blob: 029c8bb90f4c3dd470c56e5c29ebcfc05afb7b4d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 */
9#include <linux/errno.h>
10#include <linux/types.h>
11#include <linux/socket.h>
12#include <linux/in.h>
13#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/timer.h>
15#include <linux/string.h>
16#include <linux/sockios.h>
17#include <linux/net.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <net/ax25.h>
20#include <linux/inet.h>
21#include <linux/netdevice.h>
22#include <linux/skbuff.h>
23#include <net/sock.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070024#include <net/tcp_states.h>
Fabian Frederickdc8e5412014-10-17 22:00:22 +020025#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/fcntl.h>
27#include <linux/mm.h>
28#include <linux/interrupt.h>
29#include <net/netrom.h>
30
31/*
32 * This routine purges all of the queues of frames.
33 */
34void nr_clear_queues(struct sock *sk)
35{
36 struct nr_sock *nr = nr_sk(sk);
37
38 skb_queue_purge(&sk->sk_write_queue);
39 skb_queue_purge(&nr->ack_queue);
40 skb_queue_purge(&nr->reseq_queue);
41 skb_queue_purge(&nr->frag_queue);
42}
43
44/*
45 * This routine purges the input queue of those frames that have been
46 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
47 * SDL diagram.
48 */
49void nr_frames_acked(struct sock *sk, unsigned short nr)
50{
51 struct nr_sock *nrom = nr_sk(sk);
52 struct sk_buff *skb;
53
54 /*
55 * Remove all the ack-ed frames from the ack queue.
56 */
57 if (nrom->va != nr) {
58 while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
YOSHIFUJI Hideaki5f8f59d2007-02-09 23:25:09 +090059 skb = skb_dequeue(&nrom->ack_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 kfree_skb(skb);
61 nrom->va = (nrom->va + 1) % NR_MODULUS;
62 }
63 }
64}
65
66/*
67 * Requeue all the un-ack-ed frames on the output queue to be picked
68 * up by nr_kick called from the timer. This arrangement handles the
69 * possibility of an empty output queue.
70 */
71void nr_requeue_frames(struct sock *sk)
72{
73 struct sk_buff *skb, *skb_prev = NULL;
74
75 while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
76 if (skb_prev == NULL)
77 skb_queue_head(&sk->sk_write_queue, skb);
78 else
David S. Miller8728b832005-08-09 19:25:21 -070079 skb_append(skb_prev, skb, &sk->sk_write_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 skb_prev = skb;
81 }
82}
83
84/*
85 * Validate that the value of nr is between va and vs. Return true or
86 * false for testing.
87 */
88int nr_validate_nr(struct sock *sk, unsigned short nr)
89{
90 struct nr_sock *nrom = nr_sk(sk);
91 unsigned short vc = nrom->va;
92
93 while (vc != nrom->vs) {
94 if (nr == vc) return 1;
95 vc = (vc + 1) % NR_MODULUS;
96 }
97
98 return nr == nrom->vs;
99}
100
101/*
102 * Check that ns is within the receive window.
103 */
104int nr_in_rx_window(struct sock *sk, unsigned short ns)
105{
106 struct nr_sock *nr = nr_sk(sk);
107 unsigned short vc = nr->vr;
108 unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
109
110 while (vc != vt) {
111 if (ns == vc) return 1;
112 vc = (vc + 1) % NR_MODULUS;
113 }
114
115 return 0;
116}
117
118/*
119 * This routine is called when the HDLC layer internally generates a
120 * control frame.
