* [Qemu-devel] [PATCH 1/2] guest agent: add guest-file-open-pipe
2011-12-06 14:34 [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Michael Roth
@ 2011-12-06 14:34 ` Michael Roth
2011-12-06 14:34 ` [Qemu-devel] [PATCH 2/2] guest agent: add guest-exec and guest-exec-status interfaces Michael Roth
2011-12-06 14:44 ` [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Daniel P. Berrange
2 siblings, 0 replies; 9+ messages in thread
From: Michael Roth @ 2011-12-06 14:34 UTC (permalink / raw)
To: qemu-devel; +Cc: bazulay, aliguori, mdroth, agl
Creates a FIFO pair that can be used with existing file read/write
interfaces to communicate with processes spawned via the forthcoming
guest-file-exec interface.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
qapi-schema-guest.json | 24 ++++++-
qga/guest-agent-commands.c | 179 +++++++++++++++++++++++++++++++++++++------
2 files changed, 177 insertions(+), 26 deletions(-)
diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
index fde5971..4c9f063 100644
--- a/qapi-schema-guest.json
+++ b/qapi-schema-guest.json
@@ -80,18 +80,40 @@
'returns': 'int' }
##
+# @guest-file-open-pipe
+#
+# Open a pipe to in the guest to associated with a qga-spawned processes
+# for communication.
+#
+# Returns: Guest file handle on success, as per guest-file-open. This
+# handle is useable with the same interfaces as a handle returned by
+# guest-file-open.
+#
+# Since: 1.0.50
+##
+{ 'command': 'guest-file-open-pipe',
+ 'returns': 'int' }
+
+##
# @guest-file-close:
#
# Close an open file in the guest
#
# @handle: filehandle returned by guest-file-open
+# @pipe-end: #optional GuestFilePipeEnd value ("rw"/"w"/"r") to specify
+# which end of the pipe to close. Please note that closing the write
+# side of a pipe will block until the read side is closed. If you've
+# passed the read-side of the pipe to a qga-spawned process, make sure
+# the process as exited before attempting to close the write side.
#
# Returns: Nothing on success.
#
# Since: 0.15.0
##
+{ 'enum': 'GuestFilePipeEnd',
+ 'data': [ 'r', 'w', 'rw' ] }
{ 'command': 'guest-file-close',
- 'data': { 'handle': 'int' } }
+ 'data': { 'handle': 'int', '*pipe-end': 'GuestFilePipeEnd' } }
##
# @guest-file-read:
diff --git a/qga/guest-agent-commands.c b/qga/guest-agent-commands.c
index 6da9904..ae77ee4 100644
--- a/qga/guest-agent-commands.c
+++ b/qga/guest-agent-commands.c
@@ -44,6 +44,34 @@ static void slog(const char *fmt, ...)
va_end(ap);
}
+static void toggle_flags(int fd, long flags, bool set, Error **err)
+{
+ int ret, old_flags;
+
+ old_flags = fcntl(fd, F_GETFL);
+ if (old_flags == -1) {
+ error_set(err, QERR_QGA_COMMAND_FAILED,
+ "failed to fetch filehandle flags");
+ return;
+ }
+ ret = fcntl(fd, F_SETFL, set ? old_flags | flags : old_flags & ~flags);
+ if (ret == -1) {
+ error_set(err, QERR_QGA_COMMAND_FAILED,
+ "failed to set filehandle flags");
+ return;
+ }
+}
+
+static void ftoggle_flags(FILE *fh, long flags, bool set, Error **err)
+{
+ int fd;
+ if (!fh || (fd = fileno(fh)) == -1) {
+ error_set(err, QERR_QGA_COMMAND_FAILED, "invalid filehandle");
+ return;
+ }
+ toggle_flags(fd, flags, set, err);
+}
+
int64_t qmp_guest_sync(int64_t id, Error **errp)
{
return id;
@@ -102,7 +130,14 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
typedef struct GuestFileHandle {
uint64_t id;
- FILE *fh;
+ bool is_pipe;
+ union {
+ FILE *fh;
+ struct {
+ FILE *in;
+ FILE *out;
+ } pipe;
+ } stream;
QTAILQ_ENTRY(GuestFileHandle) next;
} GuestFileHandle;
@@ -110,14 +145,31 @@ static struct {
QTAILQ_HEAD(, GuestFileHandle) filehandles;
} guest_file_state;
-static void guest_file_handle_add(FILE *fh)
+static uint64_t guest_file_handle_add(FILE *fh)
{
GuestFileHandle *gfh;
gfh = g_malloc0(sizeof(GuestFileHandle));
gfh->id = fileno(fh);
- gfh->fh = fh;
+ gfh->is_pipe = false;
+ gfh->stream.fh = fh;
+
+ QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
+ return gfh->id;
+}
+
+static uint64_t guest_file_handle_add_pipe(FILE *in, FILE *out)
+{
