Logo Search packages:      
Sourcecode: nmap version File versions  Download package

pcap-usb-linux.c

/*
 * 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 1.16.2.8 2008-04-14 21:06:29 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>

#define USB_IFACE "usb"
#define USB_TEXT_DIR "/sys/kernel/debug/usbmon"
#define USB_BUS_DIR "/proc/bus/usb"
#define USB_LINE_LEN 4096


#define PIPE_IN               0x80
#define PIPE_ISOCHRONOUS      0
#define PIPE_INTERRUPT        1
#define PIPE_CONTROL          2
#define PIPE_BULK       3

#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_setfilter_linux(pcap_t *, struct bpf_program *);
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;

      /* scan procfs usb bus directory */
      dir = opendir(USB_BUS_DIR);
      if (!dir) return 0;
      while ((ret == 0) && ((data = readdir(dir)) != 0)) {
            int n;
            char* name = data->d_name;
            int 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;
}

static 
int usb_mmap(pcap_t* handle)
{
      int len = ioctl(handle->fd, MON_IOCQ_RING_SIZE);
      if (len < 0) 
            return 0;

      handle->buffer = mmap(0, len, PROT_READ, MAP_SHARED, handle->fd, 0);
      return handle->buffer != MAP_FAILED;
}

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 = usb_setfilter_linux;
      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.
                   */
                  return PCAP_ERROR_RFMON_NOTSUP;
            }

            /* binary api is available, try to use fast mmap access */
            if (usb_mmap(handle)) {
                  handle->stats_op = usb_stats_linux_bin;
                  handle->read_op = usb_read_linux_mmap;
                  handle->cleanup_op = usb_cleanup_linux_mmap;

                  /*
                   * "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;
      }
      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)
            {
                  /* 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;
            }
            handle->stats_op = usb_stats_linux;
            handle->read_op = usb_read_linux;
      }

      if (handle->opt.rfmon) {
            /*
             * Monitor mode doesn't apply to USB devices.
             */
            return PCAP_ERROR_RFMON_NOTSUP;
      }

      /*
       * "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));
            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->endpoint_number = ep_num;
      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') {
            urb_transfer |= 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;
      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 == pkth.caplen)
            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;
      handle->md.packets_read++;
      if (pkth.caplen > handle->snapshot)
            pkth.caplen = handle->snapshot;

      callback(user, &pkth, handle->buffer);
      return 1;
}

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;
      snprintf(string, USB_LINE_LEN, USB_TEXT_DIR"/%ds", handle->md.ifindex);

      int 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*/
            cnt = -1;
            int 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_setfilter_linux(pcap_t *p, struct bpf_program *fp)
{
      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_ifdrop = st.dropped;
      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->urb_len + sizeof(pcap_usb_header);
      pkth.ts.tv_sec = info.hdr->ts_sec;
      pkth.ts.tv_usec = info.hdr->ts_usec;

      handle->md.packets_read++;
      callback(user, &pkth, handle->buffer);
      return 1;
}

/*
 * 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;

      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->buffer[vec[i]];
                  if (hdr->event_type == '@') 
                        continue;

                  /* get packet info from header*/
                  pkth.caplen = hdr->data_len + sizeof(pcap_usb_header);
                  pkth.len = hdr->urb_len + sizeof(pcap_usb_header);
                  pkth.ts.tv_sec = hdr->ts_sec;
                  pkth.ts.tv_usec = hdr->ts_usec;

                  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)
{
      /* buffer must not be freed because it's memory mapped */
      /* XXX - does it need to be unmapped? */
      handle->buffer = NULL;
      pcap_cleanup_live_common(handle);
}

Generated by  Doxygen 1.6.0   Back to index