1 /*
2  * u_ether.h -- interface to USB gadget "ethernet link" utilities
3  *
4  * Copyright (C) 2003-2005,2008 David Brownell
5  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6  * Copyright (C) 2008 Nokia Corporation
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #ifndef __U_ETHER_H
15 #define __U_ETHER_H
16 
17 #include <linux/err.h>
18 #include <linux/if_ether.h>
19 #include <linux/usb/composite.h>
20 #include <linux/usb/cdc.h>
21 #include <linux/netdevice.h>
22 
23 #define QMULT_DEFAULT 5
24 
25 /*
26  * dev_addr: initial value
27  * changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx"
28  * host_addr: this address is invisible to ifconfig
29  */
30 #define USB_ETHERNET_MODULE_PARAMETERS() \
31 	static unsigned qmult = QMULT_DEFAULT;				\
32 	module_param(qmult, uint, S_IRUGO|S_IWUSR);			\
33 	MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");\
34 									\
35 	static char *dev_addr;						\
36 	module_param(dev_addr, charp, S_IRUGO);				\
37 	MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");		\
38 									\
39 	static char *host_addr;						\
40 	module_param(host_addr, charp, S_IRUGO);			\
41 	MODULE_PARM_DESC(host_addr, "Host Ethernet Address")
42 
43 struct eth_dev;
44 
45 /*
46  * This represents the USB side of an "ethernet" link, managed by a USB
47  * function which provides control and (maybe) framing.  Two functions
48  * in different configurations could share the same ethernet link/netdev,
49  * using different host interaction models.
50  *
51  * There is a current limitation that only one instance of this link may
52  * be present in any given configuration.  When that's a problem, network
53  * layer facilities can be used to package multiple logical links on this
54  * single "physical" one.
55  */
56 struct gether {
57 	struct usb_function		func;
58 
59 	/* updated by gether_{connect,disconnect} */
60 	struct eth_dev			*ioport;
61 
62 	/* endpoints handle full and/or high speeds */
63 	struct usb_ep			*in_ep;
64 	struct usb_ep			*out_ep;
65 
66 	bool				is_zlp_ok;
67 
68 	u16				cdc_filter;
69 
70 	/* hooks for added framing, as needed for RNDIS and EEM. */
71 	u32				header_len;
72 	/* NCM requires fixed size bundles */
73 	bool				is_fixed;
74 	u32				fixed_out_len;
75 	u32				fixed_in_len;
76 	bool				supports_multi_frame;
77 	struct sk_buff			*(*wrap)(struct gether *port,
78 						struct sk_buff *skb);
79 	int				(*unwrap)(struct gether *port,
80 						struct sk_buff *skb,
81 						struct sk_buff_head *list);
82 
83 	/* called on network open/close */
84 	void				(*open)(struct gether *);
85 	void				(*close)(struct gether *);
86 };
87 
88 #define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
89 			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
90 			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
91 			|USB_CDC_PACKET_TYPE_DIRECTED)
92 
93 /* variant of gether_setup that allows customizing network device name */
94 struct eth_dev *gether_setup_name(struct usb_gadget *g,
95 		const char *dev_addr, const char *host_addr,
96 		u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
97 
98 /* netdev setup/teardown as directed by the gadget driver */
99 /* gether_setup - initialize one ethernet-over-usb link
100  * @g: gadget to associated with these links
101  * @ethaddr: NULL, or a buffer in which the ethernet address of the
102  *	host side of the link is recorded
103  * Context: may sleep
104  *
105  * This sets up the single network link that may be exported by a
106  * gadget driver using this framework.  The link layer addresses are
107  * set up using module parameters.
108  *
109  * Returns a eth_dev pointer on success, or an ERR_PTR on failure
110  */
111 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
112 		const char *dev_addr, const char *host_addr,
113 		u8 ethaddr[ETH_ALEN], unsigned qmult)
114 {
115 	return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
116 }
117 
118 /*
119  * variant of gether_setup_default that allows customizing
120  * network device name
121  */
122 struct net_device *gether_setup_name_default(const char *netname);
123 
124 /*
125  * gether_register_netdev - register the net device
126  * @net: net device to register
127  *
128  * Registers the net device associated with this ethernet-over-usb link
129  *
130  */
131 int gether_register_netdev(struct net_device *net);
132 
133 /* gether_setup_default - initialize one ethernet-over-usb link
134  * Context: may sleep
135  *
136  * This sets up the single network link that may be exported by a
137  * gadget driver using this framework.  The link layer addresses
138  * are set to random values.
