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/module.h>
  10 #include <linux/proc_fs.h>
  11 #include <linux/kernel.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/fs.h>
  14 #include <linux/types.h>
  15 #include <linux/sysctl.h>
  16 #include <linux/string.h>
  17 #include <linux/socket.h>
  18 #include <linux/errno.h>
  19 #include <linux/fcntl.h>
  20 #include <linux/in.h>
  21 #include <linux/if_ether.h>     /* For the statistics structure. */
  22 #include <linux/slab.h>
  23
  24 #include <asm/system.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/io.h>
  27
  28 #include <linux/inet.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/etherdevice.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/skbuff.h>
  33
  34 #include <net/ip.h>
  35 #include <net/arp.h>
  36
  37 #include <net/ax25.h>
  38 #include <net/netrom.h>
  39
  40 /*
  41  *      Only allow IP over NET/ROM frames through if the netrom device is up.
  42  */
  43
  44 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
  45 {
  46         struct net_device_stats *stats = &dev->stats;
  47
  48         if (!netif_running(dev)) {
  49                 stats->rx_dropped++;
  50                 return 0;
  51         }
  52
  53         stats->rx_packets++;
  54         stats->rx_bytes += skb->len;
  55
  56         skb->protocol = htons(ETH_P_IP);
  57
  58         /* Spoof incoming device */
  59         skb->dev      = dev;
  60         skb->mac_header = skb->network_header;
  61         skb_reset_network_header(skb);
  62         skb->pkt_type = PACKET_HOST;
  63
  64         netif_rx(skb);
  65
  66         return 1;
  67 }
  68
  69 #ifdef CONFIG_INET
  70
  71 static int nr_rebuild_header(struct sk_buff *skb)
  72 {
  73         unsigned char *bp = skb->data;
  74
  75         if (arp_find(bp + 7, skb))
  76                 return 1;
  77
  78         bp[6] &= ~AX25_CBIT;
  79         bp[6] &= ~AX25_EBIT;
  80         bp[6] |= AX25_SSSID_SPARE;
  81         bp    += AX25_ADDR_LEN;
  82
  83         bp[6] &= ~AX25_CBIT;
  84         bp[6] |= AX25_EBIT;
  85         bp[6] |= AX25_SSSID_SPARE;
  86
  87         return 0;
  88 }
  89
  90 #else
  91
  92 static int nr_rebuild_header(struct sk_buff *skb)
  93 {
  94         return 1;
  95 }
  96
  97 #endif
  98
  99 static int nr_header(struct sk_buff *skb, struct net_device *dev,
 100                      unsigned short type,
 101                      const void *daddr, const void *saddr, unsigned len)
 102 {
 103         unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
 104
 105         memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
 106         buff[6] &= ~AX25_CBIT;
 107         buff[6] &= ~AX25_EBIT;
 108         buff[6] |= AX25_SSSID_SPARE;
 109         buff    += AX25_ADDR_LEN;
 110
 111         if (daddr != NULL)
 112                 memcpy(buff, daddr, dev->addr_len);
 113         buff[6] &= ~AX25_CBIT;
 114         buff[6] |= AX25_EBIT;
 115         buff[6] |= AX25_SSSID_SPARE;
 116         buff    += AX25_ADDR_LEN;
 117
 118         *buff++ = sysctl_netrom_network_ttl_initialiser;
 119
 120         *buff++ = NR_PROTO_IP;
 121         *buff++ = NR_PROTO_IP;
 122         *buff++ = 0;
 123         *buff++ = 0;
 124         *buff++ = NR_PROTOEXT;
 125
 126         if (daddr != NULL)
 127                 return 37;
 128
 129         return -37;
 130 }
 131
 132 static int __must_check nr_set_mac_address(struct net_device *dev, void *addr)
 133 {
 134         struct sockaddr *sa = addr;
 135         int err;
 136
 137         if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
 138                 return 0;
 139
 140         if (dev->flags & IFF_UP) {
 141                 err = ax25_listen_register((ax25_address *)sa->sa_data, NULL);
 142                 if (err)
 143                         return err;
 144
 145                 ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 146         }
 147
 148         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 149
 150         return 0;
 151 }
 152
 153 static int nr_open(struct net_device *dev)
 154 {
 155         int err;
 156
 157         err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 158         if (err)
 159                 return err;
 160
 161         netif_start_queue(dev);
 162
 163         return 0;
 164 }
 165
 166 static int nr_close(struct net_device *dev)
 167 {
 168         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 169         netif_stop_queue(dev);
 170         return 0;
 171 }
 172
 173 static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev)
 174 {
 175         struct net_device_stats *stats = &dev->stats;
 176         unsigned int len = skb->len;
 177
 178         if (!nr_route_frame(skb, NULL)) {
 179                 kfree_skb(skb);
 180                 stats->tx_errors++;
 181                 return NETDEV_TX_OK;
 182         }
 183
 184         stats->tx_packets++;
 185         stats->tx_bytes += len;
 186
 187         return NETDEV_TX_OK;
 188 }
 189
 190 static const struct header_ops nr_header_ops = {
 191         .create = nr_header,
 192         .rebuild= nr_rebuild_header,
 193 };
 194
 195 static const struct net_device_ops nr_netdev_ops = {
 196         .ndo_open               = nr_open,
 197         .ndo_stop               = nr_close,
 198         .ndo_start_xmit         = nr_xmit,
 199         .ndo_set_mac_address    = nr_set_mac_address,
 200 };
 201
 202 void nr_setup(struct net_device *dev)
 203 {
 204         dev->mtu                = NR_MAX_PACKET_SIZE;
 205         dev->netdev_ops         = &nr_netdev_ops;
 206         dev->header_ops         = &nr_header_ops;
 207         dev->hard_header_len    = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 208         dev->addr_len           = AX25_ADDR_LEN;
 209         dev->type               = ARPHRD_NETROM;
 210
 211         /* New-style flags. */
 212         dev->flags              = IFF_NOARP;
 213 }