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         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 nfgenmsg *nfmsg;
 387         struct sk_buff *entskb = entry->skb;
 388         struct net_device *indev;
 389         struct net_device *outdev;
 390         struct nf_conn *ct = NULL;
 391         enum ip_conntrack_info uninitialized_var(ctinfo);
 392         struct nfnl_ct_hook *nfnl_ct;
 393         bool csum_verify;
 394         char *secdata = NULL;
 395         u32 seclen = 0;
 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(struct nfqnl_msg_packet_hw))
 407                 + nla_total_size(sizeof(u_int32_t))     /* skbinfo */
 408                 + nla_total_size(sizeof(u_int32_t));    /* cap_len */
 409
 410         if (entskb->tstamp)
 411                 size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
 412
 413         size += nfqnl_get_bridge_size(entry);
 414
 415         if (entry->state.hook <= NF_INET_FORWARD ||
 416            (entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
 417                 csum_verify = !skb_csum_unnecessary(entskb);
 418         else
 419                 csum_verify = false;
 420
 421         outdev = entry->state.out;
 422
 423         switch ((enum nfqnl_config_mode)READ_ONCE(queue->copy_mode)) {
 424         case NFQNL_COPY_META:
 425         case NFQNL_COPY_NONE:
 426                 break;
 427
 428         case NFQNL_COPY_PACKET:
 429                 if (!(queue->flags & NFQA_CFG_F_GSO) &&
 430                     entskb->ip_summed == CHECKSUM_PARTIAL &&
 431                     skb_checksum_help(entskb))
 432                         return NULL;
 433
 434                 data_len = READ_ONCE(queue->copy_range);
 435                 if (data_len > entskb->len)
 436                         data_len = entskb->len;
 437
 438                 hlen = skb_zerocopy_headlen(entskb);
 439                 hlen = min_t(unsigned int, hlen, data_len);
 440                 size += sizeof(struct nlattr) + hlen;
 441                 cap_len = entskb->len;
 442                 break;
 443         }
 444
 445         nfnl_ct = rcu_dereference(nfnl_ct_hook);
 446
 447         if (queue->flags & NFQA_CFG_F_CONNTRACK) {
 448                 if (nfnl_ct != NULL) {
 449                         ct = nfnl_ct->get_ct(entskb, &ctinfo);
 450                         if (ct != NULL)
 451                                 size += nfnl_ct->build_size(ct);
 452                 }
 453         }
 454
 455         if (queue->flags & NFQA_CFG_F_UID_GID) {
 456                 size += (nla_total_size(sizeof(u_int32_t))      /* uid */
 457                         + nla_total_size(sizeof(u_int32_t)));   /* gid */
 458         }
 459
 460         if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
 461                 seclen = nfqnl_get_sk_secctx(entskb, &secdata);
 462                 if (seclen)
 463                         size += nla_total_size(seclen);
 464         }
 465
 466         skb = alloc_skb(size, GFP_ATOMIC);
 467         if (!skb) {
 468                 skb_tx_error(entskb);
 469                 goto nlmsg_failure;
 470         }
 471
 472         nlh = nlmsg_put(skb, 0, 0,
 473                         nfnl_msg_type(NFNL_SUBSYS_QUEUE, NFQNL_MSG_PACKET),
 474                         sizeof(struct nfgenmsg), 0);
 475         if (!nlh) {
 476                 skb_tx_error(entskb);
 477                 kfree_skb(skb);
 478                 goto nlmsg_failure;
 479         }
 480         nfmsg = nlmsg_data(nlh);
 481         nfmsg->nfgen_family = entry->state.pf;
 482         nfmsg->version = NFNETLINK_V0;
 483         nfmsg->res_id = htons(queue->queue_num);
 484
 485         nla = __nla_reserve(skb, NFQA_PACKET_HDR, sizeof(*pmsg));
 486         pmsg = nla_data(nla);
 487         pmsg->hw_protocol       = entskb->protocol;
 488         pmsg->hook              = entry->state.hook;
 489         *packet_id_ptr          = &pmsg->packet_id;
 490
 491         indev = entry->state.in;
 492         if (indev) {
 493 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 494                 if (nla_put_be32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex)))
 495                         goto nla_put_failure;
 496 #else
 497                 if (entry->state.pf == PF_BRIDGE) {
 498                         /* Case 1: indev is physical input device, we need to
 499                          * look for bridge group (when called from
 500                          * netfilter_bridge) */
 501                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 502                                          htonl(indev->ifindex)) ||
 503                         /* this is the bridge group "brX" */
 504                         /* rcu_read_lock()ed by __nf_queue */
 505                             nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 506                                          htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
 507                                 goto nla_put_failure;
 508                 } else {
 509                         int physinif;
 510
 511                         /* Case 2: indev is bridge group, we need to look for
 512                          * physical device (when called from ipv4) */
 513                         if (nla_put_be32(skb, NFQA_IFINDEX_INDEV,
 514                                          htonl(indev->ifindex)))
 515                                 goto nla_put_failure;
 516
 517                         physinif = nf_bridge_get_physinif(entskb);
 518                         if (physinif &&
 519                             nla_put_be32(skb, NFQA_IFINDEX_PHYSINDEV,
 520                                          htonl(physinif)))
 521                                 goto nla_put_failure;
 522                 }
 523 #endif
 524         }
 525
 526         if (outdev) {
 527 #if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 528                 if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex)))
 529                         goto nla_put_failure;
 530 #else
 531                 if (entry->state.pf == PF_BRIDGE) {
 532                         /* Case 1: outdev is physical output device, we need to
 533                          * look for bridge group (when called from
 534                          * netfilter_bridge) */
 535                         if (nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 536                                          htonl(outdev->ifindex)) ||
 537                         /* this is the bridge group "brX" */
 538                         /* rcu_read_lock()ed by __nf_queue */
 539                             nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 540                                          htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
 541                                 goto nla_put_failure;
 542                 } else {
 543                         int physoutif;
