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