2 This file is part of GNUnet.
3 Copyright (C) 2010, 2011, 2012 Christian Grothoff (and other contributing authors)
4 Copyright (c) 2007, 2008, Andy Green <andy@warmcat.com>
5 Copyright 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"
115 #include <sys/socket.h>
116 #include <sys/ioctl.h>
117 #include <sys/types.h>
119 #include <sys/wait.h>
120 #include <sys/time.h>
121 #include <sys/stat.h>
122 #include <netpacket/packet.h>
123 #include <linux/if_ether.h>
124 #include <linux/if.h>
125 #include <linux/wireless.h>
126 #include <netinet/in.h>
127 #include <linux/if_tun.h>
135 #include <sys/param.h>
139 #include "gnunet_protocols.h"
140 #include "plugin_transport_wlan.h"
143 * Packet format type for the messages we receive from
144 * the kernel. This is for Ethernet 10Mbps format (no
145 * performance information included).
147 #define ARPHRD_ETHER 1
151 * Packet format type for the messages we receive from
152 * the kernel. This is for plain messages (with no
153 * performance information included).
155 #define ARPHRD_IEEE80211 801
159 * Packet format type for the messages we receive from
160 * the kernel. This is for the PRISM format.
162 #define ARPHRD_IEEE80211_PRISM 802
165 * Packet format type for the messages we receive from
166 * the kernel. This is for messages with a
167 * 'struct Ieee80211RadiotapHeader' (see below).
169 #define ARPHRD_IEEE80211_FULL 803
173 * Maximum size of a message allowed in either direction
174 * (used for our receive and sent buffers).
180 /* ********* structure of messages of type ARPHRD_IEEE80211_PRISM *********** */
183 * Device name length in PRISM frames.
184 * (In the kernel, this is "WLAN_DEVNAMELEN_MAX")
186 #define PRISM_DEVICE_NAME_LENGTH 16
189 * Monitor Frame (indicator that we have a 'struct PrismHeader').
191 #define PRISM_MSGCODE_MONITOR 0x0041
194 * Mac time element. In micro-seconds.
195 * Drivers appear to use a 64bit counter to hold mactime internal
196 * the then fill the prism header with the lower 32 bits
198 #define PRISM_DID_MACTIME 0x2041
203 #define PRISM_DID_CHANNEL 0x3041
206 * Signal element. Should be the signal strength in dbm, some people
207 * suggest that instead "100 - (strength in dbm)" is used (to make this
208 * a positive integer).
210 #define PRISM_DID_SIGNAL 0x6041
215 #define PRISM_DID_NOISE 0x7041
218 * Rate element, in units/multiples of 500Khz
220 #define PRISM_DID_RATE 0x8041
224 * Value is set (supplied)
226 #define PRISM_STATUS_OK 0
229 * Value not supplied.
231 #define PRISM_STATUS_NO_VALUE 1
235 * Values in the 'struct PrismHeader'. All in host byte order (!).
240 * This has a different ID for each parameter, see
241 * PRISM_DID_* constants.
246 * See PRISM_STATUS_*-constants. Note that they are unusual: 0 = set; 1 = not set
251 * length of data (which is always a uint32_t, but presumably this can be used
252 * to specify that fewer bytes are used (with values in 'len' from 0-4). We
262 } __attribute__ ((packed));
266 * Prism header format ('struct p80211msg' in Linux). All in host byte order (!).
271 * We expect this to be a PRISM_MSGCODE_*.
276 * The length of the entire header.
281 * Name of the device that captured the packet.
283 char devname[PRISM_DEVICE_NAME_LENGTH];
285 /* followed by 'struct PrismValue's. Documentation suggests that these
286 are typically the hosttime, mactime, channel, rssi, sq, signal, noise,
287 rate, istx and frmlen values, but documentation is sparse. So we
288 will use the 'did' fields to find out what we actually got. */
290 } __attribute__ ((packed));
293 /* ****** end of structure of messages of type ARPHRD_IEEE80211_PRISM ******* */
295 /* ********** structure of messages of type ARPHRD_IEEE80211_FULL *********** */
298 * Bits in the 'it_present' bitmask from the 'struct
299 * Ieee80211RadiotapHeader'. For each value, we give the name, data
300 * type, unit and then a description below. Note that the actual size
301 * of the extension can be bigger as arguments must be padded so that
302 * args of a given length must begin at a boundary of that length.
303 * However, note that compound args are allowed (eg, 2 x uint16_t for
304 * IEEE80211_RADIOTAP_CHANNEL) so total argument length is not a
305 * reliable indicator of alignment requirement. See also
306 * 'man 9 ieee80211_radiotap'.
312 * IEEE80211_RADIOTAP_TSFT __le64 microseconds
314 * Value in microseconds of the MAC's 64-bit 802.11 Time
315 * Synchronization Function timer when the first bit of the
316 * MPDU arrived at the MAC. For received frames, only.
318 IEEE80211_RADIOTAP_TSFT = 0,
321 * IEEE80211_RADIOTAP_FLAGS uint8_t bitmap
323 * Properties of transmitted and received frames. See flags
326 IEEE80211_RADIOTAP_FLAGS = 1,
329 * IEEE80211_RADIOTAP_RATE uint8_t 500kb/s
333 IEEE80211_RADIOTAP_RATE = 2,
336 * IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap
338 * Tx/Rx frequency in MHz, followed by flags (see below).
340 IEEE80211_RADIOTAP_CHANNEL = 3,
342 * IEEE80211_RADIOTAP_FHSS __le16 see below
344 * For frequency-hopping radios, the hop set (first byte)
345 * and pattern (second byte).
347 IEEE80211_RADIOTAP_FHSS = 4,
350 * IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from
351 * one milliwatt (dBm)
353 * RF signal power at the antenna, decibel difference from
356 IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5,
359 * IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from
360 * one milliwatt (dBm)
362 * RF noise power at the antenna, decibel difference from one
365 IEEE80211_RADIOTAP_DBM_ANTNOISE = 6,
368 * IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless
370 * Quality of Barker code lock. Unitless. Monotonically
371 * nondecreasing with "better" lock strength. Called "Signal
372 * Quality" in datasheets. (Is there a standard way to measure
375 IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
378 * IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless
380 * Transmit power expressed as unitless distance from max
381 * power set at factory calibration. 0 is max power.
382 * Monotonically nondecreasing with lower power levels.
384 IEEE80211_RADIOTAP_TX_ATTENUATION = 8,
387 * IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)
389 * Transmit power expressed as decibel distance from max power
390 * set at factory calibration. 0 is max power. Monotonically
391 * nondecreasing with lower power levels.
393 IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9,
396 * IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from
397 * one milliwatt (dBm)
399 * Transmit power expressed as dBm (decibels from a 1 milliwatt
400 * reference). This is the absolute power level measured at
403 IEEE80211_RADIOTAP_DBM_TX_POWER = 10,
406 * IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index
408 * Unitless indication of the Rx/Tx antenna for this packet.
409 * The first antenna is antenna 0.
