drivers/net/wan/hdlc_cisco.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  * Cisco HDLC support
   4  *
   5  * Copyright (C) 2000 - 2003 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 static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
  38                              u16 type, void *daddr, void *saddr,
  39                              unsigned int len)
  40 {
  41         hdlc_header *data;
  42 #ifdef DEBUG_HARD_HEADER
  43         printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
  44 #endif
  45
  46         skb_push(skb, sizeof(hdlc_header));
  47         data = (hdlc_header*)skb->data;
  48         if (type == CISCO_KEEPALIVE)
  49                 data->address = CISCO_MULTICAST;
  50         else
  51                 data->address = CISCO_UNICAST;
  52         data->control = 0;
  53         data->protocol = htons(type);
  54
  55         return sizeof(hdlc_header);
  56 }
  57
  58
  59
  60 static void cisco_keepalive_send(struct net_device *dev, u32 type,
  61                                  u32 par1, u32 par2)
  62 {
  63         struct sk_buff *skb;
  64         cisco_packet *data;
  65
  66         skb = dev_alloc_skb(sizeof(hdlc_header) + sizeof(cisco_packet));
  67         if (!skb) {
  68                 printk(KERN_WARNING
  69                        "%s: Memory squeeze on cisco_keepalive_send()\n",
  70                        dev->name);
  71                 return;
  72         }
  73         skb_reserve(skb, 4);
  74         cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
  75         data = (cisco_packet*)(skb->data + 4);
  76
  77         data->type = htonl(type);
  78         data->par1 = htonl(par1);
  79         data->par2 = htonl(par2);
  80         data->rel = 0xFFFF;
  81         /* we will need do_div here if 1000 % HZ != 0 */
  82         data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
  83
  84         skb_put(skb, sizeof(cisco_packet));
  85         skb->priority = TC_PRIO_CONTROL;
  86         skb->dev = dev;
  87         skb->nh.raw = skb->data;
  88
  89         dev_queue_xmit(skb);
  90 }
  91
  92
  93
  94 static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
  95 {
  96         hdlc_header *data = (hdlc_header*)skb->data;
  97
  98         if (skb->len < sizeof(hdlc_header))
  99                 return __constant_htons(ETH_P_HDLC);
 100
 101         if (data->address != CISCO_MULTICAST &&
 102             data->address != CISCO_UNICAST)
 103                 return __constant_htons(ETH_P_HDLC);
 104
 105         switch(data->protocol) {
 106         case __constant_htons(ETH_P_IP):
 107         case __constant_htons(ETH_P_IPX):
 108         case __constant_htons(ETH_P_IPV6):
 109                 skb_pull(skb, sizeof(hdlc_header));
 110                 return data->protocol;
 111         default:
 112                 return __constant_htons(ETH_P_HDLC);
 113         }
 114 }
 115
 116
 117 static int cisco_rx(struct sk_buff *skb)
 118 {
 119         struct net_device *dev = skb->dev;
 120         hdlc_device *hdlc = dev_to_hdlc(dev);
 121         hdlc_header *data = (hdlc_header*)skb->data;
 122         cisco_packet *cisco_data;
 123         struct in_device *in_dev;
 124         u32 addr, mask;
 125
 126         if (skb->len < sizeof(hdlc_header))
 127                 goto rx_error;
 128
 129         if (data->address != CISCO_MULTICAST &&
 130             data->address != CISCO_UNICAST)
 131                 goto rx_error;
 132
 133         switch(ntohs(data->protocol)) {
 134         case CISCO_SYS_INFO:
 135                 /* Packet is not needed, drop it. */
 136                 dev_kfree_skb_any(skb);
 137                 return NET_RX_SUCCESS;
 138
 139         case CISCO_KEEPALIVE:
 140                 if (skb->len != sizeof(hdlc_header) + CISCO_PACKET_LEN &&
 141                     skb->len != sizeof(hdlc_header) + CISCO_BIG_PACKET_LEN) {
 142                         printk(KERN_INFO "%s: Invalid length of Cisco "
 143                                "control packet (%d bytes)\n",
 144                                dev->name, skb->len);
 145                         goto rx_error;
 146                 }
 147
 148                 cisco_data = (cisco_packet*)(skb->data + sizeof(hdlc_header));
 149
 150                 switch(ntohl (cisco_data->type)) {
 151                 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
 152                         in_dev = dev->ip_ptr;
 153                         addr = 0;
 154                         mask = ~0; /* is the mask correct? */
 155
 156                         if (in_dev != NULL) {
 157                                 struct in_ifaddr **ifap = &in_dev->ifa_list;
 158
 159                                 while (*ifap != NULL) {
 160                                         if (strcmp(dev->name,
 161                                                    (*ifap)->ifa_label) == 0) {
 162                                                 addr = (*ifap)->ifa_local;
 163                                                 mask = (*ifap)->ifa_mask;
 164                                                 break;
 165                                         }
 166                                         ifap = &(*ifap)->ifa_next;
 167                                 }
 168
 169                                 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
 170                                                      addr, mask);
 171                         }
 172                         dev_kfree_skb_any(skb);
 173                         return NET_RX_SUCCESS;
 174
 175                 case CISCO_ADDR_REPLY:
 176                         printk(KERN_INFO "%s: Unexpected Cisco IP address "
 177                                "reply\n", dev->name);
 178                         goto rx_error;
 179
 180                 case CISCO_KEEPALIVE_REQ:
 181                         hdlc->state.cisco.rxseq = ntohl(cisco_data->par1);
 182                         if (hdlc->state.cisco.request_sent &&
