2 * Copyright 1994, 1995 Massachusetts Institute of Technology
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5 * its documentation for any purpose and without fee is hereby
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30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
37 #include <sys/socket.h>
41 #include <net/if_var.h>
42 #include <net/route.h>
43 #include <net/route/route_ctl.h>
44 #include <net/route/route_var.h>
45 #include <net/route/nhop.h>
48 #include <netinet/in.h>
49 #include <netinet/in_var.h>
50 #include <netinet/ip.h>
51 #include <netinet/ip_icmp.h>
52 #include <netinet/ip_var.h>
55 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask,
56 struct nhop_object *nh)
58 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
62 /* XXX: RTF_LOCAL && RTF_MULTICAST */
64 rt_flags = nhop_get_rtflags(nh);
66 if (rt_flags & RTF_HOST) {
68 * Backward compatibility:
69 * if the destination is broadcast,
70 * mark route as broadcast.
71 * This behavior was useful when route cloning
72 * was in place, so there was an explicit cloned
73 * route for every broadcasted address.
74 * Currently (2020-04) there is no kernel machinery
75 * to do route cloning, though someone might explicitly
76 * add these routes to support some cases with active-active
77 * load balancing. Given that, retain this support.
79 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) {
80 rt_flags |= RTF_BROADCAST;
81 nhop_set_rtflags(nh, rt_flags);
82 nh->nh_flags |= NHF_BROADCAST;
88 * inherit interface MTU if not set or
89 * check if MTU is too large.
91 if (nh->nh_mtu == 0) {
92 nh->nh_mtu = nh->nh_ifp->if_mtu;
93 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu)
94 nh->nh_mtu = nh->nh_ifp->if_mtu;
96 /* Ensure that default route nhop has special flag */
97 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask;
98 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL &&
99 mask4->sin_addr.s_addr == 0)
100 nh->nh_flags |= NHF_DEFAULT;
102 /* Set nhop type to basic per-AF nhop */
103 if (nhop_get_type(nh) == 0) {
104 if (nh->nh_flags & NHF_GATEWAY)
105 nh_type = NH_TYPE_IPV4_ETHER_NHOP;
107 nh_type = NH_TYPE_IPV4_ETHER_RSLV;
109 nhop_set_type(nh, nh_type);
116 * Initialize our routing tree.
119 in_inithead(uint32_t fibnum)
123 rh = rt_table_init(32, AF_INET, fibnum);
127 rh->rnh_preadd = rib4_preadd;
134 in_detachhead(struct rib_head *rh)
137 rt_table_destroy(rh);
142 * This zaps old routes when the interface goes down or interface
143 * address is deleted. In the latter case, it deletes static routes
144 * that point to this address. If we don't do this, we may end up
145 * using the old address in the future. The ones we always want to
146 * get rid of are things like ARP entries, since the user might down
147 * the interface, walk over to a completely different network, and
150 struct in_ifadown_arg {
156 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh,
159 struct in_ifadown_arg *ap = xap;
161 if (nh->nh_ifa != ap->ifa)
164 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0)
171 in_ifadown(struct ifaddr *ifa, int delete)
173 struct in_ifadown_arg arg;
175 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
176 ("%s: wrong family", __func__));
181 rib_foreach_table_walk_del(AF_INET, in_ifadownkill, &arg);
182 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */