net/netfilter/nfnetlink_queue.c

   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 <[email protected]>
   7  * (C) 2007 by Patrick McHardy <[email protected]>
   8  *
   9  * Based on the old ipv4-only ip_queue.c:
  10  * (C) 2000-2002 James Morris <[email protected]>
  11  * (C) 2003-2005 Netfilter Core Team <[email protected]>
  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         rcu_read_lock();
 173         nfqnl_flush(inst, NULL, 0);
 174         rcu_read_unlock();
 175         kfree(inst);
 176         module_put(THIS_MODULE);
 177 }
 178
 179 static void
 180 __instance_destroy(struct nfqnl_instance *inst)
 181 {
 182         hlist_del_rcu(&inst->hlist);
 183         call_rcu(&inst->rcu, instance_destroy_rcu);
 184 }
 185
 186 static void
 187 instance_destroy(struct nfnl_queue_net *q, struct nfqnl_instance *inst)
 188 {
 189         spin_lock(&q->instances_lock);
 190         __instance_destroy(inst);
 191         spin_unlock(&q->instances_lock);
 192 }
 193
 194 static inline void
 195 __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 196 {
 197        list_add_tail(&entry->list, &queue->queue_list);
 198        queue->queue_total++;
 199 }
 200
 201 static void
 202 __dequeue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
 203 {
 204         list_del(&entry->list);
 205         queue->queue_total--;
 206 }
 207
 208 static struct nf_queue_entry *
 209 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
 210 {
 211         struct nf_queue_entry *entry = NULL, *i;
 212
 213         spin_lock_bh(&queue->lock);
 214
 215         list_for_each_entry(i, &queue->queue_list, list) {
 216                 if (i->id == id) {
 217                         entry = i;
 218                         break;
 219                 }
 220         }
 221
 222         if (entry)
 223                 __dequeue_entry(queue, entry);
 224
 225         spin_unlock_bh(&queue->lock);
 226
 227         return entry;
 228 }
 229
 230 static unsigned int nf_iterate(struct sk_buff *skb,
 231                                struct nf_hook_state *state,
 232                                const struct nf_hook_entries *hooks,
 233                                unsigned int *index)
 234 {
 235         const struct nf_hook_entry *hook;
 236         unsigned int verdict, i = *index;
 237
 238         while (i < hooks->num_hook_entries) {
 239                 hook = &hooks->hooks[i];
 240 repeat:
 241                 verdict = nf_hook_entry_hookfn(hook, skb, state);
 242                 if (verdict != NF_ACCEPT) {
 243                         *index = i;
 244                         if (verdict != NF_REPEAT)
 245                                 return verdict;
 246                         goto repeat;
 247                 }
 248                 i++;
 249         }
 250
 251         *index = i;
 252         return NF_ACCEPT;
 253 }
 254
 255 static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum)
 256 {
 257         switch (pf) {
 258 #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
 259         case NFPROTO_BRIDGE:
 260                 return rcu_dereference(net->nf.hooks_bridge[hooknum]);
 261 #endif
 262         case NFPROTO_IPV4:
 263                 return rcu_dereference(net->nf.hooks_ipv4[hooknum]);
 264         case NFPROTO_IPV6:
 265                 return rcu_dereference(net->nf.hooks_ipv6[hooknum]);
 266         default:
 267                 WARN_ON_ONCE(1);
 268                 return NULL;
 269         }
 270
 271         return NULL;
 272 }
 273
 274 static int nf_ip_reroute(struct sk_buff *skb, const struct nf_queue_entry *entry)
 275 {
 276 #ifdef CONFIG_INET
 277         const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
 278
 279         if (entry->state.hook == NF_INET_LOCAL_OUT) {
 280                 const struct iphdr *iph = ip_hdr(skb);
 281
 282                 if (!(iph->tos == rt_info->tos &&
 283                       skb->mark == rt_info->mark &&
 284                       iph->daddr == rt_info->daddr &&
 285                       iph->saddr == rt_info->saddr))
 286                         return ip_route_me_harder(entry->state.net, entry->state.sk,
 287                                                   skb, RTN_UNSPEC);
 288         }
 289 #endif
 290         return 0;
 291 }
 292
 293 static int nf_reroute(struct sk_buff *skb, struct nf_queue_entry *entry)
 294 {
 295         const struct nf_ipv6_ops *v6ops;
 296         int ret = 0;
 297
 298         switch (entry->state.pf) {
 299         case AF_INET:
 300                 ret = nf_ip_reroute(skb, entry);
 301                 break;
 302         case AF_INET6:
 303                 v6ops = rcu_dereference(nf_ipv6_ops);
 304                 if (v6ops)
 305                         ret = v6ops->reroute(skb, entry);
 306                 break;
 307         }
 308         return ret;
 309 }
 310
 311 /* caller must hold rcu read-side lock */
 312 static void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
 313 {
 314         const struct nf_hook_entry *hook_entry;
 315         const struct nf_hook_entries *hooks;
 316         struct sk_buff *skb = entry->skb;
 317         const struct net *net;
 318         unsigned int i;
 319         int err;
 320         u8 pf;
 321
 322         net = entry->state.net;
 323         pf = entry->state.pf;
 324
 325         hooks = nf_hook_entries_head(net, pf, entry->state.hook);
 326
 327         i = entry->hook_index;
 328         if (!hooks || i >= hooks->num_hook_entries) {
 329                 kfree_skb_reason(skb, SKB_DROP_REASON_NETFILTER_DROP);
 330                 nf_queue_entry_free(entry);
 331                 return;
 332         }
 333
 334         hook_entry = &hooks->hooks[i];
 335
 336         /* Continue traversal iff userspace said ok... */
 337         if (verdict == NF_REPEAT)
 338                 verdict = nf_hook_entry_hookfn(hook_entry, skb, &entry->state);
 339
 340         if (verdict == NF_ACCEPT) {
 341                 if (nf_reroute(skb, entry) < 0)
 342                         verdict = NF_DROP;
 343         }
 344
 345         if (verdict == NF_ACCEPT) {
 346 next_hook:
 347                 ++i;
 348                 verdict = nf_iterate(skb, &entry->state, hooks, &i);
 349         }
 350
 351         switch (verdict & NF_VERDICT_MASK) {
 352         case NF_ACCEPT:
 353         case NF_STOP:
 354                 local_bh_disable();
 355                 entry->state.okfn(entry->state.net, entry->state.sk, skb);
 356                 local_bh_enable();
 357                 break;
 358         case NF_QUEUE:
 359                 err = nf_queue(skb, &entry->state, i, verdict);
 360                 if (err == 1)
 361                         goto next_hook;
 362                 break;
 363         case NF_STOLEN:
 364                 break;
 365         default:
 366                 kfree_skb(skb);
 367         }
 368
 369         nf_queue_entry_free(entry);
 370 }
 371
 372 static void nfqnl_reinject(struct nf_queue_entry *entry, unsigned int verdict)
 373 {
 374         const struct nf_ct_hook *ct_hook;
 375
 376         if (verdict == NF_ACCEPT ||
 377             verdict == NF_REPEAT ||
 378             verdict == NF_STOP) {
 379                 unsigned int ct_verdict = verdict;
 380
 381                 rcu_read_lock();
 382                 ct_hook = rcu_dereference(nf_ct_hook);
 383                 if (ct_hook)
 384                         ct_verdict = ct_hook->update(entry->state.net, entry->skb);
 385                 rcu_read_unlock();
 386
 387                 switch (ct_verdict & NF_VERDICT_MASK) {
 388                 case NF_ACCEPT:
 389                         /* follow userspace verdict, could be REPEAT */
 390                         break;
 391                 case NF_STOLEN:
 392                         nf_queue_entry_free(entry);
 393                         return;
 394                 default:
 395                         verdict = ct_verdict & NF_VERDICT_MASK;
 396                         break;
 397                 }
 398         }
 399         nf_reinject(entry, verdict);
 400 }
 401
 402 static void
 403 nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
 404 {
