xref: /freebsd/sys/dev/vt/vt_font.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 The FreeBSD Foundation
5  *
6  * This software was developed by Ed Schouten under sponsorship from the
7  * FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/refcount.h>
38 #include <sys/systm.h>
39 
40 #include <dev/vt/vt.h>
41 
42 static MALLOC_DEFINE(M_VTFONT, "vtfont", "vt font");
43 
44 /* Some limits to prevent abnormal fonts from being loaded. */
45 #define	VTFONT_MAXMAPPINGS	65536
46 #define	VTFONT_MAXGLYPHS	131072
47 #define	VTFONT_MAXGLYPHSIZE	2097152
48 #define	VTFONT_MAXDIMENSION	128
49 
50 static uint16_t
51 vtfont_bisearch(const vfnt_map_t *map, unsigned int len, uint32_t src)
52 {
53 	int min, mid, max;
54 
55 	min = 0;
56 	max = len - 1;
57 
58 	/* Empty font map. */
59 	if (len == 0)
60 		return (0);
61 	/* Character below minimal entry. */
62 	if (src < map[0].vfm_src)
63 		return (0);
64 	/* Optimization: ASCII characters occur very often. */
65 	if (src <= map[0].vfm_src + map[0].vfm_len)
66 		return (src - map[0].vfm_src + map[0].vfm_dst);
67 	/* Character above maximum entry. */
68 	if (src > map[max].vfm_src + map[max].vfm_len)
69 		return (0);
70 
71 	/* Binary search. */
72 	while (max >= min) {
73 		mid = (min + max) / 2;
74 		if (src < map[mid].vfm_src)
75 			max = mid - 1;
76 		else if (src > map[mid].vfm_src + map[mid].vfm_len)
77 			min = mid + 1;
78 		else
79 			return (src - map[mid].vfm_src + map[mid].vfm_dst);
80 	}
81 
82 	return (0);
83 }
84 
85 const uint8_t *
86 vtfont_lookup(const struct vt_font *vf, term_char_t c)
87 {
88 	uint32_t src;
89 	uint16_t dst;
90 	size_t stride;
91 	unsigned int normal_map;
92 	unsigned int bold_map;
93 
94 	src = TCHAR_CHARACTER(c);
95 	if (TCHAR_FORMAT(c) & TF_CJK_RIGHT) {
96 		normal_map = VFNT_MAP_NORMAL_RIGHT;
97 		bold_map = VFNT_MAP_BOLD_RIGHT;
98 	} else {
99 		normal_map = VFNT_MAP_NORMAL;
100 		bold_map = VFNT_MAP_BOLD;
101 	}
102 
103 	if (TCHAR_FORMAT(c) & TF_BOLD) {
104 		dst = vtfont_bisearch(vf->vf_map[bold_map],
105 		    vf->vf_map_count[bold_map], src);
106 		if (dst != 0)
107 			goto found;
108 	}
109 	dst = vtfont_bisearch(vf->vf_map[normal_map],
110 	    vf->vf_map_count[normal_map], src);
111 
112 found:
113 	stride = howmany(vf->vf_width, 8) * vf->vf_height;
114 	return (&vf->vf_bytes[dst * stride]);
115 }
116 
117 struct vt_font *
118 vtfont_ref(struct vt_font *vf)
119 {
120 
121 	refcount_acquire(&vf->vf_refcount);
122 	return (vf);
123 }
124 
125 void
126 vtfont_unref(struct vt_font *vf)
127 {
128 	unsigned int i;
129 
130 	if (refcount_release(&vf->vf_refcount)) {
131 		for (i = 0; i < VFNT_MAPS; i++)
132 			free(vf->vf_map[i], M_VTFONT);
133 		free(vf->vf_bytes, M_VTFONT);
134 		free(vf, M_VTFONT);
135 	}
136 }
137 
138 static int
139 vtfont_validate_map(vfnt_map_t *vfm, unsigned int length,
140     unsigned int glyph_count)
141 {
142 	unsigned int i, last = 0;
143 
144 	for (i = 0; i < length; i++) {
145 		/* Not ordered. */
146 		if (i > 0 && vfm[i].vfm_src <= last)
147 			return (EINVAL);
148 		/*
149 		 * Destination extends amount of glyphs.
150 		 */
151 		if (vfm[i].vfm_dst >= glyph_count ||
152 		    vfm[i].vfm_dst + vfm[i].vfm_len >= glyph_count)
153 			return (EINVAL);
154 		last = vfm[i].vfm_src + vfm[i].vfm_len;
155 	}
156 
157 	return (0);
158 }
159 
160 int
161 vtfont_load(vfnt_t *f, struct vt_font **ret)
162 {
163 	size_t glyphsize, mapsize;
164 	struct vt_font *vf;
165 	int error;
166 	unsigned int i;
167 
168 	/* Make sure the dimensions are valid. */
169 	if (f->width < 1 || f->height < 1)
170 		return (EINVAL);
171 	if (f->width > VTFONT_MAXDIMENSION || f->height > VTFONT_MAXDIMENSION ||
172 	    f->glyph_count > VTFONT_MAXGLYPHS)
173 		return (E2BIG);
174 
175 	/* Not too many mappings. */
176 	for (i = 0; i < VFNT_MAPS; i++)
177 		if (f->map_count[i] > VTFONT_MAXMAPPINGS)
178 			return (E2BIG);
179 
180 	/* Character 0 must always be present. */
181 	if (f->glyph_count < 1)
182 		return (EINVAL);
183 
184 	glyphsize = howmany(f->width, 8) * f->height * f->glyph_count;
185 	if (glyphsize > VTFONT_MAXGLYPHSIZE)
186 		return (E2BIG);
187 
188 	/* Allocate new font structure. */
189 	vf = malloc(sizeof *vf, M_VTFONT, M_WAITOK | M_ZERO);
190 	vf->vf_bytes = malloc(glyphsize, M_VTFONT, M_WAITOK);
191 	vf->vf_height = f->height;
192 	vf->vf_width = f->width;
193 	vf->vf_refcount = 1;
194 
195 	/* Allocate, copy in, and validate mappings. */
196 	for (i = 0; i < VFNT_MAPS; i++) {
197 		vf->vf_map_count[i] = f->map_count[i];
198 		if (f->map_count[i] == 0)
199 			continue;
200 		mapsize = f->map_count[i] * sizeof(vfnt_map_t);
201 		vf->vf_map[i] = malloc(mapsize, M_VTFONT, M_WAITOK);
202 		error = copyin(f->map[i], vf->vf_map[i], mapsize);
203 		if (error)
204 			goto bad;
205 		error = vtfont_validate_map(vf->vf_map[i], vf->vf_map_count[i],
206 		    f->glyph_count);
207 		if (error)
208 			goto bad;
209 	}
210 
211 	/* Copy in glyph data. */
212 	error = copyin(f->glyphs, vf->vf_bytes, glyphsize);
213 	if (error)
214 		goto bad;
215 
216 	/* Success. */
217 	*ret = vf;
218 	return (0);
219 
220 bad:	vtfont_unref(vf);
221 	return (error);
222 }
223