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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Generic HDLC support routines for Linux4 * Point-to-point protocol support5 *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 024#define DEBUG_HARD_HEADER 025 26#define HDLC_ADDR_ALLSTATIONS 0xFF27#define HDLC_CTRL_UI 0x0328 29#define PID_LCP 0xC02130#define PID_IP 0x002131#define PID_IPCP 0x802132#define PID_IPV6 0x005733#define PID_IPV6CP 0x805734 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_CP40static const char *const code_names[CP_CODES] = {41 "0", "ConfReq", "ConfAck", "ConfNak", "ConfRej", "TermReq",42 "TermAck", "CodeRej", "ProtoRej", "EchoReq", "EchoReply", "Discard"43};44 45static char debug_buffer[64 + 3 * DEBUG_CP];46#endif47 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 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_STATE90static const char *const state_names[STATES] = {91 "Closed", "Stopped", "Stopping", "ReqSent", "AckRecv", "AckSent",92 "Opened"93};94 95static const char *const event_names[EVENTS] = {96 "Start", "Stop", "TO+", "TO-", "RCR+", "RCR-", "RCA", "RCN",97 "RTR", "RTA", "RUC", "RXJ+", "RXJ-"98};99#endif100 101static struct sk_buff_head tx_queue; /* used when holding the spin lock */102 103static int ppp_ioctl(struct net_device *dev, struct if_settings *ifs);104 105static inline struct ppp *get_ppp(struct net_device *dev)106{107 return (struct ppp *)dev_to_hdlc(dev)->state;108}109 110static 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 126static inline const char *proto_name(u16 pid)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}139 140static __be16 ppp_type_trans(struct sk_buff *skb, struct net_device *dev)141{142 struct hdlc_header *data = (struct hdlc_header *)skb->data;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) {151 case cpu_to_be16(PID_IP):152 skb_pull(skb, sizeof(struct hdlc_header));153 return htons(ETH_P_IP);154 155 case cpu_to_be16(PID_IPV6):156 skb_pull(skb, sizeof(struct hdlc_header));157 return htons(ETH_P_IPV6);158 159 default:160 return htons(ETH_P_HDLC);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_HEADER170 printk(KERN_DEBUG "%s: ppp_hard_header() called\n", dev->name);171#endif172 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 196static void ppp_tx_flush(void)197{198 struct sk_buff *skb;199 200 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_CP213 int i;214 char *ptr;215#endif216 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 return;224 225 skb_reserve(skb, sizeof(struct hdlc_header));226 227 cp = skb_put(skb, sizeof(struct cp_header));228 cp->code = code;229 cp->id = id;230 cp->len = htons(sizeof(struct cp_header) + magic_len + len);231 232 if (magic_len)233 skb_put_data(skb, &magic, magic_len);234 if (len)235 skb_put_data(skb, data, len);236 237#if DEBUG_CP238 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#endif248 249 ppp_hard_header(skb, dev, pid, NULL, NULL, 0);250 251 skb->priority = TC_PRIO_CONTROL;252 skb->dev = dev;253 skb->protocol = htons(ETH_P_HDLC);254 skb_reset_network_header(skb);255 skb_queue_tail(&tx_queue, skb);256}257 258/* State transition table (compare STD-51)259 Events Actions260 TO+ = Timeout with counter > 0 irc = Initialize-Restart-Count261 TO- = Timeout with counter expired zrc = Zero-Restart-Count262 263 RCR+ = Receive-Configure-Request (Good) scr = Send-Configure-Request264 RCR- = Receive-Configure-Request (Bad)265 RCA = Receive-Configure-Ack sca = Send-Configure-Ack266 RCN = Receive-Configure-Nak/Rej scn = Send-Configure-Nak/Rej267 268 RTR = Receive-Terminate-Request str = Send-Terminate-Request269 RTA = Receive-Terminate-Ack sta = Send-Terminate-Ack270 271 RUC = Receive-Unknown-Code scj = Send-Code-Reject272 RXJ+ = Receive-Code-Reject (permitted)273 or Receive-Protocol-Reject274 RXJ- = Receive-Code-Reject (catastrophic)275 or Receive-Protocol-Reject276*/277static int cp_table[EVENTS][STATES] = {278 /* CLOSED STOPPED STOPPING REQ_SENT ACK_RECV ACK_SENT OPENED279 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};294 295/* SCA: RCR+ must supply id, len and data296 SCN: RCR- must supply code, id, len and data297 STA: RTR must supply id298 SCJ: RUC must supply CP packet len and data */299static void ppp_cp_event(struct net_device *dev, u16 pid, u16 event, u8 code,300 u8 id, unsigned int len, const void *data)301{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_STATE311 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#endif314 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) {342 netdev_info(dev, "%s up\n", proto_name(pid));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) {353 netdev_info(dev, "%s down\n", proto_name(pid));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_STATE364 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#endif367}368 