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wifi: iwlwifi: mei: re-ask for ownership after it was taken by CSME
[linux-block.git] / drivers / net / wan / hdlc_ppp.c
CommitLineData
25763b3c 1// SPDX-License-Identifier: GPL-2.0-only
1da177e4
LT		 2/*
3 * Generic HDLC support routines for Linux
4 * Point-to-point protocol support
5 *
e022c2f0 6 * Copyright (C) 1999 - 2008 Krzysztof Halasa <khc@pm.waw.pl>
1da177e4
LT		 7 */
8
1da177e4 9#include <linux/errno.h>
4dfce407 10#include <linux/hdlc.h>
1da177e4 11#include <linux/if_arp.h>
4dfce407 12#include <linux/inetdevice.h>
1da177e4 13#include <linux/init.h>
4dfce407
KH		 14#include <linux/kernel.h>
15#include <linux/module.h>
1da177e4 16#include <linux/pkt_sched.h>
4dfce407 17#include <linux/poll.h>
4dfce407
KH		 18#include <linux/skbuff.h>
19#include <linux/slab.h>
e022c2f0
KH		 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};
2b57681f 44
e022c2f0
KH		 45static char debug_buffer[64 + 3 * DEBUG_CP];
46#endif
47
48enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5};
49
50struct hdlc_header {
51 u8 address;
52 u8 control;
53 __be16 protocol;
54};
55
56struct cp_header {
57 u8 code;
58 u8 id;
59 __be16 len;
60};
61
e022c2f0
KH		 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;
eb2a2fd9
KH		 70};
71
e022c2f0
KH		 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};
2b57681f 94
e022c2f0
KH		 95static 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
101static struct sk_buff_head tx_queue; /* used when holding the spin lock */
102
ad7eab2a 103static int ppp_ioctl(struct net_device *dev, struct if_settings *ifs);
eb2a2fd9 104
cb36c411 105static inline struct ppp *get_ppp(struct net_device *dev)
e022c2f0
KH		 106{
107 return (struct ppp *)dev_to_hdlc(dev)->state;
108}
eb2a2fd9 109
cb36c411 110static inline struct proto *get_proto(struct net_device *dev, u16 pid)
eb2a2fd9 111{
e022c2f0
KH		 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 }
eb2a2fd9 124}
1da177e4 125
cb36c411 126static inline const char *proto_name(u16 pid)
e022c2f0
KH		 127{
128 switch (pid) {
129 case PID_LCP:
130 return "LCP";
131 case PID_IPCP:
132 return "IPCP";
133 case PID_IPV6CP:
134 return "IPV6CP";
135 default:
136 return NULL;
137 }
138}
1da177e4 139
e022c2f0 140static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)
1da177e4 141{
cb36c411 142 struct hdlc_header *data = (struct hdlc_header *)skb->data;
e022c2f0
KH		 143
144 if (skb->len < sizeof(struct hdlc_header))
145 return htons(ETH_P_HDLC);
146 if (data->address != HDLC_ADDR_ALLSTATIONS ||
147 data->control != HDLC_CTRL_UI)
148 return htons(ETH_P_HDLC);
149
150 switch (data->protocol) {
09640e63 151 case cpu_to_be16(PID_IP):
e022c2f0
KH		 152 skb_pull(skb, sizeof(struct hdlc_header));
153 return htons(ETH_P_IP);
1da177e4 154
09640e63 155 case cpu_to_be16(PID_IPV6):
e022c2f0
KH		 156 skb_pull(skb, sizeof(struct hdlc_header));
157 return htons(ETH_P_IPV6);
1da177e4 158
e022c2f0
KH		 159 default:
160 return htons(ETH_P_HDLC);
1da177e4 161 }
e022c2f0 162}
