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4b47373a0d
qemu/chardev/char-socket.c
Daniel P. Berrangé 4b47373a0d chardev: fix race with client connections in tcp_chr_wait_connected 
When the 'reconnect' option is given for a client connection, the
qmp_chardev_open_socket_client method will run an asynchronous
connection attempt. The QIOChannel socket executes this is a single use
background thread, so the connection will succeed immediately (assuming
the server is listening). The chardev, however, won't get the result
from this background thread until the main loop starts running and
processes idle callbacks.

Thus when tcp_chr_wait_connected is run s->ioc will be NULL, but the
state will be TCP_CHARDEV_STATE_CONNECTING, and there may already
be an established connection that will be associated with the chardev
by the pending idle callback. tcp_chr_wait_connected doesn't check the
state, only s->ioc, so attempts to establish another connection
synchronously.

If the server allows multiple connections this is unhelpful but not a
fatal problem as the duplicate connection will get ignored by the
tcp_chr_new_client method when it sees the state is already connected.

If the server only supports a single connection, however, the
tcp_chr_wait_connected method will hang forever because the server will
not accept its synchronous connection attempt until the first connection
is closed.

To deal with this tcp_chr_wait_connected needs to synchronize with the
completion of the background connection task. To do this it needs to
create the QIOTask directly and use the qio_task_wait_thread method.
This will cancel the pending idle callback and directly dispatch the
task completion callback, allowing the connection to be associated
with the chardev. If the background connection failed, it can still
attempt a new synchronous connection.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190211182442.8542-15-berrange@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2019-02-12 17:35:56 +01:00

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/*
* 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/osdep.h"
#include "chardev/char.h"
#include "io/channel-socket.h"
#include "io/channel-tls.h"
#include "io/channel-websock.h"
#include "io/net-listener.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "qapi/error.h"
#include "qapi/clone-visitor.h"
#include "qapi/qapi-visit-sockets.h"
#include "chardev/char-io.h"
/***********************************************************/
/* TCP Net console */
#define TCP_MAX_FDS 16
typedef struct {
char buf[21];
size_t buflen;
} TCPChardevTelnetInit;
typedef enum {
TCP_CHARDEV_STATE_DISCONNECTED,
TCP_CHARDEV_STATE_CONNECTING,
TCP_CHARDEV_STATE_CONNECTED,
} TCPChardevState;
typedef struct {
Chardev parent;
QIOChannel *ioc; /* Client I/O channel */
QIOChannelSocket *sioc; /* Client master channel */
QIONetListener *listener;
GSource *hup_source;
QCryptoTLSCreds *tls_creds;
TCPChardevState state;
int max_size;
int do_telnetopt;
int do_nodelay;
int *read_msgfds;
size_t read_msgfds_num;
int *write_msgfds;
size_t write_msgfds_num;
SocketAddress *addr;
bool is_listen;
bool is_telnet;
bool is_tn3270;
GSource *telnet_source;
TCPChardevTelnetInit *telnet_init;
bool is_websock;
GSource *reconnect_timer;
int64_t reconnect_time;
bool connect_err_reported;
QIOTask *connect_task;
} SocketChardev;
#define SOCKET_CHARDEV(obj) \
OBJECT_CHECK(SocketChardev, (obj), TYPE_CHARDEV_SOCKET)
static gboolean socket_reconnect_timeout(gpointer opaque);
static void tcp_chr_telnet_init(Chardev *chr);
static void tcp_chr_change_state(SocketChardev *s, TCPChardevState state)
{
switch (state) {
case TCP_CHARDEV_STATE_DISCONNECTED:
break;
case TCP_CHARDEV_STATE_CONNECTING:
assert(s->state == TCP_CHARDEV_STATE_DISCONNECTED);
break;
case TCP_CHARDEV_STATE_CONNECTED:
assert(s->state == TCP_CHARDEV_STATE_CONNECTING);
break;
}
s->state = state;
}
static void tcp_chr_reconn_timer_cancel(SocketChardev *s)
{
if (s->reconnect_timer) {
g_source_destroy(s->reconnect_timer);
g_source_unref(s->reconnect_timer);
s->reconnect_timer = NULL;
}
}
static void qemu_chr_socket_restart_timer(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
char *name;
assert(s->state == TCP_CHARDEV_STATE_DISCONNECTED);
assert(!s->reconnect_timer);
name = g_strdup_printf("chardev-socket-reconnect-%s", chr->label);
s->reconnect_timer = qemu_chr_timeout_add_ms(chr,
s->reconnect_time * 1000,
socket_reconnect_timeout,
chr);
g_source_set_name(s->reconnect_timer, name);
g_free(name);
}
static void check_report_connect_error(Chardev *chr,
Error *err)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
if (!s->connect_err_reported) {
error_report("Unable to connect character device %s: %s",
chr->label, error_get_pretty(err));
s->connect_err_reported = true;
}
qemu_chr_socket_restart_timer(chr);
}
static void tcp_chr_accept(QIONetListener *listener,
QIOChannelSocket *cioc,
void *opaque);
static int tcp_chr_read_poll(void *opaque);
static void tcp_chr_disconnect(Chardev *chr);
/* Called with chr_write_lock held. */
static int tcp_chr_write(Chardev *chr, const uint8_t *buf, int len)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
if (s->state == TCP_CHARDEV_STATE_CONNECTED) {
int ret = io_channel_send_full(s->ioc, buf, len,
s->write_msgfds,
s->write_msgfds_num);
/* free the written msgfds in any cases
* other than ret < 0 && errno == EAGAIN
*/
if (!(ret < 0 && EAGAIN == errno)
&& s->write_msgfds_num) {
g_free(s->write_msgfds);
s->write_msgfds = 0;
s->write_msgfds_num = 0;
}
if (ret < 0 && errno != EAGAIN) {
if (tcp_chr_read_poll(chr) <= 0) {
tcp_chr_disconnect(chr);
return len;
} /* else let the read handler finish it properly */
}
return ret;
} else {
/* XXX: indicate an error ? */
return len;
}
}
static int tcp_chr_read_poll(void *opaque)
{
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(opaque);
if (s->state != TCP_CHARDEV_STATE_CONNECTED) {
return 0;
}
s->max_size = qemu_chr_be_can_write(chr);
return s->max_size;
}
static void tcp_chr_process_IAC_bytes(Chardev *chr,
SocketChardev *s,
uint8_t *buf, int *size)
{
/* Handle any telnet or tn3270 client's basic IAC options.
