* based on previous works of:
+ *
+ * Monitor-mode support for mac80211 includes code taken from the iw
+ * command; the copyright notice for that code is
+ *
+ * Copyright (c) 2007, 2008 Johannes Berg
+ * Copyright (c) 2007 Andy Lutomirski
+ * Copyright (c) 2007 Mike Kershaw
+ * Copyright (c) 2008 Gábor Stefanik
+ *
+ * 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 AUTHOR ``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 AUTHOR 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.
*/
#ifndef lint
*/
+#define _GNU_SOURCE
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
+#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
+#include <limits.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/utsname.h>
*/
#ifdef HAVE_LINUX_WIRELESS_H
#include <linux/wireless.h>
-#endif
+
+/*
+ * Got libnl?
+ */
+#ifdef HAVE_LIBNL
+#include <linux/nl80211.h>
+
+#include <netlink/genl/genl.h>
+#include <netlink/genl/family.h>
+#include <netlink/genl/ctrl.h>
+#include <netlink/msg.h>
+#include <netlink/attr.h>
+#endif /* HAVE_LIBNL */
+
+#endif /* HAVE_LINUX_WIRELESS_H */
#include "pcap-int.h"
#include "pcap/sll.h"
#ifdef IW_MODE_MONITOR
static int has_wext(int sock_fd, const char *device, char *ebuf);
#endif /* IW_MODE_MONITOR */
-static int enter_rfmon_mode_wext(pcap_t *handle, int sock_fd,
+static int enter_rfmon_mode(pcap_t *handle, int sock_fd,
const char *device);
#endif /* HAVE_PF_PACKET_SOCKETS */
static int iface_bind_old(int fd, const char *device, char *ebuf);
* Open a socket on which to attempt to get the mode.
* (We assume that if we have Wireless Extensions support
* we also have PF_PACKET support.)
+ *
+ * This also presumes that the mac80211 framework supports the
+ * Wireless Extensions, which appears to be the case at least
+ * as far back as the 2.6.22.6 kernel.
*/
sock_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (sock_fd == -1) {
return 0;
}
+#if defined(IW_MODE_MONITOR) && defined(HAVE_LIBNL)
+
+struct nl80211_state {
+ struct nl_handle *nl_handle;
+ struct nl_cache *nl_cache;
+ struct genl_family *nl80211;
+};
+
+static int
+nl80211_init(pcap_t *handle, struct nl80211_state *state, const char *device)
+{
+ state->nl_handle = nl_handle_alloc();
+ if (!state->nl_handle) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: failed to allocate netlink handle", device);
+ return PCAP_ERROR;
+ }
+
+ if (genl_connect(state->nl_handle)) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: failed to connect to generic netlink", device);
+ goto out_handle_destroy;
+ }
+
+ state->nl_cache = genl_ctrl_alloc_cache(state->nl_handle);
+ if (!state->nl_cache) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: failed to allocate generic netlink cache", device);
+ goto out_handle_destroy;
+ }
+
+ state->nl80211 = genl_ctrl_search_by_name(state->nl_cache, "nl80211");
+ if (!state->nl80211) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl80211 not found", device);
+ goto out_cache_free;
+ }
+
+ return 0;
+
+out_cache_free:
+ nl_cache_free(state->nl_cache);
+out_handle_destroy:
+ nl_handle_destroy(state->nl_handle);
+ return PCAP_ERROR;
+}
+
+static void
+nl80211_cleanup(struct nl80211_state *state)
+{
+ genl_family_put(state->nl80211);
+ nl_cache_free(state->nl_cache);
+ nl_handle_destroy(state->nl_handle);
+}
+
+static int
+add_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
+ const char *device, const char *mondevice)
+{
+ int ifindex;
+ struct nl_msg *msg;
+ int err;
+
+ ifindex = iface_get_id(sock_fd, device, handle->errbuf);
+ if (ifindex == -1)
+ return PCAP_ERROR;
+
+ msg = nlmsg_alloc();
+ if (!msg) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: failed to allocate netlink msg", device);
+ return PCAP_ERROR;
+ }
+
+ genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
+ 0, NL80211_CMD_NEW_INTERFACE, 0);
+ NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex);
+ NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, mondevice);
+ NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE, NL80211_IFTYPE_MONITOR);
+
+ err = nl_send_auto_complete(state->nl_handle, msg);
+ if (err < 0) {
+ if (err == -ENFILE) {
+ /*
+ * Device not available; our caller should just
+ * keep trying.
