| /* $NetBSD: gethnamaddr.c,v 1.91 2014/06/19 15:08:18 christos Exp $ */ |
| |
| /* |
| * ++Copyright++ 1985, 1988, 1993 |
| * - |
| * Copyright (c) 1985, 1988, 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. |
| * - |
| * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
| * |
| * 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, and that |
| * the name of Digital Equipment Corporation not be used in advertising or |
| * publicity pertaining to distribution of the document or software without |
| * specific, written prior permission. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
| * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT |
| * CORPORATION 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. |
| * - |
| * --Copyright-- |
| */ |
| |
| #include "gethnamaddr.h" |
| |
| #include <android-base/logging.h> |
| #include <arpa/inet.h> |
| #include <arpa/nameser.h> |
| #include <assert.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <netdb.h> |
| #include <netinet/in.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/param.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| #include <sys/un.h> |
| #include <unistd.h> |
| #include <functional> |
| #include <vector> |
| |
| #include "hostent.h" |
| #include "netd_resolv/resolv.h" |
| #include "resolv_cache.h" |
| #include "resolv_private.h" |
| #include "stats.pb.h" |
| |
| using android::net::NetworkDnsEventReported; |
| |
| // NetBSD uses _DIAGASSERT to null-check arguments and the like, |
| // but it's clear from the number of mistakes in their assertions |
| // that they don't actually test or ship with this. |
| #define _DIAGASSERT(e) /* nothing */ |
| |
| // TODO: unify macro ALIGNBYTES and ALIGN for all possible data type alignment of hostent |
| // buffer. |
| #define ALIGNBYTES (sizeof(uintptr_t) - 1) |
| #define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) & ~ALIGNBYTES) |
| |
| #define maybe_ok(res, nm, ok) ((ok)(nm) != 0) |
| #define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok) |
| #define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok) |
| |
| #define MAXPACKET (8 * 1024) |
| |
| typedef union { |
| HEADER hdr; |
| u_char buf[MAXPACKET]; |
| } querybuf; |
| |
| typedef union { |
| int32_t al; |
| char ac; |
| } align; |
| |
| static struct hostent* getanswer(const querybuf*, int, const char*, int, res_state, struct hostent*, |
| char*, size_t, int*); |
| static void convert_v4v6_hostent(struct hostent* hp, char** bpp, char* ep, |
| std::function<void(struct hostent* hp)> mapping_param, |
| std::function<void(char* src, char* dst)> mapping_addr); |
| static void pad_v4v6_hostent(struct hostent* hp, char** bpp, char* ep); |
| static void addrsort(char**, int, res_state); |
| |
| static int dns_gethtbyaddr(const unsigned char* uaddr, int len, int af, |
| const android_net_context* netcontext, getnamaddr* info, |
| NetworkDnsEventReported* event); |
| static int dns_gethtbyname(const char* name, int af, getnamaddr* info); |
| |
| static int gethostbyname_internal(const char* name, int af, res_state res, hostent* hp, char* hbuf, |
| size_t hbuflen, const android_net_context* netcontext, |
| NetworkDnsEventReported* event); |
| static int gethostbyname_internal_real(const char* name, int af, hostent* hp, char* buf, |
| size_t buflen); |
| |
| static int android_gethostbyaddrfornetcontext_proxy_internal(const void*, socklen_t, int, |
| struct hostent*, char*, size_t, |
| const struct android_net_context*, |
| NetworkDnsEventReported* event); |
| static int android_gethostbyaddrfornetcontext_proxy(const void* addr, socklen_t len, int af, |
