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 (C) 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>
22 #include <linux/slab.h>
23 
24 #include <asm/system.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/rose.h>
38 
rose_header(struct sk_buff * skb,struct net_device * dev,unsigned short type,const void * daddr,const void * saddr,unsigned len)39 static int rose_header(struct sk_buff *skb, struct net_device *dev,
40 		       unsigned short type,
41 		       const void *daddr, const void *saddr, unsigned len)
42 {
43 	unsigned char *buff = skb_push(skb, ROSE_MIN_LEN + 2);
44 
45 	*buff++ = ROSE_GFI | ROSE_Q_BIT;
46 	*buff++ = 0x00;
47 	*buff++ = ROSE_DATA;
48 	*buff++ = 0x7F;
49 	*buff++ = AX25_P_IP;
50 
51 	if (daddr != NULL)
52 		return 37;
53 
54 	return -37;
55 }
56 
rose_rebuild_header(struct sk_buff * skb)57 static int rose_rebuild_header(struct sk_buff *skb)
58 {
59 #ifdef CONFIG_INET
60 	struct net_device *dev = skb->dev;
61 	struct net_device_stats *stats = &dev->stats;
62 	unsigned char *bp = (unsigned char *)skb->data;
63 	struct sk_buff *skbn;
64 	unsigned int len;
65 
66 	if (arp_find(bp + 7, skb)) {
67 		return 1;
68 	}
69 
70 	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
71 		kfree_skb(skb);
72 		return 1;
73 	}
74 
75 	if (skb->sk != NULL)
76 		skb_set_owner_w(skbn, skb->sk);
77 
78 	kfree_skb(skb);
79 
80 	len = skbn->len;
81 
82 	if (!rose_route_frame(skbn, NULL)) {
83 		kfree_skb(skbn);
84 		stats->tx_errors++;
85 		return 1;
86 	}
87 
88 	stats->tx_packets++;
89 	stats->tx_bytes += len;
90 #endif
91 	return 1;
92 }
93 
rose_set_mac_address(struct net_device * dev,void * addr)94 static int rose_set_mac_address(struct net_device *dev, void *addr)
95 {
96 	struct sockaddr *sa = addr;
97 	int err;
98 
99 	if (!memcpy(dev->dev_addr, sa->sa_data, dev->addr_len))
100 		return 0;
101 
102 	if (dev->flags & IFF_UP) {
103 		err = rose_add_loopback_node((rose_address *)dev->dev_addr);
104 		if (err)
105 			return err;
106 
107 		rose_del_loopback_node((rose_address *)dev->dev_addr);
108 	}
109 
110 	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
111 
112 	return 0;
113 }
114 
rose_open(struct net_device * dev)115 static int rose_open(struct net_device *dev)
116 {
117 	int err;
118 
119 	err = rose_add_loopback_node((rose_address *)dev->dev_addr);
120 	if (err)
121 		return err;
122 
123 	netif_start_queue(dev);
124 
125 	return 0;
126 }
127 
rose_close(struct net_device * dev)128 static int rose_close(struct net_device *dev)
129 {
130 	netif_stop_queue(dev);
131 	rose_del_loopback_node((rose_address *)dev->dev_addr);
132 	return 0;
133 }
134 
rose_xmit(struct sk_buff * skb,struct net_device * dev)135 static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)
136 {
137 	struct net_device_stats *stats = &dev->stats;
138 
139 	if (!netif_running(dev)) {
140 		printk(KERN_ERR "ROSE: rose_xmit - called when iface is down\n");
141 		return NETDEV_TX_BUSY;
142 	}
143 	dev_kfree_skb(skb);
144 	stats->tx_errors++;
145 	return NETDEV_TX_OK;
146 }
147 
148 static const struct header_ops rose_header_ops = {
149 	.create	= rose_header,
150 	.rebuild= rose_rebuild_header,
151 };
152 
153 static const struct net_device_ops rose_netdev_ops = {
154 	.ndo_open		= rose_open,
155 	.ndo_stop		= rose_close,
156 	.ndo_start_xmit		= rose_xmit,
157 	.ndo_set_mac_address    = rose_set_mac_address,
158 };
159 
rose_setup(struct net_device * dev)160 void rose_setup(struct net_device *dev)
161 {
162 	dev->mtu		= ROSE_MAX_PACKET_SIZE - 2;
163 	dev->netdev_ops		= &rose_netdev_ops;
164 
165 	dev->header_ops		= &rose_header_ops;
166 	dev->hard_header_len	= AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
167 	dev->addr_len		= ROSE_ADDR_LEN;
168 	dev->type		= ARPHRD_ROSE;
169 
170 	/* New-style flags. */
171 	dev->flags		= IFF_NOARP;
172 }
173