+ */
+ nlmsg_free(msg);
+ return 0;
+ } else {
+ /*
+ * Real failure, not just "that device is not
+ * available.
+ */
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_send_auto_complete failed adding %s interface: %s",
+ device, mondevice, strerror(-err));
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+ }
+ }
+ err = nl_wait_for_ack(state->nl_handle);
+ if (err < 0) {
+ if (err == -ENFILE) {
+ /*
+ * Device not available; our caller should just
+ * keep trying.
+ */
+ nlmsg_free(msg);
+ return 0;
+ } else {
+ /*
+ * Real failure, not just "that device is not
+ * available.
+ */
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_wait_for_ack failed adding %s interface: %s",
+ device, mondevice, strerror(-err));
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+ }
+ }
+
+ /*
+ * Success.
+ */
+ nlmsg_free(msg);
+ return 1;
+
+nla_put_failure:
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_put failed adding %s interface",
+ device, mondevice);
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+}
+
+static int
+del_mon_if(pcap_t *handle, int sock_fd, struct nl80211_state *state,
+ const char *device, const char *mondevice)
+{
+ int ifindex;
+ struct nl_msg *msg;
+ int err;
+
+ ifindex = iface_get_id(sock_fd, mondevice, handle->errbuf);
+ if (ifindex == -1)
+ return PCAP_ERROR;
+
+ msg = nlmsg_alloc();
+ if (!msg) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: failed to allocate netlink msg", device);
+ return PCAP_ERROR;
+ }
+
+ genlmsg_put(msg, 0, 0, genl_family_get_id(state->nl80211), 0,
+ 0, NL80211_CMD_DEL_INTERFACE, 0);
+ NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifindex);
+
+ err = nl_send_auto_complete(state->nl_handle, msg);
+ if (err < 0) {
+ if (err == -ENFILE) {
+ /*
+ * Device not available; our caller should just
+ * keep trying.
+ */
+ nlmsg_free(msg);
+ return 0;
+ } else {
+ /*
+ * Real failure, not just "that device is not
+ * available.
+ */
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_send_auto_complete failed deleting %s interface: %s",
+ device, mondevice, strerror(-err));
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+ }
+ }
+ err = nl_wait_for_ack(state->nl_handle);
+ if (err < 0) {
+ if (err == -ENFILE) {
+ /*
+ * Device not available; our caller should just
+ * keep trying.
+ */
+ nlmsg_free(msg);
+ return 0;
+ } else {
+ /*
+ * Real failure, not just "that device is not
+ * available.
+ */
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_wait_for_ack failed adding %s interface: %s",
+ device, mondevice, strerror(-err));
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+ }
+ }
+
+ /*
+ * Success.
+ */
+ nlmsg_free(msg);
+ return 1;
+
+nla_put_failure:
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: nl_put failed deleting %s interface",
+ device, mondevice);
+ nlmsg_free(msg);
+ return PCAP_ERROR;
+}
+
+#endif /* defined(IW_MODE_MONITOR) && defined(HAVE_LIBNL) */
+
/*
* With older kernels promiscuous mode is kind of interesting because we
* have to reset the interface before exiting. The problem can't really
{
struct ifreq ifr;
#ifdef IW_MODE_MONITOR
+#ifdef HAVE_LIBNL
+ struct nl80211_state nlstate;
+ int ret;
+#endif /* HAVE_LIBNL */
struct iwreq ireq;
-#endif
+#endif /* IW_MODE_MONITOR */
- if (handle->md.must_clear != 0) {
+ if (handle->md.must_do_on_close != 0) {
/*
* There's something we have to do when closing this
* pcap_t.
