linux/net/netrom/nr_dev.c
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   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
  44int 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
  71static 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
  92static int nr_rebuild_header(struct sk_buff *skb)
  93{
  94        return 1;
  95}
  96
  97#endif
  98
  99static 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
 132static 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
 153static 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
 166static 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
 173static 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
 190static const struct header_ops nr_header_ops = {
 191        .create = nr_header,
 192        .rebuild= nr_rebuild_header,
 193};
 194
 195static 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
 202void 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}
 214
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