1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * u_ether.h -- interface to USB gadget "ethernet link" utilities
4 *
5 * Copyright (C) 2003-2005,2008 David Brownell
6 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
7 * Copyright (C) 2008 Nokia Corporation
8 */
9
10 #ifndef __U_ETHER_H
11 #define __U_ETHER_H
12
13 #include <linux/err.h>
14 #include <linux/if_ether.h>
15 #include <linux/usb/composite.h>
16 #include <linux/usb/cdc.h>
17 #include <linux/netdevice.h>
18
19 #define QMULT_DEFAULT 5
20
21 /*
22 * dev_addr: initial value
23 * changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx"
24 * host_addr: this address is invisible to ifconfig
25 */
26 #define USB_ETHERNET_MODULE_PARAMETERS() \
27 static unsigned qmult = QMULT_DEFAULT; \
28 module_param(qmult, uint, S_IRUGO|S_IWUSR); \
29 MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");\
30 \
31 static char *dev_addr; \
32 module_param(dev_addr, charp, S_IRUGO); \
33 MODULE_PARM_DESC(dev_addr, "Device Ethernet Address"); \
34 \
35 static char *host_addr; \
36 module_param(host_addr, charp, S_IRUGO); \
37 MODULE_PARM_DESC(host_addr, "Host Ethernet Address")
38
39 struct eth_dev;
40
41 /*
42 * This represents the USB side of an "ethernet" link, managed by a USB
43 * function which provides control and (maybe) framing. Two functions
44 * in different configurations could share the same ethernet link/netdev,
45 * using different host interaction models.
46 *
47 * There is a current limitation that only one instance of this link may
48 * be present in any given configuration. When that's a problem, network
49 * layer facilities can be used to package multiple logical links on this
50 * single "physical" one.
51 */
52 struct gether {
53 struct usb_function func;
54
55 /* updated by gether_{connect,disconnect} */
56 struct eth_dev *ioport;
57
58 /* endpoints handle full and/or high speeds */
59 struct usb_ep *in_ep;
60 struct usb_ep *out_ep;
61
62 bool is_zlp_ok;
63
64 u16 cdc_filter;
65
66 /* hooks for added framing, as needed for RNDIS and EEM. */
67 u32 header_len;
68 /* NCM requires fixed size bundles */
69 bool is_fixed;
70 u32 fixed_out_len;
71 u32 fixed_in_len;
72 bool supports_multi_frame;
73 struct sk_buff *(*wrap)(struct gether *port,
74 struct sk_buff *skb);
75 int (*unwrap)(struct gether *port,
76 struct sk_buff *skb,
77 struct sk_buff_head *list);
78
79 /* called on network open/close */
80 void (*open)(struct gether *);
81 void (*close)(struct gether *);
82 };
83
84 #define DEFAULT_FILTER (USB_CDC_PACKET_TYPE_BROADCAST \
85 |USB_CDC_PACKET_TYPE_ALL_MULTICAST \
86 |USB_CDC_PACKET_TYPE_PROMISCUOUS \
87 |USB_CDC_PACKET_TYPE_DIRECTED)
88
89 /* variant of gether_setup that allows customizing network device name */
90 struct eth_dev *gether_setup_name(struct usb_gadget *g,
91 const char *dev_addr, const char *host_addr,
92 u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
93
94 /* netdev setup/teardown as directed by the gadget driver */
95 /* gether_setup - initialize one ethernet-over-usb link
96 * @g: gadget to associated with these links
97 * @ethaddr: NULL, or a buffer in which the ethernet address of the
98 * host side of the link is recorded
99 * Context: may sleep
100 *
101 * This sets up the single network link that may be exported by a
102 * gadget driver using this framework. The link layer addresses are
103 * set up using module parameters.
104 *
105 * Returns a eth_dev pointer on success, or an ERR_PTR on failure
106 */
107 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
108 const char *dev_addr, const char *host_addr,
109 u8 ethaddr[ETH_ALEN], unsigned qmult)
110 {
111 return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
112 }
113
114 /*
115 * variant of gether_setup_default that allows customizing
116 * network device name
117 */
118 struct net_device *gether_setup_name_default(const char *netname);
119
120 /*
121 * gether_register_netdev - register the net device
122 * @net: net device to register
123 *
124 * Registers the net device associated with this ethernet-over-usb link
125 *
126 */
127 int gether_register_netdev(struct net_device *net);
128
129 /* gether_setup_default - initialize one ethernet-over-usb link
130 * Context: may sleep
131 *
132 * This sets up the single network link that may be exported by a
133 * gadget driver using this framework. The link layer addresses
134 * are set to random values.
