1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This is a module which is used for queueing packets and communicating with 4 * userspace via nfnetlink. 5 * 6 * (C) 2005 by Harald Welte <laforge@netfilter.org> 7 * (C) 2007 by Patrick McHardy <kaber@trash.net> 8 * 9 * Based on the old ipv4-only ip_queue.c: 10 * (C) 2000-2002 James Morris <jmorris@intercode.com.au> 11 * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org> 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/module.h> 17 #include <linux/skbuff.h> 18 #include <linux/init.h> 19 #include <linux/spinlock.h> 20 #include <linux/slab.h> 21 #include <linux/notifier.h> 22 #include <linux/netdevice.h> 23 #include <linux/netfilter.h> 24 #include <linux/proc_fs.h> 25 #include <linux/netfilter_ipv4.h> 26 #include <linux/netfilter_ipv6.h> 27 #include <linux/netfilter_bridge.h> 28 #include <linux/netfilter/nfnetlink.h> 29 #include <linux/netfilter/nfnetlink_queue.h> 30 #include <linux/netfilter/nf_conntrack_common.h> 31 #include <linux/list.h> 32 #include <linux/cgroup-defs.h> 33 #include <net/gso.h> 34 #include <net/sock.h> 35 #include <net/tcp_states.h> 36 #include <net/netfilter/nf_queue.h> 37 #include <net/netns/generic.h> 38 39 #include <linux/atomic.h> 40 41 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 42 #include "../bridge/br_private.h" 43 #endif 44 45 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 46 #include <net/netfilter/nf_conntrack.h> 47 #endif 48 49 #define NFQNL_QMAX_DEFAULT 1024 50 51 /* We're using struct nlattr which has 16bit nla_len. Note that nla_len 52 * includes the header length. Thus, the maximum packet length that we 53 * support is 65531 bytes. We send truncated packets if the specified length 54 * is larger than that. Userspace can check for presence of NFQA_CAP_LEN 55 * attribute to detect truncation. 56 */ 57 #define NFQNL_MAX_COPY_RANGE (0xffff - NLA_HDRLEN) 58 59 struct nfqnl_instance { 60 struct hlist_node hlist; /* global list of queues */ 61 struct rcu_head rcu; 62 63 u32 peer_portid; 64 unsigned int queue_maxlen; 65 unsigned int copy_range; 66 unsigned int queue_dropped; 67 unsigned int queue_user_dropped; 68 69 70 u_int16_t queue_num; /* number of this queue */ 71 u_int8_t copy_mode; 72 u_int32_t flags; /* Set using NFQA_CFG_FLAGS */ 73 /* 74 * Following fields are dirtied for each queued packet, 75 * keep them in same cache line if possible. 76 */ 77 spinlock_t lock ____cacheline_aligned_in_smp; 78 unsigned int queue_total; 79 unsigned int id_sequence; /* 'sequence' of pkt ids */ 80 struct list_head queue_list; /* packets in queue */ 81 }; 82 83 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long); 84 85 static unsigned int nfnl_queue_net_id __read_mostly; 86 87 #define INSTANCE_BUCKETS 16 88 struct nfnl_queue_net { 89 spinlock_t instances_lock; 90 struct hlist_head instance_table[INSTANCE_BUCKETS]; 91 }; 92 93 static struct nfnl_queue_net *nfnl_queue_pernet(struct net *net) 94 { 95 return net_generic(net, nfnl_queue_net_id); 96 } 97 98 static inline u_int8_t instance_hashfn(u_int16_t queue_num) 99 { 100 return ((queue_num >> 8) ^ queue_num) % INSTANCE_BUCKETS; 101 } 102 103 static struct nfqnl_instance * 104 instance_lookup(struct nfnl_queue_net *q, u_int16_t queue_num) 105 { 106 struct hlist_head *head; 107 struct nfqnl_instance *inst; 108 109 head = &q->instance_table[instance_hashfn(queue_num)]; 110 hlist_for_each_entry_rcu(inst, head, hlist) { 111 if (inst->queue_num == queue_num) 112 return inst; 113 } 114 return NULL; 115 } 116 117 static struct nfqnl_instance * 118 instance_create(struct nfnl_queue_net *q, u_int16_t queue_num, u32 portid) 119 { 120 struct nfqnl_instance *inst; 121 unsigned int h; 122 int err; 123 124 spin_lock(&q->instances_lock); 125 if (instance_lookup(q, queue_num)) { 126 err = -EEXIST; 127 goto out_unlock; 128 } 129 130 inst = kzalloc(sizeof(*inst), GFP_ATOMIC); 131 if (!inst) { 132 err = -ENOMEM; 133 goto out_unlock; 134 } 135 136 inst->queue_num = queue_num; 137 inst->peer_portid = portid; 138 inst->queue_maxlen = NFQNL_QMAX_DEFAULT; 139 inst->copy_range = NFQNL_MAX_COPY_RANGE; 140 inst->copy_mode = NFQNL_COPY_NONE; 141 spin_lock_init(&inst->lock); 142 INIT_LIST_HEAD(&inst->queue_list); 143 144 if (!try_module_get(THIS_MODULE)) { 145 err = -EAGAIN; 146 goto out_free; 147 } 148 149 h = instance_hashfn(queue_num); 150 hlist_add_head_rcu(&inst->hlist, &q->instance_table[h]); 151 152 spin_unlock(&q->instances_lock); 153 154 return inst; 155 156 out_free: 157 kfree(inst); 158 out_unlock: 159 spin_unlock(&q->instances_lock); 160 return ERR_PTR(err); 161 } 162 163 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, 164 unsigned long data); 165 166 static void 167 instance_destroy_rcu(struct rcu_head *head) 168 { 169 struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance, 170 rcu); 171 172 nfqnl_flush(inst, NULL, 0); 173 kfree(inst); 174 module_put(THIS_MODULE); 175 } 176 177 static void 178 __instance_destroy(struct nfqnl_instance *inst) 179 { 180 hlist_del_rcu(&inst->hlist); 181 call_rcu(&inst->rcu, instance_destroy_rcu); 182 } 183 184 static void 185 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst) 186 { 187 spin_lock(&q->instances_lock); 188 __instance_destroy(inst); 189 spin_unlock(&q->instances_lock); 190 } 191 192 static inline void 193 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry) 194 { 195 list_add_tail(&entry->list, &queue->queue_list); 196 queue->queue_total++; 197 } 198 199 static void 200 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry) 201 { 202 list_del(&entry->list); 203 queue->queue_total--; 204 } 205 206 static struct nf_queue_entry * 207 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id) 208 { 209 struct nf_queue_entry *entry = NULL, *i; 210 211 spin_lock_bh(&queue->lock); 212 213 list_for_each_entry(i, &queue->queue_list, list) { 214 if (i->id == id) { 215 entry = i; 216 break; 217 } 218 } 219 220 if (entry) 221 __dequeue_entry(queue, entry); 222 223 spin_unlock_bh(&queue->lock); 224 225 return entry; 226 } 227 228 static unsigned int nf_iterate(struct sk_buff *skb, 229 struct nf_hook_state *state, 230 const struct nf_hook_entries *hooks, 231 unsigned int *index) 232 { 233 const struct nf_hook_entry *hook; 234 unsigned int verdict, i = *index; 235 236 while (i < hooks->num_hook_entries) { 237 hook = &hooks->hooks[i]; 238 repeat: 239 verdict = nf_hook_entry_hookfn(hook, skb, state); 240 if (verdict != NF_ACCEPT) { 241 *index = i; 242 if (verdict != NF_REPEAT) 243 return verdict; 244 goto repeat; 245 } 246 i++; 247 } 248 249 *index = i; 250 return NF_ACCEPT; 251 } 252 253 static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum) 254 { 255 switch (pf) { 256 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE 257 case NFPROTO_BRIDGE: 258 return rcu_dereference(net->nf.hooks_bridge[hooknum]); 259 #endif 260 case NFPROTO_IPV4: 261 return rcu_dereference(net->nf.hooks_ipv4[hooknum]); 262 case NFPROTO_IPV6: 263 return rcu_dereference(net->nf.hooks_ipv6[hooknum]); 264 default: 265 WARN_ON_ONCE(1); 266 return NULL; 267 } 268 269 return NULL; 270 } 271 272 static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry) 273 { 274 #ifdef CONFIG_INET 275 const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry); 276 277 if (entry->state.hook == NF_INET_LOCAL_OUT) { 278 const struct iphdr *iph = ip_hdr(skb); 279 280 if (!(iph->tos == rt_info->tos && 281 skb->mark == rt_info->mark && 282 iph->daddr == rt_info->daddr && 283 iph->saddr == rt_info->saddr)) 284 return ip_route_me_harder(entry->state.net, entry->state.sk, 285 skb, RTN_UNSPEC); 286 } 287 #endif 288 return 0; 289 } 290 291 static int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry) 292 { 293 const struct nf_ipv6_ops *v6ops; 294 int ret = 0; 295 296 switch (entry->state.pf) { 297 case AF_INET: 298 ret = nf_ip_reroute(skb, entry); 299 break; 300 case AF_INET6: 301 v6ops = rcu_dereference(nf_ipv6_ops); 302 if (v6ops) 303 ret = v6ops->reroute(skb, entry); 304 break; 305 } 306 return ret; 307 } 308 309 /* caller must hold rcu read-side lock */ 310 static void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict) 311 { 312 const struct nf_hook_entry *hook_entry; 313 const struct nf_hook_entries *hooks; 314 struct sk_buff *skb = entry->skb; 315 const struct net *net; 316 unsigned int i; 317 int err; 318 u8 pf; 319 320 net = entry->state.net; 321 pf = entry->state.pf; 322 323 hooks = nf_hook_entries_head(net, pf, entry->state.hook); 324 325 i = entry->hook_index; 326 if (WARN_ON_ONCE(!hooks || i >= hooks->num_hook_entries)) { 327 kfree_skb_reason(skb, SKB_DROP_REASON_NETFILTER_DROP); 328 nf_queue_entry_free(entry); 329 return; 330 } 331 332 hook_entry = &hooks->hooks[i]; 333 334 /* Continue traversal iff userspace said ok... */ 335 if (verdict == NF_REPEAT) 336 verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state); 337 338 if (verdict == NF_ACCEPT) { 339 if (nf_reroute(skb, entry) < 0) 340 verdict = NF_DROP; 341 } 342 343 if (verdict == NF_ACCEPT) { 344 next_hook: 345 ++i; 346 verdict = nf_iterate(skb, &entry->state, hooks, &i); 347 } 348 349 switch (verdict & NF_VERDICT_MASK) { 350 case NF_ACCEPT: 351 case NF_STOP: 352 local_bh_disable(); 353 entry->state.okfn(entry->state.net, entry->state.sk, skb); 354 local_bh_enable(); 355 break; 356 case NF_QUEUE: 357 err = nf_queue(skb, &entry->state, i, verdict); 358 if (err == 1) 359 goto next_hook; 360 break; 361 case NF_STOLEN: 362 break; 363 default: 364 kfree_skb(skb); 365 } 366 367 nf_queue_entry_free(entry); 368 } 369 370 static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict) 371 { 372 const struct nf_ct_hook *ct_hook; 373 374 if (verdict == NF_ACCEPT || 375 verdict == NF_REPEAT || 376 verdict == NF_STOP) { 377 unsigned int ct_verdict = verdict; 378 379 rcu_read_lock(); 380 ct_hook = rcu_dereference(nf_ct_hook); 381 if (ct_hook) 382 ct_verdict = ct_hook->update(entry->state.net, entry->skb); 383 rcu_read_unlock(); 384 385 switch (ct_verdict & NF_VERDICT_MASK) { 386 case NF_ACCEPT: 387 /* follow userspace verdict, could be REPEAT */ 388 break; 389 case NF_STOLEN: 390 nf_queue_entry_free(entry); 391 return; 392 default: 393 verdict = ct_verdict & NF_VERDICT_MASK; 394 break; 395 } 396 } 397 nf_reinject(entry, verdict); 398 } 399 400 static void 401 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data) 402 { 403 struct nf_queue_entry *entry, *next; 404 405 spin_lock_bh(&queue->lock); 406 list_for_each_entry_safe(entry, next, &queue->queue_list, list) { 407 if (!cmpfn || cmpfn(entry, data)) { 408 list_del(&entry->list); 409 queue->queue_total--; 410 nfqnl_reinject(entry, NF_DROP); 411 } 412 } 413 spin_unlock_bh(&queue->lock); 414 } 415 416 static int 417 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet, 418 bool csum_verify) 419 { 420 __u32 flags = 0; 421 422 if (packet->ip_summed == CHECKSUM_PARTIAL) 423 flags = NFQA_SKB_CSUMNOTREADY; 424 else if (csum_verify) 425 flags = NFQA_SKB_CSUM_NOTVERIFIED; 426 427 if (skb_is_gso(packet)) 428 flags |= NFQA_SKB_GSO; 429 430 return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0; 431 } 432 433 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) 434 { 435 const struct cred *cred; 436 437 if (!sk_fullsock(sk)) 438 return 0; 439 440 read_lock_bh(&sk->sk_callback_lock); 441 if (sk->sk_socket && sk->sk_socket->file) { 442 cred = sk->sk_socket->file->f_cred; 443 if (nla_put_be32(skb, NFQA_UID, 444 htonl(from_kuid_munged(&init_user_ns, cred->fsuid)))) 445 goto nla_put_failure; 446 if (nla_put_be32(skb, NFQA_GID, 447 htonl(from_kgid_munged(&init_user_ns, cred->fsgid)))) 448 goto nla_put_failure; 449 } 450 read_unlock_bh(&sk->sk_callback_lock); 451 return 0; 452 453 nla_put_failure: 454 read_unlock_bh(&sk->sk_callback_lock); 455 return -1; 456 } 457 458 static int nfqnl_put_sk_classid(struct sk_buff *skb, struct sock *sk) 459 { 460 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID) 461 if (sk && sk_fullsock(sk)) { 462 u32 classid = sock_cgroup_classid(&sk->sk_cgrp_data); 463 464 if (classid && nla_put_be32(skb, NFQA_CGROUP_CLASSID, htonl(classid))) 465 return -1; 466 } 467 #endif 468 return 0; 469 } 470 471 static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) 472 { 473 u32 seclen = 0; 