* For telnet options, it satisfies char by char mode with no echo.
* For tn3270 options, it satisfies binary mode with EOR.
* All IAC options will be removed from the buf and the do_opt
* pointer will be used to track the state of the width of the
* IAC information.
*
* RFC854: "All TELNET commands consist of at least a two byte sequence.
* The commands dealing with option negotiation are three byte sequences,
* the third byte being the code for the option referenced."
* "IAC BREAK", "IAC IP", "IAC NOP" and the double IAC are two bytes.
* "IAC SB", "IAC SE" and "IAC EOR" are saved to split up data boundary
* for tn3270.
* NOP, Break and Interrupt Process(IP) might be encountered during a TN3270
* session, and NOP and IP need to be done later.
*/
int i;
int j = 0;
for (i = 0; i < *size; i++) {
if (s->do_telnetopt > 1) {
if ((unsigned char)buf[i] == IAC && s->do_telnetopt == 2) {
/* Double IAC means send an IAC */
if (j != i) {
buf[j] = buf[i];
}
j++;
s->do_telnetopt = 1;
} else {
if ((unsigned char)buf[i] == IAC_BREAK
&& s->do_telnetopt == 2) {
/* Handle IAC break commands by sending a serial break */
qemu_chr_be_event(chr, CHR_EVENT_BREAK);
s->do_telnetopt++;
} else if (s->is_tn3270 && ((unsigned char)buf[i] == IAC_EOR
|| (unsigned char)buf[i] == IAC_SB
|| (unsigned char)buf[i] == IAC_SE)
&& s->do_telnetopt == 2) {
buf[j++] = IAC;
buf[j++] = buf[i];
s->do_telnetopt++;
} else if (s->is_tn3270 && ((unsigned char)buf[i] == IAC_IP
|| (unsigned char)buf[i] == IAC_NOP)
&& s->do_telnetopt == 2) {
/* TODO: IP and NOP need to be implemented later. */
s->do_telnetopt++;
}
s->do_telnetopt++;
}
if (s->do_telnetopt >= 4) {
s->do_telnetopt = 1;
}
} else {
if ((unsigned char)buf[i] == IAC) {
s->do_telnetopt = 2;
} else {
if (j != i) {
buf[j] = buf[i];
}
j++;
}
}
}
*size = j;
}
static int tcp_get_msgfds(Chardev *chr, int *fds, int num)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
int to_copy = (s->read_msgfds_num < num) ? s->read_msgfds_num : num;
assert(num <= TCP_MAX_FDS);
if (to_copy) {
int i;
memcpy(fds, s->read_msgfds, to_copy * sizeof(int));
/* Close unused fds */
for (i = to_copy; i < s->read_msgfds_num; i++) {
close(s->read_msgfds[i]);
}
g_free(s->read_msgfds);
s->read_msgfds = 0;
s->read_msgfds_num = 0;
}
return to_copy;
}
static int tcp_set_msgfds(Chardev *chr, int *fds, int num)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
/* clear old pending fd array */
g_free(s->write_msgfds);
s->write_msgfds = NULL;
s->write_msgfds_num = 0;
if ((s->state != TCP_CHARDEV_STATE_CONNECTED) ||
!qio_channel_has_feature(s->ioc,
QIO_CHANNEL_FEATURE_FD_PASS)) {
return -1;
}
if (num) {
s->write_msgfds = g_new(int, num);
memcpy(s->write_msgfds, fds, num * sizeof(int));
}
s->write_msgfds_num = num;
return 0;
}
static ssize_t tcp_chr_recv(Chardev *chr, char *buf, size_t len)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
struct iovec iov = { .iov_base = buf, .iov_len = len };
int ret;
size_t i;
int *msgfds = NULL;
size_t msgfds_num = 0;
if (qio_channel_has_feature(s->ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
ret = qio_channel_readv_full(s->ioc, &iov, 1,
&msgfds, &msgfds_num,
NULL);
} else {
ret = qio_channel_readv_full(s->ioc, &iov, 1,
NULL, NULL,
NULL);
}
if (ret == QIO_CHANNEL_ERR_BLOCK) {
errno = EAGAIN;
ret = -1;
} else if (ret == -1) {
errno = EIO;
}
if (msgfds_num) {
/* close and clean read_msgfds */
for (i = 0; i < s->read_msgfds_num; i++) {
close(s->read_msgfds[i]);
}
if (s->read_msgfds_num) {
g_free(s->read_msgfds);
}
s->read_msgfds = msgfds;
s->read_msgfds_num = msgfds_num;
}
for (i = 0; i < s->read_msgfds_num; i++) {
int fd = s->read_msgfds[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
}
return ret;
}
static GSource *tcp_chr_add_watch(Chardev *chr, GIOCondition cond)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
return qio_channel_create_watch(s->ioc, cond);
}
static void remove_hup_source(SocketChardev *s)
{
if (s->hup_source != NULL) {
g_source_destroy(s->hup_source);
g_source_unref(s->hup_source);
s->hup_source = NULL;
}
}
static void tcp_chr_free_connection(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
