1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Authors:
5  * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
6  */
7 
8 #include <linux/if_arp.h>
9 #include <linux/module.h>
10 
11 #include <net/6lowpan.h>
12 #include <net/addrconf.h>
13 
14 #include "6lowpan_i.h"
15 
lowpan_register_netdevice(struct net_device * dev,enum lowpan_lltypes lltype)16 int lowpan_register_netdevice(struct net_device *dev,
17 			      enum lowpan_lltypes lltype)
18 {
19 	int i, ret;
20 
21 	switch (lltype) {
22 	case LOWPAN_LLTYPE_IEEE802154:
23 		dev->addr_len = EUI64_ADDR_LEN;
24 		break;
25 
26 	case LOWPAN_LLTYPE_BTLE:
27 		dev->addr_len = ETH_ALEN;
28 		break;
29 	}
30 
31 	dev->type = ARPHRD_6LOWPAN;
32 	dev->mtu = IPV6_MIN_MTU;
33 
34 	lowpan_dev(dev)->lltype = lltype;
35 
36 	spin_lock_init(&lowpan_dev(dev)->ctx.lock);
37 	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
38 		lowpan_dev(dev)->ctx.table[i].id = i;
39 
40 	dev->ndisc_ops = &lowpan_ndisc_ops;
41 
42 	ret = register_netdevice(dev);
43 	if (ret < 0)
44 		return ret;
45 
46 	lowpan_dev_debugfs_init(dev);
47 
48 	return ret;
49 }
50 EXPORT_SYMBOL(lowpan_register_netdevice);
51 
lowpan_register_netdev(struct net_device * dev,enum lowpan_lltypes lltype)52 int lowpan_register_netdev(struct net_device *dev,
53 			   enum lowpan_lltypes lltype)
54 {
55 	int ret;
56 
57 	rtnl_lock();
58 	ret = lowpan_register_netdevice(dev, lltype);
59 	rtnl_unlock();
60 	return ret;
61 }
62 EXPORT_SYMBOL(lowpan_register_netdev);
63 
lowpan_unregister_netdevice(struct net_device * dev)64 void lowpan_unregister_netdevice(struct net_device *dev)
65 {
66 	unregister_netdevice(dev);
67 	lowpan_dev_debugfs_exit(dev);
68 }
69 EXPORT_SYMBOL(lowpan_unregister_netdevice);
70 
lowpan_unregister_netdev(struct net_device * dev)71 void lowpan_unregister_netdev(struct net_device *dev)
72 {
73 	rtnl_lock();
74 	lowpan_unregister_netdevice(dev);
75 	rtnl_unlock();
76 }
77 EXPORT_SYMBOL(lowpan_unregister_netdev);
78 
addrconf_ifid_802154_6lowpan(u8 * eui,struct net_device * dev)79 int addrconf_ifid_802154_6lowpan(u8 *eui, struct net_device *dev)
80 {
81 	struct wpan_dev *wpan_dev = lowpan_802154_dev(dev)->wdev->ieee802154_ptr;
82 
83 	/* Set short_addr autoconfiguration if short_addr is present only */
84 	if (!lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr))
85 		return -1;
86 
87 	/* For either address format, all zero addresses MUST NOT be used */
88 	if (wpan_dev->pan_id == cpu_to_le16(0x0000) &&
89 	    wpan_dev->short_addr == cpu_to_le16(0x0000))
90 		return -1;
91 
92 	/* Alternatively, if no PAN ID is known, 16 zero bits may be used */
93 	if (wpan_dev->pan_id == cpu_to_le16(IEEE802154_PAN_ID_BROADCAST))
94 		memset(eui, 0, 2);
95 	else
96 		ieee802154_le16_to_be16(eui, &wpan_dev->pan_id);
97 
98 	/* The "Universal/Local" (U/L) bit shall be set to zero */
99 	eui[0] &= ~2;
100 	eui[2] = 0;
101 	eui[3] = 0xFF;
102 	eui[4] = 0xFE;
103 	eui[5] = 0;
104 	ieee802154_le16_to_be16(&eui[6], &wpan_dev->short_addr);
105 	return 0;
106 }
107 
lowpan_event(struct notifier_block * unused,unsigned long event,void * ptr)108 static int lowpan_event(struct notifier_block *unused,
109 			unsigned long event, void *ptr)
110 {
111 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
112 	struct inet6_dev *idev;
113 	struct in6_addr addr;
114 	int i;
115 
116 	if (dev->type != ARPHRD_6LOWPAN)
117 		return NOTIFY_DONE;
118 
119 	idev = __in6_dev_get(dev);
120 	if (!idev)
121 		return NOTIFY_DONE;
122 
123 	switch (event) {
124 	case NETDEV_UP:
125 	case NETDEV_CHANGE:
126 		/* (802.15.4 6LoWPAN short address slaac handling */
127 		if (lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154) &&
128 		    addrconf_ifid_802154_6lowpan(addr.s6_addr + 8, dev) == 0) {
129 			__ipv6_addr_set_half(&addr.s6_addr32[0],
130 					     htonl(0xFE800000), 0);
131 			addrconf_add_linklocal(idev, &addr, 0);
132 		}
133 		break;
134 	case NETDEV_DOWN:
135 		for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
136 			clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE,
137 				  &lowpan_dev(dev)->ctx.table[i].flags);
138 		break;
139 	default:
140 		return NOTIFY_DONE;
141 	}
142 
143 	return NOTIFY_OK;
144 }
145 
146 static struct notifier_block lowpan_notifier = {
147 	.notifier_call = lowpan_event,
148 };
149 
lowpan_module_init(void)150 static int __init lowpan_module_init(void)
151 {
152 	int ret;
153 
154 	lowpan_debugfs_init();
155 
156 	ret = register_netdevice_notifier(&lowpan_notifier);
157 	if (ret < 0) {
158 		lowpan_debugfs_exit();
159 		return ret;
160 	}
161 
162 	request_module_nowait("nhc_dest");
163 	request_module_nowait("nhc_fragment");
164 	request_module_nowait("nhc_hop");
165 	request_module_nowait("nhc_ipv6");
166 	request_module_nowait("nhc_mobility");
167 	request_module_nowait("nhc_routing");
168 	request_module_nowait("nhc_udp");
169 
170 	return 0;
171 }
172 
lowpan_module_exit(void)173 static void __exit lowpan_module_exit(void)
174 {
175 	lowpan_debugfs_exit();
176 	unregister_netdevice_notifier(&lowpan_notifier);
177 }
178 
179 module_init(lowpan_module_init);
180 module_exit(lowpan_module_exit);
181 
182 MODULE_LICENSE("GPL");
183