+ GuestFileHandle *gfh;
+
+ gfh = g_malloc0(sizeof(GuestFileHandle));
+ gfh->id = fileno(in);
+ gfh->is_pipe = true;
+ gfh->stream.pipe.in = in;
+ gfh->stream.pipe.out = out;
+
QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
+ return gfh->id;
}
static GuestFileHandle *guest_file_handle_find(int64_t id)
@@ -137,7 +189,6 @@ static GuestFileHandle *guest_file_handle_find(int64_t id)
int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, Error **err)
{
FILE *fh;
- int fd;
int64_t ret = -1;
if (!has_mode) {
@@ -153,39 +204,112 @@ int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, E
/* set fd non-blocking to avoid common use cases (like reading from a
* named pipe) from hanging the agent
*/
- fd = fileno(fh);
- ret = fcntl(fd, F_GETFL);
- ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK);
- if (ret == -1) {
- error_set(err, QERR_QGA_COMMAND_FAILED, "fcntl() failed");
+ ftoggle_flags(fh, O_NONBLOCK, true, err);
+ if (error_is_set(err)) {
fclose(fh);
return -1;
}
- guest_file_handle_add(fh);
- slog("guest-file-open, handle: %d", fd);
- return fd;
+ ret = guest_file_handle_add(fh);
+ slog("guest-file-open, handle: %ld", ret);
+ return ret;
}
-void qmp_guest_file_close(int64_t handle, Error **err)
+int64_t qmp_guest_file_open_pipe(Error **err)
+{
+ FILE *fh[2];
+ int fd[2], i;
+ int64_t ret = -1;
+
+ slog("guest-file-open-pipe called");
+
+ ret = pipe(fd);
+ if (ret == -1) {
+ error_set(err, QERR_QGA_COMMAND_FAILED, "pipe() failed");
+ return -1;
+ }
+ for (i = 0; i < 2; i++) {
+ toggle_flags(fd[i], O_NONBLOCK, true, err);
+ if (error_is_set(err)) {
+ close(fd[i]);
+ return -1;
+ }
+ }
+
+ fh[0] = fdopen(fd[0], "r");
+ if (!fh[0]) {
+ error_set(err, QERR_OPEN_FILE_FAILED, "pipe (read-side)");
+ return -1;
+ }
+ fh[1] = fdopen(fd[1], "w");
+ if (!fh[1]) {
+ fclose(fh[0]);
+ error_set(err, QERR_OPEN_FILE_FAILED, "pipe (write-side)");
+ return -1;
+ }
+ ret = guest_file_handle_add_pipe(fh[1], fh[0]);
+ slog("guest-file-open-pipe, handle: %ld", ret);
+ return ret;
+}
+
+void qmp_guest_file_close(int64_t handle, bool has_pipe_end,
+ GuestFilePipeEnd pipe_end, Error **err)
{
GuestFileHandle *gfh = guest_file_handle_find(handle);
int ret;
+ bool remove = false;
- slog("guest-file-close called, handle: %ld", handle);
+ slog("guest-file-close called, handle: %ld, pipe: %d, pipe_end: %d", handle,
+ has_pipe_end, pipe_end);
if (!gfh) {
error_set(err, QERR_FD_NOT_FOUND, "handle");
return;
}
- ret = fclose(gfh->fh);
- if (ret == -1) {
- error_set(err, QERR_QGA_COMMAND_FAILED, "fclose() failed");
- return;
+ if (gfh->is_pipe) {
+ if (!has_pipe_end) {
+ pipe_end = GUEST_FILE_PIPE_END_RW;
+ }
+ if ((pipe_end == GUEST_FILE_PIPE_END_RW ||
+ pipe_end == GUEST_FILE_PIPE_END_R) &&
+ gfh->stream.pipe.out) {
+ g_debug("closing pipe (read-side)...");
+ ret = fclose(gfh->stream.pipe.out);
+ g_debug("done closing pipe.");
+ if (ret == -1) {
+ error_set(err, QERR_INVALID_PARAMETER, "pipe (read-side)");
+ goto out_err;
+ }
+ gfh->stream.pipe.out = NULL;
+ }
+ if ((pipe_end == GUEST_FILE_PIPE_END_RW ||
+ pipe_end == GUEST_FILE_PIPE_END_W) &&
+ gfh->stream.pipe.in) {
+ g_debug("closing pipe (write-side)...");
+ ret = fclose(gfh->stream.pipe.in);
+ g_debug("done closing pipe.");
+ if (ret == -1) {
+ error_set(err, QERR_INVALID_PARAMETER, "pipe (write-side)");
+ goto out_err;
+ }
+ gfh->stream.pipe.in = NULL;
+ }
+ remove = !gfh->stream.pipe.in && !gfh->stream.pipe.out;
+ } else {
+ ret = fclose(gfh->stream.fh);
+ if (ret == -1) {
+ error_set(err, QERR_INVALID_PARAMETER, "filehandle");
+ goto out_err;
+ }
+ gfh->stream.fh = NULL;
+ remove = true;
}
- QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
- g_free(gfh);
+out_err:
+ if (remove) {
+ QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
+ g_free(gfh);
+ }
}
struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
@@ -209,10 +333,10 @@ struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
return NULL;
}
- fh = gfh->fh;
+ fh = gfh->is_pipe ? gfh->stream.pipe.out : gfh->stream.fh;
