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