libvirt/tools/virt-admin.c
Erik Skultety 6dd7e42d89 admin: Add support for connection close callbacks
As we need a client disconnect handler, we also need a mechanism to register
such handlers for a client. This patch introduced both the close callbacks and
also the client vshAdmCatchDisconnect handler to be registered with it. By
registering the handler we still need to make sure the client can react to
daemon's events like disconnect or keepalive, so asynchronous I/O event polling
is necessary to be enabled too.
2015-11-30 09:44:28 +01:00

638 lines
17 KiB
C

/*
* virt-admin.c: a shell to exercise the libvirt admin API
*
* Copyright (C) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
* Authors:
* Erik Skultety <eskultet@redhat.com>
*/
#include <config.h>
#include "virt-admin.h"
#include <errno.h>
#include <getopt.h>
#include <locale.h>
#if WITH_READLINE
# include <readline/readline.h>
# include <readline/history.h>
#endif
#include "configmake.h"
#include "internal.h"
#include "viralloc.h"
#include "virerror.h"
#include "virfile.h"
#include "virstring.h"
#include "virthread.h"
/* Gnulib doesn't guarantee SA_SIGINFO support. */
#ifndef SA_SIGINFO
# define SA_SIGINFO 0
#endif
#define VIRT_ADMIN_PROMPT "virt-admin # "
static char *progname;
static const vshCmdGrp cmdGroups[];
static const vshClientHooks hooks;
/*
* vshAdmCatchDisconnect:
*
* We get here when the connection was closed. Unlike virsh, we do not save
* the fact that the event was raised, sice there is virAdmConnectIsAlive to
* check if the communication channel has not been closed by remote party.
*/
static void
vshAdmCatchDisconnect(virAdmConnectPtr conn ATTRIBUTE_UNUSED,
int reason,
void *opaque)
{
vshControl *ctl = opaque;
const char *str = "unknown reason";
virErrorPtr error;
char *uri = NULL;
if (reason == VIR_CONNECT_CLOSE_REASON_CLIENT)
return;
error = virSaveLastError();
uri = virAdmConnectGetURI(conn);
switch ((virConnectCloseReason) reason) {
case VIR_CONNECT_CLOSE_REASON_ERROR:
str = N_("Disconnected from %s due to I/O error");
break;
case VIR_CONNECT_CLOSE_REASON_EOF:
str = N_("Disconnected from %s due to end of file");
break;
case VIR_CONNECT_CLOSE_REASON_KEEPALIVE:
str = N_("Disconnected from %s due to keepalive timeout");
break;
/* coverity[dead_error_condition] */
case VIR_CONNECT_CLOSE_REASON_CLIENT:
case VIR_CONNECT_CLOSE_REASON_LAST:
break;
}
vshError(ctl, _(str), NULLSTR(uri));
if (error) {
virSetError(error);
virFreeError(error);
}
}
static int
vshAdmConnect(vshControl *ctl, unsigned int flags)
{
vshAdmControlPtr priv = ctl->privData;
priv->conn = virAdmConnectOpen(ctl->connname, flags);
if (!priv->conn) {
if (priv->wantReconnect)
vshError(ctl, "%s", _("Failed to reconnect to the admin server"));
else
vshError(ctl, "%s", _("Failed to connect to the admin server"));
return -1;
} else {
if (virAdmConnectRegisterCloseCallback(priv->conn, vshAdmCatchDisconnect,
NULL, NULL) < 0)
vshError(ctl, "%s", _("Unable to register disconnect callback"));
if (priv->wantReconnect)
vshPrint(ctl, "%s\n", _("Reconnected to the admin server"));
else
vshPrint(ctl, "%s\n", _("Connected to the admin server"));
}
return 0;
}
static int
vshAdmDisconnect(vshControl *ctl)
{
int ret = 0;
vshAdmControlPtr priv = ctl->privData;
if (!priv->conn)
return ret;
virAdmConnectUnregisterCloseCallback(priv->conn, vshAdmCatchDisconnect);
ret = virAdmConnectClose(priv->conn);
if (ret < 0)
vshError(ctl, "%s", _("Failed to disconnect from the admin server"));
else if (ret > 0)
vshError(ctl, "%s", _("One or more references were leaked after "
"disconnect from the hypervisor"));
priv->conn = NULL;
return ret;
}
/*
* vshAdmReconnect:
*
* Reconnect to a daemon's admin server
*
*/
static void
vshAdmReconnect(vshControl *ctl)
{
vshAdmControlPtr priv = ctl->privData;
if (priv->conn)
priv->wantReconnect = true;
vshAdmDisconnect(ctl);
vshAdmConnect(ctl, 0);
priv->wantReconnect = false;
}
/*
* 'uri' command
*/
static const vshCmdInfo info_uri[] = {
{.name = "help",
.data = N_("print the admin server URI")
},
{.name = "desc",
.data = ""
},
{.name = NULL}
};
static bool
cmdURI(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
{
char *uri;
vshAdmControlPtr priv = ctl->privData;
uri = virAdmConnectGetURI(priv->conn);
if (!uri) {
vshError(ctl, "%s", _("failed to get URI"));
return false;
}
vshPrint(ctl, "%s\n", uri);
VIR_FREE(uri);
return true;
}
/* ---------------
* Command Connect
* ---------------
*/
static const vshCmdOptDef opts_connect[] = {
{.name = "name",
.type = VSH_OT_STRING,
.flags = VSH_OFLAG_EMPTY_OK,
.help = N_("daemon's admin server connection URI")
},
{.name = NULL}
};
static const vshCmdInfo info_connect[] = {
{.name = "help",
.data = N_("connect to daemon's admin server")
},
{.name = "desc",
.data = N_("Connect to a daemon's administrating server.")
