X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-ga.c;h=9b59a524619cab1f25ff3ae87a1ee2227785f1be;hb=refs%2Ftags%2Fv1.3.0-rc0;hp=ba355d878355dae9b44e249e42545e5b4cc4e9af;hpb=b3e54c689c0630e9a79f33a8b03c71296334fd36;p=qemu.git diff --git a/qemu-ga.c b/qemu-ga.c index ba355d878..9b59a5246 100644 --- a/qemu-ga.c +++ b/qemu-ga.c @@ -17,6 +17,8 @@ #include #ifndef _WIN32 #include +#include +#include #endif #include "json-streamer.h" #include "json-parser.h" @@ -26,7 +28,6 @@ #include "module.h" #include "signal.h" #include "qerror.h" -#include "error_int.h" #include "qapi/qmp-core.h" #include "qga/channel.h" #ifdef _WIN32 @@ -39,7 +40,9 @@ #else #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0" #endif -#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid" +#define QGA_STATEDIR_DEFAULT CONFIG_QEMU_LOCALSTATEDIR "/run" +#define QGA_PIDFILE_DEFAULT QGA_STATEDIR_DEFAULT "/qemu-ga.pid" +#define QGA_SENTINEL_BYTE 0xFF struct GAState { JSONMessageParser parser; @@ -53,9 +56,27 @@ struct GAState { #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; }; -static struct GAState *ga_state; +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-fsfreeze-status", + "guest-fsfreeze-thaw", + NULL +}; #ifdef _WIN32 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data, @@ -65,6 +86,15 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]); 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)) { @@ -84,40 +114,60 @@ static gboolean register_signal_handlers(void) 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; } + +/* 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 -c \n" +"Usage: %s [-m -p ] []\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" +" -p, --path device/socket path (the default for virtio-serial is:\n" +" %s)\n" " -l, --logfile set logfile path, logs to stderr by default\n" " -f, --pidfile specify pidfile (default is %s)\n" +" -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\n" #endif -" -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"" +" -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 \n" - , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT); + , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT, + QGA_STATEDIR_DEFAULT); } static const char *ga_log_level_str(GLogLevelFlags level) @@ -181,12 +231,180 @@ static void ga_log(const gchar *domain, GLogLevelFlags level, } } +void ga_set_response_delimited(GAState *s) +{ + s->delimit_response = true; +} + #ifndef _WIN32 +static bool ga_open_pidfile(const char *pidfile) +{ + int pidfd; + char pidstr[32]; + + pidfd = 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) || lseek(pidfd, 0, SEEK_SET)) { + 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; + } + + return true; + +fail: + unlink(pidfile); + 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(void) +{ + char **list_head, **list; + bool whitelisted; + int i; + + list_head = list = qmp_get_command_list(); + while (*list != NULL) { + whitelisted = false; + i = 0; + while (ga_freeze_whitelist[i] != NULL) { + if (strcmp(*list, ga_freeze_whitelist[i]) == 0) { + whitelisted = true; + } + i++; + } + if (!whitelisted) { + g_debug("disabling command: %s", *list); + qmp_disable_command(*list); + } + g_free(*list); + list++; + } + g_free(list_head); +} + +/* [re-]enable all commands, except those explicitly blacklisted by user */ +static void ga_enable_non_blacklisted(GList *blacklist) +{ + char **list_head, **list; + + list_head = list = qmp_get_command_list(); + while (*list != NULL) { + if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL && + !qmp_command_is_enabled(*list)) { + g_debug("enabling command: %s", *list); + qmp_enable_command(*list); + } + g_free(*list); + list++; + } + g_free(list_head); +} + +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 */ + ga_disable_non_whitelisted(); + 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 = fopen(s->deferred_options.log_filepath, "a"); + 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 */ + 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); + } +} + static void become_daemon(const char *pidfile) { +#ifndef _WIN32 pid_t pid, sid; - int pidfd; - char *pidstr = NULL; pid = fork(); if (pid < 0) { @@ -196,20 +414,11 @@ static void become_daemon(const char *pidfile) 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; + if (pidfile) { + if (!ga_open_pidfile(pidfile)) { + g_critical("failed to create pidfile"); + exit(EXIT_FAILURE); + } } umask(0); @@ -221,23 +430,24 @@ static void become_daemon(const char *pidfile) goto fail; } - close(STDIN_FILENO); - close(STDOUT_FILENO); - close(STDERR_FILENO); - free(pidstr); + reopen_fd_to_null(STDIN_FILENO); + reopen_fd_to_null(STDOUT_FILENO); + reopen_fd_to_null(STDERR_FILENO); return; fail: - unlink(pidfile); + 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; + QString *payload_qstr, *response_qstr; GIOStatus status; g_assert(payload && s->channel); @@ -247,10 +457,20 @@ static int send_response(GAState *s, QObject *payload) return -EINVAL; } - qstring_append_chr(payload_qstr, '\n'); - buf = qstring_get_str(payload_qstr); + 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(payload_qstr); + QDECREF(response_qstr); if (status != G_IO_STATUS_NORMAL) { return -EIO; } @@ -272,8 +492,6 @@ static void process_command(GAState *s, QDict *req) g_warning("error sending response: %s", strerror(ret)); } qobject_decref(rsp); - } else { - g_warning("error getting response"); } } @@ -299,7 +517,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) } else { g_warning("failed to parse event: %s", error_get_pretty(err)); } - qdict_put_obj(qdict, "error", error_get_qobject(err)); + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); error_free(err); } else { qdict = qobject_to_qdict(obj); @@ -316,7 +534,7 @@ static void process_event(JSONMessageParser *parser, QList *tokens) qdict = qdict_new(); g_warning("unrecognized payload format"); error_set(&err, QERR_UNSUPPORTED); - qdict_put_obj(qdict, "error", error_get_qobject(err)); + qdict_put_obj(qdict, "error", qmp_build_error_object(err)); error_free(err); } ret = send_response(s, QOBJECT(qdict)); @@ -460,9 +678,11 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]) int main(int argc, char **argv) { - const char *sopt = "hVvdm:p:l:f:b:s:"; - const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT; - const char *log_file_name = NULL; + const char *sopt = "hVvdm:p:l:f:b:s:t:"; + const char *method = NULL, *path = NULL; + const char *log_filepath = NULL; + const char *pid_filepath = QGA_PIDFILE_DEFAULT; + const char *state_dir = QGA_STATEDIR_DEFAULT; #ifdef _WIN32 const char *service = NULL; #endif @@ -478,12 +698,13 @@ int main(int argc, char **argv) { "blacklist", 1, NULL, 'b' }, #ifdef _WIN32 { "service", 1, NULL, 's' }, -#endif +#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; - FILE *log_file = stderr; + GList *blacklist = NULL; GAState *s; module_call_init(MODULE_INIT_QAPI); @@ -497,30 +718,27 @@ int main(int argc, char **argv) path = optarg; break; case 'l': - log_file_name = optarg; - log_file = fopen(log_file_name, "a"); - if (!log_file) { - g_critical("unable to open specified log file: %s", - strerror(errno)); - return EXIT_FAILURE; - } + log_filepath = optarg; break; case 'f': - pidfile = optarg; + pid_filepath = optarg; break; + 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", QGA_VERSION); + printf("QEMU Guest Agent %s\n", QEMU_VERSION); return 0; case 'd': daemonize = 1; break; case 'b': { char **list_head, **list; - if (*optarg == '?') { + if (is_help_option(optarg)) { list_head = list = qmp_get_command_list(); while (*list != NULL) { printf("%s\n", *list); @@ -533,14 +751,12 @@ int main(int argc, char **argv) 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]); + blacklist = g_list_append(blacklist, &optarg[j]); j = i + 1; } } if (j < i) { - qmp_disable_command(&optarg[j]); - g_debug("disabling command: %s", &optarg[j]); + blacklist = g_list_append(blacklist, &optarg[j]); } break; } @@ -548,7 +764,7 @@ int main(int argc, char **argv) case 's': service = optarg; if (strcmp(service, "install") == 0) { - return ga_install_service(path, log_file_name); + return ga_install_service(path, log_filepath); } else if (strcmp(service, "uninstall") == 0) { return ga_uninstall_service(); } else { @@ -567,19 +783,79 @@ int main(int argc, char **argv) } } -#ifndef _WIN32 - if (daemonize) { - g_debug("starting daemon"); - become_daemon(pidfile); - } -#endif - s = g_malloc0(sizeof(GAState)); - s->log_file = log_file; s->log_level = log_level; + s->log_file = stderr; g_log_set_default_handler(ga_log, s); g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); - s->logging_enabled = true; + ga_enable_logging(s); + s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen", + 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 filesystem 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); + ga_disable_non_whitelisted(); + } else { + if (daemonize) { + become_daemon(pid_filepath); + } + if (log_filepath) { + FILE *log_file = fopen(log_filepath, "a"); + if (!log_file) { + g_critical("unable to open specified log file: %s", + strerror(errno)); + goto out_bad; + } + s->log_file = log_file; + } + } + + 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); @@ -613,13 +889,13 @@ int main(int argc, char **argv) ga_channel_free(ga_state->channel); if (daemonize) { - unlink(pidfile); + unlink(pid_filepath); } return 0; out_bad: if (daemonize) { - unlink(pidfile); + unlink(pid_filepath); } return EXIT_FAILURE; }