Line data Source code
1 : // Copyright (c) 2009 The Chromium Authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #ifndef OPENTYPE_SANITISER_H_
6 : #define OPENTYPE_SANITISER_H_
7 :
8 : #if defined(_WIN32) || defined(__CYGWIN__)
9 : #define OTS_DLL_IMPORT __declspec(dllimport)
10 : #define OTS_DLL_EXPORT __declspec(dllexport)
11 : #else
12 : #if __GNUC__ >= 4
13 : #define OTS_DLL_IMPORT __attribute__((visibility ("default")))
14 : #define OTS_DLL_EXPORT __attribute__((visibility ("default")))
15 : #endif
16 : #endif
17 :
18 : #ifdef OTS_DLL
19 : #ifdef OTS_DLL_EXPORTS
20 : #define OTS_API OTS_DLL_EXPORT
21 : #else
22 : #define OTS_API OTS_DLL_IMPORT
23 : #endif
24 : #else
25 : #define OTS_API
26 : #endif
27 :
28 : #if defined(_WIN32)
29 : #include <stdlib.h>
30 : typedef signed char int8_t;
31 : typedef unsigned char uint8_t;
32 : typedef short int16_t;
33 : typedef unsigned short uint16_t;
34 : typedef int int32_t;
35 : typedef unsigned int uint32_t;
36 : typedef __int64 int64_t;
37 : typedef unsigned __int64 uint64_t;
38 : #define ntohl(x) _byteswap_ulong (x)
39 : #define ntohs(x) _byteswap_ushort (x)
40 : #define htonl(x) _byteswap_ulong (x)
41 : #define htons(x) _byteswap_ushort (x)
42 : #else
43 : #include <arpa/inet.h>
44 : #include <stdint.h>
45 : #endif
46 :
47 : #include <sys/types.h>
48 :
49 : #include <algorithm>
50 : #include <cassert>
51 : #include <cstddef>
52 : #include <cstring>
53 :
54 : #define OTS_TAG(c1,c2,c3,c4) ((uint32_t)((((uint8_t)(c1))<<24)|(((uint8_t)(c2))<<16)|(((uint8_t)(c3))<<8)|((uint8_t)(c4))))
55 : #define OTS_UNTAG(tag) ((uint8_t)((tag)>>24)), ((uint8_t)((tag)>>16)), ((uint8_t)((tag)>>8)), ((uint8_t)(tag))
56 :
57 : namespace ots {
58 :
59 : // -----------------------------------------------------------------------------
60 : // This is an interface for an abstract stream class which is used for writing
61 : // the serialised results out.
62 : // -----------------------------------------------------------------------------
63 : class OTSStream {
64 : public:
65 0 : OTSStream() : chksum_(0) {}
66 :
67 0 : virtual ~OTSStream() {}
68 :
69 : // This should be implemented to perform the actual write.
70 : virtual bool WriteRaw(const void *data, size_t length) = 0;
71 :
72 0 : bool Write(const void *data, size_t length) {
73 0 : if (!length) return false;
74 :
75 0 : const size_t orig_length = length;
76 0 : size_t offset = 0;
77 :
78 0 : size_t chksum_offset = Tell() & 3;
79 0 : if (chksum_offset) {
80 0 : const size_t l = std::min(length, static_cast<size_t>(4) - chksum_offset);
81 0 : uint32_t tmp = 0;
82 0 : std::memcpy(reinterpret_cast<uint8_t *>(&tmp) + chksum_offset, data, l);
83 0 : chksum_ += ntohl(tmp);
84 0 : length -= l;
85 0 : offset += l;
86 : }
87 :
88 0 : while (length >= 4) {
89 : uint32_t tmp;
90 0 : std::memcpy(&tmp, reinterpret_cast<const uint8_t *>(data) + offset,
91 0 : sizeof(uint32_t));
92 0 : chksum_ += ntohl(tmp);
93 0 : length -= 4;
94 0 : offset += 4;
95 : }
96 :
97 0 : if (length) {
98 0 : if (length > 4) return false; // not reached
99 0 : uint32_t tmp = 0;
100 0 : std::memcpy(&tmp,
101 0 : reinterpret_cast<const uint8_t*>(data) + offset, length);
102 0 : chksum_ += ntohl(tmp);
103 : }
104 :
105 0 : return WriteRaw(data, orig_length);
106 : }
107 :
108 : virtual bool Seek(off_t position) = 0;
