GNUnet  0.10.x
Data Structures | Macros | Typedefs | Enumerations | Functions | Variables
gnunet-helper-transport-wlan.c File Reference

mediator between the wlan interface and gnunet; must run as root (SUID will do) This code will work under GNU/Linux only. More...

#include "gnunet_config.h"
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <netpacket/packet.h>
#include <linux/if_ether.h>
#include <linux/if.h>
#include <linux/wireless.h>
#include <netinet/in.h>
#include <linux/if_tun.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <sys/param.h>
#include <stdint.h>
#include "gnunet_protocols.h"
#include "plugin_transport_wlan.h"
Include dependency graph for gnunet-helper-transport-wlan.c:

Go to the source code of this file.

Data Structures

struct  PrismValue
 Values in the 'struct PrismHeader'. More...
 
struct  PrismHeader
 Prism header format ('struct p80211msg' in Linux). More...
 
struct  Ieee80211RadiotapHeader
 Generic header for radiotap messages (receiving and sending). More...
 
struct  RadiotapTransmissionHeader
 Format of the header we need to prepend to messages to be sent to the Kernel. More...
 
struct  Ieee80211RadiotapHeaderIterator
 struct Ieee80211RadiotapHeaderIterator - tracks walk through present radiotap arguments in the radiotap header. More...
 
struct  HardwareInfos
 struct for storing the information of the hardware. More...
 
struct  SendBuffer
 IO buffer used for buffering data in transit (to wireless or to stdout). More...
 
struct  MessageStreamTokenizer
 Handle to a message stream tokenizer. More...
 

Macros

#define SOCKTYPE   int
 
#define FDTYPE   int
 
#define ARPHRD_ETHER   1
 Packet format type for the messages we receive from the kernel. More...
 
#define ARPHRD_IEEE80211   801
 Packet format type for the messages we receive from the kernel. More...
 
#define ARPHRD_IEEE80211_PRISM   802
 Packet format type for the messages we receive from the kernel. More...
 
#define ARPHRD_IEEE80211_FULL   803
 Packet format type for the messages we receive from the kernel. More...
 
#define MAXLINE   4096
 Maximum size of a message allowed in either direction (used for our receive and sent buffers). More...
 
#define PRISM_DEVICE_NAME_LENGTH   16
 Device name length in PRISM frames. More...
 
#define PRISM_MSGCODE_MONITOR   0x0041
 Monitor Frame (indicator that we have a 'struct PrismHeader'). More...
 
#define PRISM_DID_MACTIME   0x2041
 Mac time element. More...
 
#define PRISM_DID_CHANNEL   0x3041
 Channel element. More...
 
#define PRISM_DID_SIGNAL   0x6041
 Signal element. More...
 
#define PRISM_DID_NOISE   0x7041
 Noise element. More...
 
#define PRISM_DID_RATE   0x8041
 Rate element, in units/multiples of 500Khz. More...
 
#define PRISM_STATUS_OK   0
 Value is set (supplied) More...
 
#define PRISM_STATUS_NO_VALUE   1
 Value not supplied. More...
 
#define IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK   (1 << IEEE80211_RADIOTAP_EXT)
 Bitmask indicating an extension of the bitmask is used. More...
 
#define IEEE80211_RADIOTAP_F_CFP   0x01
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_SHORTPRE   0x02
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_WEP   0x04
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_FRAG   0x08
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_FCS   0x10
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_DATAPAD   0x20
 Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present'). More...
 
#define IEEE80211_RADIOTAP_F_RX_BADFCS   0x0001
 For IEEE80211_RADIOTAP_RX_FLAGS: frame failed crc check. More...
 
#define IEEE80211_RADIOTAP_F_TX_FAIL   0x0001
 For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): failed due to excessive retries. More...
 
#define IEEE80211_RADIOTAP_F_TX_CTS   0x0002
 For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): used cts 'protection'. More...
 
#define IEEE80211_RADIOTAP_F_TX_RTS   0x0004
 For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): used rts/cts handshake. More...
 
#define IEEE80211_RADIOTAP_F_TX_NOACK   0x0008
 For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): frame should not be ACKed. More...
 
#define IEEE80211_RADIOTAP_F_TX_NOSEQ   0x0010
 For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): sequence number handled by userspace. More...
 
#define IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK   ((1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_TX_FLAGS))
 The above 'struct RadiotapTransmissionHeader' should have the following value for 'header.it_present' based on the presence of the 'rate' and 'txflags' in the overall struct. More...
 
#define ALIGN_FACTOR   8
 To what multiple do we align messages? 8 byte should suffice for everyone for now. More...
 
#define MIN_BUFFER_SIZE   sizeof(struct GNUNET_MessageHeader)
 Smallest supported message. More...
 

Typedefs

typedef void(* MessageTokenizerCallback) (void *cls, const struct GNUNET_MessageHeader *message)
 Functions with this signature are called whenever a complete message is received by the tokenizer. More...
 

Enumerations

enum  RadiotapType {
  IEEE80211_RADIOTAP_TSFT = 0, IEEE80211_RADIOTAP_FLAGS = 1, IEEE80211_RADIOTAP_RATE = 2, IEEE80211_RADIOTAP_CHANNEL = 3,
  IEEE80211_RADIOTAP_FHSS = 4, IEEE80211_RADIOTAP_DBM_ANTSIGNAL = 5, IEEE80211_RADIOTAP_DBM_ANTNOISE = 6, IEEE80211_RADIOTAP_LOCK_QUALITY = 7,
  IEEE80211_RADIOTAP_TX_ATTENUATION = 8, IEEE80211_RADIOTAP_DB_TX_ATTENUATION = 9, IEEE80211_RADIOTAP_DBM_TX_POWER = 10, IEEE80211_RADIOTAP_ANTENNA = 11,
  IEEE80211_RADIOTAP_DB_ANTSIGNAL = 12, IEEE80211_RADIOTAP_DB_ANTNOISE = 13, IEEE80211_RADIOTAP_RX_FLAGS = 14, IEEE80211_RADIOTAP_TX_FLAGS = 15,
  IEEE80211_RADIOTAP_RTS_RETRIES = 16, IEEE80211_RADIOTAP_DATA_RETRIES = 17, IEEE80211_RADIOTAP_EXT = 31
}
 Bits in the 'it_present' bitmask from the 'struct Ieee80211RadiotapHeader'. More...
 

Functions

struct PrismValue __attribute__ ((packed))
 
static struct MessageStreamTokenizermst_create (MessageTokenizerCallback cb, void *cb_cls)
 Create a message stream tokenizer. More...
 
static int mst_receive (struct MessageStreamTokenizer *mst, const char *buf, size_t size)
 Add incoming data to the receive buffer and call the callback for all complete messages. More...
 
static void mst_destroy (struct MessageStreamTokenizer *mst)
 Destroys a tokenizer. More...
 
static int ieee80211_radiotap_iterator_init (struct Ieee80211RadiotapHeaderIterator *iterator, const struct Ieee80211RadiotapHeader *radiotap_header, size_t max_length)
 Radiotap header iteration. More...
 
static int ieee80211_radiotap_iterator_next (struct Ieee80211RadiotapHeaderIterator *iterator)
 Returns the next radiotap parser iterator arg. More...
 
static unsigned long calc_crc_osdep (const unsigned char *buf, size_t len)
 Calculate crc32, the start of the calculation. More...
 
static int check_crc_buf_osdep (const unsigned char *buf, size_t len)
 Calculate and check crc of the wlan packet. More...
 
static int get_channel_from_frequency (int32_t frequency)
 Return the channel from the frequency (in Mhz) More...
 
static int linux_get_channel (const struct HardwareInfos *dev)
 Get the channel used by our WLAN interface. More...
 
static ssize_t linux_read (struct HardwareInfos *dev, unsigned char *buf, size_t buf_size, struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *ri)
 Read from the raw socket (the wlan card), parse the packet and put the result into the buffer for transmission to 'stdout'. More...
 
static int open_device_raw (struct HardwareInfos *dev)
 Open the wireless network interface for reading/writing. More...
 
static int test_wlan_interface (const char *iface)
 Test if the given interface name really corresponds to a wireless device. More...
 
static int mac_test (const struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader, const struct HardwareInfos *dev)
 Test incoming packets mac for being our own. More...
 
static void mac_set (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader, const struct HardwareInfos *dev)
 Set the wlan header to sane values to make attacks more difficult. More...
 
static void stdin_send_hw (void *cls, const struct GNUNET_MessageHeader *hdr)
 Process data from the stdin. More...
 
int main (int argc, char *argv[])
 Main function of the helper. More...
 

Variables

uint32_t did
 This has a different ID for each parameter, see PRISM_DID_* constants. More...
 
uint16_t status
 See PRISM_STATUS_*-constants. More...
 
uint16_t len
 length of data (which is always a uint32_t, but presumably this can be used to specify that fewer bytes are used (with values in 'len' from 0-4). More...
 
uint32_t data
 The data value. More...
 
uint32_t msgcode
 We expect this to be a PRISM_MSGCODE_*. More...
 
uint32_t msglen
 The length of the entire header. More...
 
char devname [16]
 Name of the device that captured the packet. More...
 
enum RadiotapType __attribute__
 
static struct SendBuffer write_pout
 Buffer for data read from stdin to be transmitted to the wirless card. More...
 
static struct SendBuffer write_std
 Buffer for data read from the wireless card to be transmitted to stdout. More...
 

Detailed Description

mediator between the wlan interface and gnunet; must run as root (SUID will do) This code will work under GNU/Linux only.

Author
David Brodski
Christian Grothoff

This program will allow receiving and sending traffic from the WLAN interface. It will force traffic to be in 'ad-hoc' mode, use the proper MAC address of the WLAN interface and use a GNUnet-specific SSID (and a GNUnet-specific SNAP header). It only takes a single argument, which is the name of the WLAN interface to use. The program detects if the interface is not a WLAN interface and exits with an error in that case.

Once initialized, the program will first send a 'struct GNUNET_TRANSPORT_WLAN_HelperControlMessage' to 'stdout'. That message contains the MAC address of the WLAN interface. It will then read messages from the WLAN interface and send them together with performance information as 'struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage' messages to 'stdout'. Furthermore, it will read a stream of messages from 'stdin' that have the format from 'struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage'. Those messages will then be sent via the WLAN interface; however, the sender MAC address will be forced to be the correct address from our WLAN card. If 'stdin' closes, receiving from the WLAN interface will continue. If 'stdout' causes a SIGPIPE, the process dies from the signal. Errors cause an error message to be reported to 'stderr', in most cases the process also exits (with status code '1'). The program never terminates normally; it is safe to kill the process with SIGTERM or SIGKILL at any time.

Since it uses RAW sockets, the binary must be installed SUID or run as 'root'. In order to keep the security risk of the resulting SUID binary minimal, the program ONLY opens the RAW socket with root privileges, then drops them and only then starts to process command line arguments. The code also does not link against any shared libraries (except libc) and is strictly minimal (except for checking for errors). The following list of people have reviewed this code and considered it safe since the last modification (if you reviewed it, please have your name added to the list):

Definition in file gnunet-helper-transport-wlan.c.

Macro Definition Documentation

◆ SOCKTYPE

#define SOCKTYPE   int

Definition at line 113 of file gnunet-helper-transport-wlan.c.

◆ FDTYPE

#define FDTYPE   int

Definition at line 114 of file gnunet-helper-transport-wlan.c.

◆ ARPHRD_ETHER

#define ARPHRD_ETHER   1

Packet format type for the messages we receive from the kernel.

This is for Ethernet 10Mbps format (no performance information included).

Definition at line 147 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read(), open_device_raw(), and stdin_send_hw().

◆ ARPHRD_IEEE80211

#define ARPHRD_IEEE80211   801

Packet format type for the messages we receive from the kernel.

This is for plain messages (with no performance information included).

Definition at line 155 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read(), open_device_raw(), and stdin_send_hw().

◆ ARPHRD_IEEE80211_PRISM

#define ARPHRD_IEEE80211_PRISM   802

Packet format type for the messages we receive from the kernel.

This is for the PRISM format.

Definition at line 162 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read(), open_device_raw(), and stdin_send_hw().

◆ ARPHRD_IEEE80211_FULL

#define ARPHRD_IEEE80211_FULL   803

Packet format type for the messages we receive from the kernel.

This is for messages with a 'struct Ieee80211RadiotapHeader' (see below).

Definition at line 169 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read(), open_device_raw(), and stdin_send_hw().

◆ MAXLINE

#define MAXLINE   4096

Maximum size of a message allowed in either direction (used for our receive and sent buffers).

Definition at line 176 of file gnunet-helper-transport-wlan.c.

Referenced by main(), and stdin_send_hw().

◆ PRISM_DEVICE_NAME_LENGTH

#define PRISM_DEVICE_NAME_LENGTH   16

Device name length in PRISM frames.

(In the kernel, this is "WLAN_DEVNAMELEN_MAX")

Definition at line 186 of file gnunet-helper-transport-wlan.c.

◆ PRISM_MSGCODE_MONITOR

#define PRISM_MSGCODE_MONITOR   0x0041

Monitor Frame (indicator that we have a 'struct PrismHeader').

Definition at line 191 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_DID_MACTIME

#define PRISM_DID_MACTIME   0x2041

Mac time element.

In micro-seconds. Drivers appear to use a 64bit counter to hold mactime internal the then fill the prism header with the lower 32 bits

Definition at line 198 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_DID_CHANNEL

#define PRISM_DID_CHANNEL   0x3041

Channel element.

Definition at line 203 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_DID_SIGNAL

#define PRISM_DID_SIGNAL   0x6041

Signal element.

Should be the signal strength in dbm, some people suggest that instead "100 - (strength in dbm)" is used (to make this a positive integer).

Definition at line 210 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_DID_NOISE

#define PRISM_DID_NOISE   0x7041

Noise element.

Definition at line 215 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_DID_RATE

#define PRISM_DID_RATE   0x8041

Rate element, in units/multiples of 500Khz.

Definition at line 220 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_STATUS_OK

#define PRISM_STATUS_OK   0

Value is set (supplied)

Definition at line 226 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ PRISM_STATUS_NO_VALUE

#define PRISM_STATUS_NO_VALUE   1

Value not supplied.

Definition at line 231 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK

#define IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK   (1 << IEEE80211_RADIOTAP_EXT)

Bitmask indicating an extension of the bitmask is used.

(Mask corresponding to IEEE80211_RADIOTAP_EXT).

Definition at line 462 of file gnunet-helper-transport-wlan.c.

Referenced by ieee80211_radiotap_iterator_init().

◆ IEEE80211_RADIOTAP_F_CFP

#define IEEE80211_RADIOTAP_F_CFP   0x01

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame was sent/received during CFP (Contention Free Period)

Definition at line 474 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_SHORTPRE

#define IEEE80211_RADIOTAP_F_SHORTPRE   0x02

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame was sent/received with short preamble

Definition at line 484 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_WEP

#define IEEE80211_RADIOTAP_F_WEP   0x04

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame was sent/received with WEP encryption

Definition at line 494 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_FRAG

#define IEEE80211_RADIOTAP_F_FRAG   0x08

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame was sent/received with fragmentation

Definition at line 504 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_FCS

#define IEEE80211_RADIOTAP_F_FCS   0x10

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame includes FCS (CRC at the end that needs to be removeD).

Definition at line 514 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ IEEE80211_RADIOTAP_F_DATAPAD

#define IEEE80211_RADIOTAP_F_DATAPAD   0x20

Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a 'struct Ieee80211RadiotapHeader' extension if the IEEE80211_RADIOTAP_FLAGS bit is set in 'it_present').

The radiotap flags are an 8-bit field.

Frame has padding between 802.11 header and payload (to 32-bit boundary)

Definition at line 525 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_RX_BADFCS

#define IEEE80211_RADIOTAP_F_RX_BADFCS   0x0001

For IEEE80211_RADIOTAP_RX_FLAGS: frame failed crc check.

Definition at line 532 of file gnunet-helper-transport-wlan.c.

Referenced by linux_read().

◆ IEEE80211_RADIOTAP_F_TX_FAIL

#define IEEE80211_RADIOTAP_F_TX_FAIL   0x0001

For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): failed due to excessive retries.

Definition at line 538 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_TX_CTS

#define IEEE80211_RADIOTAP_F_TX_CTS   0x0002

For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): used cts 'protection'.

Definition at line 544 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_TX_RTS

#define IEEE80211_RADIOTAP_F_TX_RTS   0x0004

For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): used rts/cts handshake.

Definition at line 550 of file gnunet-helper-transport-wlan.c.

◆ IEEE80211_RADIOTAP_F_TX_NOACK

#define IEEE80211_RADIOTAP_F_TX_NOACK   0x0008

For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): frame should not be ACKed.

Definition at line 556 of file gnunet-helper-transport-wlan.c.

Referenced by stdin_send_hw().

◆ IEEE80211_RADIOTAP_F_TX_NOSEQ

#define IEEE80211_RADIOTAP_F_TX_NOSEQ   0x0010

For IEEE80211_RADIOTAP_TX_FLAGS ('txflags' in 'struct RadiotapTransmissionHeader'): sequence number handled by userspace.

Definition at line 562 of file gnunet-helper-transport-wlan.c.

Referenced by stdin_send_hw().

◆ IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK

#define IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK   ((1 << IEEE80211_RADIOTAP_RATE) | (1 << IEEE80211_RADIOTAP_TX_FLAGS))

The above 'struct RadiotapTransmissionHeader' should have the following value for 'header.it_present' based on the presence of the 'rate' and 'txflags' in the overall struct.

Definition at line 641 of file gnunet-helper-transport-wlan.c.

Referenced by stdin_send_hw().

◆ ALIGN_FACTOR

#define ALIGN_FACTOR   8

To what multiple do we align messages? 8 byte should suffice for everyone for now.

Definition at line 767 of file gnunet-helper-transport-wlan.c.

Referenced by mst_receive().

◆ MIN_BUFFER_SIZE

#define MIN_BUFFER_SIZE   sizeof(struct GNUNET_MessageHeader)

Smallest supported message.

Definition at line 772 of file gnunet-helper-transport-wlan.c.

Referenced by mst_create().

Typedef Documentation

◆ MessageTokenizerCallback

typedef void(* MessageTokenizerCallback) (void *cls, const struct GNUNET_MessageHeader *message)

Functions with this signature are called whenever a complete message is received by the tokenizer.

Parameters
clsclosure
messagethe actual message

Definition at line 782 of file gnunet-helper-transport-wlan.c.

Enumeration Type Documentation

◆ RadiotapType

Bits in the 'it_present' bitmask from the 'struct Ieee80211RadiotapHeader'.

For each value, we give the name, data type, unit and then a description below. Note that the actual size of the extension can be bigger as arguments must be padded so that args of a given length must begin at a boundary of that length. However, note that compound args are allowed (eg, 2 x uint16_t for IEEE80211_RADIOTAP_CHANNEL) so total argument length is not a reliable indicator of alignment requirement. See also 'man 9 ieee80211_radiotap'.

Enumerator
IEEE80211_RADIOTAP_TSFT 

IEEE80211_RADIOTAP_TSFT __le64 microseconds.

Value in microseconds of the MAC's 64-bit 802.11 Time Synchronization Function timer when the first bit of the MPDU arrived at the MAC. For received frames, only.

IEEE80211_RADIOTAP_FLAGS 

IEEE80211_RADIOTAP_FLAGS uint8_t bitmap.

Properties of transmitted and received frames. See flags defined below.

IEEE80211_RADIOTAP_RATE 

IEEE80211_RADIOTAP_RATE uint8_t 500kb/s.

Tx/Rx data rate

IEEE80211_RADIOTAP_CHANNEL 

IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap.

Tx/Rx frequency in MHz, followed by flags (see below).

IEEE80211_RADIOTAP_FHSS 

IEEE80211_RADIOTAP_FHSS __le16 see below.

For frequency-hopping radios, the hop set (first byte) and pattern (second byte).

IEEE80211_RADIOTAP_DBM_ANTSIGNAL 

IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from one milliwatt (dBm)

RF signal power at the antenna, decibel difference from one milliwatt.

IEEE80211_RADIOTAP_DBM_ANTNOISE 

IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from one milliwatt (dBm)

RF noise power at the antenna, decibel difference from one milliwatt.

IEEE80211_RADIOTAP_LOCK_QUALITY 

IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless.

Quality of Barker code lock. Unitless. Monotonically nondecreasing with "better" lock strength. Called "Signal Quality" in datasheets. (Is there a standard way to measure this?)

IEEE80211_RADIOTAP_TX_ATTENUATION 

IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless.

Transmit power expressed as unitless distance from max power set at factory calibration. 0 is max power. Monotonically nondecreasing with lower power levels.

IEEE80211_RADIOTAP_DB_TX_ATTENUATION 

IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)

Transmit power expressed as decibel distance from max power set at factory calibration. 0 is max power. Monotonically nondecreasing with lower power levels.

IEEE80211_RADIOTAP_DBM_TX_POWER 

IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from one milliwatt (dBm)

Transmit power expressed as dBm (decibels from a 1 milliwatt reference). This is the absolute power level measured at the antenna port.

IEEE80211_RADIOTAP_ANTENNA 

IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index.

Unitless indication of the Rx/Tx antenna for this packet. The first antenna is antenna 0.

IEEE80211_RADIOTAP_DB_ANTSIGNAL 

IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)

RF signal power at the antenna, decibel difference from an arbitrary, fixed reference.

IEEE80211_RADIOTAP_DB_ANTNOISE 

IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)

RF noise power at the antenna, decibel difference from an arbitrary, fixed reference point.

IEEE80211_RADIOTAP_RX_FLAGS 

IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap.

Properties of received frames. See flags defined below.

IEEE80211_RADIOTAP_TX_FLAGS 

IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap.

Properties of transmitted frames. See flags defined below.

IEEE80211_RADIOTAP_RTS_RETRIES 

IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data.

Number of rts retries a transmitted frame used.

IEEE80211_RADIOTAP_DATA_RETRIES 

IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data.

Number of unicast retries a transmitted frame used.

IEEE80211_RADIOTAP_EXT 

Extension bit, used to indicate that more bits are needed for the bitmask.

Definition at line 304 of file gnunet-helper-transport-wlan.c.

304  {
313 
321 
328 
342 
351 
360 
370 
379 
388 
398 
406 
414 
422 
429 
436 
443 
450 
456 };
Extension bit, used to indicate that more bits are needed for the bitmask.
IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap.
IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data.
IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)
IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap.
IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless.
IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from one milliwatt (dBm)
IEEE80211_RADIOTAP_TSFT __le64 microseconds.
IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless.
IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from one milliwatt (dBm)
IEEE80211_RADIOTAP_FLAGS uint8_t bitmap.
IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap.
IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data.
IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from one milliwatt (dBm)
IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index.
IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)
IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)
IEEE80211_RADIOTAP_FHSS __le16 see below.
IEEE80211_RADIOTAP_RATE uint8_t 500kb/s.

Function Documentation

◆ __attribute__()

struct PrismValue __attribute__ ( (packed)  )

◆ mst_create()

static struct MessageStreamTokenizer* mst_create ( MessageTokenizerCallback  cb,
void *  cb_cls 
)
static

Create a message stream tokenizer.

Parameters
cbfunction to call on completed messages
cb_clsclosure for cb
Returns
handle to tokenizer

Definition at line 831 of file gnunet-helper-transport-wlan.c.

References MessageStreamTokenizer::cb, MessageStreamTokenizer::cb_cls, MessageStreamTokenizer::curr_buf, MessageStreamTokenizer::hdr, MIN_BUFFER_SIZE, and ret.

Referenced by main().

833 {
834  struct MessageStreamTokenizer *ret;
835 
836  ret = malloc(sizeof(struct MessageStreamTokenizer));
837  if (NULL == ret)
838  {
839  fprintf(stderr, "Failed to allocate buffer for tokenizer\n");
840  exit(1);
841  }
842  ret->hdr = malloc(MIN_BUFFER_SIZE);
843  if (NULL == ret->hdr)
844  {
845  fprintf(stderr, "Failed to allocate buffer for alignment\n");
846  exit(1);
847  }
848  ret->curr_buf = MIN_BUFFER_SIZE;
849  ret->cb = cb;
850  ret->cb_cls = cb_cls;
851  return ret;
852 }
#define MIN_BUFFER_SIZE
Smallest supported message.
static int ret
Final status code.
Definition: gnunet-arm.c:89
MessageTokenizerCallback cb
Function to call on completed messages.
Handle to a message stream tokenizer.
size_t curr_buf
Size of the buffer (starting at &#39;hdr&#39;).
struct GNUNET_MessageHeader * hdr
Beginning of the buffer.
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◆ mst_receive()

static int mst_receive ( struct MessageStreamTokenizer mst,
const char *  buf,
size_t  size 
)
static

Add incoming data to the receive buffer and call the callback for all complete messages.

Parameters
msttokenizer to use
bufinput data to add
sizenumber of bytes in buf
Returns
GNUNET_OK if we are done processing (need more data) GNUNET_SYSERR if the data stream is corrupt

Definition at line 866 of file gnunet-helper-transport-wlan.c.

References ALIGN_FACTOR, MessageStreamTokenizer::cb, MessageStreamTokenizer::cb_cls, MessageStreamTokenizer::curr_buf, delta, do_align(), GNUNET_memcpy, GNUNET_MIN, GNUNET_NO, GNUNET_OK, GNUNET_YES, MessageStreamTokenizer::hdr, MessageStreamTokenizer::off, MessageStreamTokenizer::pos, ret, size, and GNUNET_MessageHeader::size.

Referenced by main().