411 IEEE80211_RADIOTAP_ANTENNA = 11,
414 * IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)
416 * RF signal power at the antenna, decibel difference from an
417 * arbitrary, fixed reference.
419 IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12,
422 * IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)
424 * RF noise power at the antenna, decibel difference from an
425 * arbitrary, fixed reference point.
427 IEEE80211_RADIOTAP_DB_ANTNOISE = 13,
430 * IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap
432 * Properties of received frames. See flags defined below.
434 IEEE80211_RADIOTAP_RX_FLAGS = 14,
437 * IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap
439 * Properties of transmitted frames. See flags defined below.
441 IEEE80211_RADIOTAP_TX_FLAGS = 15,
444 * IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data
446 * Number of rts retries a transmitted frame used.
448 IEEE80211_RADIOTAP_RTS_RETRIES = 16,
451 * IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data
453 * Number of unicast retries a transmitted frame used.
455 IEEE80211_RADIOTAP_DATA_RETRIES = 17,
458 * Extension bit, used to indicate that more bits are needed for
461 IEEE80211_RADIOTAP_EXT = 31
465 * Bitmask indicating an extension of the bitmask is used.
466 * (Mask corresponding to IEEE80211_RADIOTAP_EXT).
468 #define IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK (1 << IEEE80211_RADIOTAP_EXT)
473 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
474 * as part of a 'struct Ieee80211RadiotapHeader' extension
475 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
476 * 'it_present'). The radiotap flags are an 8-bit field.
478 * Frame was sent/received during CFP (Contention Free Period)
480 #define IEEE80211_RADIOTAP_F_CFP 0x01
483 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
484 * as part of a 'struct Ieee80211RadiotapHeader' extension
485 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
486 * 'it_present'). The radiotap flags are an 8-bit field.
488 * Frame was sent/received with short preamble
490 #define IEEE80211_RADIOTAP_F_SHORTPRE 0x02
493 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
494 * as part of a 'struct Ieee80211RadiotapHeader' extension
495 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
496 * 'it_present'). The radiotap flags are an 8-bit field.
498 * Frame was sent/received with WEP encryption
500 #define IEEE80211_RADIOTAP_F_WEP 0x04
503 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
504 * as part of a 'struct Ieee80211RadiotapHeader' extension
505 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
506 * 'it_present'). The radiotap flags are an 8-bit field.
508 * Frame was sent/received with fragmentation
510 #define IEEE80211_RADIOTAP_F_FRAG 0x08
513 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
514 * as part of a 'struct Ieee80211RadiotapHeader' extension
515 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
516 * 'it_present'). The radiotap flags are an 8-bit field.
518 * Frame includes FCS (CRC at the end that needs to be removeD).
520 #define IEEE80211_RADIOTAP_F_FCS 0x10
523 * Bit in IEEE80211_RADIOTAP_FLAGS (which we might get
524 * as part of a 'struct Ieee80211RadiotapHeader' extension
525 * if the IEEE80211_RADIOTAP_FLAGS bit is set in
526 * 'it_present'). The radiotap flags are an 8-bit field.
528 * Frame has padding between 802.11 header and payload
529 * (to 32-bit boundary)
531 #define IEEE80211_RADIOTAP_F_DATAPAD 0x20
535 * For IEEE80211_RADIOTAP_RX_FLAGS:
536 * frame failed crc check
538 #define IEEE80211_RADIOTAP_F_RX_BADFCS 0x0001
541 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
542 * failed due to excessive retries
544 #define IEEE80211_RADIOTAP_F_TX_FAIL 0x0001
547 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
548 * used cts 'protection'
550 #define IEEE80211_RADIOTAP_F_TX_CTS 0x0002
553 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
554 * used rts/cts handshake
556 #define IEEE80211_RADIOTAP_F_TX_RTS 0x0004
559 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
560 * frame should not be ACKed
562 #define IEEE80211_RADIOTAP_F_TX_NOACK 0x0008
565 * For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'):
566 * sequence number handled by userspace
568 #define IEEE80211_RADIOTAP_F_TX_NOSEQ 0x0010
572 * Generic header for radiotap messages (receiving and sending). A
573 * bit mask (it_present) determines which specific records follow.
575 * I am trying to describe precisely what the application programmer
576 * should expect in the following, and for that reason I tell the
577 * units and origin of each measurement (where it applies), or else I
578 * use sufficiently weaselly language ("is a monotonically nondecreasing
579 * function of...") that I cannot set false expectations for lawyerly
582 * The radio capture header precedes the 802.11 header.
583 * All data in the header is little endian on all platforms.
585 struct Ieee80211RadiotapHeader
588 * Version 0. Only increases for drastic changes, introduction of
589 * compatible new fields does not count.
599 * length of the whole header in bytes, including it_version,
600 * it_pad, it_len, and data fields.
605 * A bitmap telling which fields are present. Set bit 31
606 * (0x80000000) to extend the bitmap by another 32 bits. Additional
607 * extensions are made by setting bit 31.
614 * Format of the header we need to prepend to messages to be sent to the
617 struct RadiotapTransmissionHeader
621 * First we begin with the 'generic' header we also get when receiving
624 struct Ieee80211RadiotapHeader header;
627 * Transmission rate (we use 0, kernel makes up its mind anyway).
632 * Padding (we use 0). There is a requirement to pad args, so that
633 * args of a given length must begin at a boundary of that length.
634 * As our next argument is the 'it_len' with 2 bytes, we need 1 byte
640 * Transmission flags from on the IEEE80211_RADIOTAP_F_TX_* constant family.
647 * The above 'struct RadiotapTransmissionHeader' should have the
648 * following value for 'header.it_present' based on the presence of
649 * the 'rate' and 'txflags' in the overall struct.
651 #define IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK ((1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_TX_FLAGS))
656 * struct Ieee80211RadiotapHeaderIterator - tracks walk through present radiotap arguments
657 * in the radiotap header. Used when we parse radiotap packets received from the kernel.
659 struct Ieee80211RadiotapHeaderIterator
662 * pointer to the radiotap header we are walking through
664 const struct Ieee80211RadiotapHeader *rtheader;
667 * pointer to current radiotap arg
669 const uint8_t *this_arg;
672 * internal next argument pointer
677 * internal pointer to next present uint32_t (if IEEE80211_RADIOTAP_EXT is used).
679 const uint32_t *next_bitmap;
682 * length of radiotap header in host byte ordering
687 * internal shifter for current uint32_t bitmap, (it_present in host byte order),
688 * If bit 0 is set, the 'arg_index' argument is present.
690 uint32_t bitmap_shifter;
693 * IEEE80211_RADIOTAP_... index of current arg
695 unsigned int this_arg_index;
698 * internal next argument index
700 unsigned int arg_index;
705 /* ************** end of structure of ARPHRD_IEEE80211_FULL ************** */
707 /* ************************** our globals ******************************* */
710 * struct for storing the information of the hardware. There is only
717 * file descriptor for the raw socket
722 * Which format has the header that we're getting when receiving packets?
723 * Some ARPHRD_IEEE80211_XXX-value.
728 * Name of the interface, not necessarily 0-terminated (!).
730 char iface[IFNAMSIZ];
733 * MAC address of our own WLAN interface.
735 struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac;
740 * IO buffer used for buffering data in transit (to wireless or to stdout).
745 * How many bytes of data are stored in 'buf' for transmission right now?
746 * Data always starts at offset 0 and extends to 'size'.
751 * How many bytes that were stored in 'buf' did we already write to the
752 * destination? Always smaller than 'size'.
757 * Buffered data; twice the maximum allowed message size as we add some
760 char buf[MAXLINE * 2];
765 * Buffer for data read from stdin to be transmitted to the wirless card.
767 static struct SendBuffer write_pout;
770 * Buffer for data read from the wireless card to be transmitted to stdout.
772 static struct SendBuffer write_std;
776 /* *********** specialized version of server_mst.c begins here ********** */
779 * To what multiple do we align messages? 8 byte should suffice for everyone
782 #define ALIGN_FACTOR 8
785 * Smallest supported message.
787 #define MIN_BUFFER_SIZE sizeof (struct GNUNET_MessageHeader)
791 * Functions with this signature are called whenever a
792 * complete message is received by the tokenizer.
795 * @param message the actual message
797 typedef void (*MessageTokenizerCallback) (void *cls,
799 GNUNET_MessageHeader *
803 * Handle to a message stream tokenizer.
805 struct MessageStreamTokenizer
809 * Function to call on completed messages.
811 MessageTokenizerCallback cb;
819 * Size of the buffer (starting at 'hdr').
824 * How many bytes in buffer have we already processed?
829 * How many bytes in buffer are valid right now?
834 * Beginning of the buffer. Typed like this to force alignment.
836 struct GNUNET_MessageHeader *hdr;
842 * Create a message stream tokenizer.
844 * @param cb function to call on completed messages
845 * @param cb_cls closure for cb
846 * @return handle to tokenizer
848 static struct MessageStreamTokenizer *
849 mst_create (MessageTokenizerCallback cb,
852 struct MessageStreamTokenizer *ret;
854 ret = malloc (sizeof (struct MessageStreamTokenizer));
857 fprintf (stderr, "Failed to allocate buffer for tokenizer\n");
860 ret->hdr = malloc (MIN_BUFFER_SIZE);
861 if (NULL == ret->hdr)
863 fprintf (stderr, "Failed to allocate buffer for alignment\n");
866 ret->curr_buf = MIN_BUFFER_SIZE;
868 ret->cb_cls = cb_cls;
874 * Add incoming data to the receive buffer and call the
875 * callback for all complete messages.
877 * @param mst tokenizer to use
878 * @param buf input data to add
879 * @param size number of bytes in buf
880 * @return GNUNET_OK if we are done processing (need more data)
881 * GNUNET_SYSERR if the data stream is corrupt
884 mst_receive (struct MessageStreamTokenizer *mst,
885 const char *buf, size_t size)
887 const struct GNUNET_MessageHeader *hdr;
892 unsigned long offset;
896 ibuf = (char *) mst->hdr;
900 if ((mst->curr_buf - mst->off < sizeof (struct GNUNET_MessageHeader)) ||
901 (0 != (mst->off % ALIGN_FACTOR)))
903 /* need to align or need more space */
904 mst->pos -= mst->off;
905 memmove (ibuf, &ibuf[mst->off], mst->pos);
908 if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
911 GNUNET_MIN (sizeof (struct GNUNET_MessageHeader) -
912 (mst->pos - mst->off), size);
913 memcpy (&ibuf[mst->pos], buf, delta);
918 if (mst->pos - mst->off < sizeof (struct GNUNET_MessageHeader))
922 hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
923 want = ntohs (hdr->size);
924 if (want < sizeof (struct GNUNET_MessageHeader))
927 "Received invalid message from stdin\n");
930 if (mst->curr_buf - mst->off < want)
932 /* need more space */
933 mst->pos -= mst->off;
934 memmove (ibuf, &ibuf[mst->off], mst->pos);
937 if (want > mst->curr_buf)
939 mst->hdr = realloc (mst->hdr, want);
940 if (NULL == mst->hdr)
942 fprintf (stderr, "Failed to allocate buffer for alignment\n");
945 ibuf = (char *) mst->hdr;
946 mst->curr_buf = want;
948 hdr = (const struct GNUNET_MessageHeader *) &ibuf[mst->off];
949 if (mst->pos - mst->off < want)
951 delta = GNUNET_MIN (want - (mst->pos - mst->off), size);
952 memcpy (&ibuf[mst->pos], buf, delta);
957 if (mst->pos - mst->off < want)
961 mst->cb (mst->cb_cls, hdr);
963 if (mst->off == mst->pos)
965 /* reset to beginning of buffer, it's free right now! */
972 if (size < sizeof (struct GNUNET_MessageHeader))
974 offset = (unsigned long) buf;
975 need_align = (0 != offset % ALIGN_FACTOR) ? GNUNET_YES : GNUNET_NO;
976 if (GNUNET_NO == need_align)
978 /* can try to do zero-copy and process directly from original buffer */
979 hdr = (const struct GNUNET_MessageHeader *) buf;
980 want = ntohs (hdr->size);
981 if (want < sizeof (struct GNUNET_MessageHeader))
984 "Received invalid message from stdin\n");
988 break; /* or not, buffer incomplete, so copy to private buffer... */
989 mst->cb (mst->cb_cls, hdr);
995 /* need to copy to private buffer to align;
996 * yes, we go a bit more spagetti than usual here */
1002 if (size + mst->pos > mst->curr_buf)
1004 mst->hdr = realloc (mst->hdr, size + mst->pos);
1005 if (NULL == mst->hdr)
1007 fprintf (stderr, "Failed to allocate buffer for alignment\n");
1010 ibuf = (char *) mst->hdr;
1011 mst->curr_buf = size + mst->pos;
1013 if (mst->pos + size > mst->curr_buf)
1016 "Assertion failed\n");
1019 memcpy (&ibuf[mst->pos], buf, size);
1027 * Destroys a tokenizer.
1029 * @param mst tokenizer to destroy
1032 mst_destroy (struct MessageStreamTokenizer *mst)
1038 /* ***************** end of server_mst.c clone ***************** **/
1041 /* ************** code for handling of ARPHRD_IEEE80211_FULL ************** */
1044 * Radiotap header iteration
1046 * call __ieee80211_radiotap_iterator_init() to init a semi-opaque iterator
1047 * struct Ieee80211RadiotapHeaderIterator (no need to init the struct beforehand)
1048 * then loop calling __ieee80211_radiotap_iterator_next()... it returns -1
1049 * if there are no more args in the header, or the next argument type index
1050 * that is present. The iterator's this_arg member points to the start of the
1051 * argument associated with the current argument index that is present,
1052 * which can be found in the iterator's this_arg_index member. This arg
1053 * index corresponds to the IEEE80211_RADIOTAP_... defines.
