Re: [PATCH updated] net: add ability to clear per-interface networkstatistics via procfs

From: James Cammarata
Date: Sat May 17 2008 - 18:49:22 EST


This version has a bug, please check again.

Gah, you're right, fixed below.

---

--- linux-2.6.25.4/net/core/dev.c 2008-05-15 10:00:12.000000000 -0500
+++ linux-2.6.25.4-jcammara/net/core/dev.c 2008-05-17 17:45:57.000000000 -0500
@@ -2455,2 +2455,80 @@

+/**
+ * proc_net_dev_write - handle writes to /proc/net/dev
+ * @file: not used
+ * @buf: buffer to write
+ * @length: length of buf, at most PAGE_SIZE
+ * @ppos: not used
+ *
+ * Description: this provides a mechanism to clear statistics on a
+ * per-interface basis
+ * "echo 'net clear-stats ifdev' >/proc/net/dev"
+ * with "ifdev" replaced by the device name you wish to clear.
+ *
+ */
+static ssize_t proc_net_dev_write(struct file *file, const char __user *buf,
+ size_t length, loff_t *ppos)
+{
+ char *buffer, *p;
+ char devname[IFNAMSIZ];
+ struct net *net;
+ struct net_device *dev;
+ int err;
+
+ if (!buf || length > PAGE_SIZE)
+ return -EINVAL;
+
+ buffer = (char *)__get_free_page(GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ err = -EFAULT;
+ if (copy_from_user(buffer, buf, length))
+ goto out;
+
+ err = -EINVAL;
+ if (length < PAGE_SIZE)
+ buffer[length] = '\0';
+ else if (buffer[PAGE_SIZE-1])
+ goto out;
+
+ err = -ENXIO;
+ net = get_proc_net(file->f_dentry->d_inode);
+ if (!net)
+ goto out;
+
+ /*
+ * Usage: echo "net clear-stats ifdev" >/proc/net/dev
+ * with "ifdev" replaced by the device name you wish to clear.
+ */
+ if (!strncmp("net clear-stats",buffer,15)) {
+ p = buffer + 16;
+ if(sscanf(p,"%16s",devname)>0) {
+ dev = dev_get_by_name(net,devname);
+ if (dev) {
+ if (dev->get_stats) {
+ struct net_device_stats *stats =
+ dev->get_stats(dev);
+ memset(stats,0,
+ sizeof(struct net_device_stats));
+ }
+ dev_put(dev);
+ }
+ }
+ }
+
+ /*
+ * convert success returns so that we return the
+ * number of bytes consumed.
+ */
+ if (!err)
+ err = length;
+
+ put_net(net);
+
+ out:
+ free_page((unsigned long)buffer);
+ return err;
+}
+
static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
@@ -2498,2 +2576,3 @@
.read = seq_read,
+ .write = proc_net_dev_write,
.llseek = seq_lseek,
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/