868 {
869  const struct GNUNET_MessageHeader *hdr;
870  size_t delta;
871  uint16_t want;
872  char *ibuf;
873  int need_align;
874  unsigned long offset;
875  int ret;
876 
877  ret = GNUNET_OK;
878  ibuf = (char *)mst->hdr;
879  while (mst->pos > 0)
880  {
881 do_align:
882  if ((mst->curr_buf - mst->off < sizeof(struct GNUNET_MessageHeader)) ||
883  (0 != (mst->off % ALIGN_FACTOR)))
884  {
885  /* need to align or need more space */
886  mst->pos -= mst->off;
887  memmove(ibuf, &ibuf[mst->off], mst->pos);
888  mst->off = 0;
889  }
890  if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader))
891  {
892  delta =
893  GNUNET_MIN(sizeof(struct GNUNET_MessageHeader) -
894  (mst->pos - mst->off), size);
895  GNUNET_memcpy(&ibuf[mst->pos], buf, delta);
896  mst->pos += delta;
897  buf += delta;
898  size -= delta;
899  }
900  if (mst->pos - mst->off < sizeof(struct GNUNET_MessageHeader))
901  {
902  return GNUNET_OK;
903  }
904  hdr = (const struct GNUNET_MessageHeader *)&ibuf[mst->off];
905  want = ntohs(hdr->size);
906  if (want < sizeof(struct GNUNET_MessageHeader))
907  {
908  fprintf(stderr,
909  "Received invalid message from stdin\n");
910  exit(1);
911  }
912  if (mst->curr_buf - mst->off < want)
913  {
914  /* need more space */
915  mst->pos -= mst->off;
916  memmove(ibuf, &ibuf[mst->off], mst->pos);
917  mst->off = 0;
918  }
919  if (want > mst->curr_buf)
920  {
921  mst->hdr = realloc(mst->hdr, want);
922  if (NULL == mst->hdr)
923  {
924  fprintf(stderr, "Failed to allocate buffer for alignment\n");
925  exit(1);
926  }
927  ibuf = (char *)mst->hdr;
928  mst->curr_buf = want;
929  }
930  hdr = (const struct GNUNET_MessageHeader *)&ibuf[mst->off];
931  if (mst->pos - mst->off < want)
932  {
933  delta = GNUNET_MIN(want - (mst->pos - mst->off), size);
934  GNUNET_memcpy(&ibuf[mst->pos], buf, delta);
935  mst->pos += delta;
936  buf += delta;
937  size -= delta;
938  }
939  if (mst->pos - mst->off < want)
940  {
941  return GNUNET_OK;
942  }
943  mst->cb(mst->cb_cls, hdr);
944  mst->off += want;
945  if (mst->off == mst->pos)
946  {
947  /* reset to beginning of buffer, it's free right now! */
948  mst->off = 0;
949  mst->pos = 0;
950  }
951  }
952  while (size > 0)
953  {
954  if (size < sizeof(struct GNUNET_MessageHeader))
955  break;
956  offset = (unsigned long)buf;
957  need_align = (0 != offset % ALIGN_FACTOR) ? GNUNET_YES : GNUNET_NO;
958  if (GNUNET_NO == need_align)
959  {
960  /* can try to do zero-copy and process directly from original buffer */
961  hdr = (const struct GNUNET_MessageHeader *)buf;
962  want = ntohs(hdr->size);
963  if (want < sizeof(struct GNUNET_MessageHeader))
964  {
965  fprintf(stderr,
966  "Received invalid message from stdin\n");
967  exit(1);
968  }
969  if (size < want)
970  break; /* or not, buffer incomplete, so copy to private buffer... */
971  mst->cb(mst->cb_cls, hdr);
972  buf += want;
973  size -= want;
974  }
975  else
976  {
977  /* need to copy to private buffer to align;
978  * yes, we go a bit more spagetti than usual here */
979  goto do_align;
980  }
981  }
982  if (size > 0)
983  {
984  if (size + mst->pos > mst->curr_buf)
985  {
986  mst->hdr = realloc(mst->hdr, size + mst->pos);
987  if (NULL == mst->hdr)
988  {
989  fprintf(stderr, "Failed to allocate buffer for alignment\n");
990  exit(1);
991  }
992  ibuf = (char *)mst->hdr;
993  mst->curr_buf = size + mst->pos;
994  }
995  if (mst->pos + size > mst->curr_buf)
996  {
997  fprintf(stderr,
998  "Assertion failed\n");
999  exit(1);
1000  }
1001  GNUNET_memcpy(&ibuf[mst->pos], buf, size);
1002  mst->pos += size;
1003  }
1004  return ret;
1005 }
size_t off
How many bytes in buffer have we already processed?
static struct GNUNET_TIME_Relative delta
Definition: speedup.c:35
static size_t do_align(size_t start_position, size_t end_position)
Given the start and end position of a block of data, return the end position of that data after align...
Definition: fs_directory.c:480
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
size_t pos
How many bytes in buffer are valid right now?
static int ret
Final status code.
Definition: gnunet-arm.c:89
#define ALIGN_FACTOR
To what multiple do we align messages? 8 byte should suffice for everyone for now.
#define GNUNET_MIN(a, b)
Definition: gnunet_common.h:80
static char buf[2048]
static unsigned int size
Size of the "table".
Definition: peer.c:66
MessageTokenizerCallback cb
Function to call on completed messages.
size_t curr_buf
Size of the buffer (starting at &#39;hdr&#39;).
struct GNUNET_MessageHeader * hdr
Beginning of the buffer.
Header for all communications.
#define GNUNET_YES
Definition: gnunet_common.h:77
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◆ mst_destroy()

static void mst_destroy ( struct MessageStreamTokenizer mst)
static

Destroys a tokenizer.

Parameters
msttokenizer to destroy

Definition at line 1014 of file gnunet-helper-transport-wlan.c.

References MessageStreamTokenizer::hdr.

Referenced by main().

1015 {
1016  free(mst->hdr);
1017  free(mst);
1018 }
struct GNUNET_MessageHeader * hdr
Beginning of the buffer.
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◆ ieee80211_radiotap_iterator_init()

static int ieee80211_radiotap_iterator_init ( struct Ieee80211RadiotapHeaderIterator iterator,
const struct Ieee80211RadiotapHeader radiotap_header,
size_t  max_length 
)
static

Radiotap header iteration.

call __ieee80211_radiotap_iterator_init() to init a semi-opaque iterator struct Ieee80211RadiotapHeaderIterator (no need to init the struct beforehand) then loop calling __ieee80211_radiotap_iterator_next()... it returns -1 if there are no more args in the header, or the next argument type index that is present. The iterator's this_arg member points to the start of the argument associated with the current argument index that is present, which can be found in the iterator's this_arg_index member. This arg index corresponds to the IEEE80211_RADIOTAP_... defines.

Parameters
iteratoriterator to initialize
radiotap_headermessage to parse
max_lengthnumber of valid bytes in radiotap_header
Returns
0 on success, -1 on error

Definition at line 1043 of file gnunet-helper-transport-wlan.c.

References Ieee80211RadiotapHeaderIterator::arg, Ieee80211RadiotapHeaderIterator::bitmap_shifter, GNUNET_le16toh, GNUNET_le32toh, IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK, Ieee80211RadiotapHeader::it_len, Ieee80211RadiotapHeader::it_present, Ieee80211RadiotapHeader::it_version, Ieee80211RadiotapHeaderIterator::max_length, and Ieee80211RadiotapHeaderIterator::rtheader.

Referenced by linux_read().

1046 {
1047  if ((iterator == NULL) ||
1048  (radiotap_header == NULL))
1049  return -1;
1050 
1051  /* Linux only supports version 0 radiotap format */
1052  if (0 != radiotap_header->it_version)
1053  return -1;
1054 
1055  /* sanity check for allowed length and radiotap length field */
1056  if ((max_length < sizeof(struct Ieee80211RadiotapHeader)) ||
1057  (max_length < (GNUNET_le16toh(radiotap_header->it_len))))
1058  return -1;
1059 
1060  memset(iterator, 0, sizeof(struct Ieee80211RadiotapHeaderIterator));
1061  iterator->rtheader = radiotap_header;
1062  iterator->max_length = GNUNET_le16toh(radiotap_header->it_len);
1063  iterator->bitmap_shifter = GNUNET_le32toh(radiotap_header->it_present);
1064  iterator->arg = ((uint8_t *)radiotap_header) + sizeof(struct Ieee80211RadiotapHeader);
1065 
1066  /* find payload start allowing for extended bitmap(s) */
1068  {
1069  while (GNUNET_le32toh(*((uint32_t *)iterator->arg)) & IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK)
1070  {
1071  iterator->arg += sizeof(uint32_t);
1072  /*
1073  * check for insanity where the present bitmaps
1074  * keep claiming to extend up to or even beyond the
1075  * stated radiotap header length
1076  */
1077  if (iterator->arg - ((uint8_t*)iterator->rtheader) > iterator->max_length)
1078  return -1;
1079  }
1080  iterator->arg += sizeof(uint32_t);
1081  /*
1082  * no need to check again for blowing past stated radiotap
1083  * header length, becuase ieee80211_radiotap_iterator_next
1084  * checks it before it is dereferenced
1085  */
1086  }
1087  /* we are all initialized happily */
1088  return 0;
1089 }
const struct Ieee80211RadiotapHeader * rtheader
pointer to the radiotap header we are walking through
#define GNUNET_le32toh(x)
size_t max_length
length of radiotap header in host byte ordering
#define IEEE80211_RADIOTAP_PRESENT_EXTEND_MASK
Bitmask indicating an extension of the bitmask is used.
uint32_t bitmap_shifter
internal shifter for current uint32_t bitmap, (it_present in host byte order), If bit 0 is set...
uint32_t it_present
A bitmap telling which fields are present.
Generic header for radiotap messages (receiving and sending).
struct Ieee80211RadiotapHeaderIterator - tracks walk through present radiotap arguments in the radiot...
#define GNUNET_le16toh(x)
const uint8_t * arg
internal next argument pointer
uint16_t it_len
length of the whole header in bytes, including it_version, it_pad, it_len, and data fields...
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◆ ieee80211_radiotap_iterator_next()

static int ieee80211_radiotap_iterator_next ( struct Ieee80211RadiotapHeaderIterator iterator)
static

Returns the next radiotap parser iterator arg.

This function returns the next radiotap arg index (IEEE80211_RADIOTAP_...) and sets iterator->this_arg to point to the payload for the arg. It takes care of alignment handling and extended present fields. interator->this_arg can be changed by the caller. The args pointed to are in little-endian format.

Parameters
iteratorradiotap_iterator to move to next arg (if any)
Returns
next present arg index on success or -1 if no more or error

Definition at line 1105 of file gnunet-helper-transport-wlan.c.

References Ieee80211RadiotapHeaderIterator::arg, Ieee80211RadiotapHeaderIterator::arg_index, Ieee80211RadiotapHeaderIterator::bitmap_shifter, GNUNET_le32toh, IEEE80211_RADIOTAP_ANTENNA, IEEE80211_RADIOTAP_CHANNEL, IEEE80211_RADIOTAP_DATA_RETRIES, IEEE80211_RADIOTAP_DB_ANTNOISE, IEEE80211_RADIOTAP_DB_ANTSIGNAL, IEEE80211_RADIOTAP_DB_TX_ATTENUATION, IEEE80211_RADIOTAP_DBM_ANTNOISE, IEEE80211_RADIOTAP_DBM_ANTSIGNAL, IEEE80211_RADIOTAP_DBM_TX_POWER, IEEE80211_RADIOTAP_FHSS, IEEE80211_RADIOTAP_FLAGS, IEEE80211_RADIOTAP_LOCK_QUALITY, IEEE80211_RADIOTAP_RATE, IEEE80211_RADIOTAP_RTS_RETRIES, IEEE80211_RADIOTAP_RX_FLAGS, IEEE80211_RADIOTAP_TSFT, IEEE80211_RADIOTAP_TX_ATTENUATION, IEEE80211_RADIOTAP_TX_FLAGS, Ieee80211RadiotapHeaderIterator::max_length, Ieee80211RadiotapHeaderIterator::next_bitmap, Ieee80211RadiotapHeaderIterator::rtheader, Ieee80211RadiotapHeaderIterator::this_arg, and Ieee80211RadiotapHeaderIterator::this_arg_index.

Referenced by linux_read().

