1/* 2 * Copyright (c) 1983, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#include <config.h> 31 32#include <stdio.h> 33#include <ctype.h> 34#ifdef HAVE_SYS_TYPES_H 35#include <sys/types.h> 36#endif 37#ifdef HAVE_NETINET_IN_H 38#include <netinet/in.h> 39#endif 40#ifdef HAVE_NETINET_IN6_H 41#include <netinet/in6.h> 42#endif 43#ifdef HAVE_NETINET6_IN6_H 44#include <netinet6/in6.h> 45#endif 46#ifdef HAVE_RPCSVC_YPCLNT_H 47#include <rpcsvc/ypclnt.h> 48#endif 49 50#include "roken.h" 51 52int __check_rhosts_file = 1; 53char *__rcmd_errstr = 0; 54 55/* 56 * Returns "true" if match, 0 if no match. 57 */ 58static 59int 60__icheckhost(unsigned raddr, const char *lhost) 61{ 62 struct hostent *hp; 63 u_long laddr; 64 char **pp; 65 66 /* Try for raw ip address first. */ 67 if (isdigit((unsigned char)*lhost) 68 && (long)(laddr = inet_addr(lhost)) != -1) 69 return (raddr == laddr); 70 71 /* Better be a hostname. */ 72 if ((hp = gethostbyname(lhost)) == NULL) 73 return (0); 74 75 /* Spin through ip addresses. */ 76 for (pp = hp->h_addr_list; *pp; ++pp) 77 if (memcmp(&raddr, *pp, sizeof(u_long)) == 0) 78 return (1); 79 80 /* No match. */ 81 return (0); 82} 83 84/* 85 * Returns 0 if ok, -1 if not ok. 86 */ 87static 88int 89__ivaliduser(FILE *hostf, unsigned raddr, const char *luser, 90 const char *ruser) 91{ 92 char *user, *p; 93 int ch; 94 char buf[MaxHostNameLen + 128]; /* host + login */ 95 char hname[MaxHostNameLen]; 96 struct hostent *hp; 97 /* Presumed guilty until proven innocent. */ 98 int userok = 0, hostok = 0; 99#ifdef HAVE_YP_GET_DEFAULT_DOMAIN 100 char *ypdomain; 101 102 if (yp_get_default_domain(&ypdomain)) 103 ypdomain = NULL; 104#else 105#define ypdomain NULL 106#endif 107 /* We need to get the damn hostname back for netgroup matching. */ 108 if ((hp = gethostbyaddr((char *)&raddr, 109 sizeof(u_long), 110 AF_INET)) == NULL) 111 return (-1); 112 strlcpy(hname, hp->h_name, sizeof(hname)); 113 114 while (fgets(buf, sizeof(buf), hostf)) { 115 p = buf; 116 /* Skip lines that are too long. */ 117 if (strchr(p, '\n') == NULL) { 118 while ((ch = getc(hostf)) != '\n' && ch != EOF); 119 continue; 120 } 121 if (*p == '\n' || *p == '#') { 122 /* comment... */ 123 continue; 124 } 125 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 126 if (isupper((unsigned char)*p)) 127 *p = tolower((unsigned char)*p); 128 p++; 129 } 130 if (*p == ' ' || *p == '\t') { 131 *p++ = '\0'; 132 while (*p == ' ' || *p == '\t') 133 p++; 134 user = p; 135 while (*p != '\n' && *p != ' ' && 136 *p != '\t' && *p != '\0') 137 p++; 138 } else 139 user = p; 140 *p = '\0'; 141 /* 142 * Do +/- and +@/-@ checking. This looks really nasty, 143 * but it matches SunOS's behavior so far as I can tell. 144 */ 145 switch(buf[0]) { 146 case '+': 147 if (!buf[1]) { /* '+' matches all hosts */ 148 hostok = 1; 149 break; 150 } 151 if (buf[1] == '@') /* match a host by netgroup */ 152 hostok = innetgr((char *)&buf[2], 153 (char *)&hname, NULL, ypdomain); 154 else /* match a host by addr */ 155 hostok = __icheckhost(raddr,(char *)&buf[1]); 156 break; 157 case '-': /* reject '-' hosts and all their users */ 158 if (buf[1] == '@') { 159 if (innetgr((char *)&buf[2], 160 (char *)&hname, NULL, ypdomain)) 161 return(-1); 162 } else { 163 if (__icheckhost(raddr,(char *)&buf[1])) 164 return(-1); 165 } 166 break; 167 default: /* if no '+' or '-', do a simple match */ 168 hostok = __icheckhost(raddr, buf); 169 break; 170 } 171 switch(*user) { 172 case '+': 173 if (!