1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic HDLC support routines for Linux
4 * Point-to-point protocol support
5 *
6 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
7 */
8
9#include <linux/errno.h>
10#include <linux/hdlc.h>
11#include <linux/if_arp.h>
12#include <linux/inetdevice.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/pkt_sched.h>
17#include <linux/poll.h>
18#include <linux/skbuff.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22#define DEBUG_CP		0 /* also bytes# to dump */
23#define DEBUG_STATE		0
24#define DEBUG_HARD_HEADER	0
25
26#define HDLC_ADDR_ALLSTATIONS	0xFF
27#define HDLC_CTRL_UI		0x03
28
29#define PID_LCP			0xC021
30#define PID_IP			0x0021
31#define PID_IPCP		0x8021
32#define PID_IPV6		0x0057
33#define PID_IPV6CP		0x8057
34
35enum {IDX_LCP = 0, IDX_IPCP, IDX_IPV6CP, IDX_COUNT};
36enum {CP_CONF_REQ = 1, CP_CONF_ACK, CP_CONF_NAK, CP_CONF_REJ, CP_TERM_REQ,
37      CP_TERM_ACK, CP_CODE_REJ, LCP_PROTO_REJ, LCP_ECHO_REQ, LCP_ECHO_REPLY,
38      LCP_DISC_REQ, CP_CODES};
39#if DEBUG_CP
40static const char *const code_names[CP_CODES] = {
41	"0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",
42	"TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"
43};
44static char debug_buffer[64 + 3 * DEBUG_CP];
45#endif
46
47enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};
48
49struct hdlc_header {
50	u8 address;
51	u8 control;
52	__be16 protocol;
53};
54
55struct cp_header {
56	u8 code;
57	u8 id;
58	__be16 len;
59};
60
61
62struct proto {
63	struct net_device *dev;
64	struct timer_list timer;
65	unsigned long timeout;
66	u16 pid;		/* protocol ID */
67	u8 state;
68	u8 cr_id;		/* ID of last Configuration-Request */
69	u8 restart_counter;
70};
71
72struct ppp {
73	struct proto protos[IDX_COUNT];
74	spinlock_t lock;
75	unsigned long last_pong;
76	unsigned int req_timeout, cr_retries, term_retries;
77	unsigned int keepalive_interval, keepalive_timeout;
78	u8 seq;			/* local sequence number for requests */
79	u8 echo_id;		/* ID of last Echo-Request (LCP) */
80};
81
82enum {CLOSED = 0, STOPPED, STOPPING, REQ_SENT, ACK_RECV, ACK_SENT, OPENED,
83      STATES, STATE_MASK = 0xF};
84enum {START = 0, STOP, TO_GOOD, TO_BAD, RCR_GOOD, RCR_BAD, RCA, RCN, RTR, RTA,
85      RUC, RXJ_GOOD, RXJ_BAD, EVENTS};
86enum {INV = 0x10, IRC = 0x20, ZRC = 0x40, SCR = 0x80, SCA = 0x100,
87      SCN = 0x200, STR = 0x400, STA = 0x800, SCJ = 0x1000};
88
89#if DEBUG_STATE
90static const char *const state_names[STATES] = {
91	"Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",
92	"Opened"
93};
94static const char *const event_names[EVENTS] = {
95	"Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",
96	"RTR", "RTA", "RUC", "RXJ+", "RXJ-"
97};
98#endif
99
100static struct sk_buff_head tx_queue; /* used when holding the spin lock */
101
102static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
103
104static inline struct ppp* get_ppp(struct net_device *dev)
105{
106	return (struct ppp *)dev_to_hdlc(dev)->state;
107}
108
109static inline struct proto* get_proto(struct net_device *dev, u16 pid)
110{
111	struct ppp *ppp = get_ppp(dev);
112
113	switch (pid) {
114	case PID_LCP:
115		return &ppp->protos[IDX_LCP];
116	case PID_IPCP:
117		return &ppp->protos[IDX_IPCP];
118	case PID_IPV6CP:
119		return &ppp->protos[IDX_IPV6CP];
120	default:
121		return NULL;
122	}
123}
124
