1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DSA tagging protocol handling
4 *
5 * Copyright (c) 2008-2009 Marvell Semiconductor
6 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
7 * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
8 */
9
10 #include <linux/netdevice.h>
11 #include <linux/ptp_classify.h>
12 #include <linux/skbuff.h>
13 #include <net/dsa.h>
14 #include <net/dst_metadata.h>
15
16 #include "tag.h"
17 #include "user.h"
18
19 static LIST_HEAD(dsa_tag_drivers_list);
20 static DEFINE_MUTEX(dsa_tag_drivers_lock);
21
22 /* Determine if we should defer delivery of skb until we have a rx timestamp.
23 *
24 * Called from dsa_switch_rcv. For now, this will only work if tagging is
25 * enabled on the switch. Normally the MAC driver would retrieve the hardware
26 * timestamp when it reads the packet out of the hardware. However in a DSA
27 * switch, the DSA driver owning the interface to which the packet is
28 * delivered is never notified unless we do so here.
29 */
30 static bool dsa_skb_defer_rx_timestamp(struct dsa_user_priv *p,
31 struct sk_buff *skb)
32 {
33 struct dsa_switch *ds = p->dp->ds;
34 unsigned int type;
35
36 if (!ds->ops->port_rxtstamp)
37 return false;
38
39 if (skb_headroom(skb) < ETH_HLEN)
40 return false;
41
42 __skb_push(skb, ETH_HLEN);
43
44 type = ptp_classify_raw(skb);
45
46 __skb_pull(skb, ETH_HLEN);
47
48 if (type == PTP_CLASS_NONE)
49 return false;
50
51 return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);
52 }
53
54 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
55 struct packet_type *pt, struct net_device *unused)
56 {
57 struct metadata_dst *md_dst = skb_metadata_dst(skb);
58 struct dsa_port *cpu_dp = dev->dsa_ptr;
59 struct sk_buff *nskb = NULL;
60 struct dsa_user_priv *p;
61
62 if (unlikely(!cpu_dp)) {
63 kfree_skb(skb);
64 return 0;
65 }
66
67 skb = skb_unshare(skb, GFP_ATOMIC);
68 if (!skb)
69 return 0;
70
71 if (md_dst && md_dst->type == METADATA_HW_PORT_MUX) {
72 unsigned int port = md_dst->u.port_info.port_id;
73
74 skb_dst_drop(skb);
75 if (!skb_has_extensions(skb))
76 skb->slow_gro = 0;
77
78 skb->dev = dsa_conduit_find_user(dev, 0, port);
79 if (likely(skb->dev)) {
80 dsa_default_offload_fwd_mark(skb);
81 nskb = skb;
82 }
83 } else {
84 nskb = cpu_dp->rcv(skb, dev);
85 }
86
87 if (!nskb) {
88 kfree_skb(skb);
89 return 0;
90 }
91
92 skb = nskb;
93 skb_push(skb, ETH_HLEN);
94 skb->pkt_type = PACKET_HOST;
95 skb->protocol = eth_type_trans(skb, skb->dev);
96
97 if (unlikely(!dsa_user_dev_check(skb->dev))) {
98 /* Packet is to be injected directly on an upper
99 * device, e.g. a team/bond, so skip all DSA-port
100 * specific actions.
101 */
102 netif_rx(skb);
103 return 0;
104 }
105
106 p = netdev_priv(skb->dev);
107
108 if (unlikely(cpu_dp->ds->untag_bridge_pvid ||
109 cpu_dp->ds->untag_vlan_aware_bridge_pvid)) {
110 nskb = dsa_software_vlan_untag(skb);
111 if (!nskb) {
112 kfree_skb(skb);
113 return 0;
114 }
115 skb = nskb;
116 }
117
118 dev_sw_netstats_rx_add(skb->dev, skb->len + ETH_HLEN);
119
120 if (dsa_skb_defer_rx_timestamp(p, skb))
121 return 0;
122
123 gro_cells_receive(&p->gcells, skb);
124
125 return 0;
126 }
127
128 struct packet_type dsa_pack_type __read_mostly = {
129 .type = cpu_to_be16(ETH_P_XDSA),
130 .func = dsa_switch_rcv,
131 };
132
133 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
134 struct module *owner)
135 {
136 dsa_tag_driver->owner = owner;
137
138 mutex_lock(&dsa_tag_drivers_lock);
139 list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
140 mutex_unlock(&dsa_tag_drivers_lock);
141 }
142
143 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
144 unsigned int count, struct module *owner)
145 {
146 unsigned int i;
147
148 for (i = 0; i < count; i++)
149 dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
150 }
151
152 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
153 {
154 mutex_lock(&dsa_tag_drivers_lock);
155 list_del(&dsa_tag_driver->list);
156 mutex_unlock(&dsa_tag_drivers_lock);
157 }
158 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);
159
160 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
161 unsigned int count)
162 {
163 unsigned int i;
164
165 for (i = 0; i < count; i++)
166 dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
167 }
168 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);
169
170 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
171 {
172 return ops->name;
173 };
174
175 /* Function takes a reference on the module owning the tagger,
176 * so dsa_tag_driver_put must be called afterwards.
177 */
178 const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name)
179 {
180 const struct dsa_device_ops *ops = ERR_PTR(-ENOPROTOOPT);
181 struct dsa_tag_driver *dsa_tag_driver;
182
183 request_module("%s%s", DSA_TAG_DRIVER_ALIAS, name);
184
185 mutex_lock(&dsa_tag_drivers_lock);
186 list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
187 const struct dsa_device_ops *tmp = dsa_tag_driver->ops;
188
189 if (strcmp(name, tmp->name))
190 continue;
191
192 if (!try_module_get(dsa_tag_driver->owner))
193 break;
194
195 ops = tmp;
196 break;
197 }
198 mutex_unlock(&dsa_tag_drivers_lock);
199
200 return ops;
201 }
202
203 const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol)
204 {
205 struct dsa_tag_driver *dsa_tag_driver;
206 const struct dsa_device_ops *ops;
207 bool found = false;
208
209 request_module("%sid-%d", DSA_TAG_DRIVER_ALIAS, tag_protocol);
210
211 mutex_lock(&dsa_tag_drivers_lock);
212 list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
213 ops = dsa_tag_driver->ops;
214 if (ops->proto == tag_protocol) {
215 found = true;
216 break;
217 }
218 }
219
220 if (found) {
221 if (!try_module_get(dsa_tag_driver->owner))
222 ops = ERR_PTR(-ENOPROTOOPT);
223 } else {
224 ops = ERR_PTR(-ENOPROTOOPT);
225 }
226
227 mutex_unlock(&dsa_tag_drivers_lock);
228
229 return ops;
230 }
231
232 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
233 {
234 struct dsa_tag_driver *dsa_tag_driver;
235
236 mutex_lock(&dsa_tag_drivers_lock);
237 list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
238 if (dsa_tag_driver->ops == ops) {
239 module_put(dsa_tag_driver->owner);
240 break;
241 }
242 }
243 mutex_unlock(&dsa_tag_drivers_lock);
244 }
245
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.