aboutsummaryrefslogtreecommitdiff
path: root/qemu-ga.c
diff options
context:
space:
mode:
authorMichael Roth <mdroth@linux.vnet.ibm.com>2011-07-20 15:19:37 -0500
committerLuiz Capitulino <lcapitulino@gmail.com>2011-07-21 16:48:15 -0300
commit48ff7a625b3611d075d8798585df86455bb2d1fd (patch)
tree890d0c527a4c403b34ece7b02cc1c58a351bbd55 /qemu-ga.c
parent13a286d57bb5f50dbceea1fc45060a69bcb23fd1 (diff)
downloadqemu-48ff7a625b3611d075d8798585df86455bb2d1fd.zip
qemu-48ff7a625b3611d075d8798585df86455bb2d1fd.tar.gz
qemu-48ff7a625b3611d075d8798585df86455bb2d1fd.tar.bz2
guest agent: qemu-ga daemon
This is the actual guest daemon, it listens for requests over a virtio-serial/isa-serial/unix socket channel and routes them through to dispatch routines, and writes the results back to the channel in a manner similar to QMP. A shorthand invocation: qemu-ga -d Is equivalent to: qemu-ga -m virtio-serial -p /dev/virtio-ports/org.qemu.guest_agent.0 \ -f /var/run/qemu-ga.pid -d Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>
Diffstat (limited to 'qemu-ga.c')
-rw-r--r--qemu-ga.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/qemu-ga.c b/qemu-ga.c
new file mode 100644
index 0000000..1f3585c
--- /dev/null
+++ b/qemu-ga.c
@@ -0,0 +1,650 @@
+/*
+ * 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 <gio/gio.h>
+#include <getopt.h>
+#include <termios.h>
+#include <syslog.h>
+#include "qemu_socket.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"
+
+#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
+#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
+#define QGA_BAUDRATE_DEFAULT B38400 /* for isa-serial channels */
+#define QGA_TIMEOUT_DEFAULT 30*1000 /* ms */
+
+struct GAState {
+ JSONMessageParser parser;
+ GMainLoop *main_loop;
+ GSocket *conn_sock;
+ GIOChannel *conn_channel;
+ GSocket *listen_sock;
+ GIOChannel *listen_channel;
+ const char *path;
+ const char *method;
+ 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("recieved signal num %d, quitting", sig);
+
+ if (g_main_loop_is_running(ga_state->main_loop)) {
+ g_main_loop_quit(ga_state->main_loop);
+ }
+}
+
+static void 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));
+ exit(EXIT_FAILURE);
+ }
+ ret = sigaction(SIGTERM, &sigact, NULL);
+ if (ret == -1) {
+ g_error("error configuring signal handler: %s", strerror(errno));
+ }
+}
+
+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"
+" -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 void conn_channel_close(GAState *s);
+
+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 (g_strcmp0(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 conn_channel_send_buf(GIOChannel *channel, const char *buf,
+ gsize count)
+{
+ GError *err = NULL;
+ gsize written = 0;
+ GIOStatus status;
+
+ while (count) {
+ status = g_io_channel_write_chars(channel, buf, count, &written, &err);
+ g_debug("sending data, count: %d", (int)count);
+ if (err != NULL) {
+ g_warning("error sending newline: %s", err->message);
+ return err->code;
+ }
+ if (status == G_IO_STATUS_ERROR || status == G_IO_STATUS_EOF) {
+ return -EPIPE;
+ }
+
+ if (status == G_IO_STATUS_NORMAL) {
+ count -= written;
+ }
+ }
+
+ return 0;
+}
+
+static int conn_channel_send_payload(GIOChannel *channel, QObject *payload)
+{
+ int ret = 0;
+ const char *buf;
+ QString *payload_qstr;
+ GError *err = NULL;
+
+ g_assert(payload && channel);
+
+ payload_qstr = qobject_to_json(payload);
+ if (!payload_qstr) {
+ return -EINVAL;
+ }
+
+ qstring_append_chr(payload_qstr, '\n');
+ buf = qstring_get_str(payload_qstr);
+ ret = conn_channel_send_buf(channel, buf, strlen(buf));
+ if (ret) {
