112891Swpaul/* 212891Swpaul * Copyright (c) 1995 312891Swpaul * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. 412891Swpaul * 512891Swpaul * Redistribution and use in source and binary forms, with or without 612891Swpaul * modification, are permitted provided that the following conditions 712891Swpaul * are met: 812891Swpaul * 1. Redistributions of source code must retain the above copyright 912891Swpaul * notice, this list of conditions and the following disclaimer. 1012891Swpaul * 2. Redistributions in binary form must reproduce the above copyright 1112891Swpaul * notice, this list of conditions and the following disclaimer in the 1212891Swpaul * documentation and/or other materials provided with the distribution. 1312891Swpaul * 3. All advertising materials mentioning features or use of this software 1412891Swpaul * must display the following acknowledgement: 1512891Swpaul * This product includes software developed by Bill Paul. 1612891Swpaul * 4. Neither the name of the author nor the names of any co-contributors 1712891Swpaul * may be used to endorse or promote products derived from this software 1812891Swpaul * without specific prior written permission. 1912891Swpaul * 2012891Swpaul * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND 2112891Swpaul * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2212891Swpaul * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2312891Swpaul * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE 2412891Swpaul * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2512891Swpaul * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2612891Swpaul * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2712891Swpaul * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2812891Swpaul * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2912891Swpaul * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3012891Swpaul * SUCH DAMAGE. 3112891Swpaul * 3212891Swpaul */ 3312891Swpaul 34114601Sobrien#include <sys/cdefs.h> 35114601Sobrien__FBSDID("$FreeBSD$"); 3630827Scharnier 3714248Swpaul#include <stdlib.h> 3812891Swpaul#include <rpc/rpc.h> 3914240Swpaul#include <rpcsvc/yp.h> 4014240Swpaul#include <rpcsvc/yppasswd.h> 4118586Swpaul#include <rpcsvc/ypxfrd.h> 4212891Swpaul#include <sys/types.h> 4315426Swpaul#include <limits.h> 4415426Swpaul#include <db.h> 4512891Swpaul#include <sys/socket.h> 4612891Swpaul#include <netinet/in.h> 4712891Swpaul#include <arpa/inet.h> 4812891Swpaul#include <sys/stat.h> 4915426Swpaul#include <sys/fcntl.h> 5012891Swpaul#include <paths.h> 5114240Swpaul#include <errno.h> 5212891Swpaul#include <sys/param.h> 5312891Swpaul#include "yp_extern.h" 5412891Swpaul#ifdef TCP_WRAPPER 5512891Swpaul#include "tcpd.h" 5612891Swpaul#endif 5712891Swpaul 5812891Swpaulextern int debug; 5912891Swpaul 6014262Swpaul /* NIS v1 */ 6196221Sdesconst char *yp_procs[] = { 6296221Sdes "ypoldproc_null", 6396221Sdes "ypoldproc_domain", 6496221Sdes "ypoldproc_domain_nonack", 6596221Sdes "ypoldproc_match", 6696221Sdes "ypoldproc_first", 6796221Sdes "ypoldproc_next", 6896221Sdes "ypoldproc_poll", 6996221Sdes "ypoldproc_push", 7096221Sdes "ypoldproc_get", 7196221Sdes "badproc1", /* placeholder */ 7296221Sdes "badproc2", /* placeholder */ 7396221Sdes "badproc3", /* placeholder */ 7496221Sdes 7596221Sdes /* NIS v2 */ 7696221Sdes "ypproc_null", 7796221Sdes "ypproc_domain", 7896221Sdes "ypproc_domain_nonack", 7996221Sdes "ypproc_match", 8096221Sdes "ypproc_first", 8196221Sdes "ypproc_next", 8296221Sdes "ypproc_xfr", 8396221Sdes "ypproc_clear", 8496221Sdes "ypproc_all", 8596221Sdes "ypproc_master", 8696221Sdes "ypproc_order", 8796221Sdes "ypproc_maplist" 8896221Sdes}; 8914262Swpaul 9014240Swpaulstruct securenet { 9114240Swpaul struct in_addr net; 9214240Swpaul struct in_addr mask; 9314240Swpaul struct securenet *next; 9414240Swpaul}; 9514240Swpaul 9614240Swpaulstruct securenet *securenets; 9714240Swpaul 9814240Swpaul#define LINEBUFSZ 1024 9914240Swpaul 100253350Shrs#ifdef TCP_WRAPPER 101253350Shrsint hosts_ctl(char *, char *, char *, char *); 102253350Shrs#endif 103253350Shrs 10412891Swpaul/* 10514240Swpaul * Read /var/yp/securenets file and initialize the securenets 10614240Swpaul * list. If the file doesn't exist, we set up a dummy entry that 10714240Swpaul * allows all hosts to connect. 10814240Swpaul */ 10990298Sdesvoid 11090298Sdesload_securenets(void) 11114240Swpaul{ 11214240Swpaul FILE *fp; 11314240Swpaul char path[MAXPATHLEN + 2]; 11414240Swpaul char linebuf[1024 + 2]; 11514240Swpaul struct securenet *tmp; 11614240Swpaul 11714240Swpaul /* 11814240Swpaul * If securenets is not NULL, we are being called to reload 11914240Swpaul * the list; free the existing list before re-reading the 12014240Swpaul * securenets file. 12114240Swpaul */ 12290297Sdes while (securenets) { 12315426Swpaul tmp = securenets->next; 12415426Swpaul free(securenets); 12515426Swpaul securenets = tmp; 12614240Swpaul } 12714240Swpaul 12814240Swpaul snprintf(path, MAXPATHLEN, "%s/securenets", yp_dir); 12914240Swpaul 13014240Swpaul if ((fp = fopen(path, "r")) == NULL) { 13114240Swpaul if (errno == ENOENT) { 13214240Swpaul securenets = (struct securenet *)malloc(sizeof(struct securenet)); 13314240Swpaul securenets->net.s_addr = INADDR_ANY; 13414302Sadam securenets->mask.s_addr = INADDR_ANY; 13514240Swpaul securenets->next = NULL; 13614240Swpaul return; 13714240Swpaul } else { 13814240Swpaul yp_error("fopen(%s) failed: %s", path, strerror(errno)); 13914240Swpaul exit(1); 14014240Swpaul } 14114240Swpaul } 14214240Swpaul 14314240Swpaul securenets = NULL; 14414240Swpaul 14590297Sdes while (fgets(linebuf, LINEBUFSZ, fp)) { 14614240Swpaul char addr1[20], addr2[20]; 14714240Swpaul 14837681Sdes if ((linebuf[0] == '#') 14937681Sdes || (strspn(linebuf, " \t\r\n") == strlen(linebuf))) 15014240Swpaul continue; 15114240Swpaul if (sscanf(linebuf, "%s %s", addr1, addr2) < 2) { 15214240Swpaul yp_error("badly formatted securenets entry: %s", 15314240Swpaul linebuf); 15414240Swpaul continue; 15514240Swpaul } 15614240Swpaul 15714240Swpaul tmp = (struct securenet *)malloc(sizeof(struct securenet)); 15814240Swpaul 15914240Swpaul if (!inet_aton((char *)&addr1, (struct in_addr *)&tmp->net)) { 16014240Swpaul yp_error("badly formatted securenets entry: %s", addr1); 16114240Swpaul free(tmp); 16214240Swpaul continue; 16314240Swpaul } 16414240Swpaul 16514240Swpaul if (!inet_aton((char *)&addr2, (struct in_addr *)&tmp->mask)) { 16614240Swpaul yp_error("badly formatted securenets entry: %s", addr2); 16714240Swpaul free(tmp); 16814240Swpaul continue; 16914240Swpaul } 17014240Swpaul 17114240Swpaul tmp->next = securenets; 17214240Swpaul securenets = tmp; 17314240Swpaul } 17414240Swpaul 17514240Swpaul fclose(fp); 17690297Sdes 17714240Swpaul} 17814240Swpaul 17914240Swpaul/* 18012891Swpaul * Access control functions. 