},
{.name = NULL}
};
static bool
cmdConnect(vshControl *ctl, const vshCmd *cmd)
{
const char *name = NULL;
vshAdmControlPtr priv = ctl->privData;
if (vshCommandOptStringReq(ctl, cmd, "name", &name) < 0)
return false;
VIR_FREE(ctl->connname);
ctl->connname = vshStrdup(ctl, name);
vshAdmReconnect(ctl);
return !!priv->conn;
}
static void *
vshAdmConnectionHandler(vshControl *ctl)
{
vshAdmControlPtr priv = ctl->privData;
if (!virAdmConnectIsAlive(priv->conn))
vshAdmReconnect(ctl);
if (!virAdmConnectIsAlive(priv->conn)) {
vshError(ctl, "%s", _("no valid connection"));
return NULL;
}
return priv->conn;
}
/*
* Initialize connection.
*/
static bool
vshAdmInit(vshControl *ctl)
{
vshAdmControlPtr priv = ctl->privData;
/* Since we have the commandline arguments parsed, we need to
* reload our initial settings to make debugging and readline
* work properly */
vshInitReload(ctl);
if (priv->conn)
return false;
/* set up the library error handler */
virSetErrorFunc(NULL, vshErrorHandler);
if (virEventRegisterDefaultImpl() < 0)
return false;
if (virThreadCreate(&ctl->eventLoop, true, vshEventLoop, ctl) < 0)
return false;
ctl->eventLoopStarted = true;
if (ctl->connname) {
vshAdmReconnect(ctl);
/* Connecting to a named connection must succeed, but we delay
* connecting to the default connection until we need it
* (since the first command might be 'connect' which allows a
* non-default connection, or might be 'help' which needs no
* connection).
*/
if (!priv->conn) {
vshReportError(ctl);
return false;
}
}
return true;
}
static void
vshAdmDeinitTimer(int timer ATTRIBUTE_UNUSED, void *opaque ATTRIBUTE_UNUSED)
{
/* nothing to be done here */
}
/*
* Deinitialize virt-admin
*/
static void
vshAdmDeinit(vshControl *ctl)
{
vshAdmControlPtr priv = ctl->privData;
vshDeinit(ctl);
VIR_FREE(ctl->connname);
if (priv->conn)
vshAdmDisconnect(ctl);
virResetLastError();
if (ctl->eventLoopStarted) {
int timer;
virMutexLock(&ctl->lock);
ctl->quit = true;
/* HACK: Add a dummy timeout to break event loop */
timer = virEventAddTimeout(0, vshAdmDeinitTimer, NULL, NULL);
virMutexUnlock(&ctl->lock);
virThreadJoin(&ctl->eventLoop);
if (timer != -1)
virEventRemoveTimeout(timer);
ctl->eventLoopStarted = false;
}
virMutexDestroy(&ctl->lock);
}
/*
* Print usage
*/
static void
vshAdmUsage(void)
{
const vshCmdGrp *grp;
const vshCmdDef *cmd;
fprintf(stdout, _("\n%s [options]... [<command_string>]"
"\n%s [options]... <command> [args...]\n\n"
" options:\n"
" -c | --connect=URI daemon admin connection URI\n"
" -d | --debug=NUM debug level [0-4]\n"
" -h | --help this help\n"
" -l | --log=FILE output logging to file\n"
" -q | --quiet quiet mode\n"
" -v short version\n"
" -V long version\n"
" --version[=TYPE] version, TYPE is short or long (default short)\n"
" commands (non interactive mode):\n\n"), progname,
progname);
for (grp = cmdGroups; grp->name; grp++) {
fprintf(stdout, _(" %s (help keyword '%s')\n"),
grp->name, grp->keyword);
for (cmd = grp->commands; cmd->name; cmd++) {