1106 {
1107  /*
1108  * small length lookup table for all radiotap types we heard of
1109  * starting from b0 in the bitmap, so we can walk the payload
1110  * area of the radiotap header
1111  *
1112  * There is a requirement to pad args, so that args
1113  * of a given length must begin at a boundary of that length
1114  * -- but note that compound args are allowed (eg, 2 x uint16_t
1115  * for IEEE80211_RADIOTAP_CHANNEL) so total arg length is not
1116  * a reliable indicator of alignment requirement.
1117  *
1118  * upper nybble: content alignment for arg
1119  * lower nybble: content length for arg
1120  */
1121 
1122  static const uint8_t rt_sizes[] = {
1123  [IEEE80211_RADIOTAP_TSFT] = 0x88,
1124  [IEEE80211_RADIOTAP_FLAGS] = 0x11,
1125  [IEEE80211_RADIOTAP_RATE] = 0x11,
1126  [IEEE80211_RADIOTAP_CHANNEL] = 0x24,
1127  [IEEE80211_RADIOTAP_FHSS] = 0x22,
1134  [IEEE80211_RADIOTAP_ANTENNA] = 0x11,
1137  [IEEE80211_RADIOTAP_TX_FLAGS] = 0x22,
1138  [IEEE80211_RADIOTAP_RX_FLAGS] = 0x22,
1141  /*
1142  * add more here as they are defined in
1143  * include/net/ieee80211_radiotap.h
1144  */
1145  };
1146 
1147  /*
1148  * for every radiotap entry we can at
1149  * least skip (by knowing the length)...
1150  */
1151  while (iterator->arg_index < sizeof(rt_sizes))
1152  {
1153  int hit = (0 != (iterator->bitmap_shifter & 1));
1154 
1155  if (hit)
1156  {
1157  unsigned int wanted_alignment;
1158  unsigned int unalignment;
1159  /*
1160  * arg is present, account for alignment padding
1161  * 8-bit args can be at any alignment
1162  * 16-bit args must start on 16-bit boundary
1163  * 32-bit args must start on 32-bit boundary
1164  * 64-bit args must start on 64-bit boundary
1165  *
1166  * note that total arg size can differ from alignment of
1167  * elements inside arg, so we use upper nybble of length table
1168  * to base alignment on. First, 'wanted_alignment' is set to be
1169  * 1 for 8-bit, 2 for 16-bit, 4 for 32-bit and 8 for 64-bit
1170  * arguments. Then, we calculate the 'unalignment' (how many
1171  * bytes we are over by taking the difference of 'arg' and the
1172  * overall starting point modulo the desired alignment. As
1173  * desired alignments are powers of two, we can do modulo with
1174  * binary "&" (and also avoid the possibility of a division by
1175  * zero if the 'rt_sizes' table contains bogus entries).
1176  *
1177  * also note: these alignments are relative to the start of the
1178  * radiotap header. There is no guarantee that the radiotap
1179  * header itself is aligned on any kind of boundary, thus we
1180  * need to really look at the delta here.
1181  */
1182  wanted_alignment = rt_sizes[iterator->arg_index] >> 4;
1183  unalignment = (((void *)iterator->arg) - ((void *)iterator->rtheader)) & (wanted_alignment - 1);
1184  if (0 != unalignment)
1185  {
1186  /* need padding (by 'wanted_alignment - unalignment') */
1187  iterator->arg_index += wanted_alignment - unalignment;
1188  }
1189 
1190  /*
1191  * this is what we will return to user, but we need to
1192  * move on first so next call has something fresh to test
1193  */
1194  iterator->this_arg_index = iterator->arg_index;
1195  iterator->this_arg = iterator->arg;
1196 
1197  /* internally move on the size of this arg (using lower nybble from
1198  the table) */
1199  iterator->arg += rt_sizes[iterator->arg_index] & 0x0f;
1200 
1201  /*
1202  * check for insanity where we are given a bitmap that
1203  * claims to have more arg content than the length of the
1204  * radiotap section. We will normally end up equalling this
1205  * max_length on the last arg, never exceeding it.
1206  */
1207  if ((((void *)iterator->arg) - ((void *)iterator->rtheader)) > iterator->max_length)
1208  return -1;
1209  }
1210 
1211  /* Now, move on to next bit / next entry */
1212  iterator->arg_index++;
1213 
1214  if (0 == (iterator->arg_index % 32))
1215  {
1216  /* completed current uint32_t bitmap */
1217  if (0 != (iterator->bitmap_shifter & 1))
1218  {
1219  /* bit 31 was set, there is more; move to next uint32_t bitmap */
1220  iterator->bitmap_shifter = GNUNET_le32toh(*iterator->next_bitmap);
1221  iterator->next_bitmap++;
1222  }
1223  else
1224  {
1225  /* no more bitmaps: end (by setting arg_index to high, unsupported value) */
1226  iterator->arg_index = sizeof(rt_sizes);
1227  }
1228  }
1229  else
1230  {
1231  /* just try the next bit (while loop will move on) */
1232  iterator->bitmap_shifter >>= 1;
1233  }
1234 
1235  /* if we found a valid arg earlier, return it now */
1236  if (hit)
1237  return iterator->this_arg_index;
1238  }
1239 
1240  /* we don't know how to handle any more args (or there are no more),
1241  so we're done (this is not an error) */
1242  return -1;
1243 }
const struct Ieee80211RadiotapHeader * rtheader
pointer to the radiotap header we are walking through
#define GNUNET_le32toh(x)
size_t max_length
length of radiotap header in host byte ordering
IEEE80211_RADIOTAP_TX_FLAGS __le16 bitmap.
IEEE80211_RADIOTAP_RTS_RETRIES uint8_t data.
IEEE80211_RADIOTAP_DB_TX_ATTENUATION __le16 decibels (dB)
uint32_t bitmap_shifter
internal shifter for current uint32_t bitmap, (it_present in host byte order), If bit 0 is set...
unsigned int this_arg_index
IEEE80211_RADIOTAP_...
IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap.
IEEE80211_RADIOTAP_LOCK_QUALITY __le16 unitless.
IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from one milliwatt (dBm)
IEEE80211_RADIOTAP_TSFT __le64 microseconds.
IEEE80211_RADIOTAP_TX_ATTENUATION __le16 unitless.
IEEE80211_RADIOTAP_DBM_TX_POWER s8 decibels from one milliwatt (dBm)
const uint8_t * this_arg
pointer to current radiotap arg
IEEE80211_RADIOTAP_FLAGS uint8_t bitmap.
const uint32_t * next_bitmap
internal pointer to next present uint32_t (if IEEE80211_RADIOTAP_EXT is used).
IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap.
const uint8_t * arg
internal next argument pointer
IEEE80211_RADIOTAP_DATA_RETRIES uint8_t data.
IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from one milliwatt (dBm)
IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index.
IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)
unsigned int arg_index
internal next argument index
IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)
IEEE80211_RADIOTAP_FHSS __le16 see below.
IEEE80211_RADIOTAP_RATE uint8_t 500kb/s.
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◆ calc_crc_osdep()

static unsigned long calc_crc_osdep ( const unsigned char *  buf,
size_t  len 
)
static

Calculate crc32, the start of the calculation.

Parameters
bufbuffer to calc the crc
lenlen of the buffer
Returns
crc sum

Definition at line 1254 of file gnunet-helper-transport-wlan.c.

Referenced by check_crc_buf_osdep().

1255 {
1256  static const unsigned long int crc_tbl_osdep[256] = {
1257  0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
1258  0xE963A535, 0x9E6495A3,
1259  0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,
1260  0xE7B82D07, 0x90BF1D91,
1261  0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB,
1262  0xF4D4B551, 0x83D385C7,
1263  0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
1264  0xFA0F3D63, 0x8D080DF5,
1265  0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447,
1266  0xD20D85FD, 0xA50AB56B,
1267  0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75,
1268  0xDCD60DCF, 0xABD13D59,
1269  0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
1270  0xCFBA9599, 0xB8BDA50F,
1271  0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11,
1272  0xC1611DAB, 0xB6662D3D,
1273  0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,
1274  0x9FBFE4A5, 0xE8B8D433,
1275  0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
1276  0x91646C97, 0xE6635C01,
1277  0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B,
1278  0x8208F4C1, 0xF50FC457,
1279  0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49,
1280  0x8CD37CF3, 0xFBD44C65,
1281  0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
1282  0xA4D1C46D, 0xD3D6F4FB,
1283  0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,
1284  0xAA0A4C5F, 0xDD0D7CC9,
1285  0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3,
1286  0xB966D409, 0xCE61E49F,
1287  0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
1288  0xB7BD5C3B, 0xC0BA6CAD,
1289  0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF,
1290  0x04DB2615, 0x73DC1683,
1291  0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,
1292  0x0A00AE27, 0x7D079EB1,
1293  0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
1294  0x196C3671, 0x6E6B06E7,
1295  0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9,
1296  0x17B7BE43, 0x60B08ED5,
1297  0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767,
1298  0x3FB506DD, 0x48B2364B,
1299  0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
1300  0x316E8EEF, 0x4669BE79,
1301  0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703,
1302  0x220216B9, 0x5505262F,
1303  0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,
1304  0x2CD99E8B, 0x5BDEAE1D,
1305  0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
1306  0x72076785, 0x05005713,
1307  0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,
1308  0x7CDCEFB7, 0x0BDBDF21,
1309  0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B,
1310  0x6FB077E1, 0x18B74777,
1311  0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
1312  0x616BFFD3, 0x166CCF45,
1313  0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,
1314  0x4969474D, 0x3E6E77DB,
1315  0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5,
1316  0x47B2CF7F, 0x30B5FFE9,
1317  0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
1318  0x54DE5729, 0x23D967BF,
1319  0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1,
1320  0x5A05DF1B, 0x2D02EF8D
1321  };
1322 
1323  unsigned long crc = 0xFFFFFFFF;
1324 
1325  for (; len > 0; len--, buf++)
1326  crc = crc_tbl_osdep[(crc ^ *buf) & 0xFF] ^ (crc >> 8);
1327  return(~crc);
1328 }
static char buf[2048]
uint16_t len
length of data (which is always a uint32_t, but presumably this can be used to specify that fewer byt...
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◆ check_crc_buf_osdep()

static int check_crc_buf_osdep ( const unsigned char *  buf,
size_t  len 
)
static

Calculate and check crc of the wlan packet.

Parameters
bufbuffer of the packet, with len + 4 bytes of data, the last 4 bytes being the checksum
lenlength of the payload in data
Returns
0 on success (checksum matches), 1 on error

Definition at line 1340 of file gnunet-helper-transport-wlan.c.

References calc_crc_osdep(), and PrismValue::len.

Referenced by linux_read().

1341 {
1342  unsigned long crc;
1343 
1344  crc = calc_crc_osdep(buf, len);
1345  buf += len;
1346  if (((crc) & 0xFF) == buf[0] && ((crc >> 8) & 0xFF) == buf[1] &&
1347  ((crc >> 16) & 0xFF) == buf[2] && ((crc >> 24) & 0xFF) == buf[3])
1348  return 0;
1349  return 1;
1350 }
static char buf[2048]
static unsigned long calc_crc_osdep(const unsigned char *buf, size_t len)
Calculate crc32, the start of the calculation.
uint16_t len
length of data (which is always a uint32_t, but presumably this can be used to specify that fewer byt...
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◆ get_channel_from_frequency()

static int get_channel_from_frequency ( int32_t  frequency)
static

Return the channel from the frequency (in Mhz)

Parameters
frequencyof the channel
Returns
number of the channel

Definition at line 1365 of file gnunet-helper-transport-wlan.c.

Referenced by linux_get_channel().

1366 {
1367  if (frequency >= 2412 && frequency <= 2472)
1368  return (frequency - 2407) / 5;
1369  if (frequency == 2484)
1370  return 14;
1371  if (frequency >= 5000 && frequency <= 6100)
1372  return (frequency - 5000) / 5;
1373  return -1;
1374 }
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◆ linux_get_channel()

static int linux_get_channel ( const struct HardwareInfos dev)
static

Get the channel used by our WLAN interface.

Parameters
devpointer to the dev struct of the card
Returns
channel number, -1 on error

Definition at line 1384 of file gnunet-helper-transport-wlan.c.

References HardwareInfos::fd_raw, get_channel_from_frequency(), and HardwareInfos::iface.

Referenced by linux_read().

1385 {
1386  struct iwreq wrq;
1387  int32_t frequency;
1388 
1389  memset(&wrq, 0, sizeof(struct iwreq));
1390  strncpy(wrq.ifr_name, dev->iface, IFNAMSIZ);
1391  if (0 > ioctl(dev->fd_raw, SIOCGIWFREQ, &wrq))
1392  return -1;
1393  frequency = wrq.u.freq.m; /* 'iw_freq' defines 'm' as '__s32', so we keep it signed */
1394  if (100000000 < frequency)
1395  frequency /= 100000;
1396  else if (1000000 < frequency)
1397  frequency /= 1000;
1398  if (1000 < frequency)
1399  return get_channel_from_frequency(frequency);
1400  return frequency;
1401 }
static int get_channel_from_frequency(int32_t frequency)
Return the channel from the frequency (in Mhz)
int fd_raw
file descriptor for the raw socket
char iface[IFNAMSIZ]
Name of the interface, not necessarily 0-terminated (!).
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◆ linux_read()

static ssize_t linux_read ( struct HardwareInfos dev,
unsigned char *  buf,
size_t  buf_size,
struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage ri 
)
static

Read from the raw socket (the wlan card), parse the packet and put the result into the buffer for transmission to 'stdout'.

Parameters
devpointer to the struct of the wlan card
bufbuffer to read to; first bytes will be the 'struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame', followed by the actual payload
buf_sizesize of the buffer
riwhere to write radiotap_rx info
Returns
number of bytes written to 'buf'

Definition at line 1416 of file gnunet-helper-transport-wlan.c.

References ARPHRD_ETHER, ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL, ARPHRD_IEEE80211_PRISM, HardwareInfos::arptype_in, check_crc_buf_osdep(), PrismValue::data, PrismValue::did, HardwareInfos::fd_raw, GNUNET_le16toh, GNUNET_le64toh, GNUNET_memcpy, IEEE80211_RADIOTAP_ANTENNA, IEEE80211_RADIOTAP_CHANNEL, IEEE80211_RADIOTAP_DB_ANTNOISE, IEEE80211_RADIOTAP_DB_ANTSIGNAL, IEEE80211_RADIOTAP_DBM_ANTNOISE, IEEE80211_RADIOTAP_DBM_ANTSIGNAL, IEEE80211_RADIOTAP_F_FCS, IEEE80211_RADIOTAP_F_RX_BADFCS, IEEE80211_RADIOTAP_FLAGS, ieee80211_radiotap_iterator_init(), ieee80211_radiotap_iterator_next(), IEEE80211_RADIOTAP_RATE, IEEE80211_RADIOTAP_RX_FLAGS, IEEE80211_RADIOTAP_TSFT, Ieee80211RadiotapHeader::it_len, linux_get_channel(), PrismHeader::msgcode, PrismHeader::msglen, ph, PRISM_DID_CHANNEL, PRISM_DID_MACTIME, PRISM_DID_NOISE, PRISM_DID_RATE, PRISM_DID_SIGNAL, PRISM_MSGCODE_MONITOR, PRISM_STATUS_OK, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_antenna, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_channel, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_mactime, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_noise, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_power, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::ri_rate, PrismValue::status, Ieee80211RadiotapHeaderIterator::this_arg, and Ieee80211RadiotapHeaderIterator::this_arg_index.

