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/*
* BIRD -- Linux Routing Table Scanning
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <stdio.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <net/route.h>
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "lib/timer.h"
#include "lib/unix.h"
#include "lib/krt.h"
#include "lib/string.h"
static int krt_scan_fd = -1;
struct iface *
krt_temp_iface(struct krt_proto *p, char *name)
{
struct iface *i;
WALK_LIST(i, p->scan.temp_ifs)
if (!strcmp(i->name, name))
return i;
i = mb_allocz(p->p.pool, sizeof(struct iface));
strcpy(i->name, name);
add_tail(&p->scan.temp_ifs, &i->n);
return i;
}
static void
krt_parse_entry(byte *ent, struct krt_proto *p)
{
u32 dest0, gw0, mask0;
ip_addr dest, gw, mask;
unsigned int flags;
int masklen;
net *net;
byte *iface = ent;
rta a;
rte *e;
if (sscanf(ent, "%*s\t%x\t%x\t%x\t%*d\t%*d\t%*d\t%x\t", &dest0, &gw0, &flags, &mask0) != 4)
{
log(L_ERR "krt read: unable to parse `%s'", ent);
return;
}
while (*ent != '\t')
ent++;
*ent = 0;
dest = ipa_from_u32(dest0);
ipa_ntoh(dest);
gw = ipa_from_u32(gw0);
ipa_ntoh(gw);
mask = ipa_from_u32(mask0);
ipa_ntoh(mask);
if ((masklen = ipa_mklen(mask)) < 0)
{
log(L_ERR "krt read: invalid netmask %08x", mask0);
return;
}
DBG("Got %I/%d via %I flags %x\n", dest, masklen, gw, flags);
if (!(flags & RTF_UP))
{
DBG("Down.\n");
return;
}
if (flags & RTF_HOST)
masklen = 32;
if (flags & (RTF_DYNAMIC | RTF_MODIFIED)) /* Redirect route */
{
log(L_WARN "krt: Ignoring redirect to %I/%d via %I", dest, masklen, gw);
return;
}
net = net_get(p->p.table, dest, masklen);
a.proto = &p->p;
a.source = RTS_INHERIT;
a.scope = SCOPE_UNIVERSE;
a.cast = RTC_UNICAST;
a.flags = a.aflags = 0;
a.from = IPA_NONE;
a.iface = NULL;
a.eattrs = NULL;
if (flags & RTF_GATEWAY)
{
neighbor *ng = neigh_find(&p->p, &gw, 0);
if (ng && ng->scope)
a.iface = ng->iface;
else
{
log(L_WARN "Kernel told us to use non-neighbor %I for %I/%d", gw, net->n.prefix, net->n.pxlen);
return;
}
a.dest = RTD_ROUTER;
a.gw = gw;
}
else if (flags & RTF_REJECT)
{
a.dest = RTD_UNREACHABLE;
a.gw = IPA_NONE;
}
else if (isalpha(iface[0]))
{
a.dest = RTD_DEVICE;
a.gw = IPA_NONE;
a.iface = krt_temp_iface(p, iface);
}
else
{
log(L_WARN "Kernel reporting unknown route type to %I/%d", net->n.prefix, net->n.pxlen);
return;
}
e = rte_get_temp(&a);
e->net = net;
e->u.krt.src = KRT_SRC_UNKNOWN;
krt_got_route(p, e);
}
void
krt_scan_fire(struct krt_proto *p)
{
byte buf[32768];
int l, seen_hdr;
if (krt_scan_fd < 0)
{
krt_scan_fd = open("/proc/net/route", O_RDONLY);
if (krt_scan_fd < 0)
die("/proc/net/route: %m");
}
else if (lseek(krt_scan_fd, 0, SEEK_SET) < 0)
{
log(L_ERR "krt seek: %m");
return;
}
seen_hdr = 0;
while ((l = read(krt_scan_fd, buf, sizeof(buf))) > 0)
{
byte *z = buf;
if (l & 127)
{
log(L_ERR "krt read: misaligned entry: l=%d", l);
return;
}
while (l >= 128)
{
if (seen_hdr++)
krt_parse_entry(z, p);
z += 128;
l -= 128;
}
}
if (l < 0)
{
log(L_ERR "krt read: %m");
return;
}
DBG("KRT scan done, seen %d lines\n", seen_hdr);
}
void
krt_scan_construct(struct krt_config *c)
{
}
void
krt_scan_preconfig(struct config *c)
{
}
void
krt_scan_postconfig(struct krt_config *c)
{
}
void
krt_scan_start(struct krt_proto *x, int first)
{
init_list(&x->scan.temp_ifs);
}
void
krt_scan_shutdown(struct krt_proto *x, int last)
{
}
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