125static inline const char* proto_name(u16 pid)
126{
127	switch (pid) {
128	case PID_LCP:
129		return "LCP";
130	case PID_IPCP:
131		return "IPCP";
132	case PID_IPV6CP:
133		return "IPV6CP";
134	default:
135		return NULL;
136	}
137}
138
139static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
140{
141	struct hdlc_header *data = (struct hdlc_header*)skb->data;
142
143	if (skb->len < sizeof(struct hdlc_header))
144		return htons(ETH_P_HDLC);
145	if (data->address != HDLC_ADDR_ALLSTATIONS ||
146	    data->control != HDLC_CTRL_UI)
147		return htons(ETH_P_HDLC);
148
149	switch (data->protocol) {
150	case cpu_to_be16(PID_IP):
151		skb_pull(skb, sizeof(struct hdlc_header));
152		return htons(ETH_P_IP);
153
154	case cpu_to_be16(PID_IPV6):
155		skb_pull(skb, sizeof(struct hdlc_header));
156		return htons(ETH_P_IPV6);
157
158	default:
159		return htons(ETH_P_HDLC);
160	}
161}
162
163
164static int ppp_hard_header(struct sk_buff *skb, struct net_device *dev,
165			   u16 type, const void *daddr, const void *saddr,
166			   unsigned int len)
167{
168	struct hdlc_header *data;
169#if DEBUG_HARD_HEADER
170	printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);
171#endif
172
173	skb_push(skb, sizeof(struct hdlc_header));
174	data = (struct hdlc_header*)skb->data;
175
176	data->address = HDLC_ADDR_ALLSTATIONS;
177	data->control = HDLC_CTRL_UI;
178	switch (type) {
179	case ETH_P_IP:
180		data->protocol = htons(PID_IP);
181		break;
182	case ETH_P_IPV6:
183		data->protocol = htons(PID_IPV6);
184		break;
185	case PID_LCP:
186	case PID_IPCP:
187	case PID_IPV6CP:
188		data->protocol = htons(type);
189		break;
190	default:		/* unknown protocol */
191		data->protocol = 0;
192	}
193	return sizeof(struct hdlc_header);
194}
195
196
197static void ppp_tx_flush(void)
198{
199	struct sk_buff *skb;
200	while ((skb = skb_dequeue(&tx_queue)) != NULL)
201		dev_queue_xmit(skb);
202}
203
204static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
205		      u8 id, unsigned int len, const void *data)
206{
207	struct sk_buff *skb;
208	struct cp_header *cp;
209	unsigned int magic_len = 0;
210	static u32 magic;
211
212#if DEBUG_CP
213	int i;
214	char *ptr;
215#endif
216
217	if (pid == PID_LCP && (code == LCP_ECHO_REQ || code == LCP_ECHO_REPLY))
218		magic_len = sizeof(magic);
219
220	skb = dev_alloc_skb(sizeof(struct hdlc_header) +
221			    sizeof(struct cp_header) + magic_len + len);
222	if (!skb) {
223		netdev_warn(dev, "out of memory in ppp_tx_cp()\n");
224		return;
225	}
226	skb_reserve(skb, sizeof(struct hdlc_header));
227
228	cp = skb_put(skb, sizeof(struct cp_header));
229	cp->code = code;
230	cp->id = id;
231	cp->len = htons(sizeof(struct cp_header) + magic_len + len);
232
233	if (magic_len)
234		skb_put_data(skb, &magic, magic_len);
235	if (len)
236		skb_put_data(skb, data, len);
237
238#if DEBUG_CP
239	BUG_ON(code >= CP_CODES);
240	ptr = debug_buffer;
241	*ptr = '\x0';
242	for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
243		sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
244		ptr += strlen(ptr);
245	}
246	printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
247	       proto_name(pid), code_names[code], id, debug_buffer);
248#endif
249
250	ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
251
252	skb->priority = TC_PRIO_CONTROL;
253	skb->dev = dev;
254	skb->protocol = htons(ETH_P_HDLC);
