1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 5 */ 6 #include <linux/module.h> 7 #include <linux/proc_fs.h> 8 #include <linux/kernel.h> 9 #include <linux/interrupt.h> 10 #include <linux/fs.h> 11 #include <linux/types.h> 12 #include <linux/sysctl.h> 13 #include <linux/string.h> 14 #include <linux/socket.h> 15 #include <linux/errno.h> 16 #include <linux/fcntl.h> 17 #include <linux/in.h> 18 #include <linux/if_ether.h> /* For the statistics structure. */ 19 #include <linux/slab.h> 20 #include <linux/uaccess.h> 21 22 #include <asm/io.h> 23 24 #include <linux/inet.h> 25 #include <linux/netdevice.h> 26 #include <linux/etherdevice.h> 27 #include <linux/if_arp.h> 28 #include <linux/skbuff.h> 29 30 #include <net/ip.h> 31 #include <net/arp.h> 32 33 #include <net/ax25.h> 34 #include <net/netrom.h> 35 36 /* 37 * Only allow IP over NET/ROM frames through if the netrom device is up. 38 */ 39 40 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev) 41 { 42 struct net_device_stats *stats = &dev->stats; 43 44 if (!netif_running(dev)) { 45 stats->rx_dropped++; 46 return 0; 47 } 48 49 stats->rx_packets++; 50 stats->rx_bytes += skb->len; 51 52 skb->protocol = htons(ETH_P_IP); 53 54 /* Spoof incoming device */ 55 skb->dev = dev; 56 skb->mac_header = skb->network_header; 57 skb_reset_network_header(skb); 58 skb->pkt_type = PACKET_HOST; 59 60 netif_rx(skb); 61 62 return 1; 63 } 64 65 static int nr_header(struct sk_buff *skb, struct net_device *dev, 66 unsigned short type, 67 const void *daddr, const void *saddr, unsigned int len) 68 { 69 unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN); 70 71 memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len); 72 buff[6] &= ~AX25_CBIT; 73 buff[6] &= ~AX25_EBIT; 74 buff[6] |= AX25_SSSID_SPARE; 75 buff += AX25_ADDR_LEN; 76 77 if (daddr != NULL) 78 memcpy(buff, daddr, dev->addr_len); 79 buff[6] &= ~AX25_CBIT; 80 buff[6] |= AX25_EBIT; 81 buff[6] |= AX25_SSSID_SPARE; 82 buff += AX25_ADDR_LEN; 83 84 *buff++ = sysctl_netrom_network_ttl_initialiser; 85 86 *buff++ = NR_PROTO_IP; 87 *buff++ = NR_PROTO_IP; 88 *buff++ = 0; 89 *buff++ = 0; 90 *buff++ = NR_PROTOEXT; 91 92 if (daddr != NULL) 93 return 37; 94 95 return -37; 96 } 97 98 static int __must_check nr_set_mac_address(struct net_device *dev, void *addr) 99 { 100 struct sockaddr *sa = addr; 101 int err; 102 103 if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) 104 return 0; 105 106 if (dev->flags & IFF_UP) { 107 err = ax25_listen_register((ax25_address *)sa->sa_data, NULL); 108 if (err) 109 return err; 110 111 ax25_listen_release((ax25_address *)dev->dev_addr, NULL); 112 } 113 114 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); 115 116 return 0; 117 } 118 119 static int nr_open(struct net_device *dev) 120 { 121 int err; 122 123 err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL); 124 if (err) 125 return err; 126 127 netif_start_queue(dev); 128 129 return 0; 130 } 131 132 static int nr_close(struct net_device *dev) 133 { 134 ax25_listen_release((ax25_address *)dev->dev_addr, NULL); 135 netif_stop_queue(dev); 136 return 0; 137 } 138 139 static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev) 140 { 141 struct net_device_stats *stats = &dev->stats; 142 unsigned int len = skb->len; 143 144 if (!nr_route_frame(skb, NULL)) { 145 kfree_skb(skb); 146 stats->tx_errors++; 147 return NETDEV_TX_OK; 148 } 149 150 stats->tx_packets++; 151 stats->tx_bytes += len; 152 153 return NETDEV_TX_OK; 154 } 155 156 static const struct header_ops nr_header_ops = { 157 .create = nr_header, 158 }; 159 160 static const struct net_device_ops nr_netdev_ops = { 161 .ndo_open = nr_open, 162 .ndo_stop = nr_close, 163 .ndo_start_xmit = nr_xmit, 164 .ndo_set_mac_address = nr_set_mac_address, 165 }; 166 167 void nr_setup(struct net_device *dev) 168 { 169 dev->mtu = NR_MAX_PACKET_SIZE; 170 dev->netdev_ops = &nr_netdev_ops; 171 dev->header_ops = &nr_header_ops; 172 dev->hard_header_len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; 173 dev->addr_len = AX25_ADDR_LEN; 174 dev->type = ARPHRD_NETROM; 175 176 /* New-style flags. */ 177 dev->flags = IFF_NOARP; 178 } 179