afce951b |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: netg.c,v 1.1 1997/08/07 09:45:00 mdw Exp $ |
4 | * |
5 | * A local database of netgroups |
6 | * |
7 | * (c) 1997 EBI |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of `become' |
13 | * |
14 | * `Become' is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * `Become' is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with `become'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: netg.c,v $ |
32 | * Revision 1.1 1997/08/07 09:45:00 mdw |
33 | * New source file added to maintain a netgroups database. |
34 | * |
35 | */ |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | /* --- ANSI headers --- */ |
40 | |
41 | #include <ctype.h> |
42 | #include <stdio.h> |
43 | #include <stdlib.h> |
44 | #include <string.h> |
45 | |
46 | /* --- Unix headers --- */ |
47 | |
48 | #include "config.h" |
49 | |
50 | #include <sys/types.h> |
51 | |
52 | #ifdef HAVE_YP |
53 | # include <rpc/rpc.h> |
54 | # include <rpcsvc/ypclnt.h> |
55 | # include <rpcsvc/yp_prot.h> |
56 | #endif |
57 | |
58 | #include <netinet/in.h> |
59 | |
60 | #include <arpa/inet.h> |
61 | |
62 | #include <pwd.h> |
63 | #include <netdb.h> |
64 | #include <unistd.h> |
65 | |
66 | /* --- Local headers --- */ |
67 | |
68 | #include "become.h" |
69 | #include "config.h" |
70 | #include "netg.h" |
71 | #include "sym.h" |
72 | #include "userdb.h" |
73 | #include "utils.h" |
74 | |
75 | /*----- Type definitions --------------------------------------------------*/ |
76 | |
77 | /* --- Quick discussion --- * |
78 | * |
79 | * I've just noticed: netgroups are horrible. They form a directed graph |
80 | * which is really horrible; I'll have to try and turn it into something |
81 | * more sensible (which will essentially involve cutting cycles). |
82 | * |
83 | * The structure looks a little bit like a good ol' List (see Knuth 1 or |
84 | * any decent Lisp manual), but with more information in the cons cells. |
85 | */ |
86 | |
87 | /* --- @netg__cons@ --- */ |
88 | |
89 | typedef struct netg__cons { |
90 | unsigned f; |
91 | union { |
92 | struct netg__cons *cons; |
93 | struct netg__atom *atom; |
94 | } car; |
95 | struct netg__cons *cdr; |
96 | } netg__cons; |
97 | |
98 | enum { |
99 | f_cons = 1, /* The @car@ is a cons cell */ |
100 | f_visit = 2, /* Currently threaded on this cell */ |
101 | f_uncycled = 4 /* Cycles removed from here on in */ |
102 | }; |
103 | |
104 | /* --- @netg__atom@ --- */ |
105 | |
106 | typedef struct netg__atom { |
107 | char *n; /* Unresolved netgroup reference */ |
108 | char *h; /* Matched hostname */ |
109 | char *u; /* Matched user name */ |
110 | char *d; /* Matched domain name */ |
111 | } netg__atom; |
112 | |
113 | /* --- @netg__sym@ --- */ |
114 | |
115 | typedef struct netg__sym { |
116 | sym_base _base; |
117 | netg__cons *cons; |
118 | } netg__sym; |
119 | |
120 | /* --- Token types for the netgroup parser --- */ |
121 | |
122 | enum { |
123 | tok_string = 256, |
124 | tok_eof |
125 | }; |
126 | |
127 | /*----- Static variables --------------------------------------------------*/ |
128 | |
129 | static sym_table netg__table; /* Netgroup table */ |
130 | static sym_iter netg__iter; /* Iterator object for users */ |
