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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> | |
5ebfbc06 | 27 | #include <net/x25device.h> |
1da177e4 LT |
28 | |
29 | static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) | |
30 | { | |
31 | struct sock *sk; | |
32 | unsigned short frametype; | |
33 | unsigned int lci; | |
34 | ||
35 | frametype = skb->data[2]; | |
f8e1d201 | 36 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); |
1da177e4 LT |
37 | |
38 | /* | |
39 | * LCI of zero is always for us, and its always a link control | |
40 | * frame. | |
41 | */ | |
42 | if (lci == 0) { | |
43 | x25_link_control(skb, nb, frametype); | |
44 | return 0; | |
45 | } | |
46 | ||
47 | /* | |
48 | * Find an existing socket. | |
49 | */ | |
50 | if ((sk = x25_find_socket(lci, nb)) != NULL) { | |
51 | int queued = 1; | |
52 | ||
badff6d0 | 53 | skb_reset_transport_header(skb); |
1da177e4 LT |
54 | bh_lock_sock(sk); |
55 | if (!sock_owned_by_user(sk)) { | |
56 | queued = x25_process_rx_frame(sk, skb); | |
57 | } else { | |
a3a858ff | 58 | queued = !sk_add_backlog(sk, skb); |
1da177e4 LT |
59 | } |
60 | bh_unlock_sock(sk); | |
9d0f7d29 | 61 | sock_put(sk); |
1da177e4 LT |
62 | return queued; |
63 | } | |
64 | ||
65 | /* | |
66 | * Is is a Call Request ? if so process it. | |
67 | */ | |
68 | if (frametype == X25_CALL_REQUEST) | |
69 | return x25_rx_call_request(skb, nb, lci); | |
70 | ||
71 | /* | |
95a9dc43 AH |
72 | * Its not a Call Request, nor is it a control frame. |
73 | * Can we forward it? | |
1da177e4 | 74 | */ |
95a9dc43 AH |
75 | |
76 | if (x25_forward_data(lci, nb, skb)) { | |
77 | if (frametype == X25_CLEAR_CONFIRMATION) { | |
78 | x25_clear_forward_by_lci(lci); | |
79 | } | |
80 | kfree_skb(skb); | |
81 | return 1; | |
82 | } | |
83 | ||
1da177e4 LT |
84 | /* |
85 | x25_transmit_clear_request(nb, lci, 0x0D); | |
86 | */ | |
87 | ||
88 | if (frametype != X25_CLEAR_CONFIRMATION) | |
89 | printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 95 | struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
96 | { |
97 | struct sk_buff *nskb; | |
98 | struct x25_neigh *nb; | |
99 | ||
721499e8 | 100 | if (!net_eq(dev_net(dev), &init_net)) |
e730c155 EB |
101 | goto drop; |
102 | ||
1da177e4 LT |
103 | nskb = skb_copy(skb, GFP_ATOMIC); |
104 | if (!nskb) | |
105 | goto drop; | |
106 | kfree_skb(skb); | |
107 | skb = nskb; | |
108 | ||
109 | /* | |
110 | * Packet received from unrecognised device, throw it away. | |
111 | */ | |
112 | nb = x25_get_neigh(dev); | |
113 | if (!nb) { | |
114 | printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); | |
115 | goto drop; | |
116 | } | |
117 | ||
118 | switch (skb->data[0]) { | |
5ebfbc06 AH |
119 | |
120 | case X25_IFACE_DATA: | |
121 | skb_pull(skb, 1); | |
122 | if (x25_receive_data(skb, nb)) { | |
123 | x25_neigh_put(nb); | |
124 | goto out; | |
125 | } | |
126 | break; | |
127 | ||
128 | case X25_IFACE_CONNECT: | |
129 | x25_link_established(nb); | |
130 | break; | |
131 | ||
132 | case X25_IFACE_DISCONNECT: | |
133 | x25_link_terminated(nb); | |
134 | break; | |
1da177e4 LT |
135 | } |
136 | x25_neigh_put(nb); | |
137 | drop: | |
138 | kfree_skb(skb); | |
139 | out: | |
140 | return 0; | |
141 | } | |
142 | ||
143 | void x25_establish_link(struct x25_neigh *nb) | |
144 | { | |
145 | struct sk_buff *skb; | |
146 | unsigned char *ptr; | |
147 | ||
148 | switch (nb->dev->type) { | |
fddc5f3e JP |
149 | case ARPHRD_X25: |
150 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { | |
151 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
152 | return; | |
153 | } | |
154 | ptr = skb_put(skb, 1); | |
155 | *ptr = X25_IFACE_CONNECT; | |
156 | break; | |
1da177e4 LT |
157 | |
158 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
fddc5f3e JP |
159 | case ARPHRD_ETHER: |
160 | return; | |
1da177e4 | 161 | #endif |
fddc5f3e JP |
162 | default: |
163 | return; | |
1da177e4 LT |
164 | } |
165 | ||
166 | skb->protocol = htons(ETH_P_X25); | |
167 | skb->dev = nb->dev; | |
168 | ||
169 | dev_queue_xmit(skb); | |
170 | } | |
171 | ||
172 | void x25_terminate_link(struct x25_neigh *nb) | |
173 | { | |
174 | struct sk_buff *skb; | |
175 | unsigned char *ptr; | |
176 | ||
177 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
178 | if (nb->dev->type == ARPHRD_ETHER) | |
179 | return; | |
180 | #endif | |
181 | if (nb->dev->type != ARPHRD_X25) | |
182 | return; | |
183 | ||
184 | skb = alloc_skb(1, GFP_ATOMIC); | |
185 | if (!skb) { | |
186 | printk(KERN_ERR "x25_dev: out of memory\n"); | |
187 | return; | |
188 | } | |
189 | ||
190 | ptr = skb_put(skb, 1); | |
5ebfbc06 | 191 | *ptr = X25_IFACE_DISCONNECT; |
1da177e4 LT |
192 | |
193 | skb->protocol = htons(ETH_P_X25); | |
194 | skb->dev = nb->dev; | |
195 | dev_queue_xmit(skb); | |
196 | } | |
197 | ||
198 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) | |
199 | { | |
200 | unsigned char *dptr; | |
201 | ||
c1d2bbe1 | 202 | skb_reset_network_header(skb); |
1da177e4 LT |
203 | |
204 | switch (nb->dev->type) { | |
fddc5f3e JP |
205 | case ARPHRD_X25: |
206 | dptr = skb_push(skb, 1); | |
207 | *dptr = X25_IFACE_DATA; | |
208 | break; | |
1da177e4 LT |
209 | |
210 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) | |
fddc5f3e JP |
211 | case ARPHRD_ETHER: |
212 | kfree_skb(skb); | |
213 | return; | |
1da177e4 | 214 | #endif |
fddc5f3e JP |
215 | default: |
216 | kfree_skb(skb); | |
217 | return; | |
1da177e4 LT |
218 | } |
219 | ||
220 | skb->protocol = htons(ETH_P_X25); | |
221 | skb->dev = nb->dev; | |
222 | ||
223 | dev_queue_xmit(skb); | |
224 | } |