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 "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_var.h>
46 #include <net/route/nhop.h>
47 #include <net/route/shared.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>
56 extern int in_inithead(void **head, int off, u_int fibnum);
58 extern int in_detachhead(void **head, int off);
62 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask,
63 struct nhop_object *nh)
65 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
69 /* XXX: RTF_LOCAL && RTF_MULTICAST */
71 rt_flags = nhop_get_rtflags(nh);
73 if (rt_flags & RTF_HOST) {
76 * Backward compatibility:
77 * if the destination is broadcast,
78 * mark route as broadcast.
79 * This behavior was useful when route cloning
80 * was in place, so there was an explicit cloned
81 * route for every broadcasted address.
82 * Currently (2020-04) there is no kernel machinery
83 * to do route cloning, though someone might explicitly
84 * add these routes to support some cases with active-active
85 * load balancing. Given that, retain this support.
87 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) {
88 rt_flags |= RTF_BROADCAST;
89 nhop_set_rtflags(nh, rt_flags);
90 nh->nh_flags |= NHF_BROADCAST;
96 * inherit interface MTU if not set or
97 * check if MTU is too large.
99 if (nh->nh_mtu == 0) {
100 nh->nh_mtu = nh->nh_ifp->if_mtu;
101 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu)
102 nh->nh_mtu = nh->nh_ifp->if_mtu;
104 /* Ensure that default route nhop has special flag */
105 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask;
106 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL &&
107 mask4->sin_addr.s_addr == 0)
108 nh->nh_flags |= NHF_DEFAULT;
110 /* Set nhop type to basic per-AF nhop */
111 if (nhop_get_type(nh) == 0) {
112 if (nh->nh_flags & NHF_GATEWAY)
113 nh_type = NH_TYPE_IPV4_ETHER_NHOP;
115 nh_type = NH_TYPE_IPV4_ETHER_RSLV;
117 nhop_set_type(nh, nh_type);
124 * Do what we need to do when inserting a route.
126 static struct radix_node *
127 in_addroute(void *v_arg, void *n_arg, struct radix_head *head,
128 struct radix_node *treenodes)
130 struct rtentry *rt = (struct rtentry *)treenodes;
131 struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
134 * A little bit of help for both IP output and input:
135 * For host routes, we make sure that RTF_BROADCAST
136 * is set for anything that looks like a broadcast address.
137 * This way, we can avoid an expensive call to in_broadcast()
138 * in ip_output() most of the time (because the route passed
139 * to ip_output() is almost always a host route).
141 * We also do the same for local addresses, with the thought
142 * that this might one day be used to speed up ip_input().
144 * We also mark routes to multicast addresses as such, because
145 * it's easy to do and might be useful (but this is much more
146 * dubious since it's so easy to inspect the address).
148 if (rt->rt_flags & RTF_HOST) {
149 struct epoch_tracker et;
153 bcast = in_broadcast(sin->sin_addr, rt->rt_ifp);
156 rt->rt_flags |= RTF_BROADCAST;
157 else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
158 sin->sin_addr.s_addr)
159 rt->rt_flags |= RTF_LOCAL;
161 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
162 rt->rt_flags |= RTF_MULTICAST;
164 if (rt->rt_ifp != NULL) {
168 * inherit interface MTU if not set or
169 * check if MTU is too large.
171 if (rt->rt_mtu == 0) {
172 rt->rt_mtu = rt->rt_ifp->if_mtu;
173 } else if (rt->rt_mtu > rt->rt_ifp->if_mtu)
174 rt->rt_mtu = rt->rt_ifp->if_mtu;
177 return (rn_addroute(v_arg, n_arg, head, treenodes));
180 static int _in_rt_was_here;
182 * Initialize our routing tree.
185 in_inithead(void **head, int off, u_int fibnum)
189 rh = rt_table_init(32, AF_INET, fibnum);
193 rh->rnh_preadd = rib4_preadd;
194 rh->rnh_addaddr = in_addroute;
196 rt_mpath_init_rnh(rh);
200 if (_in_rt_was_here == 0 ) {
208 in_detachhead(void **head, int off)
211 rt_table_destroy((struct rib_head *)(*head));
217 * This zaps old routes when the interface goes down or interface
218 * address is deleted. In the latter case, it deletes static routes
219 * that point to this address. If we don't do this, we may end up
220 * using the old address in the future. The ones we always want to
221 * get rid of are things like ARP entries, since the user might down
222 * the interface, walk over to a completely different network, and
225 struct in_ifadown_arg {
231 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh,
234 struct in_ifadown_arg *ap = xap;
236 if (nh->nh_ifa != ap->ifa)
239 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0)
246 in_ifadown(struct ifaddr *ifa, int delete)
248 struct in_ifadown_arg arg;
250 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
251 ("%s: wrong family", __func__));
256 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg);
257 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */