1/*-
2 * Copyright 1994, 1995 Massachusetts Institute of Technology
3 *
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
14 * warranty.
15 *
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
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
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>
38#include <sys/mbuf.h>
39
40#include <net/if.h>
41#include <net/if_var.h>
42#include <net/route.h>
43#include <net/route_var.h>
44#include <net/vnet.h>
45
46#include <netinet/in.h>
47#include <netinet/in_var.h>
48#include <netinet/ip.h>
49#include <netinet/ip_icmp.h>
50#include <netinet/ip_var.h>
51
52extern int	in_inithead(void **head, int off);
53#ifdef VIMAGE
54extern int	in_detachhead(void **head, int off);
55#endif
56
57/*
58 * Do what we need to do when inserting a route.
59 */
60static struct radix_node *
61in_addroute(void *v_arg, void *n_arg, struct radix_head *head,
62    struct radix_node *treenodes)
63{
64	struct rtentry *rt = (struct rtentry *)treenodes;
65	struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
66
67	/*
68	 * A little bit of help for both IP output and input:
69	 *   For host routes, we make sure that RTF_BROADCAST
70	 *   is set for anything that looks like a broadcast address.
71	 *   This way, we can avoid an expensive call to in_broadcast()
72	 *   in ip_output() most of the time (because the route passed
73	 *   to ip_output() is almost always a host route).
74	 *
75	 *   We also do the same for local addresses, with the thought
76	 *   that this might one day be used to speed up ip_input().
77	 *
78	 * We also mark routes to multicast addresses as such, because
79	 * it's easy to do and might be useful (but this is much more
80	 * dubious since it's so easy to inspect the address).
81	 */
82	if (rt->rt_flags & RTF_HOST) {
83		if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
84			rt->rt_flags |= RTF_BROADCAST;
85		} else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
86		    sin->sin_addr.s_addr) {
87			rt->rt_flags |= RTF_LOCAL;
88		}
89	}
90	if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
91		rt->rt_flags |= RTF_MULTICAST;
92
93	if (rt->rt_ifp != NULL) {
94
95		/*
96		 * Check route MTU:
97		 * inherit interface MTU if not set or
98		 * check if MTU is too large.
99		 */
100		if (rt->rt_mtu == 0) {
101			rt->rt_mtu = rt->rt_ifp->if_mtu;
102		} else if (rt->rt_mtu > rt->rt_ifp->if_mtu)
103			rt->rt_mtu = rt->rt_ifp->if_mtu;
104	}
105
106	return (rn_addroute(v_arg, n_arg, head, treenodes));
107}
108
109static int _in_rt_was_here;
110/*
111 * Initialize our routing tree.
112 */
113int
114in_inithead(void **head, int off)
115{
116	struct rib_head *rh;
117
118	rh = rt_table_init(32);
119	if (rh == NULL)
120		return (0);
121
122	rh->rnh_addaddr = in_addroute;
123	*head = (void *)rh;
124
125	if (_in_rt_was_here == 0 ) {
126		_in_rt_was_here = 1;
127	}
128	return 1;
129}
130
131#ifdef VIMAGE
132int
133in_detachhead(void **head, int off)
134{
135
136	rt_table_destroy((struct rib_head *)(*head));
137	return (1);
138}
139#endif
140
141/*
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
148 * plug back in.
149 */
150struct in_ifadown_arg {
151	struct ifaddr *ifa;
152	int del;
153};
154
155static int
156in_ifadownkill(const struct rtentry *rt, void *xap)
157{
158	struct in_ifadown_arg *ap = xap;
159
160	if (rt->rt_ifa != ap->ifa)
161		return (0);
162
163	if ((rt->rt_flags & RTF_STATIC) != 0 && ap->del == 0)
164		return (0);
165
166	return (1);
167}
168
169void
170in_ifadown(struct ifaddr *ifa, int delete)
171{
172	struct in_ifadown_arg arg;
173
174	KASSERT(ifa->ifa_addr->sa_family == AF_INET,
175	    ("%s: wrong family", __func__));
176
177	arg.ifa = ifa;
178	arg.del = delete;
179
180	rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg);
181	ifa->ifa_flags &= ~IFA_ROUTE;		/* XXXlocking? */
182}
183
184/*
185 * inet versions of rt functions. These have fib extensions and
186 * for now will just reference the _fib variants.
187 * eventually this order will be reversed,
188 */
189void
190in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum)
191{
192	rtalloc_ign_fib(ro, ignflags, fibnum);
193}
194
195void
196in_rtredirect(struct sockaddr *dst,
197	struct sockaddr *gateway,
198	struct sockaddr *netmask,
199	int flags,
200	struct sockaddr *src,
201	u_int fibnum)
202{
203	rtredirect_fib(dst, gateway, netmask, flags, src, fibnum);
204}
205
206