mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-20 11:13:58 +08:00
[NETFILTER]: nfnetlink: use RCU for queue instances hash
Use RCU for queue instances hash. Avoids multiple atomic operations for each packet. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
David S. Miller
parent
a3c8e7fd4b
commit
9872bec773
@ -47,7 +47,7 @@
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struct nfqnl_instance {
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struct hlist_node hlist; /* global list of queues */
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atomic_t use;
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struct rcu_head rcu;
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int peer_pid;
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unsigned int queue_maxlen;
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@ -68,7 +68,7 @@ struct nfqnl_instance {
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typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
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static DEFINE_RWLOCK(instances_lock);
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static DEFINE_SPINLOCK(instances_lock);
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#define INSTANCE_BUCKETS 16
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static struct hlist_head instance_table[INSTANCE_BUCKETS];
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@ -79,52 +79,30 @@ static inline u_int8_t instance_hashfn(u_int16_t queue_num)
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}
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static struct nfqnl_instance *
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__instance_lookup(u_int16_t queue_num)
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instance_lookup(u_int16_t queue_num)
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{
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struct hlist_head *head;
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struct hlist_node *pos;
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struct nfqnl_instance *inst;
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head = &instance_table[instance_hashfn(queue_num)];
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hlist_for_each_entry(inst, pos, head, hlist) {
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hlist_for_each_entry_rcu(inst, pos, head, hlist) {
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if (inst->queue_num == queue_num)
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return inst;
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}
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return NULL;
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}
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static struct nfqnl_instance *
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instance_lookup_get(u_int16_t queue_num)
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{
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struct nfqnl_instance *inst;
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read_lock_bh(&instances_lock);
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inst = __instance_lookup(queue_num);
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if (inst)
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atomic_inc(&inst->use);
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read_unlock_bh(&instances_lock);
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return inst;
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}
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static void
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instance_put(struct nfqnl_instance *inst)
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{
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if (inst && atomic_dec_and_test(&inst->use)) {
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QDEBUG("kfree(inst=%p)\n", inst);
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kfree(inst);
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}
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}
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static struct nfqnl_instance *
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instance_create(u_int16_t queue_num, int pid)
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{
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struct nfqnl_instance *inst;
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unsigned int h;
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QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid);
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write_lock_bh(&instances_lock);
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if (__instance_lookup(queue_num)) {
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spin_lock(&instances_lock);
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if (instance_lookup(queue_num)) {
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inst = NULL;
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QDEBUG("aborting, instance already exists\n");
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goto out_unlock;
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@ -139,18 +117,17 @@ instance_create(u_int16_t queue_num, int pid)
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inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
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inst->copy_range = 0xfffff;
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inst->copy_mode = NFQNL_COPY_NONE;
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/* needs to be two, since we _put() after creation */
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atomic_set(&inst->use, 2);
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spin_lock_init(&inst->lock);
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INIT_LIST_HEAD(&inst->queue_list);
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INIT_RCU_HEAD(&inst->rcu);
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if (!try_module_get(THIS_MODULE))
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goto out_free;
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hlist_add_head(&inst->hlist,
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&instance_table[instance_hashfn(queue_num)]);
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h = instance_hashfn(queue_num);
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hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
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write_unlock_bh(&instances_lock);
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spin_unlock(&instances_lock);
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QDEBUG("successfully created new instance\n");
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@ -159,7 +136,7 @@ instance_create(u_int16_t queue_num, int pid)
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out_free:
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kfree(inst);
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out_unlock:
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write_unlock_bh(&instances_lock);
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spin_unlock(&instances_lock);
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return NULL;
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}
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@ -167,38 +144,29 @@ static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
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unsigned long data);
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static void
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_instance_destroy2(struct nfqnl_instance *inst, int lock)
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instance_destroy_rcu(struct rcu_head *head)
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{
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/* first pull it out of the global list */
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if (lock)
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write_lock_bh(&instances_lock);
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struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
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rcu);
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QDEBUG("removing instance %p (queuenum=%u) from hash\n",
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inst, inst->queue_num);
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hlist_del(&inst->hlist);
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if (lock)
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write_unlock_bh(&instances_lock);
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/* then flush all pending skbs from the queue */
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nfqnl_flush(inst, NULL, 0);
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/* and finally put the refcount */
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instance_put(inst);
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kfree(inst);
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module_put(THIS_MODULE);
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}
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static inline void
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static void
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__instance_destroy(struct nfqnl_instance *inst)
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{
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_instance_destroy2(inst, 0);
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hlist_del_rcu(&inst->hlist);
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call_rcu(&inst->rcu, instance_destroy_rcu);
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}
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static inline void
