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authorDaniel P. Berrange <berrange@redhat.com>2015-08-27 16:25:30 +0100
committerDaniel P. Berrange <berrange@redhat.com>2015-12-18 12:18:31 +0000
commit195e14d0262c5676cb9ff4b253e4b2b15c19d3f0 (patch)
tree5f75e92f0f06e28e516b7fbcb213cb0d453094df
parent2d1d0e70cf3eadca967427e71b2c5c7d031bc5c8 (diff)
downloadqemu-arm-195e14d0262c5676cb9ff4b253e4b2b15c19d3f0.tar.gz
io: add QIOChannelCommand class
Add a QIOChannel subclass that is capable of performing I/O to/from a separate process, via a pair of pipes. The command can be used for unidirectional or bi-directional I/O. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
-rw-r--r--include/io/channel-command.h91
-rw-r--r--io/Makefile.objs1
-rw-r--r--io/channel-command.c357
-rw-r--r--tests/.gitignore2
-rw-r--r--tests/Makefile3
-rw-r--r--tests/test-io-channel-command.c129
-rw-r--r--trace-events6
7 files changed, 589 insertions, 0 deletions
diff --git a/include/io/channel-command.h b/include/io/channel-command.h
new file mode 100644
index 0000000000..bd3c59946f
--- /dev/null
+++ b/include/io/channel-command.h
@@ -0,0 +1,91 @@
+/*
+ * QEMU I/O channels external command 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/>.
+ *
+ */
+
+#ifndef QIO_CHANNEL_COMMAND_H__
+#define QIO_CHANNEL_COMMAND_H__
+
+#include "io/channel.h"
+
+#define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
+#define QIO_CHANNEL_COMMAND(obj) \
+ OBJECT_CHECK(QIOChannelCommand, (obj), TYPE_QIO_CHANNEL_COMMAND)
+
+typedef struct QIOChannelCommand QIOChannelCommand;
+
+
+/**
+ * QIOChannelCommand:
+ *
+ * The QIOChannelCommand class provides a channel implementation
+ * that can transport data with an externally running command
+ * via its stdio streams.
+ */
+
+struct QIOChannelCommand {
+ QIOChannel parent;
+ int writefd;
+ int readfd;
+ pid_t pid;
+};
+
+
+/**
+ * qio_channel_command_new_pid:
+ * @writefd: the FD connected to the command's stdin
+ * @readfd: the FD connected to the command's stdout
+ * @pid: the PID of the running child command
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a channel for performing I/O with the
+ * previously spawned command identified by @pid.
+ * The two file descriptors provide the connection
+ * to command's stdio streams, either one or which
+ * may be -1 to indicate that stream is not open.
+ *
+ * The channel will take ownership of the process
+ * @pid and will kill it when closing the channel.
+ * Similarly it will take responsibility for
+ * closing the file descriptors @writefd and @readfd.
+ *
+ * Returns: the command channel object, or NULL on error
+ */
+QIOChannelCommand *
+qio_channel_command_new_pid(int writefd,
+ int readfd,
+ pid_t pid);
+
+/**
+ * qio_channel_command_new_spawn:
+ * @argv: the NULL terminated list of command arguments
+ * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a channel for performing I/O with the
+ * command to be spawned with arguments @argv.
