[NETFILTER]: Core changes required by upcoming nfnetlink_queue code

- split netfiler verdict in 16bit verdict and 16bit queue number
- add 'queuenum' argument to nf_queue_outfn_t and its users ip[6]_queue
- move NFNL_SUBSYS_ definitions from enum to #define
- introduce autoloading for nfnetlink subsystem modules
- add MODULE_ALIAS_NFNL_SUBSYS macro
- add nf_unregister_queue_handlers() to register all handlers for a given
  nf_queue_outfn_t
- add more verbose DEBUGP macro definition to nfnetlink.c
- make nfnetlink_subsys_register fail if subsys already exists
- add some more comments and debug statements to nfnetlink.c

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

1 files changed, 33 insertions, 7 deletions

diff --git a/net/core/netfilter.c b/net/core/netfilter.c
index 1ed4f3110421..3e38084ac2bd 100644
--- a/net/core/netfilter.c
+++ b/net/core/netfilter.c
@@ -221,7 +221,8 @@ static unsigned int nf_iterate(struct list_head *head,
                 verdict = elem->hook(hook, skb, indev, outdev, okfn);
                 if (verdict != NF_ACCEPT) {
 #ifdef CONFIG_NETFILTER_DEBUG
-                        if (unlikely(verdict > NF_MAX_VERDICT)) {
+                        if (unlikely((verdict & NF_VERDICT_MASK)
+                                                        > NF_MAX_VERDICT)) {
                                 NFDEBUG("Evil return from %p(%u).\n",
                                         elem->hook, hook);
                                 continue;
@@ -239,6 +240,9 @@ int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data)
 {      
         int ret;
 
+        if (pf >= NPROTO)
+                return -EINVAL;
+
         write_lock_bh(&queue_handler_lock);
         if (queue_handler[pf].outfn)
                 ret = -EBUSY;
@@ -255,6 +259,9 @@ int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data)
 /* The caller must flush their queue before this */
 int nf_unregister_queue_handler(int pf)
 {
+        if (pf >= NPROTO)
+                return -EINVAL;
+
         write_lock_bh(&queue_handler_lock);
         queue_handler[pf].outfn = NULL;
         queue_handler[pf].data = NULL;
@@ -286,6 +293,20 @@ int nf_unregister_queue_rerouter(int pf)
         return 0;
 }
 
+void nf_unregister_queue_handlers(nf_queue_outfn_t outfn)
+{
+        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;
+                }
+        }
+        write_unlock_bh(&queue_handler_lock);
+}
+
 /* 
  * Any packet that leaves via this function must come back 
  * through nf_reinject().
@@ -295,7 +316,8 @@ static int nf_queue(struct sk_buff **skb,
                     int pf, unsigned int hook,
                     struct net_device *indev,
                     struct net_device *outdev,
-                    int (*okfn)(struct sk_buff *))
+                    int (*okfn)(struct sk_buff *),
+                    unsigned int queuenum)
 {
         int status;
         struct nf_info *info;
@@ -347,7 +369,8 @@ static 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, 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);
@@ -397,9 +420,10 @@ next_hook:
         } else if (verdict == NF_DROP) {
                 kfree_skb(*pskb);
                 ret = -EPERM;
-        } else if (verdict == NF_QUEUE) {
+        } else if ((verdict & NF_VERDICT_MASK)  == NF_QUEUE) {
                 NFDEBUG("nf_hook: Verdict = QUEUE.\n");
-                if (!nf_queue(pskb, elem, pf, hook, indev, outdev, okfn))
+                if (!nf_queue(pskb, elem, pf, hook, indev, outdev, okfn,
+                              verdict >> NF_VERDICT_BITS))
                         goto next_hook;
         }
 unlock:
@@ -456,14 +480,15 @@ void nf_reinject(struct sk_buff *skb, struct nf_info *info,
                                      info->okfn, INT_MIN);
         }
 
-        switch (verdict) {
+        switch (verdict & NF_VERDICT_MASK) {
         case NF_ACCEPT:
                 info->okfn(skb);
                 break;
 
         case NF_QUEUE:
                 if (!nf_queue(&skb, elem, info->pf, info->hook, 
-                              info->indev, info->outdev, info->okfn))
+                              info->indev, info->outdev, info->okfn,
+                              verdict >> NF_VERDICT_BITS))
                         goto next_hook;
                 break;
         }
@@ -613,6 +638,7 @@ EXPORT_SYMBOL(nf_reinject);
 EXPORT_SYMBOL(nf_setsockopt);
 EXPORT_SYMBOL(nf_unregister_hook);
 EXPORT_SYMBOL(nf_unregister_queue_handler);
+EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers);
 EXPORT_SYMBOL_GPL(nf_register_queue_rerouter);
 EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter);
 EXPORT_SYMBOL(nf_unregister_sockopt);