1da177e4 163
e022c2f0
KH		 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));
cb36c411 174 data = (struct hdlc_header *)skb->data;
e022c2f0
KH		 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);
1da177e4
LT		 194}
195
e022c2f0
KH		 196static void ppp_tx_flush(void)
197{
198 struct sk_buff *skb;
2b57681f 199
e022c2f0
KH		 200 while ((skb = skb_dequeue(&tx_queue)) != NULL)
201 dev_queue_xmit(skb);
202}
1da177e4 203
e022c2f0
KH		 204static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
205 u8 id, unsigned int len, const void *data)
1da177e4 206{
e022c2f0
KH		 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);
ee58a3c7 222 if (!skb)
e022c2f0 223 return;
ee58a3c7 224
e022c2f0
KH		 225 skb_reserve(skb, sizeof(struct hdlc_header));
226
4df864c1 227 cp = skb_put(skb, sizeof(struct cp_header));
e022c2f0
KH		 228 cp->code = code;
229 cp->id = id;
230 cp->len = htons(sizeof(struct cp_header) + magic_len + len);
231
232 if (magic_len)
59ae1d12 233 skb_put_data(skb, &magic, magic_len);
e022c2f0 234 if (len)
59ae1d12 235 skb_put_data(skb, data, len);
e022c2f0
KH		 236
237#if DEBUG_CP
238 BUG_ON(code >= CP_CODES);
239 ptr = debug_buffer;
240 *ptr = '\x0';
241 for (i = 0; i < min_t(unsigned int, magic_len + len, DEBUG_CP); i++) {
242 sprintf(ptr, " %02X", skb->data[sizeof(struct cp_header) + i]);
243 ptr += strlen(ptr);
244 }
245 printk(KERN_DEBUG "%s: TX %s [%s id 0x%X]%s\n", dev->name,
246 proto_name(pid), code_names[code], id, debug_buffer);
247#endif
1da177e4 248
e022c2f0 249 ppp_hard_header(skb, dev, pid, NULL, NULL, 0);
3b04ddde 250
e022c2f0
KH		 251 skb->priority = TC_PRIO_CONTROL;
252 skb->dev = dev;
9fb030a7 253 skb->protocol = htons(ETH_P_HDLC);
e022c2f0
KH		 254 skb_reset_network_header(skb);
255 skb_queue_tail(&tx_queue, skb);
1da177e4
LT		 256}
257
e022c2f0
KH		 258/* State transition table (compare STD-51)
259 Events Actions
260 TO+ = Timeout with counter > 0 irc = Initialize-Restart-Count
261 TO- = Timeout with counter expired zrc = Zero-Restart-Count
262
263 RCR+ = Receive-Configure-Request (Good) scr = Send-Configure-Request
264 RCR- = Receive-Configure-Request (Bad)
265 RCA = Receive-Configure-Ack sca = Send-Configure-Ack
266 RCN = Receive-Configure-Nak/Rej scn = Send-Configure-Nak/Rej
267
268 RTR = Receive-Terminate-Request str = Send-Terminate-Request
269 RTA = Receive-Terminate-Ack sta = Send-Terminate-Ack
270
271 RUC = Receive-Unknown-Code scj = Send-Code-Reject
272 RXJ+ = Receive-Code-Reject (permitted)
273 or Receive-Protocol-Reject
274 RXJ- = Receive-Code-Reject (catastrophic)
275 or Receive-Protocol-Reject
276*/
277static int cp_table[EVENTS][STATES] = {
278 /* CLOSED STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED
279 0 1 2 3 4 5 6 */
280 {IRC|SCR|3, INV , INV , INV , INV , INV , INV }, /* START */
281 { INV , 0 , 0 , 0 , 0 , 0 , 0 }, /* STOP */
282 { INV , INV ,STR|2, SCR|3 ,SCR|3, SCR|5 , INV }, /* TO+ */
283 { INV , INV , 1 , 1 , 1 , 1 , INV }, /* TO- */
284 { STA|0 ,IRC|SCR|SCA|5, 2 , SCA|5 ,SCA|6, SCA|5 ,SCR|SCA|5}, /* RCR+ */
