3 * $Id: netg.c,v 1.4 1998/04/23 13:24:49 mdw Exp $
5 * A local database of netgroups
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of `become'
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.4 1998/04/23 13:24:49 mdw
33 * Switch to using the ypstuff interface to YP server.
35 * Revision 1.3 1998/01/12 16:46:17 mdw
38 * Revision 1.2 1997/08/20 16:19:11 mdw
39 * Patch memory leak. Replace `name_reinit' by `name_end' for more sensible
40 * restart. Don't try to trace when tracing's turned off.
42 * Revision 1.1 1997/08/07 09:45:00 mdw
43 * New source file added to maintain a netgroups database.
47 /*----- Header files ------------------------------------------------------*/
49 /* --- ANSI headers --- */
56 /* --- Unix headers --- */
60 #include <sys/types.h>
62 #include <netinet/in.h>
64 #include <arpa/inet.h>
70 /* --- Local headers --- */
80 /*----- Type definitions --------------------------------------------------*/
82 /* --- Quick discussion --- *
84 * I've just noticed: netgroups are horrible. They form a directed graph
85 * which is really horrible; I'll have to try and turn it into something
86 * more sensible (which will essentially involve cutting cycles).
88 * The structure looks a little bit like a good ol' List (see Knuth 1 or
89 * any decent Lisp manual), but with more information in the cons cells.
92 /* --- @netg__cons@ --- */
94 typedef struct netg__cons
{
97 struct netg__cons
*cons
;
98 struct netg__atom
*atom
;
100 struct netg__cons
*cdr
;
104 f_cons
= 1, /* The @car@ is a cons cell */
105 f_visit
= 2, /* Currently threaded on this cell */
106 f_uncycled
= 4 /* Cycles removed from here on in */
109 /* --- @netg__atom@ --- */
111 typedef struct netg__atom
{
112 char *n
; /* Unresolved netgroup reference */
113 char *h
; /* Matched hostname */
114 char *u
; /* Matched user name */
115 char *d
; /* Matched domain name */
118 /* --- @netg__sym@ --- */
120 typedef struct netg__sym
{
125 /* --- Token types for the netgroup parser --- */
132 /*----- Static variables --------------------------------------------------*/
134 static sym_table netg__table
; /* Netgroup table */
135 static sym_iter netg__iter
; /* Iterator object for users */
137 /*----- Main code ---------------------------------------------------------*/
139 /* --- @netg__lex@ --- *
141 * Arguments: @const char **p@ = pointer to next unscanned character
142 * @char *q@ = pointer to output buffer
144 * Returns: Token type (either character code or a magic number).
146 * Use: Lexes a netgroups line into tokens.
149 static int netg__lex(char **p
, char *q
)
151 /* --- Skip any leading whitespace --- */
153 while (isspace((unsigned char)**p
))
156 /* --- Now work out what we've got --- */
160 if (**p
== '(' || **p
== ')' || **p
== ',')
164 while (**p
!= 0 && **p
!= '(' && **p
!= ')' &&
165 **p
!= ',' && !isspace((unsigned char)**p
));
170 /* --- @netg__foreach@ --- *
172 * Arguments: @int st@ = YP protocol-level status code
173 * @char *k@ = pointer to string containing the key
174 * @int ksz@ = length of the key string
175 * @char *v@ = pointer to string containing the value
176 * @int vsz@ = length of the value string
177 * @char *data@ = pointer to my data information
179 * Returns: Zero to continue, nonzero for no more entries.
181 * Use: Handles each incoming netgroup, attaching it to the table.
184 static int netg__foreach(int st
, char *k
, int ksz
,
185 char *v
, int vsz
, char *data
)
190 netg__cons
*c
, **link
;
194 /* --- If something is amiss, then quit now --- */
199 /* --- Ignore empty lines from the original file --- */
204 /* --- Build my own trashable copies of the key and value --- *
206 * Note the oddness when I copy the value string. The extra byte at the
207 * beginning allows me to use the same area of memory as an output buffer
208 * for the lexer. It must be big enough; the lexer doesn't back up; and
209 * that extra byte gives me somewhere to put a terminating null byte.
212 kc
= xmalloc(ksz
+ 1);
216 vc
= xmalloc(vsz
+ 2);
217 memcpy(vc
+ 1, v
, vsz
);
220 T( trace(TRACE_DEBUG
, "debug: netgroup `%s': `%s'", kc
, vc
+ 1); )
222 /* --- Allocate a symbol in my table --- */
224 sng
= sym_find(&netg__table
, kc
, -1, sizeof(*sng
), &f
);
228 /* --- Run to the end of the list --- */
230 for (link
= &sng
->cons
; *link
; link
= &((*link
)->cdr
))
233 /* --- Now start the tricky bit --- *
235 * I have to start parsing the netgroup value string. Oh, well, it
238 * The parser is written so as to avoid saying things more often than
239 * necessary. This tends to involve @goto@s. You've been warned.
