mirrors/qemu
0
0
Fork 0
mirror of https://github.com/qemu/qemu.git synced 2024-11-26 12:23:36 +08:00
Code Issues Packages Projects Releases Wiki Activity
125b310e1d
qemu/qemu-ga.c
Michael Roth 125b310e1d qemu-ga: move channel/transport functionality into wrapper class 
This is mostly in preparation for the win32 port, which won't use
GIO channels for reasons that will be made clearer later. Here the
GAChannel class is just a loose wrapper around GIOChannel
calls/callbacks, but we also roll in the logic/configuration for
various channel types and managing unix socket connections, which makes
the abstraction much more complete and further aids in the win32 port
since isa-serial/unix-listen will not be supported initially.

There's also a bit of refactoring in the main logic to consolidate the
exit paths so we can do common cleanup for things like pid files, which
weren't always cleaned up previously.
2012-02-23 15:40:16 -06:00

511 lines
14 KiB
C
Raw Blame History

/*
* QEMU Guest Agent
*
* Copyright IBM Corp. 2011
*
* Authors:
* Adam Litke <aglitke@linux.vnet.ibm.com>
* 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 <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <glib.h>
#include <getopt.h>
#include <syslog.h>
#include "json-streamer.h"
#include "json-parser.h"
#include "qint.h"
#include "qjson.h"
#include "qga/guest-agent-core.h"
#include "module.h"
#include "signal.h"
#include "qerror.h"
#include "error_int.h"
#include "qapi/qmp-core.h"
#include "qga/channel.h"
#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
struct GAState {
JSONMessageParser parser;
GMainLoop *main_loop;
GAChannel *channel;
bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
GACommandState *command_state;
GLogLevelFlags log_level;
FILE *log_file;
bool logging_enabled;
};
static struct GAState *ga_state;
static void quit_handler(int sig)
{
g_debug("received signal num %d, quitting", sig);
if (g_main_loop_is_running(ga_state->main_loop)) {
g_main_loop_quit(ga_state->main_loop);
}
}
static gboolean register_signal_handlers(void)
{
struct sigaction sigact;
int ret;
memset(&sigact, 0, sizeof(struct sigaction));
sigact.sa_handler = quit_handler;
ret = sigaction(SIGINT, &sigact, NULL);
if (ret == -1) {
g_error("error configuring signal handler: %s", strerror(errno));
return false;
}
ret = sigaction(SIGTERM, &sigact, NULL);
if (ret == -1) {
g_error("error configuring signal handler: %s", strerror(errno));
return false;
}
return true;
}
static void usage(const char *cmd)
{
printf(
"Usage: %s -c <channel_opts>\n"
"QEMU Guest Agent %s\n"
"\n"
" -m, --method transport method: one of unix-listen, virtio-serial, or\n"
" isa-serial (virtio-serial is the default)\n"
" -p, --path device/socket path (%s is the default for virtio-serial)\n"
" -l, --logfile set logfile path, logs to stderr by default\n"
" -f, --pidfile specify pidfile (default is %s)\n"
" -v, --verbose log extra debugging information\n"
" -V, --version print version information and exit\n"
" -d, --daemonize become a daemon\n"
" -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\""
" to list available RPCs)\n"
" -h, --help display this help and exit\n"
"\n"
"Report bugs to <mdroth@linux.vnet.ibm.com>\n"
, cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT);
}
static const char *ga_log_level_str(GLogLevelFlags level)
{
switch (level & G_LOG_LEVEL_MASK) {
case G_LOG_LEVEL_ERROR:
return "error";
case G_LOG_LEVEL_CRITICAL:
return "critical";
case G_LOG_LEVEL_WARNING:
return "warning";
case G_LOG_LEVEL_MESSAGE:
return "message";
case G_LOG_LEVEL_INFO:
return "info";
case G_LOG_LEVEL_DEBUG:
return "debug";
default:
return "user";
}
}
bool ga_logging_enabled(GAState *s)
{
return s->logging_enabled;
}
void ga_disable_logging(GAState *s)
{
s->logging_enabled = false;
}
void ga_enable_logging(GAState *s)
{
s->logging_enabled = true;
}
static void ga_log(const gchar *domain, GLogLevelFlags level,
const gchar *msg, gpointer opaque)
{
GAState *s = opaque;
GTimeVal time;
