b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 | static char debug_buffer[64 + 3 * DEBUG_CP]; |
| 45 | #endif |
| 46 | |
| 47 | enum {LCP_OPTION_MRU = 1, LCP_OPTION_ACCM, LCP_OPTION_MAGIC = 5}; |
| 48 | |
| 49 | struct hdlc_header { |
| 50 | u8 address; |
| 51 | u8 control; |
| 52 | __be16 protocol; |
| 53 | }; |
| 54 | |
| 55 | struct cp_header { |
| 56 | u8 code; |
| 57 | u8 id; |
| 58 | __be16 len; |
| 59 | }; |
| 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 | static 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 | |
| 100 | static struct sk_buff_head tx_queue; /* used when holding the spin lock */ |
| 101 | |
| 102 | static int ppp_ioctl(struct net_device *dev, struct ifreq *ifr); |
| 103 | |
| 104 | static inline struct ppp* get_ppp(struct net_device *dev) |
| 105 | { |
| 106 | return (struct ppp *)dev_to_hdlc(dev)->state; |
| 107 | } |
| 108 | |
| 109 | static 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 | |
| 125 | static 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 | |
| 139 | static __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 | |
| 164 | static 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 | |
| 197 | static 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 | |
| 204 | static 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 | */ |
| 279 | static 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 */ |
| 302 | static 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 | |
| 373 | static 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 | |
| 431 | err_out: |
| 432 | dev->stats.rx_errors++; |
| 433 | kfree(out); |
| 434 | } |
| 435 | |
| 436 | static 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 | |
| 556 | rx_error: |
| 557 | dev->stats.rx_errors++; |
| 558 | out: |
| 559 | spin_unlock_irqrestore(&ppp->lock, flags); |
| 560 | dev_kfree_skb_any(skb); |
| 561 | ppp_tx_flush(); |
| 562 | return NET_RX_DROP; |
| 563 | } |
| 564 | |
| 565 | static 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 | |
| 619 | static 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 | |
| 637 | static void ppp_stop(struct net_device *dev) |
| 638 | { |
| 639 | ppp_cp_event(dev, PID_LCP, STOP, 0, 0, 0, NULL); |
| 640 | } |
| 641 | |
| 642 | static void ppp_close(struct net_device *dev) |
| 643 | { |
| 644 | ppp_tx_flush(); |
| 645 | } |
| 646 | |
| 647 | static 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 | |
| 657 | static const struct header_ops ppp_header_ops = { |
| 658 | .create = ppp_hard_header, |
| 659 | }; |
| 660 | |
| 661 | static 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 | |
| 711 | static int __init mod_init(void) |
| 712 | { |
| 713 | skb_queue_head_init(&tx_queue); |
| 714 | register_hdlc_protocol(&proto); |
| 715 | return 0; |
| 716 | } |
| 717 | |
| 718 | static void __exit mod_exit(void) |
| 719 | { |
| 720 | unregister_hdlc_protocol(&proto); |
| 721 | } |
| 722 | |
| 723 | |
| 724 | module_init(mod_init); |
| 725 | module_exit(mod_exit); |
| 726 | |
| 727 | MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); |
| 728 | MODULE_DESCRIPTION("PPP protocol support for generic HDLC"); |
| 729 | MODULE_LICENSE("GPL v2"); |