The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/in6_src.c

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    1 /*-
    2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. Neither the name of the project nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $
   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  * 4. Neither the name of the University nor the names of its contributors
   45  *    may be used to endorse or promote products derived from this software
   46  *    without specific prior written permission.
   47  *
   48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   58  * SUCH DAMAGE.
   59  *
   60  *      @(#)in_pcb.c    8.2 (Berkeley) 1/4/94
   61  */
   62 
   63 #include <sys/cdefs.h>
   64 __FBSDID("$FreeBSD$");
   65 
   66 #include "opt_inet.h"
   67 #include "opt_inet6.h"
   68 #include "opt_mpath.h"
   69 
   70 #include <sys/param.h>
   71 #include <sys/systm.h>
   72 #include <sys/lock.h>
   73 #include <sys/malloc.h>
   74 #include <sys/mbuf.h>
   75 #include <sys/priv.h>
   76 #include <sys/protosw.h>
   77 #include <sys/socket.h>
   78 #include <sys/socketvar.h>
   79 #include <sys/sockio.h>
   80 #include <sys/sysctl.h>
   81 #include <sys/errno.h>
   82 #include <sys/time.h>
   83 #include <sys/jail.h>
   84 #include <sys/kernel.h>
   85 #include <sys/rmlock.h>
   86 #include <sys/sx.h>
   87 
   88 #include <net/if.h>
   89 #include <net/if_var.h>
   90 #include <net/if_dl.h>
   91 #include <net/route.h>
   92 #include <net/if_llatbl.h>
   93 #ifdef RADIX_MPATH
   94 #include <net/radix_mpath.h>
   95 #endif
   96 
   97 #include <netinet/in.h>
   98 #include <netinet/in_var.h>
   99 #include <netinet/in_systm.h>
  100 #include <netinet/ip.h>
  101 #include <netinet/in_pcb.h>
  102 #include <netinet/ip_var.h>
  103 #include <netinet/udp.h>
  104 #include <netinet/udp_var.h>
  105 
  106 #include <netinet6/in6_var.h>
  107 #include <netinet/ip6.h>
  108 #include <netinet6/in6_fib.h>
  109 #include <netinet6/in6_pcb.h>
  110 #include <netinet6/ip6_var.h>
  111 #include <netinet6/scope6_var.h>
  112 #include <netinet6/nd6.h>
  113 
  114 static struct mtx addrsel_lock;
  115 #define ADDRSEL_LOCK_INIT()     mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
  116 #define ADDRSEL_LOCK()          mtx_lock(&addrsel_lock)
  117 #define ADDRSEL_UNLOCK()        mtx_unlock(&addrsel_lock)
  118 #define ADDRSEL_LOCK_ASSERT()   mtx_assert(&addrsel_lock, MA_OWNED)
  119 
  120 static struct sx addrsel_sxlock;
  121 #define ADDRSEL_SXLOCK_INIT()   sx_init(&addrsel_sxlock, "addrsel_sxlock")
  122 #define ADDRSEL_SLOCK()         sx_slock(&addrsel_sxlock)
  123 #define ADDRSEL_SUNLOCK()       sx_sunlock(&addrsel_sxlock)
  124 #define ADDRSEL_XLOCK()         sx_xlock(&addrsel_sxlock)
  125 #define ADDRSEL_XUNLOCK()       sx_xunlock(&addrsel_sxlock)
  126 
  127 #define ADDR_LABEL_NOTAPP (-1)
  128 static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy);
  129 #define V_defaultaddrpolicy             VNET(defaultaddrpolicy)
  130 
  131 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
  132 
  133 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
  134         struct ip6_moptions *, struct route_in6 *, struct ifnet **,
  135         struct rtentry **, int, u_int);
  136 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
  137         struct ip6_moptions *, struct ifnet **,
  138         struct ifnet *, u_int);
  139 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *,
  140         struct ip6_pktopts *, struct inpcb *, struct ucred *,
  141         struct ifnet **, struct in6_addr *);
  142 
  143 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *);
  144 
  145 static void init_policy_queue(void);
  146 static int add_addrsel_policyent(struct in6_addrpolicy *);
  147 static int delete_addrsel_policyent(struct in6_addrpolicy *);
  148 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *),
  149         void *);
  150 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *);
  151 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
  152 
  153 /*
  154  * Return an IPv6 address, which is the most appropriate for a given
  155  * destination and user specified options.
  156  * If necessary, this function lookups the routing table and returns
  157  * an entry to the caller for later use.
