diff options
Diffstat (limited to 'qemu/qga/main.c')
| -rw-r--r-- | qemu/qga/main.c | 1206 |
1 files changed, 1206 insertions, 0 deletions
diff --git a/qemu/qga/main.c b/qemu/qga/main.c new file mode 100644 index 000000000..791982ef0 --- /dev/null +++ b/qemu/qga/main.c @@ -0,0 +1,1206 @@ +/* + * 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 <glib/gstdio.h> +#ifndef _WIN32 +#include <syslog.h> +#include <sys/wait.h> +#include <sys/stat.h> +#endif +#include "qapi/qmp/json-streamer.h" +#include "qapi/qmp/json-parser.h" +#include "qapi/qmp/qint.h" +#include "qapi/qmp/qjson.h" +#include "qga/guest-agent-core.h" +#include "qemu/module.h" +#include "signal.h" +#include "qapi/qmp/qerror.h" +#include "qapi/qmp/dispatch.h" +#include "qga/channel.h" +#include "qemu/bswap.h" +#ifdef _WIN32 +#include "qga/service-win32.h" +#include "qga/vss-win32.h" +#endif +#ifdef __linux__ +#include <linux/fs.h> +#ifdef FIFREEZE +#define CONFIG_FSFREEZE +#endif +#endif + +#ifndef _WIN32 +#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0" +#define QGA_STATE_RELATIVE_DIR "run" +#define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0" +#else +#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0" +#define QGA_STATE_RELATIVE_DIR "qemu-ga" +#define QGA_SERIAL_PATH_DEFAULT "COM1" +#endif +#ifdef CONFIG_FSFREEZE +#define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook" +#endif +#define QGA_SENTINEL_BYTE 0xFF + +static struct { + const char *state_dir; + const char *pidfile; +} dfl_pathnames; + +typedef struct GAPersistentState { +#define QGA_PSTATE_DEFAULT_FD_COUNTER 1000 + int64_t fd_counter; +} GAPersistentState; + +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; +#ifdef _WIN32 + GAService service; +#endif + bool delimit_response; + bool frozen; + GList *blacklist; + const char *state_filepath_isfrozen; + struct { + const char *log_filepath; + const char *pid_filepath; + } deferred_options; +#ifdef CONFIG_FSFREEZE + const char *fsfreeze_hook; +#endif + const gchar *pstate_filepath; + GAPersistentState pstate; +}; + +struct GAState *ga_state; + +/* commands that are safe to issue while filesystems are frozen */ +static const char *ga_freeze_whitelist[] = { + "guest-ping", + "guest-info", + "guest-sync", + "guest-sync-delimited", + "guest-fsfreeze-status", + "guest-fsfreeze-thaw", + NULL +}; + +#ifdef _WIN32 +DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data, + LPVOID ctx); +VOID WINAPI service_main(DWORD argc, TCHAR *argv[]); +#endif + +static void +init_dfl_pathnames(void) +{ + g_assert(dfl_pathnames.state_dir == NULL); + g_assert(dfl_pathnames.pidfile == NULL); + dfl_pathnames.state_dir = qemu_get_local_state_pathname( + QGA_STATE_RELATIVE_DIR); + dfl_pathnames.pidfile = qemu_get_local_state_pathname( + QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid"); +} + +static void quit_handler(int sig) +{ + /* if we're frozen, don't exit unless we're absolutely forced to, + * because it's basically impossible for graceful exit to complete + * unless all log/pid files are on unfreezable filesystems. there's + * also a very likely chance killing the agent before unfreezing + * the filesystems is a mistake (or will be viewed as one later). + */ + if (ga_is_frozen(ga_state)) { + return; + } + 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); + } +} + +#ifndef _WIN32 +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)); + } + ret = sigaction(SIGTERM, &sigact, NULL); + if (ret == -1) { + g_error("error configuring signal handler: %s", strerror(errno)); + } + + return true; +} + +/* TODO: use this in place of all post-fork() fclose(std*) callers */ +void reopen_fd_to_null(int fd) +{ + int nullfd; + + nullfd = open("/dev/null", O_RDWR); + if (nullfd < 0) { + return; + } + + dup2(nullfd, fd); + + if (nullfd != fd) { + close(nullfd); + } +} +#endif + +static void usage(const char *cmd) +{ + printf( +"Usage: %s [-m <method> -p <path>] [<options>]\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 (the default for virtio-serial is:\n" +" %s,\n" +" the default for isa-serial is:\n" +" %s)\n" +" -l, --logfile set logfile path, logs to stderr by default\n" +" -f, --pidfile specify pidfile (default is %s)\n" +#ifdef CONFIG_FSFREEZE +" -F, --fsfreeze-hook\n" +" enable fsfreeze hook. Accepts an optional argument that\n" +" specifies script to run on freeze/thaw. Script will be\n" +" called with 'freeze'/'thaw' arguments accordingly.