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/*
* BIRD -- Unix Interface Scanning and Syncing
*
* (c) 1998 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <errno.h>
#define LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "lib/timer.h"
#include "unix.h"
int if_scan_sock;
int if_scan_period = 60;
static timer *if_scan_timer;
static void
scan_ifs(struct ifreq *r, int cnt)
{
struct iface i;
struct ifa a;
char *err;
unsigned fl;
ip_addr netmask;
int l;
for (cnt /= sizeof(struct ifreq); cnt; cnt--, r++)
{
bzero(&i, sizeof(i));
bzero(&a, sizeof(a));
debug("%s\n", r->ifr_ifrn.ifrn_name);
strncpy(i.name, r->ifr_ifrn.ifrn_name, sizeof(i.name) - 1);
i.name[sizeof(i.name) - 1] = 0;
i.ifa = &a;
get_sockaddr((struct sockaddr_in *) &r->ifr_addr, &a.ip, NULL);
l = ipa_classify(a.ip);
if (l < 0 || !(l & IADDR_HOST))
{
log(L_ERR "%s: Invalid interface address", i.name);
goto bad;
}
if ((l & IADDR_SCOPE_MASK) == SCOPE_HOST)
i.flags |= IF_LOOPBACK | IF_IGNORE;
if (ioctl(if_scan_sock, SIOCGIFFLAGS, r) < 0)
{
err = "SIOCGIFFLAGS";
faulty:
log(L_ERR "%s(%s): %m", err, i.name);
bad:
i.flags = (i.flags & ~IF_UP) | IF_ADMIN_DOWN;
continue;
}
fl = r->ifr_flags;
if (fl & IFF_UP)
i.flags |= IF_UP;
if (ioctl(if_scan_sock, SIOCGIFNETMASK, r) < 0)
{ err = "SIOCGIFNETMASK"; goto faulty; }
get_sockaddr((struct sockaddr_in *) &r->ifr_addr, &netmask, NULL);
l = ipa_mklen(netmask);
if (l < 0 || l == 31)
{
log(L_ERR "%s: Invalid netmask", i.name);
goto bad;
}
a.pxlen = l;
if (fl & IFF_POINTOPOINT)
{
i.flags |= IF_UNNUMBERED;
a.pxlen = BITS_PER_IP_ADDRESS;
if (ioctl(if_scan_sock, SIOCGIFDSTADDR, r) < 0)
{ err = "SIOCGIFDSTADDR"; goto faulty; }
get_sockaddr((struct sockaddr_in *) &r->ifr_addr, &a.opposite, NULL);
}
if (fl & IFF_LOOPBACK)
i.flags |= IF_LOOPBACK | IF_IGNORE;
#ifndef CONFIG_ALL_MULTICAST
if (fl & IFF_MULTICAST)
#endif
i.flags |= IF_MULTICAST;
a.prefix = ipa_and(a.ip, ipa_mkmask(a.pxlen));
if (a.pxlen < 32)
{
a.brd = ipa_or(a.prefix, ipa_not(ipa_mkmask(a.pxlen)));
if (ipa_equal(a.ip, a.prefix) || ipa_equal(a.ip, a.brd))
{
log(L_ERR "%s: Using network or broadcast address for interface", i.name);
goto bad;
}
if (fl & IFF_BROADCAST)
i.flags |= IF_BROADCAST;
if (a.pxlen < 30)
i.flags |= IF_MULTIACCESS;
else
a.opposite = ipa_opposite(a.ip);
}
else
a.brd = a.opposite;
if (ioctl(if_scan_sock, SIOCGIFMTU, r) < 0)
{ err = "SIOCGIFMTU"; goto faulty; }
i.mtu = r->ifr_mtu;
#ifdef SIOCGIFINDEX
if (ioctl(if_scan_sock, SIOCGIFINDEX, r) < 0)
{ err = "SIOCGIFINDEX"; goto faulty; }
i.index = r->ifr_ifindex;
#endif
if_update(&i);
}
}
static void
scan_if(timer *t)
{
struct ifconf ic;
static int last_ifbuf_size;
int res;
DBG("Scanning interfaces...\n");
for(;;)
{
if (last_ifbuf_size)
{
struct ifreq *r = alloca(last_ifbuf_size);
ic.ifc_ifcu.ifcu_req = r;
ic.ifc_len = last_ifbuf_size;
res = ioctl(if_scan_sock, SIOCGIFCONF, &ic);
if (res < 0 && errno != EFAULT)
die("SIOCCGIFCONF: %m");
if (res < last_ifbuf_size)
{
scan_ifs(r, ic.ifc_len);
break;
}
}
ic.ifc_ifcu.ifcu_req = NULL;
if (ioctl(if_scan_sock, SIOCGIFCONF, &ic) < 0)
die("SIOCIFCONF: %m");
ic.ifc_len += sizeof(struct ifreq);
if (last_ifbuf_size < ic.ifc_len)
{
last_ifbuf_size = ic.ifc_len;
DBG("Increased ifconf buffer size to %d\n", last_ifbuf_size);
}
}
}
void
scan_if_init(void)
{
if_scan_sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
DBG("Using socket %d for interface and route scanning\n", if_scan_sock);
if (if_scan_sock < 0)
die("Cannot create scanning socket: %m");
scan_if(NULL);
if_scan_timer = tm_new(&root_pool);
if_scan_timer->hook = scan_if;
if_scan_timer->recurrent = if_scan_period;
tm_start(if_scan_timer, if_scan_period);
}
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