  158  */
  159 #define REPLACE(r) do {\
  160         IP6STAT_INC(ip6s_sources_rule[(r)]); \
  161         rule = (r);     \
  162         /* { \
  163         char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
  164         printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
  165         } */ \
  166         goto replace; \
  167 } while(0)
  168 #define NEXT(r) do {\
  169         /* { \
  170         char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
  171         printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
  172         } */ \
  173         goto next;              /* XXX: we can't use 'continue' here */ \
  174 } while(0)
  175 #define BREAK(r) do { \
  176         IP6STAT_INC(ip6s_sources_rule[(r)]); \
  177         rule = (r);     \
  178         goto out;               /* XXX: we can't use 'break' here */ \
  179 } while(0)
  180 
  181 static int
  182 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock,
  183     struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred,
  184     struct ifnet **ifpp, struct in6_addr *srcp)
  185 {
  186         struct rm_priotracker in6_ifa_tracker;
  187         struct in6_addr dst, tmp;
  188         struct ifnet *ifp = NULL, *oifp = NULL;
  189         struct in6_ifaddr *ia = NULL, *ia_best = NULL;
  190         struct in6_pktinfo *pi = NULL;
  191         int dst_scope = -1, best_scope = -1, best_matchlen = -1;
  192         struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
  193         u_int32_t odstzone;
  194         int prefer_tempaddr;
  195         int error, rule;
  196         struct ip6_moptions *mopts;
  197 
  198         KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__));
  199 
  200         dst = dstsock->sin6_addr; /* make a copy for local operation */
  201         if (ifpp) {
  202                 /*
  203                  * Save a possibly passed in ifp for in6_selectsrc. Only
  204                  * neighbor discovery code should use this feature, where
  205                  * we may know the interface but not the FIB number holding
  206                  * the connected subnet in case someone deleted it from the
  207                  * default FIB and we need to check the interface.
  208                  */
  209                 if (*ifpp != NULL)
  210                         oifp = *ifpp;
  211                 *ifpp = NULL;
  212         }
  213 
  214         if (inp != NULL) {
  215                 INP_LOCK_ASSERT(inp);
  216                 mopts = inp->in6p_moptions;
  217         } else {
  218                 mopts = NULL;
  219         }
  220 
  221         /*
  222          * If the source address is explicitly specified by the caller,
  223          * check if the requested source address is indeed a unicast address
  224          * assigned to the node, and can be used as the packet's source
  225          * address.  If everything is okay, use the address as source.
  226          */
  227         if (opts && (pi = opts->ip6po_pktinfo) &&
  228             !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
  229                 /* get the outgoing interface */
  230                 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
  231                     fibnum))
  232                     != 0)
  233                         return (error);
  234 
  235                 /*
  236                  * determine the appropriate zone id of the source based on
  237                  * the zone of the destination and the outgoing interface.
  238                  * If the specified address is ambiguous wrt the scope zone,
  239                  * the interface must be specified; otherwise, ifa_ifwithaddr()
  240                  * will fail matching the address.
  241                  */
  242                 tmp = pi->ipi6_addr;
  243                 if (ifp) {
  244                         error = in6_setscope(&tmp, ifp, &odstzone);
  245                         if (error)
  246                                 return (error);
  247                 }
  248                 if (cred != NULL && (error = prison_local_ip6(cred,
  249                     &tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0)
  250                         return (error);
  251 
  252                 /*
  253                  * If IPV6_BINDANY socket option is set, we allow to specify
  254                  * non local addresses as source address in IPV6_PKTINFO
  255                  * ancillary data.
  256                  */
  257                 if ((inp->inp_flags & INP_BINDANY) == 0) {
  258                         ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */);
  259                         if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST |
  260                             IN6_IFF_NOTREADY))) {
  261                                 if (ia != NULL)
  262                                         ifa_free(&ia->ia_ifa);
  263                                 return (EADDRNOTAVAIL);
  264                         }
  265                         bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp));
  266                         ifa_free(&ia->ia_ifa);
  267                 } else
  268                         bcopy(&tmp, srcp, sizeof(*srcp));
  269                 pi->ipi6_addr = tmp; /* XXX: this overrides pi */
  270                 if (ifpp)
  271                         *ifpp = ifp;
  272                 return (0);
  273         }
  274 
  275         /*
  276          * Otherwise, if the socket has already bound the source, just use it.
  277          */
  278         if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
  279                 if (cred != NULL &&
  280                     (error = prison_local_ip6(cred, &inp->in6p_laddr,
  281                     ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
  282                         return (error);
  283                 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp));
  284                 return (0);
  285         }
  286 
  287         /*
  288          * Bypass source address selection and use the primary jail IP
  289          * if requested.
  290          */
  291         if (cred != NULL && !prison_saddrsel_ip6(cred, srcp))
  292                 return (0);
  293 
  294         /*
  295          * If the address is not specified, choose the best one based on
  296          * the outgoing interface and the destination address.
  297          */
  298         /* get the outgoing interface */
  299         if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
  300             (inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 0)
  301                 return (error);
  302 
  303 #ifdef DIAGNOSTIC
  304         if (ifp == NULL)        /* this should not happen */
  305                 panic("in6_selectsrc: NULL ifp");
  306 #endif
  307         error = in6_setscope(&dst, ifp, &odstzone);
  308         if (error)
  309                 return (error);
  310 
  311         rule = 0;
  312         IN6_IFADDR_RLOCK(&in6_ifa_tracker);
  313         TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
  314                 int new_scope = -1, new_matchlen = -1;
  315                 struct in6_addrpolicy *new_policy = NULL;
  316                 u_int32_t srczone, osrczone, dstzone;
  317                 struct in6_addr src;
  318                 struct ifnet *ifp1 = ia->ia_ifp;
  319 
  320                 /*
  321                  * We'll never take an address that breaks the scope zone
  322                  * of the destination.  We also skip an address if its zone
  323                  * does not contain the outgoing interface.
  324                  * XXX: we should probably use sin6_scope_id here.
