793 lines
27 KiB
C++
793 lines
27 KiB
C++
/* $NetBSD: gethnamaddr.c,v 1.91 2014/06/19 15:08:18 christos Exp $ */
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/*
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* ++Copyright++ 1985, 1988, 1993
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* -
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* Copyright (c) 1985, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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* -
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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* -
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* --Copyright--
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*/
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#include "gethnamaddr.h"
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#include <android-base/logging.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <assert.h>
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#include <ctype.h>
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#include <errno.h>
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#include <netdb.h>
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#include <netinet/in.h>
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#include <stdarg.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <unistd.h>
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#include <functional>
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#include <vector>
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#include "hostent.h"
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#include "netd_resolv/resolv.h"
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#include "res_comp.h"
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#include "res_debug.h" // p_class(), p_type()
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#include "resolv_cache.h"
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#include "resolv_private.h"
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#include "stats.pb.h"
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using android::net::NetworkDnsEventReported;
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// NetBSD uses _DIAGASSERT to null-check arguments and the like,
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// but it's clear from the number of mistakes in their assertions
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// that they don't actually test or ship with this.
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#define _DIAGASSERT(e) /* nothing */
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// TODO: unify macro ALIGNBYTES and ALIGN for all possible data type alignment of hostent
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// buffer.
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#define ALIGNBYTES (sizeof(uintptr_t) - 1)
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#define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) & ~ALIGNBYTES)
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constexpr int MAXADDRS = 35;
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typedef union {
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HEADER hdr;
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uint8_t buf[MAXPACKET];
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} querybuf;
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typedef union {
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int32_t al;
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char ac;
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} align;
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static void convert_v4v6_hostent(struct hostent* hp, char** bpp, char* ep,
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const std::function<void(struct hostent* hp)>& mapping_param,
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const std::function<void(char* src, char* dst)>& mapping_addr);
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static void pad_v4v6_hostent(struct hostent* hp, char** bpp, char* ep);
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static int dns_gethtbyaddr(const unsigned char* uaddr, int len, int af,
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const android_net_context* netcontext, getnamaddr* info,
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NetworkDnsEventReported* event);
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static int dns_gethtbyname(ResState* res, const char* name, int af, getnamaddr* info);
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#define BOUNDED_INCR(x) \
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do { \
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BOUNDS_CHECK(cp, x); \
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cp += (x); \
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} while (0)
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#define BOUNDS_CHECK(ptr, count) \
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do { \
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if (eom - (ptr) < (count)) goto no_recovery; \
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} while (0)
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static struct hostent* getanswer(const querybuf* answer, int anslen, const char* qname, int qtype,
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struct hostent* hent, char* buf, size_t buflen, int* he) {
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const HEADER* hp;
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const uint8_t* cp;
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int n;
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size_t qlen;
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const uint8_t *eom, *erdata;
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char *bp, **hap, *ep;
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int ancount, qdcount;
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int haveanswer, had_error;
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int toobig = 0;
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char tbuf[MAXDNAME];
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char* addr_ptrs[MAXADDRS];
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const char* tname;
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std::vector<char*> aliases;
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_DIAGASSERT(answer != NULL);
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_DIAGASSERT(qname != NULL);
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tname = qname;
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hent->h_name = NULL;
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eom = answer->buf + anslen;
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bool (*name_ok)(const char* dn);
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switch (qtype) {
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case T_A:
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case T_AAAA:
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name_ok = res_hnok;
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break;
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case T_PTR:
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name_ok = res_dnok;
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break;
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default:
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*he = NO_RECOVERY;
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return NULL; /* XXX should be abort(); */
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}
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/*
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* find first satisfactory answer
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*/
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hp = &answer->hdr;
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ancount = ntohs(hp->ancount);
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qdcount = ntohs(hp->qdcount);
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bp = buf;
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ep = buf + buflen;
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cp = answer->buf;
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BOUNDED_INCR(HFIXEDSZ);
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if (qdcount != 1) goto no_recovery;
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n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp));
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if ((n < 0) || !name_ok(bp)) goto no_recovery;
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BOUNDED_INCR(n + QFIXEDSZ);
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if (qtype == T_A || qtype == T_AAAA) {
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/* res_send() has already verified that the query name is the
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* same as the one we sent; this just gets the expanded name
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* (i.e., with the succeeding search-domain tacked on).
