int
kernel_routes(struct kernel_route *routes, int maxroutes)
{
int mib[6];
char *buf, *p;
size_t len;
struct rt_msghdr *rtm;
int rc, i;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = AF_UNSPEC; /* Address family */
mib[4] = NET_RT_DUMP; /* Dump the kernel routing table */
mib[5] = 0; /* No flags */
rc = sysctl(mib, 6, NULL, &len, NULL, 0);
if (rc < 0) {
perror("kernel_routes(len)");
return -1;
}
buf = malloc(len);
if(!buf) {
perror("kernel_routes(malloc)");
return -1;
}
rc = sysctl(mib, 6, buf, &len, NULL, 0);
if (rc < 0) {
perror("kernel_routes(dump)");
goto fail;
}
i = 0;
p = buf;
while(p < buf + len && i < maxroutes) {
rtm = (struct rt_msghdr*)p;
rc = parse_kernel_route(rtm, &routes[i]);
if(rc)
goto cont;
if(debug > 2)
print_kernel_route(1,&routes[i]);
i++;
cont:
p += rtm->rtm_msglen;
}
free(buf);
return i;
fail:
free(buf);
return -1;
}
static int
socket_read(int sock)
{
int rc;
struct {
struct rt_msghdr rtm;
struct sockaddr_storage addr[RTAX_MAX];
} buf;
rc = read(sock, &buf, sizeof(buf));
if(rc <= 0) {
perror("kernel_callback(read)");
return 0;
}
if(buf.rtm.rtm_msglen != rc) {
kdebugf("kernel_callback(length)\n");
return -1;
}
if(buf.rtm.rtm_type == RTM_ADD ||
buf.rtm.rtm_type == RTM_DELETE ||
buf.rtm.rtm_type == RTM_CHANGE) {
struct kernel_route route;
if(buf.rtm.rtm_errno)
return 0;
rc = parse_kernel_route(&buf.rtm, &route);
if(rc < 0)
return 0;
if(debug > 2)
print_kernel_route(1,&route);
return 1;
}
return 0;
}
static int
filter_kernel_routes(struct nlmsghdr *nh, void *data)
{
int rc;
struct kernel_route *current_route;
struct kernel_route route;
int maxroutes = 0;
struct kernel_route *routes = NULL;
int *found = NULL;
int len;
struct rtmsg *rtm;
if(data) {
void **args = (void**)data;
maxroutes = *(int*)args[0];
routes = (struct kernel_route *)args[1];
found = (int*)args[2];
}
len = nh->nlmsg_len;
if(data && *found >= maxroutes)
return 0;
if(nh->nlmsg_type != RTM_NEWROUTE &&
(data || nh->nlmsg_type != RTM_DELROUTE))
return 0;
rtm = (struct rtmsg*)NLMSG_DATA(nh);
len -= NLMSG_LENGTH(0);
if(rtm->rtm_protocol == RTPROT_BABEL)
return 0;
if(rtm->rtm_src_len != 0)
return 0;
if(data)
current_route = &routes[*found];
else
current_route = &route;
rc = parse_kernel_route_rta(rtm, len, current_route);
if(rc < 0)
return 0;
if(martian_prefix(current_route->prefix, current_route->plen))
return 0;
/* Ignore default unreachable routes; no idea where they come from. */
if(current_route->plen == 0 && current_route->metric >= KERNEL_INFINITY)
return 0;
if(debug >= 2) {
if(rc >= 0) {
print_kernel_route(nh->nlmsg_type, rtm->rtm_protocol,
rtm->rtm_type, current_route);
}
}
if (data) *found = (*found)+1;
return 1;
}
