1 /* 2 * Generic HDLC support routines for Linux 3 * Cisco HDLC support 4 * 5 * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of version 2 of the GNU General Public License 9 * as published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/poll.h> 16 #include <linux/errno.h> 17 #include <linux/if_arp.h> 18 #include <linux/init.h> 19 #include <linux/skbuff.h> 20 #include <linux/pkt_sched.h> 21 #include <linux/inetdevice.h> 22 #include <linux/lapb.h> 23 #include <linux/rtnetlink.h> 24 #include <linux/hdlc.h> 25 26 #undef DEBUG_HARD_HEADER 27 28 #define CISCO_MULTICAST 0x8F /* Cisco multicast address */ 29 #define CISCO_UNICAST 0x0F /* Cisco unicast address */ 30 #define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */ 31 #define CISCO_SYS_INFO 0x2000 /* Cisco interface/system info */ 32 #define CISCO_ADDR_REQ 0 /* Cisco address request */ 33 #define CISCO_ADDR_REPLY 1 /* Cisco address reply */ 34 #define CISCO_KEEPALIVE_REQ 2 /* Cisco keepalive request */ 35 36 37 struct hdlc_header { 38 u8 address; 39 u8 control; 40 __be16 protocol; 41 }__attribute__ ((packed)); 42 43 44 struct cisco_packet { 45 __be32 type; /* code */ 46 __be32 par1; 47 __be32 par2; 48 __be16 rel; /* reliability */ 49 __be32 time; 50 }__attribute__ ((packed)); 51 #define CISCO_PACKET_LEN 18 52 #define CISCO_BIG_PACKET_LEN 20 53 54 55 struct cisco_state { 56 cisco_proto settings; 57 58 struct timer_list timer; 59 spinlock_t lock; 60 unsigned long last_poll; 61 int up; 62 int request_sent; 63 u32 txseq; /* TX sequence number */ 64 u32 rxseq; /* RX sequence number */ 65 }; 66 67 68 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr); 69 70 71 static inline struct cisco_state * state(hdlc_device *hdlc) 72 { 73 return(struct cisco_state *)(hdlc->state); 74 } 75 76 77 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev, 78 u16 type, const void *daddr, const void *saddr, 79 unsigned int len) 80 { 81 struct hdlc_header *data; 82 #ifdef DEBUG_HARD_HEADER 83 printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name); 84 #endif 85 86 skb_push(skb, sizeof(struct hdlc_header)); 87 data = (struct hdlc_header*)skb->data; 88 if (type == CISCO_KEEPALIVE) 89 data->address = CISCO_MULTICAST; 90 else 91 data->address = CISCO_UNICAST; 92 data->control = 0; 93 data->protocol = htons(type); 94 95 return sizeof(struct hdlc_header); 96 } 97 98 99 100 static void cisco_keepalive_send(struct net_device *dev, u32 type, 101 __be32 par1, __be32 par2) 102 { 103 struct sk_buff *skb; 104 struct cisco_packet *data; 105 106 skb = dev_alloc_skb(sizeof(struct hdlc_header) + 107 sizeof(struct cisco_packet)); 108 if (!skb) { 109 printk(KERN_WARNING 110 "%s: Memory squeeze on cisco_keepalive_send()\n", 111 dev->name); 112 return; 113 } 114 skb_reserve(skb, 4); 115 cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0); 116 data = (struct cisco_packet*)(skb->data + 4); 117 118 data->type = htonl(type); 119 data->par1 = par1; 120 data->par2 = par2; 121 data->rel = __constant_htons(0xFFFF); 122 /* we will need do_div here if 1000 % HZ != 0 */ 123 data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ)); 124 125 skb_put(skb, sizeof(struct cisco_packet)); 126 skb->priority = TC_PRIO_CONTROL; 127 skb->dev = dev; 128 skb_reset_network_header(skb); 129 130 dev_queue_xmit(skb); 131 } 132 133 134 135 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev) 136 { 137 struct hdlc_header *data = (struct hdlc_header*)skb->data; 138 139 if (skb->len < sizeof(struct hdlc_header)) 140 return __constant_htons(ETH_P_HDLC); 141 142 if (data->address != CISCO_MULTICAST && 143 data->address != CISCO_UNICAST) 144 return __constant_htons(ETH_P_HDLC); 145 146 switch(data->protocol) { 147 case __constant_htons(ETH_P_IP): 148 case __constant_htons(ETH_P_IPX): 149 case __constant_htons(ETH_P_IPV6): 150 skb_pull(skb, sizeof(struct hdlc_header)); 151 return data->protocol; 152 default: 153 return __constant_htons(ETH_P_HDLC); 154 } 155 } 156 157 158 static int cisco_rx(struct sk_buff *skb) 159 { 160 struct net_device *dev = skb->dev; 161 hdlc_device *hdlc = dev_to_hdlc(dev); 162 struct cisco_state *st = state(hdlc); 163 struct hdlc_header *data = (struct hdlc_header*)skb->data; 164 struct cisco_packet *cisco_data; 165 struct in_device *in_dev; 166 __be32 addr, mask; 167 168 if (skb->len < sizeof(struct hdlc_header)) 169 goto rx_error; 170 171 if (data->address != CISCO_MULTICAST && 172 data->address != CISCO_UNICAST) 173 goto rx_error; 174 175 switch(ntohs(data->protocol)) { 176 case CISCO_SYS_INFO: 177 /* Packet is not needed, drop it. */ 178 dev_kfree_skb_any(skb); 179 return NET_RX_SUCCESS; 180 181 case CISCO_KEEPALIVE: 182 if ((skb->len != sizeof(struct hdlc_header) + 183 CISCO_PACKET_LEN) && 184 (skb->len != sizeof(struct hdlc_header) + 185 CISCO_BIG_PACKET_LEN)) { 186 printk(KERN_INFO "%s: Invalid length of Cisco control" 187 " packet (%d bytes)\n", dev->name, skb->len); 188 goto rx_error; 189 } 190 191 cisco_data = (struct cisco_packet*)(skb->data + sizeof 192 (struct hdlc_header)); 193 194 switch(ntohl (cisco_data->type)) { 195 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */ 196 in_dev = dev->ip_ptr; 197 addr = 0; 198 mask = __constant_htonl(~0); /* is the mask correct? */ 199 200 if (in_dev != NULL) { 201 struct in_ifaddr **ifap = &in_dev->ifa_list; 202 203 while (*ifap != NULL) { 204 if (strcmp(dev->name, 205 (*ifap)->ifa_label) == 0) { 206 addr = (*ifap)->ifa_local; 207 mask = (*ifap)->ifa_mask; 208 break; 209 } 210 ifap = &(*ifap)->ifa_next; 211 } 212 213 cisco_keepalive_send(dev, CISCO_ADDR_REPLY, 214 addr, mask); 215 } 216 dev_kfree_skb_any(skb); 217 return NET_RX_SUCCESS; 218 219 case CISCO_ADDR_REPLY: 220 printk(KERN_INFO "%s: Unexpected Cisco IP address " 221 "reply\n", dev->name); 222 goto rx_error; 223 224 case CISCO_KEEPALIVE_REQ: 225 spin_lock(&st->lock); 226 st->rxseq = ntohl(cisco_data->par1); 227 if (st->request_sent && 228 ntohl(cisco_data->par2) == st->txseq) { 229 st->last_poll = jiffies; 230 if (!st->up) { 231 u32 sec, min, hrs, days; 232 sec = ntohl(cisco_data->time) / 1000; 233 min = sec / 60; sec -= min * 60; 234 hrs = min / 60; min -= hrs * 60; 235 days = hrs / 24; hrs -= days * 24; 236 printk(KERN_INFO "%s: Link up (peer " 237 "uptime %ud%uh%um%us)\n", 238 dev->name, days, hrs, min, sec); 239 netif_dormant_off(dev); 240 st->up = 1; 241 } 242 } 243 spin_unlock(&st->lock); 244 245 dev_kfree_skb_any(skb); 246 return NET_RX_SUCCESS; 247 } /* switch(keepalive type) */ 248 } /* switch(protocol) */ 249 250 printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name, 251 ntohs(data->protocol)); 252 dev_kfree_skb_any(skb); 253 return NET_RX_DROP; 254 255 rx_error: 256 dev->stats.rx_errors++; /* Mark error */ 257 dev_kfree_skb_any(skb); 258 return NET_RX_DROP; 259 } 260 261 262 263 static void cisco_timer(unsigned long arg) 264 { 265 struct net_device *dev = (struct net_device *)arg; 266 hdlc_device *hdlc = dev_to_hdlc(dev); 267 struct cisco_state *st = state(hdlc); 268 269 spin_lock(&st->lock); 270 if (st->up && 271 time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) { 272 