474 #if IS_ENABLED(CONFIG_NETWORK_SECMARK) 475 if (!skb || !sk_fullsock(skb->sk)) 476 return 0; 477 478 read_lock_bh(&skb->sk->sk_callback_lock); 479 480 if (skb->secmark) 481 security_secid_to_secctx(skb->secmark, secdata, &seclen); 482 483 read_unlock_bh(&skb->sk->sk_callback_lock); 484 #endif 485 return seclen; 486 } 487 488 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) 489 { 490 struct sk_buff *entskb = entry->skb; 491 u32 nlalen = 0; 492 493 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb)) 494 return 0; 495 496 if (skb_vlan_tag_present(entskb)) 497 nlalen += nla_total_size(nla_total_size(sizeof(__be16)) + 498 nla_total_size(sizeof(__be16))); 499 500 if (entskb->network_header > entskb->mac_header) 501 nlalen += nla_total_size((entskb->network_header - 502 entskb->mac_header)); 503 504 return nlalen; 505 } 506 507 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb) 508 { 509 struct sk_buff *entskb = entry->skb; 510 511 if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb)) 512 return 0; 513 514 if (skb_vlan_tag_present(entskb)) { 515 struct nlattr *nest; 516 517 nest = nla_nest_start(skb, NFQA_VLAN); 518 if (!nest) 519 goto nla_put_failure; 520 521 if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) || 522 nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto)) 523 goto nla_put_failure; 524 525 nla_nest_end(skb, nest); 526 } 527 528 if (entskb->mac_header < entskb->network_header) { 529 int len = (int)(entskb->network_header - entskb->mac_header); 530 531 if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb))) 532 goto nla_put_failure; 533 } 534 535 return 0; 536 537 nla_put_failure: 538 return -1; 539 } 540 541 static struct sk_buff * 542 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, 543 struct nf_queue_entry *entry, 544 __be32 **packet_id_ptr) 545 { 546 size_t size; 547 size_t data_len = 0, cap_len = 0; 548 unsigned int hlen = 0; 549 struct sk_buff *skb; 550 struct nlattr *nla; 551 struct nfqnl_msg_packet_hdr *pmsg; 552 struct nlmsghdr *nlh; 553 struct sk_buff *entskb = entry->skb; 554 struct net_device *indev; 555 struct net_device *outdev; 556 struct nf_conn *ct = NULL; 557 enum ip_conntrack_info ctinfo = 0; 558 const struct nfnl_ct_hook *nfnl_ct; 559 bool csum_verify; 560 char *secdata = NULL; 561 u32 seclen = 0; 562 ktime_t tstamp; 563 564 size = nlmsg_total_size(sizeof(struct nfgenmsg)) 565 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr)) 566 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 567 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 568 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 569 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 570 + nla_total_size(sizeof(u_int32_t)) /* ifindex */ 571 #endif 572 + nla_total_size(sizeof(u_int32_t)) /* mark */ 573 + nla_total_size(sizeof(u_int32_t)) /* priority */ 574 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw)) 575 + nla_total_size(sizeof(u_int32_t)) /* skbinfo */ 576 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID) 577 + nla_total_size(sizeof(u_int32_t)) /* classid */ 578 #endif 579 + nla_total_size(sizeof(u_int32_t)); /* cap_len */ 580 581 tstamp = skb_tstamp_cond(entskb, false); 582 if (tstamp) 583 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp)); 584 585 size += nfqnl_get_bridge_size(entry); 586 587 if (entry->state.hook <= NF_INET_FORWARD || 588 (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL)) 589 csum_verify = !skb_csum_unnecessary(entskb); 590 else 591 csum_verify = false; 592 593 outdev = entry->state.out; 594 595 switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) { 596 case NFQNL_COPY_META: 597 case NFQNL_COPY_NONE: 598 break; 599 600 case NFQNL_COPY_PACKET: 601 if (!(queue->flags & NFQA_CFG_F_GSO) && 602 entskb->ip_summed == CHECKSUM_PARTIAL && 603 skb_checksum_help(entskb)) 604 return NULL; 605 606 data_len = READ_ONCE(queue->copy_range); 607 if (data_len > entskb->len) 608 data_len = entskb->len; 609 610 hlen = skb_zerocopy_headlen(entskb); 611 hlen = min_t(unsigned int, hlen, data_len); 612 size += sizeof(struct nlattr) + hlen; 613 cap_len = entskb->len; 614 break; 615 } 616 617 nfnl_ct = rcu_dereference(nfnl_ct_hook); 618 619 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 620 if (queue->flags & NFQA_CFG_F_CONNTRACK) { 621 if (nfnl_ct != NULL) { 622 ct = nf_ct_get(entskb, &ctinfo); 623 if (ct != NULL) 624 size += nfnl_ct->build_size(ct); 625 } 626 } 627 #endif 628 629 if (queue->flags & NFQA_CFG_F_UID_GID) { 630 size += (nla_total_size(sizeof(u_int32_t)) /* uid */ 631 + nla_total_size(sizeof(u_int32_t))); /* gid */ 632 } 633 634 if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) { 635 seclen = nfqnl_get_sk_secctx(entskb, &secdata); 636 if (seclen) 637 size += nla_total_size(seclen); 638 } 639 640 skb = alloc_skb(size, GFP_ATOMIC); 641 if (!skb) { 642 skb_tx_error(entskb); 643 goto nlmsg_failure; 644 } 645 646 nlh = nfnl_msg_put(skb, 0, 0, 647 nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET), 648 0, entry->state.pf, NFNETLINK_V0, 649 htons(queue->queue_num)); 650 if (!nlh) { 651 skb_tx_error(entskb); 652 kfree_skb(skb); 653 goto nlmsg_failure; 654 } 655 656 nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg)); 657 pmsg = nla_data(nla); 658 pmsg->hw_protocol = entskb->protocol; 659 pmsg->hook = entry->state.hook; 660 *packet_id_ptr = &pmsg->packet_id; 661 662 indev = entry->state.in; 663 if (indev) { 664 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 665 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex))) 666 goto nla_put_failure; 667 #else 668 if (entry->state.pf == PF_BRIDGE) { 669 /* Case 1: indev is physical input device, we need to 670 * look for bridge group (when called from 671 * netfilter_bridge) */ 672 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV, 673 htonl(indev->ifindex)) || 674 /* this is the bridge group "brX" */ 675 /* rcu_read_lock()ed by __nf_queue */ 676 nla_put_be32(skb, NFQA_IFINDEX_INDEV, 677 htonl(br_port_get_rcu(indev)->br->dev->ifindex))) 678 goto nla_put_failure; 679 } else { 680 int physinif; 681 682 /* Case 2: indev is