/* $OpenBSD: dns64_synth.c,v 1.1 2021/01/24 18:29:15 florian Exp $ */ /* * dns64/dns64.h - DNS64 module * * Copyright (c) 2009, Viagénie. All rights reserved. * * This software is open source. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 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. * * Neither the name of the NLNET LABS 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 COPYRIGHT HOLDERS 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. */ /* * Copyright (c) 2021 Florian Obser <florian@openbsd.org> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <net/route.h> #include <string.h> #include "libunbound/config.h" #include "libunbound/util/regional.h" #include "libunbound/util/data/msgencode.h" #include "libunbound/util/data/msgparse.h" #include "libunbound/util/data/msgreply.h" #include "log.h" #include "unwind.h" #include "frontend.h" #include "dns64_synth.h" extern struct dns64_prefix *dns64_prefixes; extern int dns64_prefix_count; static void synthesize_aaaa(const struct in6_addr *in6, int prefixlen, const uint8_t *a, size_t a_len, uint8_t *aaaa, size_t aaaa_len) { size_t i, pos; memcpy(aaaa, in6->s6_addr, sizeof(in6->s6_addr)); for (i = 0, pos = prefixlen / 8; i < a_len && pos < aaaa_len; i++, pos++) { if (pos == 8) aaaa[pos++] = 0; aaaa[pos] = a[i]; } } /* * Copied from unbound/dns64/dns64.c and slightly extended to work with more * than one IPv6 prefix. */ void dns64_synth_aaaa_data(const struct ub_packed_rrset_key* fk, const struct packed_rrset_data* fd, struct ub_packed_rrset_key *dk, struct packed_rrset_data **dd_out, struct regional *region) { struct packed_rrset_data *dd; size_t i, pos; int j; /* * Create synthesized AAAA RR set data. We need to allocated extra * memory for the RRs themselves. Each RR has a length, TTL, pointer to * wireformat data, 2 bytes of data length, and 16 bytes of IPv6 * address. */ if(fd->count > RR_COUNT_MAX) { *dd_out = NULL; return; /* integer overflow protection in alloc */ } if (!(dd = *dd_out = regional_alloc(region, sizeof(struct packed_rrset_data) + fd->count * dns64_prefix_count * (sizeof(size_t) + sizeof(time_t) + sizeof(uint8_t*) + 2 + 16)))) { log_warnx("out of memory"); return; } /* Copy attributes from A RR set. */ dd->ttl = fd->ttl; dd->count = fd->count * dns64_prefix_count; dd->rrsig_count = 0; dd->trust = fd->trust; dd->security = fd->security; /* Synthesize AAAA records. Adjust pointers in structure. */ dd->rr_len = (size_t*)((uint8_t*)dd + sizeof(struct packed_rrset_data)); dd->rr_data = (uint8_t**)&dd->rr_len[dd->count]; dd->rr_ttl = (time_t*)&dd->rr_data[dd->count]; for(i = 0, pos = 0; i < fd->count; ++i) { if (fd->rr_len[i] != 6 || fd->rr_data[i][0] != 0 || fd->rr_data[i][1] != 4) { *dd_out = NULL; return; } for (j = 0; j < dns64_prefix_count; j++, pos++) { dd->rr_len[pos] = 18; dd->rr_ttl[pos] = fd->rr_ttl[i]; dd->rr_data[pos] = (uint8_t*)&dd->rr_ttl[dd->count] + 18 * pos; dd->rr_data[pos][0] = 0; dd->rr_data[pos][1] = 16; synthesize_aaaa(&dns64_prefixes[j].in6, dns64_prefixes[j].prefixlen, &fd->rr_data[i][2], fd->rr_len[i]-2, &dd->rr_data[pos][2], dd->rr_len[pos]-2); } } /* * Create synthesized AAAA RR set key. This is mostly just bookkeeping, * nothing interesting here. */ if(!dk) { log_warnx("no key"); *dd_out = NULL; return; } dk->rk.dname = (uint8_t*)regional_alloc_init(region, fk->rk.dname, fk->rk.dname_len); if(!dk->rk.dname) { log_warnx("out of memory"); *dd_out = NULL; return; } dk->rk.type = htons(LDNS_RR_TYPE_AAAA); memset(&dk->entry, 0, sizeof(dk->entry)); dk->entry.key = dk; dk->entry.hash = rrset_key_hash(&dk->rk); dk->entry.data = dd; }
