diff options
Diffstat (limited to 'net/x25/x25_forward.c')
| -rw-r--r-- | net/x25/x25_forward.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/net/x25/x25_forward.c b/net/x25/x25_forward.c new file mode 100644 index 000000000..cf561f161 --- /dev/null +++ b/net/x25/x25_forward.c @@ -0,0 +1,170 @@ +/* + * 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 + */ + +#define pr_fmt(fmt) "X25: " fmt + +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <net/x25.h> + +LIST_HEAD(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) + goto out_no_route; + + if ((neigh_new = x25_get_neigh(rt->dev)) == NULL) { + /* This shouldn't 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 shouldn't 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) { + pr_warn("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); + +out_no_route: + 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 output; + + } + x25_transmit_link(skbn, nb); + + rc = 1; +output: + x25_neigh_put(nb); +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); +} |