Drop support for text-mode Linux USB captures.

We require a 2.6.27 or later kernel, so, on the platforms that we
support, binary-mode captures are supported.

This gets rid of some sscanf() calls that could overflow string buffers
if the kernel has malicious code in the support for text-mode USB
captures.

1 files changed, 102 insertions, 613 deletions

diff --git a/pcap-usb-linux.c b/pcap-usb-linux.c
index 3596428e..486fabf2 100644
--- a/pcap-usb-linux.c
+++ b/pcap-usb-linux.c
@@ -71,10 +71,6 @@
 #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
@@ -132,99 +128,13 @@ struct pcap_usb_linux {
 
 /* 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 *, int);
 static int usb_setdirection_linux(pcap_t *, pcap_direction_t);
 static void usb_cleanup_linux_mmap(pcap_t *);
 
-static int
-have_binary_usbmon(void)
-{
-	struct utsname utsname;
-	char *version_component, *endp;
-	long major, minor, subminor;
-
-	if (uname(&utsname) == 0) {
-		/*
-		 * 2.6.21 is the first release with the binary-mode
-		 * USB monitoring.
-		 */
-		version_component = utsname.release;
-		major = strtol(version_component, &endp, 10);
-		if (endp != version_component && *endp == '.') {
-			/*
-			 * OK, that was a valid major version.
-			 * Is it 3 or greater?  If so, we have binary
-			 * mode support.
-			 */
-			if (major >= 3)
-				return 1;
-
-			/*
-			 * Is it 1 or less?  If so, we don't have binary
-			 * mode support.  (In fact, we don't have any
-			 * USB monitoring....)
-			 */
-			if (major <= 1)
-				return 0;
-		}
-
-		/*
-		 * OK, this is a 2.x kernel.
-		 * What's the minor version?
-		 */
-		version_component = endp + 1;
-		minor = strtol(version_component, &endp, 10);
-		if (endp != version_component &&
-		    (*endp == '.' || *endp == '\0')) {
-			/*
-			 * OK, that was a valid minor version.
-			 * Is is 2.6 or later?  (There shouldn't be a
-			 * "later", as 2.6.x went to 3.x, but we'll
-			 * check anyway.)
-			 */
-			if (minor < 6) {
-				/*
-				 * No, so no binary support (did 2.4 have
-				 * any USB monitoring at all?)
-				 */
-				return 0;
-			}
-
-			/*
-			 * OK, this is a 2.6.x kernel.
-			 * What's the subminor version?
-			 */
-			version_component = endp + 1;
-			subminor = strtol(version_component, &endp, 10);
-			if (endp != version_component &&
-			    (*endp == '.' || *endp == '\0')) {
-				/*
-				 * OK, that was a valid subminor version.
-				 * Is it 21 or greater?
-				 */
-				if (subminor >= 21) {
-					/*
-					 * Yes - we have binary mode
-					 * support.
-					 */
-					return 1;
-				}
-			}
-		}
-	}
-
-	/*
-	 * Either uname() failed, in which case we just say "no binary
-	 * mode support", or we don't have binary mode support.
-	 */
-	return 0;
-}
-
 /* facility to add an USB device to the device list*/
 static int
 usb_dev_add(pcap_if_list_t *devlistp, int n, char *err_str)
@@ -271,115 +181,51 @@ usb_findalldevs(pcap_if_list_t *devlistp, char *err_str)
 	DIR* dir;
 	int n;
 	char* name;
-	size_t len;
-
-	if (have_binary_usbmon()) {
-		/*
-		 * We have binary-mode support.
-		 * What do the device names look like?
-		 * Split LINUX_USB_MON_DEV into a directory that we'll
-		 * scan and a file name prefix that we'll check for.
-		 */
-		pcap_strlcpy(usb_mon_dir, LINUX_USB_MON_DEV, sizeof usb_mon_dir);
-		usb_mon_prefix = strrchr(usb_mon_dir, '/');
-		if (usb_mon_prefix == NULL) {
-			/*
-			 * This "shouldn't happen".  Just give up if it
-			 * does.
-			 */
-			return 0;
-		}
-		*usb_mon_prefix++ = '\0';
-		usb_mon_prefix_len = strlen(usb_mon_prefix);
 
+	/*
+	 * We require 2.6.27 or later kernels, so we have binary-mode support.
+	 * What do the device names look like?
+	 * Split LINUX_USB_MON_DEV into a directory that we'll
+	 * scan and a file name prefix that we'll check for.
+	 */
+	pcap_strlcpy(usb_mon_dir, LINUX_USB_MON_DEV, sizeof usb_mon_dir);
+	usb_mon_prefix = strrchr(usb_mon_dir, '/');
+	if (usb_mon_prefix == NULL) {
 		/*
-		 * Open the directory and scan it.
+		 * This "shouldn't happen".  Just give up if it
+		 * does.
 		 */
-		dir = opendir(usb_mon_dir);
-		if (dir != NULL) {
-			while ((ret == 0) && ((data = readdir(dir)) != 0)) {
-				name = data->d_name;
-
-				/*
-				 * Is this a usbmon device?
-				 */
-				if (strncmp(name, usb_mon_prefix, usb_mon_prefix_len) != 0)
-					continue;	/* no */
-
-				/*
-				 * What's the device number?
-				 */
-				if (sscanf(&name[usb_mon_prefix_len], "%d", &n) == 0)
-					continue;	/* failed */
-
-				ret = usb_dev_add(devlistp, n, err_str);
-			}
-
-			closedir(dir);
-		}
 		return 0;
-	} else {
-		/*
-		 * We have only text mode support.
-		 * We don't look for the text devices because we can't
-		 * look for them without root privileges, and we don't
-		 * want to require root privileges to enumerate devices
-		 * (we want to let the user to try a device and get
-		 * an error, rather than seeing no devices and asking
-		 * "why am I not seeing devices" and forcing a long
-		 * process of poking to figure out whether it's "no
-		 * privileges" or "your kernel is too old" or "the
-		 * usbmon module isn't loaded" or...).
-		 *
-		 * Instead, we look to see what buses we have.
-		 * If the kernel is so old that it doesn't have
-		 * binary-mode support, it's also so old that
-		 * it doesn't have a "scan all buses" device.
-		 *
-		 * First, 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;
+	}
+	*usb_mon_prefix++ = '\0';
+	usb_mon_prefix_len = strlen(usb_mon_prefix);
 
-				ret = usb_dev_add(devlistp, n, err_str);
-			}
+	/*
+	 * Open the directory and scan it.
+	 */
+	dir = opendir(usb_mon_dir);
+	if (dir != NULL) {
+		while ((ret == 0) && ((data = readdir(dir)) != 0)) {
+			name = data->d_name;
 
-			closedir(dir);
-			return 0;
-		}
+			/*
+			 * Is this a usbmon device?
+			 */
+			if (strncmp(name, usb_mon_prefix, usb_mon_prefix_len) != 0)
+				continue;	/* no */
 
-		/* 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) || !PCAP_ISDIGIT(name[--len]))
-					continue;
-				while (PCAP_ISDIGIT(name[--len]));
-				if (sscanf(&name[len+1], "%d", &n) != 1)
-					continue;
-
-				ret = usb_dev_add(devlistp, n, err_str);
-			}
+			/*
+			 * What's the device number?
+			 */
+			if (sscanf(&name[usb_mon_prefix_len], "%d", &n) == 0)
+				continue;	/* failed */
 
-			closedir(dir);
-			return ret;
+			ret = usb_dev_add(devlistp, n, err_str);
 		}
 
-		/* neither of them worked */
-		return 0;
+		closedir(dir);
 	}
+	return 0;
 }
 
