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Diffstat (limited to 'include/safe_iop.h')
| -rw-r--r-- | include/safe_iop.h | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/include/safe_iop.h b/include/safe_iop.h new file mode 100644 index 0000000..0b558ca --- /dev/null +++ b/include/safe_iop.h @@ -0,0 +1,699 @@ +/* safe_iop + * License:: released in to the public domain + * Author:: Will Drewry <redpig@dataspill.org> + * Copyright 2007,2008 redpig@dataspill.org + * Some portions copyright The Android Open Source Project + * + * Unless required by applicable law or agreed to in writing, software + * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS + * OF ANY KIND, either express or implied. + * + * To Do: + * - Add varargs style interface for safe_<op>() + * - Add support for safe conversion + * - Add additional sizes to safe_iopf (currently 32-bit only) + * (this will make use of the safe conversion above) + * - Add left shift support + * - Add more test cases for interfaces (op_mixed) + * - Add more tests for edge cases I've missed? and for thoroughness + * + * History: + * = 0.3 + * - solidified code into a smaller number of macros and functions + * - added typeless functions using gcc magic (typeof) + * - deprecrated old interfaces (-DSAFE_IOP_COMPAT) + * - discover size maximums automagically + * - separated test cases for easier understanding + * - significantly expanded test cases + * - derive type maximums and minimums internally (checked in testing) + * = 0.2 + * - Removed dependence on twos complement arithmetic to allow macro-ized + * definitions + * - Added (s)size_t support + * - Added (u)int8,16,64 support + * - Added portable inlining + * - Added support for NULL result pointers + * - Added support for header-only use (safe_iop.c only needed for safe_iopf) + * = 0.1 + * - Initial release + * + * Contributors & thanks: + * - peter@valchev.net for his review, comments, and enthusiasm + * - thanks to Google for contributing some time + */ + +/* This library supplies a set of standard functions for performing and + * checking safe integer operations. The code is based on examples from + * https://www.securecoding.cert.org/confluence/display/seccode/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow + * + * Inline functions are available for specific operations. If the result + * pointer is NULL, the function will still return 1 or 0 if it would + * or would not overflow. If multiple operations need to be performed, + * safe_iopf provides a format-string driven model, but it does not yet support + * non-32 bit operations + * + * NOTE: This code assumes int32_t to be signed. + */ +#ifndef _SAFE_IOP_H +#define _SAFE_IOP_H +#include <limits.h> /* for CHAR_BIT */ +#include <assert.h> /* for type enforcement */ + +typedef enum { SAFE_IOP_TYPE_S32 = 1, + SAFE_IOP_TYPE_U32, + SAFE_IOP_TYPE_DEFAULT = SAFE_IOP_TYPE_S32, + } safe_type_t; + +#define SAFE_IOP_TYPE_PREFIXES "us" + +/* use a nice prefix :) */ +#define __sio(x) OPAQUE_SAFE_IOP_PREFIX_ ## x +#define OPAQUE_SAFE_IOP_PREFIX_var(x) __sio(VARIABLE_ ## x) +#define OPAQUE_SAFE_IOP_PREFIX_m(x) __sio(MACRO_ ## x) + + +/* A recursive macro which safely multiplies the given type together. + * _ptr may be NULL. + * mixed types or mixed sizes will unconditionally return 0; + */ +#define OPAQUE_SAFE_IOP_PREFIX_MACRO_smax(_a) \ + ((typeof(_a))(~((typeof(_a)) 1 << ((sizeof(typeof(_a)) * CHAR_BIT) - 1)))) +#define OPAQUE_SAFE_IOP_PREFIX_MACRO_smin(_a) \ + ((typeof(_a))(-__sio(m)(smax)(_a) - 1)) +#define OPAQUE_SAFE_IOP_PREFIX_MACRO_umax(_a) ((typeof(_a))(~((typeof(_a)) 0))) + +#define OPAQUE_SAFE_IOP_PREFIX_MACRO_type_enforce(__A, __B) \ + ((((__sio(m)(smin)(__A) <= ((typeof(__A))0)) && \ + (__sio(m)(smin)(__B) <= ((typeof(__B))0))) || \ + (((__sio(m)(smin)(__A) > ((typeof(__A))0))) && \ + (__sio(m)(smin)(__B) > ((typeof(__B))0)))) && \ + (sizeof(typeof(__A)) == sizeof(typeof(__B)))) + + +/* We use a non-void wrapper for assert(). This allows us to factor it away on + * -DNDEBUG but still have conditionals test the result (and optionally return + * false). + */ +#if defined(NDEBUG) +# define OPAQUE_SAFE_IOP_PREFIX_MACRO_assert(x) (x) +#else +# define OPAQUE_SAFE_IOP_PREFIX_MACRO_assert(x) ({ assert(x); 1; }) +#endif + + +/* Primary interface macros */ +/* type checking is compiled out if NDEBUG supplied. */ +#define safe_add(_ptr, __a, __b) \ + ({ int __sio(var)(ok) = 0; \ + typeof(__a) __sio(var)(_a) = (__a); \ + typeof(__b) __sio(var)(_b) = (__b); \ + typeof(_ptr) __sio(var)(p) = (_ptr); \ + if (__sio(m)(assert)(__sio(m)(type_enforce)(__sio(var)(_a), \ + __sio(var)(_b)))) { \ + if (__sio(m)(smin)(__sio(var)(_a)) <= ((typeof(__sio(var)(_a)))0)) { \ + __sio(var)(ok) = safe_sadd(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } else { \ + __sio(var)(ok) = safe_uadd(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } \ + } \ + __sio(var)(ok); }) + +#define safe_add3(_ptr, _A, _B, _C) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_add(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_add((_ptr), __sio(var)(r), __sio(var)(c))); }) + +#define safe_add4(_ptr, _A, _B, _C, _D) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_add(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_add(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_add((_ptr), __sio(var)(r), (__sio(var)(d)))); }) + +#define safe_add5(_ptr, _A, _B, _C, _D, _E) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_E) __sio(var)(e) = (_E); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_add(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_add(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_add(&(__sio(var)(r)), __sio(var)(r), __sio(var)(d)) && \ + safe_add((_ptr), __sio(var)(r), __sio(var)(e))); }) + +#define safe_sub(_ptr, __a, __b) \ + ({ int __sio(var)(ok) = 0; \ + typeof(__a) __sio(var)(_a) = (__a); \ + typeof(__b) __sio(var)(_b) = (__b); \ + typeof(_ptr) __sio(var)(p) = (_ptr); \ + if (__sio(m)(assert)(__sio(m)(type_enforce)(__sio(var)(_a), \ + __sio(var)(_b)))) { \ + if (__sio(m)(umax)(__sio(var)(_a)) <= ((typeof(__sio(var)(_a)))0)) { \ + __sio(var)(ok) = safe_ssub(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } else { \ + __sio(var)(ok) = safe_usub(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } \ + } \ + __sio(var)(ok); }) + +/* These are sequentially performed */ +#define safe_sub3(_ptr, _A, _B, _C) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_sub(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_sub((_ptr), __sio(var)(r), __sio(var)(c))); }) + +#define safe_sub4(_ptr, _A, _B, _C, _D) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_sub(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_sub(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_sub((_ptr), __sio(var)(r), (__sio(var)(d)))); }) + +#define safe_sub5(_ptr, _A, _B, _C, _D, _E) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_E) __sio(var)(e) = (_E); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_sub(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_sub(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_sub(&(__sio(var)(r)), __sio(var)(r), __sio(var)(d)) && \ + safe_sub((_ptr), __sio(var)(r), __sio(var)(e))); }) + + + +#define safe_mul(_ptr, __a, __b) \ + ({ int __sio(var)(ok) = 0; \ + typeof(__a) __sio(var)(_a) = (__a); \ + typeof(__b) __sio(var)(_b) = (__b); \ + typeof(_ptr) __sio(var)(p) = (_ptr); \ + if (__sio(m)(assert)(__sio(m)(type_enforce)(__sio(var)(_a), \ + __sio(var)(_b)))) { \ + if (__sio(m)(umax)(__sio(var)(_a)) <= ((typeof(__sio(var)(_a)))0)) { \ + __sio(var)(ok) = safe_smul(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } else { \ + __sio(var)(ok) = safe_umul(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } \ + } \ + __sio(var)(ok); }) + +#define safe_mul3(_ptr, _A, _B, _C) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mul(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mul((_ptr), __sio(var)(r), __sio(var)(c))); }) + +#define safe_mul4(_ptr, _A, _B, _C, _D) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mul(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mul(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_mul((_ptr), __sio(var)(r), (__sio(var)(d)))); }) + +#define safe_mul5(_ptr, _A, _B, _C, _D, _E) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_E) __sio(var)(e) = (_E); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mul(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mul(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_mul(&(__sio(var)(r)), __sio(var)(r), __sio(var)(d)) && \ + safe_mul((_ptr), __sio(var)(r), __sio(var)(e))); }) + +#define safe_div(_ptr, __a, __b) \ + ({ int __sio(var)(ok) = 0; \ + typeof(__a) __sio(var)(_a) = (__a); \ + typeof(__b) __sio(var)(_b) = (__b); \ + typeof(_ptr) __sio(var)(p) = (_ptr); \ + if (__sio(m)(assert)(__sio(m)(type_enforce)(__sio(var)(_a), \ + __sio(var)(_b)))) { \ + if (__sio(m)(umax)(__sio(var)(_a)) <= ((typeof(__sio(var)(_a)))0)) { \ + __sio(var)(ok) = safe_sdiv(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } else { \ + __sio(var)(ok) = safe_udiv(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } \ + } \ + __sio(var)(ok); }) + +#define safe_div3(_ptr, _A, _B, _C) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_div(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_div((_ptr), __sio(var)(r), __sio(var)(c))); }) + +#define safe_div4(_ptr, _A, _B, _C, _D) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_div(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_div(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_div((_ptr), __sio(var)(r), (__sio(var)(d)))); }) + +#define safe_div5(_ptr, _A, _B, _C, _D, _E) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_E) __sio(var)(e) = (_E); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_div(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_div(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_div(&(__sio(var)(r)), __sio(var)(r), __sio(var)(d)) && \ + safe_div((_ptr), __sio(var)(r), __sio(var)(e))); }) + +#define safe_mod(_ptr, __a, __b) \ + ({ int __sio(var)(ok) = 0; \ + typeof(__a) __sio(var)(_a) = (__a); \ + typeof(__b) __sio(var)(_b) = (__b); \ + typeof(_ptr) __sio(var)(p) = (_ptr); \ + if (__sio(m)(assert)(__sio(m)(type_enforce)(__sio(var)(_a), \ + __sio(var)(_b)))) { \ + if (__sio(m)(umax)(__sio(var)(_a)) <= ((typeof(__sio(var)(_a)))0)) { \ + __sio(var)(ok) = safe_smod(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } else { \ + __sio(var)(ok) = safe_umod(__sio(var)(p), \ + __sio(var)(_a), \ + __sio(var)(_b)); \ + } \ + } \ + __sio(var)(ok); }) + +#define safe_mod3(_ptr, _A, _B, _C) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mod(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mod((_ptr), __sio(var)(r), __sio(var)(c))); }) + +#define