Merge remote-tracking branch 'mdroth/qga-pull-5-15-12' into staging

* mdroth/qga-pull-5-15-12:
  qemu-ga: align versioning with QEMU_VERSION
  qemu-ga: fix segv after failure to open log file
  qemu-ga: guest-shutdown: use only async-signal-safe functions
  qemu-ga: guest-shutdown: become synchronous
  qemu-ga: guest-suspend: make the API synchronous
  qemu-ga: become_daemon(): reopen standard fds to /dev/null
  qemu-ga: make reopen_fd_to_null() public
  qemu-ga: guest-suspend-hybrid: don't emit a success response
  qemu-ga: guest-suspend-ram: don't emit a success response
  qemu-ga: guest-suspend-disk: don't emit a success response
  qemu-ga: guest-shutdown: don't emit a success response
  qemu-ga: don't warn on no command return
  qapi: add support for command options

9 files changed, 174 insertions, 162 deletions

diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
index 692b570..d4055d2 100644
--- a/qapi-schema-guest.json
+++ b/qapi-schema-guest.json
@@ -126,16 +126,19 @@
 # @guest-shutdown:
 #
 # Initiate guest-activated shutdown. Note: this is an asynchronous
-# shutdown request, with no guaruntee of successful shutdown. Errors
-# will be logged to guest's syslog.
+# shutdown request, with no guarantee of successful shutdown.
 #
 # @mode: #optional "halt", "powerdown" (default), or "reboot"
 #
-# Returns: Nothing on success
+# This command does NOT return a response on success. Success condition
+# is indicated by the VM exiting with a zero exit status or, when
+# running with --no-shutdown, by issuing the query-status QMP command
+# to confirm the VM status is "shutdown".
 #
 # Since: 0.15.0
 ##
-{ 'command': 'guest-shutdown', 'data': { '*mode': 'str' } }
+{ 'command': 'guest-shutdown', 'data': { '*mode': 'str' },
+  'success-response': 'no' }
 
 ##
 # @guest-file-open:
@@ -359,17 +362,21 @@
 # For the best results it's strongly recommended to have the pm-utils
 # package installed in the guest.
 #
-# Returns: nothing on success
+# This command does NOT return a response on success. There is a high chance
+# the command succeeded if the VM exits with a zero exit status or, when
+# running with --no-shutdown, by issuing the query-status QMP command to
+# to confirm the VM status is "shutdown". However, the VM could also exit
+# (or set its status to "shutdown") due to other reasons.
+#
+# The following errors may be returned:
 #          If suspend to disk is not supported, Unsupported
 #
-# Notes: o This is an asynchronous request. There's no guarantee a response
-#          will be sent
-#        o It's strongly recommended to issue the guest-sync command before
-#          sending commands when the guest resumes
+# Notes: It's strongly recommended to issue the guest-sync command before
+#        sending commands when the guest resumes
 #
 # Since: 1.1
 ##
-{ 'command': 'guest-suspend-disk' }
+{ 'command': 'guest-suspend-disk', 'success-response': 'no' }
 
 ##
 # @guest-suspend-ram
@@ -387,17 +394,21 @@
 # command.  Thus, it's *required* to query QEMU for the presence of the
 # 'system_wakeup' command before issuing guest-suspend-ram.
 #
-# Returns: nothing on success
+# This command does NOT return a response on success. There are two options
+# to check for success:
+#   1. Wait for the SUSPEND QMP event from QEMU
+#   2. Issue the query-status QMP command to confirm the VM status is
+#      "suspended"
+#
+# The following errors may be returned:
 #          If suspend to ram is not supported, Unsupported
 #
-# Notes: o This is an asynchronous request. There's no guarantee a response
-#          will be sent
-#        o It's strongly recommended to issue the guest-sync command before
-#          sending commands when the guest resumes
+# Notes: It's strongly recommended to issue the guest-sync command before
+#        sending commands when the guest resumes
 #
 # Since: 1.1
 ##
-{ 'command': 'guest-suspend-ram' }
+{ 'command': 'guest-suspend-ram', 'success-response': 'no' }
 