  325                  */
  326                 if (in6_setscope(&dst, ifp1, &dstzone) ||
  327                     odstzone != dstzone) {
  328                         continue;
  329                 }
  330                 src = ia->ia_addr.sin6_addr;
  331                 if (in6_setscope(&src, ifp, &osrczone) ||
  332                     in6_setscope(&src, ifp1, &srczone) ||
  333                     osrczone != srczone) {
  334                         continue;
  335                 }
  336 
  337                 /* avoid unusable addresses */
  338                 if ((ia->ia6_flags &
  339                      (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
  340                                 continue;
  341                 }
  342                 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
  343                         continue;
  344 
  345                 /* If jailed only take addresses of the jail into account. */
  346                 if (cred != NULL &&
  347                     prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0)
  348                         continue;
  349 
  350                 /* Rule 1: Prefer same address */
  351                 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
  352                         ia_best = ia;
  353                         BREAK(1); /* there should be no better candidate */
  354                 }
  355 
  356                 if (ia_best == NULL)
  357                         REPLACE(0);
  358 
  359                 /* Rule 2: Prefer appropriate scope */
  360                 if (dst_scope < 0)
  361                         dst_scope = in6_addrscope(&dst);
  362                 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
  363                 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
  364                         if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
  365                                 REPLACE(2);
  366                         NEXT(2);
  367                 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
  368                         if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
  369                                 NEXT(2);
  370                         REPLACE(2);
  371                 }
  372 
  373                 /*
  374                  * Rule 3: Avoid deprecated addresses.  Note that the case of
  375                  * !ip6_use_deprecated is already rejected above.
  376                  */
  377                 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
  378                         NEXT(3);
  379                 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
  380                         REPLACE(3);
  381 
  382                 /* Rule 4: Prefer home addresses */
  383                 /*
  384                  * XXX: This is a TODO.  We should probably merge the MIP6
  385                  * case above.
  386                  */
  387 
  388                 /* Rule 5: Prefer outgoing interface */
  389                 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) {
  390                         if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
  391                                 NEXT(5);
  392                         if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
  393                                 REPLACE(5);
  394                 }
  395 
  396                 /*
  397                  * Rule 6: Prefer matching label
  398                  * Note that best_policy should be non-NULL here.
  399                  */
  400                 if (dst_policy == NULL)
  401                         dst_policy = lookup_addrsel_policy(dstsock);
  402                 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
  403                         new_policy = lookup_addrsel_policy(&ia->ia_addr);
  404                         if (dst_policy->label == best_policy->label &&
  405                             dst_policy->label != new_policy->label)
  406                                 NEXT(6);
  407                         if (dst_policy->label != best_policy->label &&
  408                             dst_policy->label == new_policy->label)
  409                                 REPLACE(6);
  410                 }
  411 
  412                 /*
  413                  * Rule 7: Prefer public addresses.
  414                  * We allow users to reverse the logic by configuring
  415                  * a sysctl variable, so that privacy conscious users can
  416                  * always prefer temporary addresses.
  417                  */
  418                 if (opts == NULL ||
  419                     opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
  420                         prefer_tempaddr = V_ip6_prefer_tempaddr;
  421                 } else if (opts->ip6po_prefer_tempaddr ==
  422                     IP6PO_TEMPADDR_NOTPREFER) {
  423                         prefer_tempaddr = 0;
  424                 } else
  425                         prefer_tempaddr = 1;
  426                 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
  427                     (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
  428                         if (prefer_tempaddr)
  429                                 REPLACE(7);
  430                         else
  431                                 NEXT(7);
  432                 }
  433                 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
  434                     !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
  435                         if (prefer_tempaddr)
  436                                 NEXT(7);
  437                         else
  438                                 REPLACE(7);
  439                 }
  440 
  441                 /*
  442                  * Rule 8: prefer addresses on alive interfaces.
  443                  * This is a KAME specific rule.
  444                  */
  445                 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
  446                     !(ia->ia_ifp->if_flags & IFF_UP))
  447                         NEXT(8);
  448                 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
  449                     (ia->ia_ifp->if_flags & IFF_UP))
  450                         REPLACE(8);
  451 
  452                 /*
  453                  * Rule 9: prefer address with better virtual status.
  454                  */
  455                 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa))
  456                         REPLACE(9);
  457                 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa))
  458                         NEXT(9);
  459 
  460                 /*
  461                  * Rule 10: prefer address with `prefer_source' flag.
  462                  */
  463                 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 &&
  464                     (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0)
  465                         REPLACE(10);
  466                 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 &&
  467                     (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0)
  468                         NEXT(10);
  469 
  470                 /*
  471                  * Rule 14: Use longest matching prefix.
  472                  * Note: in the address selection draft, this rule is
  473                  * documented as "Rule 8".  However, since it is also
  474                  * documented that this rule can be overridden, we assign
  475                  * a large number so that it is easy to assign smaller numbers
  476                  * to more preferred rules.
  477                  */
  478                 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
  479                 if (best_matchlen < new_matchlen)
  480                         REPLACE(14);
  481                 if (new_matchlen < best_matchlen)
  482                         NEXT(14);
  483 
  484                 /* Rule 15 is reserved. */
  485 
  486                 /*
  487                  * Last resort: just keep the current candidate.
  488                  * Or, do we need more rules?
  489                  */
  490                 continue;
  491 
  492           replace:
  493                 ia_best = ia;
  494                 best_scope = (new_scope >= 0 ? new_scope :
  495                               in6_addrscope(&ia_best->ia_addr.sin6_addr));
  496                 best_policy = (new_policy ? new_policy :
  497                                lookup_addrsel_policy(&ia_best->ia_addr));
  498                 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
  499                                  in6_matchlen(&ia_best->ia_addr.sin6_addr,
  500                                               &dst));
  501 
  502           next:
  503                 continue;
  504 
  505           out:
  506                 break;
  507         }
  508 
  509         if ((ia = ia_best) == NULL) {
  510                 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
  511                 IP6STAT_INC(ip6s_sources_none);
  512                 return (EADDRNOTAVAIL);
  513         }
  514 
  515         /*
  516          * At this point at least one of the addresses belonged to the jail
  517          * but it could still be, that we want to further restrict it, e.g.
  518          * theoratically IN6_IS_ADDR_LOOPBACK.
  519          * It must not be IN6_IS_ADDR_UNSPECIFIED anymore.
  520          * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should
  521          * let all others previously selected pass.
  522          * Use tmp to not change ::1 on lo0 to the primary jail address.
  523          */
  524         tmp = ia->ia_addr.sin6_addr;
  525         if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL &&
  526             (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) {
  527                 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
  528                 IP6STAT_INC(ip6s_sources_none);
  529                 return (EADDRNOTAVAIL);
  530         }
  531 
  532         if (ifpp)
  533                 *ifpp = ifp;
  534 
  535         bcopy(&tmp, srcp, sizeof(*srcp));
  536         if (ia->ia_ifp == ifp)
  537                 IP6STAT_INC(ip6s_sources_sameif[best_scope]);
  538         else
  539                 IP6STAT_INC(ip6s_sources_otherif[best_scope]);
  540         if (dst_scope == best_scope)
  541                 IP6STAT_INC(ip6s_sources_samescope[best_scope]);
  542         else
  543                 IP6STAT_INC(ip6s_sources_otherscope[best_scope]);
  544         if (IFA6_IS_DEPRECATED(ia))
  545                 IP6STAT_INC(ip6s_sources_deprecated[best_scope]);
  546         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
  547         return (0);
  548 }
  549 
  550 /*
  551  * Select source address based on @inp, @dstsock and @opts.
  552  * Stores selected address to @srcp. If @scope_ambiguous is set,
  553  * embed scope from selected outgoing interface. If @hlim pointer
  554  * is provided, stores calculated hop limit there.
  555  * Returns 0 on success.
  556  */
  557 int
  558 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
  559     struct inpcb *inp, struct ucred *cred, int scope_ambiguous,
  560     struct in6_addr *srcp, int *hlim)
  561 {
  562         struct ifnet *retifp;
  563         uint32_t fibnum;
  564         int error;
  565 
  566         fibnum = inp->inp_inc.inc_fibnum;
  567         retifp = NULL;
  568 
  569         error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp);
  570         if (error != 0)
  571                 return (error);
  572 
  573         if (hlim != NULL)
  574                 *hlim = in6_selecthlim(inp, retifp);
  575 
  576         if (retifp == NULL || scope_ambiguous == 0)
  577                 return (0);
  578 
  579         /*
  580          * Application should provide a proper zone ID or the use of
  581          * default zone IDs should be enabled.  Unfortunately, some
  582          * applications do not behave as it should, so we need a
  583          * workaround.  Even if an appropriate ID is not determined
  584          * (when it's required), if we can determine the outgoing
  585          * interface. determine the zone ID based on the interface.
  586          */
  587         error = in6_setscope(&dstsock->sin6_addr, retifp, NULL);
  588 
  589         return (error);
  590 }
  591 
  592 /*
  593  * Select source address based on @fibnum, @dst and @scopeid.
  594  * Stores selected address to @srcp.
  595  * Returns 0 on success.
  596  *
  597  * Used by non-socket based consumers (ND code mostly)
  598  */
  599 int
  600 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst,
  601     uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp,
  602     int *hlim)
  603 {
  604         struct ifnet *retifp;
  605         struct sockaddr_in6 dst_sa;
  606         int error;
  607 
  608         retifp = ifp;
  609         bzero(&dst_sa, sizeof(dst_sa));
  610         dst_sa.sin6_family = AF_INET6;
  611         dst_sa.sin6_len = sizeof(dst_sa);
  612         dst_sa.sin6_addr = *dst;
  613         dst_sa.sin6_scope_id = scopeid;
  614         sa6_embedscope(&dst_sa, 0);
  615 
  616         error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp);
  617         if (hlim != NULL)
  618                 *hlim = in6_selecthlim(NULL, retifp);
  619 
  620         return (error);
  621 }
  622 
  623 /*
  624  * clone - meaningful only for bsdi and freebsd
  625  */
  626 static int
  627 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
  628     struct ip6_moptions *mopts, struct route_in6 *ro,
  629     struct ifnet **retifp, struct rtentry **retrt, int norouteok, u_int fibnum)
  630 {
  631         int error = 0;
  632         struct ifnet *ifp = NULL;
  633         struct rtentry *rt = NULL;
  634         struct sockaddr_in6 *sin6_next;
  635         struct in6_pktinfo *pi = NULL;
  636         struct in6_addr *dst = &dstsock->sin6_addr;
  637         uint32_t zoneid;
  638 #if 0
  639         char ip6buf[INET6_ADDRSTRLEN];
  640 
  641         if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
  642             dstsock->sin6_addr.s6_addr32[1] == 0 &&
  643             !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
  644                 printf("in6_selectroute: strange destination %s\n",
  645                        ip6_sprintf(ip6buf, &dstsock->sin6_addr));
  646         } else {
  647                 printf("in6_selectroute: destination = %s%%%d\n",
  648                        ip6_sprintf(ip6buf, &dstsock->sin6_addr),
  649                        dstsock->sin6_scope_id); /* for debug */
  650         }
  651 #endif
  652 
  653         /* If the caller specify the outgoing interface explicitly, use it. */
  654         if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
  655                 /* XXX boundary check is assumed to be already done. */
  656                 ifp = ifnet_byindex(pi->ipi6_ifindex);
  657                 if (ifp != NULL &&
  658                     (norouteok || retrt == NULL ||
  659                     IN6_IS_ADDR_MULTICAST(dst))) {
  660                         /*
  661                          * we do not have to check or get the route for
  662                          * multicast.