 183                             ntohl(cisco_data->par2)==hdlc->state.cisco.txseq) {
 184                                 hdlc->state.cisco.last_poll = jiffies;
 185                                 if (!hdlc->state.cisco.up) {
 186                                         u32 sec, min, hrs, days;
 187                                         sec = ntohl(cisco_data->time) / 1000;
 188                                         min = sec / 60; sec -= min * 60;
 189                                         hrs = min / 60; min -= hrs * 60;
 190                                         days = hrs / 24; hrs -= days * 24;
 191                                         printk(KERN_INFO "%s: Link up (peer "
 192                                                "uptime %ud%uh%um%us)\n",
 193                                                dev->name, days, hrs,
 194                                                min, sec);
 195                                         netif_dormant_off(dev);
 196                                         hdlc->state.cisco.up = 1;
 197                                 }
 198                         }
 199
 200                         dev_kfree_skb_any(skb);
 201                         return NET_RX_SUCCESS;
 202                 } /* switch(keepalive type) */
 203         } /* switch(protocol) */
 204
 205         printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
 206                data->protocol);
 207         dev_kfree_skb_any(skb);
 208         return NET_RX_DROP;
 209
 210  rx_error:
 211         hdlc->stats.rx_errors++; /* Mark error */
 212         dev_kfree_skb_any(skb);
 213         return NET_RX_DROP;
 214 }
 215
 216
 217
 218 static void cisco_timer(unsigned long arg)
 219 {
 220         struct net_device *dev = (struct net_device *)arg;
 221         hdlc_device *hdlc = dev_to_hdlc(dev);
 222
 223         if (hdlc->state.cisco.up &&
 224             time_after(jiffies, hdlc->state.cisco.last_poll +
 225                        hdlc->state.cisco.settings.timeout * HZ)) {
 226                 hdlc->state.cisco.up = 0;
 227                 printk(KERN_INFO "%s: Link down\n", dev->name);
 228                 netif_dormant_on(dev);
 229         }
 230
 231         cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ,
 232                              ++hdlc->state.cisco.txseq,
 233                              hdlc->state.cisco.rxseq);
 234         hdlc->state.cisco.request_sent = 1;
 235         hdlc->state.cisco.timer.expires = jiffies +
 236                 hdlc->state.cisco.settings.interval * HZ;
 237         hdlc->state.cisco.timer.function = cisco_timer;
 238         hdlc->state.cisco.timer.data = arg;
 239         add_timer(&hdlc->state.cisco.timer);
 240 }
 241
 242
 243
 244 static void cisco_start(struct net_device *dev)
 245 {
 246         hdlc_device *hdlc = dev_to_hdlc(dev);
 247         hdlc->state.cisco.up = 0;
 248         hdlc->state.cisco.request_sent = 0;
 249         hdlc->state.cisco.txseq = hdlc->state.cisco.rxseq = 0;
 250
 251         init_timer(&hdlc->state.cisco.timer);
 252         hdlc->state.cisco.timer.expires = jiffies + HZ; /*First poll after 1s*/
 253         hdlc->state.cisco.timer.function = cisco_timer;
 254         hdlc->state.cisco.timer.data = (unsigned long)dev;
 255         add_timer(&hdlc->state.cisco.timer);
 256 }
 257
 258
 259
 260 static void cisco_stop(struct net_device *dev)
 261 {
 262         hdlc_device *hdlc = dev_to_hdlc(dev);
 263         del_timer_sync(&hdlc->state.cisco.timer);
 264         netif_dormant_on(dev);
 265         hdlc->state.cisco.up = 0;
 266         hdlc->state.cisco.request_sent = 0;
 267 }
 268
 269
 270
 271 int hdlc_cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
 272 {
 273         cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
 274         const size_t size = sizeof(cisco_proto);
 275         cisco_proto new_settings;
 276         hdlc_device *hdlc = dev_to_hdlc(dev);
 277         int result;
 278
 279         switch (ifr->ifr_settings.type) {
 280         case IF_GET_PROTO:
 281                 ifr->ifr_settings.type = IF_PROTO_CISCO;
 282                 if (ifr->ifr_settings.size < size) {
 283                         ifr->ifr_settings.size = size; /* data size wanted */
 284                         return -ENOBUFS;
 285                 }
 286                 if (copy_to_user(cisco_s, &hdlc->state.cisco.settings, size))
 287                         return -EFAULT;
 288                 return 0;
 289
 290         case IF_PROTO_CISCO:
 291                 if(!capable(CAP_NET_ADMIN))
 292                         return -EPERM;
 293
 294                 if(dev->flags & IFF_UP)
 295                         return -EBUSY;
 296
 297                 if (copy_from_user(&new_settings, cisco_s, size))
 298                         return -EFAULT;
 299
 300                 if (new_settings.interval < 1 ||
 301                     new_settings.timeout < 2)
 302                         return -EINVAL;
 303
 304                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
 305
 306                 if (result)
 307                         return result;
 308
 309                 hdlc_proto_detach(hdlc);
 310                 memcpy(&hdlc->state.cisco.settings, &new_settings, size);
 311                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
 312
 313                 hdlc->proto.start = cisco_start;
 314                 hdlc->proto.stop = cisco_stop;
 315                 hdlc->proto.netif_rx = cisco_rx;
 316                 hdlc->proto.type_trans = cisco_type_trans;
 317                 hdlc->proto.id = IF_PROTO_CISCO;
 318                 dev->hard_start_xmit = hdlc->xmit;
 319                 dev->hard_header = cisco_hard_header;
 320                 dev->hard_header_cache = NULL;
 321                 dev->type = ARPHRD_CISCO;
 322                 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
 323                 dev->addr_len = 0;
 324                 netif_dormant_on(dev);
 325                 return 0;
 326         }
 327
 328         return -EINVAL;
 329 }