2 This file is part of GNUnet.
3 (C) 2010, 2011, 2012 Christian Grothoff (and other contributing authors)
4 Copyright (c) 2007, 2008, Andy Green <andy@warmcat.com>
5 Copyright (C) 2009 Thomas d'Otreppe
7 GNUnet is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published
9 by the Free Software Foundation; either version 3, or (at your
10 option) any later version.
12 GNUnet is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNUnet; see the file COPYING. If not, write to the
19 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA.
23 * @file src/transport/gnunet-helper-transport-wlan.c
24 * @brief mediator between the wlan interface and gnunet; must run as root (SUID will do)
25 * This code will work under GNU/Linux only.
26 * @author David Brodski
27 * @author Christian Grothoff
29 * This program will allow receiving and sending traffic from the WLAN
30 * interface. It will force traffic to be in 'ad-hoc' mode, use the
31 * proper MAC address of the WLAN interface and use a GNUnet-specific
32 * SSID (and a GNUnet-specific SNAP header). It only takes a single
33 * argument, which is the name of the WLAN interface to use. The
34 * program detects if the interface is not a WLAN interface and exits
35 * with an error in that case.
37 * Once initialized, the program will first send a 'struct
38 * GNUNET_TRANSPORT_WLAN_HelperControlMessage' to 'stdout'. That
39 * message contains the MAC address of the WLAN interface. It will
40 * then read messages from the WLAN interface and send them together
41 * with performance information as 'struct
42 * GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage' messages to 'stdout'.
43 * Furthermore, it will read a stream of messages from 'stdin' that
44 * have the format from 'struct
45 * GNUNET_TRANSPORT_WLAN_RadiotapSendMessage'. Those messages will
46 * then be sent via the WLAN interface; however, the sender MAC
47 * address will be forced to be the correct address from our WLAN
48 * card. If 'stdin' closes, receiving from the WLAN interface will
49 * continue. If 'stdout' causes a SIGPIPE, the process dies from the
50 * signal. Errors cause an error message to be reported to 'stderr',
51 * in most cases the process also exits (with status code '1'). The
52 * program never terminates normally; it is safe to kill the
53 * process with SIGTERM or SIGKILL at any time.
55 * Since it uses RAW sockets, the binary must be installed SUID or run
56 * as 'root'. In order to keep the security risk of the resulting
57 * SUID binary minimal, the program ONLY opens the RAW socket with
58 * root privileges, then drops them and only then starts to process
59 * command line arguments. The code also does not link against any
60 * shared libraries (except libc) and is strictly minimal (except for
61 * checking for errors). The following list of people have reviewed
62 * this code and considered it safe since the last modification (if
63 * you reviewed it, please have your name added to the list):
65 * - Christian Grothoff (Apr 3rd 2012)
69 * we use our local copy of ieee80211_radiotap.h
71 * - since we can't support extensions we don't understand
72 * - since linux does not include it in userspace headers
74 * Portions of this code were taken from the ieee80211_radiotap.h header,
77 * Copyright (c) 2003, 2004 David Young. All rights reserved.
79 * Redistribution and use in source and binary forms, with or without
80 * modification, are permitted provided that the following conditions
82 * 1. Redistributions of source code must retain the above copyright
83 * notice, this list of conditions and the following disclaimer.
84 * 2. Redistributions in binary form must reproduce the above copyright
85 * notice, this list of conditions and the following disclaimer in the
86 * documentation and/or other materials provided with the distribution.
87 * 3. The name of David Young may not be used to endorse or promote
88 * products derived from this software without specific prior
91 * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
92 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
93 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
94 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DAVID
95 * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
96 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
97 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
98 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
99 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
100 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
101 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
106 * Modifications to fit into the linux IEEE 802.11 stack,
107 * Mike Kershaw (dragorn@kismetwireless.net)
110 * parts taken from aircrack-ng, parts changend.
112 #include "gnunet_config.h"
113 #include <sys/socket.h>
114 #include <sys/ioctl.h>
115 #include <sys/types.h>
117 #include <sys/wait.h>
118 #include <sys/time.h>
119 #include <sys/stat.h>
120 #include <netpacket/packet.h>
121 #include <linux/if_ether.h>
122 #include <linux/if.h>
123 #include <linux/wireless.h>
124 #include <netinet/in.h>
125 #include <linux/if_tun.h>
133 #include <sys/param.h>
137 #include "gnunet_protocols.h"
138 #include "plugin_transport_wlan.h"
141 * Packet format type for the messages we receive from
142 * the kernel. This is for Ethernet 10Mbps format (no
143 * performance information included).
145 #define ARPHRD_ETHER 1
149 * Packet format type for the messages we receive from
150 * the kernel. This is for plain messages (with no
151 * performance information included).
153 #define ARPHRD_IEEE80211 801
157 * Packet format type for the messages we receive from
158 * the kernel. This is for the PRISM format.
160 #define ARPHRD_IEEE80211_PRISM 802
163 * Packet format type for the messages we receive from
164 * the kernel. This is for messages with a
165 * 'struct Ieee80211RadiotapHeader' (see below).
167 #define ARPHRD_IEEE80211_FULL 803
171 * Maximum size of a message allowed in either direction
172 * (used for our receive and sent buffers).
178 /* ********* structure of messages of type ARPHRD_IEEE80211_PRISM *********** */
181 * Device name length in PRISM frames.
182 * (In the kernel, this is "WLAN_DEVNAMELEN_MAX")
184 #define PRISM_DEVICE_NAME_LENGTH 16
187 * Monitor Frame (indicator that we have a 'struct PrismHeader').
189 #define PRISM_MSGCODE_MONITOR 0x0041
192 * Mac time element. In micro-seconds.
193 * Drivers appear to use a 64bit counter to hold mactime internal
194 * the then fill the prism header with the lower 32 bits
196 #define PRISM_DID_MACTIME 0x2041
201 #define PRISM_DID_CHANNEL 0x3041
204 * Signal element. Should be the signal strength in dbm, some people
205 * suggest that instead "100 - (strength in dbm)" is used (to make this
206 * a positive integer).
208 #define PRISM_DID_SIGNAL 0x6041
213 #define PRISM_DID_NOISE 0x7041
216 * Rate element, in units/multiples of 500Khz
218 #define PRISM_DID_RATE 0x8041
222 * Value is set (supplied)
224 #define PRISM_STATUS_OK 0
227 * Value not supplied.
229 #define PRISM_STATUS_NO_VALUE 1
233 * Values in the 'struct PrismHeader'. All in host byte order (!).
238 * This has a different ID for each parameter, see
239 * PRISM_DID_* constants.
244 * See PRISM_STATUS_*-constants. Note that they are unusual: 0 = set; 1 = not set
249 * length of data (which is always a uint32_t, but presumably this can be used
250 * to specify that fewer bytes are used (with values in 'len' from 0-4). We
260 } __attribute__ ((packed));
264 * Prism header format ('struct p80211msg' in Linux). All in host byte order (!).
269 * We expect this to be a PRISM_MSGCODE_*.
274 * The length of the entire header.
279 * Name of the device that captured the packet.