buf = g_malloc0(count+1);
read_count = fread(buf, 1, count, fh);
- if (ferror(fh)) {
+ if (0 && read_count == 0 && !feof(fh) && ferror(fh)) {
slog("guest-file-read failed, handle: %ld", handle);
error_set(err, QERR_QGA_COMMAND_FAILED, "fread() failed");
} else {
@@ -245,7 +369,7 @@ GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
return NULL;
}
- fh = gfh->fh;
+ fh = gfh->is_pipe ? gfh->stream.pipe.in : gfh->stream.fh;
buf = g_base64_decode(buf_b64, &buf_len);
if (!has_count) {
@@ -284,7 +408,12 @@ struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
return NULL;
}
- fh = gfh->fh;
+ if (gfh->is_pipe) {
+ error_set(err, QERR_QGA_COMMAND_FAILED, "cannot seek on a pipe");
+ return NULL;
+ }
+
+ fh = gfh->stream.fh;
ret = fseek(fh, offset, whence);
if (ret == -1) {
error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
@@ -309,7 +438,7 @@ void qmp_guest_file_flush(int64_t handle, Error **err)
return;
}
- fh = gfh->fh;
+ fh = gfh->is_pipe ? gfh->stream.pipe.in : gfh->stream.fh;
ret = fflush(fh);
if (ret == EOF) {
error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
--
1.7.4.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [Qemu-devel] [PATCH 2/2] guest agent: add guest-exec and guest-exec-status interfaces
2011-12-06 14:34 [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Michael Roth
2011-12-06 14:34 ` [Qemu-devel] [PATCH 1/2] guest agent: add guest-file-open-pipe Michael Roth
@ 2011-12-06 14:34 ` Michael Roth
2011-12-06 14:44 ` [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Daniel P. Berrange
2 siblings, 0 replies; 9+ messages in thread
From: Michael Roth @ 2011-12-06 14:34 UTC (permalink / raw)
To: qemu-devel; +Cc: bazulay, aliguori, mdroth, agl
Interfaces to execute/manage processes in the guest. Child process'
stdin/stdout/stderr can be associated with handles for communication
via read/write interfaces.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
qapi-schema-guest.json | 55 ++++++++
qga/guest-agent-commands.c | 299 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 354 insertions(+), 0 deletions(-)
diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
index 4c9f063..7bf3086 100644
--- a/qapi-schema-guest.json
+++ b/qapi-schema-guest.json
@@ -237,3 +237,58 @@
##
{ 'command': 'guest-fsfreeze-thaw',
'returns': 'int' }
+
+##
+# @guest-exec-status
+#
+# Check status of process associated with PID retrieved via guest-exec.
+# Reap the process and associated metadata if it has exited.
+#
+# @pid: pid returned from guest-exec
+# @wait: #optional whether to wait for completion or simply poll once.
+# Waiting is disallowed if a stdin/stdout/stderr handle was supplied
+# to guest-exec
+#
+# Returns: GuestExecStatus on success
+#
+{ 'type': 'GuestExecStatus',
+ 'data': { 'pid': 'int', 'exited': 'bool', 'exit-code': 'int',
+ 'handle_stdin': 'int', 'handle_stdout': 'int',
+ 'handle_stderr': 'int' } }
+{ 'command': 'guest-exec-status',
+ 'data': { 'pid': 'int', '*wait': 'bool' },
+ 'returns': 'GuestExecStatus' }
+
+##
+# @guest-exec:
+#
+# Execute a command in the guest
+#
+# If a pipe is associated with the resulting process, the
+# read/write/write sides of the process' stdin/stdout/stderr will
+# be transferred automatically, so no need to close them from the
+# client. If no handle is passed in for stdin/stdout/stderr, they
+# will be closed before executing the command.
+#
+# @path: path or executable name to execute
+# @params: #optional parameter list to pass to executable
+# @handle_stdin: #optional handle to associate with process' stdin.
+# @handle_stdout: #optional handle to associate with process' stdout
+# @handle_stderr: #optional handle to associate with process' stderr
+# @detach: #optional whether to detach the process or execute it
+# synchronously. If synchronous, passing of stdin/stdout/stderr handles
+# will be disallowed, since process can block on closing them and cause
+# a deadlock in the guest agent.
+#
+# Returns: GuestExecStatus on success.
