5113f6f70
 김현기
kernel add
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
* 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
");
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);
}
|