/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Alexander V. Chernikov
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_dl.h>
#include <net/vnet.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/route/nhop_utils.h>
#include <net/route/nhop.h>
#include <net/route/nhop_var.h>
#include <netinet/in.h>
#include <netinet6/scope6_var.h>
#include <netinet6/in6_var.h>
#define DEBUG_MOD_NAME route_ctl
#define DEBUG_MAX_LEVEL LOG_DEBUG
#include <net/route/route_debug.h>
_DECLARE_DEBUG(LOG_INFO);
/*
* This file contains control plane routing tables functions.
*
* All functions assumes they are called in net epoch.
*/
union sockaddr_union {
struct sockaddr sa;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
char _buf[32];
};
static int add_route_byinfo(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc);
static int change_route_byinfo(struct rib_head *rnh, struct rtentry *rt,
struct rt_addrinfo *info, struct route_nhop_data *nhd_orig,
struct rib_cmd_info *rc);
static int add_route_flags(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd_add, int op_flags, struct rib_cmd_info *rc);
#ifdef ROUTE_MPATH
static int add_route_flags_mpath(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd_add, struct route_nhop_data *rnd_orig,
int op_flags, struct rib_cmd_info *rc);
#endif
static int add_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc);
static int delete_route(struct rib_head *rnh, struct rtentry *rt,
struct rib_cmd_info *rc);
static int rt_delete_conditional(struct rib_head *rnh, struct rtentry *rt,
int prio, rib_filter_f_t *cb, void *cbdata, struct rib_cmd_info *rc);
static int get_prio_from_info(const struct rt_addrinfo *info);
static int nhop_get_prio(const struct nhop_object *nh);
#ifdef ROUTE_MPATH
static bool rib_can_multipath(struct rib_head *rh);
#endif
/* Per-vnet multipath routing configuration */
SYSCTL_DECL(_net_route);
#define V_rib_route_multipath VNET(rib_route_multipath)
#ifdef ROUTE_MPATH
#define _MP_FLAGS CTLFLAG_RW
#else
#define _MP_FLAGS CTLFLAG_RD
#endif
VNET_DEFINE(u_int, rib_route_multipath) = 1;
SYSCTL_UINT(_net_route, OID_AUTO, multipath, _MP_FLAGS | CTLFLAG_VNET,
&VNET_NAME(rib_route_multipath), 0, "Enable route multipath");
#undef _MP_FLAGS
#ifdef ROUTE_MPATH
VNET_DEFINE(u_int, fib_hash_outbound) = 0;
SYSCTL_UINT(_net_route, OID_AUTO, hash_outbound, CTLFLAG_RD | CTLFLAG_VNET,
&VNET_NAME(fib_hash_outbound), 0,
"Compute flowid for locally-originated packets");
/* Default entropy to add to the hash calculation for the outbound connections*/
uint8_t mpath_entropy_key[MPATH_ENTROPY_KEY_LEN] = {
0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa,
};
#endif
#if defined(INET) && defined(INET6)
FEATURE(ipv4_rfc5549_support, "Route IPv4 packets via IPv6 nexthops");
#define V_rib_route_ipv6_nexthop VNET(rib_route_ipv6_nexthop)
VNET_DEFINE_STATIC(u_int, rib_route_ipv6_nexthop) = 1;
SYSCTL_UINT(_net_route, OID_AUTO, ipv6_nexthop, CTLFLAG_RW | CTLFLAG_VNET,
&VNET_NAME(rib_route_ipv6_nexthop), 0, "Enable IPv4 route via IPv6 Next Hop address");
#endif
/* Debug bits */
SYSCTL_NODE(_net_route, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
static struct rib_head *
get_rnh(uint32_t fibnum, const struct rt_addrinfo *info)
{
struct rib_head *rnh;
struct sockaddr *dst;
KASSERT((fibnum < rt_numfibs), ("rib_add_route: bad fibnum"));
dst = info->rti_info[RTAX_DST];
rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
return (rnh);
}
#if defined(INET) && defined(INET6)
bool
rib_can_4o6_nhop(void)
{
return (!!V_rib_route_ipv6_nexthop);
}
#endif
#ifdef ROUTE_MPATH
static bool
rib_can_multipath(struct rib_head *rh)
{
int result;
CURVNET_SET(rh->rib_vnet);
result = !!V_rib_route_multipath;
CURVNET_RESTORE();
return (result);
}
/*
* Check is nhop is multipath-eligible.
* Avoid nhops without gateways and redirects.
*
* Returns 1 for multipath-eligible nexthop,
* 0 otherwise.
*/
bool
nhop_can_multipath(const struct nhop_object *nh)
{
if ((nh->nh_flags & NHF_MULTIPATH) != 0)
return (1);
if ((nh->nh_flags & NHF_GATEWAY) == 0)
return (0);
if ((nh->nh_flags & NHF_REDIRECT) != 0)
return (0);
return (1);
}
#endif
static int
get_info_weight(const struct rt_addrinfo *info, uint32_t default_weight)
{
uint32_t weight;
if (info->rti_mflags & RTV_WEIGHT)
weight = info->rti_rmx->rmx_weight;
else
weight = default_weight;
/* Keep upper 1 byte for adm distance purposes */
if (weight > RT_MAX_WEIGHT)
weight = RT_MAX_WEIGHT;
else if (weight == 0)
weight = default_weight;
return (weight);
}
/*
* File-local concept for distingushing between the normal and
* RTF_PINNED routes tha can override the "normal" one.