285 { STA|0 ,IRC|SCR|SCN|3, 2 , SCN|3 ,SCN|4, SCN|3 ,SCR|SCN|3}, /* RCR- */
286 { STA|0 , STA|1 , 2 , IRC|4 ,SCR|3, 6 , SCR|3 }, /* RCA */
287 { STA|0 , STA|1 , 2 ,IRC|SCR|3,SCR|3,IRC|SCR|5, SCR|3 }, /* RCN */
288 { STA|0 , STA|1 ,STA|2, STA|3 ,STA|3, STA|3 ,ZRC|STA|2}, /* RTR */
289 { 0 , 1 , 1 , 3 , 3 , 5 , SCR|3 }, /* RTA */
290 { SCJ|0 , SCJ|1 ,SCJ|2, SCJ|3 ,SCJ|4, SCJ|5 , SCJ|6 }, /* RUC */
291 { 0 , 1 , 2 , 3 , 3 , 5 , 6 }, /* RXJ+ */
292 { 0 , 1 , 1 , 1 , 1 , 1 ,IRC|STR|2}, /* RXJ- */
293};
294
e022c2f0
KH		 295/* SCA: RCR+ must supply id, len and data
296 SCN: RCR- must supply code, id, len and data
297 STA: RTR must supply id
298 SCJ: RUC must supply CP packet len and data */
299static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,
93bc9335 300 u8 id, unsigned int len, const void *data)
1da177e4 301{
e022c2f0
KH		 302 int old_state, action;
303 struct ppp *ppp = get_ppp(dev);
304 struct proto *proto = get_proto(dev, pid);
305
306 old_state = proto->state;
307 BUG_ON(old_state >= STATES);
308 BUG_ON(event >= EVENTS);
309
310#if DEBUG_STATE
311 printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) %s ...\n", dev->name,
312 proto_name(pid), event_names[event], state_names[proto->state]);
313#endif
314
315 action = cp_table[event][old_state];
316
317 proto->state = action & STATE_MASK;
318 if (action & (SCR | STR)) /* set Configure-Req/Terminate-Req timer */
319 mod_timer(&proto->timer, proto->timeout =
320 jiffies + ppp->req_timeout * HZ);
321 if (action & ZRC)
322 proto->restart_counter = 0;
323 if (action & IRC)
324 proto->restart_counter = (proto->state == STOPPING) ?
325 ppp->term_retries : ppp->cr_retries;
326
327 if (action & SCR) /* send Configure-Request */
328 ppp_tx_cp(dev, pid, CP_CONF_REQ, proto->cr_id = ++ppp->seq,
329 0, NULL);
330 if (action & SCA) /* send Configure-Ack */
331 ppp_tx_cp(dev, pid, CP_CONF_ACK, id, len, data);
332 if (action & SCN) /* send Configure-Nak/Reject */
333 ppp_tx_cp(dev, pid, code, id, len, data);
334 if (action & STR) /* send Terminate-Request */
335 ppp_tx_cp(dev, pid, CP_TERM_REQ, ++ppp->seq, 0, NULL);
336 if (action & STA) /* send Terminate-Ack */
337 ppp_tx_cp(dev, pid, CP_TERM_ACK, id, 0, NULL);
338 if (action & SCJ) /* send Code-Reject */
339 ppp_tx_cp(dev, pid, CP_CODE_REJ, ++ppp->seq, len, data);
340
341 if (old_state != OPENED && proto->state == OPENED) {
12a3bfef 342 netdev_info(dev, "%s up\n", proto_name(pid));
e022c2f0
KH		 343 if (pid == PID_LCP) {
344 netif_dormant_off(dev);
345 ppp_cp_event(dev, PID_IPCP, START, 0, 0, 0, NULL);
346 ppp_cp_event(dev, PID_IPV6CP, START, 0, 0, 0, NULL);
347 ppp->last_pong = jiffies;
348 mod_timer(&proto->timer, proto->timeout =
349 jiffies + ppp->keepalive_interval * HZ);
350 }
351 }
352 if (old_state == OPENED && proto->state != OPENED) {
12a3bfef 353 netdev_info(dev, "%s down\n", proto_name(pid));
e022c2f0
KH		 354 if (pid == PID_LCP) {
355 netif_dormant_on(dev);
356 ppp_cp_event(dev, PID_IPCP, STOP, 0, 0, 0, NULL);
357 ppp_cp_event(dev, PID_IPV6CP, STOP, 0, 0, 0, NULL);
