1 /* 2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> 3 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * Development of this code funded by Astaro AG (http://www.astaro.com/) 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/module.h> 15 #include <linux/netlink.h> 16 #include <linux/netfilter.h> 17 #include <linux/netfilter/nf_tables.h> 18 #include <net/netfilter/nf_tables.h> 19 #include <net/netfilter/nf_conntrack.h> 20 #include <net/netfilter/nf_conntrack_acct.h> 21 #include <net/netfilter/nf_conntrack_tuple.h> 22 #include <net/netfilter/nf_conntrack_helper.h> 23 #include <net/netfilter/nf_conntrack_ecache.h> 24 #include <net/netfilter/nf_conntrack_labels.h> 25 26 struct nft_ct { 27 enum nft_ct_keys key:8; 28 enum ip_conntrack_dir dir:8; 29 union { 30 enum nft_registers dreg:8; 31 enum nft_registers sreg:8; 32 }; 33 }; 34 35 struct nft_ct_helper_obj { 36 struct nf_conntrack_helper *helper4; 37 struct nf_conntrack_helper *helper6; 38 u8 l4proto; 39 }; 40 41 #ifdef CONFIG_NF_CONNTRACK_ZONES 42 static DEFINE_PER_CPU(struct nf_conn *, nft_ct_pcpu_template); 43 static unsigned int nft_ct_pcpu_template_refcnt __read_mostly; 44 #endif 45 46 static u64 nft_ct_get_eval_counter(const struct nf_conn_counter *c, 47 enum nft_ct_keys k, 48 enum ip_conntrack_dir d) 49 { 50 if (d < IP_CT_DIR_MAX) 51 return k == NFT_CT_BYTES ? atomic64_read(&c[d].bytes) : 52 atomic64_read(&c[d].packets); 53 54 return nft_ct_get_eval_counter(c, k, IP_CT_DIR_ORIGINAL) + 55 nft_ct_get_eval_counter(c, k, IP_CT_DIR_REPLY); 56 } 57 58 static void nft_ct_get_eval(const struct nft_expr *expr, 59 struct nft_regs *regs, 60 const struct nft_pktinfo *pkt) 61 { 62 const struct nft_ct *priv = nft_expr_priv(expr); 63 u32 *dest = ®s->data[priv->dreg]; 64 enum ip_conntrack_info ctinfo; 65 const struct nf_conn *ct; 66 const struct nf_conn_help *help; 67 const struct nf_conntrack_tuple *tuple; 68 const struct nf_conntrack_helper *helper; 69 unsigned int state; 70 71 ct = nf_ct_get(pkt->skb, &ctinfo); 72 73 switch (priv->key) { 74 case NFT_CT_STATE: 75 if (ct) 76 state = NF_CT_STATE_BIT(ctinfo); 77 else if (ctinfo == IP_CT_UNTRACKED) 78 state = NF_CT_STATE_UNTRACKED_BIT; 79 else 80 state = NF_CT_STATE_INVALID_BIT; 81 *dest = state; 82 return; 83 default: 84 break; 85 } 86 87 if (ct == NULL) 88 goto err; 89 90 switch (priv->key) { 91 case NFT_CT_DIRECTION: 92 nft_reg_store8(dest, CTINFO2DIR(ctinfo)); 93 return; 94 case NFT_CT_STATUS: 95 *dest = ct->status; 96 return; 97 #ifdef CONFIG_NF_CONNTRACK_MARK 98 case NFT_CT_MARK: 99 *dest = ct->mark; 100 return; 101 #endif 102 #ifdef CONFIG_NF_CONNTRACK_SECMARK 103 case NFT_CT_SECMARK: 104 *dest = ct->secmark; 105 return; 106 #endif 107 case NFT_CT_EXPIRATION: 108 *dest = jiffies_to_msecs(nf_ct_expires(ct)); 109 return; 110 case NFT_CT_HELPER: 111 if (ct->master == NULL) 112 goto err; 113 help = nfct_help(ct->master); 114 if (help == NULL) 115 goto err; 116 helper = rcu_dereference(help->helper); 117 if (helper == NULL) 118 goto err; 119 strncpy((char *)dest, helper->name, NF_CT_HELPER_NAME_LEN); 120 return; 121 #ifdef