/* $OpenBSD: gethostnamadr.c,v 1.11 2014/03/26 18:13:15 eric Exp $ */ /* * Copyright (c) 2012,2013 Eric Faurot * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include static int _gethostbyname(const char *, int, struct hostent *, char *, size_t, int *); static int _fillhostent(const struct hostent *, struct hostent *, char *, size_t); static struct hostent _hostent; static char _entbuf[4096]; static char *_empty[] = { NULL, }; static int _fillhostent(const struct hostent *h, struct hostent *r, char *buf, size_t len) { char **ptr, *end, *pos; size_t n, i; int naliases, naddrs; bzero(buf, len); bzero(r, sizeof(*r)); r->h_aliases = _empty; r->h_addr_list = _empty; end = buf + len; ptr = (char **)ALIGN(buf); if ((char *)ptr >= end) return (ERANGE); for (naliases = 0; h->h_aliases[naliases]; naliases++) ; for (naddrs = 0; h->h_addr_list[naddrs]; naddrs++) ; pos = (char *)(ptr + (naliases + 1) + (naddrs + 1)); if (pos >= end) return (ERANGE); r->h_name = NULL; r->h_addrtype = h->h_addrtype; r->h_length = h->h_length; r->h_aliases = ptr; r->h_addr_list = ptr + naliases + 1; n = strlcpy(pos, h->h_name, end - pos); if (n >= end - pos) return (ERANGE); r->h_name = pos; pos += n + 1; for (i = 0; i < naliases; i++) { n = strlcpy(pos, h->h_aliases[i], end - pos); if (n >= end - pos) return (ERANGE); r->h_aliases[i] = pos; pos += n + 1; } pos = (char *)ALIGN(pos); if (pos >= end) return (ERANGE); for (i = 0; i < naddrs; i++) { if (r->h_length > end - pos) return (ERANGE); memmove(pos, h->h_addr_list[i], r->h_length); r->h_addr_list[i] = pos; pos += r->h_length; } return (0); } static int _gethostbyname(const char *name, int af, struct hostent *ret, char *buf, size_t buflen, int *h_errnop) { struct asr_query *as; struct asr_result ar; int r; if (af == -1) as = gethostbyname_async(name, NULL); else as = gethostbyname2_async(name, af, NULL); if (as == NULL) return (errno); asr_run_sync(as, &ar); errno = ar.ar_errno; *h_errnop = ar.ar_h_errno; if (ar.ar_hostent == NULL) return (0); r = _fillhostent(ar.ar_hostent, ret, buf, buflen); free(ar.ar_hostent); return (r); } struct hostent * gethostbyname(const char *name) { struct hostent *h; res_init(); if (_res.options & RES_USE_INET6 && (h = gethostbyname2(name, AF_INET6))) return (h); return gethostbyname2(name, AF_INET); } struct hostent * gethostbyname2(const char *name, int af) { int r; res_init(); r = _gethostbyname(name, af, &_hostent, _entbuf, sizeof(_entbuf), &h_errno); if (r) { h_errno = NETDB_INTERNAL; errno = r; } if (h_errno) return (NULL); return (&_hostent); } struct hostent * gethostbyaddr(const void *addr, socklen_t len, int af) { struct asr_query *as; struct asr_result ar; int r; res_init(); as = gethostbyaddr_async(addr, len, af, NULL); if (as == NULL) { h_errno = NETDB_INTERNAL; return (NULL); } asr_run_sync(as, &ar); errno = ar.ar_errno; h_errno = ar.ar_h_errno; if (ar.ar_hostent == NULL) return (NULL); r = _fillhostent(ar.ar_hostent, &_hostent, _entbuf, sizeof(_entbuf)); free(ar.ar_hostent); if (r) { h_errno = NETDB_INTERNAL; errno = r; return (NULL); } return (&_hostent); }