Move adbd's legacy USB implementation to fastboot.

This code path is effectively dead in adbd, and fastboot's dependency on
libadbd makes it hard to refactor adbd's dependencies.

Bug: http://b/150317254
Test: built and flashed aosp_walleye-eng
Change-Id: I5118136d32fdcbbd011559ed0a4a71e1dc7bf064
diff --git a/fastboot/device/usb.cpp b/fastboot/device/usb.cpp
new file mode 100644
index 0000000..4bee7b2
--- /dev/null
+++ b/fastboot/device/usb.cpp
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "usb.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/functionfs.h>
+
+#include <algorithm>
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+
+using namespace std::chrono_literals;
+
+#define D(...)
+#define MAX_PACKET_SIZE_FS 64
+#define MAX_PACKET_SIZE_HS 512
+#define MAX_PACKET_SIZE_SS 1024
+
+#define USB_FFS_BULK_SIZE 16384
+
+// Number of buffers needed to fit MAX_PAYLOAD, with an extra for ZLPs.
+#define USB_FFS_NUM_BUFS ((4 * MAX_PAYLOAD / USB_FFS_BULK_SIZE) + 1)
+
+static void aio_block_init(aio_block* aiob, unsigned num_bufs) {
+    aiob->iocb.resize(num_bufs);
+    aiob->iocbs.resize(num_bufs);
+    aiob->events.resize(num_bufs);
+    aiob->num_submitted = 0;
+    for (unsigned i = 0; i < num_bufs; i++) {
+        aiob->iocbs[i] = &aiob->iocb[i];
+    }
+    memset(&aiob->ctx, 0, sizeof(aiob->ctx));
+    if (io_setup(num_bufs, &aiob->ctx)) {
+        D("[ aio: got error on io_setup (%d) ]", errno);
+    }
+}
+
+static int getMaxPacketSize(int ffs_fd) {
+    usb_endpoint_descriptor desc;
+    if (ioctl(ffs_fd, FUNCTIONFS_ENDPOINT_DESC, reinterpret_cast<unsigned long>(&desc))) {
+        D("[ could not get endpoint descriptor! (%d) ]", errno);
+        return MAX_PACKET_SIZE_HS;
+    } else {
+        return desc.wMaxPacketSize;
+    }
+}
+
+static int usb_ffs_write(usb_handle* h, const void* data, int len) {
+    D("about to write (fd=%d, len=%d)", h->bulk_in.get(), len);
+
+    const char* buf = static_cast<const char*>(data);
+    int orig_len = len;
+    while (len > 0) {
+        int write_len = std::min(USB_FFS_BULK_SIZE, len);
+        int n = write(h->bulk_in, buf, write_len);
+        if (n < 0) {
+            D("ERROR: fd = %d, n = %d: %s", h->bulk_in.get(), n, strerror(errno));
+            return -1;
+        }
+        buf += n;
+        len -= n;
+    }
+
+    D("[ done fd=%d ]", h->bulk_in.get());
+    return orig_len;
+}
+
+static int usb_ffs_read(usb_handle* h, void* data, int len, bool allow_partial) {
+    D("about to read (fd=%d, len=%d)", h->bulk_out.get(), len);
+
+    char* buf = static_cast<char*>(data);
+    int orig_len = len;
+    unsigned count = 0;
+    while (len > 0) {
+        int read_len = std::min(USB_FFS_BULK_SIZE, len);
+        int n = read(h->bulk_out, buf, read_len);
+        if (n < 0) {
+            D("ERROR: fd = %d, n = %d: %s", h->bulk_out.get(), n, strerror(errno));
+            return -1;
+        }
+        buf += n;
+        len -= n;
+        count += n;
+
+        // For fastbootd command such as "getvar all", len parameter is always set 64.
+        // But what we read is actually less than 64.
+        // For example, length 10 for "getvar all" command.
+        // If we get less data than expected, this means there should be no more data.
