xref: /linux/net/rose/rose_dev.c (revision 02bf6cc72cc2a6258411ddf1649f33a65fc9a06e)
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 
23 #include <asm/system.h>
24 #include <asm/io.h>
25 
26 #include <linux/inet.h>
27 #include <linux/netdevice.h>
28 #include <linux/etherdevice.h>
29 #include <linux/if_arp.h>
30 #include <linux/skbuff.h>
31 
32 #include <net/ip.h>
33 #include <net/arp.h>
34 
35 #include <net/ax25.h>
36 #include <net/rose.h>
37 
38 static int rose_header(struct sk_buff *skb, struct net_device *dev,
39 		       unsigned short type,
40 		       const void *daddr, const void *saddr, unsigned len)
41 {
42 	unsigned char *buff = skb_push(skb, ROSE_MIN_LEN + 2);
43 
44 	*buff++ = ROSE_GFI | ROSE_Q_BIT;
45 	*buff++ = 0x00;
46 	*buff++ = ROSE_DATA;
47 	*buff++ = 0x7F;
48 	*buff++ = AX25_P_IP;
49 
50 	if (daddr != NULL)
51 		return 37;
52 
53 	return -37;
54 }
55 
56 static int rose_rebuild_header(struct sk_buff *skb)
57 {
58 #ifdef CONFIG_INET
59 	struct net_device *dev = skb->dev;
60 	struct net_device_stats *stats = &dev->stats;
61 	unsigned char *bp = (unsigned char *)skb->data;
62 	struct sk_buff *skbn;
63 	unsigned int len;
64 
65 	if (arp_find(bp + 7, skb)) {
66 		return 1;
67 	}
68 
69 	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
70 		kfree_skb(skb);
71 		return 1;
72 	}
73 
74 	if (skb->sk != NULL)
75 		skb_set_owner_w(skbn, skb->sk);
76 
77 	kfree_skb(skb);
78 
79 	len = skbn->len;
80 
81 	if (!rose_route_frame(skbn, NULL)) {
82 		kfree_skb(skbn);
83 		stats->tx_errors++;
84 		return 1;
85 	}
86 
87 	stats->tx_packets++;
88 	stats->tx_bytes += len;
89 #endif
90 	return 1;
91 }
92 
93 static int rose_set_mac_address(struct net_device *dev, void *addr)
94 {
95 	struct sockaddr *sa = addr;
96 	int err;
97 
98 	if (!memcpy(dev->dev_addr, sa->sa_data, dev->addr_len))
99 		return 0;
100 
101 	if (dev->flags & IFF_UP) {
102 		err = rose_add_loopback_node((rose_address *)dev->dev_addr);
103 		if (err)
104 			return err;
105 
106 		rose_del_loopback_node((rose_address *)dev->dev_addr);
107 	}
108 
109 	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
110 
111 	return 0;
112 }
113 
114 static int rose_open(struct net_device *dev)
115 {
116 	int err;
117 
118 	err = rose_add_loopback_node((rose_address *)dev->dev_addr);
119 	if (err)
120 		return err;
121 
122 	netif_start_queue(dev);
123 
124 	return 0;
125 }
126 
127 static int rose_close(struct net_device *dev)
128 {
129 	netif_stop_queue(dev);
130 	rose_del_loopback_node((rose_address *)dev->dev_addr);
131 	return 0;
132 }
133 
134 static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)
135 {
136 	struct net_device_stats *stats = &dev->stats;
137 
138 	if (!netif_running(dev)) {
139 		printk(KERN_ERR "ROSE: rose_xmit - called when iface is down\n");
140 		return NETDEV_TX_BUSY;
141 	}
142 	dev_kfree_skb(skb);
143 	stats->tx_errors++;
144 	return NETDEV_TX_OK;
145 }
146 
147 static const struct header_ops rose_header_ops = {
148 	.create	= rose_header,
149 	.rebuild= rose_rebuild_header,
150 };
151 
152 static const struct net_device_ops rose_netdev_ops = {
153 	.ndo_open		= rose_open,
154 	.ndo_stop		= rose_close,
155 	.ndo_start_xmit		= rose_xmit,
156 	.ndo_set_mac_address    = rose_set_mac_address,
157 };
158 
159 void rose_setup(struct net_device *dev)
160 {
161 	dev->mtu		= ROSE_MAX_PACKET_SIZE - 2;
162 	dev->netdev_ops		= &rose_netdev_ops;
163 
164 	dev->header_ops		= &rose_header_ops;
165 	dev->hard_header_len	= AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
166 	dev->addr_len		= ROSE_ADDR_LEN;
167 	dev->type		= ARPHRD_ROSE;
168 
169 	/* New-style flags. */
170 	dev->flags		= IFF_NOARP;
171 }
172