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 #include <linux/uaccess.h> 24 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 int 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 } 213