  663                          */
  664                         goto done;
  665                 } else
  666                         goto getroute;
  667         }
  668         /*
  669          * If the destination address is a multicast address and the outgoing
  670          * interface for the address is specified by the caller, use it.
  671          */
  672         if (IN6_IS_ADDR_MULTICAST(dst) &&
  673             mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
  674                 goto done; /* we do not need a route for multicast. */
  675         }
  676         /*
  677          * If destination address is LLA or link- or node-local multicast,
  678          * use it's embedded scope zone id to determine outgoing interface.
  679          */
  680         if (IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
  681             IN6_IS_ADDR_MC_NODELOCAL(dst)) {
  682                 zoneid = ntohs(in6_getscope(dst));
  683                 if (zoneid > 0) {
  684                         ifp = in6_getlinkifnet(zoneid);
  685                         goto done;
  686                 }
  687         }
  688 
  689   getroute:
  690         /*
  691          * If the next hop address for the packet is specified by the caller,
  692          * use it as the gateway.
  693          */
  694         if (opts && opts->ip6po_nexthop) {
  695                 struct route_in6 *ron;
  696 
  697                 sin6_next = satosin6(opts->ip6po_nexthop);
  698                 if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) {
  699                         /*
  700                          * Next hop is LLA, thus it should be neighbor.
  701                          * Determine outgoing interface by zone index.
  702                          */
  703                         zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr));
  704                         if (zoneid > 0) {
  705                                 ifp = in6_getlinkifnet(zoneid);
  706                                 goto done;
  707                         }
  708                 }
  709                 ron = &opts->ip6po_nextroute;
  710                 /* Use a cached route if it exists and is valid. */
  711                 if (ron->ro_rt != NULL && (
  712                     (ron->ro_rt->rt_flags & RTF_UP) == 0 ||
  713                     ron->ro_dst.sin6_family != AF_INET6 ||
  714                     !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr,
  715                         &sin6_next->sin6_addr)))
  716                         RO_RTFREE(ron);
  717                 if (ron->ro_rt == NULL) {
  718                         ron->ro_dst = *sin6_next;
  719                         in6_rtalloc(ron, fibnum); /* multi path case? */
  720                 }
  721                 /*
  722                  * The node identified by that address must be a
  723                  * neighbor of the sending host.
  724                  */
  725                 if (ron->ro_rt == NULL ||
  726                     (ron->ro_rt->rt_flags & RTF_GATEWAY) != 0)
  727                         error = EHOSTUNREACH;
  728                 else {
  729                         rt = ron->ro_rt;
  730                         ifp = rt->rt_ifp;
  731                 }
  732                 goto done;
  733         }
  734 
  735         /*
  736          * Use a cached route if it exists and is valid, else try to allocate
  737          * a new one.  Note that we should check the address family of the
  738          * cached destination, in case of sharing the cache with IPv4.
  739          */
  740         if (ro) {
  741                 if (ro->ro_rt &&
  742                     (!(ro->ro_rt->rt_flags & RTF_UP) ||
  743                      ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
  744                      !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
  745                      dst))) {
  746                         RTFREE(ro->ro_rt);
  747                         ro->ro_rt = (struct rtentry *)NULL;
  748                 }
  749                 if (ro->ro_rt == (struct rtentry *)NULL) {
  750                         struct sockaddr_in6 *sa6;
  751 
  752                         /* No route yet, so try to acquire one */
  753                         bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
  754                         sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
  755                         *sa6 = *dstsock;
  756                         sa6->sin6_scope_id = 0;
  757 
  758 #ifdef RADIX_MPATH
  759                                 rtalloc_mpath_fib((struct route *)ro,
  760                                     ntohl(sa6->sin6_addr.s6_addr32[3]), fibnum);
  761 #else                   
  762                                 ro->ro_rt = in6_rtalloc1((struct sockaddr *)
  763                                     &ro->ro_dst, 0, 0UL, fibnum);
  764                                 if (ro->ro_rt)
  765                                         RT_UNLOCK(ro->ro_rt);
  766 #endif
  767                 }
  768                                 
  769                 /*
  770                  * do not care about the result if we have the nexthop
  771                  * explicitly specified.
  772                  */
  773                 if (opts && opts->ip6po_nexthop)
  774                         goto done;
  775 
  776                 if (ro->ro_rt) {
  777                         ifp = ro->ro_rt->rt_ifp;
  778 
  779                         if (ifp == NULL) { /* can this really happen? */
  780                                 RTFREE(ro->ro_rt);
  781                                 ro->ro_rt = NULL;
  782                         }
  783                 }
  784                 if (ro->ro_rt == NULL)
  785                         error = EHOSTUNREACH;
  786                 rt = ro->ro_rt;
  787 
  788                 /*
  789                  * Check if the outgoing interface conflicts with
  790                  * the interface specified by ipi6_ifindex (if specified).
  791                  * Note that loopback interface is always okay.
  792                  * (this may happen when we are sending a packet to one of
  793                  *  our own addresses.)
  794                  */
  795                 if (ifp && opts && opts->ip6po_pktinfo &&
  796                     opts->ip6po_pktinfo->ipi6_ifindex) {
  797                         if (!(ifp->if_flags & IFF_LOOPBACK) &&
  798                             ifp->if_index !=
  799                             opts->ip6po_pktinfo->ipi6_ifindex) {
  800                                 error = EHOSTUNREACH;
  801                                 goto done;
  802                         }
  803                 }
  804         }
  805 
  806   done:
  807         if (ifp == NULL && rt == NULL) {
  808                 /*
  809                  * This can happen if the caller did not pass a cached route
  810                  * nor any other hints.  We treat this case an error.
  811                  */
  812                 error = EHOSTUNREACH;
  813         }
  814         if (error == EHOSTUNREACH)
  815                 IP6STAT_INC(ip6s_noroute);
  816 
  817         if (retifp != NULL) {
  818                 *retifp = ifp;
  819 
  820                 /*
  821                  * Adjust the "outgoing" interface.  If we're going to loop 
  822                  * the packet back to ourselves, the ifp would be the loopback 
  823                  * interface. However, we'd rather know the interface associated 
  824                  * to the destination address (which should probably be one of 
  825                  * our own addresses.)
  826                  */
  827                 if (rt) {
  828                         if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) &&
  829                             (rt->rt_gateway->sa_family == AF_LINK))
  830                                 *retifp = 
  831                                         ifnet_byindex(((struct sockaddr_dl *)
  832                                                        rt->rt_gateway)->sdl_index);
  833                 }
  834         }
  835 
  836         if (retrt != NULL)
  837                 *retrt = rt;    /* rt may be NULL */
  838 
  839         return (error);
  840 }
  841 
  842 static int
  843 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
  844     struct ip6_moptions *mopts, struct ifnet **retifp,
  845     struct ifnet *oifp, u_int fibnum)
  846 {
  847         int error;
  848         struct route_in6 sro;
  849         struct rtentry *rt = NULL;
  850         int rt_flags;
  851 
  852         KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__));
  853 
  854         bzero(&sro, sizeof(sro));
  855         rt_flags = 0;
  856 
  857         error = selectroute(dstsock, opts, mopts, &sro, retifp, &rt, 1, fibnum);
  858 
  859         if (rt)
  860                 rt_flags = rt->rt_flags;
  861         if (rt && rt == sro.ro_rt)
  862                 RTFREE(rt);
  863 
  864         if (error != 0) {
  865                 /* Help ND. See oifp comment in in6_selectsrc(). */
  866                 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) {
  867                         *retifp = oifp;
  868                         error = 0;
  869                 }
  870                 return (error);
  871         }
  872 
  873         /*
  874          * do not use a rejected or black hole route.
  875          * XXX: this check should be done in the L2 output routine.
  876          * However, if we skipped this check here, we'd see the following
  877          * scenario:
  878          * - install a rejected route for a scoped address prefix
  879          *   (like fe80::/10)
  880          * - send a packet to a destination that matches the scoped prefix,
  881          *   with ambiguity about the scope zone.
  882          * - pick the outgoing interface from the route, and disambiguate the
  883          *   scope zone with the interface.
  884          * - ip6_output() would try to get another route with the "new"
  885          *   destination, which may be valid.
  886          * - we'd see no error on output.
  887          * Although this may not be very harmful, it should still be confusing.
  888          * We thus reject the case here.
  889          */
  890 
  891         if (rt_flags & (RTF_REJECT | RTF_BLACKHOLE)) {
  892                 error = (rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
  893                 return (error);
  894         }
  895 
  896         return (0);
  897 }
  898 
  899 /*
  900  * Public wrapper function to selectroute().
  901  *
  902  * XXX-BZ in6_selectroute() should and will grow the FIB argument. The
  903  * in6_selectroute_fib() function is only there for backward compat on stable.
  904  */
  905 int
  906 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
  907     struct ip6_moptions *mopts, struct route_in6 *ro,
  908     struct ifnet **retifp, struct rtentry **retrt)
  909 {
  910 
  911         return (selectroute(dstsock, opts, mopts, ro, retifp,
  912             retrt, 0, RT_DEFAULT_FIB));
  913 }
  914 
  915 #ifndef BURN_BRIDGES
  916 int
  917 in6_selectroute_fib(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
  918     struct ip6_moptions *mopts, struct route_in6 *ro,
  919     struct ifnet **retifp, struct rtentry **retrt, u_int fibnum)
  920 {
  921 
  922         return (selectroute(dstsock, opts, mopts, ro, retifp,
  923             retrt, 0, fibnum));
  924 }
  925 #endif
  926 
  927 /*
  928  * Default hop limit selection. The precedence is as follows:
  929  * 1. Hoplimit value specified via ioctl.
