3 * $Id: netg.c,v 1.3 1998/01/12 16:46:17 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 1.3 1998/01/12 16:46:17 mdw
35 * Revision 1.2 1997/08/20 16:19:11 mdw
36 * Patch memory leak. Replace `name_reinit' by `name_end' for more sensible
37 * restart. Don't try to trace when tracing's turned off.
39 * Revision 1.1 1997/08/07 09:45:00 mdw
40 * New source file added to maintain a netgroups database.
44 /*----- Header files ------------------------------------------------------*/
46 /* --- ANSI headers --- */
53 /* --- Unix headers --- */
57 #include <sys/types.h>
61 # include <rpcsvc/ypclnt.h>
62 # include <rpcsvc/yp_prot.h>
65 #include <netinet/in.h>
67 #include <arpa/inet.h>
73 /* --- Local headers --- */
82 /*----- Type definitions --------------------------------------------------*/
84 /* --- Quick discussion --- *
86 * I've just noticed: netgroups are horrible. They form a directed graph
87 * which is really horrible; I'll have to try and turn it into something
88 * more sensible (which will essentially involve cutting cycles).
90 * The structure looks a little bit like a good ol' List (see Knuth 1 or
91 * any decent Lisp manual), but with more information in the cons cells.
94 /* --- @netg__cons@ --- */
96 typedef struct netg__cons
{
99 struct netg__cons
*cons
;
100 struct netg__atom
*atom
;
102 struct netg__cons
*cdr
;
106 f_cons
= 1, /* The @car@ is a cons cell */
107 f_visit
= 2, /* Currently threaded on this cell */
108 f_uncycled
= 4 /* Cycles removed from here on in */
111 /* --- @netg__atom@ --- */
113 typedef struct netg__atom
{
114 char *n
; /* Unresolved netgroup reference */
115 char *h
; /* Matched hostname */
116 char *u
; /* Matched user name */
117 char *d
; /* Matched domain name */
120 /* --- @netg__sym@ --- */
122 typedef struct netg__sym
{
127 /* --- Token types for the netgroup parser --- */
134 /*----- Static variables --------------------------------------------------*/
136 static sym_table netg__table
; /* Netgroup table */
137 static sym_iter netg__iter
; /* Iterator object for users */
139 /*----- Main code ---------------------------------------------------------*/
141 /* --- @netg__lex@ --- *
143 * Arguments: @const char **p@ = pointer to next unscanned character
144 * @char *q@ = pointer to output buffer
146 * Returns: Token type (either character code or a magic number).
148 * Use: Lexes a netgroups line into tokens.
151 static int netg__lex(char **p
, char *q
)
153 /* --- Skip any leading whitespace --- */
155 while (isspace((unsigned char)**p
))
158 /* --- Now work out what we've got --- */
162 if (**p
== '(' || **p
== ')' || **p
== ',')
166 while (**p
!= 0 && **p
!= '(' && **p
!= ')' &&
167 **p
!= ',' && !isspace((unsigned char)**p
));
172 /* --- @netg__foreach@ --- *
174 * Arguments: @int st@ = YP protocol-level status code
175 * @char *k@ = pointer to string containing the key
176 * @int ksz@ = length of the key string
177 * @char *v@ = pointer to string containing the value
178 * @int vsz@ = length of the value string
179 * @char *data@ = pointer to my data information
181 * Returns: Zero to continue, nonzero for no more entries.
183 * Use: Handles each incoming netgroup, attaching it to the table.
186 static int netg__foreach(int st
, char *k
, int ksz
,
187 char *v
, int vsz
, char *data
)
192 netg__cons
*c
, **link
;
196 /* --- If something is amiss, then quit now --- */
201 /* --- Ignore empty lines from the original file --- */
206 /* --- Build my own trashable copies of the key and value --- *
208 * Note the oddness when I copy the value string. The extra byte at the
209 * beginning allows me to use the same area of memory as an output buffer
210 * for the lexer. It must be big enough; the lexer doesn't back up; and
211 * that extra byte gives me somewhere to put a terminating null byte.
214 kc
= xmalloc(ksz
+ 1);
218 vc
= xmalloc(vsz
+ 2);
219 memcpy(vc
+ 1, v
, vsz
);
222 T( trace(TRACE_DEBUG
, "debug: netgroup `%s': `%s'", kc
, vc
+ 1); )
224 /* --- Allocate a symbol in my table --- */
226 sng
= sym_find(&netg__table
, kc
, -1, sizeof(*sng
), &f
);
230 /* --- Run to the end of the list --- */
232 for (link
= &sng
->cons
; *link
; link
= &((*link
)->cdr
))
235 /* --- Now start the tricky bit --- *
237 * I have to start parsing the netgroup value string. Oh, well, it
240 * The parser is written so as to avoid saying things more often than
241 * necessary. This tends to involve @goto@s. You've been warned.
