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/* $OpenBSD: yp_bind.c,v 1.28 2016/05/30 02:53:29 guenther Exp $ */ |
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/* |
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* Copyright (c) 1992, 1993, 1996 Theo de Raadt <deraadt@theos.com> |
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* 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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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
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* 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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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/uio.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <limits.h> |
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#include <paths.h> |
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#include <rpc/rpc.h> |
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#include <rpc/xdr.h> |
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#include <rpcsvc/yp.h> |
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#include <rpcsvc/ypclnt.h> |
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#include "ypinternal.h" |
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struct dom_binding *_ypbindlist; |
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char _yp_domain[HOST_NAME_MAX+1]; |
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int _yplib_timeout = 10; |
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int |
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_yp_dobind(const char *dom, struct dom_binding **ypdb) |
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{ |
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static pid_t pid = -1; |
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char path[PATH_MAX]; |
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struct dom_binding *ysd, *ysd2; |
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struct ypbind_resp ypbr; |
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struct timeval tv; |
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struct sockaddr_in clnt_sin; |
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struct ypbind_binding *bn; |
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int clnt_sock, fd; |
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pid_t gpid; |
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CLIENT *client; |
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int new = 0, r; |
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u_short port; |
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/* |
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* test if YP is running or not |
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*/ |
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if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1) |
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return YPERR_YPBIND; |
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if (!(flock(fd, LOCK_EX | LOCK_NB) == -1 && errno == EWOULDBLOCK)) { |
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(void)close(fd); |
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return YPERR_YPBIND; |
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} |
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(void)close(fd); |
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gpid = getpid(); |
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if (!(pid == -1 || pid == gpid)) { |
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ysd = _ypbindlist; |
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while (ysd) { |
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if (ysd->dom_client) |
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clnt_destroy(ysd->dom_client); |
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ysd2 = ysd->dom_pnext; |
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free(ysd); |
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ysd = ysd2; |
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} |
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_ypbindlist = NULL; |
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} |
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pid = gpid; |
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if (ypdb != NULL) |
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*ypdb = NULL; |
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if (dom == NULL || strlen(dom) == 0) |
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return YPERR_BADARGS; |
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for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext) |
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if (strcmp(dom, ysd->dom_domain) == 0) |
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break; |
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if (ysd == NULL) { |
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if ((ysd = calloc(1, sizeof *ysd)) == NULL) |
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return YPERR_RESRC; |
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ysd->dom_socket = -1; |
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ysd->dom_vers = 0; |
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new = 1; |
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} |
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again: |
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if (ysd->dom_vers == 0) { |
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r = snprintf(path, sizeof(path), "%s/%s.%d", |
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BINDINGDIR, dom, 2); |
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if (r < 0 || r >= sizeof(path)) { |
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if (new) |
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free(ysd); |
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return YPERR_BADARGS; |
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} |
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if ((fd = open(path, O_RDONLY)) == -1) { |
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/* |
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* no binding file, YP is dead, or not yet fully |
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* alive. |
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*/ |
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goto trynet; |
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} |
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if (flock(fd, LOCK_EX | LOCK_NB) == -1 && |
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errno == EWOULDBLOCK) { |
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struct iovec iov[2]; |
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u_short ypb_port; |
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/* |
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* we fetch the ypbind port number, but do |
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* nothing with it. |
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*/ |
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iov[0].iov_base = (caddr_t) &ypb_port; |
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iov[0].iov_len = sizeof ypb_port; |
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iov[1].iov_base = (caddr_t) &ypbr; |
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iov[1].iov_len = sizeof ypbr; |
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r = readv(fd, iov, 2); |
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if (r != iov[0].iov_len + iov[1].iov_len) { |
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(void)close(fd); |
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ysd->dom_vers = -1; |
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goto again; |
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} |
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(void)close(fd); |
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goto gotdata; |
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} else { |
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/* no lock on binding file, YP is dead. */ |
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(void)close(fd); |
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if (new) |
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free(ysd); |
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return YPERR_YPBIND; |
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} |
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} |
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trynet: |
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if (ysd->dom_vers == -1 || ysd->dom_vers == 0) { |
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(void)memset(&clnt_sin, 0, sizeof clnt_sin); |
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clnt_sin.sin_len = sizeof(struct sockaddr_in); |
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clnt_sin.sin_family = AF_INET; |
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clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
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clnt_sock = RPC_ANYSOCK; |