  930  * 2. (If the outgoing interface is detected) the current
  931  *     hop limit of the interface specified by router advertisement.
  932  * 3. The system default hoplimit.
  933  */
  934 int
  935 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp)
  936 {
  937 
  938         if (in6p && in6p->in6p_hops >= 0)
  939                 return (in6p->in6p_hops);
  940         else if (ifp)
  941                 return (ND_IFINFO(ifp)->chlim);
  942         else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
  943                 struct nhop6_basic nh6;
  944                 struct in6_addr dst;
  945                 uint32_t fibnum, scopeid;
  946                 int hlim;
  947 
  948                 fibnum = in6p->inp_inc.inc_fibnum;
  949                 in6_splitscope(&in6p->in6p_faddr, &dst, &scopeid);
  950                 if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6)==0){
  951                         hlim = ND_IFINFO(nh6.nh_ifp)->chlim;
  952                         return (hlim);
  953                 }
  954         }
  955         return (V_ip6_defhlim);
  956 }
  957 
  958 /*
  959  * XXX: this is borrowed from in6_pcbbind(). If possible, we should
  960  * share this function by all *bsd*...
  961  */
  962 int
  963 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
  964 {
  965         struct socket *so = inp->inp_socket;
  966         u_int16_t lport = 0;
  967         int error, lookupflags = 0;
  968 #ifdef INVARIANTS
  969         struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
  970 #endif
  971 
  972         INP_WLOCK_ASSERT(inp);
  973         INP_HASH_WLOCK_ASSERT(pcbinfo);
  974 
  975         error = prison_local_ip6(cred, laddr,
  976             ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0));
  977         if (error)
  978                 return(error);
  979 
  980         /* XXX: this is redundant when called from in6_pcbbind */
  981         if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
  982                 lookupflags = INPLOOKUP_WILDCARD;
  983 
  984         inp->inp_flags |= INP_ANONPORT;
  985 
  986         error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags);
  987         if (error != 0)
  988                 return (error);
  989 
  990         inp->inp_lport = lport;
  991         if (in_pcbinshash(inp) != 0) {
  992                 inp->in6p_laddr = in6addr_any;
  993                 inp->inp_lport = 0;
  994                 return (EAGAIN);
  995         }
  996 
  997         return (0);
  998 }
  999 
 1000 void
 1001 addrsel_policy_init(void)
 1002 {
 1003 
 1004         init_policy_queue();
 1005 
 1006         /* initialize the "last resort" policy */
 1007         bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy));
 1008         V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
 1009 
 1010         if (!IS_DEFAULT_VNET(curvnet))
 1011                 return;
 1012 
 1013         ADDRSEL_LOCK_INIT();
 1014         ADDRSEL_SXLOCK_INIT();
 1015 }
 1016 
 1017 static struct in6_addrpolicy *
 1018 lookup_addrsel_policy(struct sockaddr_in6 *key)
 1019 {
 1020         struct in6_addrpolicy *match = NULL;
 1021 
 1022         ADDRSEL_LOCK();
 1023         match = match_addrsel_policy(key);
 1024 
 1025         if (match == NULL)
 1026                 match = &V_defaultaddrpolicy;
 1027         else
 1028                 match->use++;
 1029         ADDRSEL_UNLOCK();
 1030 
 1031         return (match);
 1032 }
 1033 
 1034 /*
 1035  * Subroutines to manage the address selection policy table via sysctl.
 1036  */
 1037 struct walkarg {
 1038         struct sysctl_req *w_req;
 1039 };
 1040 
 1041 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
 1042 SYSCTL_DECL(_net_inet6_ip6);
 1043 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
 1044         CTLFLAG_RD, in6_src_sysctl, "");
 1045 
 1046 static int
 1047 in6_src_sysctl(SYSCTL_HANDLER_ARGS)
 1048 {
 1049         struct walkarg w;
 1050 
 1051         if (req->newptr)
 1052                 return EPERM;
 1053 
 1054         bzero(&w, sizeof(w));
 1055         w.w_req = req;
 1056 
 1057         return (walk_addrsel_policy(dump_addrsel_policyent, &w));
 1058 }
 1059 
 1060 int
 1061 in6_src_ioctl(u_long cmd, caddr_t data)
 1062 {
 1063         struct in6_addrpolicy ent0;
 1064 
 1065         if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
 1066                 return (EOPNOTSUPP); /* check for safety */
 1067 
 1068         ent0 = *(struct in6_addrpolicy *)data;
 1069 
 1070         if (ent0.label == ADDR_LABEL_NOTAPP)
 1071                 return (EINVAL);
 1072         /* check if the prefix mask is consecutive. */
 1073         if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
 1074                 return (EINVAL);
 1075         /* clear trailing garbages (if any) of the prefix address. */
 1076         IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr);
 1077         ent0.use = 0;
 1078 
 1079         switch (cmd) {
 1080         case SIOCAADDRCTL_POLICY:
 1081                 return (add_addrsel_policyent(&ent0));
 1082         case SIOCDADDRCTL_POLICY:
 1083                 return (delete_addrsel_policyent(&ent0));
 1084         }
 1085 
 1086         return (0);             /* XXX: compromise compilers */
 1087 }
 1088 
 1089 /*
 1090  * The followings are implementation of the policy table using a
 1091  * simple tail queue.
