118 lines
3.0 KiB
C
118 lines
3.0 KiB
C
/* $Id: getgateway.c,v 1.6 2007/12/13 14:46:06 nanard Exp $ */
|
|
/* libnatpmp
|
|
* Copyright (c) 2007, Thomas BERNARD <miniupnp@free.fr>
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include <netinet/in.h>
|
|
#include <sys/param.h>
|
|
#if defined(BSD) || defined(__APPLE__)
|
|
#include <stdlib.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/socket.h>
|
|
#include <net/route.h>
|
|
#endif
|
|
#include "getgateway.h"
|
|
|
|
#ifdef __linux__
|
|
int getdefaultgateway(in_addr_t * addr)
|
|
{
|
|
long d, g;
|
|
char buf[256];
|
|
int line = 0;
|
|
FILE * f;
|
|
char * p;
|
|
f = fopen("/proc/net/route", "r");
|
|
if(!f)
|
|
return -1;
|
|
while(fgets(buf, sizeof(buf), f)) {
|
|
if(line > 0) {
|
|
p = buf;
|
|
while(*p && !isspace(*p))
|
|
p++;
|
|
while(*p && isspace(*p))
|
|
p++;
|
|
if(sscanf(p, "%lx%lx", &d, &g)==2) {
|
|
if(d == 0) { /* default */
|
|
*addr = g;
|
|
fclose(f);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
line++;
|
|
}
|
|
/* not found ! */
|
|
if(f)
|
|
fclose(f);
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
#if defined(BSD) || defined(__APPLE__)
|
|
|
|
#define ROUNDUP(a) \
|
|
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
|
|
|
|
int getdefaultgateway(in_addr_t * addr)
|
|
{
|
|
#if 0
|
|
/* net.route.0.inet.dump.0.0 ? */
|
|
int mib[] = {CTL_NET, PF_ROUTE, 0, AF_INET,
|
|
NET_RT_DUMP, 0, 0/*tableid*/};
|
|
#endif
|
|
/* net.route.0.inet.flags.gateway */
|
|
int mib[] = {CTL_NET, PF_ROUTE, 0, AF_INET,
|
|
NET_RT_FLAGS, RTF_GATEWAY};
|
|
size_t l;
|
|
char * buf, * p;
|
|
struct rt_msghdr * rt;
|
|
struct sockaddr * sa;
|
|
struct sockaddr * sa_tab[RTAX_MAX];
|
|
int i;
|
|
int r = -1;
|
|
if(sysctl(mib, sizeof(mib)/sizeof(int), 0, &l, 0, 0) < 0) {
|
|
return -1;
|
|
}
|
|
if(l>0) {
|
|
buf = malloc(l);
|
|
if(sysctl(mib, sizeof(mib)/sizeof(int), buf, &l, 0, 0) < 0) {
|
|
return -1;
|
|
}
|
|
for(p=buf; p<buf+l; p+=rt->rtm_msglen) {
|
|
rt = (struct rt_msghdr *)p;
|
|
sa = (struct sockaddr *)(rt + 1);
|
|
for(i=0; i<RTAX_MAX; i++) {
|
|
if(rt->rtm_addrs & (1 << i)) {
|
|
sa_tab[i] = sa;
|
|
sa = (struct sockaddr *)((char *)sa + ROUNDUP(sa->sa_len));
|
|
} else {
|
|
sa_tab[i] = NULL;
|
|
}
|
|
}
|
|
if( ((rt->rtm_addrs & (RTA_DST|RTA_GATEWAY)) == (RTA_DST|RTA_GATEWAY))
|
|
&& sa_tab[RTAX_DST]->sa_family == AF_INET
|
|
&& sa_tab[RTAX_GATEWAY]->sa_family == AF_INET) {
|
|
if(((struct sockaddr_in *)sa_tab[RTAX_DST])->sin_addr.s_addr == 0) {
|
|
*addr = ((struct sockaddr_in *)(sa_tab[RTAX_GATEWAY]))->sin_addr.s_addr;
|
|
r = 0;
|
|
}
|
|
}
|
|
}
|
|
free(buf);
|
|
}
|
|
return r;
|
|
}
|
|
#endif
|