 405         struct nf_queue_entry *entry, *next;
 406
 407         spin_lock_bh(&queue->lock);
 408         list_for_each_entry_safe(entry, next, &queue->queue_list, list) {
 409                 if (!cmpfn || cmpfn(entry, data)) {
 410                         list_del(&entry->list);
 411                         queue->queue_total--;
 412                         nfqnl_reinject(entry, NF_DROP);
 413                 }
 414         }
 415         spin_unlock_bh(&queue->lock);
 416 }
 417
 418 static int
 419 nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet,
 420                       bool csum_verify)
 421 {
 422         __u32 flags = 0;
 423
 424         if (packet->ip_summed == CHECKSUM_PARTIAL)
 425                 flags = NFQA_SKB_CSUMNOTREADY;
 426         else if (csum_verify)
 427                 flags = NFQA_SKB_CSUM_NOTVERIFIED;
 428
 429         if (skb_is_gso(packet))
 430                 flags |= NFQA_SKB_GSO;
 431
 432         return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0;
 433 }
 434
 435 static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
 436 {
 437         const struct cred *cred;
 438
 439         if (!sk_fullsock(sk))
 440                 return 0;
 441
 442         read_lock_bh(&sk->sk_callback_lock);
 443         if (sk->sk_socket && sk->sk_socket->file) {
 444                 cred = sk->sk_socket->file->f_cred;
 445                 if (nla_put_be32(skb, NFQA_UID,
 446                     htonl(from_kuid_munged(&init_user_ns, cred->fsuid))))
 447                         goto nla_put_failure;
 448                 if (nla_put_be32(skb, NFQA_GID,
 449                     htonl(from_kgid_munged(&init_user_ns, cred->fsgid))))
 450                         goto nla_put_failure;
 451         }
 452         read_unlock_bh(&sk->sk_callback_lock);
 453         return 0;
 454
 455 nla_put_failure:
 456         read_unlock_bh(&sk->sk_callback_lock);
 457         return -1;
 458 }
 459
 460 static int nfqnl_put_sk_classid(struct sk_buff *skb, struct sock *sk)
 461 {
 462 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
 463         if (sk && sk_fullsock(sk)) {
 464                 u32 classid = sock_cgroup_classid(&sk->sk_cgrp_data);
 465
 466                 if (classid && nla_put_be32(skb, NFQA_CGROUP_CLASSID, htonl(classid)))
 467                         return -1;
 468         }
 469 #endif
 470         return 0;
 471 }
 472
 473 static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
 474 {
 475         u32 seclen = 0;
 476 #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
 477         if (!skb || !sk_fullsock(skb->sk))
 478                 return 0;
 479
 480         read_lock_bh(&skb->sk->sk_callback_lock);
 481
 482         if (skb->secmark)
 483                 security_secid_to_secctx(skb->secmark, secdata, &seclen);
 484
 485         read_unlock_bh(&skb->sk->sk_callback_lock);
 486 #endif
 487         return seclen;
 488 }
 489
 490 static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
 491 {
 492         struct sk_buff *entskb = entry->skb;
 493         u32 nlalen = 0;
 494
 495         if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
 496                 return 0;
 497
 498         if (skb_vlan_tag_present(entskb))
 499                 nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
 500                                          nla_total_size(sizeof(__be16)));
 501
 502         if (entskb->network_header > entskb->mac_header)
 503                 nlalen += nla_total_size((entskb->network_header -
 504                                           entskb->mac_header));
 505
 506         return nlalen;
 507 }
 508
 509 static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
 510 {
 511         struct sk_buff *entskb = entry->skb;
 512
 513         if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
 514                 return 0;
 515
 516         if (skb_vlan_tag_present(entskb)) {
 517                 struct nlattr *nest;
 518
 519                 nest = nla_nest_start(skb, NFQA_VLAN);
 520                 if (!nest)
 521                         goto nla_put_failure;
 522
 523                 if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
 524                     nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
 525                         goto nla_put_failure;
 526
 527                 nla_nest_end(skb, nest);
 528         }
 529
 530         if (entskb->mac_header < entskb->network_header) {
 531                 int len = (int)(entskb->network_header - entskb->mac_header);
 532
 533                 if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
 534                         goto nla_put_failure;
 535         }
 536
 537         return 0;
 538
 539 nla_put_failure:
 540         return -1;
 541 }
 542
 543 static int nf_queue_checksum_help(struct sk_buff *entskb)
 544 {
 545         if (skb_csum_is_sctp(entskb))
 546                 return skb_crc32c_csum_help(entskb);
 547
 548         return skb_checksum_help(entskb);
 549 }
 550
 551 static struct sk_buff *
 552 nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
 553                            struct nf_queue_entry *entry,
 554                            __be32 **packet_id_ptr)
 555 {
 556         size_t size;
 557         size_t data_len = 0, cap_len = 0;
 558         unsigned int hlen = 0;
 559         struct sk_buff *skb;
 560         struct nlattr *nla;
 561         struct nfqnl_msg_packet_hdr *pmsg;
 562         struct nlmsghdr *nlh;
 563         struct sk_buff *entskb = entry->skb;
 564         struct net_device *indev;
 565         struct net_device *outdev;
 566         struct nf_conn *ct = NULL;
 567         enum ip_conntrack_info ctinfo = 0;
 568         const struct nfnl_ct_hook *nfnl_ct;
 569         bool csum_verify;
 570         char *secdata = NULL;
 571         u32 seclen = 0;
 572         ktime_t tstamp;
 573
 574         size = nlmsg_total_size(sizeof(struct nfgenmsg))
 575                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
 576                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 577                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 578 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 579                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 580                 + nla_total_size(sizeof(u_int32_t))     /* ifindex */
 581 #endif
 582                 + nla_total_size(sizeof(u_int32_t))     /* mark */
 583                 + nla_total_size(sizeof(u_int32_t))     /* priority */
 584                 + nla_total_size(sizeof(struct nfqnl_msg_packet_hw))
 585                 + nla_total_size(sizeof(u_int32_t))     /* skbinfo */
 586 #if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
 587                 + nla_total_size(sizeof(u_int32_t))     /* classid */
 588 #endif
 589                 + nla_total_size(sizeof(u_int32_t));    /* cap_len */
 590
 591         tstamp = skb_tstamp_cond(entskb, false);
 592         if (tstamp)
 593                 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
 594
 595         size += nfqnl_get_bridge_size(entry);
 596
 597         if (entry->state.hook <= NF_INET_FORWARD ||
 598            (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
 599                 csum_verify = !skb_csum_unnecessary(entskb);
 600         else
 601                 csum_verify = false;
 602
 603         outdev = entry->state.out;
 604
 605         switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
 606         case NFQNL_COPY_META:
 607         case NFQNL_COPY_NONE:
 608                 break;
 609
 610         case NFQNL_COPY_PACKET:
 611                 if (!(queue->flags & NFQA_CFG_F_GSO) &&
 612                     entskb->ip_summed == CHECKSUM_PARTIAL &&
 613                     nf_queue_checksum_help(entskb))
 614                         return NULL;
 615
 616                 data_len = READ_ONCE(queue->copy_range);
 617                 if (data_len > entskb->len)
 618                         data_len = entskb->len;
 619
 620                 hlen = skb_zerocopy_headlen(entskb);
 621                 hlen = min_t(unsigned int, hlen, data_len);
