/* * Copyright (C) 2007,2008,2009,2010 Red Hat, Inc. * * This is part of HarfBuzz, a text shaping library. * * Permission is hereby granted, without written agreement and without * license or royalty fees, to use, copy, modify, and distribute this * software and its documentation for any purpose, provided that the * above copyright notice and the following two paragraphs appear in * all copies of this software. * * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. * * Red Hat Author(s): Behdad Esfahbod */ #ifndef HB_OPEN_TYPES_PRIVATE_HH #define HB_OPEN_TYPES_PRIVATE_HH #include "hb-private.h" #include "hb-blob.h" /* Table/script/language-system/feature/... not found */ #define NO_INDEX ((unsigned int) 0xFFFF) /* * Casts */ /* Cast to "const char *" and "char *" */ template inline const char * CharP (const Type* X) { return reinterpret_cast(X); } template inline char * CharP (Type* X) { return reinterpret_cast(X); } #define CONST_CAST(T,X,Ofs) (*(reinterpret_cast(CharP(&(X)) + Ofs))) #define DECONST_CAST(T,X,Ofs) (*(reinterpret_cast((char *)CharP(&(X)) + Ofs))) #define CAST(T,X,Ofs) (*(reinterpret_cast(CharP(&(X)) + Ofs))) /* StructAfter(X) returns the struct T& that is placed after X. * Works with X of variable size also. X must implement get_size() */ template inline const Type& StructAfter(const TObject &X) { return * reinterpret_cast (CharP (&X) + X.get_size()); } template inline Type& StructAfter(TObject &X) { return * reinterpret_cast (CharP (&X) + X.get_size()); } /* * Class features */ /* Null objects */ /* Global nul-content Null pool. Enlarge as necessary. */ static const void *_NullPool[32 / sizeof (void *)]; /* Generic template for nul-content sizeof-sized Null objects. */ template static inline const Type& Null () { ASSERT_STATIC (sizeof (Type) <= sizeof (_NullPool)); return CONST_CAST (Type, *_NullPool, 0); } /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */ #define DEFINE_NULL_DATA(Type, size, data) \ static const char _Null##Type[size + 1] = data; \ template <> \ inline const Type& Null () { \ return CONST_CAST (Type, *_Null##Type, 0); \ } /* Accessor macro. */ #define Null(Type) Null() /* get_for_data() is a static class method returning a reference to an * instance of Type located at the input data location. It's just a * fancy, NULL-safe, cast! */ #define STATIC_DEFINE_GET_FOR_DATA(Type) \ static inline const Type& get_for_data (const char *data) \ { \ if (HB_UNLIKELY (data == NULL)) return Null(Type); \ return CONST_CAST (Type, *data, 0); \ } /* Like get_for_data(), but checks major version first. */ #define STATIC_DEFINE_GET_FOR_DATA_CHECK_MAJOR_VERSION(Type, MajorMin, MajorMax) \ static inline const Type& get_for_data (const char *data) \ { \ if (HB_UNLIKELY (data == NULL)) return Null(Type); \ const Type& t = CONST_CAST (Type, *data, 0); \ if (HB_UNLIKELY (t.version.major < MajorMin || t.version.major > MajorMax)) return Null(Type); \ return t; \ } /* * Sanitize */ #ifndef HB_DEBUG_SANITIZE #define HB_DEBUG_SANITIZE HB_DEBUG #endif #if HB_DEBUG_SANITIZE #include #define TRACE_SANITIZE_ARG_DEF , unsigned int sanitize_depth HB_GNUC_UNUSED #define TRACE_SANITIZE_ARG , sanitize_depth + 1 #define TRACE_SANITIZE_ARG_INIT , 1 #define TRACE_SANITIZE() \ HB_STMT_START { \ if (sanitize_depth < HB_DEBUG_SANITIZE) \ fprintf (stderr, "SANITIZE(%p) %-*d-> %s\n", \ (CharP (this) == CharP (&NullPool)) ? 