255	skb_reset_network_header(skb);
256	skb_queue_tail(&tx_queue, skb);
257}
258
259
260/* State transition table (compare STD-51)
261   Events                                   Actions
262   TO+  = Timeout with counter > 0          irc = Initialize-Restart-Count
263   TO-  = Timeout with counter expired      zrc = Zero-Restart-Count
264
265   RCR+ = Receive-Configure-Request (Good)  scr = Send-Configure-Request
266   RCR- = Receive-Configure-Request (Bad)
267   RCA  = Receive-Configure-Ack             sca = Send-Configure-Ack
268   RCN  = Receive-Configure-Nak/Rej         scn = Send-Configure-Nak/Rej
269
270   RTR  = Receive-Terminate-Request         str = Send-Terminate-Request
271   RTA  = Receive-Terminate-Ack             sta = Send-Terminate-Ack
272
273   RUC  = Receive-Unknown-Code              scj = Send-Code-Reject
274   RXJ+ = Receive-Code-Reject (permitted)
275       or Receive-Protocol-Reject
276   RXJ- = Receive-Code-Reject (catastrophic)
277       or Receive-Protocol-Reject
278*/
279static int cp_table[EVENTS][STATES] = {
280	/* CLOSED     STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
281	     0           1         2       3       4      5          6    */
282	{IRC|SCR|3,     INV     , INV ,   INV   , INV ,  INV    ,   INV   }, /* START */
283	{   INV   ,      0      ,  0  ,    0    ,  0  ,   0     ,    0    }, /* STOP */
284	{   INV   ,     INV     ,STR|2,  SCR|3  ,SCR|3,  SCR|5  ,   INV   }, /* TO+ */
285	{   INV   ,     INV     ,  1  ,    1    ,  1  ,    1    ,   INV   }, /* TO- */
286	{  STA|0  ,IRC|SCR|SCA|5,  2  ,  SCA|5  ,SCA|6,  SCA|5  ,SCR|SCA|5}, /* RCR+ */
287	{  STA|0  ,IRC|SCR|SCN|3,  2  ,  SCN|3  ,SCN|4,  SCN|3  ,SCR|SCN|3}, /* RCR- */
288	{  STA|0  ,    STA|1    ,  2  ,  IRC|4  ,SCR|3,    6    , SCR|3   }, /* RCA */
289	{  STA|0  ,    STA|1    ,  2  ,IRC|SCR|3,SCR|3,IRC|SCR|5, SCR|3   }, /* RCN */
290	{  STA|0  ,    STA|1    ,STA|2,  STA|3  ,STA|3,  STA|3  ,ZRC|STA|2}, /* RTR */
291	{    0    ,      1      ,  1  ,    3    ,  3  ,    5    ,  SCR|3  }, /* RTA */
292	{  SCJ|0  ,    SCJ|1    ,SCJ|2,  SCJ|3  ,SCJ|4,  SCJ|5  ,  SCJ|6  }, /* RUC */
293	{    0    ,      1      ,  2  ,    3    ,  3  ,    5    ,    6    }, /* RXJ+ */
294	{    0    ,      1      ,  1  ,    1    ,  1  ,    1    ,IRC|STR|2}, /* RXJ- */
295};
296
297
298/* SCA: RCR+ must supply id, len and data
299   SCN: RCR- must supply code, id, len and data
300   STA: RTR must supply id
301   SCJ: RUC must supply CP packet len and data */
302static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
303			 u8 id, unsigned int len, const void *data)
304{
305	int old_state, action;
306	struct ppp *ppp = get_ppp(dev);
307	struct proto *proto = get_proto(dev, pid);
308
309	old_state = proto->state;
310	BUG_ON(old_state >= STATES);
311	BUG_ON(event >= EVENTS);
312
313#if DEBUG_STATE
314	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
315	       proto_name(pid), event_names[event], state_names[proto->state]);
316#endif
317
318	action = cp_table[event][old_state];
319
320	proto->state = action & STATE_MASK;
321	if (action & (SCR | STR)) /* set Configure-Req/Terminate-Req timer */
322		mod_timer(&proto->timer, proto->timeout =
323			  jiffies + ppp->req_timeout * HZ);
324	if (action & ZRC)
325		proto->restart_counter = 0;
326	if (action & IRC)
327		proto->restart_counter = (proto->state == STOPPING) ?
