5 * o allow users to set the parameters
6 * o sync/async switching ?
8 * Note: This does _not_ implement CCITT X.25 asynchronous framing
9 * recommendations. Its primarily for testing purposes. If you wanted
10 * to do CCITT then in theory all you need is to nick the HDLC async
11 * checksum routines from ppp.c
14 * 2000-10-29 Henner Eisen lapb_data_indication() return status.
17 #include <linux/module.h>
19 #include <asm/system.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/string.h>
24 #include <linux/interrupt.h>
26 #include <linux/tty.h>
27 #include <linux/errno.h>
28 #include <linux/netdevice.h>
29 #include <linux/etherdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/if_arp.h>
32 #include <linux/x25.h>
33 #include <linux/lapb.h>
34 #include <linux/init.h>
35 #include <linux/rtnetlink.h>
38 #include <net/x25device.h>
40 static struct net_device
**x25_asy_devs
;
41 static int x25_asy_maxdev
= SL_NRUNIT
;
43 module_param(x25_asy_maxdev
, int, 0);
44 MODULE_LICENSE("GPL");
46 static int x25_asy_esc(unsigned char *p
, unsigned char *d
, int len
);
47 static void x25_asy_unesc(struct x25_asy
*sl
, unsigned char c
);
48 static void x25_asy_setup(struct net_device
*dev
);
50 /* Find a free X.25 channel, and link in this `tty' line. */
51 static struct x25_asy
*x25_asy_alloc(void)
53 struct net_device
*dev
= NULL
;
57 if (x25_asy_devs
== NULL
)
58 return NULL
; /* Master array missing ! */
60 for (i
= 0; i
< x25_asy_maxdev
; i
++) {
61 dev
= x25_asy_devs
[i
];
67 sl
= netdev_priv(dev
);
69 if (!test_and_set_bit(SLF_INUSE
, &sl
->flags
))
74 /* Sorry, too many, all slots in use */
75 if (i
>= x25_asy_maxdev
)
78 /* If no channels are available, allocate one */
81 sprintf(name
, "x25asy%d", i
);
83 dev
= alloc_netdev(sizeof(struct x25_asy
),
88 /* Initialize channel control data */
89 sl
= netdev_priv(dev
);
92 /* register device so that it can be ifconfig'ed */
93 if (register_netdev(dev
) == 0) {
94 /* (Re-)Set the INUSE bit. Very Important! */
95 set_bit(SLF_INUSE
, &sl
->flags
);
96 x25_asy_devs
[i
] = dev
;
99 printk(KERN_WARNING
"x25_asy_alloc() - register_netdev() failure.\n");
107 /* Free an X.25 channel. */
108 static void x25_asy_free(struct x25_asy
*sl
)
110 /* Free all X.25 frame buffers. */
116 if (!test_and_clear_bit(SLF_INUSE
, &sl
->flags
))
117 printk(KERN_ERR
"%s: x25_asy_free for already free unit.\n",
121 static int x25_asy_change_mtu(struct net_device
*dev
, int newmtu
)
123 struct x25_asy
*sl
= netdev_priv(dev
);
124 unsigned char *xbuff
, *rbuff
;
125 int len
= 2 * newmtu
;
127 xbuff
= kmalloc(len
+ 4, GFP_ATOMIC
);
128 rbuff
= kmalloc(len
+ 4, GFP_ATOMIC
);
130 if (xbuff
== NULL
|| rbuff
== NULL
) {
131 printk(KERN_WARNING
"%s: unable to grow X.25 buffers, MTU change cancelled.\n",
138 spin_lock_bh(&sl
->lock
);
139 xbuff
= xchg(&sl
->xbuff
, xbuff
);
141 if (sl
->xleft
<= len
) {
142 memcpy(sl
->xbuff
, sl
->xhead
, sl
->xleft
);
145 sl
->stats
.tx_dropped
++;
148 sl
->xhead
= sl
->xbuff
;
150 rbuff
= xchg(&sl
->rbuff
, rbuff
);
152 if (sl
->rcount
<= len
) {
153 memcpy(sl
->rbuff
, rbuff
, sl
->rcount
);
