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