int i;
if (s->read_msgfds_num) {
for (i = 0; i < s->read_msgfds_num; i++) {
close(s->read_msgfds[i]);
}
g_free(s->read_msgfds);
s->read_msgfds = NULL;
s->read_msgfds_num = 0;
}
remove_hup_source(s);
tcp_set_msgfds(chr, NULL, 0);
remove_fd_in_watch(chr);
object_unref(OBJECT(s->sioc));
s->sioc = NULL;
object_unref(OBJECT(s->ioc));
s->ioc = NULL;
g_free(chr->filename);
chr->filename = NULL;
tcp_chr_change_state(s, TCP_CHARDEV_STATE_DISCONNECTED);
}
static const char *qemu_chr_socket_protocol(SocketChardev *s)
{
if (s->is_telnet) {
return "telnet";
}
return s->is_websock ? "websocket" : "tcp";
}
static char *qemu_chr_socket_address(SocketChardev *s, const char *prefix)
{
switch (s->addr->type) {
case SOCKET_ADDRESS_TYPE_INET:
return g_strdup_printf("%s%s:%s:%s%s", prefix,
qemu_chr_socket_protocol(s),
s->addr->u.inet.host,
s->addr->u.inet.port,
s->is_listen ? ",server" : "");
break;
case SOCKET_ADDRESS_TYPE_UNIX:
return g_strdup_printf("%sunix:%s%s", prefix,
s->addr->u.q_unix.path,
s->is_listen ? ",server" : "");
break;
case SOCKET_ADDRESS_TYPE_FD:
return g_strdup_printf("%sfd:%s%s", prefix, s->addr->u.fd.str,
s->is_listen ? ",server" : "");
break;
case SOCKET_ADDRESS_TYPE_VSOCK:
return g_strdup_printf("%svsock:%s:%s", prefix,
s->addr->u.vsock.cid,
s->addr->u.vsock.port);
default:
abort();
}
}
static void update_disconnected_filename(SocketChardev *s)
{
Chardev *chr = CHARDEV(s);
g_free(chr->filename);
if (s->addr) {
chr->filename = qemu_chr_socket_address(s, "disconnected:");
} else {
chr->filename = g_strdup("disconnected:socket");
}
}
/* NB may be called even if tcp_chr_connect has not been
* reached, due to TLS or telnet initialization failure,
* so can *not* assume s->state == TCP_CHARDEV_STATE_CONNECTED
*/
static void tcp_chr_disconnect(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
bool emit_close = s->state == TCP_CHARDEV_STATE_CONNECTED;
tcp_chr_free_connection(chr);
if (s->listener) {
qio_net_listener_set_client_func_full(s->listener, tcp_chr_accept,
chr, NULL, chr->gcontext);
}
update_disconnected_filename(s);
if (emit_close) {
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}
if (s->reconnect_time) {
qemu_chr_socket_restart_timer(chr);
}
}
static gboolean tcp_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
{
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(opaque);
uint8_t buf[CHR_READ_BUF_LEN];
int len, size;
if ((s->state != TCP_CHARDEV_STATE_CONNECTED) ||
s->max_size <= 0) {
return TRUE;
}
len = sizeof(buf);
if (len > s->max_size) {
len = s->max_size;
}
size = tcp_chr_recv(chr, (void *)buf, len);
if (size == 0 || (size == -1 && errno != EAGAIN)) {
/* connection closed */
tcp_chr_disconnect(chr);
} else if (size > 0) {
if (s->do_telnetopt) {
tcp_chr_process_IAC_bytes(chr, s, buf, &size);
}
if (size > 0) {
qemu_chr_be_write(chr, buf, size);
}
}
return TRUE;
}
static gboolean tcp_chr_hup(QIOChannel *channel,
GIOCondition cond,
void *opaque)
{
Chardev *chr = CHARDEV(opaque);
tcp_chr_disconnect(chr);
return G_SOURCE_REMOVE;
}
static int tcp_chr_sync_read(Chardev *chr, const uint8_t *buf, int len)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
int size;
if (s->state != TCP_CHARDEV_STATE_CONNECTED) {
return 0;
}
qio_channel_set_blocking(s->ioc, true, NULL);
size = tcp_chr_recv(chr, (void *) buf, len);
qio_channel_set_blocking(s->ioc, false, NULL);
if (size == 0) {
/* connection closed */
tcp_chr_disconnect(chr);
}
return size;
}
static char *qemu_chr_compute_filename(SocketChardev *s)
{
struct sockaddr_storage *ss = &s->sioc->localAddr;
struct sockaddr_storage *ps = &s->sioc->remoteAddr;
socklen_t ss_len = s->sioc->localAddrLen;
socklen_t ps_len = s->sioc->remoteAddrLen;
char shost[NI_MAXHOST], sserv[NI_MAXSERV];
char phost[NI_MAXHOST], pserv[NI_MAXSERV];
const char *left = "", *right = "";
switch (ss->ss_family) {
#ifndef _WIN32
case AF_UNIX:
return g_strdup_printf("unix:%s%s",
((struct sockaddr_un *)(ss))->sun_path,
s->is_listen ? ",server" : "");
#endif
case AF_INET6:
left = "[";
right = "]";
/* fall through */
case AF_INET:
getnameinfo((struct sockaddr *) ss, ss_len, shost, sizeof(shost),
