[PATCH] allow to match against empty key values

4 files changed, 40 insertions, 45 deletions

diff --git a/test/udev-test.pl b/test/udev-test.pl
index ed94629dd1..27ca37115c 100644
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -806,7 +806,7 @@ EOF
 		exp_name	=> "link",
 		exp_target	=> "link",
 		exp_rem_error	=> "yes",
-		option		=> "clear",
+		option		=> "clean",
 		rules		=> <<EOF
 KERNEL=="tty0", NAME="link", SYMLINK="link"
 EOF
@@ -1006,7 +1006,7 @@ EOF
 		subsys		=> "block",
 		devpath		=> "/block/sda/sda4",
 		exp_name	=> "cdrom2",
-		option		=> "clear",
+		option		=> "clean",
 		rules		=> <<EOF
 KERNEL=="sda4", NAME="cdrom%e"
 EOF
@@ -1067,7 +1067,7 @@ EOF
 		devpath		=> "/block/sda",
 		exp_name	=> "node14",
 		exp_rem_error	=> "yes",
-		option		=> "clear",
+		option		=> "clean",
 		rules		=> <<EOF
 BUS=="scsi", KERNEL=="sda", NAME="node", OPTIONS="ignore_remove, all_partitions"
 EOF
@@ -1233,6 +1233,18 @@ EOF
 KERNEL=="ttyUSB*", NAME="serial-%s{serial}"
 EOF
 	},
+	{
+		desc		=> "match against empty key string",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "ok",
+		rules		=> <<EOF
+KERNEL=="sda", SYSFS{nothing}!="", NAME="not-1-ok"
+KERNEL=="sda", SYSFS{nothing}=="", NAME="not-2-ok"
+KERNEL=="sda", SYSFS{vendor}!="", NAME="ok"
+KERNEL=="sda", SYSFS{vendor}=="", NAME="not-3-ok"
+EOF
+	},
 );
 
 # set env
@@ -1415,7 +1427,7 @@ sub run_test {
 
 	print "\n";
 
-	if (defined($rules->{option}) && $rules->{option} eq "clear") {
+	if (defined($rules->{option}) && $rules->{option} eq "clean") {
 		system("rm -rf $udev_db");
 		system("rm -rf $udev_root");
 		mkdir($udev_root) || die "unable to create udev_root: $udev_root\n";
diff --git a/udev_rules.c b/udev_rules.c
index 00199a062f..b7905477de 100644
--- a/udev_rules.c
+++ b/udev_rules.c
@@ -463,36 +463,12 @@ static int execute_program(struct udevice *udev, const char *path, char *value,
 	return retval;
 }
 
-static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct key_pair *pair)
-{
-	char value[VALUE_SIZE];
-	int i;
-
-	if (find_sysfs_attribute(class_dev, sysfs_device, pair->name, value, sizeof(value)) != 0)
-		return -1;
-
-	/* strip trailing whitespace of value, if not asked to match for it */
-	if (!isspace(pair->value[strlen(pair->value)-1])) {
-		i = strlen(value);
-		while (i > 0 && isspace(value[i-1]))
-			value[--i] = '\0';
-		dbg("removed %i trailing whitespace chars from '%s'", strlen(value)-i, value);
-	}
-
-	dbg("compare attribute '%s' value '%s' with '%s'", pair->name, value, pair->value);
-	if (strcmp_pattern(pair->value, value) != 0)
-		return -1;
-
-	dbg("found matching attribute '%s' with value '%s'", pair->name, pair->value);
-	return 0;
-}
-
 static int match_rule(struct udevice *udev, struct udev_rule *rule,
 		      struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 {
 	struct sysfs_device *parent_device = sysfs_device;
 
-	if (rule->kernel[0] != '\0') {
+	if (rule->kernel_operation != KEY_OP_UNSET) {
 		dbg("check for " KEY_KERNEL " rule->kernel='%s' class_dev->name='%s'",
 		    rule->kernel, class_dev->name);
 		if (strcmp_pattern(rule->kernel, class_dev->name) != 0) {
@@ -507,7 +483,7 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 		dbg(KEY_KERNEL " key is true");
 	}
 
