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12#include <linux/errno.h>
13#include <linux/hdlc.h>
14#include <linux/if_arp.h>
15#include <linux/inetdevice.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/module.h>
19#include <linux/pkt_sched.h>
20#include <linux/poll.h>
21#include <linux/skbuff.h>
22#include <linux/slab.h>
23#include <linux/spinlock.h>
24
25#define DEBUG_CP 0
26#define DEBUG_STATE 0
27#define DEBUG_HARD_HEADER 0
28
29#define HDLC_ADDR_ALLSTATIONS 0xFF
30#define HDLC_CTRL_UI 0x03
31
32#define PID_LCP 0xC021
33#define PID_IP 0x0021
34#define PID_IPCP 0x8021
35#define PID_IPV6 0x0057
36#define PID_IPV6CP 0x8057
37
38enum {IDX_LCP = 0, IDX_IPCP, IDX_IPV6CP, IDX_COUNT};
39enum {CP_CONF_REQ = 1, CP_CONF_ACK, CP_CONF_NAK, CP_CONF_REJ, CP_TERM_REQ,
40 CP_TERM_ACK, CP_CODE_REJ, LCP_PROTO_REJ, LCP_ECHO_REQ, LCP_ECHO_REPLY,
41 LCP_DISC_REQ, CP_CODES};
42#if DEBUG_CP
43static const char *const code_names[CP_CODES] = {
44 "0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
45 "TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
46};
47static char debug_buffer[64 + 3 * DEBUG_CP];
48#endif
49
50enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};
51
52struct hdlc_header {
53 u8 address;
54 u8 control;
55 __be16 protocol;
56};
57
58struct cp_header {
59 u8 code;
60 u8 id;
61 __be16 len;
62};
63
64
65struct proto {
66 struct net_device *dev;
67 struct timer_list timer;
68 unsigned long timeout;
69 u16 pid;
70 u8 state;
71 u8 cr_id;
72 u8 restart_counter;
73};
74
75struct ppp {
76 struct proto protos[IDX_COUNT];
77 spinlock_t lock;
78 unsigned long last_pong;
79 unsigned int req_timeout, cr_retries, term_retries;
80 unsigned int keepalive_interval, keepalive_timeout;
81 u8 seq;
82 u8 echo_id;
83};
84
85enum {CLOSED = 0, STOPPED, STOPPING, REQ_SENT, ACK_RECV, ACK_SENT, OPENED,
86 STATES, STATE_MASK = 0xF};
87enum {START = 0, STOP, TO_GOOD, TO_BAD, RCR_GOOD, RCR_BAD, RCA, RCN, RTR, RTA,
88 RUC, RXJ_GOOD, RXJ_BAD, EVENTS};
89enum {INV = 0x10, IRC = 0x20, ZRC = 0x40, SCR = 0x80, SCA = 0x100,
90 SCN = 0x200, STR = 0x400, STA = 0x800, SCJ = 0x1000};
91
92#if DEBUG_STATE
93static const char *const state_names[STATES] = {
94 "Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
95 "Opened"
96};
97static const char *const event_names[EVENTS] = {
98 "Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
99 "RTR", "RTA", "RUC", "RXJ+", "RXJ-"
100};
101#endif
102
103static struct sk_buff_head tx_queue;
104
105static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
106
107static inline struct ppp* get_ppp(struct net_device *dev)
108{
109 return (struct ppp *)dev_to_hdlc(dev)->state;
110}
111
112static inline struct proto* get_proto(struct net_device *dev, u16 pid)
113{
114 struct ppp *ppp = get_ppp(dev);
115
116 switch (pid) {
117 case PID_LCP:
118 return &ppp->protos[IDX_LCP];
119 case PID_IPCP:
120 return &ppp->protos[IDX_IPCP];
121 case PID_IPV6CP:
122 return &ppp->protos[IDX_IPV6CP];
123 default:
124 return NULL;
125 }
126}
127
128static inline const char* proto_name(u16 pid)
129{
130 switch (pid) {
131 case PID_LCP:
132 return "LCP";
133 case PID_IPCP:
134 return "IPCP";
135 case PID_IPV6CP:
136 return "IPV6CP";
137 default:
138 return NULL;
139 }
140}
141
142static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
143{
144 struct hdlc_header *data = (struct hdlc_header*)skb->data;
145
146 if (skb->len < sizeof(struct hdlc_header))
147 return htons(ETH_P_HDLC);
148 if (data->address != HDLC_ADDR_ALLSTATIONS ||
149 data->control != HDLC_CTRL_UI)
150 return htons(ETH_P_HDLC);
151
152 switch (data->protocol) {
153 case cpu_to_be16(PID_IP):
154 skb_pull(skb, sizeof(struct hdlc_header));
155 return htons(ETH_P_IP);
156
157 case cpu_to_be16(PID_IPV6):
158 skb_pull(skb, sizeof(struct hdlc_header));
159 return htons(ETH_P_IPV6);
160
161 default:
162 return htons(ETH_P_HDLC);
163 }
164}
165
166
167static int ppp_hard_header(struct sk_buff *skb, struct net_device *dev,
168 u16 type, const void *daddr, const void *saddr,
169 unsigned int len)
170{
171 struct hdlc_header *data;
172#if DEBUG_HARD_HEADER
173 printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);
174#endif
175
176 skb_push(skb, sizeof(struct hdlc_header));
177 data = (struct hdlc_header*)skb->data;
178
179 data->address = HDLC_ADDR_ALLSTATIONS;
180 data->control = HDLC_CTRL_UI;
181 switch (type) {
182 case ETH_P_IP:
183 data->protocol = htons(PID_IP);
184 break;
185 case ETH_P_IPV6:
186 data->protocol = htons(PID_IPV6);
187 break;
188 case PID_LCP:
189 case PID_IPCP:
190 case PID_IPV6CP:
191 data->protocol = htons(type);
192 break;
193 default:
194 data->protocol = 0;
195 }
196 return sizeof(struct hdlc_header);
197}
198
199
200static void ppp_tx_flush(void)
201{
202 struct sk_buff *skb;
203 while ((skb = skb_dequeue(&tx_queue)) != NULL)
204 dev_queue_xmit(skb);
205}
206
207static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
208 u8 id, unsigned int len, const void *data)
209{
210 struct sk_buff *skb;
211 struct cp_header *cp;
212 unsigned int magic_len = 0;
213 static u32 magic;
214
215#if DEBUG_CP
216 int i;
217 char *ptr;
218#endif
219
220 if (pid == PID_LCP && (code == LCP_ECHO_REQ || code == LCP_ECHO_REPLY))
221 magic_len = sizeof(magic);
222
223 skb = dev_alloc_skb(sizeof(struct hdlc_header) +
224 sizeof(struct cp_header) + magic_len + len);
225 if (!skb) {
226 printk(KERN_WARNING "%s: out of memory in ppp_tx_cp()\n",
227 dev->name);
228 return;
229 }
230 skb_reserve(skb, sizeof(struct hdlc_header));
231
232 cp = (struct cp_header *)skb_put(skb, sizeof(struct cp_header));
233 cp->code = code;
234 cp->id = id;
235 cp->len = htons(sizeof(struct cp_header) + magic_len + len);
236
237 if (magic_len)
238 memcpy(skb_put(skb, magic_len), &magic, magic_len);
239 if (len)
240 memcpy(skb_put(skb, len), data, len);
241
242#if DEBUG_CP
243 BUG_ON(code >= CP_CODES);
244 ptr = debug_buffer;
245 *ptr = '\x0';
246 for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
247 sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
248 ptr += strlen(ptr);
249 }
250 printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
251 proto_name(pid), code_names[code], id, debug_buffer);
252#endif
253
254 ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
255
256 skb->priority = TC_PRIO_CONTROL;
257 skb->dev = dev;
258 skb_reset_network_header(skb);
259 skb_queue_tail(&tx_queue, skb);
260}
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281
282static int cp_table[EVENTS][STATES] = {
283
284
285 {IRC|SCR|3, INV , INV , INV , INV , INV , INV },
286 { INV , 0 , 0 , 0 , 0 , 0 , 0 },
287 { INV , INV ,STR|2, SCR|3 ,SCR|3, SCR|5 , INV },
288 { INV , INV , 1 , 1 , 1 , 1 , INV },
289 { STA|0 ,IRC|SCR|SCA|5, 2 , SCA|5 ,SCA|6, SCA|5 ,SCR|SCA|5},
290 { STA|0 ,IRC|SCR|SCN|3, 2 , SCN|3 ,SCN|4, SCN|3 ,SCR|SCN|3},
291 { STA|0 , STA|1 , 2 , IRC|4 ,SCR|3, 6 , SCR|3 },
292 { STA|0 , STA|1 , 2 ,IRC|SCR|3,SCR|3,IRC|SCR|5, SCR|3 },
293 { STA|0 , STA|1 ,STA|2, STA|3 ,STA|3, STA|3 ,ZRC|STA|2},
294 { 0 , 1 , 1 , 3 , 3 , 5 , SCR|3 },
295 { SCJ|0 , SCJ|1 ,SCJ|2, SCJ|3 ,SCJ|4, SCJ|5 , SCJ|6 },
296 { 0 , 1 , 2 , 3 , 3 , 5 , 6 },
297 { 0 , 1 , 1 , 1 , 1 , 1 ,IRC|STR|2},