bridge group, we need to look for 683 * physical device (when called from ipv4) */ 684 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, 685 htonl(indev->ifindex))) 686 goto nla_put_failure; 687 688 physinif = nf_bridge_get_physinif(entskb); 689 if (physinif && 690 nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV, 691 htonl(physinif))) 692 goto nla_put_failure; 693 } 694 #endif 695 } 696 697 if (outdev) { 698 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 699 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex))) 700 goto nla_put_failure; 701 #else 702 if (entry->state.pf == PF_BRIDGE) { 703 /* Case 1: outdev is physical output device, we need to 704 * look for bridge group (when called from 705 * netfilter_bridge) */ 706 if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV, 707 htonl(outdev->ifindex)) || 708 /* this is the bridge group "brX" */ 709 /* rcu_read_lock()ed by __nf_queue */ 710 nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, 711 htonl(br_port_get_rcu(outdev)->br->dev->ifindex))) 712 goto nla_put_failure; 713 } else { 714 int physoutif; 715 716 /* Case 2: outdev is bridge group, we need to look for 717 * physical output device (when called from ipv4) */ 718 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, 719 htonl(outdev->ifindex))) 720 goto nla_put_failure; 721 722 physoutif = nf_bridge_get_physoutif(entskb); 723 if (physoutif && 724 nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV, 725 htonl(physoutif))) 726 goto nla_put_failure; 727 } 728 #endif 729 } 730 731 if (entskb->mark && 732 nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark))) 733 goto nla_put_failure; 734 735 if (entskb->priority && 736 nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority))) 737 goto nla_put_failure; 738 739 if (indev && entskb->dev && 740 skb_mac_header_was_set(entskb) && 741 skb_mac_header_len(entskb) != 0) { 742 struct nfqnl_msg_packet_hw phw; 743 int len; 744 745 memset(&phw, 0, sizeof(phw)); 746 len = dev_parse_header(entskb, phw.hw_addr); 747 if (len) { 748 phw.hw_addrlen = htons(len); 749 if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw)) 750 goto nla_put_failure; 751 } 752 } 753 754 if (nfqnl_put_bridge(entry, skb) < 0) 755 goto nla_put_failure; 756 757 if (entry->state.hook <= NF_INET_FORWARD && tstamp) { 758 struct nfqnl_msg_packet_timestamp ts; 759 struct timespec64 kts = ktime_to_timespec64(tstamp); 760 761 ts.sec = cpu_to_be64(kts.tv_sec); 762 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC); 763 764 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts)) 765 goto nla_put_failure; 766 } 767 768 if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk && 769 nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) 770 goto nla_put_failure; 771 772 if (nfqnl_put_sk_classid(skb, entskb->sk) < 0) 773 goto nla_put_failure; 774 775 if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) 776 goto nla_put_failure; 777 778 if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) 779 goto nla_put_failure; 780 781 if (cap_len > data_len && 782 nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len))) 783 goto nla_put_failure; 784 785 if (nfqnl_put_packet_info(skb, entskb, csum_verify)) 786 goto nla_put_failure; 787 788 if (data_len) { 789 struct nlattr *nla; 790 791 if (skb_tailroom(skb) < sizeof(*nla) + hlen) 792 goto nla_put_failure; 793 794 nla = skb_put(skb, sizeof(*nla)); 795 nla->nla_type = NFQA_PAYLOAD; 796 nla->nla_len = nla_attr_size(data_len); 797 798 if (skb_zerocopy(skb, entskb, data_len, hlen)) 799 goto nla_put_failure; 800 } 801 802 nlh->nlmsg_len = skb->len; 803 if (seclen) 804 security_release_secctx(secdata, seclen); 805 return skb; 806 807 nla_put_failure: 808 skb_tx_error(entskb); 809 kfree_skb(skb); 810 net_err_ratelimited("nf_queue: error creating packet message\n"); 811 nlmsg_failure: 812 if (seclen) 813 security_release_secctx(secdata, seclen); 814 return NULL; 815 } 816 817 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry) 818 { 819 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 820 static const unsigned long flags = IPS_CONFIRMED | IPS_DYING; 821 const struct nf_conn *ct = (void *)skb_nfct(entry->skb); 822 823 if (ct && ((ct->status & flags) == IPS_DYING)) 824 return true; 825 #endif 826 return false; 827 } 828 829 static int 830 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue, 831 struct nf_queue_entry *entry) 832 { 833 struct sk_buff *nskb; 834 int err = -ENOBUFS; 835 __be32 *packet_id_ptr; 836 int failopen = 0; 837 838 nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr); 839 if (nskb == NULL) { 840 err = -ENOMEM; 841 goto err_out; 842 } 843 spin_lock_bh(&queue->lock); 844 845 if (nf_ct_drop_unconfirmed(entry)) 846 goto err_out_free_nskb; 847 848 if (queue->queue_total >= queue->queue_maxlen) { 849 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) { 850 failopen = 1; 851 err = 0; 852 } else { 853 queue->queue_dropped++; 854 net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n", 855 queue->queue_total); 856 } 857 goto err_out_free_nskb; 858 } 859 entry->id = ++queue->id_sequence; 860 *packet_id_ptr = htonl(entry->id); 861 862 /* nfnetlink_unicast will either free the nskb or add it to a socket */ 863 err = nfnetlink_unicast(nskb, net, queue->peer_portid); 864 if (err < 0) { 865 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) { 866 failopen = 1; 867 err = 0; 868 } else { 869 queue->queue_user_dropped++; 870 } 871 goto err_out_unlock; 872 } 873 874 __enqueue_entry(queue, entry); 875 876 spin_unlock_bh(&queue->lock); 877 return 0; 878 879 err_out_free_nskb: 880 kfree_skb(nskb); 881 err_out_unlock: 882 spin_unlock_bh(&queue->lock); 883 if (failopen) 884 nfqnl_reinject(entry, NF_ACCEPT); 885 err_out: 886 return err; 887 } 888 889 static struct nf_queue_entry * 890 nf_queue_entry_dup(struct nf_queue_entry *e) 891 { 892 struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC); 893 894 if (!entry) 895 return NULL; 896 897 if (nf_queue_entry_get_refs(entry)) 898 return entry; 899 900 kfree(entry); 901 return NULL; 902 } 903 904 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 905 /* When called from bridge netfilter, skb->data must point to MAC header 906 * before calling skb_gso_segment(). Else, original MAC header is lost 907 * and segmented skbs will be sent to wrong destination. 