From d5f91372dd3241f8b4bbe2a99aaaeda541a76bad Mon Sep 17 00:00:00 2001
From: "kay.sievers@vrfy.org" <kay.sievers@vrfy.org>
Date: Thu, 4 Mar 2004 18:59:13 -0800
Subject: [PATCH] [PATCH] conditional remove of trailing sysfs whitespace

Hey, it may never happen, that one wants to distinguish attributes by
trailing spaces, but we should not lose the control over it, just for
being lazy :)

Here we remove the trailing spaces of the sysfs attribute only if the
configured value to match doesn't have any trailing spaces by itself.
So if you put a attribute in a rule with spaces at the end, the sysfs
attribute _must_ match exactly.

Is that cool for everyone?

As usual, 2 tests are added for it with a artificial sysfs file and
a few words to the man page.
---
 namedev.c                                     | 14 ++++++++++++++
 .../host0/0:0:0:0/whitespace_test             |  1 +
 test/udev-test.pl                             | 19 +++++++++++++++++++
 udev.8                                        |  3 +++
 4 files changed, 37 insertions(+)
 create mode 100644 test/sys/devices/pci0000:00/0000:00:1e.0/0000:02:05.0/host0/0:0:0:0/whitespace_test

diff --git a/namedev.c b/namedev.c
index 9182ed1f..dfeadee1 100644
--- a/namedev.c
+++ b/namedev.c
@@ -525,6 +525,8 @@ attr_found:
 static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
 {
 	struct sysfs_attribute *tmpattr;
+	int i;
+	int len;
 
 	if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
 		return -ENODEV;
@@ -533,6 +535,18 @@ static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct
 	if (tmpattr == NULL)
 		return -ENODEV;
 
+	/* strip trailing whitespace of value, if not asked to match for it */
+	if (! isspace(pair->value[strlen(pair->value)-1])) {
+		i = len = strlen(tmpattr->value);
+		while (i > 0 &&  isspace(tmpattr->value[i-1]))
+			i--;
+		if (i < len) {
+			tmpattr->value[i] = '\0';
+			dbg("remove %i trailing whitespace chars from '%s'",
+			    len - i, tmpattr->value);
+		}
+	}
+
 	dbg("compare attribute '%s' value '%s' with '%s'",
 		  pair->file, tmpattr->value, pair->value);
 	if (strcmp_pattern(pair->value, tmpattr->value) != 0)
diff --git a/test/sys/devices/pci0000:00/0000:00:1e.0/0000:02:05.0/host0/0:0:0:0/whitespace_test b/test/sys/devices/pci0000:00/0000:00:1e.0/0000:02:05.0/host0/0:0:0:0/whitespace_test
new file mode 100644
index 00000000..e3d48f0f
--- /dev/null
+++ b/test/sys/devices/pci0000:00/0000:00:1e.0/0000:02:05.0/host0/0:0:0:0/whitespace_test
@@ -0,0 +1 @@
+WHITE  SPACE   
diff --git a/test/udev-test.pl b/test/udev-test.pl
index 60cf1690..38ea0181 100644
--- a/test/udev-test.pl
+++ b/test/udev-test.pl
@@ -465,6 +465,25 @@ EOF
 		conf     => <<EOF
 BUS="scsi", ID="*:0:0:0", NAME="scsi-0:0:0:0"
 BUS="scsi", ID="0:0:0:0", NAME="bad"
+EOF
+	},
+	{
+		desc     => "ignore SYSFS attribute whitespace",
+		subsys   => "block",
+		devpath  => "block/sda",
+		expected => "ignored",
+		conf     => <<EOF
+BUS="scsi", SYSFS{whitespace_test}="WHITE  SPACE", NAME="ignored"
+EOF
+	},
+	{
+		desc     => "do not ignore SYSFS attribute whitespace",
+		subsys   => "block",
+		devpath  => "block/sda",
+		expected => "matched-with-space",
+		conf     => <<EOF
+BUS="scsi", SYSFS{whitespace_test}="WHITE  SPACE ", NAME="wrong-to-ignore"
+BUS="scsi", SYSFS{whitespace_test}="WHITE  SPACE   ", NAME="matched-with-space"
 EOF
 	},
 );
diff --git a/udev.8 b/udev.8
index bc7308f4..76b8913f 100644
--- a/udev.8
+++ b/udev.8
@@ -178,6 +178,9 @@ Match the topological position on bus, like physical port of USB device
 Match sysfs device attribute like label, vendor, USB serial number, SCSI UUID
 or file system label.  Up to 5 different sysfs files can be checked, with
 all of the values being required in order to match the rule.
+.br
+Trailing whitespace characters in the sysfs attribute value are ignored, if
+the key doesn't have any trailing whitespace characters by itself.
 .TP
 .B PROGRAM
 Call external program. This key is valid if the program returns successful.
-- 
2.39.5