243 t
= netg__lex(&p
, vc
);
247 /* --- Start with a fresh cons cell, with an empty atom attached --- */
249 c
= xmalloc(sizeof(*c
));
250 c
->car
.atom
= xmalloc(sizeof(*c
->car
.atom
));
252 /* --- Restart here after an error --- *
254 * If I restart here, I can avoid freeing the cons cell reallocating
255 * it, which is a little silly.
259 c
->car
.atom
->n
= c
->car
.atom
->h
= c
->car
.atom
->u
= c
->car
.atom
->d
= 0;
263 /* --- Handle end-of-line --- */
268 /* --- Handle a netgroup reference --- */
270 if (t
== tok_string
) {
271 T( trace(TRACE_DEBUG
, "debug: add reference to `%s'", vc
); )
272 c
->car
.atom
->n
= xstrdup(vc
);
275 t
= netg__lex(&p
, vc
);
279 /* --- Parse our merry way through the host--user--domain triple --- */
283 t
= netg__lex(&p
, vc
);
285 if (t
== tok_string
) {
286 T( trace(TRACE_DEBUG
, "debug: add host `%s'", vc
); )
287 c
->car
.atom
->h
= xstrdup(vc
);
288 t
= netg__lex(&p
, vc
);
293 t
= netg__lex(&p
, vc
);
295 if (t
== tok_string
) {
296 T( trace(TRACE_DEBUG
, "debug: add user `%s'", vc
); )
297 c
->car
.atom
->u
= xstrdup(vc
);
298 t
= netg__lex(&p
, vc
);
303 t
= netg__lex(&p
, vc
);
305 if (t
== tok_string
) {
306 T( trace(TRACE_DEBUG
, "debug: add domain `%s'", vc
); )
307 c
->car
.atom
->d
= xstrdup(vc
);
308 t
= netg__lex(&p
, vc
);
313 t
= netg__lex(&p
, vc
);
315 /* --- Finished that, so insert this cons cell into the list --- */
321 /* --- Tidy up during scanning of a triple --- *
323 * I'll search for the closing paren, and hope that I won't miss out too
328 while (t
!= tok_eof
&& t
!= ')')
329 t
= netg__lex(&p
, vc
);
331 /* --- Other syntax oddnesses come out here --- *
333 * Snarf the token which caused the error.
337 moan("syntax error in netgroups line for `%s'", kc
);
338 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
339 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
340 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
341 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
342 t
= netg__lex(&p
, vc
);
353 /* --- @netg__dumpGroup@ --- *
355 * Arguments: @netg__cons *c@ = pointer to a list head
356 * @int lev@ = indentation level
360 * Use: Dumps the netgroup given.
365 static void netg__dumpGroup(netg__cons
*c
, int lev
)
372 /* --- Check for a cycle --- */
374 if (c
->f
& f_visit
) {
375 trace(TRACE_DEBUG
, "debug: %*scycle!", lev
* 2, "");
379 /* --- Dump the netgroup --- */
383 for (cc
= c
; cc
; cc
= cc
->cdr
) {
384 if (cc
->f
& f_cons
) {
385 trace(TRACE_DEBUG
, "debug: %*ssubnetgroup...", lev
* 2, "");
386 netg__dumpGroup(cc
->car
.cons
, lev
+ 1);
387 } else if (cc
->car
.atom
->n
) {
388 trace(TRACE_DEBUG
, "debug: %*sunresolved subgroup `%s'",
389 lev
* 2, "", cc
->car
.atom
->n
);
391 trace(TRACE_DEBUG
, "debug: %*s(%s, %s, %s)", lev
* 2, "",
392 cc
->car
.atom
->h ? cc
->car
.atom
->h
: "<all-hosts>",
393 cc
->car
.atom
->u ? cc
->car
.atom
->u
: "<all-users>",
394 cc
->car
.atom
->d ? cc
->car
.atom
->d
: "<all-domains>");
403 /* --- @netg__dump@ --- *
409 * Use: Dumps the netgroups table.
414 static void netg__dump(void)
419 trace(TRACE_DEBUG
, "debug: dumping netgroups file");
420 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
421 trace(TRACE_DEBUG
, "debug: netgroup `%s'...", sng
->_base
.name
);
422 sng
->cons
->f
&= ~f_visit
;
423 netg__dumpGroup(sng
->cons
, 1);
429 /* --- @netg_iterate@, @netg_iterate_r@ --- *
431 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
435 * Use: Starts iterating over the netgroups.
438 void netg_iterate(void) { netg_iterate_r(&netg__iter
); }
439 void netg_iterate_r(netg_iter
*i
) { sym_createIter(i
, &netg__table
); }
441 /* --- @netg_next@, @netg_next_r@ --- *
443 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
445 * Returns: An opaque pointer to the next item, or null.
