+ memset(&sll, 0, sizeof(sll));
+ sll.sll_family = AF_PACKET;
+ sll.sll_ifindex = ifindex;
+ sll.sll_protocol = htons(ETH_P_ALL);
+
+ if (bind(fd, (struct sockaddr *) &sll, sizeof(sll)) == -1) {
+ if (errno == ENETDOWN) {
+ /*
+ * Return a "network down" indication, so that
+ * the application can report that rather than
+ * saying we had a mysterious failure and
+ * suggest that they report a problem to the
+ * libpcap developers.
+ */
+ return PCAP_ERROR_IFACE_NOT_UP;
+ } else {
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "bind: %s", pcap_strerror(errno));
+ return PCAP_ERROR;
+ }
+ }
+
+ /* Any pending errors, e.g., network is down? */
+
+ if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &errlen) == -1) {
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "getsockopt: %s", pcap_strerror(errno));
+ return 0;
+ }
+
+ if (err == ENETDOWN) {
+ /*
+ * Return a "network down" indication, so that
+ * the application can report that rather than
+ * saying we had a mysterious failure and
+ * suggest that they report a problem to the
+ * libpcap developers.
+ */
+ return PCAP_ERROR_IFACE_NOT_UP;
+ } else if (err > 0) {
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "bind: %s", pcap_strerror(err));
+ return 0;
+ }
+
+ return 1;
+}
+
+#ifdef IW_MODE_MONITOR
+/*
+ * Check whether the device supports the Wireless Extensions.
+ * Returns 1 if it does, 0 if it doesn't, PCAP_ERROR_NO_SUCH_DEVICE
+ * if the device doesn't even exist.
+ */
+static int
+has_wext(int sock_fd, const char *device, char *ebuf)
+{
+ struct iwreq ireq;
+
+ strncpy(ireq.ifr_ifrn.ifrn_name, device,
+ sizeof ireq.ifr_ifrn.ifrn_name);
+ ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0;
+ if (ioctl(sock_fd, SIOCGIWNAME, &ireq) >= 0)
+ return 1; /* yes */
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno));
+ if (errno == ENODEV)
+ return PCAP_ERROR_NO_SUCH_DEVICE;
+ return 0;
+}
+
+/*
+ * Per me si va ne la citta dolente,
+ * Per me si va ne l'etterno dolore,
+ * ...
+ * Lasciate ogne speranza, voi ch'intrate.
+ *
+ * XXX - airmon-ng does special stuff with the Orinoco driver and the
+ * wlan-ng driver.
+ */
+typedef enum {
+ MONITOR_WEXT,
+ MONITOR_HOSTAP,
+ MONITOR_PRISM,
+ MONITOR_PRISM54,
+ MONITOR_ACX100,
+ MONITOR_RT2500,
+ MONITOR_RT2570,
+ MONITOR_RT73,
+ MONITOR_RTL8XXX
+} monitor_type;
+
+/*
+ * Use the Wireless Extensions, if we have them, to try to turn monitor mode
+ * on if it's not already on.
+ *
+ * Returns 1 on success, 0 if we don't support the Wireless Extensions
+ * on this device, or a PCAP_ERROR_ value if we do support them but
+ * we weren't able to turn monitor mode on.
+ */
+static int
+enter_rfmon_mode_wext(pcap_t *handle, int sock_fd, const char *device)
+{
+ /*
+ * XXX - at least some adapters require non-Wireless Extensions
+ * mechanisms to turn monitor mode on.
+ *
+ * Atheros cards might require that a separate "monitor virtual access
+ * point" be created, with later versions of the madwifi driver.
+ * airmon-ng does "wlanconfig ath create wlandev {if} wlanmode
+ * monitor -bssid", which apparently spits out a line "athN"
+ * where "athN" is the monitor mode device. To leave monitor
+ * mode, it destroys the monitor mode device.
+ *
+ * Some Intel Centrino adapters might require private ioctls to get
+ * radio headers; the ipw2200 and ipw3945 drivers allow you to
+ * configure a separate "rtapN" interface to capture in monitor
+ * mode without preventing the adapter from operating normally.
+ * (airmon-ng doesn't appear to use that, though.)
+ *
+ * It would be Truly Wonderful if mac80211 and nl80211 cleaned this
+ * up, and if all drivers were converted to mac80211 drivers.
+ *
+ * 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.
