bin/mandoc/preconv.c

   1 /*      $Id: preconv.c,v 1.16 2017/02/18 13:43:52 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 #include "mandoc.h"
  26 #include "libmandoc.h"
  27
  28 int
  29 preconv_encode(const struct buf *ib, size_t *ii, struct buf *ob, size_t *oi,
  30     int *filenc)
  31 {
  32         const unsigned char     *cu;
  33         int                      nby;
  34         unsigned int             accum;
  35
  36         cu = (const unsigned char *)ib->buf + *ii;
  37         assert(*cu & 0x80);
  38
  39         if ( ! (*filenc & MPARSE_UTF8))
  40                 goto latin;
  41
  42         nby = 1;
  43         while (nby < 5 && *cu & (1 << (7 - nby)))
  44                 nby++;
  45
  46         switch (nby) {
  47         case 2:
  48                 accum = *cu & 0x1f;
  49                 if (accum < 0x02)  /* Obfuscated ASCII. */
  50                         goto latin;
  51                 break;
  52         case 3:
  53                 accum = *cu & 0x0f;
  54                 break;
  55         case 4:
  56                 accum = *cu & 0x07;
  57                 if (accum > 0x04) /* Beyond Unicode. */
  58                         goto latin;
  59                 break;
  60         default:  /* Bad sequence header. */
  61                 goto latin;
  62         }
  63
  64         cu++;
  65         switch (nby) {
  66         case 3:
  67                 if ((accum == 0x00 && ! (*cu & 0x20)) ||  /* Use 2-byte. */
  68                     (accum == 0x0d && *cu & 0x20))  /* Surrogates. */
  69                         goto latin;
  70                 break;
  71         case 4:
  72                 if ((accum == 0x00 && ! (*cu & 0x30)) ||  /* Use 3-byte. */
  73                     (accum == 0x04 && *cu & 0x30))  /* Beyond Unicode. */
  74                         goto latin;
  75                 break;
  76         default:
  77                 break;
  78         }
  79
  80         while (--nby) {
  81                 if ((*cu & 0xc0) != 0x80)  /* Invalid continuation. */
  82                         goto latin;
  83                 accum <<= 6;
  84                 accum += *cu & 0x3f;
  85                 cu++;
  86         }
  87
  88         assert(accum > 0x7f);
  89         assert(accum < 0x110000);
  90         assert(accum < 0xd800 || accum > 0xdfff);
  91
  92         *oi += snprintf(ob->buf + *oi, 11, "\\[u%.4X]", accum);
  93         *ii = (const char *)cu - ib->buf;
  94         *filenc &= ~MPARSE_LATIN1;
  95         return 1;
  96
  97 latin:
  98         if ( ! (*filenc & MPARSE_LATIN1))
  99                 return 0;
 100
 101         *oi += snprintf(ob->buf + *oi, 11,
 102             "\\[u%.4X]", (unsigned char)ib->buf[(*ii)++]);
 103
 104         *filenc &= ~MPARSE_UTF8;
 105         return 1;
 106 }
 107
 108 int
 109 preconv_cue(const struct buf *b, size_t offset)
 110 {
 111         const char      *ln, *eoln, *eoph;
 112         size_t           sz, phsz;
 113
 114         ln = b->buf + offset;
 115         sz = b->sz - offset;
 116
 117         /* Look for the end-of-line. */
 118
 119         if (NULL == (eoln = memchr(ln, '\n', sz)))
 120                 eoln = ln + sz;
 121
 122         /* Check if we have the correct header/trailer. */
 123
 124         if ((sz = (size_t)(eoln - ln)) < 10 ||
 125             memcmp(ln, ".\\\" -*-", 7) || memcmp(eoln - 3, "-*-", 3))
 126                 return MPARSE_UTF8 | MPARSE_LATIN1;
 127
 128         /* Move after the header and adjust for the trailer. */
 129
 130         ln += 7;
 131         sz -= 10;
 132
 133         while (sz > 0) {
 134                 while (sz > 0 && ' ' == *ln) {
 135                         ln++;
 136                         sz--;
 137                 }
 138                 if (0 == sz)
 139                         break;
 140
 141                 /* Find the end-of-phrase marker (or eoln). */
 142
 143                 if (NULL == (eoph = memchr(ln, ';', sz)))
 144                         eoph = eoln - 3;
 145                 else
 146                         eoph++;
 147
 148                 /* Only account for the "coding" phrase. */
 149
 150                 if ((phsz = eoph - ln) < 7 ||
 151                     strncasecmp(ln, "coding:", 7)) {
 152                         sz -= phsz;
 153                         ln += phsz;
 154                         continue;
 155                 }
 156
 157                 sz -= 7;
 158                 ln += 7;
 159
 160                 while (sz > 0 && ' ' == *ln) {
 161                         ln++;
 162                         sz--;
 163                 }
 164                 if (0 == sz)
 165                         return 0;
 166
 167                 /* Check us against known encodings. */
 168
 169                 if (phsz > 4 && !strncasecmp(ln, "utf-8", 5))
 170                         return MPARSE_UTF8;
 171                 if (phsz > 10 && !strncasecmp(ln, "iso-latin-1", 11))
 172                         return MPARSE_LATIN1;
 173                 return 0;
 174         }
 175         return MPARSE_UTF8 | MPARSE_LATIN1;
 176 }