281 char devname[PRISM_DEVICE_NAME_LENGTH];
283 /* followed by 'struct PrismValue's. Documentation suggests that these
284 are typically the hosttime, mactime, channel, rssi, sq, signal, noise,
285 rate, istx and frmlen values, but documentation is sparse. So we
286 will use the 'did' fields to find out what we actually got. */
288 } __attribute__ ((packed));
291 /* ****** end of structure of messages of type ARPHRD_IEEE80211_PRISM ******* */
293 /* ********** structure of messages of type ARPHRD_IEEE80211_FULL *********** */
296 * Bits in the 'it_present' bitmask from the 'struct
297 * Ieee80211RadiotapHeader'. For each value, we give the name, data
298 * type, unit and then a description below. Note that the actual size
299 * of the extension can be bigger as arguments must be padded so that
300 * args of a given length must begin at a boundary of that length.
301 * However, note that compound args are allowed (eg, 2 x uint16_t for
302 * IEEE80211_RADIOTAP_CHANNEL) so total argument length is not a
303 * reliable indicator of alignment requirement. See also
304 * 'man 9 ieee80211_radiotap'.
310 * IEEE80211_RADIOTAP_TSFT __le64 microseconds
312 * Value in microseconds of the MAC's 64-bit 802.11 Time
313 * Synchronization Function timer when the first bit of the
314 * MPDU arrived at the MAC. For received frames, only.
316 IEEE80211_RADIOTAP_TSFT = 0,
319 * IEEE80211_RADIOTAP_FLAGS uint8_t bitmap
321 * Properties of transmitted and received frames. See flags
324 IEEE80211_RADIOTAP_FLAGS = 1,
327 * IEEE80211_RADIOTAP_RATE uint8_t 500kb/s
331 IEEE80211_RADIOTAP_RATE = 2,
334 * IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap
336 * Tx/Rx frequency in MHz, followed by flags (see below).
338 IEEE80211_RADIOTAP_CHANNEL = 3,
340 * IEEE80211_RADIOTAP_FHSS __le16 see below
342 * For frequency-hopping radios, the hop set (first byte)
343 * and pattern (second byte).
345 IEEE80211_RADIOTAP_FHSS = 4,
348 * IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from
349 * one milliwatt (dBm)
351 * RF signal power at the antenna, decibel difference from
354 IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
357 * IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from
358 * one milliwatt (dBm)
360 * RF noise power at the antenna, decibel difference from one
363 IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
366 * IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless
368 * Quality of Barker code lock. Unitless. Monotonically
369 * nondecreasing with "better" lock strength. Called "Signal
370 * Quality" in datasheets. (Is there a standard way to measure
373 IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
376 * IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless
378 * Transmit power expressed as unitless distance from max
379 * power set at factory calibration. 0 is max power.
380 * Monotonically nondecreasing with lower power levels.
382 IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
385 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)
387 * Transmit power expressed as decibel distance from max power
388 * set at factory calibration. 0 is max power. Monotonically
389 * nondecreasing with lower power levels.
391 IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
394 * IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from
395 * one milliwatt (dBm)
397 * Transmit power expressed as dBm (decibels from a 1 milliwatt
398 * reference). This is the absolute power level measured at
401 IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
404 * IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index
406 * Unitless indication of the Rx/Tx antenna for this packet.
407 * The first antenna is antenna 0.
409 IEEE80211_RADIOTAP_ANTENNA = 11,
412 * IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)
414 * RF signal power at the antenna, decibel difference from an
415 * arbitrary, fixed reference.
417 IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
420 * IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)
422 * RF noise power at the antenna, decibel difference from an
423 * arbitrary, fixed reference point.
425 IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
428 * IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap
430 * Properties of received frames. See flags defined below.
432 IEEE80211_RADIOTAP_RX_FLAGS = 14,
435 * IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap
437 * Properties of transmitted frames. See flags defined below.
439 IEEE80211_RADIOTAP_TX_FLAGS = 15,
442 * IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data
444 * Number of rts retries a transmitted frame used.
446 IEEE80211_RADIOTAP_RTS_RETRIES = 16,
449 * IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data
451 * Number of unicast retries a transmitted frame used.
453 IEEE80211_RADIOTAP_DATA_RETRIES = 17,
456 * Extension bit, used to indicate that more bits are needed for
459 IEEE80211_RADIOTAP_EXT = 31
463 * Bitmask indicating an extension of the bitmask is used.
464 * (Mask corresponding to IEEE80211_RADIOTAP_EXT).
466 #define IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK (1 << IEEE80211_RADIOTAP_EXT)
471 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
472 * as part of a 'struct Ieee80211RadiotapHeader' extension
473 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
474 * 'it_present'). The radiotap flags are an 8-bit field.
476 * Frame was sent/received during CFP (Contention Free Period)
478 #define IEEE80211_RADIOTAP_F_CFP 0x01
481 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
482 * as part of a 'struct Ieee80211RadiotapHeader' extension
483 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
484 * 'it_present'). The radiotap flags are an 8-bit field.
486 * Frame was sent/received with short preamble
488 #define IEEE80211_RADIOTAP_F_SHORTPRE 0x02
491 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
492 * as part of a 'struct Ieee80211RadiotapHeader' extension
493 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
494 * 'it_present'). The radiotap flags are an 8-bit field.
496 * Frame was sent/received with WEP encryption
498 #define IEEE80211_RADIOTAP_F_WEP 0x04
501 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
502 * as part of a 'struct Ieee80211RadiotapHeader' extension
503 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
504 * 'it_present'). The radiotap flags are an 8-bit field.
506 * Frame was sent/received with fragmentation
508 #define IEEE80211_RADIOTAP_F_FRAG 0x08
511 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
512 * as part of a 'struct Ieee80211RadiotapHeader' extension
513 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
514 * 'it_present'). The radiotap flags are an 8-bit field.
516 * Frame includes FCS (CRC at the end that needs to be removeD).
518 #define IEEE80211_RADIOTAP_F_FCS 0x10
521 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
522 * as part of a 'struct Ieee80211RadiotapHeader' extension
523 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
524 * 'it_present'). The radiotap flags are an 8-bit field.
526 * Frame has padding between 802.11 header and payload
527 * (to 32-bit boundary)
529 #define IEEE80211_RADIOTAP_F_DATAPAD 0x20
533 * For IEEE80211_RADIOTAP_RX_FLAGS:
534 * frame failed crc check
536 #define IEEE80211_RADIOTAP_F_RX_BADFCS 0x0001
539 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
540 * failed due to excessive retries
542 #define IEEE80211_RADIOTAP_F_TX_FAIL 0x0001
545 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
546 * used cts 'protection'
548 #define IEEE80211_RADIOTAP_F_TX_CTS 0x0002
551 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
552 * used rts/cts handshake
554 #define IEEE80211_RADIOTAP_F_TX_RTS 0x0004
557 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
558 * frame should not be ACKed
560 #define IEEE80211_RADIOTAP_F_TX_NOACK 0x0008
563 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
564 * sequence number handled by userspace
566 #define IEEE80211_RADIOTAP_F_TX_NOSEQ 0x0010
570 * Generic header for radiotap messages (receiving and sending). A
571 * bit mask (it_present) determines which specific records follow.
573 * I am trying to describe precisely what the application programmer
574 * should expect in the following, and for that reason I tell the
575 * units and origin of each measurement (where it applies), or else I
576 * use sufficiently weaselly language ("is a monotonically nondecreasing
577 * function of...") that I cannot set false expectations for lawyerly
580 * The radio capture header precedes the 802.11 header.
581 * All data in the header is little endian on all platforms.
