[NETFILTER]: Move reroute-after-queue code up to the nf_queue layer.

The rerouting functionality is required by the core, therefore it has
to be implemented by the core and not in individual queue handlers.

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

8 files changed, 199 insertions, 65 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 54b97a1baba5..d163e20ca8d9 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -198,6 +198,17 @@ extern void nf_invalidate_cache(int pf);
    Returns true or false. */
 extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
 
+struct nf_queue_rerouter {
+        void (*save)(const struct sk_buff *skb, struct nf_info *info);
+        int (*reroute)(struct sk_buff **skb, const struct nf_info *info);
+        int rer_size;
+};
+
+#define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
+
+extern int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer);
+extern int nf_unregister_queue_rerouter(int pf);
+
 #else /* !CONFIG_NETFILTER */
 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h
index 20c069a5e4ac..5d204ee7a312 100644
--- a/include/linux/netfilter_ipv6.h
+++ b/include/linux/netfilter_ipv6.h
@@ -71,4 +71,7 @@ enum nf_ip6_hook_priorities {
         NF_IP6_PRI_LAST = INT_MAX,
 };
 
+int ipv6_netfilter_init(void);
+void ipv6_netfilter_fini(void);
+
 #endif /*__LINUX_IP6_NETFILTER_H*/
diff --git a/net/core/netfilter.c b/net/core/netfilter.c
index 9849357f6129..1ed4f3110421 100644
--- a/net/core/netfilter.c
+++ b/net/core/netfilter.c
@@ -53,6 +53,9 @@ static struct nf_queue_handler_t {
         nf_queue_outfn_t outfn;
         void *data;
 } queue_handler[NPROTO];
+
+static struct nf_queue_rerouter *queue_rerouter;
+
 static DEFINE_RWLOCK(queue_handler_lock);
 
 int nf_register_hook(struct nf_hook_ops *reg)
@@ -260,11 +263,34 @@ int nf_unregister_queue_handler(int pf)
         return 0;
 }
 
+int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer)
+{
+        if (pf >= NPROTO)
+                return -EINVAL;
+
+        write_lock_bh(&queue_handler_lock);
+        memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf]));
+        write_unlock_bh(&queue_handler_lock);
+
+        return 0;
+}
+
+int nf_unregister_queue_rerouter(int pf)
+{
+        if (pf >= NPROTO)
+                return -EINVAL;
+
+        write_lock_bh(&queue_handler_lock);
+        memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf]));
+        write_unlock_bh(&queue_handler_lock);
+        return 0;
+}
+
 /* 
  * Any packet that leaves via this function must come back 
  * through nf_reinject().
  */
-static int nf_queue(struct sk_buff *skb, 
+static int nf_queue(struct sk_buff **skb, 
                     struct list_head *elem, 
                     int pf, unsigned int hook,
                     struct net_device *indev,
@@ -282,17 +308,17 @@ static int nf_queue(struct sk_buff *skb,
         read_lock(&queue_handler_lock);
         if (!queue_handler[pf].outfn) {
                 read_unlock(&queue_handler_lock);
-                kfree_skb(skb);
+                kfree_skb(*skb);
                 return 1;
         }
 
-        info = kmalloc(sizeof(*info), GFP_ATOMIC);
+        info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC);
         if (!info) {
                 if (net_ratelimit())
                         printk(KERN_ERR "OOM queueing packet %p\n",
-                               skb);
+                               *skb);
                 read_unlock(&queue_handler_lock);
-                kfree_skb(skb);
+                kfree_skb(*skb);
                 return 1;
         }
 
@@ -311,15 +337,21 @@ static int nf_queue(struct sk_buff *skb,
         if (outdev) dev_hold(outdev);
 
 #ifdef CONFIG_BRIDGE_NETFILTER
-        if (skb->nf_bridge) {
-                physindev = skb->nf_bridge->physindev;
+        if ((*skb)->nf_bridge) {
+                physindev = (*skb)->nf_bridge->physindev;
                 if (physindev) dev_hold(physindev);
-                physoutdev = skb->nf_bridge->physoutdev;
+                physoutdev = (*skb)->nf_bridge->physoutdev;
                 if (physoutdev) dev_hold(physoutdev);
         }
 #endif
+        if (queue_rerouter[pf].save)
+                queue_rerouter[pf].save(*skb, info);
+
+        status = queue_handler[pf].outfn(*skb, info, queue_handler[pf].data);
+
+        if (status >= 0 && queue_rerouter[pf].reroute)
+                status = queue_rerouter[pf].reroute(skb, info);
 
-        status = queue_handler[pf].outfn(skb, info, queue_handler[pf].data);
         read_unlock(&queue_handler_lock);
 
         if (status < 0) {
@@ -332,9 +364,11 @@ static int nf_queue(struct sk_buff *skb,
 #endif
                 module_put(info->elem->owner);
                 kfree(info);
-                kfree_skb(skb);
+                kfree_skb(*skb);
+
                 return 1;
         }
+
         return 1;
 }
 
@@ -365,7 +399,7 @@ next_hook:
                 ret = -EPERM;
         } else if (verdict == 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))
                         goto next_hook;
         }
 unlock:
@@ -428,7 +462,7 @@ void nf_reinject(struct sk_buff *skb, struct nf_info *info,
                 break;
 
         case NF_QUEUE:
-                if (!nf_queue(skb, elem, info->pf, info->hook, 
+                if (!nf_queue(&skb, elem, info->pf, info->hook, 
                               info->indev, info->outdev, info->okfn))
                         goto next_hook;
                 break;
@@ -555,6 +589,12 @@ void __init netfilter_init(void)
 {
         int i, h;
 
+        queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter),
+                                 GFP_KERNEL);
+        if (!queue_rerouter)
+                panic("netfilter: cannot allocate queue rerouter array\n");
+        memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter));
+
         for (i = 0; i < NPROTO; i++) {
                 for (h = 0; h < NF_MAX_HOOKS; h++)
                         INIT_LIST_HEAD(&nf_hooks[i][h]);
@@ -573,4 +613,6 @@ EXPORT_SYMBOL(nf_reinject);
 EXPORT_SYMBOL(nf_setsockopt);
 EXPORT_SYMBOL(nf_unregister_hook);
 EXPORT_SYMBOL(nf_unregister_queue_handler);
+EXPORT_SYMBOL_GPL(nf_register_queue_rerouter);
+EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter);
 EXPORT_SYMBOL(nf_unregister_sockopt);
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
index 6594d1c9697e..ae0779d82c5d 100644
--- a/net/ipv4/netfilter.c
+++ b/net/ipv4/netfilter.c
@@ -1,10 +1,11 @@
-#include <linux/config.h>
+/* IPv4 specific functions of netfilter core */
 
+#include <linux/config.h>
 #ifdef CONFIG_NETFILTER
 
-/* IPv4 specific functions of netfilter core */
 #include <linux/kernel.h>
 #include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
 