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*/
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n = (int) strlen(bp) + 1; /* for the \0 */
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if (n >= MAXHOSTNAMELEN) goto no_recovery;
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hent->h_name = bp;
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bp += n;
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/* The qname can be abbreviated, but h_name is now absolute. */
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qname = hent->h_name;
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}
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hent->h_addr_list = hap = addr_ptrs;
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*hap = NULL;
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haveanswer = 0;
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had_error = 0;
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while (ancount-- > 0 && cp < eom && !had_error) {
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n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp));
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if ((n < 0) || !name_ok(bp)) {
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had_error++;
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continue;
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}
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cp += n; /* name */
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BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
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int type = ntohs(*reinterpret_cast<const uint16_t*>(cp));
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cp += INT16SZ; /* type */
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int cl = ntohs(*reinterpret_cast<const uint16_t*>(cp));
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cp += INT16SZ + INT32SZ; /* class, TTL */
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n = ntohs(*reinterpret_cast<const uint16_t*>(cp));
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cp += INT16SZ; /* len */
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BOUNDS_CHECK(cp, n);
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erdata = cp + n;
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if (cl != C_IN) {
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/* XXX - debug? syslog? */
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
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n = dn_expand(answer->buf, eom, cp, tbuf, (int) sizeof tbuf);
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if ((n < 0) || !name_ok(tbuf)) {
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had_error++;
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continue;
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}
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cp += n;
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if (cp != erdata) goto no_recovery;
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/* Store alias. */
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aliases.push_back(bp);
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n = (int) strlen(bp) + 1; /* for the \0 */
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if (n >= MAXHOSTNAMELEN) {
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had_error++;
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continue;
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}
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bp += n;
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/* Get canonical name. */
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n = (int) strlen(tbuf) + 1; /* for the \0 */
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if (n > ep - bp || n >= MAXHOSTNAMELEN) {
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had_error++;
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continue;
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}
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strlcpy(bp, tbuf, (size_t)(ep - bp));
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hent->h_name = bp;
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bp += n;
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continue;
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}
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if (qtype == T_PTR && type == T_CNAME) {
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n = dn_expand(answer->buf, eom, cp, tbuf, (int) sizeof tbuf);
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if (n < 0 || !res_dnok(tbuf)) {
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had_error++;
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continue;
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}
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cp += n;
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if (cp != erdata) goto no_recovery;
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/* Get canonical name. */
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n = (int) strlen(tbuf) + 1; /* for the \0 */
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if (n > ep - bp || n >= MAXHOSTNAMELEN) {
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had_error++;
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continue;
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}
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strlcpy(bp, tbuf, (size_t)(ep - bp));
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tname = bp;
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bp += n;
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continue;
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}
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if (type != qtype) {
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if (type != T_KEY && type != T_SIG)
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LOG(DEBUG) << __func__ << ": asked for \"" << qname << " " << p_class(C_IN) << " "
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<< p_type(qtype) << "\", got type \"" << p_type(type) << "\"";
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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switch (type) {
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case T_PTR:
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if (strcasecmp(tname, bp) != 0) {
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LOG(DEBUG) << __func__ << ": asked for \"" << qname << "\", got \"" << bp
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<< "\"";
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp));
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if ((n < 0) || !res_hnok(bp)) {
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had_error++;
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break;
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}
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cp += n;
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if (cp != erdata) goto no_recovery;
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if (!haveanswer)
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hent->h_name = bp;
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else
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aliases.push_back(bp);
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if (n != -1) {
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n = (int) strlen(bp) + 1; /* for the \0 */
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if (n >= MAXHOSTNAMELEN) {
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had_error++;
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break;
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}
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bp += n;
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}
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break;
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case T_A:
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case T_AAAA:
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if (strcasecmp(hent->h_name, bp) != 0) {
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LOG(DEBUG) << __func__ << ": asked for \"" << hent->h_name << "\", got \"" << bp
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<< "\"";
