[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.
[linux-3.10.git] / net / netfilter / nfnetlink_queue.c
index 4abf62a..81fb048 100644 (file)
@@ -3,6 +3,7 @@
  * userspace via nfetlink.
  *
  * (C) 2005 by Harald Welte <laforge@netfilter.org>
+ * (C) 2007 by Patrick McHardy <kaber@trash.net>
  *
  * Based on the old ipv4-only ip_queue.c:
  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
 
 #define NFQNL_QMAX_DEFAULT 1024
 
-#if 0
-#define QDEBUG(x, args ...)    printk(KERN_DEBUG "%s(%d):%s(): " x,       \
-                                       __FILE__, __LINE__, __FUNCTION__,  \
-                                       ## args)
-#else
-#define QDEBUG(x, ...)
-#endif
-
 struct nfqnl_instance {
        struct hlist_node hlist;                /* global list of queues */
-       atomic_t use;
+       struct rcu_head rcu;
 
        int peer_pid;
        unsigned int queue_maxlen;
@@ -68,10 +61,10 @@ struct nfqnl_instance {
 
 typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
 
-static DEFINE_RWLOCK(instances_lock);
+static DEFINE_SPINLOCK(instances_lock);
 
 #define INSTANCE_BUCKETS       16
-static struct hlist_head instance_table[INSTANCE_BUCKETS];
+static struct hlist_head instance_table[INSTANCE_BUCKETS] __read_mostly;
 
 static inline u_int8_t instance_hashfn(u_int16_t queue_num)
 {
@@ -79,14 +72,14 @@ static inline u_int8_t instance_hashfn(u_int16_t queue_num)
 }
 
 static struct nfqnl_instance *
-__instance_lookup(u_int16_t queue_num)
+instance_lookup(u_int16_t queue_num)
 {
        struct hlist_head *head;
        struct hlist_node *pos;
        struct nfqnl_instance *inst;
 
        head = &instance_table[instance_hashfn(queue_num)];
-       hlist_for_each_entry(inst, pos, head, hlist) {
+       hlist_for_each_entry_rcu(inst, pos, head, hlist) {
                if (inst->queue_num == queue_num)
                        return inst;
        }
@@ -94,111 +87,79 @@ __instance_lookup(u_int16_t queue_num)
 }
 
 static struct nfqnl_instance *
-instance_lookup_get(u_int16_t queue_num)
-{
-       struct nfqnl_instance *inst;
-
-       read_lock_bh(&instances_lock);
-       inst = __instance_lookup(queue_num);
-       if (inst)
-               atomic_inc(&inst->use);
-       read_unlock_bh(&instances_lock);
-
-       return inst;
-}
-
-static void
-instance_put(struct nfqnl_instance *inst)
-{
-       if (inst && atomic_dec_and_test(&inst->use)) {
-               QDEBUG("kfree(inst=%p)\n", inst);
-               kfree(inst);
-       }
-}
-
-static struct nfqnl_instance *
 instance_create(u_int16_t queue_num, int pid)
 {
        struct nfqnl_instance *inst;
+       unsigned int h;
+       int err;
 
-       QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
-
-       write_lock_bh(&instances_lock);
-       if (__instance_lookup(queue_num)) {
-               inst = NULL;
-               QDEBUG("aborting, instance already exists\n");
+       spin_lock(&instances_lock);
+       if (instance_lookup(queue_num)) {
+               err = -EEXIST;
                goto out_unlock;
        }
 
        inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
-       if (!inst)
+       if (!inst) {
+               err = -ENOMEM;
                goto out_unlock;
+       }
 
        inst->queue_num = queue_num;
        inst->peer_pid = pid;
        inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
        inst->copy_range = 0xfffff;
        inst->copy_mode = NFQNL_COPY_NONE;
-       /* needs to be two, since we _put() after creation */
-       atomic_set(&inst->use, 2);
        spin_lock_init(&inst->lock);
        INIT_LIST_HEAD(&inst->queue_list);
+       INIT_RCU_HEAD(&inst->rcu);
 
-       if (!try_module_get(THIS_MODULE))
+       if (!try_module_get(THIS_MODULE)) {
+               err = -EAGAIN;
                goto out_free;
+       }
 
-       hlist_add_head(&inst->hlist,
-                      &instance_table[instance_hashfn(queue_num)]);
-
-       write_unlock_bh(&instances_lock);
+       h = instance_hashfn(queue_num);
+       hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
 
-       QDEBUG("successfully created new instance\n");
+       spin_unlock(&instances_lock);
 
        return inst;
 
 out_free:
        kfree(inst);
 out_unlock:
-       write_unlock_bh(&instances_lock);
-       return NULL;
+       spin_unlock(&instances_lock);
+       return ERR_PTR(err);
 }
 
 static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
                        unsigned long data);
 
 static void
-_instance_destroy2(struct nfqnl_instance *inst, int lock)
+instance_destroy_rcu(struct rcu_head *head)
 {
-       /* first pull it out of the global list */
-       if (lock)
-               write_lock_bh(&instances_lock);
-
-       QDEBUG("removing instance %p (queuenum=%u) from hash\n",
-               inst, inst->queue_num);
-       hlist_del(&inst->hlist);
+       struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
+                                                  rcu);
 
-       if (lock)
-               write_unlock_bh(&instances_lock);
-
-       /* then flush all pending skbs from the queue */
        nfqnl_flush(inst, NULL, 0);
-
-       /* and finally put the refcount */
-       instance_put(inst);
-
+       kfree(inst);
        module_put(THIS_MODULE);
 }
 
-static inline void
+static void
 __instance_destroy(struct nfqnl_instance *inst)
 {
-       _instance_destroy2(inst, 0);
+       hlist_del_rcu(&inst->hlist);
+       call_rcu(&inst->rcu, instance_destroy_rcu);
 }
 
-static inline void
+static void
 instance_destroy(struct nfqnl_instance *inst)
 {
-       _instance_destroy2(inst, 1);
+       spin_lock(&instances_lock);
+       __instance_destroy(inst);
+       spin_unlock(&instances_lock);
 }
 
 static inline void
@@ -208,35 +169,6 @@ __enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
        queue->queue_total++;
 }
 
-static inline int
-__nfqnl_set_mode(struct nfqnl_instance *queue,
-                unsigned char mode, unsigned int range)
-{
-       int status = 0;
-
-       switch (mode) {
-       case NFQNL_COPY_NONE:
-       case NFQNL_COPY_META:
-               queue->copy_mode = mode;
-               queue->copy_range = 0;
-               break;
-
-       case NFQNL_COPY_PACKET:
-               queue->copy_mode = mode;
-               /* we're using struct nlattr which has 16bit nla_len */
-               if (range > 0xffff)
-                       queue->copy_range = 0xffff;
-               else
-                       queue->copy_range = range;
-               break;
-
-       default:
-               status = -EINVAL;
-
-       }
-       return status;
-}
-
 static struct nf_queue_entry *
 find_dequeue_entry(struct nfqnl_instance *queue, unsigned int id)
 {
@@ -279,7 +211,7 @@ nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, unsigned long data)
 
 static struct sk_buff *
 nfqnl_build_packet_message(struct nfqnl_instance *queue,
-                          struct nf_queue_entry *entry, int *errp)
+                          struct nf_queue_entry *entry)
 {
        sk_buff_data_t old_tail;
        size_t size;
@@ -291,11 +223,8 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
        struct sk_buff *entskb = entry->skb;
        struct net_device *indev;
        struct net_device *outdev;
-       __be32 tmp_uint;
 
-       QDEBUG("entered\n");
-
-       size =    NLMSG_ALIGN(sizeof(struct nfgenmsg))
+       size =    NLMSG_SPACE(sizeof(struct nfgenmsg))
                + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr))
                + nla_total_size(sizeof(u_int32_t))     /* ifindex */
                + nla_total_size(sizeof(u_int32_t))     /* ifindex */
@@ -311,7 +240,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 
        spin_lock_bh(&queue->lock);
 
-       switch (queue->copy_mode) {
+       switch ((enum nfqnl_config_mode)queue->copy_mode) {
        case NFQNL_COPY_META:
        case NFQNL_COPY_NONE:
                data_len = 0;
@@ -320,7 +249,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
        case NFQNL_COPY_PACKET:
                if ((entskb->ip_summed == CHECKSUM_PARTIAL ||
                     entskb->ip_summed == CHECKSUM_COMPLETE) &&
-                   (*errp = skb_checksum_help(entskb))) {
+                   skb_checksum_help(entskb)) {
                        spin_unlock_bh(&queue->lock);
                        return NULL;
                }
@@ -332,11 +261,6 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 
                size += nla_total_size(data_len);
                break;
-
-       default:
-               *errp = -EINVAL;
-               spin_unlock_bh(&queue->lock);
-               return NULL;
        }
 
