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 44 int 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 71 static 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 92 static int nr_rebuild_header(struct sk_buff *skb) 93 { 94 return 1; 95 } 96 97 #endif 98 99 static 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 } 131 132 static 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 } 152 153 static 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 } 165 166 static 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 } 172 173 static 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 } 189 190 static const struct header_ops nr_header_ops = { 191 .create = nr_header, 192 .rebuild= nr_rebuild_header, 193 }; 194 195 static 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 }; 201 202 void 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