sserv, sizeof(sserv), NI_NUMERICHOST | NI_NUMERICSERV);
getnameinfo((struct sockaddr *) ps, ps_len, phost, sizeof(phost),
pserv, sizeof(pserv), NI_NUMERICHOST | NI_NUMERICSERV);
return g_strdup_printf("%s:%s%s%s:%s%s <-> %s%s%s:%s",
qemu_chr_socket_protocol(s),
left, shost, right, sserv,
s->is_listen ? ",server" : "",
left, phost, right, pserv);
default:
return g_strdup_printf("unknown");
}
}
static void update_ioc_handlers(SocketChardev *s)
{
Chardev *chr = CHARDEV(s);
if (s->state != TCP_CHARDEV_STATE_CONNECTED) {
return;
}
remove_fd_in_watch(chr);
chr->gsource = io_add_watch_poll(chr, s->ioc,
tcp_chr_read_poll,
tcp_chr_read, chr,
chr->gcontext);
remove_hup_source(s);
s->hup_source = qio_channel_create_watch(s->ioc, G_IO_HUP);
g_source_set_callback(s->hup_source, (GSourceFunc)tcp_chr_hup,
chr, NULL);
g_source_attach(s->hup_source, chr->gcontext);
}
static void tcp_chr_connect(void *opaque)
{
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(opaque);
g_free(chr->filename);
chr->filename = qemu_chr_compute_filename(s);
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTED);
update_ioc_handlers(s);
qemu_chr_be_event(chr, CHR_EVENT_OPENED);
}
static void tcp_chr_telnet_destroy(SocketChardev *s)
{
if (s->telnet_source) {
g_source_destroy(s->telnet_source);
g_source_unref(s->telnet_source);
s->telnet_source = NULL;
}
}
static void tcp_chr_update_read_handler(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
if (s->listener) {
/*
* It's possible that chardev context is changed in
* qemu_chr_be_update_read_handlers(). Reset it for QIO net
* listener if there is.
*/
qio_net_listener_set_client_func_full(s->listener, tcp_chr_accept,
chr, NULL, chr->gcontext);
}
if (s->telnet_source) {
tcp_chr_telnet_init(CHARDEV(s));
}
update_ioc_handlers(s);
}
static gboolean tcp_chr_telnet_init_io(QIOChannel *ioc,
GIOCondition cond G_GNUC_UNUSED,
gpointer user_data)
{
SocketChardev *s = user_data;
Chardev *chr = CHARDEV(s);
TCPChardevTelnetInit *init = s->telnet_init;
ssize_t ret;
assert(init);
ret = qio_channel_write(ioc, init->buf, init->buflen, NULL);
if (ret < 0) {
if (ret == QIO_CHANNEL_ERR_BLOCK) {
ret = 0;
} else {
tcp_chr_disconnect(chr);
goto end;
}
}
init->buflen -= ret;
if (init->buflen == 0) {
tcp_chr_connect(chr);
goto end;
}
memmove(init->buf, init->buf + ret, init->buflen);
return G_SOURCE_CONTINUE;
end:
g_free(s->telnet_init);
s->telnet_init = NULL;
g_source_unref(s->telnet_source);
s->telnet_source = NULL;
return G_SOURCE_REMOVE;
}
static void tcp_chr_telnet_init(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
TCPChardevTelnetInit *init;
size_t n = 0;
/* Destroy existing task */
tcp_chr_telnet_destroy(s);
if (s->telnet_init) {
/* We are possibly during a handshake already */
goto cont;
}
s->telnet_init = g_new0(TCPChardevTelnetInit, 1);
init = s->telnet_init;
#define IACSET(x, a, b, c) \
do { \
x[n++] = a; \
x[n++] = b; \
x[n++] = c; \
} while (0)
if (!s->is_tn3270) {
init->buflen = 12;
/* Prep the telnet negotion to put telnet in binary,
* no echo, single char mode */
IACSET(init->buf, 0xff, 0xfb, 0x01); /* IAC WILL ECHO */
IACSET(init->buf, 0xff, 0xfb, 0x03); /* IAC WILL Suppress go ahead */
IACSET(init->buf, 0xff, 0xfb, 0x00); /* IAC WILL Binary */
IACSET(init->buf, 0xff, 0xfd, 0x00); /* IAC DO Binary */
} else {
init->buflen = 21;
/* Prep the TN3270 negotion based on RFC1576 */
IACSET(init->buf, 0xff, 0xfd, 0x19); /* IAC DO EOR */
IACSET(init->buf, 0xff, 0xfb, 0x19); /* IAC WILL EOR */
IACSET(init->buf, 0xff, 0xfd, 0x00); /* IAC DO BINARY */
IACSET(init->buf, 0xff, 0xfb, 0x00); /* IAC WILL BINARY */
IACSET(init->buf, 0xff, 0xfd, 0x18); /* IAC DO TERMINAL TYPE */
IACSET(init->buf, 0xff, 0xfa, 0x18); /* IAC SB TERMINAL TYPE */
IACSET(init->buf, 0x01, 0xff, 0xf0); /* SEND IAC SE */
}
#undef IACSET
cont:
s->telnet_source = qio_channel_add_watch_source(s->ioc, G_IO_OUT,
tcp_chr_telnet_init_io,
s, NULL,
chr->gcontext);
}
static void tcp_chr_websock_handshake(QIOTask *task, gpointer user_data)
{
Chardev *chr = user_data;
SocketChardev *s = user_data;
if (qio_task_propagate_error(task, NULL)) {