 622                 size += sizeof(struct nlattr) + hlen;
 623                 cap_len = entskb->len;
 624                 break;
 625         }
 626
 627         nfnl_ct = rcu_dereference(nfnl_ct_hook);
 628
 629 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 630         if (queue->flags & NFQA_CFG_F_CONNTRACK) {
 631                 if (nfnl_ct != NULL) {
 632                         ct = nf_ct_get(entskb, &ctinfo);
 633                         if (ct != NULL)
 634                                 size += nfnl_ct->build_size(ct);
 635                 }
 636         }
 637 #endif
 638
 639         if (queue->flags & NFQA_CFG_F_UID_GID) {
 640                 size += (nla_total_size(sizeof(u_int32_t))      /* uid */
 641                         + nla_total_size(sizeof(u_int32_t)));   /* gid */
 642         }
 643
 644         if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
 645                 seclen = nfqnl_get_sk_secctx(entskb, &secdata);
 646                 if (seclen)
 647                         size += nla_total_size(seclen);
 648         }
 649
 650         skb = alloc_skb(size, GFP_ATOMIC);
 651         if (!skb) {
 652                 skb_tx_error(entskb);
 653                 goto nlmsg_failure;
 654         }
 655
 656         nlh = nfnl_msg_put(skb, 0, 0,
 657                            nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
 658                            0, entry->state.pf, NFNETLINK_V0,
 659                            htons(queue->queue_num));
 660         if (!nlh) {
 661                 skb_tx_error(entskb);
 662                 kfree_skb(skb);
 663                 goto nlmsg_failure;
 664         }
 665
 666         nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
 667         pmsg = nla_data(nla);
 668         pmsg->hw_protocol       = entskb->protocol;
 669         pmsg->hook              = entry->state.hook;
 670         *packet_id_ptr          = &pmsg->packet_id;
 671
 672         indev = entry->state.in;
 673         if (indev) {
 674 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 675                 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
 676                         goto nla_put_failure;
 677 #else
 678                 if (entry->state.pf == PF_BRIDGE) {
 679                         /* Case 1: indev is physical input device, we need to
 680                          * look for bridge group (when called from
 681                          * netfilter_bridge) */
 682                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 683                                          htonl(indev->ifindex)) ||
 684                         /* this is the bridge group "brX" */
 685                         /* rcu_read_lock()ed by __nf_queue */
 686                             nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 687                                          htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
 688                                 goto nla_put_failure;
 689                 } else {
 690                         int physinif;
 691
 692                         /* Case 2: indev is bridge group, we need to look for
 693                          * physical device (when called from ipv4) */
 694                         if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 695                                          htonl(indev->ifindex)))
 696                                 goto nla_put_failure;
 697
 698                         physinif = nf_bridge_get_physinif(entskb);
 699                         if (physinif &&
 700                             nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 701                                          htonl(physinif)))
 702                                 goto nla_put_failure;
 703                 }
 704 #endif
 705         }
 706
 707         if (outdev) {
 708 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 709                 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
 710                         goto nla_put_failure;
 711 #else
 712                 if (entry->state.pf == PF_BRIDGE) {
 713                         /* Case 1: outdev is physical output device, we need to
 714                          * look for bridge group (when called from
 715                          * netfilter_bridge) */
 716                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 717                                          htonl(outdev->ifindex)) ||
 718                         /* this is the bridge group "brX" */
 719                         /* rcu_read_lock()ed by __nf_queue */
 720                             nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 721                                          htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
 722                                 goto nla_put_failure;
 723                 } else {
 724                         int physoutif;
 725
 726                         /* Case 2: outdev is bridge group, we need to look for
 727                          * physical output device (when called from ipv4) */
 728                         if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 729                                          htonl(outdev->ifindex)))
 730                                 goto nla_put_failure;
 731
 732                         physoutif = nf_bridge_get_physoutif(entskb);
 733                         if (physoutif &&
 734                             nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 735                                          htonl(physoutif)))
 736                                 goto nla_put_failure;
 737                 }
 738 #endif
 739         }
 740
 741         if (entskb->mark &&
 742             nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
 743                 goto nla_put_failure;
 744
 745         if (entskb->priority &&
 746             nla_put_be32(skb, NFQA_PRIORITY, htonl(entskb->priority)))
 747                 goto nla_put_failure;
 748
 749         if (indev && entskb->dev &&
 750             skb_mac_header_was_set(entskb) &&
 751             skb_mac_header_len(entskb) != 0) {
 752                 struct nfqnl_msg_packet_hw phw;
 753                 int len;
 754
 755                 memset(&phw, 0, sizeof(phw));
 756                 len = dev_parse_header(entskb, phw.hw_addr);
 757                 if (len) {
 758                         phw.hw_addrlen = htons(len);
 759                         if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
 760                                 goto nla_put_failure;
 761                 }
 762         }
 763
 764         if (nfqnl_put_bridge(entry, skb) < 0)
 765                 goto nla_put_failure;
 766
 767         if (entry->state.hook <= NF_INET_FORWARD && tstamp) {
 768                 struct nfqnl_msg_packet_timestamp ts;
 769                 struct timespec64 kts = ktime_to_timespec64(tstamp);
 770
 771                 ts.sec = cpu_to_be64(kts.tv_sec);
 772                 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
 773
 774                 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
 775                         goto nla_put_failure;
 776         }
 777
 778         if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
 779             nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
 780                 goto nla_put_failure;
 781
 782         if (nfqnl_put_sk_classid(skb, entskb->sk) < 0)
 783                 goto nla_put_failure;
 784
 785         if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
 786                 goto nla_put_failure;
 787
 788         if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
 789                 goto nla_put_failure;
 790
 791         if (cap_len > data_len &&
 792             nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
 793                 goto nla_put_failure;
 794
 795         if (nfqnl_put_packet_info(skb, entskb, csum_verify))
 796                 goto nla_put_failure;
 797
 798         if (data_len) {
 799                 struct nlattr *nla;
 800
 801                 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
 802                         goto nla_put_failure;