0 : this, \ sanitize_depth, sanitize_depth, \ __PRETTY_FUNCTION__); \ } HB_STMT_END #else #define TRACE_SANITIZE_ARG_DEF #define TRACE_SANITIZE_ARG #define TRACE_SANITIZE_ARG_INIT #define TRACE_SANITIZE() HB_STMT_START {} HB_STMT_END #endif #define SANITIZE_ARG_DEF \ hb_sanitize_context_t *context TRACE_SANITIZE_ARG_DEF #define SANITIZE_ARG \ context TRACE_SANITIZE_ARG #define SANITIZE_ARG_INIT \ &context TRACE_SANITIZE_ARG_INIT typedef struct _hb_sanitize_context_t hb_sanitize_context_t; struct _hb_sanitize_context_t { const char *start, *end; int edit_count; hb_blob_t *blob; }; static HB_GNUC_UNUSED void _hb_sanitize_init (hb_sanitize_context_t *context, hb_blob_t *blob) { context->blob = blob; context->start = hb_blob_lock (blob); context->end = context->start + hb_blob_get_length (blob); context->edit_count = 0; #if HB_DEBUG_SANITIZE fprintf (stderr, "sanitize %p init [%p..%p] (%u bytes)\n", context->blob, context->start, context->end, context->end - context->start); #endif } static HB_GNUC_UNUSED void _hb_sanitize_fini (hb_sanitize_context_t *context, bool unlock) { #if HB_DEBUG_SANITIZE fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n", context->blob, context->start, context->end, context->edit_count); #endif if (unlock) hb_blob_unlock (context->blob); } static HB_GNUC_UNUSED inline bool _hb_sanitize_check (SANITIZE_ARG_DEF, const char *base, unsigned int len) { bool ret = context->start <= base && base <= context->end && (unsigned int) (context->end - base) >= len; #if HB_DEBUG_SANITIZE if (sanitize_depth < HB_DEBUG_SANITIZE) \ fprintf (stderr, "SANITIZE(%p) %-*d-> check [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \ base, sanitize_depth, sanitize_depth, base, base+len, len, context->start, context->end, ret ? "pass" : "FAIL"); #endif return ret; } static HB_GNUC_UNUSED inline bool _hb_sanitize_array (SANITIZE_ARG_DEF, const char *base, unsigned int record_size, unsigned int len) { bool overflows = len >= ((unsigned int) -1) / record_size; #if HB_DEBUG_SANITIZE if (sanitize_depth < HB_DEBUG_SANITIZE) \ fprintf (stderr, "SANITIZE(%p) %-*d-> array [%p..%p] (%d*%d=%ld bytes) in [%p..%p] -> %s\n", \ base, sanitize_depth, sanitize_depth, base, base + (record_size * len), record_size, len, (unsigned long) record_size * len, context->start, context->end, !overflows ? "does not overflow" : "OVERFLOWS FAIL"); #endif return HB_LIKELY (!overflows) && _hb_sanitize_check (SANITIZE_ARG, base, record_size * len); } static HB_GNUC_UNUSED inline bool _hb_sanitize_edit (SANITIZE_ARG_DEF, const char *base HB_GNUC_UNUSED, unsigned int len HB_GNUC_UNUSED) { bool perm = hb_blob_try_writable_inplace (context->blob); context->edit_count++; #if HB_DEBUG_SANITIZE fprintf (stderr, "SANITIZE(%p) %-*d-> edit(%u) [%p..%p] (%d bytes) in [%p..%p] -> %s\n", \ base, sanitize_depth, sanitize_depth, context->edit_count, base, base+len, len, context->start, context->end, perm ? "granted" : "REJECTED"); #endif return perm; } #define SANITIZE(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG)) #define SANITIZE2(X,Y) (SANITIZE (X) && SANITIZE (Y)) #define SANITIZE_THIS(X) HB_LIKELY ((X).sanitize (SANITIZE_ARG, CharP(this))) #define SANITIZE_THIS2(X,Y) (SANITIZE_THIS (X) && SANITIZE_THIS (Y)) #define SANITIZE_THIS3(X,Y,Z) (SANITIZE_THIS (X) && SANITIZE_THIS (Y) && SANITIZE_THIS(Z)) #define SANITIZE_BASE(X,B) HB_LIKELY ((X).sanitize (SANITIZE_ARG, B)) #define SANITIZE_BASE2(X,Y,B) (SANITIZE_BASE (X,B) && SANITIZE_BASE (Y,B)) #define SANITIZE_SELF() SANITIZE_OBJ (*this) #define SANITIZE_OBJ(X) SANITIZE_MEM(&(X), sizeof (X)) #define SANITIZE_MEM(B,L) HB_LIKELY (_hb_sanitize_check (SANITIZE_ARG, CharP(B), (L))) #define SANITIZE_ARRAY(A,S,L) HB_LIKELY (_hb_sanitize_array (SANITIZE_ARG, CharP(A), S, L)) #define NEUTER(Var, Val) \ (SANITIZE_OBJ (Var) && \ _hb_sanitize_edit (SANITIZE_ARG, CharP(&(Var)), sizeof (Var)) && \ ((Var).set (Val), true)) /* Template to sanitize an object. */ template struct Sanitizer { static hb_blob_t *sanitize (hb_blob_t *blob) { hb_sanitize_context_t context; bool sane; /* TODO is_sane() stuff */ retry: #if HB_DEBUG_SANITIZE fprintf (stderr, "Sanitizer %p start %s\n", blob, __PRETTY_FUNCTION__); #endif _hb_sanitize_init (&context, blob); Type *t = &CAST (Type, * (char *) CharP(context.start), 0); sane = t->sanitize (SANITIZE_ARG_INIT); if (sane) { if (context.edit_count) { #if HB_DEBUG_SANITIZE fprintf (stderr, "Sanitizer %p passed first round with %d edits; going a second round %s\n", blob, context.edit_count, __PRETTY_FUNCTION__); #endif /* sanitize again to ensure no toe-stepping */ context.edit_count = 0; sane = t->sanitize (SANITIZE_ARG_INIT); if (context.edit_count) { #if HB_DEBUG_SANITIZE fprintf (stderr, "Sanitizer %p requested %d edits in second round; FAILLING %s\n", blob, context.edit_count, __PRETTY_FUNCTION__); #endif sane = false; } } _hb_sanitize_fini (&context, true); } else { unsigned int edit_count = context.edit_count; _hb_sanitize_fini (&context, true); if (edit_count && !hb_blob_is_writable (blob) && hb_blob_try_writable (blob)) { /* ok, we made it writable by relocating. try again */ #if HB_DEBUG_SANITIZE fprintf (stderr, "Sanitizer %p retry %s\n", blob, __PRETTY_FUNCTION__); #endif goto retry; } } #if HB_DEBUG_SANITIZE fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "FAILED", __PRETTY_FUNCTION__); #endif if (sane) return blob; else { hb_blob_destroy (blob); return hb_blob_create_empty (); } } static const Type& lock_instance (hb_blob_t *blob) { return Type::get_for_data (hb_blob_lock (blob)); } }; /* * * The OpenType Font File: Data Types */ /* "The following data types are used in the OpenType font file. * All OpenType fonts use Motorola-style byte ordering (Big Endian):" */ /* * Int types */ template class BEInt; template class BEInt { public: inline class BEInt& operator = (Type i) { hb_be_uint16_put (v,i); return *this; } inline operator Type () const { return hb_be_uint16_get (v); } inline bool operator == (const BEInt& o) const { return hb_be_uint16_cmp (v, o.v); } inline bool operator != (const BEInt& o) const { return !(*this == o); } private: uint8_t v[2]; }; template class BEInt { public: inline class BEInt& operator = (Type i) { hb_be_uint32_put (v,i); return *this; } inline operator Type () const { return hb_be_uint32_get (v); } inline bool operator == (const BEInt& o) const { return hb_be_uint32_cmp (v, o.v); } inline bool operator != (const BEInt& o) const { return !(*this == o); } private: uint8_t v[4]; }; /* Integer types in big-endian order and no alignment requirement */ template struct IntType { static inline unsigned int get_size () { return sizeof (Type); } inline void set (Type i) { v = i; } inline operator Type(void) const { return v; } inline bool operator == (const IntType &o) const { return v == o.v; } inline bool operator != (const IntType &o) const { return v != o.v; } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); return SANITIZE_SELF (); } private: BEInt v; }; typedef IntType USHORT; /* 16-bit unsigned integer. */ typedef IntType SHORT; /* 16-bit signed integer. */ typedef IntType ULONG; /* 32-bit unsigned integer. */ typedef IntType LONG; /* 32-bit signed integer. */ ASSERT_SIZE (USHORT, 2); ASSERT_SIZE (SHORT, 2); ASSERT_SIZE (ULONG, 4); ASSERT_SIZE (LONG, 4); /* Array of four uint8s (length = 32 bits) used to identify a script, language * system, feature, or baseline */ struct Tag : ULONG { /* What the char* converters return is NOT