tcp_chr_disconnect(chr);
} else {
if (s->do_telnetopt) {
tcp_chr_telnet_init(chr);
} else {
tcp_chr_connect(chr);
}
}
}
static void tcp_chr_websock_init(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
QIOChannelWebsock *wioc = NULL;
gchar *name;
wioc = qio_channel_websock_new_server(s->ioc);
name = g_strdup_printf("chardev-websocket-server-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(wioc), name);
g_free(name);
object_unref(OBJECT(s->ioc));
s->ioc = QIO_CHANNEL(wioc);
qio_channel_websock_handshake(wioc, tcp_chr_websock_handshake, chr, NULL);
}
static void tcp_chr_tls_handshake(QIOTask *task,
gpointer user_data)
{
Chardev *chr = user_data;
SocketChardev *s = user_data;
if (qio_task_propagate_error(task, NULL)) {
tcp_chr_disconnect(chr);
} else {
if (s->is_websock) {
tcp_chr_websock_init(chr);
} else if (s->do_telnetopt) {
tcp_chr_telnet_init(chr);
} else {
tcp_chr_connect(chr);
}
}
}
static void tcp_chr_tls_init(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
QIOChannelTLS *tioc;
Error *err = NULL;
gchar *name;
if (s->is_listen) {
tioc = qio_channel_tls_new_server(
s->ioc, s->tls_creds,
NULL, /* XXX Use an ACL */
&err);
} else {
tioc = qio_channel_tls_new_client(
s->ioc, s->tls_creds,
s->addr->u.inet.host,
&err);
}
if (tioc == NULL) {
error_free(err);
tcp_chr_disconnect(chr);
return;
}
name = g_strdup_printf("chardev-tls-%s-%s",
s->is_listen ? "server" : "client",
chr->label);
qio_channel_set_name(QIO_CHANNEL(tioc), name);
g_free(name);
object_unref(OBJECT(s->ioc));
s->ioc = QIO_CHANNEL(tioc);
qio_channel_tls_handshake(tioc,
tcp_chr_tls_handshake,
chr,
NULL,
chr->gcontext);
}
static void tcp_chr_set_client_ioc_name(Chardev *chr,
QIOChannelSocket *sioc)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
char *name;
name = g_strdup_printf("chardev-tcp-%s-%s",
s->is_listen ? "server" : "client",
chr->label);
qio_channel_set_name(QIO_CHANNEL(sioc), name);
g_free(name);
}
static int tcp_chr_new_client(Chardev *chr, QIOChannelSocket *sioc)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
if (s->state != TCP_CHARDEV_STATE_CONNECTING) {
return -1;
}
s->ioc = QIO_CHANNEL(sioc);
object_ref(OBJECT(sioc));
s->sioc = sioc;
object_ref(OBJECT(sioc));
qio_channel_set_blocking(s->ioc, false, NULL);
if (s->do_nodelay) {
qio_channel_set_delay(s->ioc, false);
}
if (s->listener) {
qio_net_listener_set_client_func_full(s->listener, NULL, NULL,
NULL, chr->gcontext);
}
if (s->tls_creds) {
tcp_chr_tls_init(chr);
} else if (s->is_websock) {
tcp_chr_websock_init(chr);
} else if (s->do_telnetopt) {
tcp_chr_telnet_init(chr);
} else {
tcp_chr_connect(chr);
}
return 0;
}
static int tcp_chr_add_client(Chardev *chr, int fd)
{
int ret;
QIOChannelSocket *sioc;
SocketChardev *s = SOCKET_CHARDEV(chr);
if (s->state != TCP_CHARDEV_STATE_DISCONNECTED) {
return -1;
}
sioc = qio_channel_socket_new_fd(fd, NULL);
if (!sioc) {
return -1;
}
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
tcp_chr_set_client_ioc_name(chr, sioc);
ret = tcp_chr_new_client(chr, sioc);
object_unref(OBJECT(sioc));
return ret;
}
static void tcp_chr_accept(QIONetListener *listener,
QIOChannelSocket *cioc,
void *opaque)
{
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(chr);
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
tcp_chr_set_client_ioc_name(chr, cioc);
tcp_chr_new_client(chr, cioc);
}
static int tcp_chr_connect_client_sync(Chardev *chr, Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
QIOChannelSocket *sioc = qio_channel_socket_new();
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
tcp_chr_set_client_ioc_name(chr, sioc);
if (qio_channel_socket_connect_sync(sioc, s->addr, errp) < 0) {
tcp_chr_change_state(s, TCP_CHARDEV_STATE_DISCONNECTED);
object_unref(OBJECT(sioc));
return -1;
}
tcp_chr_new_client(chr, sioc);
object_unref(OBJECT(sioc));
return 0;
}
static void tcp_chr_accept_server_sync(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
QIOChannelSocket *sioc;
info_report("QEMU waiting for connection on: %s",
chr->filename);
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
sioc = qio_net_listener_wait_client(s->listener);