+ goto out_free;
+ }
+
+ g_io_channel_flush(channel, &err);
+ if (err != NULL) {
+ g_warning("error flushing payload: %s", err->message);
+ ret = err->code;
+ goto out_free;
+ }
+
+out_free:
+ QDECREF(payload_qstr);
+ if (err) {
+ g_error_free(err);
+ }
+ return ret;
+}
+
+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 = conn_channel_send_payload(s->conn_channel, rsp);
+ if (ret) {
+ g_warning("error sending payload: %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 = conn_channel_send_payload(s->conn_channel, QOBJECT(qdict));
+ if (ret) {
+ g_warning("error sending payload: %s", strerror(ret));
+ }
+ }
+
+ QDECREF(qdict);
+}
+
+static gboolean conn_channel_read(GIOChannel *channel, GIOCondition condition,
+ gpointer data)
+{
+ GAState *s = data;
+ gchar buf[1024];
+ gsize count;
+ GError *err = NULL;
+ memset(buf, 0, 1024);
+ GIOStatus status = g_io_channel_read_chars(channel, buf, 1024,
+ &count, &err);
+ if (err != NULL) {
+ g_warning("error reading channel: %s", err->message);
+ conn_channel_close(s);
+ g_error_free(err);
+ return false;
+ }
+ switch (status) {
+ case G_IO_STATUS_ERROR:
+ g_warning("problem");
+ return false;
+ case G_IO_STATUS_NORMAL:
+ g_debug("read data, count: %d, data: %s", (int)count, buf);
+ json_message_parser_feed(&s->parser, (char *)buf, (int)count);
+ 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;
+ case G_IO_STATUS_EOF:
+ g_debug("received EOF");
+ conn_channel_close(s);
+ if (s->virtio) {
+ return true;
+ }
+ return false;
+ default:
+ g_warning("unknown channel read status, closing");
+ conn_channel_close(s);
+ return false;
+ }
+ return true;
+}
+
+static int conn_channel_add(GAState *s, int fd)
+{
+ GIOChannel *conn_channel;
+ GError *err = NULL;
+
+ g_assert(s && !s->conn_channel);
+ conn_channel = g_io_channel_unix_new(fd);
+ g_assert(conn_channel);
+ g_io_channel_set_encoding(conn_channel, NULL, &err);
+ if (err != NULL) {
+ g_warning("error setting channel encoding to binary");
+ g_error_free(err);
+ return -1;
+ }
+ g_io_add_watch(conn_channel, G_IO_IN | G_IO_HUP,
+ conn_channel_read, s);
+ s->conn_channel = conn_channel;
+ return 0;
+}
+
+static gboolean listen_channel_accept(GIOChannel *channel,
+ GIOCondition condition, gpointer data)
+{
+ GAState *s = data;
+ GError *err = NULL;
+ g_assert(channel != NULL);
+ int ret;
+ bool accepted = false;
+
+ s->conn_sock = g_socket_accept(s->listen_sock, NULL, &err);
+ if (err != NULL) {
+ g_warning("error converting fd to gsocket: %s", err->message);
+ g_error_free(err);
+ goto out;
+ }
+ ret = conn_channel_add(s, g_socket_get_fd(s->conn_sock));
+ if (ret) {
+ g_warning("error setting up connection");
+ goto out;
+ }
+ accepted = true;
+
+out:
+ /* only accept 1 connection at a time */
+ return !accepted;
+}
+
+/* start polling for readable events on listen fd, new==true
+ * indicates we should use the existing s->listen_channel
+ */
+static int listen_channel_add(GAState *s, int listen_fd, bool new)
+{
+ GError *err = NULL;
+
+ if (new) {
+ s->listen_channel = g_io_channel_unix_new(listen_fd);
+ if (s->listen_sock) {
+ g_object_unref(s->listen_sock);
+ }
+ s->listen_sock = g_socket_new_from_fd(listen_fd, &err);
+ if (err != NULL) {
+ g_warning("error converting fd to gsocket: %s", err->message);
+ g_error_free(err);
+ return -1;
+ }
+ }
+ g_io_add_watch(s->listen_channel, G_IO_IN,
+ listen_channel_accept, s);
+ return 0;
+}
+
+/* cleanup state for closed connection/session, start accepting new
+ * connections if we're in listening mode
+ */
+static void conn_channel_close(GAState *s)
+{
+ if (strcmp(s->method, "unix-listen") == 0) {