328			ppp->term_retries : ppp->cr_retries;
329
330	if (action & SCR)	/* send Configure-Request */
331		ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
332			  0, NULL);
333	if (action & SCA)	/* send Configure-Ack */
334		ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
335	if (action & SCN)	/* send Configure-Nak/Reject */
336		ppp_tx_cp(dev, pid, code, id, len, data);
337	if (action & STR)	/* send Terminate-Request */
338		ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
339	if (action & STA)	/* send Terminate-Ack */
340		ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
341	if (action & SCJ)	/* send Code-Reject */
342		ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);
343
344	if (old_state != OPENED && proto->state == OPENED) {
345		netdev_info(dev, "%s up\n", proto_name(pid));
346		if (pid == PID_LCP) {
347			netif_dormant_off(dev);
348			ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
349			ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
350			ppp->last_pong = jiffies;
351			mod_timer(&proto->timer, proto->timeout =
352				  jiffies + ppp->keepalive_interval * HZ);
353		}
354	}
355	if (old_state == OPENED && proto->state != OPENED) {
356		netdev_info(dev, "%s down\n", proto_name(pid));
357		if (pid == PID_LCP) {
358			netif_dormant_on(dev);
359			ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
360			ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
361		}
362	}
363	if (old_state != CLOSED && proto->state == CLOSED)
364		del_timer(&proto->timer);
365
366#if DEBUG_STATE
367	printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
368	       proto_name(pid), event_names[event], state_names[proto->state]);
369#endif
370}
371
372
373static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
374			    unsigned int req_len, const u8 *data)
375{
376	static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
377	const u8 *opt;
378	u8 *out;
379	unsigned int len = req_len, nak_len = 0, rej_len = 0;
380
381	if (!(out = kmalloc(len, GFP_ATOMIC))) {
382		dev->stats.rx_dropped++;
383		return;	/* out of memory, ignore CR packet */
384	}
385
386	for (opt = data; len; len -= opt[1], opt += opt[1]) {
387		if (len < 2 || opt[1] < 2 || len < opt[1])
388			goto err_out;
389
390		if (pid == PID_LCP)
391			switch (opt[0]) {
392			case LCP_OPTION_MRU:
393				continue; /* MRU always OK and > 1500 bytes? */
394
395			case LCP_OPTION_ACCM: /* async control character map */
396				if (opt[1] < sizeof(valid_accm))
397					goto err_out;
398				if (!memcmp(opt, valid_accm,
399					    sizeof(valid_accm)))
400					continue;
401				if (!rej_len) { /* NAK it */
402					memcpy(out + nak_len, valid_accm,
403					       sizeof(valid_accm));
404					nak_len += sizeof(valid_accm);
405					continue;
406				}
407				break;
408			case LCP_OPTION_MAGIC:
409				if (len < 6)
410					goto err_out;
411				if (opt[1] != 6 || (!opt[2] && !opt[3] &&
412						    !opt[4] && !opt[5]))
413					break; /* reject invalid magic number */
414				continue;
415			}
416		/* reject this option */
417		memcpy(out + rej_len, opt, opt[1]);
418		rej_len += opt[1];
419	}
420
421	if (rej_len)
422		ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
423	else if (nak_len)
424		ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
425	else
426		ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, req_len, data);
427
428	kfree(out);
429	return;
430
431err_out:
432	dev->stats.rx_errors++;
433	kfree(out);
434}
435
436static int ppp_rx(struct sk_buff *skb)
437{
438	struct hdlc_header *hdr = (struct hdlc_header*)skb->data;
439	struct net_device *dev = skb->dev;
