ng_parse.c

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/*
 * ng_parse.c
 */
 
/*-
 * Copyright (c) 1999 Whistle Communications, Inc.
 * All rights reserved.
 * 
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Whistle Communications;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties; and
 * 2. No rights are granted, in any manner or form, to use Whistle
 *    Communications, Inc. trademarks, including the mark "WHISTLE
 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
 *    such appears in the above copyright notice or in the software.
 * 
 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * Author: Archie Cobbs <archie@freebsd.org>
 *
 * $Whistle: ng_parse.c,v 1.3 1999/11/29 01:43:48 archie Exp $
 * $FreeBSD$
 */
 
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/ctype.h>
 
#include <machine/stdarg.h>
 
#include <net/ethernet.h>
 
#include <netinet/in.h>
 
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
 
#ifdef NG_SEPARATE_MALLOC
static MALLOC_DEFINE(M_NETGRAPH_PARSE, "netgraph_parse", "netgraph parse info");
#else
#define M_NETGRAPH_PARSE M_NETGRAPH
#endif
 
/* Compute alignment for primitive integral types */
struct int16_temp {
        char    x;
        int16_t y;
};
 
struct int32_temp {
        char    x;
        int32_t y;
};
 
struct int64_temp {
        char    x;
        int64_t y;
};
 
#define INT8_ALIGNMENT          1
#define INT16_ALIGNMENT         ((size_t)&((struct int16_temp *)0)->y)
#define INT32_ALIGNMENT         ((size_t)&((struct int32_temp *)0)->y)
#define INT64_ALIGNMENT         ((size_t)&((struct int64_temp *)0)->y)
 
/* Output format for integral types */
#define INT_UNSIGNED            0
#define INT_SIGNED              1
#define INT_HEX                 2
 
/* Type of composite object: struct, array, or fixedarray */
enum comptype {
        CT_STRUCT,
        CT_ARRAY,
        CT_FIXEDARRAY,
};
 
/* Composite types helper functions */
static int      ng_parse_composite(const struct ng_parse_type *type,
                        const char *s, int *off, const u_char *start,
                        u_char *const buf, int *buflen, enum comptype ctype);
static int      ng_unparse_composite(const struct ng_parse_type *type,
                        const u_char *data, int *off, char *cbuf, int cbuflen,
                        enum comptype ctype);
static int      ng_get_composite_elem_default(const struct ng_parse_type *type,
                        int index, const u_char *start, u_char *buf,
                        int *buflen, enum comptype ctype);
static int      ng_get_composite_len(const struct ng_parse_type *type,
                        const u_char *start, const u_char *buf,
                        enum comptype ctype);
static const    struct ng_parse_type *ng_get_composite_etype(const struct
                        ng_parse_type *type, int index, enum comptype ctype);
static int      ng_parse_get_elem_pad(const struct ng_parse_type *type,
                        int index, enum comptype ctype, int posn);
 
/* Parsing helper functions */
static int      ng_parse_skip_value(const char *s, int off, int *lenp);
static int      ng_parse_append(char **cbufp, int *cbuflenp,
                        const char *fmt, ...);
 
/* Poor man's virtual method calls */
#define METHOD(t,m)     (ng_get_ ## m ## _method(t))
#define INVOKE(t,m)     (*METHOD(t,m))
 
static ng_parse_t       *ng_get_parse_method(const struct ng_parse_type *t);
static ng_unparse_t     *ng_get_unparse_method(const struct ng_parse_type *t);
static ng_getDefault_t  *ng_get_getDefault_method(const
                                struct ng_parse_type *t);
static ng_getAlign_t    *ng_get_getAlign_method(const struct ng_parse_type *t);
 
#define ALIGNMENT(t)    (METHOD(t, getAlign) == NULL ? \
                                0 : INVOKE(t, getAlign)(t))
 
/************************************************************************
                        PUBLIC FUNCTIONS
 ************************************************************************/
 
/*
 * Convert an ASCII string to binary according to the supplied type descriptor
 */
int
ng_parse(const struct ng_parse_type *type,
        const char *string, int *off, u_char *buf, int *buflen)
{
        return INVOKE(type, parse)(type, string, off, buf, buf, buflen);
}
 
/*
 * Convert binary to an ASCII string according to the supplied type descriptor
 */
int
ng_unparse(const struct ng_parse_type *type,
        const u_char *data, char *cbuf, int cbuflen)
{
        int off = 0;
 
        return INVOKE(type, unparse)(type, data, &off, cbuf, cbuflen);
}
 
/*
 * Fill in the default value according to the supplied type descriptor
 */
int
ng_parse_getDefault(const struct ng_parse_type *type, u_char *buf, int *buflen)
{
        ng_getDefault_t *const func = METHOD(type, getDefault);
 
        if (func == NULL)
                return (EOPNOTSUPP);
        return (*func)(type, buf, buf, buflen);
}
 
/************************************************************************
                        STRUCTURE TYPE
 ************************************************************************/
 
static int
ng_struct_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        return ng_parse_composite(type, s, off, start, buf, buflen, CT_STRUCT);
}
 
static int
ng_struct_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        return ng_unparse_composite(type, data, off, cbuf, cbuflen, CT_STRUCT);
}
 
static int
ng_struct_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int off = 0;
 
        return ng_parse_composite(type,
            "{}", &off, start, buf, buflen, CT_STRUCT);
}
 
static int
ng_struct_getAlign(const struct ng_parse_type *type)
{
        const struct ng_parse_struct_field *field;
        int align = 0;
 
        for (field = type->info; field->name != NULL; field++) {
                int falign = ALIGNMENT(field->type);
 
                if (falign > align)
                        align = falign;
        }
        return align;
}
 
const struct ng_parse_type ng_parse_struct_type = {
        NULL,
        NULL,
        NULL,
        ng_struct_parse,
        ng_struct_unparse,
        ng_struct_getDefault,
        ng_struct_getAlign
};
 
