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/uaccess.h>
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
nr_rx_ip(struct sk_buff * skb,struct net_device * dev)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
nr_rebuild_header(struct sk_buff * skb)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
nr_rebuild_header(struct sk_buff * skb)91 static int nr_rebuild_header(struct sk_buff *skb)
92 {
93 return 1;
94 }
95
96 #endif
97
nr_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)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 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
nr_set_mac_address(struct net_device * dev,void * addr)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
nr_open(struct net_device * dev)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
nr_close(struct net_device * dev)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
nr_xmit(struct sk_buff * skb,struct net_device * dev)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
nr_setup(struct net_device * dev)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