 803
 804                 nla = skb_put(skb, sizeof(*nla));
 805                 nla->nla_type = NFQA_PAYLOAD;
 806                 nla->nla_len = nla_attr_size(data_len);
 807
 808                 if (skb_zerocopy(skb, entskb, data_len, hlen))
 809                         goto nla_put_failure;
 810         }
 811
 812         nlh->nlmsg_len = skb->len;
 813         if (seclen)
 814                 security_release_secctx(secdata, seclen);
 815         return skb;
 816
 817 nla_put_failure:
 818         skb_tx_error(entskb);
 819         kfree_skb(skb);
 820         net_err_ratelimited("nf_queue: error creating packet message\n");
 821 nlmsg_failure:
 822         if (seclen)
 823                 security_release_secctx(secdata, seclen);
 824         return NULL;
 825 }
 826
 827 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry)
 828 {
 829 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 830         static const unsigned long flags = IPS_CONFIRMED | IPS_DYING;
 831         struct nf_conn *ct = (void *)skb_nfct(entry->skb);
 832         unsigned long status;
 833         unsigned int use;
 834
 835         if (!ct)
 836                 return false;
 837
 838         status = READ_ONCE(ct->status);
 839         if ((status & flags) == IPS_DYING)
 840                 return true;
 841
 842         if (status & IPS_CONFIRMED)
 843                 return false;
 844
 845         /* in some cases skb_clone() can occur after initial conntrack
 846          * pickup, but conntrack assumes exclusive skb->_nfct ownership for
 847          * unconfirmed entries.
 848          *
 849          * This happens for br_netfilter and with ip multicast routing.
 850          * We can't be solved with serialization here because one clone could
 851          * have been queued for local delivery.
 852          */
 853         use = refcount_read(&ct->ct_general.use);
 854         if (likely(use == 1))
 855                 return false;
 856
 857         /* Can't decrement further? Exclusive ownership. */
 858         if (!refcount_dec_not_one(&ct->ct_general.use))
 859                 return false;
 860
 861         skb_set_nfct(entry->skb, 0);
 862         /* No nf_ct_put(): we already decremented .use and it cannot
 863          * drop down to 0.
 864          */
 865         return true;
 866 #endif
 867         return false;
 868 }
 869
 870 static int
 871 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
 872                         struct nf_queue_entry *entry)
 873 {
 874         struct sk_buff *nskb;
 875         int err = -ENOBUFS;
 876         __be32 *packet_id_ptr;
 877         int failopen = 0;
 878
 879         nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
 880         if (nskb == NULL) {
 881                 err = -ENOMEM;
 882                 goto err_out;
 883         }
 884         spin_lock_bh(&queue->lock);
 885
 886         if (nf_ct_drop_unconfirmed(entry))
 887                 goto err_out_free_nskb;
 888
 889         if (queue->queue_total >= queue->queue_maxlen) {
 890                 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 891                         failopen = 1;
 892                         err = 0;
 893                 } else {
 894                         queue->queue_dropped++;
 895                         net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
 896                                              queue->queue_total);
 897                 }
 898                 goto err_out_free_nskb;
 899         }
 900         entry->id = ++queue->id_sequence;
 901         *packet_id_ptr = htonl(entry->id);
 902
 903         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 904         err = nfnetlink_unicast(nskb, net, queue->peer_portid);
 905         if (err < 0) {
 906                 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 907                         failopen = 1;
 908                         err = 0;
 909                 } else {
 910                         queue->queue_user_dropped++;
 911                 }
 912                 goto err_out_unlock;
 913         }
 914
 915         __enqueue_entry(queue, entry);
 916
 917         spin_unlock_bh(&queue->lock);
 918         return 0;
 919
 920 err_out_free_nskb:
 921         kfree_skb(nskb);
 922 err_out_unlock:
 923         spin_unlock_bh(&queue->lock);
 924         if (failopen)
 925                 nfqnl_reinject(entry, NF_ACCEPT);
 926 err_out:
 927         return err;
 928 }
 929
 930 static struct nf_queue_entry *
 931 nf_queue_entry_dup(struct nf_queue_entry *e)
 932 {
 933         struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
 934
 935         if (!entry)
 936                 return NULL;
 937
 938         if (nf_queue_entry_get_refs(entry))
 939                 return entry;
 940
 941         kfree(entry);
 942         return NULL;
 943 }
 944
 945 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 946 /* When called from bridge netfilter, skb->data must point to MAC header
 947  * before calling skb_gso_segment(). Else, original MAC header is lost
 948  * and segmented skbs will be sent to wrong destination.
 949  */
 950 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
 951 {
 952         if (nf_bridge_info_get(skb))
 953                 __skb_push(skb, skb->network_header - skb->mac_header);
 954 }
 955
 956 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
 957 {
 958         if (nf_bridge_info_get(skb))
 959                 __skb_pull(skb, skb->network_header - skb->mac_header);
 960 }
 961 #else
 962 #define nf_bridge_adjust_skb_data(s) do {} while (0)
 963 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
 964 #endif
 965
 966 static int
 967 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
 968                            struct sk_buff *skb, struct nf_queue_entry *entry)
 969 {
 970         int ret = -ENOMEM;
 971         struct nf_queue_entry *entry_seg;
 972
 973         nf_bridge_adjust_segmented_data(skb);
 974
 975         if (skb->next == NULL) { /* last packet, no need to copy entry */
 976                 struct sk_buff *gso_skb = entry->skb;
 977                 entry->skb = skb;
 978                 ret = __nfqnl_enqueue_packet(net, queue, entry);
 979                 if (ret)
 980                         entry->skb = gso_skb;
 981                 return ret;
 982         }
 983
 984         skb_mark_not_on_list(skb);
 985
 986         entry_seg = nf_queue_entry_dup(entry);
 987         if (entry_seg) {
 988                 entry_seg->skb = skb;
 989                 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
 990                 if (ret)
 991                         nf_queue_entry_free(entry_seg);
 992         }
 993         return ret;
 994 }
 995
 996 static int
 997 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 998 {
 999         unsigned int queued;
1000         struct nfqnl_instance *queue;
1001         struct sk_buff *skb, *segs, *nskb;
1002         int err = -ENOBUFS;
1003         struct net *net = entry->state.net;
1004         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1005
1006         /* rcu_read_lock()ed by nf_hook_thresh */
1007         queue = instance_lookup(q, queuenum);
1008         if (!queue)
1009                 return -ESRCH;
1010
1011         if (queue->copy_mode == NFQNL_COPY_NONE)
1012                 return -EINVAL;
1013
1014         skb = entry->skb;
1015
1016         switch (entry->state.pf) {
1017         case NFPROTO_IPV4:
1018                 skb->protocol = htons(ETH_P_IP);
1019                 break;
1020         case NFPROTO_IPV6:
1021                 skb->protocol = htons(ETH_P_IPV6);
1022                 break;
1023         }
1024
1025         if (!skb_is_gso(skb) || ((queue->flags & NFQA_CFG_F_GSO) && !skb_is_gso_sctp(skb)))
1026                 return __nfqnl_enqueue_packet(net, queue, entry);
1027
1028         nf_bridge_adjust_skb_data(skb);
1029         segs = skb_gso_segment(skb, 0);
1030         /* Does not use PTR_ERR to limit the number of error codes that can be
1031          * returned by nf_queue.  For instance, callers rely on -ESRCH to
1032          * mean 'ignore this hook'.
