qemu-e2k/qerror.c
Daniel P. Berrange 1366108981 Introduce a 'client_add' monitor command accepting an open FD
Allow client connections for VNC and socket based character
devices to be passed in over the monitor using SCM_RIGHTS.

One intended usage scenario is to start QEMU with VNC on a
UNIX domain socket. An unprivileged user which cannot access
the UNIX domain socket, can then connect to QEMU's VNC server
by passing an open FD to libvirt, which passes it onto QEMU.

 { "execute": "get_fd", "arguments": { "fdname": "myclient" } }
 { "return": {} }
 { "execute": "add_client", "arguments": { "protocol": "vnc",
                                           "fdname": "myclient",
                                           "skipauth": true } }
 { "return": {} }

In this case 'protocol' can be 'vnc' or 'spice', or the name
of a character device (eg from -chardev id=XXXX)

The 'skipauth' parameter can be used to skip any configured
VNC authentication scheme, which is useful if the mgmt layer
talking to the monitor has already authenticated the client
in another way.

* console.h: Define 'vnc_display_add_client' method
* monitor.c: Implement 'client_add' command
* qemu-char.c, qemu-char.h: Add 'qemu_char_add_client' method
* qerror.c, qerror.h: Add QERR_ADD_CLIENT_FAILED
* qmp-commands.hx: Declare 'client_add' command
* ui/vnc.c: Implement 'vnc_display_add_client' method

