[XL] Change in flashrom[master]: Plain mjason 1.6

[Stefan Reinauer (Code Review)]

Stefan Reinauer has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/75647?usp=email )

Change subject: Plain mjason 1.6
......................................................................

Plain mjason 1.6

With whitespace fixes. Because flashrom doesn't like vanilla.

Change-Id: I9f770baec883f35507bf3b7b60ef2d581db27002
Signed-off-by: Stefan Reinauer 
---
A mjson.c
A mjson.h
2 files changed, 1,016 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/47/75647/1

diff --git a/mjson.c b/mjson.c
new file mode 100644
index 0000000..ddb30d6
--- /dev/null
+++ b/mjson.c
@@ -0,0 +1,858 @@
+/****************************************************************************
+
+NAME
+   mjson.c - parse JSON into fixed-extent data structures
+
+DESCRIPTION
+   This module parses a large subset of JSON (JavaScript Object
+Notation).  Unlike more general JSON parsers, it doesn't use malloc(3)
+and doesn't support polymorphism; you need to give it a set of
+template structures describing the expected shape of the incoming
+JSON, and it will error out if that shape is not matched.  When the
+parse succeeds, attribute values will be extracted into static
+locations specified in the template structures.
+
+   The "shape" of a JSON object in the type signature of its
+attributes (and attribute values, and so on recursively down through
+all nestings of objects and arrays).  This parser is indifferent to
+the order of attributes at any level, but you have to tell it in
+advance what the type of each attribute value will be and where the
+parsed value will be stored. The template structures may supply
+default values to be used when an expected attribute is omitted.
+
+   The preceding paragraph told one fib.  A single attribute may
+actually have a span of multiple specifications with different
+syntactically distinguishable types (e.g. string vs. real vs. integer
+vs. boolean, but not signed integer vs. unsigned integer).  The parser
+will match the right spec against the actual data.
+
+   The dialect this parses has some limitations.  First, it cannot
+recognize the JSON "null" value. Second, all elements of an array must
+be of the same type. Third, characters may not be array elements (this
+restriction could be lifted)
+
+   There are separate entry points for beginning a parse of either
+JSON object or a JSON array. JSON "float" quantities are actually
+stored as doubles.
+
+   This parser processes object arrays in one of two different ways,
+defending on whether the array subtype is declared as object or
+structobject.
+
+   Object arrays take one base address per object subfield, and are
+mapped into parallel C arrays (one per subfield).  Strings are not
+supported in this kind of array, as they don't have a "natural" size
+to use as an offset multiplier.
+
+   Structobjects arrays are a way to parse a list of objects to a set
+of modifications to a corresponding array of C structs.  The trick is
+that the array object initialization has to specify both the C struct
+array's base address and the stride length (the size of the C struct).
+If you initialize the offset fields with the correct offsetof calls,
+everything will work. Strings are supported but all string storage
+has to be inline in the struct.
+
+PERMISSIONS
+   This file is Copyright (c) 2014 by Eric S. Raymond
+   SPDX-License-Identifier: BSD-2-Clause
+
+***************************************************************************/
+/* The strptime prototype is not provided unless explicitly requested.
+ * We also need to set the value high enough to signal inclusion of
+ * newer features (like clock_gettime).  See the POSIX spec for more info:
+ * http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag... */
+#define _XOPEN_SOURCE 600
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include <ctype.h>
+#include <errno.h>
+#include <time.h>
+#include <math.h>	/* for HUGE_VAL */
+
+#include "mjson.h"
+
+#define str_starts_with(s, p)	(strncmp(s, p, strlen(p)) == 0)
+
+#ifdef DEBUG_ENABLE
+static int debuglevel = 0;
+static FILE *debugfp;
+
+void json_enable_debug(int level, FILE * fp)
+/* control the level and destination of debug trace messages */
+{
+    debuglevel = level;
+    debugfp = fp;
+}
+
+static void json_trace(int errlevel, const char *fmt, ...)