1055 * @param iterator iterator to initialize
1056 * @param radiotap_header message to parse
1057 * @param max_length number of valid bytes in radiotap_header
1058 * @return 0 on success, -1 on error
1061 ieee80211_radiotap_iterator_init (struct Ieee80211RadiotapHeaderIterator *iterator,
1062 const struct Ieee80211RadiotapHeader *radiotap_header,
1065 if ( (iterator == NULL) ||
1066 (radiotap_header == NULL) )
1069 /* Linux only supports version 0 radiotap format */
1070 if (0 != radiotap_header->it_version)
1073 /* sanity check for allowed length and radiotap length field */
1074 if ( (max_length < sizeof (struct Ieee80211RadiotapHeader)) ||
1075 (max_length < (GNUNET_le16toh (radiotap_header->it_len))) )
1078 memset (iterator, 0, sizeof (struct Ieee80211RadiotapHeaderIterator));
1079 iterator->rtheader = radiotap_header;
1080 iterator->max_length = GNUNET_le16toh (radiotap_header->it_len);
1081 iterator->bitmap_shifter = GNUNET_le32toh (radiotap_header->it_present);
1082 iterator->arg = ((uint8_t *) radiotap_header) + sizeof (struct Ieee80211RadiotapHeader);
1084 /* find payload start allowing for extended bitmap(s) */
1085 if (0 != (iterator->bitmap_shifter & IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK))
1087 while (GNUNET_le32toh (*((uint32_t *) iterator->arg)) & IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK)
1089 iterator->arg += sizeof (uint32_t);
1091 * check for insanity where the present bitmaps
1092 * keep claiming to extend up to or even beyond the
1093 * stated radiotap header length
1095 if (iterator->arg - ((uint8_t*) iterator->rtheader) > iterator->max_length)
1098 iterator->arg += sizeof (uint32_t);
1100 * no need to check again for blowing past stated radiotap
1101 * header length, becuase ieee80211_radiotap_iterator_next
1102 * checks it before it is dereferenced
1105 /* we are all initialized happily */
1111 * Returns the next radiotap parser iterator arg.
1113 * This function returns the next radiotap arg index (IEEE80211_RADIOTAP_...)
1114 * and sets iterator->this_arg to point to the payload for the arg. It takes
1115 * care of alignment handling and extended present fields. interator->this_arg
1116 * can be changed by the caller. The args pointed to are in little-endian
1119 * @param iterator: radiotap_iterator to move to next arg (if any)
1120 * @return next present arg index on success or -1 if no more or error
1123 ieee80211_radiotap_iterator_next (struct Ieee80211RadiotapHeaderIterator *iterator)
1126 * small length lookup table for all radiotap types we heard of
1127 * starting from b0 in the bitmap, so we can walk the payload
1128 * area of the radiotap header
1130 * There is a requirement to pad args, so that args
1131 * of a given length must begin at a boundary of that length
1132 * -- but note that compound args are allowed (eg, 2 x uint16_t
1133 * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
1134 * a reliable indicator of alignment requirement.
1136 * upper nybble: content alignment for arg
1137 * lower nybble: content length for arg
1140 static const uint8_t rt_sizes[] = {
1141 [IEEE80211_RADIOTAP_TSFT] = 0x88,
1142 [IEEE80211_RADIOTAP_FLAGS] = 0x11,
1143 [IEEE80211_RADIOTAP_RATE] = 0x11,
1144 [IEEE80211_RADIOTAP_CHANNEL] = 0x24,
1145 [IEEE80211_RADIOTAP_FHSS] = 0x22,
1146 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = 0x11,
1147 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = 0x11,
1148 [IEEE80211_RADIOTAP_LOCK_QUALITY] = 0x22,
1149 [IEEE80211_RADIOTAP_TX_ATTENUATION] = 0x22,
1150 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = 0x22,
1151 [IEEE80211_RADIOTAP_DBM_TX_POWER] = 0x11,
1152 [IEEE80211_RADIOTAP_ANTENNA] = 0x11,
1153 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = 0x11,
1154 [IEEE80211_RADIOTAP_DB_ANTNOISE] = 0x11,
1155 [IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
1156 [IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
1157 [IEEE80211_RADIOTAP_RTS_RETRIES] = 0x11,
1158 [IEEE80211_RADIOTAP_DATA_RETRIES] = 0x11
1160 * add more here as they are defined in
1161 * include/net/ieee80211_radiotap.h
1166 * for every radiotap entry we can at
1167 * least skip (by knowing the length)...
1169 while (iterator->arg_index < sizeof (rt_sizes))
1171 int hit = (0 != (iterator->bitmap_shifter & 1));
1175 unsigned int wanted_alignment;
1176 unsigned int unalignment;
1178 * arg is present, account for alignment padding
1179 * 8-bit args can be at any alignment
1180 * 16-bit args must start on 16-bit boundary
1181 * 32-bit args must start on 32-bit boundary
1182 * 64-bit args must start on 64-bit boundary
1184 * note that total arg size can differ from alignment of
1185 * elements inside arg, so we use upper nybble of length table
1186 * to base alignment on. First, 'wanted_alignment' is set to be
1187 * 1 for 8-bit, 2 for 16-bit, 4 for 32-bit and 8 for 64-bit
1188 * arguments. Then, we calculate the 'unalignment' (how many
1189 * bytes we are over by taking the difference of 'arg' and the
1190 * overall starting point modulo the desired alignment. As
1191 * desired alignments are powers of two, we can do modulo with
1192 * binary "&" (and also avoid the possibility of a division by
1193 * zero if the 'rt_sizes' table contains bogus entries).
1195 * also note: these alignments are relative to the start of the
1196 * radiotap header. There is no guarantee that the radiotap
1197 * header itself is aligned on any kind of boundary, thus we
1198 * need to really look at the delta here.
1200 wanted_alignment = rt_sizes[iterator->arg_index] >> 4;
1201 unalignment = (((void *) iterator->arg) - ((void *) iterator->rtheader)) & (wanted_alignment - 1);
1202 if (0 != unalignment)
1204 /* need padding (by 'wanted_alignment - unalignment') */
1205 iterator->arg_index += wanted_alignment - unalignment;
1209 * this is what we will return to user, but we need to
1210 * move on first so next call has something fresh to test
1212 iterator->this_arg_index = iterator->arg_index;
1213 iterator->this_arg = iterator->arg;
1215 /* internally move on the size of this arg (using lower nybble from
1217 iterator->arg += rt_sizes[iterator->arg_index] & 0x0f;
1220 * check for insanity where we are given a bitmap that
1221 * claims to have more arg content than the length of the
1222 * radiotap section. We will normally end up equalling this
1223 * max_length on the last arg, never exceeding it.
