#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>

#include "rpc.h"

/* call ioctl system call */
ret_code if_ioctl(unsigned long request, caddr_t ifreq, int *ret)
{
    int sock;
    int err = 0;

    if(ret)
    {
        *ret = 0;
    }

    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock < 0) 
    {
        rpc_log_error("Cannot create UDP socket");
        return RET_SOCKERR;
    }
    if ((err = ioctl(sock, request, ifreq)) < 0)
    {
        rpc_log_error("Ioctl error: %s\n", strerror(errno));

    }
    
    close(sock);

    if (err < 0) 
    {
        if(ret)
        {
            *ret = err;
        }
        return RET_SYSERR;
    }

    return RET_OK;
}


/* Set a certain interface flag. */
static int if_set_flag(char *ifname, short flag, int *code)
{
    struct ifreq ifr = {0};
    ret_code ret = RET_OK;
    
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);

    ret = if_ioctl(SIOCGIFFLAGS, (caddr_t)&ifr, code);
    ASSERT_RET(ret);

    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
    ifr.ifr_flags |= flag;

    ret = if_ioctl(SIOCSIFFLAGS, (caddr_t)&ifr, code);
    ASSERT_RET(ret);
    
    return ret;
}


/* Clear a certain interface flag. */
static int if_clear_flag(char *ifname, short flag,  int *code)
{
    struct ifreq ifr = {0};
    ret_code ret;

    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);

    ret = if_ioctl(SIOCGIFFLAGS, (caddr_t)&ifr, code);
    ASSERT_RET(ret);
     
    strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
    ifr.ifr_flags &= ~flag;

    ret = if_ioctl(SIOCSIFFLAGS, (caddr_t)&ifr, code);
    ASSERT_RET(ret);

    return ret;
}

ret_code if_set_up(char *ifname, int *code)
{
    return if_set_flag(ifname, (IFF_UP | IFF_RUNNING),  code);
}

ret_code if_set_down(char *ifname, int *code)
{
    return if_clear_flag(ifname, IFF_UP,  code);
}