tcp_chr_set_client_ioc_name(chr, sioc);
tcp_chr_new_client(chr, sioc);
object_unref(OBJECT(sioc));
}
static int tcp_chr_wait_connected(Chardev *chr, Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
const char *opts[] = { "telnet", "tn3270", "websock", "tls-creds" };
bool optset[] = { s->is_telnet, s->is_tn3270, s->is_websock, s->tls_creds };
size_t i;
QEMU_BUILD_BUG_ON(G_N_ELEMENTS(opts) != G_N_ELEMENTS(optset));
for (i = 0; i < G_N_ELEMENTS(opts); i++) {
if (optset[i]) {
error_setg(errp,
"'%s' option is incompatible with waiting for "
"connection completion", opts[i]);
return -1;
}
}
tcp_chr_reconn_timer_cancel(s);
/*
* We expect states to be as follows:
*
* - server
* - wait -> CONNECTED
* - nowait -> DISCONNECTED
* - client
* - reconnect == 0 -> CONNECTED
* - reconnect != 0 -> CONNECTING
*
*/
if (s->state == TCP_CHARDEV_STATE_CONNECTING) {
if (!s->connect_task) {
error_setg(errp,
"Unexpected 'connecting' state without connect task "
"while waiting for connection completion");
return -1;
}
/*
* tcp_chr_wait_connected should only ever be run from the
* main loop thread associated with chr->gcontext, otherwise
* qio_task_wait_thread has a dangerous race condition with
* free'ing of the s->connect_task object.
*
* Acquiring the main context doesn't 100% prove we're in
* the main loop thread, but it does at least guarantee
* that the main loop won't be executed by another thread
* avoiding the race condition with the task idle callback.
*/
g_main_context_acquire(chr->gcontext);
qio_task_wait_thread(s->connect_task);
g_main_context_release(chr->gcontext);
/*
* The completion callback (qemu_chr_socket_connected) for
* s->connect_task should have set this to NULL by the time
* qio_task_wait_thread has returned.
*/
assert(!s->connect_task);
/*
* NB we are *not* guaranteed to have "s->state == ..CONNECTED"
* at this point as this first connect may be failed, so
* allow the next loop to run regardless.
*/
}
while (s->state != TCP_CHARDEV_STATE_CONNECTED) {
if (s->is_listen) {
tcp_chr_accept_server_sync(chr);
} else {
Error *err = NULL;
if (tcp_chr_connect_client_sync(chr, &err) < 0) {
if (s->reconnect_time) {
error_free(err);
g_usleep(s->reconnect_time * 1000ULL * 1000ULL);
} else {
error_propagate(errp, err);
return -1;
}
}
}
}
return 0;
}
static void char_socket_finalize(Object *obj)
{
Chardev *chr = CHARDEV(obj);
SocketChardev *s = SOCKET_CHARDEV(obj);
tcp_chr_free_connection(chr);
tcp_chr_reconn_timer_cancel(s);
qapi_free_SocketAddress(s->addr);
tcp_chr_telnet_destroy(s);
g_free(s->telnet_init);
if (s->listener) {
qio_net_listener_set_client_func_full(s->listener, NULL, NULL,
NULL, chr->gcontext);
object_unref(OBJECT(s->listener));
}
if (s->tls_creds) {
object_unref(OBJECT(s->tls_creds));
}
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}
static void qemu_chr_socket_connected(QIOTask *task, void *opaque)
{
QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(qio_task_get_source(task));
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(chr);
Error *err = NULL;
s->connect_task = NULL;
if (qio_task_propagate_error(task, &err)) {
tcp_chr_change_state(s, TCP_CHARDEV_STATE_DISCONNECTED);
check_report_connect_error(chr, err);
error_free(err);
goto cleanup;
}
s->connect_err_reported = false;
tcp_chr_new_client(chr, sioc);
cleanup:
object_unref(OBJECT(sioc));
}
static void tcp_chr_connect_client_task(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);
}
static void tcp_chr_connect_client_async(Chardev *chr)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
QIOChannelSocket *sioc;
tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
sioc = qio_channel_socket_new();
tcp_chr_set_client_ioc_name(chr, sioc);
/*
* Normally code would use the qio_channel_socket_connect_async
* method which uses a QIOTask + qio_task_set_error internally
* to avoid blocking. The tcp_chr_wait_connected method, however,
* needs a way to synchronize with completion of the background
* connect task which can't be done with the QIOChannelSocket
* async APIs. Thus we must use QIOTask directly to implement
* the non-blocking concept locally.