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-07-23 11:19:02 -05:00

506 lines
13 KiB
C

/*
* QError Module
*
* Copyright (C) 2009 Red Hat Inc.
*
* Authors:
* Luiz Capitulino <lcapitulino@redhat.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*/
#include "monitor.h"
#include "qjson.h"
#include "qerror.h"
#include "qemu-common.h"
static void qerror_destroy_obj(QObject *obj);
static const QType qerror_type = {
.code = QTYPE_QERROR,
.destroy = qerror_destroy_obj,
};
/**
* The 'desc' parameter is a printf-like string, the format of the format
* string is:
*
* %(KEY)
*
* Where KEY is a QDict key, which has to be passed to qerror_from_info().
*
* Example:
*
* "foo error on device: %(device) slot: %(slot_nr)"
*
* A single percent sign can be printed if followed by a second one,
* for example:
*
* "running out of foo: %(foo)%%"
*
* Please keep the entries in alphabetical order.
* Use "sed -n '/^static.*qerror_table\[\]/,/^};/s/QERR_/&/gp' qerror.c | sort -c"
* to check.
*/
static const QErrorStringTable qerror_table[] = {
{
.error_fmt = QERR_BAD_BUS_FOR_DEVICE,
.desc = "Device '%(device)' can't go on a %(bad_bus_type) bus",
},
{
.error_fmt = QERR_BUS_NOT_FOUND,
.desc = "Bus '%(bus)' not found",
},
{
.error_fmt = QERR_BUS_NO_HOTPLUG,
.desc = "Bus '%(bus)' does not support hotplugging",
},
{
.error_fmt = QERR_COMMAND_NOT_FOUND,
.desc = "The command %(name) has not been found",
},
{
.error_fmt = QERR_DEVICE_ENCRYPTED,
.desc = "Device '%(device)' is encrypted",
},
{
.error_fmt = QERR_DEVICE_INIT_FAILED,
.desc = "Device '%(device)' could not be initialized",
},
{
.error_fmt = QERR_DEVICE_IN_USE,
.desc = "Device '%(device)' is in use",
},
{
.error_fmt = QERR_DEVICE_LOCKED,
.desc = "Device '%(device)' is locked",
},
{
.error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
.desc = "Device '%(device)' has multiple child busses",
},
{
.error_fmt = QERR_DEVICE_NOT_ACTIVE,
.desc = "Device '%(device)' has not been activated",
},
{
.error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
.desc = "Device '%(device)' is not encrypted",
},
{
.error_fmt = QERR_DEVICE_NOT_FOUND,
.desc = "Device '%(device)' not found",
},
{
.error_fmt = QERR_DEVICE_NOT_REMOVABLE,
.desc = "Device '%(device)' is not removable",
},
{
.error_fmt = QERR_DEVICE_NO_BUS,
.desc = "Device '%(device)' has no child bus",
},
{
.error_fmt = QERR_DEVICE_NO_HOTPLUG,
.desc = "Device '%(device)' does not support hotplugging",
},
{
.error_fmt = QERR_DUPLICATE_ID,
.desc = "Duplicate ID '%(id)' for %(object)",
},
{
.error_fmt = QERR_FD_NOT_FOUND,
.desc = "File descriptor named '%(name)' not found",
},
{
.error_fmt = QERR_FD_NOT_SUPPLIED,
.desc = "No file descriptor supplied via SCM_RIGHTS",
},
{
.error_fmt = QERR_INVALID_BLOCK_FORMAT,
.desc = "Invalid block format '%(name)'",
},
{
.error_fmt = QERR_INVALID_PARAMETER,
.desc = "Invalid parameter '%(name)'",
},
{
.error_fmt = QERR_INVALID_PARAMETER_TYPE,
.desc = "Invalid parameter type, expected: %(expected)",
},
{
.error_fmt = QERR_INVALID_PARAMETER_VALUE,
.desc = "Parameter '%(name)' expects %(expected)",
},
{
.error_fmt = QERR_INVALID_PASSWORD,
.desc = "Password incorrect",
},
{
.error_fmt = QERR_JSON_PARSING,
.desc = "Invalid JSON syntax",
},
{
.error_fmt = QERR_JSON_PARSE_ERROR,
.desc = "JSON parse error, %(message)",
},
{
.error_fmt = QERR_KVM_MISSING_CAP,
.desc = "Using KVM without %(capability), %(feature) unavailable",
},
{
.error_fmt = QERR_MIGRATION_EXPECTED,
.desc = "An incoming migration is expected before this command can be executed",
},
{
.error_fmt = QERR_MISSING_PARAMETER,
.desc = "Parameter '%(name)' is missing",
},
{
.error_fmt = QERR_NO_BUS_FOR_DEVICE,
.desc = "No '%(bus)' bus found for device '%(device)'",
},
{
.error_fmt = QERR_OPEN_FILE_FAILED,
.desc = "Could not open '%(filename)'",
},
{
.error_fmt = QERR_PROPERTY_NOT_FOUND,
.desc = "Property '%(device).%(property)' not found",
},
{
.error_fmt = QERR_PROPERTY_VALUE_BAD,
.desc = "Property '%(device).%(property)' doesn't take value '%(value)'",
},
{
.error_fmt = QERR_PROPERTY_VALUE_IN_USE,
.desc = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
},
{
.error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
.desc = "Property '%(device).%(property)' can't find value '%(value)'",
},
{
.error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
.desc = "Expected '%(expected)' in QMP input",
},
{
.error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
.desc = "QMP input object member '%(member)' expects '%(expected)'",
},
{
.error_fmt = QERR_QMP_EXTRA_MEMBER,
.desc = "QMP input object member '%(member)' is unexpected",
},
{
.error_fmt = QERR_SET_PASSWD_FAILED,
.desc = "Could not set password",
},
{
.error_fmt = QERR_ADD_CLIENT_FAILED,
.desc = "Could not add client",
},
{
.error_fmt = QERR_TOO_MANY_FILES,
.desc = "Too many open files",
},
{
.error_fmt = QERR_UNDEFINED_ERROR,
.desc = "An undefined error has ocurred",
},
{
.error_fmt = QERR_UNSUPPORTED,
.desc = "this feature or command is not currently supported",
},
{
.error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
.desc = "'%(device)' uses a %(format) feature which is not "
"supported by this qemu version: %(feature)",
},
{
.error_fmt = QERR_VNC_SERVER_FAILED,
.desc = "Could not start VNC server on %(target)",
},
{
.error_fmt = QERR_QGA_LOGGING_FAILED,