\n" +" (default is %s)\n" +" If using -F with an argument, do not follow -F with a\n" +" space.\n" +" (for example: -F/var/run/fsfreezehook.sh)\n" +#endif +" -t, --statedir specify dir to store state information (absolute paths\n" +" only, 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" +#ifdef _WIN32 +" -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n" +#endif +" -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n" +" to list available RPCs)\n" +" -h, --help display this help and exit\n" +"\n" +"Report bugs to <mdroth@linux.vnet.ibm.com>\n" + , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT, + dfl_pathnames.pidfile, +#ifdef CONFIG_FSFREEZE + QGA_FSFREEZE_HOOK_DEFAULT, +#endif + dfl_pathnames.state_dir); +} + +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; +#ifndef _WIN32 + if (g_strcmp0(domain, "syslog") == 0) { + syslog(LOG_INFO, "%s: %s", level_str, msg); + } else if (level & s->log_level) { +#else + if (level & s->log_level) { +#endif + 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); + } +} + +void ga_set_response_delimited(GAState *s) +{ + s->delimit_response = true; +} + +static FILE *ga_open_logfile(const char *logfile) +{ + FILE *f; + + f = fopen(logfile, "a"); + if (!f) { + return NULL; + } + + qemu_set_cloexec(fileno(f)); + return f; +} + +#ifndef _WIN32 +static bool ga_open_pidfile(const char *pidfile) +{ + int pidfd; + char pidstr[32]; + + pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR); + if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) { + g_critical("Cannot lock pid file, %s", strerror(errno)); + if (pidfd != -1) { + close(pidfd); + } + return false; + } + + if (ftruncate(pidfd, 0)) { + g_critical("Failed to truncate pid file"); + goto fail; + } + snprintf(pidstr, sizeof(pidstr), "%d\n", getpid()); + if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) { + g_critical("Failed to write pid file"); + goto fail; + } + + /* keep pidfile open & locked forever */ + return true; + +fail: + unlink(pidfile); + close(pidfd); + return false; +} +#else /* _WIN32 */ +static bool ga_open_pidfile(const char *pidfile) +{ + return true; +} +#endif + +static gint ga_strcmp(gconstpointer str1, gconstpointer str2) +{ + return strcmp(str1, str2); +} + +/* disable commands that aren't safe for fsfreeze */ +static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque) +{ + bool whitelisted = false; + int i = 0; + const char *name = qmp_command_name(cmd); + + while (ga_freeze_whitelist[i] != NULL) { + if (strcmp(name, ga_freeze_whitelist[i]) == 0) { + whitelisted = true; + } + i++; + } + if (!whitelisted) { + g_debug("disabling command: %s", name); + qmp_disable_command(name); + } +} + +/* [re-]enable all commands, except those explicitly blacklisted by user */ +static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque) +{ + GList *blacklist = opaque; + const char *name = qmp_command_name(cmd); + + if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL && + !qmp_command_is_enabled(cmd)) { + g_debug("enabling command: %s", name); + qmp_enable_command(name); + } +} + +static bool ga_create_file(const char *path) +{ + int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR); + if (fd == -1) { + g_warning("unable to open/create file %s: %s", path, strerror(errno)); + return false; + } + close(fd); + return true; +} + +static bool ga_delete_file(const char *path) +{ + int ret = unlink(path); + if (ret == -1) { + g_warning("unable to delete file: %s: %s", path, strerror(errno)); + return false; + } + + return true; +} + +bool ga_is_frozen(GAState *s) +{ + return s->frozen; +} + +void ga_set_frozen(GAState *s) +{ + if (ga_is_frozen(s)) { + return; + } + /* disable all non-whitelisted (for frozen state) commands */ + qmp_for_each_command(ga_disable_non_whitelisted, NULL); + g_warning("disabling logging due to filesystem freeze"); + ga_disable_logging(s); + s->frozen = true; + if (!ga_create_file(s->state_filepath_isfrozen)) { + g_warning("unable to create %s, fsfreeze may not function properly", + s->state_filepath_isfrozen); + } +} + +void ga_unset_frozen(GAState *s) +{ + if (!ga_is_frozen(s)) { + return; + } + + /* if we delayed creation/opening of pid/log files due to being + * in a frozen state at start up, do it now + */ + if (s->deferred_options.log_filepath) { + s->log_file = ga_open_logfile(s->deferred_options.log_filepath); + if (!s->log_file) { + s->log_file = stderr; + } + s->deferred_options.log_filepath = NULL; + } + ga_enable_logging(s); + g_warning("logging re-enabled due to filesystem unfreeze"); + if (s->deferred_options.pid_filepath) { + if (!ga_open_pidfile(s->deferred_options.pid_filepath)) { + g_warning("failed to create/open pid file"); + } + s->deferred_options.pid_filepath = NULL; + } + + /* enable all disabled, non-blacklisted commands */ + qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist); + s->frozen = false; + if (!ga_delete_file(s->state_filepath_isfrozen)) { + g_warning("unable to delete %s, fsfreeze may not function properly", + s->state_filepath_isfrozen); + } +} + +#ifdef CONFIG_FSFREEZE +const char *ga_fsfreeze_hook(GAState *s) +{ + return s->fsfreeze_hook; +} +#endif + +static void become_daemon(const char *pidfile) +{ +#ifndef _WIN32 + pid_t pid, sid; + + pid = fork(); + if (pid < 0) { + exit(EXIT_FAILURE); + } + if (pid > 0) { + exit(EXIT_SUCCESS); + } + + if (pidfile) { + if (!ga_open_pidfile(pidfile)) { + g_critical("failed to create pidfile"); + exit(EXIT_FAILURE); + } + } + + umask(S_IRWXG | S_IRWXO); + sid = setsid(); + if (sid < 0) { + goto fail; + } + if ((chdir("/")) < 0) { + goto fail; + } + + reopen_fd_to_null(STDIN_FILENO); + reopen_fd_to_null(STDOUT_FILENO); + reopen_fd_to_null(STDERR_FILENO); + return; + +fail: + if (pidfile) { + unlink(pidfile); + } + g_critical("failed to daemonize"); + exit(EXIT_FAILURE); +#endif +} + +static int send_response(GAState *s, QObject *payload) +{ + const char *buf; + QString *payload_qstr, *response_qstr; + GIOStatus status; + + g_assert(payload && s->channel); + + payload_qstr = qobject_to_json(payload); + if (!payload_qstr) { + return -EINVAL; + } + + if (s->delimit_response) { + s->delimit_response = false; + response_qstr = qstring_new(); + qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE); + qstring_append(response_qstr, qstring_get_str(payload_qstr)); + QDECREF(payload_qstr); + } else { + response_qstr = payload_qstr; + } + + qstring_append_chr(response_qstr, '\n'); + buf = qstring_get_str(response_qstr); + status = ga_channel_write_all(s->channel, buf, strlen(buf)); + QDECREF(response_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); + } +} + +/* 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_setg(&err, QERR_JSON_PARSING); + } else { + g_warning("failed to parse event: %s", error_get_pretty(err)); + } + qdict_put_obj(qdict, "error", qmp_build_error_object(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_setg(&err, QERR_UNSUPPORTED); + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); + error_free(err); + } + ret = send_response(s, QOBJECT(qdict)); + if (ret < 0) { + 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; + } + /* fall through */ + 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 ) { + /* try the default path for the virtio-serial port */ + path = QGA_VIRTIO_PATH_DEFAULT; + } else if (strcmp(method, "isa-serial") == 0){ + /* try the default path for the serial port - COM1 */ + path = QGA_SERIAL_PATH_DEFAULT; + } else { + g_critical("must specify a path for this channel"); + return false; + } + } + + 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; +} + +#ifdef _WIN32 +DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data, + LPVOID ctx) +{ + DWORD ret = NO_ERROR; + GAService *service = &ga_state->service; + + switch (ctrl) + { + case SERVICE_CONTROL_STOP: + case SERVICE_CONTROL_SHUTDOWN: + quit_handler(SIGTERM); + service->status.dwCurrentState = SERVICE_STOP_PENDING; + SetServiceStatus(service->status_handle, &service->status); + break; + + default: + ret = ERROR_CALL_NOT_IMPLEMENTED; + } + return ret; +} + +VOID WINAPI service_main(DWORD argc, TCHAR *argv[]) +{ + GAService *service = &ga_state->service; + + service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME, + service_ctrl_handler, NULL); + + if (service->status_handle == 0) { + g_critical("Failed to register extended requests function!