*/
#define NH_PRIORITY_HIGH 2
#define NH_PRIORITY_NORMAL 1
static int
get_prio_from_info(const struct rt_addrinfo *info)
{
if (info->rti_flags & RTF_PINNED)
return (NH_PRIORITY_HIGH);
return (NH_PRIORITY_NORMAL);
}
static int
nhop_get_prio(const struct nhop_object *nh)
{
if (NH_IS_PINNED(nh))
return (NH_PRIORITY_HIGH);
return (NH_PRIORITY_NORMAL);
}
/*
* Check if specified @gw matches gw data in the nexthop @nh.
*
* Returns true if matches, false otherwise.
*/
bool
match_nhop_gw(const struct nhop_object *nh, const struct sockaddr *gw)
{
if (nh->gw_sa.sa_family != gw->sa_family)
return (false);
switch (gw->sa_family) {
case AF_INET:
return (nh->gw4_sa.sin_addr.s_addr ==
((const struct sockaddr_in *)gw)->sin_addr.s_addr);
case AF_INET6:
{
const struct sockaddr_in6 *gw6;
gw6 = (const struct sockaddr_in6 *)gw;
/*
* Currently (2020-09) IPv6 gws in kernel have their
* scope embedded. Once this becomes false, this code
* has to be revisited.
*/
if (IN6_ARE_ADDR_EQUAL(&nh->gw6_sa.sin6_addr,
&gw6->sin6_addr))
return (true);
return (false);
}
case AF_LINK:
{
const struct sockaddr_dl *sdl;
sdl = (const struct sockaddr_dl *)gw;
return (nh->gwl_sa.sdl_index == sdl->sdl_index);
}
default:
return (memcmp(&nh->gw_sa, gw, nh->gw_sa.sa_len) == 0);
}
/* NOTREACHED */
return (false);
}
/*
* Matches all nexthop with given @gw.
* Can be used as rib_filter_f callback.
*/
int
rib_match_gw(const struct rtentry *rt, const struct nhop_object *nh, void *gw_sa)
{
const struct sockaddr *gw = (const struct sockaddr *)gw_sa;
return (match_nhop_gw(nh, gw));
}
struct gw_filter_data {
const struct sockaddr *gw;
int count;
};
/*
* Matches first occurence of the gateway provided in @gwd
*/
static int
match_gw_one(const struct rtentry *rt, const struct nhop_object *nh, void *_data)
{
struct gw_filter_data *gwd = (struct gw_filter_data *)_data;
/* Return only first match to make rtsock happy */
if (match_nhop_gw(nh, gwd->gw) && gwd->count++ == 0)
return (1);
return (0);
}
/*
* Checks if data in @info matches nexhop @nh.
*
* Returns 0 on success,
* ESRCH if not matched,
* ENOENT if filter function returned false
*/
int
check_info_match_nhop(const struct rt_addrinfo *info, const struct rtentry *rt,
const struct nhop_object *nh)
{
const struct sockaddr *gw = info->rti_info[RTAX_GATEWAY];
if (info->rti_filter != NULL) {
if (info->rti_filter(rt, nh, info->rti_filterdata) == 0)
return (ENOENT);
else
return (0);
}
if ((gw != NULL) && !match_nhop_gw(nh, gw))
return (ESRCH);
return (0);
}
/*
* Runs exact prefix match based on @dst and @netmask.
* Returns matched @rtentry if found or NULL.
* If rtentry was found, saves nexthop / weight value into @rnd.
*/
static struct rtentry *
lookup_prefix_bysa(struct rib_head *rnh, const struct sockaddr *dst,
const struct sockaddr *netmask, struct route_nhop_data *rnd)
{
struct rtentry *rt;
RIB_LOCK_ASSERT(rnh);
rt = (struct rtentry *)rnh->rnh_lookup(dst, netmask, &rnh->head);
if (rt != NULL) {
rnd->rnd_nhop = rt->rt_nhop;
rnd->rnd_weight = rt->rt_weight;
} else {
rnd->rnd_nhop = NULL;
rnd->rnd_weight = 0;
}
return (rt);
}
struct rtentry *
lookup_prefix_rt(struct rib_head *rnh, const struct rtentry *rt,
struct route_nhop_data *rnd)
{
return (lookup_prefix_bysa(rnh, rt_key_const(rt), rt_mask_const(rt), rnd));
}
/*
* Runs exact prefix match based on dst/netmask from @info.
* Assumes RIB lock is held.
* Returns matched @rtentry if found or NULL.
* If rtentry was found, saves nexthop / weight value into @rnd.
*/
struct rtentry *
lookup_prefix(struct rib_head *rnh, const struct rt_addrinfo *info,
struct route_nhop_data *rnd)
{
struct rtentry *rt;
rt = lookup_prefix_bysa(rnh, info->rti_info[RTAX_DST],
info->rti_info[RTAX_NETMASK], rnd);
return (rt);
}
static bool
fill_pxmask_family(int family, int plen, struct sockaddr *_dst,
struct sockaddr **pmask)
{
if (plen == -1) {
*pmask = NULL;
return (true);
}
switch (family) {
#ifdef INET
case AF_INET:
{
struct sockaddr_in *mask = (struct sockaddr_in *)(*pmask);
struct sockaddr_in *dst= (struct sockaddr_in *)_dst;
memset(mask, 0, sizeof(*mask));
mask->sin_family = family;
mask->sin_len = sizeof(*mask);
if (plen == 32)
*pmask = NULL;
else if (plen > 32 || plen < 0)
return (false);
else {
uint32_t daddr, maddr;
maddr = htonl(plen ? ~((1 << (32 - plen)) - 1) : 0);
mask->sin_addr.s_addr = maddr;
daddr = dst->sin_addr.s_addr;
daddr = htonl(ntohl(daddr) & ntohl(maddr));
dst->sin_addr.s_addr = daddr;
}
return (true);
}
break;
#endif
#ifdef INET6
case AF_INET6:
{
struct sockaddr_in6 *mask = (struct sockaddr_in6 *)(*pmask);
struct sockaddr_in6 *dst = (struct sockaddr_in6 *)_dst;
memset(mask, 0, sizeof(*mask));
mask->sin6_family = family;
mask->sin6_len = sizeof(*mask);
if (plen == 128)
*pmask = NULL;
else if (plen > 128 || plen < 0)
return (false);
else {
ip6_writemask(&mask->sin6_addr, plen);
IN6_MASK_ADDR(&dst->sin6_addr, &mask->sin6_addr);
}
return (true);
}
break;
#endif
}
return (false);
}
/*
* Attempts to add @dst/plen prefix with nexthop/nexhopgroup data @rnd
* to the routing table.
