freebsd-nq/sys/netinet6/in6_fib.c
Alexander V. Chernikov 16c2f24169 Document requirements for the 'struct route' variations.
MFC after:	2 weeks
2020-01-21 12:00:34 +00:00

281 lines
8.2 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_inet6.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_var.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/ip_mroute.h>
#include <netinet/ip6.h>
#include <netinet6/in6_fib.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>
#include <net/if_types.h>
#ifdef INET6
static void fib6_rte_to_nh_extended(struct rtentry *rte,
const struct in6_addr *dst, uint32_t flags, struct nhop6_extended *pnh6);
static void fib6_rte_to_nh_basic(struct rtentry *rte, const struct in6_addr *dst,
uint32_t flags, struct nhop6_basic *pnh6);
static struct ifnet *fib6_get_ifaifp(struct rtentry *rte);
#define RNTORT(p) ((struct rtentry *)(p))
CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst);
/*
* Gets real interface for the @rte.
* Returns rt_ifp for !IFF_LOOPBACK routers.
* Extracts "real" address interface from interface address
* loopback routes.
*/
static struct ifnet *
fib6_get_ifaifp(struct rtentry *rte)
{
struct ifnet *ifp;
struct sockaddr_dl *sdl;
ifp = rte->rt_ifp;
if ((ifp->if_flags & IFF_LOOPBACK) &&
rte->rt_gateway->sa_family == AF_LINK) {
sdl = (struct sockaddr_dl *)rte->rt_gateway;
return (ifnet_byindex(sdl->sdl_index));
}
return (ifp);
}
static void
fib6_rte_to_nh_basic(struct rtentry *rte, const struct in6_addr *dst,
uint32_t flags, struct nhop6_basic *pnh6)
{
struct sockaddr_in6 *gw;
/* Do explicit nexthop zero unless we're copying it */
memset(pnh6, 0, sizeof(*pnh6));
if ((flags & NHR_IFAIF) != 0)
pnh6->nh_ifp = fib6_get_ifaifp(rte);
else
pnh6->nh_ifp = rte->rt_ifp;
pnh6->nh_mtu = min(rte->rt_mtu, IN6_LINKMTU(rte->rt_ifp));
if (rte->rt_flags & RTF_GATEWAY) {
gw = (struct sockaddr_in6 *)rte->rt_gateway;
pnh6->nh_addr = gw->sin6_addr;
in6_clearscope(&pnh6->nh_addr);
} else
pnh6->nh_addr = *dst;
/* Set flags */
pnh6->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
gw = (struct sockaddr_in6 *)rt_key(rte);
if (IN6_IS_ADDR_UNSPECIFIED(&gw->sin6_addr))
pnh6->nh_flags |= NHF_DEFAULT;
}
static void
fib6_rte_to_nh_extended(struct rtentry *rte, const struct in6_addr *dst,
uint32_t flags, struct nhop6_extended *pnh6)
{
struct sockaddr_in6 *gw;
/* Do explicit nexthop zero unless we're copying it */
memset(pnh6, 0, sizeof(*pnh6));
if ((flags & NHR_IFAIF) != 0)
pnh6->nh_ifp = fib6_get_ifaifp(rte);
else
pnh6->nh_ifp = rte->rt_ifp;
pnh6->nh_mtu = min(rte->rt_mtu, IN6_LINKMTU(rte->rt_ifp));
if (rte->rt_flags & RTF_GATEWAY) {
gw = (struct sockaddr_in6 *)rte->rt_gateway;
pnh6->nh_addr = gw->sin6_addr;
in6_clearscope(&pnh6->nh_addr);
} else
pnh6->nh_addr = *dst;
/* Set flags */
pnh6->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
gw = (struct sockaddr_in6 *)rt_key(rte);
if (IN6_IS_ADDR_UNSPECIFIED(&gw->sin6_addr))
pnh6->nh_flags |= NHF_DEFAULT;
}
/*
* Performs IPv6 route table lookup on @dst. Returns 0 on success.
* Stores basic nexthop info into provided @pnh6 structure.
* Note that
* - nh_ifp represents logical transmit interface (rt_ifp) by default
* - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
* - mtu from logical transmit interface will be returned.
* - nh_ifp cannot be safely dereferenced
* - nh_ifp represents rt_ifp (e.g. if looking up address on
* interface "ix0" pointer to "ix0" interface will be returned instead
* of "lo0")
* - howewer mtu from "transmit" interface will be returned.
* - scope will be embedded in nh_addr
*/
int
fib6_lookup_nh_basic(uint32_t fibnum, const struct in6_addr *dst, uint32_t scopeid,
uint32_t flags, uint32_t flowid, struct nhop6_basic *pnh6)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct sockaddr_in6 sin6;
struct rtentry *rte;
KASSERT((fibnum < rt_numfibs), ("fib6_lookup_nh_basic: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET6);
if (rh == NULL)
return (ENOENT);
/* Prepare lookup key */
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_addr = *dst;
sin6.sin6_len = sizeof(struct sockaddr_in6);
/* Assume scopeid is valid and embed it directly */
if (IN6_IS_SCOPE_LINKLOCAL(dst))
sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rte = RNTORT(rn);
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(rte->rt_ifp)) {
fib6_rte_to_nh_basic(rte, &sin6.sin6_addr, flags, pnh6);
RIB_RUNLOCK(rh);
return (0);
}
}
RIB_RUNLOCK(rh);
return (ENOENT);
}
/*
* Performs IPv6 route table lookup on @dst. Returns 0 on success.
* Stores extended nexthop info into provided @pnh6 structure.
* Note that
* - nh_ifp cannot be safely dereferenced unless NHR_REF is specified.
* - in that case you need to call fib6_free_nh_ext()
* - nh_ifp represents logical transmit interface (rt_ifp) by default
* - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
* - mtu from logical transmit interface will be returned.
* - scope will be embedded in nh_addr
*/
int
fib6_lookup_nh_ext(uint32_t fibnum, const struct in6_addr *dst,uint32_t scopeid,
uint32_t flags, uint32_t flowid, struct nhop6_extended *pnh6)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct sockaddr_in6 sin6;
struct rtentry *rte;
KASSERT((fibnum < rt_numfibs), ("fib6_lookup_nh_ext: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET6);
if (rh == NULL)
return (ENOENT);
/* Prepare lookup key */
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_addr = *dst;
/* Assume scopeid is valid and embed it directly */
if (IN6_IS_SCOPE_LINKLOCAL(dst))
sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin6, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rte = RNTORT(rn);
#ifdef RADIX_MPATH
rte = rt_mpath_select(rte, flowid);
if (rte == NULL) {
RIB_RUNLOCK(rh);
return (ENOENT);
}
#endif
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(rte->rt_ifp)) {
fib6_rte_to_nh_extended(rte, &sin6.sin6_addr, flags,
pnh6);
if ((flags & NHR_REF) != 0) {
/* TODO: Do lwref on egress ifp's */
}
RIB_RUNLOCK(rh);
return (0);
}
}
RIB_RUNLOCK(rh);
return (ENOENT);
}
void
fib6_free_nh_ext(uint32_t fibnum, struct nhop6_extended *pnh6)
{
}
#endif