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>
45 #include <netinet/in.h>
46 #include <netinet/in_var.h>
47 #include <netinet/ip.h>
48 #include <netinet/ip_icmp.h>
49 #include <netinet/ip_var.h>
51 extern int in_inithead(void **head, int off);
53 extern int in_detachhead(void **head, int off);
56 static void in_setifarnh(struct radix_node_head *rnh, uint32_t fibnum,
60 * Do what we need to do when inserting a route.
62 static struct radix_node *
63 in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
64 struct radix_node *treenodes)
66 struct rtentry *rt = (struct rtentry *)treenodes;
67 struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
69 RADIX_NODE_HEAD_WLOCK_ASSERT(head);
71 * A little bit of help for both IP output and input:
72 * For host routes, we make sure that RTF_BROADCAST
73 * is set for anything that looks like a broadcast address.
74 * This way, we can avoid an expensive call to in_broadcast()
75 * in ip_output() most of the time (because the route passed
76 * to ip_output() is almost always a host route).
78 * We also do the same for local addresses, with the thought
79 * that this might one day be used to speed up ip_input().
81 * We also mark routes to multicast addresses as such, because
82 * it's easy to do and might be useful (but this is much more
83 * dubious since it's so easy to inspect the address).
85 if (rt->rt_flags & RTF_HOST) {
86 if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
87 rt->rt_flags |= RTF_BROADCAST;
88 } else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
89 sin->sin_addr.s_addr) {
90 rt->rt_flags |= RTF_LOCAL;
93 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
94 rt->rt_flags |= RTF_MULTICAST;
96 if (rt->rt_ifp != NULL) {
100 * inherit interface MTU if not set or
101 * check if MTU is too large.
103 if (rt->rt_mtu == 0) {
104 rt->rt_mtu = rt->rt_ifp->if_mtu;
105 } else if (rt->rt_mtu > rt->rt_ifp->if_mtu)
106 rt->rt_mtu = rt->rt_ifp->if_mtu;
109 return (rn_addroute(v_arg, n_arg, head, treenodes));
112 static int _in_rt_was_here;
114 * Initialize our routing tree.
117 in_inithead(void **head, int off)
119 struct radix_node_head *rnh;
121 if (!rn_inithead(head, 32))
125 RADIX_NODE_HEAD_LOCK_INIT(rnh);
127 rnh->rnh_addaddr = in_addroute;
128 if (_in_rt_was_here == 0 ) {
136 in_detachhead(void **head, int off)
144 * This zaps old routes when the interface goes down or interface
145 * address is deleted. In the latter case, it deletes static routes
146 * that point to this address. If we don't do this, we may end up
147 * using the old address in the future. The ones we always want to
148 * get rid of are things like ARP entries, since the user might down
149 * the interface, walk over to a completely different network, and
152 struct in_ifadown_arg {
153 struct radix_node_head *rnh;
159 in_ifadownkill(struct rtentry *rt, void *xap)
161 struct in_ifadown_arg *ap = xap;
164 if (rt->rt_ifa == ap->ifa &&
165 (ap->del || !(rt->rt_flags & RTF_STATIC))) {
167 * Aquire a reference so that it can later be freed
168 * as the refcount would be 0 here in case of at least
173 * Disconnect it from the tree and permit protocols
176 rt_expunge(ap->rnh, rt);
178 * At this point it is an rttrash node, and in case
179 * the above is the only reference we must free it.
180 * If we do not noone will have a pointer and the
181 * rtentry will be leaked forever.
182 * In case someone else holds a reference, we are
183 * fine as we only decrement the refcount. In that
184 * case if the other entity calls RT_REMREF, we
185 * will still be leaking but at least we tried.
195 in_setifarnh(struct radix_node_head *rnh, uint32_t fibnum, int af,
198 struct in_ifadown_arg *arg;
200 arg = (struct in_ifadown_arg *)_arg;
206 in_ifadown(struct ifaddr *ifa, int delete)
208 struct in_ifadown_arg arg;
210 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
211 ("%s: wrong family", __func__));
216 rt_foreach_fib_walk(AF_INET, in_setifarnh, in_ifadownkill, &arg);
217 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */
221 * inet versions of rt functions. These have fib extensions and
222 * for now will just reference the _fib variants.
223 * eventually this order will be reversed,
226 in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum)
228 rtalloc_ign_fib(ro, ignflags, fibnum);
232 in_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
234 return (rtalloc1_fib(dst, report, ignflags, fibnum));
238 in_rtredirect(struct sockaddr *dst,
239 struct sockaddr *gateway,
240 struct sockaddr *netmask,
242 struct sockaddr *src,
245 rtredirect_fib(dst, gateway, netmask, flags, src, fibnum);
249 in_rtalloc(struct route *ro, u_int fibnum)
251 rtalloc_ign_fib(ro, 0UL, fibnum);