*
* @fibnum: rtable id to insert route to
* @dst: verified kernel-originated sockaddr, can be masked if plen non-empty
* @plen: prefix length (or -1 if host route or not applicable for AF)
* @op_flags: combination of RTM_F_ flags
* @rc: storage to report operation result
*
* Returns 0 on success.
*/
int
rib_add_route_px(uint32_t fibnum, struct sockaddr *dst, int plen,
struct route_nhop_data *rnd, int op_flags, struct rib_cmd_info *rc)
{
union sockaddr_union mask_storage;
struct sockaddr *netmask = &mask_storage.sa;
struct rtentry *rt = NULL;
NET_EPOCH_ASSERT();
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_ADD;
struct rib_head *rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
if (rnh == NULL)
return (EAFNOSUPPORT);
if (!fill_pxmask_family(dst->sa_family, plen, dst, &netmask)) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: invalid plen %d", plen);
return (EINVAL);
}
if (op_flags & RTM_F_CREATE) {
if ((rt = rt_alloc(rnh, dst, netmask)) == NULL) {
FIB_RH_LOG(LOG_INFO, rnh, "rtentry allocation failed");
return (ENOMEM);
}
}
return (add_route_flags(rnh, rt, rnd, op_flags, rc));
}
/*
* Attempts to delete @dst/plen prefix matching gateway @gw from the
* routing rable.
*
* @fibnum: rtable id to remove route from
* @dst: verified kernel-originated sockaddr, can be masked if plen non-empty
* @plen: prefix length (or -1 if host route or not applicable for AF)
* @gw: gateway to match
* @op_flags: combination of RTM_F_ flags
* @rc: storage to report operation result
*
* Returns 0 on success.
*/
int
rib_del_route_px_gw(uint32_t fibnum, struct sockaddr *dst, int plen,
const struct sockaddr *gw, int op_flags, struct rib_cmd_info *rc)
{
struct gw_filter_data gwd = { .gw = gw };
return (rib_del_route_px(fibnum, dst, plen, match_gw_one, &gwd, op_flags, rc));
}
/*
* Attempts to delete @dst/plen prefix matching @filter_func from the
* routing rable.
*
* @fibnum: rtable id to remove route from
* @dst: verified kernel-originated sockaddr, can be masked if plen non-empty
* @plen: prefix length (or -1 if host route or not applicable for AF)
* @filter_func: func to be called for each nexthop of the prefix for matching
* @filter_arg: argument to pass to @filter_func
* @op_flags: combination of RTM_F_ flags
* @rc: storage to report operation result
*
* Returns 0 on success.
*/
int
rib_del_route_px(uint32_t fibnum, struct sockaddr *dst, int plen,
rib_filter_f_t *filter_func, void *filter_arg, int op_flags,
struct rib_cmd_info *rc)
{
union sockaddr_union mask_storage;
struct sockaddr *netmask = &mask_storage.sa;
int error;
NET_EPOCH_ASSERT();
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_DELETE;
struct rib_head *rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
if (rnh == NULL)
return (EAFNOSUPPORT);
if (dst->sa_len > sizeof(mask_storage)) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: dst->sa_len too big: %d", dst->sa_len);
return (EINVAL);
}
if (!fill_pxmask_family(dst->sa_family, plen, dst, &netmask)) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: invalid plen %d", plen);
return (EINVAL);
}
int prio = (op_flags & RTM_F_FORCE) ? NH_PRIORITY_HIGH : NH_PRIORITY_NORMAL;
RIB_WLOCK(rnh);
struct route_nhop_data rnd;
struct rtentry *rt = lookup_prefix_bysa(rnh, dst, netmask, &rnd);
if (rt != NULL) {
error = rt_delete_conditional(rnh, rt, prio, filter_func,
filter_arg, rc);
} else
error = ESRCH;
RIB_WUNLOCK(rnh);
if (error != 0)
return (error);
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
if (rc->rc_cmd == RTM_DELETE)
rt_free(rc->rc_rt);
#ifdef ROUTE_MPATH
else {
/*
* Deleting 1 path may result in RTM_CHANGE to
* a different mpath group/nhop.
* Free old mpath group.
*/
nhop_free_any(rc->rc_nh_old);
}
#endif
return (0);
}
/*
* Tries to copy route @rt from one rtable to the rtable specified by @dst_rh.
* @rt: route to copy.
* @rnd_src: nhop and weight. Multipath routes are not supported
* @rh_dst: target rtable.
* @rc: operation result storage
*
* Return 0 on success.
*/
int
rib_copy_route(struct rtentry *rt, const struct route_nhop_data *rnd_src,
struct rib_head *rh_dst, struct rib_cmd_info *rc)
{
struct nhop_object __diagused *nh_src = rnd_src->rnd_nhop;
int error;
MPASS((nh_src->nh_flags & NHF_MULTIPATH) == 0);
IF_DEBUG_LEVEL(LOG_DEBUG2) {
char nhbuf[NHOP_PRINT_BUFSIZE], rtbuf[NHOP_PRINT_BUFSIZE];
nhop_print_buf_any(nh_src, nhbuf, sizeof(nhbuf));
rt_print_buf(rt, rtbuf, sizeof(rtbuf));
FIB_RH_LOG(LOG_DEBUG2, rh_dst, "copying %s -> %s from fib %u",
rtbuf, nhbuf, nhop_get_fibnum(nh_src));
}
struct nhop_object *nh = nhop_alloc(rh_dst->rib_fibnum, rh_dst->rib_family);
if (nh == NULL) {
FIB_RH_LOG(LOG_INFO, rh_dst, "unable to allocate new nexthop");
return (ENOMEM);
}
nhop_copy(nh, rnd_src->rnd_nhop);
nhop_set_origin(nh, nhop_get_origin(rnd_src->rnd_nhop));
nhop_set_fibnum(nh, rh_dst->rib_fibnum);
nh = nhop_get_nhop_internal(rh_dst, nh, &error);
if (error != 0) {
FIB_RH_LOG(LOG_INFO, rh_dst,
"unable to finalize new nexthop: error %d", error);
return (ENOMEM);
}
struct rtentry *rt_new = rt_alloc(rh_dst, rt_key(rt), rt_mask(rt));
if (rt_new == NULL) {
FIB_RH_LOG(LOG_INFO, rh_dst, "unable to create new rtentry");
nhop_free(nh);
return (ENOMEM);
}
struct route_nhop_data rnd = {
.rnd_nhop = nh,
.rnd_weight = rnd_src->rnd_weight
};
int op_flags = RTM_F_CREATE | (NH_IS_PINNED(nh) ? RTM_F_FORCE : 0);
error = add_route_flags(rh_dst, rt_new, &rnd, op_flags, rc);
if (error != 0) {
IF_DEBUG_LEVEL(LOG_DEBUG2) {
char buf[NHOP_PRINT_BUFSIZE];
rt_print_buf(rt_new, buf, sizeof(buf));
FIB_RH_LOG(LOG_DEBUG, rh_dst,
"Unable to add route %s: error %d", buf, error);
}
nhop_free(nh);
rt_free_immediate(rt_new);
}
return (error);
}
/*
* Adds route defined by @info into the kernel table specified by @fibnum and
* sa_family in @info->rti_info[RTAX_DST].
*
* Returns 0 on success and fills in operation metadata into @rc.
*/
int
rib_add_route(uint32_t fibnum, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct rib_head *rnh;
int error;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
/*
* Check consistency between RTF_HOST flag and netmask
* existence.
*/
if (info->rti_flags & RTF_HOST)
info->rti_info[RTAX_NETMASK] = NULL;
else if (info->rti_info[RTAX_NETMASK] == NULL) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: no RTF_HOST and empty netmask");
return (EINVAL);
}
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_ADD;
error = add_route_byinfo(rnh, info, rc);
if (error == 0)
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
return (error);
}
static int
add_route_byinfo(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct route_nhop_data rnd_add;
struct nhop_object *nh;
struct rtentry *rt;
struct sockaddr *dst, *gateway, *netmask;
int error;
dst = info->rti_info[RTAX_DST];
gateway = info->rti_info[RTAX_GATEWAY];
netmask = info->rti_info[RTAX_NETMASK];
if ((info->rti_flags & RTF_GATEWAY) && !gateway) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: RTF_GATEWAY set with empty gw");
return (EINVAL);
}
if (dst && gateway && !nhop_check_gateway(dst->sa_family, gateway->sa_family)) {
FIB_RH_LOG(LOG_DEBUG, rnh,
"error: invalid dst/gateway family combination (%d, %d)",
dst->sa_family, gateway->sa_family);
return (EINVAL);
}
if (dst->sa_len > sizeof(((struct rtentry *)NULL)->rt_dstb)) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: dst->sa_len too large: %d",
dst->sa_len);
return (EINVAL);
}
if (info->rti_ifa == NULL) {
error = rt_getifa_fib(info, rnh->rib_fibnum);
if (error)
return (error);
}
if ((rt = rt_alloc(rnh, dst, netmask)) == NULL)
return (ENOBUFS);
error = nhop_create_from_info(rnh, info, &nh);
if (error != 0) {
rt_free_immediate(rt);
return (error);
}
rnd_add.rnd_nhop = nh;
rnd_add.rnd_weight = get_info_weight(info, RT_DEFAULT_WEIGHT);
int op_flags = RTM_F_CREATE;
if (get_prio_from_info(info) == NH_PRIORITY_HIGH)
op_flags |= RTM_F_FORCE;
else
op_flags |= RTM_F_APPEND;
return (add_route_flags(rnh, rt, &rnd_add, op_flags, rc));
}
static int
add_route_flags(struct rib_head *rnh, struct rtentry *rt, struct route_nhop_data *rnd_add,
int op_flags, struct rib_cmd_info *rc)
{
struct route_nhop_data rnd_orig;
struct nhop_object *nh;
struct rtentry *rt_orig;
int error = 0;
nh = rnd_add->rnd_nhop;
RIB_WLOCK(rnh);
rt_orig = lookup_prefix_rt(rnh, rt, &rnd_orig);
if (rt_orig == NULL) {
if (op_flags & RTM_F_CREATE)
error = add_route(rnh, rt, rnd_add, rc);
else
error = ESRCH; /* no entry but creation was not required */
RIB_WUNLOCK(rnh);
if (error != 0)
goto out;
return (0);
}
if (op_flags & RTM_F_EXCL) {
/* We have existing route in the RIB but not allowed to replace. */
RIB_WUNLOCK(rnh);
error = EEXIST;
goto out;
}
/* Now either append or replace */
if (op_flags & RTM_F_REPLACE) {
if (nhop_get_prio(rnd_orig.rnd_nhop) > nhop_get_prio(rnd_add->rnd_nhop)) {
/* Old path is "better" (e.g. has PINNED flag set) */
RIB_WUNLOCK(rnh);
error = EEXIST;
goto out;
}
change_route(rnh, rt_orig, rnd_add, rc);
RIB_WUNLOCK(rnh);
nh = rc->rc_nh_old;
goto out;
}
RIB_WUNLOCK(rnh);
#ifdef ROUTE_MPATH
if ((op_flags & RTM_F_APPEND) && rib_can_multipath(rnh) &&
nhop_can_multipath(rnd_add->rnd_nhop) &&
nhop_can_multipath(rnd_orig.rnd_nhop)) {
for (int i = 0; i < RIB_MAX_RETRIES; i++) {
error = add_route_flags_mpath(rnh, rt_orig, rnd_add, &rnd_orig,
op_flags, rc);
if (error != EAGAIN)
break;
RTSTAT_INC(rts_add_retry);
}
/*
* Original nhop reference is unused in any case.