1225 if ((((void *) iterator->arg) - ((void *) iterator->rtheader)) > iterator->max_length)
1229 /* Now, move on to next bit / next entry */
1230 iterator->arg_index++;
1232 if (0 == (iterator->arg_index % 32))
1234 /* completed current uint32_t bitmap */
1235 if (0 != (iterator->bitmap_shifter & 1))
1237 /* bit 31 was set, there is more; move to next uint32_t bitmap */
1238 iterator->bitmap_shifter = GNUNET_le32toh (*iterator->next_bitmap);
1239 iterator->next_bitmap++;
1243 /* no more bitmaps: end (by setting arg_index to high, unsupported value) */
1244 iterator->arg_index = sizeof (rt_sizes);
1249 /* just try the next bit (while loop will move on) */
1250 iterator->bitmap_shifter >>= 1;
1253 /* if we found a valid arg earlier, return it now */
1255 return iterator->this_arg_index;
1258 /* we don't know how to handle any more args (or there are no more),
1259 so we're done (this is not an error) */
1265 * Calculate crc32, the start of the calculation
1267 * @param buf buffer to calc the crc
1268 * @param len len of the buffer
1271 static unsigned long
1272 calc_crc_osdep (const unsigned char *buf, size_t len)
1274 static const unsigned long int crc_tbl_osdep[256] = {
1275 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
1276 0xE963A535, 0x9E6495A3,
1277 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,
1278 0xE7B82D07, 0x90BF1D91,
1279 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB,
1280 0xF4D4B551, 0x83D385C7,
1281 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
1282 0xFA0F3D63, 0x8D080DF5,
1283 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447,
1284 0xD20D85FD, 0xA50AB56B,
1285 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75,
1286 0xDCD60DCF, 0xABD13D59,
1287 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
1288 0xCFBA9599, 0xB8BDA50F,
1289 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11,
1290 0xC1611DAB, 0xB6662D3D,
1291 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,
1292 0x9FBFE4A5, 0xE8B8D433,
1293 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
1294 0x91646C97, 0xE6635C01,
1295 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B,
1296 0x8208F4C1, 0xF50FC457,
1297 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49,
1298 0x8CD37CF3, 0xFBD44C65,
1299 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
1300 0xA4D1C46D, 0xD3D6F4FB,
1301 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,
1302 0xAA0A4C5F, 0xDD0D7CC9,
1303 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3,
1304 0xB966D409, 0xCE61E49F,
1305 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
1306 0xB7BD5C3B, 0xC0BA6CAD,
1307 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF,
1308 0x04DB2615, 0x73DC1683,
1309 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,
1310 0x0A00AE27, 0x7D079EB1,
1311 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
1312 0x196C3671, 0x6E6B06E7,
1313 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9,
1314 0x17B7BE43, 0x60B08ED5,
1315 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767,
1316 0x3FB506DD, 0x48B2364B,
1317 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
1318 0x316E8EEF, 0x4669BE79,
1319 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703,
1320 0x220216B9, 0x5505262F,
1321 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,
1322 0x2CD99E8B, 0x5BDEAE1D,
1323 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
1324 0x72076785, 0x05005713,
1325 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,
1326 0x7CDCEFB7, 0x0BDBDF21,
1327 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B,
1328 0x6FB077E1, 0x18B74777,
1329 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
1330 0x616BFFD3, 0x166CCF45,
1331 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,
1332 0x4969474D, 0x3E6E77DB,
1333 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5,
1334 0x47B2CF7F, 0x30B5FFE9,
1335 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
1336 0x54DE5729, 0x23D967BF,
1337 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1,
1338 0x5A05DF1B, 0x2D02EF8D
1341 unsigned long crc = 0xFFFFFFFF;
1343 for (; len > 0; len--, buf++)
1344 crc = crc_tbl_osdep[(crc ^ *buf) & 0xFF] ^ (crc >> 8);
1350 * Calculate and check crc of the wlan packet
1352 * @param buf buffer of the packet, with len + 4 bytes of data,
1353 * the last 4 bytes being the checksum
1354 * @param len length of the payload in data
1355 * @return 0 on success (checksum matches), 1 on error
1358 check_crc_buf_osdep (const unsigned char *buf, size_t len)
1362 crc = calc_crc_osdep (buf, len);
1364 if (((crc) & 0xFF) == buf[0] && ((crc >> 8) & 0xFF) == buf[1] &&
1365 ((crc >> 16) & 0xFF) == buf[2] && ((crc >> 24) & 0xFF) == buf[3])
1371 /* ************end of code for handling of ARPHRD_IEEE80211_FULL ************** */
1374 /* ************beginning of code for reading packets from kernel ************** */
1377 * Return the channel from the frequency (in Mhz)
1379 * @param frequency of the channel
1380 * @return number of the channel
1383 get_channel_from_frequency (int32_t frequency)
1385 if (frequency >= 2412 && frequency <= 2472)
1386 return (frequency - 2407) / 5;
1387 if (frequency == 2484)
1389 if (frequency >= 5000 && frequency <= 6100)
1390 return (frequency - 5000) / 5;
1396 * Get the channel used by our WLAN interface.
1398 * @param dev pointer to the dev struct of the card
1399 * @return channel number, -1 on error
1402 linux_get_channel (const struct HardwareInfos *dev)
1407 memset (&wrq, 0, sizeof (struct iwreq));
1408 strncpy (wrq.ifr_name, dev->iface, IFNAMSIZ);
1409 if (0 > ioctl (dev->fd_raw, SIOCGIWFREQ, &wrq))
1411 frequency = wrq.u.freq.m; /* 'iw_freq' defines 'm' as '__s32', so we keep it signed */
1412 if (100000000 < frequency)
1413 frequency /= 100000;
1414 else if (1000000 < frequency)
1416 if (1000 < frequency)
1417 return get_channel_from_frequency (frequency);
1423 * Read from the raw socket (the wlan card), parse the packet and
1424 * put the result into the buffer for transmission to 'stdout'.