1033          */
1034         if (IS_ERR_OR_NULL(segs))
1035                 goto out_err;
1036         queued = 0;
1037         err = 0;
1038         skb_list_walk_safe(segs, segs, nskb) {
1039                 if (err == 0)
1040                         err = __nfqnl_enqueue_packet_gso(net, queue,
1041                                                         segs, entry);
1042                 if (err == 0)
1043                         queued++;
1044                 else
1045                         kfree_skb(segs);
1046         }
1047
1048         if (queued) {
1049                 if (err) /* some segments are already queued */
1050                         nf_queue_entry_free(entry);
1051                 kfree_skb(skb);
1052                 return 0;
1053         }
1054  out_err:
1055         nf_bridge_adjust_segmented_data(skb);
1056         return err;
1057 }
1058
1059 static int
1060 nfqnl_mangle(void *data, unsigned int data_len, struct nf_queue_entry *e, int diff)
1061 {
1062         struct sk_buff *nskb;
1063
1064         if (diff < 0) {
1065                 unsigned int min_len = skb_transport_offset(e->skb);
1066
1067                 if (data_len < min_len)
1068                         return -EINVAL;
1069
1070                 if (pskb_trim(e->skb, data_len))
1071                         return -ENOMEM;
1072         } else if (diff > 0) {
1073                 if (data_len > 0xFFFF)
1074                         return -EINVAL;
1075                 if (diff > skb_tailroom(e->skb)) {
1076                         nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
1077                                                diff, GFP_ATOMIC);
1078                         if (!nskb)
1079                                 return -ENOMEM;
1080                         kfree_skb(e->skb);
1081                         e->skb = nskb;
1082                 }
1083                 skb_put(e->skb, diff);
1084         }
1085         if (skb_ensure_writable(e->skb, data_len))
1086                 return -ENOMEM;
1087         skb_copy_to_linear_data(e->skb, data, data_len);
1088         e->skb->ip_summed = CHECKSUM_NONE;
1089         return 0;
1090 }
1091
1092 static int
1093 nfqnl_set_mode(struct nfqnl_instance *queue,
1094                unsigned char mode, unsigned int range)
1095 {
1096         int status = 0;
1097
1098         spin_lock_bh(&queue->lock);
1099         switch (mode) {
1100         case NFQNL_COPY_NONE:
1101         case NFQNL_COPY_META:
1102                 queue->copy_mode = mode;
1103                 queue->copy_range = 0;
1104                 break;
1105
1106         case NFQNL_COPY_PACKET:
1107                 queue->copy_mode = mode;
1108                 if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
1109                         queue->copy_range = NFQNL_MAX_COPY_RANGE;
1110                 else
1111                         queue->copy_range = range;
1112                 break;
1113
1114         default:
1115                 status = -EINVAL;
1116
1117         }
1118         spin_unlock_bh(&queue->lock);
1119
1120         return status;
1121 }
1122
1123 static int
1124 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
1125 {
1126 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
1127         int physinif, physoutif;
1128
1129         physinif = nf_bridge_get_physinif(entry->skb);
1130         physoutif = nf_bridge_get_physoutif(entry->skb);
1131
1132         if (physinif == ifindex || physoutif == ifindex)
1133                 return 1;
1134 #endif
1135         if (entry->state.in)
1136                 if (entry->state.in->ifindex == ifindex)
1137                         return 1;
1138         if (entry->state.out)
1139                 if (entry->state.out->ifindex == ifindex)
1140                         return 1;
1141
1142         return 0;
1143 }
1144
1145 /* drop all packets with either indev or outdev == ifindex from all queue
1146  * instances */
1147 static void
1148 nfqnl_dev_drop(struct net *net, int ifindex)
1149 {
1150         int i;
1151         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1152
1153         rcu_read_lock();
1154
1155         for (i = 0; i < INSTANCE_BUCKETS; i++) {
1156                 struct nfqnl_instance *inst;
1157                 struct hlist_head *head = &q->instance_table[i];
1158
1159                 hlist_for_each_entry_rcu(inst, head, hlist)
1160                         nfqnl_flush(inst, dev_cmp, ifindex);
1161         }
1162
1163         rcu_read_unlock();
1164 }
1165
1166 static int
1167 nfqnl_rcv_dev_event(struct notifier_block *this,
1168                     unsigned long event, void *ptr)
1169 {
1170         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1171
1172         /* Drop any packets associated with the downed device */
1173         if (event == NETDEV_DOWN)
1174                 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
1175         return NOTIFY_DONE;
1176 }
1177
1178 static struct notifier_block nfqnl_dev_notifier = {
1179         .notifier_call  = nfqnl_rcv_dev_event,
1180 };
1181
1182 static void nfqnl_nf_hook_drop(struct net *net)
1183 {
1184         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1185         int i;
1186
1187         /* This function is also called on net namespace error unwind,
1188          * when pernet_ops->init() failed and ->exit() functions of the
1189          * previous pernet_ops gets called.
1190          *
1191          * This may result in a call to nfqnl_nf_hook_drop() before
1192          * struct nfnl_queue_net was allocated.