| const struct android_net_context* netcontext, |
| hostent** hp, NetworkDnsEventReported* event); |
| |
| #define BOUNDED_INCR(x) \ |
| do { \ |
| BOUNDS_CHECK(cp, x); \ |
| cp += (x); \ |
| } while (0) |
| |
| #define BOUNDS_CHECK(ptr, count) \ |
| do { \ |
| if (eom - (ptr) < (count)) goto no_recovery; \ |
| } while (0) |
| |
| static struct hostent* getanswer(const querybuf* answer, int anslen, const char* qname, int qtype, |
| res_state res, struct hostent* hent, char* buf, size_t buflen, |
| int* he) { |
| const HEADER* hp; |
| const u_char* cp; |
| int n; |
| size_t qlen; |
| const u_char *eom, *erdata; |
| char *bp, **hap, *ep; |
| int ancount, qdcount; |
| int haveanswer, had_error; |
| int toobig = 0; |
| char tbuf[MAXDNAME]; |
| char* addr_ptrs[MAXADDRS]; |
| const char* tname; |
| int (*name_ok)(const char*); |
| std::vector<char*> aliases; |
| |
| _DIAGASSERT(answer != NULL); |
| _DIAGASSERT(qname != NULL); |
| |
| tname = qname; |
| hent->h_name = NULL; |
| eom = answer->buf + anslen; |
| switch (qtype) { |
| case T_A: |
| case T_AAAA: |
| name_ok = res_hnok; |
| break; |
| case T_PTR: |
| name_ok = res_dnok; |
| break; |
| default: |
| *he = NO_RECOVERY; |
| return NULL; /* XXX should be abort(); */ |
| } |
| |
| /* |
| * find first satisfactory answer |
| */ |
| hp = &answer->hdr; |
| ancount = ntohs(hp->ancount); |
| qdcount = ntohs(hp->qdcount); |
| bp = buf; |
| ep = buf + buflen; |
| cp = answer->buf; |
| BOUNDED_INCR(HFIXEDSZ); |
| if (qdcount != 1) goto no_recovery; |
| |
| n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp)); |
| if ((n < 0) || !maybe_ok(res, bp, name_ok)) goto no_recovery; |
| |
| BOUNDED_INCR(n + QFIXEDSZ); |
| if (qtype == T_A || qtype == T_AAAA) { |
| /* res_send() has already verified that the query name is the |
| * same as the one we sent; this just gets the expanded name |
| * (i.e., with the succeeding search-domain tacked on). |
| */ |
| n = (int) strlen(bp) + 1; /* for the \0 */ |
| if (n >= MAXHOSTNAMELEN) goto no_recovery; |
| hent->h_name = bp; |
| bp += n; |
| /* The qname can be abbreviated, but h_name is now absolute. */ |
| qname = hent->h_name; |
| } |
| hent->h_addr_list = hap = addr_ptrs; |
| *hap = NULL; |
| haveanswer = 0; |
| had_error = 0; |
| while (ancount-- > 0 && cp < eom && !had_error) { |
| n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp)); |
| if ((n < 0) || !maybe_ok(res, bp, name_ok)) { |
| had_error++; |
| continue; |
| } |
| cp += n; /* name */ |
| BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); |
| int type = ntohs(*reinterpret_cast<const uint16_t*>(cp)); |
| cp += INT16SZ; /* type */ |
| int cl = ntohs(*reinterpret_cast<const uint16_t*>(cp)); |
| cp += INT16SZ + INT32SZ; /* class, TTL */ |
| n = ntohs(*reinterpret_cast<const uint16_t*>(cp)); |
| cp += INT16SZ; /* len */ |
| BOUNDS_CHECK(cp, n); |
| erdata = cp + n; |
| if (cl != C_IN) { |
| /* XXX - debug? syslog? */ |
| cp += n; |
| continue; /* XXX - had_error++ ? */ |
| } |
| if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { |
| n = dn_expand(answer->buf, eom, cp, tbuf, (int) sizeof tbuf); |
| if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) { |
| had_error++; |
| continue; |
| } |
| cp += n; |
| if (cp != erdata) goto no_recovery; |
| /* Store alias. */ |
| aliases.push_back(bp); |
| n = (int) strlen(bp) + 1; /* for the \0 */ |
| if (n >= MAXHOSTNAMELEN) { |
| had_error++; |
| continue; |
| } |
| bp += n; |
| /* Get canonical name. */ |
| n = (int) strlen(tbuf) + 1; /* for the \0 */ |
| if (n > ep - bp || n >= MAXHOSTNAMELEN) { |
| had_error++; |
| continue; |
| } |
| strlcpy(bp, tbuf, (size_t)(ep - bp)); |
| hent->h_name = bp; |
| bp += n; |
| continue; |
| } |
| if (qtype == T_PTR && type == T_CNAME) { |
| n = dn_expand(answer->buf, eom, cp, tbuf, (int) sizeof tbuf); |
| if (n < 0 || !maybe_dnok(res, tbuf)) { |
| had_error++; |
| continue; |
| } |
| cp += n; |
| if (cp != erdata) goto no_recovery; |
| /* Get canonical name. */ |
| n = (int) strlen(tbuf) + 1; /* for the \0 */ |
| if (n > ep - bp || n >= MAXHOSTNAMELEN) { |
| had_error++; |
| continue; |
| } |
| strlcpy(bp, tbuf, (size_t)(ep - bp)); |
| tname = bp; |
| bp += n; |
| continue; |
| } |
| if (type != qtype) { |
| if (type != T_KEY && type != T_SIG) |
| LOG(DEBUG) << __func__ << ": asked for \"" << qname << " " << p_class(C_IN) << " " |
| << p_type(qtype) << "\", got type \"" << p_type(type) << "\""; |
| cp += n; |
| continue; /* XXX - had_error++ ? */ |
| } |
| switch (type) { |
| case T_PTR: |
| if (strcasecmp(tname, bp) != 0) { |
| LOG(DEBUG) << __func__ << ": asked for \"" << qname << "\", got \"" << bp |
| << "\""; |
| cp += n; |
| continue; /* XXX - had_error++ ? */ |
| } |
| n = dn_expand(answer->buf, eom, cp, bp, (int) (ep - bp)); |
| if ((n < 0) || !maybe_hnok(res, bp)) { |
| had_error++; |
| break; |
| } |
| cp += n; |
| if (cp != erdata) goto no_recovery; |
| if (!haveanswer) |
| hent->h_name = bp; |
| else |
| aliases.push_back(bp); |
| if (n != -1) { |
| n = (int) strlen(bp) + 1; /* for the \0 */ |
| if (n >= MAXHOSTNAMELEN) { |
| had_error++; |
| break; |
| } |
| bp += n; |
| } |
| break; |
| case T_A: |
| case T_AAAA: |
| if (strcasecmp(hent->h_name, bp) != 0) { |
| LOG(DEBUG) << __func__ << ": asked for \"" << hent->h_name << "\", got \"" << bp |
| << "\""; |
| cp += n; |
| continue; /* XXX - had_error++ ? */ |
| } |
| if (n != hent->h_length) { |
| cp += n; |
| continue; |
| } |
| if (type == T_AAAA) { |
| struct in6_addr in6; |
| memcpy(&in6, cp, NS_IN6ADDRSZ); |
| if (IN6_IS_ADDR_V4MAPPED(&in6)) { |
| cp += n; |
| continue; |
| } |
| } |
| if (!haveanswer) { |
| int nn; |
| |
| hent->h_name = bp; |
| nn = (int) strlen(bp) + 1; /* for the \0 */ |
| bp += nn; |
| } |
| |
| bp += sizeof(align) - (size_t)((u_long) bp % sizeof(align)); |
| |
| if (bp + n >= ep) { |
| LOG(DEBUG) << __func__ << ": size (" << n << ") too big"; |
| had_error++; |
| continue; |
| } |
| if (hap >= &addr_ptrs[MAXADDRS - 1]) { |
| if (!toobig++) { |
| LOG(DEBUG) << __func__ << ": Too many addresses (" << MAXADDRS << ")"; |
| } |
| cp += n; |
| continue; |
| } |
| (void) memcpy(*hap++ = bp, cp, (size_t) n); |
| bp += n; |
| cp += n; |
| if (cp != erdata) goto no_recovery; |
| break; |
| default: |
| abort(); |
| } |
| if (!had_error) haveanswer++; |
| } |
| if (haveanswer) { |
| *hap = NULL; |
| /* |
| * Note: we sort even if host can take only one address |
| * in its return structures - should give it the "best" |
| * address in that case, not some random one |
| */ |
| if (res->nsort && haveanswer > 1 && qtype == T_A) addrsort(addr_ptrs, haveanswer, res); |
| if (!hent->h_name) { |
| n = (int) strlen(qname) + 1; /* for the \0 */ |
| if (n > ep - bp || n >= MAXHOSTNAMELEN) goto no_recovery; |
| strlcpy(bp, qname, (size_t)(ep - bp)); |
| hent->h_name = bp; |
| bp += n; |
| } |
| if (hent->h_addrtype == AF_INET) pad_v4v6_hostent(hent, &bp, ep); |
| goto success; |
| } |
| no_recovery: |
| *he = NO_RECOVERY; |
| return NULL; |
| success: |
| bp = (char*) ALIGN(bp); |
| aliases.push_back(nullptr); |
| qlen = aliases.size() * sizeof(*hent->h_aliases); |
| if ((size_t)(ep - bp) < qlen) goto nospc; |
| hent->h_aliases = (char**) bp; |
