2 * Copyright 1994, 1995 Massachusetts Institute of Technology
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission. M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose. It is provided "as is" without express or implied
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include "opt_mpath.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/sysctl.h>
39 #include <sys/socket.h>
43 #include <net/if_var.h>
44 #include <net/route.h>
45 #include <net/route/route_ctl.h>
46 #include <net/route/route_var.h>
47 #include <net/route/nhop.h>
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <netinet/ip.h>
53 #include <netinet/ip_icmp.h>
54 #include <netinet/ip_var.h>
57 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask,
58 struct nhop_object *nh)
60 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
64 /* XXX: RTF_LOCAL && RTF_MULTICAST */
66 rt_flags = nhop_get_rtflags(nh);
68 if (rt_flags & RTF_HOST) {
70 * Backward compatibility:
71 * if the destination is broadcast,
72 * mark route as broadcast.
73 * This behavior was useful when route cloning
74 * was in place, so there was an explicit cloned
75 * route for every broadcasted address.
76 * Currently (2020-04) there is no kernel machinery
77 * to do route cloning, though someone might explicitly
78 * add these routes to support some cases with active-active
79 * load balancing. Given that, retain this support.
81 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) {
82 rt_flags |= RTF_BROADCAST;
83 nhop_set_rtflags(nh, rt_flags);
84 nh->nh_flags |= NHF_BROADCAST;
90 * inherit interface MTU if not set or
91 * check if MTU is too large.
93 if (nh->nh_mtu == 0) {
94 nh->nh_mtu = nh->nh_ifp->if_mtu;
95 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu)
96 nh->nh_mtu = nh->nh_ifp->if_mtu;
98 /* Ensure that default route nhop has special flag */
99 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask;
100 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL &&
101 mask4->sin_addr.s_addr == 0)
102 nh->nh_flags |= NHF_DEFAULT;
104 /* Set nhop type to basic per-AF nhop */
105 if (nhop_get_type(nh) == 0) {
106 if (nh->nh_flags & NHF_GATEWAY)
107 nh_type = NH_TYPE_IPV4_ETHER_NHOP;
109 nh_type = NH_TYPE_IPV4_ETHER_RSLV;
111 nhop_set_type(nh, nh_type);
118 * Initialize our routing tree.
121 in_inithead(uint32_t fibnum)
125 rh = rt_table_init(32, AF_INET, fibnum);
129 rh->rnh_preadd = rib4_preadd;
131 rt_mpath_init_rnh(rh);
139 in_detachhead(struct rib_head *rh)
142 rt_table_destroy(rh);
147 * This zaps old routes when the interface goes down or interface
148 * address is deleted. In the latter case, it deletes static routes
149 * that point to this address. If we don't do this, we may end up
150 * using the old address in the future. The ones we always want to
151 * get rid of are things like ARP entries, since the user might down
152 * the interface, walk over to a completely different network, and
155 struct in_ifadown_arg {
161 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh,
164 struct in_ifadown_arg *ap = xap;
166 if (nh->nh_ifa != ap->ifa)
169 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0)
176 in_ifadown(struct ifaddr *ifa, int delete)
178 struct in_ifadown_arg arg;
180 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
181 ("%s: wrong family", __func__));
186 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg);
187 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */