Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * X.25 Packet Layer release 002 | |
3 | * | |
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. | |
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 | ||
20 | #include <linux/config.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/netdevice.h> | |
23 | #include <linux/skbuff.h> | |
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]; | |
35 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); | |
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 | ||
52 | skb->h.raw = skb->data; | |
53 | bh_lock_sock(sk); | |
54 | if (!sock_owned_by_user(sk)) { | |
55 | queued = x25_process_rx_frame(sk, skb); | |
56 | } else { | |
57 | sk_add_backlog(sk, skb); | |
58 | } | |
59 | bh_unlock_sock(sk); | |
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 | /* | |
70 | * Its not a Call Request, nor is it a control frame. | |
71 | * Let caller throw it away. | |
72 | */ | |
73 | /* | |
74 | x25_transmit_clear_request(nb, lci, 0x0D); | |
75 | */ | |
76 | ||
77 | if (frametype != X25_CLEAR_CONFIRMATION) | |
78 | printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 84 | struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
85 | { |
86 | struct sk_buff *nskb; | |
87 | struct x25_neigh *nb; | |
88 | ||
89 | nskb = skb_copy(skb, GFP_ATOMIC); | |
90 | if (!nskb) | |
91 | goto drop; | |
92 | kfree_skb(skb); | |
93 | skb = nskb; | |
94 | ||
95 | /* | |
96 | * Packet received from unrecognised device, throw it away. | |
97 | */ | |
98 | nb = x25_get_neigh(dev); | |
99 | if (!nb) { | |
100 | printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); | |
101 | goto drop; | |
102 | } | |
103 | ||
104 | switch (skb->data[0]) { | |
105 | case 0x00: | |
106 | skb_pull(skb, 1); | |
107 | if (x25_receive_data(skb, nb)) { | |
108 | x25_neigh_put(nb); | |
109 | goto out; | |
110 | } | |
111 | break; | |
112 | case 0x01: | |
113 | x25_link_established(nb); | |
114 | break; | |
115 | case 0x02: | |
116 | x25_link_terminated(nb); | |
117 | break; | |
118 | } | |
119 | x25_neigh_put(nb); | |
120 | drop: | |
121 | kfree_skb(skb); | |
122 | out: | |
123 | return 0; | |
124 | } | |
125 | ||
126 | void x25_establish_link(struct x25_neigh *nb) | |
127 | { | |
128 | struct sk_buff *skb; | |
129 | unsigned char *ptr; | |
130 | ||
131 | switch (nb->dev->type) { | |
132 | case ARPHRD_X25: | |
133 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { | |
134 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
135 | return; | |
136 | } | |
137 | ptr = skb_put(skb, 1); | |
138 | *ptr = 0x01; | |
139 | break; | |
140 | ||
141 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
142 | case ARPHRD_ETHER: | |
143 | return; | |
144 | #endif | |
145 | default: | |
146 | return; | |
147 | } | |
148 | ||
149 | skb->protocol = htons(ETH_P_X25); | |
150 | skb->dev = nb->dev; | |
151 | ||
152 | dev_queue_xmit(skb); | |
153 | } | |
154 | ||
155 | void x25_terminate_link(struct x25_neigh *nb) | |
156 | { | |
157 | struct sk_buff *skb; | |
158 | unsigned char *ptr; | |
159 | ||
160 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
161 | if (nb->dev->type == ARPHRD_ETHER) | |
162 | return; | |
163 | #endif | |
164 | if (nb->dev->type != ARPHRD_X25) | |
165 | return; | |
166 | ||
167 | skb = alloc_skb(1, GFP_ATOMIC); | |
168 | if (!skb) { | |
169 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
170 | return; | |
171 | } | |
172 | ||
173 | ptr = skb_put(skb, 1); | |
174 | *ptr = 0x02; | |
175 | ||
176 | skb->protocol = htons(ETH_P_X25); | |
177 | skb->dev = nb->dev; | |
178 | dev_queue_xmit(skb); | |
179 | } | |
180 | ||
181 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) | |
182 | { | |
183 | unsigned char *dptr; | |
184 | ||
185 | skb->nh.raw = skb->data; | |
186 | ||
187 | switch (nb->dev->type) { | |
188 | case ARPHRD_X25: | |
189 | dptr = skb_push(skb, 1); | |
190 | *dptr = 0x00; | |
191 | break; | |
192 | ||
193 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
194 | case ARPHRD_ETHER: | |
195 | kfree_skb(skb); | |
196 | return; | |
197 | #endif | |
198 | default: | |
199 | kfree_skb(skb); | |
200 | return; | |
201 | } | |
202 | ||
203 | skb->protocol = htons(ETH_P_X25); | |
204 | skb->dev = nb->dev; | |
205 | ||
206 | dev_queue_xmit(skb); | |
207 | } |