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 #ifdef HAVE_CONFIG_H 31 #include <config.h> 32 RCSID("$Id: iruserok.c 17879 2006-08-08 21:50:40Z lha $"); 33 #endif 34 35 #include <stdio.h> 36 #include <ctype.h> 37 #ifdef HAVE_SYS_TYPES_H 38 #include <sys/types.h> 39 #endif 40 #ifdef HAVE_NETINET_IN_H 41 #include <netinet/in.h> 42 #endif 43 #ifdef HAVE_NETINET_IN6_H 44 #include <netinet/in6.h> 45 #endif 46 #ifdef HAVE_NETINET6_IN6_H 47 #include <netinet6/in6.h> 48 #endif 49 #ifdef HAVE_RPCSVC_YPCLNT_H 50 #include <rpcsvc/ypclnt.h> 51 #endif 52 53 #include "roken.h" 54 55 int __check_rhosts_file = 1; 56 char *__rcmd_errstr = 0; 57 58 /* 59 * Returns "true" if match, 0 if no match. 60 */ 61 static 62 int 63 __icheckhost(unsigned raddr, const char *lhost) 64 { 65 struct hostent *hp; 66 u_long laddr; 67 char **pp; 68 69 /* Try for raw ip address first. */ 70 if (isdigit((unsigned char)*lhost) 71 && (long)(laddr = inet_addr(lhost)) != -1) 72 return (raddr == laddr); 73 74 /* Better be a hostname. */ 75 if ((hp = gethostbyname(lhost)) == NULL) 76 return (0); 77 78 /* Spin through ip addresses. */ 79 for (pp = hp->h_addr_list; *pp; ++pp) 80 if (memcmp(&raddr, *pp, sizeof(u_long)) == 0) 81 return (1); 82 83 /* No match. */ 84 return (0); 85 } 86 87 /* 88 * Returns 0 if ok, -1 if not ok. 89 */ 90 static 91 int 92 __ivaliduser(FILE *hostf, unsigned raddr, const char *luser, 93 const char *ruser) 94 { 95 char *user, *p; 96 int ch; 97 char buf[MaxHostNameLen + 128]; /* host + login */ 98 char hname[MaxHostNameLen]; 99 struct hostent *hp; 100 /* Presumed guilty until proven innocent. */ 101 int userok = 0, hostok = 0; 102 #ifdef HAVE_YP_GET_DEFAULT_DOMAIN 103 char *ypdomain; 104 105 if (yp_get_default_domain(&ypdomain)) 106 ypdomain = NULL; 107 #else 108 #define ypdomain NULL 109 #endif 110 /* We need to get the damn hostname back for netgroup matching. */ 111 if ((hp = gethostbyaddr((char *)&raddr, 112 sizeof(u_long), 113 AF_INET)) == NULL) 114 return (-1); 115 strlcpy(hname, hp->h_name, sizeof(hname)); 116 117 while (fgets(buf, sizeof(buf), hostf)) { 118 p = buf; 119 /* Skip lines that are too long. */ 120 if (strchr(p, '\n') == NULL) { 121 while ((ch = getc(hostf)) != '\n' && ch != EOF); 122 continue; 123 } 124 if (*p == '\n' || *p == '#') { 125 /* comment... */ 126 continue; 127 } 128 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 129 if (isupper((unsigned char)*p)) 130 *p = tolower((unsigned char)*p); 131 p++; 132 } 133 if (*p == ' ' || *p == '\t') { 134 *p++ = '\0'; 135 while (*p == ' ' || *p == '\t') 136 p++; 137 user = p; 138 while (*p != '\n' && *p != ' ' && 139 *p != '\t' && *p != '\0') 140 p++; 141 } else 142 user = p; 143 *p = '\0'; 144 /* 145 * Do +/- and +@/-@ checking. This looks really nasty, 146 * but it matches SunOS's behavior so far as I can tell. 147 */ 148 switch(buf[0]) { 149 case '+': 150 if (!buf[1]) { /* '+' matches all hosts */ 151 hostok = 1; 152 break; 153 } 154 if (buf[1] == '@') /* match a host by netgroup */ 155 hostok = innetgr((char *)&buf[2], 156 (char *)&hname, NULL, ypdomain); 157 else /* match a host by addr */ 158 hostok = __icheckhost(raddr,(char *)&buf[1]); 159 break; 160 case '-': /* reject '-' hosts and all their users */ 161 if (buf[1] == '@') { 162 if (innetgr((char *)&buf[2], 163 (char *)&hname, NULL, ypdomain)) 164 return(-1); 165 } else { 166 if (__icheckhost(raddr,(char *)&buf[1])) 167 return(-1); 168 } 169 break; 170 default: /* if no '+' or '-', do a simple match */ 171 hostok = __icheckhost(raddr, buf); 172 break; 173 } 174 switch(*user) { 175 case '+': 176 if (!