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cp += n;
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continue; /* XXX - had_error++ ? */
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}
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if (n != hent->h_length) {
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cp += n;
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continue;
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}
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if (type == T_AAAA) {
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struct in6_addr in6;
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memcpy(&in6, cp, NS_IN6ADDRSZ);
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if (IN6_IS_ADDR_V4MAPPED(&in6)) {
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cp += n;
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continue;
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}
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}
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if (!haveanswer) {
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int nn;
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hent->h_name = bp;
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nn = (int) strlen(bp) + 1; /* for the \0 */
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bp += nn;
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}
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bp += sizeof(align) - (size_t)((uintptr_t)bp % sizeof(align));
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if (bp + n >= ep) {
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LOG(DEBUG) << __func__ << ": size (" << n << ") too big";
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had_error++;
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continue;
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}
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if (hap >= &addr_ptrs[MAXADDRS - 1]) {
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if (!toobig++) {
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LOG(DEBUG) << __func__ << ": Too many addresses (" << MAXADDRS << ")";
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}
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cp += n;
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continue;
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}
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(void) memcpy(*hap++ = bp, cp, (size_t) n);
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bp += n;
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cp += n;
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if (cp != erdata) goto no_recovery;
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break;
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default:
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abort();
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}
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if (!had_error) haveanswer++;
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}
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if (haveanswer) {
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*hap = NULL;
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if (!hent->h_name) {
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n = (int) strlen(qname) + 1; /* for the \0 */
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if (n > ep - bp || n >= MAXHOSTNAMELEN) goto no_recovery;
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strlcpy(bp, qname, (size_t)(ep - bp));
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hent->h_name = bp;
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bp += n;
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}
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if (hent->h_addrtype == AF_INET) pad_v4v6_hostent(hent, &bp, ep);
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goto success;
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}
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no_recovery:
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*he = NO_RECOVERY;
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return NULL;
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success:
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bp = (char*) ALIGN(bp);
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aliases.push_back(nullptr);
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qlen = aliases.size() * sizeof(*hent->h_aliases);
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if ((size_t)(ep - bp) < qlen) goto nospc;
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hent->h_aliases = (char**) bp;
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memcpy(bp, aliases.data(), qlen);
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bp += qlen;
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n = (int) (hap - addr_ptrs);
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qlen = (n + 1) * sizeof(*hent->h_addr_list);
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if ((size_t)(ep - bp) < qlen) goto nospc;
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hent->h_addr_list = (char**) bp;
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memcpy(bp, addr_ptrs, qlen);
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*he = NETDB_SUCCESS;
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return hent;
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nospc:
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errno = ENOSPC;
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*he = NETDB_INTERNAL;
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return NULL;
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}
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int resolv_gethostbyname(const char* name, int af, hostent* hp, char* buf, size_t buflen,
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const android_net_context* netcontext, hostent** result,
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NetworkDnsEventReported* event) {
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if (name == nullptr || hp == nullptr) {
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return EAI_SYSTEM;
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}
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getnamaddr info;
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ResState res(netcontext, event);
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size_t size;
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switch (af) {
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case AF_INET:
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size = NS_INADDRSZ;
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break;
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case AF_INET6:
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size = NS_IN6ADDRSZ;
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break;
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default:
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return EAI_FAMILY;
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}
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if (buflen < size) goto nospc;
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hp->h_addrtype = af;
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hp->h_length = (int) size;
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/*
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* disallow names consisting only of digits/dots, unless
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* they end in a dot.
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*/
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if (isdigit((uint8_t)name[0])) {
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for (const char* cp = name;; ++cp) {
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if (!*cp) {
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if (*--cp == '.') break;
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/*
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* All-numeric, no dot at the end.
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* Fake up a hostent as if we'd actually
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* done a lookup.