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static void
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instance_destroy(struct nfqnl_instance *inst)
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{
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_instance_destroy2(inst, 1);
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spin_lock(&instances_lock);
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__instance_destroy(inst);
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spin_unlock(&instances_lock);
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}
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static inline void
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@ -485,7 +453,8 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
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QDEBUG("entered\n");
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queue = instance_lookup_get(queuenum);
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/* rcu_read_lock()ed by nf_hook_slow() */
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queue = instance_lookup(queuenum);
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if (!queue) {
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QDEBUG("no queue instance matching\n");
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return -EINVAL;
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@ -493,13 +462,12 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
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if (queue->copy_mode == NFQNL_COPY_NONE) {
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QDEBUG("mode COPY_NONE, aborting\n");
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status = -EAGAIN;
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goto err_out_put;
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return -EAGAIN;
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}
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nskb = nfqnl_build_packet_message(queue, entry, &status);
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if (nskb == NULL)
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goto err_out_put;
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return status;
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spin_lock_bh(&queue->lock);
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@ -526,7 +494,6 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
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__enqueue_entry(queue, entry);
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spin_unlock_bh(&queue->lock);
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instance_put(queue);
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return status;
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err_out_free_nskb:
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@ -534,9 +501,6 @@ err_out_free_nskb:
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err_out_unlock:
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spin_unlock_bh(&queue->lock);
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err_out_put:
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instance_put(queue);
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return status;
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}
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@ -616,21 +580,18 @@ nfqnl_dev_drop(int ifindex)
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QDEBUG("entering for ifindex %u\n", ifindex);
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/* this only looks like we have to hold the readlock for a way too long
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* time, issue_verdict(), nf_reinject(), ... - but we always only
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* issue NF_DROP, which is processed directly in nf_reinject() */
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read_lock_bh(&instances_lock);
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rcu_read_lock();
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for (i = 0; i < INSTANCE_BUCKETS; i++) {
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for (i = 0; i < INSTANCE_BUCKETS; i++) {
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struct hlist_node *tmp;
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struct nfqnl_instance *inst;
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struct hlist_head *head = &instance_table[i];
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hlist_for_each_entry(inst, tmp, head, hlist)
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hlist_for_each_entry_rcu(inst, tmp, head, hlist)
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nfqnl_flush(inst, dev_cmp, ifindex);
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}
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read_unlock_bh(&instances_lock);
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rcu_read_unlock();
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}
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#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
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@ -665,8 +626,8 @@ nfqnl_rcv_nl_event(struct notifier_block *this,
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int i;
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/* destroy all instances for this pid */
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write_lock_bh(&instances_lock);
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for (i = 0; i < INSTANCE_BUCKETS; i++) {
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spin_lock(&instances_lock);
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for (i = 0; i < INSTANCE_BUCKETS; i++) {
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struct hlist_node *tmp, *t2;
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struct nfqnl_instance *inst;
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struct hlist_head *head = &instance_table[i];
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@ -677,7 +638,7 @@ nfqnl_rcv_nl_event(struct notifier_block *this,
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__instance_destroy(inst);
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}
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}
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write_unlock_bh(&instances_lock);
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spin_unlock(&instances_lock);
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}
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return NOTIFY_DONE;
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}
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@ -705,18 +666,21 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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struct nf_queue_entry *entry;
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int err;
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queue = instance_lookup_get(queue_num);
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if (!queue)
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return -ENODEV;
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rcu_read_lock();
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queue = instance_lookup(queue_num);
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if (!queue) {
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err = -ENODEV;
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goto err_out_unlock;
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}
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if (queue->peer_pid != NETLINK_CB(skb).pid) {
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err = -EPERM;
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goto err_out_put;
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goto err_out_unlock;
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}
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if (!nfqa[NFQA_VERDICT_HDR]) {
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err = -EINVAL;
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goto err_out_put;
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goto err_out_unlock;
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}
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vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
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@ -724,14 +688,15 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
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err = -EINVAL;
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goto err_out_put;
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goto err_out_unlock;
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}
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entry = find_dequeue_entry(queue, ntohl(vhdr->id));
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if (entry == NULL) {
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err = -ENOENT;
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goto err_out_put;
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goto err_out_unlock;
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}
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rcu_read_unlock();
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if (nfqa[NFQA_PAYLOAD]) {
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if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
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@ -744,11 +709,10 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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nla_data(nfqa[NFQA_MARK]));
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nf_reinject(entry, verdict);
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instance_put(queue);
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return 0;
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err_out_put:
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instance_put(queue);
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err_out_unlock:
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rcu_read_unlock();
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return err;
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}
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@ -776,45 +740,61 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
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u_int16_t queue_num = ntohs(nfmsg->res_id);
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struct nfqnl_instance *queue;
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struct nfqnl_msg_config_cmd *cmd = NULL;
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int ret = 0;
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QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
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queue = instance_lookup_get(queue_num);
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if (queue && queue->peer_pid != NETLINK_CB(skb).pid) {
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ret = -EPERM;
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goto out_put;
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if (nfqa[NFQA_CFG_CMD]) {
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cmd = nla_data(nfqa[NFQA_CFG_CMD]);
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/* Commands without queue context - might sleep */
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switch (cmd->command) {
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case NFQNL_CFG_CMD_PF_BIND:
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ret = nf_register_queue_handler(ntohs(cmd->pf),
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&nfqh);
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break;
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case NFQNL_CFG_CMD_PF_UNBIND:
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ret = nf_unregister_queue_handler(ntohs(cmd->pf),
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&nfqh);
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break;
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default:
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break;
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}
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if (ret < 0)
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return ret;
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}
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if (nfqa[NFQA_CFG_CMD]) {
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struct nfqnl_msg_config_cmd *cmd;
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cmd = nla_data(nfqa[NFQA_CFG_CMD]);
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QDEBUG("found CFG_CMD\n");
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rcu_read_lock();
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queue = instance_lookup(queue_num);
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if (queue && queue->peer_pid != NETLINK_CB(skb).pid) {
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ret = -EPERM;
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goto err_out_unlock;
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}
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if (cmd != NULL) {
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switch (cmd->command) {
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case NFQNL_CFG_CMD_BIND:
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if (queue)
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return -EBUSY;
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if (queue) {
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ret = -EBUSY;
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goto err_out_unlock;
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}
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queue = instance_create(queue_num, NETLINK_CB(skb).pid);
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if (!queue)
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return -EINVAL;
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if (!queue) {
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ret = -EINVAL;
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goto err_out_unlock;
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}
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break;
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case NFQNL_CFG_CMD_UNBIND:
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if (!queue)
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return -ENODEV;
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if (!queue) {
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ret = -ENODEV;
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goto err_out_unlock;
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}
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instance_destroy(queue);
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break;
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case NFQNL_CFG_CMD_PF_BIND:
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QDEBUG("registering queue handler for pf=%u\n",
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ntohs(cmd->pf));
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ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
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break;
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case NFQNL_CFG_CMD_PF_UNBIND:
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QDEBUG("unregistering queue handler for pf=%u\n",
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ntohs(cmd->pf));
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ret = nf_unregister_queue_handler(ntohs(cmd->pf), &nfqh);
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break;
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default:
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ret = -EINVAL;
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@ -827,7 +807,7 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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if (!queue) {
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ret = -ENODEV;
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goto out_put;
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goto err_out_unlock;
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}
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params = nla_data(nfqa[NFQA_CFG_PARAMS]);
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nfqnl_set_mode(queue, params->copy_mode,
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@ -839,7 +819,7 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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if (!queue) {
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ret = -ENODEV;
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goto out_put;
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goto err_out_unlock;
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}
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queue_maxlen = nla_data(nfqa[NFQA_CFG_QUEUE_MAXLEN]);
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spin_lock_bh(&queue->lock);
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@ -847,8 +827,8 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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spin_unlock_bh(&queue->lock);
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}
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out_put:
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instance_put(queue);
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err_out_unlock:
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rcu_read_unlock();
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return ret;
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}
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@ -916,7 +896,7 @@ static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
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static void *seq_start(struct seq_file *seq, loff_t *pos)
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{
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read_lock_bh(&instances_lock);
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spin_lock(&instances_lock);
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return get_idx(seq, *pos);
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}
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@ -928,7 +908,7 @@ static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
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static void seq_stop(struct seq_file *s, void *v)
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{
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read_unlock_bh(&instances_lock);
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spin_unlock(&instances_lock);
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}
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static int seq_show(struct seq_file *s, void *v)
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@ -940,8 +920,7 @@ static int seq_show(struct seq_file *s, void *v)
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inst->peer_pid, inst->queue_total,
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inst->copy_mode, inst->copy_range,
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inst->queue_dropped, inst->queue_user_dropped,
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inst->id_sequence,
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atomic_read(&inst->use));
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inst->id_sequence, 1);
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}
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static const struct seq_operations nfqnl_seq_ops = {
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