+ *
+ * Returns: the command channel object, or NULL on error
+ */
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+ int flags,
+ Error **errp);
+
+
+#endif /* QIO_CHANNEL_COMMAND_H__ */
diff --git a/io/Makefile.objs b/io/Makefile.objs
index e3771b1ac1..1a58ccb5c2 100644
--- a/io/Makefile.objs
+++ b/io/Makefile.objs
@@ -1,4 +1,5 @@
io-obj-y = channel.o
+io-obj-y += channel-command.o
io-obj-y += channel-file.o
io-obj-y += channel-socket.o
io-obj-y += channel-tls.o
diff --git a/io/channel-command.c b/io/channel-command.c
new file mode 100644
index 0000000000..598fdab5a3
--- /dev/null
+++ b/io/channel-command.c
@@ -0,0 +1,357 @@
+/*
+ * QEMU I/O channels external command 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 "io/channel-command.h"
+#include "io/channel-watch.h"
+#include "qemu/sockets.h"
+#include "trace.h"
+
+
+QIOChannelCommand *
+qio_channel_command_new_pid(int writefd,
+ int readfd,
+ pid_t pid)
+{
+ QIOChannelCommand *ioc;
+
+ ioc = QIO_CHANNEL_COMMAND(object_new(TYPE_QIO_CHANNEL_COMMAND));
+
+ ioc->readfd = readfd;
+ ioc->writefd = writefd;
+ ioc->pid = pid;
+
+ trace_qio_channel_command_new_pid(ioc, writefd, readfd, pid);
+ return ioc;
+}
+
+
+#ifndef WIN32
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+ int flags,
+ Error **errp)
+{
+ pid_t pid = -1;
+ int stdinfd[2] = { -1, -1 };
+ int stdoutfd[2] = { -1, -1 };
+ int devnull = -1;
+ bool stdinnull = false, stdoutnull = false;
+ QIOChannelCommand *ioc;
+
+ flags = flags & O_ACCMODE;
+
+ if (flags == O_RDONLY) {
+ stdinnull = true;
+ }
+ if (flags == O_WRONLY) {
+ stdoutnull = true;
+ }
+
+ if (stdinnull || stdoutnull) {
+ devnull = open("/dev/null", O_RDWR);
+ if (!devnull) {
+ error_setg_errno(errp, errno,
+ "Unable to open /dev/null");
+ goto error;
+ }
+ }
+
+ if ((!stdinnull && pipe(stdinfd) < 0) ||
+ (!stdoutnull && pipe(stdoutfd) < 0)) {
+ error_setg_errno(errp, errno,
+ "Unable to open pipe");
+ goto error;
+ }
+
+ pid = qemu_fork(errp);
+ if (pid < 0) {
+ goto error;
+ }
+
+ if (pid == 0) { /* child */
+ dup2(stdinnull ? devnull : stdinfd[0], STDIN_FILENO);
+ dup2(stdoutnull ? devnull : stdoutfd[1], STDOUT_FILENO);
+ /* Leave stderr connected to qemu's stderr */
+
+ if (!stdinnull) {
+ close(stdinfd[0]);
+ close(stdinfd[1]);
+ }
+ if (!stdoutnull) {
+ close(stdoutfd[0]);
+ close(stdoutfd[1]);
+ }
+
+ execv(argv[0], (char * const *)argv);
+ _exit(1);
+ }
+
+ if (!stdinnull) {
+ close(stdinfd[0]);
+ }
+ if (!stdoutnull) {
+ close(stdoutfd[1]);
+ }
+
+ ioc = qio_channel_command_new_pid(stdinnull ? devnull : stdinfd[1],
+ stdoutnull ? devnull : stdoutfd[0],
+ pid);
+ trace_qio_channel_command_new_spawn(ioc, argv[0], flags);
+ return ioc;
+
+ error:
+ if (stdinfd[0] != -1) {
+ close(stdinfd[0]);
+ }
+ if (stdinfd[1] != -1) {
+ close(stdinfd[1]);
+ }
+ if (stdoutfd[0] != -1) {
+ close(stdoutfd[0]);
+ }
+ if (stdoutfd[1] != -1) {
+ close(stdoutfd[1]);
+ }
+ return NULL;
+}
+
+#else /* WIN32 */
+QIOChannelCommand *
+qio_channel_command_new_spawn(const char *const argv[],
+ int flags,
+ Error **errp)
+{
+ error_setg_errno(errp, ENOSYS,
+ "Command spawn not supported on this platform");
+ return NULL;
+}
+#endif /* WIN32 */
+
+#ifndef WIN32
+static int qio_channel_command_abort(QIOChannelCommand *ioc,
+ Error **errp)
+{
+ pid_t ret;
+ int status;
+ int step = 0;
+
+ /* See if intermediate process has exited; if not, try a nice
+ * SIGTERM followed by a more severe SIGKILL.
