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 * $FreeBSD$ 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 $.... */ 62 static const char * 63 InterpretArg(const char *from, char *to) 64 { 65 const char *env; 66 char *ptr, *startto, *endto; 67 int len; 68 69 startto = to; 70 endto = to + LINE_LEN - 1; 71 72 while(issep(*from)) 73 from++; 74 75 if (*from == '~') { 76 struct passwd *pwd; 77 78 ptr = strchr(++from, '/'); 79 len = ptr ? ptr - from : strlen(from); 80 if (len == 0) { 81 pwd = getpwuid(ID0realuid()); 82 } else { 83 strncpy(to, from, len); 84 to[len] = '\0'; 85 pwd = getpwnam(to); 86 } 87 strncpy(to, pwd ? pwd->pw_dir : _PATH_PPP, endto - to); 88 endpwent(); 89 90 *endto = '\0'; 91 to += strlen(to); 92 from += len; 93 } 94 95 while (to < endto && !issep(*from) && *from != '#' && *from != '\0') { 96 if (*from == '$') { 97 if (from[1] == '$') { 98 *to = '\0'; /* For an empty var name below */ 99 from += 2; 100 } else if (from[1] == '{') { 101 ptr = strchr(from+2, '}'); 102 if (ptr) { 103 len = ptr - from - 2; 104 if (endto - to < len ) 105 len = endto - to; 106 if (len) { 107 strncpy(to, from+2, len); 108 to[len] = '\0'; 109 from = ptr+1; 110 } else { 111 *to++ = *from++; 112 continue; 113 } 114 } else { 115 *to++ = *from++; 116 continue; 117 } 118 } else { 119 ptr = to; 120 for (from++; (isalnum(*from) || *from == '_') && ptr < endto; from++) 121 *ptr++ = *from; 122 *ptr = '\0'; 123 } 124 if (*to == '\0') 125 *to++ = '$'; 126 else if ((env = getenv(to)) != NULL) { 127 strncpy(to, env, endto - to); 128 *endto = '\0'; 129 to += strlen(to); 130 } 131 } else { 132 if (*from == '\\') 133 from++; 134 *to++ = *from++; 135 } 136 } 137 138 while (to > startto) { 139 to--; 140 if (!issep(*to)) { 141 to++; 142 break; 143 } 144 } 145 *to = '\0'; 146 147 while (issep(*from)) 148 from++; 149 150 return from; 151 } 152 153 #define CTRL_UNKNOWN (0) 154 #define CTRL_INCLUDE (1) 155 156 static int 157 DecodeCtrlCommand(char *line, char *arg) 158 { 159 const char *end; 160 161 if (!strncasecmp(line, "include", 7) && issep(line[7])) { 162 end = InterpretArg(line+8, arg); 163 if (*end && *end != '#') 164 log_Printf(LogWARN, "Usage: !include filename\n"); 165 else 166 return CTRL_INCLUDE; 167 } 168 return CTRL_UNKNOWN; 169 } 170 171 /* 172 * Initialised in system_IsValid(), set in ReadSystem(), 173 * used by system_IsValid() 174 */ 175 static int modeok; 176 static int userok; 177 static int modereq; 178 179 int 180 AllowUsers(struct cmdargs const *arg) 181 { 182 /* arg->bundle may be NULL (see system_IsValid()) ! */ 183 int f; 184 struct passwd *pwd; 185 186 userok = 0; 187 pwd = getpwuid(ID0realuid()); 188 if (pwd != NULL) 189 for (f = arg->argn; f < arg->argc; f++) 190 if (!strcmp("*", arg->argv[f]) || !strcmp(pwd->pw_name, arg->argv[f])) { 191 userok = 1; 192 break; 193 } 194 endpwent(); 195 196 return 0; 197 } 198 199 int 200 AllowModes(struct cmdargs const *arg) 201 { 202 /* arg->bundle may be NULL (see system_IsValid()) ! */ 203 int f, mode, allowed; 204 205 allowed = 0; 206 for (f = arg->argn; f < arg->argc; f++) { 207 mode = Nam2mode(arg->argv[f]); 208 if (mode == PHYS_NONE || mode == PHYS_ALL) 209 log_Printf(LogWARN, "allow modes: %s: Invalid mode\n", arg->argv[f]); 210 else 211 allowed |= mode; 212 } 213 214 modeok = modereq & allowed ? 