135 *
136 * Returns negative errno, or zero on success
137 */
138 static inline struct net_device *gether_setup_default(void)
139 {
140 return gether_setup_name_default("usb");
141 }
142
143 /**
144 * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
145 * @net: device representing this link
146 * @g: the gadget to initialize with
147 *
148 * This associates one ethernet-over-usb link with a gadget.
149 */
150 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
151
152 /**
153 * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
154 * @net: device representing this link
155 * @dev_addr: eth address of this device
156 *
157 * This sets the device-side Ethernet address of this ethernet-over-usb link
158 * if dev_addr is correct.
159 * Returns negative errno if the new address is incorrect.
160 */
161 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
162
163 /**
164 * gether_get_dev_addr - get an ethernet-over-usb link eth address
165 * @net: device representing this link
166 * @dev_addr: place to store device's eth address
167 * @len: length of the @dev_addr buffer
168 *
169 * This gets the device-side Ethernet address of this ethernet-over-usb link.
170 * Returns zero on success, else negative errno.
171 */
172 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
173
174 /**
175 * gether_set_host_addr - initialize an ethernet-over-usb link with host address
176 * @net: device representing this link
177 * @host_addr: eth address of the host
178 *
179 * This sets the host-side Ethernet address of this ethernet-over-usb link
180 * if host_addr is correct.
181 * Returns negative errno if the new address is incorrect.
182 */
183 int gether_set_host_addr(struct net_device *net, const char *host_addr);
184
185 /**
186 * gether_get_host_addr - get an ethernet-over-usb link host address
187 * @net: device representing this link
188 * @host_addr: place to store eth address of the host
189 * @len: length of the @host_addr buffer
190 *
191 * This gets the host-side Ethernet address of this ethernet-over-usb link.
192 * Returns zero on success, else negative errno.
193 */
194 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
195
196 /**
197 * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
198 * @net: device representing this link
199 * @host_addr: place to store eth address of the host
200 * @len: length of the @host_addr buffer
201 *
202 * This gets the CDC formatted host-side Ethernet address of this
203 * ethernet-over-usb link.
204 * Returns zero on success, else negative errno.
205 */
206 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
207
208 /**
209 * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
210 * @net: device representing this link
211 * @host_mac: place to store the eth address of the host
212 *
213 * This gets the binary formatted host-side Ethernet address of this
214 * ethernet-over-usb link.
215 */
216 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
217
218 /**
219 * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
220 * @net: device representing this link
221 * @qmult: queue multiplier
222 *
223 * This sets the queue length multiplier of this ethernet-over-usb link.
224 * For higher speeds use longer queues.
225 */
226 void gether_set_qmult(struct net_device *net, unsigned qmult);
227
228 /**
229 * gether_get_qmult - get an ethernet-over-usb link multiplier
230 * @net: device representing this link
231 *
232 * This gets the queue length multiplier of this ethernet-over-usb link.
233 */
234 unsigned gether_get_qmult(struct net_device *net);
235
236 /**
237 * gether_get_ifname - get an ethernet-over-usb link interface name
238 * @net: device representing this link
239 * @name: place to store the interface name
240 * @len: length of the @name buffer
241 *
242 * This gets the interface name of this ethernet-over-usb link.
243 * Returns zero on success, else negative errno.
244 */
245 int gether_get_ifname(struct net_device *net, char *name, int len);
246
247 void gether_cleanup(struct eth_dev *dev);
248
249 /* connect/disconnect is handled by individual functions */
250 struct net_device *gether_connect(struct gether *);
251 void gether_disconnect(struct gether *);
252
253 /* Some controllers can't support CDC Ethernet (ECM) ... */
254 static inline bool can_support_ecm(struct usb_gadget *gadget)
255 {
256 if (!gadget_is_altset_supported(gadget))
257 return false;
258
259 /* Everything else is *presumably* fine ... but this is a bit
260 * chancy, so be **CERTAIN** there are no hardware issues with
261 * your controller. Add it above if it can't handle CDC.
262 */
263 return true;
264 }
265
266 #endif /* __U_ETHER_H */