xref: /openbmc/linux/net/6lowpan/core.c (revision e2c75e76)
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 	switch (lltype) {
27 	case LOWPAN_LLTYPE_IEEE802154:
28 		dev->addr_len = EUI64_ADDR_LEN;
29 		break;
30 
31 	case LOWPAN_LLTYPE_BTLE:
32 		dev->addr_len = ETH_ALEN;
33 		break;
34 	}
35 
36 	dev->type = ARPHRD_6LOWPAN;
37 	dev->mtu = IPV6_MIN_MTU;
38 
39 	lowpan_dev(dev)->lltype = lltype;
40 
41 	spin_lock_init(&lowpan_dev(dev)->ctx.lock);
42 	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
43 		lowpan_dev(dev)->ctx.table[i].id = i;
44 
45 	dev->ndisc_ops = &lowpan_ndisc_ops;
46 
47 	ret = register_netdevice(dev);
48 	if (ret < 0)
49 		return ret;
50 
51 	ret = lowpan_dev_debugfs_init(dev);
52 	if (ret < 0)
53 		unregister_netdevice(dev);
54 
55 	return ret;
56 }
57 EXPORT_SYMBOL(lowpan_register_netdevice);
58 
59 int lowpan_register_netdev(struct net_device *dev,
60 			   enum lowpan_lltypes lltype)
61 {
62 	int ret;
63 
64 	rtnl_lock();
65 	ret = lowpan_register_netdevice(dev, lltype);
66 	rtnl_unlock();
67 	return ret;
68 }
69 EXPORT_SYMBOL(lowpan_register_netdev);
70 
71 void lowpan_unregister_netdevice(struct net_device *dev)
72 {
73 	unregister_netdevice(dev);
74 	lowpan_dev_debugfs_exit(dev);
75 }
76 EXPORT_SYMBOL(lowpan_unregister_netdevice);
77 
78 void lowpan_unregister_netdev(struct net_device *dev)
79 {
80 	rtnl_lock();
81 	lowpan_unregister_netdevice(dev);
82 	rtnl_unlock();
83 }
84 EXPORT_SYMBOL(lowpan_unregister_netdev);
85 
86 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
87 {
88 	struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
89 
90 	/* Set short_addr autoconfiguration if short_addr is present only */
91 	if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
92 		return -1;
93 
94 	/* For either address format, all zero addresses MUST NOT be used */
95 	if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
96 	    wpan_dev->short_addr == cpu_to_le16(0x0000))
97 		return -1;
98 
99 	/* Alternatively, if no PAN ID is known, 16 zero bits may be used */
100 	if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
101 		memset(eui, 0, 2);
102 	else
103 		ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
104 
105 	/* The "Universal/Local" (U/L) bit shall be set to zero */
106 	eui[0] &= ~2;
107 	eui[2] = 0;
108 	eui[3] = 0xFF;
109 	eui[4] = 0xFE;
110 	eui[5] = 0;
111 	ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
112 	return 0;
113 }
114 
115 static int lowpan_event(struct notifier_block *unused,
116 			unsigned long event, void *ptr)
117 {
118 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
119 	struct inet6_dev *idev;
120 	struct in6_addr addr;
121 	int i;
122 
123 	if (dev->type != ARPHRD_6LOWPAN)
124 		return NOTIFY_DONE;
125 
126 	idev = __in6_dev_get(dev);
127 	if (!idev)
128 		return NOTIFY_DONE;
129 
130 	switch (event) {
131 	case NETDEV_UP:
132 	case NETDEV_CHANGE:
133 		/* (802.15.4 6LoWPAN short address slaac handling */
134 		if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
135 		    addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
136 			__ipv6_addr_set_half(&addr.s6_addr32[0],
137 					     htonl(0xFE800000), 0);
138 			addrconf_add_linklocal(idev, &addr, 0);
139 		}
140 		break;
141 	case NETDEV_DOWN:
142 		for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
143 			clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
144 				  &lowpan_dev(dev)->ctx.table[i].flags);
145 		break;
146 	default:
147 		return NOTIFY_DONE;
148 	}
149 
150 	return NOTIFY_OK;
151 }
152 
153 static struct notifier_block lowpan_notifier = {
154 	.notifier_call = lowpan_event,
155 };
156 
157 static int __init lowpan_module_init(void)
158 {
159 	int ret;
160 
161 	ret = lowpan_debugfs_init();
162 	if (ret < 0)
163 		return ret;
164 
165 	ret = register_netdevice_notifier(&lowpan_notifier);
166 	if (ret < 0) {
167 		lowpan_debugfs_exit();
168 		return ret;
169 	}
170 
171 	request_module_nowait("nhc_dest");
172 	request_module_nowait("nhc_fragment");
173 	request_module_nowait("nhc_hop");
174 	request_module_nowait("nhc_ipv6");
175 	request_module_nowait("nhc_mobility");
176 	request_module_nowait("nhc_routing");
177 	request_module_nowait("nhc_udp");
178 
179 	return 0;
180 }
181 
182 static void __exit lowpan_module_exit(void)
183 {
184 	lowpan_debugfs_exit();
185 	unregister_netdevice_notifier(&lowpan_notifier);
186 }
187 
188 module_init(lowpan_module_init);
189 module_exit(lowpan_module_exit);
190 
191 MODULE_LICENSE("GPL");
192