*/
- if (handle->md.must_clear & MUST_CLEAR_PROMISC) {
+ if (handle->md.must_do_on_close & MUST_CLEAR_PROMISC) {
/*
* We put the interface into promiscuous mode;
* take it out of promiscuous mode.
}
#ifdef IW_MODE_MONITOR
- if (handle->md.must_clear & MUST_CLEAR_RFMON) {
+#ifdef HAVE_LIBNL
+ if (handle->md.must_do_on_close & MUST_DELETE_MONIF) {
+ ret = nl80211_init(handle, &nlstate, handle->md.device);
+ if (ret >= 0) {
+ ret = del_mon_if(handle, handle->fd, &nlstate,
+ handle->md.device, handle->md.mondevice);
+ nl80211_cleanup(&nlstate);
+ }
+ if (ret < 0) {
+ fprintf(stderr,
+ "Can't delete monitor interface %s (%s).\n"
+ "Please delete manually.\n",
+ handle->md.mondevice, handle->errbuf);
+ }
+ }
+#endif /* HAVE_LIBNL */
+
+ if (handle->md.must_do_on_close & MUST_CLEAR_RFMON) {
/*
* We put the interface into rfmon mode;
* take it out of rfmon mode.
strerror(errno));
}
}
-#endif
+#endif /* IW_MODE_MONITOR */
/*
* Take this pcap out of the list of pcaps for which we
pcap_remove_from_pcaps_to_close(handle);
}
+ if (handle->md.mondevice != NULL) {
+ free(handle->md.mondevice);
+ handle->md.mondevice = NULL;
+ }
if (handle->md.device != NULL) {
free(handle->md.device);
handle->md.device = NULL;
* because entering monitor mode could change
* the link-layer type.
*/
- err = enter_rfmon_mode_wext(handle, sock_fd, device);
+ err = enter_rfmon_mode(handle, sock_fd, device);
if (err < 0) {
/* Hard failure */
close(sock_fd);
close(sock_fd);
return PCAP_ERROR_RFMON_NOTSUP;
}
+
+ /*
+ * Either monitor mode has been turned on for
+ * the device, or we've been given a different
+ * device to open for monitor mode. If we've
+ * been given a different device, use it.
+ */
+ if (handle->md.mondevice != NULL)
+ device = handle->md.mondevice;
}
arptype = iface_get_arptype(sock_fd, device, handle->errbuf);
if (arptype < 0) {
return PCAP_ERROR_NO_SUCH_DEVICE;
return 0;
}
-#endif
/*
* Per me si va ne la citta dolente,
MONITOR_RTL8XXX
} monitor_type;
+/*
+ *
+ * If interface {if} is a mac80211 driver, the file
+ * /sys/class/net/{if}/phy80211 is a symlink to
+ * /sys/class/ieee80211/{phydev}, for some {phydev}.
+ *
+ * On Fedora 9, with a 2.6.26.3-29 kernel, my Zydas stick, at
+ * least, has a "wmaster0" device and a "wlan0" device; the
+ * latter is the one with the IP address. Both show up in
+ * "tcpdump -D" output. Capturing on the wmaster0 device
+ * captures with 802.11 headers.
+ *
+ * airmon-ng searches through /sys/class/net for devices named
+ * monN, starting with mon0; as soon as one *doesn't* exist,
+ * it chooses that as the monitor device name. If the "iw"
+ * command exists, it does "iw dev {if} interface add {monif}
+ * type monitor", where {monif} is the monitor device. It
+ * then (sigh) sleeps .1 second, and then configures the
+ * device up. Otherwise, if /sys/class/ieee80211/{phydev}/add_iface
+ * is a file, it writes {mondev}, without a newline, to that file,
+ * and again (sigh) sleeps .1 second, and then iwconfig's that
+ * device into monitor mode and configures it up. Otherwise,
+ * you can't do monitor mode.
