net/netfilter/nfnetlink_queue.c

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