telodendria/src/Json.c
Jordan Bancino d83db35df0 Use strncpy() instead of strcpy().
The OpenBSD linker is complaining about it. Even though every single
case strcpy() was used is safe, strncpy() provides a little bit of extra
security, and makes the linker happy.
2023-04-25 21:54:51 +00:00

1349 lines
29 KiB
C

/*
* Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <Json.h>
#include <Memory.h>
#include <Str.h>
#include <Util.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
struct JsonValue
{
JsonType type;
union
{
HashMap *object;
Array *array;
char *string;
long integer;
double floating;
int boolean:1;
} as;
};
typedef enum JsonToken
{
TOKEN_UNKNOWN,
TOKEN_COLON,
TOKEN_COMMA,
TOKEN_OBJECT_OPEN,
TOKEN_OBJECT_CLOSE,
TOKEN_ARRAY_OPEN,
TOKEN_ARRAY_CLOSE,
TOKEN_STRING,
TOKEN_INTEGER,
TOKEN_FLOAT,
TOKEN_BOOLEAN,
TOKEN_NULL,
TOKEN_EOF
} JsonToken;
typedef struct JsonParserState
{
Stream *stream;
JsonToken tokenType;
char *token;
size_t tokenLen;
} JsonParserState;
JsonType
JsonValueType(JsonValue * value)
{
if (!value)
{
return JSON_NULL;
}
return value->type;
}
static JsonValue *
JsonValueAllocate(void)
{
return Malloc(sizeof(JsonValue));
}
JsonValue *
JsonValueObject(HashMap * object)
{
JsonValue *value;
if (!object)
{
return NULL;
}
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_OBJECT;
value->as.object = object;
return value;
}
HashMap *
JsonValueAsObject(JsonValue * value)
{
if (!value || value->type != JSON_OBJECT)
{
return NULL;
}
return value->as.object;
}
JsonValue *
JsonValueArray(Array * array)
{
JsonValue *value;
if (!array)
{
return NULL;
}
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_ARRAY;
value->as.array = array;
return value;
}
Array *
JsonValueAsArray(JsonValue * value)
{
if (!value || value->type != JSON_ARRAY)
{
return NULL;
}
return value->as.array;
}
JsonValue *
JsonValueString(char *string)
{
JsonValue *value;
if (!string)
{
return NULL;
}
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_STRING;
value->as.string = StrDuplicate(string);
if (!value->as.string)
{
Free(value);
return NULL;
}
return value;
}
char *
JsonValueAsString(JsonValue * value)
{
if (!value || value->type != JSON_STRING)
{
return NULL;
}
return value->as.string;
}
JsonValue *
JsonValueInteger(long integer)
{
JsonValue *value;
value = JsonValueAllocate();
if (!value)
{
return 0;
}
value->type = JSON_INTEGER;
value->as.integer = integer;
return value;
}
long
JsonValueAsInteger(JsonValue * value)
{
if (!value || value->type != JSON_INTEGER)
{
return 0;
}
return value->as.integer;
}
JsonValue *
JsonValueFloat(double floating)
{
JsonValue *value;
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_FLOAT;
value->as.floating = floating;
return value;
}
double
JsonValueAsFloat(JsonValue * value)
{
if (!value || value->type != JSON_FLOAT)
{
return 0;
}
return value->as.floating;
}
JsonValue *
JsonValueBoolean(int boolean)
{
JsonValue *value;
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_BOOLEAN;
value->as.boolean = boolean;
return value;
}
int
JsonValueAsBoolean(JsonValue * value)
{
if (!value || value->type != JSON_BOOLEAN)
{
return 0;
}
return value->as.boolean;
}
JsonValue *
JsonValueNull(void)
{
JsonValue *value;
value = JsonValueAllocate();
if (!value)
{
return NULL;
}
value->type = JSON_NULL;
return value;
}
void
JsonValueFree(JsonValue * value)
{
size_t i;
Array *arr;
if (!value)
{
return;
}
switch (value->type)
{
case JSON_OBJECT:
JsonFree(value->as.object);
break;
case JSON_ARRAY:
arr = value->as.array;
for (i = 0; i < ArraySize(arr); i++)
{
JsonValueFree((JsonValue *) ArrayGet(arr, i));
}
ArrayFree(arr);
break;
case JSON_STRING:
Free(value->as.string);
break;
default:
break;
}
Free(value);
}
void
JsonEncodeString(const char *str, Stream * out)
{
size_t i;
char c;
StreamPutc(out, '"');
i = 0;
while ((c = str[i]) != '\0')
{
switch (c)
{
case '\\':
case '"':
case '/':
StreamPutc(out, '\\');
StreamPutc(out, c);
break;
case '\b':
StreamPuts(out, "\\b");
break;
case '\t':
StreamPuts(out, "\\t");
break;
case '\n':
StreamPuts(out, "\\n");
break;
case '\f':
StreamPuts(out, "\\f");
break;
case '\r':
StreamPuts(out, "\\r");
break;
default: /* Assume UTF-8 input */
/*
* RFC 4627: "All Unicode characters may be placed
* within the quotation marks except for the characters
* that must be escaped: quotation mark, reverse solidus,
* and the control characters (U+0000 through U+001F)."
