On 25/01/18(Thu) 14:55, Bryan Steele wrote:
> On Thu, Jan 25, 2018 at 07:00:43PM +0100, Martin Pieuchot wrote:
> > Diff below adds support for dumping USB transfers via bpf(4), including
> > the tcpdump(8) bits.
> >
> > I'd like special review of the new bpf_tap(9) function I'm introducing:
> > - is there a way to pass the header as a different buffer?
> > - is _bpf_tap() the best way to share code with bpf_mtap(9)?
> >
> > Concerning the kernel/userland interface, in looked at the existing
> > DLT_USB*, namely:
> > - DLT_USB_FREEBSD (a.k.a DLT_USB)
> > - DLT_USB_LINUX
> > - DLT_USB_LINUX_MMAPPED
> > - DLT_USBPCAP
> > - DLT_USB_DARWIN
> >
> > I decided to follow DLT_USBPCAP which is the most generic one beside
> > being originated from Windows. Wireshark has some support for it
> > (currently untested) so it is a nice fit.
> > The current implementation is small and I'd like to continue developing
> > it in tree.
> >
> > Here's an excerpt of what's happening when plugging a USB key:
> >
> > # tcpdump -xXi usb0
> > tcpdump: listening on usb0, link-type USBPCAP
> > [...]
> > 18:56:26.261293 bus 0 > addr 5: ep0 ctrl 0
> >
> > 18:56:26.261409 bus 0 < addr 5: ep0 ctrl 20
> > 0000: 1403 5300 6c00 6900 6d00 2000 4c00 6900 ..S.l.i.m. .L.i.
> > 0010: 6e00 6500 n.e.
> >
> > 18:56:26.261418 bus 0 > addr 5: ep0 ctrl 0
> >
> > 18:56:26.261547 bus 0 < addr 5: ep0 ctrl 2
> > 0000: 2203 ".
> >
> > 18:56:26.261552 bus 0 > addr 5: ep0 ctrl 0
> >
> > 18:56:26.261746 bus 0 < addr 5: ep0 ctrl 34
> > 0000: 2203 3000 3700 3100 3000 3500 3900 3600 ".0.7.1.0.5.9.6.
> > 0010: 3100 4100 3400 3800 4400 3600 4100 3900 1.A.4.8.D.6.A.9.
> > 0020: 3500 5.
> >
> > 18:56:26.261761 bus 0 > addr 5: ep2 bulk 31
> > 0000: 5553 4243 4c00 0000 0000 0000 0000 0600 USBCL...........
> > 0010: 0000 0000 0000 0000 0000 0000 0000 00 ...............
> >
> > Ok to put it in tree?
>
>
> This looks really cool, hopefully might be useful for diagnosing the
> constantly reattaching issues I've been seeing with USB mouses..
>
> Looks like you forgot to add print-usbpcap.c for tcpdump.
Indeed, full diff below.
