xref: /linux/net/hsr/hsr_slave.c (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
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 
8 #include "hsr_slave.h"
9 #include <linux/etherdevice.h>
10 #include <linux/if_arp.h>
11 #include <linux/if_vlan.h>
12 #include "hsr_main.h"
13 #include "hsr_device.h"
14 #include "hsr_forward.h"
15 #include "hsr_framereg.h"
16 
17 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
18 {
19 	struct sk_buff *skb = *pskb;
20 	struct hsr_port *port;
21 	u16 protocol;
22 
23 	if (!skb_mac_header_was_set(skb)) {
24 		WARN_ONCE(1, "%s: skb invalid", __func__);
25 		return RX_HANDLER_PASS;
26 	}
27 
28 	port = hsr_port_get_rcu(skb->dev);
29 	if (!port)
30 		goto finish_pass;
31 
32 	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
33 		/* Directly kill frames sent by ourselves */
34 		kfree_skb(skb);
35 		goto finish_consume;
36 	}
37 
38 	protocol = eth_hdr(skb)->h_proto;
39 	if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
40 		goto finish_pass;
41 
42 	skb_push(skb, ETH_HLEN);
43 
44 	hsr_forward_skb(skb, port);
45 
46 finish_consume:
47 	return RX_HANDLER_CONSUMED;
48 
49 finish_pass:
50 	return RX_HANDLER_PASS;
51 }
52 
53 bool hsr_port_exists(const struct net_device *dev)
54 {
55 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
56 }
57 
58 static int hsr_check_dev_ok(struct net_device *dev,
59 			    struct netlink_ext_ack *extack)
60 {
61 	/* Don't allow HSR on non-ethernet like devices */
62 	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
63 	    dev->addr_len != ETH_ALEN) {
64 		NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
65 		return -EINVAL;
66 	}
67 
68 	/* Don't allow enslaving hsr devices */
69 	if (is_hsr_master(dev)) {
70 		NL_SET_ERR_MSG_MOD(extack,
71 				   "Cannot create trees of HSR devices.");
72 		return -EINVAL;
73 	}
74 
75 	if (hsr_port_exists(dev)) {
76 		NL_SET_ERR_MSG_MOD(extack,
77 				   "This device is already a HSR slave.");
78 		return -EINVAL;
79 	}
80 
81 	if (is_vlan_dev(dev)) {
82 		NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
83 		return -EINVAL;
84 	}
85 
86 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
87 		NL_SET_ERR_MSG_MOD(extack,
88 				   "This device does not support bridging.");
89 		return -EOPNOTSUPP;
90 	}
91 
92 	/* HSR over bonded devices has not been tested, but I'm not sure it
93 	 * won't work...
94 	 */
95 
96 	return 0;
97 }
98 
99 /* Setup device to be added to the HSR bridge. */
100 static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
101 			     struct hsr_port *port,
102 			     struct netlink_ext_ack *extack)
103 
104 {
105 	struct net_device *hsr_dev;
106 	struct hsr_port *master;
107 	int res;
108 
109 	res = dev_set_promiscuity(dev, 1);
110 	if (res)
111 		return res;
112 
113 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
114 	hsr_dev = master->dev;
115 
116 	res = netdev_upper_dev_link(dev, hsr_dev, extack);
117 	if (res)
118 		goto fail_upper_dev_link;
119 
120 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
121 	if (res)
122 		goto fail_rx_handler;
123 	dev_disable_lro(dev);
124 
125 	return 0;
126 
127 fail_rx_handler:
128 	netdev_upper_dev_unlink(dev, hsr_dev);
129 fail_upper_dev_link:
130 	dev_set_promiscuity(dev, -1);
131 	return res;
132 }
133 
134 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
135 		 enum hsr_port_type type, struct netlink_ext_ack *extack)
136 {
137 	struct hsr_port *port, *master;
138 	int res;
139 
140 	if (type != HSR_PT_MASTER) {
141 		res = hsr_check_dev_ok(dev, extack);
142 		if (res)
143 			return res;
144 	}
145 
146 	port = hsr_port_get_hsr(hsr, type);
147 	if (port)
148 		return -EBUSY;	/* This port already exists */
149 
150 	port = kzalloc(sizeof(*port), GFP_KERNEL);
151 	if (!port)
152 		return -ENOMEM;
153 
154 	port->hsr = hsr;
155 	port->dev = dev;
156 	port->type = type;
157 
158 	if (type != HSR_PT_MASTER) {
159 		res = hsr_portdev_setup(hsr, dev, port, extack);
160 		if (res)
161 			goto fail_dev_setup;
162 	}
163 
164 	list_add_tail_rcu(&port->port_list, &hsr->ports);
165 	synchronize_rcu();
166 
167 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
168 	netdev_update_features(master->dev);
169 	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
170 
171 	return 0;
172 
173 fail_dev_setup:
174 	kfree(port);
175 	return res;
176 }
177 
178 void hsr_del_port(struct hsr_port *port)
179 {
180 	struct hsr_priv *hsr;
181 	struct hsr_port *master;
182 
183 	hsr = port->hsr;
184 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
185 	list_del_rcu(&port->port_list);
186 
187 	if (port != master) {
188 		netdev_update_features(master->dev);
189 		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
190 		netdev_rx_handler_unregister(port->dev);
191 		dev_set_promiscuity(port->dev, -1);
192 		netdev_upper_dev_unlink(port->dev, master->dev);
193 	}
194 
195 	synchronize_rcu();
196 
197 	kfree(port);
198 }
199