 #include <linux/tcp.h>
 #include <linux/udp.h>
@@ -76,4 +77,63 @@ int ip_route_me_harder(struct sk_buff **pskb)
         return 0;
 }
 EXPORT_SYMBOL(ip_route_me_harder);
+
+/*
+ * Extra routing may needed on local out, as the QUEUE target never
+ * returns control to the table.
+ */
+
+struct ip_rt_info {
+        u_int32_t daddr;
+        u_int32_t saddr;
+        u_int8_t tos;
+};
+
+static void queue_save(const struct sk_buff *skb, struct nf_info *info)
+{
+        struct ip_rt_info *rt_info = nf_info_reroute(info);
+
+        if (info->hook == NF_IP_LOCAL_OUT) {
+                const struct iphdr *iph = skb->nh.iph;
+
+                rt_info->tos = iph->tos;
+                rt_info->daddr = iph->daddr;
+                rt_info->saddr = iph->saddr;
+        }
+}
+
+static int queue_reroute(struct sk_buff **pskb, const struct nf_info *info)
+{
+        const struct ip_rt_info *rt_info = nf_info_reroute(info);
+
+        if (info->hook == NF_IP_LOCAL_OUT) {
+                struct iphdr *iph = (*pskb)->nh.iph;
+
+                if (!(iph->tos == rt_info->tos
+                      && iph->daddr == rt_info->daddr
+                      && iph->saddr == rt_info->saddr))
+                        return ip_route_me_harder(pskb);
+        }
+        return 0;
+}
+
+static struct nf_queue_rerouter ip_reroute = {
+        .rer_size       = sizeof(struct ip_rt_info),
+        .save           = queue_save,
+        .reroute        = queue_reroute,
+};
+
+static int init(void)
+{
+        return nf_register_queue_rerouter(PF_INET, &ip_reroute);
+}
+
+static void fini(void)
+{
+        nf_unregister_queue_rerouter(PF_INET);
+}
+
+module_init(init);
+module_exit(fini);
+
 #endif /* CONFIG_NETFILTER */
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index b237f7fcad92..78892980f42c 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -43,17 +43,10 @@
 #define NET_IPQ_QMAX 2088
 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
 
-struct ipq_rt_info {
-        __u8 tos;
-        __u32 daddr;
-        __u32 saddr;
-};
-
 struct ipq_queue_entry {
         struct list_head list;
         struct nf_info *info;
         struct sk_buff *skb;
-        struct ipq_rt_info rt_info;
 };
 
 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
@@ -305,14 +298,6 @@ ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
         entry->info = info;
         entry->skb = skb;
 
-        if (entry->info->hook == NF_IP_LOCAL_OUT) {
-                struct iphdr *iph = skb->nh.iph;
-
-                entry->rt_info.tos = iph->tos;
-                entry->rt_info.daddr = iph->daddr;
-                entry->rt_info.saddr = iph->saddr;
-        }
-
         nskb = ipq_build_packet_message(entry, &status);
         if (nskb == NULL)
                 goto err_out_free;
@@ -393,18 +378,6 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
         memcpy(e->skb->data, v->payload, v->data_len);
         e->skb->ip_summed = CHECKSUM_NONE;
 
-        /*
-         * Extra routing may needed on local out, as the QUEUE target never
-         * returns control to the table.
-         */
-        if (e->info->hook == NF_IP_LOCAL_OUT) {
-                struct iphdr *iph = e->skb->nh.iph;
-
-                if (!(iph->tos == e->rt_info.tos
-                      && iph->daddr == e->rt_info.daddr
-                      && iph->saddr == e->rt_info.saddr))
-                        return ip_route_me_harder(&e->skb);
-        }
         return 0;
 }
 
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 28d9bcab0970..574047353628 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -44,6 +44,7 @@
 #include <linux/netdevice.h>
 #include <linux/icmpv6.h>
 #include <linux/smp_lock.h>
+#include <linux/netfilter_ipv6.h>
 
 #include <net/ip.h>
 #include <net/ipv6.h>
@@ -757,6 +758,9 @@ static int __init inet6_init(void)
         err = igmp6_init(&inet6_family_ops);
         if (err)
                 goto igmp_fail;
+        err = ipv6_netfilter_init();
+        if (err)
+                goto netfilter_fail;
         /* Create /proc/foo6 entries. */
 #ifdef CONFIG_PROC_FS
         err = -ENOMEM;
@@ -813,6 +817,8 @@ proc_tcp6_fail:
         raw6_proc_exit();
 proc_raw6_fail:
 #endif
+        ipv6_netfilter_fini();
+netfilter_fail:
         igmp6_cleanup();
 igmp_fail:
         ndisc_cleanup();
@@ -852,6 +858,7 @@ static void __exit inet6_exit(void)
         ip6_route_cleanup();
         ipv6_packet_cleanup();
         igmp6_cleanup();
+        ipv6_netfilter_fini();
         ndisc_cleanup();
         icmpv6_cleanup();
 #ifdef CONFIG_SYSCTL
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index 5656d0959aba..c8daef97cf56 100644
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -5,6 +5,8 @@
 