CONFIG_NF_CONNTRACK_LABELS 122 case NFT_CT_LABELS: { 123 struct nf_conn_labels *labels = nf_ct_labels_find(ct); 124 125 if (labels) 126 memcpy(dest, labels->bits, NF_CT_LABELS_MAX_SIZE); 127 else 128 memset(dest, 0, NF_CT_LABELS_MAX_SIZE); 129 return; 130 } 131 #endif 132 case NFT_CT_BYTES: /* fallthrough */ 133 case NFT_CT_PKTS: { 134 const struct nf_conn_acct *acct = nf_conn_acct_find(ct); 135 u64 count = 0; 136 137 if (acct) 138 count = nft_ct_get_eval_counter(acct->counter, 139 priv->key, priv->dir); 140 memcpy(dest, &count, sizeof(count)); 141 return; 142 } 143 case NFT_CT_AVGPKT: { 144 const struct nf_conn_acct *acct = nf_conn_acct_find(ct); 145 u64 avgcnt = 0, bcnt = 0, pcnt = 0; 146 147 if (acct) { 148 pcnt = nft_ct_get_eval_counter(acct->counter, 149 NFT_CT_PKTS, priv->dir); 150 bcnt = nft_ct_get_eval_counter(acct->counter, 151 NFT_CT_BYTES, priv->dir); 152 if (pcnt != 0) 153 avgcnt = div64_u64(bcnt, pcnt); 154 } 155 156 memcpy(dest, &avgcnt, sizeof(avgcnt)); 157 return; 158 } 159 case NFT_CT_L3PROTOCOL: 160 nft_reg_store8(dest, nf_ct_l3num(ct)); 161 return; 162 case NFT_CT_PROTOCOL: 163 nft_reg_store8(dest, nf_ct_protonum(ct)); 164 return; 165 #ifdef CONFIG_NF_CONNTRACK_ZONES 166 case NFT_CT_ZONE: { 167 const struct nf_conntrack_zone *zone = nf_ct_zone(ct); 168 u16 zoneid; 169 170 if (priv->dir < IP_CT_DIR_MAX) 171 zoneid = nf_ct_zone_id(zone, priv->dir); 172 else 173 zoneid = zone->id; 174 175 nft_reg_store16(dest, zoneid); 176 return; 177 } 178 #endif 179 default: 180 break; 181 } 182 183 tuple = &ct->tuplehash[priv->dir].tuple; 184 switch (priv->key) { 185 case NFT_CT_SRC: 186 memcpy(dest, tuple->src.u3.all, 187 nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); 188 return; 189 case NFT_CT_DST: 190 memcpy(dest, tuple->dst.u3.all, 191 nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16); 192 return; 193 case NFT_CT_PROTO_SRC: 194 nft_reg_store16(dest, (__force u16)tuple->src.u.all); 195 return; 196 case NFT_CT_PROTO_DST: 197 nft_reg_store16(dest, (__force u16)tuple->dst.u.all); 198 return; 199 case NFT_CT_SRC_IP: 200 if (nf_ct_l3num(ct) != NFPROTO_IPV4) 201 goto err; 202 *dest = tuple->src.u3.ip; 203 return; 204 case NFT_CT_DST_IP: 205 if (nf_ct_l3num(ct) != NFPROTO_IPV4) 206 goto err; 207 *dest = tuple->dst.u3.ip; 208 return; 209 case NFT_CT_SRC_IP6: 210 if (nf_ct_l3num(ct) != NFPROTO_IPV6) 211 goto err; 212 memcpy(dest, tuple->src.u3.ip6, sizeof(struct in6_addr)); 213 return; 214 case NFT_CT_DST_IP6: 215 if (nf_ct_l3num(ct) != NFPROTO_IPV6) 216 goto err; 217 memcpy(dest, tuple->dst.u3.ip6, sizeof(struct in6_addr)); 218 return; 219 default: 220 break; 221 } 222 return; 223 err: 224 regs->verdict.code = NFT_BREAK; 225 } 226 227 #ifdef CONFIG_NF_CONNTRACK_ZONES 228 static void nft_ct_set_zone_eval(const struct nft_expr *expr, 229 struct nft_regs *regs, 230 const struct nft_pktinfo *pkt) 231 { 232 struct nf_conntrack_zone zone = { .dir = NF_CT_DEFAULT_ZONE_DIR }; 233 const struct nft_ct *priv = nft_expr_priv(expr); 234 struct sk_buff *skb = pkt->skb; 235 enum ip_conntrack_info ctinfo; 236 u16 value = nft_reg_load16(®s->data[priv->sreg]); 