[NETFILTER]: add /proc/net/netfilter interface to nf_queue

This patch adds a /proc/net/netfilter/nf_queue file, similar to the
recently-added /proc/net/netfilter/nf_log.  It indicates which queue
handler is registered to which protocol family.  This is useful since
there are now multiple queue handlers in the treee (ip[6]_queue,
nfnetlink_queue).

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 94 insertions, 25 deletions

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index ec58c4d2c667..31a9d63921d6 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -5,6 +5,7 @@
 #include <linux/proc_fs.h>
 #include <linux/skbuff.h>
 #include <linux/netfilter.h>
+#include <linux/seq_file.h>
 #include <net/protocol.h>
 
 #include "nf_internals.h"
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index 5586f843ed45..8a67bde8b640 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -5,6 +5,7 @@
 #include <linux/proc_fs.h>
 #include <linux/skbuff.h>
 #include <linux/netfilter.h>
+#include <linux/seq_file.h>
 #include <net/protocol.h>
 
 #include "nf_internals.h"
@@ -14,17 +15,12 @@
  * long term mutex.  The handler must provide an an outfn() to accept packets
  * for queueing and must reinject all packets it receives, no matter what.
  */
-static struct nf_queue_handler_t {
-        nf_queue_outfn_t outfn;
-        void *data;
-} queue_handler[NPROTO];
-
+static struct nf_queue_handler *queue_handler[NPROTO];
 static struct nf_queue_rerouter *queue_rerouter;
 
 static DEFINE_RWLOCK(queue_handler_lock);
 
-
-int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data)
+int nf_register_queue_handler(int pf, struct nf_queue_handler *qh)
 {      
         int ret;
 
@@ -32,11 +28,10 @@ int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data)
                 return -EINVAL;
 
         write_lock_bh(&queue_handler_lock);
-        if (queue_handler[pf].outfn)
+        if (queue_handler[pf])
                 ret = -EBUSY;
         else {
-                queue_handler[pf].outfn = outfn;
-                queue_handler[pf].data = data;
+                queue_handler[pf] = qh;
                 ret = 0;
         }
         write_unlock_bh(&queue_handler_lock);
@@ -52,8 +47,7 @@ int nf_unregister_queue_handler(int pf)
                 return -EINVAL;
 
         write_lock_bh(&queue_handler_lock);
-        queue_handler[pf].outfn = NULL;
-        queue_handler[pf].data = NULL;
+        queue_handler[pf] = NULL;
         write_unlock_bh(&queue_handler_lock);
         
         return 0;
@@ -85,16 +79,14 @@ int nf_unregister_queue_rerouter(int pf)
 }
 EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter);
 
-void nf_unregister_queue_handlers(nf_queue_outfn_t outfn)
+void nf_unregister_queue_handlers(struct nf_queue_handler *qh)
 {
         int pf;
 
         write_lock_bh(&queue_handler_lock);
         for (pf = 0; pf < NPROTO; pf++)  {
-                if (queue_handler[pf].outfn == outfn) {
-                        queue_handler[pf].outfn = NULL;
-                        queue_handler[pf].data = NULL;
-                }
+                if (queue_handler[pf] == qh)
+                        queue_handler[pf] = NULL;
         }
         write_unlock_bh(&queue_handler_lock);
 }
@@ -121,7 +113,7 @@ int nf_queue(struct sk_buff **skb,
 
         /* QUEUE == DROP if noone is waiting, to be safe. */
         read_lock(&queue_handler_lock);
-        if (!queue_handler[pf].outfn) {
+        if (!queue_handler[pf]->outfn) {
                 read_unlock(&queue_handler_lock);
                 kfree_skb(*skb);
                 return 1;
@@ -162,8 +154,8 @@ int nf_queue(struct sk_buff **skb,
         if (queue_rerouter[pf].save)
                 queue_rerouter[pf].save(*skb, info);
 
-        status = queue_handler[pf].outfn(*skb, info, queuenum,
-                                         queue_handler[pf].data);
+        status = queue_handler[pf]->outfn(*skb, info, queuenum,
+                                          queue_handler[pf]->data);
 
         if (status >= 0 && queue_rerouter[pf].reroute)
                 status = queue_rerouter[pf].reroute(skb, info);
@@ -259,13 +251,87 @@ void nf_reinject(struct sk_buff *skb, struct nf_info *info,
 }
 EXPORT_SYMBOL(nf_reinject);
 
+#ifdef CONFIG_PROC_FS
+static void *seq_start(struct seq_file *seq, loff_t *pos)
+{
+        if (*pos >= NPROTO)
+                return NULL;
+
+        return pos;
+}
+
+static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+        (*pos)++;
+
+        if (*pos >= NPROTO)
+                return NULL;
+
+        return pos;
+}
+
+static void seq_stop(struct seq_file *s, void *v)
+{
+
+}
+
+static int seq_show(struct seq_file *s, void *v)
+{
+        int ret;
+        loff_t *pos = v;
+        struct nf_queue_handler *qh;
+
+        read_lock_bh(&queue_handler_lock);
+        qh = queue_handler[*pos];
+        if (!qh)
+                ret = seq_printf(s, "%2lld NONE\n", *pos);
+        else
+                ret = seq_printf(s, "%2lld %s\n", *pos, qh->name);
+        read_unlock_bh(&queue_handler_lock);
+
+        return ret;
+}
+
+static struct seq_operations nfqueue_seq_ops = {
+        .start  = seq_start,
+        .next   = seq_next,
+        .stop   = seq_stop,
+        .show   = seq_show,
+};
+
+static int nfqueue_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &nfqueue_seq_ops);
+}
+
+static struct file_operations nfqueue_file_ops = {
+        .owner   = THIS_MODULE,
+        .open    = nfqueue_open,
+        .read    = seq_read,
+        .llseek  = seq_lseek,
+        .release = seq_release,
+};
+#endif /* PROC_FS */
+
+
 int __init netfilter_queue_init(void)
 {
+#ifdef CONFIG_PROC_FS
+        struct proc_dir_entry *pde;
+#endif
         queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter),
                                  GFP_KERNEL);
         if (!queue_rerouter)
                 return -ENOMEM;
 
+#ifdef CONFIG_PROC_FS
+        pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter);
+        if (!pde) {
+                kfree(queue_rerouter);
+                return -1;
+        }
+        pde->proc_fops = &nfqueue_file_ops;
+#endif
         memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter));
 
         return 0;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index bf9223084b4a..741686ff71d8 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -845,6 +845,11 @@ static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
         [NFQA_CFG_PARAMS-1]     = sizeof(struct nfqnl_msg_config_params),
 };
 
+static struct nf_queue_handler nfqh = {
+        .name   = "nf_queue",
+        .outfn  = &nfqnl_enqueue_packet,
+};
+
 static int
 nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                   struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
@@ -890,10 +895,7 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
                 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),
-                                                        nfqnl_enqueue_packet,
-                                                        NULL);
-
+                        ret = nf_register_queue_handler(ntohs(cmd->pf), &nfqh);
                         break;
                 case NFQNL_CFG_CMD_PF_UNBIND:
                         QDEBUG("unregistering queue handler for pf=%u\n",
@@ -1098,7 +1100,7 @@ init_or_cleanup(int init)
         return status;
 
 cleanup:
-        nf_unregister_queue_handlers(nfqnl_enqueue_packet);
+        nf_unregister_queue_handlers(&nfqh);
         unregister_netdevice_notifier(&nfqnl_dev_notifier);
 #ifdef CONFIG_PROC_FS
         remove_proc_entry("nfnetlink_queue", proc_net_netfilter);