1426 * @param dev pointer to the struct of the wlan card
1427 * @param buf buffer to read to; first bytes will be the 'struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame',
1428 * followed by the actual payload
1429 * @param buf_size size of the buffer
1430 * @param ri where to write radiotap_rx info
1431 * @return number of bytes written to 'buf'
1434 linux_read (struct HardwareInfos *dev,
1435 unsigned char *buf, size_t buf_size,
1436 struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *ri)
1438 unsigned char tmpbuf[buf_size];
1443 int got_channel = 0;
1444 int fcs_removed = 0;
1446 caplen = read (dev->fd_raw, tmpbuf, buf_size);
1449 if (EAGAIN == errno)
1451 fprintf (stderr, "Failed to read from RAW socket: %s\n", strerror (errno));
1455 memset (ri, 0, sizeof (*ri));
1456 switch (dev->arptype_in)
1458 case ARPHRD_IEEE80211_PRISM:
1460 const struct PrismHeader *ph;
1462 ph = (const struct PrismHeader*) tmpbuf;
1464 if ( (n < 8) || (n >= caplen) )
1465 return 0; /* invalid format */
1466 if ( (PRISM_MSGCODE_MONITOR == ph->msgcode) &&
1467 (n >= sizeof (struct PrismHeader)) )
1471 struct PrismValue pv;
1473 left = n - sizeof (struct PrismHeader);
1474 pos = (const char *) &ph[1];
1475 while (left > sizeof (struct PrismValue))
1477 left -= sizeof (struct PrismValue);
1478 memcpy (&pv, pos, sizeof (struct PrismValue));
1479 pos += sizeof (struct PrismValue);
1483 case PRISM_DID_NOISE:
1484 if (PRISM_STATUS_OK == pv.status)
1486 ri->ri_noise = pv.data;
1487 /* got_noise = 1; */
1490 case PRISM_DID_RATE:
1491 if (PRISM_STATUS_OK == pv.status)
1492 ri->ri_rate = pv.data * 500000;
1494 case PRISM_DID_CHANNEL:
1495 if (PRISM_STATUS_OK == pv.status)
1497 ri->ri_channel = pv.data;
1501 case PRISM_DID_MACTIME:
1502 if (PRISM_STATUS_OK == pv.status)
1503 ri->ri_mactime = pv.data;
1505 case PRISM_DID_SIGNAL:
1506 if (PRISM_STATUS_OK == pv.status)
1508 ri->ri_power = pv.data;
1509 /* got_signal = 1; */
1515 if ( (n < 8) || (n >= caplen) )
1516 return 0; /* invalid format */
1519 case ARPHRD_IEEE80211_FULL:
1521 struct Ieee80211RadiotapHeaderIterator iterator;
1522 struct Ieee80211RadiotapHeader *rthdr;
1524 memset (&iterator, 0, sizeof (iterator));
1525 rthdr = (struct Ieee80211RadiotapHeader *) tmpbuf;
1526 n = GNUNET_le16toh (rthdr->it_len);
1527 if ( (n < sizeof (struct Ieee80211RadiotapHeader)) || (n >= caplen))
1528 return 0; /* invalid 'it_len' */
1529 if (0 != ieee80211_radiotap_iterator_init (&iterator, rthdr, caplen))
1531 /* go through the radiotap arguments we have been given by the driver */
1532 while (0 <= ieee80211_radiotap_iterator_next (&iterator))
1534 switch (iterator.this_arg_index)
1536 case IEEE80211_RADIOTAP_TSFT:
1537 ri->ri_mactime = GNUNET_le64toh (*((uint64_t *) iterator.this_arg));
1539 case IEEE80211_RADIOTAP_DBM_ANTSIGNAL:
1542 ri->ri_power = * ((int8_t*) iterator.this_arg);
1546 case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
1549 ri->ri_power = * ((int8_t*) iterator.this_arg);
1553 case IEEE80211_RADIOTAP_DBM_ANTNOISE:
1556 ri->ri_noise = * ((int8_t*) iterator.this_arg);
1560 case IEEE80211_RADIOTAP_DB_ANTNOISE:
1563 ri->ri_noise = * ((int8_t*) iterator.this_arg);
1567 case IEEE80211_RADIOTAP_ANTENNA:
1568 ri->ri_antenna = *iterator.this_arg;
1570 case IEEE80211_RADIOTAP_CHANNEL:
1571 ri->ri_channel = *iterator.this_arg;
1574 case IEEE80211_RADIOTAP_RATE:
1575 ri->ri_rate = (*iterator.this_arg) * 500000;
1577 case IEEE80211_RADIOTAP_FLAGS:
1579 uint8_t flags = *iterator.this_arg;
1580 /* is the CRC visible at the end? if so, remove */
1581 if (0 != (flags & IEEE80211_RADIOTAP_F_FCS))
1584 caplen -= sizeof (uint32_t);
1588 case IEEE80211_RADIOTAP_RX_FLAGS:
1590 uint16_t flags = ntohs (* ((uint16_t *) iterator.this_arg));
1591 if (0 != (flags & IEEE80211_RADIOTAP_F_RX_BADFCS))
1595 } /* end of 'switch' */
1596 } /* end of the 'while' loop */
1599 case ARPHRD_IEEE80211:
1600 n = 0; /* no header */
1604 if (sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) > caplen)
1605 return 0; /* invalid */
1606 memcpy (&buf[sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame)],
1607 tmpbuf + sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame),
1608 caplen - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) - 4 /* 4 byte FCS */);
1609 return caplen - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) - 4;
1612 errno = ENOTSUP; /* unsupported format */
1617 ri->ri_channel = linux_get_channel (dev);
1619 /* detect CRC32 at the end, even if the flag wasn't set and remove it */
1620 if ( (0 == fcs_removed) &&
1621 (0 == check_crc_buf_osdep (tmpbuf + n, caplen - sizeof (uint32_t))) )
1623 /* NOTE: this heuristic can of course fail if there happens to
1624 be a matching checksum at the end. Would be good to have
1625 some data to see how often this heuristic actually works. */
1626 caplen -= sizeof (uint32_t);
1628 /* copy payload to target buffer */
1629 memcpy (buf, tmpbuf + n, caplen);
1634 /* ************end of code for reading packets from kernel ************** */
1636 /* ************other helper functions for main start here ************** */
1640 * Open the wireless network interface for reading/writing.