237 struct nf_conn *ct; 238 239 ct = nf_ct_get(skb, &ctinfo); 240 if (ct) /* already tracked */ 241 return; 242 243 zone.id = value; 244 245 switch (priv->dir) { 246 case IP_CT_DIR_ORIGINAL: 247 zone.dir = NF_CT_ZONE_DIR_ORIG; 248 break; 249 case IP_CT_DIR_REPLY: 250 zone.dir = NF_CT_ZONE_DIR_REPL; 251 break; 252 default: 253 break; 254 } 255 256 ct = this_cpu_read(nft_ct_pcpu_template); 257 258 if (likely(atomic_read(&ct->ct_general.use) == 1)) { 259 nf_ct_zone_add(ct, &zone); 260 } else { 261 /* previous skb got queued to userspace */ 262 ct = nf_ct_tmpl_alloc(nft_net(pkt), &zone, GFP_ATOMIC); 263 if (!ct) { 264 regs->verdict.code = NF_DROP; 265 return; 266 } 267 } 268 269 atomic_inc(&ct->ct_general.use); 270 nf_ct_set(skb, ct, IP_CT_NEW); 271 } 272 #endif 273 274 static void nft_ct_set_eval(const struct nft_expr *expr, 275 struct nft_regs *regs, 276 const struct nft_pktinfo *pkt) 277 { 278 const struct nft_ct *priv = nft_expr_priv(expr); 279 struct sk_buff *skb = pkt->skb; 280 #ifdef CONFIG_NF_CONNTRACK_MARK 281 u32 value = regs->data[priv->sreg]; 282 #endif 283 enum ip_conntrack_info ctinfo; 284 struct nf_conn *ct; 285 286 ct = nf_ct_get(skb, &ctinfo); 287 if (ct == NULL || nf_ct_is_template(ct)) 288 return; 289 290 switch (priv->key) { 291 #ifdef CONFIG_NF_CONNTRACK_MARK 292 case NFT_CT_MARK: 293 if (ct->mark != value) { 294 ct->mark = value; 295 nf_conntrack_event_cache(IPCT_MARK, ct); 296 } 297 break; 298 #endif 299 #ifdef CONFIG_NF_CONNTRACK_LABELS 300 case NFT_CT_LABELS: 301 nf_connlabels_replace(ct, 302 ®s->data[priv->sreg], 303 ®s->data[priv->sreg], 304 NF_CT_LABELS_MAX_SIZE / sizeof(u32)); 305 break; 306 #endif 307 #ifdef CONFIG_NF_CONNTRACK_EVENTS 308 case NFT_CT_EVENTMASK: { 309 struct nf_conntrack_ecache *e = nf_ct_ecache_find(ct); 310 u32 ctmask = regs->data[priv->sreg]; 311 312 if (e) { 313 if (e->ctmask != ctmask) 314 e->ctmask = ctmask; 315 break; 316 } 317 318 if (ctmask && !nf_ct_is_confirmed(ct)) 319 nf_ct_ecache_ext_add(ct, ctmask, 0, GFP_ATOMIC); 320 break; 321 } 322 #endif 323 default: 324 break; 325 } 326 } 327 328 static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = { 329 [NFTA_CT_DREG] = { .type = NLA_U32 }, 330 [NFTA_CT_KEY] = { .type = NLA_U32 }, 331 [NFTA_CT_DIRECTION] = { .type = NLA_U8 }, 332 [NFTA_CT_SREG] = { .type = NLA_U32 }, 333 }; 334 335 #ifdef CONFIG_NF_CONNTRACK_ZONES 336 static void nft_ct_tmpl_put_pcpu(void) 337 { 338 struct nf_conn *ct; 339 int cpu; 340 341 for_each_possible_cpu(cpu) { 342 ct = per_cpu(nft_ct_pcpu_template, cpu); 343 if (!ct) 344 break; 345 nf_ct_put(ct); 346 per_cpu(nft_ct_pcpu_template, cpu) = NULL; 347 } 348 } 349 350 static bool nft_ct_tmpl_alloc_pcpu(void) 351 { 352 struct nf_conntrack_zone zone = { .id = 0 }; 353 struct nf_conn *tmp; 354 int cpu; 355 356 if (nft_ct_pcpu_template_refcnt) 357 return true; 358 359 for_each_possible_cpu(cpu) { 360 tmp = nf_ct_tmpl_alloc(&init_net, &zone, GFP_KERNEL); 361 if (!tmp) { 362 nft_ct_tmpl_put_pcpu(); 363 return false; 364 } 365 366 atomic_set(&tmp->ct_general.use, 1); 367 per_cpu(nft_ct_pcpu_template, cpu) = tmp; 368 } 