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> | |
23 | #include <net/sock.h> | |
24 | #include <linux/if_arp.h> | |
25 | #include <net/x25.h> | |
26 | ||
27 | static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) | |
28 | { | |
29 | struct sock *sk; | |
30 | unsigned short frametype; | |
31 | unsigned int lci; | |
32 | ||
33 | frametype = skb->data[2]; | |
f8e1d201 | 34 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); |
1da177e4 LT |
35 | |
36 | /* | |
37 | * LCI of zero is always for us, and its always a link control | |
38 | * frame. | |
39 | */ | |
40 | if (lci == 0) { | |
41 | x25_link_control(skb, nb, frametype); | |
42 | return 0; | |
43 | } | |
44 | ||
45 | /* | |
46 | * Find an existing socket. | |
47 | */ | |
48 | if ((sk = x25_find_socket(lci, nb)) != NULL) { | |
49 | int queued = 1; | |
50 | ||
badff6d0 | 51 | skb_reset_transport_header(skb); |
1da177e4 LT |
52 | bh_lock_sock(sk); |
53 | if (!sock_owned_by_user(sk)) { | |
54 | queued = x25_process_rx_frame(sk, skb); | |
55 | } else { | |
56 | sk_add_backlog(sk, skb); | |
57 | } | |
58 | bh_unlock_sock(sk); | |
9d0f7d29 | 59 | sock_put(sk); |
1da177e4 LT |
60 | return queued; |
61 | } | |
62 | ||
63 | /* | |
64 | * Is is a Call Request ? if so process it. | |
65 | */ | |
66 | if (frametype == X25_CALL_REQUEST) | |
67 | return x25_rx_call_request(skb, nb, lci); | |
68 | ||
69 | /* | |
95a9dc43 AH |
70 | * Its not a Call Request, nor is it a control frame. |
71 | * Can we forward it? | |
1da177e4 | 72 | */ |
95a9dc43 AH |
73 | |
74 | if (x25_forward_data(lci, nb, skb)) { | |
75 | if (frametype == X25_CLEAR_CONFIRMATION) { | |
76 | x25_clear_forward_by_lci(lci); | |
77 | } | |
78 | kfree_skb(skb); | |
79 | return 1; | |
80 | } | |
81 | ||
1da177e4 LT |
82 | /* |
83 | x25_transmit_clear_request(nb, lci, 0x0D); | |
84 | */ | |
85 | ||
86 | if (frametype != X25_CLEAR_CONFIRMATION) | |
87 | printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 93 | struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
94 | { |
95 | struct sk_buff *nskb; | |
96 | struct x25_neigh *nb; | |
97 | ||
721499e8 | 98 | if (!net_eq(dev_net(dev), &init_net)) |
e730c155 EB |
99 | goto drop; |
100 | ||
1da177e4 LT |
101 | nskb = skb_copy(skb, GFP_ATOMIC); |
102 | if (!nskb) | |
103 | goto drop; | |
104 | kfree_skb(skb); | |
105 | skb = nskb; | |
106 | ||
107 | /* | |
108 | * Packet received from unrecognised device, throw it away. | |
109 | */ | |
110 | nb = x25_get_neigh(dev); | |
111 | if (!nb) { | |
112 | printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); | |
113 | goto drop; | |
114 | } | |
115 | ||
116 | switch (skb->data[0]) { | |
117 | case 0x00: | |
118 | skb_pull(skb, 1); | |
119 | if (x25_receive_data(skb, nb)) { | |
120 | x25_neigh_put(nb); | |
121 | goto out; | |
122 | } | |
123 | break; | |
124 | case 0x01: | |
125 | x25_link_established(nb); | |
126 | break; | |
127 | case 0x02: | |
128 | x25_link_terminated(nb); | |
129 | break; | |
130 | } | |
131 | x25_neigh_put(nb); | |
132 | drop: | |
133 | kfree_skb(skb); | |
134 | out: | |
135 | return 0; | |
136 | } | |
137 | ||
138 | void x25_establish_link(struct x25_neigh *nb) | |
139 | { | |
140 | struct sk_buff *skb; | |
141 | unsigned char *ptr; | |
142 | ||
143 | switch (nb->dev->type) { | |
144 | case ARPHRD_X25: | |
145 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { | |
146 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
147 | return; | |
148 | } | |
149 | ptr = skb_put(skb, 1); | |
150 | *ptr = 0x01; | |
151 | break; | |
152 | ||
153 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
154 | case ARPHRD_ETHER: | |
155 | return; | |
156 | #endif | |
157 | default: | |
158 | return; | |
159 | } | |
160 | ||
161 | skb->protocol = htons(ETH_P_X25); | |
162 | skb->dev = nb->dev; | |
163 | ||
164 | dev_queue_xmit(skb); | |
165 | } | |
166 | ||
167 | void x25_terminate_link(struct x25_neigh *nb) | |
168 | { | |
169 | struct sk_buff *skb; | |
170 | unsigned char *ptr; | |
171 | ||
172 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
173 | if (nb->dev->type == ARPHRD_ETHER) | |
174 | return; | |
175 | #endif | |
176 | if (nb->dev->type != ARPHRD_X25) | |
177 | return; | |
178 | ||
179 | skb = alloc_skb(1, GFP_ATOMIC); | |
180 | if (!skb) { | |
181 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
182 | return; | |
183 | } | |
184 | ||
185 | ptr = skb_put(skb, 1); | |
186 | *ptr = 0x02; | |
187 | ||
188 | skb->protocol = htons(ETH_P_X25); | |
189 | skb->dev = nb->dev; | |
190 | dev_queue_xmit(skb); | |
191 | } | |
192 | ||
193 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) | |
194 | { | |
195 | unsigned char *dptr; | |
196 | ||
c1d2bbe1 | 197 | skb_reset_network_header(skb); |
1da177e4 LT |
198 | |
199 | switch (nb->dev->type) { | |
200 | case ARPHRD_X25: | |
201 | dptr = skb_push(skb, 1); | |
202 | *dptr = 0x00; | |
203 | break; | |
204 | ||
205 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
206 | case ARPHRD_ETHER: | |
207 | kfree_skb(skb); | |
208 | return; | |
209 | #endif | |
210 | default: | |
211 | kfree_skb(skb); | |
212 | return; | |
213 | } | |
214 | ||
215 | skb->protocol = htons(ETH_P_X25); | |
216 | skb->dev = nb->dev; | |
217 | ||
218 | dev_queue_xmit(skb); | |
219 | } |