+ *
+ * All these devices are "glued" together by having the
+ * /sys/class/net/{device}/phy80211 links pointing to the same
+ * place, so, given a wmaster, wlan, or mon device, you can
+ * find the other devices by looking for devices with
+ * the same phy80211 link.
+ *
+ * To turn monitor mode off, delete the monitor interface,
+ * either with "iw dev {monif} interface del" or by sending
+ * {monif}, with no NL, down /sys/class/ieee80211/{phydev}/remove_iface
+ *
+ * Note: if you try to create a monitor device named "monN", and
+ * there's already a "monN" device, it fails, as least with
+ * the netlink interface (which is what iw uses), with a return
+ * value of -ENFILE. (Return values are negative errnos.) We
+ * could probably use that to find an unused device.
+ *
+ * Yes, you can have multiple monitor devices for a given
+ * physical device.
+*/
+
+#ifdef HAVE_LIBNL
+/*
+ * Is this a mac80211 device? If so, fill in the physical device path and
+ * return 1; if not, return 0. On an error, fill in handle->errbuf and
+ * return PCAP_ERROR.
+ */
+static int
+get_mac80211_phydev(pcap_t *handle, const char *device, char *phydev_path,
+ size_t phydev_max_pathlen)
+{
+ char *pathstr;
+ ssize_t bytes_read;
+
+ /*
+ * Generate the path string for the symlink to the physical device.
+ */
+ if (asprintf(&pathstr, "/sys/class/net/%s/phy80211", device) == -1) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: Can't generate path name string for /sys/class/net device",
+ device);
+ return PCAP_ERROR;
+ }
+ bytes_read = readlink(pathstr, phydev_path, phydev_max_pathlen);
+ if (bytes_read == -1) {
+ if (errno == ENOENT || errno == EINVAL) {
+ /*
+ * Doesn't exist, or not a symlink; assume that
+ * means it's not a mac80211 device.
+ */
+ free(pathstr);
+ return 0;
+ }
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: Can't readlink %s: %s", device, pathstr,
+ strerror(errno));
+ free(pathstr);
+ return PCAP_ERROR;
+ }
+ free(pathstr);
+ phydev_path[bytes_read] = '\0';
+ return 1;
+}
+
+static int
+enter_rfmon_mode_mac80211(pcap_t *handle, int sock_fd, const char *device)
+{
+ int ret;
+ char phydev_path[PATH_MAX+1];
+ struct nl80211_state nlstate;
+ struct ifreq ifr;
+ u_int n;
+
+ /*
+ * Is this a mac80211 device?
+ */
+ ret = get_mac80211_phydev(handle, device, phydev_path, PATH_MAX);
+ if (ret < 0)
+ return ret; /* error */
+ if (ret == 0)
+ return 0; /* no error, but not mac80211 device */
+
+ /*
+ * XXX - is this already a monN device?
+ * If so, we're done.
+ * Is that determined by old Wireless Extensions ioctls?
+ */
+
+ /*
+ * OK, it's apparently a mac80211 device.
+ * Try to find an unused monN device for it.
+ */
+ ret = nl80211_init(handle, &nlstate, device);
+ if (ret != 0)
+ return ret;
+ for (n = 0; n < UINT_MAX; n++) {
+ /*
+ * Try mon{n}.
+ */
+ char mondevice[3+10+1]; /* mon{UINT_MAX}\0 */
+
+ snprintf(mondevice, sizeof mondevice, "mon%u", n);
+ ret = add_mon_if(handle, sock_fd, &nlstate, device, mondevice);
+ if (ret == 1) {
+ handle->md.mondevice = strdup(mondevice);
+ goto added;
+ }
+ if (ret < 0) {
+ /*
+ * Hard failure. Just return ret; handle->errbuf
+ * has already been set.
+ */
+ nl80211_cleanup(&nlstate);
+ return ret;
+ }
+ }
+
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: No free monN interfaces", device);
+ nl80211_cleanup(&nlstate);
+ return PCAP_ERROR;
+
+added:
+
+#if 0
+ /*
+ * Sleep for .1 seconds.