131 | |
132 | /*----- Main code ---------------------------------------------------------*/ |
133 | |
134 | /* --- @netg__lex@ --- * |
135 | * |
136 | * Arguments: @const char **p@ = pointer to next unscanned character |
137 | * @char *q@ = pointer to output buffer |
138 | * |
139 | * Returns: Token type (either character code or a magic number). |
140 | * |
141 | * Use: Lexes a netgroups line into tokens. |
142 | */ |
143 | |
144 | static int netg__lex(char **p, char *q) |
145 | { |
146 | /* --- Skip any leading whitespace --- */ |
147 | |
148 | while (isspace((unsigned char)**p)) |
149 | (*p)++; |
150 | |
151 | /* --- Now work out what we've got --- */ |
152 | |
153 | if (**p == 0) |
154 | return (tok_eof); |
155 | if (**p == '(' || **p == ')' || **p == ',') |
156 | return (*(*p)++); |
157 | do |
158 | *q++ = *(*p)++; |
159 | while (**p != 0 && **p != '(' && **p != ')' && |
160 | **p != ',' && !isspace((unsigned char)**p)); |
161 | *q++ = 0; |
162 | return (tok_string); |
163 | } |
164 | |
165 | /* --- @netg__foreach@ --- * |
166 | * |
167 | * Arguments: @int st@ = YP protocol-level status code |
168 | * @char *k@ = pointer to string containing the key |
169 | * @int ksz@ = length of the key string |
170 | * @char *v@ = pointer to string containing the value |
171 | * @int vsz@ = length of the value string |
172 | * @char *data@ = pointer to my data information |
173 | * |
174 | * Returns: Zero to continue, nonzero for no more entries. |
175 | * |
176 | * Use: Handles each incoming netgroup, attaching it to the table. |
177 | */ |
178 | |
179 | static int netg__foreach(int st, char *k, int ksz, |
180 | char *v, int vsz, char *data) |
181 | { |
182 | char *kc, *vc; |
183 | unsigned f; |
184 | netg__sym *sng; |
185 | netg__cons *c, **link; |
186 | char *p; |
187 | int t; |
188 | |
189 | /* --- If something is amiss, then quit now --- */ |
190 | |
191 | if (st != YP_TRUE) |
192 | return (-1); |
193 | |
194 | /* --- Ignore empty lines from the original file --- */ |
195 | |
196 | if (!ksz || !vsz) |
197 | return (0); |
198 | |
199 | /* --- Build my own trashable copies of the key and value --- * |
200 | * |
201 | * Note the oddness when I copy the value string. The extra byte at the |
202 | * beginning allows me to use the same area of memory as an output buffer |
203 | * for the lexer. It must be big enough; the lexer doesn't back up; and |
204 | * that extra byte gives me somewhere to put a terminating null byte. |
205 | */ |
206 | |
207 | kc = xmalloc(ksz + 1); |
208 | memcpy(kc, k, ksz); |
209 | kc[ksz] = 0; |
210 | |
211 | vc = xmalloc(vsz + 2); |
212 | memcpy(vc + 1, v, vsz); |
213 | vc[vsz + 1] = 0; |
214 | |
215 | T( trace(TRACE_DEBUG, "debug: netgroup `%s': `%s'", kc, vc + 1); ) |
216 | |
217 | /* --- Allocate a symbol in my table --- */ |
218 | |
219 | sng = sym_find(&netg__table, kc, -1, sizeof(*sng), &f); |
220 | if (!f) |
221 | sng->cons = 0; |
222 | |
223 | /* --- Run to the end of the list --- */ |
224 | |
225 | for (link = &sng->cons; *link; link = &((*link)->cdr)) |
226 | ; |
227 | |
228 | /* --- Now start the tricky bit --- * |
229 | * |
230 | * I have to start parsing the netgroup value string. Oh, well, it |