121 */
122void nr_write_internal(struct sock *sk, int frametype)
123{
124 struct nr_sock *nr = nr_sk(sk);
125 struct sk_buff *skb;
126 unsigned char *dptr;
127 int len, timeout;
128
129 len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
130
131 switch (frametype & 0x0F) {
132 case NR_CONNREQ:
133 len += 17;
134 break;
135 case NR_CONNACK:
136 len += (nr->bpqext) ? 2 : 1;
137 break;
138 case NR_DISCREQ:
139 case NR_DISCACK:
140 case NR_INFOACK:
141 break;
142 default:
143 printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
144 return;
145 }
146
147 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
148 return;
149
150 /*
151 * Space for AX.25 and NET/ROM network header
152 */
153 skb_reserve(skb, NR_NETWORK_LEN);
154
155 dptr = skb_put(skb, skb_tailroom(skb));
156
157 switch (frametype & 0x0F) {
158 case NR_CONNREQ:
159 timeout = nr->t1 / HZ;
160 *dptr++ = nr->my_index;
161 *dptr++ = nr->my_id;
162 *dptr++ = 0;
163 *dptr++ = 0;
164 *dptr++ = frametype;
165 *dptr++ = nr->window;
166 memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
167 dptr[6] &= ~AX25_CBIT;
168 dptr[6] &= ~AX25_EBIT;
169 dptr[6] |= AX25_SSSID_SPARE;
170 dptr += AX25_ADDR_LEN;
171 memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
172 dptr[6] &= ~AX25_CBIT;
173 dptr[6] &= ~AX25_EBIT;
174 dptr[6] |= AX25_SSSID_SPARE;
175 dptr += AX25_ADDR_LEN;
176 *dptr++ = timeout % 256;
177 *dptr++ = timeout / 256;
178 break;
179
180 case NR_CONNACK:
181 *dptr++ = nr->your_index;
182 *dptr++ = nr->your_id;
183 *dptr++ = nr->my_index;
184 *dptr++ = nr->my_id;
185 *dptr++ = frametype;
186 *dptr++ = nr->window;
187 if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
188 break;
189
190 case NR_DISCREQ:
191 case NR_DISCACK:
192 *dptr++ = nr->your_index;
193 *dptr++ = nr->your_id;
194 *dptr++ = 0;
195 *dptr++ = 0;
196 *dptr++ = frametype;
197 break;
198
199 case NR_INFOACK:
200 *dptr++ = nr->your_index;
201 *dptr++ = nr->your_id;
202 *dptr++ = 0;
203 *dptr++ = nr->vr;
204 *dptr++ = frametype;
205 break;
206 }
207
208 nr_transmit_buffer(sk, skb);
209}
210
211/*
Ralf Baechlee21ce8c2005-09-12 14:27:37 -0700212 * This routine is called to send an error reply.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 */
Ralf Baechlee21ce8c2005-09-12 14:27:37 -0700214void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
216 struct sk_buff *skbn;
217 unsigned char *dptr;
218 int len;
219
220 len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
221
222 if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
223 return;
224
225 skb_reserve(skbn, 0);
226
227 dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
228
Arnaldo Carvalho de Melod626f622007-03-27 18:55:52 -0300229 skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 dptr[6] &= ~AX25_CBIT;
231 dptr[6] &= ~AX25_EBIT;
232 dptr[6] |= AX25_SSSID_SPARE;
233 dptr += AX25_ADDR_LEN;
234
Arnaldo Carvalho de Melod626f622007-03-27 18:55:52 -0300235 skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 dptr[6] &= ~AX25_CBIT;
237 dptr[6] |= AX25_EBIT;
238 dptr[6] |= AX25_SSSID_SPARE;
239 dptr += AX25_ADDR_LEN;
240
241 *dptr++ = sysctl_netrom_network_ttl_initialiser;
242
243 if (mine) {
244 *dptr++ = 0;
245 *dptr++ = 0;
246 *dptr++ = skb->data[15];
247 *dptr++ = skb->data[16];
248 } else {
249 *dptr++ = skb->data[15];
250 *dptr++ = skb->data[16];
251 *dptr++ = 0;
252 *dptr++ = 0;
253 }
254
Ralf Baechlee21ce8c2005-09-12 14:27:37 -0700255 *dptr++ = cmdflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 *dptr++ = 0;
257
258 if (!nr_route_frame(skbn, NULL))
259 kfree_skb(skbn);
260}
261
262void nr_disconnect(struct sock *sk, int reason)
263{
264 nr_stop_t1timer(sk);
265 nr_stop_t2timer(sk);
266 nr_stop_t4timer(sk);
267 nr_stop_idletimer(sk);
268
269 nr_clear_queues(sk);
270
271 nr_sk(sk)->state = NR_STATE_0;
272
273 sk->sk_state = TCP_CLOSE;
274 sk->sk_err = reason;
275 sk->sk_shutdown |= SEND_SHUTDOWN;
276
277 if (!sock_flag(sk, SOCK_DEAD)) {
278 sk->sk_state_change(sk);
279 sock_set_flag(sk, SOCK_DEAD);
280 }
281}