109 : virtual off_t Tell() const = 0;
110 :
111 0 : virtual bool Pad(size_t bytes) {
112 : static const uint32_t kZero = 0;
113 0 : while (bytes >= 4) {
114 0 : if (!Write(&kZero, 4)) return false;
115 0 : bytes -= 4;
116 : }
117 0 : while (bytes) {
118 : static const uint8_t kZerob = 0;
119 0 : if (!Write(&kZerob, 1)) return false;
120 0 : bytes--;
121 : }
122 0 : return true;
123 : }
124 :
125 0 : bool WriteU8(uint8_t v) {
126 0 : return Write(&v, sizeof(v));
127 : }
128 :
129 0 : bool WriteU16(uint16_t v) {
130 0 : v = htons(v);
131 0 : return Write(&v, sizeof(v));
132 : }
133 :
134 0 : bool WriteS16(int16_t v) {
135 0 : v = htons(v);
136 0 : return Write(&v, sizeof(v));
137 : }
138 :
139 0 : bool WriteU24(uint32_t v) {
140 0 : v = htonl(v);
141 0 : return Write(reinterpret_cast<uint8_t*>(&v)+1, 3);
142 : }
143 :
144 0 : bool WriteU32(uint32_t v) {
145 0 : v = htonl(v);
146 0 : return Write(&v, sizeof(v));
147 : }
148 :
149 0 : bool WriteS32(int32_t v) {
150 0 : v = htonl(v);
151 0 : return Write(&v, sizeof(v));
152 : }
153 :
154 0 : bool WriteR64(uint64_t v) {
155 0 : return Write(&v, sizeof(v));
156 : }
157 :
158 0 : void ResetChecksum() {
159 0 : assert((Tell() & 3) == 0);
160 0 : chksum_ = 0;
161 0 : }
162 :
163 0 : uint32_t chksum() const {
164 0 : return chksum_;
165 : }
166 :
167 : protected:
168 : uint32_t chksum_;
169 : };
170 :
171 : #ifdef __GCC__
172 : #define MSGFUNC_FMT_ATTR __attribute__((format(printf, 2, 3)))
173 : #else
174 : #define MSGFUNC_FMT_ATTR
175 : #endif
176 :
177 : enum TableAction {
178 : TABLE_ACTION_DEFAULT, // Use OTS's default action for that table
179 : TABLE_ACTION_SANITIZE, // Sanitize the table, potentially droping it
180 : TABLE_ACTION_PASSTHRU, // Serialize the table unchanged
181 : TABLE_ACTION_DROP // Drop the table
182 : };
183 :
184 : class OTS_API OTSContext {
185 : public:
186 0 : OTSContext() {}
187 0 : virtual ~OTSContext() {}
188 :
189 : // Process a given OpenType file and write out a sanitised version
190 : // output: a pointer to an object implementing the OTSStream interface. The
191 : // sanitisied output will be written to this. In the even of a failure,
192 : // partial output may have been written.
193 : // input: the OpenType file
194 : // length: the size, in bytes, of |input|
195 : // index: if the input is a font collection and index is specified, then
196 : // the corresponding font will be returned, otherwise the whole
197 : // collection. Ignored for non-collection fonts.
198 : bool Process(OTSStream *output, const uint8_t *input, size_t length, uint32_t index = -1);
199 :
200 : // This function will be called when OTS is reporting an error.
201 : // level: the severity of the generated message:
202 : // 0: error messages in case OTS fails to sanitize the font.
203 : // 1: warning messages about issue OTS fixed in the sanitized font.
204 0 : virtual void Message(int level, const char *format, ...) MSGFUNC_FMT_ATTR {}
205 :
206 : // This function will be called when OTS needs to decide what to do for a
207 : // font table.
208 : // tag: table tag formed with OTS_TAG() macro
209 0 : virtual TableAction GetTableAction(uint32_t tag) { return ots::TABLE_ACTION_DEFAULT; }
210 : };
211 :
212 : } // namespace ots
213 :
214 : #endif // OPENTYPE_SANITISER_H_
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