1 /* $Id: preconv.c,v 1.17 2018/12/13 11:55:47 schwarze Exp $ */
2 /*
3 * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
4 * Copyright (c) 2014 Ingo Schwarze <schwarze@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18 #include "config.h"
19
20 #include <sys/types.h>
21
22 #include <assert.h>
23 #include <stdio.h>
24 #include <string.h>
25
26 #include "mandoc.h"
27 #include "roff.h"
28 #include "mandoc_parse.h"
29 #include "libmandoc.h"
30
31 int
preconv_encode(const struct buf * ib,size_t * ii,struct buf * ob,size_t * oi,int * filenc)32 preconv_encode(const struct buf *ib, size_t *ii, struct buf *ob, size_t *oi,
33 int *filenc)
34 {
35 const unsigned char *cu;
36 int nby;
37 unsigned int accum;
38
39 cu = (const unsigned char *)ib->buf + *ii;
40 assert(*cu & 0x80);
41
42 if ( ! (*filenc & MPARSE_UTF8))
43 goto latin;
44
45 nby = 1;
46 while (nby < 5 && *cu & (1 << (7 - nby)))
47 nby++;
48
49 switch (nby) {
50 case 2:
51 accum = *cu & 0x1f;
52 if (accum < 0x02) /* Obfuscated ASCII. */
53 goto latin;
54 break;
55 case 3:
56 accum = *cu & 0x0f;
57 break;
58 case 4:
59 accum = *cu & 0x07;
60 if (accum > 0x04) /* Beyond Unicode. */
61 goto latin;
62 break;
63 default: /* Bad sequence header. */
64 goto latin;
65 }
66
67 cu++;
68 switch (nby) {
69 case 3:
70 if ((accum == 0x00 && ! (*cu & 0x20)) || /* Use 2-byte. */
71 (accum == 0x0d && *cu & 0x20)) /* Surrogates. */
72 goto latin;
73 break;
74 case 4:
75 if ((accum == 0x00 && ! (*cu & 0x30)) || /* Use 3-byte. */
76 (accum == 0x04 && *cu & 0x30)) /* Beyond Unicode. */
77 goto latin;
78 break;
79 default:
80 break;
81 }
82
83 while (--nby) {
84 if ((*cu & 0xc0) != 0x80) /* Invalid continuation. */
85 goto latin;
86 accum <<= 6;
87 accum += *cu & 0x3f;
88 cu++;
89 }
90
91 assert(accum > 0x7f);
92 assert(accum < 0x110000);
93 assert(accum < 0xd800 || accum > 0xdfff);
94
95 *oi += snprintf(ob->buf + *oi, 11, "\\[u%.4X]", accum);
96 *ii = (const char *)cu - ib->buf;
97 *filenc &= ~MPARSE_LATIN1;
98 return 1;
99
100 latin:
101 if ( ! (*filenc & MPARSE_LATIN1))
102 return 0;
103
104 *oi += snprintf(ob->buf + *oi, 11,
105 "\\[u%.4X]", (unsigned char)ib->buf[(*ii)++]);
106
107 *filenc &= ~MPARSE_UTF8;
108 return 1;
109 }
110
111 int
preconv_cue(const struct buf * b,size_t offset)112 preconv_cue(const struct buf *b, size_t offset)
113 {
114 const char *ln, *eoln, *eoph;
115 size_t sz, phsz;
116
117 ln = b->buf + offset;
118 sz = b->sz - offset;
119
120 /* Look for the end-of-line. */
121
122 if (NULL == (eoln = memchr(ln, '\n', sz)))
123 eoln = ln + sz;
124
125 /* Check if we have the correct header/trailer. */
126
127 if ((sz = (size_t)(eoln - ln)) < 10 ||
128 memcmp(ln, ".\\\" -*-", 7) || memcmp(eoln - 3, "-*-", 3))
129 return MPARSE_UTF8 | MPARSE_LATIN1;
130
131 /* Move after the header and adjust for the trailer. */
132
133 ln += 7;
134 sz -= 10;
135
136 while (sz > 0) {
137 while (sz > 0 && ' ' == *ln) {
138 ln++;
139 sz--;
140 }
141 if (0 == sz)
142 break;
143
144 /* Find the end-of-phrase marker (or eoln). */
145
146 if (NULL == (eoph = memchr(ln, ';', sz)))
147 eoph = eoln - 3;
148 else
149 eoph++;
150
151 /* Only account for the "coding" phrase. */
152
153 if ((phsz = eoph - ln) < 7 ||
154 strncasecmp(ln, "coding:", 7)) {
155 sz -= phsz;
156 ln += phsz;
157 continue;
158 }
159
160 sz -= 7;
161 ln += 7;
162
163 while (sz > 0 && ' ' == *ln) {
164 ln++;
165 sz--;
166 }
167 if (0 == sz)
168 return 0;
169
170 /* Check us against known encodings. */
171
172 if (phsz > 4 && !strncasecmp(ln, "utf-8", 5))
173 return MPARSE_UTF8;
174 if (phsz > 10 && !strncasecmp(ln, "iso-latin-1", 11))
175 return MPARSE_LATIN1;
176 return 0;
177 }
178 return MPARSE_UTF8 | MPARSE_LATIN1;
179 }
180