1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define TRACE_TAG USB
18
19#include "sysdeps.h"
20
21#include <ctype.h>
22#include <dirent.h>
23#include <errno.h>
24#include <fcntl.h>
25#include <linux/usb/ch9.h>
26#include <linux/usbdevice_fs.h>
27#include <linux/version.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31#include <sys/ioctl.h>
32#include <sys/time.h>
33#include <sys/types.h>
34#include <unistd.h>
35
36#include <chrono>
37#include <condition_variable>
38#include <list>
39#include <mutex>
40#include <string>
41
42#include <android-base/file.h>
43#include <android-base/stringprintf.h>
44#include <android-base/strings.h>
45
46#include "adb.h"
47#include "transport.h"
48
49using namespace std::literals;
50
51/* usb scan debugging is waaaay too verbose */
52#define DBGX(x...)
53
54struct usb_handle {
55    ~usb_handle() {
56      if (fd != -1) unix_close(fd);
57    }
58
59    std::string path;
60    int fd = -1;
61    unsigned char ep_in;
62    unsigned char ep_out;
63
64    unsigned zero_mask;
65    unsigned writeable = 1;
66
67    usbdevfs_urb urb_in;
68    usbdevfs_urb urb_out;
69
70    bool urb_in_busy = false;
71    bool urb_out_busy = false;
72    bool dead = false;
73
74    std::condition_variable cv;
75    std::mutex mutex;
76
77    // for garbage collecting disconnected devices
78    bool mark;
79
80    // ID of thread currently in REAPURB
81    pthread_t reaper_thread = 0;
82};
83
84static auto& g_usb_handles_mutex = *new std::mutex();
85static auto& g_usb_handles = *new std::list<usb_handle*>();
86
87static int is_known_device(const char* dev_name) {
88    std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
89    for (usb_handle* usb : g_usb_handles) {
90        if (usb->path == dev_name) {
91            // set mark flag to indicate this device is still alive
92            usb->mark = true;
93            return 1;
94        }
95    }
96    return 0;
97}
98
99static void kick_disconnected_devices() {
100    std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
101    // kick any devices in the device list that were not found in the device scan
102    for (usb_handle* usb : g_usb_handles) {
103        if (!usb->mark) {
104            usb_kick(usb);
105        } else {
106            usb->mark = false;
107        }
108    }
109}
110
111static inline bool contains_non_digit(const char* name) {
112    while (*name) {
113        if (!isdigit(*name++)) return true;
114    }
115    return false;
116}
117
118static void find_usb_device(const std::string& base,
119        void (*register_device_callback)
120                (const char*, const char*, unsigned char, unsigned char, int, int, unsigned))
121{
122    std::unique_ptr<DIR, int(*)(DIR*)> bus_dir(opendir(base.c_str()), closedir);
123    if (!bus_dir) return;
124
125    dirent* de;
126    while ((de = readdir(bus_dir.get())) != 0) {
127        if (contains_non_digit(de->d_name)) continue;
128
129        std::string bus_name = base + "/" + de->d_name;
130
131        std::unique_ptr<DIR, int(*)(DIR*)> dev_dir(opendir(bus_name.c_str()), closedir);
132        if (!dev_dir) continue;
133
134        while ((de = readdir(dev_dir.get()))) {
135            unsigned char devdesc[4096];
136            unsigned char* bufptr = devdesc;
137            unsigned char* bufend;
138            struct usb_device_descriptor* device;
139            struct usb_config_descriptor* config;
140            struct usb_interface_descriptor* interface;
141            struct usb_endpoint_descriptor *ep1, *ep2;
142            unsigned zero_mask = 0;
143            unsigned vid, pid;
144
145            if (contains_non_digit(de->d_name)) continue;
146
147            std::string dev_name = bus_name + "/" + de->d_name;
148            if (is_known_device(dev_name.c_str())) {
149                continue;
150            }
151
152            int fd = unix_open(dev_name.c_str(), O_RDONLY | O_CLOEXEC);
153            if (fd == -1) {
154                continue;
155            }
156
157            size_t desclength = unix_read(fd, devdesc, sizeof(devdesc));
158            bufend = bufptr + desclength;
159
160                // should have device and configuration descriptors, and atleast two endpoints
161            if (desclength < USB_DT_DEVICE_SIZE + USB_DT_CONFIG_SIZE) {
162                D("desclength %zu is too small", desclength);
163                unix_close(fd);
164                continue;
165            }
166
167            device = (struct usb_device_descriptor*)bufptr;
