net/netrom/nr_dev.c

   1 /*
   2  *      NET/ROM release 007
   3  *
   4  *      This code REQUIRES 2.1.15 or higher/ NET3.038
   5  *
   6  *      This module:
   7  *              This module is free software; you can redistribute it and/or
   8  *              modify it under the terms of the GNU General Public License
   9  *              as published by the Free Software Foundation; either version
  10  *              2 of the License, or (at your option) any later version.
  11  *
  12  *      History
  13  *      NET/ROM 001     Jonathan(G4KLX) Cloned from loopback.c
  14  *      NET/ROM 002     Steve Whitehouse(GW7RRM) fixed the set_mac_address
  15  *      NET/ROM 003     Jonathan(G4KLX) Put nr_rebuild_header into line with
  16  *                                      ax25_rebuild_header
  17  *      NET/ROM 004     Jonathan(G4KLX) Callsign registration with AX.25.
  18  *      NET/ROM 006     Hans(PE1AYX)    Fixed interface to IP layer.
  19  */
  20
  21 #include <linux/config.h>
  22 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
  23 #define __NO_VERSION__
  24 #include <linux/module.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/kernel.h>
  27 #include <linux/sched.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/fs.h>
  30 #include <linux/types.h>
  31 #include <linux/sysctl.h>
  32 #include <linux/string.h>
  33 #include <linux/socket.h>
  34 #include <linux/errno.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/in.h>
  37 #include <linux/if_ether.h>     /* For the statistics structure. */
  38
  39 #include <asm/system.h>
  40 #include <asm/uaccess.h>
  41 #include <asm/io.h>
  42
  43 #include <linux/inet.h>
  44 #include <linux/netdevice.h>
  45 #include <linux/etherdevice.h>
  46 #include <linux/if_arp.h>
  47 #include <linux/skbuff.h>
  48
  49 #include <net/ip.h>
  50 #include <net/arp.h>
  51
  52 #include <net/ax25.h>
  53 #include <net/netrom.h>
  54
  55 #ifdef CONFIG_INET
  56
  57 /*
  58  *      Only allow IP over NET/ROM frames through if the netrom device is up.
  59  */
  60
  61 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
  62 {
  63         struct net_device_stats *stats = (struct net_device_stats *)dev->priv;
  64
  65         if (!netif_running(dev)) {
  66                 stats->rx_errors++;
  67                 return 0;
  68         }
  69
  70         stats->rx_packets++;
  71         stats->rx_bytes += skb->len;
  72
  73         skb->protocol = htons(ETH_P_IP);
  74
  75         /* Spoof incoming device */
  76         skb->dev      = dev;
  77         skb->h.raw    = skb->data;
  78         skb->nh.raw   = skb->data;
  79         skb->pkt_type = PACKET_HOST;
  80
  81         ip_rcv(skb, skb->dev, NULL);
  82
  83         return 1;
  84 }
  85
  86
  87 static int nr_rebuild_header(struct sk_buff *skb)
  88 {
  89         struct net_device *dev = skb->dev;
  90         struct net_device_stats *stats = (struct net_device_stats *)dev->priv;
  91         struct sk_buff *skbn;
  92         unsigned char *bp = skb->data;
  93
  94         if (arp_find(bp + 7, skb)) {
  95                 return 1;
  96         }
  97
  98         bp[6] &= ~AX25_CBIT;
  99         bp[6] &= ~AX25_EBIT;
 100         bp[6] |= AX25_SSSID_SPARE;
 101         bp    += AX25_ADDR_LEN;
 102
 103         bp[6] &= ~AX25_CBIT;
 104         bp[6] |= AX25_EBIT;
 105         bp[6] |= AX25_SSSID_SPARE;
 106
 107         if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
 108                 kfree_skb(skb);
 109                 return 1;
 110         }
 111
 112         if (skb->sk != NULL)
 113                 skb_set_owner_w(skbn, skb->sk);
 114
 115         kfree_skb(skb);
 116
 117         if (!nr_route_frame(skbn, NULL)) {