*/
nhop_free_any(rnd_add->rnd_nhop);
if (op_flags & RTM_F_CREATE) {
if (error != 0 || rc->rc_cmd != RTM_ADD)
rt_free_immediate(rt);
}
return (error);
}
#endif
/* Out of options - free state and return error */
error = EEXIST;
out:
if (op_flags & RTM_F_CREATE)
rt_free_immediate(rt);
nhop_free_any(nh);
return (error);
}
#ifdef ROUTE_MPATH
static int
add_route_flags_mpath(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd_add, struct route_nhop_data *rnd_orig,
int op_flags, struct rib_cmd_info *rc)
{
RIB_RLOCK_TRACKER;
struct route_nhop_data rnd_new;
int error = 0;
error = nhgrp_get_addition_group(rnh, rnd_orig, rnd_add, &rnd_new);
if (error != 0) {
if (error == EAGAIN) {
/*
* Group creation failed, most probably because
* @rnd_orig data got scheduled for deletion.
* Refresh @rnd_orig data and retry.
*/
RIB_RLOCK(rnh);
lookup_prefix_rt(rnh, rt, rnd_orig);
RIB_RUNLOCK(rnh);
if (rnd_orig == NULL && !(op_flags & RTM_F_CREATE)) {
/* In this iteration route doesn't exist */
error = ENOENT;
}
}
return (error);
}
error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
if (error != 0)
return (error);
if (V_fib_hash_outbound == 0 && NH_IS_NHGRP(rc->rc_nh_new)) {
/*
* First multipath route got installed. Enable local
* outbound connections hashing.
*/
if (bootverbose)
printf("FIB: enabled flowid calculation for locally-originated packets\n");
V_fib_hash_outbound = 1;
}
return (0);
}
#endif
/*
* Removes route defined by @info from the kernel table specified by @fibnum and
* sa_family in @info->rti_info[RTAX_DST].
*
* Returns 0 on success and fills in operation metadata into @rc.
*/
int
rib_del_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc)
{
struct rib_head *rnh;
struct sockaddr *dst, *netmask;
struct sockaddr_storage mdst;
int error;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_DELETE;
dst = info->rti_info[RTAX_DST];
netmask = info->rti_info[RTAX_NETMASK];
if (netmask != NULL) {
/* Ensure @dst is always properly masked */
if (dst->sa_len > sizeof(mdst)) {
FIB_RH_LOG(LOG_DEBUG, rnh, "error: dst->sa_len too large");
return (EINVAL);
}
rt_maskedcopy(dst, (struct sockaddr *)&mdst, netmask);
dst = (struct sockaddr *)&mdst;
}
rib_filter_f_t *filter_func = NULL;
void *filter_arg = NULL;
struct gw_filter_data gwd = { .gw = info->rti_info[RTAX_GATEWAY] };
if (info->rti_filter != NULL) {
filter_func = info->rti_filter;
filter_arg = info->rti_filterdata;
} else if (gwd.gw != NULL) {
filter_func = match_gw_one;
filter_arg = &gwd;
}
int prio = get_prio_from_info(info);
RIB_WLOCK(rnh);
struct route_nhop_data rnd;
struct rtentry *rt = lookup_prefix_bysa(rnh, dst, netmask, &rnd);
if (rt != NULL) {
error = rt_delete_conditional(rnh, rt, prio, filter_func,
filter_arg, rc);
} else
error = ESRCH;
RIB_WUNLOCK(rnh);
if (error != 0)
return (error);
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
if (rc->rc_cmd == RTM_DELETE)
rt_free(rc->rc_rt);
#ifdef ROUTE_MPATH
else {
/*
* Deleting 1 path may result in RTM_CHANGE to
* a different mpath group/nhop.
* Free old mpath group.
*/
nhop_free_any(rc->rc_nh_old);
}
#endif
return (0);
}
/*
* Conditionally unlinks rtentry paths from @rnh matching @cb.
* Returns 0 on success with operation result stored in @rc.
* On error, returns:
* ESRCH - if prefix was not found or filter function failed to match
* EADDRINUSE - if trying to delete higher priority route.
