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Diffstat (limited to '')
-rw-r--r-- | lib/irs/getnameinfo.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/lib/irs/getnameinfo.c b/lib/irs/getnameinfo.c new file mode 100644 index 0000000..62c7cea --- /dev/null +++ b/lib/irs/getnameinfo.c @@ -0,0 +1,438 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/*! \file */ + +/* + * 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. + */ + +/** + * getnameinfo() returns the hostname for the struct sockaddr sa which is + * salen bytes long. The hostname is of length hostlen and is returned via + * *host. The maximum length of the hostname is 1025 bytes: #NI_MAXHOST. + * + * The name of the service associated with the port number in sa is + * returned in *serv. It is servlen bytes long. The maximum length of the + * service name is #NI_MAXSERV - 32 bytes. + * + * The flags argument sets the following bits: + * + * \li #NI_NOFQDN: + * A fully qualified domain name is not required for local hosts. + * The local part of the fully qualified domain name is returned + * instead. + * + * \li #NI_NUMERICHOST + * Return the address in numeric form, as if calling inet_ntop(), + * instead of a host name. + * + * \li #NI_NAMEREQD + * A name is required. If the hostname cannot be found in the DNS + * and this flag is set, a non-zero error code is returned. If the + * hostname is not found and the flag is not set, the address is + * returned in numeric form. + * + * \li #NI_NUMERICSERV + * The service name is returned as a digit string representing the + * port number. + * + * \li #NI_DGRAM + * Specifies that the service being looked up is a datagram + * service, and causes getservbyport() to be called with a second + * argument of "udp" instead of its default of "tcp". This is + * required for the few ports (512-514) that have different + * services for UDP and TCP. + * + * \section getnameinfo_return Return Values + * + * getnameinfo() returns 0 on success or a non-zero error code if + * an error occurs. + * + * \section getname_see See Also + * + * RFC3493, getservbyport(), + * getnamebyaddr(). inet_ntop(). + */ + +#include <stdbool.h> +#include <stdio.h> +#include <string.h> + +#include <isc/netaddr.h> +#include <isc/print.h> +#include <isc/sockaddr.h> +#include <isc/string.h> +#include <isc/util.h> + +#include <dns/byaddr.h> +#include <dns/client.h> +#include <dns/fixedname.h> +#include <dns/name.h> +#include <dns/rdata.h> +#include <dns/rdataset.h> +#include <dns/rdatastruct.h> +#include <dns/result.h> + +#include <irs/context.h> +#include <irs/netdb.h> + +#define SUCCESS 0 + +/*% afd structure definition */ +static struct afd { + int a_af; + size_t a_addrlen; + size_t a_socklen; +} afdl[] = { + /*! + * First entry is linked last... + */ + { AF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in) }, + { AF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6) }, + { 0, 0, 0 }, +}; + +/*! + * The test against 0 is there to keep the Solaris compiler + * from complaining about "end-of-loop code not reached". + */ +#define ERR(code) \ + do { \ + result = (code); \ + if (result != 0) \ + goto cleanup; \ + } while (0) + +#ifdef _WIN32 +int +getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, + DWORD hostlen, char *serv, DWORD servlen, int flags) { +#else +int +getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, + socklen_t