Imported Upstream version 1.3.0upstream/1.3.0

1 files changed, 883 insertions, 0 deletions

diff --git a/pcap-usb-linux.c b/pcap-usb-linux.c
new file mode 100644
index 0000000..f1b430c
--- /dev/null
+++ b/pcap-usb-linux.c
@@ -0,0 +1,883 @@
+/*
+ * Copyright (c) 2006 Paolo Abeni (Italy)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote 
+ * products derived from this software without specific prior written 
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * USB sniffing API implementation for Linux platform
+ * By Paolo Abeni <paolo.abeni@email.it>
+ * Modifications: Kris Katterjohn <katterjohn@gmail.com>
+ *
+ */
+#ifndef lint
+static const char rcsid[] _U_ =
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-usb-linux.c,v 1.33 2008-12-23 21:38:50 guy Exp $ (LBL)";
+#endif
+ 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcap-int.h"
+#include "pcap-usb-linux.h"
+#include "pcap/usb.h"
+
+#ifdef NEED_STRERROR_H
+#include "strerror.h"
+#endif
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <dirent.h>
+#include <byteswap.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#ifdef HAVE_LINUX_USBDEVICE_FS_H
+/*
+ * We might need <linux/compiler.h> to define __user for
+ * <linux/usbdevice_fs.h>.
+ */
+#ifdef HAVE_LINUX_COMPILER_H
+#include <linux/compiler.h>
+#endif /* HAVE_LINUX_COMPILER_H */
+#include <linux/usbdevice_fs.h>
+#endif /* HAVE_LINUX_USBDEVICE_FS_H */
+
+#define USB_IFACE "usbmon"
+#define USB_TEXT_DIR_OLD "/sys/kernel/debug/usbmon"
+#define USB_TEXT_DIR "/sys/kernel/debug/usb/usbmon"
+#define SYS_USB_BUS_DIR "/sys/bus/usb/devices"
+#define PROC_USB_BUS_DIR "/proc/bus/usb"
+#define USB_LINE_LEN 4096
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define htols(s) s
+#define htoll(l) l
+#define htol64(ll) ll
+#else
+#define htols(s) bswap_16(s)
+#define htoll(l) bswap_32(l)
+#define htol64(ll) bswap_64(ll)
+#endif
+
+struct mon_bin_stats {
+	u_int32_t queued;
+	u_int32_t dropped;
+};
+
+struct mon_bin_get {
+	pcap_usb_header *hdr;
+	void *data;
+	size_t data_len;   /* Length of data (can be zero) */
+};
+
+struct mon_bin_mfetch {
+	int32_t *offvec;   /* Vector of events fetched */
+	int32_t nfetch;    /* Number of events to fetch (out: fetched) */
+	int32_t nflush;    /* Number of events to flush */
+};
+
+#define MON_IOC_MAGIC 0x92
+
+#define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1)
+#define MON_IOCX_URB  _IOWR(MON_IOC_MAGIC, 2, struct mon_bin_hdr)
+#define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats)
+#define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4)
+#define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5)
+#define MON_IOCX_GET   _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get)
+#define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch)
+#define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8)
+
+#define MON_BIN_SETUP 	0x1 /* setup hdr is present*/
+#define MON_BIN_SETUP_ZERO 	0x2 /* setup buffer is not available */
+#define MON_BIN_DATA_ZERO 	0x4 /* data buffer is not available */
+#define MON_BIN_ERROR 	0x8
+
+/* forward declaration */
+static int usb_activate(pcap_t *);
+static int usb_stats_linux(pcap_t *, struct pcap_stat *);
+static int usb_stats_linux_bin(pcap_t *, struct pcap_stat *);
+static int usb_read_linux(pcap_t *, int , pcap_handler , u_char *);