if (cmd->flags & VSH_CMD_FLAG_ALIAS)
continue;
fprintf(stdout,
" %-30s %s\n", cmd->name,
_(vshCmddefGetInfo(cmd, "help")));
}
fprintf(stdout, "\n");
}
fprintf(stdout, "%s",
_("\n (specify help <group> for details about the commands in the group)\n"));
fprintf(stdout, "%s",
_("\n (specify help <command> for details about the command)\n\n"));
return;
}
/*
* Show version and options compiled in
*/
static void
vshAdmShowVersion(vshControl *ctl ATTRIBUTE_UNUSED)
{
/* FIXME - list a copyright blurb, as in GNU programs? */
vshPrint(ctl, _("Virt-admin command line tool of libvirt %s\n"), VERSION);
vshPrint(ctl, _("See web site at %s\n\n"), "http://libvirt.org/");
vshPrint(ctl, "%s", _("Compiled with support for:"));
#ifdef WITH_LIBVIRTD
vshPrint(ctl, " Daemon");
#endif
#ifdef ENABLE_DEBUG
vshPrint(ctl, " Debug");
#endif
#if WITH_READLINE
vshPrint(ctl, " Readline");
#endif
vshPrint(ctl, "\n");
}
static bool
vshAdmParseArgv(vshControl *ctl, int argc, char **argv)
{
int arg, debug;
size_t i;
int longindex = -1;
struct option opt[] = {
{"connect", required_argument, NULL, 'c'},
{"debug", required_argument, NULL, 'd'},
{"help", no_argument, NULL, 'h'},
{"log", required_argument, NULL, 'l'},
{"quiet", no_argument, NULL, 'q'},
{"version", optional_argument, NULL, 'v'},
{NULL, 0, NULL, 0}
};
/* Standard (non-command) options. The leading + ensures that no
* argument reordering takes place, so that command options are
* not confused with top-level virt-admin options. */
while ((arg = getopt_long(argc, argv, "+:c:d:hl:qvV", opt, &longindex)) != -1) {
switch (arg) {
case 'c':
VIR_FREE(ctl->connname);
ctl->connname = vshStrdup(ctl, optarg);
break;
case 'd':
if (virStrToLong_i(optarg, NULL, 10, &debug) < 0) {
vshError(ctl, _("option %s takes a numeric argument"),
longindex == -1 ? "-d" : "--debug");
exit(EXIT_FAILURE);
}
if (debug < VSH_ERR_DEBUG || debug > VSH_ERR_ERROR)
vshError(ctl, _("ignoring debug level %d out of range [%d-%d]"),
debug, VSH_ERR_DEBUG, VSH_ERR_ERROR);
else
ctl->debug = debug;
break;
case 'h':
vshAdmUsage();
exit(EXIT_SUCCESS);
break;
case 'l':
vshCloseLogFile(ctl);
ctl->logfile = vshStrdup(ctl, optarg);
vshOpenLogFile(ctl);
break;
case 'q':
ctl->quiet = true;
break;
case 'v':
if (STRNEQ_NULLABLE(optarg, "long")) {
puts(VERSION);
exit(EXIT_SUCCESS);
}
/* fall through */
case 'V':
vshAdmShowVersion(ctl);
exit(EXIT_SUCCESS);
case ':':
for (i = 0; opt[i].name != NULL; i++) {
if (opt[i].val == optopt)
break;
}
if (opt[i].name)
vshError(ctl, _("option '-%c'/'--%s' requires an argument"),
optopt, opt[i].name);
else
vshError(ctl, _("option '-%c' requires an argument"), optopt);
exit(EXIT_FAILURE);
case '?':
if (optopt)
vshError(ctl, _("unsupported option '-%c'. See --help."), optopt);
else
vshError(ctl, _("unsupported option '%s'. See --help."), argv[optind - 1]);
exit(EXIT_FAILURE);
default:
vshError(ctl, _("unknown option"));
exit(EXIT_FAILURE);
}
longindex = -1;
}
if (argc == optind) {