583 struct Ieee80211RadiotapHeader
586 * Version 0. Only increases for drastic changes, introduction of
587 * compatible new fields does not count.
597 * length of the whole header in bytes, including it_version,
598 * it_pad, it_len, and data fields.
603 * A bitmap telling which fields are present. Set bit 31
604 * (0x80000000) to extend the bitmap by another 32 bits. Additional
605 * extensions are made by setting bit 31.
612 * Format of the header we need to prepend to messages to be sent to the
615 struct RadiotapTransmissionHeader
619 * First we begin with the 'generic' header we also get when receiving
622 struct Ieee80211RadiotapHeader header;
625 * Transmission rate (we use 0, kernel makes up its mind anyway).
630 * Padding (we use 0). There is a requirement to pad args, so that
631 * args of a given length must begin at a boundary of that length.
632 * As our next argument is the 'it_len' with 2 bytes, we need 1 byte
638 * Transmission flags from on the IEEE80211_RADIOTAP_F_TX_* constant family.
645 * The above 'struct RadiotapTransmissionHeader' should have the
646 * following value for 'header.it_present' based on the presence of
647 * the 'rate' and 'txflags' in the overall struct.
649 #define IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK ((1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_TX_FLAGS))
654 * struct Ieee80211RadiotapHeaderIterator - tracks walk through present radiotap arguments
655 * in the radiotap header. Used when we parse radiotap packets received from the kernel.
657 struct Ieee80211RadiotapHeaderIterator
660 * pointer to the radiotap header we are walking through
662 const struct Ieee80211RadiotapHeader *rtheader;
665 * pointer to current radiotap arg
667 const uint8_t *this_arg;
670 * internal next argument pointer
675 * internal pointer to next present uint32_t (if IEEE80211_RADIOTAP_EXT is used).
677 const uint32_t *next_bitmap;
680 * length of radiotap header in host byte ordering
685 * internal shifter for current uint32_t bitmap, (it_present in host byte order),
686 * If bit 0 is set, the 'arg_index' argument is present.
688 uint32_t bitmap_shifter;
691 * IEEE80211_RADIOTAP_... index of current arg
693 unsigned int this_arg_index;
696 * internal next argument index
698 unsigned int arg_index;
703 /* ************** end of structure of ARPHRD_IEEE80211_FULL ************** */
705 /* ************************** our globals ******************************* */
708 * struct for storing the information of the hardware. There is only
715 * file descriptor for the raw socket
720 * Which format has the header that we're getting when receiving packets?
721 * Some ARPHRD_IEEE80211_XXX-value.
726 * Name of the interface, not necessarily 0-terminated (!).
728 char iface[IFNAMSIZ];
731 * MAC address of our own WLAN interface.
733 struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac;
738 * IO buffer used for buffering data in transit (to wireless or to stdout).
743 * How many bytes of data are stored in 'buf' for transmission right now?
744 * Data always starts at offset 0 and extends to 'size'.
749 * How many bytes that were stored in 'buf' did we already write to the
750 * destination? Always smaller than 'size'.
755 * Buffered data; twice the maximum allowed message size as we add some
758 char buf[MAXLINE * 2];
763 * Buffer for data read from stdin to be transmitted to the wirless card.
765 static struct SendBuffer write_pout;
768 * Buffer for data read from the wireless card to be transmitted to stdout.
770 static struct SendBuffer write_std;
774 /* *********** specialized version of server_mst.c begins here ********** */
777 * To what multiple do we align messages? 8 byte should suffice for everyone
780 #define ALIGN_FACTOR 8
783 * Smallest supported message.
785 #define MIN_BUFFER_SIZE sizeof (struct GNUNET_MessageHeader)
789 * Functions with this signature are called whenever a
790 * complete message is received by the tokenizer.
793 * @param message the actual message
795 typedef void (*MessageTokenizerCallback) (void *cls,
797 GNUNET_MessageHeader *
801 * Handle to a message stream tokenizer.
803 struct MessageStreamTokenizer
807 * Function to call on completed messages.
809 MessageTokenizerCallback cb;
817 * Size of the buffer (starting at 'hdr').
822 * How many bytes in buffer have we already processed?
827 * How many bytes in buffer are valid right now?
832 * Beginning of the buffer. Typed like this to force alignment.
834 struct GNUNET_MessageHeader *hdr;
840 * Create a message stream tokenizer.
842 * @param cb function to call on completed messages
843 * @param cb_cls closure for cb
844 * @return handle to tokenizer
846 static struct MessageStreamTokenizer *
847 mst_create (MessageTokenizerCallback cb,
850 struct MessageStreamTokenizer *ret;
852 ret = malloc (sizeof (struct MessageStreamTokenizer));
855 fprintf (stderr, "Failed to allocate buffer for tokenizer\n");
858 ret->hdr = malloc (MIN_BUFFER_SIZE);
859 if (NULL == ret->hdr)
861 fprintf (stderr, "Failed to allocate buffer for alignment\n");
864 ret->curr_buf = MIN_BUFFER_SIZE;
866 ret->cb_cls = cb_cls;
872 * Add incoming data to the receive buffer and call the
873 * callback for all complete messages.
875 * @param mst tokenizer to use
876 * @param buf input data to add
877 * @param size number of bytes in buf
878 * @return GNUNET_OK if we are done processing (need more data)
879 * GNUNET_SYSERR if the data stream is corrupt
882 mst_receive (struct MessageStreamTokenizer *mst,
883 const char *buf, size_t size)
885 const struct GNUNET_MessageHeader *hdr;
890 unsigned long offset;
894 ibuf = (char *) mst->hdr;
898 if ((mst->curr_buf - mst->off < sizeof (struct GNUNET_MessageHeader)) ||
899 (0 != (mst->off % ALIGN_FACTOR)))
901 /* need to align or need more space */
902 mst->pos -= mst->off;
903 memmove (ibuf, &ibuf[mst->off], mst->pos);
906 if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
909 GNUNET_MIN (sizeof (struct GNUNET_MessageHeader) -
910 (mst->pos - mst->off), size);
911 memcpy (&ibuf[mst->pos], buf, delta);
916 if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
920 hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
921 want = ntohs (hdr->size);
922 if (want < sizeof (struct GNUNET_MessageHeader))
925 "Received invalid message from stdin\n");
928 if (mst->curr_buf - mst->off < want)
930 /* need more space */
931 mst->pos -= mst->off;
932 memmove (ibuf, &ibuf[mst->off], mst->pos);
935 if (want > mst->curr_buf)
937 mst->hdr = realloc (mst->hdr, want);
938 if (NULL == mst->hdr)
940 fprintf (stderr, "Failed to allocate buffer for alignment\n");
943 ibuf = (char *) mst->hdr;
944 mst->curr_buf = want;
946 hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
947 if (mst->pos - mst->off < want)
949 delta = GNUNET_MIN (want - (mst->pos - mst->off), size);
950 memcpy (&ibuf[mst->pos], buf, delta);
955 if (mst->pos - mst->off < want)
959 mst->cb (mst->cb_cls, hdr);
961 if (mst->off == mst->pos)
963 /* reset to beginning of buffer, it's free right now! */
970 if (size < sizeof (struct GNUNET_MessageHeader))
972 offset = (unsigned long) buf;
973 need_align = (0 != offset % ALIGN_FACTOR) ? GNUNET_YES : GNUNET_NO;
974 if (GNUNET_NO == need_align)
976 /* can try to do zero-copy and process directly from original buffer */
977 hdr = (const struct GNUNET_MessageHeader *) buf;
978 want = ntohs (hdr->size);
979 if (want < sizeof (struct GNUNET_MessageHeader))
982 "Received invalid message from stdin\n");
986 break; /* or not, buffer incomplete, so copy to private buffer... */
987 mst->cb (mst->cb_cls, hdr);
993 /* need to copy to private buffer to align;
994 * yes, we go a bit more spagetti than usual here */
1000 if (size + mst->pos > mst->curr_buf)
1002 mst->hdr = realloc (mst->hdr, size + mst->pos);
1003 if (NULL == mst->hdr)
1005 fprintf (stderr, "Failed to allocate buffer for alignment\n");
1008 ibuf = (char *) mst->hdr;
1009 mst->curr_buf = size + mst->pos;
1011 if (mst->pos + size > mst->curr_buf)
1014 "Assertion failed\n");
1017 memcpy (&ibuf[mst->pos], buf, size);
1025 * Destroys a tokenizer.