156 sl
->stats
.rx_over_errors
++;
157 set_bit(SLF_ERROR
, &sl
->flags
);
164 spin_unlock_bh(&sl
->lock
);
172 /* Set the "sending" flag. This must be atomic, hence the ASM. */
174 static inline void x25_asy_lock(struct x25_asy
*sl
)
176 netif_stop_queue(sl
->dev
);
180 /* Clear the "sending" flag. This must be atomic, hence the ASM. */
182 static inline void x25_asy_unlock(struct x25_asy
*sl
)
184 netif_wake_queue(sl
->dev
);
187 /* Send one completely decapsulated IP datagram to the IP layer. */
189 static void x25_asy_bump(struct x25_asy
*sl
)
196 sl
->stats
.rx_bytes
+= count
;
198 skb
= dev_alloc_skb(count
+1);
200 printk(KERN_WARNING
"%s: memory squeeze, dropping packet.\n",
202 sl
->stats
.rx_dropped
++;
205 skb_push(skb
, 1); /* LAPB internal control */
206 memcpy(skb_put(skb
, count
), sl
->rbuff
, count
);
207 skb
->protocol
= x25_type_trans(skb
, sl
->dev
);
208 err
= lapb_data_received(skb
->dev
, skb
);
209 if (err
!= LAPB_OK
) {
211 printk(KERN_DEBUG
"x25_asy: data received err - %d\n", err
);
214 sl
->stats
.rx_packets
++;
218 /* Encapsulate one IP datagram and stuff into a TTY queue. */
219 static void x25_asy_encaps(struct x25_asy
*sl
, unsigned char *icp
, int len
)
222 int actual
, count
, mtu
= sl
->dev
->mtu
;
225 /* Sigh, shouldn't occur BUT ... */
227 printk(KERN_DEBUG
"%s: truncating oversized transmit packet!\n",
229 sl
->stats
.tx_dropped
++;
235 count
= x25_asy_esc(p
, (unsigned char *) sl
->xbuff
, len
);
237 /* Order of next two lines is *very* important.
238 * When we are sending a little amount of data,
239 * the transfer may be completed inside driver.write()
240 * routine, because it's running with interrupts enabled.
241 * In this case we *never* got WRITE_WAKEUP event,
242 * if we did not request it before write operation.
243 * 14 Oct 1994 Dmitry Gorodchanin.
245 set_bit(TTY_DO_WRITE_WAKEUP
, &sl
->tty
->flags
);
246 actual
= sl
->tty
->ops
->write(sl
->tty
, sl
->xbuff
, count
);
247 sl
->xleft
= count
- actual
;
248 sl
->xhead
= sl
->xbuff
+ actual
;
250 clear_bit(SLF_OUTWAIT
, &sl
->flags
); /* reset outfill flag */
254 * Called by the driver when there's room for more data. If we have
255 * more packets to send, we send them here.
257 static void x25_asy_write_wakeup(struct tty_struct
*tty
)
260 struct x25_asy
*sl
= tty
->disc_data
;
262 /* First make sure we're connected. */
263 if (!sl
|| sl
->magic
!= X25_ASY_MAGIC
|| !netif_running(sl
->dev
))
266 if (sl
->xleft
<= 0) {
267 /* Now serial buffer is almost free & we can start
268 * transmission of another packet */
269 sl
->stats
.tx_packets
++;
270 clear_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
275 actual
= tty
->ops
->write(tty
, sl
->xhead
, sl
->xleft
);
280 static void x25_asy_timeout(struct net_device
*dev
)
282 struct x25_asy
*sl
= netdev_priv(dev
);
284 spin_lock(&sl
->lock
);
285 if (netif_queue_stopped(dev
)) {
286 /* May be we must check transmitter timeout here ?
287 * 14 Oct 1994 Dmitry Gorodchanin.
289 printk(KERN_WARNING
"%s: transmit timed out, %s?\n", dev
->name
,
290 (tty_chars_in_buffer(sl
->tty
) || sl
->xleft
) ?
