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
16 LIST_HEAD(x25_forward_list);
17 DEFINE_RWLOCK(x25_forward_list_lock);
18
x25_forward_call(struct x25_address * dest_addr,struct x25_neigh * from,struct sk_buff * skb,int lci)19 int 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 shouldn't 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 shouldn't 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
83 out_put_nb:
84 x25_neigh_put(neigh_new);
85
86 out_put_route:
87 x25_route_put(rt);
88
89 out_no_route:
90 return rc;
91 }
92
93
x25_forward_data(int lci,struct x25_neigh * from,struct sk_buff * skb)94 int 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;
128 output:
129 x25_neigh_put(nb);
130 out:
131 return rc;
132 }
133
x25_clear_forward_by_lci(unsigned int lci)134 void 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
x25_clear_forward_by_dev(struct net_device * dev)152 void 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