usb_linux.c revision b2de4db941f5329f9f19e70feff5786b2d5acbb6 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <stdio.h>
30#include <stdlib.h>
31#include <unistd.h>
32#include <string.h>
33
34#include <sys/ioctl.h>
35#include <sys/types.h>
36#include <dirent.h>
37#include <fcntl.h>
38#include <errno.h>
39#include <pthread.h>
40#include <ctype.h>
41
42#include <linux/usbdevice_fs.h>
43#include <linux/usbdevice_fs.h>
44#include <linux/version.h>
45#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 20)
46#include <linux/usb/ch9.h>
47#else
48#include <linux/usb_ch9.h>
49#endif
50#include <asm/byteorder.h>
51
52#include "usb.h"
53
54#define MAX_RETRIES 5
55
56#ifdef TRACE_USB
57#define DBG1(x...) fprintf(stderr, x)
58#define DBG(x...) fprintf(stderr, x)
59#else
60#define DBG(x...)
61#define DBG1(x...)
62#endif
63
64struct usb_handle
65{
66    char fname[64];
67    int desc;
68    unsigned char ep_in;
69    unsigned char ep_out;
70};
71
72static inline int badname(const char *name)
73{
74    while(*name) {
75        if(!isdigit(*name++)) return 1;
76    }
77    return 0;
78}
79
80static int check(void *_desc, int len, unsigned type, int size)
81{
82    unsigned char *desc = _desc;
83
84    if(len < size) return -1;
85    if(desc[0] < size) return -1;
86    if(desc[0] > len) return -1;
87    if(desc[1] != type) return -1;
88
89    return 0;
90}
91
92static int filter_usb_device(int fd, char *ptr, int len, ifc_match_func callback,
93                             int *ept_in_id, int *ept_out_id, int *ifc_id)
94{
95    struct usb_device_descriptor *dev;
96    struct usb_config_descriptor *cfg;
97    struct usb_interface_descriptor *ifc;
98    struct usb_endpoint_descriptor *ept;
99    struct usb_ifc_info info;
100
101    int in, out;
102    unsigned i;
103    unsigned e;
104
105    if(check(ptr, len, USB_DT_DEVICE, USB_DT_DEVICE_SIZE))
106        return -1;
107    dev = (void*) ptr;
108    len -= dev->bLength;
109    ptr += dev->bLength;
110
111    if(check(ptr, len, USB_DT_CONFIG, USB_DT_CONFIG_SIZE))
112        return -1;
113    cfg = (void*) ptr;
114    len -= cfg->bLength;
115    ptr += cfg->bLength;
116
117    info.dev_vendor = dev->idVendor;
118    info.dev_product = dev->idProduct;
119    info.dev_class = dev->bDeviceClass;
120    info.dev_subclass = dev->bDeviceSubClass;
121    info.dev_protocol = dev->bDeviceProtocol;
122
123    // read device serial number (if there is one)
124    info.serial_number[0] = 0;
125    if (dev->iSerialNumber) {
126        struct usbdevfs_ctrltransfer  ctrl;
127        __u16 buffer[128];
128        int result;
129
130        memset(buffer, 0, sizeof(buffer));
131
132        ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE;
133        ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
134        ctrl.wValue = (USB_DT_STRING << 8) | dev->iSerialNumber;
135        ctrl.wIndex = 0;
136        ctrl.wLength = sizeof(buffer);
137        ctrl.data = buffer;
138
139        result = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
140        if (result > 0) {
141            int i;
142            // skip first word, and copy the rest to the serial string, changing shorts to bytes.
143            result /= 2;
144            for (i = 1; i < result; i++)
145                info.serial_number[i - 1] = buffer[i];
146            info.serial_number[i - 1] = 0;
147        }
148    }
149
150    for(i = 0; i < cfg->bNumInterfaces; i++) {
151        if(check(ptr, len, USB_DT_INTERFACE, USB_DT_INTERFACE_SIZE))
152            return -1;
153        ifc = (void*) ptr;
154        len -= ifc->bLength;
155        ptr += ifc->bLength;
156
157        in = -1;
158        out = -1;
159        info.ifc_class = ifc->bInterfaceClass;
160        info.ifc_subclass = ifc->bInterfaceSubClass;
161        info.ifc_protocol = ifc->bInterfaceProtocol;
162
163        for(e = 0; e < ifc->bNumEndpoints; e++) {
164            if(check(ptr, len, USB_DT_ENDPOINT, USB_DT_ENDPOINT_SIZE))
165                return -1;
166            ept = (void*) ptr;
167            len -= ept->bLength;
168            ptr += ept->bLength;
169
170            if((ept->bmAttributes & 0x03) != 0x02)
171                continue;
172
173            if(ept->bEndpointAddress & 0x80) {
174                in = ept->bEndpointAddress;
175            } else {
176                out = ept->bEndpointAddress;
177            }
178        }
179
180        info.has_bulk_in = (in != -1);
181        info.has_bulk_out = (out != -1);
182
183        if(callback(&info) == 0) {
184            *ept_in_id = in;
185            *ept_out_id = out;
186            *ifc_id = ifc->bInterfaceNumber;
187            return 0;
188        }
189    }
190
191    return -1;
192}
193