1027 * @param mst tokenizer to destroy
1030 mst_destroy (struct MessageStreamTokenizer *mst)
1036 /* ***************** end of server_mst.c clone ***************** **/
1039 /* ************** code for handling of ARPHRD_IEEE80211_FULL ************** */
1042 * Radiotap header iteration
1044 * call __ieee80211_radiotap_iterator_init() to init a semi-opaque iterator
1045 * struct Ieee80211RadiotapHeaderIterator (no need to init the struct beforehand)
1046 * then loop calling __ieee80211_radiotap_iterator_next()... it returns -1
1047 * if there are no more args in the header, or the next argument type index
1048 * that is present. The iterator's this_arg member points to the start of the
1049 * argument associated with the current argument index that is present,
1050 * which can be found in the iterator's this_arg_index member. This arg
1051 * index corresponds to the IEEE80211_RADIOTAP_... defines.
1053 * @param iterator iterator to initialize
1054 * @param radiotap_header message to parse
1055 * @param max_length number of valid bytes in radiotap_header
1056 * @return 0 on success, -1 on error
1059 ieee80211_radiotap_iterator_init (struct Ieee80211RadiotapHeaderIterator *iterator,
1060 const struct Ieee80211RadiotapHeader *radiotap_header,
1063 if ( (iterator == NULL) ||
1064 (radiotap_header == NULL) )
1067 /* Linux only supports version 0 radiotap format */
1068 if (0 != radiotap_header->it_version)
1071 /* sanity check for allowed length and radiotap length field */
1072 if ( (max_length < sizeof (struct Ieee80211RadiotapHeader)) ||
1073 (max_length < (GNUNET_le16toh (radiotap_header->it_len))) )
1076 memset (iterator, 0, sizeof (struct Ieee80211RadiotapHeaderIterator));
1077 iterator->rtheader = radiotap_header;
1078 iterator->max_length = GNUNET_le16toh (radiotap_header->it_len);
1079 iterator->bitmap_shifter = GNUNET_le32toh (radiotap_header->it_present);
1080 iterator->arg = ((uint8_t *) radiotap_header) + sizeof (struct Ieee80211RadiotapHeader);
1082 /* find payload start allowing for extended bitmap(s) */
1083 if (0 != (iterator->bitmap_shifter & IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK))
1085 while (GNUNET_le32toh (*((uint32_t *) iterator->arg)) & IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK)
1087 iterator->arg += sizeof (uint32_t);
1089 * check for insanity where the present bitmaps
1090 * keep claiming to extend up to or even beyond the
1091 * stated radiotap header length
1093 if (iterator->arg - ((uint8_t*) iterator->rtheader) > iterator->max_length)
1096 iterator->arg += sizeof (uint32_t);
1098 * no need to check again for blowing past stated radiotap
1099 * header length, becuase ieee80211_radiotap_iterator_next
1100 * checks it before it is dereferenced
1103 /* we are all initialized happily */
1109 * Returns the next radiotap parser iterator arg.
1111 * This function returns the next radiotap arg index (IEEE80211_RADIOTAP_...)
1112 * and sets iterator->this_arg to point to the payload for the arg. It takes
1113 * care of alignment handling and extended present fields. interator->this_arg
1114 * can be changed by the caller. The args pointed to are in little-endian
1117 * @param iterator: radiotap_iterator to move to next arg (if any)
1118 * @return next present arg index on success or -1 if no more or error
1121 ieee80211_radiotap_iterator_next (struct Ieee80211RadiotapHeaderIterator *iterator)
1124 * small length lookup table for all radiotap types we heard of
1125 * starting from b0 in the bitmap, so we can walk the payload
1126 * area of the radiotap header
1128 * There is a requirement to pad args, so that args
1129 * of a given length must begin at a boundary of that length
1130 * -- but note that compound args are allowed (eg, 2 x uint16_t
1131 * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
1132 * a reliable indicator of alignment requirement.
1134 * upper nybble: content alignment for arg
1135 * lower nybble: content length for arg
1138 static const uint8_t rt_sizes[] = {
1139 [IEEE80211_RADIOTAP_TSFT] = 0x88,
1140 [IEEE80211_RADIOTAP_FLAGS] = 0x11,
1141 [IEEE80211_RADIOTAP_RATE] = 0x11,
1142 [IEEE80211_RADIOTAP_CHANNEL] = 0x24,
1143 [IEEE80211_RADIOTAP_FHSS] = 0x22,
1144 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = 0x11,
1145 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = 0x11,
1146 [IEEE80211_RADIOTAP_LOCK_QUALITY] = 0x22,
1147 [IEEE80211_RADIOTAP_TX_ATTENUATION] = 0x22,
1148 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = 0x22,
1149 [IEEE80211_RADIOTAP_DBM_TX_POWER] = 0x11,
1150 [IEEE80211_RADIOTAP_ANTENNA] = 0x11,
1151 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = 0x11,
1152 [IEEE80211_RADIOTAP_DB_ANTNOISE] = 0x11,
1153 [IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
1154 [IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
1155 [IEEE80211_RADIOTAP_RTS_RETRIES] = 0x11,
1156 [IEEE80211_RADIOTAP_DATA_RETRIES] = 0x11
1158 * add more here as they are defined in
1159 * include/net/ieee80211_radiotap.h
1164 * for every radiotap entry we can at
1165 * least skip (by knowing the length)...
1167 while (iterator->arg_index < sizeof (rt_sizes))
1169 int hit = (0 != (iterator->bitmap_shifter & 1));
1173 unsigned int wanted_alignment;
1174 unsigned int unalignment;
1176 * arg is present, account for alignment padding
1177 * 8-bit args can be at any alignment
1178 * 16-bit args must start on 16-bit boundary
1179 * 32-bit args must start on 32-bit boundary
1180 * 64-bit args must start on 64-bit boundary
1182 * note that total arg size can differ from alignment of
1183 * elements inside arg, so we use upper nybble of length table
1184 * to base alignment on. First, 'wanted_alignment' is set to be
1185 * 1 for 8-bit, 2 for 16-bit, 4 for 32-bit and 8 for 64-bit
1186 * arguments. Then, we calculate the 'unalignment' (how many
1187 * bytes we are over by taking the difference of 'arg' and the
1188 * overall starting point modulo the desired alignment. As
1189 * desired alignments are powers of two, we can do modulo with
1190 * binary "&" (and also avoid the possibility of a division by
1191 * zero if the 'rt_sizes' table contains bogus entries).
