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 #include "usb.h"
18
19 #include <dirent.h>
20 #include <errno.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/ioctl.h>
25 #include <sys/mman.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28
29 #include <linux/usb/ch9.h>
30 #include <linux/usb/functionfs.h>
31
32 #include <algorithm>
33 #include <atomic>
34 #include <chrono>
35 #include <condition_variable>
36 #include <mutex>
37 #include <thread>
38
39 #include <android-base/logging.h>
40 #include <android-base/properties.h>
41
42 using namespace std::chrono_literals;
43
44 #define D(...)
45 #define MAX_PACKET_SIZE_FS 64
46 #define MAX_PACKET_SIZE_HS 512
47 #define MAX_PACKET_SIZE_SS 1024
48
49 #define USB_FFS_BULK_SIZE 16384
50
51 // Number of buffers needed to fit MAX_PAYLOAD, with an extra for ZLPs.
52 #define USB_FFS_NUM_BUFS ((4 * MAX_PAYLOAD / USB_FFS_BULK_SIZE) + 1)
53
aio_block_init(aio_block * aiob,unsigned num_bufs)54 static void aio_block_init(aio_block* aiob, unsigned num_bufs) {
55 aiob->iocb.resize(num_bufs);
56 aiob->iocbs.resize(num_bufs);
57 aiob->events.resize(num_bufs);
58 aiob->num_submitted = 0;
59 for (unsigned i = 0; i < num_bufs; i++) {
60 aiob->iocbs[i] = &aiob->iocb[i];
61 }
62 memset(&aiob->ctx, 0, sizeof(aiob->ctx));
63 if (io_setup(num_bufs, &aiob->ctx)) {
64 D("[ aio: got error on io_setup (%d) ]", errno);
65 }
66 }
67
getMaxPacketSize(int ffs_fd)68 static int getMaxPacketSize(int ffs_fd) {
69 usb_endpoint_descriptor desc;
70 if (ioctl(ffs_fd, FUNCTIONFS_ENDPOINT_DESC, reinterpret_cast<unsigned long>(&desc))) {
71 D("[ could not get endpoint descriptor! (%d) ]", errno);
72 return MAX_PACKET_SIZE_HS;
73 } else {
74 return desc.wMaxPacketSize;
75 }
76 }
77
usb_ffs_write(usb_handle * h,const void * data,int len)78 static int usb_ffs_write(usb_handle* h, const void* data, int len) {
79 D("about to write (fd=%d, len=%d)", h->bulk_in.get(), len);
80
81 const char* buf = static_cast<const char*>(data);
82 int orig_len = len;
83 while (len > 0) {
84 int write_len = std::min(USB_FFS_BULK_SIZE, len);
85 int n = write(h->bulk_in.get(), buf, write_len);
86 if (n < 0) {
87 D("ERROR: fd = %d, n = %d: %s", h->bulk_in.get(), n, strerror(errno));
88 return -1;
89 }
90 buf += n;
91 len -= n;
92 }
93
94 D("[ done fd=%d ]", h->bulk_in.get());
95 return orig_len;
96 }
97
usb_ffs_read(usb_handle * h,void * data,int len,bool allow_partial)98 static int usb_ffs_read(usb_handle* h, void* data, int len, bool allow_partial) {
99 D("about to read (fd=%d, len=%d)", h->bulk_out.get(), len);
100
101 char* buf = static_cast<char*>(data);
102 int orig_len = len;
103 unsigned count = 0;
104 while (len > 0) {
105 int read_len = std::min(USB_FFS_BULK_SIZE, len);
106 int n = read(h->bulk_out.get(), buf, read_len);
107 if (n < 0) {
108 D("ERROR: fd = %d, n = %d: %s", h->bulk_out.get(), n, strerror(errno));
109 return -1;
110 }
111 buf += n;
112 len -= n;
113 count += n;
114
115 // For fastbootd command such as "getvar all", len parameter is always set 64.
116 // But what we read is actually less than 64.
117 // For example, length 10 for "getvar all" command.
118 // If we get less data than expected, this means there should be no more data.