*/
static int
rt_delete_conditional(struct rib_head *rnh, struct rtentry *rt,
int prio, rib_filter_f_t *cb, void *cbdata, struct rib_cmd_info *rc)
{
struct nhop_object *nh = rt->rt_nhop;
#ifdef ROUTE_MPATH
if (NH_IS_NHGRP(nh)) {
struct nhgrp_object *nhg = (struct nhgrp_object *)nh;
struct route_nhop_data rnd;
int error;
if (cb == NULL)
return (ESRCH);
error = nhgrp_get_filtered_group(rnh, rt, nhg, cb, cbdata, &rnd);
if (error == 0) {
if (rnd.rnd_nhgrp == nhg) {
/* No match, unreference new group and return. */
nhop_free_any(rnd.rnd_nhop);
return (ESRCH);
}
error = change_route(rnh, rt, &rnd, rc);
}
return (error);
}
#endif
if (cb != NULL && !cb(rt, nh, cbdata))
return (ESRCH);
if (prio < nhop_get_prio(nh))
return (EADDRINUSE);
return (delete_route(rnh, rt, rc));
}
int
rib_change_route(uint32_t fibnum, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
RIB_RLOCK_TRACKER;
struct route_nhop_data rnd_orig;
struct rib_head *rnh;
struct rtentry *rt;
int error;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_CHANGE;
/* Check if updated gateway exists */
if ((info->rti_flags & RTF_GATEWAY) &&
(info->rti_info[RTAX_GATEWAY] == NULL)) {
/*
* route(8) adds RTF_GATEWAY flag if -interface is not set.
* Remove RTF_GATEWAY to enforce consistency and maintain
* compatibility..
*/
info->rti_flags &= ~RTF_GATEWAY;
}
/*
* route change is done in multiple steps, with dropping and
* reacquiring lock. In the situations with multiple processes
* changes the same route in can lead to the case when route
* is changed between the steps. Address it by retrying the operation
* multiple times before failing.
*/
RIB_RLOCK(rnh);
rt = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],
info->rti_info[RTAX_NETMASK], &rnh->head);
if (rt == NULL) {
RIB_RUNLOCK(rnh);
return (ESRCH);
}
rnd_orig.rnd_nhop = rt->rt_nhop;
rnd_orig.rnd_weight = rt->rt_weight;
RIB_RUNLOCK(rnh);
for (int i = 0; i < RIB_MAX_RETRIES; i++) {
error = change_route_byinfo(rnh, rt, info, &rnd_orig, rc);
if (error != EAGAIN)
break;
}
return (error);
}
static int
change_nhop(struct rib_head *rnh, struct rt_addrinfo *info,
struct nhop_object *nh_orig, struct nhop_object **nh_new)
{
int error;
/*
* New gateway could require new ifaddr, ifp;
* flags may also be different; ifp may be specified
* by ll sockaddr when protocol address is ambiguous
*/
if (((nh_orig->nh_flags & NHF_GATEWAY) &&
info->rti_info[RTAX_GATEWAY] != NULL) ||
info->rti_info[RTAX_IFP] != NULL ||
(info->rti_info[RTAX_IFA] != NULL &&
!sa_equal(info->rti_info[RTAX_IFA], nh_orig->nh_ifa->ifa_addr))) {
error = rt_getifa_fib(info, rnh->rib_fibnum);
if (error != 0) {
info->rti_ifa = NULL;
return (error);
}
}
error = nhop_create_from_nhop(rnh, nh_orig, info, nh_new);
info->rti_ifa = NULL;
return (error);
}
#ifdef ROUTE_MPATH
static int
change_mpath_route(struct rib_head *rnh, struct rtentry *rt,
struct rt_addrinfo *info, struct route_nhop_data *rnd_orig,
struct rib_cmd_info *rc)
{
int error = 0, found_idx = 0;
struct nhop_object *nh_orig = NULL, *nh_new;
struct route_nhop_data rnd_new = {};
const struct weightened_nhop *wn = NULL;
struct weightened_nhop *wn_new;
uint32_t num_nhops;
wn = nhgrp_get_nhops(rnd_orig->rnd_nhgrp, &num_nhops);
for (int i = 0; i < num_nhops; i++) {
if (check_info_match_nhop(info, NULL, wn[i].nh) == 0) {
nh_orig = wn[i].nh;
found_idx = i;
break;
}
}
if (nh_orig == NULL)
return (ESRCH);
error = change_nhop(rnh, info, nh_orig, &nh_new);
if (error != 0)
return (error);
wn_new = mallocarray(num_nhops, sizeof(struct weightened_nhop),
M_TEMP, M_NOWAIT | M_ZERO);
if (wn_new == NULL) {
nhop_free(nh_new);
return (EAGAIN);
}
memcpy(wn_new, wn, num_nhops * sizeof(struct weightened_nhop));
wn_new[found_idx].nh = nh_new;
wn_new[found_idx].weight = get_info_weight(info, wn[found_idx].weight);
error = nhgrp_get_group(rnh, wn_new, num_nhops, 0, &rnd_new.rnd_nhgrp);
nhop_free(nh_new);
free(wn_new, M_TEMP);
if (error != 0)
return (error);
error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
return (error);
}
#endif
static int
change_route_byinfo(struct rib_head *rnh, struct rtentry *rt,
struct rt_addrinfo *info, struct route_nhop_data *rnd_orig,
struct rib_cmd_info *rc)
{
int error = 0;
struct nhop_object *nh_orig;
struct route_nhop_data rnd_new;
nh_orig = rnd_orig->rnd_nhop;
if (nh_orig == NULL)
return (ESRCH);
#ifdef ROUTE_MPATH
if (NH_IS_NHGRP(nh_orig))
return (change_mpath_route(rnh, rt, info, rnd_orig, rc));
#endif
rnd_new.rnd_weight = get_info_weight(info, rnd_orig->rnd_weight);
error = change_nhop(rnh, info, nh_orig, &rnd_new.rnd_nhop);
if (error != 0)
return (error);
error = change_route_conditional(rnh, rt, rnd_orig, &rnd_new, rc);
return (error);
}
/*
* Insert @rt with nhop data from @rnd_new to @rnh.
