xref: /linux/net/6lowpan/core.c (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda)
1 /* This program is free software; you can redistribute it and/or modify
2  * it under the terms of the GNU General Public License version 2
3  * as published by the Free Software Foundation.
4  *
5  * This program is distributed in the hope that it will be useful,
6  * but WITHOUT ANY WARRANTY; without even the implied warranty of
7  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
8  * GNU General Public License for more details.
9  *
10  * Authors:
11  * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
12  */
13 
14 #include <linux/module.h>
15 
16 #include <net/6lowpan.h>
17 #include <net/addrconf.h>
18 
19 #include "6lowpan_i.h"
20 
21 int lowpan_register_netdevice(struct net_device *dev,
22 			      enum lowpan_lltypes lltype)
23 {
24 	int i, ret;
25 
26 	dev->addr_len = EUI64_ADDR_LEN;
27 	dev->type = ARPHRD_6LOWPAN;
28 	dev->mtu = IPV6_MIN_MTU;
29 	dev->priv_flags |= IFF_NO_QUEUE;
30 
31 	lowpan_dev(dev)->lltype = lltype;
32 
33 	spin_lock_init(&lowpan_dev(dev)->ctx.lock);
34 	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
35 		lowpan_dev(dev)->ctx.table[i].id = i;
36 
37 	dev->ndisc_ops = &lowpan_ndisc_ops;
38 
39 	ret = register_netdevice(dev);
40 	if (ret < 0)
41 		return ret;
42 
43 	ret = lowpan_dev_debugfs_init(dev);
44 	if (ret < 0)
45 		unregister_netdevice(dev);
46 
47 	return ret;
48 }
49 EXPORT_SYMBOL(lowpan_register_netdevice);
50 
51 int lowpan_register_netdev(struct net_device *dev,
52 			   enum lowpan_lltypes lltype)
53 {
54 	int ret;
55 
56 	rtnl_lock();
57 	ret = lowpan_register_netdevice(dev, lltype);
58 	rtnl_unlock();
59 	return ret;
60 }
61 EXPORT_SYMBOL(lowpan_register_netdev);
62 
63 void lowpan_unregister_netdevice(struct net_device *dev)
64 {
65 	unregister_netdevice(dev);
66 	lowpan_dev_debugfs_exit(dev);
67 }
68 EXPORT_SYMBOL(lowpan_unregister_netdevice);
69 
70 void lowpan_unregister_netdev(struct net_device *dev)
71 {
72 	rtnl_lock();
73 	lowpan_unregister_netdevice(dev);
74 	rtnl_unlock();
75 }
76 EXPORT_SYMBOL(lowpan_unregister_netdev);
77 
78 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
79 {
80 	struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
81 
82 	/* Set short_addr autoconfiguration if short_addr is present only */
83 	if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
84 		return -1;
85 
86 	/* For either address format, all zero addresses MUST NOT be used */
87 	if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
88 	    wpan_dev->short_addr == cpu_to_le16(0x0000))
89 		return -1;
90 
91 	/* Alternatively, if no PAN ID is known, 16 zero bits may be used */
92 	if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
93 		memset(eui, 0, 2);
94 	else
95 		ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
96 
97 	/* The "Universal/Local" (U/L) bit shall be set to zero */
98 	eui[0] &= ~2;
99 	eui[2] = 0;
100 	eui[3] = 0xFF;
101 	eui[4] = 0xFE;
102 	eui[5] = 0;
103 	ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
104 	return 0;
105 }
106 
107 static int lowpan_event(struct notifier_block *unused,
108 			unsigned long event, void *ptr)
109 {
110 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
111 	struct inet6_dev *idev;
112 	struct in6_addr addr;
113 	int i;
114 
115 	if (dev->type != ARPHRD_6LOWPAN)
116 		return NOTIFY_DONE;
117 
118 	idev = __in6_dev_get(dev);
119 	if (!idev)
120 		return NOTIFY_DONE;
121 
122 	switch (event) {
123 	case NETDEV_UP:
124 	case NETDEV_CHANGE:
125 		/* (802.15.4 6LoWPAN short address slaac handling */
126 		if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
127 		    addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
128 			__ipv6_addr_set_half(&addr.s6_addr32[0],
129 					     htonl(0xFE800000), 0);
130 			addrconf_add_linklocal(idev, &addr, 0);
131 		}
132 		break;
133 	case NETDEV_DOWN:
134 		for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
135 			clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
136 				  &lowpan_dev(dev)->ctx.table[i].flags);
137 		break;
138 	default:
139 		return NOTIFY_DONE;
140 	}
141 
142 	return NOTIFY_OK;
143 }
144 
145 static struct notifier_block lowpan_notifier = {
146 	.notifier_call = lowpan_event,
147 };
148 
149 static int __init lowpan_module_init(void)
150 {
151 	int ret;
152 
153 	ret = lowpan_debugfs_init();
154 	if (ret < 0)
155 		return ret;
156 
157 	ret = register_netdevice_notifier(&lowpan_notifier);
158 	if (ret < 0) {
159 		lowpan_debugfs_exit();
160 		return ret;
161 	}
162 
163 	request_module_nowait("nhc_dest");
164 	request_module_nowait("nhc_fragment");
165 	request_module_nowait("nhc_hop");
166 	request_module_nowait("nhc_ipv6");
167 	request_module_nowait("nhc_mobility");
168 	request_module_nowait("nhc_routing");
169 	request_module_nowait("nhc_udp");
170 
171 	return 0;
172 }
173 
174 static void __exit lowpan_module_exit(void)
175 {
176 	lowpan_debugfs_exit();
177 	unregister_netdevice_notifier(&lowpan_notifier);
178 }
179 
180 module_init(lowpan_module_init);
181 module_exit(lowpan_module_exit);
182 
183 MODULE_LICENSE("GPL");
184