 ##
 # @guest-suspend-hybrid
@@ -410,17 +421,21 @@
 # command.  Thus, it's *required* to query QEMU for the presence of the
 # 'system_wakeup' command before issuing guest-suspend-hybrid.
 #
-# Returns: nothing on success
+# This command does NOT return a response on success. There are two options
+# to check for success:
+#   1. Wait for the SUSPEND QMP event from QEMU
+#   2. Issue the query-status QMP command to confirm the VM status is
+#      "suspended"
+#
+# The following errors may be returned:
 #          If hybrid suspend is not supported, Unsupported
 #
-# Notes: o This is an asynchronous request. There's no guarantee a response
-#          will be sent
-#        o It's strongly recommended to issue the guest-sync command before
-#          sending commands when the guest resumes
+# Notes: It's strongly recommended to issue the guest-sync command before
+#        sending commands when the guest resumes
 #
 # Since: 1.1
 ##
-{ 'command': 'guest-suspend-hybrid' }
+{ 'command': 'guest-suspend-hybrid', 'success-response': 'no' }
 
 ##
 # @GuestIpAddressType:
diff --git a/qapi/qmp-core.h b/qapi/qmp-core.h
index 431ddbb..b0f64ba 100644
--- a/qapi/qmp-core.h
+++ b/qapi/qmp-core.h
@@ -25,16 +25,24 @@ typedef enum QmpCommandType
     QCT_NORMAL,
 } QmpCommandType;
 
+typedef enum QmpCommandOptions
+{
+    QCO_NO_OPTIONS = 0x0,
+    QCO_NO_SUCCESS_RESP = 0x1,
+} QmpCommandOptions;
+
 typedef struct QmpCommand
 {
     const char *name;
     QmpCommandType type;
     QmpCommandFunc *fn;
+    QmpCommandOptions options;
     QTAILQ_ENTRY(QmpCommand) node;
     bool enabled;
 } QmpCommand;
 
-void qmp_register_command(const char *name, QmpCommandFunc *fn);
+void qmp_register_command(const char *name, QmpCommandFunc *fn,
+                          QmpCommandOptions options);
 QmpCommand *qmp_find_command(const char *name);
 QObject *qmp_dispatch(QObject *request);
 void qmp_disable_command(const char *name);
diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 43f640a..122c1a2 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -94,8 +94,12 @@ static QObject *do_qmp_dispatch(QObject *request, Error **errp)
     switch (cmd->type) {
     case QCT_NORMAL:
         cmd->fn(args, &ret, errp);
-        if (!error_is_set(errp) && ret == NULL) {
-            ret = QOBJECT(qdict_new());
+        if (!error_is_set(errp)) {
+            if (cmd->options & QCO_NO_SUCCESS_RESP) {
+                g_assert(!ret);
+            } else if (!ret) {
+                ret = QOBJECT(qdict_new());
+            }
         }
         break;
     }
diff --git a/qapi/qmp-registry.c b/qapi/qmp-registry.c
index 43d5cde..5414613 100644
--- a/qapi/qmp-registry.c
+++ b/qapi/qmp-registry.c
@@ -17,7 +17,8 @@
 static QTAILQ_HEAD(QmpCommandList, QmpCommand) qmp_commands =
     QTAILQ_HEAD_INITIALIZER(qmp_commands);
 
-void qmp_register_command(const char *name, QmpCommandFunc *fn)
+void qmp_register_command(const char *name, QmpCommandFunc *fn,
+                          QmpCommandOptions options)
 {
     QmpCommand *cmd = g_malloc0(sizeof(*cmd));
 
@@ -25,6 +26,7 @@ void qmp_register_command(const char *name, QmpCommandFunc *fn)
     cmd->type = QCT_NORMAL;
     cmd->fn = fn;
     cmd->enabled = true;
+    cmd->options = options;
     QTAILQ_INSERT_TAIL(&qmp_commands, cmd, node);
 }
 
diff --git a/qemu-ga.c b/qemu-ga.c
index 680997e..8199da7 100644
--- a/qemu-ga.c
+++ b/qemu-ga.c
@@ -104,16 +104,9 @@ static void quit_handler(int sig)
 }
 