291 "bad line quality" : "driver error");
293 clear_bit(TTY_DO_WRITE_WAKEUP
, &sl
->tty
->flags
);
296 spin_unlock(&sl
->lock
);
299 /* Encapsulate an IP datagram and kick it into a TTY queue. */
301 static int x25_asy_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
303 struct x25_asy
*sl
= netdev_priv(dev
);
306 if (!netif_running(sl
->dev
)) {
307 printk(KERN_ERR
"%s: xmit call when iface is down\n",
313 switch (skb
->data
[0]) {
316 case 0x01: /* Connection request .. do nothing */
317 err
= lapb_connect_request(dev
);
319 printk(KERN_ERR
"x25_asy: lapb_connect_request error - %d\n", err
);
322 case 0x02: /* Disconnect request .. do nothing - hang up ?? */
323 err
= lapb_disconnect_request(dev
);
325 printk(KERN_ERR
"x25_asy: lapb_disconnect_request error - %d\n", err
);
330 skb_pull(skb
, 1); /* Remove control byte */
332 * If we are busy already- too bad. We ought to be able
333 * to queue things at this point, to allow for a little
334 * frame buffer. Oh well...
335 * -----------------------------------------------------
336 * I hate queues in X.25 driver. May be it's efficient,
337 * but for me latency is more important. ;)
339 * 14 Oct 1994 Dmitry Gorodchanin.
342 err
= lapb_data_request(dev
, skb
);
343 if (err
!= LAPB_OK
) {
344 printk(KERN_ERR
"x25_asy: lapb_data_request error - %d\n", err
);
353 * LAPB interface boilerplate
357 * Called when I frame data arrives. We did the work above - throw it
361 static int x25_asy_data_indication(struct net_device
*dev
, struct sk_buff
*skb
)
363 return netif_rx(skb
);
367 * Data has emerged from the LAPB protocol machine. We don't handle
368 * busy cases too well. Its tricky to see how to do this nicely -
369 * perhaps lapb should allow us to bounce this ?
372 static void x25_asy_data_transmit(struct net_device
*dev
, struct sk_buff
*skb
)
374 struct x25_asy
*sl
= netdev_priv(dev
);
376 spin_lock(&sl
->lock
);
377 if (netif_queue_stopped(sl
->dev
) || sl
->tty
== NULL
) {
378 spin_unlock(&sl
->lock
);
379 printk(KERN_ERR
"x25_asy: tbusy drop\n");
383 /* We were not busy, so we are now... :-) */
386 sl
->stats
.tx_bytes
+= skb
->len
;
387 x25_asy_encaps(sl
, skb
->data
, skb
->len
);
390 spin_unlock(&sl
->lock
);
394 * LAPB connection establish/down information.
397 static void x25_asy_connected(struct net_device
*dev
, int reason
)
399 struct x25_asy
*sl
= netdev_priv(dev
);
403 skb
= dev_alloc_skb(1);
405 printk(KERN_ERR
"x25_asy: out of memory\n");
409 ptr
= skb_put(skb
, 1);
412 skb
->protocol
= x25_type_trans(skb
, sl
->dev
);
416 static void x25_asy_disconnected(struct net_device
*dev
, int reason
)
418 struct x25_asy
*sl
= netdev_priv(dev
);
422 skb
= dev_alloc_skb(1);
424 printk(KERN_ERR
"x25_asy: out of memory\n");
428 ptr
= skb_put(skb
, 1);
431 skb
->protocol
= x25_type_trans(skb
, sl
->dev
);
435 static struct lapb_register_struct x25_asy_callbacks
= {
436 .connect_confirmation
= x25_asy_connected
,
437 .connect_indication
= x25_asy_connected
,
438 .disconnect_confirmation
= x25_asy_disconnected
,
439 .disconnect_indication
= x25_asy_disconnected
,
440 .data_indication
= x25_asy_data_indication
,
441 .data_transmit
= x25_asy_data_transmit
,
446 /* Open the low-level part of the X.25 channel. Easy! */
447 static int x25_asy_open(struct net_device
*dev
)
449 struct x25_asy
*sl
= netdev_priv(dev
);
457 * Allocate the X.25 frame buffers:
459 * rbuff Receive buffer.
460 * xbuff Transmit buffer.