*(user+1)) { /* '+' matches all users */ 177 userok = 1; 178 break; 179 } 180 if (*(user+1) == '@') /* match a user by netgroup */ 181 userok = innetgr(user+2, NULL, (char *)ruser, 182 ypdomain); 183 else /* match a user by direct specification */ 184 userok = !(strcmp(ruser, user+1)); 185 break; 186 case '-': /* if we matched a hostname, */ 187 if (hostok) { /* check for user field rejections */ 188 if (!*(user+1)) 189 return(-1); 190 if (*(user+1) == '@') { 191 if (innetgr(user+2, NULL, 192 (char *)ruser, ypdomain)) 193 return(-1); 194 } else { 195 if (!strcmp(ruser, user+1)) 196 return(-1); 197 } 198 } 199 break; 200 default: /* no rejections: try to match the user */ 201 if (hostok) 202 userok = !(strcmp(ruser,*user ? user : luser)); 203 break; 204 } 205 if (hostok && userok) 206 return(0); 207 } 208 return (-1); 209 } 210 211 /* 212 * New .rhosts strategy: We are passed an ip address. We spin through 213 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 214 * has ip addresses, we don't have to trust a nameserver. When it 215 * contains hostnames, we spin through the list of addresses the nameserver 216 * gives us and look for a match. 217 * 218 * Returns 0 if ok, -1 if not ok. 219 */ 220 int ROKEN_LIB_FUNCTION 221 iruserok(unsigned raddr, int superuser, const char *ruser, const char *luser) 222 { 223 char *cp; 224 struct stat sbuf; 225 struct passwd *pwd; 226 FILE *hostf; 227 uid_t uid; 228 int first; 229 char pbuf[MaxPathLen]; 230 231 first = 1; 232 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 233 again: 234 if (hostf) { 235 if (__ivaliduser(hostf, raddr, luser, ruser) == 0) { 236 fclose(hostf); 237 return (0); 238 } 239 fclose(hostf); 240 } 241 if (first == 1 && (__check_rhosts_file || superuser)) { 242 first = 0; 243 if ((pwd = k_getpwnam((char*)luser)) == NULL) 244 return (-1); 245 snprintf (pbuf, sizeof(pbuf), "%s/.rhosts", pwd->pw_dir); 246 247 /* 248 * Change effective uid while opening .rhosts. If root and 249 * reading an NFS mounted file system, can't read files that 250 * are protected read/write owner only. 251 */ 252 uid = geteuid(); 253 if (seteuid(pwd->pw_uid) < 0) 254 return (-1); 255 hostf = fopen(pbuf, "r"); 256 seteuid(uid); 257 258 if (hostf == NULL) 259 return (-1); 260 /* 261 * If not a regular file, or is owned by someone other than 262 * user or root or if writeable by anyone but the owner, quit. 263 */ 264 cp = NULL; 265 if (lstat(pbuf, &sbuf) < 0) 266 cp = ".rhosts lstat failed"; 267 else if (!S_ISREG(sbuf.st_mode)) 268 cp = ".rhosts not regular file"; 269 else if (fstat(fileno(hostf), &sbuf) < 0) 270 cp = ".rhosts fstat failed"; 271 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 272 cp = "bad .rhosts owner"; 273 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 274 cp = ".rhosts writeable by other than owner"; 275 /* If there were any problems, quit. */ 276 if (cp) { 277 __rcmd_errstr = cp; 278 fclose(hostf); 279 return (-1); 280 } 281 goto again; 282 } 283 return (-1); 284 } 285