1193 * also note: these alignments are relative to the start of the
1194 * radiotap header. There is no guarantee that the radiotap
1195 * header itself is aligned on any kind of boundary, thus we
1196 * need to really look at the delta here.
1198 wanted_alignment = rt_sizes[iterator->arg_index] >> 4;
1199 unalignment = (((void *) iterator->arg) - ((void *) iterator->rtheader)) & (wanted_alignment - 1);
1200 if (0 != unalignment)
1202 /* need padding (by 'wanted_alignment - unalignment') */
1203 iterator->arg_index += wanted_alignment - unalignment;
1207 * this is what we will return to user, but we need to
1208 * move on first so next call has something fresh to test
1210 iterator->this_arg_index = iterator->arg_index;
1211 iterator->this_arg = iterator->arg;
1213 /* internally move on the size of this arg (using lower nybble from
1215 iterator->arg += rt_sizes[iterator->arg_index] & 0x0f;
1218 * check for insanity where we are given a bitmap that
1219 * claims to have more arg content than the length of the
1220 * radiotap section. We will normally end up equalling this
1221 * max_length on the last arg, never exceeding it.
1223 if ((((void *) iterator->arg) - ((void *) iterator->rtheader)) > iterator->max_length)
1227 /* Now, move on to next bit / next entry */
1228 iterator->arg_index++;
1230 if (0 == (iterator->arg_index % 32))
1232 /* completed current uint32_t bitmap */
1233 if (0 != (iterator->bitmap_shifter & 1))
1235 /* bit 31 was set, there is more; move to next uint32_t bitmap */
1236 iterator->bitmap_shifter = GNUNET_le32toh (*iterator->next_bitmap);
1237 iterator->next_bitmap++;
1241 /* no more bitmaps: end (by setting arg_index to high, unsupported value) */
1242 iterator->arg_index = sizeof (rt_sizes);
1247 /* just try the next bit (while loop will move on) */
1248 iterator->bitmap_shifter >>= 1;
1251 /* if we found a valid arg earlier, return it now */
1253 return iterator->this_arg_index;
1256 /* we don't know how to handle any more args (or there are no more),
1257 so we're done (this is not an error) */
1263 * Calculate crc32, the start of the calculation
1265 * @param buf buffer to calc the crc
1266 * @param len len of the buffer
1269 static unsigned long
1270 calc_crc_osdep (const unsigned char *buf, size_t len)
1272 static const unsigned long int crc_tbl_osdep[256] = {
1273 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
1274 0xE963A535, 0x9E6495A3,
1275 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,
1276 0xE7B82D07, 0x90BF1D91,
1277 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB,
1278 0xF4D4B551, 0x83D385C7,
1279 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
1280 0xFA0F3D63, 0x8D080DF5,
1281 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447,
1282 0xD20D85FD, 0xA50AB56B,
1283 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75,
1284 0xDCD60DCF, 0xABD13D59,
1285 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
1286 0xCFBA9599, 0xB8BDA50F,
1287 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11,
1288 0xC1611DAB, 0xB6662D3D,
1289 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,
1290 0x9FBFE4A5, 0xE8B8D433,
1291 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
1292 0x91646C97, 0xE6635C01,
1293 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B,
1294 0x8208F4C1, 0xF50FC457,
1295 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49,
1296 0x8CD37CF3, 0xFBD44C65,
1297 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
1298 0xA4D1C46D, 0xD3D6F4FB,
1299 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,
1300 0xAA0A4C5F, 0xDD0D7CC9,
1301 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3,
1302 0xB966D409, 0xCE61E49F,
1303 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
1304 0xB7BD5C3B, 0xC0BA6CAD,
1305 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF,
1306 0x04DB2615, 0x73DC1683,
1307 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,
1308 0x0A00AE27, 0x7D079EB1,
1309 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
1310 0x196C3671, 0x6E6B06E7,
1311 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9,
1312 0x17B7BE43, 0x60B08ED5,
1313 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767,
1314 0x3FB506DD, 0x48B2364B,
1315 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
1316 0x316E8EEF, 0x4669BE79,
1317 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703,
1318 0x220216B9, 0x5505262F,
1319 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,
1320 0x2CD99E8B, 0x5BDEAE1D,
1321 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
1322 0x72076785, 0x05005713,
1323 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,
1324 0x7CDCEFB7, 0x0BDBDF21,
1325 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B,
1326 0x6FB077E1, 0x18B74777,
1327 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
1328 0x616BFFD3, 0x166CCF45,
1329 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,
1330 0x4969474D, 0x3E6E77DB,
1331 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5,
1332 0x47B2CF7F, 0x30B5FFE9,
1333 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
1334 0x54DE5729, 0x23D967BF,
1335 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1,
1336 0x5A05DF1B, 0x2D02EF8D
1339 unsigned long crc = 0xFFFFFFFF;
1341 for (; len > 0; len--, buf++)
1342 crc = crc_tbl_osdep[(crc ^ *buf) & 0xFF] ^ (crc >> 8);
1348 * Calculate and check crc of the wlan packet
1350 * @param buf buffer of the packet, with len + 4 bytes of data,
1351 * the last 4 bytes being the checksum
1352 * @param len length of the payload in data
1353 * @return 0 on success (checksum matches), 1 on error
1356 check_crc_buf_osdep (const unsigned char *buf, size_t len)
1360 crc = calc_crc_osdep (buf, len);
1362 if (((crc) & 0xFF) == buf[0] && ((crc >> 8) & 0xFF) == buf[1] &&
1363 ((crc >> 16) & 0xFF) == buf[2] && ((crc >> 24) & 0xFF) == buf[3])
1369 /* ************end of code for handling of ARPHRD_IEEE80211_FULL ************** */
1372 /* ************beginning of code for reading packets from kernel ************** */
1375 * Return the channel from the frequency (in Mhz)
1377 * @param frequency of the channel
1378 * @return number of the channel
1381 get_channel_from_frequency (int32_t frequency)
1383 if (frequency >= 2412 && frequency <= 2472)
1384 return (frequency - 2407) / 5;
1385 if (frequency == 2484)
1387 if (frequency >= 5000 && frequency <= 6100)
1388 return (frequency - 5000) / 5;
1394 * Get the channel used by our WLAN interface.
1396 * @param dev pointer to the dev struct of the card
1397 * @return channel number, -1 on error
1400 linux_get_channel (const struct HardwareInfos *dev)
1405 memset (&wrq, 0, sizeof (struct iwreq));
1406 strncpy (wrq.ifr_name, dev->iface, IFNAMSIZ);
1407 if (0 > ioctl (dev->fd_raw, SIOCGIWFREQ, &wrq))
1409 frequency = wrq.u.freq.m; /* 'iw_freq' defines 'm' as '__s32', so we keep it signed */
1410 if (100000000 < frequency)
1411 frequency /= 100000;
1412 else if (1000000 < frequency)
1414 if (1000 < frequency)
1415 return get_channel_from_frequency (frequency);
1421 * Read from the raw socket (the wlan card), parse the packet and
1422 * put the result into the buffer for transmission to 'stdout'.