const char *level_str = ga_log_level_str(level);
if (!ga_logging_enabled(s)) {
return;
}
level &= G_LOG_LEVEL_MASK;
if (domain && strcmp(domain, "syslog") == 0) {
syslog(LOG_INFO, "%s: %s", level_str, msg);
} else if (level & s->log_level) {
g_get_current_time(&time);
fprintf(s->log_file,
"%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
fflush(s->log_file);
}
}
static void become_daemon(const char *pidfile)
{
pid_t pid, sid;
int pidfd;
char *pidstr = NULL;
pid = fork();
if (pid < 0) {
exit(EXIT_FAILURE);
}
if (pid > 0) {
exit(EXIT_SUCCESS);
}
pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR);
if (pidfd == -1) {
g_critical("Cannot create pid file, %s", strerror(errno));
exit(EXIT_FAILURE);
}
if (asprintf(&pidstr, "%d", getpid()) == -1) {
g_critical("Cannot allocate memory");
goto fail;
}
if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
free(pidstr);
g_critical("Failed to write pid file");
goto fail;
}
umask(0);
sid = setsid();
if (sid < 0) {
goto fail;
}
if ((chdir("/")) < 0) {
goto fail;
}
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
free(pidstr);
return;
fail:
unlink(pidfile);
g_critical("failed to daemonize");
exit(EXIT_FAILURE);
}
static int send_response(GAState *s, QObject *payload)
{
const char *buf;
QString *payload_qstr;
GIOStatus status;
g_assert(payload && s->channel);
payload_qstr = qobject_to_json(payload);
if (!payload_qstr) {
return -EINVAL;
}
qstring_append_chr(payload_qstr, '\n');
buf = qstring_get_str(payload_qstr);
status = ga_channel_write_all(s->channel, buf, strlen(buf));
QDECREF(payload_qstr);
if (status != G_IO_STATUS_NORMAL) {
return -EIO;
}
return 0;
}
static void process_command(GAState *s, QDict *req)
{
QObject *rsp = NULL;
int ret;
g_assert(req);
g_debug("processing command");
rsp = qmp_dispatch(QOBJECT(req));
if (rsp) {
ret = send_response(s, rsp);
if (ret) {
g_warning("error sending response: %s", strerror(ret));
}
qobject_decref(rsp);
} else {
g_warning("error getting response");
}
}
/* handle requests/control events coming in over the channel */
static void process_event(JSONMessageParser *parser, QList *tokens)
{
GAState *s = container_of(parser, GAState, parser);
QObject *obj;
QDict *qdict;
Error *err = NULL;
int ret;
g_assert(s && parser);
g_debug("process_event: called");
obj = json_parser_parse_err(tokens, NULL, &err);
if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
qobject_decref(obj);
qdict = qdict_new();
if (!err) {
g_warning("failed to parse event: unknown error");
error_set(&err, QERR_JSON_PARSING);
} else {
g_warning("failed to parse event: %s", error_get_pretty(err));
}
qdict_put_obj(qdict, "error", error_get_qobject(err));
error_free(err);
} else {
qdict = qobject_to_qdict(obj);
}
g_assert(qdict);
/* handle host->guest commands */
if (qdict_haskey(qdict, "execute")) {
process_command(s, qdict);
} else {
if (!qdict_haskey(qdict, "error")) {
QDECREF(qdict);
qdict = qdict_new();
g_warning("unrecognized payload format");
error_set(&err, QERR_UNSUPPORTED);
qdict_put_obj(qdict, "error", error_get_qobject(err));
error_free(err);
}
ret = send_response(s, QOBJECT(qdict));
if (ret) {
g_warning("error sending error response: %s", strerror(ret));
}
}
QDECREF(qdict);
}
/* false return signals GAChannel to close the current client connection */
static gboolean channel_event_cb(GIOCondition condition, gpointer data)
{
GAState *s = data;
gchar buf[QGA_READ_COUNT_DEFAULT+1];
gsize count;
GError *err = NULL;
GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
if (err != NULL) {
g_warning("error reading channel: %s", err->message);
g_error_free(err);
return false;
}
switch (status) {
case G_IO_STATUS_ERROR:
g_warning("error reading channel");
return false;
case G_IO_STATUS_NORMAL:
buf[count] = 0;
g_debug("read data, count: %d, data: %s", (int)count, buf);
json_message_parser_feed(&s->parser, (char *)buf, (int)count);
break;
case G_IO_STATUS_EOF:
g_debug("received EOF");
if (!s->virtio) {
return false;
}
case G_IO_STATUS_AGAIN:
/* virtio causes us to spin here when no process is attached to
* host-side chardev. sleep a bit to mitigate this
*/
if (s->virtio) {
usleep(100*1000);
}
return true;
default:
g_warning("unknown channel read status, closing");
return false;
}
return true;
}
static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
{
GAChannelMethod channel_method;
if (method == NULL) {
method = "virtio-serial";
}
if (path == NULL) {
if (strcmp(method, "virtio-serial") != 0) {
g_critical("must specify a path for this channel");
return false;
}
/* try the default path for the virtio-serial port */
path = QGA_VIRTIO_PATH_DEFAULT;
}
if (strcmp(method, "virtio-serial") == 0) {
s->virtio = true; /* virtio requires special handling in some cases */
channel_method = GA_CHANNEL_VIRTIO_SERIAL;
} else if (strcmp(method, "isa-serial") == 0) {
channel_method = GA_CHANNEL_ISA_SERIAL;
} else if (strcmp(method, "unix-listen") == 0) {
channel_method = GA_CHANNEL_UNIX_LISTEN;
} else {
g_critical("unsupported channel method/type: %s", method);
return false;
}
s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
if (!s->channel) {
g_critical("failed to create guest agent channel");
return false;
}
return true;
}
int main(int argc, char **argv)
{
const char *sopt = "hVvdm:p:l:f:b:";
const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT;
const struct option lopt[] = {
{ "help", 0, NULL, 'h' },
{ "version", 0, NULL, 'V' },
{ "logfile", 0, NULL, 'l' },
{ "pidfile", 0, NULL, 'f' },
{ "verbose", 0, NULL, 'v' },
{ "method", 0, NULL, 'm' },
{ "path", 0, NULL, 'p' },
{ "daemonize", 0, NULL, 'd' },
{ "blacklist", 0, NULL, 'b' },
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0, ch, daemonize = 0, i, j, len;
GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
FILE *log_file = stderr;
GAState *s;
module_call_init(MODULE_INIT_QAPI);
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 'm':
method = optarg;
break;
case 'p':
path = optarg;
break;
case 'l':
log_file = fopen(optarg, "a");
if (!log_file) {
g_critical("unable to open specified log file: %s",
strerror(errno));
return EXIT_FAILURE;
}
break;
case 'f':
pidfile = optarg;
break;
case 'v':
/* enable all log levels */
log_level = G_LOG_LEVEL_MASK;
break;
case 'V':
printf("QEMU Guest Agent %s\n", QGA_VERSION);
return 0;
case 'd':
daemonize = 1;
break;
case 'b': {
char **list_head, **list;
if (*optarg == '?') {
list_head = list = qmp_get_command_list();
while (*list != NULL) {
printf("%s\n", *list);
g_free(*list);
list++;
}
g_free(list_head);
return 0;
}
for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
if (optarg[i] == ',') {
optarg[i] = 0;
qmp_disable_command(&optarg[j]);
g_debug("disabling command: %s", &optarg[j]);
j = i + 1;
}
}
if (j < i) {
qmp_disable_command(&optarg[j]);
g_debug("disabling command: %s", &optarg[j]);
}
break;
}
case 'h':
usage(argv[0]);
return 0;
case '?':
g_print("Unknown option, try '%s --help' for more information.\n",
argv[0]);
return EXIT_FAILURE;
}
}
if (daemonize) {
g_debug("starting daemon");
become_daemon(pidfile);
}
s = g_malloc0(sizeof(GAState));
s->log_file = log_file;
s->log_level = log_level;
g_log_set_default_handler(ga_log, s);
g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
s->logging_enabled = true;
s->command_state = ga_command_state_new();
ga_command_state_init(s, s->command_state);
ga_command_state_init_all(s->command_state);
json_message_parser_init(&s->parser, process_event);
ga_state = s;
if (!register_signal_handlers()) {
g_critical("failed to register signal handlers");
goto out_bad;
}
s->main_loop = g_main_loop_new(NULL, false);
if (!channel_init(ga_state, method, path)) {
g_critical("failed to initialize guest agent channel");
goto out_bad;
}
g_main_loop_run(ga_state->main_loop);
ga_command_state_cleanup_all(ga_state->command_state);
ga_channel_free(ga_state->channel);
if (daemonize) {
unlink(pidfile);
}
return 0;
out_bad:
if (daemonize) {
unlink(pidfile);
}
return EXIT_FAILURE;
}
Reference in New Issue View Git Blame Copy Permalink