macOS raw net

raw.c

#include <sys/socket.h>
#include <net/bpf.h>
#include <net/if.h>
#include <net/ethernet.h>
#include <errno.h>

#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <sys/ioctl.h>


int open_bpf() {
    char buf[100];
    int bpf = -1;
    for (int i=0; i<99; i++) {
        sprintf(buf, "/dev/bpf%d", i);
        bpf = open(buf, O_RDWR);
        if (bpf != -1) {
            return bpf;
        }
    }
    return -1;
}

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

    int s;
    unsigned char packet[100];
 
    int d;
    
    d = open_bpf();
    if (d == -1) {
        printf("bpf open failed\n");
        return 1;
    }
    printf("bpf opened %d\n", d);
    
    struct ifreq iface;
    strcpy(iface.ifr_name, "en0");
    if (ioctl(d, BIOCSETIF, &iface) > 0) {
        printf("can't bind\n");
        return 1;
    }
    uint flag = 1;
    if (ioctl(d, BIOCGHDRCMPLT, &flag) == -1) {
        printf("e1 %s\n", strerror(errno));
    }
    struct ether_header he;
    he.ether_type = 0;
    he.ether_dhost[0] = 10;
    he.ether_dhost[1] = 10;
    he.ether_dhost[2] = 10;
    he.ether_dhost[3] = 10;
    
    he.ether_shost[0] = 10;
    he.ether_shost[1] = 10;
 
    int r = write(d, &he, 100);
    printf("write res %d", r);
    
    return 0;
}