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 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 hdlc_header *data = (struct hdlc_header*)skb->data; 162 struct cisco_packet *cisco_data; 163 struct in_device *in_dev; 164 __be32 addr, mask; 165 166 if (skb->len < sizeof(struct hdlc_header)) 167 goto rx_error; 168 169 if (data->address != CISCO_MULTICAST && 170 data->address != CISCO_UNICAST) 171 goto rx_error; 172 173 switch(ntohs(data->protocol)) { 174 case CISCO_SYS_INFO: 175 /* Packet is not needed, drop it. */ 176 dev_kfree_skb_any(skb); 177 return NET_RX_SUCCESS; 178 179 case CISCO_KEEPALIVE: 180 if ((skb->len != sizeof(struct hdlc_header) + 181 CISCO_PACKET_LEN) && 182 (skb->len != sizeof(struct hdlc_header) + 183 CISCO_BIG_PACKET_LEN)) { 184 printk(KERN_INFO "%s: Invalid length of Cisco control" 185 " packet (%d bytes)\n", dev->name, skb->len); 186 goto rx_error; 187 } 188 189 cisco_data = (struct cisco_packet*)(skb->data + sizeof 190 (struct hdlc_header)); 191 192 switch(ntohl (cisco_data->type)) { 193 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */ 194 in_dev = dev->ip_ptr; 195 addr = 0; 196 mask = __constant_htonl(~0); /* is the mask correct? */ 197 198 if (in_dev != NULL) { 199 struct in_ifaddr **ifap = &in_dev->ifa_list; 200 201 while (*ifap != NULL) { 202 if (strcmp(dev->name, 203 (*ifap)->ifa_label) == 0) { 204 addr = (*ifap)->ifa_local; 205 mask = (*ifap)->ifa_mask; 206 break; 207 } 208 ifap = &(*ifap)->ifa_next; 209 } 210 211 cisco_keepalive_send(dev, CISCO_ADDR_REPLY, 212 addr, mask); 213 } 214 dev_kfree_skb_any(skb); 215 return NET_RX_SUCCESS; 216 217 case CISCO_ADDR_REPLY: 218 printk(KERN_INFO "%s: Unexpected Cisco IP address " 219 "reply\n", dev->name); 220 goto rx_error; 221 222 case CISCO_KEEPALIVE_REQ: 223 state(hdlc)->rxseq = ntohl(cisco_data->par1); 224 if (state(hdlc)->request_sent && 225 ntohl(cisco_data->par2) == state(hdlc)->txseq) { 226 state(hdlc)->last_poll = jiffies; 227 if (!state(hdlc)->up) { 228 u32 sec, min, hrs, days; 229 sec = ntohl(cisco_data->time) / 1000; 230 min = sec / 60; sec -= min * 60; 231 hrs = min / 60; min -= hrs * 60; 232 days = hrs / 24; hrs -= days * 24; 233 printk(KERN_INFO "%s: Link up (peer " 234 "uptime %ud%uh%um%us)\n", 235 dev->name, days, hrs, 236 min, sec); 237 netif_dormant_off(dev); 238 state(hdlc)->up = 1; 239 } 240 } 241 242 dev_kfree_skb_any(skb); 243 return NET_RX_SUCCESS; 244 } /* switch(keepalive type) */ 245 } /* switch(protocol) */ 246 247 printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name, 248 ntohs(data->protocol)); 249 dev_kfree_skb_any(skb); 250 return NET_RX_DROP; 251 252 rx_error: 253 dev_to_hdlc(dev)->stats.rx_errors++; /* Mark error */ 254 dev_kfree_skb_any(skb); 255 return NET_RX_DROP; 256 } 257 258 259 260 static void cisco_timer(unsigned long arg) 261 { 262 struct net_device *dev = (struct net_device *)arg; 263 hdlc_device *hdlc = dev_to_hdlc(dev); 264 265 if (state(hdlc)->up && 266 time_after(jiffies, state(hdlc)->last_poll + 267 state(hdlc)->settings.timeout * HZ)) { 268 state(hdlc)->up = 0; 269 printk(KERN_INFO "%s: Link down\n", dev->name); 270 netif_dormant_on(dev); 271 } 272 273 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, 