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
19bool hsr_invalid_dan_ingress_frame(__be16 protocol)
20{
21 return (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR));
22}
23
24static 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(dev: skb->dev);
41 if (!port)
42 goto finish_pass;
43 hsr = port->hsr;
44
45 if (hsr_addr_is_self(hsr: port->hsr, addr: 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 port->type != HSR_PT_INTERLINK &&
59 hsr->proto_ops->invalid_dan_ingress_frame &&
60 hsr->proto_ops->invalid_dan_ingress_frame(protocol))
61 goto finish_pass;
62
63 skb_push(skb, ETH_HLEN);
64 skb_reset_mac_header(skb);
65 if ((!hsr->prot_version && protocol == htons(ETH_P_PRP)) ||
66 protocol == htons(ETH_P_HSR))
67 skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);
68 skb_reset_mac_len(skb);
69
70 /* Only the frames received over the interlink port will assign a
71 * sequence number and require synchronisation vs other sender.
72 */
73 if (port->type == HSR_PT_INTERLINK) {
74 spin_lock_bh(lock: &hsr->seqnr_lock);
75 hsr_forward_skb(skb, port);
76 spin_unlock_bh(lock: &hsr->seqnr_lock);
77 } else {
78 hsr_forward_skb(skb, port);
79 }
80
81finish_consume:
82 return RX_HANDLER_CONSUMED;
83
84finish_pass:
85 return RX_HANDLER_PASS;
86}
87
88bool hsr_port_exists(const struct net_device *dev)
89{
90 return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
91}
92
93static int hsr_check_dev_ok(struct net_device *dev,
94 struct netlink_ext_ack *extack)
95{
96 /* Don't allow HSR on non-ethernet like devices */
97 if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
98 dev->addr_len != ETH_ALEN) {
99 NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
100 return -EINVAL;
101 }
102
103 /* Don't allow enslaving hsr devices */
104 if (is_hsr_master(dev)) {
105 NL_SET_ERR_MSG_MOD(extack,
106 "Cannot create trees of HSR devices.");
107 return -EINVAL;
108 }
109
110 if (hsr_port_exists(dev)) {
111 NL_SET_ERR_MSG_MOD(extack,
112 "This device is already a HSR slave.");
113 return -EINVAL;
114 }
115
116 if (is_vlan_dev(dev)) {
117 NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
118 return -EINVAL;
119 }
120
121 if (dev->priv_flags & IFF_DONT_BRIDGE) {
122 NL_SET_ERR_MSG_MOD(extack,
123 "This device does not support bridging.");
124 return -EOPNOTSUPP;
125 }
126
127 /* HSR over bonded devices has not been tested, but I'm not sure it
128 * won't work...
129 */
130
131 return 0;
132}
133
134/* Setup device to be added to the HSR bridge. */
135static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
136 struct hsr_port *port,
137 struct netlink_ext_ack *extack)
138
139{
140 struct net_device *hsr_dev;
141 struct hsr_port *master;
142 int res;
143
144 /* Don't use promiscuous mode for offload since L2 frame forward
145 * happens at the offloaded hardware.
146 */
147 if (!port->hsr->fwd_offloaded) {
148 res = dev_set_promiscuity(dev, inc: 1);
149 if (res)
150 return res;
151 }
152
153 master = hsr_port_get_hsr(hsr, pt: HSR_PT_MASTER);
154 hsr_dev = master->dev;
155
156 res = netdev_upper_dev_link(dev, upper_dev: hsr_dev, extack);
157 if (res)
158 goto fail_upper_dev_link;
159
160 res = netdev_rx_handler_register(dev, rx_handler: hsr_handle_frame, rx_handler_data: port);
161 if (res)
162 goto fail_rx_handler;
163 dev_disable_lro(dev);
164
165 return 0;
166
167fail_rx_handler:
168 netdev_upper_dev_unlink(dev, upper_dev: hsr_dev);
169fail_upper_dev_link:
170 if (!port->hsr->fwd_offloaded)
171 dev_set_promiscuity(dev, inc: -1);
172
173 return res;
174}
175
176int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
177 enum hsr_port_type type, struct netlink_ext_ack *extack)
178{
179 struct hsr_port *port, *master;
180 int res;
181
182 if (type != HSR_PT_MASTER) {
183 res = hsr_check_dev_ok(dev, extack);
184 if (res)
185 return res;
186 }
187
188 port = hsr_port_get_hsr(hsr, pt: type);
189 if (port)
190 return -EBUSY; /* This port already exists */
191
192 port = kzalloc(sizeof(*port), GFP_KERNEL);
193 if (!port)
194 return -ENOMEM;
195
196 port->hsr = hsr;
197 port->dev = dev;
198 port->type = type;
199 ether_addr_copy(dst: port->original_macaddress, src: dev->dev_addr);
200
201 if (type != HSR_PT_MASTER) {
202 res = hsr_portdev_setup(hsr, dev, port, extack);
203 if (res)
204 goto fail_dev_setup;
205 }
206
207 list_add_tail_rcu(new: &port->port_list, head: &hsr->ports);
208
209 master = hsr_port_get_hsr(hsr, pt: HSR_PT_MASTER);
210 netdev_update_features(dev: master->dev);
211 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
212
213 return 0;
214
215fail_dev_setup:
216 kfree(objp: port);
217 return res;
218}
219
220void hsr_del_port(struct hsr_port *port)
221{
222 struct hsr_priv *hsr;
223 struct hsr_port *master;
224
225 hsr = port->hsr;
226 master = hsr_port_get_hsr(hsr, pt: HSR_PT_MASTER);
227 list_del_rcu(entry: &port->port_list);
228
229 if (port != master) {
230 netdev_update_features(dev: master->dev);
231 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
232 netdev_rx_handler_unregister(dev: port->dev);
233 if (!port->hsr->fwd_offloaded)
234 dev_set_promiscuity(dev: port->dev, inc: -1);
235 netdev_upper_dev_unlink(dev: port->dev, upper_dev: master->dev);
236 eth_hw_addr_set(dev: port->dev, addr: port->original_macaddress);
237 }
238
239 kfree_rcu(port, rcu);
240}
241

source code of linux/net/hsr/hsr_slave.c