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->tail;
  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 unsigned short cisco_type_trans(struct sk_buff *skb,
  95                                        struct net_device *dev)
  96 {
  97         hdlc_header *data = (hdlc_header*)skb->data;
  98
  99         if (skb->len < sizeof(hdlc_header))
 100                 return __constant_htons(ETH_P_HDLC);
 101
 102         if (data->address != CISCO_MULTICAST &&
 103             data->address != CISCO_UNICAST)
 104                 return __constant_htons(ETH_P_HDLC);
 105
 106         switch(data->protocol) {
 107         case __constant_htons(ETH_P_IP):
 108         case __constant_htons(ETH_P_IPX):
 109         case __constant_htons(ETH_P_IPV6):
 110                 skb_pull(skb, sizeof(hdlc_header));
 111                 return data->protocol;
 112         default:
 113                 return __constant_htons(ETH_P_HDLC);
 114         }
 115 }
 116
 117
 118 static int cisco_rx(struct sk_buff *skb)
 119 {
 120         struct net_device *dev = skb->dev;
 121         hdlc_device *hdlc = dev_to_hdlc(dev);
 122         hdlc_header *data = (hdlc_header*)skb->data;
 123         cisco_packet *cisco_data;
 124         struct in_device *in_dev;
 125         u32 addr, mask;
 126
 127         if (skb->len < sizeof(hdlc_header))
 128                 goto rx_error;
 129
 130         if (data->address != CISCO_MULTICAST &&
 131             data->address != CISCO_UNICAST)
 132                 goto rx_error;
 133
 134         switch(ntohs(data->protocol)) {
 135         case CISCO_SYS_INFO:
 136                 /* Packet is not needed, drop it. */
 137                 dev_kfree_skb_any(skb);
 138                 return NET_RX_SUCCESS;
 139
 140         case CISCO_KEEPALIVE:
 141                 if (skb->len != sizeof(hdlc_header) + CISCO_PACKET_LEN &&
 142                     skb->len != sizeof(hdlc_header) + CISCO_BIG_PACKET_LEN) {
 143                         printk(KERN_INFO "%s: Invalid length of Cisco "
 144                                "control packet (%d bytes)\n",
 145                                dev->name, skb->len);
 146                         goto rx_error;
 147                 }
 148
 149                 cisco_data = (cisco_packet*)(skb->data + sizeof(hdlc_header));
 150
 151                 switch(ntohl (cisco_data->type)) {
 152                 case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
 153                         in_dev = dev->ip_ptr;
 154                         addr = 0;
 155                         mask = ~0; /* is the mask correct? */
 156
 157                         if (in_dev != NULL) {
 158                                 struct in_ifaddr **ifap = &in_dev->ifa_list;
 159
 160                                 while (*ifap != NULL) {
 161                                         if (strcmp(dev->name,
 162                                                    (*ifap)->ifa_label) == 0) {
 163                                                 addr = (*ifap)->ifa_local;
 164                                                 mask = (*ifap)->ifa_mask;
 165                                                 break;
 166                                         }
 167                                         ifap = &(*ifap)->ifa_next;
 168                                 }
 169
 170                                 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
 171                                                      addr, mask);
 172                         }
 173                         dev_kfree_skb_any(skb);
 174                         return NET_RX_SUCCESS;
 175
 176                 case CISCO_ADDR_REPLY:
 177                         printk(KERN_INFO "%s: Unexpected Cisco IP address "
 178                                "reply\n", dev->name);
 179                         goto rx_error;
 180
 181                 case CISCO_KEEPALIVE_REQ:
 182                         hdlc->state.cisco.rxseq = ntohl(cisco_data->par1);
 183                         if (hdlc->state.cisco.request_sent &&
 184                             ntohl(cisco_data->par2)==hdlc->state.cisco.txseq) {
 185                                 hdlc->state.cisco.last_poll = jiffies;
 186                                 if (!hdlc->state.cisco.up) {
 187                                         u32 sec, min, hrs, days;
 188                                         sec = ntohl(cisco_data->time) / 1000;
 189                                         min = sec / 60; sec -= min * 60;
 190                                         hrs = min / 60; min -= hrs * 60;
 191                                         days = hrs / 24; hrs -= days * 24;
 192                                         printk(KERN_INFO "%s: Link up (peer "
 193                                                "uptime %ud%uh%um%us)\n",
 194                                                dev->name, days, hrs,
 195                                                min, sec);
 196                                         netif_carrier_on(dev);