 /*
@@ -630,7 +476,6 @@ usb_activate(pcap_t* handle)
 {
 	struct pcap_usb_linux *handlep = handle->priv;
 	char 		full_path[USB_LINE_LEN];
-	int		ret;
 
 	/*
 	 * Turn a negative snapshot value (invalid), a snapshot value of
@@ -663,166 +508,97 @@ usb_activate(pcap_t* handle)
 		return PCAP_ERROR;
 	}
 
-	if (have_binary_usbmon())
+	/*
+	 * We require 2.6.27 or later kernels, so we have binary-mode support.
+	 * Try to open the binary interface.
+	 */
+	snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handlep->bus_index);
+	handle->fd = open(full_path, O_RDONLY, 0);
+	if (handle->fd < 0)
 	{
 		/*
-		 * We have binary-mode support.
-		 * Try to open the binary interface.
+		 * The attempt failed; why?
 		 */
-		snprintf(full_path, USB_LINE_LEN, LINUX_USB_MON_DEV"%d", handlep->bus_index);
-		handle->fd = open(full_path, O_RDONLY, 0);
-		if (handle->fd < 0)
-		{
+		switch (errno) {
+
+		case ENOENT:
 			/*
-			 * The attempt failed; why?
+			 * The device doesn't exist.
+			 * That could either mean that there's
+			 * no support for monitoring USB buses
+			 * (which probably means "the usbmon
+			 * module isn't loaded") or that there
+			 * is but that *particular* device
+			 * doesn't exist (no "scan all buses"
+			 * device if the bus index is 0, no
+			 * such bus if the bus index isn't 0).
 			 */
-			switch (errno) {
+			return PCAP_ERROR_NO_SUCH_DEVICE;
 
-			case ENOENT:
-				/*
-				 * The device doesn't exist.
-				 * That could either mean that there's
-				 * no support for monitoring USB buses
-				 * (which probably means "the usbmon
-				 * module isn't loaded") or that there
-				 * is but that *particular* device
-				 * doesn't exist (no "scan all buses"
-				 * device if the bus index is 0, no
-				 * such bus if the bus index isn't 0).
-				 */
-				return PCAP_ERROR_NO_SUCH_DEVICE;
-
-			case EACCES:
-				/*
-				 * We didn't have permission to open it.
-				 */
-				return PCAP_ERROR_PERM_DENIED;
-
-			default:
-				/*
-				 * Something went wrong.
-				 */
-				pcap_fmt_errmsg_for_errno(handle->errbuf,
-				    PCAP_ERRBUF_SIZE, errno,
-				    "Can't open USB bus file %s", full_path);
-				return PCAP_ERROR;
-			}
-		}
-
-		if (handle->opt.rfmon)
-		{
+		case EACCES:
 			/*
-			 * Monitor mode doesn't apply to USB devices.
+			 * We didn't have permission to open it.
 			 */
-			close(handle->fd);
-			return PCAP_ERROR_RFMON_NOTSUP;
-		}
-
-		/* try to use fast mmap access */
-		if (usb_mmap(handle))
-		{
-			/* We succeeded. */
-			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;
-#ifdef HAVE_LINUX_USBDEVICE_FS_H
-			probe_devices(handlep->bus_index);
-#endif
+			return PCAP_ERROR_PERM_DENIED;
 
+		default:
 			/*
-			 * "handle->fd" is a real file, so
-			 * "select()" and "poll()" work on it.
+			 * Something went wrong.
 			 */
-			handle->selectable_fd = handle->fd;
-			return 0;
+			pcap_fmt_errmsg_for_errno(handle->errbuf,
+			    PCAP_ERRBUF_SIZE, errno,
+			    "Can't open USB bus file %s", full_path);
+			return PCAP_ERROR;
 		}
+	}
 
