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 u32 txseq; /* TX sequence number, 0 = none */ 62 u32 rxseq; /* RX sequence number */ 63 }; 64 65 66 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr); 67 68 69 static inline struct cisco_state* state(hdlc_device *hdlc) 70 { 71 return (struct cisco_state *)hdlc->state; 72 } 73 74 75 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev, 76 u16 type, const void *daddr, const void *saddr, 77 unsigned int len) 78 { 79 struct hdlc_header *data; 80 #ifdef DEBUG_HARD_HEADER 81 printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name); 82 #endif 83 84 skb_push(skb, sizeof(struct hdlc_header)); 85 data = (struct hdlc_header*)skb->data; 86 if (type == CISCO_KEEPALIVE) 87 data->address = CISCO_MULTICAST; 88 else 89 data->address = CISCO_UNICAST; 90 data->control = 0; 91 data->protocol = htons(type); 92 93 return sizeof(struct hdlc_header); 94 } 95 96 97 98 static void cisco_keepalive_send(struct net_device *dev, u32 type, 99 __be32 par1, __be32 par2) 100 { 101 struct sk_buff *skb; 102 struct cisco_packet *data; 103 104 skb = dev_alloc_skb(sizeof(struct hdlc_header) + 105 sizeof(struct cisco_packet)); 106 if (!skb) { 107 printk(KERN_WARNING 108 "%s: Memory squeeze on cisco_keepalive_send()\n", 109 dev->name); 110 return; 111 } 112 skb_reserve(skb, 4); 113 cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0); 114 data = (struct cisco_packet*)(skb->data + 4); 115 116 data->type = htonl(type); 117 data->par1 = par1; 118 data->par2 = par2; 119 data->rel = cpu_to_be16(0xFFFF); 120 /* we will need do_div here if 1000 % HZ != 0 */ 121 data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ)); 122 123 skb_put(skb, sizeof(struct cisco_packet)); 124 skb->priority = TC_PRIO_CONTROL; 125 skb->dev = dev; 126 skb_reset_network_header(skb); 127 128 dev_queue_xmit(skb); 129 } 130 131 132 133 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev) 134 { 135 struct hdlc_header *data = (struct hdlc_header*)skb->data; 136 137 if (skb->len < sizeof(struct hdlc_header)) 138 return cpu_to_be16(ETH_P_HDLC); 139 140 if (data->address != CISCO_MULTICAST && 141 data->address != CISCO_UNICAST) 142 return cpu_to_be16(ETH_P_HDLC); 143 144 switch(data->protocol) { 145 case cpu_to_be16(ETH_P_IP): 146 case cpu_to_be16(ETH_P_IPX): 147 case cpu_to_be16(ETH_P_IPV6): 148 skb_pull(skb, sizeof(struct hdlc_header)); 149 return data->protocol; 150 default: 151 return cpu_to_be16(ETH_P_HDLC); 152 } 153 } 154 155 156 static int cisco_rx(struct sk_buff *skb) 157 { 158 struct net_device *dev = skb->dev; 159 hdlc_device *hdlc = dev_to_hdlc(dev); 160 struct cisco_state *st = state(hdlc); 161 struct hdlc_header *data = (struct hdlc_header*)skb->data; 162 struct cisco_packet *cisco_data; 163 struct in_device *in_dev; 164 __be32 addr, mask; 165 u32 ack; 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 = ~cpu_to_be32(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 ack = ntohl(cisco_data->par2); 227 if (ack && (ack == st->txseq || 228 /* our current REQ may be in transit */ 229 ack == st->txseq - 1)) { 230 st->last_poll = jiffies; 231 if (!st->up) { 232 u32 sec, min, hrs, days; 233 sec = ntohl(cisco_data->time) / 1000; 234 min = sec / 60; sec -= min * 60; 235 hrs = min / 60; min -= hrs * 60; 236 days = hrs / 24; hrs -= days * 24; 237 printk(KERN_INFO "%s: Link up (peer " 238 "uptime %ud%uh%um%us)\n", 239 dev->name, days, hrs, min, sec); 240 netif_dormant_off(dev); 241 st->up = 1; 242 } 243 } 244 spin_unlock(&st->lock); 245 246 dev_kfree_skb_any(skb); 247 return NET_RX_SUCCESS; 248 } /* switch(keepalive type) */ 249 } /* switch(protocol) */ 250 251 printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name, 252 ntohs(data->protocol)); 253 dev_kfree_skb_any(skb); 254 return NET_RX_DROP; 255 256 rx_error: 257 dev->stats.rx_errors++; /* Mark error */ 258 dev_kfree_skb_any(skb); 259 return NET_RX_DROP; 260 } 261 262 263 264 static void cisco_timer(unsigned long arg) 265 { 266 struct net_device *dev = (struct net_device *)arg; 267 hdlc_device *hdlc = dev_to_hdlc(dev); 268 struct cisco_state *st = state(hdlc); 269 270 spin_lock(&st->lock); 271 if (st->up && 272 time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) { 273 st->up = 0; 274 printk(KERN_INFO "%s: Link down\n", dev->name); 275 netif_dormant_on(dev); 276 } 277 278 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq), 279 htonl(st->rxseq)); 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 = st->txseq = st->rxseq = 0; 298 spin_unlock_irqrestore(&st->lock, flags); 299 300 init_timer(&st->timer); 301 st->timer.expires = jiffies + HZ; /* First poll after 1 s */ 302 st->timer.function = cisco_timer; 303 st->timer.data = (unsigned long)dev; 304 add_timer(&st->timer); 305 } 306 307 308 309 static void cisco_stop(struct net_device *dev) 310 { 311 hdlc_device *hdlc = dev_to_hdlc(dev); 312 struct cisco_state *st = state(hdlc); 313 unsigned long flags; 314 315 del_timer_sync(&st->timer); 316 317 spin_lock_irqsave(&st->lock, flags); 318 netif_dormant_on(dev); 319 st->up = st->txseq = 0; 320 spin_unlock_irqrestore(&st->lock, flags); 321 } 322 323 324 static struct hdlc_proto proto = { 325 .start = cisco_start, 326 .stop = cisco_stop, 327 .type_trans = cisco_type_trans, 328 .ioctl = cisco_ioctl, 329 .netif_rx = cisco_rx, 330 .module = THIS_MODULE, 331 }; 332 333 static const struct header_ops cisco_header_ops = { 334 .create = cisco_hard_header, 335 }; 336 337 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr) 338 { 339 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco; 340 const size_t size = sizeof(cisco_proto); 341 cisco_proto new_settings; 342 hdlc_device *hdlc = dev_to_hdlc(dev); 343 int result; 344 345 switch (ifr->ifr_settings.type) { 346 case IF_GET_PROTO: 347 if (dev_to_hdlc(dev)->proto != &proto) 348 return -EINVAL; 349 ifr->ifr_settings.type = IF_PROTO_CISCO; 350 if (ifr->ifr_settings.size < size) { 351 ifr->ifr_settings.size = size; /* data size wanted */ 352 return -ENOBUFS; 353 } 354 if (copy_to_user(cisco_s, &state(hdlc)->settings, size)) 355 return -EFAULT; 356 return 0; 357 358 case IF_PROTO_CISCO: 359 if (!capable(CAP_NET_ADMIN)) 360 return -EPERM; 361 362 if (dev->flags & IFF_UP) 363 return -EBUSY; 364 365 if (copy_from_user(&new_settings, cisco_s, size)) 366 return -EFAULT; 367 368 if (new_settings.interval < 1 || 369 new_settings.timeout < 2) 370 return -EINVAL; 371 372 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); 373 if (result) 374 return result; 375 376 result = attach_hdlc_protocol(dev, &proto, 377 sizeof(struct cisco_state)); 378 if (result) 379 return result; 380 381 memcpy(&state(hdlc)->settings, &new_settings, size); 382 spin_lock_init(&state(hdlc)->lock); 383 dev->header_ops = &cisco_header_ops; 384 dev->type = ARPHRD_CISCO; 385 netif_dormant_on(dev); 386 return 0; 387 } 388 389 return -EINVAL; 390 } 391 392 393 static int __init mod_init(void) 394 { 395 register_hdlc_protocol(&proto); 396 return 0; 397 } 398 399 400 401 static void __exit mod_exit(void) 402 { 403 unregister_hdlc_protocol(&proto); 404 } 405 406 407 module_init(mod_init); 408 module_exit(mod_exit); 409 410 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 411 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC"); 412 MODULE_LICENSE("GPL v2"); 413