net/netfilter/nfnetlink_queue.c

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