\n"); + return; + } + + service->status.dwServiceType = SERVICE_WIN32; + service->status.dwCurrentState = SERVICE_RUNNING; + service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN; + service->status.dwWin32ExitCode = NO_ERROR; + service->status.dwServiceSpecificExitCode = NO_ERROR; + service->status.dwCheckPoint = 0; + service->status.dwWaitHint = 0; + SetServiceStatus(service->status_handle, &service->status); + + g_main_loop_run(ga_state->main_loop); + + service->status.dwCurrentState = SERVICE_STOPPED; + SetServiceStatus(service->status_handle, &service->status); +} +#endif + +static void set_persistent_state_defaults(GAPersistentState *pstate) +{ + g_assert(pstate); + pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER; +} + +static void persistent_state_from_keyfile(GAPersistentState *pstate, + GKeyFile *keyfile) +{ + g_assert(pstate); + g_assert(keyfile); + /* if any fields are missing, either because the file was tampered with + * by agents of chaos, or because the field wasn't present at the time the + * file was created, the best we can ever do is start over with the default + * values. so load them now, and ignore any errors in accessing key-value + * pairs + */ + set_persistent_state_defaults(pstate); + + if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) { + pstate->fd_counter = + g_key_file_get_integer(keyfile, "global", "fd_counter", NULL); + } +} + +static void persistent_state_to_keyfile(const GAPersistentState *pstate, + GKeyFile *keyfile) +{ + g_assert(pstate); + g_assert(keyfile); + + g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter); +} + +static gboolean write_persistent_state(const GAPersistentState *pstate, + const gchar *path) +{ + GKeyFile *keyfile = g_key_file_new(); + GError *gerr = NULL; + gboolean ret = true; + gchar *data = NULL; + gsize data_len; + + g_assert(pstate); + + persistent_state_to_keyfile(pstate, keyfile); + data = g_key_file_to_data(keyfile, &data_len, &gerr); + if (gerr) { + g_critical("failed to convert persistent state to string: %s", + gerr->message); + ret = false; + goto out; + } + + g_file_set_contents(path, data, data_len, &gerr); + if (gerr) { + g_critical("failed to write persistent state to %s: %s", + path, gerr->message); + ret = false; + goto out; + } + +out: + if (gerr) { + g_error_free(gerr); + } + if (keyfile) { + g_key_file_free(keyfile); + } + g_free(data); + return ret; +} + +static gboolean read_persistent_state(GAPersistentState *pstate, + const gchar *path, gboolean frozen) +{ + GKeyFile *keyfile = NULL; + GError *gerr = NULL; + struct stat st; + gboolean ret = true; + + g_assert(pstate); + + if (stat(path, &st) == -1) { + /* it's okay if state file doesn't exist, but any other error + * indicates a permissions issue or some other misconfiguration + * that we likely won't be able to recover from. + */ + if (errno != ENOENT) { + g_critical("unable to access state file at path %s: %s", + path, strerror(errno)); + ret = false; + goto out; + } + + /* file doesn't exist. initialize state to default values and + * attempt to save now. (we could wait till later when we have + * modified state we need to commit, but if there's a problem, + * such as a missing parent directory, we want to catch it now) + * + * there is a potential scenario where someone either managed to + * update the agent from a version that didn't use a key store + * while qemu-ga thought the filesystem was frozen, or + * deleted the key store prior to issuing a fsfreeze, prior + * to restarting the agent. in this case we go ahead and defer + * initial creation till we actually have modified state to + * write, otherwise fail to recover from freeze. + */ + set_persistent_state_defaults(pstate); + if (!frozen) { + ret = write_persistent_state(pstate, path); + if (!ret) { + g_critical("unable to create state file at path %s", path); + ret = false; + goto out; + } + } + ret = true; + goto