*(user+1)) { /* '+' matches all users */ 174 userok = 1; 175 break; 176 } 177 if (*(user+1) == '@') /* match a user by netgroup */ 178 userok = innetgr(user+2, NULL, (char *)ruser, 179 ypdomain); 180 else /* match a user by direct specification */ 181 userok = !(strcmp(ruser, user+1)); 182 break; 183 case '-': /* if we matched a hostname, */ 184 if (hostok) { /* check for user field rejections */ 185 if (!*(user+1)) 186 return(-1); 187 if (*(user+1) == '@') { 188 if (innetgr(user+2, NULL, 189 (char *)ruser, ypdomain)) 190 return(-1); 191 } else { 192 if (!strcmp(ruser, user+1)) 193 return(-1); 194 } 195 } 196 break; 197 default: /* no rejections: try to match the user */ 198 if (hostok) 199 userok = !(strcmp(ruser,*user ? user : luser)); 200 break; 201 } 202 if (hostok && userok) 203 return(0); 204 } 205 return (-1); 206} 207 208/* 209 * New .rhosts strategy: We are passed an ip address. We spin through 210 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 211 * has ip addresses, we don't have to trust a nameserver. When it 212 * contains hostnames, we spin through the list of addresses the nameserver 213 * gives us and look for a match. 214 * 215 * Returns 0 if ok, -1 if not ok. 216 */ 217ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL 218iruserok(unsigned raddr, int superuser, const char *ruser, const char *luser) 219{ 220 char *cp; 221 struct stat sbuf; 222 struct passwd *pwd; 223 FILE *hostf; 224 uid_t uid; 225 int first; 226 char pbuf[MaxPathLen]; 227 228 first = 1; 229 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 230again: 231 if (hostf) { 232 if (__ivaliduser(hostf, raddr, luser, ruser) == 0) { 233 fclose(hostf); 234 return (0); 235 } 236 fclose(hostf); 237 } 238 if (first == 1 && (__check_rhosts_file || superuser)) { 239 first = 0; 240 if ((pwd = k_getpwnam((char*)luser)) == NULL) 241 return (-1); 242 snprintf (pbuf, sizeof(pbuf), "%s/.rhosts", pwd->pw_dir); 243 244 /* 245 * Change effective uid while opening .rhosts. If root and 246 * reading an NFS mounted file system, can't read files that 247 * are protected read/write owner only. 248 */ 249 uid = geteuid(); 250 if (seteuid(pwd->pw_uid) < 0) 251 return (-1); 252 hostf = fopen(pbuf, "r"); 253 seteuid(uid); 254 255 if (hostf == NULL) 256 return (-1); 257 /* 258 * If not a regular file, or is owned by someone other than 259 * user or root or if writeable by anyone but the owner, quit. 260 */ 261 cp = NULL; 262 if (lstat(pbuf, &sbuf) < 0) 263 cp = ".rhosts lstat failed"; 264 else if (!S_ISREG(sbuf.st_mode)) 265 cp = ".rhosts not regular file"; 266 else if (fstat(fileno(hostf), &sbuf) < 0) 267 cp = ".rhosts fstat failed"; 268 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 269 cp = "bad .rhosts owner"; 270 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 271 cp = ".rhosts writeable by other than owner"; 272 /* If there were any problems, quit. */ 273 if (cp) { 274 __rcmd_errstr = cp; 275 fclose(hostf); 276 return (-1); 277 } 278 goto again; 279 } 280 return (-1); 281} 282