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 static void in_setifarnh(struct radix_node_head *rnh, uint32_t fibnum, 57 int af, void *_arg); 58 59 /* 60 * Do what we need to do when inserting a route. 61 */ 62 static struct radix_node * 63 in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, 64 struct radix_node *treenodes) 65 { 66 struct rtentry *rt = (struct rtentry *)treenodes; 67 struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt); 68 69 RADIX_NODE_HEAD_WLOCK_ASSERT(head); 70 /* 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). 77 * 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(). 80 * 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). 84 */ 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; 91 } 92 } 93 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) 94 rt->rt_flags |= RTF_MULTICAST; 95 96 if (rt->rt_ifp != NULL) { 97 98 /* 99 * Check route MTU: 100 * inherit interface MTU if not set or 101 * check if MTU is too large. 102 */ 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; 107 } 108 109 return (rn_addroute(v_arg, n_arg, head, treenodes)); 110 } 111 112 static int _in_rt_was_here; 113 /* 114 * Initialize our routing tree. 115 */ 116 int 117 in_inithead(void **head, int off) 118 { 119 struct radix_node_head *rnh; 120 121 if (!rn_inithead(head, 32)) 122 return 0; 123 124 rnh = *head; 125 RADIX_NODE_HEAD_LOCK_INIT(rnh); 126 127 rnh->rnh_addaddr = in_addroute; 128 if (_in_rt_was_here == 0 ) { 129 _in_rt_was_here = 1; 130 } 131 return 1; 132 } 133 134 #ifdef VIMAGE 135 int 136 in_detachhead(void **head, int off) 137 { 138 139 return (1); 140 } 141 #endif 142 143 /* 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 150 * plug back in. 151 */ 152 struct in_ifadown_arg { 153 struct radix_node_head *rnh; 154 struct ifaddr *ifa; 155 int del; 156 }; 157 158 static int 159 in_ifadownkill(struct rtentry *rt, void *xap) 160 { 161 struct in_ifadown_arg *ap = xap; 162 163 RT_LOCK(rt); 164 if (rt->rt_ifa == ap->ifa && 165 (ap->del || !(rt->rt_flags & RTF_STATIC))) { 166 /* 167 * Aquire a reference so that it can later be freed 168 * as the refcount would be 0 here in case of at least 169 * ap->del. 170 */ 171 RT_ADDREF(rt); 172 /* 173 * Disconnect it from the tree and permit protocols 174 * to cleanup. 175 */ 176 rt_expunge(ap->rnh, rt); 177 /* 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. 186 */ 187 RTFREE_LOCKED(rt); 188 return (0); 189 } 190 RT_UNLOCK(rt); 191 return 0; 192 } 193 194 static void 195 in_setifarnh(struct radix_node_head *rnh, uint32_t fibnum, int af, 196 void *_arg) 197 { 198 struct in_ifadown_arg *arg; 199 200 arg = (struct in_ifadown_arg *)_arg; 201 202 arg->rnh = rnh; 203 } 204 205 void 206 in_ifadown(struct ifaddr *ifa, int delete) 207 { 208 struct in_ifadown_arg arg; 209 210 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 211 ("%s: wrong family", __func__)); 212 213 arg.ifa = ifa; 214 arg.del = delete; 215 216 rt_foreach_fib_walk(AF_INET, in_setifarnh, in_ifadownkill, &arg); 217 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 218 } 219 220 /* 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, 224 */ 225 void 226 in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum) 227 { 228 rtalloc_ign_fib(ro, ignflags, fibnum); 229 } 230 231 struct rtentry * 232 in_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum) 233 { 234 return (rtalloc1_fib(dst, report, ignflags, fibnum)); 235 } 236 237 void 238 in_rtredirect(struct sockaddr *dst, 239 struct sockaddr *gateway, 240 struct sockaddr *netmask, 241 int flags, 242 struct sockaddr *src, 243 u_int fibnum) 244 { 245 rtredirect_fib(dst, gateway, netmask, flags, src, fibnum); 246 } 247 248 void 249 in_rtalloc(struct route *ro, u_int fibnum) 250 { 251 rtalloc_ign_fib(ro, 0UL, fibnum); 252 } 253 254