diff options
Diffstat (limited to 'qemu-ga.c')
| -rw-r--r-- | qemu-ga.c | 218 |
1 files changed, 173 insertions, 45 deletions
@@ -18,6 +18,7 @@ #ifndef _WIN32 #include <syslog.h> #include <sys/wait.h> +#include <sys/stat.h> #endif #include "json-streamer.h" #include "json-parser.h" @@ -41,6 +42,7 @@ #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 "/tmp" #define QGA_SENTINEL_BYTE 0xFF struct GAState { @@ -58,6 +60,11 @@ struct GAState { bool delimit_response; bool frozen; GList *blacklist; + const char *state_filepath_isfrozen; + struct { + const char *log_filepath; + const char *pid_filepath; + } deferred_options; }; struct GAState *ga_state; @@ -147,6 +154,8 @@ static void usage(const char *cmd) " %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" @@ -158,7 +167,8 @@ static void usage(const char *cmd) " -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); + , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT, + QGA_STATEDIR_DEFAULT); } static const char *ga_log_level_str(GLogLevelFlags level) @@ -227,6 +237,41 @@ 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)); + return false; + } + + if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) { + g_critical("Failed to truncate pid file"); + goto fail; + } + sprintf(pidstr, "%d", 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); @@ -277,6 +322,28 @@ static void ga_enable_non_blacklisted(GList *blacklist) 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; @@ -292,6 +359,10 @@ void ga_set_frozen(GAState *s) 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) @@ -300,20 +371,38 @@ void ga_unset_frozen(GAState *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"); + 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); + } } -#ifndef _WIN32 static void become_daemon(const char *pidfile) { +#ifndef _WIN32 pid_t pid, sid; - int pidfd; - char *pidstr = NULL; pid = fork(); if (pid < 0) { @@ -323,20 +412,11 @@ 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); @@ -351,15 +431,14 @@ static void become_daemon(const char *pidfile) close(STDIN_FILENO); close(STDOUT_FILENO); close(STDERR_FILENO); - free(pidstr); return; fail: unlink(pidfile); g_critical("failed to daemonize"); exit(EXIT_FAILURE); -} #endif +} static int send_response(GAState *s, QObject *payload) { @@ -597,9 +676,11 @@ 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 @@ -616,11 +697,11 @@ int main(int argc, char **argv) #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; - FILE *log_file = stderr; GList *blacklist = NULL; GAState *s; @@ -635,17 +716,14 @@ 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; @@ -684,7 +762,7 @@ 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 { @@ -703,20 +781,70 @@ 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) { + s->log_file = fopen(log_filepath, "a"); + if (!s->log_file) { + g_critical("unable to open specified log file: %s", + strerror(errno)); + goto out_bad; + } + } + } + if (blacklist) { s->blacklist = blacklist; do { @@ -758,13 +886,13 @@ 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; } |