+#
+# Since: 1.0.50
+##
+{ 'type': 'GuestExecParam',
+ 'data': { 'param': 'str' } }
+{ 'command': 'guest-exec',
+ 'data': { 'path': 'str', '*params': ['GuestExecParam'],
+ '*handle_stdin': 'int', '*handle_stdout': 'int',
+ '*handle_stderr': 'int',
+ '*detach': 'bool' },
+ 'returns': 'GuestExecStatus' }
diff --git a/qga/guest-agent-commands.c b/qga/guest-agent-commands.c
index ae77ee4..11f9d00 100644
--- a/qga/guest-agent-commands.c
+++ b/qga/guest-agent-commands.c
@@ -450,6 +450,304 @@ static void guest_file_init(void)
QTAILQ_INIT(&guest_file_state.filehandles);
}
+typedef struct GuestExecInfo {
+ pid_t pid;
+ char **params;
+ GuestFileHandle *gfh_stdin;
+ GuestFileHandle *gfh_stdout;
+ GuestFileHandle *gfh_stderr;
+ QTAILQ_ENTRY(GuestExecInfo) next;
+} GuestExecInfo;
+
+static struct {
+ QTAILQ_HEAD(, GuestExecInfo) processes;
+} guest_exec_state;
+
+static void guest_exec_info_add(pid_t pid, char **params,
+ GuestFileHandle *in, GuestFileHandle *out,
+ GuestFileHandle *error, Error **err)
+{
+ GuestExecInfo *gei;
+
+ gei = g_malloc0(sizeof(*gei));
+ gei->pid = pid;
+ gei->params = params;
+ gei->gfh_stdin = in;
+ gei->gfh_stdout = out;
+ gei->gfh_stderr = error;
+ QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next);
+}
+
+static GuestExecInfo *guest_exec_info_find(pid_t pid)
+{
+ GuestExecInfo *gei;
+
+ QTAILQ_FOREACH(gei, &guest_exec_state.processes, next)
+ {
+ if (gei->pid == pid) {
+ return gei;
+ }
+ }
+
+ return NULL;
+}
+
+#include <sys/wait.h>
+#include <sys/types.h>
+GuestExecStatus *qmp_guest_exec_status(int64_t pid, bool has_wait,
+ bool wait, Error **err)
+{
+ GuestExecInfo *gei;
+ GuestExecStatus *ges;
+ int status, ret;
+ char **ptr;
+
+ slog("guest-exec-status called");
+
+ gei = guest_exec_info_find(pid);
+ if (gei == NULL) {
+ error_set(err, QERR_INVALID_PARAMETER, "pid");
+ return NULL;
+ }
+
+ ret = waitpid(gei->pid, &status, WNOHANG);
+ if (ret == -1) {
+ error_set(err, QERR_UNDEFINED_ERROR);
+ return NULL;
+ }
+
+ ges = g_malloc0(sizeof(*ges));
+ ges->handle_stdin = gei->gfh_stdin ? gei->gfh_stdin->id : -1;
+ ges->handle_stdout = gei->gfh_stdout ? gei->gfh_stdout->id : -1;
+ ges->handle_stderr = gei->gfh_stderr ? gei->gfh_stderr->id : -1;
+ ges->pid = gei->pid;
+ if (ret == 0) {
+ ges->exited = false;
+ } else {
+ ges->exited = true;
+ /* reap child info once user has successfully wait()'d */
+ QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
+ for (ptr = gei->params; ptr && *ptr != NULL; ptr++) {
+ g_free(*ptr);
+ }
+ g_free(gei->params);
+ g_free(gei);
+ }
+ return ges;
+}
+
+static char **extract_param_array(const char *path,
+ const GuestExecParamList *entry)
+{
+ const GuestExecParamList *head;
+ GuestExecParam *param_container;
+ int count = 2; /* reserve 2 for path and NULL terminator */
+ int i = 0;
+ char **param_array;
+
+ for (head = entry; head != NULL; head = head->next) {
+ param_container = head->value;
+ printf("value: %s\n", param_container->param);
+ count++;
+ }
+
+ param_array = g_malloc0((count) * sizeof(*param_array));
+ param_array[i++] = strdup(path);
+
+ for (head = entry; head != NULL; head = head->next) {
+ param_container = head->value;
+ /* NULL-terminated list, so if they passed us a NULL param dup
+ * in an emptry string to avoid client-induced memory leak
+ */
+ if (param_container->param) {
+ param_array[i] = strdup(param_container->param);
+ } else {
+ param_array[i] = strdup("");
+ }
+ i++;
+ }
+
+ return param_array;
+}
+
+GuestExecStatus *qmp_guest_exec(const char *path,
+ bool has_params,
+ GuestExecParamList *params,
+ bool has_handle_stdin,
+ int64_t handle_stdin,
+ bool has_handle_stdout,
+ int64_t handle_stdout,
+ bool has_handle_stderr,
+ int64_t handle_stderr,
+ bool has_detach, bool detach,
+ Error **err)
+{
+ int ret, fd;
+ Error *local_err = NULL;
+ GuestExecStatus *ges;
+ GuestFileHandle *gfh_stdin = NULL;
