/*

Copyright (c) 2007, 2008 by Juliusz Chroboczek

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

*/

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <errno.h>

#include <assert.h>

#include <sys/time.h>

#include <netinet/in.h>

#include "babeld.h"

#include "kernel.h"

#include "neighbour.h"

#include "message.h"

#include "route.h"

#include "xroute.h"

#include "util.h"

#include "configuration.h"

#include "interface.h"

#include "local.h"

static struct xroute *xroutes;

static int numxroutes = 0, maxxroutes = 0;

struct xroute *

find_xroute(const unsigned char *prefix, unsigned char plen,

const unsigned char *src_prefix, unsigned char src_plen)

{

int i;

for(i = 0; i < numxroutes; i++) {

if(xroutes[i].plen == plen &&

memcmp(xroutes[i].prefix, prefix, 16) == 0 &&

xroutes[i].src_plen == src_plen &&

memcmp(xroutes[i].src_prefix, src_prefix, 16) == 0)

return &xroutes[i];

}

return NULL;

}

void

flush_xroute(struct xroute *xroute)

{

int i;

i = xroute - xroutes;

assert(i >= 0 && i < numxroutes);

local_notify_xroute(xroute, LOCAL_FLUSH);

if(i != numxroutes - 1)

memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));

numxroutes--;

VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));

if(numxroutes == 0) {

free(xroutes);

xroutes = NULL;

maxxroutes = 0;

} else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {

struct xroute *new_xroutes;

int n = maxxroutes / 2;

new_xroutes = realloc(xroutes, n * sizeof(struct xroute));

if(new_xroutes == NULL)

return;

xroutes = new_xroutes;

maxxroutes = n;

}

}

int

add_xroute(unsigned char prefix[16], unsigned char plen,

unsigned char src_prefix[16], unsigned char src_plen,

unsigned short metric, unsigned int ifindex, int proto)

{

struct xroute *xroute = find_xroute(prefix, plen, src_prefix, src_plen);

if(xroute) {

if(xroute->metric <= metric)

return 0;

xroute->metric = metric;

local_notify_xroute(xroute, LOCAL_CHANGE);

return 1;

}

if(numxroutes >= maxxroutes) {

struct xroute *new_xroutes;

int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;

new_xroutes = xroutes == NULL ?

malloc(n * sizeof(struct xroute)) :

realloc(xroutes, n * sizeof(struct xroute));

if(new_xroutes == NULL)

return -1;

maxxroutes = n;

xroutes = new_xroutes;

}

memcpy(xroutes[numxroutes].prefix, prefix, 16);

xroutes[numxroutes].plen = plen;

memcpy(xroutes[numxroutes].src_prefix, src_prefix, 16);

xroutes[numxroutes].src_plen = src_plen;

xroutes[numxroutes].metric = metric;

xroutes[numxroutes].ifindex = ifindex;

xroutes[numxroutes].proto = proto;

numxroutes++;

local_notify_xroute(&xroutes[numxroutes - 1], LOCAL_ADD);

return 1;

}

/* Returns an overestimate of the number of xroutes. */

int

xroutes_estimate()

{

return numxroutes;

}

struct xroute_stream {

int index;

};

struct

xroute_stream *

xroute_stream()

{

struct xroute_stream *stream = malloc(sizeof(struct xroute_stream));

if(stream == NULL)

return NULL;

stream->index = 0;

return stream;

}

struct xroute *

xroute_stream_next(struct xroute_stream *stream)

{

if(stream->index < numxroutes)

return &xroutes[stream->index++];

else

return NULL;

}

void

xroute_stream_done(struct xroute_stream *stream)

{

free(stream);

}

static int

filter_route(struct kernel_route *route, void *data) {

void **args = (void**)data;

int maxroutes = *(int*)args[0];

struct kernel_route *routes = (struct kernel_route *)args[1];

int *found = (int*)args[2];

if(*found >= maxroutes)

return -1;

if(martian_prefix(route->prefix, route->plen) ||

martian_prefix(route->src_prefix, route->src_plen))

return 0;

routes[*found] = *route;

++ *found;

return 0;

}

static int

kernel_routes(struct kernel_route *routes, int maxroutes)

{

int found = 0;

void *data[3] = { &maxroutes, routes, &found };

struct kernel_filter filter = {0};

filter.route = filter_route;

filter.route_closure = data;

kernel_dump(CHANGE_ROUTE, &filter);

return found;

}

static int

filter_address(struct kernel_addr *addr, void *data) {

void **args = (void **)data;

int maxroutes = *(int *)args[0];

struct kernel_route *routes = (struct kernel_route*)args[1];

int *found = (int *)args[2];

int ifindex = *(int*)args[3];

int ll = args[4] ? !!*(int*)args[4] : 0;

struct kernel_route *route = NULL;

if(*found >= maxroutes)

return 0;

if(ll == !IN6_IS_ADDR_LINKLOCAL(&addr->addr))

return 0;