440	struct ppp *ppp = get_ppp(dev);
441	struct proto *proto;
442	struct cp_header *cp;
443	unsigned long flags;
444	unsigned int len;
445	u16 pid;
446#if DEBUG_CP
447	int i;
448	char *ptr;
449#endif
450
451	spin_lock_irqsave(&ppp->lock, flags);
452	/* Check HDLC header */
453	if (skb->len < sizeof(struct hdlc_header))
454		goto rx_error;
455	cp = skb_pull(skb, sizeof(struct hdlc_header));
456	if (hdr->address != HDLC_ADDR_ALLSTATIONS ||
457	    hdr->control != HDLC_CTRL_UI)
458		goto rx_error;
459
460	pid = ntohs(hdr->protocol);
461	proto = get_proto(dev, pid);
462	if (!proto) {
463		if (ppp->protos[IDX_LCP].state == OPENED)
464			ppp_tx_cp(dev, PID_LCP, LCP_PROTO_REJ,
465				  ++ppp->seq, skb->len + 2, &hdr->protocol);
466		goto rx_error;
467	}
468
469	len = ntohs(cp->len);
470	if (len < sizeof(struct cp_header) /* no complete CP header? */ ||
471	    skb->len < len /* truncated packet? */)
472		goto rx_error;
473	skb_pull(skb, sizeof(struct cp_header));
474	len -= sizeof(struct cp_header);
475
476	/* HDLC and CP headers stripped from skb */
477#if DEBUG_CP
478	if (cp->code < CP_CODES)
479		sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],
480			cp->id);
481	else
482		sprintf(debug_buffer, "[code %u id 0x%X]", cp->code, cp->id);
483	ptr = debug_buffer + strlen(debug_buffer);
484	for (i = 0; i < min_t(unsigned int, len, DEBUG_CP); i++) {
485		sprintf(ptr, " %02X", skb->data[i]);
486		ptr += strlen(ptr);
487	}
488	printk(KERN_DEBUG "%s: RX %s %s\n", dev->name, proto_name(pid),
489	       debug_buffer);
490#endif
491
492	/* LCP only */
493	if (pid == PID_LCP)
494		switch (cp->code) {
495		case LCP_PROTO_REJ:
496			pid = ntohs(*(__be16*)skb->data);
497			if (pid == PID_LCP || pid == PID_IPCP ||
498			    pid == PID_IPV6CP)
499				ppp_cp_event(dev, pid, RXJ_BAD, 0, 0,
500					     0, NULL);
501			goto out;
502
503		case LCP_ECHO_REQ: /* send Echo-Reply */
504			if (len >= 4 && proto->state == OPENED)
505				ppp_tx_cp(dev, PID_LCP, LCP_ECHO_REPLY,
506					  cp->id, len - 4, skb->data + 4);
507			goto out;
508
509		case LCP_ECHO_REPLY:
510			if (cp->id == ppp->echo_id)
511				ppp->last_pong = jiffies;
512			goto out;
513
514		case LCP_DISC_REQ: /* discard */
515			goto out;
516		}
517
518	/* LCP, IPCP and IPV6CP */
519	switch (cp->code) {
520	case CP_CONF_REQ:
521		ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
522		break;
523
524	case CP_CONF_ACK:
525		if (cp->id == proto->cr_id)
526			ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
527		break;
528
529	case CP_CONF_REJ:
530	case CP_CONF_NAK:
531		if (cp->id == proto->cr_id)
532			ppp_cp_event(dev, pid, RCN, 0, 0, 0, NULL);
533		break;
534
535	case CP_TERM_REQ:
536		ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
537		break;
538
539	case CP_TERM_ACK:
540		ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
541		break;
542
543	case CP_CODE_REJ:
544		ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
545		break;
546
547	default:
548		len += sizeof(struct cp_header);
549		if (len > dev->mtu)
550			len = dev->mtu;
551		ppp_cp_event(dev, pid, RUC, 0, 0, len, cp);
552		break;
553	}
554	goto out;
555
556rx_error:
557	dev->stats.rx_errors++;
558out:
559	spin_unlock_irqrestore(&ppp->lock, flags);
560	dev_kfree_skb_any(skb);
561	ppp_tx_flush();
562	return NET_RX_DROP;
563}
564
565static void ppp_timer(struct timer_list *t)
566{
567	struct proto *proto = from_timer(proto, t, timer);
568	struct ppp *ppp = get_ppp(proto->dev);
569	unsigned long flags;
570
571	spin_lock_irqsave(&ppp->lock, flags);
572	/* mod_timer could be called after we entered this function but
573	 * before we got the lock.
