usb_linux.c revision c500be926cf07c43aeb828ae86b04b856c6b7c63 
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, int writable,
93                             ifc_match_func callback,
94                             int *ept_in_id, int *ept_out_id, int *ifc_id)
95{
96    struct usb_device_descriptor *dev;
97    struct usb_config_descriptor *cfg;
98    struct usb_interface_descriptor *ifc;
99    struct usb_endpoint_descriptor *ept;
100    struct usb_ifc_info info;
101
102    int in, out;
103    unsigned i;
104    unsigned e;
105
106    if(check(ptr, len, USB_DT_DEVICE, USB_DT_DEVICE_SIZE))
107        return -1;
108    dev = (void*) ptr;
109    len -= dev->bLength;
110    ptr += dev->bLength;
111
112    if(check(ptr, len, USB_DT_CONFIG, USB_DT_CONFIG_SIZE))
113        return -1;
114    cfg = (void*) ptr;
115    len -= cfg->bLength;
116    ptr += cfg->bLength;
117
118    info.dev_vendor = dev->idVendor;
119    info.dev_product = dev->idProduct;
120    info.dev_class = dev->bDeviceClass;
121    info.dev_subclass = dev->bDeviceSubClass;
122    info.dev_protocol = dev->bDeviceProtocol;
123    info.writable = writable;
124
125    // read device serial number (if there is one)
126    info.serial_number[0] = 0;
127    if (dev->iSerialNumber) {
128        struct usbdevfs_ctrltransfer  ctrl;
129        __u16 buffer[128];
130        int result;
131
132        memset(buffer, 0, sizeof(buffer));
133
134        ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE;
135        ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
136        ctrl.wValue = (USB_DT_STRING << 8) | dev->iSerialNumber;
137        ctrl.wIndex = 0;
138        ctrl.wLength = sizeof(buffer);
139        ctrl.data = buffer;
140
141        result = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
142        if (result > 0) {
143            int i;
144            // skip first word, and copy the rest to the serial string, changing shorts to bytes.
145            result /= 2;
146            for (i = 1; i < result; i++)
147                info.serial_number[i - 1] = buffer[i];
148            info.serial_number[i - 1] = 0;
149        }
150    }
151
152    for(i = 0; i < cfg->bNumInterfaces; i++) {
153        if(check(ptr, len, USB_DT_INTERFACE, USB_DT_INTERFACE_SIZE))
154            return -1;
155        ifc = (void*) ptr;
156        len -= ifc->bLength;
157        ptr += ifc->bLength;
158
159        in = -1;
160        out = -1;
161        info.ifc_class = ifc->bInterfaceClass;
162        info.ifc_subclass = ifc->bInterfaceSubClass;
163        info.ifc_protocol = ifc->bInterfaceProtocol;
164
165        for(e = 0; e < ifc->bNumEndpoints; e++) {
166            if(check(ptr, len, USB_DT_ENDPOINT, USB_DT_ENDPOINT_SIZE))
167                return -1;
168            ept = (void*) ptr;
169            len -= ept->bLength;
170            ptr += ept->bLength;
171
172            if((ept->bmAttributes & 0x03) != 0x02)
173                continue;
174
175            if(ept->bEndpointAddress & 0x80) {
176                in = ept->bEndpointAddress;
177            } else {
178                out = ept->bEndpointAddress;
179            }
180        }
181
182        info.has_bulk_in = (in != -1);
183        info.has_bulk_out = (out != -1);
184
185        if(callback(&info) == 0) {
186            *ept_in_id = in;
187            *ept_out_id = out;
188            *ifc_id = ifc->bInterfaceNumber;
189            return 0;
190        }
191    }
192
193    return -1;
194}
195
196static usb_handle *find_usb_device(const char *base, ifc_match_func callback)
197{
198    usb_handle *usb = 0;
199    char busname[64], devname[64];
200    char desc[1024];
201    int n, in, out, ifc;
202
203    DIR *busdir, *devdir;
204    struct dirent *de;
205    int fd;
206    int writable;
207
208    busdir = opendir(base);
209    if(busdir == 0) return 0;
210
211    while((de = readdir(busdir)) && (usb == 0)) {
212        if(badname(de->d_name)) continue;
213
214        sprintf(busname, "%s/%s", base, de->d_name);
215        devdir = opendir(busname);
216        if(devdir == 0) continue;
217
218//        DBG("[ scanning %s ]\n", busname);
219        while((de = readdir(devdir)) && (usb == 0)) {
220
221            if(badname(de->d_name)) continue;
222            sprintf(devname, "%s/%s", busname, de->d_name);
223
224//            DBG("[ scanning %s ]\n", devname);
225            writable = 1;
226            if((fd = open(devname, O_RDWR)) < 0) {
227                // Check if we have read-only access, so we can give a helpful
228                // diagnostic like "adb devices" does.