1424 * @param dev pointer to the struct of the wlan card
1425 * @param buf buffer to read to; first bytes will be the 'struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame',
1426 * followed by the actual payload
1427 * @param buf_size size of the buffer
1428 * @param ri where to write radiotap_rx info
1429 * @return number of bytes written to 'buf'
1432 linux_read (struct HardwareInfos *dev,
1433 unsigned char *buf, size_t buf_size,
1434 struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *ri)
1436 unsigned char tmpbuf[buf_size];
1441 int got_channel = 0;
1442 int fcs_removed = 0;
1444 caplen = read (dev->fd_raw, tmpbuf, buf_size);
1447 if (EAGAIN == errno)
1449 fprintf (stderr, "Failed to read from RAW socket: %s\n", strerror (errno));
1453 memset (ri, 0, sizeof (*ri));
1454 switch (dev->arptype_in)
1456 case ARPHRD_IEEE80211_PRISM:
1458 const struct PrismHeader *ph;
1460 ph = (const struct PrismHeader*) tmpbuf;
1462 if ( (n < 8) || (n >= caplen) )
1463 return 0; /* invalid format */
1464 if ( (PRISM_MSGCODE_MONITOR == ph->msgcode) &&
1465 (n >= sizeof (struct PrismHeader)) )
1469 struct PrismValue pv;
1471 left = n - sizeof (struct PrismHeader);
1472 pos = (const char *) &ph[1];
1473 while (left > sizeof (struct PrismValue))
1475 left -= sizeof (struct PrismValue);
1476 memcpy (&pv, pos, sizeof (struct PrismValue));
1477 pos += sizeof (struct PrismValue);
1481 case PRISM_DID_NOISE:
1482 if (PRISM_STATUS_OK == pv.status)
1484 ri->ri_noise = pv.data;
1488 case PRISM_DID_RATE:
1489 if (PRISM_STATUS_OK == pv.status)
1490 ri->ri_rate = pv.data * 500000;
1492 case PRISM_DID_CHANNEL:
1493 if (PRISM_STATUS_OK == pv.status)
1495 ri->ri_channel = pv.data;
1499 case PRISM_DID_MACTIME:
1500 if (PRISM_STATUS_OK == pv.status)
1501 ri->ri_mactime = pv.data;
1503 case PRISM_DID_SIGNAL:
1504 if (PRISM_STATUS_OK == pv.status)
1506 ri->ri_power = pv.data;
1513 if ( (n < 8) || (n >= caplen) )
1514 return 0; /* invalid format */
1517 case ARPHRD_IEEE80211_FULL:
1519 struct Ieee80211RadiotapHeaderIterator iterator;
1520 struct Ieee80211RadiotapHeader *rthdr;
1522 memset (&iterator, 0, sizeof (iterator));
1523 rthdr = (struct Ieee80211RadiotapHeader *) tmpbuf;
1524 n = GNUNET_le16toh (rthdr->it_len);
1525 if ( (n < sizeof (struct Ieee80211RadiotapHeader)) || (n >= caplen))
1526 return 0; /* invalid 'it_len' */
1527 if (0 != ieee80211_radiotap_iterator_init (&iterator, rthdr, caplen))
1529 /* go through the radiotap arguments we have been given by the driver */
1530 while (0 <= ieee80211_radiotap_iterator_next (&iterator))
1532 switch (iterator.this_arg_index)
1534 case IEEE80211_RADIOTAP_TSFT:
1535 ri->ri_mactime = GNUNET_le64toh (*((uint64_t *) iterator.this_arg));
1537 case IEEE80211_RADIOTAP_DBM_ANTSIGNAL:
1540 ri->ri_power = * ((int8_t*) iterator.this_arg);
1544 case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
1547 ri->ri_power = * ((int8_t*) iterator.this_arg);
1551 case IEEE80211_RADIOTAP_DBM_ANTNOISE:
1554 ri->ri_noise = * ((int8_t*) iterator.this_arg);
1558 case IEEE80211_RADIOTAP_DB_ANTNOISE:
1561 ri->ri_noise = * ((int8_t*) iterator.this_arg);
1565 case IEEE80211_RADIOTAP_ANTENNA:
1566 ri->ri_antenna = *iterator.this_arg;
1568 case IEEE80211_RADIOTAP_CHANNEL:
1569 ri->ri_channel = *iterator.this_arg;
1572 case IEEE80211_RADIOTAP_RATE:
1573 ri->ri_rate = (*iterator.this_arg) * 500000;
1575 case IEEE80211_RADIOTAP_FLAGS:
1577 uint8_t flags = *iterator.this_arg;
1578 /* is the CRC visible at the end? if so, remove */
1579 if (0 != (flags & IEEE80211_RADIOTAP_F_FCS))
1582 caplen -= sizeof (uint32_t);
1586 case IEEE80211_RADIOTAP_RX_FLAGS:
1588 uint16_t flags = ntohs (* ((uint16_t *) iterator.this_arg));
1589 if (0 != (flags & IEEE80211_RADIOTAP_F_RX_BADFCS))
1593 } /* end of 'switch' */
1594 } /* end of the 'while' loop */
1597 case ARPHRD_IEEE80211:
1598 n = 0; /* no header */
1602 if (sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) > caplen)
1603 return 0; /* invalid */
1604 memcpy (&buf[sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame)],
1605 tmpbuf + sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame),
1606 caplen - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) - 4 /* 4 byte FCS */);
1607 return caplen - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) - 4;
1610 errno = ENOTSUP; /* unsupported format */
1615 ri->ri_channel = linux_get_channel (dev);
1617 /* detect CRC32 at the end, even if the flag wasn't set and remove it */
1618 if ( (0 == fcs_removed) &&
1619 (0 == check_crc_buf_osdep (tmpbuf + n, caplen - sizeof (uint32_t))) )
1621 /* NOTE: this heuristic can of course fail if there happens to
1622 be a matching checksum at the end. Would be good to have
1623 some data to see how often this heuristic actually works. */
1624 caplen -= sizeof (uint32_t);
1626 /* copy payload to target buffer */
1627 memcpy (buf, tmpbuf + n, caplen);
1632 /* ************end of code for reading packets from kernel ************** */
1634 /* ************other helper functions for main start here ************** */
1638 * Open the wireless network interface for reading/writing.
