |
| 1779 | if (IS_ERR(new_table)) { |
| 1780 | ret = PTR_ERR(new_table); |
| 1781 | goto out_free; |
| 1782 | } |
| 1783 | |
| 1784 | /* set res now, will see skbs right after nf_register_net_hooks */ |
| 1785 | WRITE_ONCE(*res, new_table); |
| 1786 | |
| 1787 | ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); |
| 1788 | if (ret != 0) { |
| 1789 | __ipt_unregister_table(net, new_table); |
| 1790 | *res = NULL; |
| 1791 | } |
| 1792 | |
| 1793 | return ret; |
| 1794 | |
| 1795 | out_free: |
| 1796 | xt_free_table_info(newinfo); |
| 1797 | return ret; |
| 1798 | } |
| 1799 | |
| 1800 | void ipt_unregister_table(struct net *net, struct xt_table *table, |
| 1801 | const struct nf_hook_ops *ops) |
| 1802 | { |
| 1803 | nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); |
| 1804 | __ipt_unregister_table(net, table); |
| 1805 | } |
| 1806 | |
| 1807 | /* Returns 1 if the type and code is matched by the range, 0 otherwise */ |
| 1808 | static inline bool |
| 1809 | icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, |
| 1810 | u_int8_t type, u_int8_t code, |
| 1811 | bool invert) |
| 1812 | { |
| 1813 | return ((test_type == 0xFF) || |
| 1814 | (type == test_type && code >= min_code && code <= max_code)) |
| 1815 | ^ invert; |
| 1816 | } |
| 1817 | |
| 1818 | static bool |
| 1819 | icmp_match(const struct sk_buff *skb, struct xt_action_param *par) |
| 1820 | { |
| 1821 | const struct icmphdr *ic; |
| 1822 | struct icmphdr _icmph; |
| 1823 | const struct ipt_icmp *icmpinfo = par->matchinfo; |
| 1824 | |
| 1825 | /* Must not be a fragment. */ |
| 1826 | if (par->fragoff != 0) |
| 1827 | return false; |
| 1828 | |
| 1829 | ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); |
| 1830 | if (ic == NULL) { |
| 1831 | /* We've been asked to examine this packet, and we |
| 1832 | * can't. Hence, no choice but to drop. |
| 1833 | */ |
| 1834 | par->hotdrop = true; |
| 1835 | return false; |
| 1836 | } |
| 1837 | |
| 1838 | return icmp_type_code_match(icmpinfo->type, |
| 1839 | icmpinfo->code[0], |
| 1840 | icmpinfo->code[1], |
| 1841 | ic->type, ic->code, |
| 1842 | !!(icmpinfo->invflags&IPT_ICMP_INV)); |
| 1843 | } |
| 1844 | |
| 1845 | static int icmp_checkentry(const struct xt_mtchk_param *par) |
| 1846 | { |
| 1847 | const struct ipt_icmp *icmpinfo = par->matchinfo; |
| 1848 | |
| 1849 | /* Must specify no unknown invflags */ |
| 1850 | return (icmpinfo->invflags & ~IPT_ICMP_INV) ? -EINVAL : 0; |
| 1851 | } |
| 1852 | |
| 1853 | static struct xt_target ipt_builtin_tg[] __read_mostly = { |
| 1854 | { |
| 1855 | .name = XT_STANDARD_TARGET, |
| 1856 | .targetsize = sizeof(int), |
| 1857 | .family = NFPROTO_IPV4, |
| 1858 | #ifdef CONFIG_COMPAT |
| 1859 | .compatsize = sizeof(compat_int_t), |
| 1860 | .compat_from_user = compat_standard_from_user, |
| 1861 | .compat_to_user = compat_standard_to_user, |
| 1862 | #endif |
| 1863 | }, |
| 1864 | { |
| 1865 | .name = XT_ERROR_TARGET, |
| 1866 | .target = ipt_error, |
| 1867 | .targetsize = XT_FUNCTION_MAXNAMELEN, |
| 1868 | .family = NFPROTO_IPV4, |
| 1869 | }, |
| 1870 | }; |
