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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * X.25 Packet Layer release 002 | |
3 | * | |
f8e1d201 YH |
4 | * This is ALPHA test software. This code may break your machine, randomly fail to work with new |
5 | * releases, misbehave and/or generally screw up. It might even work. | |
1da177e4 LT |
6 | * |
7 | * This code REQUIRES 2.1.15 or higher | |
8 | * | |
9 | * This module: | |
10 | * This module is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | * | |
15 | * History | |
16 | * X.25 001 Jonathan Naylor Started coding. | |
17 | * 2000-09-04 Henner Eisen Prevent freeing a dangling skb. | |
18 | */ | |
19 | ||
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/skbuff.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
1da177e4 LT |
24 | #include <net/sock.h> |
25 | #include <linux/if_arp.h> | |
26 | #include <net/x25.h> | |
27 | ||
28 | static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) | |
29 | { | |
30 | struct sock *sk; | |
31 | unsigned short frametype; | |
32 | unsigned int lci; | |
33 | ||
34 | frametype = skb->data[2]; | |
f8e1d201 | 35 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); |
1da177e4 LT |
36 | |
37 | /* | |
38 | * LCI of zero is always for us, and its always a link control | |
39 | * frame. | |
40 | */ | |
41 | if (lci == 0) { | |
42 | x25_link_control(skb, nb, frametype); | |
43 | return 0; | |
44 | } | |
45 | ||
46 | /* | |
47 | * Find an existing socket. | |
48 | */ | |
49 | if ((sk = x25_find_socket(lci, nb)) != NULL) { | |
50 | int queued = 1; | |
51 | ||
badff6d0 | 52 | skb_reset_transport_header(skb); |
1da177e4 LT |
53 | bh_lock_sock(sk); |
54 | if (!sock_owned_by_user(sk)) { | |
55 | queued = x25_process_rx_frame(sk, skb); | |
56 | } else { | |
a3a858ff | 57 | queued = !sk_add_backlog(sk, skb); |
1da177e4 LT |
58 | } |
59 | bh_unlock_sock(sk); | |
9d0f7d29 | 60 | sock_put(sk); |
1da177e4 LT |
61 | return queued; |
62 | } | |
63 | ||
64 | /* | |
65 | * Is is a Call Request ? if so process it. | |
66 | */ | |
67 | if (frametype == X25_CALL_REQUEST) | |
68 | return x25_rx_call_request(skb, nb, lci); | |
69 | ||
70 | /* | |
95a9dc43 AH |
71 | * Its not a Call Request, nor is it a control frame. |
72 | * Can we forward it? | |
1da177e4 | 73 | */ |
95a9dc43 AH |
74 | |
75 | if (x25_forward_data(lci, nb, skb)) { | |
76 | if (frametype == X25_CLEAR_CONFIRMATION) { | |
77 | x25_clear_forward_by_lci(lci); | |
78 | } | |
79 | kfree_skb(skb); | |
80 | return 1; | |
81 | } | |
82 | ||
1da177e4 LT |
83 | /* |
84 | x25_transmit_clear_request(nb, lci, 0x0D); | |
85 | */ | |
86 | ||
87 | if (frametype != X25_CLEAR_CONFIRMATION) | |
88 | printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 94 | struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
95 | { |
96 | struct sk_buff *nskb; | |
97 | struct x25_neigh *nb; | |
98 | ||
721499e8 | 99 | if (!net_eq(dev_net(dev), &init_net)) |
e730c155 EB |
100 | goto drop; |
101 | ||
1da177e4 LT |
102 | nskb = skb_copy(skb, GFP_ATOMIC); |
103 | if (!nskb) | |
104 | goto drop; | |
105 | kfree_skb(skb); | |
106 | skb = nskb; | |
107 | ||
108 | /* | |
109 | * Packet received from unrecognised device, throw it away. | |
110 | */ | |
111 | nb = x25_get_neigh(dev); | |
112 | if (!nb) { | |
113 | printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); | |
114 | goto drop; | |
115 | } | |
116 | ||
117 | switch (skb->data[0]) { | |
118 | case 0x00: | |
119 | skb_pull(skb, 1); | |
120 | if (x25_receive_data(skb, nb)) { | |
121 | x25_neigh_put(nb); | |
122 | goto out; | |
123 | } | |
124 | break; | |
125 | case 0x01: | |
126 | x25_link_established(nb); | |
127 | break; | |
128 | case 0x02: | |
129 | x25_link_terminated(nb); | |
130 | break; | |
131 | } | |
132 | x25_neigh_put(nb); | |
133 | drop: | |
134 | kfree_skb(skb); | |
135 | out: | |
136 | return 0; | |
137 | } | |
138 | ||
139 | void x25_establish_link(struct x25_neigh *nb) | |
140 | { | |
141 | struct sk_buff *skb; | |
142 | unsigned char *ptr; | |
143 | ||
144 | switch (nb->dev->type) { | |
145 | case ARPHRD_X25: | |
146 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { | |
147 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
148 | return; | |
149 | } | |
150 | ptr = skb_put(skb, 1); | |
151 | *ptr = 0x01; | |
152 | break; | |
153 | ||
154 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
155 | case ARPHRD_ETHER: | |
156 | return; | |
157 | #endif | |
158 | default: | |
159 | return; | |
160 | } | |
161 | ||
162 | skb->protocol = htons(ETH_P_X25); | |
163 | skb->dev = nb->dev; | |
164 | ||
165 | dev_queue_xmit(skb); | |
166 | } | |
167 | ||
168 | void x25_terminate_link(struct x25_neigh *nb) | |
169 | { | |
170 | struct sk_buff *skb; | |
171 | unsigned char *ptr; | |
172 | ||
173 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
174 | if (nb->dev->type == ARPHRD_ETHER) | |
175 | return; | |
176 | #endif | |
177 | if (nb->dev->type != ARPHRD_X25) | |
178 | return; | |
179 | ||
180 | skb = alloc_skb(1, GFP_ATOMIC); | |
181 | if (!skb) { | |
182 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
183 | return; | |
184 | } | |
185 | ||
186 | ptr = skb_put(skb, 1); | |
187 | *ptr = 0x02; | |
188 | ||
189 | skb->protocol = htons(ETH_P_X25); | |
190 | skb->dev = nb->dev; | |
191 | dev_queue_xmit(skb); | |
192 | } | |
193 | ||
194 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) | |
195 | { | |
196 | unsigned char *dptr; | |
197 | ||
c1d2bbe1 | 198 | skb_reset_network_header(skb); |
1da177e4 LT |
199 | |
200 | switch (nb->dev->type) { | |
201 | case ARPHRD_X25: | |
202 | dptr = skb_push(skb, 1); | |
203 | *dptr = 0x00; | |
204 | break; | |
205 | ||
206 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
207 | case ARPHRD_ETHER: | |
208 | kfree_skb(skb); | |
209 | return; | |
210 | #endif | |
211 | default: | |
212 | kfree_skb(skb); | |
213 | return; | |
214 | } | |
215 | ||
216 | skb->protocol = htons(ETH_P_X25); | |
217 | skb->dev = nb->dev; | |
218 | ||
219 | dev_queue_xmit(skb); | |
220 | } |