+ */
+ rewait:
+ trace_qio_channel_command_abort(ioc, ioc->pid);
+ ret = waitpid(ioc->pid, &status, WNOHANG);
+ trace_qio_channel_command_wait(ioc, ioc->pid, ret, status);
+ if (ret == (pid_t)-1) {
+ if (errno == EINTR) {
+ goto rewait;
+ } else {
+ error_setg_errno(errp, errno,
+ "Cannot wait on pid %llu",
+ (unsigned long long)ioc->pid);
+ return -1;
+ }
+ } else if (ret == 0) {
+ if (step == 0) {
+ kill(ioc->pid, SIGTERM);
+ } else if (step == 1) {
+ kill(ioc->pid, SIGKILL);
+ } else {
+ error_setg(errp,
+ "Process %llu refused to die",
+ (unsigned long long)ioc->pid);
+ return -1;
+ }
+ usleep(10 * 1000);
+ goto rewait;
+ }
+
+ return 0;
+}
+#endif /* ! WIN32 */
+
+
+static void qio_channel_command_init(Object *obj)
+{
+ QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+ ioc->readfd = -1;
+ ioc->writefd = -1;
+ ioc->pid = -1;
+}
+
+static void qio_channel_command_finalize(Object *obj)
+{
+ QIOChannelCommand *ioc = QIO_CHANNEL_COMMAND(obj);
+ if (ioc->readfd != -1) {
+ close(ioc->readfd);
+ ioc->readfd = -1;
+ }
+ if (ioc->writefd != -1) {
+ close(ioc->writefd);
+ ioc->writefd = -1;
+ }
+ if (ioc->pid > 0) {
+#ifndef WIN32
+ qio_channel_command_abort(ioc, NULL);
+#endif
+ }
+}
+
+
+static ssize_t qio_channel_command_readv(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int **fds,
+ size_t *nfds,
+ Error **errp)
+{
+ QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+ ssize_t ret;
+
+ retry:
+ ret = readv(cioc->readfd, iov, niov);
+ if (ret < 0) {
+ if (errno == EAGAIN ||
+ errno == EWOULDBLOCK) {
+ return QIO_CHANNEL_ERR_BLOCK;
+ }
+ if (errno == EINTR) {
+ goto retry;
+ }
+
+ error_setg_errno(errp, errno,
+ "Unable to read from command");
+ return -1;
+ }
+
+ return ret;
+}
+
+static ssize_t qio_channel_command_writev(QIOChannel *ioc,
+ const struct iovec *iov,
+ size_t niov,
+ int *fds,
+ size_t nfds,
+ Error **errp)
+{
+ QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+ ssize_t ret;
+
+ retry:
+ ret = writev(cioc->writefd, iov, niov);
+ if (ret <= 0) {
+ if (errno == EAGAIN ||
+ errno == EWOULDBLOCK) {
+ return QIO_CHANNEL_ERR_BLOCK;
+ }
+ if (errno == EINTR) {
+ goto retry;
+ }
+ error_setg_errno(errp, errno, "%s",
+ "Unable to write to command");
+ return -1;
+ }
+ return ret;
+}
+
+static int qio_channel_command_set_blocking(QIOChannel *ioc,
+ bool enabled,
+ Error **errp)
+{
+ QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+
+ if (enabled) {
+ qemu_set_block(cioc->writefd);
+ qemu_set_block(cioc->readfd);
+ } else {
+ qemu_set_nonblock(cioc->writefd);
+ qemu_set_nonblock(cioc->readfd);
+ }
+
+ return 0;
+}
+
+
+static int qio_channel_command_close(QIOChannel *ioc,
+ Error **errp)
+{
+ QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+ int rv = 0;
+
+ /* We close FDs before killing, because that
+ * gives a better chance of clean shutdown
+ */
+ if (close(cioc->writefd) < 0) {
+ rv = -1;
+ }
+ if (close(cioc->readfd) < 0) {
+ rv = -1;
+ }
+#ifndef WIN32
+ if (qio_channel_command_abort(cioc, errp) < 0) {
+ return -1;
+ }
+#endif
+ if (rv < 0) {
+ error_setg_errno(errp, errno, "%s",
+ "Unable to close command");
+ }
+ return rv;
+}
+
+
