usb_linux.c revision 913eb8bf874fcec647667bd7113da65b6e38488a 
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
64/* The max bulk size for linux is 16384 which is defined
65 * in drivers/usb/core/devio.c.
66 */
67#define MAX_USBFS_BULK_SIZE (16 * 1024)
68
69struct usb_handle
70{
71    char fname[64];
72    int desc;
73    unsigned char ep_in;
74    unsigned char ep_out;
75};
76
77static inline int badname(const char *name)
78{
79    while(*name) {
80        if(!isdigit(*name++)) return 1;
81    }
82    return 0;
83}
84
85static int check(void *_desc, int len, unsigned type, int size)
86{
87    unsigned char *desc = _desc;
88
89    if(len < size) return -1;
90    if(desc[0] < size) return -1;
91    if(desc[0] > len) return -1;
92    if(desc[1] != type) return -1;
93
94    return 0;
95}
96
97static int filter_usb_device(int fd, char *ptr, int len, int writable,
98                             ifc_match_func callback,
99                             int *ept_in_id, int *ept_out_id, int *ifc_id)
100{
101    struct usb_device_descriptor *dev;
102    struct usb_config_descriptor *cfg;
103    struct usb_interface_descriptor *ifc;
104    struct usb_endpoint_descriptor *ept;
105    struct usb_ifc_info info;
106
107    int in, out;
108    unsigned i;
109    unsigned e;
110
111    if(check(ptr, len, USB_DT_DEVICE, USB_DT_DEVICE_SIZE))
112        return -1;
113    dev = (void*) ptr;
114    len -= dev->bLength;
115    ptr += dev->bLength;
116
117    if(check(ptr, len, USB_DT_CONFIG, USB_DT_CONFIG_SIZE))
118        return -1;
119    cfg = (void*) ptr;
120    len -= cfg->bLength;
121    ptr += cfg->bLength;
122
123    info.dev_vendor = dev->idVendor;
124    info.dev_product = dev->idProduct;
125    info.dev_class = dev->bDeviceClass;
126    info.dev_subclass = dev->bDeviceSubClass;
127    info.dev_protocol = dev->bDeviceProtocol;
128    info.writable = writable;
129
130    // read device serial number (if there is one)
131    info.serial_number[0] = 0;
132    if (dev->iSerialNumber) {
133        struct usbdevfs_ctrltransfer  ctrl;
134        __u16 buffer[128];
135        int result;
136
137        memset(buffer, 0, sizeof(buffer));
138
139        ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE;
140        ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
141        ctrl.wValue = (USB_DT_STRING << 8) | dev->iSerialNumber;
142        ctrl.wIndex = 0;
143        ctrl.wLength = sizeof(buffer);
144        ctrl.data = buffer;
145	ctrl.timeout = 50;
146
147        result = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
148        if (result > 0) {
149            int i;
150            // skip first word, and copy the rest to the serial string, changing shorts to bytes.
151            result /= 2;
152            for (i = 1; i < result; i++)
153                info.serial_number[i - 1] = buffer[i];
154            info.serial_number[i - 1] = 0;
155        }
156    }
157
158    for(i = 0; i < cfg->bNumInterfaces; i++) {
159        if(check(ptr, len, USB_DT_INTERFACE, USB_DT_INTERFACE_SIZE))
160            return -1;
161        ifc = (void*) ptr;
162        len -= ifc->bLength;
163        ptr += ifc->bLength;
164
165        in = -1;
166        out = -1;
167        info.ifc_class = ifc->bInterfaceClass;
168        info.ifc_subclass = ifc->bInterfaceSubClass;
169        info.ifc_protocol = ifc->bInterfaceProtocol;
170
171        for(e = 0; e < ifc->bNumEndpoints; e++) {
172            if(check(ptr, len, USB_DT_ENDPOINT, USB_DT_ENDPOINT_SIZE))
173                return -1;
174            ept = (void*) ptr;
175            len -= ept->bLength;
176            ptr += ept->bLength;
177
178            if((ept->bmAttributes & 0x03) != 0x02)
179                continue;
180
181            if(ept->bEndpointAddress & 0x80) {
182                in = ept->bEndpointAddress;
183            } else {
184                out = ept->bEndpointAddress;
185            }
186        }
187
188        info.has_bulk_in = (in != -1);
189        info.has_bulk_out = (out != -1);
190
191        if(callback(&info) == 0) {
192            *ept_in_id = in;
193            *ept_out_id = out;
194            *ifc_id = ifc->bInterfaceNumber;
195            return 0;
196        }
197    }
198
199    return -1;
200}
201
202static usb_handle *find_usb_device(const char *base, ifc_match_func callback)
203{
204    usb_handle *usb = 0;
205    char busname[64], devname[64];
206    char desc[1024];
207    int n, in, out, ifc;
208
209    DIR *busdir, *devdir;
210    struct dirent *de;
211    int fd;
212    int writable;
213
214    busdir = opendir(base);
215    if(busdir == 0) return 0;
216
217    while((de = readdir(busdir)) && (usb == 0)) {
218        if(badname(de->d_name)) continue;
219
220        sprintf(busname, "%s/%s", base, de->d_name);
221        devdir = opendir(busname);
222        if(devdir == 0) continue;
223
224//        DBG("[ scanning %s ]\n", busname);
225        while((de = readdir(devdir)) && (usb == 0)) {
226
227            if(badname(de->d_name)) continue;
228            sprintf(devname, "%s/%s", busname, de->d_name);
229
230//            DBG("[ scanning %s ]\n", devname);
231            writable = 1;
232            if((fd = open(devname, O_RDWR)) < 0) {
233                // Check if we have read-only access, so we can give a helpful
234                // diagnostic like "adb devices" does.