168            bufptr += USB_DT_DEVICE_SIZE;
169
170            if((device->bLength != USB_DT_DEVICE_SIZE) || (device->bDescriptorType != USB_DT_DEVICE)) {
171                unix_close(fd);
172                continue;
173            }
174
175            vid = device->idVendor;
176            pid = device->idProduct;
177            DBGX("[ %s is V:%04x P:%04x ]\n", dev_name.c_str(), vid, pid);
178
179                // should have config descriptor next
180            config = (struct usb_config_descriptor *)bufptr;
181            bufptr += USB_DT_CONFIG_SIZE;
182            if (config->bLength != USB_DT_CONFIG_SIZE || config->bDescriptorType != USB_DT_CONFIG) {
183                D("usb_config_descriptor not found");
184                unix_close(fd);
185                continue;
186            }
187
188                // loop through all the descriptors and look for the ADB interface
189            while (bufptr < bufend) {
190                unsigned char length = bufptr[0];
191                unsigned char type = bufptr[1];
192
193                if (type == USB_DT_INTERFACE) {
194                    interface = (struct usb_interface_descriptor *)bufptr;
195                    bufptr += length;
196
197                    if (length != USB_DT_INTERFACE_SIZE) {
198                        D("interface descriptor has wrong size");
199                        break;
200                    }
201
202                    DBGX("bInterfaceClass: %d,  bInterfaceSubClass: %d,"
203                         "bInterfaceProtocol: %d, bNumEndpoints: %d\n",
204                         interface->bInterfaceClass, interface->bInterfaceSubClass,
205                         interface->bInterfaceProtocol, interface->bNumEndpoints);
206
207                    if (interface->bNumEndpoints == 2 &&
208                            is_adb_interface(vid, pid, interface->bInterfaceClass,
209                            interface->bInterfaceSubClass, interface->bInterfaceProtocol))  {
210
211                        struct stat st;
212                        char pathbuf[128];
213                        char link[256];
214                        char *devpath = nullptr;
215
216                        DBGX("looking for bulk endpoints\n");
217                            // looks like ADB...
218                        ep1 = (struct usb_endpoint_descriptor *)bufptr;
219                        bufptr += USB_DT_ENDPOINT_SIZE;
220                            // For USB 3.0 SuperSpeed devices, skip potential
221                            // USB 3.0 SuperSpeed Endpoint Companion descriptor
222                        if (bufptr+2 <= devdesc + desclength &&
223                            bufptr[0] == USB_DT_SS_EP_COMP_SIZE &&
224                            bufptr[1] == USB_DT_SS_ENDPOINT_COMP) {
225                            bufptr += USB_DT_SS_EP_COMP_SIZE;
226                        }
227                        ep2 = (struct usb_endpoint_descriptor *)bufptr;
228                        bufptr += USB_DT_ENDPOINT_SIZE;
229                        if (bufptr+2 <= devdesc + desclength &&
230                            bufptr[0] == USB_DT_SS_EP_COMP_SIZE &&
231                            bufptr[1] == USB_DT_SS_ENDPOINT_COMP) {
232                            bufptr += USB_DT_SS_EP_COMP_SIZE;
233                        }
234
235                        if (bufptr > devdesc + desclength ||
236                            ep1->bLength != USB_DT_ENDPOINT_SIZE ||
237                            ep1->bDescriptorType != USB_DT_ENDPOINT ||
238                            ep2->bLength != USB_DT_ENDPOINT_SIZE ||
239                            ep2->bDescriptorType != USB_DT_ENDPOINT) {
240                            D("endpoints not found");
241                            break;
242                        }
243
244                            // both endpoints should be bulk
245                        if (ep1->bmAttributes != USB_ENDPOINT_XFER_BULK ||
246                            ep2->bmAttributes != USB_ENDPOINT_XFER_BULK) {
247                            D("bulk endpoints not found");
248                            continue;
249                        }
250                            /* aproto 01 needs 0 termination */
251                        if(interface->bInterfaceProtocol == 0x01) {
252                            zero_mask = ep1->wMaxPacketSize - 1;
253                        }
254
255                            // we have a match.  now we just need to figure out which is in and which is out.