/************************************************************************
                        FIXED LENGTH ARRAY TYPE
 ************************************************************************/
 
static int
ng_fixedarray_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        return ng_parse_composite(type,
            s, off, start, buf, buflen, CT_FIXEDARRAY);
}
 
static int
ng_fixedarray_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        return ng_unparse_composite(type,
                data, off, cbuf, cbuflen, CT_FIXEDARRAY);
}
 
static int
ng_fixedarray_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int off = 0;
 
        return ng_parse_composite(type,
            "[]", &off, start, buf, buflen, CT_FIXEDARRAY);
}
 
static int
ng_fixedarray_getAlign(const struct ng_parse_type *type)
{
        const struct ng_parse_fixedarray_info *fi = type->info;
 
        return ALIGNMENT(fi->elementType);
}
 
const struct ng_parse_type ng_parse_fixedarray_type = {
        NULL,
        NULL,
        NULL,
        ng_fixedarray_parse,
        ng_fixedarray_unparse,
        ng_fixedarray_getDefault,
        ng_fixedarray_getAlign
};
 
/************************************************************************
                        VARIABLE LENGTH ARRAY TYPE
 ************************************************************************/
 
static int
ng_array_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        return ng_parse_composite(type, s, off, start, buf, buflen, CT_ARRAY);
}
 
static int
ng_array_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        return ng_unparse_composite(type, data, off, cbuf, cbuflen, CT_ARRAY);
}
 
static int
ng_array_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int off = 0;
 
        return ng_parse_composite(type,
            "[]", &off, start, buf, buflen, CT_ARRAY);
}
 
static int
ng_array_getAlign(const struct ng_parse_type *type)
{
        const struct ng_parse_array_info *ai = type->info;
 
        return ALIGNMENT(ai->elementType);
}
 
const struct ng_parse_type ng_parse_array_type = {
        NULL,
        NULL,
        NULL,
        ng_array_parse,
        ng_array_unparse,
        ng_array_getDefault,
        ng_array_getAlign
};
 
/************************************************************************
                                INT8 TYPE
 ************************************************************************/
 
static int
ng_int8_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        long val;
        int8_t val8;
        char *eptr;
 
        val = strtol(s + *off, &eptr, 0);
        if (val < (int8_t)0x80 || val > (u_int8_t)0xff || eptr == s + *off)
                return (EINVAL);
        *off = eptr - s;
        val8 = (int8_t)val;
        bcopy(&val8, buf, sizeof(int8_t));
        *buflen = sizeof(int8_t);
        return (0);
}
 
static int
ng_int8_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *fmt;
        int fval;
        int error;
        int8_t val;
 
        bcopy(data + *off, &val, sizeof(int8_t));
        switch ((intptr_t)type->info) {
        case INT_SIGNED:
                fmt = "%d";
                fval = val;
                break;
        case INT_UNSIGNED:
                fmt = "%u";
                fval = (u_int8_t)val;
                break;
        case INT_HEX:
                fmt = "0x%x";
                fval = (u_int8_t)val;
                break;
        default:
                panic("%s: unknown type", __func__);
        }
        if ((error = ng_parse_append(&cbuf, &cbuflen, fmt, fval)) != 0)
                return (error);
        *off += sizeof(int8_t);
        return (0);
}
 
static int
ng_int8_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int8_t val;
 
        if (*buflen < sizeof(int8_t))
                return (ERANGE);
        val = 0;
        bcopy(&val, buf, sizeof(int8_t));
        *buflen = sizeof(int8_t);
        return (0);
}
 
static int
ng_int8_getAlign(const struct ng_parse_type *type)
{
        return INT8_ALIGNMENT;
}
 
const struct ng_parse_type ng_parse_int8_type = {
        NULL,
        (void *)INT_SIGNED,
        NULL,
        ng_int8_parse,
        ng_int8_unparse,
        ng_int8_getDefault,
        ng_int8_getAlign
};
 
const struct ng_parse_type ng_parse_uint8_type = {
        &ng_parse_int8_type,
        (void *)INT_UNSIGNED
};
 
const struct ng_parse_type ng_parse_hint8_type = {
        &ng_parse_int8_type,
        (void *)INT_HEX
};
 
/************************************************************************
                                INT16 TYPE
 ************************************************************************/
 
static int
ng_int16_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        long val;
        int16_t val16;
        char *eptr;
 
        val = strtol(s + *off, &eptr, 0);
        if (val < (int16_t)0x8000
            || val > (u_int16_t)0xffff || eptr == s + *off)
                return (EINVAL);
        *off = eptr - s;
        val16 = (int16_t)val;
        bcopy(&val16, buf, sizeof(int16_t));
        *buflen = sizeof(int16_t);
        return (0);
}
 
static int
ng_int16_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *fmt;
        int fval;
        int error;
        int16_t val;
 
        bcopy(data + *off, &val, sizeof(int16_t));
        switch ((intptr_t)type->info) {
        case INT_SIGNED:
                fmt = "%d";
                fval = val;
                break;
        case INT_UNSIGNED:
                fmt = "%u";
                fval = (u_int16_t)val;
                break;
        case INT_HEX:
                fmt = "0x%x";
                fval = (u_int16_t)val;
                break;
        default:
                panic("%s: unknown type", __func__);
        }
        if ((error = ng_parse_append(&cbuf, &cbuflen, fmt, fval)) != 0)
                return (error);
        *off += sizeof(int16_t);
        return (0);
}
 
static int
ng_int16_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int16_t val;
 
        if (*buflen < sizeof(int16_t))
                return (ERANGE);
        val = 0;
        bcopy(&val, buf, sizeof(int16_t));
        *buflen = sizeof(int16_t);
        return (0);
}
 
static int
ng_int16_getAlign(const struct ng_parse_type *type)
{
        return INT16_ALIGNMENT;
}
 
const struct ng_parse_type ng_parse_int16_type = {
        NULL,
        (void *)INT_SIGNED,
        NULL,
        ng_int16_parse,
        ng_int16_unparse,
        ng_int16_getDefault,
        ng_int16_getAlign
};
 
const struct ng_parse_type ng_parse_uint16_type = {
        &ng_parse_int16_type,
        (void *)INT_UNSIGNED
};
 
const struct ng_parse_type ng_parse_hint16_type = {
        &ng_parse_int16_type,
        (void *)INT_HEX
};
 
