Make ljson more strict (#482)

This commit is contained in:
Gautham 2022-07-13 15:09:19 +05:30 committed by GitHub
parent 30cc2c8dc1
commit 12d9f7ade6
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GPG key ID: 4AEE18F83AFDEB23
6 changed files with 116 additions and 131 deletions

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@ -31,10 +31,14 @@
#include "third_party/lua/lua.h"
#include "tool/net/ljson.h"
#define TOP_LEVEL 0
#define ARRAY_VAL 1
#define OBJECT_KEY 2
#define OBJECT_VAL 3
#define AFTER_VALUE 0x01u
#define ARRAY_SINGLE 0x02u
#define ARRAY_END 0x04u
#define OBJECT_KEY 0x10u
#define OBJECT_VAL 0x20u
#define OBJECT_END 0x40u
#define TOP_LEVEL 64
static struct DecodeJson Parse(struct lua_State *L, const char *p,
const char *e, int context, int depth) {
@ -58,7 +62,8 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
break;
case ',': // present in list and object
if (context == ARRAY_VAL || context == OBJECT_KEY) {
if (0 != (context & AFTER_VALUE)) {
context = 0;
a = p;
break;
} else {
@ -66,7 +71,8 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
case ':': // present only in object after key
if (context == OBJECT_VAL) {
if (0 != (context & OBJECT_VAL)) {
context = 0;
a = p;
break;
} else {
@ -74,7 +80,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
case 'n': // null
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
if (p + 3 <= e && READ32LE(p - 1) == READ32LE("null")) {
lua_pushnil(L);
return (struct DecodeJson){1, p + 3};
@ -83,7 +89,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
case 'f': // false
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
if (p + 4 <= e && READ32LE(p) == READ32LE("alse")) {
lua_pushboolean(L, false);
return (struct DecodeJson){1, p + 4};
@ -92,7 +98,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
case 't': // true
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
if (p + 3 <= e && READ32LE(p - 1) == READ32LE("true")) {
lua_pushboolean(L, true);
return (struct DecodeJson){1, p + 3};
@ -104,7 +110,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
return (struct DecodeJson){-1, "object key must be string"};
case '-': // negative
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
if (p < e && isdigit(*p)) {
d = -1;
break;
@ -113,7 +119,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
case '0': // zero or number
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
if (p < e) {
if ((*p == '.' || *p == 'e' || *p == 'E')) {
goto UseDubble;
@ -125,7 +131,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
return (struct DecodeJson){1, p};
case '1' ... '9': // integer
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
for (x = (c - '0') * d; p < e; ++p) {
c = *p & 255;
if (isdigit(c)) {
@ -148,11 +154,11 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
return (struct DecodeJson){1, a + c};
case '[': // Array
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
lua_newtable(L);
i = 0;
r = Parse(L, p, e, ARRAY_SINGLE | ARRAY_END, depth - 1);
for (;;) {
r = Parse(L, p, e, ARRAY_VAL, depth - 1);
if (UNLIKELY(r.rc == -1)) {
lua_pop(L, 1);
return r;
@ -162,6 +168,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
break;
}
lua_rawseti(L, -2, i++ + 1);
r = Parse(L, p, e, AFTER_VALUE | ARRAY_END, depth - 1);
}
if (!i) {
// we need this kludge so `[]` won't round-trip as `{}`
@ -171,24 +178,24 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
return (struct DecodeJson){1, p};
case ']':
if (context == ARRAY_VAL) {
if (0 != (context & ARRAY_END)) {
return (struct DecodeJson){0, p};
} else {
return (struct DecodeJson){-1, "unexpected ']'"};
}
case '}':
if (context == OBJECT_KEY) {
if (0 != (context & OBJECT_END)) {
return (struct DecodeJson){0, p};
} else {
return (struct DecodeJson){-1, "unexpected '}'"};
}
case '{': // Object
if (UNLIKELY(context == OBJECT_KEY)) goto BadObjectKey;
if (UNLIKELY(0 != (context & OBJECT_KEY))) goto BadObjectKey;
lua_newtable(L);
r = Parse(L, p, e, OBJECT_KEY | OBJECT_END, depth - 1);
for (;;) {
r = Parse(L, p, e, OBJECT_KEY, depth - 1);
if (r.rc == -1) {
lua_pop(L, 1);
return r;
@ -208,6 +215,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
}
p = r.p;
lua_settable(L, -3);
r = Parse(L, p, e, OBJECT_KEY | AFTER_VALUE | OBJECT_END, depth - 1);
}
return (struct DecodeJson){1, p};
@ -355,7 +363,7 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
return (struct DecodeJson){-1, "illegal character"};
}
}
if (UNLIKELY(context == TOP_LEVEL)) {
if (UNLIKELY(depth == TOP_LEVEL)) {
return (struct DecodeJson){0, 0};
} else {
return (struct DecodeJson){-1, "unexpected eof"};
@ -386,10 +394,10 @@ static struct DecodeJson Parse(struct lua_State *L, const char *p,
* @return r.p is string describing error if `rc < 0`
*/
struct DecodeJson DecodeJson(struct lua_State *L, const char *p, size_t n) {
int depth = 64;
int depth = TOP_LEVEL;
if (n == -1) n = p ? strlen(p) : 0;
if (lua_checkstack(L, depth * 4)) {
return Parse(L, p, p + n, TOP_LEVEL, depth);
return Parse(L, p, p + n, 0, depth);
} else {
return (struct DecodeJson){-1, "can't set stack depth"};
}