nul-terminated. Print using "%.4s" */ inline operator const char* (void) const { return CharP(this); } inline operator char* (void) { return CharP(this); } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); /* Note: Only accept ASCII-visible tags (mind DEL) * This is one of the few places (only place?) that we check * for data integrity, as opposed to just boundary checks. */ return SANITIZE_SELF () && (((uint32_t) *this) & 0x80808080) == 0; } }; ASSERT_SIZE (Tag, 4); DEFINE_NULL_DATA (Tag, 4, " "); /* Glyph index number, same as uint16 (length = 16 bits) */ typedef USHORT GlyphID; /* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */ typedef USHORT Offset; /* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */ typedef ULONG LongOffset; /* CheckSum */ struct CheckSum : ULONG { static uint32_t CalcTableChecksum (ULONG *Table, uint32_t Length) { uint32_t Sum = 0L; ULONG *EndPtr = Table+((Length+3) & ~3) / ULONG::get_size (); while (Table < EndPtr) Sum += *Table++; return Sum; } }; ASSERT_SIZE (CheckSum, 4); /* * Version Numbers */ struct FixedVersion { inline operator uint32_t (void) const { return (major << 16) + minor; } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); return SANITIZE_SELF (); } USHORT major; USHORT minor; }; ASSERT_SIZE (FixedVersion, 4); /* * Template subclasses of Offset and LongOffset that do the dereferencing. * Use: (this+memberName) */ template struct GenericOffsetTo : OffsetType { inline const Type& operator () (const void *base) const { unsigned int offset = *this; if (HB_UNLIKELY (!offset)) return Null(Type); return CONST_CAST(Type, *CharP(base), offset); } inline bool sanitize (SANITIZE_ARG_DEF, void *base) { TRACE_SANITIZE (); if (!SANITIZE_SELF ()) return false; unsigned int offset = *this; if (HB_UNLIKELY (!offset)) return true; return SANITIZE (CAST(Type, *CharP(base), offset)) || NEUTER (CAST(OffsetType,*this,0), 0); } inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) { TRACE_SANITIZE (); if (!SANITIZE_SELF ()) return false; unsigned int offset = *this; if (HB_UNLIKELY (!offset)) return true; return SANITIZE_BASE (CAST(Type, *CharP(base), offset), base2) || NEUTER (CAST(OffsetType,*this,0), 0); } inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) { TRACE_SANITIZE (); if (!SANITIZE_SELF ()) return false; unsigned int offset = *this; if (HB_UNLIKELY (!offset)) return true; return SANITIZE_BASE (CAST(Type, *CharP(base), offset), user_data) || NEUTER (CAST(OffsetType,*this,0), 0); } }; template inline const Type& operator + (const Base &base, GenericOffsetTo offset) { return offset (base); } template struct OffsetTo : GenericOffsetTo {}; template struct LongOffsetTo : GenericOffsetTo {}; /* * Array Types */ template struct GenericArrayOf { const Type *array(void) const { return &StructAfter (len); } Type *array(void) { return &StructAfter (len); } const Type *sub_array (unsigned int start_offset, unsigned int *pcount /* IN/OUT */) const { unsigned int count = len; if (HB_UNLIKELY (start_offset > count)) count = 0; else count -= start_offset; count = MIN (count, *pcount); *pcount = count; return array() + start_offset; } inline const Type& operator [] (unsigned int i) const { if (HB_UNLIKELY (i >= len)) return Null(Type); return array()[i]; } inline unsigned int get_size () const { return len.get_size () + len * Type::get_size (); } inline bool sanitize_shallow (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); return SANITIZE_SELF() && SANITIZE_ARRAY (this, Type::get_size (), len); } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; /* Note: for structs that do not reference