Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[wrt350n-kernel.git] / net / ax25 / ax25_out.c
blob4a8b64e58c0c10e021a8eb41814dcda82f0083e3
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 (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
8 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
9 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/socket.h>
14 #include <linux/in.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/timer.h>
18 #include <linux/string.h>
19 #include <linux/sockios.h>
20 #include <linux/spinlock.h>
21 #include <linux/net.h>
22 #include <net/ax25.h>
23 #include <linux/inet.h>
24 #include <linux/netdevice.h>
25 #include <linux/skbuff.h>
26 #include <linux/netfilter.h>
27 #include <net/sock.h>
28 #include <asm/uaccess.h>
29 #include <asm/system.h>
30 #include <linux/fcntl.h>
31 #include <linux/mm.h>
32 #include <linux/interrupt.h>
34 static DEFINE_SPINLOCK(ax25_frag_lock);
36 ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_address *src, ax25_address *dest, ax25_digi *digi, struct net_device *dev)
38 ax25_dev *ax25_dev;
39 ax25_cb *ax25;
42 * Take the default packet length for the device if zero is
43 * specified.
45 if (paclen == 0) {
46 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
47 return NULL;
49 paclen = ax25_dev->values[AX25_VALUES_PACLEN];
53 * Look for an existing connection.
55 if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
56 ax25_output(ax25, paclen, skb);
57 return ax25; /* It already existed */
60 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
61 return NULL;
63 if ((ax25 = ax25_create_cb()) == NULL)
64 return NULL;
66 ax25_fillin_cb(ax25, ax25_dev);
68 ax25->source_addr = *src;
69 ax25->dest_addr = *dest;
71 if (digi != NULL) {
72 ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
73 if (ax25->digipeat == NULL) {
74 ax25_cb_put(ax25);
75 return NULL;
79 switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
80 case AX25_PROTO_STD_SIMPLEX:
81 case AX25_PROTO_STD_DUPLEX:
82 ax25_std_establish_data_link(ax25);
83 break;
85 #ifdef CONFIG_AX25_DAMA_SLAVE
86 case AX25_PROTO_DAMA_SLAVE:
87 if (ax25_dev->dama.slave)
88 ax25_ds_establish_data_link(ax25);
89 else
90 ax25_std_establish_data_link(ax25);
91 break;
92 #endif
95 ax25_cb_add(ax25);
97 ax25->state = AX25_STATE_1;
99 ax25_start_heartbeat(ax25);
101 ax25_output(ax25, paclen, skb);
103 return ax25; /* We had to create it */
106 EXPORT_SYMBOL(ax25_send_frame);
109 * All outgoing AX.25 I frames pass via this routine. Therefore this is
110 * where the fragmentation of frames takes place. If fragment is set to
111 * zero then we are not allowed to do fragmentation, even if the frame
112 * is too large.
114 void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb)
116 struct sk_buff *skbn;
117 unsigned char *p;
118 int frontlen, len, fragno, ka9qfrag, first = 1;
120 <<<<<<< HEAD:net/ax25/ax25_out.c
121 =======
122 if (paclen < 16) {
123 WARN_ON_ONCE(1);
124 kfree_skb(skb);
125 return;
128 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:net/ax25/ax25_out.c
129 if ((skb->len - 1) > paclen) {
130 if (*skb->data == AX25_P_TEXT) {
131 skb_pull(skb, 1); /* skip PID */
132 ka9qfrag = 0;
133 } else {
134 paclen -= 2; /* Allow for fragment control info */
135 ka9qfrag = 1;
138 fragno = skb->len / paclen;
139 if (skb->len % paclen == 0) fragno--;
141 frontlen = skb_headroom(skb); /* Address space + CTRL */
143 while (skb->len > 0) {
144 spin_lock_bh(&ax25_frag_lock);
145 if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
146 spin_unlock_bh(&ax25_frag_lock);
147 printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
148 return;
151 if (skb->sk != NULL)
152 skb_set_owner_w(skbn, skb->sk);
154 spin_unlock_bh(&ax25_frag_lock);
156 len = (paclen > skb->len) ? skb->len : paclen;
158 if (ka9qfrag == 1) {
159 skb_reserve(skbn, frontlen + 2);
160 skb_set_network_header(skbn,
161 skb_network_offset(skb));
162 skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
163 p = skb_push(skbn, 2);
165 *p++ = AX25_P_SEGMENT;
167 *p = fragno--;
168 if (first) {
169 *p |= AX25_SEG_FIRST;
170 first = 0;
172 } else {
173 skb_reserve(skbn, frontlen + 1);
174 skb_set_network_header(skbn,
175 skb_network_offset(skb));
176 skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
177 p = skb_push(skbn, 1);
178 *p = AX25_P_TEXT;
181 skb_pull(skb, len);
182 skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
185 kfree_skb(skb);
186 } else {
187 skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */
190 switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
191 case AX25_PROTO_STD_SIMPLEX:
192 case AX25_PROTO_STD_DUPLEX:
193 ax25_kick(ax25);
194 break;
196 #ifdef CONFIG_AX25_DAMA_SLAVE
198 * A DAMA slave is _required_ to work as normal AX.25L2V2
199 * if no DAMA master is available.