1642 * @param dev pointer to the device struct
1643 * @return 0 on success
1646 open_device_raw (struct HardwareInfos *dev)
1650 struct packet_mreq mr;
1651 struct sockaddr_ll sll;
1653 /* find the interface index */
1654 memset (&ifr, 0, sizeof (ifr));
1655 strncpy (ifr.ifr_name, dev->iface, IFNAMSIZ);
1656 if (-1 == ioctl (dev->fd_raw, SIOCGIFINDEX, &ifr))
1658 fprintf (stderr, "ioctl(SIOCGIFINDEX) on interface `%.*s' failed: %s\n",
1659 IFNAMSIZ, dev->iface, strerror (errno));
1663 /* lookup the hardware type */
1664 memset (&sll, 0, sizeof (sll));
1665 sll.sll_family = AF_PACKET;
1666 sll.sll_ifindex = ifr.ifr_ifindex;
1667 sll.sll_protocol = htons (ETH_P_ALL);
1668 if (-1 == ioctl (dev->fd_raw, SIOCGIFHWADDR, &ifr))
1670 fprintf (stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1671 IFNAMSIZ, dev->iface, strerror (errno));
1674 if (((ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1675 (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1676 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1677 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL)) )
1679 fprintf (stderr, "Error: interface `%.*s' is not using a supported hardware address family (got %d)\n",
1680 IFNAMSIZ, dev->iface,
1681 ifr.ifr_hwaddr.sa_family);
1685 /* lookup iw mode */
1686 memset (&wrq, 0, sizeof (struct iwreq));
1687 strncpy (wrq.ifr_name, dev->iface, IFNAMSIZ);
1688 if (-1 == ioctl (dev->fd_raw, SIOCGIWMODE, &wrq))
1690 /* most probably not supported (ie for rtap ipw interface) *
1691 * so just assume its correctly set... */
1692 wrq.u.mode = IW_MODE_MONITOR;
1695 if ( (wrq.u.mode != IW_MODE_MONITOR) &&
1696 (wrq.u.mode != IW_MODE_ADHOC) )
1698 fprintf (stderr, "Error: interface `%.*s' is not in monitor or ad-hoc mode (got %d)\n",
1699 IFNAMSIZ, dev->iface,
1704 /* Is interface st to up, broadcast & running ? */
1705 if ((ifr.ifr_flags | IFF_UP | IFF_BROADCAST | IFF_RUNNING) != ifr.ifr_flags)
1707 /* Bring interface up */
1708 ifr.ifr_flags |= IFF_UP | IFF_BROADCAST | IFF_RUNNING;
1710 if (-1 == ioctl (dev->fd_raw, SIOCSIFFLAGS, &ifr))
1712 fprintf (stderr, "ioctl(SIOCSIFFLAGS) on interface `%.*s' failed: %s\n",
1713 IFNAMSIZ, dev->iface, strerror (errno));
1718 /* bind the raw socket to the interface */
1719 if (-1 == bind (dev->fd_raw, (struct sockaddr *) &sll, sizeof (sll)))
1721 fprintf (stderr, "Failed to bind interface `%.*s': %s\n", IFNAMSIZ,
1722 dev->iface, strerror (errno));
1726 /* lookup the hardware type */
1727 if (-1 == ioctl (dev->fd_raw, SIOCGIFHWADDR, &ifr))
1729 fprintf (stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1730 IFNAMSIZ, dev->iface, strerror (errno));
1734 memcpy (&dev->pl_mac, ifr.ifr_hwaddr.sa_data, MAC_ADDR_SIZE);
1735 dev->arptype_in = ifr.ifr_hwaddr.sa_family;
1736 if ((ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1737 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1738 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1739 (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL))
1741 fprintf (stderr, "Unsupported hardware link type %d on interface `%.*s'\n",
1742 ifr.ifr_hwaddr.sa_family, IFNAMSIZ, dev->iface);
1746 /* enable promiscuous mode */
1747 memset (&mr, 0, sizeof (mr));
1748 mr.mr_ifindex = sll.sll_ifindex;
1749 mr.mr_type = PACKET_MR_PROMISC;
1751 setsockopt (dev->fd_raw, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mr,
1755 "Failed to enable promiscuous mode on interface `%.*s'\n",
1765 * Test if the given interface name really corresponds to a wireless
1768 * @param iface name of the interface
1769 * @return 0 on success, 1 on error
1772 test_wlan_interface (const char *iface)
1778 ret = snprintf (strbuf, sizeof (strbuf),
1779 "/sys/class/net/%s/phy80211/subsystem",
1781 if ((ret < 0) || (ret >= sizeof (strbuf)) || (0 != stat (strbuf, &sbuf)))
1784 "Did not find 802.11 interface `%s'. Exiting.\n",
1793 * Test incoming packets mac for being our own.
1795 * @param taIeeeHeader buffer of the packet
1796 * @param dev the Hardware_Infos struct
1797 * @return 0 if mac belongs to us, 1 if mac is for another target
1800 mac_test (const struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader,
1801 const struct HardwareInfos *dev)
1803 static struct GNUNET_TRANSPORT_WLAN_MacAddress all_zeros;
1805 if ( (0 == memcmp (&taIeeeHeader->addr3, &all_zeros, MAC_ADDR_SIZE)) ||
1806 (0 == memcmp (&taIeeeHeader->addr1, &all_zeros, MAC_ADDR_SIZE)) )
1807 return 0; /* some drivers set no Macs, then assume it is all for us! */
1809 if (0 != memcmp (&taIeeeHeader->addr3, &mac_bssid_gnunet, MAC_ADDR_SIZE))
1810 return 1; /* not a GNUnet ad-hoc package */
1811 if ( (0 == memcmp (&taIeeeHeader->addr1, &dev->pl_mac, MAC_ADDR_SIZE)) ||
1812 (0 == memcmp (&taIeeeHeader->addr1, &bc_all_mac, MAC_ADDR_SIZE)) )
1813 return 0; /* for us, or broadcast */
1814 return 1; /* not for us */
1819 * Set the wlan header to sane values to make attacks more difficult
1821 * @param taIeeeHeader pointer to the header of the packet
1822 * @param dev pointer to the Hardware_Infos struct
1825 mac_set (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader,
1826 const struct HardwareInfos *dev)
1828 taIeeeHeader->frame_control = htons (IEEE80211_FC0_TYPE_DATA);
1829 taIeeeHeader->addr2 = dev->pl_mac;
1830 taIeeeHeader->addr3 = mac_bssid_gnunet;
1835 * Process data from the stdin. Takes the message, prepends the
1836 * radiotap transmission header, forces the sender MAC to be correct
1837 * and puts it into our buffer for transmission to the kernel.
1839 * @param cls pointer to the device struct ('struct HardwareInfos*')
1840 * @param hdr pointer to the start of the packet
1843 stdin_send_hw (void *cls, const struct GNUNET_MessageHeader *hdr)
1845 struct HardwareInfos *dev = cls;
1846 const struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage *header;
1847 struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *wlanheader;
1849 struct RadiotapTransmissionHeader rtheader;
1850 struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame etheader;
1852 sendsize = ntohs (hdr->size);
1854 sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage)) ||
1855 (GNUNET_MESSAGE_TYPE_WLAN_DATA_TO_HELPER != ntohs (hdr->type)) )
1857 fprintf (stderr, "Received malformed message\n");
1860 sendsize -= (sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage) - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame));
1861 if (MAXLINE < sendsize)
1863 fprintf (stderr, "Packet too big for buffer\n");
1866 header = (const struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage *) hdr;
1867 switch (dev->arptype_in)
1869 case ARPHRD_IEEE80211_PRISM:
1870 case ARPHRD_IEEE80211_FULL:
1871 case ARPHRD_IEEE80211:
1872 rtheader.header.it_version = 0;
1873 rtheader.header.it_pad = 0;
1874 rtheader.header.it_len = GNUNET_htole16 (sizeof (rtheader));
1875 rtheader.header.it_present = GNUNET_htole16 (IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK);
1876 rtheader.rate = header->rate;
1878 rtheader.txflags = GNUNET_htole16 (IEEE80211_RADIOTAP_F_TX_NOACK | IEEE80211_RADIOTAP_F_TX_NOSEQ);
1879 memcpy (write_pout.buf, &rtheader, sizeof (rtheader));
1880 memcpy (&write_pout.buf[sizeof (rtheader)], &header->frame, sendsize);
1881 wlanheader = (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *) &write_pout.buf[sizeof (rtheader)];
1883 /* payload contains MAC address, but we don't trust it, so we'll
1884 * overwrite it with OUR MAC address to prevent mischief */
1885 mac_set (wlanheader, dev);
1886 write_pout.size = sendsize + sizeof (rtheader);
1889 etheader.dst = header->frame.addr1;
1890 /* etheader.src = header->frame.addr2; --- untrusted input */
1891 etheader.src = dev->pl_mac;
1892 etheader.type = htons (ETH_P_IP);
1893 memcpy (write_pout.buf, ðeader, sizeof (etheader));
1894 memcpy (&write_pout.buf[sizeof (etheader)], &header[1], sendsize - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame));
1895 write_pout.size = sendsize - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame) + sizeof (etheader);
1899 "Unsupported ARPTYPE!\n");
1906 * Main function of the helper. This code accesses a WLAN interface
1907 * in monitoring mode (layer 2) and then forwards traffic in both
1908 * directions between the WLAN interface and stdin/stdout of this
1909 * process. Error messages are written to stdout.