1640 * @param dev pointer to the device struct
1641 * @return 0 on success
1644 open_device_raw (struct HardwareInfos *dev)
1648 struct packet_mreq mr;
1649 struct sockaddr_ll sll;
1651 /* find the interface index */
1652 memset (&ifr, 0, sizeof (ifr));
1653 strncpy (ifr.ifr_name, dev->iface, IFNAMSIZ);
1654 if (-1 == ioctl (dev->fd_raw, SIOCGIFINDEX, &ifr))
1656 fprintf (stderr, "ioctl(SIOCGIFINDEX) on interface `%.*s' failed: %s\n",
1657 IFNAMSIZ, dev->iface, strerror (errno));
1661 /* lookup the hardware type */
1662 memset (&sll, 0, sizeof (sll));
1663 sll.sll_family = AF_PACKET;
1664 sll.sll_ifindex = ifr.ifr_ifindex;
1665 sll.sll_protocol = htons (ETH_P_ALL);
1666 if (-1 == ioctl (dev->fd_raw, SIOCGIFHWADDR, &ifr))
1668 fprintf (stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1669 IFNAMSIZ, dev->iface, strerror (errno));
1672 if (((ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1673 (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1674 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1675 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL)) )
1677 fprintf (stderr, "Error: interface `%.*s' is not using a supported hardware address family (got %d)\n",
1678 IFNAMSIZ, dev->iface,
1679 ifr.ifr_hwaddr.sa_family);
1683 /* lookup iw mode */
1684 memset (&wrq, 0, sizeof (struct iwreq));
1685 strncpy (wrq.ifr_name, dev->iface, IFNAMSIZ);
1686 if (-1 == ioctl (dev->fd_raw, SIOCGIWMODE, &wrq))
1688 /* most probably not supported (ie for rtap ipw interface) *
1689 * so just assume its correctly set... */
1690 wrq.u.mode = IW_MODE_MONITOR;
1693 if ( (wrq.u.mode != IW_MODE_MONITOR) &&
1694 (wrq.u.mode != IW_MODE_ADHOC) )
1696 fprintf (stderr, "Error: interface `%.*s' is not in monitor or ad-hoc mode (got %d)\n",
1697 IFNAMSIZ, dev->iface,
1702 /* Is interface st to up, broadcast & running ? */
1703 if ((ifr.ifr_flags | IFF_UP | IFF_BROADCAST | IFF_RUNNING) != ifr.ifr_flags)
1705 /* Bring interface up */
1706 ifr.ifr_flags |= IFF_UP | IFF_BROADCAST | IFF_RUNNING;
1708 if (-1 == ioctl (dev->fd_raw, SIOCSIFFLAGS, &ifr))
1710 fprintf (stderr, "ioctl(SIOCSIFFLAGS) on interface `%.*s' failed: %s\n",
1711 IFNAMSIZ, dev->iface, strerror (errno));
1716 /* bind the raw socket to the interface */
1717 if (-1 == bind (dev->fd_raw, (struct sockaddr *) &sll, sizeof (sll)))
1719 fprintf (stderr, "Failed to bind interface `%.*s': %s\n", IFNAMSIZ,
1720 dev->iface, strerror (errno));
1724 /* lookup the hardware type */
1725 if (-1 == ioctl (dev->fd_raw, SIOCGIFHWADDR, &ifr))
1727 fprintf (stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1728 IFNAMSIZ, dev->iface, strerror (errno));
1732 memcpy (&dev->pl_mac, ifr.ifr_hwaddr.sa_data, MAC_ADDR_SIZE);
1733 dev->arptype_in = ifr.ifr_hwaddr.sa_family;
1734 if ((ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1735 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1736 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1737 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL))
1739 fprintf (stderr, "Unsupported hardware link type %d on interface `%.*s'\n",
1740 ifr.ifr_hwaddr.sa_family, IFNAMSIZ, dev->iface);
1744 /* enable promiscuous mode */
1745 memset (&mr, 0, sizeof (mr));
1746 mr.mr_ifindex = sll.sll_ifindex;
1747 mr.mr_type = PACKET_MR_PROMISC;
1749 setsockopt (dev->fd_raw, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mr,
1753 "Failed to enable promiscuous mode on interface `%.*s'\n",
1763 * Test if the given interface name really corresponds to a wireless
1766 * @param iface name of the interface
1767 * @return 0 on success, 1 on error
1770 test_wlan_interface (const char *iface)
1776 ret = snprintf (strbuf, sizeof (strbuf),
1777 "/sys/class/net/%s/phy80211/subsystem",
1779 if ((ret < 0) || (ret >= sizeof (strbuf)) || (0 != stat (strbuf, &sbuf)))
1782 "Did not find 802.11 interface `%s'. Exiting.\n",
1791 * Test incoming packets mac for being our own.
1793 * @param taIeeeHeader buffer of the packet
1794 * @param dev the Hardware_Infos struct
1795 * @return 0 if mac belongs to us, 1 if mac is for another target
1798 mac_test (const struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader,
1799 const struct HardwareInfos *dev)
1801 static struct GNUNET_TRANSPORT_WLAN_MacAddress all_zeros;
1803 if ( (0 == memcmp (&taIeeeHeader->addr3, &all_zeros, MAC_ADDR_SIZE)) ||
1804 (0 == memcmp (&taIeeeHeader->addr1, &all_zeros, MAC_ADDR_SIZE)) )
1805 return 0; /* some drivers set no Macs, then assume it is all for us! */
1807 if (0 != memcmp (&taIeeeHeader->addr3, &mac_bssid_gnunet, MAC_ADDR_SIZE))
1808 return 1; /* not a GNUnet ad-hoc package */
1809 if ( (0 == memcmp (&taIeeeHeader->addr1, &dev->pl_mac, MAC_ADDR_SIZE)) ||
1810 (0 == memcmp (&taIeeeHeader->addr1, &bc_all_mac, MAC_ADDR_SIZE)) )
1811 return 0; /* for us, or broadcast */
1812 return 1; /* not for us */
1817 * Set the wlan header to sane values to make attacks more difficult
1819 * @param taIeeeHeader pointer to the header of the packet
1820 * @param dev pointer to the Hardware_Infos struct
1823 mac_set (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader,
1824 const struct HardwareInfos *dev)
1826 taIeeeHeader->frame_control = htons (IEEE80211_FC0_TYPE_DATA);
1827 taIeeeHeader->addr2 = dev->pl_mac;
1828 taIeeeHeader->addr3 = mac_bssid_gnunet;
1833 * Process data from the stdin. Takes the message, prepends the
1834 * radiotap transmission header, forces the sender MAC to be correct
1835 * and puts it into our buffer for transmission to the kernel.
1837 * @param cls pointer to the device struct ('struct HardwareInfos*')
1838 * @param hdr pointer to the start of the packet
1841 stdin_send_hw (void *cls, const struct GNUNET_MessageHeader *hdr)
1843 struct HardwareInfos *dev = cls;
1844 const struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage *header;
1845 struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *wlanheader;
1847 struct RadiotapTransmissionHeader rtheader;
1848 struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame etheader;
1850 sendsize = ntohs (hdr->size);
1852 sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage)) ||
1853 (GNUNET_MESSAGE_TYPE_WLAN_DATA_TO_HELPER != ntohs (hdr->type)) )
1855 fprintf (stderr, "Received malformed message\n");
1858 sendsize -= (sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage) - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame));
1859 if (MAXLINE < sendsize)
1861 fprintf (stderr, "Packet too big for buffer\n");
1864 header = (const struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage *) hdr;
1865 switch (dev->arptype_in)
1867 case ARPHRD_IEEE80211_PRISM:
1868 case ARPHRD_IEEE80211_FULL:
1869 case ARPHRD_IEEE80211:
1870 rtheader.header.it_version = 0;
1871 rtheader.header.it_pad = 0;
1872 rtheader.header.it_len = GNUNET_htole16 (sizeof (rtheader));
1873 rtheader.header.it_present = GNUNET_htole16 (IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK);
1874 rtheader.rate = header->rate;
1876 rtheader.txflags = GNUNET_htole16 (IEEE80211_RADIOTAP_F_TX_NOACK | IEEE80211_RADIOTAP_F_TX_NOSEQ);
1877 memcpy (write_pout.buf, &rtheader, sizeof (rtheader));
1878 memcpy (&write_pout.buf[sizeof (rtheader)], &header->frame, sendsize);
1879 wlanheader = (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *) &write_pout.buf[sizeof (rtheader)];
1881 /* payload contains MAC address, but we don't trust it, so we'll
1882 * overwrite it with OUR MAC address to prevent mischief */
1883 mac_set (wlanheader, dev);
1884 write_pout.size = sendsize + sizeof (rtheader);
1887 etheader.dst = header->frame.addr1;
1888 /* etheader.src = header->frame.addr2; --- untrusted input */
1889 etheader.src = dev->pl_mac;
1890 etheader.type = htons (ETH_P_IP);
1891 memcpy (write_pout.buf, ðeader, sizeof (etheader));
1892 memcpy (&write_pout.buf[sizeof (etheader)], &header[1], sendsize - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame));
1893 write_pout.size = sendsize - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame) + sizeof (etheader);
1897 "Unsupported ARPTYPE!\n");
1904 * Main function of the helper. This code accesses a WLAN interface
1905 * in monitoring mode (layer 2) and then forwards traffic in both
1906 * directions between the WLAN interface and stdin/stdout of this
1907 * process. Error messages are written to stdout.
