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 52 extern int in_inithead(void **head, int off, u_int fibnum); 53 #ifdef VIMAGE 54 extern int in_detachhead(void **head, int off); 55 #endif 56 57 /* 58 * Do what we need to do when inserting a route. 59 */ 60 static struct radix_node * 61 in_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 struct epoch_tracker et; 84 bool bcast; 85 86 NET_EPOCH_ENTER(et); 87 bcast = in_broadcast(sin->sin_addr, rt->rt_ifp); 88 NET_EPOCH_EXIT(et); 89 if (bcast) 90 rt->rt_flags |= RTF_BROADCAST; 91 else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr == 92 sin->sin_addr.s_addr) 93 rt->rt_flags |= RTF_LOCAL; 94 } 95 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) 96 rt->rt_flags |= RTF_MULTICAST; 97 98 if (rt->rt_ifp != NULL) { 99 100 /* 101 * Check route MTU: 102 * inherit interface MTU if not set or 103 * check if MTU is too large. 104 */ 105 if (rt->rt_mtu == 0) { 106 rt->rt_mtu = rt->rt_ifp->if_mtu; 107 } else if (rt->rt_mtu > rt->rt_ifp->if_mtu) 108 rt->rt_mtu = rt->rt_ifp->if_mtu; 109 } 110 111 return (rn_addroute(v_arg, n_arg, head, treenodes)); 112 } 113 114 static int _in_rt_was_here; 115 /* 116 * Initialize our routing tree. 117 */ 118 int 119 in_inithead(void **head, int off, u_int fibnum) 120 { 121 struct rib_head *rh; 122 123 rh = rt_table_init(32, AF_INET, fibnum); 124 if (rh == NULL) 125 return (0); 126 127 rh->rnh_addaddr = in_addroute; 128 *head = (void *)rh; 129 130 if (_in_rt_was_here == 0 ) { 131 _in_rt_was_here = 1; 132 } 133 return 1; 134 } 135 136 #ifdef VIMAGE 137 int 138 in_detachhead(void **head, int off) 139 { 140 141 rt_table_destroy((struct rib_head *)(*head)); 142 return (1); 143 } 144 #endif 145 146 /* 147 * This zaps old routes when the interface goes down or interface 148 * address is deleted. In the latter case, it deletes static routes 149 * that point to this address. If we don't do this, we may end up 150 * using the old address in the future. The ones we always want to 151 * get rid of are things like ARP entries, since the user might down 152 * the interface, walk over to a completely different network, and 153 * plug back in. 154 */ 155 struct in_ifadown_arg { 156 struct ifaddr *ifa; 157 int del; 158 }; 159 160 static int 161 in_ifadownkill(const struct rtentry *rt, void *xap) 162 { 163 struct in_ifadown_arg *ap = xap; 164 165 if (rt->rt_ifa != ap->ifa) 166 return (0); 167 168 if ((rt->rt_flags & RTF_STATIC) != 0 && ap->del == 0) 169 return (0); 170 171 return (1); 172 } 173 174 void 175 in_ifadown(struct ifaddr *ifa, int delete) 176 { 177 struct in_ifadown_arg arg; 178 179 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 180 ("%s: wrong family", __func__)); 181 182 arg.ifa = ifa; 183 arg.del = delete; 184 185 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg); 186 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 187 } 188 189 /* 190 * inet versions of rt functions. These have fib extensions and 191 * for now will just reference the _fib variants. 192 * eventually this order will be reversed, 193 */ 194 void 195 in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum) 196 { 197 rtalloc_ign_fib(ro, ignflags, fibnum); 198 } 199 200