 544
 545                         /* Case 2: outdev is bridge group, we need to look for
 546                          * physical output device (when called from ipv4) */
 547                         if (nla_put_be32(skb, NFQA_IFINDEX_OUTDEV,
 548                                          htonl(outdev->ifindex)))
 549                                 goto nla_put_failure;
 550
 551                         physoutif = nf_bridge_get_physoutif(entskb);
 552                         if (physoutif &&
 553                             nla_put_be32(skb, NFQA_IFINDEX_PHYSOUTDEV,
 554                                          htonl(physoutif)))
 555                                 goto nla_put_failure;
 556                 }
 557 #endif
 558         }
 559
 560         if (entskb->mark &&
 561             nla_put_be32(skb, NFQA_MARK, htonl(entskb->mark)))
 562                 goto nla_put_failure;
 563
 564         if (indev && entskb->dev &&
 565             entskb->mac_header != entskb->network_header) {
 566                 struct nfqnl_msg_packet_hw phw;
 567                 int len;
 568
 569                 memset(&phw, 0, sizeof(phw));
 570                 len = dev_parse_header(entskb, phw.hw_addr);
 571                 if (len) {
 572                         phw.hw_addrlen = htons(len);
 573                         if (nla_put(skb, NFQA_HWADDR, sizeof(phw), &phw))
 574                                 goto nla_put_failure;
 575                 }
 576         }
 577
 578         if (nfqnl_put_bridge(entry, skb) < 0)
 579                 goto nla_put_failure;
 580
 581         if (entry->state.hook <= NF_INET_FORWARD && entskb->tstamp) {
 582                 struct nfqnl_msg_packet_timestamp ts;
 583                 struct timespec64 kts = ktime_to_timespec64(entskb->tstamp);
 584
 585                 ts.sec = cpu_to_be64(kts.tv_sec);
 586                 ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);
 587
 588                 if (nla_put(skb, NFQA_TIMESTAMP, sizeof(ts), &ts))
 589                         goto nla_put_failure;
 590         }
 591
 592         if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk &&
 593             nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
 594                 goto nla_put_failure;
 595
 596         if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
 597                 goto nla_put_failure;
 598
 599         if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
 600                 goto nla_put_failure;
 601
 602         if (cap_len > data_len &&
 603             nla_put_be32(skb, NFQA_CAP_LEN, htonl(cap_len)))
 604                 goto nla_put_failure;
 605
 606         if (nfqnl_put_packet_info(skb, entskb, csum_verify))
 607                 goto nla_put_failure;
 608
 609         if (data_len) {
 610                 struct nlattr *nla;
 611
 612                 if (skb_tailroom(skb) < sizeof(*nla) + hlen)
 613                         goto nla_put_failure;
 614
 615                 nla = skb_put(skb, sizeof(*nla));
 616                 nla->nla_type = NFQA_PAYLOAD;
 617                 nla->nla_len = nla_attr_size(data_len);
 618
 619                 if (skb_zerocopy(skb, entskb, data_len, hlen))
 620                         goto nla_put_failure;
 621         }
 622
 623         nlh->nlmsg_len = skb->len;
 624         if (seclen)
 625                 security_release_secctx(secdata, seclen);
 626         return skb;
 627
 628 nla_put_failure:
 629         skb_tx_error(entskb);
 630         kfree_skb(skb);
 631         net_err_ratelimited("nf_queue: error creating packet message\n");
 632 nlmsg_failure:
 633         if (seclen)
 634                 security_release_secctx(secdata, seclen);
 635         return NULL;
 636 }
 637
 638 static bool nf_ct_drop_unconfirmed(const struct nf_queue_entry *entry)
 639 {
 640 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 641         static const unsigned long flags = IPS_CONFIRMED | IPS_DYING;
 642         const struct nf_conn *ct = (void *)skb_nfct(entry->skb);
 643
 644         if (ct && ((ct->status & flags) == IPS_DYING))
 645                 return true;
 646 #endif
 647         return false;
 648 }
 649
 650 static int
 651 __nfqnl_enqueue_packet(struct net *net, struct nfqnl_instance *queue,
 652                         struct nf_queue_entry *entry)
 653 {
 654         struct sk_buff *nskb;
 655         int err = -ENOBUFS;
 656         __be32 *packet_id_ptr;
 657         int failopen = 0;
 658
 659         nskb = nfqnl_build_packet_message(net, queue, entry, &packet_id_ptr);
 660         if (nskb == NULL) {
 661                 err = -ENOMEM;
 662                 goto err_out;
 663         }
 664         spin_lock_bh(&queue->lock);
 665
 666         if (nf_ct_drop_unconfirmed(entry))
 667                 goto err_out_free_nskb;
 668
 669         if (queue->queue_total >= queue->queue_maxlen) {
 670                 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 671                         failopen = 1;
 672                         err = 0;
 673                 } else {
 674                         queue->queue_dropped++;
 675                         net_warn_ratelimited("nf_queue: full at %d entries, dropping packets(s)\n",
 676                                              queue->queue_total);
 677                 }
 678                 goto err_out_free_nskb;
 679         }
 680         entry->id = ++queue->id_sequence;
 681         *packet_id_ptr = htonl(entry->id);
 682
 683         /* nfnetlink_unicast will either free the nskb or add it to a socket */
 684         err = nfnetlink_unicast(nskb, net, queue->peer_portid, MSG_DONTWAIT);
 685         if (err < 0) {
 686                 if (queue->flags & NFQA_CFG_F_FAIL_OPEN) {
 687                         failopen = 1;
 688                         err = 0;
 689                 } else {
 690                         queue->queue_user_dropped++;
 691                 }
 692                 goto err_out_unlock;
 693         }
 694
 695         __enqueue_entry(queue, entry);
 696
 697         spin_unlock_bh(&queue->lock);
 698         return 0;
 699
 700 err_out_free_nskb:
 701         kfree_skb(nskb);
 702 err_out_unlock:
 703         spin_unlock_bh(&queue->lock);
 704         if (failopen)
 705                 nfqnl_reinject(entry, NF_ACCEPT);
 706 err_out:
 707         return err;
 708 }
 709
 710 static struct nf_queue_entry *
 711 nf_queue_entry_dup(struct nf_queue_entry *e)
 712 {
 713         struct nf_queue_entry *entry = kmemdup(e, e->size, GFP_ATOMIC);
 714         if (entry)
 715                 nf_queue_entry_get_refs(entry);
 716         return entry;
 717 }
 718
 719 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 720 /* When called from bridge netfilter, skb->data must point to MAC header
 721  * before calling skb_gso_segment(). Else, original MAC header is lost
 722  * and segmented skbs will be sent to wrong destination.
