Split different methods of getting a font into different functions

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>

1 files changed, 92 insertions, 43 deletions

diff --git a/src/libkfont/kdfontop.c b/src/libkfont/kdfontop.c
index cd93ce9d..5a496e45 100644
--- a/src/libkfont/kdfontop.c
+++ b/src/libkfont/kdfontop.c
@@ -10,6 +10,7 @@
 #include <errno.h>
 #include <stdlib.h> /* free() */
 #include <string.h>
+#include <limits.h>
 #include <sys/ioctl.h>
 #include <linux/kd.h>
 
@@ -45,75 +46,95 @@ 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
-kfont_get_font(struct kfont_context *ctx, int fd, unsigned char *buf, unsigned int *count,
-        unsigned int *width, unsigned int *height)
+static int
+get_font_kdfontop(struct kfont_context *ctx, int consolefd,
+		unsigned char *buf,
+		unsigned int *count,
+		unsigned int *width,
+		unsigned 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) {
-		*count = cfo.charcount;
-		if (height)
-			*height = cfo.height;
-		if (width)
-			*width = cfo.width;
-		return 0;
+	errno = 0;
+
+	if (ioctl(consolefd, KDFONTOP, &cfo)) {
+		if (errno != ENOSYS && errno != EINVAL) {
+			KFONT_ERR(ctx, "ioctl(KDFONTOP): %m");
+			return -1;
+		}
+		return 1;
 	}
 
-	if (errno != ENOSYS && errno != EINVAL) {
-		KFONT_ERR(ctx, "ioctl(KDFONTOP): %m");
+	*count = cfo.charcount;
+	if (height)
+		*height = cfo.height;
+	if (width)
+		*width = cfo.width;
+	return 0;
+}
+
+static int
+get_font_giofontx(struct kfont_context *ctx, int consolefd,
+		unsigned char *buf,
+		unsigned int *count,
+		unsigned int *width,
+		unsigned int *height)
+{
+	struct consolefontdesc cfd;
+
+	if (*count > USHRT_MAX) {
+		KFONT_ERR(ctx, _("GIO_FONTX: the number of characters in the font cannot be more than %d"), USHRT_MAX);
 		return -1;
 	}
 
-	/* The other methods do not support width != 8 */
-	if (width)
-		*width = 8;
-	/* Second attempt: GIO_FONTX */
-	cfd.charcount  = *count;
+	cfd.charcount  = (unsigned short) *count;
 	cfd.charheight = 0;
 	cfd.chardata   = (char *)buf;
 
-	i = ioctl(fd, GIO_FONTX, &cfd);
-	if (!i) {
-		*count = cfd.charcount;
-		if (height)
-			*height = cfd.charheight;
-		return 0;
-	}
+	errno = 0;
 
-	if (errno != ENOSYS && errno != EINVAL) {
-		KFONT_ERR(ctx, "ioctl(GIO_FONTX): %m");
-		return -1;
+	if (ioctl(consolefd, GIO_FONTX, &cfd)) {
+		if (errno != ENOSYS && errno != EINVAL) {
+			KFONT_ERR(ctx, "ioctl(GIO_FONTX): %m");
+			return -1;
+		}
+		return 1;
 	}
 
-	/* Third attempt: GIO_FONT */
-	if (*count < 256) {
-		KFONT_ERR(ctx, _("bug: getfont called with count<256"));
+	*count = cfd.charcount;
+	if (height)
+		*height = cfd.charheight;
+	if (width)
+		*width = 8; /* This method do not support width != 8 */
+	return 0;
+}
+
+static int
+get_font_giofont(struct kfont_context *ctx, int consolefd,
+		unsigned char *buf,
+		unsigned int *count,
+		unsigned int *width,
+		unsigned int *height)
+{
+	if (*count != 256) {
+		KFONT_ERR(ctx, _("getfont called with count<256"));
 		return -1;
 	}
 
 	if (!buf) {
-		KFONT_ERR(ctx, _("bug: getfont using GIO_FONT needs buf."));
+		KFONT_ERR(ctx, _("getfont using GIO_FONT needs buf"));
 		return -1;
 	}
 
-	i = ioctl(fd, GIO_FONT, buf);
-	if (i) {
+	errno = 0;
+
+	if (ioctl(consolefd, GIO_FONT, buf)) {
 		KFONT_ERR(ctx, "ioctl(GIO_FONT): %m");
 		return -1;
 	}
@@ -121,10 +142,38 @@ kfont_get_font(struct kfont_context *ctx, int fd, unsigned char *buf, unsigned i
 	*count = 256;
 	if (height)
 		*height = 0; /* undefined, at most 32 */
-
+	if (width)
+		*width = 8; /* This method do not support width != 8 */
 	return 0;
 }
 
+/*
+ * 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
+kfont_get_font(struct kfont_context *ctx, int fd, unsigned char *buf,
+		unsigned int *count,
+		unsigned int *width,
+		unsigned int *height)
+{
+	int ret;
+
+	/* First attempt: KDFONTOP */
+	ret = get_font_kdfontop(ctx, fd, buf, count, width, height);
+	if (ret <= 0)
+		return ret;
+
+	/* Second attempt: GIO_FONTX */
+	ret = get_font_giofontx(ctx, fd, buf, count, width, height);
+	if (ret <= 0)
+		return ret;
+
+	/* Third attempt: GIO_FONT */
+	return get_font_giofont(ctx, fd, buf, count, width, height);
+}
+
 int unsigned
 kfont_get_fontsize(struct kfont_context *ctx, int fd)
 {