*
* This technically covers the above cases for backspace,
* tab, newline, feed, and carriage return characters,
* but we can save bytes if we encode those as their
* more human-readable representation.
*/
if (c <= 0x001F)
{
StreamPrintf(out, "\\u%04x", c);
}
else
{
StreamPutc(out, c);
}
break;
}
i++;
}
StreamPutc(out, '"');
}
static char *
JsonDecodeString(Stream * in)
{
const size_t strBlockSize = 16;
size_t i;
size_t len;
size_t allocated;
char *str;
int c;
char a[5];
unsigned long utf8;
char *utf8Ptr;
len = 0;
allocated = strBlockSize;
str = Malloc(allocated * sizeof(char));
if (!str)
{
return NULL;
}
while ((c = StreamGetc(in)) != EOF)
{
if (c <= 0x001F)
{
/* Bad byte; these must be escaped */
Free(str);
return NULL;
}
switch (c)
{
case '"':
if (len >= allocated)
{
char *tmp;
allocated += 1;
tmp = Realloc(str, allocated * sizeof(char));
if (!tmp)
{
Free(str);
return NULL;
}
str = tmp;
}
str[len] = '\0';
return str;
break;
case '\\':
c = StreamGetc(in);
switch (c)
{
case '\\':
case '"':
case '/':
a[0] = c;
a[1] = '\0';
break;
case 'b':
a[0] = '\b';
a[1] = '\0';
break;
case 't':
a[0] = '\t';
a[1] = '\0';
break;
case 'n':
a[0] = '\n';
a[1] = '\0';
break;
case 'f':
a[0] = '\f';
a[1] = '\0';
break;
case 'r':
a[0] = '\r';
a[1] = '\0';
break;
case 'u':
/* Read 4 characters into a */
if (!StreamGets(in, a, sizeof(a)))
{
Free(str);
return NULL;
}
/* Interpret characters as a hex number */
if (sscanf(a, "%04lx", &utf8) != 1)
{
/* Bad hex value */
Free(str);
return NULL;
}
if (utf8 == 0)
{
/*
* We read in a 0000, null. There is no
* circumstance in which putting a null
* character into our buffer will end well.
*
* There's also really no legitimate use
* for the null character in our JSON anyway;
* it's likely an attempted exploit.
*
* So lets just strip it out. Don't even
* include it in the string. There should be
* no harm in ignoring it.
*/
continue;
}
/* Encode the 4-byte UTF-8 buffer into a series
* of 1-byte characters */
utf8Ptr = StrUtf8Encode(utf8);
if (!utf8Ptr)
{
/* Mem error */
Free(str);
return NULL;
}
/* Move the output of StrUtf8Encode() into our
* local buffer */
strncpy(a, utf8Ptr, sizeof(a));
Free(utf8Ptr);
break;
default:
/* Bad escape value */
Free(str);
return NULL;
}
break;
default:
a[0] = c;
a[1] = '\0';
break;
}
/* Append buffer a */
i = 0;
while (a[i] != '\0')
{
if (len >= allocated)
{
char *tmp;
allocated += strBlockSize;
tmp = Realloc(str, allocated * sizeof(char));
if (!tmp)
{
Free(str);
return NULL;
}
str = tmp;
}
str[len] = a[i];
len++;
i++;
}
}
Free(str);
return NULL;
}
void
JsonEncodeValue(JsonValue * value, Stream * out, int level)
{
size_t i;
size_t len;
Array *arr;
switch (value->type)
{
case JSON_OBJECT:
JsonEncode(value->as.object, out, level >= 0 ? level : level);
break;
case JSON_ARRAY:
arr = value->as.array;
len = ArraySize(arr);
StreamPutc(out, '[');
for (i = 0; i < len; i++)
{
if (level >= 0)
{
StreamPrintf(out, "\n%*s", level + 2, "");
}
JsonEncodeValue(ArrayGet(arr, i), out, level >= 0 ? level + 2 : level);
if (i < len - 1)
{
StreamPutc(out, ',');
}
}
if (level >= 0)
{
StreamPrintf(out, "\n%*s", level, "");
}
StreamPutc(out, ']');
break;
case JSON_STRING:
JsonEncodeString(value->as.string, out);
break;
case JSON_INTEGER:
StreamPrintf(out, "%ld", value->as.integer);
break;
case JSON_FLOAT:
StreamPrintf(out, "%f", value->as.floating);
break;
case JSON_BOOLEAN:
if (value->as.boolean)
{
StreamPuts(out, "true");
}
else
{
StreamPuts(out, "false");
}
break;
case JSON_NULL:
StreamPuts(out, "null");
break;
default:
return;
}
}
int
JsonEncode(HashMap * object, Stream * out, int level)