574	 */
575	if (timer_pending(&proto->timer)) {
576		spin_unlock_irqrestore(&ppp->lock, flags);
577		return;
578	}
579	switch (proto->state) {
580	case STOPPING:
581	case REQ_SENT:
582	case ACK_RECV:
583	case ACK_SENT:
584		if (proto->restart_counter) {
585			ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
586				     0, NULL);
587			proto->restart_counter--;
588		} else if (netif_carrier_ok(proto->dev))
589			ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
590				     0, NULL);
591		else
592			ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
593				     0, NULL);
594		break;
595
596	case OPENED:
597		if (proto->pid != PID_LCP)
598			break;
599		if (time_after(jiffies, ppp->last_pong +
600			       ppp->keepalive_timeout * HZ)) {
601			netdev_info(proto->dev, "Link down\n");
602			ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
603			ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
604		} else {	/* send keep-alive packet */
605			ppp->echo_id = ++ppp->seq;
606			ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
607				  ppp->echo_id, 0, NULL);
608			proto->timer.expires = jiffies +
609				ppp->keepalive_interval * HZ;
610			add_timer(&proto->timer);
611		}
612		break;
613	}
614	spin_unlock_irqrestore(&ppp->lock, flags);
615	ppp_tx_flush();
616}
617
618
619static void ppp_start(struct net_device *dev)
620{
621	struct ppp *ppp = get_ppp(dev);
622	int i;
623
624	for (i = 0; i < IDX_COUNT; i++) {
625		struct proto *proto = &ppp->protos[i];
626		proto->dev = dev;
627		timer_setup(&proto->timer, ppp_timer, 0);
628		proto->state = CLOSED;
629	}
630	ppp->protos[IDX_LCP].pid = PID_LCP;
631	ppp->protos[IDX_IPCP].pid = PID_IPCP;
632	ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;
633
634	ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
635}
636
637static void ppp_stop(struct net_device *dev)
638{
639	ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
640}
641
642static void ppp_close(struct net_device *dev)
643{
644	ppp_tx_flush();
645}
646
647static struct hdlc_proto proto = {
648	.start		= ppp_start,
649	.stop		= ppp_stop,
650	.close		= ppp_close,
651	.type_trans	= ppp_type_trans,
652	.ioctl		= ppp_ioctl,
653	.netif_rx	= ppp_rx,
654	.module		= THIS_MODULE,
655};
656
657static const struct header_ops ppp_header_ops = {
658	.create = ppp_hard_header,
659};
660
661static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr)
662{
663	hdlc_device *hdlc = dev_to_hdlc(dev);
664	struct ppp *ppp;
665	int result;
666
667	switch (ifr->ifr_settings.type) {
668	case IF_GET_PROTO:
669		if (dev_to_hdlc(dev)->proto != &proto)
670			return -EINVAL;
671		ifr->ifr_settings.type = IF_PROTO_PPP;
672		return 0; /* return protocol only, no settable parameters */
673
674	case IF_PROTO_PPP:
675		if (!capable(CAP_NET_ADMIN))
676			return -EPERM;
677
678		if (dev->flags & IFF_UP)
679			return -EBUSY;
680
681		/* no settable parameters */
682
683		result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
684		if (result)
685			return result;
686
687		result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
688		if (result)
689			return result;
690
691		ppp = get_ppp(dev);
692		spin_lock_init(&ppp->lock);
693		ppp->req_timeout = 2;
694		ppp->cr_retries = 10;
695		ppp->term_retries = 2;
696		ppp->keepalive_interval = 10;
697		ppp->keepalive_timeout = 60;
698
699		dev->hard_header_len = sizeof(struct hdlc_header);
700		dev->header_ops = &ppp_header_ops;
701		dev->type = ARPHRD_PPP;
702		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
703		netif_dormant_on(dev);
704		return 0;
705	}
706
707	return -EINVAL;
708}
709
710
711static int __init mod_init(void)
712{
713	skb_queue_head_init(&tx_queue);
714	register_hdlc_protocol(&proto);
715	return 0;
716}
717
718static void __exit mod_exit(void)
719{
720	unregister_hdlc_protocol(&proto);
721}
722
723
724module_init(mod_init);
725module_exit(mod_exit);
726
727MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
728MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
729MODULE_LICENSE("GPL v2");
730