Merge tag 'qemu-macppc-20230206' of https://github.com/mcayland/qemu into staging
[qemu.git] / io / channel-command.c
blob74516252bae536bb2dbb21878f839cbd648605a7
1 /*
2 * QEMU I/O channels external command driver
4 * Copyright (c) 2015 Red Hat, Inc.
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
21 #include "qemu/osdep.h"
22 #include "io/channel-command.h"
23 #include "io/channel-watch.h"
24 #include "qapi/error.h"
25 #include "qemu/module.h"
26 #include "qemu/sockets.h"
27 #include "trace.h"
29 /**
30 * qio_channel_command_new_pid:
31 * @writefd: the FD connected to the command's stdin
32 * @readfd: the FD connected to the command's stdout
33 * @pid: the PID/HANDLE of the running child command
34 * @errp: pointer to a NULL-initialized error object
36 * Create a channel for performing I/O with the
37 * previously spawned command identified by @pid.
38 * The two file descriptors provide the connection
39 * to command's stdio streams, either one or which
40 * may be -1 to indicate that stream is not open.
42 * The channel will take ownership of the process
43 * @pid and will kill it when closing the channel.
44 * Similarly it will take responsibility for
45 * closing the file descriptors @writefd and @readfd.
47 * Returns: the command channel object, or NULL on error
49 static QIOChannelCommand *
50 qio_channel_command_new_pid(int writefd,
51 int readfd,
52 GPid pid)
54 QIOChannelCommand *ioc;
56 ioc = QIO_CHANNEL_COMMAND(object_new(TYPE_QIO_CHANNEL_COMMAND));
58 ioc->readfd = readfd;
59 ioc->writefd = writefd;
60 ioc->pid = pid;
62 trace_qio_channel_command_new_pid(ioc, writefd, readfd,
63 #ifdef WIN32
64 GetProcessId(pid)
65 #else
66 pid
67 #endif
69 return ioc;
72 QIOChannelCommand *
73 qio_channel_command_new_spawn(const char *const argv[],
74 int flags,
75 Error **errp)
77 g_autoptr(GError) err = NULL;
78 GPid pid = 0;
79 GSpawnFlags gflags = G_SPAWN_CLOEXEC_PIPES | G_SPAWN_DO_NOT_REAP_CHILD;
80 int stdinfd = -1, stdoutfd = -1;
82 flags = flags & O_ACCMODE;
83 gflags |= flags == O_WRONLY ? G_SPAWN_STDOUT_TO_DEV_NULL : 0;
85 if (!g_spawn_async_with_pipes(NULL, (char **)argv, NULL, gflags, NULL, NULL,
86 &pid,
87 flags == O_RDONLY ? NULL : &stdinfd,
88 flags == O_WRONLY ? NULL : &stdoutfd,
89 NULL, &err)) {
90 error_setg(errp, "%s", err->message);
91 return NULL;
94 return qio_channel_command_new_pid(stdinfd, stdoutfd, pid);
97 #ifndef WIN32
98 static int qio_channel_command_abort(QIOChannelCommand *ioc,
99 Error **errp)
101 pid_t ret;
102 int status;
103 int step = 0;
105 /* See if intermediate process has exited; if not, try a nice
106 * SIGTERM followed by a more severe SIGKILL.
108 rewait:
109 trace_qio_channel_command_abort(ioc, ioc->pid);
110 ret = waitpid(ioc->pid, &status, WNOHANG);
111 trace_qio_channel_command_wait(ioc, ioc->pid, ret, status);
112 if (ret == (pid_t)-1) {
113 if (errno == EINTR) {
114 goto rewait;
115 } else {
116 error_setg_errno(errp, errno,
117 "Cannot wait on pid %llu",
118 (unsigned long long)ioc->pid);
119 return -1;
121 } else if (ret == 0) {
122 if (step == 0) {
123 kill(ioc->pid, SIGTERM);
124 } else if (step == 1) {
125 kill(ioc->pid, SIGKILL);
126 } else {
127 error_setg(errp,
128 "Process %llu refused to die",
129 (unsigned long long)ioc->pid);
130 return -1;
132 step++;
133 usleep(10 * 1000);
134 goto rewait;
137 return 0;
139 #else
140 static int qio_channel_command_abort(QIOChannelCommand *ioc,
141 Error **errp)
143 DWORD ret;
145 TerminateProcess(ioc->pid, 0);
146 ret = WaitForSingleObject(ioc->pid, 1000);
147 if (ret != WAIT_OBJECT_0) {
148 error_setg(errp,
149 "Process %llu refused to die",
150 (unsigned long long)GetProcessId(ioc->pid));
151 return -1;
154 return 0;
156 #endif /* ! WIN32 */
159 static void qio_channel_command_init(Object *obj)
161 QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
162 ioc->readfd = -1;
163 ioc->writefd = -1;
164 ioc->pid = 0;
167 static void qio_channel_command_finalize(Object *obj)
169 QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
170 if (ioc->readfd != -1) {
171 close(ioc->readfd);
173 if (ioc->writefd != -1 &&
174 ioc->writefd != ioc->readfd) {
175 close(ioc->writefd);
177 ioc->writefd = ioc->readfd = -1;
178 if (ioc->pid > 0) {
179 qio_channel_command_abort(ioc, NULL);
180 g_spawn_close_pid(ioc->pid);
184 #ifdef WIN32
185 static bool win32_fd_poll(int fd, gushort events)
187 GPollFD pfd = { .fd = _get_osfhandle(fd), .events = events };
188 int res;
190 do {
191 res = g_poll(&pfd, 1, 0);
192 } while (res < 0 && errno == EINTR);