358 }
359 }
360 if (old_state != CLOSED && proto->state == CLOSED)
361 del_timer(&proto->timer);
362
363#if DEBUG_STATE
364 printk(KERN_DEBUG "%s: %s ppp_cp_event(%s) ... %s\n", dev->name,
365 proto_name(pid), event_names[event], state_names[proto->state]);
366#endif
1da177e4
LT		 367}
368
e022c2f0 369static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,
93bc9335 370 unsigned int req_len, const u8 *data)
e022c2f0
KH		 371{
372 static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };
93bc9335
KH		 373 const u8 *opt;
374 u8 *out;
375 unsigned int len = req_len, nak_len = 0, rej_len = 0;
e022c2f0 376
4ec47952
PL		 377 out = kmalloc(len, GFP_ATOMIC);
378 if (!out) {
e022c2f0
KH		 379 dev->stats.rx_dropped++;
380 return; /* out of memory, ignore CR packet */
381 }
382
383 for (opt = data; len; len -= opt[1], opt += opt[1]) {
66d42ed8
DC		 384 if (len < 2 || opt[1] < 2 || len < opt[1])
385 goto err_out;
e022c2f0
KH		 386
387 if (pid == PID_LCP)
388 switch (opt[0]) {
389 case LCP_OPTION_MRU:
390 continue; /* MRU always OK and > 1500 bytes? */
391
392 case LCP_OPTION_ACCM: /* async control character map */
66d42ed8
DC		 393 if (opt[1] < sizeof(valid_accm))
394 goto err_out;
e022c2f0
KH		 395 if (!memcmp(opt, valid_accm,
396 sizeof(valid_accm)))
397 continue;
398 if (!rej_len) { /* NAK it */
399 memcpy(out + nak_len, valid_accm,
400 sizeof(valid_accm));
401 nak_len += sizeof(valid_accm);
402 continue;
403 }
404 break;
405 case LCP_OPTION_MAGIC:
66d42ed8
DC		 406 if (len < 6)
407 goto err_out;
e022c2f0
KH		 408 if (opt[1] != 6 || (!opt[2] && !opt[3] &&
409 !opt[4] && !opt[5]))
410 break; /* reject invalid magic number */
411 continue;
412 }
413 /* reject this option */
414 memcpy(out + rej_len, opt, opt[1]);
415 rej_len += opt[1];
416 }
417
418 if (rej_len)
419 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_REJ, id, rej_len, out);
420 else if (nak_len)
421 ppp_cp_event(dev, pid, RCR_BAD, CP_CONF_NAK, id, nak_len, out);
422 else
93bc9335 423 ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, req_len, data);
e022c2f0
KH		 424
425 kfree(out);
66d42ed8
DC		 426 return;
427
428err_out:
429 dev->stats.rx_errors++;
430 kfree(out);
e022c2f0
KH		 431}
432
433static int ppp_rx(struct sk_buff *skb)
434{
cb36c411 435 struct hdlc_header *hdr = (struct hdlc_header *)skb->data;
e022c2f0
KH		 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 /* Check HDLC header */
450 if (skb->len < sizeof(struct hdlc_header))
451 goto rx_error;
af72868b 452 cp = skb_pull(skb, sizeof(struct hdlc_header));
e022c2f0
KH		 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) /* no complete CP header? */ ||
468 skb->len < len /* truncated packet? */)
469 goto rx_error;
470 skb_pull(skb, sizeof(struct cp_header));
471 len -= sizeof(struct cp_header);
472
473 /* HDLC and CP headers stripped from skb */
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 /* LCP only */
490 if (pid == PID_LCP)
491 switch (cp->code) {
492 case LCP_PROTO_REJ:
