xref: /freebsd/sys/dev/vt/vt_font.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 2009 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Ed Schouten under sponsorship from the
6  * FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/refcount.h>
37 #include <sys/systm.h>
38 
39 #include <dev/vt/vt.h>
40 
41 static MALLOC_DEFINE(M_VTFONT, "vtfont", "vt font");
42 
43 /* Some limits to prevent abnormal fonts from being loaded. */
44 #define	VTFONT_MAXMAPPINGS	65536
45 #define	VTFONT_MAXGLYPHSIZE	2097152
46 #define	VTFONT_MAXDIMENSION	128
47 
48 static uint16_t
49 vtfont_bisearch(const struct vt_font_map *map, unsigned int len, uint32_t src)
50 {
51 	int min, mid, max;
52 
53 	min = 0;
54 	max = len - 1;
55 
56 	/* Empty font map. */
57 	if (len == 0)
58 		return (0);
59 	/* Character below minimal entry. */
60 	if (src < map[0].vfm_src)
61 		return (0);
62 	/* Optimization: ASCII characters occur very often. */
63 	if (src <= map[0].vfm_src + map[0].vfm_len)
64 		return (src - map[0].vfm_src + map[0].vfm_dst);
65 	/* Character above maximum entry. */
66 	if (src > map[max].vfm_src + map[max].vfm_len)
67 		return (0);
68 
69 	/* Binary search. */
70 	while (max >= min) {
71 		mid = (min + max) / 2;
72 		if (src < map[mid].vfm_src)
73 			max = mid - 1;
74 		else if (src > map[mid].vfm_src + map[mid].vfm_len)
75 			min = mid + 1;
76 		else
77 			return (src - map[mid].vfm_src + map[mid].vfm_dst);
78 	}
79 
80 	return (0);
81 }
82 
83 const uint8_t *
84 vtfont_lookup(const struct vt_font *vf, term_char_t c)
85 {
86 	uint32_t src;
87 	uint16_t dst;
88 	size_t stride;
89 	unsigned int normal_map;
90 	unsigned int bold_map;
91 
92 	/*
93 	 * No support for printing right hand sides for CJK fullwidth
94 	 * characters. Simply print a space and assume that the left
95 	 * hand side describes the entire character.
96 	 */
97 	src = TCHAR_CHARACTER(c);
98 	if (TCHAR_FORMAT(c) & TF_CJK_RIGHT) {
99 		normal_map = VFNT_MAP_NORMAL_RIGHT;
100 		bold_map = VFNT_MAP_BOLD_RIGHT;
101 	} else {
102 		normal_map = VFNT_MAP_NORMAL;
103 		bold_map = VFNT_MAP_BOLD;
104 	}
105 
106 	if (TCHAR_FORMAT(c) & TF_BOLD) {
107 		dst = vtfont_bisearch(vf->vf_map[bold_map],
108 		    vf->vf_map_count[bold_map], src);
109 		if (dst != 0)
110 			goto found;
111 	}
112 	dst = vtfont_bisearch(vf->vf_map[normal_map],
113 	    vf->vf_map_count[normal_map], src);
114 
115 found:
116 	stride = howmany(vf->vf_width, 8) * vf->vf_height;
117 	return (&vf->vf_bytes[dst * stride]);
118 }
119 
120 struct vt_font *
121 vtfont_ref(struct vt_font *vf)
122 {
123 
124 	refcount_acquire(&vf->vf_refcount);
125 	return (vf);
126 }
127 
128 void
129 vtfont_unref(struct vt_font *vf)
130 {
131 	unsigned int i;
132 
133 	if (refcount_release(&vf->vf_refcount)) {
134 		for (i = 0; i < VFNT_MAPS; i++)
135 			free(vf->vf_map[i], M_VTFONT);
136 		free(vf->vf_bytes, M_VTFONT);
137 		free(vf, M_VTFONT);
138 	}
139 }
140 
141 static int
142 vtfont_validate_map(struct vt_font_map *vfm, unsigned int length,
143     unsigned int glyph_count)
144 {
145 	unsigned int i, last = 0;
146 
147 	for (i = 0; i < length; i++) {
148 		/* Not ordered. */
149 		if (i > 0 && vfm[i].vfm_src <= last)
150 			return (EINVAL);
151 		/*
152 		 * Destination extends amount of glyphs.
153 		 */
154 		if (vfm[i].vfm_dst >= glyph_count ||
155 		    vfm[i].vfm_dst + vfm[i].vfm_len >= glyph_count)
156 			return (EINVAL);
157 		last = vfm[i].vfm_src + vfm[i].vfm_len;
158 	}
159 
160 	return (0);
161 }
162 
163 int
164 vtfont_load(vfnt_t *f, struct vt_font **ret)
165 {
166 	size_t glyphsize, mapsize;
167 	struct vt_font *vf;
168 	int error;
169 	unsigned int i;
170 
171 	/* Make sure the dimensions are valid. */
172 	if (f->width < 1 || f->height < 1)
173 		return (EINVAL);
174 	if (f->width > VTFONT_MAXDIMENSION || f->height > VTFONT_MAXDIMENSION)
175 		return (E2BIG);
176 
177 	/* Not too many mappings. */
178 	for (i = 0; i < VFNT_MAPS; i++)
179 		if (f->map_count[i] > VTFONT_MAXMAPPINGS)
180 			return (E2BIG);
181 
182 	/* Character 0 must always be present. */
183 	if (f->glyph_count < 1)
184 		return (EINVAL);
185 
186 	glyphsize = howmany(f->width, 8) * f->height * f->glyph_count;
187 	if (glyphsize > VTFONT_MAXGLYPHSIZE)
188 		return (E2BIG);
189 
190 	/* Allocate new font structure. */
191 	vf = malloc(sizeof *vf, M_VTFONT, M_WAITOK | M_ZERO);
192 	vf->vf_bytes = malloc(glyphsize, M_VTFONT, M_WAITOK);
193 	vf->vf_height = f->height;
194 	vf->vf_width = f->width;
195 	vf->vf_refcount = 1;
196 
197 	/* Allocate, copy in, and validate mappings. */
198 	for (i = 0; i < VFNT_MAPS; i++) {
199 		vf->vf_map_count[i] = f->map_count[i];
200 		if (f->map_count[i] == 0)
201 			continue;
202 		mapsize = f->map_count[i] * sizeof(struct vt_font_map);
203 		vf->vf_map[i] = malloc(mapsize, M_VTFONT, M_WAITOK);
204 		error = copyin(f->map[i], vf->vf_map[i], mapsize);
205 		if (error)
206 			goto bad;
207 		error = vtfont_validate_map(vf->vf_map[i], vf->vf_map_count[i],
208 		    f->glyph_count);
209 		if (error)
210 			goto bad;
211 	}
212 
213 	/* Copy in glyph data. */
214 	error = copyin(f->glyphs, vf->vf_bytes, glyphsize);
215 	if (error)
216 		goto bad;
217 
218 	/* Success. */
219 	*ret = vf;
220 	return (0);
221 
222 bad:	vtfont_unref(vf);
223 	return (error);
224 }
225