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*/
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goto fake;
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}
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if (!isdigit((uint8_t)*cp) && *cp != '.') break;
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}
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}
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if ((isxdigit((uint8_t)name[0]) && strchr(name, ':') != NULL) || name[0] == ':') {
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for (const char* cp = name;; ++cp) {
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if (!*cp) {
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if (*--cp == '.') break;
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/*
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* All-IPv6-legal, no dot at the end.
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* Fake up a hostent as if we'd actually
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* done a lookup.
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*/
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goto fake;
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}
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if (!isxdigit((uint8_t)*cp) && *cp != ':' && *cp != '.') break;
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}
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}
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info.hp = hp;
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info.buf = buf;
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info.buflen = buflen;
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if (_hf_gethtbyname2(name, af, &info)) {
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int error = dns_gethtbyname(&res, name, af, &info);
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if (error != 0) return error;
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}
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*result = hp;
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return 0;
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nospc:
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return EAI_MEMORY;
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fake:
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HENT_ARRAY(hp->h_addr_list, 1, buf, buflen);
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HENT_ARRAY(hp->h_aliases, 0, buf, buflen);
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hp->h_aliases[0] = NULL;
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if (size > buflen) goto nospc;
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if (inet_pton(af, name, buf) <= 0) {
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return EAI_NODATA;
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}
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hp->h_addr_list[0] = buf;
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hp->h_addr_list[1] = NULL;
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buf += size;
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buflen -= size;
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HENT_SCOPY(hp->h_name, name, buf, buflen);
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*result = hp;
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return 0;
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}
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int resolv_gethostbyaddr(const void* addr, socklen_t len, int af, hostent* hp, char* buf,
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size_t buflen, const struct android_net_context* netcontext,
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hostent** result, NetworkDnsEventReported* event) {
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const uint8_t* uaddr = (const uint8_t*)addr;
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socklen_t size;
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struct getnamaddr info;
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_DIAGASSERT(addr != NULL);
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if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
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(IN6_IS_ADDR_LINKLOCAL((const struct in6_addr*) addr) ||
|
|
IN6_IS_ADDR_SITELOCAL((const struct in6_addr*) addr))) {
|
|
return EAI_NODATA;
|
|
}
|
|
if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
|
|
(IN6_IS_ADDR_V4MAPPED((const struct in6_addr*) addr) ||
|
|
IN6_IS_ADDR_V4COMPAT((const struct in6_addr*) addr))) {
|
|
/* Unmap. */
|
|
uaddr += NS_IN6ADDRSZ - NS_INADDRSZ;
|
|
addr = uaddr;
|
|
af = AF_INET;
|
|
len = NS_INADDRSZ;
|
|
}
|
|
switch (af) {
|
|
case AF_INET:
|
|
size = NS_INADDRSZ;
|
|
break;
|
|
case AF_INET6:
|
|
size = NS_IN6ADDRSZ;
|
|
break;
|
|
default:
|
|
return EAI_FAMILY;
|
|
}
|
|
if (size != len) {
|
|
// TODO: Consider converting to a private extended EAI_* error code.
|
|
// Currently, the EAI_* value has no corresponding error code for invalid argument socket
|
|
// length. In order to not rely on errno, convert the original error code pair, EAI_SYSTEM
|
|
// and EINVAL, to EAI_FAIL.
|
|
return EAI_FAIL;
|
|
}
|
|
info.hp = hp;
|
|
info.buf = buf;
|
|
info.buflen = buflen;
|
|
if (_hf_gethtbyaddr(uaddr, len, af, &info)) {
|
|
int error = dns_gethtbyaddr(uaddr, len, af, netcontext, &info, event);
|
|
if (error != 0) return error;
|
|
}
|
|
*result = hp;
|
|
return 0;
|
|
}
|
|
|
|
// TODO: Consider leaving function without returning error code as _gethtent() does because
|
|
// the error code of the caller does not currently return to netd.
|
|
struct hostent* netbsd_gethostent_r(FILE* hf, struct hostent* hent, char* buf, size_t buflen,
|
|
int* he) {
|
|
char *name;
|
|
char* cp;
|
|
int af, len;
|
|
size_t anum;
|
|
struct in6_addr host_addr;
|
|
std::vector<char*> aliases;
|
|
|
|
if (hf == NULL) {
|
|
*he = NETDB_INTERNAL;
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
char* p = NULL;
|
|
|
|
// Allocate a new space to read file lines like upstream does.