/************************************************************************
                                INT32 TYPE
 ************************************************************************/
 
static int
ng_int32_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        long val;                       /* assumes long is at least 32 bits */
        int32_t val32;
        char *eptr;
 
        if ((intptr_t)type->info == INT_SIGNED)
                val = strtol(s + *off, &eptr, 0);
        else
                val = strtoul(s + *off, &eptr, 0);
        if (val < (int32_t)0x80000000
            || val > (u_int32_t)0xffffffff || eptr == s + *off)
                return (EINVAL);
        *off = eptr - s;
        val32 = (int32_t)val;
        bcopy(&val32, buf, sizeof(int32_t));
        *buflen = sizeof(int32_t);
        return (0);
}
 
static int
ng_int32_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *fmt;
        long fval;
        int error;
        int32_t val;
 
        bcopy(data + *off, &val, sizeof(int32_t));
        switch ((intptr_t)type->info) {
        case INT_SIGNED:
                fmt = "%ld";
                fval = val;
                break;
        case INT_UNSIGNED:
                fmt = "%lu";
                fval = (u_int32_t)val;
                break;
        case INT_HEX:
                fmt = "0x%lx";
                fval = (u_int32_t)val;
                break;
        default:
                panic("%s: unknown type", __func__);
        }
        if ((error = ng_parse_append(&cbuf, &cbuflen, fmt, fval)) != 0)
                return (error);
        *off += sizeof(int32_t);
        return (0);
}
 
static int
ng_int32_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int32_t val;
 
        if (*buflen < sizeof(int32_t))
                return (ERANGE);
        val = 0;
        bcopy(&val, buf, sizeof(int32_t));
        *buflen = sizeof(int32_t);
        return (0);
}
 
static int
ng_int32_getAlign(const struct ng_parse_type *type)
{
        return INT32_ALIGNMENT;
}
 
const struct ng_parse_type ng_parse_int32_type = {
        NULL,
        (void *)INT_SIGNED,
        NULL,
        ng_int32_parse,
        ng_int32_unparse,
        ng_int32_getDefault,
        ng_int32_getAlign
};
 
const struct ng_parse_type ng_parse_uint32_type = {
        &ng_parse_int32_type,
        (void *)INT_UNSIGNED
};
 
const struct ng_parse_type ng_parse_hint32_type = {
        &ng_parse_int32_type,
        (void *)INT_HEX
};
 
/************************************************************************
                                INT64 TYPE
 ************************************************************************/
 
static int
ng_int64_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        quad_t val;
        int64_t val64;
        char *eptr;
 
        val = strtoq(s + *off, &eptr, 0);
        if (eptr == s + *off)
                return (EINVAL);
        *off = eptr - s;
        val64 = (int64_t)val;
        bcopy(&val64, buf, sizeof(int64_t));
        *buflen = sizeof(int64_t);
        return (0);
}
 
static int
ng_int64_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *fmt;
        long long fval;
        int64_t val;
        int error;
 
        bcopy(data + *off, &val, sizeof(int64_t));
        switch ((intptr_t)type->info) {
        case INT_SIGNED:
                fmt = "%lld";
                fval = val;
                break;
        case INT_UNSIGNED:
                fmt = "%llu";
                fval = (u_int64_t)val;
                break;
        case INT_HEX:
                fmt = "0x%llx";
                fval = (u_int64_t)val;
                break;
        default:
                panic("%s: unknown type", __func__);
        }
        if ((error = ng_parse_append(&cbuf, &cbuflen, fmt, fval)) != 0)
                return (error);
        *off += sizeof(int64_t);
        return (0);
}
 
static int
ng_int64_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        int64_t val;
 
        if (*buflen < sizeof(int64_t))
                return (ERANGE);
        val = 0;
        bcopy(&val, buf, sizeof(int64_t));
        *buflen = sizeof(int64_t);
        return (0);
}
 
static int
ng_int64_getAlign(const struct ng_parse_type *type)
{
        return INT64_ALIGNMENT;
}
 
const struct ng_parse_type ng_parse_int64_type = {
        NULL,
        (void *)INT_SIGNED,
        NULL,
        ng_int64_parse,
        ng_int64_unparse,
        ng_int64_getDefault,
        ng_int64_getAlign
};
 
const struct ng_parse_type ng_parse_uint64_type = {
        &ng_parse_int64_type,
        (void *)INT_UNSIGNED
};
 
const struct ng_parse_type ng_parse_hint64_type = {
        &ng_parse_int64_type,
        (void *)INT_HEX
};
 
/************************************************************************
                                STRING TYPE
 ************************************************************************/
 
static int
ng_string_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        char *sval;
        int len;
        int slen;
 
        if ((sval = ng_get_string_token(s, off, &len, &slen)) == NULL)
                return (EINVAL);
        *off += len;
        bcopy(sval, buf, slen + 1);
        free(sval, M_NETGRAPH_PARSE);
        *buflen = slen + 1;
        return (0);
}
 
static int
ng_string_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *const raw = (const char *)data + *off;
        char *const s = ng_encode_string(raw, strlen(raw));
        int error;
 
        if (s == NULL)
                return (ENOMEM);
        if ((error = ng_parse_append(&cbuf, &cbuflen, "%s", s)) != 0) {
                free(s, M_NETGRAPH_PARSE);
                return (error);
        }
        *off += strlen(raw) + 1;
        free(s, M_NETGRAPH_PARSE);
        return (0);
}
 
static int
ng_string_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
 
        if (*buflen < 1)
                return (ERANGE);
        buf[0] = (u_char)'\0';
        *buflen = 1;
        return (0);
}
 
const struct ng_parse_type ng_parse_string_type = {
        NULL,
        NULL,
        NULL,
        ng_string_parse,
        ng_string_unparse,
        ng_string_getDefault,
        NULL
};
 
