qemu/io/channel-socket.c
Daniel P. Berrangé 73564c407c io: ensure UNIX client doesn't unlink server socket
The qio_channel_socket_close method for was mistakenly unlinking the
UNIX server socket, even if the channel was a client connection. This
was not noticed with chardevs, since they never call close, but with the
VNC server, this caused the VNC server socket to be deleted after the
first client quit.

The qio_channel_socket_close method also needlessly reimplemented the
logic that already exists in socket_listen_cleanup(). Just call that
method directly, for listen sockets only.

This fixes a regression introduced in QEMU 3.0.0 with

  commit d66f78e1ea
  Author: Pavel Balaev <mail@void.so>
  Date:   Mon May 21 19:17:35 2018 +0300

    Delete AF_UNIX socket after close

Fixes launchpad #1795100

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-01-24 12:23:35 +00:00

788 lines
22 KiB
C

/*
* QEMU I/O channels sockets driver
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/qapi-visit-sockets.h"
#include "io/channel-socket.h"
#include "io/channel-watch.h"
#include "trace.h"
#include "qapi/clone-visitor.h"
#define SOCKET_MAX_FDS 16
SocketAddress *
qio_channel_socket_get_local_address(QIOChannelSocket *ioc,
Error **errp)
{
return socket_sockaddr_to_address(&ioc->localAddr,
ioc->localAddrLen,
errp);
}
SocketAddress *
qio_channel_socket_get_remote_address(QIOChannelSocket *ioc,
Error **errp)
{
return socket_sockaddr_to_address(&ioc->remoteAddr,
ioc->remoteAddrLen,
errp);
}
QIOChannelSocket *
qio_channel_socket_new(void)
{
QIOChannelSocket *sioc;
QIOChannel *ioc;
sioc = QIO_CHANNEL_SOCKET(object_new(TYPE_QIO_CHANNEL_SOCKET));
sioc->fd = -1;
ioc = QIO_CHANNEL(sioc);
qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
#ifdef WIN32
ioc->event = CreateEvent(NULL, FALSE, FALSE, NULL);
#endif
trace_qio_channel_socket_new(sioc);
return sioc;
}
static int
qio_channel_socket_set_fd(QIOChannelSocket *sioc,
int fd,
Error **errp)
{
if (sioc->fd != -1) {
error_setg(errp, "Socket is already open");
return -1;
}
sioc->fd = fd;
sioc->remoteAddrLen = sizeof(sioc->remoteAddr);
sioc->localAddrLen = sizeof(sioc->localAddr);
if (getpeername(fd, (struct sockaddr *)&sioc->remoteAddr,
&sioc->remoteAddrLen) < 0) {
if (errno == ENOTCONN) {
memset(&sioc->remoteAddr, 0, sizeof(sioc->remoteAddr));
sioc->remoteAddrLen = sizeof(sioc->remoteAddr);
} else {
error_setg_errno(errp, errno,
"Unable to query remote socket address");
goto error;
}
}
if (getsockname(fd, (struct sockaddr *)&sioc->localAddr,
&sioc->localAddrLen) < 0) {
error_setg_errno(errp, errno,
"Unable to query local socket address");
goto error;
}
#ifndef WIN32
if (sioc->localAddr.ss_family == AF_UNIX) {
QIOChannel *ioc = QIO_CHANNEL(sioc);
qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS);
}
#endif /* WIN32 */
return 0;
error:
sioc->fd = -1; /* Let the caller close FD on failure */
return -1;
}
QIOChannelSocket *
qio_channel_socket_new_fd(int fd,
Error **errp)
{
QIOChannelSocket *ioc;
ioc = qio_channel_socket_new();
if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
object_unref(OBJECT(ioc));
return NULL;
}
trace_qio_channel_socket_new_fd(ioc, fd);
return ioc;
}
int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