st->up = 0; 273 printk(KERN_INFO "%s: Link down\n", dev->name); 274 netif_dormant_on(dev); 275 } 276 277 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq), 278 htonl(st->rxseq)); 279 st->request_sent = 1; 280 spin_unlock(&st->lock); 281 282 st->timer.expires = jiffies + st->settings.interval * HZ; 283 st->timer.function = cisco_timer; 284 st->timer.data = arg; 285 add_timer(&st->timer); 286 } 287 288 289 290 static void cisco_start(struct net_device *dev) 291 { 292 hdlc_device *hdlc = dev_to_hdlc(dev); 293 struct cisco_state *st = state(hdlc); 294 unsigned long flags; 295 296 spin_lock_irqsave(&st->lock, flags); 297 st->up = 0; 298 st->request_sent = 0; 299 st->txseq = st->rxseq = 0; 300 spin_unlock_irqrestore(&st->lock, flags); 301 302 init_timer(&st->timer); 303 st->timer.expires = jiffies + HZ; /* First poll after 1 s */ 304 st->timer.function = cisco_timer; 305 st->timer.data = (unsigned long)dev; 306 add_timer(&st->timer); 307 } 308 309 310 311 static void cisco_stop(struct net_device *dev) 312 { 313 hdlc_device *hdlc = dev_to_hdlc(dev); 314 struct cisco_state *st = state(hdlc); 315 unsigned long flags; 316 317 del_timer_sync(&st->timer); 318 319 spin_lock_irqsave(&st->lock, flags); 320 netif_dormant_on(dev); 321 st->up = 0; 322 st->request_sent = 0; 323 spin_unlock_irqrestore(&st->lock, flags); 324 } 325 326 327 static struct hdlc_proto proto = { 328 .start = cisco_start, 329 .stop = cisco_stop, 330 .type_trans = cisco_type_trans, 331 .ioctl = cisco_ioctl, 332 .netif_rx = cisco_rx, 333 .module = THIS_MODULE, 334 }; 335 336 static const struct header_ops cisco_header_ops = { 337 .create = cisco_hard_header, 338 }; 339 340 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr) 341 { 342 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco; 343 const size_t size = sizeof(cisco_proto); 344 cisco_proto new_settings; 345 hdlc_device *hdlc = dev_to_hdlc(dev); 346 int result; 347 348 switch (ifr->ifr_settings.type) { 349 case IF_GET_PROTO: 350 if (dev_to_hdlc(dev)->proto != &proto) 351 return -EINVAL; 352 ifr->ifr_settings.type = IF_PROTO_CISCO; 353 if (ifr->ifr_settings.size < size) { 354 ifr->ifr_settings.size = size; /* data size wanted */ 355 return -ENOBUFS; 356 } 357 if (copy_to_user(cisco_s, &state(hdlc)->settings, size)) 358 return -EFAULT; 359 return 0; 360 361 case IF_PROTO_CISCO: 362 if(!capable(CAP_NET_ADMIN)) 363 return -EPERM; 364 365 if(dev->flags & IFF_UP) 366 return -EBUSY; 367 368 if (copy_from_user(&new_settings, cisco_s, size)) 369 return -EFAULT; 370 371 if (new_settings.interval < 1 || 372 new_settings.timeout < 2) 373 return -EINVAL; 374 375 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); 376 if (result) 377 return result; 378 379 result = attach_hdlc_protocol(dev, &proto, 380 sizeof(struct cisco_state)); 381 if (result) 382 return result; 383 384 memcpy(&state(hdlc)->settings, &new_settings, size); 385 spin_lock_init(&state(hdlc)->lock); 386 dev->hard_start_xmit = hdlc->xmit; 387 dev->header_ops = &cisco_header_ops; 388 dev->type = ARPHRD_CISCO; 389 netif_dormant_on(dev); 390 return 0; 391 } 392 393 return -EINVAL; 394 } 395 396 397 static int __init mod_init(void) 398 { 399 register_hdlc_protocol(&proto); 400 return 0; 401 } 402 403 404 405 static void __exit mod_exit(void) 406 { 407 unregister_hdlc_protocol(&proto); 408 } 409 410 411 module_init(mod_init); 412 module_exit(mod_exit); 413 414 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 415 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC"); 416 MODULE_LICENSE("GPL v2"); 417