139  *
140  * Returns negative errno, or zero on success
141  */
142 static inline struct net_device *gether_setup_default(void)
143 {
144 	return gether_setup_name_default("usb");
145 }
146 
147 /**
148  * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
149  * @net: device representing this link
150  * @g: the gadget to initialize with
151  *
152  * This associates one ethernet-over-usb link with a gadget.
153  */
154 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
155 
156 /**
157  * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
158  * @net: device representing this link
159  * @dev_addr: eth address of this device
160  *
161  * This sets the device-side Ethernet address of this ethernet-over-usb link
162  * if dev_addr is correct.
163  * Returns negative errno if the new address is incorrect.
164  */
165 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
166 
167 /**
168  * gether_get_dev_addr - get an ethernet-over-usb link eth address
169  * @net: device representing this link
170  * @dev_addr: place to store device's eth address
171  * @len: length of the @dev_addr buffer
172  *
173  * This gets the device-side Ethernet address of this ethernet-over-usb link.
174  * Returns zero on success, else negative errno.
175  */
176 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
177 
178 /**
179  * gether_set_host_addr - initialize an ethernet-over-usb link with host address
180  * @net: device representing this link
181  * @host_addr: eth address of the host
182  *
183  * This sets the host-side Ethernet address of this ethernet-over-usb link
184  * if host_addr is correct.
185  * Returns negative errno if the new address is incorrect.
186  */
187 int gether_set_host_addr(struct net_device *net, const char *host_addr);
188 
189 /**
190  * gether_get_host_addr - get an ethernet-over-usb link host address
191  * @net: device representing this link
192  * @host_addr: place to store eth address of the host
193  * @len: length of the @host_addr buffer
194  *
195  * This gets the host-side Ethernet address of this ethernet-over-usb link.
196  * Returns zero on success, else negative errno.
197  */
198 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
199 
200 /**
201  * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
202  * @net: device representing this link
203  * @host_addr: place to store eth address of the host
204  * @len: length of the @host_addr buffer
205  *
206  * This gets the CDC formatted host-side Ethernet address of this
207  * ethernet-over-usb link.
208  * Returns zero on success, else negative errno.
209  */
210 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
211 
212 /**
213  * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
214  * @net: device representing this link
215  * @host_mac: place to store the eth address of the host
216  *
217  * This gets the binary formatted host-side Ethernet address of this
218  * ethernet-over-usb link.
219  */
220 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
221 
222 /**
223  * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
224  * @net: device representing this link
225  * @qmult: queue multiplier
226  *
227  * This sets the queue length multiplier of this ethernet-over-usb link.
228  * For higher speeds use longer queues.
229  */
230 void gether_set_qmult(struct net_device *net, unsigned qmult);
231 
232 /**
233  * gether_get_qmult - get an ethernet-over-usb link multiplier
234  * @net: device representing this link
235  *
236  * This gets the queue length multiplier of this ethernet-over-usb link.
237  */
238 unsigned gether_get_qmult(struct net_device *net);
239 
240 /**
241  * gether_get_ifname - get an ethernet-over-usb link interface name
242  * @net: device representing this link
243  * @name: place to store the interface name
244  * @len: length of the @name buffer
245  *
246  * This gets the interface name of this ethernet-over-usb link.
247  * Returns zero on success, else negative errno.
248  */
249 int gether_get_ifname(struct net_device *net, char *name, int len);
250 
251 void gether_cleanup(struct eth_dev *dev);
252 
253 /* connect/disconnect is handled by individual functions */
254 struct net_device *gether_connect(struct gether *);
255 void gether_disconnect(struct gether *);
256 
257 /* Some controllers can't support CDC Ethernet (ECM) ... */
258 static inline bool can_support_ecm(struct usb_gadget *gadget)
259 {
260 	if (!gadget_is_altset_supported(gadget))
261 		return false;
262 
263 	/* Everything else is *presumably* fine ... but this is a bit
264 	 * chancy, so be **CERTAIN** there are no hardware issues with
265 	 * your controller.  Add it above if it can't handle CDC.
266 	 */
267 	return true;
268 }
269 
270 #endif /* __U_ETHER_H */
271