+ */
+ int err;
+ struct iwreq ireq;
+ struct iw_priv_args *priv;
+ monitor_type montype;
+ int i;
+ __u32 cmd;
+ int args[2];
+ int channel;
+
+ /*
+ * Does this device *support* the Wireless Extensions?
+ */
+ err = has_wext(sock_fd, device, handle->errbuf);
+ if (err <= 0)
+ return err; /* either it doesn't or the device doesn't even exist */
+ /*
+ * Try to get all the Wireless Extensions private ioctls
+ * supported by this device.
+ *
+ * First, get the size of the buffer we need, by supplying no
+ * buffer and a length of 0. If the device supports private
+ * ioctls, it should return E2BIG, with ireq.u.data.length set
+ * to the length we need. If it doesn't support them, it should
+ * return EOPNOTSUPP.
+ */
+ memset(&ireq, 0, sizeof ireq);
+ strncpy(ireq.ifr_ifrn.ifrn_name, device,
+ sizeof ireq.ifr_ifrn.ifrn_name);
+ ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0;
+ ireq.u.data.pointer = (void *)args;
+ ireq.u.data.length = 0;
+ ireq.u.data.flags = 0;
+ if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) != -1) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: SIOCGIWPRIV with a zero-length buffer didn't fail!",
+ device);
+ return PCAP_ERROR;
+ }
+ if (errno == EOPNOTSUPP) {
+ /*
+ * No private ioctls, so we assume that there's only one
+ * DLT_ for monitor mode.
+ */
+ return 0;
+ }
+ if (errno != E2BIG) {
+ /*
+ * Failed.
+ */
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno));
+ return PCAP_ERROR;
+ }
+ priv = malloc(ireq.u.data.length * sizeof (struct iw_priv_args));
+ if (priv == NULL) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "malloc: %s", pcap_strerror(errno));
+ return PCAP_ERROR;
+ }
+ ireq.u.data.pointer = (void *)priv;
+ if (ioctl(sock_fd, SIOCGIWPRIV, &ireq) == -1) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "%s: SIOCGIWPRIV: %s", device, pcap_strerror(errno));
+ free(priv);
+ return PCAP_ERROR;
+ }
+
+ /*
+ * Look for private ioctls to turn monitor mode on or, if
+ * monitor mode is on, to set the header type.
+ */
+ montype = MONITOR_WEXT;
+ cmd = 0;
+ for (i = 0; i < ireq.u.data.length; i++) {
+ if (strcmp(priv[i].name, "monitor_type") == 0) {
+ /*
+ * Hostap driver, use this one.
+ * Set monitor mode first.
+ * You can set it to 0 to get DLT_IEEE80211,
+ * 1 to get DLT_PRISM, 2 to get
+ * DLT_IEEE80211_RADIO_AVS, and, with more
+ * recent versions of the driver, 3 to get
+ * DLT_IEEE80211_RADIO.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED))
+ break;
+ if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1)
+ break;
+ montype = MONITOR_HOSTAP;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "set_prismhdr") == 0) {
+ /*
+ * Prism54 driver, use this one.
+ * Set monitor mode first.
+ * You can set it to 2 to get DLT_IEEE80211
+ * or 3 or get DLT_PRISM.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED))
+ break;
+ if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1)
+ break;
+ montype = MONITOR_PRISM54;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "forceprismheader") == 0) {
+ /*
+ * RT2570 driver, use this one.
+ * Do this after turning monitor mode on.
+ * You can set it to 1 to get DLT_PRISM or 2
+ * to get DLT_IEEE80211.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED))
+ break;
+ if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1)
+ break;
+ montype = MONITOR_RT2570;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "forceprism") == 0) {
+ /*
+ * RT73 driver, use this one.
+ * Do this after turning monitor mode on.
+ * Its argument is a *string*; you can
+ * set it to "1" to get DLT_PRISM or "2"
+ * to get DLT_IEEE80211.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_CHAR)
+ break;
+ if (priv[i].set_args & IW_PRIV_SIZE_FIXED)
+ break;
+ montype = MONITOR_RT73;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "prismhdr") == 0) {
+ /*
+ * One of the RTL8xxx drivers, use this one.
+ * It can only be done after monitor mode
+ * has been turned on. You can set it to 1
+ * to get DLT_PRISM or 0 to get DLT_IEEE80211.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED))
+ break;
+ if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 1)
+ break;
+ montype = MONITOR_RTL8XXX;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "rfmontx") == 0) {
+ /*
+ * RT2500 or RT61 driver, use this one.