 723  */
 724 static void nf_bridge_adjust_skb_data(struct sk_buff *skb)
 725 {
 726         if (nf_bridge_info_get(skb))
 727                 __skb_push(skb, skb->network_header - skb->mac_header);
 728 }
 729
 730 static void nf_bridge_adjust_segmented_data(struct sk_buff *skb)
 731 {
 732         if (nf_bridge_info_get(skb))
 733                 __skb_pull(skb, skb->network_header - skb->mac_header);
 734 }
 735 #else
 736 #define nf_bridge_adjust_skb_data(s) do {} while (0)
 737 #define nf_bridge_adjust_segmented_data(s) do {} while (0)
 738 #endif
 739
 740 static int
 741 __nfqnl_enqueue_packet_gso(struct net *net, struct nfqnl_instance *queue,
 742                            struct sk_buff *skb, struct nf_queue_entry *entry)
 743 {
 744         int ret = -ENOMEM;
 745         struct nf_queue_entry *entry_seg;
 746
 747         nf_bridge_adjust_segmented_data(skb);
 748
 749         if (skb->next == NULL) { /* last packet, no need to copy entry */
 750                 struct sk_buff *gso_skb = entry->skb;
 751                 entry->skb = skb;
 752                 ret = __nfqnl_enqueue_packet(net, queue, entry);
 753                 if (ret)
 754                         entry->skb = gso_skb;
 755                 return ret;
 756         }
 757
 758         skb_mark_not_on_list(skb);
 759
 760         entry_seg = nf_queue_entry_dup(entry);
 761         if (entry_seg) {
 762                 entry_seg->skb = skb;
 763                 ret = __nfqnl_enqueue_packet(net, queue, entry_seg);
 764                 if (ret)
 765                         nf_queue_entry_free(entry_seg);
 766         }
 767         return ret;
 768 }
 769
 770 static int
 771 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 772 {
 773         unsigned int queued;
 774         struct nfqnl_instance *queue;
 775         struct sk_buff *skb, *segs, *nskb;
 776         int err = -ENOBUFS;
 777         struct net *net = entry->state.net;
 778         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
 779
 780         /* rcu_read_lock()ed by nf_hook_thresh */
 781         queue = instance_lookup(q, queuenum);
 782         if (!queue)
 783                 return -ESRCH;
 784
 785         if (queue->copy_mode == NFQNL_COPY_NONE)
 786                 return -EINVAL;
 787
 788         skb = entry->skb;
 789
 790         switch (entry->state.pf) {
 791         case NFPROTO_IPV4:
 792                 skb->protocol = htons(ETH_P_IP);
 793                 break;
 794         case NFPROTO_IPV6:
 795                 skb->protocol = htons(ETH_P_IPV6);
 796                 break;
 797         }
 798
 799         if ((queue->flags & NFQA_CFG_F_GSO) || !skb_is_gso(skb))
 800                 return __nfqnl_enqueue_packet(net, queue, entry);
 801
 802         nf_bridge_adjust_skb_data(skb);
 803         segs = skb_gso_segment(skb, 0);
 804         /* Does not use PTR_ERR to limit the number of error codes that can be
 805          * returned by nf_queue.  For instance, callers rely on -ESRCH to
 806          * mean 'ignore this hook'.