+/* assemble command in printf(3) style */
+{
+    if (errlevel <= debuglevel) {
+	char buf[BUFSIZ];
+	va_list ap;
+
+	(void)strncpy(buf, "json: ", BUFSIZ-1);
+	buf[BUFSIZ-1] = '\0';
+	va_start(ap, fmt);
+	(void)vsnprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), fmt,
+			ap);
+	va_end(ap);
+
+	(void)fputs(buf, debugfp);
+    }
+}
+
+# define json_debug_trace(args) (void) json_trace args
+#else
+# define json_debug_trace(args) do { } while (0)
+#endif /* DEBUG_ENABLE */
+
+static char *json_target_address(const struct json_attr_t *cursor,
+					     const struct json_array_t
+					     *parent, int offset)
+{
+    char *targetaddr = NULL;
+    if (parent == NULL || parent->element_type != t_structobject) {
+	/* ordinary case - use the address in the cursor structure */
+	switch (cursor->type) {
+	case t_ignore:
+	    targetaddr = NULL;
+	    break;
+	case t_integer:
+	    targetaddr = (char *)&cursor->addr.integer[offset];
+	    break;
+	case t_uinteger:
+	    targetaddr = (char *)&cursor->addr.uinteger[offset];
+	    break;
+	case t_short:
+	    targetaddr = (char *)&cursor->addr.shortint[offset];
+	    break;
+	case t_ushort:
+	    targetaddr = (char *)&cursor->addr.ushortint[offset];
+	    break;
+	case t_time:
+	case t_real:
+	    targetaddr = (char *)&cursor->addr.real[offset];
+	    break;
+	case t_string:
+	    targetaddr = cursor->addr.string;
+	    break;
+	case t_boolean:
+	    targetaddr = (char *)&cursor->addr.boolean[offset];
+	    break;
+	case t_character:
+	    targetaddr = (char *)&cursor->addr.character[offset];
+	    break;
+	default:
+	    targetaddr = NULL;
+	    break;
+	}
+    } else
+	/* tricky case - hacking a member in an array of structures */
+	targetaddr =
+	    parent->arr.objects.base + (offset * parent->arr.objects.stride) +
+	    cursor->addr.offset;
+    json_debug_trace((1, "Target address for %s (offset %d) is %p\n",
+		      cursor->attribute, offset, targetaddr));
+    return targetaddr;
+}
+
+#ifdef TIME_ENABLE
+static double iso8601_to_unix(char *isotime)
+/* ISO8601 UTC to Unix UTC */
+{
+    double usec;
+    struct tm tm;
+
+    char *dp = strptime(isotime, "%Y-%m-%dT%H:%M:%S", &tm);
+    if (dp == NULL)
+	return (double)HUGE_VAL;
+    if (*dp == '.')
+	usec = strtod(dp, NULL);
+    else
+	usec = 0;
+    return (double)timegm(&tm) + usec;
+}
+#endif /* TIME_ENABLE */
+
+static int json_internal_read_object(const char *cp,
+				     const struct json_attr_t *attrs,
+				     const struct json_array_t *parent,
+				     int offset,
+				     const char **end)
+{
+    enum
+    { init, await_attr, in_attr, await_value, in_val_string,
+	in_escape, in_val_token, post_val, post_element
+    } state = 0;
+#ifdef DEBUG_ENABLE
+    char *statenames[] = {
+	"init", "await_attr", "in_attr", "await_value", "in_val_string",
+	"in_escape", "in_val_token", "post_val", "post_element",
+    };
+#endif /* DEBUG_ENABLE */
+    char attrbuf[JSON_ATTR_MAX + 1], *pattr = NULL;
+    char valbuf[JSON_VAL_MAX + 1], *pval = NULL;
+    bool value_quoted = false;
+    char uescape[5];		/* enough space for 4 hex digits and a NUL */
+    const struct json_attr_t *cursor;
+    int substatus, n, maxlen = 0;
+    unsigned int u;
+    const struct json_enum_t *mp;
+    char *lptr;
+
+    if (end != NULL)
+	*end = NULL;	/* give it a well-defined value on parse failure */
+
+    /* stuff fields with defaults in case they're omitted in the JSON input */
+    for (cursor = attrs; cursor->attribute != NULL; cursor++)
+	if (!cursor->nodefault) {
+	    lptr = json_target_address(cursor, parent, offset);
+	    if (lptr != NULL)
+		switch (cursor->type) {
+		case t_integer:
+		    memcpy(lptr, &cursor->dflt.integer, sizeof(int));
+		    break;
+		case t_uinteger:
+		    memcpy(lptr, &cursor->dflt.uinteger, sizeof(unsigned int));
+		    break;
+		case t_short:
+		    memcpy(lptr, &cursor->dflt.shortint, sizeof(short));
+		    break;
+		case t_ushort:
+		    memcpy(lptr, &cursor->dflt.ushortint,
+		           sizeof(unsigned short));
+		    break;
+		case t_time:
+		case t_real:
+		    memcpy(lptr, &cursor->dflt.real, sizeof(double));
+		    break;
+		case t_string:
+		    if (parent != NULL
+			&& parent->element_type != t_structobject
+			&& offset > 0)
+			return JSON_ERR_NOPARSTR;
+		    lptr[0] = '\0';
+		    break;
+		case t_boolean:
+		    memcpy(lptr, &cursor->dflt.boolean, sizeof(bool));
+		    break;
+		case t_character:
+		    lptr[0] = cursor->dflt.character;
+		    break;
+		case t_object:	/* silences a compiler warning */
+		case t_structobject:
+		case t_array:
+		case t_check:
+		case t_ignore:
+		    break;
+		}
+	}
+
+    json_debug_trace((1, "JSON parse of '%s' begins.\n", cp));
+
+    /* parse input JSON */
+    for (; *cp != '\0'; cp++) {
+	json_debug_trace((2, "State %-14s, looking at '%c' (%p)\n",
+			  statenames[state], *cp, cp));
+	switch (state) {
+	case init:
+	    if (isspace((unsigned char) *cp))
+		continue;
+	    else if (*cp == '{')
+		state = await_attr;
+	    else {
+		json_debug_trace((1,
+				  "Non-WS when expecting object start.\n"));
+		if (end != NULL)
+		    *end = cp;
+		return JSON_ERR_OBSTART;
+	    }
+	    break;
+	case await_attr:
+	    if (isspace((unsigned char) *cp))
+		continue;
+	    else if (*cp == '"') {
+		state = in_attr;
+		pattr = attrbuf;
+		if (end != NULL)
+		    *end = cp;
+	    } else if (*cp == '}')
+		break;
+	    else {
+		json_debug_trace((1, "Non-WS when expecting attribute.\n"));
+		if (end != NULL)
+		    *end = cp;
+		return JSON_ERR_ATTRSTART;
+	    }
+	    break;
+	case in_attr:
+	    if (pattr == NULL)
+		/* don't update end here, leave at attribute start */
+		return JSON_ERR_NULLPTR;
+	    if (*cp == '"') {
+		*pattr++ = '\0';
+		json_debug_trace((1, "Collected attribute name %s\n",
+				  attrbuf));
+		for (cursor = attrs; cursor->attribute != NULL; cursor++) {
+		    json_debug_trace((2, "Checking against %s\n",
+				      cursor->attribute));
+		    if (strcmp(cursor->attribute, attrbuf) == 0)
+			break;
+		    if (strcmp(cursor->attribute, "") == 0 &&
+			    cursor->type == t_ignore) {
+			break;
+		    }
+		}
+		if (cursor->attribute == NULL) {
+		    json_debug_trace((1,
+				      "Unknown attribute name '%s'"
+                                      " (attributes begin with '%s').\n",
+				      attrbuf, attrs->attribute));
+		    /* don't update end here, leave at attribute start */
+		    return JSON_ERR_BADATTR;
+		}
+		state = await_value;
+		if (cursor->type == t_string)
+		    maxlen = (int)cursor->len - 1;
+		else if (cursor->type == t_check)
+		    maxlen = (int)strlen(cursor->dflt.check);
+		else if (cursor->type == t_time || cursor->type == t_ignore)
+		    maxlen = JSON_VAL_MAX;
+		else if (cursor->map != NULL)
+		    maxlen = (int)sizeof(valbuf) - 1;
+		pval = valbuf;
+	    } else if (pattr >= attrbuf + JSON_ATTR_MAX - 1) {
+		json_debug_trace((1, "Attribute name too long.\n"));
+		/* don't update end here, leave at attribute start */
+		return JSON_ERR_ATTRLEN;
+	    } else
+		*pattr++ = *cp;
+	    break;
+	case await_value:
+	    if (isspace((unsigned char) *cp) || *cp == ':')
+		continue;
+	    else if (*cp == '[') {
+		if (cursor->type != t_array) {
+		    json_debug_trace((1,
+				      "Saw [ when not expecting array.\n"));
+		    if (end != NULL)
+			*end = cp;
+		    return JSON_ERR_NOARRAY;
+		}
+		substatus = json_read_array(cp, &cursor->addr.array, &cp);
+		if (substatus != 0)
+		    return substatus;
+		state = post_element;
+	    } else if (cursor->type == t_array) {
+		json_debug_trace((1,
+				  "Array element was specified, but no [.\n"));
+		if (end != NULL)
+		    *end = cp;
+		return JSON_ERR_NOBRAK;