+ GuestFileHandle *gfh_stdout = NULL;
+ GuestFileHandle *gfh_stderr = NULL;
+ char **param_array;
+
+ slog("guest-exec called");
+
+ if (!has_detach) {
+ detach = false;
+ }
+
+ param_array = extract_param_array(path, has_params ? params : NULL);
+
+ /* processes can block writing to a pipe, so don't allow redirect
+ * to a pipe unless we're doing detached/asynchronous exec()
+ */
+ if (has_handle_stdin) {
+ gfh_stdin = guest_file_handle_find(handle_stdin);
+ if (!gfh_stdin) {
+ error_set(err, QERR_FD_NOT_FOUND, "handle_stdin");
+ return NULL;
+ }
+ if (!detach && gfh_stdin->is_pipe) {
+ error_set(err, QERR_QGA_COMMAND_FAILED,
+ "can't use stdin pipe for non-detached exec()");
+ return NULL;
+ }
+ } else {
+ handle_stdin = -1;
+ }
+ if (has_handle_stdout) {
+ gfh_stdout = guest_file_handle_find(handle_stdout);
+ if (!gfh_stdout) {
+ error_set(err, QERR_FD_NOT_FOUND, "handle_stdout");
+ return NULL;
+ }
+ if (!detach && gfh_stdout->is_pipe) {
+ error_set(err, QERR_QGA_COMMAND_FAILED,
+ "can't use stdout pipe for non-detached exec()");
+ return NULL;
+ }
+ } else {
+ handle_stdin = -1;
+ }
+ if (has_handle_stderr) {
+ gfh_stderr = guest_file_handle_find(handle_stderr);
+ if (!gfh_stderr) {
+ error_set(err, QERR_FD_NOT_FOUND, "handle_stderr");
+ return NULL;
+ }
+ if (!detach && gfh_stderr->is_pipe) {
+ error_set(err, QERR_QGA_COMMAND_FAILED,
+ "can't use stderr pipe for non-detached exec()");
+ return NULL;
+ }
+ } else {
+ handle_stderr = -1;
+ }
+
+ ret = fork();
+ if (ret < 0) {
+ error_set(err, QERR_UNDEFINED_ERROR);
+ return NULL;
+ } else if (ret == 0) {
+ slog("guest-exec child spawned");
+ /* exec the command */
+ setsid();
+ if (has_handle_stdin) {
+ if (gfh_stdin->is_pipe) {
+ fclose(gfh_stdin->stream.pipe.in); /* parent writes to this */
+ fd = fileno(gfh_stdin->stream.pipe.out);
+ } else {
+ fd = fileno(gfh_stdin->stream.fh);
+ }
+ dup2(fd, STDIN_FILENO);
+ /* processes don't seem to like O_NONBLOCK std in/out/err */
+ toggle_flags(fd, O_NONBLOCK, false, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ } else {
+ fclose(stdin);
+ }
+ if (has_handle_stdout) {
+ if (gfh_stdout->is_pipe) {
+ fclose(gfh_stdout->stream.pipe.out); /* parent reads this end */
+ fd = fileno(gfh_stdout->stream.pipe.in);
+ } else {
+ fd = fileno(gfh_stdout->stream.fh);
+ }
+ dup2(fd, STDOUT_FILENO);
+ toggle_flags(fd, O_NONBLOCK, false, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ } else {
+ fclose(stdout);
+ }
+ if (has_handle_stderr) {
+ if (gfh_stderr->is_pipe) {
+ fclose(gfh_stderr->stream.pipe.out); /* parent reads this end */
+ fd = fileno(gfh_stderr->stream.pipe.in);
+ } else {
+ fd = fileno(gfh_stderr->stream.fh);
+ }
+ dup2(fd, STDERR_FILENO);
+ toggle_flags(fd, O_NONBLOCK, false, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ } else {
+ fclose(stderr);
+ }
+
+ ret = execvp(path, (char * const*)param_array);
+ if (ret) {
+ slog("guest-exec child failed: %s", strerror(errno));
+ }
+ exit(!!ret);
+ }
+
+ if (has_handle_stdin && gfh_stdin->is_pipe) {
+ /* child reads from this end, not us */
+ qmp_guest_file_close(gfh_stdin->id, true, GUEST_FILE_PIPE_END_R, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ }
+ if (has_handle_stdout && gfh_stdout->is_pipe) {
+ /* child writes to this end, not us */
+ qmp_guest_file_close(gfh_stdout->id, true, GUEST_FILE_PIPE_END_W, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ }
+ if (has_handle_stderr && gfh_stderr->is_pipe) {
+ /* child writes to this end, not us */
+ qmp_guest_file_close(gfh_stderr->id, true, GUEST_FILE_PIPE_END_W, err);
+ if (error_is_set(err)) {
+ return NULL;
+ }
+ }
+ guest_exec_info_add(ret, param_array, gfh_stdin, gfh_stdout, gfh_stderr,
+ &local_err);
+ if (local_err) {
+ error_propagate(err, local_err);
+ return NULL;
+ }
+
+ /* return initial status, or wait for completion if !detach */
+ if (!detach) {
+ ges = qmp_guest_exec_status(ret, true, true, err);