{
size_t index;
size_t count;
char *key;
JsonValue *value;
if (!object || !out)
{
return 0;
}
count = 0;
while (HashMapIterate(object, &key, (void **) &value))
{
count++;
}
StreamPutc(out, '{');
if (level >= 0)
{
StreamPutc(out, '\n');
}
index = 0;
while (HashMapIterate(object, &key, (void **) &value))
{
if (level >= 0)
{
StreamPrintf(out, "%*s", level + 2, "");
}
JsonEncodeString(key, out);
StreamPutc(out, ':');
if (level >= 0)
{
StreamPutc(out, ' ');
}
JsonEncodeValue(value, out, level >= 0 ? level + 2 : level);
if (index < count - 1)
{
StreamPutc(out, ',');
}
if (level >= 0)
{
StreamPutc(out, '\n');
}
index++;
}
if (level >= 0)
{
StreamPrintf(out, "%*s", level, "");
}
StreamPutc(out, '}');
return 1;
}
void
JsonFree(HashMap * object)
{
char *key;
JsonValue *value;
if (!object)
{
return;
}
while (HashMapIterate(object, &key, (void **) &value))
{
JsonValueFree(value);
}
HashMapFree(object);
}
JsonValue *
JsonValueDuplicate(JsonValue * val)
{
JsonValue *new;
size_t i;
if (!val)
{
return NULL;
}
new = JsonValueAllocate();
if (!new)
{
return NULL;
}
new->type = val->type;
switch (val->type)
{
case JSON_OBJECT:
new->as.object = JsonDuplicate(val->as.object);
break;
case JSON_ARRAY:
new->as.array = ArrayCreate();
for (i = 0; i < ArraySize(val->as.array); i++)
{
ArrayAdd(new->as.array, JsonValueDuplicate(ArrayGet(val->as.array, i)));
}
break;
case JSON_STRING:
new->as.string = StrDuplicate(val->as.string);
break;
case JSON_INTEGER:
case JSON_FLOAT:
case JSON_BOOLEAN:
/* These are by value, not by reference */
new->as = val->as;
case JSON_NULL:
default:
break;
}
return new;
}
HashMap *
JsonDuplicate(HashMap * object)
{
HashMap *new;
char *key;
JsonValue *val;
if (!object)
{
return NULL;
}
new = HashMapCreate();
if (!new)
{
return NULL;
}
while (HashMapIterate(object, &key, (void **) &val))
{
HashMapSet(new, key, JsonValueDuplicate(val));
}
return new;
}
static int
JsonConsumeWhitespace(JsonParserState * state)
{
static const int nRetries = 5;
static const int delay = 2;
int c;
int tries = 0;
int readFlg = 0;
while (1)
{
c = StreamGetc(state->stream);
if (StreamEof(state->stream))
{
break;
}
if (StreamError(state->stream))
{
if (errno == EAGAIN)
{
StreamClearError(state->stream);
tries++;
if (tries >= nRetries || readFlg)
{
break;
}
else
{
UtilSleepMillis(delay);
continue;
}
}
else
{
break;
}
}
/* As soon as we've successfully read a byte, treat future
* EAGAINs as EOF, because some clients don't properly shutdown
* their sockets. */
readFlg = 1;
tries = 0;
if (!isspace(c))
{
break;
}
}
return c;
}
static void
JsonTokenSeek(JsonParserState * state)
{
int c = JsonConsumeWhitespace(state);
if (StreamEof(state->stream))
{
state->tokenType = TOKEN_EOF;
return;
}
if (state->token)
{
Free(state->token);
state->token = NULL;
}
switch (c)
{
case ':':
state->tokenType = TOKEN_COLON;
break;
case ',':
state->tokenType = TOKEN_COMMA;
break;
case '{':
state->tokenType = TOKEN_OBJECT_OPEN;
break;
case '}':
state->tokenType = TOKEN_OBJECT_CLOSE;
break;
case '[':
state->tokenType = TOKEN_ARRAY_OPEN;
break;
case ']':
state->tokenType = TOKEN_ARRAY_CLOSE;
break;
case '"':
state->token = JsonDecodeString(state->stream);
if (!state->token)
{
state->tokenType = TOKEN_EOF;
return;
}
state->tokenType = TOKEN_STRING;
state->tokenLen = strlen(state->token);
break;
default:
if (c == '-' || isdigit(c))
{
int isFloat = 0;
size_t allocated = 16;
state->tokenLen = 1;
state->token = Malloc(allocated);
if (!state->token)
{
state->tokenType = TOKEN_EOF;
return;
}
state->token[0] = c;
while ((c = StreamGetc(state->stream)) != EOF)
{
if (c == '.')