* Returns 0 on success and stores operation results in @rc.
*/
static int
add_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc)
{
struct radix_node *rn;
RIB_WLOCK_ASSERT(rnh);
rt->rt_nhop = rnd->rnd_nhop;
rt->rt_weight = rnd->rnd_weight;
rn = rnh->rnh_addaddr(rt_key(rt), rt_mask_const(rt), &rnh->head, rt->rt_nodes);
if (rn != NULL) {
if (!NH_IS_NHGRP(rnd->rnd_nhop) && nhop_get_expire(rnd->rnd_nhop))
tmproutes_update(rnh, rt, rnd->rnd_nhop);
/* Finalize notification */
rib_bump_gen(rnh);
rnh->rnh_prefixes++;
rc->rc_cmd = RTM_ADD;
rc->rc_rt = rt;
rc->rc_nh_old = NULL;
rc->rc_nh_new = rnd->rnd_nhop;
rc->rc_nh_weight = rnd->rnd_weight;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
return (0);
}
/* Existing route or memory allocation failure. */
return (EEXIST);
}
/*
* Unconditionally deletes @rt from @rnh.
*/
static int
delete_route(struct rib_head *rnh, struct rtentry *rt, struct rib_cmd_info *rc)
{
RIB_WLOCK_ASSERT(rnh);
/* Route deletion requested. */
struct radix_node *rn;
rn = rnh->rnh_deladdr(rt_key_const(rt), rt_mask_const(rt), &rnh->head);
if (rn == NULL)
return (ESRCH);
rt = RNTORT(rn);
rt->rte_flags &= ~RTF_UP;
rib_bump_gen(rnh);
rnh->rnh_prefixes--;
rc->rc_cmd = RTM_DELETE;
rc->rc_rt = rt;
rc->rc_nh_old = rt->rt_nhop;
rc->rc_nh_new = NULL;
rc->rc_nh_weight = rt->rt_weight;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
return (0);
}
/*
* Switch @rt nhop/weigh to the ones specified in @rnd.
* Returns 0 on success.
*/
int
change_route(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd, struct rib_cmd_info *rc)
{
struct nhop_object *nh_orig;
RIB_WLOCK_ASSERT(rnh);
nh_orig = rt->rt_nhop;
if (rnd->rnd_nhop == NULL)
return (delete_route(rnh, rt, rc));
/* Changing nexthop & weight to a new one */
rt->rt_nhop = rnd->rnd_nhop;
rt->rt_weight = rnd->rnd_weight;
if (!NH_IS_NHGRP(rnd->rnd_nhop) && nhop_get_expire(rnd->rnd_nhop))
tmproutes_update(rnh, rt, rnd->rnd_nhop);
/* Finalize notification */
rib_bump_gen(rnh);
rc->rc_cmd = RTM_CHANGE;
rc->rc_rt = rt;
rc->rc_nh_old = nh_orig;
rc->rc_nh_new = rnd->rnd_nhop;
rc->rc_nh_weight = rnd->rnd_weight;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
return (0);
}
/*
* Conditionally update route nhop/weight IFF data in @nhd_orig is
* consistent with the current route data.
* Nexthop in @nhd_new is consumed.
*/
int
change_route_conditional(struct rib_head *rnh, struct rtentry *rt,
struct route_nhop_data *rnd_orig, struct route_nhop_data *rnd_new,
struct rib_cmd_info *rc)
{
struct rtentry *rt_new;
int error = 0;
IF_DEBUG_LEVEL(LOG_DEBUG2) {
char buf_old[NHOP_PRINT_BUFSIZE], buf_new[NHOP_PRINT_BUFSIZE];
nhop_print_buf_any(rnd_orig->rnd_nhop, buf_old, NHOP_PRINT_BUFSIZE);
nhop_print_buf_any(rnd_new->rnd_nhop, buf_new, NHOP_PRINT_BUFSIZE);
FIB_LOG(LOG_DEBUG2, rnh->rib_fibnum, rnh->rib_family,
"trying change %s -> %s", buf_old, buf_new);
}
RIB_WLOCK(rnh);
struct route_nhop_data rnd;
rt_new = lookup_prefix_rt(rnh, rt, &rnd);
if (rt_new == NULL) {
if (rnd_orig->rnd_nhop == NULL)
error = add_route(rnh, rt, rnd_new, rc);
else {
/*
* Prefix does not exist, which was not our assumption.
* Update @rnd_orig with the new data and return
*/
rnd_orig->rnd_nhop = NULL;
rnd_orig->rnd_weight = 0;
error = EAGAIN;
}
} else {
/* Prefix exists, try to update */
if (rnd_orig->rnd_nhop == rt_new->rt_nhop) {
/*
* Nhop/mpath group hasn't changed. Flip
* to the new precalculated one and return
*/
error = change_route(rnh, rt_new, rnd_new, rc);
} else {
/* Update and retry */
rnd_orig->rnd_nhop = rt_new->rt_nhop;
rnd_orig->rnd_weight = rt_new->rt_weight;
error = EAGAIN;
}
}
RIB_WUNLOCK(rnh);
if (error == 0) {
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
if (rnd_orig->rnd_nhop != NULL)
nhop_free_any(rnd_orig->rnd_nhop);
} else {
if (rnd_new->rnd_nhop != NULL)
nhop_free_any(rnd_new->rnd_nhop);
}
return (error);
}
/*
* Performs modification of routing table specificed by @action.