safe_mod4(_ptr, _A, _B, _C, _D) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C); \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mod(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mod(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_mod((_ptr), __sio(var)(r), (__sio(var)(d)))); }) + +#define safe_mod5(_ptr, _A, _B, _C, _D, _E) \ +({ typeof(_A) __sio(var)(a) = (_A); \ + typeof(_B) __sio(var)(b) = (_B); \ + typeof(_C) __sio(var)(c) = (_C), \ + typeof(_D) __sio(var)(d) = (_D); \ + typeof(_E) __sio(var)(e) = (_E); \ + typeof(_A) __sio(var)(r) = 0; \ + (safe_mod(&(__sio(var)(r)), __sio(var)(a), __sio(var)(b)) && \ + safe_mod(&(__sio(var)(r)), __sio(var)(r), __sio(var)(c)) && \ + safe_mod(&(__sio(var)(r)), __sio(var)(r), __sio(var)(d)) && \ + safe_mod((_ptr), __sio(var)(r), __sio(var)(e))); }) + +/*** Safe integer operation implementation macros ***/ + +#define safe_uadd(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((typeof(_a))(_b) <= (typeof(_a))(__sio(m)(umax)(_a) - (_a))) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) + (_b); } \ + __sio(var)(ok) = 1; \ + } __sio(var)(ok); }) + +#define safe_sadd(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 1; \ + if (((_b) > (typeof(_a))0) && ((_a) > (typeof(_a))0)) { /*>0*/ \ + if ((_a) > (typeof(_a))(__sio(m)(smax)(_a) - (_b))) __sio(var)(ok) = 0; \ + } else if (!((_b) > (typeof(_a))0) && !((_a) > (typeof(_a))0)) { /*<0*/ \ + if ((_a) < (typeof(_a))(__sio(m)(smin)(_a) - (_b))) __sio(var)(ok) = 0; \ + } \ + if (__sio(var)(ok) && (_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) + (_b); } \ + __sio(var)(ok); }) + +#define safe_usub(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((_a) >= (_b)) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) - (_b); } \ + __sio(var)(ok) = 1; \ + } \ + __sio(var)(ok); }) + +#define safe_ssub(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if (!((_b) <= 0 && (_a) > (__sio(m)(smax)(_a) + (_b))) && \ + !((_b) > 0 && (_a) < (__sio(m)(smin)(_a) + (_b)))) { \ + __sio(var)(ok) = 1; \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) - (_b); } \ + } \ + __sio(var)(ok); }) + +#define safe_umul(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if (!(_b) || (_a) <= (__sio(m)(umax)(_a) / (_b))) { \ + __sio(var)(ok) = 1; \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) * (_b); } \ + } \ + __sio(var)(ok); }) + +#define safe_smul(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 1; \ + if ((_a) > 0) { /* a is positive */ \ + if ((_b) > 0) { /* b and a are positive */ \ + if ((_a) > (__sio(m)(smax)(_a) / (_b))) { \ + __sio(var)(ok) = 0; \ + } \ + } /* end if a and b are positive */ \ + else { /* a positive, b non-positive */ \ + if ((_b) < (__sio(m)(smin)(_a) / (_a))) { \ + __sio(var)(ok) = 0; \ + } \ + } /* a positive, b non-positive */ \ + } /* end if a is positive */ \ + else { /* a is non-positive */ \ + if ((_b) > 0) { /* a is non-positive, b is positive */ \ + if ((_a) < (__sio(m)(smin)(_a) / (_b))) { \ + __sio(var)(ok) = 0; \ + } \ + } /* end if a is non-positive, b is positive */ \ + else { /* a and b are non-positive */ \ + if( ((_a) != 0) && ((_b) < (__sio(m)(smax)(_a) / (_a)))) { \ + __sio(var)(ok) = 0; \ + } \ + } /* end if a and b are non-positive */ \ + } /* end if a is non-positive */ \ + if (__sio(var)(ok) && (_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) * (_b); } \ + __sio(var)(ok); }) + +/* div-by-zero is the only thing addressed */ +#define safe_udiv(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((_b) != 0) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) / (_b); } \ + __sio(var)(ok) = 1; \ + } \ + __sio(var)(ok); }) + +/* Addreses div by zero and smin -1 */ +#define safe_sdiv(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((_b) != 0 && \ + (((_a) != __sio(m)(smin)(_a)) || ((_b) != (typeof(_b))-1))) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) / (_b); } \ + __sio(var)(ok) = 1; \ + } \ + __sio(var)(ok); }) + +#define safe_umod(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((_b) != 0) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) % (_b); } \ + __sio(var)(ok) = 1; \ + } \ + __sio(var)(ok); }) + +#define safe_smod(_ptr, _a, _b) \ + ({ int __sio(var)(ok) = 0; \ + if ((_b) != 0 && \ + (((_a) != __sio(m)(smin)(_a)) || ((_b) != (typeof(_b))-1))) { \ + if ((_ptr)) { *((typeof(_a)*)(_ptr)) = (_a) % (_b); } \ + __sio(var)(ok) = 1; \ + } \ + __sio(var)(ok); }) + +#if SAFE_IOP_COMPAT +/* These are used for testing for easy type enforcement */ +#include <sys/types.h> +#include <limits.h> + +#ifndef SAFE_IOP_INLINE +# if defined(__GNUC__) && (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 0) +# define SAFE_IOP_INLINE __attribute__((always_inline)) static inline +# else +# define SAFE_IOP_INLINE static inline +# endif +#endif + +#define MAKE_UADD(_prefix, _bits, _type, _max) \ + SAFE_IOP_INLINE \ + int safe_add##_prefix##_bits (_type *result, _type value, _type a) { \ + return safe_uadd(result, value, a); \ + } + +#define MAKE_SADD(_prefix, _bits, _type, _max) \ + SAFE_IOP_INLINE \ + int safe_add##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_sadd(result, value, a); \ + } + +#define MAKE_USUB(_prefix, _bits, _type) \ + SAFE_IOP_INLINE \ + int safe_sub##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_usub(result, value, a); \ + } + +#define MAKE_SSUB(_prefix, _bits, _type, _min, _max) \ + SAFE_IOP_INLINE \ + int safe_sub##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_ssub(result, value, a); \ + } + +#define MAKE_UMUL(_prefix, _bits, _type, _max) \ + SAFE_IOP_INLINE \ + int safe_mul##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_umul(result, value, a); \ + } + + +#define MAKE_SMUL(_prefix, _bits, _type, _max, _min) \ + SAFE_IOP_INLINE \ + int safe_mul##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_smul(result, value, a); \ + } + +#define MAKE_UDIV(_prefix, _bits, _type) \ + SAFE_IOP_INLINE \ + int safe_div##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_udiv(result, value, a); \ + } + +#define MAKE_SDIV(_prefix, _bits, _type, _min) \ + SAFE_IOP_INLINE \ + int safe_div##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_sdiv(result, value, a); \ + } + +#define MAKE_UMOD(_prefix, _bits, _type) \ + SAFE_IOP_INLINE \ + int safe_mod##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_umod(result, value, a); \ + } + +#define MAKE_SMOD(_prefix, _bits, _type, _min) \ + SAFE_IOP_INLINE \ + int safe_mod##_prefix##_bits(_type *result, _type value, _type a) { \ + return safe_smod(result, value, a); \ + } + +/* __LP64__ is given by GCC. Without more work, this is bound to GCC. */ +#if __LP64__ == 1 || __SIZEOF_LONG__ > __SIZEOF_INT__ +# define SAFE_INT64_MAX 0x7fffffffffffffffL +# define SAFE_UINT64_MAX 0xffffffffffffffffUL +# define SAFE_INT64_MIN (-SAFE_INT64_MAX - 1L) +#elif __SIZEOF_LONG__ == __SIZEOF_INT__ +# define SAFE_INT64_MAX 0x7fffffffffffffffLL +# define SAFE_UINT64_MAX 0xffffffffffffffffULL +# define SAFE_INT64_MIN (-SAFE_INT64_MAX - 1LL) +#else +# warning "64-bit support disabled" +# define SAFE_IOP_NO_64 1 +#endif + +/* Assumes SSIZE_MAX */ +#ifndef SSIZE_MIN +# if SSIZE_MAX == LONG_MAX +# define SSIZE_MIN LONG_MIN +# elif SSIZE_MAX == LONG_LONG_MAX +# define SSIZE_MIN LONG_LONG_MIN +# else +# error "SSIZE_MIN is not defined and could not be