/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "qemu/error-report.h"
#include "qemu/iov.h"
#include "qemu/sockets.h"
#include "qemu/coroutine.h"
#include "migration/qemu-file.h"
#include "migration/qemu-file-internal.h"
typedef struct QEMUFileSocket {
int fd;
QEMUFile *file;
} QEMUFileSocket;
static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
QEMUFileSocket *s = opaque;
ssize_t len;
ssize_t size = iov_size(iov, iovcnt);
ssize_t offset = 0;
int err;
while (size > 0) {
len = iov_send(s->fd, iov, iovcnt, offset, size);
if (len > 0) {
size -= len;
offset += len;
}
if (size > 0) {
err = socket_error();
if (err != EAGAIN && err != EWOULDBLOCK) {
error_report("socket_writev_buffer: Got err=%d for (%zu/%zu)",
err, (size_t)size, (size_t)len);
/*
* If I've already sent some but only just got the error, I
* could return the amount validly sent so far and wait for the
* next call to report the error, but I'd rather flag the error
* immediately.
*/
return -err;
}
/* Emulate blocking */
GPollFD pfd;
pfd.fd = s->fd;
pfd.events = G_IO_OUT | G_IO_ERR;
pfd.revents = 0;
TFR(err = g_poll(&pfd, 1, -1 /* no timeout */));
/* Errors other than EINTR intentionally ignored */
}
}
return offset;
}
static int socket_get_fd(void *opaque)
{
QEMUFileSocket *s = opaque;
return s->fd;
}
static ssize_t socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
size_t size)
{
QEMUFileSocket *s = opaque;
ssize_t len;
for (;;) {
len = qemu_recv(s->fd, buf, size, 0);
if (len != -1) {
break;
}
if (socket_error() == EAGAIN) {
yield_until_fd_readable(s->fd);
} else if (socket_error() != EINTR) {
break;
}
}
if (len == -1) {
len = -socket_error();
}
return len;
}
static int socket_close(void *opaque)
{
QEMUFileSocket *s = opaque;
closesocket(s->fd);
g_free(s);
return 0;
}
static int socket_shutdown(void *opaque, bool rd, bool wr)
{
QEMUFileSocket *s = opaque;
if (shutdown(s->fd, rd ? (wr ? SHUT_RDWR : SHUT_RD) : SHUT_WR)) {
return -errno;
} else {
return 0;
}
}
static int socket_return_close(void *opaque)
{
QEMUFileSocket *s = opaque;
/*
* Note: We don't close the socket, that should be done by the forward
* path.
*/
g_free(s);
return 0;
}
static const QEMUFileOps socket_return_read_ops = {
.get_fd = socket_get_fd,
.get_buffer = socket_get_buffer,
.close = socket_return_close,
.shut_down = socket_shutdown,
};
static const QEMUFileOps socket_return_write_ops = {
.get_fd = socket_get_fd,
.writev_buffer = socket_writev_buffer,
.close = socket_return_close,
.shut_down = socket_shutdown,
};
/*
* Give a QEMUFile* off the same socket but data in the opposite
* direction.
*/
static QEMUFile *socket_get_return_path(void *opaque)
{
QEMUFileSocket *forward = opaque;
QEMUFileSocket *reverse;
if (qemu_file_get_error(forward->file)) {
/* If the forward file is in error, don't try and open a return */
return NULL;
}
reverse = g_malloc0(sizeof(QEMUFileSocket));
reverse->fd = forward->fd;
/* I don't think there's a better way to tell which direction 'this' is */
if (forward->file->ops->get_buffer != NULL) {
/* being called from the read side, so we need to be able to write */
return qemu_fopen_ops(reverse, &socket_return_write_ops);
} else {
return qemu_fopen_ops(reverse, &socket_return_read_ops);
}
}
static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
QEMUFileSocket *s = opaque;
ssize_t len, offset;
ssize_t size = iov_size(iov, iovcnt);
ssize_t total = 0;
assert(iovcnt > 0);
offset = 0;
while (size > 0) {
/* Find the next start position; skip all full-sized vector elements */
while (offset >= iov[0].iov_len) {
offset -= iov[0].iov_len;
iov++, iovcnt--;
}
/* skip `offset' bytes from the (now) first element, undo it on exit */
assert(iovcnt > 0);
iov[0].iov_base += offset;
iov[0].iov_len -= offset;
do {
len = writev(s->fd, iov, iovcnt);
} while (len == -1 && errno == EINTR);
if (len == -1) {
return -errno;
}
/* Undo the changes above */
iov[0].iov_base -= offset;
iov[0].iov_len += offset;
/* Prepare for the next iteration */
offset += len;
total += len;
size -= len;
}
return total;
}
static ssize_t unix_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
size_t size)
{
QEMUFileSocket *s = opaque;
ssize_t len;
for (;;) {
len = read(s->fd, buf, size);
if (len != -1) {
break;
}
if (errno == EAGAIN) {
yield_until_fd_readable(s->fd);
} else if (errno != EINTR) {
break;
}
}
if (len == -1) {
len = -errno;
}
return len;
}
static int unix_close(void *opaque)
{
QEMUFileSocket *s = opaque;
close(s->fd);
g_free(s);
return 0;
}
static const QEMUFileOps unix_read_ops = {
.get_fd = socket_get_fd,
.get_buffer = unix_get_buffer,
.close = unix_close
};
static const QEMUFileOps unix_write_ops = {
.get_fd = socket_get_fd,
.writev_buffer = unix_writev_buffer,
.close = unix_close
};
QEMUFile *qemu_fdopen(int fd, const char *mode)
{
QEMUFileSocket *s;
if (mode == NULL ||
(mode[0] != 'r' && mode[0] != 'w') ||
mode[1] != 'b' || mode[2] != 0) {
fprintf(stderr, "qemu_fdopen: Argument validity check failed\n");
return NULL;
}
s = g_new0(QEMUFileSocket, 1);
s->fd = fd;
if (mode[0] == 'r') {
s->file = qemu_fopen_ops(s, &unix_read_ops);
} else {
s->file = qemu_fopen_ops(s, &unix_write_ops);
}
return s->file;
}
static const QEMUFileOps socket_read_ops = {
.get_fd = socket_get_fd,
.get_buffer = socket_get_buffer,
.close = socket_close,
.shut_down = socket_shutdown,
.get_return_path = socket_get_return_path
};
static const QEMUFileOps socket_write_ops = {
.get_fd = socket_get_fd,
.writev_buffer = socket_writev_buffer,
.close = socket_close,
.shut_down = socket_shutdown,
.get_return_path = socket_get_return_path
};
QEMUFile *qemu_fopen_socket(int fd, const char *mode)
{
QEMUFileSocket *s;
if (qemu_file_mode_is_not_valid(mode)) {
return NULL;
}
s = g_new0(QEMUFileSocket, 1);
s->fd = fd;
if (mode[0] == 'w') {
qemu_set_block(s->fd);
s->file = qemu_fopen_ops(s, &socket_write_ops);
} else {
s->file = qemu_fopen_ops(s, &socket_read_ops);
}
return s->file;
}
