incubator-nuttx/net/route/net_router.c

415 lines
12 KiB
C

/****************************************************************************
* net/route/net_router.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <nuttx/net/ip.h>
#include "devif/devif.h"
#include "route/cacheroute.h"
#include "route/route.h"
#include "utils/utils.h"
#if defined(CONFIG_NET) && defined(CONFIG_NET_ROUTE)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
# define IPv4_ROUTER entry.router
#else
# define IPv4_ROUTER router
#endif
#ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
# define IPv6_ROUTER entry.router
#else
# define IPv6_ROUTER router
#endif
/****************************************************************************
* Private Types
****************************************************************************/
#ifdef CONFIG_NET_IPv4
struct route_ipv4_match_s
{
in_addr_t target; /* Target IPv4 address on remote network */
#ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
struct net_route_ipv4_s entry; /* Full entry from the IPv4 routing table */
#else
in_addr_t router; /* IPv4 address of router a local networks */
#endif
#ifdef CONFIG_ROUTE_LONGEST_MATCH
/* Only match prefix longer than prefixlen, equals to entry.netmask if we
* have got a match (then we only find longer prefix later).
* Range: -1 ~ 32
*/
int8_t prefixlen;
#endif
};
#endif
#ifdef CONFIG_NET_IPv6
struct route_ipv6_match_s
{
net_ipv6addr_t target; /* Target IPv6 address on remote network */
#ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
struct net_route_ipv6_s entry; /* Full entry from the IPv6 routing table */
#else
net_ipv6addr_t router; /* IPv6 address of router a local networks */
#endif
#ifdef CONFIG_ROUTE_LONGEST_MATCH
/* Only match prefix longer than prefixlen, equals to entry.netmask if we
* have got a match (then we only find longer prefix later).
* Range: -1 ~ 128
*/
int16_t prefixlen;
#endif
};
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: net_ipv4_match
*
* Description:
* Return 1 if the IPv4 route is available
*
* Input Parameters:
* route - The next route to examine
* arg - The match values (cast to void*)
*
* Returned Value:
* 0 if the entry is not a match; 1 if the entry matched and was cleared.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv4
static int net_ipv4_match(FAR struct net_route_ipv4_s *route, FAR void *arg)
{
FAR struct route_ipv4_match_s *match =
(FAR struct route_ipv4_match_s *)arg;
#ifdef CONFIG_ROUTE_LONGEST_MATCH
int8_t prefixlen = (int8_t)net_ipv4_mask2pref(route->netmask);
#endif
/* To match, the masked target addresses must be the same. In the event
* of multiple matches, only the first is returned. There is not (yet) any
* concept for the precedence of networks.
*/
if (net_ipv4addr_maskcmp(route->target, match->target, route->netmask)
#ifdef CONFIG_ROUTE_LONGEST_MATCH
&& prefixlen > match->prefixlen
#endif
)
{
#ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
/* They match.. Copy the entire routing table entry */
memcpy(&match->entry, route, sizeof(struct net_route_ipv4_s));
#else
/* They match.. Copy the router address */
net_ipv4addr_copy(match->router, route->router);
#endif
#ifdef CONFIG_ROUTE_LONGEST_MATCH
/* Cache the prefix length */
match->prefixlen = prefixlen;
#else
return 1;
#endif
}
return 0;
}
#endif /* CONFIG_NET_IPv4 */
/****************************************************************************
* Name: net_ipv6_match
*
* Description:
* Return 1 if the IPv6 route is available
*
* Input Parameters:
* route - The next route to examine
* arg - The match values (cast to void*)
*
* Returned Value:
* 0 if the entry is not a match; 1 if the entry matched and was cleared.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
static int net_ipv6_match(FAR struct net_route_ipv6_s *route, FAR void *arg)
{
FAR struct route_ipv6_match_s *match =
(FAR struct route_ipv6_match_s *)arg;
#ifdef CONFIG_ROUTE_LONGEST_MATCH
int16_t prefixlen = (int16_t)net_ipv6_mask2pref(route->netmask);
#endif
/* To match, the masked target addresses must be the same. In the event
* of multiple matches, only the first is returned. There is not (yet) any
* concept for the precedence of networks.
*/
if (net_ipv6addr_maskcmp(route->target, match->target, route->netmask)
#ifdef CONFIG_ROUTE_LONGEST_MATCH
&& prefixlen > match->prefixlen
#endif
)
{
#ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
/* They match.. Copy the entire routing table entry */
memcpy(&match->entry, route, sizeof(struct net_route_ipv6_s));
#else
/* They match.. Copy the router address */
net_ipv6addr_copy(match->router, route->router);
#endif
#ifdef CONFIG_ROUTE_LONGEST_MATCH
/* Cache the prefix length */
match->prefixlen = prefixlen;
#else
return 1;
#endif
}
return 0;
}
#endif /* CONFIG_NET_IPv6 */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: net_ipv4_router
*
* Description:
* Given an IPv4 address on a external network, return the address of the
* router on a local network that can forward to the external network.
