Merge changes If9782396,If033c815

// This file descriptor can be used as a standard pipe/socket descriptor.

//

// 'pipeName' is the name of the emulator service you want to connect to,

// and must begin with 'pipe:' (e.g. 'pipe:camera' or 'pipe:opengles').

//

// and should begin with 'pipe:' (e.g. 'pipe:camera' or 'pipe:opengles').

// For backward compatibility, the 'pipe:' prefix can be omitted, and in

// that case, qemu_pipe_open will add it for you.

// On success, return a valid file descriptor, or -1/errno on failure. E.g.:

//

// EINVAL  -> unknown/unsupported pipeName

#include <errno.h>

#include <stdio.h>

#include <android-base/file.h>

using android::base::ReadFully;

using android::base::WriteFully;

// Define QEMU_PIPE_DEBUG if you want to print error messages when an error

// occurs during pipe operations. The macro should simply take a printf-style

#  define  QEMU_PIPE_DEBUG(...)   (void)0

#endif

// Try to open a new Qemu fast-pipe. This function returns a file descriptor

// that can be used to communicate with a named service managed by the

// emulator.

//

// This file descriptor can be used as a standard pipe/socket descriptor.

//

// 'pipeName' is the name of the emulator service you want to connect to,

// and must begin with 'pipe:' (e.g. 'pipe:camera' or 'pipe:opengles').

//

// On success, return a valid file descriptor, or -1/errno on failure. E.g.:

//

// EINVAL  -> unknown/unsupported pipeName

// ENOSYS  -> fast pipes not available in this system.

//

// ENOSYS should never happen, except if you're trying to run within a

// misconfigured emulator.

//

// You should be able to open several pipes to the same pipe service,

// except for a few special cases (e.g. GSM modem), where EBUSY will be

// returned if more than one client tries to connect to it.

int qemu_pipe_open(const char* pipeName) {

    // Sanity check.

    if (!pipeName || memcmp(pipeName, "pipe:", 5) != 0) {

    if (!pipeName) {

        errno = EINVAL;

        return -1;

    }

    // Write the pipe name, *including* the trailing zero which is necessary.

    size_t pipeNameLen = strlen(pipeName);

    ssize_t ret = TEMP_FAILURE_RETRY(write(fd, pipeName, pipeNameLen + 1U));

    if (ret != (ssize_t)pipeNameLen + 1) {

        QEMU_PIPE_DEBUG("%s: Could not connect to %s pipe service: %s",

                        __FUNCTION__, pipeName, strerror(errno));

        if (ret == 0) {

            errno = ECONNRESET;

        } else if (ret > 0) {

            errno = EINVAL;

        }

        return -1;

    if (WriteFully(fd, pipeName, pipeNameLen + 1U)) {

        return fd;

    }

    // now, add 'pipe:' prefix and try again

    // Note: host side will wait for the trailing '\0' to start

    // service lookup.

    const char pipe_prefix[] = "pipe:";

    if (WriteFully(fd, pipe_prefix, strlen(pipe_prefix)) &&

            WriteFully(fd, pipeName, pipeNameLen + 1U)) {

        return fd;

    }

    QEMU_PIPE_DEBUG("%s: Could not write to %s pipe service: %s",

            __FUNCTION__, pipeName, strerror(errno));

    close(fd);

    return -1;

}

// Send a framed message |buff| of |len| bytes through the |fd| descriptor.

// This really adds a 4-hexchar prefix describing the payload size.

// Returns 0 on success, and -1 on error.

int qemu_pipe_frame_send(int fd, const void* buff, size_t len) {

    char header[5];

    snprintf(header, sizeof(header), "%04zx", len);

    ssize_t ret = TEMP_FAILURE_RETRY(write(fd, header, 4));

    if (ret != 4) {

    if (!WriteFully(fd, header, 4)) {

        QEMU_PIPE_DEBUG("Can't write qemud frame header: %s", strerror(errno));

        return -1;

    }

    ret = TEMP_FAILURE_RETRY(write(fd, buff, len));

    if (ret != (ssize_t)len) {

    if (!WriteFully(fd, buff, len)) {

        QEMU_PIPE_DEBUG("Can't write qemud frame payload: %s", strerror(errno));

        return -1;

    }

    return 0;

}

// Read a frame message from |fd|, and store it into |buff| of |len| bytes.

// If the framed message is larger than |len|, then this returns -1 and the

// content is lost. Otherwise, this returns the size of the message. NOTE:

// empty messages are possible in a framed wire protocol and do not mean

// end-of-stream.

int qemu_pipe_frame_recv(int fd, void* buff, size_t len) {

    char header[5];

    ssize_t ret = TEMP_FAILURE_RETRY(read(fd, header, 4));

    if (ret != 4) {

    if (!ReadFully(fd, header, 4)) {

        QEMU_PIPE_DEBUG("Can't read qemud frame header: %s", strerror(errno));

        return -1;

    }

                        len);

        return -1;

    }

    ret = TEMP_FAILURE_RETRY(read(fd, buff, size));

    if (ret != (ssize_t)size) {

    if (!ReadFully(fd, buff, size)) {

        QEMU_PIPE_DEBUG("Could not read qemud frame payload: %s",

                        strerror(errno));

        return -1;