908 */ 909 static void nf_bridge_adjust_skb_data(struct sk_buff *skb) 910 { 911 if (nf_bridge_info_get(skb)) 912 __skb_push(skb, skb->network_header - skb->mac_header); 913 } 914 915 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb) 916 { 917 if (nf_bridge_info_get(skb)) 918 __skb_pull(skb, skb->network_header - skb->mac_header); 919 } 920 #else 921 #define nf_bridge_adjust_skb_data(s) do {} while (0) 922 #define nf_bridge_adjust_segmented_data(s) do {} while (0) 923 #endif 924 925 static int 926 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue, 927 struct sk_buff *skb, struct nf_queue_entry *entry) 928 { 929 int ret = -ENOMEM; 930 struct nf_queue_entry *entry_seg; 931 932 nf_bridge_adjust_segmented_data(skb); 933 934 if (skb->next == NULL) { /* last packet, no need to copy entry */ 935 struct sk_buff *gso_skb = entry->skb; 936 entry->skb = skb; 937 ret = __nfqnl_enqueue_packet(net, queue, entry); 938 if (ret) 939 entry->skb = gso_skb; 940 return ret; 941 } 942 943 skb_mark_not_on_list(skb); 944 945 entry_seg = nf_queue_entry_dup(entry); 946 if (entry_seg) { 947 entry_seg->skb = skb; 948 ret = __nfqnl_enqueue_packet(net, queue, entry_seg); 949 if (ret) 950 nf_queue_entry_free(entry_seg); 951 } 952 return ret; 953 } 954 955 static int 956 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum) 957 { 958 unsigned int queued; 959 struct nfqnl_instance *queue; 960 struct sk_buff *skb, *segs, *nskb; 961 int err = -ENOBUFS; 962 struct net *net = entry->state.net; 963 struct nfnl_queue_net *q = nfnl_queue_pernet(net); 964 965 /* rcu_read_lock()ed by nf_hook_thresh */ 966 queue = instance_lookup(q, queuenum); 967 if (!queue) 968 return -ESRCH; 969 970 if (queue->copy_mode == NFQNL_COPY_NONE) 971 return -EINVAL; 972 973 skb = entry->skb; 974 975 switch (entry->state.pf) { 976 case NFPROTO_IPV4: 977 skb->protocol = htons(ETH_P_IP); 978 break; 979 case NFPROTO_IPV6: 980 skb->protocol = htons(ETH_P_IPV6); 981 break; 982 } 983 984 if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb)) 985 return __nfqnl_enqueue_packet(net, queue, entry); 986 987 nf_bridge_adjust_skb_data(skb); 988 segs = skb_gso_segment(skb, 0); 989 /* Does not use PTR_ERR to limit the number of error codes that can be 990 * returned by nf_queue. For instance, callers rely on -ESRCH to 991 * mean 'ignore this hook'. 992 */ 993 if (IS_ERR_OR_NULL(segs)) 994 goto out_err; 995 queued = 0; 996 err = 0; 997 skb_list_walk_safe(segs, segs, nskb) { 998 if (err == 0) 999 err = __nfqnl_enqueue_packet_gso(net, queue, 1000 segs, entry); 1001 if (err == 0) 1002 queued++; 1003 else 1004 kfree_skb(segs); 1005 } 1006 1007 if (queued) { 1008 if (err) /* some segments are already queued */ 1009 nf_queue_entry_free(entry); 1010 kfree_skb(skb); 1011 return 0; 1012 } 1013 out_err: 1014 nf_bridge_adjust_segmented_data(skb); 1015 return err; 1016 } 1017 1018 static int 1019 nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff) 1020 { 1021 struct sk_buff *nskb; 1022 1023 if (diff < 0) { 1024 unsigned int min_len = skb_transport_offset(e->skb); 1025 1026 if (data_len < min_len) 1027 return -EINVAL; 1028 1029 if (pskb_trim(e->skb, data_len)) 1030 return -ENOMEM; 1031 } else if (diff > 0) { 1032 if (data_len > 0xFFFF) 1033 return -EINVAL; 1034 if (diff > skb_tailroom(e->skb)) { 1035 nskb = skb_copy_expand(e->skb, skb_headroom(e->skb), 1036 diff, GFP_ATOMIC); 1037 if (!nskb) 1038 return -ENOMEM; 1039 kfree_skb(e->skb); 1040 e->skb = nskb; 1041 } 1042 skb_put(e->skb, diff); 1043 } 1044 if (skb_ensure_writable(e->skb, data_len)) 1045 return -ENOMEM; 1046 skb_copy_to_linear_data(e->skb, data, data_len); 1047 e->skb->ip_summed = CHECKSUM_NONE; 1048 return 0; 1049 } 1050 1051 static int 1052 nfqnl_set_mode(struct nfqnl_instance *queue, 1053 unsigned char mode, unsigned int range) 1054 { 1055 int status = 0; 1056 1057 spin_lock_bh(&queue->lock); 1058 switch (mode) { 1059 case NFQNL_COPY_NONE: 1060 case NFQNL_COPY_META: 1061 queue->copy_mode = mode; 1062 queue->copy_range = 0; 1063 break; 1064 1065 case NFQNL_COPY_PACKET: 1066 queue->copy_mode = mode; 1067 if (range == 0 || range > NFQNL_MAX_COPY_RANGE) 1068 queue->copy_range = NFQNL_MAX_COPY_RANGE; 1069 else 1070 queue->copy_range = range; 1071 break; 1072 1073 default: 1074 status = -EINVAL; 1075 1076 } 1077 spin_unlock_bh(&queue->lock); 1078 1079 return status; 1080 } 1081 1082 static int 1083 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex) 1084 { 1085 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 1086 int physinif, physoutif; 1087 1088 physinif = nf_bridge_get_physinif(entry->skb); 1089 physoutif = nf_bridge_get_physoutif(entry->skb); 1090 1091 if (physinif == ifindex || physoutif == ifindex) 1092 return 1; 1093 #endif 1094 if (entry->state.in) 1095 if (entry->state.in->ifindex == ifindex) 1096 return 1; 1097 if (entry->state.out) 1098 if (entry->state.out->ifindex == ifindex) 1099 return 1; 1100 1101 return 0; 1102 } 1103 1104 /* drop all packets with either indev or outdev == ifindex from all queue 1105 * instances */ 1106 static void 1107 nfqnl_dev_drop(struct net *net, int ifindex) 1108 { 1109 int i; 1110 struct nfnl_queue_net *q = nfnl_queue_pernet(net); 1111 1112 rcu_read_lock(); 1113 1114 for (i = 0; i < INSTANCE_BUCKETS; i++) { 1115 struct nfqnl_instance *inst; 1116 struct hlist_head *head = &q->instance_table[i]; 1117 1118 hlist_for_each_entry_rcu(inst, head, hlist) 1119 nfqnl_flush(inst, dev_cmp, ifindex); 1120 } 1121 1122 rcu_read_unlock(); 1123 } 1124 1125 static int 1126 nfqnl_rcv_dev_event(struct notifier_block *this, 1127 unsigned long event, void *ptr) 1128 { 1129 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1130 1131 /* Drop any packets associated with the downed device */ 1132 if (event == NETDEV_DOWN) 1133 nfqnl_dev_drop(dev_net(dev), dev->ifindex); 1134 return NOTIFY_DONE; 1135 } 1136 1137 static struct notifier_block nfqnl_dev_notifier = { 1138 .notifier_call = nfqnl_rcv_dev_event, 1139 }; 1140 1141 static void nfqnl_nf_hook_drop(struct net *net) 1142 { 1143 struct nfnl_queue_net *q = nfnl_queue_pernet(net); 1144 int i; 1145 1146 /* This function is also called on net namespace error unwind, 1147 * when pernet_ops->init() failed and ->exit() functions of the 1148 * previous pernet_ops gets called. 