Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / netrom / nr_subr.c
blob6a947ae50dbdd9865e2607041a4b12f2a7e13fcc
1 /*
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.
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>
14 #include <linux/timer.h>
15 #include <linux/string.h>
16 #include <linux/sockios.h>
17 #include <linux/net.h>
18 #include <linux/slab.h>
19 #include <net/ax25.h>
20 #include <linux/inet.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/fcntl.h>
28 #include <linux/mm.h>
29 #include <linux/interrupt.h>
30 #include <net/netrom.h>
33 * This routine purges all of the queues of frames.
35 void nr_clear_queues(struct sock *sk)
37 struct nr_sock *nr = nr_sk(sk);
39 skb_queue_purge(&sk->sk_write_queue);
40 skb_queue_purge(&nr->ack_queue);
41 skb_queue_purge(&nr->reseq_queue);
42 skb_queue_purge(&nr->frag_queue);
46 * This routine purges the input queue of those frames that have been
47 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
48 * SDL diagram.
50 void nr_frames_acked(struct sock *sk, unsigned short nr)
52 struct nr_sock *nrom = nr_sk(sk);
53 struct sk_buff *skb;
56 * Remove all the ack-ed frames from the ack queue.
58 if (nrom->va != nr) {
59 while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
60 skb = skb_dequeue(&nrom->ack_queue);
61 kfree_skb(skb);
62 nrom->va = (nrom->va + 1) % NR_MODULUS;
68 * Requeue all the un-ack-ed frames on the output queue to be picked
69 * up by nr_kick called from the timer. This arrangement handles the
70 * possibility of an empty output queue.
72 void nr_requeue_frames(struct sock *sk)
74 struct sk_buff *skb, *skb_prev = NULL;
76 while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
77 if (skb_prev == NULL)
78 skb_queue_head(&sk->sk_write_queue, skb);
79 else
80 skb_append(skb_prev, skb, &sk->sk_write_queue);
81 skb_prev = skb;
86 * Validate that the value of nr is between va and vs. Return true or
87 * false for testing.
89 int nr_validate_nr(struct sock *sk, unsigned short nr)
91 struct nr_sock *nrom = nr_sk(sk);
92 unsigned short vc = nrom->va;
94 while (vc != nrom->vs) {
95 if (nr == vc) return 1;
96 vc = (vc + 1) % NR_MODULUS;
99 return nr == nrom->vs;
103 * Check that ns is within the receive window.
105 int nr_in_rx_window(struct sock *sk, unsigned short ns)
107 struct nr_sock *nr = nr_sk(sk);
108 unsigned short vc = nr->vr;
109 unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
111 while (vc != vt) {
112 if (ns == vc) return 1;
113 vc = (vc + 1) % NR_MODULUS;
116 return 0;
120 * This routine is called when the HDLC layer internally generates a
121 * control frame.
123 void nr_write_internal(struct sock *sk, int frametype)
125 struct nr_sock *nr = nr_sk(sk);
126 struct sk_buff *skb;
127 unsigned char *dptr;
128 int len, timeout;
130 len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
132 switch (frametype & 0x0F) {
133 case NR_CONNREQ:
134 len += 17;
135 break;
136 case NR_CONNACK:
137 len += (nr->bpqext) ? 2 : 1;
138 break;
139 case NR_DISCREQ:
140 case NR_DISCACK:
141 case NR_INFOACK:
142 break;
143 default:
144 printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
145 return;
148 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
149 return;
152 * Space for AX.25 and NET/ROM network header
154 skb_reserve(skb, NR_NETWORK_LEN);
156 dptr = skb_put(skb, skb_tailroom(skb));
158 switch (frametype & 0x0F) {
159 case NR_CONNREQ:
160 timeout = nr->t1 / HZ;
161 *dptr++ = nr->my_index;
162 *dptr++ = nr->my_id;
163 *dptr++ = 0;
164 *dptr++ = 0;
165 *dptr++ = frametype;
166 *dptr++ = nr->window;
167 memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
168 dptr[6] &= ~AX25_CBIT;
169 dptr[6] &= ~AX25_EBIT;
170 dptr[6] |= AX25_SSSID_SPARE;
171 dptr += AX25_ADDR_LEN;
172 memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
173 dptr[6] &= ~AX25_CBIT;
174 dptr[6] &= ~AX25_EBIT;
175 dptr[6] |= AX25_SSSID_SPARE;
176 dptr += AX25_ADDR_LEN;
177 *dptr++ = timeout % 256;
178 *dptr++ = timeout / 256;
179 break;
181 case NR_CONNACK:
182 *dptr++ = nr->your_index;
183 *dptr++ = nr->your_id;
184 *dptr++ = nr->my_index;
185 *dptr++ = nr->my_id;
186 *dptr++ = frametype;
187 *dptr++ = nr->window;
188 if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
189 break;
191 case NR_DISCREQ:
192 case NR_DISCACK:
193 *dptr++ = nr->your_index;
194 *dptr++ = nr->your_id;
195 *dptr++ = 0;
196 *dptr++ = 0;
197 *dptr++ = frametype;
198 break;
200 case NR_INFOACK:
201 *dptr++ = nr->your_index;
202 *dptr++ = nr->your_id;
203 *dptr++ = 0;
204 *dptr++ = nr->vr;
205 *dptr++ = frametype;
206 break;
209 nr_transmit_buffer(sk, skb);
213 * This routine is called to send an error reply.
215 void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
217 struct sk_buff *skbn;
218 unsigned char *dptr;
219 int len;
221 len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
223 if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
224 return;
226 skb_reserve(skbn, 0);
228 dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
230 skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
231 dptr[6] &= ~AX25_CBIT;
232 dptr[6] &= ~AX25_EBIT;
233 dptr[6] |= AX25_SSSID_SPARE;
234 dptr += AX25_ADDR_LEN;
236 skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
237 dptr[6] &= ~AX25_CBIT;
238 dptr[6] |= AX25_EBIT;
239 dptr[6] |= AX25_SSSID_SPARE;
240 dptr += AX25_ADDR_LEN;
242 *dptr++ = sysctl_netrom_network_ttl_initialiser;
244 if (mine) {
245 *dptr++ = 0;
246 *dptr++ = 0;
247 *dptr++ = skb->data[15];
248 *dptr++ = skb->data[16];
249 } else {
250 *dptr++ = skb->data[15];
251 *dptr++ = skb->data[16];
252 *dptr++ = 0;
253 *dptr++ = 0;
256 *dptr++ = cmdflags;
257 *dptr++ = 0;
259 if (!nr_route_frame(skbn, NULL))
260 kfree_skb(skbn);
263 void nr_disconnect(struct sock *sk, int reason)
265 nr_stop_t1timer(sk);
266 nr_stop_t2timer(sk);
267 nr_stop_t4timer(sk);
268 nr_stop_idletimer(sk);
270 nr_clear_queues(sk);
272 nr_sk(sk)->state = NR_STATE_0;
274 sk->sk_state = TCP_CLOSE;
275 sk->sk_err = reason;
276 sk->sk_shutdown |= SEND_SHUTDOWN;
278 if (!sock_flag(sk, SOCK_DEAD)) {
279 sk->sk_state_change(sk);
280 sock_set_flag(sk, SOCK_DEAD);