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client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS, |
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&clnt_sock, 0, 0); |
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if (client == NULL) { |
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clnt_pcreateerror("clnttcp_create"); |
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if (new) |
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free(ysd); |
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switch (rpc_createerr.cf_error.re_errno) { |
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case ECONNREFUSED: |
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return YPERR_YPBIND; |
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case ENOMEM: |
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return YPERR_RESRC; |
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default: |
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return YPERR_YPERR; |
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} |
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} |
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if (ntohs(clnt_sin.sin_port) >= IPPORT_RESERVED || |
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ntohs(clnt_sin.sin_port) == 20) { |
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/* |
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* YP was not running, but someone has registered |
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* ypbind with portmap -- this simply means YP is |
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* not running. |
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*/ |
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clnt_destroy(client); |
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if (new) |
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free(ysd); |
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return YPERR_YPBIND; |
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} |
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tv.tv_sec = _yplib_timeout; |
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tv.tv_usec = 0; |
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r = clnt_call(client, YPBINDPROC_DOMAIN, xdr_domainname, |
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&dom, xdr_ypbind_resp, &ypbr, tv); |
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if (r != RPC_SUCCESS) { |
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clnt_destroy(client); |
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ysd->dom_vers = -1; |
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goto again; |
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} |
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clnt_destroy(client); |
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gotdata: |
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bn = &ypbr.ypbind_resp_u.ypbind_bindinfo; |
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memcpy(&port, &bn->ypbind_binding_port, sizeof port); |
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if (ntohs(port) >= IPPORT_RESERVED || |
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ntohs(port) == 20) { |
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/* |
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* This is bullshit -- the ypbind wants me to |
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* communicate to an insecure ypserv. We are |
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* within rights to syslog this as an attack, |
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* but for now we'll simply ignore it; real YP |
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* is obviously not running. |
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*/ |
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if (new) |
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free(ysd); |
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return YPERR_YPBIND; |
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} |
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(void)memset(&ysd->dom_server_addr, 0, |
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sizeof ysd->dom_server_addr); |
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ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in); |
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ysd->dom_server_addr.sin_family = AF_INET; |
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memcpy(&ysd->dom_server_addr.sin_port, |
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&bn->ypbind_binding_port, |
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sizeof(ysd->dom_server_addr.sin_port)); |
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memcpy(&ysd->dom_server_addr.sin_addr.s_addr, |
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&bn->ypbind_binding_addr, |
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sizeof(ysd->dom_server_addr.sin_addr.s_addr)); |
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ysd->dom_server_port = ysd->dom_server_addr.sin_port; |
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ysd->dom_vers = YPVERS; |
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strlcpy(ysd->dom_domain, dom, sizeof ysd->dom_domain); |
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} |
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tv.tv_sec = _yplib_timeout / 2; |
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tv.tv_usec = 0; |
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if (ysd->dom_client) |
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clnt_destroy(ysd->dom_client); |
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ysd->dom_socket = RPC_ANYSOCK; |
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ysd->dom_client = clntudp_create(&ysd->dom_server_addr, |
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YPPROG, YPVERS, tv, &ysd->dom_socket); |
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if (ysd->dom_client == NULL) { |
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clnt_pcreateerror("clntudp_create"); |
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ysd->dom_vers = -1; |
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goto again; |
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} |
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if (fcntl(ysd->dom_socket, F_SETFD, FD_CLOEXEC) == -1) |
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perror("fcntl: F_SETFD"); |
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if (new) { |
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ysd->dom_pnext = _ypbindlist; |
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_ypbindlist = ysd; |
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} |
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if (ypdb != NULL) |
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*ypdb = ysd; |
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return 0; |
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} |
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void |
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_yp_unbind(struct dom_binding *ypb) |
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{ |
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clnt_destroy(ypb->dom_client); |
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ypb->dom_client = NULL; |
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ypb->dom_socket = -1; |
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} |
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int |
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yp_bind(const char *dom) |
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{ |
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return _yp_dobind(dom, NULL); |
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} |
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DEF_WEAK(yp_bind); |
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void |
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yp_unbind(const char *dom) |
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{ |
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struct dom_binding *ypb, *ypbp; |
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ypbp = NULL; |
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for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) { |
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if (strcmp(dom, ypb->dom_domain) == 0) { |
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clnt_destroy(ypb->dom_client); |
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if (ypbp) |
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ypbp->dom_pnext = ypb->dom_pnext; |
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else |
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_ypbindlist = ypb->dom_pnext; |
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free(ypb); |
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return; |
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} |
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ypbp = ypb; |
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} |
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} |