369 370 return true; 371 } 372 #endif 373 374 static int nft_ct_get_init(const struct nft_ctx *ctx, 375 const struct nft_expr *expr, 376 const struct nlattr * const tb[]) 377 { 378 struct nft_ct *priv = nft_expr_priv(expr); 379 unsigned int len; 380 int err; 381 382 priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY])); 383 priv->dir = IP_CT_DIR_MAX; 384 switch (priv->key) { 385 case NFT_CT_DIRECTION: 386 if (tb[NFTA_CT_DIRECTION] != NULL) 387 return -EINVAL; 388 len = sizeof(u8); 389 break; 390 case NFT_CT_STATE: 391 case NFT_CT_STATUS: 392 #ifdef CONFIG_NF_CONNTRACK_MARK 393 case NFT_CT_MARK: 394 #endif 395 #ifdef CONFIG_NF_CONNTRACK_SECMARK 396 case NFT_CT_SECMARK: 397 #endif 398 case NFT_CT_EXPIRATION: 399 if (tb[NFTA_CT_DIRECTION] != NULL) 400 return -EINVAL; 401 len = sizeof(u32); 402 break; 403 #ifdef CONFIG_NF_CONNTRACK_LABELS 404 case NFT_CT_LABELS: 405 if (tb[NFTA_CT_DIRECTION] != NULL) 406 return -EINVAL; 407 len = NF_CT_LABELS_MAX_SIZE; 408 break; 409 #endif 410 case NFT_CT_HELPER: 411 if (tb[NFTA_CT_DIRECTION] != NULL) 412 return -EINVAL; 413 len = NF_CT_HELPER_NAME_LEN; 414 break; 415 416 case NFT_CT_L3PROTOCOL: 417 case NFT_CT_PROTOCOL: 418 /* For compatibility, do not report error if NFTA_CT_DIRECTION 419 * attribute is specified. 420 */ 421 len = sizeof(u8); 422 break; 423 case NFT_CT_SRC: 424 case NFT_CT_DST: 425 if (tb[NFTA_CT_DIRECTION] == NULL) 426 return -EINVAL; 427 428 switch (ctx->family) { 429 case NFPROTO_IPV4: 430 len = FIELD_SIZEOF(struct nf_conntrack_tuple, 431 src.u3.ip); 432 break; 433 case NFPROTO_IPV6: 434 case NFPROTO_INET: 435 len = FIELD_SIZEOF(struct nf_conntrack_tuple, 436 src.u3.ip6); 437 break; 438 default: 439 return -EAFNOSUPPORT; 440 } 441 break; 442 case NFT_CT_SRC_IP: 443 case NFT_CT_DST_IP: 444 if (tb[NFTA_CT_DIRECTION] == NULL) 445 return -EINVAL; 446 447 len = FIELD_SIZEOF(struct nf_conntrack_tuple, src.u3.ip); 448 break; 449 case NFT_CT_SRC_IP6: 450 case NFT_CT_DST_IP6: 451 if (tb[NFTA_CT_DIRECTION] == NULL) 452 return -EINVAL; 453 454 len = FIELD_SIZEOF(struct nf_conntrack_tuple, src.u3.ip6); 455 break; 456 case NFT_CT_PROTO_SRC: 457 case NFT_CT_PROTO_DST: 458 if (tb[NFTA_CT_DIRECTION] == NULL) 459 return -EINVAL; 460 len = FIELD_SIZEOF(struct nf_conntrack_tuple, src.u.all); 461 break; 462 case NFT_CT_BYTES: 463 case NFT_CT_PKTS: 464 case NFT_CT_AVGPKT: 465 len = sizeof(u64); 466 break; 467 #ifdef CONFIG_NF_CONNTRACK_ZONES 468 case NFT_CT_ZONE: 469 len = sizeof(u16); 470 break; 471 #endif 472 default: 473 return -EOPNOTSUPP; 474 } 475 476 if (tb[NFTA_CT_DIRECTION] != NULL) { 477 priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]); 478 switch (priv->dir) { 479 case IP_CT_DIR_ORIGINAL: 480 case IP_CT_DIR_REPLY: 481 break; 482 default: 483 return -EINVAL; 484 } 485 } 486 487 priv->dreg = nft_parse_register(tb[NFTA_CT_DREG]); 488 err = nft_validate_register_store(ctx, priv->dreg, NULL, 489 NFT_DATA_VALUE, len); 490 if (err < 0) 491 return err; 492 493 err = nf_ct_netns_get(ctx->net, ctx->family); 494 if (err < 0) 495 return err; 496 497 if (priv->key == NFT_CT_BYTES || 498 priv->key == NFT_CT_PKTS || 499 priv->key == NFT_CT_AVGPKT) 500 nf_ct_set_acct(ctx->net, true); 501 502 return 0; 503 } 504 505 static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv) 506 { 507 switch (priv->key) { 508 #ifdef CONFIG_NF_CONNTRACK_LABELS 509 case NFT_CT_LABELS: 510 nf_connlabels_put(ctx->net); 511 break; 512 #endif 513 #ifdef CONFIG_NF_CONNTRACK_ZONES 514 case NFT_CT_ZONE: 515 if (--nft_ct_pcpu_template_refcnt == 0) 516 nft_ct_tmpl_put_pcpu(); 517 #endif 518 default: 519 break; 520 } 521 } 522 523 static int nft_ct_set_init(const struct nft_ctx *ctx, 524 const struct nft_expr *expr, 525 const struct nlattr * const tb[]) 526 { 527 struct nft_ct *priv = nft_expr_priv(expr); 528 unsigned int len; 529 int err; 530 531 priv->dir = IP_CT_DIR_MAX; 532 priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY])); 533 switch (priv->key) { 534 #ifdef CONFIG_NF_CONNTRACK_MARK 535 case NFT_CT_MARK: 536 if (tb[NFTA_CT_DIRECTION]) 537 return -EINVAL; 538 len = FIELD_SIZEOF(struct nf_conn, mark); 539 break; 540 #endif 541 #ifdef CONFIG_NF_CONNTRACK_LABELS 542 case NFT_CT_LABELS: 543 if (tb[NFTA_CT_DIRECTION]) 544 return -EINVAL; 545 len = NF_CT_LABELS_MAX_SIZE; 546 err = nf_connlabels_get(ctx->net, (len * BITS_PER_BYTE) - 1); 547 if (err) 548 return err; 549 break; 550 #endif 551 #ifdef CONFIG_NF_CONNTRACK_ZONES 552 case NFT_CT_ZONE: 553 if (!nft_ct_tmpl_alloc_pcpu()) 554 return -ENOMEM; 555 nft_ct_pcpu_template_refcnt++; 556 len = sizeof(u16); 557 break; 558 #endif 559 #ifdef CONFIG_NF_CONNTRACK_EVENTS 560 case NFT_CT_EVENTMASK: 561 if (tb[NFTA_CT_DIRECTION]) 562 return -EINVAL; 563 len = sizeof(u32); 564 break; 565 #endif 566 default: 567 return -EOPNOTSUPP; 568 } 569 570 if (tb[NFTA_CT_DIRECTION]) { 571 priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]); 572 switch (priv->dir) { 573 case IP_CT_DIR_ORIGINAL: 574 case IP_CT_DIR_REPLY: 575 break; 576 default: 577 err = -EINVAL; 578 goto err1; 579 } 580 } 581 582 priv->sreg = nft_parse_register(tb[NFTA_CT_SREG]); 583 err = nft_validate_register_load(priv->sreg, len); 584 if (err < 0) 585 goto err1; 586 587 err = nf_ct_netns_get(ctx->net, ctx->family); 588 if (err < 0) 589 goto err1; 590 591 return 0; 592 593 err1: 594 __nft_ct_set_destroy(ctx, priv); 595 return err; 596 } 597 598 static void nft_ct_get_destroy(const struct nft_ctx *ctx, 599 const struct nft_expr *expr) 600 { 601 nf_ct_netns_put(ctx->net, ctx->family); 602 } 603 604 static void nft_ct_set_destroy(const struct nft_ctx *ctx, 605 const struct nft_expr *expr) 606 { 607 struct nft_ct *priv = nft_expr_priv(expr); 608 609 __nft_ct_set_destroy(ctx, priv); 610 nf_ct_netns_put(ctx->net, ctx->family); 611 } 612 613 static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr) 614 { 615 const struct nft_ct *priv = nft_expr_priv(expr); 616 617 if (nft_dump_register(skb, NFTA_CT_DREG, priv->dreg)) 618 goto nla_put_failure; 619 if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) 620 goto nla_put_failure; 621 622 switch (priv->key) { 623 case NFT_CT_SRC: 624 case NFT_CT_DST: 625 case NFT_CT_SRC_IP: 626 case NFT_CT_DST_IP: 627 