+static int usb_read_linux_bin(pcap_t *, int , pcap_handler , u_char *);
+static int usb_read_linux_mmap(pcap_t *, int , pcap_handler , u_char *);
+static int usb_inject_linux(pcap_t *, const void *, size_t);
+static int usb_setdirection_linux(pcap_t *, pcap_direction_t);
+static void usb_cleanup_linux_mmap(pcap_t *);
+
+/* facility to add an USB device to the device list*/
+static int 
+usb_dev_add(pcap_if_t** alldevsp, int n, char *err_str)
+{
+	char dev_name[10];
+	char dev_descr[30]; 
+	snprintf(dev_name, 10, USB_IFACE"%d", n);
+	snprintf(dev_descr, 30, "USB bus number %d", n);
+
+	if (pcap_add_if(alldevsp, dev_name, 0, 
+	    dev_descr, err_str) < 0)
+		return -1;
+	return 0; 
+}
+
+int 
+usb_platform_finddevs(pcap_if_t **alldevsp, char *err_str)
+{
+	struct dirent* data;
+	int ret = 0;
+	DIR* dir;
+	int n;
+	char* name;
+	size_t len;
+
+	/* try scanning sysfs usb bus directory */
+	dir = opendir(SYS_USB_BUS_DIR);
+	if (dir != NULL) {
+		while ((ret == 0) && ((data = readdir(dir)) != 0)) {
+			name = data->d_name;
+
+			if (strncmp(name, "usb", 3) != 0)
+				continue;
+
+			if (sscanf(&name[3], "%d", &n) == 0) 
+				continue;
+
+			ret = usb_dev_add(alldevsp, n, err_str);
+		}
+
+		closedir(dir);
+		return ret;
+	}
+
+	/* that didn't work; try scanning procfs usb bus directory */
+	dir = opendir(PROC_USB_BUS_DIR);
+	if (dir != NULL) {
+		while ((ret == 0) && ((data = readdir(dir)) != 0)) {
+			name = data->d_name;
+			len = strlen(name);
+
+			/* if this file name does not end with a number it's not of our interest */
+			if ((len < 1) || !isdigit(name[--len]))
+				continue;
+			while (isdigit(name[--len]));
+			if (sscanf(&name[len+1], "%d", &n) != 1) 
+				continue;
+
+			ret = usb_dev_add(alldevsp, n, err_str);
+		}
+
+		closedir(dir);
+		return ret;
+	}
+
+	/* neither of them worked */
+	return 0;
+}
+
+static 
+int usb_mmap(pcap_t* handle)
+{
+	int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE);
+	if (len < 0) 
+		return 0;
+
+	handle->md.mmapbuflen = len;
+	handle->md.mmapbuf = mmap(0, handle->md.mmapbuflen, PROT_READ,
+	    MAP_SHARED, handle->fd, 0);
+	return handle->md.mmapbuf != MAP_FAILED;
+}
+
+#define CTRL_TIMEOUT    (5*1000)        /* milliseconds */
+
+#define USB_DIR_IN		0x80
+#define USB_TYPE_STANDARD	0x00
+#define USB_RECIP_DEVICE	0x00
+
+#define USB_REQ_GET_DESCRIPTOR	6
+
+#define USB_DT_DEVICE		1
+
+/* probe the descriptors of the devices attached to the bus */
+/* the descriptors will end up in the captured packet stream */
+/* and be decoded by external apps like wireshark */
+/* without these identifying probes packet data can't be fully decoded */
+static void
+probe_devices(int bus)
+{
+	struct usbdevfs_ctrltransfer ctrl;
+	struct dirent* data;
+	int ret = 0;
+	char buf[40];
+	DIR* dir;
+
+	/* scan usb bus directories for device nodes */
+	snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d", bus);
+	dir = opendir(buf);
+	if (!dir)
+		return;
+
+	while ((ret >= 0) && ((data = readdir(dir)) != 0)) {
+		int fd;
+		char* name = data->d_name;
+
+		if (name[0] == '.')
+			continue;
+
+		snprintf(buf, sizeof(buf), "/dev/bus/usb/%03d/%s", bus, data->d_name);
+		
+		fd = open(buf, O_RDWR);
+		if (fd == -1)
+			continue;
+
+		/*
+		 * Sigh.  Different kernels have different member names
+		 * for this structure.