ctl->imode = true;
} else {
/* parse command */
ctl->imode = false;
if (argc - optind == 1) {
vshDebug(ctl, VSH_ERR_INFO, "commands: \"%s\"\n", argv[optind]);
return vshCommandStringParse(ctl, argv[optind]);
} else {
return vshCommandArgvParse(ctl, argc - optind, argv + optind);
}
}
return true;
}
static const vshCmdDef vshAdmCmds[] = {
VSH_CMD_CD,
VSH_CMD_ECHO,
VSH_CMD_EXIT,
VSH_CMD_HELP,
VSH_CMD_PWD,
VSH_CMD_QUIT,
{.name = "uri",
.handler = cmdURI,
.opts = NULL,
.info = info_uri,
.flags = 0
},
{.name = "connect",
.handler = cmdConnect,
.opts = opts_connect,
.info = info_connect,
.flags = VSH_CMD_FLAG_NOCONNECT
},
{.name = NULL}
};
static const vshCmdGrp cmdGroups[] = {
{"Virt-admin itself", "virt-admin", vshAdmCmds},
{NULL, NULL, NULL}
};
static const vshClientHooks hooks = {
.connHandler = vshAdmConnectionHandler
};
int
main(int argc, char **argv)
{
vshControl _ctl, *ctl = &_ctl;
vshAdmControl virtAdminCtl;
const char *defaultConn;
bool ret = true;
memset(ctl, 0, sizeof(vshControl));
memset(&virtAdminCtl, 0, sizeof(vshAdmControl));
ctl->name = "virt-admin"; /* hardcoded name of the binary */
ctl->log_fd = -1; /* Initialize log file descriptor */
ctl->debug = VSH_DEBUG_DEFAULT;
ctl->hooks = &hooks;
ctl->eventPipe[0] = -1;
ctl->eventPipe[1] = -1;
ctl->privData = &virtAdminCtl;
if (!(progname = strrchr(argv[0], '/')))
progname = argv[0];
else
progname++;
ctl->progname = progname;
if (!setlocale(LC_ALL, "")) {
perror("setlocale");
/* failure to setup locale is not fatal */
}
if (!bindtextdomain(PACKAGE, LOCALEDIR)) {
perror("bindtextdomain");
return EXIT_FAILURE;
}
if (!textdomain(PACKAGE)) {
perror("textdomain");
return EXIT_FAILURE;
}
if (isatty(STDIN_FILENO)) {
ctl->istty = true;
#ifndef WIN32
if (tcgetattr(STDIN_FILENO, &ctl->termattr) < 0)
ctl->istty = false;
#endif
}
if (virMutexInit(&ctl->lock) < 0) {
vshError(ctl, "%s", _("Failed to initialize mutex"));
return EXIT_FAILURE;
}
virFileActivateDirOverride(argv[0]);
if ((defaultConn = virGetEnvBlockSUID("LIBVIRT_DEFAULT_ADMIN_URI")))
ctl->connname = vshStrdup(ctl, defaultConn);
if (!vshInit(ctl, cmdGroups, NULL))
exit(EXIT_FAILURE);
if (!vshAdmParseArgv(ctl, argc, argv) ||
!vshAdmInit(ctl)) {
vshAdmDeinit(ctl);
exit(EXIT_FAILURE);
}
if (!ctl->imode) {
ret = vshCommandRun(ctl, ctl->cmd);
} else {
/* interactive mode */
if (!ctl->quiet) {
vshPrint(ctl,
_("Welcome to %s, the administrating virtualization "
"interactive terminal.\n\n"),
progname);
vshPrint(ctl, "%s",
_("Type: 'help' for help with commands\n"
" 'quit' to quit\n\n"));
}
do {
ctl->cmdstr = vshReadline(ctl, VIRT_ADMIN_PROMPT);
if (ctl->cmdstr == NULL)
break; /* EOF */
if (*ctl->cmdstr) {
#if WITH_READLINE
add_history(ctl->cmdstr);
#endif
if (vshCommandStringParse(ctl, ctl->cmdstr))
vshCommandRun(ctl, ctl->cmd);
}
VIR_FREE(ctl->cmdstr);
} while (ctl->imode);
if (ctl->cmdstr == NULL)
fputc('\n', stdout); /* line break after alone prompt */
}
vshAdmDeinit(ctl);
exit(ret ? EXIT_SUCCESS : EXIT_FAILURE);
}