/************************************************************************
                        FIXED BUFFER STRING TYPE
 ************************************************************************/
 
static int
ng_fixedstring_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        const struct ng_parse_fixedstring_info *const fi = type->info;
        char *sval;
        int len;
        int slen;
 
        if ((sval = ng_get_string_token(s, off, &len, &slen)) == NULL)
                return (EINVAL);
        if (slen + 1 > fi->bufSize) {
                free(sval, M_NETGRAPH_PARSE);
                return (E2BIG);
        }
        *off += len;
        bcopy(sval, buf, slen);
        free(sval, M_NETGRAPH_PARSE);
        bzero(buf + slen, fi->bufSize - slen);
        *buflen = fi->bufSize;
        return (0);
}
 
static int
ng_fixedstring_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const struct ng_parse_fixedstring_info *const fi = type->info;
        int error, temp = *off;
 
        if ((error = ng_string_unparse(type, data, &temp, cbuf, cbuflen)) != 0)
                return (error);
        *off += fi->bufSize;
        return (0);
}
 
static int
ng_fixedstring_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        const struct ng_parse_fixedstring_info *const fi = type->info;
 
        if (*buflen < fi->bufSize)
                return (ERANGE);
        bzero(buf, fi->bufSize);
        *buflen = fi->bufSize;
        return (0);
}
 
const struct ng_parse_type ng_parse_fixedstring_type = {
        NULL,
        NULL,
        NULL,
        ng_fixedstring_parse,
        ng_fixedstring_unparse,
        ng_fixedstring_getDefault,
        NULL
};
 
const struct ng_parse_fixedstring_info ng_parse_nodebuf_info = {
        NG_NODESIZ
};
const struct ng_parse_type ng_parse_nodebuf_type = {
        &ng_parse_fixedstring_type,
        &ng_parse_nodebuf_info
};
 
const struct ng_parse_fixedstring_info ng_parse_hookbuf_info = {
        NG_HOOKSIZ
};
const struct ng_parse_type ng_parse_hookbuf_type = {
        &ng_parse_fixedstring_type,
        &ng_parse_hookbuf_info
};
 
const struct ng_parse_fixedstring_info ng_parse_pathbuf_info = {
        NG_PATHSIZ
};
const struct ng_parse_type ng_parse_pathbuf_type = {
        &ng_parse_fixedstring_type,
        &ng_parse_pathbuf_info
};
 
const struct ng_parse_fixedstring_info ng_parse_typebuf_info = {
        NG_TYPESIZ
};
const struct ng_parse_type ng_parse_typebuf_type = {
        &ng_parse_fixedstring_type,
        &ng_parse_typebuf_info
};
 
const struct ng_parse_fixedstring_info ng_parse_cmdbuf_info = {
        NG_CMDSTRSIZ
};
const struct ng_parse_type ng_parse_cmdbuf_type = {
        &ng_parse_fixedstring_type,
        &ng_parse_cmdbuf_info
};
 
/************************************************************************
                        EXPLICITLY SIZED STRING TYPE
 ************************************************************************/
 
static int
ng_sizedstring_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        char *sval;
        int len;
        int slen;
 
        if ((sval = ng_get_string_token(s, off, &len, &slen)) == NULL)
                return (EINVAL);
        if (slen > USHRT_MAX) {
                free(sval, M_NETGRAPH_PARSE);
                return (EINVAL);
        }
        *off += len;
        *((u_int16_t *)buf) = (u_int16_t)slen;
        bcopy(sval, buf + 2, slen);
        free(sval, M_NETGRAPH_PARSE);
        *buflen = 2 + slen;
        return (0);
}
 
static int
ng_sizedstring_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        const char *const raw = (const char *)data + *off + 2;
        const int slen = *((const u_int16_t *)(data + *off));
        char *const s = ng_encode_string(raw, slen);
        int error;
 
        if (s == NULL)
                return (ENOMEM);
        if ((error = ng_parse_append(&cbuf, &cbuflen, "%s", s)) != 0) {
                free(s, M_NETGRAPH_PARSE);
                return (error);
        }
        free(s, M_NETGRAPH_PARSE);
        *off += slen + 2;
        return (0);
}
 
static int
ng_sizedstring_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        if (*buflen < 2)
                return (ERANGE);
        bzero(buf, 2);
        *buflen = 2;
        return (0);
}
 
const struct ng_parse_type ng_parse_sizedstring_type = {
        NULL,
        NULL,
        NULL,
        ng_sizedstring_parse,
        ng_sizedstring_unparse,
        ng_sizedstring_getDefault,
        NULL
};
 
/************************************************************************
                        IP ADDRESS TYPE
 ************************************************************************/
 
static int
ng_ipaddr_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        int i, error;
 
        for (i = 0; i < 4; i++) {
                if ((error = ng_int8_parse(&ng_parse_int8_type,
                    s, off, start, buf + i, buflen)) != 0)
                        return (error);
                if (i < 3) {
                        if (s[*off] != '.')
                                return (EINVAL);
                        (*off)++;
                }
        }
        *buflen = 4;
        return (0);
}
 
static int
ng_ipaddr_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        struct in_addr ip;
        int error;
 
        bcopy(data + *off, &ip, sizeof(ip));
        if ((error = ng_parse_append(&cbuf, &cbuflen, "%d.%d.%d.%d",
            ((u_char *)&ip)[0], ((u_char *)&ip)[1],
            ((u_char *)&ip)[2], ((u_char *)&ip)[3])) != 0)
                return (error);
        *off += sizeof(ip);
        return (0);
}
 
static int
ng_ipaddr_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        struct in_addr ip = { 0 };
 
        if (*buflen < sizeof(ip))
                return (ERANGE);
        bcopy(&ip, buf, sizeof(ip));
        *buflen = sizeof(ip);
        return (0);
}
 
const struct ng_parse_type ng_parse_ipaddr_type = {
        NULL,
        NULL,
        NULL,
        ng_ipaddr_parse,
        ng_ipaddr_unparse,
        ng_ipaddr_getDefault,
        ng_int32_getAlign
};
 
