254 lines
7.3 KiB
C
254 lines
7.3 KiB
C
/*
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Florenc Caminade
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Thomas FLayols
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Etienne Arlaud
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Jurij Podgoršek
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Receive raw 802.11 packet and filter ESP-NOW vendor specific action frame using BPF filters.
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https://hackaday.io/project/161896
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https://github.com/thomasfla/Linux-ESPNOW
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Adapted from :
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https://stackoverflow.com/questions/10824827/raw-sockets-communication-over-wifi-receiver-not-able-to-receive-packets
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1/Find your wifi interface:
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$ iwconfig
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2/Setup your interface in monitor mode :
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$ sudo ifconfig wlp5s0 down
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$ sudo iwconfig wlp5s0 mode monitor
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$ sudo ifconfig wlp5s0 up
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3/Run this code as root
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*/
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <linux/if_arp.h>
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#include <arpa/inet.h>
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#include <assert.h>
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#include <linux/filter.h>
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// Debug?
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#define DEBUG
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// Booleans
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#include <stdbool.h>
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// OSC
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#include "lo/lo.h"
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#include "lo/lo_lowlevel.h"
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#include "lo/lo_osc_types.h"
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#define PACKET_LENGTH 400 //Approximate
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#define MAX_PACKET_LEN 1000
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// ESPNOW data payload starts at byte 60
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#define ESP_DATA_OFFSET 57
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// Sensor message
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#include "../src/sensor_msg.h"
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// Maksimalno stevilo
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#define ST_SPREJEMNIKOV 10
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uint8_t odcitekId;
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sensor_msg odcitki[ST_SPREJEMNIKOV];
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bool poslji[ST_SPREJEMNIKOV];
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#include <sys/time.h>
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struct timeval cas;
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struct timeval zdaj;
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int eps = 0;
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/*our MAC address*/
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//{0xF8, 0x1A, 0x67, 0xB7, 0xeB, 0x0B};
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/*ESP8266 host MAC address*/
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//{0x84,0xF3,0xEB,0x73,0x55,0x0D};
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//filter action frame packets
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//Equivalent for tcp dump :
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//type 0 subtype 0xd0 and wlan[24:4]=0x7f18fe34 and wlan[32]=221 and wlan[33:4]&0xffffff = 0x18fe34 and wlan[37]=0x4
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//NB : There is no filter on source or destination addresses, so this code will 'receive' the action frames sent by this computer...
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#define FILTER_LENGTH 20
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static struct sock_filter bpfcode[FILTER_LENGTH] = {
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{ 0x30, 0, 0, 0x00000003 }, // ldb [3] // radiotap header length : MS byte
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{ 0x64, 0, 0, 0x00000008 }, // lsh #8 // left shift it
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{ 0x7, 0, 0, 0x00000000 }, // tax // 'store' it in X register
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{ 0x30, 0, 0, 0x00000002 }, // ldb [2] // radiotap header length : LS byte
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{ 0x4c, 0, 0, 0x00000000 }, // or x // combine A & X to get radiotap header length in A
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{ 0x7, 0, 0, 0x00000000 }, // tax // 'store' it in X
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{ 0x50, 0, 0, 0x00000000 }, // ldb [x + 0] // right after radiotap header is the type and subtype
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{ 0x54, 0, 0, 0x000000fc }, // and #0xfc // mask the interesting bits, a.k.a 0b1111 1100
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{ 0x15, 0, 10, 0x000000d0 }, // jeq #0xd0 jt 9 jf 19 // compare the types (0) and subtypes (0xd)
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{ 0x40, 0, 0, 0x00000018 }, // Ld [x + 24] // 24 bytes after radiotap header is the end of MAC header, so it is category and OUI (for action frame layer)
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{ 0x15, 0, 8, 0x7f18fe34 }, // jeq #0x7f18fe34 jt 11 jf 19 // Compare with category = 127 (Vendor specific) and OUI 18:fe:34
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{ 0x50, 0, 0, 0x00000020 }, // ldb [x + 32] // Begining of Vendor specific content + 4 ?random? bytes : element id
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{ 0x15, 0, 6, 0x000000dd }, // jeq #0xdd jt 13 jf 19 // element id should be 221 (according to the doc)
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{ 0x40, 0, 0, 0x00000021 }, // Ld [x + 33] // OUI (again!) on 3 LS bytes
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{ 0x54, 0, 0, 0x00ffffff }, // and #0xffffff // Mask the 3 LS bytes
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{ 0x15, 0, 3, 0x0018fe34 }, // jeq #0x18fe34 jt 16 jf 19 // Compare with OUI 18:fe:34
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{ 0x50, 0, 0, 0x00000025 }, // ldb [x + 37] // Type
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{ 0x15, 0, 1, 0x00000004 }, // jeq #0x4 jt 18 jf 19 // Compare type with type 0x4 (corresponding to ESP_NOW)
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{ 0x6, 0, 0, 0x00040000 }, // ret #262144 // return 'True'
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{ 0x6, 0, 0, 0x00000000 }, // ret #0 // return 'False'
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};
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void print_packet(uint8_t *data, int len) {
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/*
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char macNaslov[18];
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snprintf(macNaslov, sizeof(macNaslov), "%02x:%02x:%02x:%02x:%02x:%02x",
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mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
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printf("%s\n", macNaslov);
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*/
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//printf("Prejel podatke dolzine %i \n", len);
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// ID senzorja
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odcitekId = (uint8_t) data[ESP_DATA_OFFSET];
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// Vrednosti
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memcpy(&odcitki[odcitekId], data + ESP_DATA_OFFSET, sizeof(sensor_msg));
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poslji[odcitekId] = true;