 118                 kfree_skb(skbn);
 119                 stats->tx_errors++;
 120         }
 121
 122         stats->tx_packets++;
 123         stats->tx_bytes += skbn->len;
 124
 125         return 1;
 126 }
 127
 128 #else
 129
 130 static int nr_rebuild_header(struct sk_buff *skb)
 131 {
 132         return 1;
 133 }
 134
 135 #endif
 136
 137 static int nr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
 138         void *daddr, void *saddr, unsigned len)
 139 {
 140         unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
 141
 142         memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
 143         buff[6] &= ~AX25_CBIT;
 144         buff[6] &= ~AX25_EBIT;
 145         buff[6] |= AX25_SSSID_SPARE;
 146         buff    += AX25_ADDR_LEN;
 147
 148         if (daddr != NULL)
 149                 memcpy(buff, daddr, dev->addr_len);
 150         buff[6] &= ~AX25_CBIT;
 151         buff[6] |= AX25_EBIT;
 152         buff[6] |= AX25_SSSID_SPARE;
 153         buff    += AX25_ADDR_LEN;
 154
 155         *buff++ = sysctl_netrom_network_ttl_initialiser;
 156
 157         *buff++ = NR_PROTO_IP;
 158         *buff++ = NR_PROTO_IP;
 159         *buff++ = 0;
 160         *buff++ = 0;
 161         *buff++ = NR_PROTOEXT;
 162
 163         if (daddr != NULL)
 164                 return 37;
 165
 166         return -37;
 167 }
 168
 169 static int nr_set_mac_address(struct net_device *dev, void *addr)
 170 {
 171         struct sockaddr *sa = addr;
 172
 173         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 174
 175         memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
 176
 177         ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 178
 179         return 0;
 180 }
 181
 182 static int nr_open(struct net_device *dev)
 183 {
 184         MOD_INC_USE_COUNT;
 185         netif_start_queue(dev);
 186         ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
 187         return 0;
 188 }
 189
 190 static int nr_close(struct net_device *dev)
 191 {
 192         netif_stop_queue(dev);
 193         ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
 194         MOD_DEC_USE_COUNT;
 195         return 0;
 196 }
 197
 198 static int nr_xmit(struct sk_buff *skb, struct net_device *dev)
 199 {
 200         struct net_device_stats *stats = (struct net_device_stats *)dev->priv;
 201         dev_kfree_skb(skb);
 202         stats->tx_errors++;
 203         return 0;
 204 }
 205
 206 static struct net_device_stats *nr_get_stats(struct net_device *dev)
 207 {
 208         return (struct net_device_stats *)dev->priv;
 209 }
 210
 211 int nr_init(struct net_device *dev)
 212 {
 213         dev->mtu                = NR_MAX_PACKET_SIZE;
 214         dev->hard_start_xmit    = nr_xmit;
 215         dev->open               = nr_open;
 216         dev->stop               = nr_close;
 217
 218         dev->hard_header        = nr_header;
 219         dev->hard_header_len    = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + NR_NETWORK_LEN + NR_TRANSPORT_LEN;
 220         dev->addr_len           = AX25_ADDR_LEN;
 221         dev->type               = ARPHRD_NETROM;
 222         dev->rebuild_header     = nr_rebuild_header;
 223         dev->set_mac_address    = nr_set_mac_address;
 224
 225         /* New-style flags. */
 226         dev->flags              = 0;
 227
 228         if ((dev->priv = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL)) == NULL)
 229                 return -ENOMEM;
 230
 231         memset(dev->priv, 0, sizeof(struct net_device_stats));
 232
 233         dev->get_stats = nr_get_stats;
 234
 235         dev_init_buffers(dev);
 236
 237         return 0;
 238 };
 239
 240 #endif