[NETFILTER]: Add refcounting and /proc/net/netfilter interface to nfnetlink_queue
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 2403261..eab309e 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -20,6 +20,7 @@
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
+#include <linux/proc_fs.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/nfnetlink.h>
@@ -48,6 +49,7 @@
struct nfqnl_instance {
struct hlist_node hlist; /* global list of queues */
+ atomic_t use;
int peer_pid;
unsigned int queue_maxlen;
@@ -105,17 +107,28 @@
}
static struct nfqnl_instance *
-instance_lookup(u_int16_t queue_num)
+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)
{
@@ -141,6 +154,8 @@
inst->copy_range = 0xfffff;
inst->copy_mode = NFQNL_COPY_NONE;
atomic_set(&inst->id_sequence, 0);
+ /* needs to be two, since we _put() after creation */
+ atomic_set(&inst->use, 2);
inst->lock = SPIN_LOCK_UNLOCKED;
INIT_LIST_HEAD(&inst->queue_list);
@@ -182,8 +197,8 @@
/* then flush all pending skbs from the queue */
nfqnl_flush(inst, NF_DROP);
- /* and finally free the data structure */
- kfree(inst);
+ /* and finally put the refcount */
+ instance_put(inst);
module_put(THIS_MODULE);
}
@@ -471,7 +486,7 @@
QDEBUG("entered\n");
- queue = instance_lookup(queuenum);
+ queue = instance_lookup_get(queuenum);
if (!queue) {
QDEBUG("no queue instance matching\n");
return -EINVAL;
@@ -479,7 +494,8 @@
if (queue->copy_mode == NFQNL_COPY_NONE) {
QDEBUG("mode COPY_NONE, aborting\n");
- return -EAGAIN;
+ status = -EAGAIN;
+ goto err_out_put;
}
entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
@@ -487,7 +503,8 @@
if (net_ratelimit())
printk(KERN_ERR
"nf_queue: OOM in nfqnl_enqueue_packet()\n");
- return -ENOMEM;
+ status = -ENOMEM;
+ goto err_out_put;
}
entry->info = info;
@@ -523,6 +540,7 @@
__enqueue_entry(queue, entry);
spin_unlock_bh(&queue->lock);
+ instance_put(queue);
return status;
err_out_free_nskb:
@@ -533,6 +551,8 @@
err_out_free:
kfree(entry);
+err_out_put:
+ instance_put(queue);
return status;
}
@@ -685,6 +705,12 @@
.notifier_call = nfqnl_rcv_nl_event,
};
+static const int nfqa_verdict_min[NFQA_MAX] = {
+ [NFQA_VERDICT_HDR-1] = sizeof(struct nfqnl_msg_verdict_hdr),
+ [NFQA_MARK-1] = sizeof(u_int32_t),
+ [NFQA_PAYLOAD-1] = 0,
+};
+
static int
nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
@@ -696,26 +722,40 @@
struct nfqnl_instance *queue;
unsigned int verdict;
struct nfqnl_queue_entry *entry;
+ int err;
- queue = instance_lookup(queue_num);
+ if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) {
+ QDEBUG("bad attribute size\n");
+ return -EINVAL;
+ }
+
+ queue = instance_lookup_get(queue_num);
if (!queue)
return -ENODEV;
- if (queue->peer_pid != NETLINK_CB(skb).pid)
- return -EPERM;
+ if (queue->peer_pid != NETLINK_CB(skb).pid) {
+ err = -EPERM;
+ goto err_out_put;
+ }
- if (!nfqa[NFQA_VERDICT_HDR-1])
- return -EINVAL;
+ if (!nfqa[NFQA_VERDICT_HDR-1]) {
+ err = -EINVAL;
+ goto err_out_put;
+ }
vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
verdict = ntohl(vhdr->verdict);
- if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)
- return -EINVAL;
+ if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
+ err = -EINVAL;
+ goto err_out_put;
+ }
entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
- if (entry == NULL)
- return -ENOENT;
+ if (entry == NULL) {
+ err = -ENOENT;
+ goto err_out_put;
+ }
if (nfqa[NFQA_PAYLOAD-1]) {
if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
@@ -727,7 +767,12 @@
skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1]));
issue_verdict(entry, verdict);
+ instance_put(queue);
return 0;
+
+err_out_put:
+ instance_put(queue);
+ return err;
}
static int
@@ -737,6 +782,11 @@
return -ENOTSUPP;
}
+static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
+ [NFQA_CFG_CMD-1] = sizeof(struct nfqnl_msg_config_cmd),
+ [NFQA_CFG_PARAMS-1] = sizeof(struct nfqnl_msg_config_params),
+};
+
static int
nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
@@ -744,10 +794,16 @@
struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
u_int16_t queue_num = ntohs(nfmsg->res_id);
struct nfqnl_instance *queue;
+ int ret = 0;
QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
- queue = instance_lookup(queue_num);
+ if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) {
+ QDEBUG("bad attribute size\n");
+ return -EINVAL;
+ }
+
+ queue = instance_lookup_get(queue_num);
if (nfqa[NFQA_CFG_CMD-1]) {
struct nfqnl_msg_config_cmd *cmd;
cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
