1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009 The FreeBSD Foundation
5 * All rights reserved.
6 *
7 * This software was developed by Ed Schouten under sponsorship from the
8 * FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include <sys/param.h>
36#include <sys/kernel.h>
37#include <sys/malloc.h>
38#include <sys/refcount.h>
39#include <sys/systm.h>
40
41#include <dev/vt/vt.h>
42
43static MALLOC_DEFINE(M_VTFONT, "vtfont", "vt font");
44
45/* Some limits to prevent abnormal fonts from being loaded. */
46#define	VTFONT_MAXMAPPINGS	65536
47#define	VTFONT_MAXGLYPHS	131072
48#define	VTFONT_MAXGLYPHSIZE	2097152
49#define	VTFONT_MAXDIMENSION	128
50
51static uint16_t
52vtfont_bisearch(const vfnt_map_t *map, unsigned int len, uint32_t src)
53{
54	int min, mid, max;
55
56	min = 0;
57	max = len - 1;
58
59	/* Empty font map. */
60	if (len == 0)
61		return (0);
62	/* Character below minimal entry. */
63	if (src < map[0].vfm_src)
64		return (0);
65	/* Optimization: ASCII characters occur very often. */
66	if (src <= map[0].vfm_src + map[0].vfm_len)
67		return (src - map[0].vfm_src + map[0].vfm_dst);
68	/* Character above maximum entry. */
69	if (src > map[max].vfm_src + map[max].vfm_len)
70		return (0);
71
72	/* Binary search. */
73	while (max >= min) {
74		mid = (min + max) / 2;
75		if (src < map[mid].vfm_src)
76			max = mid - 1;
77		else if (src > map[mid].vfm_src + map[mid].vfm_len)
78			min = mid + 1;
79		else
80			return (src - map[mid].vfm_src + map[mid].vfm_dst);
81	}
82
83	return (0);
84}
85
86const uint8_t *
87vtfont_lookup(const struct vt_font *vf, term_char_t c)
88{
89	uint32_t src;
90	uint16_t dst;
91	size_t stride;
92	unsigned int normal_map;
93	unsigned int bold_map;
94
95	src = TCHAR_CHARACTER(c);
96	if (TCHAR_FORMAT(c) & TF_CJK_RIGHT) {
97		normal_map = VFNT_MAP_NORMAL_RIGHT;
98		bold_map = VFNT_MAP_BOLD_RIGHT;
99	} else {
100		normal_map = VFNT_MAP_NORMAL;
101		bold_map = VFNT_MAP_BOLD;
102	}
103
104	if (TCHAR_FORMAT(c) & TF_BOLD) {
105		dst = vtfont_bisearch(vf->vf_map[bold_map],
106		    vf->vf_map_count[bold_map], src);
107		if (dst != 0)
108			goto found;
109	}
110	dst = vtfont_bisearch(vf->vf_map[normal_map],
111	    vf->vf_map_count[normal_map], src);
112
113found:
114	stride = howmany(vf->vf_width, 8) * vf->vf_height;
115	return (&vf->vf_bytes[dst * stride]);
116}
117
118struct vt_font *
119vtfont_ref(struct vt_font *vf)
120{
121
122	refcount_acquire(&vf->vf_refcount);
123	return (vf);
124}
125
126void
127vtfont_unref(struct vt_font *vf)
128{
129	unsigned int i;
130
131	if (refcount_release(&vf->vf_refcount)) {
132		for (i = 0; i < VFNT_MAPS; i++)
133			free(vf->vf_map[i], M_VTFONT);
134		free(vf->vf_bytes, M_VTFONT);
135		free(vf, M_VTFONT);
136	}
137}
138
139static int
140vtfont_validate_map(vfnt_map_t *vfm, unsigned int length,
141    unsigned int glyph_count)
142{
143	unsigned int i, last = 0;
144
145	for (i = 0; i < length; i++) {
146		/* Not ordered. */
147		if (i > 0 && vfm[i].vfm_src <= last)
148			return (EINVAL);
149		/*
150		 * Destination extends amount of glyphs.
151		 */
152		if (vfm[i].vfm_dst >= glyph_count ||
153		    vfm[i].vfm_dst + vfm[i].vfm_len >= glyph_count)
154			return (EINVAL);
155		last = vfm[i].vfm_src + vfm[i].vfm_len;
156	}
157
158	return (0);
159}
160
161int
162vtfont_load(vfnt_t *f, struct vt_font **ret)
163{
164	size_t glyphsize, mapsize;
165	struct vt_font *vf;
166	int error;
167	unsigned int i;
168
169	/* Make sure the dimensions are valid. */
170	if (f->width < 1 || f->height < 1)
171		return (EINVAL);
172	if (f->width > VTFONT_MAXDIMENSION || f->height > VTFONT_MAXDIMENSION ||
173	    f->glyph_count > VTFONT_MAXGLYPHS)
174		return (E2BIG);
175
176	/* Not too many mappings. */
177	for (i = 0; i < VFNT_MAPS; i++)
178		if (f->map_count[i] > VTFONT_MAXMAPPINGS)
179			return (E2BIG);
180
181	/* Character 0 must always be present. */
182	if (f->glyph_count < 1)
183		return (EINVAL);
184
185	glyphsize = howmany(f->width, 8) * f->height * f->glyph_count;
186	if (glyphsize > VTFONT_MAXGLYPHSIZE)
187		return (E2BIG);
188
189	/* Allocate new font structure. */
190	vf = malloc(sizeof *vf, M_VTFONT, M_WAITOK | M_ZERO);
191	vf->vf_bytes = malloc(glyphsize, M_VTFONT, M_WAITOK);
192	vf->vf_height = f->height;
193	vf->vf_width = f->width;
194	vf->vf_refcount = 1;
195
196	/* Allocate, copy in, and validate mappings. */
197	for (i = 0; i < VFNT_MAPS; i++) {
198		vf->vf_map_count[i] = f->map_count[i];
199		if (f->map_count[i] == 0)
200			continue;
201		mapsize = f->map_count[i] * sizeof(vfnt_map_t);
202		vf->vf_map[i] = malloc(mapsize, M_VTFONT, M_WAITOK);
203		error = copyin(f->map[i], vf->vf_map[i], mapsize);
204		if (error)
205			goto bad;
206		error = vtfont_validate_map(vf->vf_map[i], vf->vf_map_count[i],
207		    f->glyph_count);
208		if (error)
209			goto bad;
210	}
211
212	/* Copy in glyph data. */
213	error = copyin(f->glyphs, vf->vf_bytes, glyphsize);
214	if (error)
215		goto bad;
216
217	/* Success. */
218	*ret = vf;
219	return (0);
220
221bad:	vtfont_unref(vf);
222	return (error);
223}
224