+	    } else if (*cp == '{') {
+		if (cursor->type != t_object) {
+		    json_debug_trace((1,
+				      "Saw { when not expecting object.\n"));
+		    if (end != NULL)
+			*end = cp;
+		    return JSON_ERR_NOARRAY;
+		}
+		substatus = json_read_object(cp, cursor->addr.attrs, &cp);
+		if (substatus != 0)
+		    return substatus;
+		--cp;	// last } will be re-consumed by cp++ at end of loop
+		state = post_element;
+	    } else if (cursor->type == t_object) {
+		json_debug_trace((1,
+				  "Object element was specified, but no {.\n"));
+		if (end != NULL)
+		    *end = cp;
+		return JSON_ERR_NOCURLY;
+	    } else if (*cp == '"') {
+		value_quoted = true;
+		state = in_val_string;
+		pval = valbuf;
+	    } else {
+		value_quoted = false;
+		state = in_val_token;
+		pval = valbuf;
+		*pval++ = *cp;
+	    }
+	    break;
+	case in_val_string:
+	    if (pval == NULL)
+		/* don't update end here, leave at value start */
+		return JSON_ERR_NULLPTR;
+	    if (*cp == '\')
+		state = in_escape;
+	    else if (*cp == '"') {
+		*pval++ = '\0';
+		json_debug_trace((1, "Collected string value %s\n", valbuf));
+		state = post_val;
+	    } else if (pval > valbuf + JSON_VAL_MAX - 1
+		       || pval > valbuf + maxlen) {
+		json_debug_trace((1, "String value too long.\n"));
+		/* don't update end here, leave at value start */
+		return JSON_ERR_STRLONG;	/*  */
+	    } else
+		*pval++ = *cp;
+	    break;
+	case in_escape:
+	    if (pval == NULL)
+		/* don't update end here, leave at value start */
+		return JSON_ERR_NULLPTR;
+	    else if (pval > valbuf + JSON_VAL_MAX - 1
+		       || pval > valbuf + maxlen) {
+		json_debug_trace((1, "String value too long.\n"));
+		/* don't update end here, leave at value start */
+		return JSON_ERR_STRLONG;	/*  */
+	    }
+	    switch (*cp) {
+	    case 'b':
+		*pval++ = '\b';
+		break;
+	    case 'f':
+		*pval++ = '\f';
+		break;
+	    case 'n':
+		*pval++ = '\n';
+		break;
+	    case 'r':
+		*pval++ = '\r';
+		break;
+	    case 't':
+		*pval++ = '\t';
+		break;
+	    case 'u':
+                cp++;                   /* skip the 'u' */
+		for (n = 0; n < 4 && isxdigit(*cp); n++)
+		    uescape[n] = *cp++;
+                uescape[n] = '\0';      /* terminate */
+		--cp;
+                /* ECMA-404 says JSON \u must have 4 hex digits */
+		if ((4 != n) || (1 != sscanf(uescape, "%4x", &u))) {
+		    return JSON_ERR_BADSTRING;
+                }
+		*pval++ = (unsigned char)u;  /* truncate values above 0xff */
+		break;
+	    default:		/* handles double quote and solidus */
+		*pval++ = *cp;
+		break;
+	    }
+	    state = in_val_string;
+	    break;
+	case in_val_token:
+	    if (pval == NULL)
+		/* don't update end here, leave at value start */
+		return JSON_ERR_NULLPTR;
+	    if (isspace((unsigned char) *cp) || *cp == ',' || *cp == '}') {
+		*pval = '\0';
+		json_debug_trace((1, "Collected token value %s.\n", valbuf));
+		state = post_val;
+		if (*cp == '}' || *cp == ',')
+		    --cp;
+	    } else if (pval > valbuf + JSON_VAL_MAX - 1) {
+		json_debug_trace((1, "Token value too long.\n"));
+		/* don't update end here, leave at value start */
+		return JSON_ERR_TOKLONG;
+	    } else
+		*pval++ = *cp;
+	    break;
+	case post_val:
+	    // Ignore whitespace after either string or token values.
+	    if (isspace(*cp)) {
+		    while (*cp != '\0' && isspace((unsigned char) *cp)) {
+			++cp;
+		    }
+		    json_debug_trace((1, "Skipped trailing whitespace: value "%s"\n", valbuf));
+	    }
+	    /*
+	     * We know that cursor points at the first spec matching
+	     * the current attribute.  We don't know that it's *the*
+	     * correct spec; our dialect allows there to be any number
+	     * of adjacent ones with the same attrname but different
+	     * types.  Here's where we try to seek forward for a
+	     * matching type/attr pair if we're not looking at one.
