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