* Table is specified by @fibnum and sa_family in @info->rti_info[RTAX_DST].
* Needs to be run in network epoch.
*
* Returns 0 on success and fills in @rc with action result.
*/
int
rib_action(uint32_t fibnum, int action, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
int error;
switch (action) {
case RTM_ADD:
error = rib_add_route(fibnum, info, rc);
break;
case RTM_DELETE:
error = rib_del_route(fibnum, info, rc);
break;
case RTM_CHANGE:
error = rib_change_route(fibnum, info, rc);
break;
default:
error = ENOTSUP;
}
return (error);
}
struct rt_delinfo
{
struct rib_head *rnh;
struct rtentry *head;
rib_filter_f_t *filter_f;
void *filter_arg;
int prio;
struct rib_cmd_info rc;
};
/*
* Conditionally unlinks rtenties or paths from radix tree based
* on the callback data passed in @arg.
*/
static int
rt_checkdelroute(struct radix_node *rn, void *arg)
{
struct rt_delinfo *di = (struct rt_delinfo *)arg;
struct rtentry *rt = (struct rtentry *)rn;
if (rt_delete_conditional(di->rnh, rt, di->prio,
di->filter_f, di->filter_arg, &di->rc) != 0)
return (0);
/*
* Add deleted rtentries to the list to GC them
* after dropping the lock.
*
* XXX: Delayed notifications not implemented
* for nexthop updates.
*/
if (di->rc.rc_cmd == RTM_DELETE) {
/* Add to the list and return */
rt->rt_chain = di->head;
di->head = rt;
#ifdef ROUTE_MPATH
} else {
/*
* RTM_CHANGE to a different nexthop or nexthop group.
* Free old multipath group.
*/
nhop_free_any(di->rc.rc_nh_old);
#endif
}
return (0);
}
/*
* Iterates over a routing table specified by @fibnum and @family and
* deletes elements marked by @filter_f.
* @fibnum: rtable id
* @family: AF_ address family
* @filter_f: function returning non-zero value for items to delete
* @arg: data to pass to the @filter_f function
* @report: true if rtsock notification is needed.
*/
void
rib_walk_del(u_int fibnum, int family, rib_filter_f_t *filter_f, void *filter_arg,
bool report)
{
struct rib_head *rnh;
struct rtentry *rt;
struct nhop_object *nh;
struct epoch_tracker et;
rnh = rt_tables_get_rnh(fibnum, family);
if (rnh == NULL)
return;
struct rt_delinfo di = {
.rnh = rnh,
.filter_f = filter_f,
.filter_arg = filter_arg,
.prio = NH_PRIORITY_NORMAL,
};
NET_EPOCH_ENTER(et);
RIB_WLOCK(rnh);
rnh->rnh_walktree(&rnh->head, rt_checkdelroute, &di);
RIB_WUNLOCK(rnh);
/* We might have something to reclaim. */
bzero(&di.rc, sizeof(di.rc));
di.rc.rc_cmd = RTM_DELETE;
while (di.head != NULL) {
rt = di.head;
di.head = rt->rt_chain;
rt->rt_chain = NULL;
nh = rt->rt_nhop;
di.rc.rc_rt = rt;
di.rc.rc_nh_old = nh;
rib_notify(rnh, RIB_NOTIFY_DELAYED, &di.rc);
if (report) {
#ifdef ROUTE_MPATH
struct nhgrp_object *nhg;
const struct weightened_nhop *wn;
uint32_t num_nhops;
if (NH_IS_NHGRP(nh)) {
nhg = (struct nhgrp_object *)nh;
wn = nhgrp_get_nhops(nhg, &num_nhops);
for (int i = 0; i < num_nhops; i++)
rt_routemsg(RTM_DELETE, rt, wn[i].nh, fibnum);
} else
#endif
rt_routemsg(RTM_DELETE, rt, nh, fibnum);
}
rt_free(rt);
}
NET_EPOCH_EXIT(et);
}
static int
rt_delete_unconditional(struct radix_node *rn, void *arg)
{
struct rtentry *rt = RNTORT(rn);
struct rib_head *rnh = (struct rib_head *)arg;
rn = rnh->rnh_deladdr(rt_key(rt), rt_mask(rt), &rnh->head);
if (RNTORT(rn) == rt)
rt_free(rt);
return (0);
}
/*
* Removes all routes from the routing table without executing notifications.
* rtentres will be removed after the end of a current epoch.
*/
static void
rib_flush_routes(struct rib_head *rnh)
{
RIB_WLOCK(rnh);
rnh->rnh_walktree(&rnh->head, rt_delete_unconditional, rnh);
RIB_WUNLOCK(rnh);
}
void
rib_flush_routes_family(int family)
{
struct rib_head *rnh;
for (uint32_t fibnum = 0; fibnum < rt_numfibs; fibnum++) {
if ((rnh = rt_tables_get_rnh(fibnum, family)) != NULL)
rib_flush_routes(rnh);
}
}
const char *
rib_print_family(int family)
{
switch (family) {
case AF_INET:
return ("inet");
case AF_INET6:
return ("inet6");
case AF_LINK:
return ("link");
}
return ("unknown");
}