 197                                         hdlc->state.cisco.up = 1;
 198                                 }
 199                         }
 200
 201                         dev_kfree_skb_any(skb);
 202                         return NET_RX_SUCCESS;
 203                 } /* switch(keepalive type) */
 204         } /* switch(protocol) */
 205
 206         printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
 207                data->protocol);
 208         dev_kfree_skb_any(skb);
 209         return NET_RX_DROP;
 210
 211  rx_error:
 212         hdlc->stats.rx_errors++; /* Mark error */
 213         dev_kfree_skb_any(skb);
 214         return NET_RX_DROP;
 215 }
 216
 217
 218
 219 static void cisco_timer(unsigned long arg)
 220 {
 221         struct net_device *dev = (struct net_device *)arg;
 222         hdlc_device *hdlc = dev_to_hdlc(dev);
 223
 224         if (hdlc->state.cisco.up &&
 225             time_after(jiffies, hdlc->state.cisco.last_poll +
 226                        hdlc->state.cisco.settings.timeout * HZ)) {
 227                 hdlc->state.cisco.up = 0;
 228                 printk(KERN_INFO "%s: Link down\n", dev->name);
 229                 netif_carrier_off(dev);
 230         }
 231
 232         cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ,
 233                              ++hdlc->state.cisco.txseq,
 234                              hdlc->state.cisco.rxseq);
 235         hdlc->state.cisco.request_sent = 1;
 236         hdlc->state.cisco.timer.expires = jiffies +
 237                 hdlc->state.cisco.settings.interval * HZ;
 238         hdlc->state.cisco.timer.function = cisco_timer;
 239         hdlc->state.cisco.timer.data = arg;
 240         add_timer(&hdlc->state.cisco.timer);
 241 }
 242
 243
 244
 245 static void cisco_start(struct net_device *dev)
 246 {
 247         hdlc_device *hdlc = dev_to_hdlc(dev);
 248         hdlc->state.cisco.up = 0;
 249         hdlc->state.cisco.request_sent = 0;
 250         hdlc->state.cisco.txseq = hdlc->state.cisco.rxseq = 0;
 251
 252         init_timer(&hdlc->state.cisco.timer);
 253         hdlc->state.cisco.timer.expires = jiffies + HZ; /*First poll after 1s*/
 254         hdlc->state.cisco.timer.function = cisco_timer;
 255         hdlc->state.cisco.timer.data = (unsigned long)dev;
 256         add_timer(&hdlc->state.cisco.timer);
 257 }
 258
 259
 260
 261 static void cisco_stop(struct net_device *dev)
 262 {
 263         hdlc_device *hdlc = dev_to_hdlc(dev);
 264         del_timer_sync(&hdlc->state.cisco.timer);
 265         if (netif_carrier_ok(dev))
 266                 netif_carrier_off(dev);
 267         hdlc->state.cisco.up = 0;
 268         hdlc->state.cisco.request_sent = 0;
 269 }
 270
 271
 272
 273 int hdlc_cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
 274 {
 275         cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
 276         const size_t size = sizeof(cisco_proto);
 277         cisco_proto new_settings;
 278         hdlc_device *hdlc = dev_to_hdlc(dev);
 279         int result;
 280
 281         switch (ifr->ifr_settings.type) {
 282         case IF_GET_PROTO:
 283                 ifr->ifr_settings.type = IF_PROTO_CISCO;
 284                 if (ifr->ifr_settings.size < size) {
 285                         ifr->ifr_settings.size = size; /* data size wanted */
 286                         return -ENOBUFS;
 287                 }
 288                 if (copy_to_user(cisco_s, &hdlc->state.cisco.settings, size))
 289                         return -EFAULT;
 290                 return 0;
 291
 292         case IF_PROTO_CISCO:
 293                 if(!capable(CAP_NET_ADMIN))
 294                         return -EPERM;
 295
 296                 if(dev->flags & IFF_UP)
 297                         return -EBUSY;
 298
 299                 if (copy_from_user(&new_settings, cisco_s, size))
 300                         return -EFAULT;
 301
 302                 if (new_settings.interval < 1 ||
 303                     new_settings.timeout < 2)
 304                         return -EINVAL;
 305
 306                 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
 307
 308                 if (result)
 309                         return result;
 310
 311                 hdlc_proto_detach(hdlc);
 312                 memcpy(&hdlc->state.cisco.settings, &new_settings, size);
 313                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
 314
 315                 hdlc->proto.start = cisco_start;
 316                 hdlc->proto.stop = cisco_stop;
 317                 hdlc->proto.netif_rx = cisco_rx;
 318                 hdlc->proto.type_trans = cisco_type_trans;
 319                 hdlc->proto.id = IF_PROTO_CISCO;
 320                 dev->hard_start_xmit = hdlc->xmit;
 321                 dev->hard_header = cisco_hard_header;
 322                 dev->hard_header_cache = NULL;
 323                 dev->type = ARPHRD_CISCO;
 324                 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
 325                 dev->addr_len = 0;
 326                 return 0;
 327         }
 328
 329         return -EINVAL;
 330 }