net/netrom/nr_dev.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   8  */
   9 #include <linux/config.h>
  10 #include <linux/module.h>
  11 #include <linux/proc_fs.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/fs.h>
  16 #include <linux/types.h>
  17 #include <linux/sysctl.h>
  18 #include <linux/string.h>
  19 #include <linux/socket.h>
  20 #include <linux/errno.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/in.h>
  23 #include <linux/if_ether.h>     /* For the statistics structure. */
  24
  25 #include <asm/system.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/io.h>
  28
  29 #include <linux/inet.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/etherdevice.h>
  32 #include <linux/if_arp.h>
  33 #include <linux/skbuff.h>
  34
  35 #include <net/ip.h>
  36 #include <net/arp.h>
  37
  38 #include <net/ax25.h>
  39 #include <net/netrom.h>
  40
  41 #ifdef CONFIG_INET
  42
  43 /*
  44  *      Only allow IP over NET/ROM frames through if the netrom device is up.
  45  */
  46
  47 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
  48 {
  49         struct net_device_stats *stats = netdev_priv(dev);
  50
  51         if (!netif_running(dev)) {
  52                 stats->rx_errors++;
  53                 return 0;
  54         }
  55
  56         stats->rx_packets++;
  57         stats->rx_bytes += skb->len;
  58
  59         skb->protocol = htons(ETH_P_IP);
  60
  61         /* Spoof incoming device */
  62         skb->dev      = dev;
  63         skb->h.raw    = skb->data;
  64         skb->nh.raw   = skb->data;
  65         skb->pkt_type = PACKET_HOST;
  66
  67         ip_rcv(skb, skb->dev, NULL);
  68
  69         return 1;
  70 }
  71
  72
  73 static int nr_rebuild_header(struct sk_buff *skb)
  74 {
  75         struct net_device *dev = skb->dev;
  76         struct net_device_stats *stats = netdev_priv(dev);
  77         struct sk_buff *skbn;
  78         unsigned char *bp = skb->data;
  79         int len;
  80
  81         if (arp_find(bp + 7, skb)) {
  82                 return 1;
  83         }
  84
  85         bp[6] &= ~AX25_CBIT;
  86         bp[6] &= ~AX25_EBIT;
  87         bp[6] |= AX25_SSSID_SPARE;
  88         bp    += AX25_ADDR_LEN;
  89
  90         bp[6] &= ~AX25_CBIT;
  91         bp[6] |= AX25_EBIT;
  92         bp[6] |= AX25_SSSID_SPARE;
  93
  94         if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
  95                 kfree_skb(skb);
  96                 return 1;
  97         }
  98
  99         if (skb->sk != NULL)
 100                 skb_set_owner_w(skbn, skb->sk);
 101
 102         kfree_skb(skb);
 103
 104         len = skbn->len;
 105
 106         if (!nr_route_frame(skbn, NULL)) {
 107                 kfree_skb(skbn);
 108                 stats->tx_errors++;
 109         }
 110
 111         stats->tx_packets++;
 112         stats->tx_bytes += len;
 113
 114         return 1;
 115 }
 116
 117 #else
 118
 119 static int nr_rebuild_header(struct sk_buff *skb)
 120 {
 121         return 1;
 122 }
 123
 124 #endif
 125
 126 static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
 127         void *daddr, void *saddr, unsigned len)
 128 {
 129         unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
 130
 131         memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
 132         buff[6] &= ~AX25_CBIT;
 133         buff[6] &= ~AX25_EBIT;
 134         buff[6] |= AX25_SSSID_SPARE;
 135         buff    += AX25_ADDR_LEN;
 136
 137         if (daddr != NULL)
 138                 memcpy(buff, daddr, dev->addr_len);
 139         buff[6] &= ~AX25_CBIT;
 140         buff[6] |= AX25_EBIT;
 141         buff[6] |= AX25_SSSID_SPARE;
 142         buff    += AX25_ADDR_LEN;
 143
 144         *buff++ = sysctl_netrom_network_ttl_initialiser;
 145
 146         *buff++ = NR_PROTO_IP;
 147         *buff++ = NR_PROTO_IP;
 148         *buff++ = 0;
 149         *buff++ = 0;
 150         *buff++ = NR_PROTOEXT;
 151
 152         if (daddr != NULL)
 153                 return 37;
 154
 155         return -37;
 156 }
 157
 158 static int nr_set_mac_address(struct net_device *dev, void *addr)
 159 {
 160         struct sockaddr *sa = addr;
 161
 162         if (dev->flags & IFF_UP)
 163                 ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 164
 165         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 166
 167         if (dev->flags & IFF_UP)
 168                 ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 169
 170         return 0;
 171 }
 172
 173 static int nr_open(struct net_device *dev)
 174 {
 175         netif_start_queue(dev);
 176         ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 177         return 0;
 178 }
 179
 180 static int nr_close(struct net_device *dev)
 181 {
 182         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 183         netif_stop_queue(dev);
 184         return 0;
 185 }
 186
 187 static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
 188 {
 189         struct net_device_stats *stats = netdev_priv(dev);
 190         dev_kfree_skb(skb);
 191         stats->tx_errors++;
 192         return 0;
 193 }
 194
 195 static struct net_device_stats *nr_get_stats(struct net_device *dev)
 196 {
 197         return netdev_priv(dev);
 198 }
 199
 200 void nr_setup(struct net_device *dev)
 201 {
 202         SET_MODULE_OWNER(dev);
 203         dev->mtu                = NR_MAX_PACKET_SIZE;
 204         dev->hard_start_xmit    = nr_xmit;
 205         dev->open               = nr_open;
 206         dev->stop               = nr_close;
 207
 208         dev->hard_header        = nr_header;
 209         dev->hard_header_len    = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 210         dev->addr_len           = AX25_ADDR_LEN;
 211         dev->type               = ARPHRD_NETROM;
 212         dev->tx_queue_len       = 40;
 213         dev->rebuild_header     = nr_rebuild_header;
 214         dev->set_mac_address    = nr_set_mac_address;
 215
 216         /* New-style flags. */
 217         dev->flags              = 0;
 218
 219         dev->get_stats          = nr_get_stats;
 220 }