1149 * 1150 * This may result in a call to nfqnl_nf_hook_drop() before 1151 * struct nfnl_queue_net was allocated. 1152 */ 1153 if (!q) 1154 return; 1155 1156 for (i = 0; i < INSTANCE_BUCKETS; i++) { 1157 struct nfqnl_instance *inst; 1158 struct hlist_head *head = &q->instance_table[i]; 1159 1160 hlist_for_each_entry_rcu(inst, head, hlist) 1161 nfqnl_flush(inst, NULL, 0); 1162 } 1163 } 1164 1165 static int 1166 nfqnl_rcv_nl_event(struct notifier_block *this, 1167 unsigned long event, void *ptr) 1168 { 1169 struct netlink_notify *n = ptr; 1170 struct nfnl_queue_net *q = nfnl_queue_pernet(n->net); 1171 1172 if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) { 1173 int i; 1174 1175 /* destroy all instances for this portid */ 1176 spin_lock(&q->instances_lock); 1177 for (i = 0; i < INSTANCE_BUCKETS; i++) { 1178 struct hlist_node *t2; 1179 struct nfqnl_instance *inst; 1180 struct hlist_head *head = &q->instance_table[i]; 1181 1182 hlist_for_each_entry_safe(inst, t2, head, hlist) { 1183 if (n->portid == inst->peer_portid) 1184 __instance_destroy(inst); 1185 } 1186 } 1187 spin_unlock(&q->instances_lock); 1188 } 1189 return NOTIFY_DONE; 1190 } 1191 1192 static struct notifier_block nfqnl_rtnl_notifier = { 1193 .notifier_call = nfqnl_rcv_nl_event, 1194 }; 1195 1196 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = { 1197 [NFQA_VLAN_TCI] = { .type = NLA_U16}, 1198 [NFQA_VLAN_PROTO] = { .type = NLA_U16}, 1199 }; 1200 1201 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = { 1202 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) }, 1203 [NFQA_MARK] = { .type = NLA_U32 }, 1204 [NFQA_PAYLOAD] = { .type = NLA_UNSPEC }, 1205 [NFQA_CT] = { .type = NLA_UNSPEC }, 1206 [NFQA_EXP] = { .type = NLA_UNSPEC }, 1207 [NFQA_VLAN] = { .type = NLA_NESTED }, 1208 [NFQA_PRIORITY] = { .type = NLA_U32 }, 1209 }; 1210 1211 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = { 1212 [NFQA_VERDICT_HDR] = { .len = sizeof(struct nfqnl_msg_verdict_hdr) }, 1213 [NFQA_MARK] = { .type = NLA_U32 }, 1214 [NFQA_PRIORITY] = { .type = NLA_U32 }, 1215 }; 1216 1217 static struct nfqnl_instance * 1218 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid) 1219 { 1220 struct nfqnl_instance *queue; 1221 1222 queue = instance_lookup(q, queue_num); 1223 if (!queue) 1224 return ERR_PTR(-ENODEV); 1225 1226 if (queue->peer_portid != nlportid) 1227 return ERR_PTR(-EPERM); 1228 1229 return queue; 1230 } 1231 1232 static struct nfqnl_msg_verdict_hdr* 1233 verdicthdr_get(const struct nlattr * const nfqa[]) 1234 { 1235 struct nfqnl_msg_verdict_hdr *vhdr; 1236 unsigned int verdict; 1237 1238 if (!nfqa[NFQA_VERDICT_HDR]) 1239 return NULL; 1240 1241 vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]); 1242 verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK; 1243 if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN) 1244 return NULL; 1245 return vhdr; 1246 } 1247 1248 static int nfq_id_after(unsigned int id, unsigned int max) 1249 { 1250 return (int)(id - max) > 0; 1251 } 1252 1253 static int nfqnl_recv_verdict_batch(struct sk_buff *skb, 1254 const struct nfnl_info *info, 1255 const struct nlattr * const nfqa[]) 1256 { 1257 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net); 1258 u16 queue_num = ntohs(info->nfmsg->res_id); 1259 struct nf_queue_entry *entry, *tmp; 1260 struct nfqnl_msg_verdict_hdr *vhdr; 1261 struct nfqnl_instance *queue; 1262 unsigned int verdict, maxid; 1263 LIST_HEAD(batch_list); 1264 1265 queue = verdict_instance_lookup(q, queue_num, 1266 NETLINK_CB(skb).portid); 1267 if (IS_ERR(queue)) 1268 return PTR_ERR(queue); 1269 1270 vhdr = verdicthdr_get(nfqa); 1271 if (!vhdr) 1272 return -EINVAL; 1273 1274 verdict = ntohl(vhdr->verdict); 1275 maxid = ntohl(vhdr->id); 1276 1277 spin_lock_bh(&queue->lock); 1278 1279 list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) { 1280 if (nfq_id_after(entry->id, maxid)) 1281 break; 1282 __dequeue_entry(queue, entry); 1283 list_add_tail(&entry->list, &batch_list); 1284 } 1285 1286 spin_unlock_bh(&queue->lock); 1287 1288 if (list_empty(&batch_list)) 1289 return -ENOENT; 1290 1291 list_for_each_entry_safe(entry, tmp, &batch_list, list) { 1292 if (nfqa[NFQA_MARK]) 1293 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); 1294 1295 if (nfqa[NFQA_PRIORITY]) 1296 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY])); 1297 1298 nfqnl_reinject(entry, verdict); 1299 } 1300 return 0; 1301 } 1302 1303 static struct nf_conn *nfqnl_ct_parse(const struct nfnl_ct_hook *nfnl_ct, 1304 const struct nlmsghdr *nlh, 1305 const struct nlattr * const nfqa[], 1306 struct nf_queue_entry *entry, 1307 enum ip_conntrack_info *ctinfo) 1308 { 1309 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 1310 struct nf_conn *ct; 1311 1312 ct = nf_ct_get(entry->skb, ctinfo); 1313 if (ct == NULL) 1314 return NULL; 1315 1316 if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0) 1317 return NULL; 1318 1319 if (nfqa[NFQA_EXP]) 1320 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct, 1321 NETLINK_CB(entry->skb).portid, 1322 nlmsg_report(nlh)); 1323 return ct; 1324 #else 1325 return NULL; 1326 #endif 1327 } 1328 1329 static int nfqa_parse_bridge(struct nf_queue_entry *entry, 1330 const struct nlattr * const nfqa[]) 1331 { 1332 if (nfqa[NFQA_VLAN]) { 1333 struct nlattr *tb[NFQA_VLAN_MAX + 1]; 1334 int err; 1335 1336 err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX, 1337 nfqa[NFQA_VLAN], 1338 nfqa_vlan_policy, NULL); 1339 if (err < 0) 1340 return err; 1341 1342 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO]) 1343 return -EINVAL; 1344 1345 __vlan_hwaccel_put_tag(entry->skb, 1346 nla_get_be16(tb[NFQA_VLAN_PROTO]), 1347 ntohs(nla_get_be16(tb[NFQA_VLAN_TCI]))); 1348 } 1349 1350 if (nfqa[NFQA_L2HDR]) { 1351 int mac_header_len = entry->skb->network_header - 1352 entry->skb->mac_header; 1353 1354 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR])) 1355 return -EINVAL; 1356 else if (mac_header_len > 0) 1357 memcpy(skb_mac_header(entry->skb), 1358 nla_data(nfqa[NFQA_L2HDR]), 1359 mac_header_len); 1360 } 1361 1362 return 0; 1363 } 1364 1365 static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info, 1366 const struct nlattr * const nfqa[]) 1367 { 1368 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net); 1369 u_int16_t queue_num = ntohs(info->nfmsg->res_id); 1370 const struct nfnl_ct_hook *nfnl_ct; 1371 struct nfqnl_msg_verdict_hdr *vhdr; 1372 enum ip_conntrack_info ctinfo; 1373 struct nfqnl_instance *queue; 1374 struct nf_queue_entry *entry; 1375 struct nf_conn *ct = NULL; 1376 unsigned int verdict; 1377 int err; 1378 1379 queue = verdict_instance_lookup(q, queue_num, 1380 NETLINK_CB(skb).portid); 1381 if (IS_ERR(queue)) 1382 return PTR_ERR(queue); 1383 1384 vhdr = verdicthdr_get(nfqa); 1385 if (!vhdr) 1386 return -EINVAL; 1387 1388 verdict = ntohl(vhdr->verdict); 1389 1390 entry = find_dequeue_entry(queue, ntohl(vhdr->id)); 1391 if (entry == NULL) 1392 return -ENOENT; 1393 1394 /* rcu lock already held from nfnl->call_rcu. */ 1395 nfnl_ct = rcu_dereference(nfnl_ct_hook); 1396 1397 if (nfqa[NFQA_CT]) { 1398 if (nfnl_ct != NULL) 1399 ct = nfqnl_ct_parse(nfnl_ct, info->nlh, nfqa, entry, 1400 &ctinfo); 1401 } 1402 1403 if (entry->state.pf == PF_BRIDGE) { 1404 err = nfqa_parse_bridge(entry, nfqa); 1405 if (err < 0) 1406 return err; 1407 } 1408 1409 if (nfqa[NFQA_PAYLOAD]) { 1410 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]); 1411 int diff = payload_len - entry->skb->len; 1412 1413 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]), 1414 payload_len, entry, diff) < 0) 1415 verdict = NF_DROP; 1416 1417 if (ct && diff) 1418 nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff); 1419 } 1420 1421 if (nfqa[NFQA_MARK]) 1422 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK])); 1423 1424 if (nfqa[NFQA_PRIORITY]) 1425 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY])); 1426 1427 nfqnl_reinject(entry, verdict); 1428 return 0; 1429 } 1430 1431 static int nfqnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info, 1432 const struct nlattr * const cda[]) 1433 { 1434 return -ENOTSUPP; 1435 } 1436 1437 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = { 1438 [NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) }, 1439 [NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) }, 1440 [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 }, 1441 [NFQA_CFG_MASK] = { .type = NLA_U32 }, 1442 [NFQA_CFG_FLAGS] = { .type = NLA_U32 }, 1443 }; 1444 1445 static const struct nf_queue_handler nfqh = { 1446 .outfn = nfqnl_enqueue_packet, 1447 .nf_hook_drop = nfqnl_nf_hook_drop, 1448 }; 1449 1450 static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info, 1451 const struct nlattr * const nfqa[]) 1452 { 1453 struct nfnl_queue_net *q = nfnl_queue_pernet(info->net); 1454 u_int16_t queue_num = ntohs(info->nfmsg->res_id); 1455 struct nfqnl_msg_config_cmd *cmd = NULL; 1456 struct nfqnl_instance *queue; 1457 __u32 flags = 0, mask = 0; 1458 int ret = 0; 1459 1460 if (nfqa[NFQA_CFG_CMD]) { 1461 cmd = nla_data(nfqa[NFQA_CFG_CMD]); 1462 1463 /* Obsolete commands without queue context */ 1464 switch (cmd->command) { 1465 case NFQNL_CFG_CMD_PF_BIND: return 0; 1466 case NFQNL_CFG_CMD_PF_UNBIND: return 0; 1467 } 1468 } 1469 1470 /* Check if we support these flags in first place, dependencies should 1471 * be there too not to break atomicity. 1472 */ 1473 if (nfqa[NFQA_CFG_FLAGS]) { 1474 if (!nfqa[NFQA_CFG_MASK]) { 1475 /* A mask is needed to specify which flags are being 1476 * changed. 1477 */ 1478 return -EINVAL; 1479 } 1480 1481 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS])); 1482 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK])); 1483 1484 if (flags >= NFQA_CFG_F_MAX) 1485 return -EOPNOTSUPP; 1486 1487 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK) 1488 if (flags & mask & NFQA_CFG_F_SECCTX) 1489 return -EOPNOTSUPP; 1490 #endif 1491 if ((flags & mask & NFQA_CFG_F_CONNTRACK) && 1492 !rcu_access_pointer(nfnl_ct_hook)) { 1493 #ifdef CONFIG_MODULES 1494 nfnl_unlock(NFNL_SUBSYS_QUEUE); 1495 request_module("ip_conntrack_netlink"); 1496 nfnl_lock(NFNL_SUBSYS_QUEUE); 1497 if (rcu_access_pointer(nfnl_ct_hook)) 1498 return -EAGAIN; 1499 #endif 1500 return -EOPNOTSUPP; 1501 } 1502 } 1503 1504 rcu_read_lock(); 1505 queue = instance_lookup(q, queue_num); 1506 if (queue && queue->peer_portid != NETLINK_CB(skb).portid) { 1507 ret = -EPERM; 1508 goto err_out_unlock; 1509 } 1510 1511 if (cmd != NULL) { 1512 switch (cmd->command) { 1513 case NFQNL_CFG_CMD_BIND: 1514 if (queue) { 1515 ret = -EBUSY; 1516 goto err_out_unlock; 1517 } 1518 queue = instance_create(q, queue_num, 1519 NETLINK_CB(skb).portid); 1520 if (IS_ERR(queue)) { 1521 ret = PTR_ERR(queue); 1522 goto err_out_unlock; 1523 } 1524 break; 1525 case NFQNL_CFG_CMD_UNBIND: 1526 if (!queue) { 1527 ret = -ENODEV; 1528 goto err_out_unlock; 1529 } 1530 instance_destroy(q, queue); 1531 goto err_out_unlock; 1532 case NFQNL_CFG_CMD_PF_BIND: 1533 case NFQNL_CFG_CMD_PF_UNBIND: 1534 break; 1535 default: 1536 ret = -ENOTSUPP; 1537 goto err_out_unlock; 1538 } 1539 } 1540 1541 if (!queue) { 1542 ret = -ENODEV; 1543 goto err_out_unlock; 1544 } 1545 1546 if (nfqa[NFQA_CFG_PARAMS]) { 1547 struct nfqnl_msg_config_params *params = 1548 nla_data(nfqa[NFQA_CFG_PARAMS]); 1549 1550 nfqnl_set_mode(queue, params->copy_mode, 1551 ntohl(params->copy_range)); 1552 } 1553 1554 if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) { 1555 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]); 1556 1557 spin_lock_bh(&queue->lock); 1558 queue->queue_maxlen = ntohl(*queue_maxlen); 1559 spin_unlock_bh(&queue->lock); 1560 } 1561 1562 if (nfqa[NFQA_CFG_FLAGS]) { 1563 spin_lock_bh(&queue->lock); 1564 queue->flags &= ~mask; 1565 queue->flags |= flags & mask; 1566 spin_unlock_bh(&queue->lock); 1567 } 1568 1569 err_out_unlock: 