274 htonl(++state(hdlc)->txseq), 275 htonl(state(hdlc)->rxseq)); 276 state(hdlc)->request_sent = 1; 277 state(hdlc)->timer.expires = jiffies + 278 state(hdlc)->settings.interval * HZ; 279 state(hdlc)->timer.function = cisco_timer; 280 state(hdlc)->timer.data = arg; 281 add_timer(&state(hdlc)->timer); 282 } 283 284 285 286 static void cisco_start(struct net_device *dev) 287 { 288 hdlc_device *hdlc = dev_to_hdlc(dev); 289 state(hdlc)->up = 0; 290 state(hdlc)->request_sent = 0; 291 state(hdlc)->txseq = state(hdlc)->rxseq = 0; 292 293 init_timer(&state(hdlc)->timer); 294 state(hdlc)->timer.expires = jiffies + HZ; /*First poll after 1s*/ 295 state(hdlc)->timer.function = cisco_timer; 296 state(hdlc)->timer.data = (unsigned long)dev; 297 add_timer(&state(hdlc)->timer); 298 } 299 300 301 302 static void cisco_stop(struct net_device *dev) 303 { 304 hdlc_device *hdlc = dev_to_hdlc(dev); 305 del_timer_sync(&state(hdlc)->timer); 306 netif_dormant_on(dev); 307 state(hdlc)->up = 0; 308 state(hdlc)->request_sent = 0; 309 } 310 311 312 static struct hdlc_proto proto = { 313 .start = cisco_start, 314 .stop = cisco_stop, 315 .type_trans = cisco_type_trans, 316 .ioctl = cisco_ioctl, 317 .netif_rx = cisco_rx, 318 .module = THIS_MODULE, 319 }; 320 321 static const struct header_ops cisco_header_ops = { 322 .create = cisco_hard_header, 323 }; 324 325 static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr) 326 { 327 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco; 328 const size_t size = sizeof(cisco_proto); 329 cisco_proto new_settings; 330 hdlc_device *hdlc = dev_to_hdlc(dev); 331 int result; 332 333 switch (ifr->ifr_settings.type) { 334 case IF_GET_PROTO: 335 if (dev_to_hdlc(dev)->proto != &proto) 336 return -EINVAL; 337 ifr->ifr_settings.type = IF_PROTO_CISCO; 338 if (ifr->ifr_settings.size < size) { 339 ifr->ifr_settings.size = size; /* data size wanted */ 340 return -ENOBUFS; 341 } 342 if (copy_to_user(cisco_s, &state(hdlc)->settings, size)) 343 return -EFAULT; 344 return 0; 345 346 case IF_PROTO_CISCO: 347 if(!capable(CAP_NET_ADMIN)) 348 return -EPERM; 349 350 if(dev->flags & IFF_UP) 351 return -EBUSY; 352 353 if (copy_from_user(&new_settings, cisco_s, size)) 354 return -EFAULT; 355 356 if (new_settings.interval < 1 || 357 new_settings.timeout < 2) 358 return -EINVAL; 359 360 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); 361 if (result) 362 return result; 363 364 result = attach_hdlc_protocol(dev, &proto, 365 sizeof(struct cisco_state)); 366 if (result) 367 return result; 368 369 memcpy(&state(hdlc)->settings, &new_settings, size); 370 dev->hard_start_xmit = hdlc->xmit; 371 dev->header_ops = &cisco_header_ops; 372 dev->type = ARPHRD_CISCO; 373 netif_dormant_on(dev); 374 return 0; 375 } 376 377 return -EINVAL; 378 } 379 380 381 static int __init mod_init(void) 382 { 383 register_hdlc_protocol(&proto); 384 return 0; 385 } 386 387 388 389 static void __exit mod_exit(void) 390 { 391 unregister_hdlc_protocol(&proto); 392 } 393 394 395 module_init(mod_init); 396 module_exit(mod_exit); 397 398 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 399 MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC"); 400 MODULE_LICENSE("GPL v2"); 401