{
if (state->tokenLen > 1 && !isFloat)
{
isFloat = 1;
}
else
{
state->tokenType = TOKEN_UNKNOWN;
return;
}
}
else if (!isdigit(c))
{
StreamUngetc(state->stream, c);
break;
}
if (state->tokenLen >= allocated)
{
char *tmp;
allocated += 16;
tmp = Realloc(state->token, allocated);
if (!tmp)
{
state->tokenType = TOKEN_EOF;
return;
}
state->token = tmp;
}
state->token[state->tokenLen] = c;
state->tokenLen++;
}
if (state->token[state->tokenLen - 1] == '.')
{
state->tokenType = TOKEN_UNKNOWN;
return;
}
state->token[state->tokenLen] = '\0';
if (isFloat)
{
state->tokenType = TOKEN_FLOAT;
}
else
{
state->tokenType = TOKEN_INTEGER;
}
}
else
{
state->tokenLen = 8;
state->token = Malloc(state->tokenLen);
if (!state->token)
{
state->tokenType = TOKEN_EOF;
return;
}
state->token[0] = c;
switch (c)
{
case 't':
if (!StreamGets(state->stream, state->token + 1, 4))
{
state->tokenType = TOKEN_EOF;
Free(state->token);
state->token = NULL;
return;
}
if (!strcmp("true", state->token))
{
state->tokenType = TOKEN_BOOLEAN;
state->tokenLen = 5;
}
else
{
state->tokenType = TOKEN_UNKNOWN;
Free(state->token);
state->token = NULL;
}
break;
case 'f':
if (!StreamGets(state->stream, state->token + 1, 5))
{
state->tokenType = TOKEN_EOF;
Free(state->token);
state->token = NULL;
return;
}
if (!strcmp("false", state->token))
{
state->tokenType = TOKEN_BOOLEAN;
state->tokenLen = 6;
}
else
{
state->tokenType = TOKEN_UNKNOWN;
Free(state->token);
state->token = NULL;
}
break;
case 'n':
if (!StreamGets(state->stream, state->token + 1, 4))
{
state->tokenType = TOKEN_EOF;
Free(state->token);
state->token = NULL;
return;
}
if (!strcmp("null", state->token))
{
state->tokenType = TOKEN_NULL;
}
else
{
state->tokenType = TOKEN_UNKNOWN;
Free(state->token);
state->token = NULL;
}
break;
default:
state->tokenType = TOKEN_UNKNOWN;
Free(state->token);
state->token = NULL;
break;
}
}
}
}
static int
JsonExpect(JsonParserState * state, JsonToken token)
{
return state->tokenType == token;
}
static Array *
JsonDecodeArray(JsonParserState *);
static HashMap *
JsonDecodeObject(JsonParserState *);
static JsonValue *
JsonDecodeValue(JsonParserState * state)
{
JsonValue *value;
char *strValue;
switch (state->tokenType)
{
case TOKEN_OBJECT_OPEN:
value = JsonValueObject(JsonDecodeObject(state));
break;
case TOKEN_ARRAY_OPEN:
value = JsonValueArray(JsonDecodeArray(state));
break;
case TOKEN_STRING:
strValue = Malloc(state->tokenLen + 1);
if (!strValue)
{
return NULL;
}
strncpy(strValue, state->token, state->tokenLen + 1);
value = JsonValueString(strValue);
Free(strValue);
break;
case TOKEN_INTEGER:
value = JsonValueInteger(atol(state->token));
break;
case TOKEN_FLOAT:
value = JsonValueFloat(atof(state->token));
break;
case TOKEN_BOOLEAN:
value = JsonValueBoolean(state->token[0] == 't');
break;
case TOKEN_NULL:
value = JsonValueNull();
break;
default:
value = NULL;
break;
}
return value;
}
static HashMap *
JsonDecodeObject(JsonParserState * state)
{
