blkid: Correct the label name for exfatandroid-p-preview-3android-p-preview-2p-preview-2

Volume label name is 16 bit unicode string according to spec.
Currently blkid labels the device without converting it to
utf-8 chars due to which incorrect label is displayed.

Bug: 74184636
Test: manual
Change-Id: Ib16204c75c2cdf675d480e9c66f484bb3c51108e

1 files changed, 34 insertions, 1 deletions

diff --git a/lib/blkid/probe.c b/lib/blkid/probe.c
index 865d9aa3..0293b903 100644
--- a/lib/blkid/probe.c
+++ b/lib/blkid/probe.c
@@ -1160,6 +1160,37 @@ static void unicode_16be_to_utf8(unsigned char *str, int out_len,
 	str[j] = '\0';
 }
 
+static void unicode_16le_to_utf8(unsigned char *str, int out_len,
+				 const unsigned char *buf, int in_len)
+{
+	int i, j;
+	unsigned int c;
+
+	for (i = j = 0; i + 2 <= in_len; i += 2) {
+		c = (buf[i+1] << 8) | buf[i];
+		if (c == 0) {
+			str[j] = '\0';
+			break;
+		} else if (c < 0x80) {
+			if (j+1 >= out_len)
+				break;
+			str[j++] = (unsigned char) c;
+		} else if (c < 0x800) {
+			if (j+2 >= out_len)
+				break;
+			str[j++] = (unsigned char) (0xc0 | (c >> 6));
+			str[j++] = (unsigned char) (0x80 | (c & 0x3f));
+		} else {
+			if (j+3 >= out_len)
+				break;
+			str[j++] = (unsigned char) (0xe0 | (c >> 12));
+			str[j++] = (unsigned char) (0x80 | ((c >> 6) & 0x3f));
+			str[j++] = (unsigned char) (0x80 | (c & 0x3f));
+		}
+	}
+	str[j] = '\0';
+}
+
 static int probe_hfs(struct blkid_probe *probe __BLKID_ATTR((unused)),
 			 struct blkid_magic *id __BLKID_ATTR((unused)),
 			 unsigned char *buf)
@@ -1482,7 +1513,9 @@ static int probe_exfat(struct blkid_probe *probe, struct blkid_magic *id,
 
     label = find_exfat_entry_label(probe, sb);
     if (label) {
-        blkid_set_tag(probe->dev, "LABEL", label->name, label->length);
+        char utf8_label[128];
+        unicode_16le_to_utf8(utf8_label, sizeof(utf8_label), label->name, label->length * 2);
+        blkid_set_tag(probe->dev, "LABEL", utf8_label, 0);
     } else {
         blkid_set_tag(probe->dev, "LABEL", "disk", 4);
     }