1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
|
/*
* USB CDC EEM network interface driver
* Copyright (C) 2009 Oberthur Technologies
* by Omar Laazimani, Olivier Condemine
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ctype.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/crc32.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>
#include <linux/gfp.h>
/*
* This driver is an implementation of the CDC "Ethernet Emulation
* Model" (EEM) specification, which encapsulates Ethernet frames
* for transport over USB using a simpler USB device model than the
* previous CDC "Ethernet Control Model" (ECM, or "CDC Ethernet").
*
* For details, see www.usb.org/developers/devclass_docs/CDC_EEM10.pdf
*
* This version has been tested with GIGAntIC WuaoW SIM Smart Card on 2.6.24,
* 2.6.27 and 2.6.30rc2 kernel.
* It has also been validated on Openmoko Om 2008.12 (based on 2.6.24 kernel).
* build on 23-April-2009
*/
#define EEM_HEAD 2 /* 2 byte header */
/*-------------------------------------------------------------------------*/
static void eem_linkcmd_complete(struct urb *urb)
{
dev_kfree_skb(urb->context);
usb_free_urb(urb);
}
static void eem_linkcmd(struct usbnet *dev, struct sk_buff *skb)
{
struct urb *urb;
int status;
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb)
goto fail;
usb_fill_bulk_urb(urb, dev->udev, dev->out,
skb->data, skb->len, eem_linkcmd_complete, skb);
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status) {
usb_free_urb(urb);
fail:
dev_kfree_skb(skb);
netdev_warn(dev->net, "link cmd failure\n");
return;
}
}
static int eem_bind(struct usbnet *dev, struct usb_interface *intf)
{
int status = 0;
status = usbnet_get_endpoints(dev, intf);
if (status < 0) {
usb_set_intfdata(intf, NULL);
usb_driver_release_interface(driver_of(intf), intf);
return status;
}
/* no jumbogram (16K) support for now */
dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN;
return 0;
}
/*
* EEM permits packing multiple Ethernet frames into USB transfers
* (a "bundle"), but for TX we don't try to do that.
*/
static struct sk_buff *eem_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
gfp_t flags)
{
struct sk_buff *skb2 = NULL;
u16 len = skb->len;
u32 crc = 0;
int padlen = 0;
/* When ((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket) is
* zero, stick two bytes of zero length EEM packet on the end.
* Else the framework would add invalid single byte padding,
* since it can't know whether ZLPs will be handled right by
* all the relevant hardware and software.
*/
if (!((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket))
padlen += 2;
if (!skb_cloned(skb)) {
int headroom = skb_headroom(skb);
int tailroom = skb_tailroom(skb);
if ((tailroom >= ETH_FCS_LEN + padlen) &&
(headroom >= EEM_HEAD))
goto done;
if ((headroom + tailroom)
> (EEM_HEAD + ETH_FCS_LEN + padlen)) {
skb->data = memmove(skb->head +
EEM_HEAD,
skb->data,
skb->len);
skb_set_tail_pointer(skb, len);
goto done;
}
}
skb2 = skb_copy_expand(skb, EEM_HEAD, ETH_FCS_LEN + padlen, flags);
if (!skb2)
return NULL;
dev_kfree_skb_any(skb);
skb = skb2;
done:
/* we don't use the "no Ethernet CRC" option */
crc = crc32_le(~0, skb->data, skb->len);
crc = ~crc;
put_unaligned_le32(crc, skb_put(skb, 4));
/* EEM packet header format:
* b0..13: length of ethernet frame
* b14: bmCRC (1 == valid Ethernet CRC)
* b15: bmType (0 == data)
*/
len = skb->len;
put_unaligned_le16(BIT(14) | len, skb_push(skb, 2));
/* Bundle a zero length EEM packet if needed */
if (padlen)
put_unaligned_le16(0, skb_put(skb, 2));
return skb;
}
static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
/*
* Our task here is to strip off framing, leaving skb with one
* data frame for the usbnet framework code to process. But we
* may have received multiple EEM payloads, or command payloads.