 1092  * XXX such details should be hidden.
 1093  * XXX implementation using binary tree should be more efficient.
 1094  */
 1095 struct addrsel_policyent {
 1096         TAILQ_ENTRY(addrsel_policyent) ape_entry;
 1097         struct in6_addrpolicy ape_policy;
 1098 };
 1099 
 1100 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
 1101 
 1102 static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab);
 1103 #define V_addrsel_policytab             VNET(addrsel_policytab)
 1104 
 1105 static void
 1106 init_policy_queue(void)
 1107 {
 1108 
 1109         TAILQ_INIT(&V_addrsel_policytab);
 1110 }
 1111 
 1112 static int
 1113 add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
 1114 {
 1115         struct addrsel_policyent *new, *pol;
 1116 
 1117         new = malloc(sizeof(*new), M_IFADDR,
 1118                M_WAITOK);
 1119         ADDRSEL_XLOCK();
 1120         ADDRSEL_LOCK();
 1121 
 1122         /* duplication check */
 1123         TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
 1124                 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
 1125                                        &pol->ape_policy.addr.sin6_addr) &&
 1126                     IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
 1127                                        &pol->ape_policy.addrmask.sin6_addr)) {
 1128                         ADDRSEL_UNLOCK();
 1129                         ADDRSEL_XUNLOCK();
 1130                         free(new, M_IFADDR);
 1131                         return (EEXIST);        /* or override it? */
 1132                 }
 1133         }
 1134 
 1135         bzero(new, sizeof(*new));
 1136 
 1137         /* XXX: should validate entry */
 1138         new->ape_policy = *newpolicy;
 1139 
 1140         TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry);
 1141         ADDRSEL_UNLOCK();
 1142         ADDRSEL_XUNLOCK();
 1143 
 1144         return (0);
 1145 }
 1146 
 1147 static int
 1148 delete_addrsel_policyent(struct in6_addrpolicy *key)
 1149 {
 1150         struct addrsel_policyent *pol;
 1151 
 1152         ADDRSEL_XLOCK();
 1153         ADDRSEL_LOCK();
 1154 
 1155         /* search for the entry in the table */
 1156         TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
 1157                 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
 1158                     &pol->ape_policy.addr.sin6_addr) &&
 1159                     IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
 1160                     &pol->ape_policy.addrmask.sin6_addr)) {
 1161                         break;
 1162                 }
 1163         }
 1164         if (pol == NULL) {
 1165                 ADDRSEL_UNLOCK();
 1166                 ADDRSEL_XUNLOCK();
 1167                 return (ESRCH);
 1168         }
 1169 
 1170         TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry);
 1171         ADDRSEL_UNLOCK();
 1172         ADDRSEL_XUNLOCK();
 1173         free(pol, M_IFADDR);
 1174 
 1175         return (0);
 1176 }
 1177 
 1178 static int
 1179 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
 1180 {
 1181         struct addrsel_policyent *pol;
 1182         int error = 0;
 1183 
 1184         ADDRSEL_SLOCK();
 1185         TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
 1186                 if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
 1187                         ADDRSEL_SUNLOCK();
 1188                         return (error);
 1189                 }
 1190         }
 1191         ADDRSEL_SUNLOCK();
 1192         return (error);
 1193 }
 1194 
 1195 static int
 1196 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
 1197 {
 1198         int error = 0;
 1199         struct walkarg *w = arg;
 1200 
 1201         error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
 1202 
 1203         return (error);
 1204 }
 1205 
 1206 static struct in6_addrpolicy *
 1207 match_addrsel_policy(struct sockaddr_in6 *key)
 1208 {
 1209         struct addrsel_policyent *pent;
 1210         struct in6_addrpolicy *bestpol = NULL, *pol;
 1211         int matchlen, bestmatchlen = -1;
 1212         u_char *mp, *ep, *k, *p, m;
 1213 
 1214         TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) {
 1215                 matchlen = 0;
 1216 
 1217                 pol = &pent->ape_policy;
 1218                 mp = (u_char *)&pol->addrmask.sin6_addr;
 1219                 ep = mp + 16;   /* XXX: scope field? */
 1220                 k = (u_char *)&key->sin6_addr;
 1221                 p = (u_char *)&pol->addr.sin6_addr;
 1222                 for (; mp < ep && *mp; mp++, k++, p++) {
 1223                         m = *mp;
 1224                         if ((*k & m) != *p)
 1225                                 goto next; /* not match */
 1226                         if (m == 0xff) /* short cut for a typical case */
 1227                                 matchlen += 8;
 1228                         else {
 1229                                 while (m >= 0x80) {
 1230                                         matchlen++;
 1231                                         m <<= 1;
 1232                                 }
 1233                         }
 1234                 }
 1235 
 1236                 /* matched.  check if this is better than the current best. */
 1237                 if (bestpol == NULL ||
 1238                     matchlen > bestmatchlen) {
 1239                         bestpol = pol;
 1240                         bestmatchlen = matchlen;
 1241                 }
 1242 
 1243           next:
 1244                 continue;
 1245         }
 1246 
 1247         return (bestpol);
 1248 }

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