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