out; + } + + keyfile = g_key_file_new(); + g_key_file_load_from_file(keyfile, path, 0, &gerr); + if (gerr) { + g_critical("error loading persistent state from path: %s, %s", + path, gerr->message); + ret = false; + goto out; + } + + persistent_state_from_keyfile(pstate, keyfile); + +out: + if (keyfile) { + g_key_file_free(keyfile); + } + if (gerr) { + g_error_free(gerr); + } + + return ret; +} + +int64_t ga_get_fd_handle(GAState *s, Error **errp) +{ + int64_t handle; + + g_assert(s->pstate_filepath); + /* we blacklist commands and avoid operations that potentially require + * writing to disk when we're in a frozen state. this includes opening + * new files, so we should never get here in that situation + */ + g_assert(!ga_is_frozen(s)); + + handle = s->pstate.fd_counter++; + + /* This should never happen on a reasonable timeframe, as guest-file-open + * would have to be issued 2^63 times */ + if (s->pstate.fd_counter == INT64_MAX) { + abort(); + } + + if (!write_persistent_state(&s->pstate, s->pstate_filepath)) { + error_setg(errp, "failed to commit persistent state to disk"); + return -1; + } + + return handle; +} + +static void ga_print_cmd(QmpCommand *cmd, void *opaque) +{ + printf("%s\n", qmp_command_name(cmd)); +} + +int main(int argc, char **argv) +{ + const char *sopt = "hVvdm:p:l:f:F::b:s:t:"; + const char *method = NULL, *path = NULL; + const char *log_filepath = NULL; + const char *pid_filepath; +#ifdef CONFIG_FSFREEZE + const char *fsfreeze_hook = NULL; +#endif + const char *state_dir; +#ifdef _WIN32 + const char *service = NULL; +#endif + const struct option lopt[] = { + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + { "logfile", 1, NULL, 'l' }, + { "pidfile", 1, NULL, 'f' }, +#ifdef CONFIG_FSFREEZE + { "fsfreeze-hook", 2, NULL, 'F' }, +#endif + { "verbose", 0, NULL, 'v' }, + { "method", 1, NULL, 'm' }, + { "path", 1, NULL, 'p' }, + { "daemonize", 0, NULL, 'd' }, + { "blacklist", 1, NULL, 'b' }, +#ifdef _WIN32 + { "service", 1, NULL, 's' }, +#endif + { "statedir", 1, NULL, 't' }, + { 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; + GList *blacklist = NULL; + GAState *s; + + module_call_init(MODULE_INIT_QAPI); + + init_dfl_pathnames(); + pid_filepath = dfl_pathnames.pidfile; + state_dir = dfl_pathnames.state_dir; + + 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_filepath = optarg; + break; + case 'f': + pid_filepath = optarg; + break; +#ifdef CONFIG_FSFREEZE + case 'F': + fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT; + break; +#endif + case 't': + state_dir = optarg; + break; + case 'v': + /* enable all log levels */ + log_level = G_LOG_LEVEL_MASK; + break; + case 'V': + printf("QEMU Guest Agent %s\n", QEMU_VERSION); + return 0; + case 'd': + daemonize = 1; + break; + case 'b': { + if (is_help_option(optarg)) { + qmp_for_each_command(ga_print_cmd, NULL); + return 0; + } + for (j = 0, i = 0, len = strlen(optarg); i < len; i++) { + if (optarg[i] == ',') { + optarg[i] = 0; + blacklist = g_list_append(blacklist, &optarg[j]); + j = i + 1; + } + } + if (j < i) { + blacklist = g_list_append(blacklist, &optarg[j]); + } + break; + } +#ifdef _WIN32 + case 's': + service = optarg; + if (strcmp(service, "install") == 0) { + const char *fixed_state_dir; + + /* If the user passed the "-t" option, we save that state dir + * in the service. Otherwise we let the service fetch the state + * dir from the environment when it starts. + */ + fixed_state_dir = (state_dir == dfl_pathnames.state_dir) ? + NULL : + state_dir; + if (ga_install_vss_provider()) { + return EXIT_FAILURE; + } + if (ga_install_service(path, log_filepath, fixed_state_dir)) { + return EXIT_FAILURE; + } + return 0; + } else if (strcmp(service, "uninstall") == 0) { + ga_uninstall_vss_provider(); + return ga_uninstall_service(); + } else if (strcmp(service, "vss-install") == 0) { + if (ga_install_vss_provider()) { + return EXIT_FAILURE; + } + return EXIT_SUCCESS; + } else if (strcmp(service, "vss-uninstall") == 0) { + ga_uninstall_vss_provider(); + return EXIT_SUCCESS; + } else { + printf("Unknown service command.\n"); + return EXIT_FAILURE; + } + break; +#endif + case 'h': + usage(argv[0]); + return 0; + case '?': + g_print("Unknown option, try '%s --help' for more information.