-	if (rule->subsystem[0] != '\0') {
+	if (rule->subsystem_operation != KEY_OP_UNSET) {
 		dbg("check for " KEY_SUBSYSTEM " rule->subsystem='%s' class_dev->name='%s'",
 		    rule->subsystem, class_dev->name);
 		if (strcmp_pattern(rule->subsystem, udev->subsystem) != 0) {
@@ -552,7 +528,7 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 	/* walk up the chain of physical devices and find a match */
 	while (1) {
 		/* check for matching driver */
-		if (rule->driver[0] != '\0') {
+		if (rule->driver_operation != KEY_OP_UNSET) {
 			if (parent_device == NULL) {
 				dbg("device has no sysfs_device");
 				goto exit;
@@ -572,7 +548,7 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 		}
 
 		/* check for matching bus value */
-		if (rule->bus[0] != '\0') {
+		if (rule->bus_operation != KEY_OP_UNSET) {
 			if (parent_device == NULL) {
 				dbg("device has no sysfs_device");
 				goto exit;
@@ -592,7 +568,7 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 		}
 
 		/* check for matching bus id */
-		if (rule->id[0] != '\0') {
+		if (rule->id_operation != KEY_OP_UNSET) {
 			if (parent_device == NULL) {
 				dbg("device has no sysfs_device");
 				goto exit;
@@ -617,9 +593,23 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 			dbg("check " KEY_SYSFS " pairs");
 			for (i = 0; i < rule->sysfs_pair_count; i++) {
 				struct key_pair *pair;
+				char value[VALUE_SIZE];
 
 				pair = &rule->sysfs_pair[i];
-				if (compare_sysfs_attribute(class_dev, parent_device, pair) != 0) {
+				if (find_sysfs_attribute(class_dev, parent_device, pair->name, value, sizeof(value)) != 0)
+					goto try_parent;
+
+				/* strip trailing whitespace of value, if not asked to match for it */
+				if (!isspace(pair->value[strlen(pair->value)-1])) {
+					size_t len = strlen(value);
+
+					while (len > 0 && isspace(value[len-1]))
+						value[--len] = '\0';
+					dbg("removed %i trailing whitespace chars from '%s'", strlen(value)-len, value);
+				}
+
+				dbg("compare attribute '%s' value '%s' with '%s'", pair->name, value, pair->value);
+				if (strcmp_pattern(pair->value, value) != 0) {
 					dbg(KEY_SYSFS "{'%s'} is not matching", pair->name);
 					if (pair->operation != KEY_OP_NOMATCH)
 						goto try_parent;
@@ -644,7 +634,7 @@ try_parent:
 	}
 
 	/* execute external program */
-	if (rule->program[0] != '\0') {
+	if (rule->program_operation != KEY_OP_UNSET) {
 		char program[PATH_SIZE];
 
 		dbg("check " KEY_PROGRAM);
@@ -663,7 +653,7 @@ try_parent:
 	}
 
 	/* check for matching result of external program */
-	if (rule->result[0] != '\0') {
+	if (rule->result_operation != KEY_OP_UNSET) {
 		dbg("check for " KEY_RESULT " rule->result='%s', udev->program_result='%s'",
 		   rule->result, udev->program_result);
 		if (strcmp_pattern(rule->result, udev->program_result) != 0) {
diff --git a/udev_rules.h b/udev_rules.h
index 423a6f641e..561ba1687d 100644
--- a/udev_rules.h
+++ b/udev_rules.h
@@ -55,7 +55,7 @@
 #define RULEFILE_SUFFIX		".rules"
 
 enum key_operation {
-	KEY_OP_UNKNOWN,
+	KEY_OP_UNSET,
 	KEY_OP_MATCH,
 	KEY_OP_NOMATCH,
 	KEY_OP_ADD,
diff --git a/udev_rules_parse.c b/udev_rules_parse.c
index 71ca482728..3c1631ab49 100644
--- a/udev_rules_parse.c
+++ b/udev_rules_parse.c
@@ -236,7 +236,7 @@ static int rules_parse(const char *filename)
 		while (1) {
 			char *key;
 			char *value;
-			enum key_operation operation = KEY_OP_UNKNOWN;
+			enum key_operation operation = KEY_OP_UNSET;
 
 			retval = get_key(&linepos, &key, &operation, &value);
 			if (retval)
@@ -408,13 +408,6 @@ static int rules_parse(const char *filename)
 		if (!valid)
 			goto error;
 
-		/* simple plausibility checks for given keys */
-		if ((rule.sysfs_pair[0].name[0] == '\0') ^
-		    (rule.sysfs_pair[0].value[0] == '\0')) {
-			err("inconsistency in " KEY_SYSFS " key");
-			goto error;
-		}
-
 		if ((rule.result[0] != '\0') && (program_given == 0)) {
 			info(KEY_RESULT " is only useful when " KEY_PROGRAM " is called in any rule before");
 			goto error;