+ } else {
+ ges = qmp_guest_exec_status(ret, true, false, err);
+ }
+ return ges;
+}
+
+static void guest_exec_init(void)
+{
+ QTAILQ_INIT(&guest_exec_state.processes);
+}
+
#if defined(CONFIG_FSFREEZE)
static void disable_logging(void)
{
@@ -687,4 +985,5 @@ void ga_command_state_init(GAState *s, GACommandState *cs)
ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup);
#endif
ga_command_state_add(cs, guest_file_init, NULL);
+ ga_command_state_add(cs, guest_exec_init, NULL);
}
--
1.7.4.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution
2011-12-06 14:34 [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Michael Roth
2011-12-06 14:34 ` [Qemu-devel] [PATCH 1/2] guest agent: add guest-file-open-pipe Michael Roth
2011-12-06 14:34 ` [Qemu-devel] [PATCH 2/2] guest agent: add guest-exec and guest-exec-status interfaces Michael Roth
@ 2011-12-06 14:44 ` Daniel P. Berrange
2011-12-06 16:43 ` Michael Roth
2 siblings, 1 reply; 9+ messages in thread
From: Daniel P. Berrange @ 2011-12-06 14:44 UTC (permalink / raw)
To: Michael Roth; +Cc: bazulay, aliguori, qemu-devel, agl
On Tue, Dec 06, 2011 at 08:34:06AM -0600, Michael Roth wrote:
> The code is still in rough shape, but while we're on the topic of guest agents
> I wanted to put out a working example of how exec functionality can be added
> to qemu-ga to provide a mechansim for building arbitrarilly high-level
> interfaces.
>
> The hope is that by allowing qemu-ga to execute commands in the guest, paired
> with file read/write access, we can instrument a guest "on the fly" to support
> any type of hyperviser functionality, and do so without dramatically enlarging
> the role qemu-ga plays as a small, QEMU-specific agent that is tightly
> integrated with QEMU/QMP/libvirt.
>
> These patches add the following interfaces:
>
> guest-file-open-pipe
> guest-exec
> guest-exec-status
>
> The guest-file-open-pipe interface is analagous to the existing guest-file-open
> interface (it might be best to roll it into it actually): it returns a handle
> that can be handled via the existing guest-file-{read,write,flush,close}
> interface. Internally it creates a FIFO pair that we can use to associate
> handles to the stdin/stdout/stderr of a guest-exec spawned process. We can also
> also use them to redirect output into other processes, giving us the basic
> tools to build a basic shell (or a full-blown one if we add TTY support) using
> a single qemu-ga.
>
> Theoretically we can even deploy other agents, including session-level agents,
> and communicate with them via these same handles. Thus, ovirt could deploy and
> run an agent via qemu-ga, Spice could deploy vdagent, etc. Since the interface
> is somewhat tedious, I'm working on a wrapper script to try out some of
> these scenarios, but a basic use case using the raw QMP interface is included
> below.
>
> Any thoughts/comments on this approach are appreciated.
>
> EXAMPLE USAGE (execute `top -b -n1`):
>
> {'execute': 'guest-file-open-pipe'}
> {'return': 6}
>
> {'execute': 'guest-exec', \
> 'arguments': {'detach': True, \
> 'handle_stdout': 6, \
> 'params': [{'param': '-b'}, \
> {'param': '-n1'}], \
> 'path': 'top'}}
This feels like a rather verbose way of specifying
the ARGV. Why not just allow
{'execute': 'guest-exec', \
'arguments': {'detach': True, \
'handle_stdout': 6, \
'params': ['-b', '-n1'], \
'path': 'top'}}
Or even
{'execute': 'guest-exec', \
'arguments': {'detach': True, \
'handle_stdout': 6, \
'argv': ['top', '-b', '-n1']}} \
and just use the first element of argv as the binary to
execute. Also you might need to set env variables for
some tools, so we'd want
{'execute': 'guest-exec', \
'arguments': {'detach': True, \
'handle_stdout': 6, \
'argv': ['top', '-b', '-n1'], \
'env' : ['TMPDIR=/wibble']}}
and perhaps also you might want to run as a non-root
user, so allow a username/groupname ?