 #ifndef _WIN32
-/* reap _all_ terminated children */
-static void child_handler(int sig)
-{
-    int status;
-    while (waitpid(-1, &status, WNOHANG) > 0) /* NOTHING */;
-}
-
 static gboolean register_signal_handlers(void)
 {
-    struct sigaction sigact, sigact_chld;
+    struct sigaction sigact;
     int ret;
 
     memset(&sigact, 0, sizeof(struct sigaction));
@@ -130,15 +123,24 @@ static gboolean register_signal_handlers(void)
         return false;
     }
 
-    memset(&sigact_chld, 0, sizeof(struct sigaction));
-    sigact_chld.sa_handler = child_handler;
-    sigact_chld.sa_flags = SA_NOCLDSTOP;
-    ret = sigaction(SIGCHLD, &sigact_chld, 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;
     }
 
-    return true;
+    dup2(nullfd, fd);
+
+    if (nullfd != fd) {
+        close(nullfd);
+    }
 }
 #endif
 
@@ -167,7 +169,7 @@ 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, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT,
     QGA_STATEDIR_DEFAULT);
 }
 
@@ -428,9 +430,9 @@ static void become_daemon(const char *pidfile)
         goto fail;
     }
 
-    close(STDIN_FILENO);
-    close(STDOUT_FILENO);
-    close(STDERR_FILENO);
+    reopen_fd_to_null(STDIN_FILENO);
+    reopen_fd_to_null(STDOUT_FILENO);
+    reopen_fd_to_null(STDERR_FILENO);
     return;
 
 fail:
@@ -488,8 +490,6 @@ 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");
     }
 }
 
@@ -729,7 +729,7 @@ int main(int argc, char **argv)
             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;
@@ -836,12 +836,13 @@ int main(int argc, char **argv)
             become_daemon(pid_filepath);
         }
         if (log_filepath) {
-            s->log_file = fopen(log_filepath, "a");
-            if (!s->log_file) {
+            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;
         }
     }
 
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index e448431..7664be1 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -34,29 +34,11 @@
 #endif
 #endif
 
-#if defined(__linux__)
-/* TODO: use this in place of all post-fork() fclose(std*) callers */
-static 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 /* defined(__linux__) */
-
 void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
 {
-    int ret;
     const char *shutdown_flag;
+    pid_t rpid, pid;
+    int status;
 
     slog("guest-shutdown called, mode: %s", mode);
     if (!has_mode || strcmp(mode, "powerdown") == 0) {
@@ -71,23 +53,30 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
         return;
     }
 
-    ret = fork();
-    if (ret == 0) {
+    pid = fork();
+    if (pid == 0) {
         /* child, start the shutdown */
         setsid();
-        fclose(stdin);
-        fclose(stdout);
-        fclose(stderr);
-
-        ret = execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
-                    "hypervisor initiated shutdown", (char*)NULL);
-        if (ret) {
-            slog("guest-shutdown failed: %s", strerror(errno));
-        }
-        exit(!!ret);
-    } else if (ret < 0) {
-        error_set(err, QERR_UNDEFINED_ERROR);
+        reopen_fd_to_null(0);
+        reopen_fd_to_null(1);
+        reopen_fd_to_null(2);
+
+        execle("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
+               "hypervisor initiated shutdown", (char*)NULL, environ);
+        _exit(EXIT_FAILURE);
+    } else if (pid < 0) {
+        goto exit_err;
+    }
+
+    do {
+        rpid = waitpid(pid, &status, 0);
+    } while (rpid == -1 && errno == EINTR);
+    if (rpid == pid && WIFEXITED(status) && !WEXITSTATUS(status)) {
+        return;
     }
+
+exit_err:
+    error_set(err, QERR_UNDEFINED_ERROR);
 }
 
 typedef struct GuestFileHandle {
@@ -531,117 +520,88 @@ static void guest_fsfreeze_cleanup(void)
 #define SUSPEND_SUPPORTED 0
 #define SUSPEND_NOT_SUPPORTED 1
 
