qemu/qerror.c

352 lines
8.5 KiB
C

/*
* QError: QEMU Error data-type.
*
* 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 "qjson.h"
#include "qerror.h"
#include "qstring.h"
#include "sysemu.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)%%"
*/
static const QErrorStringTable qerror_table[] = {
{
.error_fmt = QERR_COMMAND_NOT_FOUND,
.desc = "The command %(name) has not been found",
},
{
.error_fmt = QERR_DEVICE_ENCRYPTED,
.desc = "The %(device) is encrypted",
},
{
.error_fmt = QERR_DEVICE_LOCKED,
.desc = "Device %(device) is locked",
},
{
.error_fmt = QERR_DEVICE_NOT_ACTIVE,
.desc = "The %(device) device has not been activated by the guest",
},
{
.error_fmt = QERR_DEVICE_NOT_FOUND,
.desc = "The %(device) device has not been found",
},
{
.error_fmt = QERR_DEVICE_NOT_REMOVABLE,
.desc = "Device %(device) is not removable",
},
{
.error_fmt = QERR_FD_NOT_FOUND,
.desc = "Failed to find file descriptor named %(name)",
},
{
.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_PASSWORD,
.desc = "The entered password is invalid",
},
{
.error_fmt = QERR_JSON_PARSING,
.desc = "Invalid JSON syntax",
},
{
.error_fmt = QERR_KVM_MISSING_CAP,
.desc = "Using KVM without %(capability), %(feature) unavailable",
},
{
.error_fmt = QERR_MISSING_PARAMETER,
.desc = "Parameter %(name) is missing",
},
{
.error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
.desc = "Bad QMP input object",
},
{
.error_fmt = QERR_SET_PASSWD_FAILED,
.desc = "Could not set password",
},
{
.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_VNC_SERVER_FAILED,
.desc = "Could not start VNC server on %(target)",
},
{}
};
/**
* 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 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 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();
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 QError *qerror, int c)
{
qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
}
static const char *append_field(QString *outstr, const QError *qerror,
const char *start)
{
QObject *obj;
QDict *qdict;
QString *key_qs;
const char *end, *key;
if (*start != '%')
parse_error(qerror, '%');
start++;
if (*start != '(')
parse_error(qerror, '(');
start++;
end = strchr(start, ')');
if (!end)
parse_error(qerror, ')');
key_qs = qstring_from_substr(start, 0, end - start - 1);
key = qstring_get_str(key_qs);
qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
obj = qdict_get(qdict, key);
if (!obj) {
qerror_abort(qerror, "key '%s' not found in QDict", key);
}
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:
qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
}
QDECREF(key_qs);
return ++end;
}
/**
* qerror_human(): Format QError data into human-readable string.
*
* Formats according to member 'desc' of the specified QError object.
*/
QString *qerror_human(const QError *qerror)
{
const char *p;
QString *qstring;
assert(qerror->entry != NULL);
qstring = qstring_new();
for (p = qerror->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(qstring, qerror, p);
}
}
return qstring;
}
/**
* qerror_print(): Print QError data
*
* This function will print the member 'desc' of the specified QError object,
* it uses qemu_error() for this, so that the output is routed to the right
* place (ie. stderr or Monitor's device).
*/
void qerror_print(const QError *qerror)
{
QString *qstring = qerror_human(qerror);
qemu_error("%s\n", qstring_get_str(qstring));
QDECREF(qstring);
}
/**
* 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);
}