guessed" +# endif +#endif + + + +#ifndef SAFE_IOP_NO_64 + MAKE_UADD(u, 64, u_int64_t, SAFE_UINT64_MAX) +#endif +MAKE_UADD(,szt, size_t, SIZE_MAX) +MAKE_UADD(u, 32, u_int32_t, UINT_MAX) +MAKE_UADD(u, 16, u_int16_t, USHRT_MAX) +MAKE_UADD(u, 8, u_int8_t, UCHAR_MAX) + +#ifndef SAFE_IOP_NO_64 + MAKE_SADD(s, 64, int64_t, SAFE_INT64_MAX) +#endif +MAKE_SADD(s, szt, ssize_t, SSIZE_MAX) +MAKE_SADD(s, 32, int32_t, INT_MAX) +MAKE_SADD(s, 16, int16_t, SHRT_MAX) +MAKE_SADD(s, 8, int8_t, SCHAR_MAX) + +#ifndef SAFE_IOP_NO_64 + MAKE_USUB(u, 64, u_int64_t) +#endif +MAKE_USUB(, szt, size_t) +MAKE_USUB(u, 32, u_int32_t) +MAKE_USUB(u, 16, u_int16_t) +MAKE_USUB(u, 8, u_int8_t) + +#ifndef SAFE_IOP_NO_64 + MAKE_SSUB(s, 64, int64_t, SAFE_INT64_MIN, SAFE_INT64_MAX) +#endif +MAKE_SSUB(s, szt, ssize_t, SSIZE_MIN, SSIZE_MAX) +MAKE_SSUB(s, 32, int32_t, INT_MIN, INT_MAX) +MAKE_SSUB(s, 16, int16_t, SHRT_MIN, SHRT_MAX) +MAKE_SSUB(s, 8, int8_t, SCHAR_MIN, SCHAR_MAX) + + +#ifndef SAFE_IOP_NO_64 + MAKE_UMUL(u, 64, u_int64_t, SAFE_UINT64_MAX) +#endif +MAKE_UMUL(, szt, size_t, SIZE_MAX) +MAKE_UMUL(u, 32, u_int32_t, UINT_MAX) +MAKE_UMUL(u, 16, u_int16_t, USHRT_MAX) +MAKE_UMUL(u, 8, u_int8_t, UCHAR_MAX) + +#ifndef SAFE_IOP_NO_64 + MAKE_SMUL(s, 64, int64_t, SAFE_INT64_MAX, SAFE_INT64_MIN) +#endif +MAKE_SMUL(s, szt, ssize_t, SSIZE_MAX, SSIZE_MIN) +MAKE_SMUL(s, 32, int32_t, INT_MAX, INT_MIN) +MAKE_SMUL(s, 16, int16_t, SHRT_MAX, SHRT_MIN) +MAKE_SMUL(s, 8, int8_t, SCHAR_MAX, SCHAR_MIN) + + +#ifndef SAFE_IOP_NO_64 + MAKE_UDIV(u, 64, u_int64_t) +#endif +MAKE_UDIV(, szt, size_t) +MAKE_UDIV(u, 32, u_int32_t) +MAKE_UDIV(u, 16, u_int16_t) +MAKE_UDIV(u, 8, u_int8_t) + +#ifndef SAFE_IOP_NO_64 + MAKE_SDIV(s, 64, int64_t, SAFE_INT64_MIN) +#endif +MAKE_SDIV(s, szt, ssize_t, SSIZE_MIN) +MAKE_SDIV(s, 32, int32_t, INT_MIN) +MAKE_SDIV(s, 16, int16_t, SHRT_MIN) +MAKE_SDIV(s, 8, int8_t, SCHAR_MIN) + + +#ifndef SAFE_IOP_NO_64 + MAKE_UMOD(u, 64, u_int64_t) +#endif +MAKE_UMOD(, szt, size_t) +MAKE_UMOD(u, 32, u_int32_t) +MAKE_UMOD(u, 16, u_int16_t) +MAKE_UMOD(u, 8, u_int8_t) + +#ifndef SAFE_IOP_NO_64 + MAKE_SMOD(s, 64, int64_t, SAFE_INT64_MIN) +#endif +MAKE_SMOD(s, szt, ssize_t, SSIZE_MIN) +MAKE_SMOD(s, 32, int32_t, INT_MIN) +MAKE_SMOD(s, 16, int16_t, SHRT_MIN) +MAKE_SMOD(s, 8, int8_t, SCHAR_MIN) + +/* Cleanup the macro spam */ +#undef MAKE_SMUL +#undef MAKE_UMUL +#undef MAKE_SSUB +#undef MAKE_USUB +#undef MAKE_SADD +#undef MAKE_UADD +#undef MAKE_UDIV +#undef MAKE_SDIV +#undef MAKE_UMOD +#undef MAKE_SMOD + +#endif /* SAFE_IOP_COMPAT */ + + + +/* safe_iopf + * + * Takes in a character array which specifies the operations + * to perform on a given value. The value will be assumed to be + * of the type specified for each operation. + * + * Currently accepted format syntax is: + * [type_marker]operation... + * The type marker may be any of the following: + * - s32 for signed int32 + * - u32 for unsigned int32 + * If no type_marker is specified, it is assumed to be s32. + * + * Currently, this only performs correctly with 32-bit integers. + * + * The operation must be one of the following: + * - * -- multiplication + * - / -- division + * - - -- subtraction + * - + -- addition + * - % -- modulo (remainder) + * + * Whitespace will be ignored. + * + * Args: + * - pointer to the final result (this must be at least the size of int32) + * - array of format characters + * - all remaining arguments are derived from the format + * Output: + * - Returns 1 on success leaving the result in value + * - Returns 0 on failure leaving the contents of value *unknown* + */ + +int safe_iopf(void *result, const char *const fmt, ...); + + +#endif /* _SAFE_IOP_H */ |