/* Copyright Coraid, Inc. 2006.  All rights reserved. */

/* Modified the original with BSD license by Lluis Batlle */

#include <sys/types.h>

#include <sys/socket.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/time.h>

#include <features.h>    /* for the glibc version number */

#if __GLIBC__ >= 2 && __GLIBC_MINOR >= 1

#include <netpacket/packet.h>

#include <net/ethernet.h>     /* the L2 protocols */

#else

#include <asm/types.h>

#include <linux/if_packet.h>

#include <linux/if_ether.h>   /* The L2 protocols */

#endif

#include <sys/ioctl.h>

#include <net/if.h>

#include <netinet/in.h>

#include <linux/fs.h>

#include <sys/stat.h>

#include "main.h"

#include "eth_linux.h"

enum {

    ETH_SERVER_PROTO = 0xCACA,

    ETH_CLIENT_PROTO = 0xCACC

};

static int fd;

static enum Eth_type eth_type;

static char srcaddr[6];

static int debug = 0;

static void dump(unsigned char *buf, int len)

{

  int i;

  for(i=0; i < len; ++i)

  {

    printf("%x ", (int) buf[i]);

  }

  putchar('\n');

}

// return the index of device 'name'

static int getindx(int s, char *name)

{

    struct ifreq xx;

    int n;

    strncpy(xx.ifr_name, name, sizeof(xx.ifr_name));

    xx.ifr_name[sizeof(xx.ifr_name)-1] = 0;

    n = ioctl(s, SIOCGIFINDEX, &xx);

    if (n == -1)

        return -1;

    return xx.ifr_ifindex;

}

// get us a raw connection to an interface

int eth_open(char *eth, enum Eth_type type)

{

    int i, n;

    struct sockaddr_ll sa;

    struct ifreq xx;

    short int proto_num;

    if (type == ETH_SERVER)

    {

        dump_line("eth_open for server\n");

        proto_num = htons(ETH_SERVER_PROTO);

    }

    else if (type == ETH_CLIENT)

    {

        dump_line("eth_open for client\n");

        proto_num = htons(ETH_CLIENT_PROTO);

    }

    else

        return -1;

    /* Note the type server or client for this process */

    eth_type = type;

    memset(&sa, 0, sizeof sa);

    fd = socket(PF_PACKET, SOCK_DGRAM, proto_num);

    if (fd == -1) {

        perror("got bad socket");

        return -1;

    }

    i = getindx(fd, eth);

    sa.sll_family = AF_PACKET;

    sa.sll_protocol = proto_num;

    sa.sll_ifindex = i;

    n = bind(fd, (struct sockaddr *)&sa, sizeof sa);

    if (n == -1) {

        perror("bind funky");

        return -1;

    }

    strncpy(xx.ifr_name, eth, sizeof(xx.ifr_name));

    xx.ifr_name[sizeof(xx.ifr_name)-1] = 0;

    n = ioctl(fd, SIOCGIFHWADDR, &xx);

    if (n == -1) {

        perror("Can't get hw addr");

        return -1;

    }

    memmove(srcaddr, xx.ifr_hwaddr.sa_data, 6);

    return fd;

}

int eth_recv(char *buf, int len, char *partner_mac)

{

    struct sockaddr_ll sa;

    int sa_len = sizeof(sa);

    int res;

    dump_line("eth_recv\n");

    res = recvfrom(fd, buf, len, 0, (struct sockaddr *) &sa, &sa_len);

    if (debug) {

        printf("read %d bytes\r\n", res);

        dump(buf, res);

    }

    /* Assume sa_len will be ok */

    if (partner_mac)

        memcpy(partner_mac, sa.sll_addr, sa.sll_halen);

    return res;

}

int eth_send(char *dev, char *mac, void *p, int len)

{

    struct sockaddr_ll sa;

    int i;

    i = getindx(fd, dev);

    sa.sll_family = AF_PACKET;

    if (eth_type == ETH_SERVER)

    {

        dump_line("eth_send from server to client\n");

        sa.sll_protocol = htons(ETH_CLIENT_PROTO);

    }

    else if (eth_type == ETH_CLIENT)

    {

        dump_line("eth_send from client to server\n");

        sa.sll_protocol = htons(ETH_SERVER_PROTO);

    }

    else

        return -1;

    sa.sll_ifindex = i;

    sa.sll_halen = 6;

    memcpy(sa.sll_addr, mac, 6);

    if (debug) {

        printf("sending %d bytes to eth_protocol %hi\r\n", len, sa.sll_protocol);

        dump(p, len);

    }

    if (len > 1500)

        len = 1500;

    return sendto(fd, p, len, 0, (struct sockaddr*) &sa, sizeof(sa));

}