| memcpy(bp, aliases.data(), qlen); |
| |
| bp += qlen; |
| n = (int) (hap - addr_ptrs); |
| qlen = (n + 1) * sizeof(*hent->h_addr_list); |
| if ((size_t)(ep - bp) < qlen) goto nospc; |
| hent->h_addr_list = (char**) bp; |
| memcpy(bp, addr_ptrs, qlen); |
| *he = NETDB_SUCCESS; |
| return hent; |
| nospc: |
| errno = ENOSPC; |
| *he = NETDB_INTERNAL; |
| return NULL; |
| } |
| |
| static int gethostbyname_internal_real(const char* name, int af, hostent* hp, char* buf, |
| size_t buflen) { |
| getnamaddr info; |
| size_t size; |
| |
| _DIAGASSERT(name != NULL); |
| |
| switch (af) { |
| case AF_INET: |
| size = NS_INADDRSZ; |
| break; |
| case AF_INET6: |
| size = NS_IN6ADDRSZ; |
| break; |
| default: |
| return EAI_FAMILY; |
| } |
| if (buflen < size) goto nospc; |
| |
| hp->h_addrtype = af; |
| hp->h_length = (int) size; |
| |
| /* |
| * disallow names consisting only of digits/dots, unless |
| * they end in a dot. |
| */ |
| if (isdigit((u_char) name[0])) { |
| for (const char* cp = name;; ++cp) { |
| if (!*cp) { |
| if (*--cp == '.') break; |
| /* |
| * All-numeric, no dot at the end. |
| * Fake up a hostent as if we'd actually |
| * done a lookup. |
| */ |
| goto fake; |
| } |
| if (!isdigit((u_char) *cp) && *cp != '.') break; |
| } |
| } |
| if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) || name[0] == ':') { |
| for (const char* cp = name;; ++cp) { |
| if (!*cp) { |
| if (*--cp == '.') break; |
| /* |
| * All-IPv6-legal, no dot at the end. |
| * Fake up a hostent as if we'd actually |
| * done a lookup. |
| */ |
| goto fake; |
| } |
| if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.') break; |
| } |
| } |
| |
| info.hp = hp; |
| info.buf = buf; |
| info.buflen = buflen; |
| if (_hf_gethtbyname2(name, af, &info)) { |
| int error = dns_gethtbyname(name, af, &info); |
| if (error != 0) return error; |
| } |
| return 0; |
| nospc: |
| return EAI_MEMORY; |
| fake: |
| HENT_ARRAY(hp->h_addr_list, 1, buf, buflen); |
| HENT_ARRAY(hp->h_aliases, 0, buf, buflen); |
| |
| hp->h_aliases[0] = NULL; |
| if (size > buflen) goto nospc; |
| |
| if (inet_pton(af, name, buf) <= 0) { |
| return EAI_NODATA; |
| } |
| hp->h_addr_list[0] = buf; |
| hp->h_addr_list[1] = NULL; |
| buf += size; |
| buflen -= size; |
| HENT_SCOPY(hp->h_name, name, buf, buflen); |
| return 0; |
| } |
| |
| // very similar in proxy-ness to android_getaddrinfo_proxy |
| static int gethostbyname_internal(const char* name, int af, res_state res, hostent* hp, char* hbuf, |
| size_t hbuflen, const android_net_context* netcontext, |
| NetworkDnsEventReported* event) { |
| res_setnetcontext(res, netcontext, event); |
| return gethostbyname_internal_real(name, af, hp, hbuf, hbuflen); |
| } |
| |
| static int android_gethostbyaddrfornetcontext_real(const void* addr, socklen_t len, int af, |
| struct hostent* hp, char* buf, size_t buflen, |
| const struct android_net_context* netcontext, |
| NetworkDnsEventReported* event) { |
| const u_char* uaddr = (const u_char*) addr; |
| socklen_t size; |
| struct getnamaddr info; |
| |
| _DIAGASSERT(addr != NULL); |
| |
| if (af == AF_INET6 && len == NS_IN6ADDRSZ && |
| (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; |
| } |
| return 0; |
| } |
| |
| static int android_gethostbyaddrfornetcontext_proxy_internal( |
| const void* addr, socklen_t len, int af, struct hostent* hp, char* hbuf, size_t hbuflen, |
| const struct android_net_context* netcontext, NetworkDnsEventReported* event) { |
| return android_gethostbyaddrfornetcontext_real(addr, len, af, hp, hbuf, hbuflen, netcontext, |
| event); |
| } |
| |
