On 08/30/2012 11:03 AM, Michael S. Tsirkin wrote:

On Thu, Aug 30, 2012 at 10:51:35AM -0400, Vlad Yasevich wrote:

quoted

On 08/30/2012 10:44 AM, Michael S. Tsirkin wrote:

quoted

On Thu, Aug 30, 2012 at 10:36:34AM -0400, Vlad Yasevich wrote:

quoted

On 08/30/2012 10:26 AM, Michael S. Tsirkin wrote:

quoted

On Thu, Aug 30, 2012 at 10:05:16AM -0400, Vlad Yasevich wrote:

quoted

On 08/30/2012 08:27 AM, Michael S. Tsirkin wrote:

quoted

On Thu, Aug 23, 2012 at 03:29:55PM -0400, Vlad Yasevich wrote:

quoted

Add a binary sysfs file that will dump out vlans currently configured on the
port.

I initially though of creating a sysfs object per vlan.  That would
have made it easy to see which vlans are configured without any
tools.
But that could result in a lot of objects being created, so I abandoned it.

I did think about a text interface, but due to a page of output
limitation, I didn't go that route.  The reason is that if someone
cats the file, they may not see all the vlans configured.  So I
decided on the binary interface, since a binary interface with a
tool to read it could avoid the single page limitation.

-vlad

Maybe it's not needed in sysfs then - expose it to
brctl or whatever.

brctl uses sysfs for almost everything any more :)

-vlad

How about a long string of 0 and 1's?
And a separate one for untagged vlans.

that would work too.  You really don't like the binary interface, huh?

-vlad

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---
  include/linux/if_bridge.h |    1 +
  net/bridge/br_if.c        |   34 ++++++++++++++++++++++++++++++++++
  net/bridge/br_private.h   |    2 ++
  net/bridge/br_sysfs_if.c  |   28 ++++++++++++++++++++++++++++
  4 files changed, 65 insertions(+), 0 deletions(-)

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index ab750dd..d0f869b 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h

@@ -20,6 +20,7 @@
  #define SYSFS_BRIDGE_PORT_SUBDIR "brif"
  #define SYSFS_BRIDGE_PORT_ATTR	"brport"
  #define SYSFS_BRIDGE_PORT_LINK	"bridge"
+#define SYSFS_BRIDGE_PORT_VLANS "vlans"

  #define BRCTL_VERSION 1

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 90c1038..3963748 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c

@@ -510,6 +510,40 @@ int br_del_port_vlan(struct net_bridge_port *p, unsigned long vlan)
  	return 0;
  }

+size_t br_port_fill_vlans(struct net_bridge_port *p, char* buf,
+			unsigned long max, unsigned long skip)
+{
+	unsigned long *map;
+	unsigned short *vid = (unsigned short *)buf;
+	unsigned short i;
+	int num = 0;
+
+	if (skip > (VLAN_N_VID+1))
+		return -EINVAL;
+
+	memset(buf, 0, max * sizeof(unsigned short));

Isn't max is in bytes? why is this safe?

quoted

+
+	rcu_read_lock();
+	map = rcu_dereference(p->vlan_map);
+	if (!map)
+		goto out;
+
+	for (i = skip + 1; i < VLAN_N_VID + 1; i++) {

Isn't skip in bytes too? Why do you compare it to i which is
in dwords?

quoted

+		if (test_bit(i, map)) {
+			if (num > max)
+				goto out;
+
+			*vid = i-1;
+			vid++;
+			num++;
+		}
+	}
+out:
+	rcu_read_unlock();
+
+	return num*sizeof(unsigned short);
+}
+
  void __net_exit br_net_exit(struct net *net)
  {
  	struct net_device *dev;

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 5639c1c..cf95cd7 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h

@@ -404,6 +404,8 @@ extern netdev_features_t br_features_recompute(struct net_bridge *br,
  	netdev_features_t features);
  extern int br_set_port_vlan(struct net_bridge_port *p, unsigned long vid);
  extern int br_del_port_vlan(struct net_bridge_port *p, unsigned long vid);
+extern size_t br_port_fill_vlans(struct net_bridge_port *p, char *buf,
+				unsigned long max, unsigned long skip);

  /* br_input.c */
  extern int br_handle_frame_finish(struct sk_buff *skb);

diff --git a/net/bridge/br_sysfs_if.c b/net/bridge/br_sysfs_if.c
index 13b36bd..a81e2ef 100644
--- a/net/bridge/br_sysfs_if.c
+++ b/net/bridge/br_sysfs_if.c

@@ -234,6 +234,29 @@ const struct sysfs_ops brport_sysfs_ops = {
  };

  /*
+ * Export the vlan table for a given port as a binary file.
+ * The records are unsgined shorts.
+ *
+ * Returns the number of bytes read.
+ */
+static ssize_t brport_vlans_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr,
+				char *buf, loff_t off, size_t count)
+{
+	struct net_bridge_port *p = to_brport(kobj);
+
+	return br_port_fill_vlans(p, buf,
+				count/sizeof(unsigned short),
+				off/sizeof(unsigned short));
+}
+
+static struct bin_attribute port_vlans = {
+	.attr = { .name = SYSFS_BRIDGE_PORT_VLANS,
+		  .mode = S_IRUGO, },
+	.read = brport_vlans_read,
+};
+
+/*
   * Add sysfs entries to ethernet device added to a bridge.
   * Creates a brport subdirectory with bridge attributes.
   * Puts symlink in bridge's brif subdirectory

@@ -255,6 +278,11 @@ int br_sysfs_addif(struct net_bridge_port *p)
  			return err;
  	}

+	err = sysfs_create_bin_file(&p->kobj, &port_vlans);
+	if (err) {
+		return err;
+	}
+
  	strlcpy(p->sysfs_name, p->dev->name, IFNAMSIZ);
  	return sysfs_create_link(br->ifobj, &p->kobj, p->sysfs_name);
  }
--

1.7.7.6

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