298};
299
300
301
302
303
304
305static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
306 u8 id, unsigned int len, const void *data)
307{
308 int old_state, action;
309 struct ppp *ppp = get_ppp(dev);
310 struct proto *proto = get_proto(dev, pid);
311
312 old_state = proto->state;
313 BUG_ON(old_state >= STATES);
314 BUG_ON(event >= EVENTS);
315
316#if DEBUG_STATE
317 printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
318 proto_name(pid), event_names[event], state_names[proto->state]);
319#endif
320
321 action = cp_table[event][old_state];
322
323 proto->state = action & STATE_MASK;
324 if (action & (SCR | STR))
325 mod_timer(&proto->timer, proto->timeout =
326 jiffies + ppp->req_timeout * HZ);
327 if (action & ZRC)
328 proto->restart_counter = 0;
329 if (action & IRC)
330 proto->restart_counter = (proto->state == STOPPING) ?
331 ppp->term_retries : ppp->cr_retries;
332
333 if (action & SCR)
334 ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
335 0, NULL);
336 if (action & SCA)
337 ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
338 if (action & SCN)
339 ppp_tx_cp(dev, pid, code, id, len, data);
340 if (action & STR)
341 ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
342 if (action & STA)
343 ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
344 if (action & SCJ)
345 ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);
346
347 if (old_state != OPENED && proto->state == OPENED) {
348 printk(KERN_INFO "%s: %s up\n", dev->name, proto_name(pid));
349 if (pid == PID_LCP) {
350 netif_dormant_off(dev);
351 ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
352 ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
353 ppp->last_pong = jiffies;
354 mod_timer(&proto->timer, proto->timeout =
355 jiffies + ppp->keepalive_interval * HZ);
356 }
357 }
358 if (old_state == OPENED && proto->state != OPENED) {
359 printk(KERN_INFO "%s: %s down\n", dev->name, proto_name(pid));
360 if (pid == PID_LCP) {
361 netif_dormant_on(dev);
362 ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
363 ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
364 }
365 }
366 if (old_state != CLOSED && proto->state == CLOSED)
367 del_timer(&proto->timer);
368
369#if DEBUG_STATE
370 printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
371 proto_name(pid), event_names[event], state_names[proto->state]);
372#endif
373}
374
375
376static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
377 unsigned int req_len, const u8 *data)
378{
379 static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
380 const u8 *opt;
381 u8 *out;
382 unsigned int len = req_len, nak_len = 0, rej_len = 0;
383
384 if (!(out = kmalloc(len, GFP_ATOMIC))) {
385 dev->stats.rx_dropped++;
386 return;
387 }
388
389 for (opt = data; len; len -= opt[1], opt += opt[1]) {
390 if (len < 2 || len < opt[1]) {
391 dev->stats.rx_errors++;
392 kfree(out);
393 return;
394 }
395
396 if (pid == PID_LCP)
397 switch (opt[0]) {
398 case LCP_OPTION_MRU:
399 continue;
400
401 case LCP_OPTION_ACCM:
402 if (!memcmp(opt, valid_accm,
403 sizeof(valid_accm)))
404 continue;
405 if (!rej_len) {
406 memcpy(out + nak_len, valid_accm,
407 sizeof(valid_accm));
408 nak_len += sizeof(valid_accm);
409 continue;
410 }
411 break;
412 case LCP_OPTION_MAGIC:
413 if (opt[1] != 6 || (!opt[2] && !opt[3] &&
414 !opt[4] && !opt[5]))
415 break;
416 continue;
417 }
418
419 memcpy(out + rej_len, opt, opt[1]);
420 rej_len += opt[1];
421 }
422
423 if (rej_len)
424 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
425 else if (nak_len)
426 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
