in6_src.c revision 1.4
1/* $OpenBSD: in6_src.c,v 1.4 2000/02/28 11:55:22 itojun Exp $ */ 2 3/* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32/* 33 * Copyright (c) 1982, 1986, 1991, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. All advertising materials mentioning features or use of this software 45 * must display the following acknowledgement: 46 * This product includes software developed by the University of 47 * California, Berkeley and its contributors. 48 * 4. Neither the name of the University nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 * 64 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 65 */ 66 67#include <sys/param.h> 68#include <sys/systm.h> 69#include <sys/malloc.h> 70#include <sys/mbuf.h> 71#include <sys/protosw.h> 72#include <sys/socket.h> 73#include <sys/socketvar.h> 74#include <sys/ioctl.h> 75#include <sys/errno.h> 76#include <sys/time.h> 77#include <sys/proc.h> 78 79#include <net/if.h> 80#include <net/route.h> 81 82#include <netinet/in.h> 83#include <netinet/in_var.h> 84#include <netinet/in_systm.h> 85#include <netinet/ip.h> 86#include <netinet/in_pcb.h> 87#include <netinet6/in6_var.h> 88#include <netinet/ip6.h> 89#include <netinet6/ip6_var.h> 90#include <netinet6/nd6.h> 91 92#include "loop.h" 93 94extern struct ifnet loif[NLOOP]; 95 96/* 97 * Return an IPv6 address, which is the most appropriate for given 98 * destination and user specified options. 99 * If necessary, this function lookups the routing table and return 100 * an entry to the caller for later use. 101 */ 102struct in6_addr * 103in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp) 104 struct sockaddr_in6 *dstsock; 105 struct ip6_pktopts *opts; 106 struct ip6_moptions *mopts; 107 struct route_in6 *ro; 108 struct in6_addr *laddr; 109 int *errorp; 110{ 111 struct in6_addr *dst; 112 struct in6_ifaddr *ia6 = 0; 113 struct in6_pktinfo *pi = NULL; 114 115 dst = &dstsock->sin6_addr; 116 *errorp = 0; 117 118 /* 119 * If the source address is explicitly specified by the caller, 120 * use it. 121 */ 122 if (opts && (pi = opts->ip6po_pktinfo) && 123 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) 124 return(&pi->ipi6_addr); 125 126 /* 127 * If the source address is not specified but the socket(if any) 128 * is already bound, use the bound address. 129 */ 130 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) 131 return(laddr); 132 133 /* 134 * If the caller doesn't specify the source address but 135 * the outgoing interface, use an address associated with 136 * the interface. 137 */ 138 if (pi && pi->ipi6_ifindex) { 139 /* XXX boundary check is assumed to be already done. */ 140 ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], 141 dst); 142 if (ia6 == 0) { 143 *errorp = EADDRNOTAVAIL; 144 return(0); 145 } 146 return(&satosin6(&ia6->ia_addr)->sin6_addr); 147 } 148 149 /* 150 * If the destination address is a link-local unicast address or 151 * a multicast address, and if the outgoing interface is specified 152 * by the sin6_scope_id filed, use an address associated with the 153 * interface. 154 * XXX: We're now trying to define more specific semantics of 155 * sin6_scope_id field, so this part will be rewritten in 156 * the near future. 157 */ 158 if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && 159 dstsock->sin6_scope_id) { 160 /* 161 * I'm not sure if boundary check for scope_id is done 162 * somewhere... 163 */ 164 if (dstsock->sin6_scope_id < 0 || 165 if_index < dstsock->sin6_scope_id) { 166 *errorp = ENXIO; /* XXX: better error? */ 167 return(0); 168 } 169 ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], 170 dst); 171 if (ia6 == 0) { 172 *errorp = EADDRNOTAVAIL; 173 return(0); 174 } 175 return(&satosin6(&ia6->ia_addr)->sin6_addr); 176 } 177 178 /* 179 * If the destination address is a multicast address and 180 * the outgoing interface for the address is specified 181 * by the caller, use an address associated with the interface. 