+		 */
+#ifdef HAVE_USBDEVFS_CTRLTRANSFER_BREQUESTTYPE
+		ctrl.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
+		ctrl.bRequest = USB_REQ_GET_DESCRIPTOR;
+		ctrl.wValue = USB_DT_DEVICE << 8;
+		ctrl.wIndex = 0;
+ 		ctrl.wLength = sizeof(buf);
+#else
+		ctrl.requesttype = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
+		ctrl.request = USB_REQ_GET_DESCRIPTOR;
+		ctrl.value = USB_DT_DEVICE << 8;
+		ctrl.index = 0;
+ 		ctrl.length = sizeof(buf);
+#endif
+		ctrl.data = buf;
+		ctrl.timeout = CTRL_TIMEOUT;
+
+		ret = ioctl(fd, USBDEVFS_CONTROL, &ctrl);
+
+		close(fd);
+	}
+	closedir(dir);
+}
+
+pcap_t *
+usb_create(const char *device, char *ebuf)
+{
+	pcap_t *p;
+
+	p = pcap_create_common(device, ebuf);
+	if (p == NULL)
+		return (NULL);
+
+	p->activate_op = usb_activate;
+	return (p);
+}
+
+static int
+usb_activate(pcap_t* handle)
+{
+	char 		full_path[USB_LINE_LEN];
+
+	/* Initialize some components of the pcap structure. */
+	handle->bufsize = handle->snapshot;
+	handle->offset = 0;
+	handle->linktype = DLT_USB_LINUX;
+
+	handle->inject_op = usb_inject_linux;
+	handle->setfilter_op = install_bpf_program; /* no kernel filtering */
+	handle->setdirection_op = usb_setdirection_linux;
+	handle->set_datalink_op = NULL;	/* can't change data link type */
+	handle->getnonblock_op = pcap_getnonblock_fd;
+	handle->setnonblock_op = pcap_setnonblock_fd;
+
+	/*get usb bus index from device name */
+	if (sscanf(handle->opt.source, USB_IFACE"%d", &handle->md.ifindex) != 1)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			"Can't get USB bus index from %s", handle->opt.source);
+		return PCAP_ERROR;
+	}
+
+	/*now select the read method: try to open binary interface */
+	snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handle->md.ifindex);  
+	handle->fd = open(full_path, O_RDONLY, 0);
+	if (handle->fd >= 0)
+	{
+		if (handle->opt.rfmon) {
+			/*
+			 * Monitor mode doesn't apply to USB devices.
+			 */
+			close(handle->fd);
+			return PCAP_ERROR_RFMON_NOTSUP;
+		}
+
+		/* binary api is available, try to use fast mmap access */
+		if (usb_mmap(handle)) {
+			handle->linktype = DLT_USB_LINUX_MMAPPED;
+			handle->stats_op = usb_stats_linux_bin;
+			handle->read_op = usb_read_linux_mmap;
+			handle->cleanup_op = usb_cleanup_linux_mmap;
+			probe_devices(handle->md.ifindex);
+
+			/*
+			 * "handle->fd" is a real file, so "select()" and
+			 * "poll()" work on it.
+			 */
+			handle->selectable_fd = handle->fd;
+			return 0;
+		}
+
+		/* can't mmap, use plain binary interface access */
+		handle->stats_op = usb_stats_linux_bin;
+		handle->read_op = usb_read_linux_bin;
+		probe_devices(handle->md.ifindex);
+	}
+	else {
+		/*Binary interface not available, try open text interface */
+		snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handle->md.ifindex);  
+		handle->fd = open(full_path, O_RDONLY, 0);
+		if (handle->fd < 0)
+		{
+			if (errno == ENOENT)
+			{
+				/*
+				 * Not found at the new location; try
+				 * the old location.
+				 */
+				snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%dt", handle->md.ifindex);  
+				handle->fd = open(full_path, O_RDONLY, 0);
+			}
+			if (handle->fd < 0) {
+				/* no more fallback, give it up*/
+				snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+					"Can't open USB bus file %s: %s", full_path, strerror(errno));
+				return PCAP_ERROR;
+			}
+		}
+
+		if (handle->opt.rfmon) {
+			/*
+			 * Monitor mode doesn't apply to USB devices.