 807          */
 808         if (IS_ERR_OR_NULL(segs))
 809                 goto out_err;
 810         queued = 0;
 811         err = 0;
 812         skb_list_walk_safe(segs, segs, nskb) {
 813                 if (err == 0)
 814                         err = __nfqnl_enqueue_packet_gso(net, queue,
 815                                                         segs, entry);
 816                 if (err == 0)
 817                         queued++;
 818                 else
 819                         kfree_skb(segs);
 820         }
 821
 822         if (queued) {
 823                 if (err) /* some segments are already queued */
 824                         nf_queue_entry_free(entry);
 825                 kfree_skb(skb);
 826                 return 0;
 827         }
 828  out_err:
 829         nf_bridge_adjust_segmented_data(skb);
 830         return err;
 831 }
 832
 833 static int
 834 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e, int diff)
 835 {
 836         struct sk_buff *nskb;
 837
 838         if (diff < 0) {
 839                 if (pskb_trim(e->skb, data_len))
 840                         return -ENOMEM;
 841         } else if (diff > 0) {
 842                 if (data_len > 0xFFFF)
 843                         return -EINVAL;
 844                 if (diff > skb_tailroom(e->skb)) {
 845                         nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
 846                                                diff, GFP_ATOMIC);
 847                         if (!nskb)
 848                                 return -ENOMEM;
 849                         kfree_skb(e->skb);
 850                         e->skb = nskb;
 851                 }
 852                 skb_put(e->skb, diff);
 853         }
 854         if (skb_ensure_writable(e->skb, data_len))
 855                 return -ENOMEM;
 856         skb_copy_to_linear_data(e->skb, data, data_len);
 857         e->skb->ip_summed = CHECKSUM_NONE;
 858         return 0;
 859 }
 860
 861 static int
 862 nfqnl_set_mode(struct nfqnl_instance *queue,
 863                unsigned char mode, unsigned int range)
 864 {
 865         int status = 0;
 866
 867         spin_lock_bh(&queue->lock);
 868         switch (mode) {
 869         case NFQNL_COPY_NONE:
 870         case NFQNL_COPY_META:
 871                 queue->copy_mode = mode;
 872                 queue->copy_range = 0;
 873                 break;
 874
 875         case NFQNL_COPY_PACKET:
 876                 queue->copy_mode = mode;
 877                 if (range == 0 || range > NFQNL_MAX_COPY_RANGE)
 878                         queue->copy_range = NFQNL_MAX_COPY_RANGE;
 879                 else
 880                         queue->copy_range = range;
 881                 break;
 882
 883         default:
 884                 status = -EINVAL;
 885
 886         }
 887         spin_unlock_bh(&queue->lock);
 888
 889         return status;
 890 }
 891
 892 static int
 893 dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
 894 {
 895 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 896         int physinif, physoutif;
 897
 898         physinif = nf_bridge_get_physinif(entry->skb);
 899         physoutif = nf_bridge_get_physoutif(entry->skb);
 900
 901         if (physinif == ifindex || physoutif == ifindex)
 902                 return 1;
 903 #endif
 904         if (entry->state.in)
 905                 if (entry->state.in->ifindex == ifindex)
 906                         return 1;
 907         if (entry->state.out)
 908                 if (entry->state.out->ifindex == ifindex)
 909                         return 1;
 910
 911         return 0;
 912 }
 913
 914 /* drop all packets with either indev or outdev == ifindex from all queue
 915  * instances */
 916 static void
 917 nfqnl_dev_drop(struct net *net, int ifindex)
 918 {
 919         int i;
 920         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
 921
 922         rcu_read_lock();
 923
 924         for (i = 0; i < INSTANCE_BUCKETS; i++) {
 925                 struct nfqnl_instance *inst;
 926                 struct hlist_head *head = &q->instance_table[i];
 927
 928                 hlist_for_each_entry_rcu(inst, head, hlist)
 929                         nfqnl_flush(inst, dev_cmp, ifindex);
 930         }
 931
 932         rcu_read_unlock();
 933 }
 934
 935 static int
 936 nfqnl_rcv_dev_event(struct notifier_block *this,
 937                     unsigned long event, void *ptr)
 938 {
 939         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 940
 941         /* Drop any packets associated with the downed device */
 942         if (event == NETDEV_DOWN)
 943                 nfqnl_dev_drop(dev_net(dev), dev->ifindex);
 944         return NOTIFY_DONE;
 945 }
 946
 947 static struct notifier_block nfqnl_dev_notifier = {
 948         .notifier_call  = nfqnl_rcv_dev_event,
 949 };
 950
 951 static void nfqnl_nf_hook_drop(struct net *net)
 952 {
 953         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
 954         int i;
 955
 956         for (i = 0; i < INSTANCE_BUCKETS; i++) {
 957                 struct nfqnl_instance *inst;
 958                 struct hlist_head *head = &q->instance_table[i];
 959
 960                 hlist_for_each_entry_rcu(inst, head, hlist)
 961                         nfqnl_flush(inst, NULL, 0);
 962         }
 963 }
 964
 965 static int
 966 nfqnl_rcv_nl_event(struct notifier_block *this,
 967                    unsigned long event, void *ptr)
 968 {
 969         struct netlink_notify *n = ptr;
 970         struct nfnl_queue_net *q = nfnl_queue_pernet(n->net);
 971
 972         if (event == NETLINK_URELEASE && n->protocol == NETLINK_NETFILTER) {
 973                 int i;
 974
 975                 /* destroy all instances for this portid */
 976                 spin_lock(&q->instances_lock);
 977                 for (i = 0; i < INSTANCE_BUCKETS; i++) {
 978                         struct hlist_node *t2;