@@ -766,17 +822,19 @@
if (!queue)
return -ENODEV;
- if (queue->peer_pid != NETLINK_CB(skb).pid)
- return -EPERM;
+ if (queue->peer_pid != NETLINK_CB(skb).pid) {
+ ret = -EPERM;
+ goto out_put;
+ }
instance_destroy(queue);
break;
case NFQNL_CFG_CMD_PF_BIND:
QDEBUG("registering queue handler for pf=%u\n",
ntohs(cmd->pf));
- return nf_register_queue_handler(ntohs(cmd->pf),
- nfqnl_enqueue_packet,
- NULL);
+ ret = nf_register_queue_handler(ntohs(cmd->pf),
+ nfqnl_enqueue_packet,
+ NULL);
break;
case NFQNL_CFG_CMD_PF_UNBIND:
@@ -784,20 +842,23 @@
ntohs(cmd->pf));
/* This is a bug and a feature. We can unregister
* other handlers(!) */
- return nf_unregister_queue_handler(ntohs(cmd->pf));
+ ret = nf_unregister_queue_handler(ntohs(cmd->pf));
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
} else {
if (!queue) {
QDEBUG("no config command, and no instance ENOENT\n");
- return -ENOENT;
+ ret = -ENOENT;
+ goto out_put;
}
if (queue->peer_pid != NETLINK_CB(skb).pid) {
QDEBUG("no config command, and wrong pid\n");
- return -EPERM;
+ ret = -EPERM;
+ goto out_put;
}
}
@@ -809,7 +870,9 @@
ntohl(params->copy_range));
}
- return 0;
+out_put:
+ instance_put(queue);
+ return ret;
}
static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
@@ -829,14 +892,132 @@
.cb = nfqnl_cb,
};
+#ifdef CONFIG_PROC_FS
+struct iter_state {
+ unsigned int bucket;
+};
+
+static struct hlist_node *get_first(struct seq_file *seq)
+{
+ struct iter_state *st = seq->private;
+
+ if (!st)
+ return NULL;
+
+ for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
+ if (!hlist_empty(&instance_table[st->bucket]))
+ return instance_table[st->bucket].first;
+ }
+ return NULL;
+}
+
+static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
+{
+ struct iter_state *st = seq->private;
+
+ h = h->next;
+ while (!h) {
+ if (++st->bucket >= INSTANCE_BUCKETS)
+ return NULL;
+
+ h = instance_table[st->bucket].first;
+ }
+ return h;
+}
+
+static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
+{
+ struct hlist_node *head;
+ head = get_first(seq);
+
+ if (head)
+ while (pos && (head = get_next(seq, head)))
+ pos--;
+ return pos ? NULL : head;
+}
+
+static void *seq_start(struct seq_file *seq, loff_t *pos)
+{
+ read_lock_bh(&instances_lock);
+ return get_idx(seq, *pos);
+}
+
+static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return get_next(s, v);
+}
+
+static void seq_stop(struct seq_file *s, void *v)
+{
+ read_unlock_bh(&instances_lock);
+}
+
+static int seq_show(struct seq_file *s, void *v)
+{
+ const struct nfqnl_instance *inst = v;
+
+ return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
+ inst->queue_num,
+ inst->peer_pid, inst->queue_total,
+ inst->copy_mode, inst->copy_range,
+ inst->queue_dropped, inst->queue_user_dropped,
+ atomic_read(&inst->id_sequence),
+ atomic_read(&inst->use));
+}
+
+static struct seq_operations nfqnl_seq_ops = {
+ .start = seq_start,
+ .next = seq_next,
+ .stop = seq_stop,
+ .show = seq_show,
+};
+
+static int nfqnl_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ struct iter_state *is;
+ int ret;
+
+ is = kmalloc(sizeof(*is), GFP_KERNEL);
+ if (!is)
+ return -ENOMEM;
+ memset(is, 0, sizeof(*is));
+ ret = seq_open(file, &nfqnl_seq_ops);
+ if (ret < 0)
+ goto out_free;
+ seq = file->private_data;
+ seq->private = is;
+ return ret;
+out_free:
+ kfree(is);
+ return ret;
+}
+
+static struct file_operations nfqnl_file_ops = {
+ .owner = THIS_MODULE,
+ .open = nfqnl_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+#endif /* PROC_FS */
+
static int
init_or_cleanup(int init)
{
- int status = -ENOMEM;
+ int i, status = -ENOMEM;
+#ifdef CONFIG_PROC_FS
+ struct proc_dir_entry *proc_nfqueue;
+#endif
if (!init)
goto cleanup;
+ for (i = 0; i < INSTANCE_BUCKETS; i++)
+ INIT_HLIST_HEAD(&instance_table[i]);
+
netlink_register_notifier(&nfqnl_rtnl_notifier);
status = nfnetlink_subsys_register(&nfqnl_subsys);
if (status < 0) {
@@ -844,14 +1025,25 @@
goto cleanup_netlink_notifier;
}
+#ifdef CONFIG_PROC_FS
+ proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
+ proc_net_netfilter);
+ if (!proc_nfqueue)
+ goto cleanup_subsys;
+ proc_nfqueue->proc_fops = &nfqnl_file_ops;
+#endif
+
register_netdevice_notifier(&nfqnl_dev_notifier);
+
return status;
cleanup:
nf_unregister_queue_handlers(nfqnl_enqueue_packet);
unregister_netdevice_notifier(&nfqnl_dev_notifier);
+#ifdef CONFIG_PROC_FS
+cleanup_subsys:
+#endif
nfnetlink_subsys_unregister(&nfqnl_subsys);
-
cleanup_netlink_notifier:
netlink_unregister_notifier(&nfqnl_rtnl_notifier);
return status;