+	if (handle->opt.rfmon)
+	{
 		/*
-		 * We failed; try plain binary interface access.
-		 *
-		 * Attempt to set the ring size as appropriate for
-		 * the snapshot length, reducing the snapshot length
-		 * if that'd make the ring bigger than the kernel
-		 * supports.
+		 * Monitor mode doesn't apply to USB devices.
 		 */
-		if (usb_set_ring_size(handle, (int)sizeof(pcap_usb_header)) == -1) {
-			/* Failed. */
-			close(handle->fd);
-			return PCAP_ERROR;
-		}
+		close(handle->fd);
+		return PCAP_ERROR_RFMON_NOTSUP;
+	}
+
+	/* try to use fast mmap access */
+	if (usb_mmap(handle))
+	{
+		/* We succeeded. */
+		handle->linktype = DLT_USB_LINUX_MMAPPED;
 		handle->stats_op = usb_stats_linux_bin;
-		handle->read_op = usb_read_linux_bin;
+		handle->read_op = usb_read_linux_mmap;
+		handle->cleanup_op = usb_cleanup_linux_mmap;
 #ifdef HAVE_LINUX_USBDEVICE_FS_H
 		probe_devices(handlep->bus_index);
 #endif
-	}
-	else {
+
 		/*
-		 * We don't have binary mode support.
-		 * Try opening the text-mode device.
+		 * "handle->fd" is a real file, so
+		 * "select()" and "poll()" work on it.
 		 */
-		snprintf(full_path, USB_LINE_LEN, USB_TEXT_DIR"/%dt", handlep->bus_index);
-		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", handlep->bus_index);
-				handle->fd = open(full_path, O_RDONLY, 0);
-			}
-			if (handle->fd < 0) {
-				if (errno == ENOENT)
-				{
-					/*
-					 * The problem is that the file
-					 * doesn't exist.  Report that as
-					 * "no such device".  (That could
-					 * mean "no such USB bus" or
-					 * "monitoring not supported".)
-					 */
-					ret = PCAP_ERROR_NO_SUCH_DEVICE;
-				}
-				else if (errno == EACCES)
-				{
-					/*
-					 * The problem is that we don't
-					 * have sufficient permission to
-					 * open the file.  Report that.
-					 */
-					ret = PCAP_ERROR_PERM_DENIED;
-				}
-				else
-				{
-					/*
-					 * Some other error.
-					 */
-					ret = PCAP_ERROR;
-				}
-				pcap_fmt_errmsg_for_errno(handle->errbuf,
-				    PCAP_ERRBUF_SIZE, errno,
-				    "Can't open USB bus file %s",
-				    full_path);
-				return ret;
-			}
-		}
-
-		if (handle->opt.rfmon)
-		{
-			/*
-			 * Monitor mode doesn't apply to USB devices.
-			 */
-			close(handle->fd);
-			return PCAP_ERROR_RFMON_NOTSUP;
-		}
+		handle->selectable_fd = handle->fd;
+		return 0;
+	}
 
-		handle->stats_op = usb_stats_linux;
-		handle->read_op = usb_read_linux;
+	/*
+	 * We failed; try plain binary interface access.
+	 *
+	 * Attempt to set the ring size as appropriate for
+	 * the snapshot length, reducing the snapshot length
+	 * if that'd make the ring bigger than the kernel
+	 * supports.
+	 */
+	if (usb_set_ring_size(handle, (int)sizeof(pcap_usb_header)) == -1) {
+		/* Failed. */
+		close(handle->fd);
+		return PCAP_ERROR;
 	}
+	handle->stats_op = usb_stats_linux_bin;
+	handle->read_op = usb_read_linux_bin;
+#ifdef HAVE_LINUX_USBDEVICE_FS_H
+	probe_devices(handlep->bus_index);
+#endif
 