cb36c411 493 pid = ntohs(*(__be16 *)skb->data);
e022c2f0
KH		 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: /* send Echo-Reply */
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: /* discard */
512 goto out;
513 }
514
515 /* LCP, IPCP and IPV6CP */
516 switch (cp->code) {
517 case CP_CONF_REQ:
518 ppp_cp_parse_cr(dev, pid, cp->id, len, skb->data);
c8d755b5 519 break;
e022c2f0
KH		 520
521 case CP_CONF_ACK:
522 if (cp->id == proto->cr_id)
523 ppp_cp_event(dev, pid, RCA, 0, 0, 0, NULL);
c8d755b5 524 break;
e022c2f0
KH		 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);
c8d755b5 530 break;
e022c2f0
KH		 531
532 case CP_TERM_REQ:
533 ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);
c8d755b5 534 break;
e022c2f0
KH		 535
536 case CP_TERM_ACK:
537 ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);
c8d755b5 538 break;
e022c2f0
KH		 539
540 case CP_CODE_REJ:
541 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);
c8d755b5 542 break;
e022c2f0
KH		 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);
c8d755b5 549 break;
e022c2f0
KH		 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
e99e88a9 562static void ppp_timer(struct timer_list *t)
e022c2f0 563{
e99e88a9 564 struct proto *proto = from_timer(proto, t, timer);
e022c2f0
KH		 565 struct ppp *ppp = get_ppp(proto->dev);
566 unsigned long flags;
567
568 spin_lock_irqsave(&ppp->lock, flags);
1fef7359
XH		 569 /* mod_timer could be called after we entered this function but
570 * before we got the lock.
571 */
572 if (timer_pending(&proto->timer)) {
573 spin_unlock_irqrestore(&ppp->lock, flags);
574 return;
575 }
e022c2f0
KH		 576 switch (proto->state) {
577 case STOPPING:
578 case REQ_SENT:
579 case ACK_RECV:
580 case ACK_SENT:
581 if (proto->restart_counter) {
582 ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
583 0, NULL);
584 proto->restart_counter--;
b6c3bad1
DD		 585 } else if (netif_carrier_ok(proto->dev))
586 ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,
587 0, NULL);
588 else
e022c2f0
KH		 589 ppp_cp_event(proto->dev, proto->pid, TO_BAD, 0, 0,
590 0, NULL);
591 break;
592
593 case OPENED:
594 if (proto->pid != PID_LCP)
595 break;
596 if (time_after(jiffies, ppp->last_pong +
597 ppp->keepalive_timeout * HZ)) {
12a3bfef 598 netdev_info(proto->dev, "Link down\n");
e022c2f0
KH		 599 ppp_cp_event(proto->dev, PID_LCP, STOP, 0, 0, 0, NULL);
600 ppp_cp_event(proto->dev, PID_LCP, START, 0, 0, 0, NULL);
601 } else { /* send keep-alive packet */
602 ppp->echo_id = ++ppp->seq;
603 ppp_tx_cp(proto->dev, PID_LCP, LCP_ECHO_REQ,
604 ppp->echo_id, 0, NULL);
605 proto->timer.expires = jiffies +
606 ppp->keepalive_interval * HZ;
607 add_timer(&proto->timer);
608 }
609 break;
610 }
611 spin_unlock_irqrestore(&ppp->lock, flags);
612 ppp_tx_flush();
613}
614
e022c2f0
KH		 615static void ppp_start(struct net_device *dev)
616{
617 struct ppp *ppp = get_ppp(dev);
618 int i;
619
620 for (i = 0; i < IDX_COUNT; i++) {
621 struct proto *proto = &ppp->protos[i];
2b57681f 622
e022c2f0 623 proto->dev = dev;