427 else
428 ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, req_len, data);
429
430 kfree(out);
431}
432
433static int ppp_rx(struct sk_buff *skb)
434{
435 struct hdlc_header *hdr = (struct hdlc_header*)skb->data;
436 struct net_device *dev = skb->dev;
437 struct ppp *ppp = get_ppp(dev);
438 struct proto *proto;
439 struct cp_header *cp;
440 unsigned long flags;
441 unsigned int len;
442 u16 pid;
443#if DEBUG_CP
444 int i;
445 char *ptr;
446#endif
447
448 spin_lock_irqsave(&ppp->lock, flags);
449
450 if (skb->len < sizeof(struct hdlc_header))
451 goto rx_error;
452 cp = (struct cp_header*)skb_pull(skb, sizeof(struct hdlc_header));
453 if (hdr->address != HDLC_ADDR_ALLSTATIONS ||
454 hdr->control != HDLC_CTRL_UI)
455 goto rx_error;
456
457 pid = ntohs(hdr->protocol);
458 proto = get_proto(dev, pid);
459 if (!proto) {
460 if (ppp->protos[IDX_LCP].state == OPENED)
461 ppp_tx_cp(dev, PID_LCP, LCP_PROTO_REJ,
462 ++ppp->seq, skb->len + 2, &hdr->protocol);
463 goto rx_error;
464 }
465
466 len = ntohs(cp->len);
467 if (len < sizeof(struct cp_header) ||
468 skb->len < len )
469 goto rx_error;
470 skb_pull(skb, sizeof(struct cp_header));
471 len -= sizeof(struct cp_header);
472
473
474#if DEBUG_CP
475 if (cp->code < CP_CODES)
476 sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],
477 cp->id);
478 else
479 sprintf(debug_buffer, "[code %u id 0x%X]", cp->code, cp->id);
480 ptr = debug_buffer + strlen(debug_buffer);
481 for (i = 0; i < min_t(unsigned int, len, DEBUG_CP); i++) {
482 sprintf(ptr, " %02X", skb->data[i]);
483 ptr += strlen(ptr);
484 }
485 printk(KERN_DEBUG "%s: RX %s %s\n", dev->name, proto_name(pid),
486 debug_buffer);
487#endif
488
489
490 if (pid == PID_LCP)
491 switch (cp->code) {
492 case LCP_PROTO_REJ:
493 pid = ntohs(*(__be16*)skb->data);
494 if (pid == PID_LCP || pid == PID_IPCP ||
495 pid == PID_IPV6CP)
496 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0,
497 0, NULL);
498 goto out;
499
500 case LCP_ECHO_REQ:
501 if (len >= 4 && proto->state == OPENED)
502 ppp_tx_cp(dev, PID_LCP, LCP_ECHO_REPLY,
503 cp->id, len - 4, skb->data + 4);
504 goto out;
505
506 case LCP_ECHO_REPLY:
507 if (cp->id == ppp->echo_id)
508 ppp->last_pong = jiffies;
509 goto out;
510
511 case LCP_DISC_REQ:
512 goto out;
513 }
514
515
516 switch (cp->code) {
517 case CP_CONF_REQ:
518 ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
519 goto out;
520
521 case CP_CONF_ACK:
522 if (cp->id == proto->cr_id)
523 ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
524 goto out;
525
526 case CP_CONF_REJ:
527 case CP_CONF_NAK:
528 if (cp->id == proto->cr_id)
529 ppp_cp_event(dev, pid, RCN, 0, 0, 0, NULL);
530 goto out;
531
532 case CP_TERM_REQ:
533 ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
534 goto out;
535
536 case CP_TERM_ACK:
537 ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
538 goto out;
539
540 case CP_CODE_REJ:
541 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
542 goto out;
543
544 default:
545 len += sizeof(struct cp_header);
546 if (len > dev->mtu)
547 len = dev->mtu;
548 ppp_cp_event(dev, pid, RUC, 0, 0, len, cp);
549 goto out;
550 }
551 goto out;
552
553rx_error:
554 dev->stats.rx_errors++;
555out:
556 spin_unlock_irqrestore(&ppp->lock, flags);
557 dev_kfree_skb_any(skb);
558 ppp_tx_flush();
559 return NET_RX_DROP;
560}
561
562static void ppp_timer(unsigned long arg)
563{
564 struct proto *proto = (struct proto *)arg;
565 struct ppp *ppp = get_ppp(proto->dev);
566 unsigned long flags;
567
568 spin_lock_irqsave(&ppp->lock, flags);
569 switch (proto->state) {
