6 files changed, 220 insertions, 8 deletions

diff --git a/include/net/x25.h b/include/net/x25.h
index e47fe440d9d7..3b1190514d92 100644
--- a/include/net/x25.h
+++ b/include/net/x25.h
@@ -161,6 +161,14 @@ struct x25_sock {
         unsigned long           vc_facil_mask;  /* inc_call facilities mask */
 };
 
+struct x25_forward {
+        struct list_head        node;
+        unsigned int            lci;
+        struct net_device       *dev1;
+        struct net_device       *dev2;
+        atomic_t                refcnt;
+};
+
 static inline struct x25_sock *x25_sk(const struct sock *sk)
 {
         return (struct x25_sock *)sk;
@@ -198,6 +206,13 @@ extern int x25_negotiate_facilities(struct sk_buff *, struct sock *,
                                 struct x25_dte_facilities *);
 extern void x25_limit_facilities(struct x25_facilities *, struct x25_neigh *);
 
+/* x25_forward.c */
+extern void x25_clear_forward_by_lci(unsigned int lci);
+extern void x25_clear_forward_by_dev(struct net_device *);
+extern int x25_forward_data(int, struct x25_neigh *, struct sk_buff *);
+extern int x25_forward_call(struct x25_address *, struct x25_neigh *,
+                                struct sk_buff *, int);
+
 /* x25_in.c */
 extern int  x25_process_rx_frame(struct sock *, struct sk_buff *);
 extern int  x25_backlog_rcv(struct sock *, struct sk_buff *);
@@ -282,6 +297,8 @@ extern struct hlist_head x25_list;
 extern rwlock_t x25_list_lock;
 extern struct list_head x25_route_list;
 extern rwlock_t x25_route_list_lock;
+extern struct list_head x25_forward_list;
+extern rwlock_t x25_forward_list_lock;
 
 extern int x25_proc_init(void);
 extern void x25_proc_exit(void);
diff --git a/net/x25/Makefile b/net/x25/Makefile
index 587a71aa411d..a2c34ab6f194 100644
--- a/net/x25/Makefile
+++ b/net/x25/Makefile
@@ -6,5 +6,5 @@ obj-$(CONFIG_X25) += x25.o
 
 x25-y                   := af_x25.o x25_dev.o x25_facilities.o x25_in.o \
                            x25_link.o x25_out.o x25_route.o x25_subr.o \
-                           x25_timer.o x25_proc.o
+                           x25_timer.o x25_proc.o x25_forward.o
 x25-$(CONFIG_SYSCTL)    += sysctl_net_x25.o
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index b5c80b189902..0872025821c5 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -846,7 +846,7 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
         struct x25_address source_addr, dest_addr;
         struct x25_facilities facilities;
         struct x25_dte_facilities dte_facilities;
-        int len, rc;
+        int len, addr_len, rc;
 
         /*
          *      Remove the LCI and frame type.
@@ -857,7 +857,8 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
          *      Extract the X.25 addresses and convert them to ASCII strings,
          *      and remove them.
          */
-        skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
+        addr_len = x25_addr_ntoa(skb->data, &source_addr, &dest_addr);
+        skb_pull(skb, addr_len);
 
         /*
          *      Get the length of the facilities, skip past them for the moment
@@ -873,11 +874,27 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
         sk = x25_find_listener(&source_addr,skb);
         skb_push(skb,len);
 
+        if (sk != NULL && sk_acceptq_is_full(sk)) {
+                goto out_sock_put;
+        }
+
         /*
-         *      We can't accept the Call Request.
+         *      We dont have any listeners for this incoming call.
+         *      Try forwarding it.
          */
-        if (sk == NULL || sk_acceptq_is_full(sk))
-                goto out_clear_request;
+        if (sk == NULL) {
+                skb_push(skb, addr_len + X25_STD_MIN_LEN);
+                if (x25_forward_call(&dest_addr, nb, skb, lci) > 0)
+                {
+                        /* Call was forwarded, dont process it any more */
+                        kfree_skb(skb);
+                        rc = 1;
+                        goto out;
+                } else {
+                        /* No listeners, can't forward, clear the call */
+                        goto out_clear_request;
+                }
+        }
 
         /*
          *      Try to reach a compromise on the requested facilities.
@@ -1598,6 +1615,9 @@ void x25_kill_by_neigh(struct x25_neigh *nb)
                         x25_disconnect(s, ENETUNREACH, 0, 0);
 
         write_unlock_bh(&x25_list_lock);
+
+        /* Remove any related forwards */
+        x25_clear_forward_by_dev(nb->dev);
 }
 
 static int __init x25_init(void)
diff --git a/net/x25/x25_dev.c b/net/x25/x25_dev.c
index 328d80f000ad..f099fd6a7c0e 100644
--- a/net/x25/x25_dev.c
+++ b/net/x25/x25_dev.c
@@ -67,9 +67,18 @@ static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
                 return x25_rx_call_request(skb, nb, lci);
 