245 t
= netg__lex(&p
, vc
);
249 /* --- Start with a fresh cons cell, with an empty atom attached --- */
251 c
= xmalloc(sizeof(*c
));
252 c
->car
.atom
= xmalloc(sizeof(*c
->car
.atom
));
254 /* --- Restart here after an error --- *
256 * If I restart here, I can avoid freeing the cons cell reallocating
257 * it, which is a little silly.
261 c
->car
.atom
->n
= c
->car
.atom
->h
= c
->car
.atom
->u
= c
->car
.atom
->d
= 0;
265 /* --- Handle end-of-line --- */
270 /* --- Handle a netgroup reference --- */
272 if (t
== tok_string
) {
273 T( trace(TRACE_DEBUG
, "debug: add reference to `%s'", vc
); )
274 c
->car
.atom
->n
= xstrdup(vc
);
277 t
= netg__lex(&p
, vc
);
281 /* --- Parse our merry way through the host--user--domain triple --- */
285 t
= netg__lex(&p
, vc
);
287 if (t
== tok_string
) {
288 T( trace(TRACE_DEBUG
, "debug: add host `%s'", vc
); )
289 c
->car
.atom
->h
= xstrdup(vc
);
290 t
= netg__lex(&p
, vc
);
295 t
= netg__lex(&p
, vc
);
297 if (t
== tok_string
) {
298 T( trace(TRACE_DEBUG
, "debug: add user `%s'", vc
); )
299 c
->car
.atom
->u
= xstrdup(vc
);
300 t
= netg__lex(&p
, vc
);
305 t
= netg__lex(&p
, vc
);
307 if (t
== tok_string
) {
308 T( trace(TRACE_DEBUG
, "debug: add domain `%s'", vc
); )
309 c
->car
.atom
->d
= xstrdup(vc
);
310 t
= netg__lex(&p
, vc
);
315 t
= netg__lex(&p
, vc
);
317 /* --- Finished that, so insert this cons cell into the list --- */
323 /* --- Tidy up during scanning of a triple --- *
325 * I'll search for the closing paren, and hope that I won't miss out too
330 while (t
!= tok_eof
&& t
!= ')')
331 t
= netg__lex(&p
, vc
);
333 /* --- Other syntax oddnesses come out here --- *
335 * Snarf the token which caused the error.
339 moan("syntax error in netgroups line for `%s'", kc
);
340 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
341 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
342 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
343 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
344 t
= netg__lex(&p
, vc
);
355 /* --- @netg__dumpGroup@ --- *
357 * Arguments: @netg__cons *c@ = pointer to a list head
358 * @int lev@ = indentation level
362 * Use: Dumps the netgroup given.
367 static void netg__dumpGroup(netg__cons
*c
, int lev
)
374 /* --- Check for a cycle --- */
376 if (c
->f
& f_visit
) {
377 trace(TRACE_DEBUG
, "debug: %*scycle!", lev
* 2, "");
381 /* --- Dump the netgroup --- */
385 for (cc
= c
; cc
; cc
= cc
->cdr
) {
386 if (cc
->f
& f_cons
) {
387 trace(TRACE_DEBUG
, "debug: %*ssubnetgroup...", lev
* 2, "");
388 netg__dumpGroup(cc
->car
.cons
, lev
+ 1);
389 } else if (cc
->car
.atom
->n
) {
390 trace(TRACE_DEBUG
, "debug: %*sunresolved subgroup `%s'",
391 lev
* 2, "", cc
->car
.atom
->n
);
393 trace(TRACE_DEBUG
, "debug: %*s(%s, %s, %s)", lev
* 2, "",
394 cc
->car
.atom
->h ? cc
->car
.atom
->h
: "<all-hosts>",
395 cc
->car
.atom
->u ? cc
->car
.atom
->u
: "<all-users>",
396 cc
->car
.atom
->d ? cc
->car
.atom
->d
: "<all-domains>");
405 /* --- @netg__dump@ --- *
411 * Use: Dumps the netgroups table.
416 static void netg__dump(void)
421 trace(TRACE_DEBUG
, "debug: dumping netgroups file");
422 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
423 trace(TRACE_DEBUG
, "debug: netgroup `%s'...", sng
->_base
.name
);
424 sng
->cons
->f
&= ~f_visit
;
425 netg__dumpGroup(sng
->cons
, 1);
431 /* --- @netg_iterate@, @netg_iterate_r@ --- *
433 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
437 * Use: Starts iterating over the netgroups.
440 void netg_iterate(void) { netg_iterate_r(&netg__iter
); }
441 void netg_iterate_r(netg_iter
*i
) { sym_createIter(i
, &netg__table
); }
443 /* --- @netg_next@, @netg_next_r@ --- *
445 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
447 * Returns: An opaque pointer to the next item, or null.