case NFT_CT_SRC_IP6: 628 case NFT_CT_DST_IP6: 629 case NFT_CT_PROTO_SRC: 630 case NFT_CT_PROTO_DST: 631 if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir)) 632 goto nla_put_failure; 633 break; 634 case NFT_CT_BYTES: 635 case NFT_CT_PKTS: 636 case NFT_CT_AVGPKT: 637 case NFT_CT_ZONE: 638 if (priv->dir < IP_CT_DIR_MAX && 639 nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir)) 640 goto nla_put_failure; 641 break; 642 default: 643 break; 644 } 645 646 return 0; 647 648 nla_put_failure: 649 return -1; 650 } 651 652 static int nft_ct_set_dump(struct sk_buff *skb, const struct nft_expr *expr) 653 { 654 const struct nft_ct *priv = nft_expr_priv(expr); 655 656 if (nft_dump_register(skb, NFTA_CT_SREG, priv->sreg)) 657 goto nla_put_failure; 658 if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key))) 659 goto nla_put_failure; 660 661 switch (priv->key) { 662 case NFT_CT_ZONE: 663 if (priv->dir < IP_CT_DIR_MAX && 664 nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir)) 665 goto nla_put_failure; 666 break; 667 default: 668 break; 669 } 670 671 return 0; 672 673 nla_put_failure: 674 return -1; 675 } 676 677 static struct nft_expr_type nft_ct_type; 678 static const struct nft_expr_ops nft_ct_get_ops = { 679 .type = &nft_ct_type, 680 .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), 681 .eval = nft_ct_get_eval, 682 .init = nft_ct_get_init, 683 .destroy = nft_ct_get_destroy, 684 .dump = nft_ct_get_dump, 685 }; 686 687 static const struct nft_expr_ops nft_ct_set_ops = { 688 .type = &nft_ct_type, 689 .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), 690 .eval = nft_ct_set_eval, 691 .init = nft_ct_set_init, 692 .destroy = nft_ct_set_destroy, 693 .dump = nft_ct_set_dump, 694 }; 695 696 #ifdef CONFIG_NF_CONNTRACK_ZONES 697 static const struct nft_expr_ops nft_ct_set_zone_ops = { 698 .type = &nft_ct_type, 699 .size = NFT_EXPR_SIZE(sizeof(struct nft_ct)), 700 .eval = nft_ct_set_zone_eval, 701 .init = nft_ct_set_init, 702 .destroy = nft_ct_set_destroy, 703 .dump = nft_ct_set_dump, 704 }; 705 #endif 706 707 static const struct nft_expr_ops * 708 nft_ct_select_ops(const struct nft_ctx *ctx, 709 const struct nlattr * const tb[]) 710 { 711 if (tb[NFTA_CT_KEY] == NULL) 712 return ERR_PTR(-EINVAL); 713 714 if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG]) 715 return ERR_PTR(-EINVAL); 716 717 if (tb[NFTA_CT_DREG]) 718 return &nft_ct_get_ops; 719 720 if (tb[NFTA_CT_SREG]) { 721 #ifdef CONFIG_NF_CONNTRACK_ZONES 722 if (nla_get_be32(tb[NFTA_CT_KEY]) == htonl(NFT_CT_ZONE)) 723 return &nft_ct_set_zone_ops; 724 #endif 725 return &nft_ct_set_ops; 726 } 727 728 return ERR_PTR(-EINVAL); 729 } 730 731 static struct nft_expr_type nft_ct_type __read_mostly = { 732 .name = "ct", 733 .select_ops = nft_ct_select_ops, 734 .policy = nft_ct_policy, 735 .maxattr = NFTA_CT_MAX, 736 .owner = THIS_MODULE, 737 }; 738 739 static void nft_notrack_eval(const struct nft_expr *expr, 740 struct nft_regs *regs, 741 const struct nft_pktinfo *pkt) 742 { 743 struct sk_buff *skb = pkt->skb; 744 enum ip_conntrack_info ctinfo; 745 struct nf_conn *ct; 746 747 