Referenced by main().

1419 {
1420  unsigned char tmpbuf[buf_size];
1421  ssize_t caplen;
1422  size_t n;
1423  int got_signal = 0;
1424  int got_noise = 0;
1425  int got_channel = 0;
1426  int fcs_removed = 0;
1427 
1428  caplen = read(dev->fd_raw, tmpbuf, buf_size);
1429  if (0 > caplen)
1430  {
1431  if (EAGAIN == errno)
1432  return 0;
1433  fprintf(stderr, "Failed to read from RAW socket: %s\n", strerror(errno));
1434  return -1;
1435  }
1436 
1437  memset(ri, 0, sizeof(*ri));
1438  switch (dev->arptype_in)
1439  {
1441  {
1442  const struct PrismHeader *ph;
1443 
1444  ph = (const struct PrismHeader*)tmpbuf;
1445  n = ph->msglen;
1446  if ((n < 8) || (n >= caplen))
1447  return 0; /* invalid format */
1448  if ((PRISM_MSGCODE_MONITOR == ph->msgcode) &&
1449  (n >= sizeof(struct PrismHeader)))
1450  {
1451  const char *pos;
1452  size_t left;
1453  struct PrismValue pv;
1454 
1455  left = n - sizeof(struct PrismHeader);
1456  pos = (const char *)&ph[1];
1457  while (left > sizeof(struct PrismValue))
1458  {
1459  left -= sizeof(struct PrismValue);
1460  GNUNET_memcpy(&pv, pos, sizeof(struct PrismValue));
1461  pos += sizeof(struct PrismValue);
1462 
1463  switch (pv.did)
1464  {
1465  case PRISM_DID_NOISE:
1466  if (PRISM_STATUS_OK == pv.status)
1467  {
1468  ri->ri_noise = pv.data;
1469  /* got_noise = 1; */
1470  }
1471  break;
1472 
1473  case PRISM_DID_RATE:
1474  if (PRISM_STATUS_OK == pv.status)
1475  ri->ri_rate = pv.data * 500000;
1476  break;
1477 
1478  case PRISM_DID_CHANNEL:
1479  if (PRISM_STATUS_OK == pv.status)
1480  {
1481  ri->ri_channel = pv.data;
1482  got_channel = 1;
1483  }
1484  break;
1485 
1486  case PRISM_DID_MACTIME:
1487  if (PRISM_STATUS_OK == pv.status)
1488  ri->ri_mactime = pv.data;
1489  break;
1490 
1491  case PRISM_DID_SIGNAL:
1492  if (PRISM_STATUS_OK == pv.status)
1493  {
1494  ri->ri_power = pv.data;
1495  /* got_signal = 1; */
1496  }
1497  break;
1498  }
1499  }
1500  }
1501  if ((n < 8) || (n >= caplen))
1502  return 0; /* invalid format */
1503  }
1504  break;
1505 
1506  case ARPHRD_IEEE80211_FULL:
1507  {
1509  struct Ieee80211RadiotapHeader *rthdr;
1510 
1511  memset(&iterator, 0, sizeof(iterator));
1512  rthdr = (struct Ieee80211RadiotapHeader *)tmpbuf;
1513  n = GNUNET_le16toh(rthdr->it_len);
1514  if ((n < sizeof(struct Ieee80211RadiotapHeader)) || (n >= caplen))
1515  return 0; /* invalid 'it_len' */
1516  if (0 != ieee80211_radiotap_iterator_init(&iterator, rthdr, caplen))
1517  return 0;
1518  /* go through the radiotap arguments we have been given by the driver */
1520  {
1521  switch (iterator.this_arg_index)
1522  {
1524  ri->ri_mactime = GNUNET_le64toh(*((uint64_t *)iterator.this_arg));
1525  break;
1526 
1528  if (!got_signal)
1529  {
1530  ri->ri_power = *((int8_t*)iterator.this_arg);
1531  got_signal = 1;
1532  }
1533  break;
1534 
1536  if (!got_signal)
1537  {
1538  ri->ri_power = *((int8_t*)iterator.this_arg);
1539  got_signal = 1;
1540  }
1541  break;
1542 
1544  if (!got_noise)
1545  {
1546  ri->ri_noise = *((int8_t*)iterator.this_arg);
1547  got_noise = 1;
1548  }
1549  break;
1550 
1552  if (!got_noise)
1553  {
1554  ri->ri_noise = *((int8_t*)iterator.this_arg);
1555  got_noise = 1;
1556  }
1557  break;
1558 
1560  ri->ri_antenna = *iterator.this_arg;
1561  break;
1562 
1564  ri->ri_channel = *iterator.this_arg;
1565  got_channel = 1;
1566  break;
1567 
1569  ri->ri_rate = (*iterator.this_arg) * 500000;
1570  break;
1571 
1573  {
1574  uint8_t flags = *iterator.this_arg;
1575  /* is the CRC visible at the end? if so, remove */
1576  if (0 != (flags & IEEE80211_RADIOTAP_F_FCS))
1577  {
1578  fcs_removed = 1;
1579  caplen -= sizeof(uint32_t);
1580  }
1581  break;
1582  }
1583 
1585  {
1586  uint16_t flags = ntohs(*((uint16_t *)iterator.this_arg));
1587  if (0 != (flags & IEEE80211_RADIOTAP_F_RX_BADFCS))
1588  return 0;
1589  }
1590  break;
1591  } /* end of 'switch' */
1592  } /* end of the 'while' loop */
1593  }
1594  break;
1595 
1596  case ARPHRD_IEEE80211:
1597  n = 0; /* no header */
1598  break;
1599 
1600  case ARPHRD_ETHER:
1601  {
1602  if (sizeof(struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame) > caplen)
1603  return 0; /* invalid */
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;
1608  }
1609 
1610  default:
1611  errno = ENOTSUP; /* unsupported format */
1612  return -1;
1613  }
1614  caplen -= n;
1615  if (!got_channel)
1616  ri->ri_channel = linux_get_channel(dev);
1617 
1618  /* detect CRC32 at the end, even if the flag wasn't set and remove it */
1619  if ((0 == fcs_removed) &&
1620  (0 == check_crc_buf_osdep(tmpbuf + n, caplen - sizeof(uint32_t))))
1621  {
1622  /* NOTE: this heuristic can of course fail if there happens to
1623  be a matching checksum at the end. Would be good to have
1624  some data to see how often this heuristic actually works. */
1625  caplen -= sizeof(uint32_t);
1626  }
1627  /* copy payload to target buffer */
1628  GNUNET_memcpy(buf, tmpbuf + n, caplen);
1629  return caplen;
1630 }
static int iterator(void *cls, const struct GNUNET_PeerIdentity *key, void *value)
Iterator over hash map entries.
uint64_t ri_mactime
IEEE80211_RADIOTAP_TSFT, 0 if unknown.
int32_t ri_noise
either IEEE80211_RADIOTAP_DBM_ANTNOISE or IEEE80211_RADIOTAP_DB_ANTNOISE, 0 if unknown.
#define ARPHRD_IEEE80211_PRISM
Packet format type for the messages we receive from the kernel.
Prism header format (&#39;struct p80211msg&#39; in Linux).
#define PRISM_DID_CHANNEL
Channel element.
uint32_t ri_rate
IEEE80211_RADIOTAP_RATE * 50000, 0 if unknown.
static struct GNUNET_ATS_PerformanceHandle * ph
ATS performance handle used.
Definition: gnunet-ats.c:116
#define PRISM_DID_NOISE
Noise element.
#define ARPHRD_IEEE80211_FULL
Packet format type for the messages we receive from the kernel.
static int ieee80211_radiotap_iterator_init(struct Ieee80211RadiotapHeaderIterator *iterator, const struct Ieee80211RadiotapHeader *radiotap_header, size_t max_length)
Radiotap header iteration.
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define PRISM_MSGCODE_MONITOR
Monitor Frame (indicator that we have a &#39;struct PrismHeader&#39;).
uint32_t ri_antenna
IEEE80211_RADIOTAP_ANTENNA, 0 if unknown.
generic definitions for IEEE 802.3 frames
static int linux_get_channel(const struct HardwareInfos *dev)
Get the channel used by our WLAN interface.
#define PRISM_STATUS_OK
Value is set (supplied)
IEEE80211_RADIOTAP_RX_FLAGS __le16 bitmap.
uint32_t msgcode
We expect this to be a PRISM_MSGCODE_*.
static int check_crc_buf_osdep(const unsigned char *buf, size_t len)
Calculate and check crc of the wlan packet.
Values in the &#39;struct PrismHeader&#39;.
IEEE80211_RADIOTAP_DBM_ANTSIGNAL s8 decibels from one milliwatt (dBm)
#define IEEE80211_RADIOTAP_F_RX_BADFCS
For IEEE80211_RADIOTAP_RX_FLAGS: frame failed crc check.
uint32_t msglen
The length of the entire header.
IEEE80211_RADIOTAP_TSFT __le64 microseconds.
static char buf[2048]
#define ARPHRD_ETHER
Packet format type for the messages we receive from the kernel.
Generic header for radiotap messages (receiving and sending).
#define PRISM_DID_SIGNAL
Signal element.
struct Ieee80211RadiotapHeaderIterator - tracks walk through present radiotap arguments in the radiot...
IEEE80211_RADIOTAP_FLAGS uint8_t bitmap.
int fd_raw
file descriptor for the raw socket
#define GNUNET_le16toh(x)
IEEE80211_RADIOTAP_CHANNEL 2 x __le16 MHz, bitmap.
static int ieee80211_radiotap_iterator_next(struct Ieee80211RadiotapHeaderIterator *iterator)
Returns the next radiotap parser iterator arg.
#define IEEE80211_RADIOTAP_F_FCS
Bit in IEEE80211_RADIOTAP_FLAGS (which we might get as part of a &#39;struct Ieee80211RadiotapHeader&#39; ext...
uint32_t ri_channel
IEEE80211_RADIOTAP_CHANNEL, 0 if unknown.
IEEE80211_RADIOTAP_DBM_ANTNOISE s8 decibels from one milliwatt (dBm)
generic definitions for IEEE 802.11 frames
#define PRISM_DID_MACTIME
Mac time element.
int arptype_in
Which format has the header that we&#39;re getting when receiving packets? Some ARPHRD_IEEE80211_XXX-valu...
int32_t ri_power
from radiotap either IEEE80211_RADIOTAP_DBM_ANTSIGNAL or IEEE80211_RADIOTAP_DB_ANTSIGNAL, 0 if unknown.
#define ARPHRD_IEEE80211
Packet format type for the messages we receive from the kernel.
IEEE80211_RADIOTAP_ANTENNA uint8_t antenna index.
uint16_t it_len
length of the whole header in bytes, including it_version, it_pad, it_len, and data fields...
IEEE80211_RADIOTAP_DB_ANTNOISE uint8_t decibel (dB)
IEEE80211_RADIOTAP_DB_ANTSIGNAL uint8_t decibel (dB)
#define GNUNET_le64toh(x)
#define PRISM_DID_RATE
Rate element, in units/multiples of 500Khz.
IEEE80211_RADIOTAP_RATE uint8_t 500kb/s.
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◆ open_device_raw()

static int open_device_raw ( struct HardwareInfos dev)
static

Open the wireless network interface for reading/writing.

Parameters
devpointer to the device struct
Returns
0 on success

Definition at line 1645 of file gnunet-helper-transport-wlan.c.

References ARPHRD_ETHER, ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL, ARPHRD_IEEE80211_PRISM, HardwareInfos::arptype_in, HardwareInfos::fd_raw, GNUNET_memcpy, HardwareInfos::iface, MAC_ADDR_SIZE, and HardwareInfos::pl_mac.

Referenced by main().

1646 {
1647  struct ifreq ifr;
1648  struct iwreq wrq;
1649  struct packet_mreq mr;
1650  struct sockaddr_ll sll;
1651 
1652  /* find the interface index */
1653  memset(&ifr, 0, sizeof(ifr));
1654  strncpy(ifr.ifr_name, dev->iface, IFNAMSIZ);
1655  if (-1 == ioctl(dev->fd_raw, SIOCGIFINDEX, &ifr))
1656  {
1657  fprintf(stderr, "ioctl(SIOCGIFINDEX) on interface `%.*s' failed: %s\n",
1658  IFNAMSIZ, dev->iface, strerror(errno));
1659  return 1;
1660  }
1661 
1662  /* lookup the hardware type */
1663  memset(&sll, 0, sizeof(sll));
1664  sll.sll_family = AF_PACKET;
1665  sll.sll_ifindex = ifr.ifr_ifindex;
1666  sll.sll_protocol = htons(ETH_P_ALL);
1667  if (-1 == ioctl(dev->fd_raw, SIOCGIFHWADDR, &ifr))
1668  {
1669  fprintf(stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1670  IFNAMSIZ, dev->iface, strerror(errno));
1671  return 1;
1672  }
1673  if (((ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1674  (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1675  (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1676  (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL)))
1677  {
1678  fprintf(stderr, "Error: interface `%.*s' is not using a supported hardware address family (got %d)\n",
1679  IFNAMSIZ, dev->iface,
1680  ifr.ifr_hwaddr.sa_family);
1681  return 1;
1682  }
1683 
1684  /* lookup iw mode */
1685  memset(&wrq, 0, sizeof(struct iwreq));
1686  strncpy(wrq.ifr_name, dev->iface, IFNAMSIZ);
1687  if (-1 == ioctl(dev->fd_raw, SIOCGIWMODE, &wrq))
1688  {
1689  /* most probably not supported (ie for rtap ipw interface) *
1690  * so just assume its correctly set... */
1691  wrq.u.mode = IW_MODE_MONITOR;
1692  }
1693 
1694  if ((wrq.u.mode != IW_MODE_MONITOR) &&
1695  (wrq.u.mode != IW_MODE_ADHOC))
1696  {
1697  fprintf(stderr, "Error: interface `%.*s' is not in monitor or ad-hoc mode (got %d)\n",
1698  IFNAMSIZ, dev->iface,
1699  wrq.u.mode);
1700  return 1;
1701  }
1702 
1703  /* Is interface st to up, broadcast & running ? */
1704  if ((ifr.ifr_flags | IFF_UP | IFF_BROADCAST | IFF_RUNNING) != ifr.ifr_flags)
1705  {
1706  /* Bring interface up */
1707  ifr.ifr_flags |= IFF_UP | IFF_BROADCAST | IFF_RUNNING;
1708 
1709  if (-1 == ioctl(dev->fd_raw, SIOCSIFFLAGS, &ifr))
1710  {
1711  fprintf(stderr, "ioctl(SIOCSIFFLAGS) on interface `%.*s' failed: %s\n",
1712  IFNAMSIZ, dev->iface, strerror(errno));
1713  return 1;
1714  }
1715  }
1716 
1717  /* bind the raw socket to the interface */
1718  if (-1 == bind(dev->fd_raw, (struct sockaddr *)&sll, sizeof(sll)))
1719  {
1720  fprintf(stderr, "Failed to bind interface `%.*s': %s\n", IFNAMSIZ,
1721  dev->iface, strerror(errno));
1722  return 1;
1723  }
1724 
1725  /* lookup the hardware type */
1726  if (-1 == ioctl(dev->fd_raw, SIOCGIFHWADDR, &ifr))
1727  {
1728  fprintf(stderr, "ioctl(SIOCGIFHWADDR) on interface `%.*s' failed: %s\n",
1729  IFNAMSIZ, dev->iface, strerror(errno));
1730  return 1;
1731  }
1732 
1733  GNUNET_memcpy(&dev->pl_mac, ifr.ifr_hwaddr.sa_data, MAC_ADDR_SIZE);
1734  dev->arptype_in = ifr.ifr_hwaddr.sa_family;
1735  if ((ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) &&
1736  (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211) &&
1737  (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_PRISM) &&
1738  (ifr.ifr_hwaddr.sa_family != ARPHRD_IEEE80211_FULL))
1739  {
1740  fprintf(stderr, "Unsupported hardware link type %d on interface `%.*s'\n",
1741  ifr.ifr_hwaddr.sa_family, IFNAMSIZ, dev->iface);
1742  return 1;
1743  }
1744 
1745  /* enable promiscuous mode */
1746  memset(&mr, 0, sizeof(mr));
1747  mr.mr_ifindex = sll.sll_ifindex;
1748  mr.mr_type = PACKET_MR_PROMISC;
1749  if (0 !=
1750  setsockopt(dev->fd_raw, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mr,
1751  sizeof(mr)))
1752  {
1753  fprintf(stderr,
1754  "Failed to enable promiscuous mode on interface `%.*s'\n",
1755  IFNAMSIZ,
1756  dev->iface);
1757  return 1;
1758  }
1759  return 0;
1760 }
#define MAC_ADDR_SIZE
Number fo bytes in a mac address.
#define ARPHRD_IEEE80211_PRISM
Packet format type for the messages we receive from the kernel.
struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac
MAC address of our own bluetooth interface.
#define ARPHRD_IEEE80211_FULL
Packet format type for the messages we receive from the kernel.
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define ARPHRD_ETHER
Packet format type for the messages we receive from the kernel.
int fd_raw
file descriptor for the raw socket
int arptype_in
Which format has the header that we&#39;re getting when receiving packets? Some ARPHRD_IEEE80211_XXX-valu...
char iface[IFNAMSIZ]
Name of the interface, not necessarily 0-terminated (!).
#define ARPHRD_IEEE80211
Packet format type for the messages we receive from the kernel.
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◆ test_wlan_interface()

static int test_wlan_interface ( const char *  iface)
static

Test if the given interface name really corresponds to a wireless device.

Parameters
ifacename of the interface
Returns
0 on success, 1 on error

Definition at line 1771 of file gnunet-helper-transport-wlan.c.

References ret.

Referenced by main().

1772 {
1773  char strbuf[512];
1774  struct stat sbuf;
1775  int ret;
1776 
1777  ret = snprintf(strbuf, sizeof(strbuf),
1778  "/sys/class/net/%s/phy80211/subsystem",
1779  iface);
1780  if ((ret < 0) || (ret >= sizeof(strbuf)) || (0 != stat(strbuf, &sbuf)))
1781  {
1782  fprintf(stderr,
1783  "Did not find 802.11 interface `%s'. Exiting.\n",
1784  iface);
1785  exit(1);
1786  }
1787  return 0;
1788 }
static int ret
Final status code.
Definition: gnunet-arm.c:89
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◆ mac_test()

static int mac_test ( const struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame taIeeeHeader,
const struct HardwareInfos dev 
)
static

Test incoming packets mac for being our own.

Parameters
taIeeeHeaderbuffer of the packet
devthe Hardware_Infos struct
Returns
0 if mac belongs to us, 1 if mac is for another target

Definition at line 1799 of file gnunet-helper-transport-wlan.c.

References GNUNET_TRANSPORT_WLAN_Ieee80211Frame::addr1, GNUNET_TRANSPORT_WLAN_Ieee80211Frame::addr3, bc_all_mac, MAC_ADDR_SIZE, mac_bssid_gnunet, and HardwareInfos::pl_mac.

Referenced by main().

1801 {
1803 
1804  if ((0 == memcmp(&taIeeeHeader->addr3, &all_zeros, MAC_ADDR_SIZE)) ||
1805  (0 == memcmp(&taIeeeHeader->addr1, &all_zeros, MAC_ADDR_SIZE)))
1806  return 0; /* some drivers set no Macs, then assume it is all for us! */
1807 
1808  if (0 != memcmp(&taIeeeHeader->addr3, &mac_bssid_gnunet, MAC_ADDR_SIZE))
1809  return 1; /* not a GNUnet ad-hoc package */
1810  if ((0 == memcmp(&taIeeeHeader->addr1, &dev->pl_mac, MAC_ADDR_SIZE)) ||
1811  (0 == memcmp(&taIeeeHeader->addr1, &bc_all_mac, MAC_ADDR_SIZE)))
1812  return 0; /* for us, or broadcast */
1813  return 1; /* not for us */
1814 }
#define MAC_ADDR_SIZE
Number fo bytes in a mac address.
struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac
MAC address of our own bluetooth interface.
static GNUNET_NETWORK_STRUCT_END const struct GNUNET_TRANSPORT_WLAN_MacAddress mac_bssid_gnunet
GNUnet bssid.
static struct GNUNET_PeerIdentity all_zeros
Peer identity that is all zeros, used as a way to indicate "all peers".
struct GNUNET_TRANSPORT_WLAN_MacAddress addr3
Address 3: BSSID in ad-hoc mode, Destination if station, source if AP.
static const struct GNUNET_TRANSPORT_WLAN_MacAddress bc_all_mac
Broadcast MAC.
struct GNUNET_TRANSPORT_WLAN_MacAddress addr1
Address 1: destination address in ad-hoc mode or AP, BSSID if station,.
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◆ mac_set()

static void mac_set ( struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame taIeeeHeader,
const struct HardwareInfos dev 
)
static

Set the wlan header to sane values to make attacks more difficult.

Parameters
taIeeeHeaderpointer to the header of the packet
devpointer to the Hardware_Infos struct

Definition at line 1824 of file gnunet-helper-transport-wlan.c.

References GNUNET_TRANSPORT_WLAN_Ieee80211Frame::addr2, GNUNET_TRANSPORT_WLAN_Ieee80211Frame::addr3, GNUNET_TRANSPORT_WLAN_Ieee80211Frame::frame_control, IEEE80211_FC0_TYPE_DATA, mac_bssid_gnunet, and HardwareInfos::pl_mac.

Referenced by stdin_send_hw().

1826 {
1827  taIeeeHeader->frame_control = htons(IEEE80211_FC0_TYPE_DATA);
1828  taIeeeHeader->addr2 = dev->pl_mac;
1829  taIeeeHeader->addr3 = mac_bssid_gnunet;
1830 }
struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac
MAC address of our own bluetooth interface.
#define IEEE80211_FC0_TYPE_DATA
static GNUNET_NETWORK_STRUCT_END const struct GNUNET_TRANSPORT_WLAN_MacAddress mac_bssid_gnunet
GNUnet bssid.
uint16_t frame_control
802.11 Frame Control field.
struct GNUNET_TRANSPORT_WLAN_MacAddress addr3
Address 3: BSSID in ad-hoc mode, Destination if station, source if AP.
struct GNUNET_TRANSPORT_WLAN_MacAddress addr2
Address 2: source address if in ad-hoc-mode or station, BSSID if AP.
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◆ stdin_send_hw()

static void stdin_send_hw ( void *  cls,
const struct GNUNET_MessageHeader hdr 
)
static

Process data from the stdin.

Takes the message, prepends the radiotap transmission header, forces the sender MAC to be correct and puts it into our buffer for transmission to the kernel.

Parameters
clspointer to the device struct ('struct HardwareInfos*')
hdrpointer to the start of the packet

Definition at line 1842 of file gnunet-helper-transport-wlan.c.

References GNUNET_TRANSPORT_WLAN_Ieee80211Frame::addr1, ARPHRD_ETHER, ARPHRD_IEEE80211, ARPHRD_IEEE80211_FULL, ARPHRD_IEEE80211_PRISM, HardwareInfos::arptype_in, SendBuffer::buf, GNUNET_TRANSPORT_WLAN_Ieee8023Frame::dst, GNUNET_TRANSPORT_WLAN_RadiotapSendMessage::frame, GNUNET_htole16, GNUNET_memcpy, GNUNET_MESSAGE_TYPE_WLAN_DATA_TO_HELPER, GNUNET_TRANSPORT_WLAN_RadiotapSendMessage::header, RadiotapTransmissionHeader::header, IEEE80211_RADIOTAP_F_TX_NOACK, IEEE80211_RADIOTAP_F_TX_NOSEQ, IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK, Ieee80211RadiotapHeader::it_len, Ieee80211RadiotapHeader::it_pad, Ieee80211RadiotapHeader::it_present, Ieee80211RadiotapHeader::it_version, mac_set(), MAXLINE, RadiotapTransmissionHeader::pad1, HardwareInfos::pl_mac, GNUNET_TRANSPORT_WLAN_RadiotapSendMessage::rate, RadiotapTransmissionHeader::rate, SendBuffer::size, GNUNET_MessageHeader::size, GNUNET_TRANSPORT_WLAN_Ieee8023Frame::src, RadiotapTransmissionHeader::txflags, GNUNET_TRANSPORT_WLAN_Ieee8023Frame::type, GNUNET_MessageHeader::type, and write_pout.

Referenced by main().

