USB: usbmon: Add binary API v1
This patch adds an extension to the binary API so it reaches parity with
existing text API (so-called "1u"). The extension delivers additional data,
such as ISO descriptors and the interrupt interval.
Signed-Off-By: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt
index 2704819..6c3c625 100644
--- a/Documentation/usb/usbmon.txt
+++ b/Documentation/usb/usbmon.txt
@@ -229,16 +229,26 @@
int status; /* 28: */
unsigned int length; /* 32: Length of data (submitted or actual) */
unsigned int len_cap; /* 36: Delivered length */
- unsigned char setup[8]; /* 40: Only for Control 'S' */
-}; /* 48 bytes total */
+ union { /* 40: */
+ unsigned char setup[SETUP_LEN]; /* Only for Control S-type */
+ struct iso_rec { /* Only for ISO */
+ int error_count;
+ int numdesc;
+ } iso;
+ } s;
+ int interval; /* 48: Only for Interrupt and ISO */
+ int start_frame; /* 52: For ISO */
+ unsigned int xfer_flags; /* 56: copy of URB's transfer_flags */
+ unsigned int ndesc; /* 60: Actual number of ISO descriptors */
+}; /* 64 total length */
These events can be received from a character device by reading with read(2),
-with an ioctl(2), or by accessing the buffer with mmap.
+with an ioctl(2), or by accessing the buffer with mmap. However, read(2)
+only returns first 48 bytes for compatibility reasons.
The character device is usually called /dev/usbmonN, where N is the USB bus
number. Number zero (/dev/usbmon0) is special and means "all buses".
-However, this feature is not implemented yet. Note that specific naming
-policy is set by your Linux distribution.
+Note that specific naming policy is set by your Linux distribution.
If you create /dev/usbmon0 by hand, make sure that it is owned by root
and has mode 0600. Otherwise, unpriviledged users will be able to snoop
@@ -279,9 +289,10 @@
This call returns the current size of the buffer in bytes.
MON_IOCX_GET, defined as _IOW(MON_IOC_MAGIC, 6, struct mon_get_arg)
+ MON_IOCX_GETX, defined as _IOW(MON_IOC_MAGIC, 10, struct mon_get_arg)
-This call waits for events to arrive if none were in the kernel buffer,
-then returns the first event. Its argument is a pointer to the following
+These calls wait for events to arrive if none were in the kernel buffer,
+then return the first event. The argument is a pointer to the following
structure:
struct mon_get_arg {
@@ -294,6 +305,8 @@
pointed by hdr contains the next event structure, and the data buffer contains
the data, if any. The event is removed from the kernel buffer.
+The MON_IOCX_GET copies 48 bytes, MON_IOCX_GETX copies 64 bytes.
+
MON_IOCX_MFETCH, defined as _IOWR(MON_IOC_MAGIC, 7, struct mon_mfetch_arg)
This ioctl is primarily used when the application accesses the buffer