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/* $OpenBSD: gethostnamadr.c,v 1.13 2015/09/14 07:38:37 guenther Exp $ */ |
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/* |
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* Copyright (c) 2012,2013 Eric Faurot <eric@openbsd.org> |
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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. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/param.h> /* ALIGN */ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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#include <netdb.h> |
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#include <asr.h> |
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#include <errno.h> |
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#include <resolv.h> |
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#include <stdint.h> |
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#include <stdlib.h> |
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#include <string.h> |
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static int _gethostbyname(const char *, int, struct hostent *, char *, size_t, |
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int *); |
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static int _fillhostent(const struct hostent *, struct hostent *, char *, |
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size_t); |
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static struct hostent _hostent; |
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static char _entbuf[4096]; |
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static char *_empty[] = { NULL, }; |
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static int |
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_fillhostent(const struct hostent *h, struct hostent *r, char *buf, size_t len) |
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{ |
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char **ptr, *end, *pos; |
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size_t n, i; |
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int naliases, naddrs; |
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bzero(buf, len); |
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bzero(r, sizeof(*r)); |
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r->h_aliases = _empty; |
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r->h_addr_list = _empty; |
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end = buf + len; |
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ptr = (char **)ALIGN(buf); |
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if ((char *)ptr >= end) |
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return (ERANGE); |
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for (naliases = 0; h->h_aliases[naliases]; naliases++) |
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; |
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for (naddrs = 0; h->h_addr_list[naddrs]; naddrs++) |
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; |
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pos = (char *)(ptr + (naliases + 1) + (naddrs + 1)); |
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if (pos >= end) |
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return (ERANGE); |
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r->h_name = NULL; |
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r->h_addrtype = h->h_addrtype; |
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r->h_length = h->h_length; |
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r->h_aliases = ptr; |
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r->h_addr_list = ptr + naliases + 1; |
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n = strlcpy(pos, h->h_name, end - pos); |
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if (n >= end - pos) |
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return (ERANGE); |
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r->h_name = pos; |
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pos += n + 1; |
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for (i = 0; i < naliases; i++) { |
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n = strlcpy(pos, h->h_aliases[i], end - pos); |
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if (n >= end - pos) |
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return (ERANGE); |
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r->h_aliases[i] = pos; |
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pos += n + 1; |
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} |
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pos = (char *)ALIGN(pos); |
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if (pos >= end) |
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return (ERANGE); |
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for (i = 0; i < naddrs; i++) { |
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if (r->h_length > end - pos) |
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return (ERANGE); |
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memmove(pos, h->h_addr_list[i], r->h_length); |
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r->h_addr_list[i] = pos; |
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pos += r->h_length; |
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} |
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return (0); |
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} |
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static int |
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_gethostbyname(const char *name, int af, struct hostent *ret, char *buf, |
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size_t buflen, int *h_errnop) |
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{ |
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struct asr_query *as; |
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struct asr_result ar; |
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int r; |
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if (af == -1) |
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as = gethostbyname_async(name, NULL); |
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else |
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as = gethostbyname2_async(name, af, NULL); |
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if (as == NULL) |
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return (errno); |
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asr_run_sync(as, &ar); |
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errno = ar.ar_errno; |
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*h_errnop = ar.ar_h_errno; |
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if (ar.ar_hostent == NULL) |
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return (0); |
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r = _fillhostent(ar.ar_hostent, ret, buf, buflen); |
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free(ar.ar_hostent); |
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return (r); |
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} |
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struct hostent * |
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gethostbyname(const char *name) |
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{ |
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struct hostent *h; |
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res_init(); |
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if (_res.options & RES_USE_INET6 && |
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(h = gethostbyname2(name, AF_INET6))) |
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return (h); |
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return gethostbyname2(name, AF_INET); |
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} |
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DEF_WEAK(gethostbyname); |
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struct hostent * |
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gethostbyname2(const char *name, int af) |
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{ |
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int r; |
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res_init(); |
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r = _gethostbyname(name, af, &_hostent, _entbuf, sizeof(_entbuf), |
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&h_errno); |
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if (r) { |
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h_errno = NETDB_INTERNAL; |
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errno = r; |
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} |
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if (h_errno) |
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return (NULL); |
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return (&_hostent); |
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} |
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DEF_WEAK(gethostbyname2); |
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struct hostent * |
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gethostbyaddr(const void *addr, socklen_t len, int af) |
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{ |
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struct asr_query *as; |
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struct asr_result ar; |
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int r; |
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res_init(); |
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as = gethostbyaddr_async(addr, len, af, NULL); |
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if (as == NULL) { |
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h_errno = NETDB_INTERNAL; |
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return (NULL); |
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} |
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asr_run_sync(as, &ar); |
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errno = ar.ar_errno; |
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h_errno = ar.ar_h_errno; |
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if (ar.ar_hostent == NULL) |
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return (NULL); |
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r = _fillhostent(ar.ar_hostent, &_hostent, _entbuf, sizeof(_entbuf)); |
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free(ar.ar_hostent); |
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if (r) { |
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h_errno = NETDB_INTERNAL; |
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errno = r; |
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return (NULL); |
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} |
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return (&_hostent); |
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} |