/************************************************************************
                        ETHERNET ADDRESS TYPE
 ************************************************************************/
 
static int
ng_enaddr_parse(const struct ng_parse_type *type,
        const char *s, int *const off, const u_char *const start,
        u_char *const buf, int *const buflen)
{
        char *eptr;
        u_long val;
        int i;
 
        if (*buflen < ETHER_ADDR_LEN)
                return (ERANGE);
        for (i = 0; i < ETHER_ADDR_LEN; i++) {
                val = strtoul(s + *off, &eptr, 16);
                if (val > 0xff || eptr == s + *off)
                        return (EINVAL);
                buf[i] = (u_char)val;
                *off = (eptr - s);
                if (i < ETHER_ADDR_LEN - 1) {
                        if (*eptr != ':')
                                return (EINVAL);
                        (*off)++;
                }
        }
        *buflen = ETHER_ADDR_LEN;
        return (0);
}
 
static int
ng_enaddr_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        int len;
 
        len = snprintf(cbuf, cbuflen, "%02x:%02x:%02x:%02x:%02x:%02x",
            data[*off], data[*off + 1], data[*off + 2],
            data[*off + 3], data[*off + 4], data[*off + 5]);
        if (len >= cbuflen)
                return (ERANGE);
        *off += ETHER_ADDR_LEN;
        return (0);
}
 
const struct ng_parse_type ng_parse_enaddr_type = {
        NULL,
        NULL,
        NULL,
        ng_enaddr_parse,
        ng_enaddr_unparse,
        NULL,
        0
};
 
/************************************************************************
                        BYTE ARRAY TYPE
 ************************************************************************/
 
/* Get the length of a byte array */
static int
ng_parse_bytearray_subtype_getLength(const struct ng_parse_type *type,
        const u_char *start, const u_char *buf)
{
        ng_parse_array_getLength_t *const getLength = type->private;
 
        return (*getLength)(type, start, buf);
}
 
/* Byte array element type is hex int8 */
static const struct ng_parse_array_info ng_parse_bytearray_subtype_info = {
        &ng_parse_hint8_type,
        &ng_parse_bytearray_subtype_getLength,
        NULL
};
static const struct ng_parse_type ng_parse_bytearray_subtype = {
        &ng_parse_array_type,
        &ng_parse_bytearray_subtype_info
};
 
static int
ng_bytearray_parse(const struct ng_parse_type *type,
        const char *s, int *off, const u_char *const start,
        u_char *const buf, int *buflen)
{
        char *str;
        int toklen;
        int slen;
 
        /* We accept either an array of bytes or a string constant */
        if ((str = ng_get_string_token(s, off, &toklen, &slen)) != NULL) {
                ng_parse_array_getLength_t *const getLength = type->info;
                int arraylen;
 
                arraylen = (*getLength)(type, start, buf);
                if (arraylen > *buflen) {
                        free(str, M_NETGRAPH_PARSE);
                        return (ERANGE);
                }
                if (slen > arraylen) {
                        free(str, M_NETGRAPH_PARSE);
                        return (E2BIG);
                }
                bcopy(str, buf, slen);
                bzero(buf + slen, arraylen - slen);
                free(str, M_NETGRAPH_PARSE);
                *off += toklen;
                *buflen = arraylen;
                return (0);
        } else {
                struct ng_parse_type subtype;
 
                subtype = ng_parse_bytearray_subtype;
                subtype.private = __DECONST(void *, type->info);
                return ng_array_parse(&subtype, s, off, start, buf, buflen);
        }
}
 
static int
ng_bytearray_unparse(const struct ng_parse_type *type,
        const u_char *data, int *off, char *cbuf, int cbuflen)
{
        struct ng_parse_type subtype;
 
        subtype = ng_parse_bytearray_subtype;
        subtype.private = __DECONST(void *, type->info);
        return ng_array_unparse(&subtype, data, off, cbuf, cbuflen);
}
 
static int
ng_bytearray_getDefault(const struct ng_parse_type *type,
        const u_char *const start, u_char *buf, int *buflen)
{
        struct ng_parse_type subtype;
 
        subtype = ng_parse_bytearray_subtype;
        subtype.private = __DECONST(void *, type->info);
        return ng_array_getDefault(&subtype, start, buf, buflen);
}
 
const struct ng_parse_type ng_parse_bytearray_type = {
        NULL,
        NULL,
        NULL,
        ng_bytearray_parse,
        ng_bytearray_unparse,
        ng_bytearray_getDefault,
        NULL
};
 
/************************************************************************
                        STRUCT NG_MESG TYPE
 ************************************************************************/
 
/* Get msg->header.arglen when "buf" is pointing to msg->data */
static int
ng_parse_ng_mesg_getLength(const struct ng_parse_type *type,
        const u_char *start, const u_char *buf)
{
        const struct ng_mesg *msg;
 
        msg = (const struct ng_mesg *)(buf - sizeof(*msg));
        return msg->header.arglen;
}
 
/* Type for the variable length data portion of a struct ng_mesg */
static const struct ng_parse_type ng_msg_data_type = {
        &ng_parse_bytearray_type,
        &ng_parse_ng_mesg_getLength
};
 
/* Type for the entire struct ng_mesg header with data section */
static const struct ng_parse_struct_field ng_parse_ng_mesg_type_fields[]
        = NG_GENERIC_NG_MESG_INFO(&ng_msg_data_type);
const struct ng_parse_type ng_parse_ng_mesg_type = {
        &ng_parse_struct_type,
        &ng_parse_ng_mesg_type_fields,
};
 
/************************************************************************
                        COMPOSITE HELPER ROUTINES
 ************************************************************************/
 
/*
 * Convert a structure or array from ASCII to binary
 */
static int
ng_parse_composite(const struct ng_parse_type *type, const char *s,
        int *off, const u_char *const start, u_char *const buf, int *buflen,
        const enum comptype ctype)
{
        const int num = ng_get_composite_len(type, start, buf, ctype);
        int nextIndex = 0;              /* next implicit array index */
        u_int index;                    /* field or element index */
        int *foff;                      /* field value offsets in string */
        int align, len, blen, error = 0;
 
        /* Initialize */
        foff = malloc(num * sizeof(*foff), M_NETGRAPH_PARSE, M_NOWAIT | M_ZERO);
        if (foff == NULL) {
                error = ENOMEM;
                goto done;
        }
 
        /* Get opening brace/bracket */
        if (ng_parse_get_token(s, off, &len)
            != (ctype == CT_STRUCT ? T_LBRACE : T_LBRACKET)) {
                error = EINVAL;
                goto done;
        }
        *off += len;
 
        /* Get individual element value positions in the string */
        for (;;) {
                enum ng_parse_token tok;
 
                /* Check for closing brace/bracket */
                tok = ng_parse_get_token(s, off, &len);
                if (tok == (ctype == CT_STRUCT ? T_RBRACE : T_RBRACKET)) {
                        *off += len;
                        break;
                }
 