+	     */
+	    for (;;) {
+		int seeking = cursor->type;
+		if (value_quoted && (cursor->type == t_string
+                    || cursor->type == t_time))
+		    break;
+		if ((strcmp(valbuf, "true")==0 || strcmp(valbuf, "false")==0
+			|| isdigit((unsigned char) valbuf[0]))
+			&& seeking == t_boolean)
+		    break;
+		if (isdigit((unsigned char) valbuf[0])) {
+		    bool decimal = strchr(valbuf, '.') != NULL;
+		    if (decimal && seeking == t_real)
+			break;
+		    if (!decimal && (seeking == t_integer
+                                     || seeking == t_uinteger))
+			break;
+		}
+		if (cursor[1].attribute==NULL)	/* out of possiblities */
+		    break;
+		if (strcmp(cursor[1].attribute, attrbuf)!=0)
+		    break;
+		++cursor;
+	    }
+	    if (value_quoted
+		&& (cursor->type != t_string && cursor->type != t_character
+		    && cursor->type != t_check && cursor->type != t_time
+		    && cursor->type != t_ignore && cursor->map == 0)) {
+		json_debug_trace((1, "Saw quoted value when expecting"
+                                  " non-string.\n"));
+		return JSON_ERR_QNONSTRING;
+	    }
+	    if (!value_quoted
+		&& (cursor->type == t_string || cursor->type == t_check
+		    || cursor->type == t_time || cursor->map != 0)) {
+		json_debug_trace((1, "Didn't see quoted value when expecting"
+                                  " string.\n"));
+		return JSON_ERR_NONQSTRING;
+	    }
+	    if (cursor->map != 0) {
+		for (mp = cursor->map; mp->name != NULL; mp++)
+		    if (strcmp(mp->name, valbuf) == 0) {
+			goto foundit;
+		    }
+		json_debug_trace((1, "Invalid enumerated value string "%s".\n",
+				  valbuf));
+		return JSON_ERR_BADENUM;
+	      foundit:
+		(void)snprintf(valbuf, sizeof(valbuf), "%d", mp->value);
+	    }
+	    lptr = json_target_address(cursor, parent, offset);
+	    if (lptr != NULL)
+		switch (cursor->type) {
+		case t_integer:
+		    {
+			int tmp = atoi(valbuf);
+			memcpy(lptr, &tmp, sizeof(int));
+		    }
+		    break;
+		case t_uinteger:
+		    {
+			unsigned int tmp = (unsigned int)atoi(valbuf);
+			memcpy(lptr, &tmp, sizeof(unsigned int));
+		    }
+		    break;
+		case t_short:
+		    {
+			short tmp = atoi(valbuf);
+			memcpy(lptr, &tmp, sizeof(short));
+		    }
+		    break;
+		case t_ushort:
+		    {
+			unsigned short tmp = (unsigned int)atoi(valbuf);
+			memcpy(lptr, &tmp, sizeof(unsigned short));
+		    }
+		    break;
+		case t_time:
+#ifdef TIME_ENABLE
+		    {
+			double tmp = iso8601_to_unix(valbuf);
+			memcpy(lptr, &tmp, sizeof(double));
+		    }
+#endif /* TIME_ENABLE */
+		    break;
+		case t_real:
+		    {
+			double tmp = atof(valbuf);
+			memcpy(lptr, &tmp, sizeof(double));
+		    }
+		    break;
+		case t_string:
+		    if (parent != NULL
+			&& parent->element_type != t_structobject
+			&& offset > 0)
+			return JSON_ERR_NOPARSTR;
+		    else {
+			size_t vl = strlen(valbuf), cl = cursor->len-1;
+			memset(lptr, '\0', cl);
+			memcpy(lptr, valbuf, vl < cl ? vl : cl);
+		    }
+		    break;
+		case t_boolean:
+		    {
+			bool tmp = (strcmp(valbuf, "true") == 0 || strtol(valbuf, NULL, 0));
+			memcpy(lptr, &tmp, sizeof(bool));
+		    }
+		    break;
+		case t_character:
+		    if (strlen(valbuf) > 1)
+			/* don't update end here, leave at value start */
+			return JSON_ERR_STRLONG;
+		    else
+			lptr[0] = valbuf[0];
+		    break;
+		case t_ignore:	/* silences a compiler warning */
+		case t_object:	/* silences a compiler warning */
+		case t_structobject:
+		case t_array:
+		    break;
+		case t_check:
+		    if (strcmp(cursor->dflt.check, valbuf) != 0) {
+			json_debug_trace((1, "Required attribute value %s"
+                                          " not present.\n",
+					  cursor->dflt.check));
+			/* don't update end here, leave at start of attribute */