ct = nf_ct_get(pkt->skb, &ctinfo); 748 /* Previously seen (loopback or untracked)? Ignore. */ 749 if (ct || ctinfo == IP_CT_UNTRACKED) 750 return; 751 752 nf_ct_set(skb, ct, IP_CT_UNTRACKED); 753 } 754 755 static struct nft_expr_type nft_notrack_type; 756 static const struct nft_expr_ops nft_notrack_ops = { 757 .type = &nft_notrack_type, 758 .size = NFT_EXPR_SIZE(0), 759 .eval = nft_notrack_eval, 760 }; 761 762 static struct nft_expr_type nft_notrack_type __read_mostly = { 763 .name = "notrack", 764 .ops = &nft_notrack_ops, 765 .owner = THIS_MODULE, 766 }; 767 768 static int nft_ct_helper_obj_init(const struct nft_ctx *ctx, 769 const struct nlattr * const tb[], 770 struct nft_object *obj) 771 { 772 struct nft_ct_helper_obj *priv = nft_obj_data(obj); 773 struct nf_conntrack_helper *help4, *help6; 774 char name[NF_CT_HELPER_NAME_LEN]; 775 int family = ctx->family; 776 777 if (!tb[NFTA_CT_HELPER_NAME] || !tb[NFTA_CT_HELPER_L4PROTO]) 778 return -EINVAL; 779 780 priv->l4proto = nla_get_u8(tb[NFTA_CT_HELPER_L4PROTO]); 781 if (!priv->l4proto) 782 return -ENOENT; 783 784 nla_strlcpy(name, tb[NFTA_CT_HELPER_NAME], sizeof(name)); 785 786 if (tb[NFTA_CT_HELPER_L3PROTO]) 787 family = ntohs(nla_get_be16(tb[NFTA_CT_HELPER_L3PROTO])); 788 789 help4 = NULL; 790 help6 = NULL; 791 792 switch (family) { 793 case NFPROTO_IPV4: 794 if (ctx->family == NFPROTO_IPV6) 795 return -EINVAL; 796 797 help4 = nf_conntrack_helper_try_module_get(name, family, 798 priv->l4proto); 799 break; 800 case NFPROTO_IPV6: 801 if (ctx->family == NFPROTO_IPV4) 802 return -EINVAL; 803 804 help6 = nf_conntrack_helper_try_module_get(name, family, 805 priv->l4proto); 806 break; 807 case NFPROTO_NETDEV: /* fallthrough */ 808 case NFPROTO_BRIDGE: /* same */ 809 case NFPROTO_INET: 810 help4 = nf_conntrack_helper_try_module_get(name, NFPROTO_IPV4, 811 priv->l4proto); 812 help6 = nf_conntrack_helper_try_module_get(name, NFPROTO_IPV6, 813 priv->l4proto); 814 break; 815 default: 816 return -EAFNOSUPPORT; 817 } 818 819 /* && is intentional; only error if INET found neither ipv4 or ipv6 */ 820 if (!help4 && !help6) 821 return -ENOENT; 822 823 priv->helper4 = help4; 824 priv->helper6 = help6; 825 826 return 0; 827 } 828 829 static void nft_ct_helper_obj_destroy(const struct nft_ctx *ctx, 830 struct nft_object *obj) 831 { 832 struct nft_ct_helper_obj *priv = nft_obj_data(obj); 833 834 if (priv->helper4) 835 nf_conntrack_helper_put(priv->helper4); 836 if (priv->helper6) 837 nf_conntrack_helper_put(priv->helper6); 838 } 839 840 static void nft_ct_helper_obj_eval(struct nft_object *obj, 841 struct nft_regs *regs, 842 const struct nft_pktinfo *pkt) 843 { 844 const struct nft_ct_helper_obj *priv = nft_obj_data(obj); 845 struct nf_conn *ct = (struct nf_conn *)skb_nfct(pkt->skb); 846 struct nf_conntrack_helper *to_assign = NULL; 847 struct nf_conn_help *help; 848 849 if (!ct || 850 nf_ct_is_confirmed(ct) || 851 nf_ct_is_template(ct) || 852 priv->l4proto != nf_ct_protonum(ct)) 853 return; 854 855 switch (nf_ct_l3num(ct)) { 856 case NFPROTO_IPV4: 857 to_assign = priv->helper4; 858 break; 859 case NFPROTO_IPV6: 