        entry->id = queue->id_sequence++;
@@ -364,69 +288,57 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 
        indev = entry->indev;
        if (indev) {
-               tmp_uint = htonl(indev->ifindex);
 #ifndef CONFIG_BRIDGE_NETFILTER
-               NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint);
+               NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV, htonl(indev->ifindex));
 #else
                if (entry->pf == PF_BRIDGE) {
                        /* Case 1: indev is physical input device, we need to
                         * look for bridge group (when called from
                         * netfilter_bridge) */
-                       NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV, sizeof(tmp_uint),
-                               &tmp_uint);
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV,
+                                    htonl(indev->ifindex));
                        /* this is the bridge group "brX" */
-                       tmp_uint = htonl(indev->br_port->br->dev->ifindex);
-                       NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
-                               &tmp_uint);
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV,
+                                    htonl(indev->br_port->br->dev->ifindex));
                } else {
                        /* Case 2: indev is bridge group, we need to look for
                         * physical device (when called from ipv4) */
-                       NLA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint),
-                               &tmp_uint);
-                       if (entskb->nf_bridge
-                           && entskb->nf_bridge->physindev) {
-                               tmp_uint = htonl(entskb->nf_bridge->physindev->ifindex);
-                               NLA_PUT(skb, NFQA_IFINDEX_PHYSINDEV,
-                                       sizeof(tmp_uint), &tmp_uint);
-                       }
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_INDEV,
+                                    htonl(indev->ifindex));
+                       if (entskb->nf_bridge && entskb->nf_bridge->physindev)
+                               NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSINDEV,
+                                            htonl(entskb->nf_bridge->physindev->ifindex));
                }
 #endif
        }
 
        if (outdev) {
-               tmp_uint = htonl(outdev->ifindex);
 #ifndef CONFIG_BRIDGE_NETFILTER
-               NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint);
+               NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV, htonl(outdev->ifindex));
 #else
                if (entry->pf == PF_BRIDGE) {
                        /* Case 1: outdev is physical output device, we need to
                         * look for bridge group (when called from
                         * netfilter_bridge) */
-                       NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV, sizeof(tmp_uint),
-                               &tmp_uint);
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV,
+                                    htonl(outdev->ifindex));
                        /* this is the bridge group "brX" */
-                       tmp_uint = htonl(outdev->br_port->br->dev->ifindex);
-                       NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
-                               &tmp_uint);
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV,
+                                    htonl(outdev->br_port->br->dev->ifindex));
                } else {
                        /* Case 2: outdev is bridge group, we need to look for
                         * physical output device (when called from ipv4) */
-                       NLA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint),
-                               &tmp_uint);
-                       if (entskb->nf_bridge
-                           && entskb->nf_bridge->physoutdev) {
-                               tmp_uint = htonl(entskb->nf_bridge->physoutdev->ifindex);
-                               NLA_PUT(skb, NFQA_IFINDEX_PHYSOUTDEV,
-                                       sizeof(tmp_uint), &tmp_uint);
-                       }
+                       NLA_PUT_BE32(skb, NFQA_IFINDEX_OUTDEV,
+                                    htonl(outdev->ifindex));
+                       if (entskb->nf_bridge && entskb->nf_bridge->physoutdev)
+                               NLA_PUT_BE32(skb, NFQA_IFINDEX_PHYSOUTDEV,
+                                            htonl(entskb->nf_bridge->physoutdev->ifindex));
                }
 #endif
        }
 
-       if (entskb->mark) {
-               tmp_uint = htonl(entskb->mark);
-               NLA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint);
-       }
+       if (entskb->mark)
+               NLA_PUT_BE32(skb, NFQA_MARK, htonl(entskb->mark));
 
        if (indev && entskb->dev) {
                struct nfqnl_msg_packet_hw phw;
@@ -448,7 +360,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 
        if (data_len) {
                struct nlattr *nla;
-               int size = nla_attr_size(data_len);
+               int sz = nla_attr_size(data_len);
 
                if (skb_tailroom(skb) < nla_total_size(data_len)) {
                        printk(KERN_WARNING "nf_queue: no tailroom!\n");
@@ -457,7 +369,7 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
 
                nla = (struct nlattr *)skb_put(skb, nla_total_size(data_len));
                nla->nla_type = NFQA_PAYLOAD;
-               nla->nla_len = size;
+               nla->nla_len = sz;
 
