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
68static 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
101static 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
122static 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
135static 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
142static 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
159static const struct header_ops nr_header_ops = {
160	.create	= nr_header,
161};
162
163static 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
170void 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