860 to_assign = priv->helper6; 861 break; 862 default: 863 WARN_ON_ONCE(1); 864 return; 865 } 866 867 if (!to_assign) 868 return; 869 870 if (test_bit(IPS_HELPER_BIT, &ct->status)) 871 return; 872 873 help = nf_ct_helper_ext_add(ct, to_assign, GFP_ATOMIC); 874 if (help) { 875 rcu_assign_pointer(help->helper, to_assign); 876 set_bit(IPS_HELPER_BIT, &ct->status); 877 } 878 } 879 880 static int nft_ct_helper_obj_dump(struct sk_buff *skb, 881 struct nft_object *obj, bool reset) 882 { 883 const struct nft_ct_helper_obj *priv = nft_obj_data(obj); 884 const struct nf_conntrack_helper *helper; 885 u16 family; 886 887 if (priv->helper4 && priv->helper6) { 888 family = NFPROTO_INET; 889 helper = priv->helper4; 890 } else if (priv->helper6) { 891 family = NFPROTO_IPV6; 892 helper = priv->helper6; 893 } else { 894 family = NFPROTO_IPV4; 895 helper = priv->helper4; 896 } 897 898 if (nla_put_string(skb, NFTA_CT_HELPER_NAME, helper->name)) 899 return -1; 900 901 if (nla_put_u8(skb, NFTA_CT_HELPER_L4PROTO, priv->l4proto)) 902 return -1; 903 904 if (nla_put_be16(skb, NFTA_CT_HELPER_L3PROTO, htons(family))) 905 return -1; 906 907 return 0; 908 } 909 910 static const struct nla_policy nft_ct_helper_policy[NFTA_CT_HELPER_MAX + 1] = { 911 [NFTA_CT_HELPER_NAME] = { .type = NLA_STRING, 912 .len = NF_CT_HELPER_NAME_LEN - 1 }, 913 [NFTA_CT_HELPER_L3PROTO] = { .type = NLA_U16 }, 914 [NFTA_CT_HELPER_L4PROTO] = { .type = NLA_U8 }, 915 }; 916 917 static struct nft_object_type nft_ct_helper_obj_type; 918 static const struct nft_object_ops nft_ct_helper_obj_ops = { 919 .type = &nft_ct_helper_obj_type, 920 .size = sizeof(struct nft_ct_helper_obj), 921 .eval = nft_ct_helper_obj_eval, 922 .init = nft_ct_helper_obj_init, 923 .destroy = nft_ct_helper_obj_destroy, 924 .dump = nft_ct_helper_obj_dump, 925 }; 926 927 static struct nft_object_type nft_ct_helper_obj_type __read_mostly = { 928 .type = NFT_OBJECT_CT_HELPER, 929 .ops = &nft_ct_helper_obj_ops, 930 .maxattr = NFTA_CT_HELPER_MAX, 931 .policy = nft_ct_helper_policy, 932 .owner = THIS_MODULE, 933 }; 934 935 static int __init nft_ct_module_init(void) 936 { 937 int err; 938 939 BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE > NFT_REG_SIZE); 940 941 err = nft_register_expr(&nft_ct_type); 942 if (err < 0) 943 return err; 944 945 err = nft_register_expr(&nft_notrack_type); 946 if (err < 0) 947 goto err1; 948 949 err = nft_register_obj(&nft_ct_helper_obj_type); 950 if (err < 0) 951 goto err2; 952 953 return 0; 954 955 err2: 956 nft_unregister_expr(&nft_notrack_type); 957 err1: 958 nft_unregister_expr(&nft_ct_type); 959 return err; 960 } 961 962 static void __exit nft_ct_module_exit(void) 963 { 964 nft_unregister_obj(&nft_ct_helper_obj_type); 965 nft_unregister_expr(&nft_notrack_type); 966 nft_unregister_expr(&nft_ct_type); 967 } 968 969 module_init(nft_ct_module_init); 970 module_exit(nft_ct_module_exit); 971 972 MODULE_LICENSE("GPL"); 973 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); 974 MODULE_ALIAS_NFT_EXPR("ct"); 975 MODULE_ALIAS_NFT_EXPR("notrack"); 976 MODULE_ALIAS_NFT_OBJ(NFT_OBJECT_CT_HELPER); 977