231 | * could be worse. |
232 | * |
233 | * The parser is written so as to avoid saying things more often than |
234 | * necessary. This tends to involve @goto@s. You've been warned. |
235 | */ |
236 | |
237 | p = vc + 1; |
238 | t = netg__lex(&p, vc); |
239 | |
240 | for (;;) { |
241 | |
242 | /* --- Start with a fresh cons cell, with an empty atom attached --- */ |
243 | |
244 | c = xmalloc(sizeof(*c)); |
245 | c->car.atom = xmalloc(sizeof(*c->car.atom)); |
246 | |
247 | /* --- Restart here after an error --- * |
248 | * |
249 | * If I restart here, I can avoid freeing the cons cell reallocating |
250 | * it, which is a little silly. |
251 | */ |
252 | |
253 | duff_restart: |
254 | c->car.atom->n = c->car.atom->h = c->car.atom->u = c->car.atom->d = 0; |
255 | c->f = 0; |
256 | c->cdr = 0; |
257 | |
258 | /* --- Handle end-of-line --- */ |
259 | |
260 | if (t == tok_eof) |
261 | break; |
262 | |
263 | /* --- Handle a netgroup reference --- */ |
264 | |
265 | if (t == tok_string) { |
266 | T( trace(TRACE_DEBUG, "debug: add reference to `%s'", vc); ) |
267 | c->car.atom->n = xstrdup(vc); |
268 | *link = c; |
269 | link = &c->cdr; |
270 | t = netg__lex(&p, vc); |
271 | continue; |
272 | } |
273 | |
274 | /* --- Parse our merry way through the host--user--domain triple --- */ |
275 | |
276 | if (t != '(') |
277 | goto duff; |
278 | t = netg__lex(&p, vc); |
279 | |
280 | if (t == tok_string) { |
281 | T( trace(TRACE_DEBUG, "debug: add host `%s'", vc); ) |
282 | c->car.atom->h = xstrdup(vc); |
283 | t = netg__lex(&p, vc); |
284 | } |
285 | |
286 | if (t != ',') |
287 | goto duff_paren; |
288 | t = netg__lex(&p, vc); |
289 | |
290 | if (t == tok_string) { |
291 | T( trace(TRACE_DEBUG, "debug: add user `%s'", vc); ) |
292 | c->car.atom->u = xstrdup(vc); |
293 | t = netg__lex(&p, vc); |
294 | } |
295 | |
296 | if (t != ',') |
297 | goto duff_paren; |
298 | t = netg__lex(&p, vc); |
299 | |
300 | if (t == tok_string) { |
301 | T( trace(TRACE_DEBUG, "debug: add domain `%s'", vc); ) |
302 | c->car.atom->d = xstrdup(vc); |
303 | t = netg__lex(&p, vc); |
304 | } |
305 | |
306 | if (t != ')') |
307 | goto duff_paren; |
308 | t = netg__lex(&p, vc); |
309 | |
310 | /* --- Finished that, so insert this cons cell into the list --- */ |
311 | |
312 | *link = c; |
313 | link = &c->cdr; |
314 | continue; |
315 | |
316 | /* --- Tidy up during scanning of a triple --- * |
317 | * |
318 | * I'll search for the closing paren, and hope that I won't miss out too |
319 | * much. |
320 | */ |
321 | |
322 | duff_paren: |
323 | while (t != tok_eof && t != ')') |
324 | t = netg__lex(&p, vc); |
325 | |
326 | /* --- Other syntax oddnesses come out here --- * |
327 | * |
328 | * Snarf the token which caused the error. |
329 | */ |
330 | |
331 | duff: |
332 | moan("syntax error in netgroups line for `%s'", kc); |
333 | if (c->car.atom->n) free(c->car.atom->n); |
334 | if (c->car.atom->h) free(c->car.atom->h); |
335 | if (c->car.atom->u) free(c->car.atom->u); |
336 | if (c->car.atom->d) free(c->car.atom->d); |
337 | t = netg__lex(&p, vc); |
338 | goto duff_restart; |
339 | } |
340 | |
341 | free(kc); |
342 | free(vc); |
343 | return (0); |
344 | } |
345 | |
346 | /* --- @netg__dumpGroup@ --- * |
347 | * |
348 | * Arguments: @netg__cons *c@ = pointer to a list head |
349 | * @int lev@ = indentation level |
350 | * |
351 | * Returns: --- |
352 | * |
353 | * Use: Dumps the netgroup given. |
354 | */ |
355 | |
356 | #ifdef TRACING |
357 | |
358 | static void netg__dumpGroup(netg__cons *c, int lev) |
359 | { |
360 | netg__cons *cc; |
361 | |
362 | if (!c) |
363 | return; |
364 | |
365 | /* --- Check for a cycle --- */ |
366 | |
367 | if (c->f & f_visit) { |
368 | trace(TRACE_DEBUG, "debug: %*scycle!", lev * 2, ""); |
369 | return; |
370 | } |
371 | |
372 | /* --- Dump the netgroup --- */ |
373 | |
374 | c->f |= f_visit; |
375 | |
376 | for (cc = c; cc; cc = cc->cdr) { |
377 | if (cc->f & f_cons) { |
378 | trace(TRACE_DEBUG, "debug: %*ssubnetgroup...", lev * 2, ""); |
379 | netg__dumpGroup(cc->car.cons, lev + 1); |
380 | } else if (cc->car.atom->n) { |
381 | trace(TRACE_DEBUG, "debug: %*sunresolved subgroup `%s'", |
382 | lev * 2, "", cc->car.atom->n); |
383 | } else { |
384 | trace(TRACE_DEBUG, "debug: %*s(%s, %s, %s)", lev * 2, "", |
385 | cc->car.atom->h ? cc->car.atom->h : "<all-hosts>", |
386 | cc->car.atom->u ? cc->car.atom->u : "<all-users>", |
387 | cc->car.atom->d ? cc->car.atom->d : "<all-domains>"); |
388 | } |
389 | } |
390 | |
391 | c->f &= ~f_visit; |
392 | } |
393 | |
394 | #endif |
395 | |
396 | /* --- @netg__dump@ --- * |
397 | * |
398 | * Arguments: --- |
399 | * |
400 | * Returns: --- |
401 | * |
402 | * Use: Dumps the netgroups table. |
403 | */ |
404 | |
405 | static void netg__dump(void) |
406 | { |
407 | sym_iter i; |
408 | netg__sym *sng; |
409 | |
410 | #ifdef TRACING |
411 | trace(TRACE_DEBUG, "debug: dumping netgroups file"); |
412 | for (sym_createIter(&i, &netg__table); (sng = sym_next(&i)) != 0; ) { |
413 | trace(TRACE_DEBUG, "debug: netgroup `%s'...", sng->_base.name); |
414 | sng->cons->f &= ~f_visit; |
415 | netg__dumpGroup(sng->cons, 1); |
416 | } |
417 | #endif |
418 | } |
419 | |
420 | /* --- @netg_iterate@, @netg_iterate_r@ --- * |
421 | * |
422 | * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object |
423 | * |
424 | * Returns: --- |
425 | * |
426 | * Use: Starts iterating over the netgroups. |
427 | */ |
428 | |
429 | void netg_iterate(void) { netg_iterate_r(&netg__iter); } |
430 | void netg_iterate_r(netg_iter *i) { sym_createIter(i, &netg__table); } |
431 | |
432 | /* --- @netg_next@, @netg_next_r@ --- * |
433 | * |
434 | * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object |
435 | * |
436 | * Returns: An opaque pointer to the next item, or null. |
437 | * |
438 | * Use: Returns the next netgroup. |
439 | */ |
440 | |
441 | netg *netg_next(void) { return (netg_next_r(&netg__iter)); } |
442 | netg *netg_next_r(netg_iter *i) { return (sym_next(i)); } |
443 | |
444 | /* --- @netg_name@ --- * |
445 | * |
446 | * Arguments: @netg *n@ = netgroup handle returned by @netg_next@. |
447 | * |
448 | * Returns: A pointer to the name; you may not modify this string. |
449 | * |
450 | * Use: Returns the name of a netgroup. |
451 | */ |
452 | |
453 | const char *netg_name(netg *n) { return (n->_base.name); } |
454 | |
455 | /* --- @netg_scan@ --- * |
456 | * |
457 | * Arguments: @netg *n@ = a netgroup handle returned by @netg_next@ |