18112891Swpaul * 18212891Swpaul * yp_access() checks the mapname and client host address and watches for 18312891Swpaul * the following things: 18412891Swpaul * 185194968Sbrian * - If the client is referencing one of the master.passwd.* or shadow.* maps, 186194968Sbrian * it must be using a privileged port to make its RPC to us. If it is, then 187194968Sbrian * we can assume that the caller is root and allow the RPC to succeed. If it 18812891Swpaul * isn't access is denied. 18912891Swpaul * 19014240Swpaul * - The client's IP address is checked against the securenets rules. 19114240Swpaul * There are two kinds of securenets support: the built-in support, 19215426Swpaul * which is very simple and depends on the presence of a 19314240Swpaul * /var/yp/securenets file, and tcp-wrapper support, which requires 19414240Swpaul * Wietse Venema's libwrap.a and tcpd.h. (Since the tcp-wrapper 19514240Swpaul * package does not ship with FreeBSD, we use the built-in support 19615426Swpaul * by default. Users can recompile the server with the tcp-wrapper library 19714240Swpaul * if they already have it installed and want to use hosts.allow and 19872091Sasmodai * hosts.deny to control access instead of having a separate securenets 19914240Swpaul * file.) 20012891Swpaul * 20114240Swpaul * If no /var/yp/securenets file is present, the host access checks 20214240Swpaul * are bypassed and all hosts are allowed to connect. 20314240Swpaul * 20415426Swpaul * The yp_validdomain() function checks the domain specified by the caller 20512891Swpaul * to make sure it's actually served by this server. This is more a sanity 20612891Swpaul * check than an a security check, but this seems to be the best place for 20712891Swpaul * it. 20812891Swpaul */ 20912891Swpaul 21019161Swpaul#ifdef DB_CACHE 21190298Sdesint 21290298Sdesyp_access(const char *map, const char *domain, const struct svc_req *rqstp) 21319161Swpaul#else 21490298Sdesint 21590298Sdesyp_access(const char *map, const struct svc_req *rqstp) 21619161Swpaul#endif 21712891Swpaul{ 21812891Swpaul struct sockaddr_in *rqhost; 219159117Scperciva int status_securenets = 0; 220159117Scperciva#ifdef TCP_WRAPPER 221159117Scperciva int status_tcpwrap; 222159117Scperciva#endif 22316044Swpaul static unsigned long oldaddr = 0; 22414240Swpaul struct securenet *tmp; 22596221Sdes const char *yp_procedure = NULL; 22616118Swpaul char procbuf[50]; 22712891Swpaul 22816118Swpaul if (rqstp->rq_prog != YPPASSWDPROG && rqstp->rq_prog != YPPROG) { 22996221Sdes snprintf(procbuf, sizeof(procbuf), "#%lu/#%lu", 23096221Sdes (unsigned long)rqstp->rq_prog, 23196221Sdes (unsigned long)rqstp->rq_proc); 23216118Swpaul yp_procedure = (char *)&procbuf; 23316118Swpaul } else { 23416118Swpaul yp_procedure = rqstp->rq_prog == YPPASSWDPROG ? 23516118Swpaul "yppasswdprog_update" : 23616118Swpaul yp_procs[rqstp->rq_proc + (12 * (rqstp->rq_vers - 1))]; 23716118Swpaul } 23814262Swpaul 23912891Swpaul rqhost = svc_getcaller(rqstp->rq_xprt); 24012891Swpaul 24112891Swpaul if (debug) { 24230827Scharnier yp_error("procedure %s called from %s:%d", yp_procedure, 24314262Swpaul inet_ntoa(rqhost->sin_addr), 24412891Swpaul ntohs(rqhost->sin_port)); 24512891Swpaul if (map != NULL) 24630827Scharnier yp_error("client is referencing map \"%s\".", map); 24712891Swpaul } 24812891Swpaul 