                if (skb_copy_bits(entskb, 0, nla_data(nla), data_len))
                        BUG();
@@ -470,7 +382,6 @@ nlmsg_failure:
 nla_put_failure:
        if (skb)
                kfree_skb(skb);
-       *errp = -EINVAL;
        if (net_ratelimit())
                printk(KERN_ERR "nf_queue: error creating packet message\n");
        return NULL;
@@ -479,27 +390,21 @@ nla_put_failure:
 static int
 nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 {
-       int status = -EINVAL;
        struct sk_buff *nskb;
        struct nfqnl_instance *queue;
+       int err;
 
-       QDEBUG("entered\n");
-
-       queue = instance_lookup_get(queuenum);
-       if (!queue) {
-               QDEBUG("no queue instance matching\n");
-               return -EINVAL;
-       }
+       /* rcu_read_lock()ed by nf_hook_slow() */
+       queue = instance_lookup(queuenum);
+       if (!queue)
+               goto err_out;
 
-       if (queue->copy_mode == NFQNL_COPY_NONE) {
-               QDEBUG("mode COPY_NONE, aborting\n");
-               status = -EAGAIN;
-               goto err_out_put;
-       }
+       if (queue->copy_mode == NFQNL_COPY_NONE)
+               goto err_out;
 
-       nskb = nfqnl_build_packet_message(queue, entry, &status);
+       nskb = nfqnl_build_packet_message(queue, entry);
        if (nskb == NULL)
-               goto err_out_put;
+               goto err_out;
 
        spin_lock_bh(&queue->lock);
 
@@ -508,7 +413,6 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
 
        if (queue->queue_total >= queue->queue_maxlen) {
                queue->queue_dropped++;
-               status = -ENOSPC;
                if (net_ratelimit())
                          printk(KERN_WARNING "nf_queue: full at %d entries, "
                                 "dropping packets(s). Dropped: %d\n",
@@ -517,8 +421,8 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
        }
 
        /* nfnetlink_unicast will either free the nskb or add it to a socket */
-       status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
-       if (status < 0) {
+       err = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT);
+       if (err < 0) {
                queue->queue_user_dropped++;
                goto err_out_unlock;
        }
@@ -526,25 +430,21 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
        __enqueue_entry(queue, entry);
 
        spin_unlock_bh(&queue->lock);
-       instance_put(queue);
-       return status;
+       return 0;
 
 err_out_free_nskb:
        kfree_skb(nskb);
-
 err_out_unlock:
        spin_unlock_bh(&queue->lock);
-
-err_out_put:
-       instance_put(queue);
-       return status;
+err_out:
+       return -1;
 }
 
 static int
 nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
 {
+       struct sk_buff *nskb;
        int diff;
-       int err;
 
        diff = data_len - e->skb->len;
        if (diff < 0) {
@@ -554,14 +454,16 @@ nfqnl_mangle(void *data, int data_len, struct nf_queue_entry *e)
                if (data_len > 0xFFFF)
                        return -EINVAL;
                if (diff > skb_tailroom(e->skb)) {
-                       err = pskb_expand_head(e->skb, 0,
+                       nskb = skb_copy_expand(e->skb, 0,
                                               diff - skb_tailroom(e->skb),
                                               GFP_ATOMIC);
-                       if (err) {
+                       if (!nskb) {
                                printk(KERN_WARNING "nf_queue: OOM "
                                      "in mangle, dropping packet\n");
-                               return err;
+                               return -ENOMEM;
                        }
+                       kfree_skb(e->skb);
+                       e->skb = nskb;
                }
                skb_put(e->skb, diff);
        }
@@ -576,10 +478,29 @@ static int
 nfqnl_set_mode(struct nfqnl_instance *queue,
               unsigned char mode, unsigned int range)
 {
-       int status;
+       int status = 0;
 
        spin_lock_bh(&queue->lock);
-       status = __nfqnl_set_mode(queue, mode, range);
+       switch (mode) {
+       case NFQNL_COPY_NONE:
+       case NFQNL_COPY_META:
+               queue->copy_mode = mode;
+               queue->copy_range = 0;
+               break;
+
+       case NFQNL_COPY_PACKET:
+               queue->copy_mode = mode;
+               /* we're using struct nlattr which has 16bit nla_len */
+               if (range > 0xffff)
+                       queue->copy_range = 0xffff;
+               else
+                       queue->copy_range = range;
+               break;
+
+       default:
+               status = -EINVAL;
+
+       }
        spin_unlock_bh(&queue->lock);
 
        return status;
@@ -614,23 +535,18 @@ nfqnl_dev_drop(int ifindex)
 {
        int i;
 