| // 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) { |
| const size_t line_buf_size = sizeof(res_get_static()->hostbuf); |
| 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. |
| * To keep reentrancy we cannot use res_get_static()->hostbuf here, |
| * as the buffer may be used to store content for a previous hostent |
| * returned by non-reentrant functions like gethostbyname(). |
| */ |
| 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; |
| |
| res_state res = res_get_state(); |
| if (res == NULL) goto nospc; |
| 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, |
| std::function<void(struct hostent* hp)> map_param, |
| 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)((u_long) *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 void addrsort(char** ap, int num, res_state res) { |
| int i, j; |
| char** p; |
| short aval[MAXADDRS]; |
| int needsort = 0; |
| |
| _DIAGASSERT(ap != NULL); |
| |
| p = ap; |
| for (i = 0; i < num; i++, p++) { |
| for (j = 0; (unsigned) j < res->nsort; j++) |
| if (res->sort_list[j].addr.s_addr == |
| (((struct in_addr*) (void*) (*p))->s_addr & res->sort_list[j].mask)) |
| break; |
| aval[i] = j; |
| if (needsort == 0 && i > 0 && j < aval[i - 1]) needsort = i; |
| } |
| if (!needsort) return; |
| |
| while (needsort < num) { |
| for (j = needsort - 1; j >= 0; j--) { |
| if (aval[j] > aval[j + 1]) { |
| char* hp; |
| |
| i = aval[j]; |
| aval[j] = aval[j + 1]; |
| aval[j + 1] = i; |
| |
| hp = ap[j]; |
| ap[j] = ap[j + 1]; |
| ap[j + 1] = hp; |
| } else |
| break; |
| } |
| needsort++; |
| } |
| } |
| |
| static int dns_gethtbyname(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>(); |
| |
| res_state res = res_get_state(); |
| if (!res) return EAI_MEMORY; |
| |
| 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, res, 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>(); |
| |
| res_state res = res_get_state(); |
| if (!res) return EAI_MEMORY; |
| |
| res_setnetcontext(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, res, 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; |
| } |
| |
| /* |
| * Non-reentrant versions. |
| */ |
| |
| int android_gethostbynamefornetcontext(const char* name, int af, |
| const struct android_net_context* netcontext, hostent** hp, |
| NetworkDnsEventReported* event) { |
| assert(event != nullptr); |
| |
| res_state res = res_get_state(); |
| if (res == NULL) return EAI_MEMORY; |
| res_static* rs = res_get_static(); // For thread-safety. |
| int error; |
| error = gethostbyname_internal(name, af, res, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), |
| netcontext, event); |
| if (error == 0) { |
| *hp = &rs->host; |
| } |
| return error; |
| } |
| |
| int android_gethostbyaddrfornetcontext(const void* addr, socklen_t len, int af, |
| const struct android_net_context* netcontext, hostent** hp, |
| NetworkDnsEventReported* event) { |
| return android_gethostbyaddrfornetcontext_proxy(addr, len, af, netcontext, hp, event); |
| } |
| |
| static int android_gethostbyaddrfornetcontext_proxy(const void* addr, socklen_t len, int af, |
| const struct android_net_context* netcontext, |
| hostent** hp, NetworkDnsEventReported* event) { |
| assert(event != nullptr); |
| |
| struct res_static* rs = res_get_static(); // For thread-safety. |
| int error = android_gethostbyaddrfornetcontext_proxy_internal( |
| addr, len, af, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), netcontext, event); |
| if (error == 0) *hp = &rs->host; |
| return error; |
| } |
| |
| 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 |
| } |
| } |