other structs, * we do not need to call their sanitize() as we already did * a bound check on the aggregate array size, hence the return. */ return true; /* We do keep this code though to make sure the structs pointed * to do have a simple sanitize(), ie. they do not reference * other structs. */ unsigned int count = len; for (unsigned int i = 0; i < count; i++) if (!SANITIZE (array()[i])) return false; return true; } inline bool sanitize (SANITIZE_ARG_DEF, void *base) { TRACE_SANITIZE (); if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; unsigned int count = len; for (unsigned int i = 0; i < count; i++) if (!array()[i].sanitize (SANITIZE_ARG, base)) return false; return true; } inline bool sanitize (SANITIZE_ARG_DEF, void *base, void *base2) { TRACE_SANITIZE (); if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; unsigned int count = len; for (unsigned int i = 0; i < count; i++) if (!array()[i].sanitize (SANITIZE_ARG, base, base2)) return false; return true; } inline bool sanitize (SANITIZE_ARG_DEF, void *base, unsigned int user_data) { TRACE_SANITIZE (); if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; unsigned int count = len; for (unsigned int i = 0; i < count; i++) if (!array()[i].sanitize (SANITIZE_ARG, base, user_data)) return false; return true; } LenType len; /*Type array[VAR];*/ }; /* An array with a USHORT number of elements. */ template struct ArrayOf : GenericArrayOf {}; /* An array with a ULONG number of elements. */ template struct LongArrayOf : GenericArrayOf {}; /* Array of Offset's */ template struct OffsetArrayOf : ArrayOf > {}; /* Array of LongOffset's */ template struct LongOffsetArrayOf : ArrayOf > {}; /* LongArray of LongOffset's */ template struct LongOffsetLongArrayOf : LongArrayOf > {}; /* Array of offsets relative to the beginning of the array itself. */ template struct OffsetListOf : OffsetArrayOf { inline const Type& operator [] (unsigned int i) const { if (HB_UNLIKELY (i >= this->len)) return Null(Type); return this+this->array()[i]; } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); return OffsetArrayOf::sanitize (SANITIZE_ARG, CharP(this)); } inline bool sanitize (SANITIZE_ARG_DEF, unsigned int user_data) { TRACE_SANITIZE (); return OffsetArrayOf::sanitize (SANITIZE_ARG, CharP(this), user_data); } }; /* An array with a USHORT number of elements, * starting at second element. */ template struct HeadlessArrayOf { const Type *array(void) const { return &StructAfter (len); } Type *array(void) { return &StructAfter (len); } inline const Type& operator [] (unsigned int i) const { if (HB_UNLIKELY (i >= len || !i)) return Null(Type); return array()[i-1]; } inline unsigned int get_size () const { return len.get_size () + (len ? len - 1 : 0) * Type::get_size (); } inline bool sanitize_shallow (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); return SANITIZE_SELF() && SANITIZE_ARRAY (this, Type::get_size (), len); } inline bool sanitize (SANITIZE_ARG_DEF) { TRACE_SANITIZE (); if (!HB_LIKELY (sanitize_shallow (SANITIZE_ARG))) return false; /* Note: for structs that do not reference other structs, * we do not need to call their sanitize() as we already did * a bound check on the aggregate array size, hence the return. */ return true; /* We do keep this code though to make sure the structs pointed * to do have a simple sanitize(), ie. they do not reference * other structs. */ unsigned int count = len ? len - 1 : 0; Type *a = array(); for (unsigned int i = 0; i < count; i++) if (!SANITIZE (a[i])) return false; return true; } USHORT len; /*Type array[VAR];*/ }; #endif /* HB_OPEN_TYPE_PRIVATE_HH */