369static void ppp_cp_parse_cr(struct net_device *dev, u16 pid, u8 id,370 unsigned int req_len, const u8 *data)371{372 static u8 const valid_accm[6] = { LCP_OPTION_ACCM, 6, 0, 0, 0, 0 };373 const u8 *opt;374 u8 *out;375 unsigned int len = req_len, nak_len = 0, rej_len = 0;376 377 out = kmalloc(len, GFP_ATOMIC);378 if (!out) {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]) {384 if (len < 2 || opt[1] < 2 || len < opt[1])385 goto err_out;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 */393 if (opt[1] < sizeof(valid_accm))394 goto err_out;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:406 if (len < 6)407 goto err_out;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 else423 ppp_cp_event(dev, pid, RCR_GOOD, CP_CONF_ACK, id, req_len, data);424 425 kfree(out);426 return;427 428err_out:429 dev->stats.rx_errors++;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_CP444 int i;445 char *ptr;446#endif447 448 spin_lock_irqsave(&ppp->lock, flags);449 /* Check HDLC header */450 if (skb->len < sizeof(struct hdlc_header))451 goto rx_error;452 cp = 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) /* 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_CP475 if (cp->code < CP_CODES)476 sprintf(debug_buffer, "[%s id 0x%X]", code_names[cp->code],477 cp->id);478 else479 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#endif488 489 /* LCP only */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: /* 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);519 break;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 break;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 break;531 532 case CP_TERM_REQ:533 ppp_cp_event(dev, pid, RTR, 0, cp->id, 0, NULL);534 break;535 536 case CP_TERM_ACK:537 ppp_cp_event(dev, pid, RTA, 0, 0, 0, NULL);538 break;539 540 case CP_CODE_REJ:541 ppp_cp_event(dev, pid, RXJ_BAD, 0, 0, 0, NULL);542 break;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 break;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(struct timer_list *t)563{564 struct proto *proto = from_timer(proto, t, timer);565 struct ppp *ppp = get_ppp(proto->dev);566 unsigned long flags;567 568 spin_lock_irqsave(&ppp->lock, flags);569 /* mod_timer could be called after we entered this function but570 * before we got the lock.571 */572 if (timer_pending(&proto->timer)) {573 spin_unlock_irqrestore(&ppp->lock, flags);574 return;575 }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--;585 } else if (netif_carrier_ok(proto->dev))586 ppp_cp_event(proto->dev, proto->pid, TO_GOOD, 0, 0,587 0, NULL);588 else589 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)) {598 netdev_info(proto->dev, "Link down\n");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 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];622 623 proto->dev = dev;624 timer_setup(&proto->timer, ppp_timer, 0);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}638 639static void ppp_close(struct net_device *dev)640{641 ppp_tx_flush();642}643 644static struct hdlc_proto proto = {645 .start = ppp_start,646 .stop = ppp_stop,647 .close = ppp_close,648 .type_trans = ppp_type_trans,649 .ioctl = ppp_ioctl,650 .netif_rx = ppp_rx,651 .module = THIS_MODULE,652};653 654static const struct header_ops ppp_header_ops = {655 .create = ppp_hard_header,656};657 658static int ppp_ioctl(struct net_device *dev, struct if_settings *ifs)659{660 hdlc_device *hdlc = dev_to_hdlc(dev);661 struct ppp *ppp;662 int result;663 664 switch (ifs->type) {665 case IF_GET_PROTO:666 if (dev_to_hdlc(dev)->proto != &proto)667 return -EINVAL;668 ifs->type = IF_PROTO_PPP;669 return 0; /* return protocol only, no settable parameters */670 671 case IF_PROTO_PPP:672 if (!capable(CAP_NET_ADMIN))673 return -EPERM;674 675 if (dev->flags & IFF_UP)676 return -EBUSY;677 678 /* no settable parameters */679 680 result = hdlc->attach(dev, ENCODING_NRZ,681 PARITY_CRC16_PR1_CCITT);682 if (result)683 return result;684 685 result = attach_hdlc_protocol(dev, &proto, sizeof(struct ppp));686 if (result)687 return result;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;696 697 dev->hard_header_len = sizeof(struct hdlc_header);698 dev->header_ops = &ppp_header_ops;699 dev->type = ARPHRD_PPP;700 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);701 netif_dormant_on(dev);702 return 0;703 }704 705 return -EINVAL;706}707 708static int __init hdlc_ppp_init(void)709{710 skb_queue_head_init(&tx_queue);711 register_hdlc_protocol(&proto);712 return 0;713}714 715static void __exit hdlc_ppp_exit(void)716{717 unregister_hdlc_protocol(&proto);718}719 720module_init(hdlc_ppp_init);721module_exit(hdlc_ppp_exit);722 723MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");724MODULE_DESCRIPTION("PPP protocol support for generic HDLC");725MODULE_LICENSE("GPL v2");726