 979                         struct nfqnl_instance *inst;
 980                         struct hlist_head *head = &q->instance_table[i];
 981
 982                         hlist_for_each_entry_safe(inst, t2, head, hlist) {
 983                                 if (n->portid == inst->peer_portid)
 984                                         __instance_destroy(inst);
 985                         }
 986                 }
 987                 spin_unlock(&q->instances_lock);
 988         }
 989         return NOTIFY_DONE;
 990 }
 991
 992 static struct notifier_block nfqnl_rtnl_notifier = {
 993         .notifier_call  = nfqnl_rcv_nl_event,
 994 };
 995
 996 static const struct nla_policy nfqa_vlan_policy[NFQA_VLAN_MAX + 1] = {
 997         [NFQA_VLAN_TCI]         = { .type = NLA_U16},
 998         [NFQA_VLAN_PROTO]       = { .type = NLA_U16},
 999 };
1000
1001 static const struct nla_policy nfqa_verdict_policy[NFQA_MAX+1] = {
1002         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1003         [NFQA_MARK]             = { .type = NLA_U32 },
1004         [NFQA_PAYLOAD]          = { .type = NLA_UNSPEC },
1005         [NFQA_CT]               = { .type = NLA_UNSPEC },
1006         [NFQA_EXP]              = { .type = NLA_UNSPEC },
1007         [NFQA_VLAN]             = { .type = NLA_NESTED },
1008 };
1009
1010 static const struct nla_policy nfqa_verdict_batch_policy[NFQA_MAX+1] = {
1011         [NFQA_VERDICT_HDR]      = { .len = sizeof(struct nfqnl_msg_verdict_hdr) },
1012         [NFQA_MARK]             = { .type = NLA_U32 },
1013 };
1014
1015 static struct nfqnl_instance *
1016 verdict_instance_lookup(struct nfnl_queue_net *q, u16 queue_num, u32 nlportid)
1017 {
1018         struct nfqnl_instance *queue;
1019
1020         queue = instance_lookup(q, queue_num);
1021         if (!queue)
1022                 return ERR_PTR(-ENODEV);
1023
1024         if (queue->peer_portid != nlportid)
1025                 return ERR_PTR(-EPERM);
1026
1027         return queue;
1028 }
1029
1030 static struct nfqnl_msg_verdict_hdr*
1031 verdicthdr_get(const struct nlattr * const nfqa[])
1032 {
1033         struct nfqnl_msg_verdict_hdr *vhdr;
1034         unsigned int verdict;
1035
1036         if (!nfqa[NFQA_VERDICT_HDR])
1037                 return NULL;
1038
1039         vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
1040         verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
1041         if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
1042                 return NULL;
1043         return vhdr;
1044 }
1045
1046 static int nfq_id_after(unsigned int id, unsigned int max)
1047 {
1048         return (int)(id - max) > 0;
1049 }
1050
1051 static int nfqnl_recv_verdict_batch(struct net *net, struct sock *ctnl,
1052                                     struct sk_buff *skb,
1053                                     const struct nlmsghdr *nlh,
1054                                     const struct nlattr * const nfqa[],
1055                                     struct netlink_ext_ack *extack)
1056 {
1057         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1058         struct nf_queue_entry *entry, *tmp;
1059         unsigned int verdict, maxid;
1060         struct nfqnl_msg_verdict_hdr *vhdr;
1061         struct nfqnl_instance *queue;
1062         LIST_HEAD(batch_list);
1063         u16 queue_num = ntohs(nfmsg->res_id);
1064         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1065
1066         queue = verdict_instance_lookup(q, queue_num,
1067                                         NETLINK_CB(skb).portid);
1068         if (IS_ERR(queue))
1069                 return PTR_ERR(queue);
1070
1071         vhdr = verdicthdr_get(nfqa);
1072         if (!vhdr)
1073                 return -EINVAL;
1074
1075         verdict = ntohl(vhdr->verdict);
1076         maxid = ntohl(vhdr->id);
1077
1078         spin_lock_bh(&queue->lock);
1079
1080         list_for_each_entry_safe(entry, tmp, &queue->queue_list, list) {
1081                 if (nfq_id_after(entry->id, maxid))
1082                         break;
1083                 __dequeue_entry(queue, entry);
1084                 list_add_tail(&entry->list, &batch_list);
1085         }
1086
1087         spin_unlock_bh(&queue->lock);
1088
1089         if (list_empty(&batch_list))
1090                 return -ENOENT;
1091
1092         list_for_each_entry_safe(entry, tmp, &batch_list, list) {
1093                 if (nfqa[NFQA_MARK])
1094                         entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1095
1096                 nfqnl_reinject(entry, verdict);
1097         }
1098         return 0;
1099 }
1100
1101 static struct nf_conn *nfqnl_ct_parse(struct nfnl_ct_hook *nfnl_ct,
1102                                       const struct nlmsghdr *nlh,
1103                                       const struct nlattr * const nfqa[],
1104                                       struct nf_queue_entry *entry,
1105                                       enum ip_conntrack_info *ctinfo)
1106 {
1107         struct nf_conn *ct;
1108
1109         ct = nfnl_ct->get_ct(entry->skb, ctinfo);
1110         if (ct == NULL)
1111                 return NULL;
1112
1113         if (nfnl_ct->parse(nfqa[NFQA_CT], ct) < 0)
1114                 return NULL;
1115
1116         if (nfqa[NFQA_EXP])
1117                 nfnl_ct->attach_expect(nfqa[NFQA_EXP], ct,
1118                                       NETLINK_CB(entry->skb).portid,
1119                                       nlmsg_report(nlh));
1120         return ct;
1121 }
1122
1123 static int nfqa_parse_bridge(struct nf_queue_entry *entry,
1124                              const struct nlattr * const nfqa[])
1125 {
1126         if (nfqa[NFQA_VLAN]) {
1127                 struct nlattr *tb[NFQA_VLAN_MAX + 1];
1128                 int err;
1129
1130                 err = nla_parse_nested_deprecated(tb, NFQA_VLAN_MAX,
1131                                                   nfqa[NFQA_VLAN],