458 | * @int (*proc)(netg *n, const char *host, const char *user,@ |
459 | * @const char *domain, void *ctx)@ = function to call |
460 | * for each member. |
461 | * @void *ctx@ = context pointer to pass to @proc@. |
462 | * |
463 | * Returns: Zero if all went well, or the nonzero return value from |
464 | * @proc@. |
465 | * |
466 | * Use: Passes all the members of the netgroup to a given function. |
467 | * The function is given the names, directly from the NIS |
468 | * netgroup map, except that any empty entries are passed as |
469 | * null pointers rather than empty strings. You may not modify |
470 | * any of the strings. The enumeration function, @proc@, may |
471 | * return nonzero to stop itself from being called any more; |
472 | * if this happens, the value it returns becomes the result of |
473 | * this function. If all the items are enumerated OK, this |
474 | * function returns zero. |
475 | */ |
476 | |
477 | static int netg__doScan(netg__cons *c, |
478 | netg *n, |
479 | int (*proc)(netg */*n*/, const char */*host*/, |
480 | const char */*user*/, |
481 | const char */*domain*/, void */*ctx*/), |
482 | void *ctx) |
483 | { |
484 | int e; |
485 | |
486 | while (c) { |
487 | if (c->f & f_cons) |
488 | e = netg__doScan(c->car.cons, n, proc, ctx); |
489 | else |
490 | e = proc(n, c->car.atom->h, c->car.atom->u, c->car.atom->d, ctx); |
491 | if (e) |
492 | return (e); |
493 | c = c->cdr; |
494 | } |
495 | return (0); |
496 | } |
497 | |
498 | int netg_scan(netg *n, |
499 | int (*proc)(netg */*n*/, const char */*host*/, |
500 | const char */*user*/, const char */*domain*/, |
501 | void */*ctx*/), |
502 | void *ctx) |
503 | { |
504 | return (netg__doScan(n->cons, n, proc, ctx)); |
505 | } |
506 | |
507 | /* --- @netg__breakCycle@ --- * |
508 | * |
509 | * Arguments: @netg__cons *c@ = pointer to a list |
510 | * |
511 | * Returns: --- |
512 | * |
513 | * Use: Scans the given list (recursively) and breaks any cycles it |
514 | * finds. |
515 | */ |
516 | |
517 | static void netg__breakCycle(netg__cons *c) |
518 | { |
519 | netg__cons *cc; |
520 | |
521 | if (!c || c->f & f_uncycled) |
522 | return; |
523 | |
524 | c->f |= f_visit; |
525 | for (cc = c; cc; cc = cc->cdr) { |
526 | if (~cc->f & f_cons) |
527 | continue; |
528 | if (cc->car.cons->f & f_visit) { |
529 | T( trace(TRACE_DEBUG, "debug: cycle in netgroups"); ) |
530 | cc->car.cons = 0; |
531 | } else |
532 | netg__breakCycle(cc->car.cons); |
533 | } |
534 | c->f &= ~f_visit; |
535 | c->f |= f_uncycled; |
536 | } |
537 | |
538 | /* --- @netg_init@ --- * |
539 | * |
540 | * Arguments: --- |
541 | * |
542 | * Returns: --- |
543 | * |
544 | * Use: Reads the netgroup database and turns it into something nice. |
545 | */ |
546 | |
547 | void netg_init(void) |
548 | { |
549 | char *ypdom; |
550 | |
551 | /* --- Initialise my symbol table --- */ |
552 | |
553 | sym_createTable(&netg__table); |
554 | |
555 | /* --- Bind myself unto a YP server --- */ |
556 | |
557 | if (yp_get_default_domain(&ypdom) || |
558 | yp_bind(ypdom)) |
559 | return; |
560 | |
561 | /* --- Now try to read all the netgroup entries --- */ |
562 | |
563 | { |
564 | static struct ypall_callback ncb = { netg__foreach, 0 }; |
