This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / usb / mon / mon_stat.c

diff --git a/drivers/usb/mon/mon_stat.c b/drivers/usb/mon/mon_stat.c
new file mode 100644 (file)
index 0000000..6e4b165
--- /dev/null
+++ b/drivers/usb/mon/mon_stat.c
@@ -0,0 +1,74 @@
+/*
+ * The USB Monitor, inspired by Dave Harding's USBMon.
+ *
+ * This is the 's' or 'stat' reader which debugs usbmon itself.
+ * Note that this code blows through locks, so make sure that
+ * /dbg/usbmon/0s is well protected from non-root users.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <asm/uaccess.h>
+
+#include "usb_mon.h"
+
+#define STAT_BUF_SIZE  80
+
+struct snap {
+       int slen;
+       char str[STAT_BUF_SIZE];
+};
+
+static int mon_stat_open(struct inode *inode, struct file *file)
+{
+       struct mon_bus *mbus;
+       struct snap *sp;
+
+       if ((sp = kmalloc(sizeof(struct snap), GFP_KERNEL)) == NULL)
+               return -ENOMEM;
+
+       mbus = inode->u.generic_ip;
+
+       sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
+           "nreaders %d text_lost %u\n",
+           mbus->nreaders, mbus->cnt_text_lost);
+
+       file->private_data = sp;
+       return 0;
+}
+
+static ssize_t mon_stat_read(struct file *file, char __user *buf,
+                               size_t nbytes, loff_t *ppos)
+{
+       struct snap *sp = file->private_data;
+       loff_t pos = *ppos;
+       int cnt;
+
+       if (pos < 0 || pos >= sp->slen)
+               return 0;
+       if (nbytes == 0)
+               return 0;
+       if ((cnt = sp->slen - pos) > nbytes)
+               cnt = nbytes;
+       if (copy_to_user(buf, sp->str + pos, cnt))
+               return -EFAULT;
+       *ppos = pos + cnt;
+       return cnt;
+}
+
+static int mon_stat_release(struct inode *inode, struct file *file)
+{
+       return 0;
+}
+
+struct file_operations mon_fops_stat = {
+       .owner =        THIS_MODULE,
+       .open =         mon_stat_open,
+       .llseek =       no_llseek,
+       .read =         mon_stat_read,
+       /* .write =     mon_stat_write, */
+       /* .poll =              mon_stat_poll, */
+       /* .ioctl =     mon_stat_ioctl, */
+       .release =      mon_stat_release,
+};