465 sl
->rbuff
= kmalloc(len
+ 4, GFP_KERNEL
);
466 if (sl
->rbuff
== NULL
)
468 sl
->xbuff
= kmalloc(len
+ 4, GFP_KERNEL
);
469 if (sl
->xbuff
== NULL
)
475 sl
->flags
&= (1 << SLF_INUSE
); /* Clear ESCAPE & ERROR flags */
477 netif_start_queue(dev
);
482 err
= lapb_register(dev
, &x25_asy_callbacks
);
495 /* Close the low-level part of the X.25 channel. Easy! */
496 static int x25_asy_close(struct net_device
*dev
)
498 struct x25_asy
*sl
= netdev_priv(dev
);
501 spin_lock(&sl
->lock
);
503 clear_bit(TTY_DO_WRITE_WAKEUP
, &sl
->tty
->flags
);
505 netif_stop_queue(dev
);
508 err
= lapb_unregister(dev
);
510 printk(KERN_ERR
"x25_asy_close: lapb_unregister error -%d\n",
512 spin_unlock(&sl
->lock
);
517 * Handle the 'receiver data ready' interrupt.
518 * This function is called by the 'tty_io' module in the kernel when
519 * a block of X.25 data has been received, which can now be decapsulated
520 * and sent on to some IP layer for further processing.
523 static void x25_asy_receive_buf(struct tty_struct
*tty
,
524 const unsigned char *cp
, char *fp
, int count
)
526 struct x25_asy
*sl
= tty
->disc_data
;
528 if (!sl
|| sl
->magic
!= X25_ASY_MAGIC
|| !netif_running(sl
->dev
))
532 /* Read the characters out of the buffer */
535 if (!test_and_set_bit(SLF_ERROR
, &sl
->flags
))
536 sl
->stats
.rx_errors
++;
540 x25_asy_unesc(sl
, *cp
++);
545 * Open the high-level part of the X.25 channel.
546 * This function is called by the TTY module when the
547 * X.25 line discipline is called for. Because we are
548 * sure the tty line exists, we only have to link it to
549 * a free X.25 channel...
552 static int x25_asy_open_tty(struct tty_struct
*tty
)
554 struct x25_asy
*sl
= tty
->disc_data
;
557 if (tty
->ops
->write
== NULL
)
560 /* First make sure we're not already connected. */
561 if (sl
&& sl
->magic
== X25_ASY_MAGIC
)
564 /* OK. Find a free X.25 channel to use. */
565 sl
= x25_asy_alloc();
571 tty
->receive_room
= 65536;
572 tty_driver_flush_buffer(tty
);
573 tty_ldisc_flush(tty
);
575 /* Restore default settings */
576 sl
->dev
->type
= ARPHRD_X25
;
578 /* Perform the low-level X.25 async init */
579 err
= x25_asy_open(sl
->dev
);
582 /* Done. We have linked the TTY line to a channel. */
583 return sl
->dev
->base_addr
;
588 * Close down an X.25 channel.
589 * This means flushing out any pending queues, and then restoring the
590 * TTY line discipline to what it was before it got hooked to X.25
591 * (which usually is TTY again).
593 static void x25_asy_close_tty(struct tty_struct
*tty
)
595 struct x25_asy
*sl
= tty
->disc_data
;
597 /* First make sure we're connected. */
598 if (!sl
|| sl
->magic
!= X25_ASY_MAGIC
)
602 if (sl
->dev
->flags
& IFF_UP
)
606 tty
->disc_data
= NULL
;
612 static struct net_device_stats
*x25_asy_get_stats(struct net_device
*dev
)
614 struct x25_asy
*sl
= netdev_priv(dev
);
619 /************************************************************************
620 * STANDARD X.25 ENCAPSULATION *
621 ************************************************************************/
623 static int x25_asy_esc(unsigned char *s
, unsigned char *d
, int len
)
625 unsigned char *ptr
= d
;
629 * Send an initial END character to flush out any
630 * data that may have accumulated in the receiver
634 *ptr
++ = X25_END
; /* Send 10111110 bit seq */
637 * For each byte in the packet, send the appropriate
638 * character sequence, according to the X.25 protocol.