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution
2011-12-06 14:44 ` [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution Daniel P. Berrange
@ 2011-12-06 16:43 ` Michael Roth
2011-12-18 12:56 ` Alon Levy
0 siblings, 1 reply; 9+ messages in thread
From: Michael Roth @ 2011-12-06 16:43 UTC (permalink / raw)
To: Daniel P. Berrange; +Cc: bazulay, aliguori, qemu-devel, agl
On 12/06/2011 08:44 AM, Daniel P. Berrange wrote:
> On Tue, Dec 06, 2011 at 08:34:06AM -0600, Michael Roth wrote:
>> The code is still in rough shape, but while we're on the topic of guest agents
>> I wanted to put out a working example of how exec functionality can be added
>> to qemu-ga to provide a mechansim for building arbitrarilly high-level
>> interfaces.
>>
>> The hope is that by allowing qemu-ga to execute commands in the guest, paired
>> with file read/write access, we can instrument a guest "on the fly" to support
>> any type of hyperviser functionality, and do so without dramatically enlarging
>> the role qemu-ga plays as a small, QEMU-specific agent that is tightly
>> integrated with QEMU/QMP/libvirt.
>>
>> These patches add the following interfaces:
>>
>> guest-file-open-pipe
>> guest-exec
>> guest-exec-status
>>
>> The guest-file-open-pipe interface is analagous to the existing guest-file-open
>> interface (it might be best to roll it into it actually): it returns a handle
>> that can be handled via the existing guest-file-{read,write,flush,close}
>> interface. Internally it creates a FIFO pair that we can use to associate
>> handles to the stdin/stdout/stderr of a guest-exec spawned process. We can also
>> also use them to redirect output into other processes, giving us the basic
>> tools to build a basic shell (or a full-blown one if we add TTY support) using
>> a single qemu-ga.
>>
>> Theoretically we can even deploy other agents, including session-level agents,
>> and communicate with them via these same handles. Thus, ovirt could deploy and
>> run an agent via qemu-ga, Spice could deploy vdagent, etc. Since the interface
>> is somewhat tedious, I'm working on a wrapper script to try out some of
>> these scenarios, but a basic use case using the raw QMP interface is included
>> below.
>>
>> Any thoughts/comments on this approach are appreciated.
>>
>> EXAMPLE USAGE (execute `top -b -n1`):
>>
>> {'execute': 'guest-file-open-pipe'}
>> {'return': 6}
>>
>> {'execute': 'guest-exec', \
>> 'arguments': {'detach': True, \
>> 'handle_stdout': 6, \
>> 'params': [{'param': '-b'}, \
>> {'param': '-n1'}], \
>> 'path': 'top'}}
>
> This feels like a rather verbose way of specifying
> the ARGV. Why not just allow
>
> {'execute': 'guest-exec', \
> 'arguments': {'detach': True, \
> 'handle_stdout': 6, \
> 'params': ['-b', '-n1'], \
> 'path': 'top'}}
>
> Or even
>
>
> {'execute': 'guest-exec', \
> 'arguments': {'detach': True, \
> 'handle_stdout': 6, \
> 'argv': ['top', '-b', '-n1']}} \
>
Agreed, this would look way nicer and is what I was shooting for
initially. Unfortunately, the QAPI-generated QMP marshalling code, and
the visitor interfaces it uses, expects lists to be of structured types.
We might be able to special-case it for int and char* arrays though and
open-code it though...
The problem I ran into when I looked at it though is that the QMP
request is a QObject at that point that's contained inside a Visitor. So
to manipulate it we'd have to extract the QList and manipulate it
outside the visitor, which would be difficult since the Visitor is using
a stack to manage it's traversal of the QObject based on the visitor
calls we make, so it's difficult to pull it out of there...
Although, maybe we could just add a qmp_input_vistor_stack_top() that
gives us the top of the stack, then call it at the appropriate point in
the marshalling code and key into it to get qobj{'argv'} and whatnot.
It's kinda hacky, but it's QMP-specific, and useful, so it might be
worth it.
Alternatively, we could introduce another Visitor interface for handling
lists of int64_t and char*.
So maybe it's not so bad, I'll look into it more.
> and just use the first element of argv as the binary to
> execute. Also you might need to set env variables for
> some tools, so we'd want
>
> {'execute': 'guest-exec', \
> 'arguments': {'detach': True, \
> 'handle_stdout': 6, \
> 'argv': ['top', '-b', '-n1'], \
> 'env' : ['TMPDIR=/wibble']}}
>
> and perhaps also you might want to run as a non-root
> user, so allow a username/groupname ?
>
Good idea, this would open up a lot of potential use cases (X
session/display management, copy/paste, etc).
> Regards,
> Daniel
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [Qemu-devel] [PATCH 0/2] [RFC] qemu-ga: add support for guest command execution
2011-12-06 16:43 ` Michael Roth
@ 2011-12-18 12:56 ` Alon Levy
0 siblings, 0 replies; 9+ messages in thread
From: Alon Levy @ 2011-12-18 12:56 UTC (permalink / raw)
To: Michael Roth; +Cc: bazulay, aliguori, qemu-devel, agl
On Tue, Dec 06, 2011 at 10:43:42AM -0600, Michael Roth wrote:
> On 12/06/2011 08:44 AM, Daniel P. Berrange wrote:
> >On Tue, Dec 06, 2011 at 08:34:06AM -0600, Michael Roth wrote:
> >>The code is still in rough shape, but while we're on the topic of guest agents
> >>I wanted to put out a working example of how exec functionality can be added
> >>to qemu-ga to provide a mechansim for building arbitrarilly high-level
> >>interfaces.