1193          */
1194         if (!q)
1195                 return;
1196
1197         for (i = 0; i < INSTANCE_BUCKETS; i++) {
1198                 struct nfqnl_instance *inst;
1199                 struct hlist_head *head = &q->instance_table[i];
1200
1201                 hlist_for_each_entry_rcu(inst, head, hlist)
1202                         nfqnl_flush(inst, NULL, 0);
1203         }
1204 }
1205
1206 static int
1207 nfqnl_rcv_nl_event(struct notifier_block *this,
1208                    unsigned long event, void *ptr)
1209 {
1210         struct netlink_notify *n = ptr;
1211         struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
1212
1213         if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
1214                 int i;
1215
1216                 /* destroy all instances for this portid */
1217                 spin_lock(&q->instances_lock);
1218                 for (i = 0; i < INSTANCE_BUCKETS; i++) {
1219                         struct hlist_node *t2;
1220                         struct nfqnl_instance *inst;
1221                         struct hlist_head *head = &q->instance_table[i];
1222
1223                         hlist_for_each_entry_safe(inst, t2, head, hlist) {
1224                                 if (n->portid == inst->peer_portid)
1225                                         __instance_destroy(inst);
1226                         }
1227                 }
1228                 spin_unlock(&q->instances_lock);
1229         }
1230         return NOTIFY_DONE;
1231 }
1232
1233 static struct notifier_block nfqnl_rtnl_notifier = {
1234         .notifier_call  = nfqnl_rcv_nl_event,
1235 };
1236
1237 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
1238         [NFQA_VLAN_TCI]         = { .type = NLA_U16},
1239         [NFQA_VLAN_PROTO]       = { .type = NLA_U16},
1240 };
1241
1242 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
1243         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1244         [NFQA_MARK]             = { .type = NLA_U32 },
1245         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
1246         [NFQA_CT]               = { .type = NLA_UNSPEC },
1247         [NFQA_EXP]              = { .type = NLA_UNSPEC },
1248         [NFQA_VLAN]             = { .type = NLA_NESTED },
1249         [NFQA_PRIORITY]         = { .type = NLA_U32 },
1250 };
1251
1252 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
1253         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1254         [NFQA_MARK]             = { .type = NLA_U32 },
1255         [NFQA_PRIORITY]         = { .type = NLA_U32 },
1256 };
1257
1258 static struct nfqnl_instance *
1259 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1260 {
1261         struct nfqnl_instance *queue;
1262
1263         queue = instance_lookup(q, queue_num);
1264         if (!queue)
1265                 return ERR_PTR(-ENODEV);
1266
1267         if (queue->peer_portid != nlportid)
1268                 return ERR_PTR(-EPERM);
1269
1270         return queue;
1271 }
1272
1273 static struct nfqnl_msg_verdict_hdr*
1274 verdicthdr_get(const struct nlattr * const nfqa[])
1275 {
1276         struct nfqnl_msg_verdict_hdr *vhdr;
1277         unsigned int verdict;
1278
1279         if (!nfqa[NFQA_VERDICT_HDR])
1280                 return NULL;
1281
1282         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1283         verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1284         if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1285                 return NULL;
1286         return vhdr;
1287 }
1288
1289 static int nfq_id_after(unsigned int id, unsigned int max)
1290 {
1291         return (int)(id - max) > 0;
1292 }
1293
1294 static int nfqnl_recv_verdict_batch(struct sk_buff *skb,
1295                                     const struct nfnl_info *info,
1296                                     const struct nlattr * const nfqa[])
1297 {
1298         struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1299         u16 queue_num = ntohs(info->nfmsg->res_id);
1300         struct nf_queue_entry *entry, *tmp;
1301         struct nfqnl_msg_verdict_hdr *vhdr;
1302         struct nfqnl_instance *queue;
1303         unsigned int verdict, maxid;
1304         LIST_HEAD(batch_list);
1305
1306         queue = verdict_instance_lookup(q, queue_num,
1307                                         NETLINK_CB(skb).portid);
1308         if (IS_ERR(queue))
1309                 return PTR_ERR(queue);
1310
1311         vhdr = verdicthdr_get(nfqa);
1312         if (!vhdr)
1313                 return -EINVAL;
1314
1315         verdict = ntohl(vhdr->verdict);
1316         maxid = ntohl(vhdr->id);
1317
1318         spin_lock_bh(&queue->lock);
1319
1320         list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1321                 if (nfq_id_after(entry->id, maxid))
1322                         break;
1323                 __dequeue_entry(queue, entry);
1324                 list_add_tail(&entry->list, &batch_list);
1325         }
1326
1327         spin_unlock_bh(&queue->lock);
1328
1329         if (list_empty(&batch_list))
1330                 return -ENOENT;
1331
1332         list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1333                 if (nfqa[NFQA_MARK])
1334                         entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1335
1336                 if (nfqa[NFQA_PRIORITY])
1337                         entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1338
1339                 nfqnl_reinject(entry, verdict);
1340         }
1341         return 0;
1342 }
1343
1344 static struct nf_conn *nfqnl_ct_parse(const struct nfnl_ct_hook *nfnl_ct,
1345                                       const struct nlmsghdr *nlh,
1346                                       const struct nlattr * const nfqa[],
1347                                       struct nf_queue_entry *entry,
1348                                       enum ip_conntrack_info *ctinfo)
1349 {
1350 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1351         struct nf_conn *ct;
1352
1353         ct = nf_ct_get(entry->skb, ctinfo);
1354         if (ct == NULL)
1355                 return NULL;
1356
1357         if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1358                 return NULL;
1359
1360         if (nfqa[NFQA_EXP])
1361                 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1362                                       NETLINK_CB(entry->skb).portid,
1363                                       nlmsg_report(nlh));
1364         return ct;
1365 #else
1366         return NULL;
1367 #endif
1368 }
1369
1370 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1371                              const struct nlattr * const nfqa[])
1372 {
1373         if (nfqa[NFQA_VLAN]) {
1374                 struct nlattr *tb[NFQA_VLAN_MAX + 1];
1375                 int err;
1376
1377                 err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
1378                                                   nfqa[NFQA_VLAN],
1379                                                   nfqa_vlan_policy, NULL);
1380                 if (err < 0)
1381                         return err;
1382
1383                 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1384                         return -EINVAL;
1385
1386                 __vlan_hwaccel_put_tag(entry->skb,
1387                         nla_get_be16(tb[NFQA_VLAN_PROTO]),
1388                         ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
1389         }
1390
1391         if (nfqa[NFQA_L2HDR]) {
1392                 int mac_header_len = entry->skb->network_header -
1393                         entry->skb->mac_header;
1394
1395                 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1396                         return -EINVAL;
1397                 else if (mac_header_len > 0)
1398                         memcpy(skb_mac_header(entry->skb),
1399                                nla_data(nfqa[NFQA_L2HDR]),