                /* For arrays, the 'name' (ie, index) is optional, so
                   distinguish name from values by seeing if the next
                   token is an equals sign */
                if (ctype != CT_STRUCT) {
                        u_long ul;
                        int len2, off2;
                        char *eptr;
 
                        /* If an opening brace/bracket, index is implied */
                        if (tok == T_LBRACE || tok == T_LBRACKET) {
                                index = nextIndex++;
                                goto gotIndex;
                        }
 
                        /* Might be an index, might be a value, either way... */
                        if (tok != T_WORD) {
                                error = EINVAL;
                                goto done;
                        }
 
                        /* If no equals sign follows, index is implied */
                        off2 = *off + len;
                        if (ng_parse_get_token(s, &off2, &len2) != T_EQUALS) {
                                index = nextIndex++;
                                goto gotIndex;
                        }
 
                        /* Index was specified explicitly; parse it */
                        ul = strtoul(s + *off, &eptr, 0);
                        if (ul == ULONG_MAX || eptr - (s + *off) != len) {
                                error = EINVAL;
                                goto done;
                        }
                        index = (u_int)ul;
                        nextIndex = index + 1;
                        *off += len + len2;
                } else {                        /* a structure field */
                        const struct ng_parse_struct_field *const
                            fields = type->info;
 
                        /* Find the field by name (required) in field list */
                        if (tok != T_WORD) {
                                error = EINVAL;
                                goto done;
                        }
                        for (index = 0; index < num; index++) {
                                const struct ng_parse_struct_field *const
                                    field = &fields[index];
 
                                if (strncmp(&s[*off], field->name, len) == 0
                                    && field->name[len] == '\0')
                                        break;
                        }
                        if (index == num) {
                                error = ENOENT;
                                goto done;
                        }
                        *off += len;
 
                        /* Get equals sign */
                        if (ng_parse_get_token(s, off, &len) != T_EQUALS) {
                                error = EINVAL;
                                goto done;
                        }
                        *off += len;
                }
gotIndex:
 
                /* Check array index */
                if (index >= num) {
                        error = E2BIG;
                        goto done;
                }
 
                /* Save value's position and skip over it for now */
                if (foff[index] != 0) {
                        error = EALREADY;               /* duplicate */
                        goto done;
                }
                while (isspace(s[*off]))
                        (*off)++;
                foff[index] = *off;
                if ((error = ng_parse_skip_value(s, *off, &len)) != 0)
                        goto done;
                *off += len;
        }
 
        /* Now build binary structure from supplied values and defaults */
        for (blen = index = 0; index < num; index++) {
                const struct ng_parse_type *const
                    etype = ng_get_composite_etype(type, index, ctype);
                int k, pad, vlen;
 
                /* Zero-pad any alignment bytes */
                pad = ng_parse_get_elem_pad(type, index, ctype, blen);
                for (k = 0; k < pad; k++) {
                        if (blen >= *buflen) {
                                error = ERANGE;
                                goto done;
                        }
                        buf[blen++] = 0;
                }
 
                /* Get value */
                vlen = *buflen - blen;
                if (foff[index] == 0) {         /* use default value */
                        error = ng_get_composite_elem_default(type, index,
                            start, buf + blen, &vlen, ctype);
                } else {                        /* parse given value */
                        *off = foff[index];
                        error = INVOKE(etype, parse)(etype,
                            s, off, start, buf + blen, &vlen);
                }
                if (error != 0)
                        goto done;
                blen += vlen;
        }
 
        /* Make total composite structure size a multiple of its alignment */
        if ((align = ALIGNMENT(type)) != 0) {
                while (blen % align != 0) {
                        if (blen >= *buflen) {
                                error = ERANGE;
                                goto done;
                        }
                        buf[blen++] = 0;
                }
        }
 
        /* Done */
        *buflen = blen;
done:
        if (foff != NULL)
                free(foff, M_NETGRAPH_PARSE);
        return (error);
}
 
/*
 * Convert an array or structure from binary to ASCII
 */
static int
ng_unparse_composite(const struct ng_parse_type *type, const u_char *data,
        int *off, char *cbuf, int cbuflen, const enum comptype ctype)
{
        const struct ng_mesg *const hdr
            = (const struct ng_mesg *)(data - sizeof(*hdr));
        const int num = ng_get_composite_len(type, data, data + *off, ctype);
        const int workSize = 20 * 1024;         /* XXX hard coded constant */
        int nextIndex = 0, didOne = 0;
        int error, index;
        u_char *workBuf;
 
        /* Get workspace for checking default values */
        workBuf = malloc(workSize, M_NETGRAPH_PARSE, M_NOWAIT);
        if (workBuf == NULL)
                return (ENOMEM);
 
        /* Opening brace/bracket */
        if ((error = ng_parse_append(&cbuf, &cbuflen, "%c",
            (ctype == CT_STRUCT) ? '{' : '[')) != 0)
                goto fail;
 
        /* Do each item */
        for (index = 0; index < num; index++) {
                const struct ng_parse_type *const
                    etype = ng_get_composite_etype(type, index, ctype);
 
                /* Skip any alignment pad bytes */
                *off += ng_parse_get_elem_pad(type, index, ctype, *off);
 
                /*
                 * See if element is equal to its default value; skip if so.
                 * Copy struct ng_mesg header for types that peek into it.
                 */
                if (sizeof(*hdr) + *off < workSize) {
                        int tempsize = workSize - sizeof(*hdr) - *off;
 
                        bcopy(hdr, workBuf, sizeof(*hdr) + *off);
                        if (ng_get_composite_elem_default(type, index, workBuf
                              + sizeof(*hdr), workBuf + sizeof(*hdr) + *off,
                              &tempsize, ctype) == 0
                            && bcmp(workBuf + sizeof(*hdr) + *off,
                              data + *off, tempsize) == 0) {
                                *off += tempsize;
                                continue;
                        }
                }
 
                /* Print name= */
                if ((error = ng_parse_append(&cbuf, &cbuflen, " ")) != 0)
                        goto fail;
                if (ctype != CT_STRUCT) {
                        if (index != nextIndex) {
                                nextIndex = index;
                                if ((error = ng_parse_append(&cbuf,
                                    &cbuflen, "%d=", index)) != 0)
                                        goto fail;
                        }
                        nextIndex++;
                } else {
                        const struct ng_parse_struct_field *const
                            fields = type->info;
 