1132                                                   nfqa_vlan_policy, NULL);
1133                 if (err < 0)
1134                         return err;
1135
1136                 if (!tb[NFQA_VLAN_TCI] || !tb[NFQA_VLAN_PROTO])
1137                         return -EINVAL;
1138
1139                 __vlan_hwaccel_put_tag(entry->skb,
1140                         nla_get_be16(tb[NFQA_VLAN_PROTO]),
1141                         ntohs(nla_get_be16(tb[NFQA_VLAN_TCI])));
1142         }
1143
1144         if (nfqa[NFQA_L2HDR]) {
1145                 int mac_header_len = entry->skb->network_header -
1146                         entry->skb->mac_header;
1147
1148                 if (mac_header_len != nla_len(nfqa[NFQA_L2HDR]))
1149                         return -EINVAL;
1150                 else if (mac_header_len > 0)
1151                         memcpy(skb_mac_header(entry->skb),
1152                                nla_data(nfqa[NFQA_L2HDR]),
1153                                mac_header_len);
1154         }
1155
1156         return 0;
1157 }
1158
1159 static int nfqnl_recv_verdict(struct net *net, struct sock *ctnl,
1160                               struct sk_buff *skb,
1161                               const struct nlmsghdr *nlh,
1162                               const struct nlattr * const nfqa[],
1163                               struct netlink_ext_ack *extack)
1164 {
1165         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1166         u_int16_t queue_num = ntohs(nfmsg->res_id);
1167         struct nfqnl_msg_verdict_hdr *vhdr;
1168         struct nfqnl_instance *queue;
1169         unsigned int verdict;
1170         struct nf_queue_entry *entry;
1171         enum ip_conntrack_info uninitialized_var(ctinfo);
1172         struct nfnl_ct_hook *nfnl_ct;
1173         struct nf_conn *ct = NULL;
1174         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1175         int err;
1176
1177         queue = verdict_instance_lookup(q, queue_num,
1178                                         NETLINK_CB(skb).portid);
1179         if (IS_ERR(queue))
1180                 return PTR_ERR(queue);
1181
1182         vhdr = verdicthdr_get(nfqa);
1183         if (!vhdr)
1184                 return -EINVAL;
1185
1186         verdict = ntohl(vhdr->verdict);
1187
1188         entry = find_dequeue_entry(queue, ntohl(vhdr->id));
1189         if (entry == NULL)
1190                 return -ENOENT;
1191
1192         /* rcu lock already held from nfnl->call_rcu. */
1193         nfnl_ct = rcu_dereference(nfnl_ct_hook);
1194
1195         if (nfqa[NFQA_CT]) {
1196                 if (nfnl_ct != NULL)
1197                         ct = nfqnl_ct_parse(nfnl_ct, nlh, nfqa, entry, &ctinfo);
1198         }
1199
1200         if (entry->state.pf == PF_BRIDGE) {
1201                 err = nfqa_parse_bridge(entry, nfqa);
1202                 if (err < 0)
1203                         return err;
1204         }
1205
1206         if (nfqa[NFQA_PAYLOAD]) {
1207                 u16 payload_len = nla_len(nfqa[NFQA_PAYLOAD]);
1208                 int diff = payload_len - entry->skb->len;
1209
1210                 if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
1211                                  payload_len, entry, diff) < 0)
1212                         verdict = NF_DROP;
1213
1214                 if (ct && diff)
1215                         nfnl_ct->seq_adjust(entry->skb, ct, ctinfo, diff);
1216         }
1217
1218         if (nfqa[NFQA_MARK])
1219                 entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
1220
1221         nfqnl_reinject(entry, verdict);
1222         return 0;
1223 }
1224
1225 static int nfqnl_recv_unsupp(struct net *net, struct sock *ctnl,
1226                              struct sk_buff *skb, const struct nlmsghdr *nlh,
1227                              const struct nlattr * const nfqa[],
1228                              struct netlink_ext_ack *extack)
1229 {
1230         return -ENOTSUPP;
1231 }
1232
1233 static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
1234         [NFQA_CFG_CMD]          = { .len = sizeof(struct nfqnl_msg_config_cmd) },
1235         [NFQA_CFG_PARAMS]       = { .len = sizeof(struct nfqnl_msg_config_params) },
1236         [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 },
1237         [NFQA_CFG_MASK]         = { .type = NLA_U32 },
1238         [NFQA_CFG_FLAGS]        = { .type = NLA_U32 },
1239 };
1240
1241 static const struct nf_queue_handler nfqh = {
1242         .outfn          = nfqnl_enqueue_packet,
1243         .nf_hook_drop   = nfqnl_nf_hook_drop,
1244 };
1245
1246 static int nfqnl_recv_config(struct net *net, struct sock *ctnl,
1247                              struct sk_buff *skb, const struct nlmsghdr *nlh,
1248                              const struct nlattr * const nfqa[],
1249                              struct netlink_ext_ack *extack)
1250 {
1251         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1252         u_int16_t queue_num = ntohs(nfmsg->res_id);
1253         struct nfqnl_instance *queue;
1254         struct nfqnl_msg_config_cmd *cmd = NULL;
1255         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1256         __u32 flags = 0, mask = 0;
1257         int ret = 0;
1258
1259         if (nfqa[NFQA_CFG_CMD]) {
1260                 cmd = nla_data(nfqa[NFQA_CFG_CMD]);
1261
1262                 /* Obsolete commands without queue context */
1263                 switch (cmd->command) {
1264                 case NFQNL_CFG_CMD_PF_BIND: return 0;
1265                 case NFQNL_CFG_CMD_PF_UNBIND: return 0;
1266                 }
1267         }
1268
1269         /* Check if we support these flags in first place, dependencies should
1270          * be there too not to break atomicity.
1271          */
1272         if (nfqa[NFQA_CFG_FLAGS]) {
1273                 if (!nfqa[NFQA_CFG_MASK]) {
1274                         /* A mask is needed to specify which flags are being
1275                          * changed.