-/**
- * This function forks twice and the information about the mode support
- * status is passed to the qemu-ga process via a pipe.
- *
- * This approach allows us to keep the way we reap terminated children
- * in qemu-ga quite simple.
- */
 static void bios_supports_mode(const char *pmutils_bin, const char *pmutils_arg,
                                const char *sysfile_str, Error **err)
 {
-    pid_t pid;
-    ssize_t ret;
     char *pmutils_path;
-    int status, pipefds[2];
-
-    if (pipe(pipefds) < 0) {
-        error_set(err, QERR_UNDEFINED_ERROR);
-        return;
-    }
+    pid_t pid, rpid;
+    int status;
 
     pmutils_path = g_find_program_in_path(pmutils_bin);
 
     pid = fork();
     if (!pid) {
-        struct sigaction act;
-
-        memset(&act, 0, sizeof(act));
-        act.sa_handler = SIG_DFL;
-        sigaction(SIGCHLD, &act, NULL);
+        char buf[32]; /* hopefully big enough */
+        ssize_t ret;
+        int fd;
 
         setsid();
-        close(pipefds[0]);
         reopen_fd_to_null(0);
         reopen_fd_to_null(1);
         reopen_fd_to_null(2);
 
-        pid = fork();
-        if (!pid) {
-            int fd;
-            char buf[32]; /* hopefully big enough */
-
-            if (pmutils_path) {
-                execle(pmutils_path, pmutils_bin, pmutils_arg, NULL, environ);
-            }
-
-            /*
-             * If we get here either pm-utils is not installed or execle() has
-             * failed. Let's try the manual method if the caller wants it.
-             */
-
-            if (!sysfile_str) {
-                _exit(SUSPEND_NOT_SUPPORTED);
-            }
-
-            fd = open(LINUX_SYS_STATE_FILE, O_RDONLY);
-            if (fd < 0) {
-                _exit(SUSPEND_NOT_SUPPORTED);
-            }
+        if (pmutils_path) {
+            execle(pmutils_path, pmutils_bin, pmutils_arg, NULL, environ);
+        }
 
-            ret = read(fd, buf, sizeof(buf)-1);
-            if (ret <= 0) {
-                _exit(SUSPEND_NOT_SUPPORTED);
-            }
-            buf[ret] = '\0';
+        /*
+         * If we get here either pm-utils is not installed or execle() has
+         * failed. Let's try the manual method if the caller wants it.
+         */
 
-            if (strstr(buf, sysfile_str)) {
-                _exit(SUSPEND_SUPPORTED);
-            }
+        if (!sysfile_str) {
+            _exit(SUSPEND_NOT_SUPPORTED);
+        }
 
+        fd = open(LINUX_SYS_STATE_FILE, O_RDONLY);
+        if (fd < 0) {
             _exit(SUSPEND_NOT_SUPPORTED);
         }
 
-        if (pid > 0) {
-            wait(&status);
-        } else {
-            status = SUSPEND_NOT_SUPPORTED;
+        ret = read(fd, buf, sizeof(buf)-1);
+        if (ret <= 0) {
+            _exit(SUSPEND_NOT_SUPPORTED);
         }
+        buf[ret] = '\0';
 
-        ret = write(pipefds[1], &status, sizeof(status));
-        if (ret != sizeof(status)) {
-            _exit(EXIT_FAILURE);
+        if (strstr(buf, sysfile_str)) {
+            _exit(SUSPEND_SUPPORTED);
         }
 
