qemu/qga/commands.c

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/*
* QEMU Guest Agent common/cross-platform command implementations
*
* Copyright IBM Corp. 2012
*
* Authors:
* Michael Roth <mdroth@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <glib.h>
#include "qga/guest-agent-core.h"
#include "qga-qmp-commands.h"
#include "qapi/qmp/qerror.h"
/* 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,
* and use the QERR_QGA_LOGGING_DISABLED to generate an error
*/
void slog(const gchar *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
va_end(ap);
}
int64_t qmp_guest_sync_delimited(int64_t id, Error **errp)
{
ga_set_response_delimited(ga_state);
return id;
}
int64_t qmp_guest_sync(int64_t id, Error **errp)
{
return id;
}
void qmp_guest_ping(Error **errp)
{
slog("guest-ping called");
}
static void qmp_command_info(QmpCommand *cmd, void *opaque)
{
GuestAgentInfo *info = opaque;
GuestAgentCommandInfo *cmd_info;
GuestAgentCommandInfoList *cmd_info_list;
cmd_info = g_new0(GuestAgentCommandInfo, 1);
cmd_info->name = g_strdup(qmp_command_name(cmd));
cmd_info->enabled = qmp_command_is_enabled(cmd);
cmd_info->success_response = qmp_has_success_response(cmd);
cmd_info_list = g_new0(GuestAgentCommandInfoList, 1);
cmd_info_list->value = cmd_info;
cmd_info_list->next = info->supported_commands;
info->supported_commands = cmd_info_list;
}
struct GuestAgentInfo *qmp_guest_info(Error **errp)
{
GuestAgentInfo *info = g_new0(GuestAgentInfo, 1);
info->version = g_strdup(QEMU_VERSION);
qmp_for_each_command(qmp_command_info, info);
return info;
}
struct GuestExecInfo {
GPid pid;
int64_t pid_numeric;
gint status;
bool finished;
QTAILQ_ENTRY(GuestExecInfo) next;
};
typedef struct GuestExecInfo GuestExecInfo;
static struct {
QTAILQ_HEAD(, GuestExecInfo) processes;
} guest_exec_state = {
.processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes),
};
static int64_t gpid_to_int64(GPid pid)
{
#ifdef G_OS_WIN32
return GetProcessId(pid);
#else
return (int64_t)pid;
#endif
}
static GuestExecInfo *guest_exec_info_add(GPid pid)
{
GuestExecInfo *gei;
gei = g_new0(GuestExecInfo, 1);
gei->pid = pid;
gei->pid_numeric = gpid_to_int64(pid);
QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next);
return gei;
}
static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric)
{
GuestExecInfo *gei;
QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) {
if (gei->pid_numeric == pid_numeric) {
return gei;
}
}
return NULL;
}
GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err)
{
GuestExecInfo *gei;
GuestExecStatus *ges;
slog("guest-exec-status called, pid: %u", (uint32_t)pid);
gei = guest_exec_info_find(pid);
if (gei == NULL) {
error_setg(err, QERR_INVALID_PARAMETER, "pid");
return NULL;
}
ges = g_new0(GuestExecStatus, 1);
ges->exited = gei->finished;
if (gei->finished) {
/* Glib has no portable way to parse exit status.
* On UNIX, we can get either exit code from normal termination
* or signal number.
* On Windows, it is either the same exit code or the exception
* value for an unhandled exception that caused the process
* to terminate.
* See MSDN for GetExitCodeProcess() and ntstatus.h for possible
* well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV
* References:
* https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx
* https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx
*/
#ifdef G_OS_WIN32
/* Additionally WIN32 does not provide any additional information
* on whetherthe child exited or terminated via signal.
* We use this simple range check to distingish application exit code
* (usually value less then 256) and unhandled exception code with
* ntstatus (always value greater then 0xC0000005). */
if ((uint32_t)gei->status < 0xC0000000U) {
ges->has_exitcode = true;
ges->exitcode = gei->status;
} else {
ges->has_signal = true;
ges->signal = gei->status;
}
#else
if (WIFEXITED(gei->status)) {
ges->has_exitcode = true;
ges->exitcode = WEXITSTATUS(gei->status);
} else if (WIFSIGNALED(gei->status)) {
ges->has_signal = true;
ges->signal = WTERMSIG(gei->status);
}
#endif
QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
g_free(gei);
}
return ges;
}
/* Get environment variables or arguments array for execve(). */
static char **guest_exec_get_args(const strList *entry, bool log)
{
const strList *it;
int count = 1, i = 0; /* reserve for NULL terminator */
char **args;
char *str; /* for logging array of arguments */
size_t str_size = 1;
for (it = entry; it != NULL; it = it->next) {
count++;
str_size += 1 + strlen(it->value);
}
str = g_malloc(str_size);
*str = 0;
args = g_malloc(count * sizeof(char *));
for (it = entry; it != NULL; it = it->next) {
args[i++] = it->value;
pstrcat(str, str_size, it->value);
if (it->next) {
pstrcat(str, str_size, " ");
}
}
args[i] = NULL;
if (log) {
slog("guest-exec called: \"%s\"", str);
}
g_free(str);
return args;
}
static void guest_exec_child_watch(GPid pid, gint status, gpointer data)
{
GuestExecInfo *gei = (GuestExecInfo *)data;
g_debug("guest_exec_child_watch called, pid: %d, status: %u",
(int32_t)gpid_to_int64(pid), (uint32_t)status);
gei->status = status;
gei->finished = true;
g_spawn_close_pid(pid);
}
GuestExec *qmp_guest_exec(const char *path,
bool has_arg, strList *arg,
bool has_env, strList *env,
bool has_input_data, const char *input_data,
bool has_capture_output, bool capture_output,
Error **err)
{
GPid pid;
GuestExec *ge = NULL;
GuestExecInfo *gei;
char **argv, **envp;
strList arglist;
gboolean ret;
GError *gerr = NULL;
arglist.value = (char *)path;
arglist.next = has_arg ? arg : NULL;
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,
NULL, NULL, &pid, NULL, NULL, NULL, &gerr);
if (!ret) {
error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message);
g_error_free(gerr);
goto done;
}
ge = g_new0(GuestExec, 1);
ge->pid = gpid_to_int64(pid);
gei = guest_exec_info_add(pid);
g_child_watch_add(pid, guest_exec_child_watch, gei);
done:
g_free(argv);
g_free(envp);
return ge;
}