565 | yp_all(ypdom, "netgroup", &ncb); |
566 | } |
567 | |
568 | /* --- Unbind from the server --- */ |
569 | |
570 | yp_unbind(ypdom); |
571 | |
572 | /* --- Dump the table --- */ |
573 | |
574 | IF_TRACING(TRACE_DEBUG, netg__dump(); ) |
575 | |
576 | /* --- Now resolve all the remaining references --- */ |
577 | |
578 | { |
579 | sym_iter i; |
580 | netg__sym *sng, *ng; |
581 | netg__cons *c; |
582 | netg__atom *a; |
583 | |
584 | for (sym_createIter(&i, &netg__table); (sng = sym_next(&i)) != 0; ) { |
585 | for (c = sng->cons; c; c = c->cdr) { |
586 | if ((c->f & f_cons) == 0 && c->car.atom->n) { |
587 | a = c->car.atom; |
588 | ng = sym_find(&netg__table, a->n, -1, 0, 0); |
589 | if (!ng) { |
590 | moan("undefined netgroup `%s' (ignored)", a->n); |
591 | c->car.atom = 0; |
592 | } else { |
593 | c->car.cons = ng->cons; |
594 | c->f |= f_cons; |
595 | } |
596 | free(a->n); |
597 | free(a); |
598 | } |
599 | } |
600 | } |
601 | } |
602 | |
603 | /* --- Remove cycles in the netgroups table --- */ |
604 | |
605 | { |
606 | sym_iter i; |
607 | netg__sym *sng; |
608 | |
609 | for (sym_createIter(&i, &netg__table); (sng = sym_next(&i)) != 0; ) |
610 | sng->cons->f &= ~f_uncycled; |
611 | for (sym_createIter(&i, &netg__table); (sng = sym_next(&i)) != 0; ) |
612 | netg__breakCycle(sng->cons); |
613 | } |
614 | |
615 | /* --- Dump the table again --- */ |
616 | |
617 | IF_TRACING(TRACE_DEBUG, netg__dump(); ) |
618 | } |
619 | |
620 | /* --- @netg_reinit@ --- * |
621 | * |
622 | * Arguments: --- |
623 | * |
624 | * Returns: --- |
625 | * |
626 | * Use: Forces a re-read of the netgroups file. |
627 | */ |
628 | |
629 | void netg_reinit(void) |
630 | { |
631 | sym_iter i; |
632 | netg__sym *sng; |
633 | netg__cons *c, *cc; |
634 | |
635 | /* --- Remove all the old netgroups rubbish --- */ |
636 | |
637 | for (sym_createIter(&i, &netg__table); (sng = sym_next(&i)) != 0; ) { |
638 | c = sng->cons; |
639 | while (c) { |
640 | cc = c->cdr; |
641 | if (~c->f & f_cons) { |
642 | if (c->car.atom->n) free(c->car.atom->n); |
643 | if (c->car.atom->h) free(c->car.atom->h); |
644 | if (c->car.atom->u) free(c->car.atom->u); |
645 | if (c->car.atom->d) free(c->car.atom->d); |
646 | } |
647 | free(c); |
648 | c = cc; |
649 | } |
650 | sym_remove(&netg__table, sng); |
651 | } |
652 | |
653 | /* --- Now rebuild the world --- */ |
654 | |
655 | netg_init(); |
656 | } |
657 | |
658 | /*----- Test driver -------------------------------------------------------*/ |
659 | |
660 | #ifdef TEST_RIG |
661 | |
662 | int scanner(netg *n, const char *h, const char *u, const char *d, void *c) |
663 | { |
664 | fprintf(stderr, " %s, %s, %s\n", |
665 | h ? h : "<any>", u ? u : "<any>", d ? d : "<any>"); |
666 | return (0); |
667 | } |
668 | |
669 | int main(void) |
670 | { |
671 | netg *n; |
672 | ego("netg-test"); |
673 | traceon(stderr, TRACE_ALL); |
674 | netg_init(); |
675 | for (netg_iterate(); (n = netg_next()) != 0; ) { |
676 | fprintf(stderr, "netgroup %s\n", netg_name(n)); |
677 | netg_scan(n, scanner, 0); |
678 | } |
679 | return (0); |
680 | } |
681 | |
682 | #endif |
683 | |
684 | /*----- That's all, folks -------------------------------------------------*/ |