256                        unsigned char local_ep_in, local_ep_out;
257                        if (ep1->bEndpointAddress & USB_ENDPOINT_DIR_MASK) {
258                            local_ep_in = ep1->bEndpointAddress;
259                            local_ep_out = ep2->bEndpointAddress;
260                        } else {
261                            local_ep_in = ep2->bEndpointAddress;
262                            local_ep_out = ep1->bEndpointAddress;
263                        }
264
265                            // Determine the device path
266                        if (!fstat(fd, &st) && S_ISCHR(st.st_mode)) {
267                            snprintf(pathbuf, sizeof(pathbuf), "/sys/dev/char/%d:%d",
268                                     major(st.st_rdev), minor(st.st_rdev));
269                            ssize_t link_len = readlink(pathbuf, link, sizeof(link) - 1);
270                            if (link_len > 0) {
271                                link[link_len] = '\0';
272                                const char* slash = strrchr(link, '/');
273                                if (slash) {
274                                    snprintf(pathbuf, sizeof(pathbuf),
275                                             "usb:%s", slash + 1);
276                                    devpath = pathbuf;
277                                }
278                            }
279                        }
280
281                        register_device_callback(dev_name.c_str(), devpath,
282                                local_ep_in, local_ep_out,
283                                interface->bInterfaceNumber, device->iSerialNumber, zero_mask);
284                        break;
285                    }
286                } else {
287                    bufptr += length;
288                }
289            } // end of while
290
291            unix_close(fd);
292        }
293    }
294}
295
296static int usb_bulk_write(usb_handle* h, const void* data, int len) {
297    std::unique_lock<std::mutex> lock(h->mutex);
298    D("++ usb_bulk_write ++");
299
300    usbdevfs_urb* urb = &h->urb_out;
301    memset(urb, 0, sizeof(*urb));
302    urb->type = USBDEVFS_URB_TYPE_BULK;
303    urb->endpoint = h->ep_out;
304    urb->status = -1;
305    urb->buffer = const_cast<void*>(data);
306    urb->buffer_length = len;
307
308    if (h->dead) {
309        errno = EINVAL;
310        return -1;
311    }
312
313    if (TEMP_FAILURE_RETRY(ioctl(h->fd, USBDEVFS_SUBMITURB, urb)) == -1) {
314        return -1;
315    }
316
317    h->urb_out_busy = true;
318    while (true) {
319        auto now = std::chrono::system_clock::now();
320        if (h->cv.wait_until(lock, now + 5s) == std::cv_status::timeout || h->dead) {
321            // TODO: call USBDEVFS_DISCARDURB?
322            errno = ETIMEDOUT;
323            return -1;
324        }
325        if (!h->urb_out_busy) {
326            if (urb->status != 0) {
327                errno = -urb->status;
328                return -1;
329            }
330            return urb->actual_length;
331        }
332    }
333}
334
335static int usb_bulk_read(usb_handle* h, void* data, int len) {
336    std::unique_lock<std::mutex> lock(h->mutex);
337    D("++ usb_bulk_read ++");
338
339    usbdevfs_urb* urb = &h->urb_in;
340    memset(urb, 0, sizeof(*urb));
341    urb->type = USBDEVFS_URB_TYPE_BULK;
342    urb->endpoint = h->ep_in;
343    urb->status = -1;
344    urb->buffer = data;
345    urb->buffer_length = len;
346
347    if (h->dead) {
348        errno = EINVAL;
349        return -1;
350    }
351
352    if (TEMP_FAILURE_RETRY(ioctl(h->fd, USBDEVFS_SUBMITURB, urb)) == -1) {
353        return -1;
354    }
355
356    h->urb_in_busy = true;
357    while (true) {
358        D("[ reap urb - wait ]");
359        h->reaper_thread = pthread_self();
360        int fd = h->fd;
361        lock.unlock();
362
363        // This ioctl must not have TEMP_FAILURE_RETRY because we send SIGALRM to break out.