 	/*
 	 * "handle->fd" is a real file, so "select()" and "poll()"
@@ -848,213 +624,6 @@ 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 _U_, pcap_handler callback, u_char *user)
-{
-	/* see:
-	* /usr/src/linux/Documentation/usb/usbmon.txt
-	* for message format
-	*/
-	struct pcap_usb_linux *handlep = handle->priv;
-	unsigned timestamp;
-	int tag, cnt, ep_num, dev_addr, dummy, ret, urb_len, data_len;
-	ssize_t read_ret;
-	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 {
-		read_ret = read(handle->fd, line, USB_LINE_LEN - 1);
-		if (handle->break_loop)
-		{
-			handle->break_loop = 0;
-			return -2;
-		}
-	} while ((read_ret == -1) && (errno == EINTR));
-	if (read_ret < 0)
-	{
-		if (errno == EAGAIN)
-			return 0;	/* no data there */
-
-		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
-		    errno, "Can't read from fd %d", handle->fd);
-		return -1;
-	}
-
-	/* read urb header; %n argument may increment return value, but it's
-	* not mandatory, so does not count on it*/
-	string[read_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)
-	{
-		char string_truncated[181];
-
-		strncpy(string_truncated, string, sizeof(string_truncated));
-		string_truncated[sizeof(string_truncated) - 1] = 0;
-		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
-			 "Can't parse USB bus message '%s', too few tokens (expected 8 got %d)",
-			 string_truncated, ret);
-		return -1;
-	}
-	uhdr->id = tag;
-	uhdr->device_address = dev_addr;
-	uhdr->bus_id = handlep->bus_index;
-	uhdr->status = 0;
-	string += cnt;
-
-	/* don't use usbmon provided timestamp, since it have low precision*/
-	if (gettimeofday(&pkth.ts, NULL) < 0)
-	{
-		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
-		    errno, "Can't get timestamp for message '%s'", string);
-		return -1;
-	}
-	uhdr->ts_sec = pkth.ts.tv_sec;
-	uhdr->ts_usec = (int32_t)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 < (bpf_u_int32)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 > (bpf_u_int32)handle->snapshot)
-		pkth.caplen = (bpf_u_int32)handle->snapshot;
-
-	if (handle->fcode.bf_insns == NULL ||
-	    pcap_filter(handle->fcode.bf_insns, handle->buffer,
-	      pkth.len, pkth.caplen)) {
-		handlep->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 _U_, int size _U_)
 {
@@ -1064,85 +633,6 @@ usb_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_)
 }
 
 static int
-usb_stats_linux(pcap_t *handle, struct pcap_stat *stats)
-{
-	struct pcap_usb_linux *handlep = handle->priv;
-	int dummy, cnt;
-	ssize_t ret, consumed;
-	char string[USB_LINE_LEN];
-	char token[USB_LINE_LEN];
-	char * ptr = string;
-	int fd;
-
-	snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handlep->bus_index);
-	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", handlep->bus_index);
-			fd = open(string, O_RDONLY, 0);
-		}
-		if (fd < 0) {
-			pcap_fmt_errmsg_for_errno(handle->errbuf,
-			    PCAP_ERRBUF_SIZE, errno,
-			    "Can't open USB stats file %s", string);
-			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;
-
-	stats->ps_recv = handlep->packets_read;
-	stats->ps_drop = 0;	/* unless we find text_lost */
-	stats->ps_ifdrop = 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, "text_lost") == 0)
-			ntok = sscanf(ptr, "%d%n", &stats->ps_drop, &cnt);
-		else
-			ntok = sscanf(ptr, "%d%n", &dummy, &cnt);
-		if ((ntok != 1) || (cnt < 0))
-			break;
-		consumed += cnt;
-		ptr += cnt;
-	}
-
-	return 0;
-}
-
-static int
 usb_setdirection_linux(pcap_t *p, pcap_direction_t d)
 {
 	/*
@@ -1153,7 +643,6 @@ usb_setdirection_linux(pcap_t *p, pcap_direction_t d)
 	return 0;
 }
 
-
 static int
 usb_stats_linux_bin(pcap_t *handle, struct pcap_stat *stats)
 {