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 * Frame handler other utility functions for HSR and PRP.
8 */
9
10 #include "hsr_slave.h"
11 #include <linux/etherdevice.h>
12 #include <linux/if_arp.h>
13 #include <linux/if_vlan.h>
14 #include "hsr_main.h"
15 #include "hsr_device.h"
16 #include "hsr_forward.h"
17 #include "hsr_framereg.h"
18
hsr_invalid_dan_ingress_frame(__be16 protocol)19 bool hsr_invalid_dan_ingress_frame(__be16 protocol)
20 {
21 return (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR));
22 }
23
hsr_handle_frame(struct sk_buff ** pskb)24 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
25 {
26 struct sk_buff *skb = *pskb;
27 struct hsr_port *port;
28 struct hsr_priv *hsr;
29 __be16 protocol;
30
31 /* Packets from dev_loopback_xmit() do not have L2 header, bail out */
32 if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
33 return RX_HANDLER_PASS;
34
35 if (!skb_mac_header_was_set(skb)) {
36 WARN_ONCE(1, "%s: skb invalid", __func__);
37 return RX_HANDLER_PASS;
38 }
39
40 port = hsr_port_get_rcu(skb->dev);
41 if (!port)
42 goto finish_pass;
43 hsr = port->hsr;
44
45 if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
46 /* Directly kill frames sent by ourselves */
47 kfree_skb(skb);
48 goto finish_consume;
49 }
50
51 /* For HSR, only tagged frames are expected (unless the device offloads
52 * HSR tag removal), but for PRP there could be non tagged frames as
53 * well from Single attached nodes (SANs).
54 */
55 protocol = eth_hdr(skb)->h_proto;
56
57 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
58 hsr->proto_ops->invalid_dan_ingress_frame &&
59 hsr->proto_ops->invalid_dan_ingress_frame(protocol))
60 goto finish_pass;
61
62 skb_push(skb, ETH_HLEN);
63 skb_reset_mac_header(skb);
64 if ((!hsr->prot_version && protocol == htons(ETH_P_PRP)) ||
65 protocol == htons(ETH_P_HSR))
66 skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);
67 skb_reset_mac_len(skb);
68
69 hsr_forward_skb(skb, port);
70
71 finish_consume:
72 return RX_HANDLER_CONSUMED;
73
74 finish_pass:
75 return RX_HANDLER_PASS;
76 }
77
hsr_port_exists(const struct net_device * dev)78 bool hsr_port_exists(const struct net_device *dev)
79 {
80 return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
81 }
82
hsr_check_dev_ok(struct net_device * dev,struct netlink_ext_ack * extack)83 static int hsr_check_dev_ok(struct net_device *dev,
84 struct netlink_ext_ack *extack)
85 {
86 /* Don't allow HSR on non-ethernet like devices */
87 if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
88 dev->addr_len != ETH_ALEN) {
89 NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
90 return -EINVAL;
91 }
92
93 /* Don't allow enslaving hsr devices */
94 if (is_hsr_master(dev)) {
95 NL_SET_ERR_MSG_MOD(extack,
96 "Cannot create trees of HSR devices.");
97 return -EINVAL;
98 }
99
100 if (hsr_port_exists(dev)) {
101 NL_SET_ERR_MSG_MOD(extack,
102 "This device is already a HSR slave.");
103 return -EINVAL;
104 }
105
106 if (is_vlan_dev(dev)) {
107 NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
108 return -EINVAL;
109 }
110
111 if (dev->priv_flags & IFF_DONT_BRIDGE) {
112 NL_SET_ERR_MSG_MOD(extack,
113 "This device does not support bridging.");
114 return -EOPNOTSUPP;
115 }
116
117 /* HSR over bonded devices has not been tested, but I'm not sure it
118 * won't work...
119 */
120
121 return 0;
122 }
123
124 /* Setup device to be added to the HSR bridge. */
hsr_portdev_setup(struct hsr_priv * hsr,struct net_device * dev,struct hsr_port * port,struct netlink_ext_ack * extack)125 static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
126 struct hsr_port *port,
127 struct netlink_ext_ack *extack)
128
129 {
130 struct net_device *hsr_dev;
131 struct hsr_port *master;
132 int res;
133
134 /* Don't use promiscuous mode for offload since L2 frame forward
135 * happens at the offloaded hardware.
136 */
137 if (!port->hsr->fwd_offloaded) {
138 res = dev_set_promiscuity(dev, 1);
139 if (res)
140 return res;
141 }
142
143 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
144 hsr_dev = master->dev;
145
146 res = netdev_upper_dev_link(dev, hsr_dev, extack);
147 if (res)
148 goto fail_upper_dev_link;
149
150 res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
151 if (res)
152 goto fail_rx_handler;
153 dev_disable_lro(dev);
154
155 return 0;
156
157 fail_rx_handler:
158 netdev_upper_dev_unlink(dev, hsr_dev);
159 fail_upper_dev_link:
160 if (!port->hsr->fwd_offloaded)
161 dev_set_promiscuity(dev, -1);
162
163 return res;
164 }
165
hsr_add_port(struct hsr_priv * hsr,struct net_device * dev,enum hsr_port_type type,struct netlink_ext_ack * extack)166 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
167 enum hsr_port_type type, struct netlink_ext_ack *extack)
168 {
169 struct hsr_port *port, *master;
170 int res;
171
172 if (type != HSR_PT_MASTER) {
173 res = hsr_check_dev_ok(dev, extack);
174 if (res)
175 return res;
176 }
177
178 port = hsr_port_get_hsr(hsr, type);
179 if (port)
180 return -EBUSY; /* This port already exists */
181
182 port = kzalloc(sizeof(*port), GFP_KERNEL);
183 if (!port)
184 return -ENOMEM;
185
186 port->hsr = hsr;
187 port->dev = dev;
188 port->type = type;
189
190 if (type != HSR_PT_MASTER) {
191 res = hsr_portdev_setup(hsr, dev, port, extack);
192 if (res)
193 goto fail_dev_setup;
194 }
195
196 list_add_tail_rcu(&port->port_list, &hsr->ports);
197 synchronize_rcu();
198
199 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
200 netdev_update_features(master->dev);
201 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
202
203 return 0;
204
205 fail_dev_setup:
206 kfree(port);
207 return res;
208 }
209
hsr_del_port(struct hsr_port * port)210 void hsr_del_port(struct hsr_port *port)
211 {
212 struct hsr_priv *hsr;
213 struct hsr_port *master;
214
215 hsr = port->hsr;
216 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
217 list_del_rcu(&port->port_list);
218
219 if (port != master) {
220 netdev_update_features(master->dev);
221 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
222 netdev_rx_handler_unregister(port->dev);
223 if (!port->hsr->fwd_offloaded)
224 dev_set_promiscuity(port->dev, -1);
225 netdev_upper_dev_unlink(port->dev, master->dev);
226 }
227
228 synchronize_rcu();
229
230 kfree(port);
231 }
232