         /*
-         *      Its not a Call Request, nor is it a control frame.
-         *      Let caller throw it away.
+         *      Its not a Call Request, nor is it a control frame.
+         *      Can we forward it?
          */
+
+        if (x25_forward_data(lci, nb, skb)) {
+                if (frametype == X25_CLEAR_CONFIRMATION) {
+                        x25_clear_forward_by_lci(lci);
+                }
+                kfree_skb(skb);
+                return 1;
+        }
+
 /*
         x25_transmit_clear_request(nb, lci, 0x0D);
 */
diff --git a/net/x25/x25_forward.c b/net/x25/x25_forward.c
new file mode 100644
index 000000000000..d339e0c810a8
--- /dev/null
+++ b/net/x25/x25_forward.c
@@ -0,0 +1,163 @@
+/*
+ *      This module:
+ *              This module is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ *      History
+ *      03-01-2007      Added forwarding for x.25       Andrew Hendry
+ */
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <net/x25.h>
+
+struct list_head x25_forward_list = LIST_HEAD_INIT(x25_forward_list);
+DEFINE_RWLOCK(x25_forward_list_lock);
+
+int x25_forward_call(struct x25_address *dest_addr, struct x25_neigh *from,
+                        struct sk_buff *skb, int lci)
+{
+        struct x25_route *rt;
+        struct x25_neigh *neigh_new = NULL;
+        struct list_head *entry;
+        struct x25_forward *x25_frwd, *new_frwd;
+        struct sk_buff *skbn;
+        short same_lci = 0;
+        int rc = 0;
+
+        if ((rt = x25_get_route(dest_addr)) != NULL) {
+
+                if ((neigh_new = x25_get_neigh(rt->dev)) == NULL) {
+                        /* This shouldnt happen, if it occurs somehow
+                         * do something sensible
+                         */
+                        goto out_put_route;
+                }
+
+                /* Avoid a loop. This is the normal exit path for a
+                 * system with only one x.25 iface and default route
+                 */
+                if (rt->dev == from->dev) {
+                        goto out_put_nb;
+                }
+
+                /* Remote end sending a call request on an already
+                 * established LCI? It shouldnt happen, just in case..
+                 */
+                read_lock_bh(&x25_forward_list_lock);
+                list_for_each(entry, &x25_forward_list) {
+                        x25_frwd = list_entry(entry, struct x25_forward, node);
+                        if (x25_frwd->lci == lci) {
+                                printk(KERN_WARNING "X.25: call request for lci which is already registered!, transmitting but not registering new pair\n");
+                                same_lci = 1;
+                        }
+                }
+                read_unlock_bh(&x25_forward_list_lock);
+
+                /* Save the forwarding details for future traffic */
+                if (!same_lci){
+                        if ((new_frwd = kmalloc(sizeof(struct x25_forward),
+                                                        GFP_ATOMIC)) == NULL){
+                                rc = -ENOMEM;
+                                goto out_put_nb;
+                        }
+                        new_frwd->lci = lci;
+                        new_frwd->dev1 = rt->dev;
+                        new_frwd->dev2 = from->dev;
+                        write_lock_bh(&x25_forward_list_lock);
+                        list_add(&new_frwd->node, &x25_forward_list);
+                        write_unlock_bh(&x25_forward_list_lock);
+                }
+
+                /* Forward the call request */
+                if ( (skbn = skb_clone(skb, GFP_ATOMIC)) == NULL){
+                        goto out_put_nb;
+                }
+                x25_transmit_link(skbn, neigh_new);
+                rc = 1;
+        }
+
+
+out_put_nb:
+        x25_neigh_put(neigh_new);
+
+out_put_route:
+        x25_route_put(rt);
+        return rc;
+}
+
+
+int x25_forward_data(int lci, struct x25_neigh *from, struct sk_buff *skb) {
+
+        struct x25_forward *frwd;
+        struct list_head *entry;
+        struct net_device *peer = NULL;
+        struct x25_neigh *nb;
+        struct sk_buff *skbn;
+        int rc = 0;
+
+        read_lock_bh(&x25_forward_list_lock);
+        list_for_each(entry, &x25_forward_list) {
+                frwd = list_entry(entry, struct x25_forward, node);
+                if (frwd->lci == lci) {
+                        /* The call is established, either side can send */
+                        if (from->dev == frwd->dev1) {
+                                peer = frwd->dev2;
+                        } else {
+                                peer = frwd->dev1;
+                        }
+                        break;
+                }
+        }
+        read_unlock_bh(&x25_forward_list_lock);
+
+        if ( (nb = x25_get_neigh(peer)) == NULL)
+                goto out;
+
+        if ( (skbn = pskb_copy(skb, GFP_ATOMIC)) == NULL){
+                goto out;
+
+        }
+        x25_transmit_link(skbn, nb);
+
+        x25_neigh_put(nb);
+        rc = 1;
+out:
+        return rc;
+}
+
+void x25_clear_forward_by_lci(unsigned int lci)
+{
+        struct x25_forward *fwd;
+        struct list_head *entry, *tmp;
+
+        write_lock_bh(&x25_forward_list_lock);
+
+        list_for_each_safe(entry, tmp, &x25_forward_list) {
+                fwd = list_entry(entry, struct x25_forward, node);
+                if (fwd->lci == lci) {
+                        list_del(&fwd->node);
+                        kfree(fwd);
+                }
+        }
+        write_unlock_bh(&x25_forward_list_lock);
+}
+
+
+void x25_clear_forward_by_dev(struct net_device *dev)
+{
+        struct x25_forward *fwd;
+        struct list_head *entry, *tmp;
+
+        write_lock_bh(&x25_forward_list_lock);
+
+        list_for_each_safe(entry, tmp, &x25_forward_list) {
+                fwd = list_entry(entry, struct x25_forward, node);
+                if ((fwd->dev1 == dev) || (fwd->dev2 == dev)){
+                        list_del(&fwd->node);
+                        kfree(fwd);
+                }
+        }
+        write_unlock_bh(&x25_forward_list_lock);
+}
diff --git a/net/x25/x25_route.c b/net/x25/x25_route.c
index 2a3fe986b245..883a848bca5b 100644
--- a/net/x25/x25_route.c
+++ b/net/x25/x25_route.c
@@ -119,6 +119,9 @@ void x25_route_device_down(struct net_device *dev)
                         __x25_remove_route(rt);
         }
         write_unlock_bh(&x25_route_list_lock);
+
+        /* Remove any related forwarding */
+        x25_clear_forward_by_dev(dev);
 }
 
 /*