SocketAddress *addr,
Error **errp)
{
int fd;
trace_qio_channel_socket_connect_sync(ioc, addr);
fd = socket_connect(addr, errp);
if (fd < 0) {
trace_qio_channel_socket_connect_fail(ioc);
return -1;
}
trace_qio_channel_socket_connect_complete(ioc, fd);
if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
close(fd);
return -1;
}
return 0;
}
static void qio_channel_socket_connect_worker(QIOTask *task,
gpointer opaque)
{
QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
SocketAddress *addr = opaque;
Error *err = NULL;
qio_channel_socket_connect_sync(ioc, addr, &err);
qio_task_set_error(task, err);
}
void qio_channel_socket_connect_async(QIOChannelSocket *ioc,
SocketAddress *addr,
QIOTaskFunc callback,
gpointer opaque,
GDestroyNotify destroy,
GMainContext *context)
{
QIOTask *task = qio_task_new(
OBJECT(ioc), callback, opaque, destroy);
SocketAddress *addrCopy;
addrCopy = QAPI_CLONE(SocketAddress, addr);
/* socket_connect() does a non-blocking connect(), but it
* still blocks in DNS lookups, so we must use a thread */
trace_qio_channel_socket_connect_async(ioc, addr);
qio_task_run_in_thread(task,
qio_channel_socket_connect_worker,
addrCopy,
(GDestroyNotify)qapi_free_SocketAddress,
context);
}
int qio_channel_socket_listen_sync(QIOChannelSocket *ioc,
SocketAddress *addr,
Error **errp)
{
int fd;
trace_qio_channel_socket_listen_sync(ioc, addr);
fd = socket_listen(addr, errp);
if (fd < 0) {
trace_qio_channel_socket_listen_fail(ioc);
return -1;
}
trace_qio_channel_socket_listen_complete(ioc, fd);
if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
close(fd);
return -1;
}
qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_LISTEN);
return 0;
}
static void qio_channel_socket_listen_worker(QIOTask *task,
gpointer opaque)
{
QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
SocketAddress *addr = opaque;
Error *err = NULL;
qio_channel_socket_listen_sync(ioc, addr, &err);
qio_task_set_error(task, err);
}
void qio_channel_socket_listen_async(QIOChannelSocket *ioc,
SocketAddress *addr,
QIOTaskFunc callback,
gpointer opaque,
GDestroyNotify destroy,
GMainContext *context)
{
QIOTask *task = qio_task_new(
OBJECT(ioc), callback, opaque, destroy);
SocketAddress *addrCopy;
addrCopy = QAPI_CLONE(SocketAddress, addr);
/* socket_listen() blocks in DNS lookups, so we must use a thread */
trace_qio_channel_socket_listen_async(ioc, addr);
qio_task_run_in_thread(task,
qio_channel_socket_listen_worker,
addrCopy,
(GDestroyNotify)qapi_free_SocketAddress,
context);
}
int qio_channel_socket_dgram_sync(QIOChannelSocket *ioc,
SocketAddress *localAddr,
SocketAddress *remoteAddr,
Error **errp)
{
int fd;
trace_qio_channel_socket_dgram_sync(ioc, localAddr, remoteAddr);
fd = socket_dgram(remoteAddr, localAddr, errp);
if (fd < 0) {
trace_qio_channel_socket_dgram_fail(ioc);
return -1;
}
trace_qio_channel_socket_dgram_complete(ioc, fd);
if (qio_channel_socket_set_fd(ioc, fd, errp) < 0) {
close(fd);
return -1;
}
return 0;
}
struct QIOChannelSocketDGramWorkerData {
SocketAddress *localAddr;
SocketAddress *remoteAddr;
};
static void qio_channel_socket_dgram_worker_free(gpointer opaque)
{
struct QIOChannelSocketDGramWorkerData *data = opaque;
qapi_free_SocketAddress(data->localAddr);