Index: sys/net/bpf.c
===================================================================
RCS file: /cvs/src/sys/net/bpf.c,v
retrieving revision 1.166
diff -u -p -r1.166 bpf.c
--- sys/net/bpf.c 24 Jan 2018 00:25:17 -0000 1.166
+++ sys/net/bpf.c 25 Jan 2018 14:02:58 -0000
@@ -1226,35 +1226,24 @@ bpf_mcopy(const void *src_arg, void *dst
}
}
-/*
- * like bpf_mtap, but copy fn can be given. used by various bpf_mtap*
- */
int
-_bpf_mtap(caddr_t arg, const struct mbuf *m, u_int direction,
- void (*cpfn)(const void *, void *, size_t))
+_bpf_tap(caddr_t arg, u_char *pkt, size_t pktlen, u_int direction,
+ void (*cpfn)(const void *, void *, size_t), int mfilter)
{
struct bpf_if *bp = (struct bpf_if *)arg;
struct srp_ref sr;
struct bpf_d *d;
- size_t pktlen, slen;
- const struct mbuf *m0;
+ size_t slen;
struct timeval tv;
int gottime = 0;
int drop = 0;
- if (m == NULL)
+ if (pkt == NULL)
return (0);
- if (cpfn == NULL)
- cpfn = bpf_mcopy;
-
if (bp == NULL)
return (0);
- pktlen = 0;
- for (m0 = m; m0 != NULL; m0 = m0->m_next)
- pktlen += m0->m_len;
-
SRPL_FOREACH(d, &sr, &bp->bif_dlist, bd_next) {
atomic_inc_long(&d->bd_rcount);
@@ -1268,7 +1257,11 @@ _bpf_mtap(caddr_t arg, const struct mbuf
bf = srp_enter(&bsr, &d->bd_rfilter);
if (bf != NULL)
fcode = bf->bf_insns;
- slen = bpf_mfilter(fcode, m, pktlen);
+ if (mfilter) {
+ const struct mbuf *m = (const struct mbuf *)pkt;
+ slen = bpf_mfilter(fcode, m, pktlen);
+ } else
+ slen = bpf_filter(fcode, pkt, pktlen, pktlen);
srp_leave(&bsr);
}
@@ -1277,8 +1270,7 @@ _bpf_mtap(caddr_t arg, const struct mbuf
microtime(&tv);
mtx_enter(&d->bd_mtx);
- bpf_catchpacket(d, (u_char *)m, pktlen, slen, cpfn,
- &tv);
+ bpf_catchpacket(d, pkt, pktlen, slen, cpfn, &tv);
mtx_leave(&d->bd_mtx);
if (d->bd_fildrop)
@@ -1290,6 +1282,35 @@ _bpf_mtap(caddr_t arg, const struct mbuf
return (drop);
}
+int
+bpf_tap(caddr_t arg, u_char *pkt, size_t pktlen, u_int direction)
+{
+ return _bpf_tap(arg, pkt, pktlen, direction, bcopy, 0);
+}
+
+/*
+ * like bpf_mtap, but copy fn can be given. used by various bpf_mtap*
+ */
+int
+_bpf_mtap(caddr_t arg, const struct mbuf *m, u_int direction,
+ void (*cpfn)(const void *, void *, size_t))
+{
+ const struct mbuf *m0;
+ size_t pktlen;
+
+ if (m == NULL)
+ return (0);
+
+ if (cpfn == NULL)
+ cpfn = bpf_mcopy;
+
+ pktlen = 0;
+ for (m0 = m; m0 != NULL; m0 = m0->m_next)
+ pktlen += m0->m_len;
+
+ return _bpf_tap(arg, (u_char *)m, pktlen, direction, cpfn, 1);
+}
+
/*
* Incoming linkage from device drivers, when packet is in an mbuf chain.
*/
@@ -1790,7 +1811,7 @@ bpf_mbuf_copy(const struct mbuf *m, u_in
for (;;) {
count = min(m->m_len - off, len);
-
+
memcpy(cp, m->m_data + off, count);
len -= count;
Index: sys/net/bpf.h
===================================================================
RCS file: /cvs/src/sys/net/bpf.h,v
retrieving revision 1.63
diff -u -p -r1.63 bpf.h
--- sys/net/bpf.h 24 Jan 2018 00:25:17 -0000 1.63
+++ sys/net/bpf.h 25 Jan 2018 16:06:35 -0000
@@ -201,6 +201,7 @@ struct bpf_hdr {
#define DLT_USER13 160 /* Reserved for private use */
#define DLT_USER14 161 /* Reserved for private use */
#define DLT_USER15 162 /* Reserved for private use */
+#define DLT_USBPCAP 249 /* USBPcap */
#define DLT_MPLS 219 /* MPLS Provider Edge header */
#define DLT_OPENFLOW 267 /* in-kernel OpenFlow, by pcap */
@@ -306,6 +307,7 @@ struct ifnet;
struct mbuf;
int bpf_validate(struct bpf_insn *, int);
+int bpf_tap(caddr_t arg, u_char *, size_t, u_int);
int bpf_mtap(caddr_t, const struct mbuf *, u_int);
int bpf_mtap_hdr(caddr_t, caddr_t, u_int, const struct mbuf *, u_int,
void (*)(const void *, void *, size_t));
Index: usr.sbin/tcpdump/Makefile
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/Makefile,v
retrieving revision 1.62
diff -u -p -r1.62 Makefile
--- usr.sbin/tcpdump/Makefile 30 Oct 2017 10:07:44 -0000 1.62
+++ usr.sbin/tcpdump/Makefile 25 Jan 2018 17:10:15 -0000
@@ -49,7 +49,7 @@ SRCS= tcpdump.c addrtoname.c privsep.c p
print-etherip.c print-lwres.c print-lldp.c print-cdp.c print-pflog.c \
print-pfsync.c pf_print_state.c print-ofp.c ofp_map.c \
print-udpencap.c print-carp.c \
- print-802_11.c print-iapp.c print-mpls.c print-slow.c \
+ print-802_11.c print-iapp.c print-mpls.c print-slow.c print-usbpcap.c \
gmt2local.c savestr.c setsignal.c in_cksum.c
# TCP OS Fingerprinting
Index: usr.sbin/tcpdump/interface.h
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/interface.h,v
retrieving revision 1.69
diff -u -p -r1.69 interface.h
--- usr.sbin/tcpdump/interface.h 16 Nov 2016 13:47:27 -0000 1.69
+++ usr.sbin/tcpdump/interface.h 25 Jan 2018 17:13:09 -0000
@@ -276,6 +276,8 @@ extern void slow_print(const u_char *, u
extern void gtp_print(const u_char *, u_int, u_short, u_short);
extern void ofp_print(const u_char *, u_int);
extern void ofp_if_print(u_char *, const struct pcap_pkthdr *, const u_char *);
+extern void usbpcap_if_print(u_char *, const struct pcap_pkthdr *,
+ const u_char *);
#ifdef INET6
extern void ip6_print(const u_char *, u_int);
Index: usr.sbin/tcpdump/print-usbpcap.c
===================================================================
RCS file: usr.sbin/tcpdump/print-usbpcap.c
diff -N usr.sbin/tcpdump/print-usbpcap.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ usr.sbin/tcpdump/print-usbpcap.c 25 Jan 2018 17:44:57 -0000
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2018 Martin Pieuchot <[email protected]>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <dev/usb/usb.h>
+#include <dev/usb/usbpcap.h>
+
+#include <pcap.h>
+
+#include "interface.h"
+
+#ifndef nitems
+#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
+#endif
+
+const char *usbpcap_xfer_type[] = {"isoc", "intr", "ctrl", "bulk"};
+
+void
+usbpcap_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
+{
+ u_int length = h->len;
+ u_int caplen = h->caplen;
