1 /* 2 * System configuration routines 3 * 4 * Written by Toshiharu OHNO (tony-o@iij.ad.jp) 5 * 6 * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the Internet Initiative Japan, Inc. The name of the 14 * IIJ may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 * $Id: systems.c,v 1.44 1999/05/09 20:02:26 brian Exp $ 21 * 22 * TODO: 23 */ 24 #include <sys/param.h> 25 26 #include <ctype.h> 27 #include <pwd.h> 28 #include <stdio.h> 29 #include <stdlib.h> 30 #include <string.h> 31 #include <termios.h> 32 #include <unistd.h> 33 34 #include "defs.h" 35 #include "command.h" 36 #include "log.h" 37 #include "id.h" 38 #include "systems.h" 39 40 #define issep(ch) ((ch) == ' ' || (ch) == '\t') 41 42 FILE * 43 OpenSecret(const char *file) 44 { 45 FILE *fp; 46 char line[100]; 47 48 snprintf(line, sizeof line, "%s/%s", _PATH_PPP, file); 49 fp = ID0fopen(line, "r"); 50 if (fp == NULL) 51 log_Printf(LogWARN, "OpenSecret: Can't open %s.\n", line); 52 return (fp); 53 } 54 55 void 56 CloseSecret(FILE *fp) 57 { 58 fclose(fp); 59 } 60 61 /* Move string from ``from'' to ``to'', interpreting ``~'' and $.... */ 62 static void 63 InterpretArg(char *from, char *to) 64 { 65 const char *env; 66 char *ptr, *startto, *endto; 67 int len; 68 69 startto = to; 70 endto = to + LINE_LEN - 1; 71 72 while(issep(*from)) 73 from++; 74 if (*from == '~') { 75 ptr = strchr(++from, '/'); 76 len = ptr ? ptr - from : strlen(from); 77 if (len == 0) { 78 if ((env = getenv("HOME")) == NULL) 79 env = _PATH_PPP; 80 strncpy(to, env, endto - to); 81 } else { 82 struct passwd *pwd; 83 84 strncpy(to, from, len); 85 to[len] = '\0'; 86 pwd = getpwnam(to); 87 if (pwd) 88 strncpy(to, pwd->pw_dir, endto-to); 89 else 90 strncpy(to, _PATH_PPP, endto - to); 91 endpwent(); 92 } 93 *endto = '\0'; 94 to += strlen(to); 95 from += len; 96 } 97 98 while (to < endto && *from != '\0') { 99 if (*from == '$') { 100 if (from[1] == '$') { 101 *to = '\0'; /* For an empty var name below */ 102 from += 2; 103 } else if (from[1] == '{') { 104 ptr = strchr(from+2, '}'); 105 if (ptr) { 106 len = ptr - from - 2; 107 if (endto - to < len ) 108 len = endto - to; 109 if (len) { 110 strncpy(to, from+2, len); 111 to[len] = '\0'; 112 from = ptr+1; 113 } else { 114 *to++ = *from++; 115 continue; 116 } 117 } else { 118 *to++ = *from++; 119 continue; 120 } 121 } else { 122 ptr = to; 123 for (from++; (isalnum(*from) || *from == '_') && ptr < endto; from++) 124 *ptr++ = *from; 125 *ptr = '\0'; 126 } 127 if (*to == '\0') 128 *to++ = '$'; 129 else if ((env = getenv(to)) != NULL) { 130 strncpy(to, env, endto - to); 131 *endto = '\0'; 132 to += strlen(to); 133 } 134 } else 135 *to++ = *from++; 136 } 137 while (to > startto) { 138 to--; 139 if (!issep(*to)) { 140 to++; 141 break; 142 } 143 } 144 *to = '\0'; 145 } 146 147 #define CTRL_UNKNOWN (0) 148 #define CTRL_INCLUDE (1) 149 150 static int 151 DecodeCtrlCommand(char *line, char *arg) 152 { 153 if (!strncasecmp(line, "include", 7) && issep(line[7])) { 154 InterpretArg(line+8, arg); 155 return CTRL_INCLUDE; 156 } 157 return CTRL_UNKNOWN; 158 } 159 160 /* 161 * Initialised in system_IsValid(), set in ReadSystem(), 162 * used by system_IsValid() 163 */ 164 static int modeok; 165 static int userok; 166 static int modereq; 167 168 int 169 AllowUsers(struct cmdargs const *arg) 170 { 171 /* arg->bundle may be NULL (see system_IsValid()) ! */ 172 int f; 173 char *user; 174 175 userok = 0; 176 user = getlogin(); 177 if (user && *user) 178 for (f = arg->argn; f < arg->argc; f++) 179 if (!strcmp("*", arg->argv[f]) || !strcmp(user, arg->argv[f])) { 180 userok = 1; 181 break; 182 } 183 184 return 0; 185 } 186 187 int 188 AllowModes(struct cmdargs const *arg) 189 { 190 /* arg->bundle may be NULL (see system_IsValid()) ! */ 191 int f, mode, allowed; 192 193 allowed = 0; 194 for (f = arg->argn; f < arg->argc; f++) { 195 mode = Nam2mode(arg->argv[f]); 196 if (mode == PHYS_NONE || mode == PHYS_ALL) 197 log_Printf(LogWARN, "allow modes: %s: Invalid mode\n", arg->argv[f]); 198 else 199 allowed |= mode; 200 } 201 202 modeok = modereq & allowed ? 1 : 0; 203 return 0; 204 } 205 206 static char * 207 strip(char *line) 208 { 209 int len; 210 211 len = strlen(line); 212 while (len && (line[len-1] == '\n' || line[len-1] == '\r' || 213 issep(line[len-1]))) 214 line[--len] = '\0'; 215 216 while (issep(*line)) 217 line++; 218 219 if (*line == '#') 220 *line = '\0'; 221 222 return line; 223 } 224 225 static int 226 xgets(char *buf, int buflen, FILE *fp) 227 { 228 int len, n; 229 230 n = 0; 231 while (fgets(buf, buflen-1, fp)) { 232 n++; 233 buf[buflen-1] = '\0'; 234 len = strlen(buf); 235 while (len && (buf[len-1] == '\n' || buf[len-1] == '\r')) 236 buf[--len] = '\0'; 237 if (len && buf[len-1] == '\\') { 238 buf += len - 1; 239 buflen -= len - 1; 240 if (!buflen) /* No buffer space */ 241 break; 242 } else 243 break; 244 } 245 return n; 246 } 247 248 /* Values for ``how'' in ReadSystem */ 249 #define SYSTEM_EXISTS 1 250 #define SYSTEM_VALIDATE 2 251 #define SYSTEM_EXEC 3 252 253 /* Returns -2 for ``file not found'' and -1 for ``label not found'' */ 254 255 static int 256 ReadSystem(struct bundle *bundle, const char *name, const char *file, 257 struct prompt *prompt, struct datalink *cx, int how) 258 { 259 FILE *fp; 260 char *cp, *wp; 261 int n, len; 262 char line[LINE_LEN]; 263 char filename[MAXPATHLEN]; 264 int linenum; 265 int argc; 266 char *argv[MAXARGS]; 267 int allowcmd; 268 int indent; 269 char arg[LINE_LEN]; 270 271 if (*file == '/') 272 snprintf(filename, sizeof filename, "%s", file); 273 else 274 snprintf(filename, sizeof filename, "%s/%s", _PATH_PPP, file); 275 fp = ID0fopen(filename, "r"); 276 if (fp == NULL) { 277 log_Printf(LogDEBUG, "ReadSystem: Can't open %s.\n", filename); 278 return -2; 279 } 280 log_Printf(LogDEBUG, "ReadSystem: Checking %s (%s).