570 case STOPPING:
571 case REQ_SENT:
572 case ACK_RECV:
573 case ACK_SENT:
574 if (proto->restart_counter) {
575 ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
576 0, NULL);
577 proto->restart_counter--;
578 } else
579 ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
580 0, NULL);
581 break;
582
583 case OPENED:
584 if (proto->pid != PID_LCP)
585 break;
586 if (time_after(jiffies, ppp->last_pong +
587 ppp->keepalive_timeout * HZ)) {
588 printk(KERN_INFO "%s: Link down\n", proto->dev->name);
589 ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
590 ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
591 } else {
592 ppp->echo_id = ++ppp->seq;
593 ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
594 ppp->echo_id, 0, NULL);
595 proto->timer.expires = jiffies +
596 ppp->keepalive_interval * HZ;
597 add_timer(&proto->timer);
598 }
599 break;
600 }
601 spin_unlock_irqrestore(&ppp->lock, flags);
602 ppp_tx_flush();
603}
604
605
606static void ppp_start(struct net_device *dev)
607{
608 struct ppp *ppp = get_ppp(dev);
609 int i;
610
611 for (i = 0; i < IDX_COUNT; i++) {
612 struct proto *proto = &ppp->protos[i];
613 proto->dev = dev;
614 init_timer(&proto->timer);
615 proto->timer.function = ppp_timer;
616 proto->timer.data = (unsigned long)proto;
617 proto->state = CLOSED;
618 }
619 ppp->protos[IDX_LCP].pid = PID_LCP;
620 ppp->protos[IDX_IPCP].pid = PID_IPCP;
621 ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;
622
623 ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
624}
625
626static void ppp_stop(struct net_device *dev)
627{
628 ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
629}
630
631static void ppp_close(struct net_device *dev)
632{
633 ppp_tx_flush();
634}
635
636static struct hdlc_proto proto = {
637 .start = ppp_start,
638 .stop = ppp_stop,
639 .close = ppp_close,
640 .type_trans = ppp_type_trans,
641 .ioctl = ppp_ioctl,
642 .netif_rx = ppp_rx,
643 .module = THIS_MODULE,
644};
645
646static const struct header_ops ppp_header_ops = {
647 .create = ppp_hard_header,
648};
649
650static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
651{
652 hdlc_device *hdlc = dev_to_hdlc(dev);
653 struct ppp *ppp;
654 int result;
655
656 switch (ifr->ifr_settings.type) {
657 case IF_GET_PROTO:
658 if (dev_to_hdlc(dev)->proto != &proto)
659 return -EINVAL;
660 ifr->ifr_settings.type = IF_PROTO_PPP;
661 return 0;
662
663 case IF_PROTO_PPP:
664 if (!capable(CAP_NET_ADMIN))
665 return -EPERM;
666
667 if (dev->flags & IFF_UP)
668 return -EBUSY;
669
670
671
672 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
673 if (result)
674 return result;
675
676 result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
677 if (result)
678 return result;
679
680 ppp = get_ppp(dev);
681 spin_lock_init(&ppp->lock);
682 ppp->req_timeout = 2;
683 ppp->cr_retries = 10;
684 ppp->term_retries = 2;
685 ppp->keepalive_interval = 10;
686 ppp->keepalive_timeout = 60;
687
688 dev->hard_header_len = sizeof(struct hdlc_header);
689 dev->header_ops = &ppp_header_ops;
690 dev->type = ARPHRD_PPP;
691 netif_dormant_on(dev);
692 return 0;
693 }
694
695 return -EINVAL;
696}
697
698
699static int __init mod_init(void)
700{
701 skb_queue_head_init(&tx_queue);
702 register_hdlc_protocol(&proto);
703 return 0;
704}
705
706static void __exit mod_exit(void)
707{
708 unregister_hdlc_protocol(&proto);
709}
710
711
712module_init(mod_init);
713module_exit(mod_exit);
714
715MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
716MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
717MODULE_LICENSE("GPL v2");
718