1276                          */
1277                         return -EINVAL;
1278                 }
1279
1280                 flags = ntohl(nla_get_be32(nfqa[NFQA_CFG_FLAGS]));
1281                 mask = ntohl(nla_get_be32(nfqa[NFQA_CFG_MASK]));
1282
1283                 if (flags >= NFQA_CFG_F_MAX)
1284                         return -EOPNOTSUPP;
1285
1286 #if !IS_ENABLED(CONFIG_NETWORK_SECMARK)
1287                 if (flags & mask & NFQA_CFG_F_SECCTX)
1288                         return -EOPNOTSUPP;
1289 #endif
1290                 if ((flags & mask & NFQA_CFG_F_CONNTRACK) &&
1291                     !rcu_access_pointer(nfnl_ct_hook)) {
1292 #ifdef CONFIG_MODULES
1293                         nfnl_unlock(NFNL_SUBSYS_QUEUE);
1294                         request_module("ip_conntrack_netlink");
1295                         nfnl_lock(NFNL_SUBSYS_QUEUE);
1296                         if (rcu_access_pointer(nfnl_ct_hook))
1297                                 return -EAGAIN;
1298 #endif
1299                         return -EOPNOTSUPP;
1300                 }
1301         }
1302
1303         rcu_read_lock();
1304         queue = instance_lookup(q, queue_num);
1305         if (queue && queue->peer_portid != NETLINK_CB(skb).portid) {
1306                 ret = -EPERM;
1307                 goto err_out_unlock;
1308         }
1309
1310         if (cmd != NULL) {
1311                 switch (cmd->command) {
1312                 case NFQNL_CFG_CMD_BIND:
1313                         if (queue) {
1314                                 ret = -EBUSY;
1315                                 goto err_out_unlock;
1316                         }
1317                         queue = instance_create(q, queue_num,
1318                                                 NETLINK_CB(skb).portid);
1319                         if (IS_ERR(queue)) {
1320                                 ret = PTR_ERR(queue);
1321                                 goto err_out_unlock;
1322                         }
1323                         break;
1324                 case NFQNL_CFG_CMD_UNBIND:
1325                         if (!queue) {
1326                                 ret = -ENODEV;
1327                                 goto err_out_unlock;
1328                         }
1329                         instance_destroy(q, queue);
1330                         goto err_out_unlock;
1331                 case NFQNL_CFG_CMD_PF_BIND:
1332                 case NFQNL_CFG_CMD_PF_UNBIND:
1333                         break;
1334                 default:
1335                         ret = -ENOTSUPP;
1336                         goto err_out_unlock;
1337                 }
1338         }
1339
1340         if (!queue) {
1341                 ret = -ENODEV;
1342                 goto err_out_unlock;
1343         }
1344
1345         if (nfqa[NFQA_CFG_PARAMS]) {
1346                 struct nfqnl_msg_config_params *params =
1347                         nla_data(nfqa[NFQA_CFG_PARAMS]);
1348
1349                 nfqnl_set_mode(queue, params->copy_mode,
1350                                 ntohl(params->copy_range));
1351         }
1352
1353         if (nfqa[NFQA_CFG_QUEUE_MAXLEN]) {
1354                 __be32 *queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
1355
1356                 spin_lock_bh(&queue->lock);
1357                 queue->queue_maxlen = ntohl(*queue_maxlen);
1358                 spin_unlock_bh(&queue->lock);
1359         }
1360
1361         if (nfqa[NFQA_CFG_FLAGS]) {
1362                 spin_lock_bh(&queue->lock);
1363                 queue->flags &= ~mask;
1364                 queue->flags |= flags & mask;
1365                 spin_unlock_bh(&queue->lock);
1366         }
1367
1368 err_out_unlock:
1369         rcu_read_unlock();
1370         return ret;
1371 }
1372
1373 static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
1374         [NFQNL_MSG_PACKET]      = { .call_rcu = nfqnl_recv_unsupp,
1375                                     .attr_count = NFQA_MAX, },
1376         [NFQNL_MSG_VERDICT]     = { .call_rcu = nfqnl_recv_verdict,
1377                                     .attr_count = NFQA_MAX,
1378                                     .policy = nfqa_verdict_policy },
1379         [NFQNL_MSG_CONFIG]      = { .call = nfqnl_recv_config,
1380                                     .attr_count = NFQA_CFG_MAX,
1381                                     .policy = nfqa_cfg_policy },
1382         [NFQNL_MSG_VERDICT_BATCH]={ .call_rcu = nfqnl_recv_verdict_batch,
1383                                     .attr_count = NFQA_MAX,
1384                                     .policy = nfqa_verdict_batch_policy },
1385 };
1386
1387 static const struct nfnetlink_subsystem nfqnl_subsys = {
1388         .name           = "nf_queue",
1389         .subsys_id      = NFNL_SUBSYS_QUEUE,
1390         .cb_count       = NFQNL_MSG_MAX,
1391         .cb             = nfqnl_cb,
1392 };
1393
1394 #ifdef CONFIG_PROC_FS
1395 struct iter_state {
1396         struct seq_net_private p;
1397         unsigned int bucket;
1398 };
1399
1400 static struct hlist_node *get_first(struct seq_file *seq)
1401 {
1402         struct iter_state *st = seq->private;
1403         struct net *net;
1404         struct nfnl_queue_net *q;
1405
1406         if (!st)
1407                 return NULL;
1408
1409         net = seq_file_net(seq);
1410         q = nfnl_queue_pernet(net);
1411         for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
1412                 if (!hlist_empty(&q->instance_table[st->bucket]))
1413                         return q->instance_table[st->bucket].first;
1414         }
1415         return NULL;
1416 }
1417
