/*

 * kdfontop.c - export getfont(), getfontsize() and putfont()

 *

 * Font handling differs between various kernel versions.

 * Hide the differences in this file.

 */

#include "config.h"

#include <stdio.h>

#include <errno.h>

#include <stdlib.h> /* free() */

#include <sys/ioctl.h>

#include <linux/kd.h>

#include "kdfontop.h"

#include "nls.h"

#include "version.h"

#ifdef COMPAT_HEADERS

#include "compat/linux-kd.h"

#endif

int restorefont(int fd)

{

	if (ioctl(fd, PIO_FONTRESET, 0)) {

		perror("PIO_FONTRESET");

		return -1;

	}

	return 0;

}

int font_charheight(unsigned char *buf, int count, int width)

{

	int h, i, x;

	int bytewidth = (width + 7) / 8;

	for (h = 32; h > 0; h--)

		for (i = 0; i < count; i++)

			for (x = 0; x < bytewidth; x++)

				if (buf[(32 * i + h - 1) * bytewidth + x])

					goto nonzero;

nonzero:

	return h;

}

/*

 * May be called with buf==NULL if we only want info.

 * May be called with width==NULL and height==NULL.

 * Must not exit - we may have cleanup to do.

 */

int getfont(int fd, unsigned char *buf, int *count, int *width, int *height)

{

	struct consolefontdesc cfd;

	struct console_font_op cfo;

	int i;

	/* First attempt: KDFONTOP */

	cfo.op    = KD_FONT_OP_GET;

	cfo.flags = 0;

	cfo.width = cfo.height = 32;

	cfo.charcount          = *count;

	cfo.data               = buf;

	i                      = ioctl(fd, KDFONTOP, &cfo;;

	if (i == 0) {

		*count = cfo.charcount;

		if (height)

			*height = cfo.height;

		if (width)

			*width = cfo.width;

		return 0;

	}

	if (errno != ENOSYS && errno != EINVAL) {

		perror("getfont: KDFONTOP");

		return -1;

	}

	/* The other methods do not support width != 8 */

	if (width)

		*width = 8;

	/* Second attempt: GIO_FONTX */

	cfd.charcount  = *count;

	cfd.charheight = 0;

	cfd.chardata   = (char *)buf;

	i              = ioctl(fd, GIO_FONTX, &cfd;;

	if (i == 0) {

		*count = cfd.charcount;

		if (height)

			*height = cfd.charheight;

		return 0;

	}

	if (errno != ENOSYS && errno != EINVAL) {

		perror("getfont: GIO_FONTX");

		return -1;

	}

	/* Third attempt: GIO_FONT */

	if (*count < 256) {

		fprintf(stderr, _("bug: getfont called with count<256\n"));

		return -1;

	}

	if (!buf) {

		fprintf(stderr, _("bug: getfont using GIO_FONT needs buf.\n"));

		return -1;

	}

	i = ioctl(fd, GIO_FONT, buf);

	if (i) {

		perror("getfont: GIO_FONT");

		return -1;

	}

	*count = 256;

	if (height)

		*height = 0; /* undefined, at most 32 */

	return 0;

}

int getfontsize(int fd)

{

	int count;

	int i;

	count = 0;

	i     = getfont(fd, NULL, &count, NULL, NULL);

	return (i == 0) ? count : 256;

}

int putfont(int fd, unsigned char *buf, int count, int width, int height)

{

	struct consolefontdesc cfd;

	struct console_font_op cfo;

	int i;

	if (!width)

		width = 8;

	if (!height)

		height = font_charheight(buf, count, width);

	/* First attempt: KDFONTOP */

	cfo.op        = KD_FONT_OP_SET;

	cfo.flags     = 0;

	cfo.width     = width;

	cfo.height    = height;

	cfo.charcount = count;

	cfo.data      = buf;

	i             = ioctl(fd, KDFONTOP, &cfo;;

	if (i == 0)

		return 0;

	if (width != 8 || (errno != ENOSYS && errno != EINVAL)) {

		perror("putfont: KDFONTOP");

		return -1;

	}

	/* Variation on first attempt: in case count is not 256 or 512

	   round up and try again. */

	if (errno == EINVAL && width == 8 && count != 256 && count < 512) {

		int ct               = ((count > 256) ? 512 : 256);

		unsigned char *mybuf = malloc(32 * ct);

		if (!mybuf) {

			fprintf(stderr, _("%s: out of memory\n"), progname);

			return -1;

		}

		memset(mybuf, 0, 32 * ct);

		memcpy(mybuf, buf, 32 * count);

		cfo.data      = mybuf;

		cfo.charcount = ct;

		i             = ioctl(fd, KDFONTOP, &cfo;;

		free(mybuf);

		if (i == 0)

			return 0;

	}

	/* Second attempt: PIO_FONTX */

	cfd.charcount  = count;

	cfd.charheight = height;

	cfd.chardata   = (char *)buf;

	i              = ioctl(fd, PIO_FONTX, &cfd;;

	if (i == 0)

		return 0;

	if (errno != ENOSYS && errno != EINVAL) {

		fprintf(stderr, "%s: putfont: %d,%dx%d:failed: %d\n", progname, count, width, height, i);

		perror("putfont: PIO_FONTX");

		return -1;

	}

	/* Third attempt: PIO_FONT */

	/* This will load precisely 256 chars, independent of count */

	i = ioctl(fd, PIO_FONT, buf);

	if (i) {

		fprintf(stderr, "%s: putfont: %d,%dx%d:  failed: %d\n", progname, count, width, height, i);

		perror("putfont: PIO_FONT");

		return -1;

	}

	return 0;

}