24912891Swpaul /* Check the map name if one was supplied. */ 25012891Swpaul if (map != NULL) { 25118586Swpaul if (strchr(map, '/')) { 25218586Swpaul yp_error("embedded slash in map name \"%s\" -- \ 25318586Swpaulpossible spoof attempt from %s:%d", 25418586Swpaul map, inet_ntoa(rqhost->sin_addr), 25518586Swpaul ntohs(rqhost->sin_port)); 25621366Swpaul return(1); 25718586Swpaul } 25819161Swpaul#ifdef DB_CACHE 25919161Swpaul if ((yp_testflag((char *)map, (char *)domain, YP_SECURE) || 26019161Swpaul#else 261194968Sbrian if ((strstr(map, "master.passwd.") || strstr(map, "shadow.") || 26219161Swpaul#endif 26318586Swpaul (rqstp->rq_prog == YPPROG && 26418586Swpaul rqstp->rq_proc == YPPROC_XFR) || 26518586Swpaul (rqstp->rq_prog == YPXFRD_FREEBSD_PROG && 26618586Swpaul rqstp->rq_proc == YPXFRD_GETMAP)) && 26718586Swpaul ntohs(rqhost->sin_port) >= IPPORT_RESERVED) { 26830827Scharnier yp_error("access to %s denied -- client %s:%d \ 26918586Swpaulnot privileged", map, inet_ntoa(rqhost->sin_addr), ntohs(rqhost->sin_port)); 27012891Swpaul return(1); 27112891Swpaul } 27212891Swpaul } 27312891Swpaul 27412891Swpaul#ifdef TCP_WRAPPER 275159117Scperciva status_tcpwrap = hosts_ctl("ypserv", STRING_UNKNOWN, 27614240Swpaul inet_ntoa(rqhost->sin_addr), ""); 277159117Scperciva#endif 27814240Swpaul tmp = securenets; 27990297Sdes while (tmp) { 28014240Swpaul if (((rqhost->sin_addr.s_addr & ~tmp->mask.s_addr) 28114240Swpaul | tmp->net.s_addr) == rqhost->sin_addr.s_addr) { 282159117Scperciva status_securenets = 1; 28314240Swpaul break; 28414240Swpaul } 28514240Swpaul tmp = tmp->next; 28614240Swpaul } 287159117Scperciva 288159117Scperciva#ifdef TCP_WRAPPER 289159117Scperciva if (status_securenets == 0 || status_tcpwrap == 0) { 290159117Scperciva#else 291159117Scperciva if (status_securenets == 0) { 29214240Swpaul#endif 293159117Scperciva /* 294228990Suqs * One of the following two events occurred: 295159117Scperciva * 296159117Scperciva * (1) The /var/yp/securenets exists and the remote host does not 297159117Scperciva * match any of the networks specified in it. 298159117Scperciva * (2) The hosts.allow file has denied access and TCP_WRAPPER is 299159117Scperciva * defined. 300159117Scperciva * 301159117Scperciva * In either case deny access. 302159117Scperciva */ 30314240Swpaul if (rqhost->sin_addr.s_addr != oldaddr) { 30414240Swpaul yp_error("connect from %s:%d to procedure %s refused", 30514240Swpaul inet_ntoa(rqhost->sin_addr), 30614240Swpaul ntohs(rqhost->sin_port), 30714262Swpaul yp_procedure); 30814240Swpaul oldaddr = rqhost->sin_addr.s_addr; 30914240Swpaul } 31012891Swpaul return(1); 31112891Swpaul } 31212891Swpaul return(0); 31312891Swpaul 31412891Swpaul} 31512891Swpaul 31690298Sdesint 31790298Sdesyp_validdomain(const char *domain) 31812891Swpaul{ 31912891Swpaul struct stat statbuf; 32012891Swpaul char dompath[MAXPATHLEN + 2]; 32112891Swpaul 32212891Swpaul if (domain == NULL || strstr(domain, "binding") || 32312891Swpaul !strcmp(domain, ".") || !strcmp(domain, "..") || 32414240Swpaul strchr(domain, '/') || strlen(domain) > YPMAXDOMAIN) 32512891Swpaul return(1); 32612891Swpaul 32712891Swpaul snprintf(dompath, sizeof(dompath), "%s/%s", yp_dir, domain); 32812891Swpaul 32912891Swpaul if (stat(dompath, &statbuf) < 0 || !S_ISDIR(statbuf.st_mode)) 33012891Swpaul return(1); 33112891Swpaul 33215426Swpaul 33312891Swpaul return(0); 33412891Swpaul} 335