| 1871 | |
| 1872 | static struct nf_sockopt_ops ipt_sockopts = { |
| 1873 | .pf = PF_INET, |
| 1874 | .set_optmin = IPT_BASE_CTL, |
| 1875 | .set_optmax = IPT_SO_SET_MAX+1, |
| 1876 | .set = do_ipt_set_ctl, |
| 1877 | #ifdef CONFIG_COMPAT |
| 1878 | .compat_set = compat_do_ipt_set_ctl, |
| 1879 | #endif |
| 1880 | .get_optmin = IPT_BASE_CTL, |
| 1881 | .get_optmax = IPT_SO_GET_MAX+1, |
| 1882 | .get = do_ipt_get_ctl, |
| 1883 | #ifdef CONFIG_COMPAT |
| 1884 | .compat_get = compat_do_ipt_get_ctl, |
| 1885 | #endif |
| 1886 | .owner = THIS_MODULE, |
| 1887 | }; |
| 1888 | |
| 1889 | static struct xt_match ipt_builtin_mt[] __read_mostly = { |
| 1890 | { |
| 1891 | .name = "icmp", |
| 1892 | .match = icmp_match, |
| 1893 | .matchsize = sizeof(struct ipt_icmp), |
| 1894 | .checkentry = icmp_checkentry, |
| 1895 | .proto = IPPROTO_ICMP, |
| 1896 | .family = NFPROTO_IPV4, |
| 1897 | .me = THIS_MODULE, |
| 1898 | }, |
| 1899 | }; |
| 1900 | |
| 1901 | static int __net_init ip_tables_net_init(struct net *net) |
| 1902 | { |
| 1903 | return xt_proto_init(net, NFPROTO_IPV4); |
| 1904 | } |
| 1905 | |
| 1906 | static void __net_exit ip_tables_net_exit(struct net *net) |
| 1907 | { |
| 1908 | xt_proto_fini(net, NFPROTO_IPV4); |
| 1909 | } |
| 1910 | |
| 1911 | static struct pernet_operations ip_tables_net_ops = { |
| 1912 | .init = ip_tables_net_init, |
| 1913 | .exit = ip_tables_net_exit, |
| 1914 | }; |
| 1915 | |
| 1916 | static int __init ip_tables_init(void) |
| 1917 | { |
| 1918 | int ret; |
| 1919 | |
| 1920 | ret = register_pernet_subsys(&ip_tables_net_ops); |
| 1921 | if (ret < 0) |
| 1922 | goto err1; |
| 1923 | |
| 1924 | /* No one else will be downing sem now, so we won't sleep */ |
| 1925 | ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); |
| 1926 | if (ret < 0) |
| 1927 | goto err2; |
| 1928 | ret = xt_register_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); |
| 1929 | if (ret < 0) |
| 1930 | goto err4; |
| 1931 | |
| 1932 | /* Register setsockopt */ |
| 1933 | ret = nf_register_sockopt(&ipt_sockopts); |
| 1934 | if (ret < 0) |
| 1935 | goto err5; |
| 1936 | |
| 1937 | pr_info("(C) 2000-2006 Netfilter Core Team\n"); |
| 1938 | return 0; |
| 1939 | |
| 1940 | err5: |
| 1941 | xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); |
| 1942 | err4: |
| 1943 | xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); |
| 1944 | err2: |
| 1945 | unregister_pernet_subsys(&ip_tables_net_ops); |
| 1946 | err1: |
| 1947 | return ret; |
| 1948 | } |
| 1949 | |
| 1950 | static void __exit ip_tables_fini(void) |
| 1951 | { |
| 1952 | nf_unregister_sockopt(&ipt_sockopts); |
| 1953 | |
| 1954 | xt_unregister_matches(ipt_builtin_mt, ARRAY_SIZE(ipt_builtin_mt)); |
| 1955 | xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); |
| 1956 | unregister_pernet_subsys(&ip_tables_net_ops); |
| 1957 | } |
| 1958 | |
| 1959 | EXPORT_SYMBOL(ipt_register_table); |
| 1960 | EXPORT_SYMBOL(ipt_unregister_table); |
| 1961 | EXPORT_SYMBOL(ipt_do_table); |
| 1962 | module_init(ip_tables_init); |
| 1963 | module_exit(ip_tables_fini); |