1909 * @param argc number of arguments, must be 2
1910 * @param argv arguments only argument is the name of the interface (i.e. 'mon0')
1911 * @return 0 on success (never happens, as we don't return unless aborted), 1 on error
1914 main (int argc, char *argv[])
1916 struct HardwareInfos dev;
1917 char readbuf[MAXLINE];
1922 struct MessageStreamTokenizer *stdin_mst;
1926 /* assert privs so we can modify the firewall rules! */
1928 #ifdef HAVE_SETRESUID
1929 if (0 != setresuid (uid, 0, 0))
1931 fprintf (stderr, "Failed to setresuid to root: %s\n", strerror (errno));
1935 if (0 != seteuid (0))
1937 fprintf (stderr, "Failed to seteuid back to root: %s\n", strerror (errno));
1942 /* make use of SGID capabilities on POSIX */
1943 memset (&dev, 0, sizeof (dev));
1944 dev.fd_raw = socket (PF_PACKET, SOCK_RAW, htons (ETH_P_ALL));
1945 raw_eno = errno; /* remember for later */
1947 /* now that we've dropped root rights, we can do error checking */
1951 "You must specify the name of the interface as the first and only argument to this program.\n");
1952 if (-1 != dev.fd_raw)
1953 (void) close (dev.fd_raw);
1957 if (-1 == dev.fd_raw)
1959 fprintf (stderr, "Failed to create raw socket: %s\n", strerror (raw_eno));
1962 if (dev.fd_raw >= FD_SETSIZE)
1964 fprintf (stderr, "File descriptor too large for select (%d > %d)\n",
1965 dev.fd_raw, FD_SETSIZE);
1966 (void) close (dev.fd_raw);
1969 if (0 != test_wlan_interface (argv[1]))
1971 (void) close (dev.fd_raw);
1974 strncpy (dev.iface, argv[1], IFNAMSIZ);
1975 if (0 != open_device_raw (&dev))
1977 (void) close (dev.fd_raw);
1983 uid_t uid = getuid ();
1984 #ifdef HAVE_SETRESUID
1985 if (0 != setresuid (uid, uid, uid))
1987 fprintf (stderr, "Failed to setresuid: %s\n", strerror (errno));
1988 if (-1 != dev.fd_raw)
1989 (void) close (dev.fd_raw);
1993 if (0 != (setuid (uid) | seteuid (uid)))
1995 fprintf (stderr, "Failed to setuid: %s\n", strerror (errno));
1996 if (-1 != dev.fd_raw)
1997 (void) close (dev.fd_raw);
2004 /* send MAC address of the WLAN interface to STDOUT first */
2006 struct GNUNET_TRANSPORT_WLAN_HelperControlMessage macmsg;
2008 macmsg.hdr.size = htons (sizeof (macmsg));
2009 macmsg.hdr.type = htons (GNUNET_MESSAGE_TYPE_WLAN_HELPER_CONTROL);
2010 memcpy (&macmsg.mac, &dev.pl_mac, sizeof (struct GNUNET_TRANSPORT_WLAN_MacAddress));
2011 memcpy (write_std.buf, &macmsg, sizeof (macmsg));
2012 write_std.size = sizeof (macmsg);
2015 stdin_mst = mst_create (&stdin_send_hw, &dev);
2021 if ((0 == write_pout.size) && (1 == stdin_open))
2023 FD_SET (STDIN_FILENO, &rfds);
2024 maxfd = MAX (maxfd, STDIN_FILENO);
2026 if (0 == write_std.size)
2028 FD_SET (dev.fd_raw, &rfds);
2029 maxfd = MAX (maxfd, dev.fd_raw);
2032 if (0 < write_std.size)
2034 FD_SET (STDOUT_FILENO, &wfds);
2035 maxfd = MAX (maxfd, STDOUT_FILENO);
2037 if (0 < write_pout.size)
2039 FD_SET (dev.fd_raw, &wfds);
2040 maxfd = MAX (maxfd, dev.fd_raw);
2043 int retval = select (maxfd + 1, &rfds, &wfds, NULL, NULL);
2044 if ((-1 == retval) && (EINTR == errno))
2048 fprintf (stderr, "select failed: %s\n", strerror (errno));
2052 if (FD_ISSET (STDOUT_FILENO, &wfds))
2055 write (STDOUT_FILENO, write_std.buf + write_std.pos,
2056 write_std.size - write_std.pos);
2059 fprintf (stderr, "Failed to write to STDOUT: %s\n", strerror (errno));
2062 write_std.pos += ret;
2063 if (write_std.pos == write_std.size)
2069 if (FD_ISSET (dev.fd_raw, &wfds))
2072 write (dev.fd_raw, write_pout.buf + write_std.pos,
2073 write_pout.size - write_pout.pos);
2076 fprintf (stderr, "Failed to write to WLAN device: %s\n",
2080 write_pout.pos += ret;
2081 if ((write_pout.pos != write_pout.size) && (0 != ret))
2083 /* we should not get partial sends with packet-oriented devices... */
2084 fprintf (stderr, "Write error, partial send: %u/%u\n",
2085 (unsigned int) write_pout.pos,
2086 (unsigned int) write_pout.size);
2089 if (write_pout.pos == write_pout.size)
2092 write_pout.size = 0;
2096 if (FD_ISSET (STDIN_FILENO, &rfds))
2099 read (STDIN_FILENO, readbuf, sizeof (readbuf));
2102 fprintf (stderr, "Read error from STDIN: %s\n", strerror (errno));
2107 /* stop reading... */
2110 mst_receive (stdin_mst, readbuf, ret);
2113 if (FD_ISSET (dev.fd_raw, &rfds))
2115 struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *rrm;
2118 rrm = (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *) write_std.buf;
2120 linux_read (&dev, (unsigned char *) &rrm->frame,
2121 sizeof (write_std.buf)
2122 - sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage)
2123 + sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame),
2127 fprintf (stderr, "Read error from raw socket: %s\n", strerror (errno));
2130 if ((0 < ret) && (0 == mac_test (&rrm->frame, &dev)))
2132 write_std.size = ret
2133 + sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage)
2134 - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame);
2135 rrm->header.size = htons (write_std.size);
2136 rrm->header.type = htons (GNUNET_MESSAGE_TYPE_WLAN_DATA_FROM_HELPER);
2140 /* Error handling, try to clean up a bit at least */
2141 mst_destroy (stdin_mst);
2142 (void) close (dev.fd_raw);
2143 return 1; /* we never exit 'normally' */
2146 /* end of gnunet-helper-transport-wlan.c */