+ * It has one one-byte parameter; set
+ * u.data.length to 1 and u.data.pointer to
+ * point to the parameter.
+ * It doesn't itself turn monitor mode on.
+ * You can set it to 1 to allow transmitting
+ * in monitor mode(?) and get DLT_IEEE80211,
+ * or set it to 0 to disallow transmitting in
+ * monitor mode(?) and get DLT_PRISM.
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if ((priv[i].set_args & IW_PRIV_SIZE_MASK) != 2)
+ break;
+ montype = MONITOR_RT2500;
+ cmd = priv[i].cmd;
+ break;
+ }
+ if (strcmp(priv[i].name, "monitor") == 0) {
+ /*
+ * Either ACX100 or hostap, use this one.
+ * It turns monitor mode on.
+ * If it takes two arguments, it's ACX100;
+ * the first argument is 1 for DLT_PRISM
+ * or 2 for DLT_IEEE80211, and the second
+ * argument is the channel on which to
+ * run. If it takes one argument, it's
+ * HostAP, and the argument is 2 for
+ * DLT_IEEE80211 and 3 for DLT_PRISM.
+ *
+ * If we see this, we don't quit, as this
+ * might be a version of the hostap driver
+ * that also supports "monitor_type".
+ */
+ if ((priv[i].set_args & IW_PRIV_TYPE_MASK) != IW_PRIV_TYPE_INT)
+ break;
+ if (!(priv[i].set_args & IW_PRIV_SIZE_FIXED))
+ break;
+ switch (priv[i].set_args & IW_PRIV_SIZE_MASK) {
+
+ case 1:
+ montype = MONITOR_PRISM;
+ cmd = priv[i].cmd;
+ break;
+
+ case 2:
+ montype = MONITOR_ACX100;
+ cmd = priv[i].cmd;
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+ free(priv);
+
+ /*
+ * XXX - ipw3945? islism?
+ */
+
+ /*
+ * Get the old mode.
+ */
+ strncpy(ireq.ifr_ifrn.ifrn_name, device,
+ sizeof ireq.ifr_ifrn.ifrn_name);
+ ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0;
+ if (ioctl(sock_fd, SIOCGIWMODE, &ireq) == -1) {
+ /*
+ * We probably won't be able to set the mode, either.
+ */
+ return PCAP_ERROR_RFMON_NOTSUP;
+ }
+
+ /*
+ * Is it currently in monitor mode?
+ */
+ if (ireq.u.mode == IW_MODE_MONITOR) {
+ /*
+ * Yes. Just leave things as they are.
+ * We don't offer multiple link-layer types, as
+ * changing the link-layer type out from under
+ * somebody else capturing in monitor mode would
+ * be considered rude.
+ */
+ return 1;
+ }
+ /*
+ * No. We have to put the adapter into rfmon mode.
+ */
+
+ /*
+ * If we haven't already done so, arrange to have
+ * "pcap_close_all()" called when we exit.
+ */
+ if (!pcap_do_addexit(handle)) {
+ /*
+ * "atexit()" failed; don't put the interface
+ * in rfmon mode, just give up.
+ */
+ return PCAP_ERROR_RFMON_NOTSUP;
+ }
+
+ /*
+ * Save the old mode.
+ */
+ handle->md.oldmode = ireq.u.mode;
+
+ /*
+ * Put the adapter in rfmon mode. How we do this depends
+ * on whether we have a special private ioctl or not.
+ */
+ if (montype == MONITOR_PRISM) {
+ /*
+ * We have the "monitor" private ioctl, but none of
+ * the other private ioctls. Use this, and select
+ * the Prism header.
+ *
+ * If it fails, just fall back on SIOCSIWMODE.
+ */
+ memset(&ireq, 0, sizeof ireq);
+ strncpy(ireq.ifr_ifrn.ifrn_name, device,
+ sizeof ireq.ifr_ifrn.ifrn_name);
+ ireq.ifr_ifrn.ifrn_name[sizeof ireq.ifr_ifrn.ifrn_name - 1] = 0;
+ ireq.u.data.length = 1; /* 1 argument */
+ args[0] = 3; /* request Prism header */
+ memcpy(ireq.u.name, args, IFNAMSIZ);
+ if (ioctl(sock_fd, cmd, &ireq) != -1) {
+ /*
+ * Success.
+ * Note that we have to put the old mode back
+ * when we close the device.
+ */
+ handle->md.must_do_on_close |= MUST_CLEAR_RFMON;
projects / libpcap / blobdiff