freebsd-skq/sys/netinet/in_fib.c
2020-09-01 21:19:14 +00:00

246 lines
6.3 KiB
C

/*-
* Copyright (c) 2015
* Alexander V. Chernikov <melifaro@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_route.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/route/route_var.h>
#include <net/route/nhop.h>
#include <net/vnet.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_fib.h>
#ifdef INET
/* Verify struct route compatiblity */
/* Assert 'struct route_in' is compatible with 'struct route' */
CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4);
/*
* Looks up path in fib @fibnum specified by @dst.
* Returns path nexthop on success. Nexthop is safe to use
* within the current network epoch. If longer lifetime is required,
* one needs to pass NHR_REF as a flag. This will return referenced
* nexthop.
*/
struct nhop_object *
fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
uint32_t flags, uint32_t flowid)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct rtentry *rt;
struct nhop_object *nh;
KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET);
if (rh == NULL)
return (NULL);
/* Prepare lookup key */
struct sockaddr_in sin4;
memset(&sin4, 0, sizeof(sin4));
sin4.sin_family = AF_INET;
sin4.sin_len = sizeof(struct sockaddr_in);
sin4.sin_addr = dst;
nh = NULL;
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rt = RNTORT(rn);
#ifdef RADIX_MPATH
if (rt_mpath_next(rt) != NULL)
rt = rt_mpath_selectrte(rt, flowid);
#endif
nh = rt->rt_nhop;
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(nh->nh_ifp)) {
if (flags & NHR_REF)
nhop_ref_object(nh);
RIB_RUNLOCK(rh);
return (nh);
}
}
RIB_RUNLOCK(rh);
RTSTAT_INC(rts_unreach);
return (NULL);
}
inline static int
check_urpf(const struct nhop_object *nh, uint32_t flags,
const struct ifnet *src_if)
{
if (src_if != NULL && nh->nh_aifp == src_if) {
return (1);
}
if (src_if == NULL) {
if ((flags & NHR_NODEFAULT) == 0)
return (1);
else if ((nh->nh_flags & NHF_DEFAULT) == 0)
return (1);
}
return (0);
}
#ifdef RADIX_MPATH
inline static int
check_urpf_mpath(struct rtentry *rt, uint32_t flags,
const struct ifnet *src_if)
{
while (rt != NULL) {
if (check_urpf(rt->rt_nhop, flags, src_if) != 0)
return (1);
rt = rt_mpath_next(rt);
}
return (0);
}
#endif
/*
* Performs reverse path forwarding lookup.
* If @src_if is non-zero, verifies that at least 1 path goes via
* this interface.
* If @src_if is zero, verifies that route exist.
* if @flags contains NHR_NOTDEFAULT, do not consider default route.
*
* Returns 1 if route matching conditions is found, 0 otherwise.
*/
int
fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
uint32_t flags, const struct ifnet *src_if)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct rtentry *rt;
int ret;
KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET);
if (rh == NULL)
return (0);
/* Prepare lookup key */
struct sockaddr_in sin4;
memset(&sin4, 0, sizeof(sin4));
sin4.sin_len = sizeof(struct sockaddr_in);
sin4.sin_addr = dst;
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rt = RNTORT(rn);
#ifdef RADIX_MPATH
ret = check_urpf_mpath(rt, flags, src_if);
#else
ret = check_urpf(rt->rt_nhop, flags, src_if);
#endif
RIB_RUNLOCK(rh);
return (ret);
}
RIB_RUNLOCK(rh);
return (0);
}
struct nhop_object *
fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
uint32_t flags)
{
struct rib_head *rh;
struct radix_node *rn;
struct rtentry *rt;
struct nhop_object *nh;
KASSERT((fibnum < rt_numfibs), ("fib4_lookup_debugnet: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET);
if (rh == NULL)
return (NULL);
/* Prepare lookup key */
struct sockaddr_in sin4;
memset(&sin4, 0, sizeof(sin4));
sin4.sin_family = AF_INET;
sin4.sin_len = sizeof(struct sockaddr_in);
sin4.sin_addr = dst;
nh = NULL;
/* unlocked lookup */
rn = rh->rnh_matchaddr((void *)&sin4, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rt = RNTORT(rn);
#ifdef RADIX_MPATH
if (rt_mpath_next(rt) != NULL)
rt = rt_mpath_selectrte(rt, 0);
#endif
nh = rt->rt_nhop;
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(nh->nh_ifp)) {
if (flags & NHR_REF)
nhop_ref_object(nh);
return (nh);
}
}
return (NULL);
}
#endif