+ const struct usbpcap_hdr *uph;
+
+ ts_print(&h->ts);
+
+ /* check length */
+ if (caplen < sizeof(uint16_t)) {
+ printf("[|usb]");
+ goto out;
+ }
+ uph = (struct usbpcap_hdr *)p;
+ if (uph->hlen < sizeof(*uph)) {
+ printf("[usb: invalid header length %u!]", uph->hlen);
+ goto out;
+ }
+
+ if (caplen < uph->hlen) {
+ printf("[|usb]");
+ goto out;
+ }
+
+ printf("bus %u %c addr %u: ep%u",
+ uph->bus, ((uph->info & USBPCAP_INFO_PDO_TO_FDO) ? '<' : '>'),
+ uph->devaddr, UE_GET_ADDR(uph->epaddr));
+
+ if (uph->xfertype < nitems(usbpcap_xfer_type))
+ printf(" %s", usbpcap_xfer_type[uph->xfertype]);
+ else
+ printf(" ??");
+
+ printf(" %u", uph->dlen);
+
+ if (xflag)
+ default_print(p + sizeof(*uph), length - sizeof(*uph));
+out:
+ putchar('\n');
+}
Index: usr.sbin/tcpdump/tcpdump.c
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/tcpdump.c,v
retrieving revision 1.81
diff -u -p -r1.81 tcpdump.c
--- usr.sbin/tcpdump/tcpdump.c 8 Dec 2017 17:04:15 -0000 1.81
+++ usr.sbin/tcpdump/tcpdump.c 25 Jan 2018 17:10:08 -0000
@@ -127,6 +127,7 @@ static struct printer printers[] = {
{ ieee802_11_if_print, DLT_IEEE802_11 },
{ ieee802_11_radio_if_print, DLT_IEEE802_11_RADIO },
{ ofp_if_print, DLT_OPENFLOW },
+ { usbpcap_if_print, DLT_USBPCAP },
{ NULL, 0 },
};
Index: lib/libpcap/gencode.c
===================================================================
RCS file: /cvs/src/lib/libpcap/gencode.c,v
retrieving revision 1.46
diff -u -p -r1.46 gencode.c
--- lib/libpcap/gencode.c 20 Nov 2016 12:45:26 -0000 1.46
+++ lib/libpcap/gencode.c 25 Jan 2018 17:09:17 -0000
@@ -787,6 +787,8 @@ init_linktype(type)
off_nl = 12;
return;
+ case DLT_USBPCAP:
+ /* FALLTHROUGH */
case DLT_RAW:
off_linktype = -1;
off_nl = 0;
Index: lib/libpcap/pcap.c
===================================================================
RCS file: /cvs/src/lib/libpcap/pcap.c,v
retrieving revision 1.20
diff -u -p -r1.20 pcap.c
--- lib/libpcap/pcap.c 16 Nov 2016 13:47:27 -0000 1.20
+++ lib/libpcap/pcap.c 25 Jan 2018 17:09:23 -0000
@@ -326,6 +326,7 @@ DLT_CHOICE(DLT_IEEE802_11, "IEEE 802.11
DLT_CHOICE(DLT_PFLOG, "Packet filter logging, by pcap people"),
DLT_CHOICE(DLT_IEEE802_11_RADIO, "IEEE 802.11 plus WLAN header"),
DLT_CHOICE(DLT_OPENFLOW, "OpenFlow"),
+DLT_CHOICE(DLT_USBPCAP, "USB"),
#undef DLT_CHOICE
{ NULL, NULL, -1}
};
Index: sys/dev/usb/usb.c
===================================================================
RCS file: /cvs/src/sys/dev/usb/usb.c,v
retrieving revision 1.114
diff -u -p -r1.114 usb.c
--- sys/dev/usb/usb.c 29 Jul 2017 18:26:14 -0000 1.114
+++ sys/dev/usb/usb.c 25 Jan 2018 17:41:40 -0000
@@ -63,6 +63,8 @@
#include <machine/bus.h>
#include <dev/usb/usbdivar.h>
+#include <dev/usb/usb_mem.h>
+#include <dev/usb/usbpcap.h>
#ifdef USB_DEBUG
#define DPRINTF(x) do { if (usbdebug) printf x; } while (0)
@@ -183,6 +185,11 @@ usb_attach(struct device *parent, struct
}
printf("\n");
+#if NBPFILTER > 0
+ bpfsattach(&sc->sc_bus->bpf, sc->sc_dev.dv_xname, DLT_USBPCAP,
+ sizeof(struct usbpcap_hdr));
+#endif
+
/* Make sure not to use tsleep() if we are cold booting. */
if (cold)
sc->sc_bus->use_polling++;
@@ -973,5 +980,75 @@ usb_detach(struct device *self, int flag
sc->sc_bus->soft = NULL;
}
+#if NBPFILTER > 0
+ bpfsdetach(&sc->sc_bus->bpf);
+#endif
return (0);
+}
+
+void
+usb_tap(struct usbd_bus *bus, struct usbd_xfer *xfer, uint8_t dir)
+{
+#if NBPFILTER > 0
+ struct usb_softc *sc = (struct usb_softc *)bus->usbctl;
+ usb_endpoint_descriptor_t *ed = xfer->pipe->endpoint->edesc;
+ struct usbpcap_hdr *uph;
+ unsigned int bpfdir;
+ uint32_t len, dlen;
+ uint8_t *buf, info = 0;
+
+ if (dir == USBTAP_DIR_OUT) {
+ bpfdir = BPF_DIRECTION_OUT;
+ if (usbd_xfer_isread(xfer))
+ dlen = 0;
+ else
+ dlen = xfer->length;
+ } else { /* USBTAP_DIR_IN */
+ info = USBPCAP_INFO_PDO_TO_FDO;
+ bpfdir = BPF_DIRECTION_IN;
+ if (usbd_xfer_isread(xfer))
+ dlen = xfer->actlen;
+ else
+ dlen = 0;
+ }
+
+ len = sizeof(*uph) + dlen;
+
+ buf = malloc(len, M_TEMP, M_NOWAIT);
+ if (buf == NULL)
+ return;
+
+ uph = (struct usbpcap_hdr *)buf;
+ uph->hlen = htole32(sizeof(*uph));
+ uph->id = 0; /* not yet used */
+ uph->status = htole32(xfer->status);
+ uph->function = 0; /* not yet used */
+ uph->info = info;
+ uph->bus = htole32(sc->sc_dev.dv_unit);
+ uph->devaddr = htole16(xfer->device->address);
+ uph->epaddr = ed->bEndpointAddress;
+
+ switch (UE_GET_XFERTYPE(ed->bmAttributes)) {
+ case UE_CONTROL:
+ uph->xfertype = USBPCAP_TRANSFER_CONTROL;
+ break;
+ case UE_ISOCHRONOUS:
+ uph->xfertype = USBPCAP_TRANSFER_ISOCHRONOUS;
+ break;
+ case UE_BULK:
+ uph->xfertype = USBPCAP_TRANSFER_BULK;
+ break;
+ case UE_INTERRUPT:
+ uph->xfertype = USBPCAP_TRANSFER_INTERRUPT;
+ break;
+ }
+
+ uph->dlen = dlen;
+ if (dlen)
+ memcpy(buf + sizeof(*uph), KERNADDR(&xfer->dmabuf, 0), dlen);
+
+ bpf_tap(bus->bpf, buf, len, bpfdir);
+
+ free(buf, M_TEMP, len);
+#endif
}
Index: sys/dev/usb/usbdi.c
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdi.c,v
retrieving revision 1.96
diff -u -p -r1.96 usbdi.c
--- sys/dev/usb/usbdi.c 21 Sep 2017 07:44:06 -0000 1.96
+++ sys/dev/usb/usbdi.c 25 Jan 2018 16:59:55 -0000
@@ -320,6 +320,8 @@ usbd_transfer(struct usbd_xfer *xfer)
usb_syncmem(&xfer->dmabuf, 0, xfer->length,
BUS_DMASYNC_PREREAD);
+ usb_tap(bus, xfer, USBTAP_DIR_OUT);
+
err = pipe->methods->transfer(xfer);
if (err != USBD_IN_PROGRESS && err != USBD_NORMAL_COMPLETION) {
@@ -715,7 +717,8 @@ void
usb_transfer_complete(struct usbd_xfer *xfer)
{
struct usbd_pipe *pipe = xfer->pipe;
- int polling = pipe->device->bus->use_polling;
+ struct usbd_bus *bus = pipe->device->bus;
+ int polling = bus->use_polling;
int status, flags;
#if 0
@@ -759,7 +762,7 @@ usb_transfer_complete(struct usbd_xfer *
/* if we allocated the buffer in usbd_transfer() we free it here. */
if (xfer->rqflags & URQ_AUTO_DMABUF) {
if (!pipe->repeat) {