+static GSource *qio_channel_command_create_watch(QIOChannel *ioc,
+ GIOCondition condition)
+{
+ QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
+ return qio_channel_create_fd_pair_watch(ioc,
+ cioc->readfd,
+ cioc->writefd,
+ condition);
+}
+
+
+static void qio_channel_command_class_init(ObjectClass *klass,
+ void *class_data G_GNUC_UNUSED)
+{
+ QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
+
+ ioc_klass->io_writev = qio_channel_command_writev;
+ ioc_klass->io_readv = qio_channel_command_readv;
+ ioc_klass->io_set_blocking = qio_channel_command_set_blocking;
+ ioc_klass->io_close = qio_channel_command_close;
+ ioc_klass->io_create_watch = qio_channel_command_create_watch;
+}
+
+static const TypeInfo qio_channel_command_info = {
+ .parent = TYPE_QIO_CHANNEL,
+ .name = TYPE_QIO_CHANNEL_COMMAND,
+ .instance_size = sizeof(QIOChannelCommand),
+ .instance_init = qio_channel_command_init,
+ .instance_finalize = qio_channel_command_finalize,
+ .class_init = qio_channel_command_class_init,
+};
+
+static void qio_channel_command_register_types(void)
+{
+ type_register_static(&qio_channel_command_info);
+}
+
+type_init(qio_channel_command_register_types);
diff --git a/tests/.gitignore b/tests/.gitignore
index 810b4f0bee..cc9aeec717 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -24,6 +24,8 @@ test-cutils
test-hbitmap
test-int128
test-iov
+test-io-channel-command
+test-io-channel-command.fifo
test-io-channel-file
test-io-channel-file.txt
test-io-channel-socket
diff --git a/tests/Makefile b/tests/Makefile
index 9d95350dcd..40c3855c4d 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -88,6 +88,7 @@ check-unit-y += tests/test-io-task$(EXESUF)
check-unit-y += tests/test-io-channel-socket$(EXESUF)
check-unit-y += tests/test-io-channel-file$(EXESUF)
check-unit-$(CONFIG_GNUTLS) += tests/test-io-channel-tls$(EXESUF)
+check-unit-y += tests/test-io-channel-command$(EXESUF)
check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
@@ -482,6 +483,8 @@ tests/test-io-channel-file$(EXESUF): tests/test-io-channel-file.o \
tests/test-io-channel-tls$(EXESUF): tests/test-io-channel-tls.o \
tests/crypto-tls-x509-helpers.o tests/pkix_asn1_tab.o \
tests/io-channel-helpers.o $(test-io-obj-y)
+tests/test-io-channel-command$(EXESUF): tests/test-io-channel-command.o \
+ tests/io-channel-helpers.o $(test-io-obj-y)
libqos-obj-y = tests/libqos/pci.o tests/libqos/fw_cfg.o tests/libqos/malloc.o
libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
diff --git a/tests/test-io-channel-command.c b/tests/test-io-channel-command.c
new file mode 100644
index 0000000000..03cac36a3f
--- /dev/null
+++ b/tests/test-io-channel-command.c
@@ -0,0 +1,129 @@
+/*
+ * QEMU I/O channel command test
+ *
+ * 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 "io/channel-command.h"
+#include "io-channel-helpers.h"
+
+#ifndef WIN32
+static void test_io_channel_command_fifo(bool async)
+{
+#define TEST_FIFO "tests/test-io-channel-command.fifo"
+ QIOChannel *src, *dst;
+ QIOChannelTest *test;
+ char *srcfifo = g_strdup_printf("PIPE:%s,wronly", TEST_FIFO);
+ char *dstfifo = g_strdup_printf("PIPE:%s,rdonly", TEST_FIFO);