+        if (allow_partial && n < read_len) {
+            orig_len = count;
+            break;
+        }
+    }
+
+    D("[ done fd=%d ]", h->bulk_out.get());
+    return orig_len;
+}
+
+static int usb_ffs_do_aio(usb_handle* h, const void* data, int len, bool read) {
+    aio_block* aiob = read ? &h->read_aiob : &h->write_aiob;
+    bool zero_packet = false;
+
+    int num_bufs = len / h->io_size + (len % h->io_size == 0 ? 0 : 1);
+    const char* cur_data = reinterpret_cast<const char*>(data);
+    int packet_size = getMaxPacketSize(aiob->fd);
+
+    if (posix_madvise(const_cast<void*>(data), len, POSIX_MADV_SEQUENTIAL | POSIX_MADV_WILLNEED) <
+        0) {
+        D("[ Failed to madvise: %d ]", errno);
+    }
+
+    for (int i = 0; i < num_bufs; i++) {
+        int buf_len = std::min(len, static_cast<int>(h->io_size));
+        io_prep(&aiob->iocb[i], aiob->fd, cur_data, buf_len, 0, read);
+
+        len -= buf_len;
+        cur_data += buf_len;
+
+        if (len == 0 && buf_len % packet_size == 0 && read) {
+            // adb does not expect the device to send a zero packet after data transfer,
+            // but the host *does* send a zero packet for the device to read.
+            zero_packet = h->reads_zero_packets;
+        }
+    }
+    if (zero_packet) {
+        io_prep(&aiob->iocb[num_bufs], aiob->fd, reinterpret_cast<const void*>(cur_data),
+                packet_size, 0, read);
+        num_bufs += 1;
+    }
+
+    while (true) {
+        if (TEMP_FAILURE_RETRY(io_submit(aiob->ctx, num_bufs, aiob->iocbs.data())) < num_bufs) {
+            PLOG(ERROR) << "aio: got error submitting " << (read ? "read" : "write");
+            return -1;
+        }
+        if (TEMP_FAILURE_RETRY(io_getevents(aiob->ctx, num_bufs, num_bufs, aiob->events.data(),
+                                            nullptr)) < num_bufs) {
+            PLOG(ERROR) << "aio: got error waiting " << (read ? "read" : "write");
+            return -1;
+        }
+        if (num_bufs == 1 && aiob->events[0].res == -EINTR) {
+            continue;
+        }
+        int ret = 0;
+        for (int i = 0; i < num_bufs; i++) {
+            if (aiob->events[i].res < 0) {
+                errno = -aiob->events[i].res;
+                PLOG(ERROR) << "aio: got error event on " << (read ? "read" : "write")
+                            << " total bufs " << num_bufs;
+                return -1;
+            }
+            ret += aiob->events[i].res;
+        }
+        return ret;
+    }
+}
+
+static int usb_ffs_aio_read(usb_handle* h, void* data, int len, bool /* allow_partial */) {
+    return usb_ffs_do_aio(h, data, len, true);
+}
+
+static int usb_ffs_aio_write(usb_handle* h, const void* data, int len) {
+    return usb_ffs_do_aio(h, data, len, false);
+}
+
+static void usb_ffs_close(usb_handle* h) {
+    LOG(INFO) << "closing functionfs transport";
+
+    h->bulk_out.reset();
+    h->bulk_in.reset();
+
+    // Notify usb_adb_open_thread to open a new connection.
+    h->lock.lock();
+    h->open_new_connection = true;
+    h->lock.unlock();
+    h->notify.notify_one();
+}
+
+usb_handle* create_usb_handle(unsigned num_bufs, unsigned io_size) {
+    usb_handle* h = new usb_handle();
+
+    if (android::base::GetBoolProperty("sys.usb.ffs.aio_compat", false)) {
+        // Devices on older kernels (< 3.18) will not have aio support for ffs
+        // unless backported. Fall back on the non-aio functions instead.
+        h->write = usb_ffs_write;
+        h->read = usb_ffs_read;
+    } else {
+        h->write = usb_ffs_aio_write;
+        h->read = usb_ffs_aio_read;
+        aio_block_init(&h->read_aiob, num_bufs);
+        aio_block_init(&h->write_aiob, num_bufs);
+    }
+    h->io_size = io_size;
+    h->close = usb_ffs_close;
+    return h;
+}