Commit 838ab636 authored by Harald Welte's avatar Harald Welte Committed by David S. Miller
Browse files

[NETFILTER]: Add refcounting and /proc/net/netfilter interface to nfnetlink_queue


Signed-off-by: default avatarHarald Welte <laforge@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 32519f11
......@@ -81,5 +81,6 @@ enum nfqnl_attr_config {
NFQA_CFG_PARAMS, /* nfqnl_msg_config_params */
__NFQA_CFG_MAX
};
#define NFQA_CFG_MAX (__NFQA_CFG_MAX-1)
#endif /* _NFNETLINK_QUEUE_H */
......@@ -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_queue_entry {
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 @@ __instance_lookup(u_int16_t queue_num)
}
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 @@ instance_create(u_int16_t queue_num, int pid)
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 @@ _instance_destroy2(struct nfqnl_instance *inst, int lock)
/* 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 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
__enqueue_entry(queue, entry);
spin_unlock_bh(&queue->lock);
instance_put(queue);
return status;
err_out_free_nskb:
......@@ -533,6 +551,8 @@ err_out_unlock:
err_out_free:
kfree(entry);
err_out_put:
instance_put(queue);
return status;
}
......@@ -685,6 +705,12 @@ static struct notifier_block nfqnl_rtnl_notifier = {
.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 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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 @@ nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
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 @@ 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;
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 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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 @@ static struct nfnetlink_subsystem nfqnl_subsys = {
.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 @@ init_or_cleanup(int init)
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;
......
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