> >>
> >>The hope is that by allowing qemu-ga to execute commands in the guest, paired
> >>with file read/write access, we can instrument a guest "on the fly" to support
> >>any type of hyperviser functionality, and do so without dramatically enlarging
> >>the role qemu-ga plays as a small, QEMU-specific agent that is tightly
> >>integrated with QEMU/QMP/libvirt.
> >>
> >>These patches add the following interfaces:
> >>
> >>guest-file-open-pipe
> >>guest-exec
> >>guest-exec-status
> >>
> >>The guest-file-open-pipe interface is analagous to the existing guest-file-open
> >>interface (it might be best to roll it into it actually): it returns a handle
> >>that can be handled via the existing guest-file-{read,write,flush,close}
> >>interface. Internally it creates a FIFO pair that we can use to associate
> >>handles to the stdin/stdout/stderr of a guest-exec spawned process. We can also
> >>also use them to redirect output into other processes, giving us the basic
> >>tools to build a basic shell (or a full-blown one if we add TTY support) using
> >>a single qemu-ga.
> >>
> >>Theoretically we can even deploy other agents, including session-level agents,
> >>and communicate with them via these same handles. Thus, ovirt could deploy and
> >>run an agent via qemu-ga, Spice could deploy vdagent, etc. Since the interface
> >>is somewhat tedious, I'm working on a wrapper script to try out some of
> >>these scenarios, but a basic use case using the raw QMP interface is included
> >>below.
> >>
> >>Any thoughts/comments on this approach are appreciated.
Is there a seperate transport (another virtio channel) for the launched
guest process? I'm thinking as usual on the copy/paste functionallity,
when passing a large buffer, I would not want to block any other future
qemu-ga command. Also I would like to avoid having to uuencode/decode
the traffic.
> >>
> >>EXAMPLE USAGE (execute `top -b -n1`):
> >>
> >>{'execute': 'guest-file-open-pipe'}
> >>{'return': 6}
> >>
> >>{'execute': 'guest-exec', \
> >> 'arguments': {'detach': True, \
> >> 'handle_stdout': 6, \
> >> 'params': [{'param': '-b'}, \
> >> {'param': '-n1'}], \
> >> 'path': 'top'}}
> >
> >This feels like a rather verbose way of specifying
> >the ARGV. Why not just allow
> >
> > {'execute': 'guest-exec', \
> > 'arguments': {'detach': True, \
> > 'handle_stdout': 6, \
> > 'params': ['-b', '-n1'], \
> > 'path': 'top'}}
> >
> >Or even
> >
> >
> > {'execute': 'guest-exec', \
> > 'arguments': {'detach': True, \
> > 'handle_stdout': 6, \
> > 'argv': ['top', '-b', '-n1']}} \
> >
>
> Agreed, this would look way nicer and is what I was shooting for
> initially. Unfortunately, the QAPI-generated QMP marshalling code,
> and the visitor interfaces it uses, expects lists to be of
> structured types. We might be able to special-case it for int and
> char* arrays though and open-code it though...
>
> The problem I ran into when I looked at it though is that the QMP
> request is a QObject at that point that's contained inside a
> Visitor. So to manipulate it we'd have to extract the QList and
> manipulate it outside the visitor, which would be difficult since
> the Visitor is using a stack to manage it's traversal of the QObject
> based on the visitor calls we make, so it's difficult to pull it out
> of there...
>
> Although, maybe we could just add a qmp_input_vistor_stack_top()
> that gives us the top of the stack, then call it at the appropriate
> point in the marshalling code and key into it to get qobj{'argv'}
> and whatnot. It's kinda hacky, but it's QMP-specific, and useful, so
> it might be worth it.
>
> Alternatively, we could introduce another Visitor interface for
> handling lists of int64_t and char*.
>
> So maybe it's not so bad, I'll look into it more.
>
> >and just use the first element of argv as the binary to
> >execute. Also you might need to set env variables for
> >some tools, so we'd want
> >
> > {'execute': 'guest-exec', \
> > 'arguments': {'detach': True, \
> > 'handle_stdout': 6, \
> > 'argv': ['top', '-b', '-n1'], \
> > 'env' : ['TMPDIR=/wibble']}}
> >
> >and perhaps also you might want to run as a non-root
> >user, so allow a username/groupname ?
> >
>
> Good idea, this would open up a lot of potential use cases (X
> session/display management, copy/paste, etc).
>
> >Regards,
> >Daniel
>
>
^ permalink raw reply [flat|nested] 9+ messages in thread