449 * Use: Returns the next netgroup.
452 netg
*netg_next(void) { return (netg_next_r(&netg__iter
)); }
453 netg
*netg_next_r(netg_iter
*i
) { return (sym_next(i
)); }
455 /* --- @netg_name@ --- *
457 * Arguments: @netg *n@ = netgroup handle returned by @netg_next@.
459 * Returns: A pointer to the name; you may not modify this string.
461 * Use: Returns the name of a netgroup.
464 const char *netg_name(netg
*n
) { return (n
->_base
.name
); }
466 /* --- @netg_scan@ --- *
468 * Arguments: @netg *n@ = a netgroup handle returned by @netg_next@
469 * @int (*proc)(netg *n, const char *host, const char *user,@
470 * @const char *domain, void *ctx)@ = function to call
472 * @void *ctx@ = context pointer to pass to @proc@.
474 * Returns: Zero if all went well, or the nonzero return value from
477 * Use: Passes all the members of the netgroup to a given function.
478 * The function is given the names, directly from the NIS
479 * netgroup map, except that any empty entries are passed as
480 * null pointers rather than empty strings. You may not modify
481 * any of the strings. The enumeration function, @proc@, may
482 * return nonzero to stop itself from being called any more;
483 * if this happens, the value it returns becomes the result of
484 * this function. If all the items are enumerated OK, this
485 * function returns zero.
488 static int netg__doScan(netg__cons
*c
,
490 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
491 const char */
*user*/
,
492 const char */
*domain*/
, void */
*ctx*/
),
499 e
= netg__doScan(c
->car
.cons
, n
, proc
, ctx
);
501 e
= proc(n
, c
->car
.atom
->h
, c
->car
.atom
->u
, c
->car
.atom
->d
, ctx
);
509 int netg_scan(netg
*n
,
510 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
511 const char */
*user*/
, const char */
*domain*/
,
515 return (netg__doScan(n
->cons
, n
, proc
, ctx
));
518 /* --- @netg__breakCycle@ --- *
520 * Arguments: @netg__cons *c@ = pointer to a list
524 * Use: Scans the given list (recursively) and breaks any cycles it
528 static void netg__breakCycle(netg__cons
*c
)
532 if (!c
|| c
->f
& f_uncycled
)
536 for (cc
= c
; cc
; cc
= cc
->cdr
) {
539 if (cc
->car
.cons
->f
& f_visit
) {
540 T( trace(TRACE_DEBUG
, "debug: cycle in netgroups"); )
543 netg__breakCycle(cc
->car
.cons
);
549 /* --- @netg_init@ --- *
555 * Use: Reads the netgroup database and turns it into something nice.
562 /* --- Initialise my symbol table --- */
564 sym_createTable(&netg__table
);
566 /* --- Bind myself unto a YP server --- */
568 if (yp_get_default_domain(&ypdom
) ||
572 /* --- Now try to read all the netgroup entries --- */
575 static struct ypall_callback ncb
= { netg__foreach
, 0 };
576 yp_all(ypdom
, "netgroup", &ncb
);
579 /* --- Unbind from the server --- */
583 /* --- Dump the table --- */
585 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
587 /* --- Now resolve all the remaining references --- */
595 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
596 for (c
= sng
->cons
; c
; c
= c
->cdr
) {
597 if ((c
->f
& f_cons
) == 0 && c
->car
.atom
->n
) {
599 ng
= sym_find(&netg__table
, a
->n
, -1, 0, 0);
601 moan("undefined netgroup `%s' (ignored)", a
->n
);
604 c
->car
.cons
= ng
->cons
;
614 /* --- Remove cycles in the netgroups table --- */
620 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
621 sng
->cons
->f
&= ~f_uncycled
;
622 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
623 netg__breakCycle(sng
->cons
);
626 /* --- Dump the table again --- */
628 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
631 /* --- @netg_end@ --- *
637 * Use: Empties the netgroups database.
646 /* --- Remove all the old netgroups rubbish --- */
648 for (sym_createIter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
652 if (~c
->f
& f_cons
) {
653 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
654 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
655 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
656 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
662 sym_remove(&netg__table
, sng
);
665 sym_destroyTable(&netg__table
);
668 /*----- Test driver -------------------------------------------------------*/
672 int scanner(netg
*n
, const char *h
, const char *u
, const char *d
, void *c
)
674 fprintf(stderr
, " %s, %s, %s\n",
675 h ? h
: "<any>", u ? u
: "<any>", d ? d
: "<any>");
683 traceon(stderr
, TRACE_ALL
);
685 for (netg_iterate(); (n
= netg_next()) != 0; ) {
686 fprintf(stderr
, "netgroup %s\n", netg_name(n
));
687 netg_scan(n
, scanner
, 0);
694 /*----- That's all, folks -------------------------------------------------*/