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authorYuri Pudgorodskiy <yur@virtuozzo.com>2015-10-13 18:41:23 +0300
committerMichael Roth <mdroth@linux.vnet.ibm.com>2015-10-19 18:31:54 -0500
commita1853dca74362551ec1434b2e15acfcdd53caa99 (patch)
tree2a8ca7e59cfda1867ef3b77ca8f10c70e00848e8 /qga
parentf74df9bfce6d133fc64d6b878327849ed2b89b4b (diff)
downloadqemu-arm-a1853dca74362551ec1434b2e15acfcdd53caa99.tar.gz
qga: guest-exec simple stdin/stdout/stderr redirection
Implemented with base64-encoded strings in qga json protocol. Glib portable GIOChannel is used for data I/O. Optinal stdin parameter of guest-exec command is now used as stdin content for spawned subprocess. If capture-output bool flag is specified, guest-exec redirects out/err file descriptiors internally to pipes and collects subprocess output. Guest-exe-status is modified to return this collected data to requestor in base64 encoding. Signed-off-by: Yuri Pudgorodskiy <yur@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> * switch from 'struct GuestIOExecData' to 'GuestIOExecData' * s/TRUE/true/g, s/FALSE/false/g for gboolean return values * s/inp_data/input_data/ Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Diffstat (limited to 'qga')
-rw-r--r--qga/commands.c189
-rw-r--r--qga/qapi-schema.json7
2 files changed, 187 insertions, 9 deletions
diff --git a/qga/commands.c b/qga/commands.c
index 68e8cfab18..0f80ce65a4 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -15,6 +15,11 @@
#include "qga-qmp-commands.h"
#include "qapi/qmp/qerror.h"
+/* Maximum captured guest-exec out_data/err_data - 16MB */
+#define GUEST_EXEC_MAX_OUTPUT (16*1024*1024)
+/* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */
+#define GUEST_EXEC_IO_SIZE (4*1024)
+
/* Note: in some situations, like with the fsfreeze, logging may be
* temporarilly disabled. if it is necessary that a command be able
* to log for accounting purposes, check ga_logging_enabled() beforehand,
@@ -71,11 +76,25 @@ struct GuestAgentInfo *qmp_guest_info(Error **errp)
return info;
}
+struct GuestExecIOData {
+ guchar *data;
+ gsize size;
+ gsize length;
+ gint closed;
+ bool truncated;
+ const char *name;
+};
+typedef struct GuestExecIOData GuestExecIOData;
+
struct GuestExecInfo {
GPid pid;
int64_t pid_numeric;
gint status;
- bool finished;
+ bool has_output;
+ gint finished;
+ GuestExecIOData in;
+ GuestExecIOData out;
+ GuestExecIOData err;
QTAILQ_ENTRY(GuestExecInfo) next;
};
typedef struct GuestExecInfo GuestExecInfo;
@@ -134,9 +153,18 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err)
}
ges = g_new0(GuestExecStatus, 1);
- ges->exited = gei->finished;
- if (gei->finished) {
+ bool finished = g_atomic_int_get(&gei->finished);
+
+ /* need to wait till output channels are closed
+ * to be sure we captured all output at this point */
+ if (gei->has_output) {
+ finished = finished && g_atomic_int_get(&gei->out.closed);
+ finished = finished && g_atomic_int_get(&gei->err.closed);
+ }
+
+ ges->exited = finished;
+ if (finished) {
/* Glib has no portable way to parse exit status.
* On UNIX, we can get either exit code from normal termination
* or signal number.
@@ -171,6 +199,20 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err)
ges->signal = WTERMSIG(gei->status);
}
#endif
+ if (gei->out.length > 0) {
+ ges->has_out_data = true;
+ ges->out_data = g_base64_encode(gei->out.data, gei->out.length);
+ g_free(gei->out.data);
+ ges->has_out_truncated = gei->out.truncated;
+ }
+
+ if (gei->err.length > 0) {
+ ges->has_err_data = true;
+ ges->err_data = g_base64_encode(gei->err.data, gei->err.length);
+ g_free(gei->err.data);
+ ges->has_err_truncated = gei->err.truncated;
+ }
+
QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
g_free(gei);
}
@@ -241,6 +283,98 @@ static void guest_exec_task_setup(gpointer data)
#endif
}
+static gboolean guest_exec_input_watch(GIOChannel *ch,
+ GIOCondition cond, gpointer p_)
+{
+ GuestExecIOData *p = (GuestExecIOData *)p_;
+ gsize bytes_written = 0;
+ GIOStatus status;
+ GError *gerr = NULL;
+
+ /* nothing left to write */
+ if (p->size == p->length) {
+ goto done;
+ }
+
+ status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length,
+ p->size - p->length, &bytes_written, &gerr);
+
+ /* can be not 0 even if not G_IO_STATUS_NORMAL */
+ if (bytes_written != 0) {
+ p->length += bytes_written;
+ }
+
+ /* continue write, our callback will be called again */
+ if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) {
+ return true;
+ }
+
+ if (gerr) {
+ g_warning("qga: i/o error writing to input_data channel: %s",
+ gerr->message);
+ g_error_free(gerr);
+ }
+
+done:
+ g_io_channel_shutdown(ch, true, NULL);
+ g_io_channel_unref(ch);
+ g_atomic_int_set(&p->closed, 1);
+ g_free(p->data);
+
+ return false;
+}
+
+static gboolean guest_exec_output_watch(GIOChannel *ch,
+ GIOCondition cond, gpointer p_)
+{
+ GuestExecIOData *p = (GuestExecIOData *)p_;
+ gsize bytes_read;
+ GIOStatus gstatus;
+
+ if (cond == G_IO_HUP || cond == G_IO_ERR) {
+ goto close;
+ }
+
+ if (p->size == p->length) {
+ gpointer t = NULL;
+ if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) {
+ t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE);
+ }
+ if (t == NULL) {
+ /* ignore truncated output */
+ gchar buf[GUEST_EXEC_IO_SIZE];
+
+ p->truncated = true;
+ gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf),
+ &bytes_read, NULL);
+ if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
+ goto close;
+ }
+
+ return true;
+ }
+ p->size += GUEST_EXEC_IO_SIZE;
+ p->data = t;
+ }
+
+ /* Calling read API once.
+ * On next available data our callback will be called again */
+ gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length,
+ p->size - p->length, &bytes_read, NULL);
+ if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) {
+ goto close;
+ }
+
+ p->length += bytes_read;
+
+ return true;
+
+close:
+ g_io_channel_unref(ch);
+ g_atomic_int_set(&p->closed, 1);
+ return false;
+}
+
GuestExec *qmp_guest_exec(const char *path,
bool has_arg, strList *arg,
bool has_env, strList *env,
@@ -255,6 +389,10 @@ GuestExec *qmp_guest_exec(const char *path,
strList arglist;
gboolean ret;
GError *gerr = NULL;
+ gint in_fd, out_fd, err_fd;
+ GIOChannel *in_ch, *out_ch, *err_ch;
+ GSpawnFlags flags;
+ bool has_output = (has_capture_output && capture_output);
arglist.value = (char *)path;
arglist.next = has_arg ? arg : NULL;
@@ -262,11 +400,14 @@ GuestExec *qmp_guest_exec(const char *path,
argv = guest_exec_get_args(&arglist, true);
envp = guest_exec_get_args(has_env ? env : NULL, false);
- ret = g_spawn_async_with_pipes(NULL, argv, envp,
- G_SPAWN_SEARCH_PATH |
- G_SPAWN_DO_NOT_REAP_CHILD |
- G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL,
- guest_exec_task_setup, NULL, &pid, NULL, NULL, NULL, &gerr);
+ flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD;
+ if (!has_output) {
+ flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL;
+ }
+
+ ret = g_spawn_async_with_pipes(NULL, argv, envp, flags,
+ guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL,
+ has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr);
if (!ret) {
error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message);
g_error_free(gerr);
@@ -277,8 +418,40 @@ GuestExec *qmp_guest_exec(const char *path,
ge->pid = gpid_to_int64(pid);
gei = guest_exec_info_add(pid);
+ gei->has_output = has_output;
g_child_watch_add(pid, guest_exec_child_watch, gei);
+ if (has_input_data) {
+ gei->in.data = g_base64_decode(input_data, &gei->in.size);
+#ifdef G_OS_WIN32
+ in_ch = g_io_channel_win32_new_fd(in_fd);
+#else
+ in_ch = g_io_channel_unix_new(in_fd);
+#endif
+ g_io_channel_set_encoding(in_ch, NULL, NULL);
+ g_io_channel_set_buffered(in_ch, false);
+ g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL);
+ g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in);
+ }
+
+ if (has_output) {
+#ifdef G_OS_WIN32
+ out_ch = g_io_channel_win32_new_fd(out_fd);
+ err_ch = g_io_channel_win32_new_fd(err_fd);
+#else
+ out_ch = g_io_channel_unix_new(out_fd);
+ err_ch = g_io_channel_unix_new(err_fd);
+#endif
+ g_io_channel_set_encoding(out_ch, NULL, NULL);
+ g_io_channel_set_encoding(err_ch, NULL, NULL);
+ g_io_channel_set_buffered(out_ch, false);
+ g_io_channel_set_buffered(err_ch, false);
+ g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP,
+ guest_exec_output_watch, &gei->out);
+ g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP,
+ guest_exec_output_watch, &gei->err);
+ }
+
done:
g_free(argv);
g_free(envp);
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 4900b5e937..78362e071d 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -941,12 +941,17 @@
# @err-data: #optional base64-encoded stderr of the process
# Note: @out-data and @err-data are present only
# if 'capture-output' was specified for 'guest-exec'
+# @out-truncated: #optional true if stdout was not fully captured
+# due to size limitation.
+# @err-truncated: #optional true if stderr was not fully captured
+# due to size limitation.
#
# Since: 2.5
##
{ 'struct': 'GuestExecStatus',
'data': { 'exited': 'bool', '*exitcode': 'int', '*signal': 'int',
- '*out-data': 'str', '*err-data': 'str' }}
+ '*out-data': 'str', '*err-data': 'str',
+ '*out-truncated': 'bool', '*err-truncated': 'bool' }}
##
# @guest-exec-status
#