+			 */
+			close(handle->fd);
+			return PCAP_ERROR_RFMON_NOTSUP;
+		}
+
+		handle->stats_op = usb_stats_linux;
+		handle->read_op = usb_read_linux;
+	}
+
+	/*
+	 * "handle->fd" is a real file, so "select()" and "poll()"
+	 * work on it.
+	 */
+	handle->selectable_fd = handle->fd;
+
+	/* for plain binary access and text access we need to allocate the read
+	 * buffer */
+	handle->buffer = malloc(handle->bufsize);
+	if (!handle->buffer) {
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			 "malloc: %s", pcap_strerror(errno));
+		close(handle->fd);
+		return PCAP_ERROR;
+	}
+	return 0;
+}
+
+static inline int 
+ascii_to_int(char c)
+{
+	return c < 'A' ? c- '0': ((c<'a') ? c - 'A' + 10: c-'a'+10);
+}
+
+/*
+ * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 
+ * <linux-kernel-source>/drivers/usb/mon/mon_text.c for urb string 
+ * format description
+ */
+static int
+usb_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
+{
+	/* see:
+	* /usr/src/linux/Documentation/usb/usbmon.txt 
+	* for message format
+	*/
+	unsigned timestamp;
+	int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len;
+	char etype, pipeid1, pipeid2, status[16], urb_tag, line[USB_LINE_LEN];
+	char *string = line;
+	u_char * rawdata = handle->buffer;
+	struct pcap_pkthdr pkth;
+	pcap_usb_header* uhdr = (pcap_usb_header*)handle->buffer;
+	u_char urb_transfer=0;
+	int incoming=0;
+
+	/* ignore interrupt system call errors */
+	do {
+		ret = read(handle->fd, line, USB_LINE_LEN - 1);
+		if (handle->break_loop)
+		{
+			handle->break_loop = 0;
+			return -2;
+		}
+	} while ((ret == -1) && (errno == EINTR));
+	if (ret < 0)
+	{
+		if (errno == EAGAIN)
+			return 0;	/* no data there */
+
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+		    "Can't read from fd %d: %s", handle->fd, strerror(errno));
+		return -1;
+	}
+
+	/* read urb header; %n argument may increment return value, but it's 
+	* not mandatory, so does not count on it*/
+	string[ret] = 0;
+	ret = sscanf(string, "%x %d %c %c%c:%d:%d %s%n", &tag, &timestamp, &etype, 
+		&pipeid1, &pipeid2, &dev_addr, &ep_num, status, 
+		&cnt);
+	if (ret < 8)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+		    "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)",
+		    string, ret);
+		return -1;
+	}
+	uhdr->id = tag;
+	uhdr->device_address = dev_addr;
+	uhdr->bus_id = handle->md.ifindex;
+	uhdr->status = 0;
+	string += cnt;
+
+	/* don't use usbmon provided timestamp, since it have low precision*/
+	if (gettimeofday(&pkth.ts, NULL) < 0) 
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			"Can't get timestamp for message '%s' %d:%s", 
+			string, errno, strerror(errno));
+		return -1;
+	}
+	uhdr->ts_sec = pkth.ts.tv_sec;
+	uhdr->ts_usec = pkth.ts.tv_usec;
+
+	/* parse endpoint information */
+	if (pipeid1 == 'C')
+		urb_transfer = URB_CONTROL;
+	else if (pipeid1 == 'Z')
+		urb_transfer = URB_ISOCHRONOUS;
+	else if (pipeid1 == 'I')
+		urb_transfer = URB_INTERRUPT;
+	else if (pipeid1 == 'B')
+		urb_transfer = URB_BULK;
+	if (pipeid2 == 'i') {
+		ep_num |= URB_TRANSFER_IN;
+		incoming = 1;
+	}
+	if (etype == 'C')
+		incoming = !incoming;
+
+	/* direction check*/
+	if (incoming)
+	{
+		if (handle->direction == PCAP_D_OUT)
+			return 0;
+	}
+	else
+		if (handle->direction == PCAP_D_IN)
+			return 0;
+	uhdr->event_type = etype;
+	uhdr->transfer_type = urb_transfer;
+	uhdr->endpoint_number = ep_num;
+	pkth.caplen = sizeof(pcap_usb_header);