- usb_freemem(pipe->device->bus, &xfer->dmabuf);
+ usb_freemem(bus, &xfer->dmabuf);
xfer->rqflags &= ~URQ_AUTO_DMABUF;
}
}
@@ -778,7 +781,7 @@ usb_transfer_complete(struct usbd_xfer *
pipe->repeat, SIMPLEQ_FIRST(&pipe->queue)));
/* Count completed transfers. */
- ++pipe->device->bus->stats.uds_requests
+ ++bus->stats.uds_requests
[pipe->endpoint->edesc->bmAttributes & UE_XFERTYPE];
xfer->done = 1;
@@ -788,6 +791,8 @@ usb_transfer_complete(struct usbd_xfer *
xfer->actlen, xfer->length));
xfer->status = USBD_SHORT_XFER;
}
+
+ usb_tap(bus, xfer, USBTAP_DIR_IN);
/*
* We cannot dereference ``xfer'' after calling the callback as
Index: sys/dev/usb/usbdivar.h
===================================================================
RCS file: /cvs/src/sys/dev/usb/usbdivar.h,v
retrieving revision 1.72
diff -u -p -r1.72 usbdivar.h
--- sys/dev/usb/usbdivar.h 8 Apr 2017 02:57:25 -0000 1.72
+++ sys/dev/usb/usbdivar.h 25 Jan 2018 17:02:27 -0000
@@ -35,6 +35,11 @@
#ifndef _USBDIVAR_H_
#define _USBDIVAR_H_
+#include "bpfilter.h"
+#if NBPFILTER > 0
+#include <net/bpf.h>
+#endif
+
#include <sys/timeout.h>
/* From usb_mem.h */
@@ -100,6 +105,9 @@ struct usbd_bus {
/* Filled by HC driver */
struct device bdev; /* base device, host adapter */
struct usbd_bus_methods *methods;
+#if NBPFILTER > 0
+ caddr_t bpf;
+#endif
u_int32_t pipe_size; /* size of a pipe struct */
/* Filled by usb driver */
struct usbd_device *root_hub;
@@ -253,6 +261,10 @@ int usbd_detach(struct usbd_device *, s
void usb_needs_explore(struct usbd_device *, int);
void usb_needs_reattach(struct usbd_device *);
void usb_schedsoftintr(struct usbd_bus *);
+void usb_tap(struct usbd_bus *, struct usbd_xfer *, uint8_t);
+
+#define USBTAP_DIR_OUT 0
+#define USBTAP_DIR_IN 1
#define UHUB_UNK_CONFIGURATION -1
#define UHUB_UNK_INTERFACE -1
Index: sys/dev/usb/usbpcap.h
===================================================================
RCS file: sys/dev/usb/usbpcap.h
diff -N sys/dev/usb/usbpcap.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ sys/dev/usb/usbpcap.h 25 Jan 2018 17:05:08 -0000
@@ -0,0 +1,45 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2018 Martin Pieuchot
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _USBCAP_H_
+#define _USBCAP_H_
+
+/*
+ * DLT_USBPCAP header.
+ */
+struct usbpcap_hdr {
+ uint16_t hlen; /* header length */
+ uint64_t id; /* request ID */
+ uint32_t status; /* USB status code */
+ uint16_t function; /* stack function ID */
+ uint8_t info; /* info flags */
+#define USBPCAP_INFO_PDO_TO_FDO (1 << 0)
+
+ uint16_t bus; /* bus number */
+ uint16_t devaddr; /* device address */
+ uint8_t epaddr; /* endpoint's `bEndpointAddress' */
+ uint8_t xfertype; /* transfer type */
+#define USBPCAP_TRANSFER_ISOCHRONOUS 0
+#define USBPCAP_TRANSFER_INTERRUPT 1
+#define USBPCAP_TRANSFER_CONTROL 2
+#define USBPCAP_TRANSFER_BULK 3
+
+ uint32_t dlen; /* data length */
+} __attribute__((packed));
+
+#endif /* _USBCAP_H_ */