1911 * @param argc number of arguments, must be 2
1912 * @param argv arguments only argument is the name of the interface (i.e. 'mon0')
1913 * @return 0 on success (never happens, as we don't return unless aborted), 1 on error
1916 main (int argc, char *argv[])
1918 struct HardwareInfos dev;
1919 char readbuf[MAXLINE];
1924 struct MessageStreamTokenizer *stdin_mst;
1928 /* assert privs so we can modify the firewall rules! */
1930 #ifdef HAVE_SETRESUID
1931 if (0 != setresuid (uid, 0, 0))
1933 fprintf (stderr, "Failed to setresuid to root: %s\n", strerror (errno));
1937 if (0 != seteuid (0))
1939 fprintf (stderr, "Failed to seteuid back to root: %s\n", strerror (errno));
1944 /* make use of SGID capabilities on POSIX */
1945 memset (&dev, 0, sizeof (dev));
1946 dev.fd_raw = socket (PF_PACKET, SOCK_RAW, htons (ETH_P_ALL));
1947 raw_eno = errno; /* remember for later */
1949 /* now that we've dropped root rights, we can do error checking */
1953 "You must specify the name of the interface as the first and only argument to this program.\n");
1954 if (-1 != dev.fd_raw)
1955 (void) close (dev.fd_raw);
1959 if (-1 == dev.fd_raw)
1961 fprintf (stderr, "Failed to create raw socket: %s\n", strerror (raw_eno));
1964 if (dev.fd_raw >= FD_SETSIZE)
1966 fprintf (stderr, "File descriptor too large for select (%d > %d)\n",
1967 dev.fd_raw, FD_SETSIZE);
1968 (void) close (dev.fd_raw);
1971 if (0 != test_wlan_interface (argv[1]))
1973 (void) close (dev.fd_raw);
1976 strncpy (dev.iface, argv[1], IFNAMSIZ);
1977 if (0 != open_device_raw (&dev))
1979 (void) close (dev.fd_raw);
1985 uid_t uid = getuid ();
1986 #ifdef HAVE_SETRESUID
1987 if (0 != setresuid (uid, uid, uid))
1989 fprintf (stderr, "Failed to setresuid: %s\n", strerror (errno));
1990 if (-1 != dev.fd_raw)
1991 (void) close (dev.fd_raw);
1995 if (0 != (setuid (uid) | seteuid (uid)))
1997 fprintf (stderr, "Failed to setuid: %s\n", strerror (errno));
1998 if (-1 != dev.fd_raw)
1999 (void) close (dev.fd_raw);
2006 /* send MAC address of the WLAN interface to STDOUT first */
2008 struct GNUNET_TRANSPORT_WLAN_HelperControlMessage macmsg;
2010 macmsg.hdr.size = htons (sizeof (macmsg));
2011 macmsg.hdr.type = htons (GNUNET_MESSAGE_TYPE_WLAN_HELPER_CONTROL);
2012 memcpy (&macmsg.mac, &dev.pl_mac, sizeof (struct GNUNET_TRANSPORT_WLAN_MacAddress));
2013 memcpy (write_std.buf, &macmsg, sizeof (macmsg));
2014 write_std.size = sizeof (macmsg);
2017 stdin_mst = mst_create (&stdin_send_hw, &dev);
2023 if ((0 == write_pout.size) && (1 == stdin_open))
2025 FD_SET (STDIN_FILENO, &rfds);
2026 maxfd = MAX (maxfd, STDIN_FILENO);
2028 if (0 == write_std.size)
2030 FD_SET (dev.fd_raw, &rfds);
2031 maxfd = MAX (maxfd, dev.fd_raw);
2034 if (0 < write_std.size)
2036 FD_SET (STDOUT_FILENO, &wfds);
2037 maxfd = MAX (maxfd, STDOUT_FILENO);
2039 if (0 < write_pout.size)
2041 FD_SET (dev.fd_raw, &wfds);
2042 maxfd = MAX (maxfd, dev.fd_raw);
2045 int retval = select (maxfd + 1, &rfds, &wfds, NULL, NULL);
2046 if ((-1 == retval) && (EINTR == errno))
2050 fprintf (stderr, "select failed: %s\n", strerror (errno));
2054 if (FD_ISSET (STDOUT_FILENO, &wfds))
2057 write (STDOUT_FILENO, write_std.buf + write_std.pos,
2058 write_std.size - write_std.pos);
2061 fprintf (stderr, "Failed to write to STDOUT: %s\n", strerror (errno));
2064 write_std.pos += ret;
2065 if (write_std.pos == write_std.size)
2071 if (FD_ISSET (dev.fd_raw, &wfds))
2074 write (dev.fd_raw, write_pout.buf + write_std.pos,
2075 write_pout.size - write_pout.pos);
2078 fprintf (stderr, "Failed to write to WLAN device: %s\n",
2082 write_pout.pos += ret;
2083 if ((write_pout.pos != write_pout.size) && (0 != ret))
2085 /* we should not get partial sends with packet-oriented devices... */
2086 fprintf (stderr, "Write error, partial send: %u/%u\n",
2087 (unsigned int) write_pout.pos,
2088 (unsigned int) write_pout.size);
2091 if (write_pout.pos == write_pout.size)
2094 write_pout.size = 0;
2098 if (FD_ISSET (STDIN_FILENO, &rfds))
2101 read (STDIN_FILENO, readbuf, sizeof (readbuf));
2104 fprintf (stderr, "Read error from STDIN: %s\n", strerror (errno));
2109 /* stop reading... */
2112 mst_receive (stdin_mst, readbuf, ret);
2115 if (FD_ISSET (dev.fd_raw, &rfds))
2117 struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *rrm;
2120 rrm = (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *) write_std.buf;
2122 linux_read (&dev, (unsigned char *) &rrm->frame,
2123 sizeof (write_std.buf)
2124 - sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage)
2125 + sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame),
2129 fprintf (stderr, "Read error from raw socket: %s\n", strerror (errno));
2132 if ((0 < ret) && (0 == mac_test (&rrm->frame, &dev)))
2134 write_std.size = ret
2135 + sizeof (struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage)
2136 - sizeof (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame);
2137 rrm->header.size = htons (write_std.size);
2138 rrm->header.type = htons (GNUNET_MESSAGE_TYPE_WLAN_DATA_FROM_HELPER);
2142 /* Error handling, try to clean up a bit at least */
2143 mst_destroy (stdin_mst);
2144 (void) close (dev.fd_raw);
2145 return 1; /* we never exit 'normally' */
2148 /* end of gnunet-helper-transport-wlan.c */