193 if (res == 0) {
194 return false;
197 return true;
199 #endif
201 static ssize_t qio_channel_command_readv(QIOChannel *ioc,
202 const struct iovec *iov,
203 size_t niov,
204 int **fds,
205 size_t *nfds,
206 Error **errp)
208 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
209 ssize_t ret;
211 #ifdef WIN32
212 if (!cioc->blocking && !win32_fd_poll(cioc->readfd, G_IO_IN)) {
213 return QIO_CHANNEL_ERR_BLOCK;
215 #endif
217 retry:
218 ret = readv(cioc->readfd, iov, niov);
219 if (ret < 0) {
220 if (errno == EAGAIN) {
221 return QIO_CHANNEL_ERR_BLOCK;
223 if (errno == EINTR) {
224 goto retry;
227 error_setg_errno(errp, errno,
228 "Unable to read from command");
229 return -1;
232 return ret;
235 static ssize_t qio_channel_command_writev(QIOChannel *ioc,
236 const struct iovec *iov,
237 size_t niov,
238 int *fds,
239 size_t nfds,
240 int flags,
241 Error **errp)
243 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
244 ssize_t ret;
246 #ifdef WIN32
247 if (!cioc->blocking && !win32_fd_poll(cioc->writefd, G_IO_OUT)) {
248 return QIO_CHANNEL_ERR_BLOCK;
250 #endif
252 retry:
253 ret = writev(cioc->writefd, iov, niov);
254 if (ret <= 0) {
255 if (errno == EAGAIN) {
256 return QIO_CHANNEL_ERR_BLOCK;
258 if (errno == EINTR) {
259 goto retry;
261 error_setg_errno(errp, errno, "%s",
262 "Unable to write to command");
263 return -1;
265 return ret;
268 static int qio_channel_command_set_blocking(QIOChannel *ioc,
269 bool enabled,
270 Error **errp)
272 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
274 #ifdef WIN32
275 cioc->blocking = enabled;
276 #else
278 if ((cioc->writefd >= 0 && !g_unix_set_fd_nonblocking(cioc->writefd, !enabled, NULL)) ||
279 (cioc->readfd >= 0 && !g_unix_set_fd_nonblocking(cioc->readfd, !enabled, NULL))) {
280 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
281 return -1;
283 #endif
284 return 0;
288 static int qio_channel_command_close(QIOChannel *ioc,
289 Error **errp)
291 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
292 int rv = 0;
293 #ifndef WIN32
294 pid_t wp;
295 #endif
297 /* We close FDs before killing, because that
298 * gives a better chance of clean shutdown
300 if (cioc->readfd != -1 &&
301 close(cioc->readfd) < 0) {
302 rv = -1;
304 if (cioc->writefd != -1 &&
305 cioc->writefd != cioc->readfd &&
306 close(cioc->writefd) < 0) {
307 rv = -1;
309 cioc->writefd = cioc->readfd = -1;
311 #ifndef WIN32
312 do {
313 wp = waitpid(cioc->pid, NULL, 0);
314 } while (wp == (pid_t)-1 && errno == EINTR);
315 if (wp == (pid_t)-1) {
316 error_setg_errno(errp, errno, "Failed to wait for pid %llu",
317 (unsigned long long)cioc->pid);
318 return -1;
320 #else
321 WaitForSingleObject(cioc->pid, INFINITE);
322 #endif
324 if (rv < 0) {
325 error_setg_errno(errp, errno, "%s",
326 "Unable to close command");
328 return rv;
332 static void qio_channel_command_set_aio_fd_handler(QIOChannel *ioc,
333 AioContext *ctx,
334 IOHandler *io_read,
335 IOHandler *io_write,
336 void *opaque)
338 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
339 aio_set_fd_handler(ctx, cioc->readfd, false,
340 io_read, NULL, NULL, NULL, opaque);
341 aio_set_fd_handler(ctx, cioc->writefd, false,
342 NULL, io_write, NULL, NULL, opaque);
346 static GSource *qio_channel_command_create_watch(QIOChannel *ioc,
347 GIOCondition condition)
349 QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
350 return qio_channel_create_fd_pair_watch(ioc,
351 cioc->readfd,
352 cioc->writefd,
353 condition);
357 static void qio_channel_command_class_init(ObjectClass *klass,
358 void *class_data G_GNUC_UNUSED)
360 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
362 ioc_klass->io_writev = qio_channel_command_writev;
363 ioc_klass->io_readv = qio_channel_command_readv;
364 ioc_klass->io_set_blocking = qio_channel_command_set_blocking;
365 ioc_klass->io_close = qio_channel_command_close;
366 ioc_klass->io_create_watch = qio_channel_command_create_watch;
367 ioc_klass->io_set_aio_fd_handler = qio_channel_command_set_aio_fd_handler;
370 static const TypeInfo qio_channel_command_info = {
371 .parent = TYPE_QIO_CHANNEL,
372 .name = TYPE_QIO_CHANNEL_COMMAND,
373 .instance_size = sizeof(QIOChannelCommand),
374 .instance_init = qio_channel_command_init,
375 .instance_finalize = qio_channel_command_finalize,
376 .class_init = qio_channel_command_class_init,
379 static void qio_channel_command_register_types(void)
381 type_register_static(&qio_channel_command_info);
384 type_init(qio_channel_command_register_types);