e99e88a9 624 timer_setup(&proto->timer, ppp_timer, 0);
e022c2f0
KH		 625 proto->state = CLOSED;
626 }
627 ppp->protos[IDX_LCP].pid = PID_LCP;
628 ppp->protos[IDX_IPCP].pid = PID_IPCP;
629 ppp->protos[IDX_IPV6CP].pid = PID_IPV6CP;
630
631 ppp_cp_event(dev, PID_LCP, START, 0, 0, 0, NULL);
632}
633
634static void ppp_stop(struct net_device *dev)
635{
636 ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL);
637}
1da177e4 638
31f634a6
KH		 639static void ppp_close(struct net_device *dev)
640{
641 ppp_tx_flush();
642}
643
eb2a2fd9 644static struct hdlc_proto proto = {
e022c2f0
KH		 645 .start = ppp_start,
646 .stop = ppp_stop,
31f634a6 647 .close = ppp_close,
eb2a2fd9
KH		 648 .type_trans = ppp_type_trans,
649 .ioctl = ppp_ioctl,
e022c2f0 650 .netif_rx = ppp_rx,
eb2a2fd9
KH		 651 .module = THIS_MODULE,
652};
653
e022c2f0
KH		 654static const struct header_ops ppp_header_ops = {
655 .create = ppp_hard_header,
656};
eb2a2fd9 657
ad7eab2a 658static int ppp_ioctl(struct net_device *dev, struct if_settings *ifs)
1da177e4
LT		 659{
660 hdlc_device *hdlc = dev_to_hdlc(dev);
e022c2f0 661 struct ppp *ppp;
1da177e4
LT		 662 int result;
663
ad7eab2a 664 switch (ifs->type) {
1da177e4 665 case IF_GET_PROTO:
eb2a2fd9
KH		 666 if (dev_to_hdlc(dev)->proto != &proto)
667 return -EINVAL;
ad7eab2a 668 ifs->type = IF_PROTO_PPP;
1da177e4
LT		 669 return 0; /* return protocol only, no settable parameters */
670
671 case IF_PROTO_PPP:
e022c2f0 672 if (!capable(CAP_NET_ADMIN))
1da177e4
LT		 673 return -EPERM;
674
e022c2f0 675 if (dev->flags & IFF_UP)
1da177e4
LT		 676 return -EBUSY;
677
678 /* no settable parameters */
679
37cb4b9c
PL		 680 result = hdlc->attach(dev, ENCODING_NRZ,
681 PARITY_CRC16_PR1_CCITT);
1da177e4
LT		 682 if (result)
683 return result;
684
e022c2f0 685 result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));
eb2a2fd9
KH		 686 if (result)
687 return result;
e022c2f0
KH		 688
689 ppp = get_ppp(dev);
690 spin_lock_init(&ppp->lock);
691 ppp->req_timeout = 2;
692 ppp->cr_retries = 10;
693 ppp->term_retries = 2;
694 ppp->keepalive_interval = 10;
695 ppp->keepalive_timeout = 60;
696
e022c2f0
KH		 697 dev->hard_header_len = sizeof(struct hdlc_header);
698 dev->header_ops = &ppp_header_ops;
1da177e4 699 dev->type = ARPHRD_PPP;
2f8364a2 700 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
e022c2f0 701 netif_dormant_on(dev);
1da177e4
LT		 702 return 0;
703 }
704
705 return -EINVAL;
706}
eb2a2fd9 707
a1739c30 708static int __init hdlc_ppp_init(void)
eb2a2fd9 709{
e022c2f0 710 skb_queue_head_init(&tx_queue);
eb2a2fd9
KH		 711 register_hdlc_protocol(&proto);
712 return 0;
713}
714
a1739c30 715static void __exit hdlc_ppp_exit(void)
eb2a2fd9
KH		 716{
717 unregister_hdlc_protocol(&proto);
718}
719
a1739c30
RD		 720module_init(hdlc_ppp_init);
721module_exit(hdlc_ppp_exit);
eb2a2fd9
KH		 722
723MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
724MODULE_DESCRIPTION("PPP protocol support for generic HDLC");
725MODULE_LICENSE("GPL v2");
Linux 6.x block layer and io_uring tree(s)