* So we must process _everything_ as if it's a header, except
* maybe the last data payload
*
* REVISIT the framework needs updating so that when we consume
* all payloads (the last or only message was a command, or a
* zero length EEM packet) that is not accounted as an rx_error.
*/
do {
struct sk_buff *skb2 = NULL;
u16 header;
u16 len = 0;
/* incomplete EEM header? */
if (skb->len < EEM_HEAD)
return 0;
/*
* EEM packet header format:
* b0..14: EEM type dependent (Data or Command)
* b15: bmType
*/
header = get_unaligned_le16(skb->data);
skb_pull(skb, EEM_HEAD);
/*
* The bmType bit helps to denote when EEM
* packet is data or command :
* bmType = 0 : EEM data payload
* bmType = 1 : EEM (link) command
*/
if (header & BIT(15)) {
u16 bmEEMCmd;
/*
* EEM (link) command packet:
* b0..10: bmEEMCmdParam
* b11..13: bmEEMCmd
* b14: bmReserved (must be 0)
* b15: 1 (EEM command)
*/
if (header & BIT(14)) {
netdev_dbg(dev->net, "reserved command %04x\n",
header);
continue;
}
bmEEMCmd = (header >> 11) & 0x7;
switch (bmEEMCmd) {
/* Responding to echo requests is mandatory. */
case 0: /* Echo command */
len = header & 0x7FF;
/* bogus command? */
if (skb->len < len)
return 0;
skb2 = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!skb2))
goto next;
skb_trim(skb2, len);
put_unaligned_le16(BIT(15) | (1 << 11) | len,
skb_push(skb2, 2));
eem_linkcmd(dev, skb2);
break;
/*
* Host may choose to ignore hints.
* - suspend: peripheral ready to suspend
* - response: suggest N millisec polling
* - response complete: suggest N sec polling
*/
case 2: /* Suspend hint */
case 3: /* Response hint */
case 4: /* Response complete hint */
continue;
/*
* Hosts should never receive host-to-peripheral
* or reserved command codes; or responses to an
* echo command we didn't send.
*/
case 1: /* Echo response */
case 5: /* Tickle */
default: /* reserved */
netdev_warn(dev->net,
"unexpected link command %d\n",
bmEEMCmd);
continue;
}
} else {
u32 crc, crc2;
int is_last;
/* zero length EEM packet? */
if (header == 0)
continue;
/*
* EEM data packet header :
* b0..13: length of ethernet frame
* b14: bmCRC
* b15: 0 (EEM data)
*/
len = header & 0x3FFF;
/* bogus EEM payload? */
if (skb->len < len)
return 0;
/* bogus ethernet frame? */
if (len < (ETH_HLEN + ETH_FCS_LEN))
goto next;
/*
* Treat the last payload differently: framework
* code expects our "fixup" to have stripped off
* headers, so "skb" is a data packet (or error).
* Else if it's not the last payload, keep "skb"
* for further processing.
*/
is_last = (len == skb->len);
if (is_last)
skb2 = skb;
else {
skb2 = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!skb2))
return 0;
}
/*
* The bmCRC helps to denote when the CRC field in
* the Ethernet frame contains a calculated CRC:
* bmCRC = 1 : CRC is calculated
* bmCRC = 0 : CRC = 0xDEADBEEF
*/
if (header & BIT(14)) {
crc = get_unaligned_le32(skb2->data
+ len - ETH_FCS_LEN);
crc2 = ~crc32_le(~0, skb2->data, skb2->len
- ETH_FCS_LEN);
} else {
crc = get_unaligned_be32(skb2->data
+ len - ETH_FCS_LEN);
crc2 = 0xdeadbeef;
}
skb_trim(skb2, len - ETH_FCS_LEN);
if (is_last)
return crc == crc2;
if (unlikely(crc != crc2)) {
dev->net->stats.rx_errors++;
dev_kfree_skb_any(skb2);
} else
usbnet_skb_return(dev, skb2);
}
next:
skb_pull(skb, len);
} while (skb->len);
return 1;
}
static const struct driver_info eem_info = {
.description
|