1/* 2 * This module: 3 * This module is free software; you can redistribute it and/or 4 * modify it under the terms of the GNU General Public License 5 * as published by the Free Software Foundation; either version 6 * 2 of the License, or (at your option) any later version. 7 * 8 * History 9 * 03-01-2007 Added forwarding for x.25 Andrew Hendry 10 */ 11#include <linux/if_arp.h> 12#include <linux/init.h> 13#include <linux/slab.h> 14#include <net/x25.h> 15 16LIST_HEAD(x25_forward_list); 17DEFINE_RWLOCK(x25_forward_list_lock); 18 19int x25_forward_call(struct x25_address *dest_addr, struct x25_neigh *from, 20 struct sk_buff *skb, int lci) 21{ 22 struct x25_route *rt; 23 struct x25_neigh *neigh_new = NULL; 24 struct list_head *entry; 25 struct x25_forward *x25_frwd, *new_frwd; 26 struct sk_buff *skbn; 27 short same_lci = 0; 28 int rc = 0; 29 30 if ((rt = x25_get_route(dest_addr)) == NULL) 31 goto out_no_route; 32 33 if ((neigh_new = x25_get_neigh(rt->dev)) == NULL) { 34 /* This shouldnt happen, if it occurs somehow 35 * do something sensible 36 */ 37 goto out_put_route; 38 } 39 40 /* Avoid a loop. This is the normal exit path for a 41 * system with only one x.25 iface and default route 42 */ 43 if (rt->dev == from->dev) { 44 goto out_put_nb; 45 } 46 47 /* Remote end sending a call request on an already 48 * established LCI? It shouldnt happen, just in case.. 49 */ 50 read_lock_bh(&x25_forward_list_lock); 51 list_for_each(entry, &x25_forward_list) { 52 x25_frwd = list_entry(entry, struct x25_forward, node); 53 if (x25_frwd->lci == lci) { 54 printk(KERN_WARNING "X.25: call request for lci which is already registered!, transmitting but not registering new pair\n"); 55 same_lci = 1; 56 } 57 } 58 read_unlock_bh(&x25_forward_list_lock); 59 60 /* Save the forwarding details for future traffic */ 61 if (!same_lci){ 62 if ((new_frwd = kmalloc(sizeof(struct x25_forward), 63 GFP_ATOMIC)) == NULL){ 64 rc = -ENOMEM; 65 goto out_put_nb; 66 } 67 new_frwd->lci = lci; 68 new_frwd->dev1 = rt->dev; 69 new_frwd->dev2 = from->dev; 70 write_lock_bh(&x25_forward_list_lock); 71 list_add(&new_frwd->node, &x25_forward_list); 72 write_unlock_bh(&x25_forward_list_lock); 73 } 74 75 /* Forward the call request */ 76 if ( (skbn = skb_clone(skb, GFP_ATOMIC)) == NULL){ 77 goto out_put_nb; 78 } 79 x25_transmit_link(skbn, neigh_new); 80 rc = 1; 81 82 83out_put_nb: 84 x25_neigh_put(neigh_new); 85 86out_put_route: 87 x25_route_put(rt); 88 89out_no_route: 90 return rc; 91} 92 93 94int x25_forward_data(int lci, struct x25_neigh *from, struct sk_buff *skb) { 95 96 struct x25_forward *frwd; 97 struct list_head *entry; 98 struct net_device *peer = NULL; 99 struct x25_neigh *nb; 100 struct sk_buff *skbn; 101 int rc = 0; 102 103 read_lock_bh(&x25_forward_list_lock); 104 list_for_each(entry, &x25_forward_list) { 105 frwd = list_entry(entry, struct x25_forward, node); 106 if (frwd->lci == lci) { 107 /* The call is established, either side can send */ 108 if (from->dev == frwd->dev1) { 109 peer = frwd->dev2; 110 } else { 111 peer = frwd->dev1; 112 } 113 break; 114 } 115 } 116 read_unlock_bh(&x25_forward_list_lock); 117 118 if ( (nb = x25_get_neigh(peer)) == NULL) 119 goto out; 120 121 if ( (skbn = pskb_copy(skb, GFP_ATOMIC)) == NULL){ 122 goto output; 123 124 } 125 x25_transmit_link(skbn, nb); 126 127 rc = 1; 128output: 129 x25_neigh_put(nb); 130out: 131 return rc; 132} 133 134void x25_clear_forward_by_lci(unsigned int lci) 135{ 136 struct x25_forward *fwd; 137 struct list_head *entry, *tmp; 138 139 write_lock_bh(&x25_forward_list_lock); 140 141 list_for_each_safe(entry, tmp, &x25_forward_list) { 142 fwd = list_entry(entry, struct x25_forward, node); 143 if (fwd->lci == lci) { 144 list_del(&fwd->node); 145 kfree(fwd); 146 } 147 } 148 write_unlock_bh(&x25_forward_list_lock); 149} 150 151 152void x25_clear_forward_by_dev(struct net_device *dev) 153{ 154 struct x25_forward *fwd; 155 struct list_head *entry, *tmp; 156 157 write_lock_bh(&x25_forward_list_lock); 158 159 list_for_each_safe(entry, tmp, &x25_forward_list) { 160 fwd = list_entry(entry, struct x25_forward, node); 161 if ((fwd->dev1 == dev) || (fwd->dev2 == dev)){ 162 list_del(&fwd->node); 163 kfree(fwd); 164 } 165 } 166 write_unlock_bh(&x25_forward_list_lock); 167} 168