1400                                mac_header_len);
1401         }
1402
1403         return 0;
1404 }
1405
1406 static int nfqnl_recv_verdict(struct sk_buff *skb, const struct nfnl_info *info,
1407                               const struct nlattr * const nfqa[])
1408 {
1409         struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1410         u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1411         const struct nfnl_ct_hook *nfnl_ct;
1412         struct nfqnl_msg_verdict_hdr *vhdr;
1413         enum ip_conntrack_info ctinfo;
1414         struct nfqnl_instance *queue;
1415         struct nf_queue_entry *entry;
1416         struct nf_conn *ct = NULL;
1417         unsigned int verdict;
1418         int err;
1419
1420         queue = verdict_instance_lookup(q, queue_num,
1421                                         NETLINK_CB(skb).portid);
1422         if (IS_ERR(queue))
1423                 return PTR_ERR(queue);
1424
1425         vhdr = verdicthdr_get(nfqa);
1426         if (!vhdr)
1427                 return -EINVAL;
1428
1429         verdict = ntohl(vhdr->verdict);
1430
1431         entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1432         if (entry == NULL)
1433                 return -ENOENT;
1434
1435         /* rcu lock already held from nfnl->call_rcu. */
1436         nfnl_ct = rcu_dereference(nfnl_ct_hook);
1437
1438         if (nfqa[NFQA_CT]) {
1439                 if (nfnl_ct != NULL)
1440                         ct = nfqnl_ct_parse(nfnl_ct, info->nlh, nfqa, entry,
1441                                             &ctinfo);
1442         }
1443
1444         if (entry->state.pf == PF_BRIDGE) {
1445                 err = nfqa_parse_bridge(entry, nfqa);
1446                 if (err < 0)
1447                         return err;
1448         }
1449
1450         if (nfqa[NFQA_PAYLOAD]) {
1451                 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1452                 int diff = payload_len - entry->skb->len;
1453
1454                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1455                                  payload_len, entry, diff) < 0)
1456                         verdict = NF_DROP;
1457
1458                 if (ct && diff)
1459                         nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1460         }
1461
1462         if (nfqa[NFQA_MARK])
1463                 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1464
1465         if (nfqa[NFQA_PRIORITY])
1466                 entry->skb->priority = ntohl(nla_get_be32(nfqa[NFQA_PRIORITY]));
1467
1468         nfqnl_reinject(entry, verdict);
1469         return 0;
1470 }
1471
1472 static int nfqnl_recv_unsupp(struct sk_buff *skb, const struct nfnl_info *info,
1473                              const struct nlattr * const cda[])
1474 {
1475         return -ENOTSUPP;
1476 }
1477
1478 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1479         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
1480         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
1481         [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 },
1482         [NFQA_CFG_MASK]         = { .type = NLA_U32 },
1483         [NFQA_CFG_FLAGS]        = { .type = NLA_U32 },
1484 };
1485
1486 static const struct nf_queue_handler nfqh = {
1487         .outfn          = nfqnl_enqueue_packet,
1488         .nf_hook_drop   = nfqnl_nf_hook_drop,
1489 };
1490
1491 static int nfqnl_recv_config(struct sk_buff *skb, const struct nfnl_info *info,
1492                              const struct nlattr * const nfqa[])
1493 {
1494         struct nfnl_queue_net *q = nfnl_queue_pernet(info->net);
1495         u_int16_t queue_num = ntohs(info->nfmsg->res_id);
1496         struct nfqnl_msg_config_cmd *cmd = NULL;
1497         struct nfqnl_instance *queue;
1498         __u32 flags = 0, mask = 0;
1499         int ret = 0;
1500
1501         if (nfqa[NFQA_CFG_CMD]) {
1502                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1503
1504                 /* Obsolete commands without queue context */
1505                 switch (cmd->command) {
1506                 case NFQNL_CFG_CMD_PF_BIND: return 0;
1507                 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1508                 }
1509         }
1510
1511         /* Check if we support these flags in first place, dependencies should
1512          * be there too not to break atomicity.
1513          */
1514         if (nfqa[NFQA_CFG_FLAGS]) {
1515                 if (!nfqa[NFQA_CFG_MASK]) {
1516                         /* A mask is needed to specify which flags are being
1517                          * changed.
1518                          */
1519                         return -EINVAL;
1520                 }
1521
1522                 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1523                 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1524
1525                 if (flags >= NFQA_CFG_F_MAX)
1526                         return -EOPNOTSUPP;
1527
1528 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1529                 if (flags & mask & NFQA_CFG_F_SECCTX)
1530                         return -EOPNOTSUPP;
1531 #endif
1532                 if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1533                     !rcu_access_pointer(nfnl_ct_hook)) {
1534 #ifdef CONFIG_MODULES
1535                         nfnl_unlock(NFNL_SUBSYS_QUEUE);
1536                         request_module("ip_conntrack_netlink");
1537                         nfnl_lock(NFNL_SUBSYS_QUEUE);
1538                         if (rcu_access_pointer(nfnl_ct_hook))
1539                                 return -EAGAIN;
1540 #endif
1541                         return -EOPNOTSUPP;
1542                 }
1543         }
1544
1545         rcu_read_lock();
1546         queue = instance_lookup(q, queue_num);
1547         if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1548                 ret = -EPERM;
1549                 goto err_out_unlock;
1550         }
1551
1552         if (cmd != NULL) {
1553                 switch (cmd->command) {
1554                 case NFQNL_CFG_CMD_BIND:
1555                         if (queue) {
1556                                 ret = -EBUSY;
1557                                 goto err_out_unlock;
1558                         }
1559                         queue = instance_create(q, queue_num,
1560                                                 NETLINK_CB(skb).portid);
1561                         if (IS_ERR(queue)) {
1562                                 ret = PTR_ERR(queue);
1563                                 goto err_out_unlock;
1564                         }
1565                         break;
1566                 case NFQNL_CFG_CMD_UNBIND:
1567                         if (!queue) {
1568                                 ret = -ENODEV;
1569                                 goto err_out_unlock;
1570                         }
1571                         instance_destroy(q, queue);
1572                         goto err_out_unlock;
1573                 case NFQNL_CFG_CMD_PF_BIND:
1574                 case NFQNL_CFG_CMD_PF_UNBIND:
1575                         break;
1576                 default:
1577                         ret = -ENOTSUPP;
1578                         goto err_out_unlock;
1579                 }
1580         }
1581
1582         if (!queue) {
1583                 ret = -ENODEV;
1584                 goto err_out_unlock;
1585         }
1586
1587         if (nfqa[NFQA_CFG_PARAMS]) {
1588                 struct nfqnl_msg_config_params *params =
1589                         nla_data(nfqa[NFQA_CFG_PARAMS]);
1590
1591                 nfqnl_set_mode(queue, params->copy_mode,
1592                                 ntohl(params->copy_range));
1593         }
1594
1595         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1596                 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1597
1598                 spin_lock_bh(&queue->lock);