*/
s->connect_task = qio_task_new(OBJECT(sioc),
qemu_chr_socket_connected,
chr, NULL);
qio_task_run_in_thread(s->connect_task,
tcp_chr_connect_client_task,
s->addr,
NULL,
chr->gcontext);
}
static gboolean socket_reconnect_timeout(gpointer opaque)
{
Chardev *chr = CHARDEV(opaque);
SocketChardev *s = SOCKET_CHARDEV(opaque);
g_source_unref(s->reconnect_timer);
s->reconnect_timer = NULL;
if (chr->be_open) {
return false;
}
tcp_chr_connect_client_async(chr);
return false;
}
static int qmp_chardev_open_socket_server(Chardev *chr,
bool is_telnet,
bool is_waitconnect,
Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
char *name;
if (is_telnet) {
s->do_telnetopt = 1;
}
s->listener = qio_net_listener_new();
name = g_strdup_printf("chardev-tcp-listener-%s", chr->label);
qio_net_listener_set_name(s->listener, name);
g_free(name);
if (qio_net_listener_open_sync(s->listener, s->addr, errp) < 0) {
object_unref(OBJECT(s->listener));
s->listener = NULL;
return -1;
}
qapi_free_SocketAddress(s->addr);
s->addr = socket_local_address(s->listener->sioc[0]->fd, errp);
update_disconnected_filename(s);
if (is_waitconnect) {
tcp_chr_accept_server_sync(chr);
} else {
qio_net_listener_set_client_func_full(s->listener,
tcp_chr_accept,
chr, NULL,
chr->gcontext);
}
return 0;
}
static int qmp_chardev_open_socket_client(Chardev *chr,
int64_t reconnect,
Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
if (reconnect > 0) {
s->reconnect_time = reconnect;
tcp_chr_connect_client_async(chr);
return 0;
} else {
return tcp_chr_connect_client_sync(chr, errp);
}
}
static bool qmp_chardev_validate_socket(ChardevSocket *sock,
SocketAddress *addr,
Error **errp)
{
/* Validate any options which have a dependency on address type */
switch (addr->type) {
case SOCKET_ADDRESS_TYPE_FD:
if (sock->has_reconnect) {
error_setg(errp,
"'reconnect' option is incompatible with "
"'fd' address type");
return false;
}
if (sock->has_tls_creds &&
!(sock->has_server && sock->server)) {
error_setg(errp,
"'tls_creds' option is incompatible with "
"'fd' address type as client");
return false;
}
break;
case SOCKET_ADDRESS_TYPE_UNIX:
if (sock->has_tls_creds) {
error_setg(errp,
"'tls_creds' option is incompatible with "
"'unix' address type");
return false;
}
break;
case SOCKET_ADDRESS_TYPE_INET:
break;
case SOCKET_ADDRESS_TYPE_VSOCK:
if (sock->has_tls_creds) {
error_setg(errp,
"'tls_creds' option is incompatible with "
"'vsock' address type");
return false;
}
default:
break;
}
/* Validate any options which have a dependancy on client vs server */
if (!sock->has_server || sock->server) {
if (sock->has_reconnect) {
error_setg(errp,
"'reconnect' option is incompatible with "
"socket in server listen mode");
return false;
}
} else {
if (sock->has_websocket && sock->websocket) {
error_setg(errp, "%s", "Websocket client is not implemented");
return false;
}
if (sock->has_wait) {
error_setg(errp, "%s",
"'wait' option is incompatible with "
"socket in client connect mode");
return false;
}
}
return true;
}
static void qmp_chardev_open_socket(Chardev *chr,
ChardevBackend *backend,
bool *be_opened,
Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(chr);
ChardevSocket *sock = backend->u.socket.data;
bool do_nodelay = sock->has_nodelay ? sock->nodelay : false;
bool is_listen = sock->has_server ? sock->server : true;
bool is_telnet = sock->has_telnet ? sock->telnet : false;
bool is_tn3270 = sock->has_tn3270 ? sock->tn3270 : false;
bool is_waitconnect = sock->has_wait ? sock->wait : false;
bool is_websock = sock->has_websocket ? sock->websocket : false;
int64_t reconnect = sock->has_reconnect ? sock->reconnect : 0;
SocketAddress *addr;
s->is_listen = is_listen;
s->is_telnet = is_telnet;
s->is_tn3270 = is_tn3270;
s->is_websock = is_websock;
s->do_nodelay = do_nodelay;
if (sock->tls_creds) {
Object *creds;
creds = object_resolve_path_component(
object_get_objects_root(), sock->tls_creds);
if (!creds) {
error_setg(errp, "No TLS credentials with id '%s'",
sock->tls_creds);
return;
}
s->tls_creds = (QCryptoTLSCreds *)
object_dynamic_cast(creds,
TYPE_QCRYPTO_TLS_CREDS);
if (!s->tls_creds) {
error_setg(errp, "Object with id '%s' is not TLS credentials",
sock->tls_creds);
return;
}
object_ref(OBJECT(s->tls_creds));
if (is_listen) {
if (s->tls_creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
error_setg(errp, "%s",
"Expected TLS credentials for server endpoint");
return;
}
} else {
if (s->tls_creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
error_setg(errp, "%s",
"Expected TLS credentials for client endpoint");
return;
}
}
}
s->addr = addr = socket_address_flatten(sock->addr);
if (!qmp_chardev_validate_socket(sock, addr, errp)) {
return;
}
qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE);
/* TODO SOCKET_ADDRESS_FD where fd has AF_UNIX */
if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_FD_PASS);
}
/* be isn't opened until we get a connection */
*be_opened = false;
update_disconnected_filename(s);
if (s->is_listen) {
if (qmp_chardev_open_socket_server(chr, is_telnet || is_tn3270,
is_waitconnect, errp) < 0) {
return;
}
} else {
if (qmp_chardev_open_socket_client(chr, reconnect, errp) < 0) {
return;
}
}
}
static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
Error **errp)
{
const char *path = qemu_opt_get(opts, "path");
const char *host = qemu_opt_get(opts, "host");
const char *port = qemu_opt_get(opts, "port");
const char *fd = qemu_opt_get(opts, "fd");
SocketAddressLegacy *addr;
ChardevSocket *sock;
if ((!!path + !!fd + !!host) != 1) {
error_setg(errp,
"Exactly one of 'path', 'fd' or 'host' required");
return;
}
if (host && !port) {
error_setg(errp, "chardev: socket: no port given");
return;
}
backend->type = CHARDEV_BACKEND_KIND_SOCKET;
sock = backend->u.socket.data = g_new0(ChardevSocket, 1);
qemu_chr_parse_common(opts, qapi_ChardevSocket_base(sock));
sock->has_nodelay = qemu_opt_get(opts, "delay");
sock->nodelay = !qemu_opt_get_bool(opts, "delay", true);
/*
* We have different default to QMP for 'server', hence
* we can't just check for existence of 'server'
*/
sock->has_server = true;
sock->server = qemu_opt_get_bool(opts, "server", false);
sock->has_telnet = qemu_opt_get(opts, "telnet");
sock->telnet = qemu_opt_get_bool(opts, "telnet", false);
sock->has_tn3270 = qemu_opt_get(opts, "tn3270");
sock->tn3270 = qemu_opt_get_bool(opts, "tn3270", false);
sock->has_websocket = qemu_opt_get(opts, "websocket");
sock->websocket = qemu_opt_get_bool(opts, "websocket", false);
/*
* We have different default to QMP for 'wait' when 'server'
* is set, hence we can't just check for existence of 'wait'
*/
sock->has_wait = qemu_opt_find(opts, "wait") || sock->server;
sock->wait = qemu_opt_get_bool(opts, "wait", true);
sock->has_reconnect = qemu_opt_find(opts, "reconnect");
sock->reconnect = qemu_opt_get_number(opts, "reconnect", 0);
sock->has_tls_creds = qemu_opt_get(opts, "tls-creds");
sock->tls_creds = g_strdup(qemu_opt_get(opts, "tls-creds"));
addr = g_new0(SocketAddressLegacy, 1);
if (path) {
UnixSocketAddress *q_unix;
addr->type = SOCKET_ADDRESS_LEGACY_KIND_UNIX;
q_unix = addr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
q_unix->path = g_strdup(path);
} else if (host) {
addr->type = SOCKET_ADDRESS_LEGACY_KIND_INET;
addr->u.inet.data = g_new(InetSocketAddress, 1);
*addr->u.inet.data = (InetSocketAddress) {
.host = g_strdup(host),
.port = g_strdup(port),
.has_to = qemu_opt_get(opts, "to"),
.to = qemu_opt_get_number(opts, "to", 0),
.has_ipv4 = qemu_opt_get(opts, "ipv4"),
.ipv4 = qemu_opt_get_bool(opts, "ipv4", 0),
.has_ipv6 = qemu_opt_get(opts, "ipv6"),
.ipv6 = qemu_opt_get_bool(opts, "ipv6", 0),
};
} else if (fd) {
addr->type = SOCKET_ADDRESS_LEGACY_KIND_FD;
addr->u.fd.data = g_new(String, 1);
addr->u.fd.data->str = g_strdup(fd);
} else {
g_assert_not_reached();
}
sock->addr = addr;
}
static void
char_socket_get_addr(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(obj);
visit_type_SocketAddress(v, name, &s->addr, errp);
}
static bool
char_socket_get_connected(Object *obj, Error **errp)
{
SocketChardev *s = SOCKET_CHARDEV(obj);
return s->state == TCP_CHARDEV_STATE_CONNECTED;
}
static void char_socket_class_init(ObjectClass *oc, void *data)
{
ChardevClass *cc = CHARDEV_CLASS(oc);
cc->parse = qemu_chr_parse_socket;
cc->open = qmp_chardev_open_socket;
cc->chr_wait_connected = tcp_chr_wait_connected;
cc->chr_write = tcp_chr_write;
cc->chr_sync_read = tcp_chr_sync_read;
cc->chr_disconnect = tcp_chr_disconnect;
cc->get_msgfds = tcp_get_msgfds;
cc->set_msgfds = tcp_set_msgfds;
cc->chr_add_client = tcp_chr_add_client;
cc->chr_add_watch = tcp_chr_add_watch;
cc->chr_update_read_handler = tcp_chr_update_read_handler;
object_class_property_add(oc, "addr", "SocketAddress",
char_socket_get_addr, NULL,
NULL, NULL, &error_abort);
object_class_property_add_bool(oc, "connected", char_socket_get_connected,
NULL, &error_abort);
}
static const TypeInfo char_socket_type_info = {
.name = TYPE_CHARDEV_SOCKET,
.parent = TYPE_CHARDEV,
.instance_size = sizeof(SocketChardev),
.instance_finalize = char_socket_finalize,
.class_init = char_socket_class_init,
};
static void register_types(void)
{
type_register_static(&char_socket_type_info);
}
type_init(register_types);
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