-       QDEBUG("entering for ifindex %u\n", ifindex);
-
-       /* this only looks like we have to hold the readlock for a way too long
-        * time, issue_verdict(),  nf_reinject(), ... - but we always only
-        * issue NF_DROP, which is processed directly in nf_reinject() */
-       read_lock_bh(&instances_lock);
+       rcu_read_lock();
 
-       for  (i = 0; i < INSTANCE_BUCKETS; i++) {
+       for (i = 0; i < INSTANCE_BUCKETS; i++) {
                struct hlist_node *tmp;
                struct nfqnl_instance *inst;
                struct hlist_head *head = &instance_table[i];
 
-               hlist_for_each_entry(inst, tmp, head, hlist)
+               hlist_for_each_entry_rcu(inst, tmp, head, hlist)
                        nfqnl_flush(inst, dev_cmp, ifindex);
        }
 
-       read_unlock_bh(&instances_lock);
+       rcu_read_unlock();
 }
 
 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
@@ -641,7 +557,7 @@ nfqnl_rcv_dev_event(struct notifier_block *this,
 {
        struct net_device *dev = ptr;
 
-       if (dev->nd_net != &init_net)
+       if (dev_net(dev) != &init_net)
                return NOTIFY_DONE;
 
        /* Drop any packets associated with the downed device */
@@ -665,8 +581,8 @@ nfqnl_rcv_nl_event(struct notifier_block *this,
                int i;
 
                /* destroy all instances for this pid */
-               write_lock_bh(&instances_lock);
-               for  (i = 0; i < INSTANCE_BUCKETS; i++) {
+               spin_lock(&instances_lock);
+               for (i = 0; i < INSTANCE_BUCKETS; i++) {
                        struct hlist_node *tmp, *t2;
                        struct nfqnl_instance *inst;
                        struct hlist_head *head = &instance_table[i];
@@ -677,7 +593,7 @@ nfqnl_rcv_nl_event(struct notifier_block *this,
                                        __instance_destroy(inst);
                        }
                }
-               write_unlock_bh(&instances_lock);
+               spin_unlock(&instances_lock);
        }
        return NOTIFY_DONE;
 }
@@ -705,18 +621,21 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
        struct nf_queue_entry *entry;
        int err;
 
-       queue = instance_lookup_get(queue_num);
-       if (!queue)
-               return -ENODEV;
+       rcu_read_lock();
+       queue = instance_lookup(queue_num);
+       if (!queue) {
+               err = -ENODEV;
+               goto err_out_unlock;
+       }
 
        if (queue->peer_pid != NETLINK_CB(skb).pid) {
                err = -EPERM;
-               goto err_out_put;
+               goto err_out_unlock;
        }
 
        if (!nfqa[NFQA_VERDICT_HDR]) {
                err = -EINVAL;
-               goto err_out_put;
+               goto err_out_unlock;
        }
 
        vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
@@ -724,14 +643,15 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
 
        if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
                err = -EINVAL;
-               goto err_out_put;
+               goto err_out_unlock;
        }
 
        entry = find_dequeue_entry(queue, ntohl(vhdr->id));
        if (entry == NULL) {
                err = -ENOENT;
-               goto err_out_put;
+               goto err_out_unlock;
        }
+       rcu_read_unlock();
 
        if (nfqa[NFQA_PAYLOAD]) {
                if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
@@ -740,15 +660,13 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
        }
 
        if (nfqa[NFQA_MARK])
-               entry->skb->mark = ntohl(*(__be32 *)
-                                        nla_data(nfqa[NFQA_MARK]));
+               entry->skb->mark = ntohl(nla_get_be32(nfqa[NFQA_MARK]));
 
        nf_reinject(entry, verdict);
-       instance_put(queue);
        return 0;
 
-err_out_put:
-       instance_put(queue);
+err_out_unlock:
+       rcu_read_unlock();
        return err;
 }
 
@@ -776,48 +694,55 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
        struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
        u_int16_t queue_num = ntohs(nfmsg->res_id);
        struct nfqnl_instance *queue;
+       struct nfqnl_msg_config_cmd *cmd = NULL;
        int ret = 0;
 