*
* Input Parameters:
* target - An IPv4 address on a remote network to use in the lookup.
* router - The address of router on a local network that can forward
* our packets to the target.
* prefixlen - The prefix length of previously matched routes (maybe on
* device), will only match prefix longer than prefixlen.
* Range: -1(match all) ~ 32(match none)
*
* Returned Value:
* OK on success; Negated errno on failure.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv4
int net_ipv4_router(in_addr_t target, FAR in_addr_t *router,
int8_t prefixlen)
{
struct route_ipv4_match_s match;
int ret;
/* Just early return for long prefix, maybe already got exact match. */
if (prefixlen >= 32)
{
return -ENOENT;
}
/* Do not route the special broadcast IP address */
if (net_ipv4addr_cmp(target, INADDR_BROADCAST))
{
return -ENOENT;
}
/* Set up the comparison structure */
memset(&match, 0, sizeof(struct route_ipv4_match_s));
net_ipv4addr_copy(match.target, target);
#ifdef CONFIG_ROUTE_LONGEST_MATCH
match.prefixlen = prefixlen;
#endif
#ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
/* First see if we can find a router entry in the cache */
ret = net_foreachcache_ipv4(net_ipv4_match, &match);
if (ret <= 0)
#endif
{
/* Not found in the cache. Try to find a router entry with the
* routing table that can forward to this address
*/
ret = net_foreachroute_ipv4(net_ipv4_match, &match);
}
/* Did we find a route? */
#ifdef CONFIG_ROUTE_LONGEST_MATCH
UNUSED(ret);
if (match.prefixlen <= prefixlen)
#else
if (ret <= 0)
#endif
{
/* No.. there is no route for this address */
return -ENOENT;
}
/* We found a route. */
#ifdef CONFIG_ROUTE_IPv4_CACHEROUTE
/* Add the route to the cache. If the route is already in the cache, this
* will update it to the most recently accessed.
*/
net_addcache_ipv4(&match.entry);
#endif
/* Return the router address. */
net_ipv4addr_copy(*router, match.IPv4_ROUTER);
return OK;
}
#endif /* CONFIG_NET_IPv4 */
/****************************************************************************
* Name: net_ipv6_router
*
* Description:
* Given an IPv6 address on a external network, return the address of the
* router on a local network that can forward to the external network.
*
* Input Parameters:
* target - An IPv6 address on a remote network to use in the lookup.
* router - The address of router on a local network that can forward
* our packets to the target.
* prefixlen - The prefix length of previously matched routes (maybe on
* device), will only match prefix longer than prefixlen.
* Range: -1(match all) ~ 128(match none)
*
* Returned Value:
* OK on success; Negated errno on failure.
*
****************************************************************************/
#ifdef CONFIG_NET_IPv6
int net_ipv6_router(const net_ipv6addr_t target, net_ipv6addr_t router,
int16_t prefixlen)
{
struct route_ipv6_match_s match;
int ret;
/* Just early return for long prefix, maybe already got exact match. */
if (prefixlen >= 128)
{
return -ENOENT;
}
/* Do not route to any the special IPv6 multicast addresses */
if (target[0] == HTONS(0xff02))
{
return -ENOENT;
}
/* Set up the comparison structure */
memset(&match, 0, sizeof(struct route_ipv6_match_s));
net_ipv6addr_copy(match.target, target);
#ifdef CONFIG_ROUTE_LONGEST_MATCH
match.prefixlen = prefixlen;
#endif
#ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
/* First see if we can find a router entry in the cache */
ret = net_foreachcache_ipv6(net_ipv6_match, &match);
if (ret <= 0)
#endif
{
/* Not found in the cache. Try to find a router entry with the
* routing table that can forward to this address
*/
ret = net_foreachroute_ipv6(net_ipv6_match, &match);
}
/* Did we find a route? */
#ifdef CONFIG_ROUTE_LONGEST_MATCH
UNUSED(ret);
if (match.prefixlen <= prefixlen)
#else
if (ret <= 0)
#endif
{
/* No.. there is no route for this address */
return -ENOENT;
}
/* We found a route. */
#ifdef CONFIG_ROUTE_IPv6_CACHEROUTE
/* Add the route to the cache. If the route is already in the cache, this
* will update it to the most recently accessed.
*/
net_addcache_ipv6(&match.entry);
#endif
/* Return the router address. */
net_ipv6addr_copy(router, match.IPv6_ROUTER);
return OK;
}
#endif /* CONFIG_NET_IPv6 */
#endif /* CONFIG_NET && CONFIG_NET_ROUTE */