qapi_free_SocketAddress(data->remoteAddr);
g_free(data);
}
static void qio_channel_socket_dgram_worker(QIOTask *task,
gpointer opaque)
{
QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
struct QIOChannelSocketDGramWorkerData *data = opaque;
Error *err = NULL;
/* socket_dgram() blocks in DNS lookups, so we must use a thread */
qio_channel_socket_dgram_sync(ioc, data->localAddr,
data->remoteAddr, &err);
qio_task_set_error(task, err);
}
void qio_channel_socket_dgram_async(QIOChannelSocket *ioc,
SocketAddress *localAddr,
SocketAddress *remoteAddr,
QIOTaskFunc callback,
gpointer opaque,
GDestroyNotify destroy,
GMainContext *context)
{
QIOTask *task = qio_task_new(
OBJECT(ioc), callback, opaque, destroy);
struct QIOChannelSocketDGramWorkerData *data = g_new0(
struct QIOChannelSocketDGramWorkerData, 1);
data->localAddr = QAPI_CLONE(SocketAddress, localAddr);
data->remoteAddr = QAPI_CLONE(SocketAddress, remoteAddr);
trace_qio_channel_socket_dgram_async(ioc, localAddr, remoteAddr);
qio_task_run_in_thread(task,
qio_channel_socket_dgram_worker,
data,
qio_channel_socket_dgram_worker_free,
context);
}
QIOChannelSocket *
qio_channel_socket_accept(QIOChannelSocket *ioc,
Error **errp)
{
QIOChannelSocket *cioc;
cioc = qio_channel_socket_new();
cioc->remoteAddrLen = sizeof(ioc->remoteAddr);
cioc->localAddrLen = sizeof(ioc->localAddr);
retry:
trace_qio_channel_socket_accept(ioc);
cioc->fd = qemu_accept(ioc->fd, (struct sockaddr *)&cioc->remoteAddr,
&cioc->remoteAddrLen);
if (cioc->fd < 0) {
if (errno == EINTR) {
goto retry;
}
error_setg_errno(errp, errno, "Unable to accept connection");
trace_qio_channel_socket_accept_fail(ioc);
goto error;
}
if (getsockname(cioc->fd, (struct sockaddr *)&cioc->localAddr,
&cioc->localAddrLen) < 0) {
error_setg_errno(errp, errno,
"Unable to query local socket address");
goto error;
}
#ifndef WIN32
if (cioc->localAddr.ss_family == AF_UNIX) {
QIOChannel *ioc_local = QIO_CHANNEL(cioc);
qio_channel_set_feature(ioc_local, QIO_CHANNEL_FEATURE_FD_PASS);
}
#endif /* WIN32 */
trace_qio_channel_socket_accept_complete(ioc, cioc, cioc->fd);
return cioc;
error:
object_unref(OBJECT(cioc));
return NULL;
}
static void qio_channel_socket_init(Object *obj)
{
QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
ioc->fd = -1;
}
static void qio_channel_socket_finalize(Object *obj)
{
QIOChannelSocket *ioc = QIO_CHANNEL_SOCKET(obj);
if (ioc->fd != -1) {
QIOChannel *ioc_local = QIO_CHANNEL(ioc);
if (qio_channel_has_feature(ioc_local, QIO_CHANNEL_FEATURE_LISTEN)) {
Error *err = NULL;
socket_listen_cleanup(ioc->fd, &err);
if (err) {
error_report_err(err);
err = NULL;
}
}
#ifdef WIN32
WSAEventSelect(ioc->fd, NULL, 0);
#endif
closesocket(ioc->fd);
ioc->fd = -1;
}
}
#ifndef WIN32
static void qio_channel_socket_copy_fds(struct msghdr *msg,
int **fds, size_t *nfds)
{
struct cmsghdr *cmsg;
*nfds = 0;
*fds = NULL;
for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
int fd_size, i;
int gotfds;
if (cmsg->cmsg_len < CMSG_LEN(sizeof(int)) ||
cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS) {
continue;
}
fd_size = cmsg->cmsg_len - CMSG_LEN(0);
if (!fd_size) {
continue;
}
gotfds = fd_size / sizeof(int);
*fds = g_renew(int, *fds, *nfds + gotfds);
memcpy(*fds + *nfds, CMSG_DATA(cmsg), fd_size);