+			return JSON_ERR_CHECKFAIL;
+		    }
+		    break;
+		}
+	    __attribute__ ((fallthrough));
+	case post_element:
+	    if (isspace((unsigned char) *cp))
+		continue;
+	    else if (*cp == ',')
+		state = await_attr;
+	    else if (*cp == '}') {
+		++cp;
+		goto good_parse;
+	    } else {
+		json_debug_trace((1, "Garbage while expecting comma or }\n"));
+		if (end != NULL)
+		    *end = cp;
+		return JSON_ERR_BADTRAIL;
+	    }
+	    break;
+	}
+    }
+
+  good_parse:
+    /* in case there's another object following, consume trailing WS */
+    while (*cp != '\0' && isspace((unsigned char) *cp))
+	++cp;
+    if (end != NULL)
+	*end = cp;
+    json_debug_trace((1, "JSON parse ends.\n"));
+    return 0;
+}
+
+int json_read_array(const char *cp, const struct json_array_t *arr,
+		    const char **end)
+{
+    int substatus, offset, arrcount;
+    char *tp;
+
+    if (end != NULL)
+	*end = NULL;	/* give it a well-defined value on parse failure */
+
+    json_debug_trace((1, "Entered json_read_array()\n"));
+
+    while (isspace((unsigned char) *cp))
+	cp++;
+    if (*cp != '[') {
+	json_debug_trace((1, "Didn't find expected array start\n"));
+	return JSON_ERR_ARRAYSTART;
+    } else
+	cp++;
+
+    tp = arr->arr.strings.store;
+    arrcount = 0;
+
+    /* Check for empty array */
+    while (isspace((unsigned char) *cp))
+	cp++;
+    if (*cp == ']')
+	goto breakout;
+
+    for (offset = 0; offset < arr->maxlen; offset++) {
+	char *ep = NULL;
+	json_debug_trace((1, "Looking at %s\n", cp));
+	switch (arr->element_type) {
+	case t_string:
+	    if (isspace((unsigned char) *cp))
+		cp++;
+	    if (*cp != '"')
+		return JSON_ERR_BADSTRING;
+	    else
+		++cp;
+	    arr->arr.strings.ptrs[offset] = tp;
+	    for (; tp - arr->arr.strings.store < arr->arr.strings.storelen;
+		 tp++)
+		if (*cp == '"') {
+		    ++cp;
+		    *tp++ = '\0';
+		    goto stringend;
+		} else if (*cp == '\0') {
+		    json_debug_trace((1,
+				      "Bad string syntax in string list.\n"));
+		    return JSON_ERR_BADSTRING;
+		} else {
+		    *tp = *cp++;
+		}
+	    json_debug_trace((1, "Bad string syntax in string list.\n"));
+	    return JSON_ERR_BADSTRING;
+	  stringend:
+	    break;
+	case t_object:
+	case t_structobject:
+	    substatus =
+		json_internal_read_object(cp, arr->arr.objects.subtype, arr,
+					  offset, &cp);
+	    if (substatus != 0) {
+		if (end != NULL)
+		    end = &cp;
+		return substatus;
+	    }
+	    break;
+	case t_integer:
+	    arr->arr.integers.store[offset] = (int)strtol(cp, &ep, 0);
+	    if (ep == cp)
+		return JSON_ERR_BADNUM;
+	    else
+		cp = ep;
+	    break;
+	case t_uinteger:
+	    arr->arr.uintegers.store[offset] = (unsigned int)strtoul(cp,
+                                                                     &ep, 0);
+	    if (ep == cp)
+		return JSON_ERR_BADNUM;
+	    else
+		cp = ep;
+	    break;
+	case t_short:
+	    arr->arr.shorts.store[offset] = (short)strtol(cp, &ep, 0);
+	    if (ep == cp)
+		return JSON_ERR_BADNUM;
+	    else
+		cp = ep;
+	    break;
+	case t_ushort:
+	    arr->arr.ushorts.store[offset] = (unsigned short)strtol(cp, &ep, 0);
+	    if (ep == cp)
+		return JSON_ERR_BADNUM;
+	    else
+		cp = ep;
+	    break;
+#ifdef TIME_ENABLE
+	case t_time:
+	    if (*cp != '"')
+		return JSON_ERR_BADSTRING;
+	    else
+		++cp;
+	    arr->arr.reals.store[offset] = iso8601_to_unix((char *)cp);
+	    if (arr->arr.reals.store[offset] >= HUGE_VAL)
+		return JSON_ERR_BADNUM;
+	    while (*cp && *cp != '"')
+		cp++;
+	    if (*cp != '"')
+		return JSON_ERR_BADSTRING;
+	    else
+		++cp;
+	    break;
+#endif /* TIME_ENABLE */
+	case t_real:
+	    arr->arr.reals.store[offset] = strtod(cp, &ep);
+	    if (ep == cp)
+		return JSON_ERR_BADNUM;
+	    else
+		cp = ep;
+	    break;
+	case t_boolean:
+	    if (str_starts_with(cp, "true")) {
+		arr->arr.booleans.store[offset] = true;
+		cp += 4;
+	    }
+	    else if (str_starts_with(cp, "false")) {
+		arr->arr.booleans.store[offset] = false;
+		cp += 5;
+	    } else {
+		int val = strtol(cp, &ep, 0);
+		if (ep == cp)
+		    return JSON_ERR_BADNUM;
+		else {
+		    arr->arr.booleans.store[offset] = (bool) val;
+		    cp = ep;
+		}
+	    }
+	    break;
+	case t_character:
+	case t_array:
+	case t_check:
+	case t_ignore:
+	    json_debug_trace((1, "Invalid array subtype.\n"));
+	    return JSON_ERR_SUBTYPE;
+	}
+	arrcount++;
+	if (isspace((unsigned char) *cp))
+	    cp++;
+	if (*cp == ']') {
+	    json_debug_trace((1, "End of array found.\n"));
+	    goto breakout;
+	} else if (*cp == ',')
+	    cp++;
+	else {
+	    json_debug_trace((1, "Bad trailing syntax on array.\n"));
+	    return JSON_ERR_BADSUBTRAIL;
+	}
+    }
+    json_debug_trace((1, "Too many elements in array.\n"));
+    if (end != NULL)
+	*end = cp;
+    return JSON_ERR_SUBTOOLONG;
+  breakout:
+    if (arr->count != NULL)
+	*(arr->count) = arrcount;
+    if (end != NULL)
+	*end = cp;
+    json_debug_trace((1, "leaving json_read_array() with %d elements\n",
+		      arrcount));
+    return 0;
+}
+
+int json_read_object(const char *cp, const struct json_attr_t *attrs,
+		     const char **end)
+{
+    int st;
+
+    json_debug_trace((1, "json_read_object() sees '%s'\n", cp));
+    st = json_internal_read_object(cp, attrs, NULL, 0, end);
+    return st;
+}
+
+const char *json_error_string(int err)
+{
+    const char *errors[] = {
+	"unknown error while parsing JSON",
+	"non-whitespace when expecting object start",
+	"non-whitespace when expecting attribute start",
+	"unknown attribute name",
+	"attribute name too long",
+	"saw [ when not expecting array",
+	"array element specified, but no [",
+	"string value too long",
+	"token value too long",
+	"garbage while expecting comma or } or ]",
+	"didn't find expected array start",
+	"error while parsing object array",
+	"too many array elements",
+	"garbage while expecting array comma",
+	"unsupported array element type",
+	"error while string parsing",
+	"check attribute not matched",
+	"can't support strings in parallel arrays",
+	"invalid enumerated value",
+	"saw quoted value when expecting nonstring",
+	"didn't see quoted value when expecting string",
+	"other data conversion error",
+	"unexpected null value or attribute pointer",
+	"object element specified, but no {",
+    };
+
+    if (err <= 0 || err >= (int)(sizeof(errors) / sizeof(errors[0])))
+	return errors[0];
+    else
+	return errors[err];
+}
+
+/* end */
diff --git a/mjson.h b/mjson.h
new file mode 100644
index 0000000..dd36e15
--- /dev/null
+++ b/mjson.h
@@ -0,0 +1,158 @@
+/* Structures for JSON parsing using only fixed-extent memory
+ *
+ * This file is Copyright (c) 2010 by the GPSD project
+ * SPDX-License-Identifier: BSD-2-clause
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <ctype.h>
+#ifdef TIME_ENABLE
+#include <time.h>
+#endif /* TIME_ENABLE */
+
+typedef enum {t_integer, t_uinteger, t_real,
+	      t_string, t_boolean, t_character,
+	      t_time,
+	      t_object, t_structobject, t_array,
+	      t_check, t_ignore,
+	      t_short, t_ushort}
+    json_type;
+
+struct json_enum_t {
+    char	*name;
+    int		value;
+};
+
+struct json_array_t {
+    json_type element_type;
+    union {
+	struct {
+	    const struct json_attr_t *subtype;
+	    char *base;
+	    size_t stride;
+	} objects;
+	struct {
+	    char **ptrs;
+	    char *store;
+	    int storelen;
+	} strings;
+	struct {
+	    int *store;
+	} integers;
+	struct {
+	    unsigned int *store;
+	} uintegers;
+	struct {
+	    short *store;