229                writable = 0;
230                if((fd = open(devname, O_RDONLY)) < 0) {
231                    continue;
232                }
233            }
234
235            n = read(fd, desc, sizeof(desc));
236
237            if(filter_usb_device(fd, desc, n, writable, callback,
238                                 &in, &out, &ifc) == 0) {
239                usb = calloc(1, sizeof(usb_handle));
240                strcpy(usb->fname, devname);
241                usb->ep_in = in;
242                usb->ep_out = out;
243                usb->desc = fd;
244
245                n = ioctl(fd, USBDEVFS_CLAIMINTERFACE, &ifc);
246                if(n != 0) {
247                    close(fd);
248                    free(usb);
249                    usb = 0;
250                    continue;
251                }
252            } else {
253                close(fd);
254            }
255        }
256        closedir(devdir);
257    }
258    closedir(busdir);
259
260    return usb;
261}
262
263int usb_write(usb_handle *h, const void *_data, int len)
264{
265    unsigned char *data = (unsigned char*) _data;
266    unsigned count = 0;
267    struct usbdevfs_bulktransfer bulk;
268    int n;
269
270    if(h->ep_out == 0) {
271        return -1;
272    }
273
274    if(len == 0) {
275        bulk.ep = h->ep_out;
276        bulk.len = 0;
277        bulk.data = data;
278        bulk.timeout = 0;
279
280        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
281        if(n != 0) {
282            fprintf(stderr,"ERROR: n = %d, errno = %d (%s)\n",
283                    n, errno, strerror(errno));
284            return -1;
285        }
286        return 0;
287    }
288
289    while(len > 0) {
290        int xfer;
291        xfer = (len > 4096) ? 4096 : len;
292
293        bulk.ep = h->ep_out;
294        bulk.len = xfer;
295        bulk.data = data;
296        bulk.timeout = 0;
297
298        n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
299        if(n != xfer) {
300            DBG("ERROR: n = %d, errno = %d (%s)\n",
301                n, errno, strerror(errno));
302            return -1;
303        }
304
305        count += xfer;
306        len -= xfer;
307        data += xfer;
308    }
309
310    return count;
311}
312
313int usb_read(usb_handle *h, void *_data, int len)
314{
315    unsigned char *data = (unsigned char*) _data;
316    unsigned count = 0;
317    struct usbdevfs_bulktransfer bulk;
318    int n, retry;
319
320    if(h->ep_in == 0) {
321        return -1;
322    }
323
324    while(len > 0) {
325        int xfer = (len > 4096) ? 4096 : len;
326
327        bulk.ep = h->ep_in;
328        bulk.len = xfer;
329        bulk.data = data;
330        bulk.timeout = 0;
331        retry = 0;
332
333        do{
334           DBG("[ usb read %d fd = %d], fname=%s\n", xfer, h->desc, h->fname);
335           n = ioctl(h->desc, USBDEVFS_BULK, &bulk);
336           DBG("[ usb read %d ] = %d, fname=%s, Retry %d \n", xfer, n, h->fname, retry);
337
338           if( n < 0 ) {
339            DBG1("ERROR: n = %d, errno = %d (%s)\n",n, errno, strerror(errno));
340            if ( ++retry > MAX_RETRIES ) return -1;
341            sleep( 1 );
342           }
343        }
344        while( n < 0 );
345
346        count += n;
347        len -= n;
348        data += n;
349
350        if(n < xfer) {
351            break;
352        }
353    }
354
355    return count;
356}
357
358void usb_kick(usb_handle *h)
359{
360    int fd;
361
362    fd = h->desc;
363    h->desc = -1;
364    if(fd >= 0) {
365        close(fd);
366        DBG("[ usb closed %d ]\n", fd);
367    }
368}
369
370int usb_close(usb_handle *h)
371{
372    int fd;
373
374    fd = h->desc;
375    h->desc = -1;
376    if(fd >= 0) {
377        close(fd);
378        DBG("[ usb closed %d ]\n", fd);
379    }
380
381    return 0;
382}
383
384usb_handle *usb_open(ifc_match_func callback)
385{
386    return find_usb_device("/dev/bus/usb", callback);
387}
388