for (i = 0; i < gotfds; i++) {
int fd = (*fds)[*nfds + i];
if (fd < 0) {
continue;
}
/* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */
qemu_set_block(fd);
#ifndef MSG_CMSG_CLOEXEC
qemu_set_cloexec(fd);
#endif
}
*nfds += gotfds;
}
}
static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int **fds,
size_t *nfds,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
ssize_t ret;
struct msghdr msg = { NULL, };
char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
int sflags = 0;
memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS));
#ifdef MSG_CMSG_CLOEXEC
sflags |= MSG_CMSG_CLOEXEC;
#endif
msg.msg_iov = (struct iovec *)iov;
msg.msg_iovlen = niov;
if (fds && nfds) {
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
}
retry:
ret = recvmsg(sioc->fd, &msg, sflags);
if (ret < 0) {
if (errno == EAGAIN) {
return QIO_CHANNEL_ERR_BLOCK;
}
if (errno == EINTR) {
goto retry;
}
error_setg_errno(errp, errno,
"Unable to read from socket");
return -1;
}
if (fds && nfds) {
qio_channel_socket_copy_fds(&msg, fds, nfds);
}
return ret;
}
static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int *fds,
size_t nfds,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
ssize_t ret;
struct msghdr msg = { NULL, };
char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
size_t fdsize = sizeof(int) * nfds;
struct cmsghdr *cmsg;
memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS));
msg.msg_iov = (struct iovec *)iov;
msg.msg_iovlen = niov;
if (nfds) {
if (nfds > SOCKET_MAX_FDS) {
error_setg_errno(errp, EINVAL,
"Only %d FDs can be sent, got %zu",
SOCKET_MAX_FDS, nfds);
return -1;
}
msg.msg_control = control;
msg.msg_controllen = CMSG_SPACE(sizeof(int) * nfds);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(fdsize);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
memcpy(CMSG_DATA(cmsg), fds, fdsize);
}
retry:
ret = sendmsg(sioc->fd, &msg, 0);
if (ret <= 0) {
if (errno == EAGAIN) {
return QIO_CHANNEL_ERR_BLOCK;
}
if (errno == EINTR) {
goto retry;
}
error_setg_errno(errp, errno,
"Unable to write to socket");
return -1;
}
return ret;
}
#else /* WIN32 */
static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int **fds,
size_t *nfds,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
ssize_t done = 0;
ssize_t i;
for (i = 0; i < niov; i++) {
ssize_t ret;
retry:
ret = recv(sioc->fd,
iov[i].iov_base,
iov[i].iov_len,
0);
if (ret < 0) {
if (errno == EAGAIN) {
if (done) {
return done;
} else {
return QIO_CHANNEL_ERR_BLOCK;
}
} else if (errno == EINTR) {
goto retry;
} else {
error_setg_errno(errp, errno,
"Unable to read from socket");
return -1;
}
}
done += ret;
if (ret < iov[i].iov_len) {
return done;
}
}
return done;
}
static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
const struct iovec *iov,
size_t niov,
int *fds,
size_t nfds,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
ssize_t done = 0;
ssize_t i;
for (i = 0; i < niov; i++) {
ssize_t ret;
retry:
ret = send(sioc->fd,
iov[i].iov_base,
iov[i].iov_len,
0);
if (ret < 0) {
if (errno == EAGAIN) {
if (done) {
return done;
} else {
return QIO_CHANNEL_ERR_BLOCK;
}
} else if (errno == EINTR) {
goto retry;
} else {
error_setg_errno(errp, errno,
"Unable to write to socket");
return -1;
}
}
done += ret;