1570 rcu_read_unlock(); 1571 return ret; 1572 } 1573 1574 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { 1575 [NFQNL_MSG_PACKET] = { 1576 .call = nfqnl_recv_unsupp, 1577 .type = NFNL_CB_RCU, 1578 .attr_count = NFQA_MAX, 1579 }, 1580 [NFQNL_MSG_VERDICT] = { 1581 .call = nfqnl_recv_verdict, 1582 .type = NFNL_CB_RCU, 1583 .attr_count = NFQA_MAX, 1584 .policy = nfqa_verdict_policy 1585 }, 1586 [NFQNL_MSG_CONFIG] = { 1587 .call = nfqnl_recv_config, 1588 .type = NFNL_CB_MUTEX, 1589 .attr_count = NFQA_CFG_MAX, 1590 .policy = nfqa_cfg_policy 1591 }, 1592 [NFQNL_MSG_VERDICT_BATCH] = { 1593 .call = nfqnl_recv_verdict_batch, 1594 .type = NFNL_CB_RCU, 1595 .attr_count = NFQA_MAX, 1596 .policy = nfqa_verdict_batch_policy 1597 }, 1598 }; 1599 1600 static const struct nfnetlink_subsystem nfqnl_subsys = { 1601 .name = "nf_queue", 1602 .subsys_id = NFNL_SUBSYS_QUEUE, 1603 .cb_count = NFQNL_MSG_MAX, 1604 .cb = nfqnl_cb, 1605 }; 1606 1607 #ifdef CONFIG_PROC_FS 1608 struct iter_state { 1609 struct seq_net_private p; 1610 unsigned int bucket; 1611 }; 1612 1613 static struct hlist_node *get_first(struct seq_file *seq) 1614 { 1615 struct iter_state *st = seq->private; 1616 struct net *net; 1617 struct nfnl_queue_net *q; 1618 1619 if (!st) 1620 return NULL; 1621 1622 net = seq_file_net(seq); 1623 q = nfnl_queue_pernet(net); 1624 for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) { 1625 if (!hlist_empty(&q->instance_table[st->bucket])) 1626 return q->instance_table[st->bucket].first; 1627 } 1628 return NULL; 1629 } 1630 1631 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h) 1632 { 1633 struct iter_state *st = seq->private; 1634 struct net *net = seq_file_net(seq); 1635 1636 h = h->next; 1637 while (!h) { 1638 struct nfnl_queue_net *q; 1639 1640 if (++st->bucket >= INSTANCE_BUCKETS) 1641 return NULL; 1642 1643 q = nfnl_queue_pernet(net); 1644 h = q->instance_table[st->bucket].first; 1645 } 1646 return h; 1647 } 1648 1649 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos) 1650 { 1651 struct hlist_node *head; 1652 head = get_first(seq); 1653 1654 if (head) 1655 while (pos && (head = get_next(seq, head))) 1656 pos--; 1657 return pos ? NULL : head; 1658 } 1659 1660 static void *seq_start(struct seq_file *s, loff_t *pos) 1661 __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock) 1662 { 1663 spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock); 1664 return get_idx(s, *pos); 1665 } 1666 1667 static void *seq_next(struct seq_file *s, void *v, loff_t *pos) 1668 { 1669 (*pos)++; 1670 return get_next(s, v); 1671 } 1672 1673 static void seq_stop(struct seq_file *s, void *v) 1674 __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock) 1675 { 1676 spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock); 1677 } 1678 1679 static int seq_show(struct seq_file *s, void *v) 1680 { 1681 const struct nfqnl_instance *inst = v; 1682 1683 seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n", 1684 inst->queue_num, 1685 inst->peer_portid, inst->queue_total, 1686 inst->copy_mode, inst->copy_range, 1687 inst->queue_dropped, inst->queue_user_dropped, 1688 inst->id_sequence, 1); 1689 return 0; 1690 } 1691 1692 static const struct seq_operations nfqnl_seq_ops = { 1693 .start = seq_start, 1694 .next = seq_next, 1695 .stop = seq_stop, 1696 .show = seq_show, 1697 }; 1698 #endif /* PROC_FS */ 1699 1700 static int __net_init nfnl_queue_net_init(struct net *net) 1701 { 1702 unsigned int i; 1703 struct nfnl_queue_net *q = nfnl_queue_pernet(net); 1704 1705 for (i = 0; i < INSTANCE_BUCKETS; i++) 1706 INIT_HLIST_HEAD(&q->instance_table[i]); 1707 1708 spin_lock_init(&q->instances_lock); 1709 1710 #ifdef CONFIG_PROC_FS 1711 if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter, 1712 &nfqnl_seq_ops, sizeof(struct iter_state))) 1713 return -ENOMEM; 1714 #endif 1715 return 0; 1716 } 1717 1718 static void __net_exit nfnl_queue_net_exit(struct net *net) 1719 { 1720 struct nfnl_queue_net *q = nfnl_queue_pernet(net); 1721 unsigned int i; 1722 1723 #ifdef CONFIG_PROC_FS 1724 remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter); 1725 #endif 1726 for (i = 0; i < INSTANCE_BUCKETS; i++) 1727 WARN_ON_ONCE(!hlist_empty(&q->instance_table[i])); 1728 } 1729 1730 static struct pernet_operations nfnl_queue_net_ops = { 1731 .init = nfnl_queue_net_init, 1732 .exit = nfnl_queue_net_exit, 1733 .id = &nfnl_queue_net_id, 1734 .size = sizeof(struct nfnl_queue_net), 1735 }; 1736 1737 static int __init nfnetlink_queue_init(void) 1738 { 1739 int status; 1740 1741 status = register_pernet_subsys(&nfnl_queue_net_ops); 1742 if (status < 0) { 1743 pr_err("failed to register pernet ops\n"); 1744 goto out; 1745 } 1746 1747 netlink_register_notifier(&nfqnl_rtnl_notifier); 1748 status = nfnetlink_subsys_register(&nfqnl_subsys); 1749 if (status < 0) { 1750 pr_err("failed to create netlink socket\n"); 1751 goto cleanup_netlink_notifier; 1752 } 1753 1754 status = register_netdevice_notifier(&nfqnl_dev_notifier); 1755 if (status < 0) { 1756 pr_err("failed to register netdevice notifier\n"); 1757 goto cleanup_netlink_subsys; 1758 } 1759 1760 nf_register_queue_handler(&nfqh); 1761 1762 return status; 1763 1764 cleanup_netlink_subsys: 1765 nfnetlink_subsys_unregister(&nfqnl_subsys); 1766 cleanup_netlink_notifier: 1767 netlink_unregister_notifier(&nfqnl_rtnl_notifier); 1768 unregister_pernet_subsys(&nfnl_queue_net_ops); 1769 out: 1770 return status; 1771 } 1772 1773 static void __exit nfnetlink_queue_fini(void) 1774 { 1775 nf_unregister_queue_handler(); 1776 unregister_netdevice_notifier(&nfqnl_dev_notifier); 1777 nfnetlink_subsys_unregister(&nfqnl_subsys); 1778 netlink_unregister_notifier(&nfqnl_rtnl_notifier); 1779 unregister_pernet_subsys(&nfnl_queue_net_ops); 1780 1781 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1782 } 1783 1784 MODULE_DESCRIPTION("netfilter packet queue handler"); 1785 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); 1786 MODULE_LICENSE("GPL"); 1787 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); 1788 1789 module_init(nfnetlink_queue_init); 1790 module_exit(nfnetlink_queue_fini); 1791