645 *ptr
++ = X25_ESCAPE(X25_END
);
649 *ptr
++ = X25_ESCAPE(X25_ESC
);
660 static void x25_asy_unesc(struct x25_asy
*sl
, unsigned char s
)
665 if (!test_and_clear_bit(SLF_ERROR
, &sl
->flags
)
668 clear_bit(SLF_ESCAPE
, &sl
->flags
);
672 set_bit(SLF_ESCAPE
, &sl
->flags
);
674 case X25_ESCAPE(X25_ESC
):
675 case X25_ESCAPE(X25_END
):
676 if (test_and_clear_bit(SLF_ESCAPE
, &sl
->flags
))
680 if (!test_bit(SLF_ERROR
, &sl
->flags
)) {
681 if (sl
->rcount
< sl
->buffsize
) {
682 sl
->rbuff
[sl
->rcount
++] = s
;
685 sl
->stats
.rx_over_errors
++;
686 set_bit(SLF_ERROR
, &sl
->flags
);
691 /* Perform I/O control on an active X.25 channel. */
692 static int x25_asy_ioctl(struct tty_struct
*tty
, struct file
*file
,
693 unsigned int cmd
, unsigned long arg
)
695 struct x25_asy
*sl
= tty
->disc_data
;
697 /* First make sure we're connected. */
698 if (!sl
|| sl
->magic
!= X25_ASY_MAGIC
)
703 if (copy_to_user((void __user
*)arg
, sl
->dev
->name
,
704 strlen(sl
->dev
->name
) + 1))
710 return tty_mode_ioctl(tty
, file
, cmd
, arg
);
714 static int x25_asy_open_dev(struct net_device
*dev
)
716 struct x25_asy
*sl
= netdev_priv(dev
);
722 /* Initialise the X.25 driver. Called by the device init code */
723 static void x25_asy_setup(struct net_device
*dev
)
725 struct x25_asy
*sl
= netdev_priv(dev
);
727 sl
->magic
= X25_ASY_MAGIC
;
729 spin_lock_init(&sl
->lock
);
730 set_bit(SLF_INUSE
, &sl
->flags
);
733 * Finish setting up the DEVICE info.
737 dev
->hard_start_xmit
= x25_asy_xmit
;
738 dev
->tx_timeout
= x25_asy_timeout
;
739 dev
->watchdog_timeo
= HZ
*20;
740 dev
->open
= x25_asy_open_dev
;
741 dev
->stop
= x25_asy_close
;
742 dev
->get_stats
= x25_asy_get_stats
;
743 dev
->change_mtu
= x25_asy_change_mtu
;
744 dev
->hard_header_len
= 0;
746 dev
->type
= ARPHRD_X25
;
747 dev
->tx_queue_len
= 10;
749 /* New-style flags. */
750 dev
->flags
= IFF_NOARP
;
753 static struct tty_ldisc_ops x25_ldisc
= {
754 .owner
= THIS_MODULE
,
755 .magic
= TTY_LDISC_MAGIC
,
757 .open
= x25_asy_open_tty
,
758 .close
= x25_asy_close_tty
,
759 .ioctl
= x25_asy_ioctl
,
760 .receive_buf
= x25_asy_receive_buf
,
761 .write_wakeup
= x25_asy_write_wakeup
,
764 static int __init
init_x25_asy(void)
766 if (x25_asy_maxdev
< 4)
767 x25_asy_maxdev
= 4; /* Sanity */
769 printk(KERN_INFO
"X.25 async: version 0.00 ALPHA "
770 "(dynamic channels, max=%d).\n", x25_asy_maxdev
);
772 x25_asy_devs
= kcalloc(x25_asy_maxdev
, sizeof(struct net_device
*),
775 printk(KERN_WARNING
"X25 async: Can't allocate x25_asy_ctrls[] "
776 "array! Uaargh! (-> No X.25 available)\n");
780 return tty_register_ldisc(N_X25
, &x25_ldisc
);
784 static void __exit
exit_x25_asy(void)
786 struct net_device
*dev
;
789 for (i
= 0; i
< x25_asy_maxdev
; i
++) {
790 dev
= x25_asy_devs
[i
];
792 struct x25_asy
*sl
= netdev_priv(dev
);
794 spin_lock_bh(&sl
->lock
);
798 spin_unlock_bh(&sl
->lock
);
800 * VSV = if dev->start==0, then device
801 * unregistered while close proc.
803 unregister_netdev(dev
);
809 tty_unregister_ldisc(N_X25
);
812 module_init(init_x25_asy
);
813 module_exit(exit_x25_asy
);