Re: [PATCH 2.6.20] kobject net ifindex + rename

On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote:

On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote:

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On 28-02-2007 02:27, Jean Tourrilhes wrote:

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	Hi all,

...

quoted

	Patch for 2.6.20 is attached. The patch was tested on a system
running the hotplug scripts, and on another system running udev.

	Have fun...

	Jean

Signed-off-by: Jean Tourrilhes <redacted>

---------------------------------------------------------

...

quoted

diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c

--- linux/net/core/net-sysfs.j1.c	2007-02-27 15:01:08.000000000 -0800
+++ linux/net/core/net-sysfs.c	2007-02-27 15:06:49.000000000 -0800

@@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
 	if ((size <= 0) || (i >= num_envp))
 		return -ENOMEM;
 
+	/* pass ifindex to uevent.
+	 * ifindex is useful as it won't change (interface name may change)
+	 * and is what RtNetlink uses natively. */
+	envp[i++] = buf;
+	n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
+	buf += n;
+	size -= n;
+
+	if ((size <= 0) || (i >= num_envp))

Btw.:
1. if size == 10 and snprintf returns 9 (without NULL)
   then n == 10 (with NULL), so isn't it enough (here and above):
 
	if ((size < 0) || (i >= num_envp))

	I just cut'n'pasted the code a few line above. If the original
code is incorrect, it need fixing. And it will need fixing in probably
a lot of places.

I think you're kind of responsible for your part, at least.

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2. shouldn't there be (here and above):
 
		envp[--i] = NULL;

	No, envp is local, so who cares.

But envp[i] isn't (at least here). So, I guess, a caller
of this function could care.

quoted

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+ 	if ((size <= 0) || (i >= num_envp))
+ 		return -ENOMEM;

And one more thing (not necessarily for you):
ENOBUFS is probably more adequate here.

Cheers,
Jarek P.