182 * There is a sanity check here; if the destination has node-local 183 * scope, the outgoing interfacde should be a loopback address. 184 * Even if the outgoing interface is not specified, we also 185 * choose a loopback interface as the outgoing interface. 186 */ 187 if (IN6_IS_ADDR_MULTICAST(dst)) { 188 struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; 189 190 if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) { 191 ifp = &loif[0]; 192 } 193 194 if (ifp) { 195 ia6 = in6_ifawithscope(ifp, dst); 196 if (ia6 == 0) { 197 *errorp = EADDRNOTAVAIL; 198 return(0); 199 } 200 return(&satosin6(&ia6->ia_addr)->sin6_addr); 201 } 202 } 203 204 /* 205 * If the next hop address for the packet is specified 206 * by caller, use an address associated with the route 207 * to the next hop. 208 */ 209 { 210 struct sockaddr_in6 *sin6_next; 211 struct rtentry *rt; 212 213 if (opts && opts->ip6po_nexthop) { 214 sin6_next = satosin6(opts->ip6po_nexthop); 215 rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); 216 if (rt) { 217 ia6 = in6_ifawithscope(rt->rt_ifp, dst); 218 if (ia6 == 0) 219 ia6 = ifatoia6(rt->rt_ifa); 220 } 221 if (ia6 == 0) { 222 *errorp = EADDRNOTAVAIL; 223 return(0); 224 } 225 return(&satosin6(&ia6->ia_addr)->sin6_addr); 226 } 227 } 228 229 /* 230 * If route is known or can be allocated now, 231 * our src addr is taken from the i/f, else punt. 232 */ 233 if (ro) { 234 if (ro->ro_rt && 235 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) { 236 RTFREE(ro->ro_rt); 237 ro->ro_rt = (struct rtentry *)0; 238 } 239 if (ro->ro_rt == (struct rtentry *)0 || 240 ro->ro_rt->rt_ifp == (struct ifnet *)0) { 241 /* No route yet, so try to acquire one */ 242 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); 243 ro->ro_dst.sin6_family = AF_INET6; 244 ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6); 245 ro->ro_dst.sin6_addr = *dst; 246 if (!IN6_IS_ADDR_MULTICAST(dst)) { 247 rtalloc((struct route *)ro); 248 } 249 } 250 251 /* 252 * in_pcbconnect() checks out IFF_LOOPBACK to skip using 253 * the address. But we don't know why it does so. 254 * It is necessary to ensure the scope even for lo0 255 * so doesn't check out IFF_LOOPBACK. 256 */ 257 258 if (ro->ro_rt) { 259 ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst); 260 if (ia6 == 0) /* xxx scope error ?*/ 261 ia6 = ifatoia6(ro->ro_rt->rt_ifa); 262 } 263#if 0 264 /* 265 * xxx The followings are necessary? (kazu) 266 * I don't think so. 267 * It's for SO_DONTROUTE option in IPv4.(jinmei) 268 */ 269 if (ia6 == 0) { 270 struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0}; 271 272 sin6->sin6_addr = *dst; 273 274 ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6))); 275 if (ia6 == 0) 276 ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6))); 277 if (ia6 == 0) 278 return(0); 279 return(&satosin6(&ia6->ia_addr)->sin6_addr); 280 } 281#endif /* 0 */ 282 if (ia6 == 0) { 283 *errorp = EHOSTUNREACH; /* no route */ 284 return(0); 285 } 286 return(&satosin6(&ia6->ia_addr)->sin6_addr); 287 } 288 289 *errorp = EADDRNOTAVAIL; 290 return(0); 291} 292 293/* 294 * Default hop limit selection. The precedence is as follows: 295 * 1. Hoplimit valued specified via ioctl. 296 * 2. (If the outgoing interface is detected) the current 297 * hop limit of the interface specified by router advertisement. 298 * 3. The system default hoplimit. 299*/ 300int 301in6_selecthlim(inp, ifp) 302 struct inpcb *inp; 303 struct ifnet *ifp; 304{ 305 if (inp && inp->inp_hops >= 0) 306 return(inp->inp_hops); 307 else if (ifp) 308 return(nd_ifinfo[ifp->if_index].chlim); 309 else 310 return(ip6_defhlim); 311} 312