364        usbdevfs_urb* out = nullptr;
365        int res = ioctl(fd, USBDEVFS_REAPURB, &out);
366        int saved_errno = errno;
367
368        lock.lock();
369        h->reaper_thread = 0;
370        if (h->dead) {
371            errno = EINVAL;
372            return -1;
373        }
374        if (res < 0) {
375            if (saved_errno == EINTR) {
376                continue;
377            }
378            D("[ reap urb - error ]");
379            errno = saved_errno;
380            return -1;
381        }
382        D("[ urb @%p status = %d, actual = %d ]", out, out->status, out->actual_length);
383
384        if (out == &h->urb_in) {
385            D("[ reap urb - IN complete ]");
386            h->urb_in_busy = false;
387            if (urb->status != 0) {
388                errno = -urb->status;
389                return -1;
390            }
391            return urb->actual_length;
392        }
393        if (out == &h->urb_out) {
394            D("[ reap urb - OUT compelete ]");
395            h->urb_out_busy = false;
396            h->cv.notify_all();
397        }
398    }
399}
400
401
402int usb_write(usb_handle *h, const void *_data, int len)
403{
404    D("++ usb_write ++");
405
406    unsigned char *data = (unsigned char*) _data;
407    int n = usb_bulk_write(h, data, len);
408    if (n != len) {
409        D("ERROR: n = %d, errno = %d (%s)", n, errno, strerror(errno));
410        return -1;
411    }
412
413    if (h->zero_mask && !(len & h->zero_mask)) {
414        // If we need 0-markers and our transfer is an even multiple of the packet size,
415        // then send a zero marker.
416        return usb_bulk_write(h, _data, 0);
417    }
418
419    D("-- usb_write --");
420    return 0;
421}
422
423int usb_read(usb_handle *h, void *_data, int len)
424{
425    unsigned char *data = (unsigned char*) _data;
426    int n;
427
428    D("++ usb_read ++");
429    while(len > 0) {
430        int xfer = len;
431
432        D("[ usb read %d fd = %d], path=%s", xfer, h->fd, h->path.c_str());
433        n = usb_bulk_read(h, data, xfer);
434        D("[ usb read %d ] = %d, path=%s", xfer, n, h->path.c_str());
435        if(n != xfer) {
436            if((errno == ETIMEDOUT) && (h->fd != -1)) {
437                D("[ timeout ]");
438                if(n > 0){
439                    data += n;
440                    len -= n;
441                }
442                continue;
443            }
444            D("ERROR: n = %d, errno = %d (%s)",
445                n, errno, strerror(errno));
446            return -1;
447        }
448
449        len -= xfer;
450        data += xfer;
451    }
452
453    D("-- usb_read --");
454    return 0;
455}
456
457void usb_kick(usb_handle* h) {
458    std::lock_guard<std::mutex> lock(h->mutex);
459    D("[ kicking %p (fd = %d) ]", h, h->fd);
460    if (!h->dead) {
461        h->dead = true;
462
463        if (h->writeable) {
464            /* HACK ALERT!
465            ** Sometimes we get stuck in ioctl(USBDEVFS_REAPURB).
466            ** This is a workaround for that problem.
