1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011-2014 Autronica Fire and Security AS
3  *
4  * Author(s):
5  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
6  *
7  * Event handling for HSR and PRP devices.
8  */
9 
10 #include <linux/netdevice.h>
11 #include <net/rtnetlink.h>
12 #include <linux/rculist.h>
13 #include <linux/timer.h>
14 #include <linux/etherdevice.h>
15 #include "hsr_main.h"
16 #include "hsr_device.h"
17 #include "hsr_netlink.h"
18 #include "hsr_framereg.h"
19 #include "hsr_slave.h"
20 
21 static bool hsr_slave_empty(struct hsr_priv *hsr)
22 {
23 	struct hsr_port *port;
24 
25 	hsr_for_each_port(hsr, port)
26 		if (port->type != HSR_PT_MASTER)
27 			return false;
28 	return true;
29 }
30 
31 static int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
32 			     void *ptr)
33 {
34 	struct hsr_port *port, *master;
35 	struct net_device *dev;
36 	struct hsr_priv *hsr;
37 	LIST_HEAD(list_kill);
38 	int mtu_max;
39 	int res;
40 
41 	dev = netdev_notifier_info_to_dev(ptr);
42 	port = hsr_port_get_rtnl(dev);
43 	if (!port) {
44 		if (!is_hsr_master(dev))
45 			return NOTIFY_DONE;	/* Not an HSR device */
46 		hsr = netdev_priv(dev);
47 		port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
48 		if (!port) {
49 			/* Resend of notification concerning removed device? */
50 			return NOTIFY_DONE;
51 		}
52 	} else {
53 		hsr = port->hsr;
54 	}
55 
56 	switch (event) {
57 	case NETDEV_UP:		/* Administrative state DOWN */
58 	case NETDEV_DOWN:	/* Administrative state UP */
59 	case NETDEV_CHANGE:	/* Link (carrier) state changes */
60 		hsr_check_carrier_and_operstate(hsr);
61 		break;
62 	case NETDEV_CHANGENAME:
63 		if (is_hsr_master(dev))
64 			hsr_debugfs_rename(dev);
65 		break;
66 	case NETDEV_CHANGEADDR:
67 		if (port->type == HSR_PT_MASTER) {
68 			/* This should not happen since there's no
69 			 * ndo_set_mac_address() for HSR devices - i.e. not
70 			 * supported.
71 			 */
72 			break;
73 		}
74 
75 		master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
76 
77 		if (port->type == HSR_PT_SLAVE_A) {
78 			eth_hw_addr_set(master->dev, dev->dev_addr);
79 			call_netdevice_notifiers(NETDEV_CHANGEADDR,
80 						 master->dev);
81 
82 			if (hsr->prot_version == PRP_V1) {
83 				port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
84 				if (port) {
85 					eth_hw_addr_set(port->dev, dev->dev_addr);
86 					call_netdevice_notifiers(NETDEV_CHANGEADDR,
87 								 port->dev);
88 				}
89 			}
90 		}
91 
92 		/* Make sure we recognize frames from ourselves in hsr_rcv() */
93 		port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
94 		res = hsr_create_self_node(hsr,
95 					   master->dev->dev_addr,
96 					   port ?
97 						port->dev->dev_addr :
98 						master->dev->dev_addr);
99 		if (res)
100 			netdev_warn(master->dev,
101 				    "Could not update HSR node address.\n");
102 		break;
103 	case NETDEV_CHANGEMTU:
104 		if (port->type == HSR_PT_MASTER)
105 			break; /* Handled in ndo_change_mtu() */
106 		mtu_max = hsr_get_max_mtu(port->hsr);
107 		master = hsr_port_get_hsr(port->hsr, HSR_PT_MASTER);
108 		WRITE_ONCE(master->dev->mtu, mtu_max);
109 		break;
110 	case NETDEV_UNREGISTER:
111 		if (!is_hsr_master(dev)) {
112 			master = hsr_port_get_hsr(port->hsr, HSR_PT_MASTER);
113 			hsr_del_port(port);
114 			if (hsr_slave_empty(master->hsr)) {
115 				const struct rtnl_link_ops *ops;
116 
117 				ops = master->dev->rtnl_link_ops;
118 				ops->dellink(master->dev, &list_kill);
119 				unregister_netdevice_many(&list_kill);
120 			}
121 		}
122 		break;
123 	case NETDEV_PRE_TYPE_CHANGE:
124 		/* HSR works only on Ethernet devices. Refuse slave to change
125 		 * its type.
126 		 */
127 		return NOTIFY_BAD;
128 	}
129 
130 	return NOTIFY_DONE;
131 }
132 
133 struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt)
134 {
135 	struct hsr_port *port;
136 
137 	hsr_for_each_port(hsr, port)
138 		if (port->type == pt)
139 			return port;
140 	return NULL;
141 }
142 
143 int hsr_get_version(struct net_device *dev, enum hsr_version *ver)
144 {
145 	struct hsr_priv *hsr;
146 
147 	hsr = netdev_priv(dev);
148 	*ver = hsr->prot_version;
149 
150 	return 0;
151 }
152 EXPORT_SYMBOL(hsr_get_version);
153 
154 static struct notifier_block hsr_nb = {
155 	.notifier_call = hsr_netdev_notify,	/* Slave event notifications */
156 };
157 
158 static int __init hsr_init(void)
159 {
160 	int err;
161 
162 	BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
163 
164 	err = register_netdevice_notifier(&hsr_nb);
165 	if (err)
166 		return err;
167 
168 	err = hsr_netlink_init();
169 	if (err) {
170 		unregister_netdevice_notifier(&hsr_nb);
171 		return err;
172 	}
173 
174 	return 0;
175 }
176 
177 static void __exit hsr_exit(void)
178 {
179 	hsr_netlink_exit();
180 	hsr_debugfs_remove_root();
181 	unregister_netdevice_notifier(&hsr_nb);
182 }
183 
184 module_init(hsr_init);
185 module_exit(hsr_exit);
186 MODULE_DESCRIPTION("High-availability Seamless Redundancy (HSR) driver");
187 MODULE_LICENSE("GPL");
188