.desc = "Guest agent failed to log non-optional log statement",
},
{
.error_fmt = QERR_QGA_COMMAND_FAILED,
.desc = "Guest agent command failed, error was '%(message)'",
},
{}
};
/**
* qerror_new(): Create a new QError
*
* Return strong reference.
*/
QError *qerror_new(void)
{
QError *qerr;
qerr = qemu_mallocz(sizeof(*qerr));
QOBJECT_INIT(qerr, &qerror_type);
return qerr;
}
static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
fprintf(stderr, "qerror: -> ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
abort();
}
static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
const char *fmt, va_list *va)
{
QObject *obj;
obj = qobject_from_jsonv(fmt, va);
if (!obj) {
qerror_abort(qerr, "invalid format '%s'", fmt);
}
if (qobject_type(obj) != QTYPE_QDICT) {
qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
}
qerr->error = qobject_to_qdict(obj);
obj = qdict_get(qerr->error, "class");
if (!obj) {
qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
}
if (qobject_type(obj) != QTYPE_QSTRING) {
qerror_abort(qerr, "'class' key value should be a QString");
}
obj = qdict_get(qerr->error, "data");
if (!obj) {
qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
}
if (qobject_type(obj) != QTYPE_QDICT) {
qerror_abort(qerr, "'data' key value should be a QDICT");
}
}
static void qerror_set_desc(QError *qerr, const char *fmt)
{
int i;
// FIXME: inefficient loop
for (i = 0; qerror_table[i].error_fmt; i++) {
if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
qerr->entry = &qerror_table[i];
return;
}
}
qerror_abort(qerr, "error format '%s' not found", fmt);
}
/**
* qerror_from_info(): Create a new QError from error information
*
* The information consists of:
*
* - file the file name of where the error occurred
* - linenr the line number of where the error occurred
* - func the function name of where the error occurred
* - fmt JSON printf-like dictionary, there must exist keys 'class' and
* 'data'
* - va va_list of all arguments specified by fmt
*
* Return strong reference.
*/
QError *qerror_from_info(const char *file, int linenr, const char *func,
const char *fmt, va_list *va)
{
QError *qerr;
qerr = qerror_new();
loc_save(&qerr->loc);
qerr->linenr = linenr;
qerr->file = file;
qerr->func = func;
if (!fmt) {
qerror_abort(qerr, "QDict not specified");
}
qerror_set_data(qerr, fmt, va);
qerror_set_desc(qerr, fmt);
return qerr;
}
static void parse_error(const QErrorStringTable *entry, int c)
{
fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
abort();
}
static const char *append_field(QDict *error, QString *outstr,
const QErrorStringTable *entry,
const char *start)
{
QObject *obj;
QDict *qdict;
QString *key_qs;
const char *end, *key;
if (*start != '%')
parse_error(entry, '%');
start++;
if (*start != '(')
parse_error(entry, '(');
start++;
end = strchr(start, ')');
if (!end)
parse_error(entry, ')');
key_qs = qstring_from_substr(start, 0, end - start - 1);
key = qstring_get_str(key_qs);
qdict = qobject_to_qdict(qdict_get(error, "data"));
obj = qdict_get(qdict, key);
if (!obj) {
abort();
}
switch (qobject_type(obj)) {
case QTYPE_QSTRING:
qstring_append(outstr, qdict_get_str(qdict, key));
break;
case QTYPE_QINT:
qstring_append_int(outstr, qdict_get_int(qdict, key));
break;
default:
abort();
}
QDECREF(key_qs);
return ++end;
}
static QString *qerror_format_desc(QDict *error,
const QErrorStringTable *entry)
{
QString *qstring;
const char *p;
assert(entry != NULL);
qstring = qstring_new();
for (p = entry->desc; *p != '\0';) {
if (*p != '%') {
qstring_append_chr(qstring, *p++);
} else if (*(p + 1) == '%') {
qstring_append_chr(qstring, '%');
p += 2;
} else {
p = append_field(error, qstring, entry, p);
}
}
return qstring;
}
QString *qerror_format(const char *fmt, QDict *error)
{
const QErrorStringTable *entry = NULL;
int i;
for (i = 0; qerror_table[i].error_fmt; i++) {
if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
entry = &qerror_table[i];
break;
}
}
return qerror_format_desc(error, entry);
}
/**
* qerror_human(): Format QError data into human-readable string.
*/
QString *qerror_human(const QError *qerror)
{
return qerror_format_desc(qerror->error, qerror->entry);
}
/**
* qerror_print(): Print QError data
*
* This function will print the member 'desc' of the specified QError object,
* it uses error_report() for this, so that the output is routed to the right
* place (ie. stderr or Monitor's device).
*/
void qerror_print(QError *qerror)
{
QString *qstring = qerror_human(qerror);
loc_push_restore(&qerror->loc);
error_report("%s", qstring_get_str(qstring));
loc_pop(&qerror->loc);
QDECREF(qstring);
}
void qerror_report_internal(const char *file, int linenr, const char *func,
const char *fmt, ...)
{
va_list va;
QError *qerror;
va_start(va, fmt);
qerror = qerror_from_info(file, linenr, func, fmt, &va);
va_end(va);
if (monitor_cur_is_qmp()) {
monitor_set_error(cur_mon, qerror);
} else {
qerror_print(qerror);
QDECREF(qerror);
}
}
/**
* qobject_to_qerror(): Convert a QObject into a QError
*/
QError *qobject_to_qerror(const QObject *obj)
{
if (qobject_type(obj) != QTYPE_QERROR) {
return NULL;
}
return container_of(obj, QError, base);
}
/**
* qerror_destroy_obj(): Free all memory allocated by a QError
*/
static void qerror_destroy_obj(QObject *obj)
{
QError *qerr;
assert(obj != NULL);
qerr = qobject_to_qerror(obj);
QDECREF(qerr->error);
qemu_free(qerr);
}