-       QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
+       if (nfqa[NFQA_CFG_CMD]) {
+               cmd = nla_data(nfqa[NFQA_CFG_CMD]);
+
+               /* Commands without queue context - might sleep */
+               switch (cmd->command) {
+               case NFQNL_CFG_CMD_PF_BIND:
+                       return nf_register_queue_handler(ntohs(cmd->pf),
+                                                        &nfqh);
+               case NFQNL_CFG_CMD_PF_UNBIND:
+                       return nf_unregister_queue_handler(ntohs(cmd->pf),
+                                                          &nfqh);
+               }
+       }
 
-       queue = instance_lookup_get(queue_num);
+       rcu_read_lock();
+       queue = instance_lookup(queue_num);
        if (queue && queue->peer_pid != NETLINK_CB(skb).pid) {
                ret = -EPERM;
-               goto out_put;
+               goto err_out_unlock;
        }
 
-       if (nfqa[NFQA_CFG_CMD]) {
-               struct nfqnl_msg_config_cmd *cmd;
-
-               cmd = nla_data(nfqa[NFQA_CFG_CMD]);
-               QDEBUG("found CFG_CMD\n");
-
+       if (cmd != NULL) {
                switch (cmd->command) {
                case NFQNL_CFG_CMD_BIND:
-                       if (queue)
-                               return -EBUSY;
-
+                       if (queue) {
+                               ret = -EBUSY;
+                               goto err_out_unlock;
+                       }
                        queue = instance_create(queue_num, NETLINK_CB(skb).pid);
-                       if (!queue)
-                               return -EINVAL;
+                       if (IS_ERR(queue)) {
+                               ret = PTR_ERR(queue);
+                               goto err_out_unlock;
+                       }
                        break;
                case NFQNL_CFG_CMD_UNBIND:
-                       if (!queue)
-                               return -ENODEV;
+                       if (!queue) {
+                               ret = -ENODEV;
+                               goto err_out_unlock;
+                       }
                        instance_destroy(queue);
                        break;
                case NFQNL_CFG_CMD_PF_BIND:
-                       QDEBUG("registering queue handler for pf=%u\n",
-                               ntohs(cmd->pf));
-                       ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
-                       break;
                case NFQNL_CFG_CMD_PF_UNBIND:
-                       QDEBUG("unregistering queue handler for pf=%u\n",
-                               ntohs(cmd->pf));
-                       ret = nf_unregister_queue_handler(ntohs(cmd->pf), &nfqh);
                        break;
                default:
-                       ret = -EINVAL;
+                       ret = -ENOTSUPP;
                        break;
                }
        }
@@ -827,7 +752,7 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 
                if (!queue) {
                        ret = -ENODEV;
-                       goto out_put;
+                       goto err_out_unlock;
                }
                params = nla_data(nfqa[NFQA_CFG_PARAMS]);
                nfqnl_set_mode(queue, params->copy_mode,
@@ -839,7 +764,7 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 
                if (!queue) {
                        ret = -ENODEV;
-                       goto out_put;
+                       goto err_out_unlock;
                }
                queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
                spin_lock_bh(&queue->lock);
@@ -847,8 +772,8 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                spin_unlock_bh(&queue->lock);
        }
 
-out_put:
-       instance_put(queue);
+err_out_unlock:
+       rcu_read_unlock();
        return ret;
 }
 
@@ -915,8 +840,9 @@ static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
 }
 
 static void *seq_start(struct seq_file *seq, loff_t *pos)
+       __acquires(instances_lock)
 {
-       read_lock_bh(&instances_lock);
+       spin_lock(&instances_lock);
        return get_idx(seq, *pos);
 }
 
@@ -927,8 +853,9 @@ static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
 }
 
 static void seq_stop(struct seq_file *s, void *v)
+       __releases(instances_lock)
 {
-       read_unlock_bh(&instances_lock);
+       spin_unlock(&instances_lock);
 }
 
 static int seq_show(struct seq_file *s, void *v)
@@ -940,8 +867,7 @@ static int seq_show(struct seq_file *s, void *v)
                          inst->peer_pid, inst->queue_total,
                          inst->copy_mode, inst->copy_range,
                          inst->queue_dropped, inst->queue_user_dropped,
-                         inst->id_sequence,
-                         atomic_read(&inst->use));
+                         inst->id_sequence, 1);
 }
 
 static const struct seq_operations nfqnl_seq_ops = {