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_dropped++;
  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->mac.raw  = skb->nh.raw;
  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         unsigned char *bp = skb->data;
  75
  76         if (arp_find(bp + 7, skb))
  77                 return 1;
  78
  79         bp[6] &= ~AX25_CBIT;
  80         bp[6] &= ~AX25_EBIT;
  81         bp[6] |= AX25_SSSID_SPARE;
  82         bp    += AX25_ADDR_LEN;
  83
  84         bp[6] &= ~AX25_CBIT;
  85         bp[6] |= AX25_EBIT;
  86         bp[6] |= AX25_SSSID_SPARE;
  87
  88         return 0;
  89 }
  90
  91 #else
  92
  93 static int nr_rebuild_header(struct sk_buff *skb)
  94 {
  95         return 1;
  96 }
  97
  98 #endif
  99
 100 static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
 101         void *daddr, 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 nr_set_mac_address(struct net_device *dev, void *addr)
 133 {
 134         struct sockaddr *sa = addr;
 135
 136         if (dev->flags & IFF_UP)
 137                 ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 138
 139         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 140
 141         if (dev->flags & IFF_UP)
 142                 ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 143
 144         return 0;
 145 }
 146
 147 static int nr_open(struct net_device *dev)
 148 {
 149         netif_start_queue(dev);
 150         ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 151         return 0;
 152 }
 153
 154 static int nr_close(struct net_device *dev)
 155 {
 156         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 157         netif_stop_queue(dev);
 158         return 0;
 159 }
 160
 161 static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
 162 {
 163         struct nr_private *nr = netdev_priv(dev);
 164         struct net_device_stats *stats = &nr->stats;
 165         unsigned int len = skb->len;
 166
 167         if (!nr_route_frame(skb, NULL)) {
 168                 kfree_skb(skb);
 169                 stats->tx_errors++;
 170                 return 0;
 171         }
 172
 173         stats->tx_packets++;
 174         stats->tx_bytes += len;
 175
 176         return 0;
 177 }
 178
 179 static struct net_device_stats *nr_get_stats(struct net_device *dev)
 180 {
 181         struct nr_private *nr = netdev_priv(dev);
 182
 183         return &nr->stats;
 184 }
 185
 186 void nr_setup(struct net_device *dev)
 187 {
 188         SET_MODULE_OWNER(dev);
 189         dev->mtu                = NR_MAX_PACKET_SIZE;
 190         dev->hard_start_xmit    = nr_xmit;
 191         dev->open               = nr_open;
 192         dev->stop               = nr_close;
 193
 194         dev->hard_header        = nr_header;
 195         dev->hard_header_len    = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 196         dev->addr_len           = AX25_ADDR_LEN;
 197         dev->type               = ARPHRD_NETROM;
 198         dev->rebuild_header     = nr_rebuild_header;
 199         dev->set_mac_address    = nr_set_mac_address;
 200
 201         /* New-style flags. */
 202         dev->flags              = IFF_NOARP;
 203
 204         dev->get_stats          = nr_get_stats;
 205 }