HashMap *obj = HashMapCreate();
int comma = 0;
if (!obj)
{
return NULL;
}
do
{
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_STRING))
{
char *key = Malloc(state->tokenLen + 1);
JsonValue *value;
if (!key)
{
goto error;
}
strncpy(key, state->token, state->tokenLen + 1);
JsonTokenSeek(state);
if (!JsonExpect(state, TOKEN_COLON))
{
Free(key);
goto error;
}
JsonTokenSeek(state);
value = JsonDecodeValue(state);
if (!value)
{
Free(key);
goto error;
}
/* If there's an existing value at this key, discard it. */
JsonValueFree(HashMapSet(obj, key, value));
Free(key);
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_COMMA))
{
comma = 1;
continue;
}
if (JsonExpect(state, TOKEN_OBJECT_CLOSE))
{
break;
}
goto error;
}
else if (!comma && JsonExpect(state, TOKEN_OBJECT_CLOSE))
{
break;
}
else
{
goto error;
}
} while (!JsonExpect(state, TOKEN_EOF));
return obj;
error:
JsonFree(obj);
return NULL;
}
static Array *
JsonDecodeArray(JsonParserState * state)
{
Array *arr = ArrayCreate();
size_t i;
int comma = 0;
if (!arr)
{
return NULL;
}
do
{
JsonValue *value;
JsonTokenSeek(state);
if (!comma && JsonExpect(state, TOKEN_ARRAY_CLOSE))
{
break;
}
value = JsonDecodeValue(state);
if (!value)
{
goto error;
}
ArrayAdd(arr, value);
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_COMMA))
{
comma = 1;
continue;
}
if (JsonExpect(state, TOKEN_ARRAY_CLOSE))
{
break;
}
goto error;
} while (!JsonExpect(state, TOKEN_EOF));
return arr;
error:
for (i = 0; i < ArraySize(arr); i++)
{
JsonValueFree((JsonValue *) ArrayGet(arr, i));
}
ArrayFree(arr);
return NULL;
}
HashMap *
JsonDecode(Stream * stream)
{
HashMap *result;
JsonParserState state;
state.stream = stream;
state.token = NULL;
JsonTokenSeek(&state);
if (!JsonExpect(&state, TOKEN_OBJECT_OPEN))
{
return NULL;
}
result = JsonDecodeObject(&state);
if (state.token)
{
Free(state.token);
}
return result;
}
JsonValue *
JsonGet(HashMap * json, size_t nArgs,...)
{
va_list argp;
HashMap *tmp = json;
JsonValue *val = NULL;
size_t i;
if (!json || !nArgs)
{
return NULL;
}
va_start(argp, nArgs);
for (i = 0; i < nArgs - 1; i++)
{
char *key = va_arg(argp, char *);
val = HashMapGet(tmp, key);
if (!val)
{
goto finish;
}
if (JsonValueType(val) != JSON_OBJECT)
{
val = NULL;
goto finish;
}
tmp = JsonValueAsObject(val);
}
val = HashMapGet(tmp, va_arg(argp, char *));
finish:
va_end(argp);
return val;
}
JsonValue *
JsonSet(HashMap * json, JsonValue * newVal, size_t nArgs,...)
{
HashMap *tmp = json;
JsonValue *val = NULL;
size_t i;
va_list argp;
if (!json || !newVal || !nArgs)
{
return NULL;
}
va_start(argp, nArgs);
for (i = 0; i < nArgs - 1; i++)
{
char *key = va_arg(argp, char *);
val = HashMapGet(tmp, key);
if (!val)
{
val = JsonValueObject(HashMapCreate());
HashMapSet(tmp, key, val);
}
if (JsonValueType(val) != JSON_OBJECT)
{
val = NULL;
goto finish;
}
tmp = JsonValueAsObject(val);
}
val = HashMapSet(tmp, va_arg(argp, char *), newVal);
finish:
va_end(argp);
return val;
}