1599                 queue->queue_maxlen = ntohl(*queue_maxlen);
1600                 spin_unlock_bh(&queue->lock);
1601         }
1602
1603         if (nfqa[NFQA_CFG_FLAGS]) {
1604                 spin_lock_bh(&queue->lock);
1605                 queue->flags &= ~mask;
1606                 queue->flags |= flags & mask;
1607                 spin_unlock_bh(&queue->lock);
1608         }
1609
1610 err_out_unlock:
1611         rcu_read_unlock();
1612         return ret;
1613 }
1614
1615 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1616         [NFQNL_MSG_PACKET]      = {
1617                 .call           = nfqnl_recv_unsupp,
1618                 .type           = NFNL_CB_RCU,
1619                 .attr_count     = NFQA_MAX,
1620         },
1621         [NFQNL_MSG_VERDICT]     = {
1622                 .call           = nfqnl_recv_verdict,
1623                 .type           = NFNL_CB_RCU,
1624                 .attr_count     = NFQA_MAX,
1625                 .policy         = nfqa_verdict_policy
1626         },
1627         [NFQNL_MSG_CONFIG]      = {
1628                 .call           = nfqnl_recv_config,
1629                 .type           = NFNL_CB_MUTEX,
1630                 .attr_count     = NFQA_CFG_MAX,
1631                 .policy         = nfqa_cfg_policy
1632         },
1633         [NFQNL_MSG_VERDICT_BATCH] = {
1634                 .call           = nfqnl_recv_verdict_batch,
1635                 .type           = NFNL_CB_RCU,
1636                 .attr_count     = NFQA_MAX,
1637                 .policy         = nfqa_verdict_batch_policy
1638         },
1639 };
1640
1641 static const struct nfnetlink_subsystem nfqnl_subsys = {
1642         .name           = "nf_queue",
1643         .subsys_id      = NFNL_SUBSYS_QUEUE,
1644         .cb_count       = NFQNL_MSG_MAX,
1645         .cb             = nfqnl_cb,
1646 };
1647
1648 #ifdef CONFIG_PROC_FS
1649 struct iter_state {
1650         struct seq_net_private p;
1651         unsigned int bucket;
1652 };
1653
1654 static struct hlist_node *get_first(struct seq_file *seq)
1655 {
1656         struct iter_state *st = seq->private;
1657         struct net *net;
1658         struct nfnl_queue_net *q;
1659
1660         if (!st)
1661                 return NULL;
1662
1663         net = seq_file_net(seq);
1664         q = nfnl_queue_pernet(net);
1665         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1666                 if (!hlist_empty(&q->instance_table[st->bucket]))
1667                         return q->instance_table[st->bucket].first;
1668         }
1669         return NULL;
1670 }
1671
1672 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1673 {
1674         struct iter_state *st = seq->private;
1675         struct net *net = seq_file_net(seq);
1676
1677         h = h->next;
1678         while (!h) {
1679                 struct nfnl_queue_net *q;
1680
1681                 if (++st->bucket >= INSTANCE_BUCKETS)
1682                         return NULL;
1683
1684                 q = nfnl_queue_pernet(net);
1685                 h = q->instance_table[st->bucket].first;
1686         }
1687         return h;
1688 }
1689
1690 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1691 {
1692         struct hlist_node *head;
1693         head = get_first(seq);
1694
1695         if (head)
1696                 while (pos && (head = get_next(seq, head)))
1697                         pos--;
1698         return pos ? NULL : head;
1699 }
1700
1701 static void *seq_start(struct seq_file *s, loff_t *pos)
1702         __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1703 {
1704         spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1705         return get_idx(s, *pos);
1706 }
1707
1708 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1709 {
1710         (*pos)++;
1711         return get_next(s, v);
1712 }
1713
1714 static void seq_stop(struct seq_file *s, void *v)
1715         __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1716 {
1717         spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1718 }
1719
1720 static int seq_show(struct seq_file *s, void *v)
1721 {
1722         const struct nfqnl_instance *inst = v;
1723
1724         seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1725                    inst->queue_num,
1726                    inst->peer_portid, inst->queue_total,
1727                    inst->copy_mode, inst->copy_range,
1728                    inst->queue_dropped, inst->queue_user_dropped,
1729                    inst->id_sequence, 1);
1730         return 0;
1731 }
1732
1733 static const struct seq_operations nfqnl_seq_ops = {
1734         .start  = seq_start,
1735         .next   = seq_next,
1736         .stop   = seq_stop,
1737         .show   = seq_show,
1738 };
1739 #endif /* PROC_FS */
1740
1741 static int __net_init nfnl_queue_net_init(struct net *net)
1742 {
1743         unsigned int i;
1744         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1745
1746         for (i = 0; i < INSTANCE_BUCKETS; i++)
1747                 INIT_HLIST_HEAD(&q->instance_table[i]);
1748
1749         spin_lock_init(&q->instances_lock);
1750
1751 #ifdef CONFIG_PROC_FS
1752         if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
1753                         &nfqnl_seq_ops, sizeof(struct iter_state)))
1754                 return -ENOMEM;
1755 #endif
1756         return 0;
1757 }
1758
1759 static void __net_exit nfnl_queue_net_exit(struct net *net)
1760 {
1761         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1762         unsigned int i;
1763
1764 #ifdef CONFIG_PROC_FS
1765         remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1766 #endif
1767         for (i = 0; i < INSTANCE_BUCKETS; i++)
1768                 WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
1769 }
1770
1771 static struct pernet_operations nfnl_queue_net_ops = {
1772         .init           = nfnl_queue_net_init,
1773         .exit           = nfnl_queue_net_exit,
1774         .id             = &nfnl_queue_net_id,
1775         .size           = sizeof(struct nfnl_queue_net),
1776 };
1777
1778 static int __init nfnetlink_queue_init(void)
1779 {
1780         int status;
1781
1782         status = register_pernet_subsys(&nfnl_queue_net_ops);
1783         if (status < 0) {
1784                 pr_err("failed to register pernet ops\n");
1785                 goto out;
1786         }
1787
1788         netlink_register_notifier(&nfqnl_rtnl_notifier);
1789         status = nfnetlink_subsys_register(&nfqnl_subsys);
1790         if (status < 0) {
1791                 pr_err("failed to create netlink socket\n");
1792                 goto cleanup_netlink_notifier;
1793         }
1794
1795         status = register_netdevice_notifier(&nfqnl_dev_notifier);
1796         if (status < 0) {
1797                 pr_err("failed to register netdevice notifier\n");
1798                 goto cleanup_netlink_subsys;
1799         }
1800
1801         nf_register_queue_handler(&nfqh);
1802
1803         return status;
1804
1805 cleanup_netlink_subsys:
1806         nfnetlink_subsys_unregister(&nfqnl_subsys);
1807 cleanup_netlink_notifier:
1808         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1809         unregister_pernet_subsys(&nfnl_queue_net_ops);
1810 out:
1811         return status;
1812 }
1813
1814 static void __exit nfnetlink_queue_fini(void)
1815 {
1816         nf_unregister_queue_handler();
1817         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1818         nfnetlink_subsys_unregister(&nfqnl_subsys);
1819         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1820         unregister_pernet_subsys(&nfnl_queue_net_ops);
1821
1822         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1823 }
1824
1825 MODULE_DESCRIPTION("netfilter packet queue handler");
1826 MODULE_AUTHOR("Harald Welte <[email protected]>");
1827 MODULE_LICENSE("GPL");
1828 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1829
1830 module_init(nfnetlink_queue_init);
1831 module_exit(nfnetlink_queue_fini);