\n", + argv[0]); + return EXIT_FAILURE; + } + } + +#ifdef _WIN32 + /* On win32 the state directory is application specific (be it the default + * or a user override). We got past the command line parsing; let's create + * the directory (with any intermediate directories). If we run into an + * error later on, we won't try to clean up the directory, it is considered + * persistent. + */ + if (g_mkdir_with_parents(state_dir, S_IRWXU) == -1) { + g_critical("unable to create (an ancestor of) the state directory" + " '%s': %s", state_dir, strerror(errno)); + return EXIT_FAILURE; + } +#endif + + s = g_malloc0(sizeof(GAState)); + s->log_level = log_level; + s->log_file = stderr; +#ifdef CONFIG_FSFREEZE + s->fsfreeze_hook = fsfreeze_hook; +#endif + g_log_set_default_handler(ga_log, s); + g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); + ga_enable_logging(s); + s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen", + state_dir); + s->pstate_filepath = g_strdup_printf("%s/qga.state", state_dir); + s->frozen = false; + +#ifndef _WIN32 + /* check if a previous instance of qemu-ga exited with filesystems' state + * marked as frozen. this could be a stale value (a non-qemu-ga process + * or reboot may have since unfrozen them), but better to require an + * uneeded unfreeze than to risk hanging on start-up + */ + struct stat st; + if (stat(s->state_filepath_isfrozen, &st) == -1) { + /* it's okay if the file doesn't exist, but if we can't access for + * some other reason, such as permissions, there's a configuration + * that needs to be addressed. so just bail now before we get into + * more trouble later + */ + if (errno != ENOENT) { + g_critical("unable to access state file at path %s: %s", + s->state_filepath_isfrozen, strerror(errno)); + return EXIT_FAILURE; + } + } else { + g_warning("previous instance appears to have exited with frozen" + " filesystems. deferring logging/pidfile creation and" + " disabling non-fsfreeze-safe commands until" + " guest-fsfreeze-thaw is issued, or filesystems are" + " manually unfrozen and the file %s is removed", + s->state_filepath_isfrozen); + s->frozen = true; + } +#endif + + if (ga_is_frozen(s)) { + if (daemonize) { + /* delay opening/locking of pidfile till filesystems are unfrozen */ + s->deferred_options.pid_filepath = pid_filepath; + become_daemon(NULL); + } + if (log_filepath) { + /* delay opening the log file till filesystems are unfrozen */ + s->deferred_options.log_filepath = log_filepath; + } + ga_disable_logging(s); + qmp_for_each_command(ga_disable_non_whitelisted, NULL); + } else { + if (daemonize) { + become_daemon(pid_filepath); + } + if (log_filepath) { + FILE *log_file = ga_open_logfile(log_filepath); + if (!log_file) { + g_critical("unable to open specified log file: %s", + strerror(errno)); + goto out_bad; + } + s->log_file = log_file; + } + } + + /* load persistent state from disk */ + if (!read_persistent_state(&s->pstate, + s->pstate_filepath, + ga_is_frozen(s))) { + g_critical("failed to load persistent state"); + goto out_bad; + } + + blacklist = ga_command_blacklist_init(blacklist); + if (blacklist) { + s->blacklist = blacklist; + do { + g_debug("disabling command: %s", (char *)blacklist->data); + qmp_disable_command(blacklist->data); + blacklist = g_list_next(blacklist); + } while (blacklist); + } + 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; +#ifndef _WIN32 + if (!register_signal_handlers()) { + g_critical("failed to register signal handlers"); + goto out_bad; + } +#endif + + 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; + } +#ifndef _WIN32 + g_main_loop_run(ga_state->main_loop); +#else + if (daemonize) { + SERVICE_TABLE_ENTRY service_table[] = { + { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } }; + StartServiceCtrlDispatcher(service_table); + } else { + g_main_loop_run(ga_state->main_loop); + } +#endif + + ga_command_state_cleanup_all(ga_state->command_state); + ga_channel_free(ga_state->channel); + + if (daemonize) { + unlink(pid_filepath); + } + return 0; + +out_bad: + if (daemonize) { + unlink(pid_filepath); + } + return EXIT_FAILURE; +} |