USB: add binary API to usbmon

This patch adds a new, "binary" API in addition to the old, text API usbmon
had before. The new API allows for less CPU use, and it allows to capture
all data from a packet where old API only captured 32 bytes at most. There
are some limitations and conditions to this, e.g. in case someone constructs
a URB with 1GB of data, it's not likely to be captured, because even the
huge buffers of the new reader are finite. Nonetheless, I expect this new
capability to capture all data for all real life scenarios.

The downside is, a special user mode application is required where cat(1)
worked before. I have sample code at http://people.redhat.com/zaitcev/linux/
and Paolo Abeni is working on patching libpcap.

This patch was initially written by Paolo and later I tweaked it, and
we had a little back-and-forth. So this is a jointly authored patch, but
I am submitting this I am responsible for the bugs.

Signed-off-by: Paolo Abeni <paolo.abeni@email.it>
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 27 insertions, 3 deletions

diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index ab9d02d5df77..4f949ce8a7f3 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -17,9 +17,11 @@
 struct mon_bus {
 	struct list_head bus_link;
 	spinlock_t lock;
+	struct usb_bus *u_bus;
+
+	int text_inited;
 	struct dentry *dent_s;		/* Debugging file */
 	struct dentry *dent_t;		/* Text interface file */
-	struct usb_bus *u_bus;
 	int uses_dma;
 
 	/* Ref */
@@ -48,13 +50,35 @@ struct mon_reader {
 void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r);
 void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r);
 
+struct mon_bus *mon_bus_lookup(unsigned int num);
+
+int /*bool*/ mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+void mon_text_del(struct mon_bus *mbus);
+// void mon_bin_add(struct mon_bus *);
+
+int __init mon_text_init(void);
+void __exit mon_text_exit(void);
+int __init mon_bin_init(void);
+void __exit mon_bin_exit(void);
+
 /*
- */
+ * DMA interface.
+ *
+ * XXX The vectored side needs a serious re-thinking. Abstracting vectors,
+ * like in Paolo's original patch, produces a double pkmap. We need an idea.
+*/
 extern char mon_dmapeek(unsigned char *dst, dma_addr_t dma_addr, int len);
 
+struct mon_reader_bin;
+extern void mon_dmapeek_vec(const struct mon_reader_bin *rp,
+    unsigned int offset, dma_addr_t dma_addr, unsigned int len);
+extern unsigned int mon_copy_to_buff(const struct mon_reader_bin *rp,
+    unsigned int offset, const unsigned char *from, unsigned int len);
+
+/*
+ */
 extern struct mutex mon_lock;
 
-extern const struct file_operations mon_fops_text;
 extern const struct file_operations mon_fops_stat;
 
 #endif /* __USB_MON_H */