447 * Use: Returns the next netgroup.
450 netg
*netg_next(void) { return (netg_next_r(&netg__iter
)); }
451 netg
*netg_next_r(netg_iter
*i
) { return (sym_next(i
)); }
453 /* --- @netg_name@ --- *
455 * Arguments: @netg *n@ = netgroup handle returned by @netg_next@.
457 * Returns: A pointer to the name; you may not modify this string.
459 * Use: Returns the name of a netgroup.
462 const char *netg_name(netg
*n
) { return (n
->_base
.name
); }
464 /* --- @netg_scan@ --- *
466 * Arguments: @netg *n@ = a netgroup handle returned by @netg_next@
467 * @int (*proc)(netg *n, const char *host, const char *user,@
468 * @const char *domain, void *ctx)@ = function to call
470 * @void *ctx@ = context pointer to pass to @proc@.
472 * Returns: Zero if all went well, or the nonzero return value from
475 * Use: Passes all the members of the netgroup to a given function.
476 * The function is given the names, directly from the NIS
477 * netgroup map, except that any empty entries are passed as
478 * null pointers rather than empty strings. You may not modify
479 * any of the strings. The enumeration function, @proc@, may
480 * return nonzero to stop itself from being called any more;
481 * if this happens, the value it returns becomes the result of
482 * this function. If all the items are enumerated OK, this
483 * function returns zero.
486 static int netg__doScan(netg__cons
*c
,
488 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
489 const char */
*user*/
,
490 const char */
*domain*/
, void */
*ctx*/
),
497 e
= netg__doScan(c
->car
.cons
, n
, proc
, ctx
);
499 e
= proc(n
, c
->car
.atom
->h
, c
->car
.atom
->u
, c
->car
.atom
->d
, ctx
);
507 int netg_scan(netg
*n
,
508 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
509 const char */
*user*/
, const char */
*domain*/
,
513 return (netg__doScan(n
->cons
, n
, proc
, ctx
));
516 /* --- @netg__breakCycle@ --- *
518 * Arguments: @netg__cons *c@ = pointer to a list
522 * Use: Scans the given list (recursively) and breaks any cycles it
526 static void netg__breakCycle(netg__cons
*c
)
530 if (!c
|| c
->f
& f_uncycled
)
534 for (cc
= c
; cc
; cc
= cc
->cdr
) {
537 if (cc
->car
.cons
->f
& f_visit
) {
538 T( trace(TRACE_DEBUG
, "debug: cycle in netgroups"); )
541 netg__breakCycle(cc
->car
.cons
);
547 /* --- @netg_init@ --- *
553 * Use: Reads the netgroup database and turns it into something nice.
558 /* --- Initialise my symbol table --- */
560 sym_createTable(&netg__table
);
562 /* --- Bind myself unto a YP server --- */
568 /* --- Now try to read all the netgroup entries --- */
571 static struct ypall_callback ncb
= { netg__foreach
, 0 };
572 yp_all(yp_domain
, "netgroup", &ncb
);
575 /* --- Dump the table --- */
577 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
579 /* --- Now resolve all the remaining references --- */
587 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
588 for (c
= sng
->cons
; c
; c
= c
->cdr
) {
589 if ((c
->f
& f_cons
) == 0 && c
->car
.atom
->n
) {
591 ng
= sym_find(&netg__table
, a
->n
, -1, 0, 0);
593 moan("undefined netgroup `%s' (ignored)", a
->n
);
596 c
->car
.cons
= ng
->cons
;
606 /* --- Remove cycles in the netgroups table --- */
612 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
613 sng
->cons
->f
&= ~f_uncycled
;
614 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
615 netg__breakCycle(sng
->cons
);
618 /* --- Dump the table again --- */
620 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
623 /* --- @netg_end@ --- *
629 * Use: Empties the netgroups database.
638 /* --- Remove all the old netgroups rubbish --- */
640 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
644 if (~c
->f
& f_cons
) {
645 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
646 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
647 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
648 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
654 sym_remove(&netg__table
, sng
);
657 sym_destroyTable(&netg__table
);
660 /*----- Test driver -------------------------------------------------------*/
664 int scanner(netg
*n
, const char *h
, const char *u
, const char *d
, void *c
)
666 fprintf(stderr
, " %s, %s, %s\n",
667 h ? h
: "<any>", u ? u
: "<any>", d ? d
: "<any>");
675 traceon(stderr
, TRACE_ALL
);
677 for (netg_iterate(); (n
= netg_next()) != 0; ) {
678 fprintf(stderr
, "netgroup %s\n", netg_name(n
));
679 netg_scan(n
, scanner
, 0);
686 /*----- That's all, folks -------------------------------------------------*/