                        if ((error = ng_parse_append(&cbuf,
                            &cbuflen, "%s=", fields[index].name)) != 0)
                                goto fail;
                }
 
                /* Print value */
                if ((error = INVOKE(etype, unparse)
                    (etype, data, off, cbuf, cbuflen)) != 0) {
                        free(workBuf, M_NETGRAPH_PARSE);
                        return (error);
                }
                cbuflen -= strlen(cbuf);
                cbuf += strlen(cbuf);
                didOne = 1;
        }
 
        /* Closing brace/bracket */
        error = ng_parse_append(&cbuf, &cbuflen, "%s%c",
            didOne ? " " : "", (ctype == CT_STRUCT) ? '}' : ']');
 
fail:
        /* Clean up after failure */
        free(workBuf, M_NETGRAPH_PARSE);
        return (error);
}
 
/*
 * Generate the default value for an element of an array or structure
 * Returns EOPNOTSUPP if default value is unspecified.
 */
static int
ng_get_composite_elem_default(const struct ng_parse_type *type,
        int index, const u_char *const start, u_char *buf, int *buflen,
        const enum comptype ctype)
{
        const struct ng_parse_type *etype;
        ng_getDefault_t *func;
 
        switch (ctype) {
        case CT_STRUCT:
                break;
        case CT_ARRAY:
            {
                const struct ng_parse_array_info *const ai = type->info;
 
                if (ai->getDefault != NULL) {
                        return (*ai->getDefault)(type,
                            index, start, buf, buflen);
                }
                break;
            }
        case CT_FIXEDARRAY:
            {
                const struct ng_parse_fixedarray_info *const fi = type->info;
 
                if (*fi->getDefault != NULL) {
                        return (*fi->getDefault)(type,
                            index, start, buf, buflen);
                }
                break;
            }
        default:
            panic("%s", __func__);
        }
 
        /* Default to element type default */
        etype = ng_get_composite_etype(type, index, ctype);
        func = METHOD(etype, getDefault);
        if (func == NULL)
                return (EOPNOTSUPP);
        return (*func)(etype, start, buf, buflen);
}
 
/*
 * Get the number of elements in a struct, variable or fixed array.
 */
static int
ng_get_composite_len(const struct ng_parse_type *type,
        const u_char *const start, const u_char *buf,
        const enum comptype ctype)
{
        switch (ctype) {
        case CT_STRUCT:
            {
                const struct ng_parse_struct_field *const fields = type->info;
                int numFields = 0;
 
                for (numFields = 0; ; numFields++) {
                        const struct ng_parse_struct_field *const
                                fi = &fields[numFields];
 
                        if (fi->name == NULL)
                                break;
                }
                return (numFields);
            }
        case CT_ARRAY:
            {
                const struct ng_parse_array_info *const ai = type->info;
 
                return (*ai->getLength)(type, start, buf);
            }
        case CT_FIXEDARRAY:
            {
                const struct ng_parse_fixedarray_info *const fi = type->info;
 
                return fi->length;
            }
        default:
            panic("%s", __func__);
        }
        return (0);
}
 
/*
 * Return the type of the index'th element of a composite structure
 */
static const struct ng_parse_type *
ng_get_composite_etype(const struct ng_parse_type *type,
        int index, const enum comptype ctype)
{
        const struct ng_parse_type *etype = NULL;
 
        switch (ctype) {
        case CT_STRUCT:
            {
                const struct ng_parse_struct_field *const fields = type->info;
 
                etype = fields[index].type;
                break;
            }
        case CT_ARRAY:
            {
                const struct ng_parse_array_info *const ai = type->info;
 
                etype = ai->elementType;
                break;
            }
        case CT_FIXEDARRAY:
            {
                const struct ng_parse_fixedarray_info *const fi = type->info;
 
                etype = fi->elementType;
                break;
            }
        default:
            panic("%s", __func__);
        }
        return (etype);
}
 
/*
 * Get the number of bytes to skip to align for the next
 * element in a composite structure.
 */
static int
ng_parse_get_elem_pad(const struct ng_parse_type *type,
        int index, enum comptype ctype, int posn)
{
        const struct ng_parse_type *const
            etype = ng_get_composite_etype(type, index, ctype);
        int align;
 
        /* Get element's alignment, and possibly override */
        align = ALIGNMENT(etype);
        if (ctype == CT_STRUCT) {
                const struct ng_parse_struct_field *const fields = type->info;
 
                if (fields[index].alignment != 0)
                        align = fields[index].alignment;
        }
 
        /* Return number of bytes to skip to align */
        return (align ? (align - (posn % align)) % align : 0);
}
 
/************************************************************************
                        PARSING HELPER ROUTINES
 ************************************************************************/
 
/*
 * Append to a fixed length string buffer.
 */
static int
ng_parse_append(char **cbufp, int *cbuflenp, const char *fmt, ...)
{
        va_list args;
        int len;
 
        va_start(args, fmt);
        len = vsnprintf(*cbufp, *cbuflenp, fmt, args);
        va_end(args);
        if (len >= *cbuflenp)
                return ERANGE;
        *cbufp += len;
        *cbuflenp -= len;
 
        return (0);
}
 
/*
 * Skip over a value
 */
static int
ng_parse_skip_value(const char *s, int off0, int *lenp)
{
        int len, nbracket, nbrace;
        int off = off0;
 
        len = nbracket = nbrace = 0;
        do {
                switch (ng_parse_get_token(s, &off, &len)) {
                case T_LBRACKET:
                        nbracket++;
                        break;
                case T_LBRACE:
                        nbrace++;
                        break;
                case T_RBRACKET:
                        if (nbracket-- == 0)
                                return (EINVAL);
                        break;
                case T_RBRACE:
                        if (nbrace-- == 0)
                                return (EINVAL);
                        break;
                case T_EOF:
                        return (EINVAL);
                default:
                        break;
                }
                off += len;
        } while (nbracket > 0 || nbrace > 0);
        *lenp = off - off0;
        return (0);
}
 