1418 static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
1419 {
1420         struct iter_state *st = seq->private;
1421         struct net *net = seq_file_net(seq);
1422
1423         h = h->next;
1424         while (!h) {
1425                 struct nfnl_queue_net *q;
1426
1427                 if (++st->bucket >= INSTANCE_BUCKETS)
1428                         return NULL;
1429
1430                 q = nfnl_queue_pernet(net);
1431                 h = q->instance_table[st->bucket].first;
1432         }
1433         return h;
1434 }
1435
1436 static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
1437 {
1438         struct hlist_node *head;
1439         head = get_first(seq);
1440
1441         if (head)
1442                 while (pos && (head = get_next(seq, head)))
1443                         pos--;
1444         return pos ? NULL : head;
1445 }
1446
1447 static void *seq_start(struct seq_file *s, loff_t *pos)
1448         __acquires(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1449 {
1450         spin_lock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1451         return get_idx(s, *pos);
1452 }
1453
1454 static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
1455 {
1456         (*pos)++;
1457         return get_next(s, v);
1458 }
1459
1460 static void seq_stop(struct seq_file *s, void *v)
1461         __releases(nfnl_queue_pernet(seq_file_net(s))->instances_lock)
1462 {
1463         spin_unlock(&nfnl_queue_pernet(seq_file_net(s))->instances_lock);
1464 }
1465
1466 static int seq_show(struct seq_file *s, void *v)
1467 {
1468         const struct nfqnl_instance *inst = v;
1469
1470         seq_printf(s, "%5u %6u %5u %1u %5u %5u %5u %8u %2d\n",
1471                    inst->queue_num,
1472                    inst->peer_portid, inst->queue_total,
1473                    inst->copy_mode, inst->copy_range,
1474                    inst->queue_dropped, inst->queue_user_dropped,
1475                    inst->id_sequence, 1);
1476         return 0;
1477 }
1478
1479 static const struct seq_operations nfqnl_seq_ops = {
1480         .start  = seq_start,
1481         .next   = seq_next,
1482         .stop   = seq_stop,
1483         .show   = seq_show,
1484 };
1485 #endif /* PROC_FS */
1486
1487 static int __net_init nfnl_queue_net_init(struct net *net)
1488 {
1489         unsigned int i;
1490         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1491
1492         for (i = 0; i < INSTANCE_BUCKETS; i++)
1493                 INIT_HLIST_HEAD(&q->instance_table[i]);
1494
1495         spin_lock_init(&q->instances_lock);
1496
1497 #ifdef CONFIG_PROC_FS
1498         if (!proc_create_net("nfnetlink_queue", 0440, net->nf.proc_netfilter,
1499                         &nfqnl_seq_ops, sizeof(struct iter_state)))
1500                 return -ENOMEM;
1501 #endif
1502         nf_register_queue_handler(net, &nfqh);
1503         return 0;
1504 }
1505
1506 static void __net_exit nfnl_queue_net_exit(struct net *net)
1507 {
1508         struct nfnl_queue_net *q = nfnl_queue_pernet(net);
1509         unsigned int i;
1510
1511         nf_unregister_queue_handler(net);
1512 #ifdef CONFIG_PROC_FS
1513         remove_proc_entry("nfnetlink_queue", net->nf.proc_netfilter);
1514 #endif
1515         for (i = 0; i < INSTANCE_BUCKETS; i++)
1516                 WARN_ON_ONCE(!hlist_empty(&q->instance_table[i]));
1517 }
1518
1519 static void nfnl_queue_net_exit_batch(struct list_head *net_exit_list)
1520 {
1521         synchronize_rcu();
1522 }
1523
1524 static struct pernet_operations nfnl_queue_net_ops = {
1525         .init           = nfnl_queue_net_init,
1526         .exit           = nfnl_queue_net_exit,
1527         .exit_batch     = nfnl_queue_net_exit_batch,
1528         .id             = &nfnl_queue_net_id,
1529         .size           = sizeof(struct nfnl_queue_net),
1530 };
1531
1532 static int __init nfnetlink_queue_init(void)
1533 {
1534         int status;
1535
1536         status = register_pernet_subsys(&nfnl_queue_net_ops);
1537         if (status < 0) {
1538                 pr_err("failed to register pernet ops\n");
1539                 goto out;
1540         }
1541
1542         netlink_register_notifier(&nfqnl_rtnl_notifier);
1543         status = nfnetlink_subsys_register(&nfqnl_subsys);
1544         if (status < 0) {
1545                 pr_err("failed to create netlink socket\n");
1546                 goto cleanup_netlink_notifier;
1547         }
1548
1549         status = register_netdevice_notifier(&nfqnl_dev_notifier);
1550         if (status < 0) {
1551                 pr_err("failed to register netdevice notifier\n");
1552                 goto cleanup_netlink_subsys;
1553         }
1554
1555         return status;
1556
1557 cleanup_netlink_subsys:
1558         nfnetlink_subsys_unregister(&nfqnl_subsys);
1559 cleanup_netlink_notifier:
1560         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1561         unregister_pernet_subsys(&nfnl_queue_net_ops);
1562 out:
1563         return status;
1564 }
1565
1566 static void __exit nfnetlink_queue_fini(void)
1567 {
1568         unregister_netdevice_notifier(&nfqnl_dev_notifier);
1569         nfnetlink_subsys_unregister(&nfqnl_subsys);
1570         netlink_unregister_notifier(&nfqnl_rtnl_notifier);
1571         unregister_pernet_subsys(&nfnl_queue_net_ops);
1572
1573         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1574 }
1575
1576 MODULE_DESCRIPTION("netfilter packet queue handler");
1577 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
1578 MODULE_LICENSE("GPL");
1579 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE);
1580
1581 module_init(nfnetlink_queue_init);
1582 module_exit(nfnetlink_queue_fini);