1 : 0; 215 return 0; 216 } 217 218 static char * 219 strip(char *line) 220 { 221 int len; 222 223 len = strlen(line); 224 while (len && (line[len-1] == '\n' || line[len-1] == '\r' || 225 issep(line[len-1]))) 226 line[--len] = '\0'; 227 228 while (issep(*line)) 229 line++; 230 231 if (*line == '#') 232 *line = '\0'; 233 234 return line; 235 } 236 237 static int 238 xgets(char *buf, int buflen, FILE *fp) 239 { 240 int len, n; 241 242 n = 0; 243 while (fgets(buf, buflen-1, fp)) { 244 n++; 245 buf[buflen-1] = '\0'; 246 len = strlen(buf); 247 while (len && (buf[len-1] == '\n' || buf[len-1] == '\r')) 248 buf[--len] = '\0'; 249 if (len && buf[len-1] == '\\') { 250 buf += len - 1; 251 buflen -= len - 1; 252 if (!buflen) /* No buffer space */ 253 break; 254 } else 255 break; 256 } 257 return n; 258 } 259 260 /* Values for ``how'' in ReadSystem */ 261 #define SYSTEM_EXISTS 1 262 #define SYSTEM_VALIDATE 2 263 #define SYSTEM_EXEC 3 264 265 static char * 266 GetLabel(char *line, const char *filename, int linenum) 267 { 268 char *argv[MAXARGS]; 269 int argc, len; 270 271 argc = MakeArgs(line, argv, MAXARGS, PARSE_REDUCE); 272 273 if (argc == 2 && !strcmp(argv[1], ":")) 274 return argv[0]; 275 276 if (argc != 1 || (len = strlen(argv[0])) < 2 || argv[0][len-1] != ':') { 277 log_Printf(LogWARN, "Bad label in %s (line %d) - missing colon\n", 278 filename, linenum); 279 return NULL; 280 } 281 argv[0][len-1] = '\0'; /* Lose the ':' */ 282 283 return argv[0]; 284 } 285 286 /* Returns -2 for ``file not found'' and -1 for ``label not found'' */ 287 288 static int 289 ReadSystem(struct bundle *bundle, const char *name, const char *file, 290 struct prompt *prompt, struct datalink *cx, int how) 291 { 292 FILE *fp; 293 char *cp; 294 int n, len; 295 char line[LINE_LEN]; 296 char filename[MAXPATHLEN]; 297 int linenum; 298 int argc; 299 char *argv[MAXARGS]; 300 int allowcmd; 301 int indent; 302 char arg[LINE_LEN]; 303 struct prompt *op; 304 305 if (*file == '/') 306 snprintf(filename, sizeof filename, "%s", file); 307 else 308 snprintf(filename, sizeof filename, "%s/%s", _PATH_PPP, file); 309 fp = ID0fopen(filename, "r"); 310 if (fp == NULL) { 311 log_Printf(LogDEBUG, "ReadSystem: Can't open %s.\n", filename); 312 return -2; 313 } 314 log_Printf(LogDEBUG, "ReadSystem: Checking %s (%s).