467            */
468            if (h->reaper_thread) {
469                pthread_kill(h->reaper_thread, SIGALRM);
470            }
471
472            /* cancel any pending transactions
473            ** these will quietly fail if the txns are not active,
474            ** but this ensures that a reader blocked on REAPURB
475            ** will get unblocked
476            */
477            ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_in);
478            ioctl(h->fd, USBDEVFS_DISCARDURB, &h->urb_out);
479            h->urb_in.status = -ENODEV;
480            h->urb_out.status = -ENODEV;
481            h->urb_in_busy = false;
482            h->urb_out_busy = false;
483            h->cv.notify_all();
484        } else {
485            unregister_usb_transport(h);
486        }
487    }
488}
489
490int usb_close(usb_handle* h) {
491    std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
492    g_usb_handles.remove(h);
493
494    D("-- usb close %p (fd = %d) --", h, h->fd);
495
496    delete h;
497
498    return 0;
499}
500
501static void register_device(const char* dev_name, const char* dev_path,
502                            unsigned char ep_in, unsigned char ep_out,
503                            int interface, int serial_index,
504                            unsigned zero_mask) {
505    // Since Linux will not reassign the device ID (and dev_name) as long as the
506    // device is open, we can add to the list here once we open it and remove
507    // from the list when we're finally closed and everything will work out
508    // fine.
509    //
510    // If we have a usb_handle on the list of handles with a matching name, we
511    // have no further work to do.
512    {
513        std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
514        for (usb_handle* usb: g_usb_handles) {
515            if (usb->path == dev_name) {
516                return;
517            }
518        }
519    }
520
521    D("[ usb located new device %s (%d/%d/%d) ]", dev_name, ep_in, ep_out, interface);
522    std::unique_ptr<usb_handle> usb(new usb_handle);
523    usb->path = dev_name;
524    usb->ep_in = ep_in;
525    usb->ep_out = ep_out;
526    usb->zero_mask = zero_mask;
527
528    // Initialize mark so we don't get garbage collected after the device scan.
529    usb->mark = true;
530
531    usb->fd = unix_open(usb->path.c_str(), O_RDWR | O_CLOEXEC);
532    if (usb->fd == -1) {
533        // Opening RW failed, so see if we have RO access.
534        usb->fd = unix_open(usb->path.c_str(), O_RDONLY | O_CLOEXEC);
535        if (usb->fd == -1) {
536            D("[ usb open %s failed: %s]", usb->path.c_str(), strerror(errno));
537            return;
538        }
539        usb->writeable = 0;
540    }
541
542    D("[ usb opened %s%s, fd=%d]",
543      usb->path.c_str(), (usb->writeable ? "" : " (read-only)"), usb->fd);
544
545    if (usb->writeable) {
546        if (ioctl(usb->fd, USBDEVFS_CLAIMINTERFACE, &interface) != 0) {
547            D("[ usb ioctl(%d, USBDEVFS_CLAIMINTERFACE) failed: %s]", usb->fd, strerror(errno));
548            return;
549        }
550    }
551
552    // Read the device's serial number.
553    std::string serial_path = android::base::StringPrintf(
554        "/sys/bus/usb/devices/%s/serial", dev_path + 4);
555    std::string serial;
556    if (!android::base::ReadFileToString(serial_path, &serial)) {
557        D("[ usb read %s failed: %s ]", serial_path.c_str(), strerror(errno));
558        // We don't actually want to treat an unknown serial as an error because
559        // devices aren't able to communicate a serial number in early bringup.
560        // http://b/20883914
561        serial = "";
562    }
563    serial = android::base::Trim(serial);
564
565    // Add to the end of the active handles.
566    usb_handle* done_usb = usb.release();
567    {
568        std::lock_guard<std::mutex> lock(g_usb_handles_mutex);
569        g_usb_handles.push_back(done_usb);
570    }
571    register_usb_transport(done_usb, serial.c_str(), dev_path, done_usb->writeable);
572}
573
574static void device_poll_thread(void*) {
575    adb_thread_setname("device poll");
576    D("Created device thread");
577    while (true) {
578        // TODO: Use inotify.
579        find_usb_device("/dev/bus/usb", register_device);
580        kick_disconnected_devices();
581        sleep(1);
582    }
583}
584
585void usb_init() {
586    struct sigaction actions;
587    memset(&actions, 0, sizeof(actions));
588    sigemptyset(&actions.sa_mask);
589    actions.sa_flags = 0;
590    actions.sa_handler = [](int) {};
591    sigaction(SIGALRM, &actions, nullptr);
592
593    if (!adb_thread_create(device_poll_thread, nullptr)) {
594        fatal_errno("cannot create device_poll thread");
595    }
596}
597