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); 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 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 114 in_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 132 int 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 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 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 189 in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum) 190 { 191 rtalloc_ign_fib(ro, ignflags, fibnum); 192 } 193 194 void 195 in_rtredirect(struct sockaddr *dst, 196 struct sockaddr *gateway, 197 struct sockaddr *netmask, 198 int flags, 199 struct sockaddr *src, 200 u_int fibnum) 201 { 202 rtredirect_fib(dst, gateway, netmask, flags, src, fibnum); 203 } 204 205