+	rawdata += sizeof(pcap_usb_header);
+
+	/* check if this is a setup packet */
+	ret = sscanf(status, "%d", &dummy);
+	if (ret != 1)
+	{
+		/* this a setup packet, setup data can be filled with underscore if
+		* usbmon has not been able to read them, so we must parse this fields as 
+		* strings */
+		pcap_usb_setup* shdr;
+		char str1[3], str2[3], str3[5], str4[5], str5[5];
+		ret = sscanf(string, "%s %s %s %s %s%n", str1, str2, str3, str4, 
+		str5, &cnt);
+		if (ret < 5)
+		{
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+				"Can't parse USB bus message '%s', too few tokens (expected 5 got %d)",
+				string, ret);
+			return -1;
+		}
+		string += cnt;
+
+		/* try to convert to corresponding integer */
+		shdr = &uhdr->setup;
+		shdr->bmRequestType = strtoul(str1, 0, 16);
+		shdr->bRequest = strtoul(str2, 0, 16);
+		shdr->wValue = htols(strtoul(str3, 0, 16));
+		shdr->wIndex = htols(strtoul(str4, 0, 16));
+		shdr->wLength = htols(strtoul(str5, 0, 16));
+
+		uhdr->setup_flag = 0;
+	}
+	else 
+		uhdr->setup_flag = 1;
+
+	/* read urb data */
+	ret = sscanf(string, " %d%n", &urb_len, &cnt);
+	if (ret < 1)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+		  "Can't parse urb length from '%s'", string);
+		return -1;
+	}
+	string += cnt;
+
+	/* urb tag is not present if urb length is 0, so we can stop here 
+	 * text parsing */
+	pkth.len = urb_len+pkth.caplen;
+	uhdr->urb_len = urb_len;
+	uhdr->data_flag = 1;
+	data_len = 0;
+	if (uhdr->urb_len == 0)
+		goto got;
+
+	/* check for data presence; data is present if and only if urb tag is '=' */
+	if (sscanf(string, " %c", &urb_tag) != 1)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			"Can't parse urb tag from '%s'", string);
+		return -1;
+	}
+
+	if (urb_tag != '=') 
+		goto got;
+
+	/* skip urb tag and following space */
+	string += 3;
+
+	/* if we reach this point we got some urb data*/
+	uhdr->data_flag = 0;
+
+	/* read all urb data; if urb length is greater then the usbmon internal 
+	 * buffer length used by the kernel to spool the URB, we get only
+	 * a partial information.
+	 * At least until linux 2.6.17 there is no way to set usbmon intenal buffer
+	 * length and default value is 130. */
+	while ((string[0] != 0) && (string[1] != 0) && (pkth.caplen < handle->snapshot))
+	{
+		rawdata[0] = ascii_to_int(string[0]) * 16 + ascii_to_int(string[1]);
+		rawdata++;
+		string+=2;
+		if (string[0] == ' ')
+			string++;
+		pkth.caplen++;
+		data_len++;
+	}
+
+got:
+	uhdr->data_len = data_len;
+	if (pkth.caplen > handle->snapshot)
+		pkth.caplen = handle->snapshot;
+
+	if (handle->fcode.bf_insns == NULL ||
+	    bpf_filter(handle->fcode.bf_insns, handle->buffer,
+	      pkth.len, pkth.caplen)) {
+		handle->md.packets_read++;
+		callback(user, &pkth, handle->buffer);
+		return 1;
+	}
+	return 0;	/* didn't pass filter */
+}
+
+static int
+usb_inject_linux(pcap_t *handle, const void *buf, size_t size)
+{
+	snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
+		"USB devices");
+	return (-1);
+}
+
+static int 
+usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
+{
+	int dummy, ret, consumed, cnt;
+	char string[USB_LINE_LEN];
+	char token[USB_LINE_LEN];
+	char * ptr = string;
+	int fd;
+
+	snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handle->md.ifindex);
+	fd = open(string, O_RDONLY, 0);
+	if (fd < 0)
+	{
+		if (errno == ENOENT)
+		{
+			/*
+			 * Not found at the new location; try the old
+			 * location.
+			 */
+			snprintf(string, USB_LINE_LEN, USB_TEXT_DIR_OLD"/%ds", handle->md.ifindex);
+			fd = open(string, O_RDONLY, 0);
+		}
+		if (fd < 0) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+				"Can't open USB stats file %s: %s", 
+				string, strerror(errno));
+			return -1;
+		}
+	}
+
+	/* read stats line */
+	do {
+		ret = read(fd, string, USB_LINE_LEN-1);
+	} while ((ret == -1) && (errno == EINTR));
+	close(fd);
+
+	if (ret < 0)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			"Can't read stats from fd %d ", fd);
+		return -1;
+	}
+	string[ret] = 0;
+
+	/* extract info on dropped urbs */
+	for (consumed=0; consumed < ret; ) {
+		/* from the sscanf man page: 
+ 		 * The C standard says: "Execution of a %n directive does 
+ 		 * not increment the assignment count returned at the completion
+		 * of  execution" but the Corrigendum seems to contradict this.
+		 * Do not make any assumptions on the effect of %n conversions 
+		 * on the return value and explicitly check for cnt assignmet*/
+		int ntok;
+
+		cnt = -1;
+		ntok = sscanf(ptr, "%s%n", token, &cnt);
+		if ((ntok < 1) || (cnt < 0))
+			break;
+		consumed += cnt;
+		ptr += cnt;
+		if (strcmp(token, "nreaders") == 0)
+			ret = sscanf(ptr, "%d", &stats->ps_drop);
+		else 
+			ret = sscanf(ptr, "%d", &dummy);
+		if (ntok != 1)
+			break;
+		consumed += cnt;
+		ptr += cnt;
+	}
+
+	stats->ps_recv = handle->md.packets_read;
+	stats->ps_ifdrop = 0;
+	return 0;
+}
+
+static int 
+usb_setdirection_linux(pcap_t *p, pcap_direction_t d)
+{
+	p->direction = d;
+	return 0;
+}
+
+
+static int 
+usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats)
+{
+	int ret;
+	struct mon_bin_stats st;
+	ret = ioctl(handle->fd, MON_IOCG_STATS, &st);
+	if (ret < 0)
+	{
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			"Can't read stats from fd %d:%s ", handle->fd, strerror(errno));
+		return -1;
+	}
+
+	stats->ps_recv = handle->md.packets_read + st.queued;
+	stats->ps_drop = st.dropped;
+	stats->ps_ifdrop = 0;
+	return 0;
+}
+
+/*
+ * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 
+ * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI
+ */
+static int
+usb_read_linux_bin(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
+{
+	struct mon_bin_get info;
+	int ret;
+	struct pcap_pkthdr pkth;
+	int clen = handle->snapshot - sizeof(pcap_usb_header);
+
+	/* the usb header is going to be part of 'packet' data*/
+	info.hdr = (pcap_usb_header*) handle->buffer;
+	info.data = handle->buffer + sizeof(pcap_usb_header);
+	info.data_len = clen;
+
+	/* ignore interrupt system call errors */
+	do {
+		ret = ioctl(handle->fd, MON_IOCX_GET, &info);
+		if (handle->break_loop)
+		{
+			handle->break_loop = 0;
+			return -2;
+		}
+	} while ((ret == -1) && (errno == EINTR));
+	if (ret < 0)
+	{
+		if (errno == EAGAIN)
+			return 0;	/* no data there */
+
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+		    "Can't read from fd %d: %s", handle->fd, strerror(errno));
+		return -1;
+	}
+
+	/* we can get less that than really captured from kernel, depending on
+	 * snaplen, so adjust header accordingly */
+	if (info.hdr->data_len < clen)
