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/vnet.h>
44
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>
50
51 extern int in_inithead(void **head, int off);
52 #ifdef VIMAGE
53 extern int in_detachhead(void **head, int off);
54 #endif
55
56 /*
57 * Do what we need to do when inserting a route.
58 */
59 static struct radix_node *
in_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node * treenodes)60 in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
61 struct radix_node *treenodes)
62 {
63 struct rtentry *rt = (struct rtentry *)treenodes;
64 struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
65
66 RADIX_NODE_HEAD_WLOCK_ASSERT(head);
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
109 static int _in_rt_was_here;
110 /*
111 * Initialize our routing tree.
112 */
113 int
in_inithead(void ** head,int off)114 in_inithead(void **head, int off)
115 {
116 struct radix_node_head *rnh;
117
118 if (!rn_inithead(head, 32))
119 return 0;
120
121 rnh = *head;
122 RADIX_NODE_HEAD_LOCK_INIT(rnh);
123
124 rnh->rnh_addaddr = in_addroute;
125 if (_in_rt_was_here == 0 ) {
126 _in_rt_was_here = 1;
127 }
128 return 1;
129 }
130
131 #ifdef VIMAGE
132 int
in_detachhead(void ** head,int off)133 in_detachhead(void **head, int off)
134 {
135
136 return (rn_detachhead(head));
137 }
138 #endif
139
140 /*
141 * This zaps old routes when the interface goes down or interface
142 * address is deleted. In the latter case, it deletes static routes
143 * that point to this address. If we don't do this, we may end up
144 * using the old address in the future. The ones we always want to
145 * get rid of are things like ARP entries, since the user might down
146 * the interface, walk over to a completely different network, and
147 * plug back in.
148 */
149 struct in_ifadown_arg {
150 struct ifaddr *ifa;
151 int del;
152 };
153
154 static int
in_ifadownkill(const struct rtentry * rt,void * xap)155 in_ifadownkill(const struct rtentry *rt, void *xap)
156 {
157 struct in_ifadown_arg *ap = xap;
158
159 if (rt->rt_ifa != ap->ifa)
160 return (0);
161
162 if ((rt->rt_flags & RTF_STATIC) != 0 && ap->del == 0)
163 return (0);
164
165 return (1);
166 }
167
168 void
in_ifadown(struct ifaddr * ifa,int delete)169 in_ifadown(struct ifaddr *ifa, int delete)
170 {
171 struct in_ifadown_arg arg;
172
173 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
174 ("%s: wrong family", __func__));
175
176 arg.ifa = ifa;
177 arg.del = delete;
178
179 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg);
180 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */
181 }
182
183 /*
184 * inet versions of rt functions. These have fib extensions and
185 * for now will just reference the _fib variants.
186 * eventually this order will be reversed,
187 */
188 void
in_rtalloc_ign(struct route * ro,u_long ignflags,u_int fibnum)189 in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum)
190 {
191 rtalloc_ign_fib(ro, ignflags, fibnum);
192 }
193
194 struct rtentry *
in_rtalloc1(struct sockaddr * dst,int report,u_long ignflags,u_int fibnum)195 in_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
196 {
197 return (rtalloc1_fib(dst, report, ignflags, fibnum));
198 }
199
200 void
in_rtredirect(struct sockaddr * dst,struct sockaddr * gateway,struct sockaddr * netmask,int flags,struct sockaddr * src,u_int fibnum)201 in_rtredirect(struct sockaddr *dst,
202 struct sockaddr *gateway,
203 struct sockaddr *netmask,
204 int flags,
205 struct sockaddr *src,
206 u_int fibnum)
207 {
208 rtredirect_fib(dst, gateway, netmask, flags, src, fibnum);
209 }
210
211 void
in_rtalloc(struct route * ro,u_int fibnum)212 in_rtalloc(struct route *ro, u_int fibnum)
213 {
214 rtalloc_ign_fib(ro, 0UL, fibnum);
215 }
216
217