|
|
const size_t line_buf_size = MAXPACKET;
|
|
if ((p = (char*) malloc(line_buf_size)) == NULL) {
|
|
goto nospc;
|
|
}
|
|
for (;;) {
|
|
if (!fgets(p, line_buf_size, hf)) {
|
|
free(p);
|
|
*he = HOST_NOT_FOUND;
|
|
return NULL;
|
|
}
|
|
if (*p == '#') {
|
|
continue;
|
|
}
|
|
if (!(cp = strpbrk(p, "#\n"))) {
|
|
continue;
|
|
}
|
|
*cp = '\0';
|
|
if (!(cp = strpbrk(p, " \t"))) continue;
|
|
*cp++ = '\0';
|
|
if (inet_pton(AF_INET6, p, &host_addr) > 0) {
|
|
af = AF_INET6;
|
|
len = NS_IN6ADDRSZ;
|
|
} else {
|
|
if (inet_pton(AF_INET, p, &host_addr) <= 0) continue;
|
|
af = AF_INET;
|
|
len = NS_INADDRSZ;
|
|
}
|
|
|
|
/* if this is not something we're looking for, skip it. */
|
|
if (hent->h_addrtype != 0 && hent->h_addrtype != af) continue;
|
|
if (hent->h_length != 0 && hent->h_length != len) continue;
|
|
|
|
while (*cp == ' ' || *cp == '\t') cp++;
|
|
if ((cp = strpbrk(name = cp, " \t")) != NULL) *cp++ = '\0';
|
|
while (cp && *cp) {
|
|
if (*cp == ' ' || *cp == '\t') {
|
|
cp++;
|
|
continue;
|
|
}
|
|
aliases.push_back(cp);
|
|
if ((cp = strpbrk(cp, " \t")) != NULL) *cp++ = '\0';
|
|
}
|
|
break;
|
|
}
|
|
hent->h_length = len;
|
|
hent->h_addrtype = af;
|
|
HENT_ARRAY(hent->h_addr_list, 1, buf, buflen);
|
|
anum = aliases.size();
|
|
HENT_ARRAY(hent->h_aliases, anum, buf, buflen);
|
|
HENT_COPY(hent->h_addr_list[0], &host_addr, hent->h_length, buf, buflen);
|
|
hent->h_addr_list[1] = NULL;
|
|
|
|
/* Reserve space for mapping IPv4 address to IPv6 address in place */
|
|
if (hent->h_addrtype == AF_INET) {
|
|
HENT_COPY(buf, NAT64_PAD, sizeof(NAT64_PAD), buf, buflen);
|
|
}
|
|
|
|
HENT_SCOPY(hent->h_name, name, buf, buflen);
|
|
for (size_t i = 0; i < anum; i++) HENT_SCOPY(hent->h_aliases[i], aliases[i], buf, buflen);
|
|
hent->h_aliases[anum] = NULL;
|
|
*he = NETDB_SUCCESS;
|
|
free(p);
|
|
return hent;
|
|
nospc:
|
|
free(p);
|
|
errno = ENOSPC;
|
|
*he = NETDB_INTERNAL;
|
|
return NULL;
|
|
}
|
|
|
|
static void convert_v4v6_hostent(struct hostent* hp, char** bpp, char* ep,
|
|
const std::function<void(struct hostent* hp)>& map_param,
|
|
const std::function<void(char* src, char* dst)>& map_addr) {
|
|
_DIAGASSERT(hp != NULL);
|
|
_DIAGASSERT(bpp != NULL);
|
|
_DIAGASSERT(ep != NULL);
|
|
|
|
if (hp->h_addrtype != AF_INET || hp->h_length != NS_INADDRSZ) return;
|
|
map_param(hp);
|
|
for (char** ap = hp->h_addr_list; *ap; ap++) {
|
|
int i = (int)(sizeof(align) - (size_t)((uintptr_t)*bpp % sizeof(align)));
|
|
|
|
if (ep - *bpp < (i + NS_IN6ADDRSZ)) {
|
|
/* Out of memory. Truncate address list here. XXX */
|
|
*ap = NULL;
|
|
return;
|
|
}
|
|
*bpp += i;
|
|