\n", name, filename); 281 282 linenum = 0; 283 while ((n = xgets(line, sizeof line, fp))) { 284 linenum += n; 285 if (issep(*line)) 286 continue; 287 288 cp = strip(line); 289 290 switch (*cp) { 291 case '\0': /* empty/comment */ 292 break; 293 294 case '!': 295 switch (DecodeCtrlCommand(cp+1, arg)) { 296 case CTRL_INCLUDE: 297 log_Printf(LogCOMMAND, "%s: Including \"%s\"\n", filename, arg); 298 n = ReadSystem(bundle, name, arg, prompt, cx, how); 299 log_Printf(LogCOMMAND, "%s: Done include of \"%s\"\n", filename, arg); 300 if (!n) 301 return 0; /* got it */ 302 break; 303 default: 304 log_Printf(LogWARN, "%s: %s: Invalid command\n", filename, cp); 305 break; 306 } 307 break; 308 309 default: 310 wp = strchr(cp, ':'); 311 if (wp == NULL || wp[1] != '\0') { 312 log_Printf(LogWARN, "Bad rule in %s (line %d) - missing colon.\n", 313 filename, linenum); 314 continue; 315 } 316 *wp = '\0'; 317 cp = strip(cp); /* lose any spaces between the label and the ':' */ 318 319 if (strcmp(cp, name) == 0) { 320 /* We're in business */ 321 if (how == SYSTEM_EXISTS) 322 return 0; 323 while ((n = xgets(line, sizeof line, fp))) { 324 linenum += n; 325 indent = issep(*line); 326 cp = strip(line); 327 328 if (*cp == '\0') /* empty / comment */ 329 continue; 330 331 if (!indent) { /* start of next section */ 332 if (*cp != '!') { 333 wp = strchr(cp, ':'); 334 if ((how == SYSTEM_EXEC) && (wp == NULL || wp[1] != '\0')) 335 log_Printf(LogWARN, "Unindented command (%s line %d) -" 336 " ignored\n", filename, linenum); 337 } 338 break; 339 } 340 341 len = strlen(cp); 342 argc = command_Interpret(cp, len, argv); 343 allowcmd = argc > 0 && !strcasecmp(argv[0], "allow"); 344 if ((!(how == SYSTEM_EXEC) && allowcmd) || 345 ((how == SYSTEM_EXEC) && !allowcmd)) 346 command_Run(bundle, argc, (char const *const *)argv, prompt, 347 name, cx); 348 } 349 350 fclose(fp); /* everything read - get out */ 351 return 0; 352 } 353 break; 354 } 355 } 356 fclose(fp); 357 return -1; 358 } 359 360 const char * 361 system_IsValid(const char *name, struct prompt *prompt, int mode) 362 { 363 /* 364 * Note: The ReadSystem() calls only result in calls to the Allow* 365 * functions. arg->bundle will be set to NULL for these commands ! 366 */ 367 int def, how, rs; 368 369 def = !strcmp(name, "default"); 370 how = ID0realuid() == 0 ? SYSTEM_EXISTS : SYSTEM_VALIDATE; 371 userok = 0; 372 modeok = 1; 373 modereq = mode; 374 375 rs = ReadSystem(NULL, "default", CONFFILE, prompt, NULL, how); 376 377 if (!def) { 378 if (rs == -1) 379 rs = 0; /* we don't care that ``default'' doesn't exist */ 380 381 if (rs == 0) 382 rs = ReadSystem(NULL, name, CONFFILE, prompt, NULL, how); 383 384 if (rs == -1) 385 return "Configuration label not found"; 386 387 if (rs == -2) 388 return _PATH_PPP "/" CONFFILE ": File not found"; 389 } 390 391 if (how == SYSTEM_EXISTS) 392 userok = modeok = 1; 393 394 if (!userok) 395 return "User access denied"; 396 397 if (!modeok) 398 return "Mode denied for this label"; 399 400 return NULL; 401 } 402 403 int 404 system_Select(struct bundle *bundle, const char *name, const char *file, 405 struct prompt *prompt, struct datalink *cx) 406 { 407 userok = modeok = 1; 408 modereq = PHYS_ALL; 409 return ReadSystem(bundle, name, file, prompt, cx, SYSTEM_EXEC); 410 } 411