+	} shorts;
+	struct {
+	    unsigned short *store;
+	} ushorts;
+	struct {
+	    double *store;
+	} reals;
+	struct {
+	    bool *store;
+	} booleans;
+    } arr;
+    int *count, maxlen;
+};
+
+struct json_attr_t {
+    char *attribute;
+    json_type type;
+    union {
+	int *integer;
+	unsigned int *uinteger;
+	short *shortint;
+	unsigned short *ushortint;
+	double *real;
+	char *string;
+	bool *boolean;
+	char *character;
+	const struct json_attr_t *attrs;
+	const struct json_array_t array;
+	size_t offset;
+    } addr;
+    union {
+	int integer;
+	unsigned int uinteger;
+	short shortint;
+	unsigned short ushortint;
+	double real;
+	bool boolean;
+	char character;
+	char *check;
+    } dflt;
+    size_t len;
+    const struct json_enum_t *map;
+    bool nodefault;
+};
+
+#define JSON_ATTR_MAX	31	/* max chars in JSON attribute name */
+#define JSON_VAL_MAX	512	/* max chars in JSON value part */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+int json_read_object(const char *, const struct json_attr_t *,
+		     const char **);
+int json_read_array(const char *, const struct json_array_t *,
+		    const char **);
+const char *json_error_string(int);
+
+#ifdef TIME_ENABLE
+extern time_t timegm(struct tm *tm);
+#endif /* TIME_ENABLE */
+
+void json_enable_debug(int, FILE *);
+#ifdef __cplusplus
+}
+#endif
+
+#define JSON_ERR_OBSTART	1	/* non-WS when expecting object start */
+#define JSON_ERR_ATTRSTART	2	/* non-WS when expecting attrib start */
+#define JSON_ERR_BADATTR	3	/* unknown attribute name */
+#define JSON_ERR_ATTRLEN	4	/* attribute name too long */
+#define JSON_ERR_NOARRAY	5	/* saw [ when not expecting array */
+#define JSON_ERR_NOBRAK 	6	/* array element specified, but no [ */
+#define JSON_ERR_STRLONG	7	/* string value too long */
+#define JSON_ERR_TOKLONG	8	/* token value too long */
+#define JSON_ERR_BADTRAIL	9	/* garbage while expecting comma or } or ] */
+#define JSON_ERR_ARRAYSTART	10	/* didn't find expected array start */
+#define JSON_ERR_OBJARR 	11	/* error while parsing object array */
+#define JSON_ERR_SUBTOOLONG	12	/* too many array elements */
+#define JSON_ERR_BADSUBTRAIL	13	/* garbage while expecting array comma */
+#define JSON_ERR_SUBTYPE	14	/* unsupported array element type */
+#define JSON_ERR_BADSTRING	15	/* error while string parsing */
+#define JSON_ERR_CHECKFAIL	16	/* check attribute not matched */
+#define JSON_ERR_NOPARSTR	17	/* can't support strings in parallel arrays */
+#define JSON_ERR_BADENUM	18	/* invalid enumerated value */
+#define JSON_ERR_QNONSTRING	19	/* saw quoted value when expecting nonstring */
+#define JSON_ERR_NONQSTRING	19	/* didn't see quoted value when expecting string */
+#define JSON_ERR_MISC		20	/* other data conversion error */
+#define JSON_ERR_BADNUM		21	/* error while parsing a numerical argument */
+#define JSON_ERR_NULLPTR	22	/* unexpected null value or attribute pointer */
+#define JSON_ERR_NOCURLY	23	/* object element specified, but no { */
+
+/*
+ * Use the following macros to declare template initializers for structobject
+ * arrays.  Writing the equivalents out by hand is error-prone.
+ *
+ * STRUCTOBJECT takes a structure name s, and a fieldname f in s.
+ *
+ * STRUCTARRAY takes the name of a structure array, a pointer to a an
+ * initializer defining the subobject type, and the address of an integer to
+ * store the length in.
+ */
+#define STRUCTOBJECT(s, f)	.addr.offset = offsetof(s, f)
+#define STRUCTARRAY(a, e, n) \
+	.addr.array.element_type = t_structobject, \
+	.addr.array.arr.objects.subtype = e, \
+	.addr.array.arr.objects.base = (char*)a, \
+	.addr.array.arr.objects.stride = sizeof(a[0]), \
+	.addr.array.count = n, \
+	.addr.array.maxlen = (int)(sizeof(a)/sizeof(a[0]))
+
+/* json.h ends here */