1843 {
1844  struct HardwareInfos *dev = cls;
1846  struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *wlanheader;
1847  size_t sendsize;
1848  struct RadiotapTransmissionHeader rtheader;
1849  struct GNUNET_TRANSPORT_WLAN_Ieee8023Frame etheader;
1850 
1851  sendsize = ntohs(hdr->size);
1852  if ((sendsize <
1855  {
1856  fprintf(stderr, "Received malformed message\n");
1857  exit(1);
1858  }
1859  sendsize -= (sizeof(struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage) - sizeof(struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame));
1860  if (MAXLINE < sendsize)
1861  {
1862  fprintf(stderr, "Packet too big for buffer\n");
1863  exit(1);
1864  }
1865  header = (const struct GNUNET_TRANSPORT_WLAN_RadiotapSendMessage *)hdr;
1866  switch (dev->arptype_in)
1867  {
1869  case ARPHRD_IEEE80211_FULL:
1870  case ARPHRD_IEEE80211:
1871  rtheader.header.it_version = 0;
1872  rtheader.header.it_pad = 0;
1873  rtheader.header.it_len = GNUNET_htole16(sizeof(rtheader));
1875  rtheader.rate = header->rate;
1876  rtheader.pad1 = 0;
1878  GNUNET_memcpy(write_pout.buf, &rtheader, sizeof(rtheader));
1879  GNUNET_memcpy(&write_pout.buf[sizeof(rtheader)], &header->frame, sendsize);
1880  wlanheader = (struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *)&write_pout.buf[sizeof(rtheader)];
1881 
1882  /* payload contains MAC address, but we don't trust it, so we'll
1883  * overwrite it with OUR MAC address to prevent mischief */
1884  mac_set(wlanheader, dev);
1885  write_pout.size = sendsize + sizeof(rtheader);
1886  break;
1887 
1888  case ARPHRD_ETHER:
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  GNUNET_memcpy(write_pout.buf, &etheader, sizeof(etheader));
1894  GNUNET_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);
1896  break;
1897 
1898  default:
1899  fprintf(stderr,
1900  "Unsupported ARPTYPE!\n");
1901  break;
1902  }
1903 }
#define ARPHRD_IEEE80211_PRISM
Packet format type for the messages we receive from the kernel.
struct for storing the information of the hardware.
struct GNUNET_TRANSPORT_WLAN_MacAddress pl_mac
MAC address of our own bluetooth interface.
#define ARPHRD_IEEE80211_FULL
Packet format type for the messages we receive from the kernel.
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
static void mac_set(struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader, const struct HardwareInfos *dev)
Set the wlan header to sane values to make attacks more difficult.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
generic definitions for IEEE 802.3 frames
uint16_t type
The type of the message (GNUNET_MESSAGE_TYPE_XXXX), in big-endian format.
size_t size
How many bytes of data are stored in &#39;buf&#39; for transmission right now? Data always starts at offset 0...
struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame frame
IEEE Frame to transmit (the sender MAC address will be overwritten by the helper as it does not trust...
#define GNUNET_MESSAGE_TYPE_WLAN_DATA_TO_HELPER
Type of data messages from the plugin to the gnunet-wlan-helper.
Format of the header we need to prepend to messages to be sent to the Kernel.
#define ARPHRD_ETHER
Packet format type for the messages we receive from the kernel.
#define IEEE80211_RADIOTAP_F_TX_NOSEQ
For IEEE80211_RADIOTAP_TX_FLAGS (&#39;txflags&#39; in &#39;struct RadiotapTransmissionHeader&#39;): sequence number h...
#define GNUNET_htole16(x)
struct GNUNET_MessageHeader header
Type is &#39;GNUNET_MESSAGE_TYPE_WLAN_DATA_TO_HELPER&#39;.
#define IEEE80211_RADIOTAP_OUR_TRANSMISSION_HEADER_MASK
The above &#39;struct RadiotapTransmissionHeader&#39; should have the following value for &#39;header...
#define IEEE80211_RADIOTAP_F_TX_NOACK
For IEEE80211_RADIOTAP_TX_FLAGS (&#39;txflags&#39; in &#39;struct RadiotapTransmissionHeader&#39;): frame should not ...
char buf[4096 *2]
Buffered data; twice the maximum allowed message size as we add some headers.
generic definitions for IEEE 802.11 frames
#define MAXLINE
Maximum size of a message allowed in either direction (used for our receive and sent buffers)...
int arptype_in
Which format has the header that we&#39;re getting when receiving packets? Some ARPHRD_IEEE80211_XXX-valu...
static struct SendBuffer write_pout
Buffer for data read from stdin to be transmitted to the wirless card.
#define ARPHRD_IEEE80211
Packet format type for the messages we receive from the kernel.
Message from the plugin to the WLAN helper: send the given message with the given connection paramete...
struct GNUNET_TRANSPORT_WLAN_MacAddress addr1
Address 1: destination address in ad-hoc mode or AP, BSSID if station,.
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◆ main()

int main ( int  argc,
char *  argv[] 
)

Main function of the helper.

This code accesses a WLAN interface in monitoring mode (layer 2) and then forwards traffic in both directions between the WLAN interface and stdin/stdout of this process. Error messages are written to stdout.

Parameters
argcnumber of arguments, must be 2
argvarguments only argument is the name of the interface (i.e. 'mon0')
Returns
0 on success (never happens, as we don't return unless aborted), 1 on error

Definition at line 1917 of file gnunet-helper-transport-wlan.c.

References SendBuffer::buf, HardwareInfos::fd_raw, GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage::frame, GNUNET_memcpy, GNUNET_MESSAGE_TYPE_WLAN_DATA_FROM_HELPER, GNUNET_MESSAGE_TYPE_WLAN_HELPER_CONTROL, GNUNET_TRANSPORT_WLAN_HelperControlMessage::hdr, HardwareInfos::iface, linux_read(), GNUNET_TRANSPORT_WLAN_HelperControlMessage::mac, mac_test(), MAXLINE, mst_create(), mst_destroy(), mst_receive(), open_device_raw(), HardwareInfos::pl_mac, SendBuffer::pos, ret, SendBuffer::size, GNUNET_MessageHeader::size, stdin_mst, stdin_send_hw(), test_wlan_interface(), GNUNET_MessageHeader::type, write_pout, and write_std.

1918 {
1919  struct HardwareInfos dev;
1920  char readbuf[MAXLINE];
1921  int maxfd;
1922  fd_set rfds;
1923  fd_set wfds;
1924  int stdin_open;
1926  int raw_eno;
1927 
1928  /* assert privs so we can modify the firewall rules! */
1929  {
1930 #ifdef HAVE_SETRESUID
1931  uid_t uid = getuid();
1932 
1933  if (0 != setresuid(uid, 0, 0))
1934  {
1935  fprintf(stderr,
1936  "Failed to setresuid to root: %s\n",
1937  strerror(errno));
1938  return 254;
1939  }
1940 #else
1941  if (0 != seteuid(0))
1942  {
1943  fprintf(stderr,
1944  "Failed to seteuid back to root: %s\n", strerror(errno));
1945  return 254;
1946  }
1947 #endif
1948  }
1949 
1950  /* make use of SGID capabilities on POSIX */
1951  memset(&dev, 0, sizeof(dev));
1952  dev.fd_raw = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
1953  raw_eno = errno; /* remember for later */
1954 
1955  /* now that we've dropped root rights, we can do error checking */
1956  if (2 != argc)
1957  {
1958  fprintf(stderr,
1959  "You must specify the name of the interface as the first and only argument to this program.\n");
1960  if (-1 != dev.fd_raw)
1961  (void)close(dev.fd_raw);
1962  return 1;
1963  }
1964 
1965  if (-1 == dev.fd_raw)
1966  {
1967  fprintf(stderr, "Failed to create raw socket: %s\n", strerror(raw_eno));
1968  return 1;
1969  }
1970  if (dev.fd_raw >= FD_SETSIZE)
1971  {
1972  fprintf(stderr, "File descriptor too large for select (%d > %d)\n",
1973  dev.fd_raw, FD_SETSIZE);
1974  (void)close(dev.fd_raw);
1975  return 1;
1976  }
1977  if (0 != test_wlan_interface(argv[1]))
1978  {
1979  (void)close(dev.fd_raw);
1980  return 1;
1981  }
1982  strncpy(dev.iface, argv[1], IFNAMSIZ);
1983  if (0 != open_device_raw(&dev))
1984  {
1985  (void)close(dev.fd_raw);
1986  return 1;
1987  }
1988 
1989  /* drop privs */
1990  {
1991  uid_t uid = getuid();
1992 #ifdef HAVE_SETRESUID
1993  if (0 != setresuid(uid, uid, uid))
1994  {
1995  fprintf(stderr, "Failed to setresuid: %s\n", strerror(errno));
1996  if (-1 != dev.fd_raw)
1997  (void)close(dev.fd_raw);
1998  return 1;
1999  }
2000 #else
2001  if (0 != (setuid(uid) | seteuid(uid)))
2002  {
2003  fprintf(stderr, "Failed to setuid: %s\n", strerror(errno));
2004  if (-1 != dev.fd_raw)
2005  (void)close(dev.fd_raw);
2006  return 1;
2007  }
2008 #endif
2009  }
2010 
2011 
2012  /* send MAC address of the WLAN interface to STDOUT first */
2013  {
2015 
2016  macmsg.hdr.size = htons(sizeof(macmsg));
2017  macmsg.hdr.type = htons(GNUNET_MESSAGE_TYPE_WLAN_HELPER_CONTROL);
2018  GNUNET_memcpy(&macmsg.mac, &dev.pl_mac, sizeof(struct GNUNET_TRANSPORT_WLAN_MacAddress));
2019  GNUNET_memcpy(write_std.buf, &macmsg, sizeof(macmsg));
2020  write_std.size = sizeof(macmsg);
2021  }
2022 
2023  stdin_mst = mst_create(&stdin_send_hw, &dev);
2024  stdin_open = 1;
2025  while (1)
2026  {
2027  maxfd = -1;
2028  FD_ZERO(&rfds);
2029  if ((0 == write_pout.size) && (1 == stdin_open))
2030  {
2031  FD_SET(STDIN_FILENO, &rfds);
2032  maxfd = MAX(maxfd, STDIN_FILENO);
2033  }
2034  if (0 == write_std.size)
2035  {
2036  FD_SET(dev.fd_raw, &rfds);
2037  maxfd = MAX(maxfd, dev.fd_raw);
2038  }
2039  FD_ZERO(&wfds);
2040  if (0 < write_std.size)
2041  {
2042  FD_SET(STDOUT_FILENO, &wfds);
2043  maxfd = MAX(maxfd, STDOUT_FILENO);
2044  }
2045  if (0 < write_pout.size)
2046  {
2047  FD_SET(dev.fd_raw, &wfds);
2048  maxfd = MAX(maxfd, dev.fd_raw);
2049  }
2050  {
2051  int retval = select(maxfd + 1, &rfds, &wfds, NULL, NULL);
2052  if ((-1 == retval) && (EINTR == errno))
2053  continue;
2054  if (0 > retval)
2055  {
2056  fprintf(stderr, "select failed: %s\n", strerror(errno));
2057  break;
2058  }
2059  }
2060  if (FD_ISSET(STDOUT_FILENO, &wfds))
2061  {
2062  ssize_t ret =
2063  write(STDOUT_FILENO, write_std.buf + write_std.pos,
2065  if (0 > ret)
2066  {
2067  fprintf(stderr, "Failed to write to STDOUT: %s\n", strerror(errno));
2068  break;
2069  }
2070  write_std.pos += ret;
2071  if (write_std.pos == write_std.size)
2072  {
2073  write_std.pos = 0;
2074  write_std.size = 0;
2075  }
2076  }
2077  if (FD_ISSET(dev.fd_raw, &wfds))
2078  {
2079  ssize_t ret =
2080  write(dev.fd_raw, write_pout.buf + write_pout.pos,
2082  if (0 > ret)
2083  {
2084  fprintf(stderr, "Failed to write to WLAN device: %s\n",
2085  strerror(errno));
2086  break;
2087  }
2088  write_pout.pos += ret;
2089  if ((write_pout.pos != write_pout.size) && (0 != ret))
2090  {
2091  /* we should not get partial sends with packet-oriented devices... */
2092  fprintf(stderr, "Write error, partial send: %u/%u\n",
2093  (unsigned int)write_pout.pos,
2094  (unsigned int)write_pout.size);
2095  break;
2096  }
2097  if (write_pout.pos == write_pout.size)
2098  {
2099  write_pout.pos = 0;
2100  write_pout.size = 0;
2101  }
2102  }
2103 
2104  if (FD_ISSET(STDIN_FILENO, &rfds))
2105  {
2106  ssize_t ret =
2107  read(STDIN_FILENO, readbuf, sizeof(readbuf));
2108  if (0 > ret)
2109  {
2110  fprintf(stderr, "Read error from STDIN: %s\n", strerror(errno));
2111  break;
2112  }
2113  if (0 == ret)
2114  {
2115  /* stop reading... */
2116  stdin_open = 0;
2117  }
2118  mst_receive(stdin_mst, readbuf, ret);
2119  }
2120 
2121  if (FD_ISSET(dev.fd_raw, &rfds))
2122  {
2124  ssize_t ret;
2125 
2127  ret =
2128  linux_read(&dev, (unsigned char *)&rrm->frame,
2129  sizeof(write_std.buf)
2131  + sizeof(struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame),
2132  rrm);
2133  if (0 > ret)
2134  {
2135  fprintf(stderr, "Read error from raw socket: %s\n", strerror(errno));
2136  break;
2137  }
2138  if ((0 < ret) && (0 == mac_test(&rrm->frame, &dev)))
2139  {
2140  write_std.size = ret
2142  - sizeof(struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame);
2143  rrm->header.size = htons(write_std.size);
2145  }
2146  }
2147  }
2148  /* Error handling, try to clean up a bit at least */
2149  mst_destroy(stdin_mst);
2150  (void)close(dev.fd_raw);
2151  return 1; /* we never exit 'normally' */
2152 }
#define GNUNET_MESSAGE_TYPE_WLAN_HELPER_CONTROL
Control message between the gnunet-wlan-helper and the daemon (with the MAC).
static struct MessageStreamTokenizer * mst_create(MessageTokenizerCallback cb, void *cb_cls)
Create a message stream tokenizer.
struct GNUNET_MessageHeader hdr
Message header.
struct for storing the information of the hardware.
static void stdin_send_hw(void *cls, const struct GNUNET_MessageHeader *hdr)
Process data from the stdin.
struct GNUNET_MessageHeader header
Type is &#39;GNUNET_MESSAGE_TYPE_WLAN_DATA_FROM_HELPER&#39;.
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
struct GNUNET_MessageStreamTokenizer * stdin_mst
Tokenizer for the data we get from stdin.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
static int ret
Final status code.
Definition: gnunet-arm.c:89
static struct SendBuffer write_std
Buffer for data read from the wireless card to be transmitted to stdout.
Format of a WLAN Control Message.
Message from the WLAN helper to the plugin: we have received the given message with the given perform...
uint16_t type
The type of the message (GNUNET_MESSAGE_TYPE_XXXX), in big-endian format.
size_t size
How many bytes of data are stored in &#39;buf&#39; for transmission right now? Data always starts at offset 0...
static int mac_test(const struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame *taIeeeHeader, const struct HardwareInfos *dev)
Test incoming packets mac for being our own.
struct GNUNET_TRANSPORT_WLAN_Ieee80211Frame frame
IEEE Frame.
static int open_device_raw(struct HardwareInfos *dev)
Open the wireless network interface for reading/writing.
static ssize_t linux_read(struct HardwareInfos *dev, unsigned char *buf, size_t buf_size, struct GNUNET_TRANSPORT_WLAN_RadiotapReceiveMessage *ri)
Read from the raw socket (the wlan card), parse the packet and put the result into the buffer for tra...
static void mst_destroy(struct MessageStreamTokenizer *mst)
Destroys a tokenizer.
char buf[4096 *2]
Buffered data; twice the maximum allowed message size as we add some headers.
static int test_wlan_interface(const char *iface)
Test if the given interface name really corresponds to a wireless device.
Handle to a message stream tokenizer.
generic definitions for IEEE 802.11 frames
#define MAXLINE
Maximum size of a message allowed in either direction (used for our receive and sent buffers)...
static struct SendBuffer write_pout
Buffer for data read from stdin to be transmitted to the wirless card.
#define GNUNET_MESSAGE_TYPE_WLAN_DATA_FROM_HELPER
Type of data messages from the gnunet-wlan-helper to the plugin.
static int mst_receive(struct MessageStreamTokenizer *mst, const char *buf, size_t size)
Add incoming data to the receive buffer and call the callback for all complete messages.
size_t pos
How many bytes that were stored in &#39;buf&#39; did we already write to the destination? Always smaller than...
Here is the call graph for this function:

Variable Documentation

◆ did

uint32_t did

This has a different ID for each parameter, see PRISM_DID_* constants.

Definition at line 72 of file gnunet-helper-transport-wlan.c.

◆ status

uint16_t status

◆ len

uint16_t len

length of data (which is always a uint32_t, but presumably this can be used to specify that fewer bytes are used (with values in 'len' from 0-4).

We ignore this field.

Definition at line 84 of file gnunet-helper-transport-wlan.c.

Referenced by gnunet-chk.AESKey::__init__(), gnunet-chk.Chk::__init__(), address_notification(), aes_128_cbc_decrypt(), aes_128_cbc_encrypt(), gnunet-chk::aes_pad_(), check_crc_buf_osdep(), check_union_p2p_strata_estimator(), clear_from_s5r_rbuf(), client_receive(), client_send_cb(), gnunet-chk::compute_rootchk(), connect_probe_continuation(), create_keys(), create_string_array(), curl_upload_cb(), dht_get_string_handler(), dns_value_to_string(), do_accept(), do_dns_read(), do_write(), gnunet-chk::encode_data_to_string(), encrypt_existing_match(), exchange(), expand_dollar(), gnunet_pyexpect.pexpect::expect(), extract_fixed_blob(), extract_rsa_public_key(), extract_rsa_signature(), extract_string(), extract_varsize_blob(), find_typedefs::find_typedefs(), GCP_path_entry_add(), get_cb(), gnunet_janitor::get_process_list(), find_typedefs::get_td_from_function_signature(), find_typedefs::get_td_from_simple_type(), GNUNET_ABE_cpabe_serialize_key(), GNUNET_ABE_cpabe_serialize_master_key(), GNUNET_CONFIGURATION_expand_dollar(), GNUNET_CONFIGURATION_serialize(), GNUNET_CONTAINER_multihashmap32_create(), GNUNET_CONTAINER_multihashmap_create(), GNUNET_CONTAINER_multipeermap_create(), GNUNET_CONTAINER_multishortmap_create(), GNUNET_CONTAINER_multiuuidmap_create(), GNUNET_CRYPTO_cpabe_serialize_key(), GNUNET_CRYPTO_cpabe_serialize_master_key(), GNUNET_CRYPTO_hkdf_v(), GNUNET_DISK_directory_create(), GNUNET_DISK_directory_create_for_file(), GNUNET_DISK_file_copy(), GNUNET_DISK_file_map(), GNUNET_DNSPARSER_builder_add_name(), GNUNET_FS_search_start_probe_(), GNUNET_NAT_register(), GNUNET_NETWORK_socket_close(), GNUNET_OS_init(), GNUNET_OS_start_process_s(), GNUNET_PQ_exec_prepared(), GNUNET_RECLAIM_ATTRIBUTE_list_serialize(), GNUNET_RECLAIM_ATTRIBUTE_list_serialize_get_size(), GNUNET_REST_create_response(), GNUNET_STRINGS_base64_decode(), GNUNET_STRINGS_base64_encode(), GNUNET_STRINGS_conv(), GNUNET_STRINGS_data_to_string_alloc(), GNUNET_STRINGS_filename_expand(), GNUNET_STRINGS_parse_ipv4_policy(), GNUNET_STRINGS_parse_ipv6_policy(), GNUNET_STRINGS_parse_uri(), GNUNET_STRINGS_utf8_tolower(), GNUNET_STRINGS_utf8_toupper(), GST_stats_init(), handle_connection_broken(), handle_connection_create_ack(), handle_connection_destroy(), handle_data(), handle_tunnel_encrypted(), handle_tunnel_kx(), handle_tunnel_kx_auth(), handle_union_p2p_strata_estimator(), http_common_address_from_socket(), initialize_key_to_element(), libgnunet_plugin_transport_tcp_init(), libgnunet_plugin_transport_unix_done(), main(), modify_request(), needs_parens(), neighbours_connect_notification(), on_appsink_new_sample(), packetizer(), parse_fixed_data(), parse_name(), parse_rsa_public_key(), prepare_ipv4_packet(), prepare_ipv6_packet(), print_peer_list(), process_sblock(), put_cb(), read_cpabe(), read_from_the_socket(), regex_add(), REGEX_BLOCK_create(), REGEX_BLOCK_get_key(), REGEX_BLOCK_iterate(), regex_combine(), regex_edge_iterator(), REGEX_INTERNAL_search(), REGEX_TEST_generate_random_string(), REGEX_TEST_read_from_file(), reply_to_dns(), resolver_lookup_get_next_label(), run(), s2i_full(), find_typedefs::scan_dir(), select_write_cb(), send_icmp_packet_via_tun(), send_lookup_response(), send_tcp_packet_via_tun(), send_udp_packet_via_tun(), setup_data_transfer(), start_insert(), transmit_ready(), try_old_ax_keys(), try_top_down_reconstruction(), union_accept(), unix_real_send(), View_change_len(), View_create(), write_cpabe(), and write_pid_file().

◆ data

uint32_t data

The data value.

Definition at line 89 of file gnunet-helper-transport-wlan.c.

Referenced by add_to_meta_counter(), bind_abstime(), bind_nbotime(), bind_rsa_pub(), bind_rsa_sig(), bind_u16(), bind_u32(), bind_u64(), cadet_reply_proc(), check_pkey(), client_schedule(), configuration_receiver(), conversation_value_to_string(), copy_from_reader(), count_and_separate_strings(), credential_value_to_string(), data_to_ecdsa_value(), data_to_eddsa_value(), dht_get_id_handler(), dht_get_string_accept_handler(), dht_get_string_handler(), display_records_from_block(), dns_value_to_string(), do_read(), do_udp_read(), extract_result_cb(), filter_tickets_cb(), GDS_CLIENTS_handle_reply(), GDS_ROUTING_process(), gen_topo_from_file(), get_records_and_call_iterator(), gns_value_to_string(), GNUNET_ATS_TEST_logging_write_to_file(), GNUNET_CONTAINER_bloomfilter_or(), GNUNET_CRYPTO_crc8_n(), GNUNET_CRYPTO_ecdsa_sign(), GNUNET_CRYPTO_ecdsa_verify(), GNUNET_CRYPTO_eddsa_sign(), GNUNET_CRYPTO_eddsa_verify(), GNUNET_CRYPTO_rsa_blind(), GNUNET_CRYPTO_rsa_verify(), GNUNET_DNSPARSER_bin_to_hex(), GNUNET_DNSPARSER_hex_to_bin(), GNUNET_FRIENDS_parse(), GNUNET_FS_data_reader_copy_(), GNUNET_GNSRECORD_records_deserialize(), GNUNET_GNSRECORD_records_get_size(), GNUNET_GNSRECORD_records_serialize(), GNUNET_JSON_from_gnsrecord(), GNUNET_NAT_stun_handle_packet_(), GNUNET_RECLAIM_ATTRIBUTE_list_deserialize(), GNUNET_SECRETSHARING_share_read(), GNUNET_SQ_bind(), GNUNET_STRINGS_base64_encode(), GNUNET_STRINGS_data_to_string(), GNUNET_TESTBED_controller_link(), GNUNET_TESTBED_extract_config_(), GNUNET_TESTBED_forward_operation_msg_(), GNUNET_TESTBED_get_slave_config_(), GNUNET_TESTBED_hosts_load_from_file(), GNUNET_TESTBED_overlay_connect(), GNUNET_TESTBED_peer_create(), GNUNET_TESTBED_peer_get_information(), GNUNET_TESTBED_peer_manage_service(), GNUNET_TESTBED_peer_start(), GNUNET_TESTBED_peer_stop(), GNUNET_TESTBED_peer_update_configuration(), GNUNET_TESTBED_service_connect(), GNUNET_TESTBED_shutdown_peers(), handle_cred_collection_cb(), handle_dht_p2p_result(), handle_dht_reply(), handle_dht_response(), handle_dht_result(), handle_gns_resolution_result(), handle_link_controllers_result(), handle_op_fail_event(), handle_opsuccess(), handle_peer_conevent(), handle_peer_config(), handle_peer_create_success(), handle_peer_event(), handle_results(), heap_plugin_put(), iter_finished(), load_search_strings(), lookup_authz_cb(), lookup_redirect_uri_result(), main(), make_file(), merge_with_nick_records(), message_sent_cont(), mpi_to_sexp(), namestore_postgres_store_records(), namestore_sqlite_store_records(), no_more_local_results(), normalize_metadata(), oprelease_link_controllers(), oprelease_manage_service(), oprelease_overlay_connect(), oprelease_peer_getinfo(), oprelease_peer_reconfigure(), oprelease_service_connect(), opstart_get_slave_config(), opstart_link_controllers(), opstart_manage_service(), opstart_overlay_connect(), opstart_peer_create(), opstart_peer_getinfo(), opstart_peer_reconfigure(), opstart_peer_start(), opstart_peer_stop(), opstart_service_connect(), parse_attr(), parse_gnsrecordobject(), parse_result_call_iterator(), parse_variable_data(), policy_filename_cb(), postgres_plugin_get_random(), process_client_result(), process_kblock_for_unindex(), process_local_reply(), process_lookup_result(), process_result(), process_tickets(), put_cb(), qconv_abs_time(), qconv_rsa_public_key(), qconv_rsa_signature(), qconv_uint16(), qconv_uint32(), qconv_uint64(), recursive_gns2dns_resolution(), reply_to_dns(), result_processor(), revoke_attrs_cb(), rsa_sign_mpi(), run(), run_zbar(), rvk_ticket_update(), simple_session_add(), simple_session_update(), sqlite_plugin_del(), stdin_receiver(), store_and_free_entries(), stream_read_callback(), ticket_iter(), try_reconnect(), try_send_tcp(), unindex_process(), update_counters(), update_tickets(), write_bw_gnuplot_script(), write_rtt_gnuplot_script(), and write_throughput_gnuplot_script().

◆ msgcode

uint32_t msgcode

We expect this to be a PRISM_MSGCODE_*.

Definition at line 71 of file gnunet-helper-transport-wlan.c.

◆ msglen

uint32_t msglen

The length of the entire header.

Definition at line 76 of file gnunet-helper-transport-wlan.c.

◆ devname

char devname[16]

Name of the device that captured the packet.

Definition at line 81 of file gnunet-helper-transport-wlan.c.

◆ __attribute__

struct PrismHeader __attribute__

◆ write_pout

struct SendBuffer write_pout
static

Buffer for data read from stdin to be transmitted to the wirless card.

Definition at line 752 of file gnunet-helper-transport-wlan.c.

Referenced by main(), and stdin_send_hw().

◆ write_std

struct SendBuffer write_std
static

Buffer for data read from the wireless card to be transmitted to stdout.

Definition at line 757 of file gnunet-helper-transport-wlan.c.

Referenced by main().