235                writable = 0;
236                if((fd = open(devname, O_RDONLY)) < 0) {
237                    continue;
238                }
239            }
240
241            n = read(fd, desc, sizeof(desc));
242
243            if(filter_usb_device(fd, desc, n, writable, callback,
244                                 &in, &out, &ifc) == 0) {
245                usb = calloc(1, sizeof(usb_handle));
246                strcpy(usb->fname, devname);
247                usb->ep_in = in;
248                usb->ep_out = out;
249                usb->desc = fd;
250
251                n = ioctl(fd, USBDEVFS_CLAIMINTERFACE, &ifc);
252                if(n != 0) {
253                    close(fd);
254                    free(usb);
255                    usb = 0;
256                    continue;
257                }
258            } else {
259                close(fd);
260            }
261        }
262        closedir(devdir);
263    }
264    closedir(busdir);
265
266    return usb;
267}
268
269int usb_write(usb_handle *h, const void *_data, int len)
270{
271    unsigned char *data = (unsigned char*) _data;
272    unsigned count = 0;
273    struct usbdevfs_bulktransfer bulk;
274    int n;
275
276    if(h->ep_out == 0) {
277        return -1;
278    }
279
280    if(len == 0) {
281        bulk.ep = h->ep_out;
282        bulk.len = 0;
283        bulk.data = data;
284        bulk.timeout = 0;
285
286        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
287        if(n != 0) {
288            fprintf(stderr,"ERROR: n = %d, errno = %d (%s)\n",
289                    n, errno, strerror(errno));
290            return -1;
291        }
292        return 0;
293    }
294
295    while(len > 0) {
296        int xfer;
297        xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
298
299        bulk.ep = h->ep_out;
300        bulk.len = xfer;
301        bulk.data = data;
302        bulk.timeout = 0;
303
304        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
305        if(n != xfer) {
306            DBG("ERROR: n = %d, errno = %d (%s)\n",
307                n, errno, strerror(errno));
308            return -1;
309        }
310
311        count += xfer;
312        len -= xfer;
313        data += xfer;
314    }
315
316    return count;
317}
318
319int usb_read(usb_handle *h, void *_data, int len)
320{
321    unsigned char *data = (unsigned char*) _data;
322    unsigned count = 0;
323    struct usbdevfs_bulktransfer bulk;
324    int n, retry;
325
326    if(h->ep_in == 0) {
327        return -1;
328    }
329
330    while(len > 0) {
331        int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
332
333        bulk.ep = h->ep_in;
334        bulk.len = xfer;
335        bulk.data = data;
336        bulk.timeout = 0;
337        retry = 0;
338
339        do{
340           DBG("[ usb read %d fd = %d], fname=%s\n", xfer, h->desc, h->fname);
341           n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
342           DBG("[ usb read %d ] = %d, fname=%s, Retry %d \n", xfer, n, h->fname, retry);
343
344           if( n < 0 ) {
345            DBG1("ERROR: n = %d, errno = %d (%s)\n",n, errno, strerror(errno));
346            if ( ++retry > MAX_RETRIES ) return -1;
347            sleep( 1 );
348           }
349        }
350        while( n < 0 );
351
352        count += n;
353        len -= n;
354        data += n;
355
356        if(n < xfer) {
357            break;
358        }
359    }
360
361    return count;
362}
363
364void usb_kick(usb_handle *h)
365{
366    int fd;
367
368    fd = h->desc;
369    h->desc = -1;
370    if(fd >= 0) {
371        close(fd);
372        DBG("[ usb closed %d ]\n", fd);
373    }
374}
375
376int usb_close(usb_handle *h)
377{
378    int fd;
379
380    fd = h->desc;
381    h->desc = -1;
382    if(fd >= 0) {
383        close(fd);
384        DBG("[ usb closed %d ]\n", fd);
385    }
386
387    return 0;
388}
389
390usb_handle *usb_open(ifc_match_func callback)
391{
392    return find_usb_device("/dev/bus/usb", callback);
393}
394