/*
 * Find the next token in the string, starting at offset *startp.
 * Returns the token type, with *startp pointing to the first char
 * and *lenp the length.
 */
enum ng_parse_token
ng_parse_get_token(const char *s, int *startp, int *lenp)
{
        char *t;
        int i;
 
        while (isspace(s[*startp]))
                (*startp)++;
        switch (s[*startp]) {
        case '\0':
                *lenp = 0;
                return T_EOF;
        case '{':
                *lenp = 1;
                return T_LBRACE;
        case '}':
                *lenp = 1;
                return T_RBRACE;
        case '[':
                *lenp = 1;
                return T_LBRACKET;
        case ']':
                *lenp = 1;
                return T_RBRACKET;
        case '=':
                *lenp = 1;
                return T_EQUALS;
        case '"':
                if ((t = ng_get_string_token(s, startp, lenp, NULL)) == NULL)
                        return T_ERROR;
                free(t, M_NETGRAPH_PARSE);
                return T_STRING;
        default:
                for (i = *startp + 1; s[i] != '\0' && !isspace(s[i])
                    && s[i] != '{' && s[i] != '}' && s[i] != '['
                    && s[i] != ']' && s[i] != '=' && s[i] != '"'; i++)
                        ;
                *lenp = i - *startp;
                return T_WORD;
        }
}
 
/*
 * Get a string token, which must be enclosed in double quotes.
 * The normal C backslash escapes are recognized.
 */
char *
ng_get_string_token(const char *s, int *startp, int *lenp, int *slenp)
{
        char *cbuf, *p;
        int start, off;
        int slen;
 
        while (isspace(s[*startp]))
                (*startp)++;
        start = *startp;
        if (s[*startp] != '"')
                return (NULL);
        cbuf = malloc(strlen(s + start), M_NETGRAPH_PARSE, M_NOWAIT);
        if (cbuf == NULL)
                return (NULL);
        strcpy(cbuf, s + start + 1);
        for (slen = 0, off = 1, p = cbuf; *p != '\0'; slen++, off++, p++) {
                if (*p == '"') {
                        *p = '\0';
                        *lenp = off + 1;
                        if (slenp != NULL)
                                *slenp = slen;
                        return (cbuf);
                } else if (p[0] == '\\' && p[1] != '\0') {
                        int x, k;
                        char *v;
 
                        strcpy(p, p + 1);
                        v = p;
                        switch (*p) {
                        case 't':
                                *v = '\t';
                                off++;
                                continue;
                        case 'n':
                                *v = '\n';
                                off++;
                                continue;
                        case 'r':
                                *v = '\r';
                                off++;
                                continue;
                        case 'v':
                                *v =  '\v';
                                off++;
                                continue;
                        case 'f':
                                *v =  '\f';
                                off++;
                                continue;
                        case '"':
                                *v =  '"';
                                off++;
                                continue;
                        case '0': case '1': case '2': case '3':
                        case '4': case '5': case '6': case '7':
                                for (x = k = 0;
                                    k < 3 && *v >= '0' && *v <= '7'; v++) {
                                        x = (x << 3) + (*v - '0');
                                        off++;
                                }
                                *--v = (char)x;
                                break;
                        case 'x':
                                for (v++, x = k = 0;
                                    k < 2 && isxdigit(*v); v++) {
                                        x = (x << 4) + (isdigit(*v) ?
                                              (*v - '0') :
                                              (tolower(*v) - 'a' + 10));
                                        off++;
                                }
                                *--v = (char)x;
                                break;
                        default:
                                continue;
                        }
                        strcpy(p, v);
                }
        }
        free(cbuf, M_NETGRAPH_PARSE);
        return (NULL);          /* no closing quote */
}
 
/*
 * Encode a string so it can be safely put in double quotes.
 * Caller must free the result. Exactly "slen" characters
 * are encoded.
 */
char *
ng_encode_string(const char *raw, int slen)
{
        char *cbuf;
        int off = 0;
        int i;
 
        cbuf = malloc(strlen(raw) * 4 + 3, M_NETGRAPH_PARSE, M_NOWAIT);
        if (cbuf == NULL)
                return (NULL);
        cbuf[off++] = '"';
        for (i = 0; i < slen; i++, raw++) {
                switch (*raw) {
                case '\t':
                        cbuf[off++] = '\\';
                        cbuf[off++] = 't';
                        break;
                case '\f':
                        cbuf[off++] = '\\';
                        cbuf[off++] = 'f';
                        break;
                case '\n':
                        cbuf[off++] = '\\';
                        cbuf[off++] = 'n';
                        break;
                case '\r':
                        cbuf[off++] = '\\';
                        cbuf[off++] = 'r';
                        break;
                case '\v':
                        cbuf[off++] = '\\';
                        cbuf[off++] = 'v';
                        break;
                case '"':
                case '\\':
                        cbuf[off++] = '\\';
                        cbuf[off++] = *raw;
                        break;
                default:
                        if (*raw < 0x20 || *raw > 0x7e) {
                                off += sprintf(cbuf + off,
                                    "\\x%02x", (u_char)*raw);
                                break;
                        }
                        cbuf[off++] = *raw;
                        break;
                }
        }
        cbuf[off++] = '"';
        cbuf[off] = '\0';
        return (cbuf);
}
 
/************************************************************************
                        VIRTUAL METHOD LOOKUP
 ************************************************************************/
 
static ng_parse_t *
ng_get_parse_method(const struct ng_parse_type *t)
{
        while (t != NULL && t->parse == NULL)
                t = t->supertype;
        return (t ? t->parse : NULL);
}
 
static ng_unparse_t *
ng_get_unparse_method(const struct ng_parse_type *t)
{
        while (t != NULL && t->unparse == NULL)
                t = t->supertype;
        return (t ? t->unparse : NULL);
}
 
static ng_getDefault_t *
ng_get_getDefault_method(const struct ng_parse_type *t)
{
        while (t != NULL && t->getDefault == NULL)
                t = t->supertype;
        return (t ? t->getDefault : NULL);
}
 
static ng_getAlign_t *
ng_get_getAlign_method(const struct ng_parse_type *t)
{
        while (t != NULL && t->getAlign == NULL)
                t = t->supertype;
        return (t ? t->getAlign : NULL);
}