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 /*
  42  *      Only allow IP over NET/ROM frames through if the netrom device is up.
  43  */
  44
  45 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
  46 {
  47         struct net_device_stats *stats = netdev_priv(dev);
  48
  49         if (!netif_running(dev)) {
  50                 stats->rx_errors++;
  51                 return 0;
  52         }
  53
  54         stats->rx_packets++;
  55         stats->rx_bytes += skb->len;
  56
  57         skb->protocol = htons(ETH_P_IP);
  58
  59         /* Spoof incoming device */
  60         skb->dev      = dev;
  61         skb->h.raw    = skb->data;
  62         skb->nh.raw   = skb->data;
  63         skb->pkt_type = PACKET_HOST;
  64
  65         netif_rx(skb);
  66
  67         return 1;
  68 }
  69
  70 #ifdef CONFIG_INET
  71
  72 static int nr_rebuild_header(struct sk_buff *skb)
  73 {
  74         struct net_device *dev = skb->dev;
  75         struct net_device_stats *stats = netdev_priv(dev);
  76         struct sk_buff *skbn;
  77         unsigned char *bp = skb->data;
  78         int len;
  79
  80         if (arp_find(bp + 7, skb)) {
  81                 return 1;
  82         }
  83
  84         bp[6] &= ~AX25_CBIT;
  85         bp[6] &= ~AX25_EBIT;
  86         bp[6] |= AX25_SSSID_SPARE;
  87         bp    += AX25_ADDR_LEN;
  88
  89         bp[6] &= ~AX25_CBIT;
  90         bp[6] |= AX25_EBIT;
  91         bp[6] |= AX25_SSSID_SPARE;
  92
  93         if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
  94                 kfree_skb(skb);
  95                 return 1;
  96         }
  97
  98         if (skb->sk != NULL)
  99                 skb_set_owner_w(skbn, skb->sk);
 100
 101         kfree_skb(skb);
 102
 103         len = skbn->len;
 104
 105         if (!nr_route_frame(skbn, NULL)) {
 106                 kfree_skb(skbn);
 107                 stats->tx_errors++;
 108         }
 109
 110         stats->tx_packets++;
 111         stats->tx_bytes += len;
 112
 113         return 1;
 114 }
 115
 116 #else
 117
 118 static int nr_rebuild_header(struct sk_buff *skb)
 119 {
 120         return 1;
 121 }
 122
 123 #endif
 124
 125 static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
 126         void *daddr, void *saddr, unsigned len)
 127 {
 128         unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
 129
 130         memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
 131         buff[6] &= ~AX25_CBIT;
 132         buff[6] &= ~AX25_EBIT;
 133         buff[6] |= AX25_SSSID_SPARE;
 134         buff    += AX25_ADDR_LEN;
 135
 136         if (daddr != NULL)
 137                 memcpy(buff, daddr, dev->addr_len);
 138         buff[6] &= ~AX25_CBIT;
 139         buff[6] |= AX25_EBIT;
 140         buff[6] |= AX25_SSSID_SPARE;
 141         buff    += AX25_ADDR_LEN;
 142
 143         *buff++ = sysctl_netrom_network_ttl_initialiser;
 144
 145         *buff++ = NR_PROTO_IP;
 146         *buff++ = NR_PROTO_IP;
 147         *buff++ = 0;
 148         *buff++ = 0;
 149         *buff++ = NR_PROTOEXT;
 150
 151         if (daddr != NULL)
 152                 return 37;
 153
 154         return -37;
 155 }
 156
 157 static int nr_set_mac_address(struct net_device *dev, void *addr)
 158 {
 159         struct sockaddr *sa = addr;
 160
 161         if (dev->flags & IFF_UP)
 162                 ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 163
 164         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 165
 166         if (dev->flags & IFF_UP)
 167                 ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 168
 169         return 0;
 170 }
 171
 172 static int nr_open(struct net_device *dev)
 173 {
 174         netif_start_queue(dev);
 175         ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 176         return 0;
 177 }
 178
 179 static int nr_close(struct net_device *dev)
 180 {
 181         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 182         netif_stop_queue(dev);
 183         return 0;
 184 }
 185
 186 static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
 187 {
 188         struct net_device_stats *stats = netdev_priv(dev);
 189         dev_kfree_skb(skb);
 190         stats->tx_errors++;
 191         return 0;
 192 }
 193
 194 static struct net_device_stats *nr_get_stats(struct net_device *dev)
 195 {
 196         return netdev_priv(dev);
 197 }
 198
 199 void nr_setup(struct net_device *dev)
 200 {
 201         SET_MODULE_OWNER(dev);
 202         dev->mtu                = NR_MAX_PACKET_SIZE;
 203         dev->hard_start_xmit    = nr_xmit;
 204         dev->open               = nr_open;
 205         dev->stop               = nr_close;
 206
 207         dev->hard_header        = nr_header;
 208         dev->hard_header_len    = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 209         dev->addr_len           = AX25_ADDR_LEN;
 210         dev->type               = ARPHRD_NETROM;
 211         dev->tx_queue_len       = 40;
 212         dev->rebuild_header     = nr_rebuild_header;
 213         dev->set_mac_address    = nr_set_mac_address;
 214
 215         /* New-style flags. */
 216         dev->flags              = 0;
 217
 218         dev->get_stats          = nr_get_stats;
 219 }