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
43int 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
70static 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
91static int nr_rebuild_header(struct sk_buff *skb)
92{
93	return 1;
94}
95
96#endif
97
98static int nr_header(struct sk_buff *skb, struct net_device *dev,
99		     unsigned short type,
100		     const void *daddr, const void *saddr, unsigned int 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
131static 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
152static 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
165static 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
172static 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
189static const struct header_ops nr_header_ops = {
190	.create	= nr_header,
191	.rebuild= nr_rebuild_header,
192};
193
194static 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
201void 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