if (ret < iov[i].iov_len) {
return done;
}
}
return done;
}
#endif /* WIN32 */
static int
qio_channel_socket_set_blocking(QIOChannel *ioc,
bool enabled,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
if (enabled) {
qemu_set_block(sioc->fd);
} else {
qemu_set_nonblock(sioc->fd);
}
return 0;
}
static void
qio_channel_socket_set_delay(QIOChannel *ioc,
bool enabled)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
int v = enabled ? 0 : 1;
qemu_setsockopt(sioc->fd,
IPPROTO_TCP, TCP_NODELAY,
&v, sizeof(v));
}
static void
qio_channel_socket_set_cork(QIOChannel *ioc,
bool enabled)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
int v = enabled ? 1 : 0;
socket_set_cork(sioc->fd, v);
}
static int
qio_channel_socket_close(QIOChannel *ioc,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
int rc = 0;
if (sioc->fd != -1) {
#ifdef WIN32
WSAEventSelect(sioc->fd, NULL, 0);
#endif
if (qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_LISTEN)) {
socket_listen_cleanup(sioc->fd, errp);
}
if (closesocket(sioc->fd) < 0) {
sioc->fd = -1;
error_setg_errno(errp, errno,
"Unable to close socket");
return -1;
}
sioc->fd = -1;
}
return rc;
}
static int
qio_channel_socket_shutdown(QIOChannel *ioc,
QIOChannelShutdown how,
Error **errp)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
int sockhow;
switch (how) {
case QIO_CHANNEL_SHUTDOWN_READ:
sockhow = SHUT_RD;
break;
case QIO_CHANNEL_SHUTDOWN_WRITE:
sockhow = SHUT_WR;
break;
case QIO_CHANNEL_SHUTDOWN_BOTH:
default:
sockhow = SHUT_RDWR;
break;
}
if (shutdown(sioc->fd, sockhow) < 0) {
error_setg_errno(errp, errno,
"Unable to shutdown socket");
return -1;
}
return 0;
}
static void qio_channel_socket_set_aio_fd_handler(QIOChannel *ioc,
AioContext *ctx,
IOHandler *io_read,
IOHandler *io_write,
void *opaque)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
aio_set_fd_handler(ctx, sioc->fd, false, io_read, io_write, NULL, opaque);
}
static GSource *qio_channel_socket_create_watch(QIOChannel *ioc,
GIOCondition condition)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
return qio_channel_create_socket_watch(ioc,
sioc->fd,
condition);
}
static void qio_channel_socket_class_init(ObjectClass *klass,
void *class_data G_GNUC_UNUSED)
{
QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
ioc_klass->io_writev = qio_channel_socket_writev;
ioc_klass->io_readv = qio_channel_socket_readv;
ioc_klass->io_set_blocking = qio_channel_socket_set_blocking;
ioc_klass->io_close = qio_channel_socket_close;
ioc_klass->io_shutdown = qio_channel_socket_shutdown;
ioc_klass->io_set_cork = qio_channel_socket_set_cork;
ioc_klass->io_set_delay = qio_channel_socket_set_delay;
ioc_klass->io_create_watch = qio_channel_socket_create_watch;
ioc_klass->io_set_aio_fd_handler = qio_channel_socket_set_aio_fd_handler;
}
static const TypeInfo qio_channel_socket_info = {
.parent = TYPE_QIO_CHANNEL,
.name = TYPE_QIO_CHANNEL_SOCKET,
.instance_size = sizeof(QIOChannelSocket),
.instance_init = qio_channel_socket_init,
.instance_finalize = qio_channel_socket_finalize,
.class_init = qio_channel_socket_class_init,
};
static void qio_channel_socket_register_types(void)
{
type_register_static(&qio_channel_socket_info);
}
type_init(qio_channel_socket_register_types);