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#ifdef DEBUG
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printf("senzor %i\n", odcitekId);
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printf("aX: %f \n", odcitki[odcitekId].aX);
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printf("aY: %f \n", odcitki[odcitekId].aY);
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printf("aZ: %f \n", odcitki[odcitekId].aZ);
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printf("qW: %f \n", odcitki[odcitekId].qW);
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printf("qX: %f \n", odcitki[odcitekId].qX);
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printf("qY: %f \n", odcitki[odcitekId].qY);
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printf("qZ: %f \n", odcitki[odcitekId].qZ);
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printf("bat: %f \n", odcitki[odcitekId].bat);
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#endif
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eps += 1;
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gettimeofday(&zdaj, NULL);
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if (zdaj.tv_sec != cas.tv_sec) {
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printf("Paketov na sekundo: %i\n", eps);
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eps = 0;
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gettimeofday(&cas, NULL);
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}
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return;
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// @TODO locen thread za posiljanje?
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char glava[32];
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lo_bundle svezenj;
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lo_message m;
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char* sporocilo;
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size_t dolzina;
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for (int i = 0; i < ST_SPREJEMNIKOV; i++) {
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if (poslji[i]) {
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// Ustvarim bundle (svezenj)
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svezenj = lo_bundle_new(LO_TT_IMMEDIATE);
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// Dodamo sporocila
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sprintf(glava, "/ww/%d/acc", i);
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m = lo_message_new();
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lo_message_add_float(m, odcitki[i].aX);
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lo_message_add_float(m, odcitki[i].aY);
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lo_message_add_float(m, odcitki[i].aZ);
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//free(sporocilo);
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lo_bundle_add_message(svezenj, glava, m);
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sprintf(glava, "/ww/%d/quat", i);
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m = lo_message_new();
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lo_message_add_float(m, odcitki[i].qW);
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lo_message_add_float(m, odcitki[i].aX);
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lo_message_add_float(m, odcitki[i].aY);
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lo_message_add_float(m, odcitki[i].aZ);
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lo_bundle_add_message(svezenj, glava, m);
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sporocilo = lo_bundle_serialise(svezenj, NULL, &dolzina);
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lo_bundle_pp(svezenj);
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printf("%s\n", sporocilo);
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lo_bundle_free(svezenj);
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//printf("%s\n", glava);
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//free(sporocilo);
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}
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}
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/* DEBUG - print whole raw packet
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for (int i = 0; i < len; i++) {
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printf("0x%02x ", data[i]);
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}
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printf("\n");
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*/
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}
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int create_raw_socket(char *dev, struct sock_fprog *bpf)
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{
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struct sockaddr_ll sll;
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struct ifreq ifr;
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int fd, ifi, rb, attach_filter;
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bzero(&sll, sizeof(sll));
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bzero(&ifr, sizeof(ifr));
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fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
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assert(fd != -1);
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strncpy((char *)ifr.ifr_name, dev, IFNAMSIZ);
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ifi = ioctl(fd, SIOCGIFINDEX, &ifr);
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assert(ifi != -1);
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sll.sll_protocol = htons(ETH_P_ALL);
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sll.sll_family = PF_PACKET;
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sll.sll_ifindex = ifr.ifr_ifindex;
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sll.sll_pkttype = PACKET_OTHERHOST;
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rb = bind(fd, (struct sockaddr *)&sll, sizeof(sll));
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assert(rb != -1);
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attach_filter = setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, bpf, sizeof(*bpf));
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assert(attach_filter != -1);
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return fd;
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}
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int main(int argc, char **argv)
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{
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assert(argc == 2);
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uint8_t buff[MAX_PACKET_LEN] = {0};
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int sock_fd;
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char *dev = argv[1];
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struct sock_fprog bpf = {FILTER_LENGTH, bpfcode};
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sock_fd = create_raw_socket(dev, &bpf); /* Creating the raw socket */
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printf("\n Waiting to receive packets ........ \n");
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gettimeofday(&cas, NULL);
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while (1)
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{
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int len = recvfrom(sock_fd, buff, MAX_PACKET_LEN, MSG_TRUNC, NULL, 0);
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if (len < 0) {
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perror("Socket receive failed or error");
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break;
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} else {
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//printf("len:%d\n", len);
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print_packet(buff, len);
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}
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}
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close(sock_fd);
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return 0;
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}
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