hostlen, char *serv, socklen_t servlen, int flags) { +#endif + struct afd *afd = NULL; + struct servent *sp; + unsigned short port = 0; +#ifdef IRS_PLATFORM_HAVESALEN + size_t len; +#endif /* ifdef IRS_PLATFORM_HAVESALEN */ + int family, i; + const void *addr = NULL; + char *p; +#if 0 + unsigned long v4a; + unsigned char pfx; +#endif /* if 0 */ + char numserv[sizeof("65000")]; + char numaddr[sizeof("abcd:abcd:abcd:abcd:abcd:abcd:255.255.255.255") + + 1 + sizeof("4294967295")]; + const char *proto; + int result = SUCCESS; + + if (sa == NULL) { + ERR(EAI_FAIL); + } + +#ifdef IRS_PLATFORM_HAVESALEN + len = sa->sa_len; + if (len != salen) { + ERR(EAI_FAIL); + } +#endif /* ifdef IRS_PLATFORM_HAVESALEN */ + + family = sa->sa_family; + for (i = 0; afdl[i].a_af; i++) { + if (afdl[i].a_af == family) { + { + afd = &afdl[i]; + goto found; + } + } + } + ERR(EAI_FAMILY); + +found: + if (salen != afd->a_socklen) { + ERR(EAI_FAIL); + } + + switch (family) { + case AF_INET: + port = ((const struct sockaddr_in *)sa)->sin_port; + addr = &((const struct sockaddr_in *)sa)->sin_addr.s_addr; + break; + + case AF_INET6: + port = ((const struct sockaddr_in6 *)sa)->sin6_port; + addr = ((const struct sockaddr_in6 *)sa)->sin6_addr.s6_addr; + break; + + default: + UNREACHABLE(); + } + proto = ((flags & NI_DGRAM) != 0) ? "udp" : "tcp"; + + if (serv == NULL || servlen == 0U) { + /* + * Caller does not want service. + */ + } else if ((flags & NI_NUMERICSERV) != 0 || + (sp = getservbyport(port, proto)) == NULL) + { + snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); + if ((strlen(numserv) + 1) > servlen) { + ERR(EAI_OVERFLOW); + } + strlcpy(serv, numserv, servlen); + } else { + if ((strlen(sp->s_name) + 1) > servlen) { + ERR(EAI_OVERFLOW); + } + strlcpy(serv, sp->s_name, servlen); + } + +#if 0 + switch (sa->sa_family) { + case AF_INET: + v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr; + if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) { + flags |= NI_NUMERICHOST; + } + v4a >>= IN_CLASSA_NSHIFT; + if (v4a == 0 || v4a == IN_LOOPBACKNET) { + flags |= NI_NUMERICHOST; + } + break; + + case AF_INET6: + pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0]; + if (pfx == 0 || pfx == 0xfe || pfx == 0xff) { + flags |= NI_NUMERICHOST; + } + break; + } +#endif /* if 0 */ + + if (host == NULL || hostlen == 0U) { + /* + * do nothing in this case. + * in case you are wondering if "&&" is more correct than + * "||" here: RFC3493 says that host == NULL or hostlen == 0 + * means that the caller does not want the result. + */ + } else if ((flags & NI_NUMERICHOST) != 0) { + if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) == + NULL) + { + ERR(EAI_SYSTEM); + } +#if defined(IRS_HAVE_SIN6_SCOPE_ID) + if (afd->a_af == AF_INET6 && + ((const struct sockaddr_in6 *)sa)->sin6_scope_id) + { + char *p = numaddr + strlen(numaddr); + const char *stringscope = NULL; +#ifdef VENDOR_SPECIFIC + /* + * Vendors may want to add support for + * non-numeric scope identifier. + */ + stringscope = foo; +#endif /* ifdef VENDOR_SPECIFIC */ + if (stringscope == NULL) { + snprintf(p, sizeof(numaddr) - (p - numaddr), + "%%%u", + ((const struct sockaddr_in6 *)sa) + ->sin6_scope_id); + } else { + snprintf(p, sizeof(numaddr) - (p - numaddr), + "%%%s", stringscope); + } + } +#endif /* if defined(IRS_HAVE_SIN6_SCOPE_ID) */ + if (strlen(numaddr) + 1 > hostlen) { + ERR(EAI_OVERFLOW); + } + strlcpy(host, numaddr, hostlen); + } else { + isc_netaddr_t netaddr; + dns_fixedname_t ptrfname; + dns_name_t *ptrname; + irs_context_t *irsctx = NULL; + dns_client_t *client; + bool found = false; + dns_namelist_t answerlist; + dns_rdataset_t *rdataset; + isc_region_t hostregion; + char hoststr[1024]; /* is this enough? */ + isc_result_t iresult; + + /* Get IRS context and the associated DNS client object */ + iresult = irs_context_get(&irsctx); + if (iresult != ISC_R_SUCCESS) { + ERR(EAI_FAIL); + } + client = irs_context_getdnsclient(irsctx); + + /* Make query name */ + isc_netaddr_fromsockaddr(&netaddr, (const isc_sockaddr_t *)sa); + ptrname = dns_fixedname_initname(&ptrfname); + iresult = dns_byaddr_createptrname(&netaddr, 0, ptrname); + if (iresult != ISC_R_SUCCESS) { + ERR(EAI_FAIL); + } + + /* Get the PTR RRset */ + ISC_LIST_INIT(answerlist); + iresult = dns_client_resolve(client, ptrname, dns_rdataclass_in, + dns_rdatatype_ptr, 0, &answerlist); + switch (iresult) { + case ISC_R_SUCCESS: + /* + * a 'non-existent' error is not necessarily fatal for + * getnameinfo(). + */ + case DNS_R_NCACHENXDOMAIN: + case DNS_R_NCACHENXRRSET: + break; + case DNS_R_SIGINVALID: + case DNS_R_SIGEXPIRED: + case DNS_R_SIGFUTURE: + case DNS_R_KEYUNAUTHORIZED: + case DNS_R_MUSTBESECURE: + case DNS_R_COVERINGNSEC: + case DNS_R_NOTAUTHORITATIVE: + case DNS_R_NOVALIDKEY: + case DNS_R_NOVALIDDS: + case DNS_R_NOVALIDSIG: + /* + * Don't use ERR as GCC 7 wants to raise a + * warning with ERR about possible falling + * through which is impossible. + */ + result = EAI_INSECUREDATA; + goto cleanup; + default: + ERR(EAI_FAIL); + } + + /* Parse the answer for the hostname */ + for (ptrname = ISC_LIST_HEAD(answerlist); ptrname != NULL; + ptrname = ISC_LIST_NEXT(ptrname, link)) + { + for (rdataset = ISC_LIST_HEAD(ptrname->list); + rdataset != NULL; + rdataset = ISC_LIST_NEXT(rdataset, link)) + { + if (!dns_rdataset_isassociated(rdataset)) { + continue; + } + if (rdataset->type != dns_rdatatype_ptr) { + continue; + } + + for (iresult = dns_rdataset_first(rdataset); + iresult == ISC_R_SUCCESS; + iresult = dns_rdataset_next(rdataset)) + { + dns_rdata_t rdata; + dns_rdata_ptr_t rdata_ptr; + isc_buffer_t b; + + dns_rdata_init(&rdata); + dns_rdataset_current(rdataset, &rdata); + dns_rdata_tostruct(&rdata, &rdata_ptr, + NULL); + + isc_buffer_init(&b, hoststr, + sizeof(hoststr)); + iresult = dns_name_totext( + &rdata_ptr.ptr, true, &b); + dns_rdata_freestruct(&rdata_ptr); + if (iresult == ISC_R_SUCCESS) { + /* + * We ignore the rest of the + * answer. After all, + * getnameinfo() can return + * at most one hostname. + */ + found = true; + isc_buffer_usedregion( + &b, &hostregion); + goto ptrfound; + } + } + } + } + ptrfound: + dns_client_freeresanswer(client, &answerlist); + if (found) { + if ((flags & NI_NOFQDN) != 0) { + p = strchr(hoststr, '.'); + if (p) { + *p = '\0'; + } + } + if (hostregion.length + 1 > hostlen) { + ERR(EAI_OVERFLOW); + } + snprintf(host, hostlen, "%.*s", (int)hostregion.length, + (char *)hostregion.base); + } else { + if ((flags & NI_NAMEREQD) != 0) { + ERR(EAI_NONAME); + } + if (inet_ntop(afd->a_af, addr, numaddr, + sizeof(numaddr)) == NULL) + { + ERR(EAI_SYSTEM); + } + if ((strlen(numaddr) + 1) > hostlen) { + ERR(EAI_OVERFLOW); + } + strlcpy(host, numaddr, hostlen); + } + } + result = SUCCESS; + +cleanup: + return (result); +} |