+ const char *srcargv[] = {
+ "/bin/socat", "-", srcfifo, NULL,
+ };
+ const char *dstargv[] = {
+ "/bin/socat", dstfifo, "-", NULL,
+ };
+
+ unlink(TEST_FIFO);
+ if (access("/bin/socat", X_OK) < 0) {
+ return; /* Pretend success if socat is not present */
+ }
+ if (mkfifo(TEST_FIFO, 0600) < 0) {
+ abort();
+ }
+ src = QIO_CHANNEL(qio_channel_command_new_spawn(srcargv,
+ O_WRONLY,
+ &error_abort));
+ dst = QIO_CHANNEL(qio_channel_command_new_spawn(dstargv,
+ O_RDONLY,
+ &error_abort));
+
+ test = qio_channel_test_new();
+ qio_channel_test_run_threads(test, async, src, dst);
+ qio_channel_test_validate(test);
+
+ object_unref(OBJECT(src));
+ object_unref(OBJECT(dst));
+
+ g_free(srcfifo);
+ g_free(dstfifo);
+ unlink(TEST_FIFO);
+}
+
+
+static void test_io_channel_command_fifo_async(void)
+{
+ test_io_channel_command_fifo(true);
+}
+
+static void test_io_channel_command_fifo_sync(void)
+{
+ test_io_channel_command_fifo(false);
+}
+
+
+static void test_io_channel_command_echo(bool async)
+{
+ QIOChannel *ioc;
+ QIOChannelTest *test;
+ const char *socatargv[] = {
+ "/bin/socat", "-", "-", NULL,
+ };
+
+ if (access("/bin/socat", X_OK) < 0) {
+ return; /* Pretend success if socat is not present */
+ }
+
+ ioc = QIO_CHANNEL(qio_channel_command_new_spawn(socatargv,
+ O_RDWR,
+ &error_abort));
+ test = qio_channel_test_new();
+ qio_channel_test_run_threads(test, async, ioc, ioc);
+ qio_channel_test_validate(test);
+
+ object_unref(OBJECT(ioc));
+}
+
+
+static void test_io_channel_command_echo_async(void)
+{
+ test_io_channel_command_echo(true);
+}
+
+static void test_io_channel_command_echo_sync(void)
+{
+ test_io_channel_command_echo(false);
+}
+#endif
+
+int main(int argc, char **argv)
+{
+ module_call_init(MODULE_INIT_QOM);
+
+ g_test_init(&argc, &argv, NULL);
+
+#ifndef WIN32
+ g_test_add_func("/io/channel/command/fifo/sync",
+ test_io_channel_command_fifo_sync);
+ g_test_add_func("/io/channel/command/fifo/async",
+ test_io_channel_command_fifo_async);
+ g_test_add_func("/io/channel/command/echo/sync",
+ test_io_channel_command_echo_sync);
+ g_test_add_func("/io/channel/command/echo/async",
+ test_io_channel_command_echo_async);
+#endif
+
+ return g_test_run();
+}
diff --git a/trace-events b/trace-events
index ae6ad22f38..6f036384a8 100644
--- a/trace-events
+++ b/trace-events
@@ -1858,3 +1858,9 @@ qio_channel_websock_handshake_pending(void *ioc, int status) "Websock handshake
qio_channel_websock_handshake_reply(void *ioc) "Websock handshake reply ioc=%p"
qio_channel_websock_handshake_fail(void *ioc) "Websock handshake fail ioc=%p"
qio_channel_websock_handshake_complete(void *ioc) "Websock handshake complete ioc=%p"
+
+# io/channel-command.c
+qio_channel_command_new_pid(void *ioc, int writefd, int readfd, int pid) "Command new pid ioc=%p writefd=%d readfd=%d pid=%d"
+qio_channel_command_new_spawn(void *ioc, const char *binary, int flags) "Command new spawn ioc=%p binary=%s flags=%d"
+qio_channel_command_abort(void *ioc, int pid) "Command abort ioc=%p pid=%d"
+qio_channel_command_wait(void *ioc, int pid, int ret, int status) "Command abort ioc=%p pid=%d ret=%d status=%d"