/* $FreeBSD: src/sys/netinet6/in6_src.c,v 1.1.2.3 2002/02/26 18:02:06 ume Exp $ */ /* $KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 1982, 1986, 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94 */ #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef ENABLE_DEFAULT_SCOPE #include #endif #include #define ADDR_LABEL_NOTAPP (-1) struct in6_addrpolicy defaultaddrpolicy; static void init_policy_queue(void); static int add_addrsel_policyent(struct in6_addrpolicy *); static int delete_addrsel_policyent(struct in6_addrpolicy *); static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *), void *); static int dump_addrsel_policyent(struct in6_addrpolicy *, void *); /* * Return an IPv6 address, which is the most appropriate for a given * destination and user specified options. * If necessary, this function lookups the routing table and returns * an entry to the caller for later use. */ struct in6_addr * in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts, struct ip6_moptions *mopts, struct route_in6 *ro, struct in6_addr *laddr, int *errorp, struct thread *td) { struct sockaddr_in6 jsin6; struct ucred *cred = NULL; struct in6_addr *dst; struct in6_ifaddr *ia6 = NULL; struct in6_pktinfo *pi = NULL; int jailed = 0; if (td && td->td_proc && td->td_proc->p_ucred) cred = td->td_proc->p_ucred; if (cred && cred->cr_prison) jailed = 1; jsin6.sin6_family = AF_INET6; dst = &dstsock->sin6_addr; *errorp = 0; /* * If the source address is explicitly specified by the caller, * use it. */ if (opts && (pi = opts->ip6po_pktinfo) && !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) { jsin6.sin6_addr = pi->ipi6_addr; if (jailed && !jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) { return(0); } else { return (&pi->ipi6_addr); } } /* * If the source address is not specified but the socket(if any) * is already bound, use the bound address. */ if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr)) { jsin6.sin6_addr = *laddr; if (jailed && !jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) { return(0); } else { return (laddr); } } /* * If the caller doesn't specify the source address but * the outgoing interface, use an address associated with * the interface. */ if (pi && pi->ipi6_ifindex) { /* XXX boundary check is assumed to be already done. */ ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex], dst, cred); if (ia6 && jailed) { jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; if (!jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) ia6 = NULL; } if (ia6 == NULL) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } /* * If the destination address is a link-local unicast address or * a multicast address, and if the outgoing interface is specified * by the sin6_scope_id filed, use an address associated with the * interface. * XXX: We're now trying to define more specific semantics of * sin6_scope_id field, so this part will be rewritten in * the near future. */ if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) && dstsock->sin6_scope_id) { /* * I'm not sure if boundary check for scope_id is done * somewhere... */ if (dstsock->sin6_scope_id < 0 || if_index < dstsock->sin6_scope_id) { *errorp = ENXIO; /* XXX: better error? */ return (0); } ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id], dst, cred); if (ia6 && jailed) { jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; if (!jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) ia6 = NULL; } if (ia6 == NULL) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } /* * If the destination address is a multicast address and * the outgoing interface for the address is specified * by the caller, use an address associated with the interface. * There is a sanity check here; if the destination has node-local * scope, the outgoing interfacde should be a loopback address. * Even if the outgoing interface is not specified, we also * choose a loopback interface as the outgoing interface. */ if (!jailed && IN6_IS_ADDR_MULTICAST(dst)) { struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL; if (ifp == NULL && IN6_IS_ADDR_MC_INTFACELOCAL(dst)) { ifp = loif; } if (ifp) { ia6 = in6_ifawithscope(ifp, dst, cred); if (ia6 == NULL) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } } /* * If the next hop address for the packet is specified * by caller, use an address associated with the route * to the next hop. */ { struct sockaddr_in6 *sin6_next; struct rtentry *rt; if (opts && opts->ip6po_nexthop) { sin6_next = satosin6(opts->ip6po_nexthop); rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL); if (rt) { ia6 = in6_ifawithscope(rt->rt_ifp, dst, cred); if (ia6 == NULL) ia6 = ifatoia6(rt->rt_ifa); } if (ia6 && jailed) { jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; if (!jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) ia6 = NULL; } if (ia6 == NULL) { *errorp = EADDRNOTAVAIL; return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } } /* * If route is known or can be allocated now, * our src addr is taken from the i/f, else punt. */ if (ro) { if (ro->ro_rt && (!(ro->ro_rt->rt_flags & RTF_UP) || satosin6(&ro->ro_dst)->sin6_family != AF_INET6 || !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst))) { RTFREE(ro->ro_rt); ro->ro_rt = NULL; } if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) { struct sockaddr_in6 *sa6; /* No route yet, so try to acquire one */ bzero(&ro->ro_dst, sizeof(struct sockaddr_in6)); sa6 = &ro->ro_dst; sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(struct sockaddr_in6); sa6->sin6_addr = *dst; sa6->sin6_scope_id = dstsock->sin6_scope_id; if (!jailed && IN6_IS_ADDR_MULTICAST(dst)) { ro->ro_rt = rtpurelookup((struct sockaddr *)&ro->ro_dst); } else { rtalloc((struct route *)ro); } } /* * in_pcbconnect() checks out IFF_LOOPBACK to skip using * the address. But we don't know why it does so. * It is necessary to ensure the scope even for lo0 * so doesn't check out IFF_LOOPBACK. */ if (ro->ro_rt) { ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst, cred); if (ia6 && jailed) { jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; if (!jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) ia6 = NULL; } if (ia6 == NULL) /* xxx scope error ?*/ ia6 = ifatoia6(ro->ro_rt->rt_ifa); if (ia6 && jailed) { jsin6.sin6_addr = (&ia6->ia_addr)->sin6_addr; if (!jailed_ip(cred->cr_prison, (struct sockaddr *)&jsin6)) ia6 = NULL; } } if (ia6 == NULL) { *errorp = EHOSTUNREACH; /* no route */ return (0); } return (&satosin6(&ia6->ia_addr)->sin6_addr); } *errorp = EADDRNOTAVAIL; return (0); } /* * Default hop limit selection. The precedence is as follows: * 1. Hoplimit value specified via ioctl. * 2. (If the outgoing interface is detected) the current * hop limit of the interface specified by router advertisement. * 3. The system default hoplimit. */ int in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp) { int hlim; if (in6p && in6p->in6p_hops >= 0) { return (in6p->in6p_hops); } else if (ifp) { hlim = ND_IFINFO(ifp)->chlim; if (hlim < ip6_minhlim) hlim = ip6_minhlim; } else { hlim = ip6_defhlim; } return (hlim); } static boolean_t in6_pcbporthash_update(struct inpcbportinfo *portinfo, struct inpcb *inp, u_short lport, struct ucred *cred, int wild) { struct inpcbporthead *porthash; /* * This has to be atomic. If the porthash is shared across multiple * protocol threads, e.g. tcp and udp, then the token must be held. */ porthash = in_pcbporthash_head(portinfo, lport); GET_PORTHASH_TOKEN(porthash); if (in6_pcblookup_local(porthash, &inp->in6p_laddr, lport, wild, cred) != NULL) { REL_PORTHASH_TOKEN(porthash); return FALSE; } inp->inp_lport = lport; in_pcbinsporthash(porthash, inp); REL_PORTHASH_TOKEN(porthash); return TRUE; } /* * XXX: this is borrowed from in6_pcbbind(). If possible, we should * share this function by all *bsd*... */ int in6_pcbsetlport(struct in6_addr *laddr, struct inpcb *inp, struct thread *td) { struct socket *so = inp->inp_socket; uint16_t lport, first, last, step, first0, last0; int count, error = 0, wild = 0; struct inpcbinfo *pcbinfo = inp->inp_pcbinfo; struct inpcbportinfo *portinfo; struct ucred *cred = NULL; int portinfo_first, portinfo_idx; uint32_t cut; /* XXX: this is redundant when called from in6_pcbbind */ if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0) wild = INPLOOKUP_WILDCARD; if (td->td_proc && td->td_proc->p_ucred) cred = td->td_proc->p_ucred; inp->inp_flags |= INP_ANONPORT; step = pcbinfo->portinfo_cnt; portinfo_first = mycpuid % pcbinfo->portinfo_cnt; portinfo_idx = portinfo_first; if (inp->inp_flags & INP_HIGHPORT) { first0 = ipport_hifirstauto; /* sysctl */ last0 = ipport_hilastauto; } else if (inp->inp_flags & INP_LOWPORT) { if ((error = priv_check(td, PRIV_ROOT)) != 0) return error; first0 = ipport_lowfirstauto; /* 1023 */ last0 = ipport_lowlastauto; /* 600 */ } else { first0 = ipport_firstauto; /* sysctl */ last0 = ipport_lastauto; } if (first0 > last0) { lport = last0; last0 = first0; first0 = lport; } KKASSERT(last0 >= first0); cut = karc4random(); loop: portinfo = &pcbinfo->portinfo[portinfo_idx]; first = first0; last = last0; /* * Simple check to ensure all ports are not used up causing * a deadlock here. */ in_pcbportrange(&last, &first, portinfo->offset, step); lport = last - first; count = lport / step; lport = rounddown(cut % lport, step) + first; KKASSERT(lport % step == portinfo->offset); for (;;) { if (count-- < 0) { /* completely used? */ error = EAGAIN; break; } if (__predict_false(lport < first || lport > last)) { lport = first; KKASSERT(lport % step == portinfo->offset); } if (in6_pcbporthash_update(portinfo, inp, htons(lport), cred, wild)) { error = 0; break; } lport += step; KKASSERT(lport % step == portinfo->offset); } if (error) { /* Try next portinfo */ portinfo_idx++; portinfo_idx %= pcbinfo->portinfo_cnt; if (portinfo_idx != portinfo_first) goto loop; /* Undo any address bind that may have occurred above. */ inp->in6p_laddr = kin6addr_any; } return error; } /* * Generate kernel-internal form (scopeid embedded into s6_addr16[1]). * If the address scope of is link-local, embed the interface index in the * address. The routine determines our precedence * between advanced API scope/interface specification and basic API * specification. * * This function should be nuked in the future, when we get rid of embedded * scopeid thing. * * XXX actually, it is over-specification to return ifp against sin6_scope_id. * there can be multiple interfaces that belong to a particular scope zone * (in specification, we have 1:N mapping between a scope zone and interfaces). * we may want to change the function to return something other than ifp. */ int in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6, #ifdef HAVE_NRL_INPCB struct inpcb *in6p, #define in6p_outputopts inp_outputopts6 #define in6p_moptions inp_moptions6 #else struct in6pcb *in6p, #endif struct ifnet **ifpp) { struct ifnet *ifp = NULL; u_int32_t scopeid; *in6 = sin6->sin6_addr; scopeid = sin6->sin6_scope_id; if (ifpp) *ifpp = NULL; /* * don't try to read sin6->sin6_addr beyond here, since the caller may * ask us to overwrite existing sockaddr_in6 */ #ifdef ENABLE_DEFAULT_SCOPE if (scopeid == 0) scopeid = scope6_addr2default(in6); #endif if (IN6_IS_SCOPE_LINKLOCAL(in6)) { struct in6_pktinfo *pi; /* * KAME assumption: link id == interface id */ if (in6p && in6p->in6p_outputopts && (pi = in6p->in6p_outputopts->ip6po_pktinfo) && pi->ipi6_ifindex) { ifp = ifindex2ifnet[pi->ipi6_ifindex]; in6->s6_addr16[1] = htons(pi->ipi6_ifindex); } else if (in6p && IN6_IS_ADDR_MULTICAST(in6) && in6p->in6p_moptions && in6p->in6p_moptions->im6o_multicast_ifp) { ifp = in6p->in6p_moptions->im6o_multicast_ifp; in6->s6_addr16[1] = htons(ifp->if_index); } else if (scopeid) { /* boundary check */ if (scopeid < 0 || if_index < scopeid) return ENXIO; /* XXX EINVAL? */ ifp = ifindex2ifnet[scopeid]; /* XXX assignment to 16bit from 32bit variable */ in6->s6_addr16[1] = htons(scopeid & 0xffff); } if (ifpp) *ifpp = ifp; } return 0; } #ifdef HAVE_NRL_INPCB #undef in6p_outputopts #undef in6p_moptions #endif /* * generate standard sockaddr_in6 from embedded form. * touches sin6_addr and sin6_scope_id only. * * this function should be nuked in the future, when we get rid of * embedded scopeid thing. */ int in6_recoverscope(struct sockaddr_in6 *sin6, const struct in6_addr *in6, struct ifnet *ifp) { u_int32_t zoneid; sin6->sin6_addr = *in6; /* * don't try to read *in6 beyond here, since the caller may * ask us to overwrite existing sockaddr_in6 */ sin6->sin6_scope_id = 0; if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) { /* * KAME assumption: link id == interface id */ zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]); if (zoneid) { /* sanity check */ if (zoneid < 0 || if_index < zoneid) return ENXIO; if (ifp && ifp->if_index != zoneid) return ENXIO; sin6->sin6_addr.s6_addr16[1] = 0; sin6->sin6_scope_id = zoneid; } } return 0; } /* * just clear the embedded scope identifier. */ void in6_clearscope(struct in6_addr *addr) { if (IN6_IS_SCOPE_LINKLOCAL(addr) || IN6_IS_ADDR_MC_INTFACELOCAL(addr)) addr->s6_addr16[1] = 0; } void addrsel_policy_init(void) { init_policy_queue(); /* initialize the "last resort" policy */ bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy)); defaultaddrpolicy.label = ADDR_LABEL_NOTAPP; } /* * Subroutines to manage the address selection policy table via sysctl. */ struct walkarg { struct sysctl_req *w_req; }; static int in6_src_sysctl(SYSCTL_HANDLER_ARGS); SYSCTL_DECL(_net_inet6_ip6); SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy, CTLFLAG_RD, in6_src_sysctl, "Address selection policy"); static int in6_src_sysctl(SYSCTL_HANDLER_ARGS) { struct walkarg w; if (req->newptr) return EPERM; bzero(&w, sizeof(w)); w.w_req = req; return (walk_addrsel_policy(dump_addrsel_policyent, &w)); } int in6_src_ioctl(u_long cmd, caddr_t data) { int i; struct in6_addrpolicy ent0; if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) return (EOPNOTSUPP); /* check for safety */ ent0 = *(struct in6_addrpolicy *)data; if (ent0.label == ADDR_LABEL_NOTAPP) return (EINVAL); /* check if the prefix mask is consecutive. */ if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) return (EINVAL); /* clear trailing garbages (if any) of the prefix address. */ for (i = 0; i < 4; i++) { ent0.addr.sin6_addr.s6_addr32[i] &= ent0.addrmask.sin6_addr.s6_addr32[i]; } ent0.use = 0; switch (cmd) { case SIOCAADDRCTL_POLICY: return (add_addrsel_policyent(&ent0)); case SIOCDADDRCTL_POLICY: return (delete_addrsel_policyent(&ent0)); } return (0); /* XXX: compromise compilers */ } /* * The followings are implementation of the policy table using a * simple tail queue. * XXX such details should be hidden. * XXX implementation using binary tree should be more efficient. */ struct addrsel_policyent { TAILQ_ENTRY(addrsel_policyent) ape_entry; struct in6_addrpolicy ape_policy; }; TAILQ_HEAD(addrsel_policyhead, addrsel_policyent); struct addrsel_policyhead addrsel_policytab; static void init_policy_queue(void) { TAILQ_INIT(&addrsel_policytab); } static int add_addrsel_policyent(struct in6_addrpolicy *newpolicy) { struct addrsel_policyent *new, *pol; /* duplication check */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (SA6_ARE_ADDR_EQUAL(&newpolicy->addr, &pol->ape_policy.addr) && SA6_ARE_ADDR_EQUAL(&newpolicy->addrmask, &pol->ape_policy.addrmask)) { return (EEXIST); /* or override it? */ } } new = kmalloc(sizeof(*new), M_IFADDR, M_WAITOK | M_ZERO); /* XXX: should validate entry */ new->ape_policy = *newpolicy; TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry); return (0); } static int delete_addrsel_policyent(struct in6_addrpolicy *key) { struct addrsel_policyent *pol; /* search for the entry in the table */ for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if (SA6_ARE_ADDR_EQUAL(&key->addr, &pol->ape_policy.addr) && SA6_ARE_ADDR_EQUAL(&key->addrmask, &pol->ape_policy.addrmask)) { break; } } if (pol == NULL) return (ESRCH); TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry); kfree(pol, M_IFADDR); return (0); } static int walk_addrsel_policy(int(*callback)(struct in6_addrpolicy *, void *), void *w) { struct addrsel_policyent *pol; int error = 0; for (pol = TAILQ_FIRST(&addrsel_policytab); pol; pol = TAILQ_NEXT(pol, ape_entry)) { if ((error = (*callback)(&pol->ape_policy, w)) != 0) return (error); } return (error); } static int dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg) { int error = 0; struct walkarg *w = arg; error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol)); return (error); }