+ g_io_channel_shutdown(s->conn_channel, true, NULL);
+ g_object_unref(s->conn_sock);
+ s->conn_sock = NULL;
+ listen_channel_add(s, 0, false);
+ } else if (strcmp(s->method, "virtio-serial") == 0) {
+ /* we spin on EOF for virtio-serial, so back off a bit. also,
+ * dont close the connection in this case, it'll resume normal
+ * operation when another process connects to host chardev
+ */
+ usleep(100*1000);
+ goto out_noclose;
+ }
+ g_io_channel_unref(s->conn_channel);
+ s->conn_channel = NULL;
+out_noclose:
+ return;
+}
+
+static void init_guest_agent(GAState *s)
+{
+ struct termios tio;
+ int ret, fd;
+
+ if (s->method == NULL) {
+ /* try virtio-serial as our default */
+ s->method = "virtio-serial";
+ }
+
+ if (s->path == NULL) {
+ if (strcmp(s->method, "virtio-serial") != 0) {
+ g_critical("must specify a path for this channel");
+ exit(EXIT_FAILURE);
+ }
+ /* try the default path for the virtio-serial port */
+ s->path = QGA_VIRTIO_PATH_DEFAULT;
+ }
+
+ if (strcmp(s->method, "virtio-serial") == 0) {
+ s->virtio = true;
+ fd = qemu_open(s->path, O_RDWR | O_NONBLOCK | O_ASYNC);
+ if (fd == -1) {
+ g_critical("error opening channel: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ ret = conn_channel_add(s, fd);
+ if (ret) {
+ g_critical("error adding channel to main loop");
+ exit(EXIT_FAILURE);
+ }
+ } else if (strcmp(s->method, "isa-serial") == 0) {
+ fd = qemu_open(s->path, O_RDWR | O_NOCTTY);
+ if (fd == -1) {
+ g_critical("error opening channel: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ tcgetattr(fd, &tio);
+ /* set up serial port for non-canonical, dumb byte streaming */
+ tio.c_iflag &= ~(IGNBRK | BRKINT | IGNPAR | PARMRK | INPCK | ISTRIP |
+ INLCR | IGNCR | ICRNL | IXON | IXOFF | IXANY |
+ IMAXBEL);
+ tio.c_oflag = 0;
+ tio.c_lflag = 0;
+ tio.c_cflag |= QGA_BAUDRATE_DEFAULT;
+ /* 1 available byte min or reads will block (we'll set non-blocking
+ * elsewhere, else we have to deal with read()=0 instead)
+ */
+ tio.c_cc[VMIN] = 1;
+ tio.c_cc[VTIME] = 0;
+ /* flush everything waiting for read/xmit, it's garbage at this point */
+ tcflush(fd, TCIFLUSH);
+ tcsetattr(fd, TCSANOW, &tio);
+ ret = conn_channel_add(s, fd);
+ if (ret) {
+ g_error("error adding channel to main loop");
+ }
+ } else if (strcmp(s->method, "unix-listen") == 0) {
+ fd = unix_listen(s->path, NULL, strlen(s->path));
+ if (fd == -1) {
+ g_critical("error opening path: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ ret = listen_channel_add(s, fd, true);
+ if (ret) {
+ g_critical("error binding/listening to specified socket");
+ exit(EXIT_FAILURE);
+ }
+ } else {
+ g_critical("unsupported channel method/type: %s", s->method);
+ exit(EXIT_FAILURE);
+ }
+
+ json_message_parser_init(&s->parser, process_event);
+ s->main_loop = g_main_loop_new(NULL, false);
+}
+
+int main(int argc, char **argv)
+{
+ const char *sopt = "hVvdm:p:l:f:";
+ 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' },
+ { NULL, 0, NULL, 0 }
+ };
+ int opt_ind = 0, ch, daemonize = 0;
+ GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
+ FILE *log_file = stderr;
+ GAState *s;
+
+ 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 '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);
+ }
+
+ g_type_init();
+ g_thread_init(NULL);
+
+ s = qemu_mallocz(sizeof(GAState));
+ s->conn_channel = NULL;
+ s->path = path;
+ s->method = method;
+ 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;
+ ga_state = s;
+
+ module_call_init(MODULE_INIT_QAPI);
+ init_guest_agent(ga_state);
+ register_signal_handlers();
+
+ g_main_loop_run(ga_state->main_loop);
+
+ unlink(pidfile);
+
+ return 0;
+}