+ */
+ delay.tv_sec = 0;
+ delay.tv_nsec = 500000000;
+ nanosleep(&delay, NULL);
+#endif
+
+ /*
+ * Now configure the monitor interface up.
+ */
+ memset(&ifr, 0, sizeof(ifr));
+ strncpy(ifr.ifr_name, handle->md.mondevice, sizeof(ifr.ifr_name));
+ if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) == -1) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: Can't get flags for %s: %s", device,
+ handle->md.mondevice, strerror(errno));
+ del_mon_if(handle, sock_fd, &nlstate, device,
+ handle->md.mondevice);
+ nl80211_cleanup(&nlstate);
+ return PCAP_ERROR;
+ }
+ ifr.ifr_flags |= IFF_UP|IFF_RUNNING;
+ if (ioctl(sock_fd, SIOCSIFFLAGS, &ifr) == -1) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: Can't set flags for %s: %s", device,
+ handle->md.mondevice, strerror(errno));
+ del_mon_if(handle, sock_fd, &nlstate, device,
+ handle->md.mondevice);
+ nl80211_cleanup(&nlstate);
+ return PCAP_ERROR;
+ }
+
+ /*
+ * Success. Clean up the libnl state.
+ */
+ nl80211_cleanup(&nlstate);
+
+ /*
+ * Note that we have to delete the monitor device when we close
+ * the handle.
+ */
+ handle->md.must_do_on_close |= MUST_DELETE_MONIF;
+
+ /*
+ * Add this to the list of pcaps to close when we exit.
+ */
+ pcap_add_to_pcaps_to_close(handle);
+
+ return 1;
+}
+#endif /* HAVE_LIBNL */
+
/*
* Use the Wireless Extensions, if we have them, to try to turn monitor mode
* on if it's not already on.
static int
enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device)
{
-#ifdef IW_MODE_MONITOR
/*
* XXX - at least some adapters require non-Wireless Extensions
* mechanisms to turn monitor mode on.
* Note that we have to put the old mode back
* when we close the device.
*/
- handle->md.must_clear |= MUST_CLEAR_RFMON;
+ handle->md.must_do_on_close |= MUST_CLEAR_RFMON;
/*
* Add this to the list of pcaps to close
* Note that we have to put the old mode back when we
* close the device.
*/
- handle->md.must_clear |= MUST_CLEAR_RFMON;
+ handle->md.must_do_on_close |= MUST_CLEAR_RFMON;
/*
* Add this to the list of pcaps to close when we exit.
pcap_add_to_pcaps_to_close(handle);
return 1;
-#else
+}
+#endif /* IW_MODE_MONITOR */
+
+/*
+ * Try various mechanisms to enter monitor mode.
+ */
+static int
+enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device)
+{
+#ifdef IW_MODE_MONITOR
+ int ret;
+
+#ifdef HAVE_LIBNL
+ ret = enter_rfmon_mode_mac80211(handle, sock_fd, device);
+ if (ret < 0)
+ return ret; /* error attempting to do so */
+ if (ret == 1)
+ return 1; /* success */
+#endif /* HAVE_LIBNL */
+
+ ret = enter_rfmon_mode_wext(handle, sock_fd, device);
+ if (ret < 0)
+ return ret; /* error attempting to do so */
+ if (ret == 1)
+ return 1; /* success */
+#endif /* IW_MODE_MONITOR */
+
/*
- * We don't have the Wireless Extensions available, so we can't
- * do monitor mode.
+ * Either none of the mechanisms we know about work or none
+ * of those mechanisms are available, so we can't do monitor
+ * mode.
*/
return 0;
-#endif
}
#endif /* HAVE_PF_PACKET_SOCKETS */
pcap_strerror(errno));
return PCAP_ERROR;
}
- handle->md.must_clear |= MUST_CLEAR_PROMISC;
+ handle->md.must_do_on_close |= MUST_CLEAR_PROMISC;
/*
* Add this to the list of pcaps
projects / libpcap / commitdiff