\n", name, filename); 315 316 linenum = 0; 317 while ((n = xgets(line, sizeof line, fp))) { 318 linenum += n; 319 if (issep(*line)) 320 continue; 321 322 cp = strip(line); 323 324 switch (*cp) { 325 case '\0': /* empty/comment */ 326 break; 327 328 case '!': 329 switch (DecodeCtrlCommand(cp+1, arg)) { 330 case CTRL_INCLUDE: 331 log_Printf(LogCOMMAND, "%s: Including \"%s\"\n", filename, arg); 332 n = ReadSystem(bundle, name, arg, prompt, cx, how); 333 log_Printf(LogCOMMAND, "%s: Done include of \"%s\"\n", filename, arg); 334 if (!n) 335 return 0; /* got it */ 336 break; 337 default: 338 log_Printf(LogWARN, "%s: %s: Invalid command\n", filename, cp); 339 break; 340 } 341 break; 342 343 default: 344 if ((cp = GetLabel(cp, filename, linenum)) == NULL) 345 continue; 346 347 if (strcmp(cp, name) == 0) { 348 /* We're in business */ 349 if (how == SYSTEM_EXISTS) 350 return 0; 351 while ((n = xgets(line, sizeof line, fp))) { 352 linenum += n; 353 indent = issep(*line); 354 cp = strip(line); 355 356 if (*cp == '\0') /* empty / comment */ 357 continue; 358 359 if (!indent) { /* start of next section */ 360 if (*cp != '!' && how == SYSTEM_EXEC) 361 cp = GetLabel(cp, filename, linenum); 362 break; 363 } 364 365 len = strlen(cp); 366 if ((argc = command_Interpret(cp, len, argv)) < 0) 367 log_Printf(LogWARN, "%s: %d: Syntax error\n", filename, linenum); 368 else { 369 allowcmd = argc > 0 && !strcasecmp(argv[0], "allow"); 370 if ((how != SYSTEM_EXEC && allowcmd) || 371 (how == SYSTEM_EXEC && !allowcmd)) { 372 /* 373 * Disable any context so that warnings are given to everyone, 374 * including syslog. 375 */ 376 op = log_PromptContext; 377 log_PromptContext = NULL; 378 command_Run(bundle, argc, (char const *const *)argv, prompt, 379 name, cx); 380 log_PromptContext = op; 381 } 382 } 383 } 384 385 fclose(fp); /* everything read - get out */ 386 return 0; 387 } 388 break; 389 } 390 } 391 fclose(fp); 392 return -1; 393 } 394 395 const char * 396 system_IsValid(const char *name, struct prompt *prompt, int mode) 397 { 398 /* 399 * Note: The ReadSystem() calls only result in calls to the Allow* 400 * functions. arg->bundle will be set to NULL for these commands ! 401 */ 402 int def, how, rs; 403 404 def = !strcmp(name, "default"); 405 how = ID0realuid() == 0 ? SYSTEM_EXISTS : SYSTEM_VALIDATE; 406 userok = 0; 407 modeok = 1; 408 modereq = mode; 409 410 rs = ReadSystem(NULL, "default", CONFFILE, prompt, NULL, how); 411 412 if (!def) { 413 if (rs == -1) 414 rs = 0; /* we don't care that ``default'' doesn't exist */ 415 416 if (rs == 0) 417 rs = ReadSystem(NULL, name, CONFFILE, prompt, NULL, how); 418 419 if (rs == -1) 420 return "Configuration label not found"; 421 422 if (rs == -2) 423 return _PATH_PPP "/" CONFFILE ": File not found"; 424 } 425 426 if (how == SYSTEM_EXISTS) 427 userok = modeok = 1; 428 429 if (!userok) 430 return "User access denied"; 431 432 if (!modeok) 433 return "Mode denied for this label"; 434 435 return NULL; 436 } 437 438 int 439 system_Select(struct bundle *bundle, const char *name, const char *file, 440 struct prompt *prompt, struct datalink *cx) 441 { 442 userok = modeok = 1; 443 modereq = PHYS_ALL; 444 return ReadSystem(bundle, name, file, prompt, cx, SYSTEM_EXEC); 445 } 446