map_addr(*ap, *bpp);
|
|
*ap = *bpp;
|
|
*bpp += NS_IN6ADDRSZ;
|
|
}
|
|
}
|
|
|
|
/* Reserve space for mapping IPv4 address to IPv6 address in place */
|
|
static void pad_v4v6_hostent(struct hostent* hp, char** bpp, char* ep) {
|
|
convert_v4v6_hostent(hp, bpp, ep,
|
|
[](struct hostent* hp) {
|
|
(void) hp; /* unused */
|
|
},
|
|
[](char* src, char* dst) {
|
|
memcpy(dst, src, NS_INADDRSZ);
|
|
memcpy(dst + NS_INADDRSZ, NAT64_PAD, sizeof(NAT64_PAD));
|
|
});
|
|
}
|
|
|
|
static int dns_gethtbyname(ResState* res, const char* name, int addr_type, getnamaddr* info) {
|
|
int n, type;
|
|
info->hp->h_addrtype = addr_type;
|
|
|
|
switch (info->hp->h_addrtype) {
|
|
case AF_INET:
|
|
info->hp->h_length = NS_INADDRSZ;
|
|
type = T_A;
|
|
break;
|
|
case AF_INET6:
|
|
info->hp->h_length = NS_IN6ADDRSZ;
|
|
type = T_AAAA;
|
|
break;
|
|
default:
|
|
return EAI_FAMILY;
|
|
}
|
|
auto buf = std::make_unique<querybuf>();
|
|
|
|
int he;
|
|
n = res_nsearch(res, name, C_IN, type, buf->buf, (int)sizeof(buf->buf), &he);
|
|
if (n < 0) {
|
|
LOG(DEBUG) << __func__ << ": res_nsearch failed (" << n << ")";
|
|
// Return h_errno (he) to catch more detailed errors rather than EAI_NODATA.
|
|
// Note that res_nsearch() doesn't set the pair NETDB_INTERNAL and errno.
|
|
// See also herrnoToAiErrno().
|
|
return herrnoToAiErrno(he);
|
|
}
|
|
hostent* hp = getanswer(buf.get(), n, name, type, info->hp, info->buf, info->buflen, &he);
|
|
if (hp == NULL) return herrnoToAiErrno(he);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dns_gethtbyaddr(const unsigned char* uaddr, int len, int af,
|
|
const android_net_context* netcontext, getnamaddr* info,
|
|
NetworkDnsEventReported* event) {
|
|
char qbuf[MAXDNAME + 1], *qp, *ep;
|
|
int n;
|
|
int advance;
|
|
|
|
info->hp->h_length = len;
|
|
info->hp->h_addrtype = af;
|
|
|
|
switch (info->hp->h_addrtype) {
|
|
case AF_INET:
|
|
(void) snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", (uaddr[3] & 0xff),
|
|
(uaddr[2] & 0xff), (uaddr[1] & 0xff), (uaddr[0] & 0xff));
|
|
break;
|
|
|
|
case AF_INET6:
|
|
qp = qbuf;
|
|
ep = qbuf + sizeof(qbuf) - 1;
|
|
for (n = NS_IN6ADDRSZ - 1; n >= 0; n--) {
|
|
advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.", uaddr[n] & 0xf,
|
|
((unsigned int) uaddr[n] >> 4) & 0xf);
|
|
if (advance > 0 && qp + advance < ep)
|
|
qp += advance;
|
|
else {
|
|
// TODO: Consider converting to a private extended EAI_* error code.
|
|
// Currently, the EAI_* value has no corresponding error code for an internal
|
|
// out of buffer space. In order to not rely on errno, convert the original
|
|
// error code EAI_SYSTEM to EAI_MEMORY.
