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 static int nr_header(struct sk_buff *skb, struct net_device *dev, 69 unsigned short type, 70 const void *daddr, const void *saddr, unsigned int len) 71 { 72 unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN); 73 74 memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len); 75 buff[6] &= ~AX25_CBIT; 76 buff[6] &= ~AX25_EBIT; 77 buff[6] |= AX25_SSSID_SPARE; 78 buff += AX25_ADDR_LEN; 79 80 if (daddr != NULL) 81 memcpy(buff, daddr, dev->addr_len); 82 buff[6] &= ~AX25_CBIT; 83 buff[6] |= AX25_EBIT; 84 buff[6] |= AX25_SSSID_SPARE; 85 buff += AX25_ADDR_LEN; 86 87 *buff++ = sysctl_netrom_network_ttl_initialiser; 88 89 *buff++ = NR_PROTO_IP; 90 *buff++ = NR_PROTO_IP; 91 *buff++ = 0; 92 *buff++ = 0; 93 *buff++ = NR_PROTOEXT; 94 95 if (daddr != NULL) 96 return 37; 97 98 return -37; 99 } 100 101 static int __must_check nr_set_mac_address(struct net_device *dev, void *addr) 102 { 103 struct sockaddr *sa = addr; 104 int err; 105 106 if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) 107 return 0; 108 109 if (dev->flags & IFF_UP) { 110 err = ax25_listen_register((ax25_address *)sa->sa_data, NULL); 111 if (err) 112 return err; 113 114 ax25_listen_release((ax25_address *)dev->dev_addr, NULL); 115 } 116 117 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 118 119 return 0; 120 } 121 122 static int nr_open(struct net_device *dev) 123 { 124 int err; 125 126 err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL); 127 if (err) 128 return err; 129 130 netif_start_queue(dev); 131 132 return 0; 133 } 134 135 static int nr_close(struct net_device *dev) 136 { 137 ax25_listen_release((ax25_address *)dev->dev_addr, NULL); 138 netif_stop_queue(dev); 139 return 0; 140 } 141 142 static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev) 143 { 144 struct net_device_stats *stats = &dev->stats; 145 unsigned int len = skb->len; 146 147 if (!nr_route_frame(skb, NULL)) { 148 kfree_skb(skb); 149 stats->tx_errors++; 150 return NETDEV_TX_OK; 151 } 152 153 stats->tx_packets++; 154 stats->tx_bytes += len; 155 156 return NETDEV_TX_OK; 157 } 158 159 static const struct header_ops nr_header_ops = { 160 .create = nr_header, 161 }; 162 163 static const struct net_device_ops nr_netdev_ops = { 164 .ndo_open = nr_open, 165 .ndo_stop = nr_close, 166 .ndo_start_xmit = nr_xmit, 167 .ndo_set_mac_address = nr_set_mac_address, 168 }; 169 170 void nr_setup(struct net_device *dev) 171 { 172 dev->mtu = NR_MAX_PACKET_SIZE; 173 dev->netdev_ops = &nr_netdev_ops; 174 dev->header_ops = &nr_header_ops; 175 dev->hard_header_len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; 176 dev->addr_len = AX25_ADDR_LEN; 177 dev->type = ARPHRD_NETROM; 178 179 /* New-style flags. */ 180 dev->flags = IFF_NOARP; 181 } 182