119 if (allow_partial && n < read_len) {
120 orig_len = count;
121 break;
122 }
123 }
124
125 D("[ done fd=%d ]", h->bulk_out.get());
126 return orig_len;
127 }
128
usb_ffs_do_aio(usb_handle * h,const void * data,int len,bool read)129 static int usb_ffs_do_aio(usb_handle* h, const void* data, int len, bool read) {
130 aio_block* aiob = read ? &h->read_aiob : &h->write_aiob;
131 bool zero_packet = false;
132
133 int num_bufs = len / h->io_size + (len % h->io_size == 0 ? 0 : 1);
134 const char* cur_data = reinterpret_cast<const char*>(data);
135 int packet_size = getMaxPacketSize(aiob->fd);
136
137 if (posix_madvise(const_cast<void*>(data), len, POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED) <
138 0) {
139 D("[ Failed to madvise: %d ]", errno);
140 }
141
142 for (int i = 0; i < num_bufs; i++) {
143 int buf_len = std::min(len, static_cast<int>(h->io_size));
144 io_prep(&aiob->iocb[i], aiob->fd, cur_data, buf_len, 0, read);
145
146 len -= buf_len;
147 cur_data += buf_len;
148
149 if (len == 0 && buf_len % packet_size == 0 && read) {
150 // adb does not expect the device to send a zero packet after data transfer,
151 // but the host *does* send a zero packet for the device to read.
152 zero_packet = h->reads_zero_packets;
153 }
154 }
155 if (zero_packet) {
156 io_prep(&aiob->iocb[num_bufs], aiob->fd, reinterpret_cast<const void*>(cur_data),
157 packet_size, 0, read);
158 num_bufs += 1;
159 }
160
161 while (true) {
162 if (TEMP_FAILURE_RETRY(io_submit(aiob->ctx, num_bufs, aiob->iocbs.data())) < num_bufs) {
163 PLOG(ERROR) << "aio: got error submitting " << (read ? "read" : "write");
164 return -1;
165 }
166 if (TEMP_FAILURE_RETRY(io_getevents(aiob->ctx, num_bufs, num_bufs, aiob->events.data(),
167 nullptr)) < num_bufs) {
168 PLOG(ERROR) << "aio: got error waiting " << (read ? "read" : "write");
169 return -1;
170 }
171 if (num_bufs == 1 && aiob->events[0].res == -EINTR) {
172 continue;
173 }
174 int ret = 0;
175 for (int i = 0; i < num_bufs; i++) {
176 if (aiob->events[i].res < 0) {
177 errno = -aiob->events[i].res;
178 PLOG(ERROR) << "aio: got error event on " << (read ? "read" : "write")
179 << " total bufs " << num_bufs;
180 return -1;
181 }
182 ret += aiob->events[i].res;
183 }
184 return ret;
185 }
186 }
187
usb_ffs_aio_read(usb_handle * h,void * data,int len,bool)188 static int usb_ffs_aio_read(usb_handle* h, void* data, int len, bool /* allow_partial */) {
189 return usb_ffs_do_aio(h, data, len, true);
190 }
191
usb_ffs_aio_write(usb_handle * h,const void * data,int len)192 static int usb_ffs_aio_write(usb_handle* h, const void* data, int len) {
193 return usb_ffs_do_aio(h, data, len, false);
194 }
195
usb_ffs_close(usb_handle * h)196 static void usb_ffs_close(usb_handle* h) {
197 LOG(INFO) << "closing functionfs transport";
198
199 h->bulk_out.reset();
200 h->bulk_in.reset();
201
202 // Notify usb_adb_open_thread to open a new connection.
203 h->lock.lock();
204 h->open_new_connection = true;
205 h->lock.unlock();
206 h->notify.notify_one();
207 }
208
create_usb_handle(unsigned num_bufs,unsigned io_size)209 usb_handle* create_usb_handle(unsigned num_bufs, unsigned io_size) {
210 usb_handle* h = new usb_handle();
211
212 if (android::base::GetBoolProperty("sys.usb.ffs.aio_compat", false)) {
213 // Devices on older kernels (< 3.18) will not have aio support for ffs
214 // unless backported. Fall back on the non-aio functions instead.
215 h->write = usb_ffs_write;
216 h->read = usb_ffs_read;
217 } else {
218 h->write = usb_ffs_aio_write;
219 h->read = usb_ffs_aio_read;
220 aio_block_init(&h->read_aiob, num_bufs);
221 aio_block_init(&h->write_aiob, num_bufs);
222 }
223 h->io_size = io_size;
224 h->close = usb_ffs_close;
225 return h;
226 }
227