|
|
return EAI_MEMORY;
|
|
}
|
|
}
|
|
if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) {
|
|
// TODO: Consider converting to a private extended EAI_* error code.
|
|
// Currently, the EAI_* value has no corresponding error code for an internal
|
|
// out of buffer space. In order to not rely on errno, convert the original
|
|
// error code EAI_SYSTEM to EAI_MEMORY.
|
|
return EAI_MEMORY;
|
|
}
|
|
break;
|
|
default:
|
|
return EAI_FAMILY;
|
|
}
|
|
|
|
auto buf = std::make_unique<querybuf>();
|
|
|
|
ResState res(netcontext, event);
|
|
int he;
|
|
n = res_nquery(&res, qbuf, C_IN, T_PTR, buf->buf, (int)sizeof(buf->buf), &he);
|
|
if (n < 0) {
|
|
LOG(DEBUG) << __func__ << ": res_nquery failed (" << n << ")";
|
|
// Note that res_nquery() doesn't set the pair NETDB_INTERNAL and errno.
|
|
// Return h_errno (he) to catch more detailed errors rather than EAI_NODATA.
|
|
// See also herrnoToAiErrno().
|
|
return herrnoToAiErrno(he);
|
|
}
|
|
hostent* hp = getanswer(buf.get(), n, qbuf, T_PTR, info->hp, info->buf, info->buflen, &he);
|
|
if (hp == NULL) return herrnoToAiErrno(he);
|
|
|
|
char* bf = (char*) (hp->h_addr_list + 2);
|
|
size_t blen = (size_t)(bf - info->buf);
|
|
if (blen + info->hp->h_length > info->buflen) goto nospc;
|
|
hp->h_addr_list[0] = bf;
|
|
hp->h_addr_list[1] = NULL;
|
|
memcpy(bf, uaddr, (size_t) info->hp->h_length);
|
|
|
|
/* Reserve enough space for mapping IPv4 address to IPv6 address in place */
|
|
if (info->hp->h_addrtype == AF_INET) {
|
|
if (blen + NS_IN6ADDRSZ > info->buflen) goto nospc;
|
|
// Pad zero to the unused address space
|
|
memcpy(bf + NS_INADDRSZ, NAT64_PAD, sizeof(NAT64_PAD));
|
|
}
|
|
|
|
return 0;
|
|
|
|
nospc:
|
|
return EAI_MEMORY;
|
|
}
|
|
|
|
int herrnoToAiErrno(int he) {
|
|
switch (he) {
|
|
// extended h_errno
|
|
case NETD_RESOLV_H_ERRNO_EXT_TIMEOUT:
|
|
return NETD_RESOLV_TIMEOUT;
|
|
// legacy h_errno
|
|
case NETDB_SUCCESS:
|
|
return 0;
|
|
case HOST_NOT_FOUND: // TODO: Perhaps convert HOST_NOT_FOUND to EAI_NONAME instead
|
|
case NO_DATA: // NO_ADDRESS
|
|
return EAI_NODATA;
|
|
case TRY_AGAIN:
|
|
return EAI_AGAIN;
|
|
case NETDB_INTERNAL:
|
|
// TODO: Remove ENOSPC and call abort() immediately whenever any allocation fails.
|
|
if (errno == ENOSPC) return EAI_MEMORY;
|
|
// Theoretically, this should not happen. Leave this here just in case.
|
|
// Currently, getanswer() of {gethnamaddr, getaddrinfo}.cpp, res_nsearch() and
|
|
// res_searchN() use this function to convert error code. Only getanswer()
|
|
// of gethnamaddr.cpp may return the error code pair, herrno NETDB_INTERNAL and
|
|
// errno ENOSPC, which has already converted to EAI_MEMORY. The remaining functions
|
|
// don't set the pair herrno and errno.
|
|
return EAI_SYSTEM; // see errno for detail
|
|
case NO_RECOVERY:
|
|
default:
|
|
return EAI_FAIL; // TODO: Perhaps convert default to EAI_MAX (unknown error) instead
|
|
}
|
|
}
|