fix volume label parsing

Not probing volumes ourselves and reading from the udev db (commit
79b92dbdf65b8c978d5a8f6fb2b421aac83c3de3) caused a regression: udevadm
info's ID_FS_LABEL is mangled, e. g. spaces appear as '_'. Use
ID_FS_LABEL_ENC instead and use a new hal/util.c function
hal_util_decode_escape() to decode those.

https://launchpad.net/bugs/347370

4 files changed, 47 insertions, 5 deletions

diff --git a/hald/linux/coldplug.c b/hald/linux/coldplug.c
index 16fa34ce..276382d8 100644
--- a/hald/linux/coldplug.c
+++ b/hald/linux/coldplug.c
@@ -159,6 +159,7 @@ hal_util_init_sysfs_to_udev_map (void)
 	int udevinfo_exitcode;
 	UdevInfo *info = NULL;
 	char *p;
+	int len;
 
 	sysfs_to_udev_map = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, udev_info_free);
 
@@ -252,8 +253,10 @@ hal_util_init_sysfs_to_udev_map (void)
 			info->fsversion = &line[17];
 		} else if (strncmp(line, "E: ID_FS_UUID=", 14) == 0) {
 			info->fsuuid = &line[14];
-		} else if (strncmp(line, "E: ID_FS_LABEL=", 15) == 0) {
-			info->fslabel = &line[15];
+		} else if (strncmp(line, "E: ID_FS_LABEL_ENC=", 19) == 0) {
+			len = strlen (&line[15]);
+			info->fslabel = g_malloc0 (len + 1);
+			hal_util_decode_escape (&line[19], info->fslabel, len + 1);
 		}
 	}
 
diff --git a/hald/linux/osspec.c b/hald/linux/osspec.c
index 4599c7cf..56e3b654 100644
--- a/hald/linux/osspec.c
+++ b/hald/linux/osspec.c
@@ -128,7 +128,7 @@ hald_udev_data (GIOChannel *source, GIOCondition condition, gpointer user_data)
 	while (bufpos < sizeof (buf)) {
 		size_t keylen;
 		char *key;
-		char *str;
+		char *str, *dstr;
 
 		key = &buf[bufpos];
 		keylen = strlen(key);
@@ -206,11 +206,15 @@ hald_udev_data (GIOChannel *source, GIOCondition condition, gpointer user_data)
 				g_strlcpy (hotplug_event->sysfs.fsuuid, str, sizeof(hotplug_event->sysfs.fsuuid));
 				g_free (str);
 			}
-		} else if (strncmp(key, "ID_FS_LABEL=", 12) == 0) {
-			if ((str = hal_util_strdup_valid_utf8(&key[12])) != NULL ) {
+		} else if (strncmp(key, "ID_FS_LABEL_ENC=", 16) == 0) {
+			dstr = g_malloc0 (keylen - 15);
+			hal_util_decode_escape (&key[16], dstr, sizeof(hotplug_event->sysfs.fslabel));
+
+			if ((str = hal_util_strdup_valid_utf8(dstr)) != NULL ) {
 				g_strlcpy (hotplug_event->sysfs.fslabel, str, sizeof(hotplug_event->sysfs.fslabel));
 				g_free (str);
 			}
+			g_free (dstr);
 		}
 	}
 
diff --git a/hald/util.c b/hald/util.c
index c7f80abe..7fa3011b 100644
--- a/hald/util.c
+++ b/hald/util.c
@@ -1228,3 +1228,36 @@ is_valid_interface_name (const char *name) {
   	return TRUE;
 }
 
+static int
+hexdigit (char c)
+{
+	if (c >= '0' && c <= '9')
+		return c - '0';
+	if (c >= 'a' && c <= 'f')
+		return c - 'a';
+	if (c >= 'A' && c <= 'F')
+		return c - 'A';
+	HAL_ERROR (("'%c' is not a valid hex digit", c));
+	return 0;
+}
+
+/* Decode string with \xNN escapes */
+void
+hal_util_decode_escape (const char* src, char* result, int maxlen)
+{
+	int len;
+
+	if (src == NULL || maxlen == 0)
+		return;
+
+	for (len = 0; len < maxlen && *src; ++len) {
+		/* note that C's short-circuiting avoids reading past \0 */
+		if (*src == '\\' && src[1] == 'x' && isalnum (src[2]) && isalnum (src[3])) {
+			result[len] = (hexdigit(src[2]) << 4) | hexdigit(src[3]);
+			src += 4;
+		} else
+			result[len] = *src++;
+	}
+}
+
+
diff --git a/hald/util.h b/hald/util.h
index 5377e359..c2a1584b 100644
--- a/hald/util.h
+++ b/hald/util.h
@@ -117,4 +117,6 @@ char *hal_util_readlink (const char *link);
 
 gboolean is_valid_interface_name (const char *name);
 
+void hal_util_decode_escape (const char* src, char* result, int maxlen);
+
 #endif /* UTIL_H */