 #include <linux/kernel.h>
 #include <linux/ipv6.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
 #include <net/dst.h>
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
@@ -40,4 +42,64 @@ int ip6_route_me_harder(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(ip6_route_me_harder);
 
+/*
+ * Extra routing may needed on local out, as the QUEUE target never
+ * returns control to the table.
+ */
+
+struct ip6_rt_info {
+        struct in6_addr daddr;
+        struct in6_addr saddr;
+};
+
+static void save(const struct sk_buff *skb, struct nf_info *info)
+{
+        struct ip6_rt_info *rt_info = nf_info_reroute(info);
+
+        if (info->hook == NF_IP6_LOCAL_OUT) {
+                struct ipv6hdr *iph = skb->nh.ipv6h;
+
+                rt_info->daddr = iph->daddr;
+                rt_info->saddr = iph->saddr;
+        }
+}
+
+static int reroute(struct sk_buff **pskb, const struct nf_info *info)
+{
+        struct ip6_rt_info *rt_info = nf_info_reroute(info);
+
+        if (info->hook == NF_IP6_LOCAL_OUT) {
+                struct ipv6hdr *iph = (*pskb)->nh.ipv6h;
+                if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
+                    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr))
+                        return ip6_route_me_harder(*pskb);
+        }
+        return 0;
+}
+
+static struct nf_queue_rerouter ip6_reroute = {
+        .rer_size       = sizeof(struct ip6_rt_info),
+        .save           = &save,
+        .reroute        = &reroute,
+};
+
+int __init ipv6_netfilter_init(void)
+{
+        return nf_register_queue_rerouter(PF_INET6, &ip6_reroute);
+}
+
+void ipv6_netfilter_fini(void)
+{
+        nf_unregister_queue_rerouter(PF_INET6);
+}
+
+#else /* CONFIG_NETFILTER */
+int __init ipv6_netfilter_init(void)
+{
+        return 0;
+}
+
+void ipv6_netfilter_fini(void)
+{
+}
 #endif /* CONFIG_NETFILTER */
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 1c3d247a22cc..c45d8f8815de 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -47,16 +47,10 @@
 #define NET_IPQ_QMAX 2088
 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
 
-struct ipq_rt_info {
-        struct in6_addr daddr;
-        struct in6_addr saddr;
-};
-
 struct ipq_queue_entry {
         struct list_head list;
         struct nf_info *info;
         struct sk_buff *skb;
-        struct ipq_rt_info rt_info;
 };
 
 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
@@ -302,13 +296,6 @@ ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
         entry->info = info;
         entry->skb = skb;
 
-        if (entry->info->hook == NF_IP_LOCAL_OUT) {
-                struct ipv6hdr *iph = skb->nh.ipv6h;
-
-                entry->rt_info.daddr = iph->daddr;
-                entry->rt_info.saddr = iph->saddr;
-        }
-
         nskb = ipq_build_packet_message(entry, &status);
         if (nskb == NULL)
                 goto err_out_free;
@@ -389,17 +376,6 @@ ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
         memcpy(e->skb->data, v->payload, v->data_len);
         e->skb->ip_summed = CHECKSUM_NONE;
 
-        /*
-         * Extra routing may needed on local out, as the QUEUE target never
-         * returns control to the table.
-         * Not a nice way to cmp, but works
-         */
-        if (e->info->hook == NF_IP_LOCAL_OUT) {
-                struct ipv6hdr *iph = e->skb->nh.ipv6h;
-                if (!ipv6_addr_equal(&iph->daddr, &e->rt_info.daddr) ||
-                    !ipv6_addr_equal(&iph->saddr, &e->rt_info.saddr))
-                        return ip6_route_me_harder(e->skb);
-        }
         return 0;
 }