194static usb_handle *find_usb_device(const char *base, ifc_match_func callback)
195{
196    usb_handle *usb = 0;
197    char busname[64], devname[64];
198    char desc[1024];
199    int n, in, out, ifc;
200
201    DIR *busdir, *devdir;
202    struct dirent *de;
203    int fd;
204
205    busdir = opendir(base);
206    if(busdir == 0) return 0;
207
208    while((de = readdir(busdir)) && (usb == 0)) {
209        if(badname(de->d_name)) continue;
210
211        sprintf(busname, "%s/%s", base, de->d_name);
212        devdir = opendir(busname);
213        if(devdir == 0) continue;
214
215//        DBG("[ scanning %s ]\n", busname);
216        while((de = readdir(devdir)) && (usb == 0)) {
217
218            if(badname(de->d_name)) continue;
219            sprintf(devname, "%s/%s", busname, de->d_name);
220
221//            DBG("[ scanning %s ]\n", devname);
222            if((fd = open(devname, O_RDWR)) < 0) {
223                continue;
224            }
225
226            n = read(fd, desc, sizeof(desc));
227
228            if(filter_usb_device(fd, desc, n, callback, &in, &out, &ifc) == 0){
229                usb = calloc(1, sizeof(usb_handle));
230                strcpy(usb->fname, devname);
231                usb->ep_in = in;
232                usb->ep_out = out;
233                usb->desc = fd;
234
235                n = ioctl(fd, USBDEVFS_CLAIMINTERFACE, &ifc);
236                if(n != 0) {
237                    close(fd);
238                    free(usb);
239                    usb = 0;
240                    continue;
241                }
242            } else {
243                close(fd);
244            }
245        }
246        closedir(devdir);
247    }
248    closedir(busdir);
249
250    return usb;
251}
252
253int usb_write(usb_handle *h, const void *_data, int len)
254{
255    unsigned char *data = (unsigned char*) _data;
256    unsigned count = 0;
257    struct usbdevfs_bulktransfer bulk;
258    int n;
259
260    if(h->ep_out == 0) {
261        return -1;
262    }
263
264    if(len == 0) {
265        bulk.ep = h->ep_out;
266        bulk.len = 0;
267        bulk.data = data;
268        bulk.timeout = 0;
269
270        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
271        if(n != 0) {
272            fprintf(stderr,"ERROR: n = %d, errno = %d (%s)\n",
273                    n, errno, strerror(errno));
274            return -1;
275        }
276        return 0;
277    }
278
279    while(len > 0) {
280        int xfer;
281        xfer = (len > 4096) ? 4096 : len;
282
283        bulk.ep = h->ep_out;
284        bulk.len = xfer;
285        bulk.data = data;
286        bulk.timeout = 0;
287
288        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
289        if(n != xfer) {
290            DBG("ERROR: n = %d, errno = %d (%s)\n",
291                n, errno, strerror(errno));
292            return -1;
293        }
294
295        count += xfer;
296        len -= xfer;
297        data += xfer;
298    }
299
300    return count;
301}
302
303int usb_read(usb_handle *h, void *_data, int len)
304{
305    unsigned char *data = (unsigned char*) _data;
306    unsigned count = 0;
307    struct usbdevfs_bulktransfer bulk;
308    int n, retry;
309
310    if(h->ep_in == 0) {
311        return -1;
312    }
313
314    while(len > 0) {
315        int xfer = (len > 4096) ? 4096 : len;
316
317        bulk.ep = h->ep_in;
318        bulk.len = xfer;
319        bulk.data = data;
320        bulk.timeout = 0;
321        retry = 0;
322
323        do{
324           DBG("[ usb read %d fd = %d], fname=%s\n", xfer, h->desc, h->fname);
325           n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
326           DBG("[ usb read %d ] = %d, fname=%s, Retry %d \n", xfer, n, h->fname, retry);
327
328           if( n < 0 ) {
329            DBG1("ERROR: n = %d, errno = %d (%s)\n",n, errno, strerror(errno));
330            if ( ++retry > MAX_RETRIES ) return -1;
331            sleep( 1 );
332           }
333        }
334        while( n < 0 );
335
336        count += n;
337        len -= n;
338        data += n;
339
340        if(n < xfer) {
341            break;
342        }
343    }
344
345    return count;
346}
347
348void usb_kick(usb_handle *h)
349{
350    int fd;
351
352    fd = h->desc;
353    h->desc = -1;
354    if(fd >= 0) {
355        close(fd);
356        DBG("[ usb closed %d ]\n", fd);
357    }
358}
359
360int usb_close(usb_handle *h)
361{
362    int fd;
363
364    fd = h->desc;
365    h->desc = -1;
366    if(fd >= 0) {
367        close(fd);
368        DBG("[ usb closed %d ]\n", fd);
369    }
370
371    return 0;
372}
373
374usb_handle *usb_open(ifc_match_func callback)
375{
376    return find_usb_device("/dev/bus/usb", callback);
377}
378
379
380