-        _exit(EXIT_SUCCESS);
+        _exit(SUSPEND_NOT_SUPPORTED);
     }
 
-    close(pipefds[1]);
     g_free(pmutils_path);
 
     if (pid < 0) {
-        error_set(err, QERR_UNDEFINED_ERROR);
-        goto out;
-    }
-
-    ret = read(pipefds[0], &status, sizeof(status));
-    if (ret == sizeof(status) && WIFEXITED(status) &&
-        WEXITSTATUS(status) == SUSPEND_SUPPORTED) {
-            goto out;
+        goto undef_err;
+    }
+
+    do {
+        rpid = waitpid(pid, &status, 0);
+    } while (rpid == -1 && errno == EINTR);
+    if (rpid == pid && WIFEXITED(status)) {
+        switch (WEXITSTATUS(status)) {
+        case SUSPEND_SUPPORTED:
+            return;
+        case SUSPEND_NOT_SUPPORTED:
+            error_set(err, QERR_UNSUPPORTED);
+            return;
+        default:
+            goto undef_err;
+        }
     }
 
-    error_set(err, QERR_UNSUPPORTED);
-
-out:
-    close(pipefds[0]);
+undef_err:
+    error_set(err, QERR_UNDEFINED_ERROR);
 }
 
 static void guest_suspend(const char *pmutils_bin, const char *sysfile_str,
                           Error **err)
 {
-    pid_t pid;
     char *pmutils_path;
+    pid_t rpid, pid;
+    int status;
 
     pmutils_path = g_find_program_in_path(pmutils_bin);
 
@@ -683,9 +643,18 @@ static void guest_suspend(const char *pmutils_bin, const char *sysfile_str,
     g_free(pmutils_path);
 
     if (pid < 0) {
-        error_set(err, QERR_UNDEFINED_ERROR);
+        goto exit_err;
+    }
+
+    do {
+        rpid = waitpid(pid, &status, 0);
+    } while (rpid == -1 && errno == EINTR);
+    if (rpid == pid && WIFEXITED(status) && !WEXITSTATUS(status)) {
         return;
     }
+
+exit_err:
+    error_set(err, QERR_UNDEFINED_ERROR);
 }
 
 void qmp_guest_suspend_disk(Error **err)
diff --git a/qga/commands.c b/qga/commands.c
index 5bcceaa..46b0b08 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -52,7 +52,7 @@ struct GuestAgentInfo *qmp_guest_info(Error **err)
     GuestAgentCommandInfoList *cmd_info_list;
     char **cmd_list_head, **cmd_list;
 
-    info->version = g_strdup(QGA_VERSION);
+    info->version = g_strdup(QEMU_VERSION);
 
     cmd_list_head = cmd_list = qmp_get_command_list();
     if (*cmd_list_head == NULL) {
diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h
index bbb8b9b..49a7abe 100644
--- a/qga/guest-agent-core.h
+++ b/qga/guest-agent-core.h
@@ -13,7 +13,6 @@
 #include "qapi/qmp-core.h"
 #include "qemu-common.h"
 
-#define QGA_VERSION "1.0"
 #define QGA_READ_COUNT_DEFAULT 4096
 
 typedef struct GAState GAState;
@@ -35,3 +34,7 @@ void ga_set_response_delimited(GAState *s);
 bool ga_is_frozen(GAState *s);
 void ga_set_frozen(GAState *s);
 void ga_unset_frozen(GAState *s);
+
+#ifndef _WIN32
+void reopen_fd_to_null(int fd);
+#endif
diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 0b4f0a0..9eed40e 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -291,14 +291,24 @@ out:
 
     return ret
 
+def option_value_matches(opt, val, cmd):
+    if opt in cmd and cmd[opt] == val:
+        return True
+    return False
+
 def gen_registry(commands):
     registry=""
     push_indent()
     for cmd in commands:
+        options = 'QCO_NO_OPTIONS'
+        if option_value_matches('success-response', 'no', cmd):
+            options = 'QCO_NO_SUCCESS_RESP'
+
         registry += mcgen('''
-qmp_register_command("%(name)s", qmp_marshal_input_%(c_name)s);
+qmp_register_command("%(name)s", qmp_marshal_input_%(c_name)s, %(opts)s);
 ''',
-                     name=cmd['command'], c_name=c_fun(cmd['command']))
+                     name=cmd['command'], c_name=c_fun(cmd['command']),
+                     opts=options)
     pop_indent()
     ret = mcgen('''
 static void qmp_init_marshal(void)