/* Copyright (C) 1997-2013 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #include <string.h> #include <rpcsvc/nis.h> #include "nis_xdr.h" #include "nis_intern.h" #include <libnsl.h> nis_result * nis_lookup (const_nis_name name, const unsigned int flags) { nis_result *res = calloc (1, sizeof (nis_result)); struct ns_request req; nis_name *names; nis_error status; int link_first_try = 0; int count_links = 0; /* We will follow only 16 links in the deep */ int done = 0; int name_nr = 0; nis_name namebuf[2] = {NULL, NULL}; if (res == NULL) return NULL; if ((flags & EXPAND_NAME) && (name[strlen (name) - 1] != '.')) { names = nis_getnames (name); if (names == NULL) { NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE; return res; } } else { names = namebuf; names[0] = (nis_name)name; } req.ns_name = names[0]; while (!done) { dir_binding bptr; directory_obj *dir = NULL; req.ns_object.ns_object_len = 0; req.ns_object.ns_object_val = NULL; status = __prepare_niscall (req.ns_name, &dir, &bptr, flags); if (__builtin_expect (status != NIS_SUCCESS, 0)) { NIS_RES_STATUS (res) = status; goto out; } do { static const struct timeval RPCTIMEOUT = {10, 0}; enum clnt_stat result; again: result = clnt_call (bptr.clnt, NIS_LOOKUP, (xdrproc_t) _xdr_ns_request, (caddr_t) &req, (xdrproc_t) _xdr_nis_result, (caddr_t) res, RPCTIMEOUT); if (result != RPC_SUCCESS) status = NIS_RPCERROR; else { status = NIS_SUCCESS; if (NIS_RES_STATUS (res) == NIS_SUCCESS) { if (__type_of (NIS_RES_OBJECT (res)) == NIS_LINK_OBJ && (flags & FOLLOW_LINKS)) /* We are following links */ { /* if we hit the link limit, bail */ if (count_links > NIS_MAXLINKS) { NIS_RES_STATUS (res) = NIS_LINKNAMEERROR; break; } ++count_links; req.ns_name = strdupa (NIS_RES_OBJECT (res)->LI_data.li_name); /* The following is a non-obvious optimization. A nis_freeresult call would call xdr_free as the following code. But it also would unnecessarily free the result structure. We avoid this here along with the necessary tests. */ xdr_free ((xdrproc_t) _xdr_nis_result, (char *) res); memset (res, '\0', sizeof (*res)); link_first_try = 1; /* Try at first the old binding */ goto again; } } else if (NIS_RES_STATUS (res) == NIS_SYSTEMERROR || NIS_RES_STATUS (res) == NIS_NOSUCHNAME || NIS_RES_STATUS (res) == NIS_NOT_ME) { if (link_first_try) { __nisbind_destroy (&bptr); nis_free_directory (dir); /* Otherwise __nisfind_server will not do anything. */ dir = NULL; if (__nisfind_server (req.ns_name, 1, &dir, &bptr, flags & ~MASTER_ONLY) != NIS_SUCCESS) goto out; } else if (__nisbind_next (&bptr) != NIS_SUCCESS) { /* No more servers to search. Try parent. */ const char *ndomain = __nis_domain_of (req.ns_name); req.ns_name = strdupa (ndomain); if (strcmp (req.ns_name, ".") == 0) { NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE; goto out; } __nisbind_destroy (&bptr); nis_free_directory (dir); dir = NULL; status = __prepare_niscall (req.ns_name, &dir, &bptr, flags); if (__builtin_expect (status != NIS_SUCCESS, 0)) { NIS_RES_STATUS (res) = status; goto out; } goto again; } while (__nisbind_connect (&bptr) != NIS_SUCCESS) { if (__nisbind_next (&bptr) != NIS_SUCCESS) { nis_free_directory (dir); goto out; } } goto again; } break; } link_first_try = 0; /* Set it back */ } while ((flags & HARD_LOOKUP) && status == NIS_RPCERROR); __nisbind_destroy (&bptr); nis_free_directory (dir); if (status != NIS_SUCCESS) { NIS_RES_STATUS (res) = status; goto out; } switch (NIS_RES_STATUS (res)) { case NIS_PARTIAL: case NIS_SUCCESS: case NIS_S_SUCCESS: case NIS_LINKNAMEERROR: /* We follow to max links */ case NIS_UNAVAIL: /* NIS+ is not installed, or all servers are down */ ++done; break; default: /* Try the next domainname if we don't follow a link */ if (count_links) { free (req.ns_name); NIS_RES_STATUS (res) = NIS_LINKNAMEERROR; ++done; break; } ++name_nr; if (names[name_nr] == NULL) { ++done; break; } req.ns_name = names[name_nr]; break; } } out: if (names != namebuf) nis_freenames (names); return res; } libnsl_hidden_def (nis_lookup)