/* ifindex may be 0 -- see kernel_addresses */

if(ifindex && addr->ifindex != ifindex)

return 0;

route = &routes[*found];

memcpy(route->prefix, addr->addr.s6_addr, 16);

route->plen = 128;

route->metric = 0;

route->ifindex = addr->ifindex;

route->proto = RTPROT_BABEL_LOCAL;

memset(route->gw, 0, 16);

++ *found;

return 1;

}

/* ifindex is 0 for all interfaces. ll indicates whether we are

interested in link-local or global addresses. */

int

kernel_addresses(int ifindex, int ll, struct kernel_route *routes,

int maxroutes)

{

int found = 0;

void *data[5] = { &maxroutes, routes, &found, &ifindex, &ll };

struct kernel_filter filter = {0};

filter.addr = filter_address;

filter.addr_closure = data;

kernel_dump(CHANGE_ADDR, &filter);

return found;

}

int

check_xroutes(int send_updates)

{

int i, j, metric, export, change = 0, rc;

struct kernel_route *routes;

struct filter_result filter_result = {0};

int numroutes, numaddresses;

static int maxroutes = 8;

const int maxmaxroutes = 16 * 1024;

debugf("\nChecking kernel routes.\n");

again:

routes = calloc(maxroutes, sizeof(struct kernel_route));

if(routes == NULL)

return -1;

rc = kernel_addresses(0, 0, routes, maxroutes);

if(rc < 0) {

perror("kernel_addresses");

numroutes = 0;

} else {

numroutes = rc;

}

if(numroutes >= maxroutes)

goto resize;

numaddresses = numroutes;

rc = kernel_routes(routes + numroutes, maxroutes - numroutes);

if(rc < 0)

fprintf(stderr, "Couldn't get kernel routes.\n");

else

numroutes += rc;

if(numroutes >= maxroutes)

goto resize;

/* Apply filter to kernel routes (e.g. change the source prefix). */

for(i = numaddresses; i < numroutes; i++) {

filter_result.src_prefix = NULL;

redistribute_filter(routes[i].prefix, routes[i].plen,

routes[i].src_prefix, routes[i].src_plen,

routes[i].ifindex, routes[i].proto,

&filter_result);

if(filter_result.src_prefix) {

memcpy(routes[i].src_prefix, filter_result.src_prefix, 16);

routes[i].src_plen = filter_result.src_plen;

}

}

/* Check for any routes that need to be flushed */

i = 0;

while(i < numxroutes) {

export = 0;

metric = redistribute_filter(xroutes[i].prefix, xroutes[i].plen,

xroutes[i].src_prefix, xroutes[i].src_plen,

xroutes[i].ifindex, xroutes[i].proto,

NULL);

if(metric < INFINITY && metric == xroutes[i].metric) {

for(j = 0; j < numroutes; j++) {

if(xroutes[i].plen == routes[j].plen &&

memcmp(xroutes[i].prefix, routes[j].prefix, 16) == 0 &&

xroutes[i].ifindex == routes[j].ifindex &&

xroutes[i].proto == routes[j].proto) {

export = 1;

break;

}

}

}

if(!export) {

unsigned char prefix[16], plen;

unsigned char src_prefix[16], src_plen;

struct babel_route *route;

memcpy(prefix, xroutes[i].prefix, 16);

plen = xroutes[i].plen;

memcpy(src_prefix, xroutes[i].src_prefix, 16);

src_plen = xroutes[i].src_plen;

flush_xroute(&xroutes[i]);

route = find_best_route(prefix, plen, src_prefix, src_plen, 1,NULL);

if(route)

install_route(route);

/* send_update_resend only records the prefix, so the update

will only be sent after we perform all of the changes. */

if(send_updates)

send_update_resend(NULL, prefix, plen, src_prefix, src_plen);

change = 1;

} else {

i++;

}

}

/* Add any new routes */

for(i = 0; i < numroutes; i++) {

if(martian_prefix(routes[i].prefix, routes[i].plen))

continue;

metric = redistribute_filter(routes[i].prefix, routes[i].plen,

routes[i].src_prefix, routes[i].src_plen,

routes[i].ifindex, routes[i].proto, NULL);

if(metric < INFINITY) {

rc = add_xroute(routes[i].prefix, routes[i].plen,

routes[i].src_prefix, routes[i].src_plen,

metric, routes[i].ifindex, routes[i].proto);

if(rc > 0) {

struct babel_route *route;

route = find_installed_route(routes[i].prefix, routes[i].plen,

routes[i].src_prefix,

routes[i].src_plen);

if(route) {

if(allow_duplicates < 0 ||

routes[i].metric < allow_duplicates)

uninstall_route(route);

}

change = 1;

if(send_updates)

send_update(NULL, 0, routes[i].prefix, routes[i].plen,

routes[i].src_prefix, routes[i].src_plen);

}

}

}

free(routes);

/* Set up maxroutes for the next call. */

maxroutes = MIN(numroutes + 8, maxmaxroutes);

return change;

resize:

free(routes);

if(maxroutes >= maxmaxroutes)

return -1;

maxroutes = MIN(maxmaxroutes, 2 * maxroutes);

goto again;

}