+		clen = info.hdr->data_len;
+	info.hdr->data_len = clen;
+	pkth.caplen = clen + sizeof(pcap_usb_header);
+	pkth.len = info.hdr->data_len + sizeof(pcap_usb_header);
+	pkth.ts.tv_sec = info.hdr->ts_sec;
+	pkth.ts.tv_usec = info.hdr->ts_usec;
+
+	if (handle->fcode.bf_insns == NULL ||
+	    bpf_filter(handle->fcode.bf_insns, handle->buffer,
+	      pkth.len, pkth.caplen)) {
+		handle->md.packets_read++;
+		callback(user, &pkth, handle->buffer);
+		return 1;
+	}
+
+	return 0;	/* didn't pass filter */
+}
+
+/*
+ * see <linux-kernel-source>/Documentation/usb/usbmon.txt and 
+ * <linux-kernel-source>/drivers/usb/mon/mon_bin.c binary ABI
+ */
+#define VEC_SIZE 32
+static int
+usb_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
+{
+	struct mon_bin_mfetch fetch;
+	int32_t vec[VEC_SIZE];
+	struct pcap_pkthdr pkth;
+	pcap_usb_header* hdr;
+	int nflush = 0;
+	int packets = 0;
+	int clen, max_clen;
+
+	max_clen = handle->snapshot - sizeof(pcap_usb_header);
+
+	for (;;) {
+		int i, ret;
+		int limit = max_packets - packets;
+		if (limit <= 0)
+			limit = VEC_SIZE;
+		if (limit > VEC_SIZE)
+			limit = VEC_SIZE;
+
+		/* try to fetch as many events as possible*/
+		fetch.offvec = vec;
+		fetch.nfetch = limit;
+		fetch.nflush = nflush;
+		/* ignore interrupt system call errors */
+		do {
+			ret = ioctl(handle->fd, MON_IOCX_MFETCH, &fetch);
+			if (handle->break_loop)
+			{
+				handle->break_loop = 0;
+				return -2;
+			}
+		} while ((ret == -1) && (errno == EINTR));
+		if (ret < 0)
+		{
+			if (errno == EAGAIN)
+				return 0;	/* no data there */
+
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+			    "Can't mfetch fd %d: %s", handle->fd, strerror(errno));
+			return -1;
+		}
+
+		/* keep track of processed events, we will flush them later */
+		nflush = fetch.nfetch;
+		for (i=0; i<fetch.nfetch; ++i) {
+			/* discard filler */
+			hdr = (pcap_usb_header*) &handle->md.mmapbuf[vec[i]];
+			if (hdr->event_type == '@') 
+				continue;
+
+			/* we can get less that than really captured from kernel, depending on
+	 		* snaplen, so adjust header accordingly */
+			clen = max_clen;
+			if (hdr->data_len < clen)
+				clen = hdr->data_len;
+
+			/* get packet info from header*/
+			pkth.caplen = clen + sizeof(pcap_usb_header_mmapped);
+			pkth.len = hdr->data_len + sizeof(pcap_usb_header_mmapped);
+			pkth.ts.tv_sec = hdr->ts_sec;
+			pkth.ts.tv_usec = hdr->ts_usec;
+
+			if (handle->fcode.bf_insns == NULL ||
+			    bpf_filter(handle->fcode.bf_insns, (u_char*) hdr,
+			      pkth.len, pkth.caplen)) {
+				handle->md.packets_read++;
+				callback(user, &pkth, (u_char*) hdr);
+				packets++;
+			}
+		}
+
+		/* with max_packets <= 0 we stop afer the first chunk*/
+		if ((max_packets <= 0) || (packets == max_packets))
+			break;
+	}
+
+	/* flush pending events*/
+	ioctl(handle->fd, MON_IOCH_MFLUSH, nflush);
+	return packets;
+}
+
+static void
+usb_cleanup_linux_mmap(pcap_t* handle)
+{
+	/* if we have a memory-mapped buffer, unmap it */
+	if (handle->md.mmapbuf != NULL) {
+		munmap(handle->md.mmapbuf, handle->md.mmapbuflen);
+		handle->md.mmapbuf = NULL;
+	}
+	pcap_cleanup_live_common(handle);
+}