#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"
#include "netconfig.h"

static char *if_parse_name(char *name, char *p)
{
    while (isspace(*p))
	p++;
    while (*p) {
	if (isspace(*p))
	    break;
	if (*p == ':') {	/* could be an alias */
	    char *dot = p, *dotname = name;
	    *name++ = *p++;
	    while (isdigit(*p))
		*name++ = *p++;
	    if (*p != ':') {	/* it wasn't, backup */
		p = dot;
		name = dotname;
	    }
	    if (*p == '\0')
		return NULL;
	    p++;
	    break;
	}
	*name++ = *p++;
    }
    *name++ = '\0';
    return p;
}


/* 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);
}

int if_readlist(caddr_t ifcfg, int max_port)
{
    struct ifreq *ifreq = (struct ifreq *)ifcfg;
    char name[128] = {0};
    char buf[512] = {0};
    int i = 0;
    FILE *fh;

    fh = fopen(PATH_PROCNET_DEV, "r");
    if (!fh) {
		return 0;
	}	
    
    fgets(buf, sizeof buf, fh);	/* eat line */
    fgets(buf, sizeof buf, fh);

    while (fgets(buf, sizeof buf, fh)) {
        if(i >= max_port){
            break;
        }
        
        memset(name, 0, 128);
        if_parse_name(name, buf);
        if(strlen(name) != 0){
            strncpy(ifreq[i].ifr_name, name, sizeof(ifreq[i].ifr_name));
            i++;
        }
    }

    fclose(fh);
    return i;
}