201 case AX25_PROTO_DAMA_SLAVE:
202 if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25);
203 break;
204 #endif
209 * This procedure is passed a buffer descriptor for an iframe. It builds
210 * the rest of the control part of the frame and then writes it out.
212 static void ax25_send_iframe(ax25_cb *ax25, struct sk_buff *skb, int poll_bit)
214 unsigned char *frame;
216 if (skb == NULL)
217 return;
219 skb_reset_network_header(skb);
221 if (ax25->modulus == AX25_MODULUS) {
222 frame = skb_push(skb, 1);
224 *frame = AX25_I;
225 *frame |= (poll_bit) ? AX25_PF : 0;
226 *frame |= (ax25->vr << 5);
227 *frame |= (ax25->vs << 1);
228 } else {
229 frame = skb_push(skb, 2);
231 frame[0] = AX25_I;
232 frame[0] |= (ax25->vs << 1);
233 frame[1] = (poll_bit) ? AX25_EPF : 0;
234 frame[1] |= (ax25->vr << 1);
237 ax25_start_idletimer(ax25);
239 ax25_transmit_buffer(ax25, skb, AX25_COMMAND);
242 void ax25_kick(ax25_cb *ax25)
244 struct sk_buff *skb, *skbn;
245 int last = 1;
246 unsigned short start, end, next;
248 if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4)
249 return;
251 if (ax25->condition & AX25_COND_PEER_RX_BUSY)
252 return;
254 if (skb_peek(&ax25->write_queue) == NULL)
255 return;
257 start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs;
258 end = (ax25->va + ax25->window) % ax25->modulus;
260 if (start == end)
261 return;
263 <<<<<<< HEAD:net/ax25/ax25_out.c
264 ax25->vs = start;
266 =======
267 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:net/ax25/ax25_out.c
269 * Transmit data until either we're out of data to send or
270 * the window is full. Send a poll on the final I frame if
271 * the window is filled.
275 * Dequeue the frame and copy it.
276 <<<<<<< HEAD:net/ax25/ax25_out.c
277 =======
278 * Check for race with ax25_clear_queues().
279 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:net/ax25/ax25_out.c
281 skb = skb_dequeue(&ax25->write_queue);
282 <<<<<<< HEAD:net/ax25/ax25_out.c
283 =======
284 if (!skb)
285 return;
287 ax25->vs = start;
288 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:net/ax25/ax25_out.c
290 do {
291 if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
292 skb_queue_head(&ax25->write_queue, skb);
293 break;
296 if (skb->sk != NULL)
297 skb_set_owner_w(skbn, skb->sk);
299 next = (ax25->vs + 1) % ax25->modulus;
300 last = (next == end);
303 * Transmit the frame copy.
304 * bke 960114: do not set the Poll bit on the last frame
305 * in DAMA mode.
307 switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
308 case AX25_PROTO_STD_SIMPLEX:
309 case AX25_PROTO_STD_DUPLEX:
310 ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF);
311 break;
313 #ifdef CONFIG_AX25_DAMA_SLAVE
314 case AX25_PROTO_DAMA_SLAVE:
315 ax25_send_iframe(ax25, skbn, AX25_POLLOFF);
316 break;
317 #endif
320 ax25->vs = next;
323 * Requeue the original data frame.
325 skb_queue_tail(&ax25->ack_queue, skb);
327 } while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL);
329 ax25->condition &= ~AX25_COND_ACK_PENDING;
331 if (!ax25_t1timer_running(ax25)) {
332 ax25_stop_t3timer(ax25);
333 ax25_calculate_t1(ax25);
334 ax25_start_t1timer(ax25);
338 void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type)
340 struct sk_buff *skbn;
341 unsigned char *ptr;
342 int headroom;
344 if (ax25->ax25_dev == NULL) {
345 ax25_disconnect(ax25, ENETUNREACH);
346 return;
349 headroom = ax25_addr_size(ax25->digipeat);
351 if (skb_headroom(skb) < headroom) {
352 if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) {
353 printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
354 kfree_skb(skb);
355 return;
358 if (skb->sk != NULL)
359 skb_set_owner_w(skbn, skb->sk);
361 kfree_skb(skb);
362 skb = skbn;
365 ptr = skb_push(skb, headroom);
367 ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
369 ax25_queue_xmit(skb, ax25->ax25_dev->dev);
373 * A small shim to dev_queue_xmit to add the KISS control byte, and do
374 * any packet forwarding in operation.
376 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev)
378 unsigned char *ptr;
380 skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(dev));
382 ptr = skb_push(skb, 1);
383 *ptr = 0x00; /* KISS */
385 dev_queue_xmit(skb);
388 int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr)
390 if (ax25->vs == nr) {
391 ax25_frames_acked(ax25, nr);
392 ax25_calculate_rtt(ax25);
393 ax25_stop_t1timer(ax25);
394 ax25_start_t3timer(ax25);
395 return 1;
396 } else {
397 if (ax25->va != nr) {
398 ax25_frames_acked(ax25, nr);
399 ax25_calculate_t1(ax25);
400 ax25_start_t1timer(ax25);
401 return 1;
404 return 0;