b92e83a4e89cc2889aa886c79dce85e12aeebc4b
3 * $Id: netg.c,v 1.7 2004/04/08 01:36:20 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 /*----- Header files ------------------------------------------------------*/
31 /* --- ANSI headers --- */
38 /* --- Unix headers --- */
42 #include <sys/types.h>
44 #include <netinet/in.h>
46 #include <arpa/inet.h>
52 /* --- mLib headers --- */
54 #include <mLib/alloc.h>
55 #include <mLib/report.h>
57 #include <mLib/trace.h>
59 /* --- Local headers --- */
67 /*----- Type definitions --------------------------------------------------*/
69 /* --- Quick discussion --- *
71 * I've just noticed: netgroups are horrible. They form a directed graph
72 * which is really horrible; I'll have to try and turn it into something
73 * more sensible (which will essentially involve cutting cycles).
75 * The structure looks a little bit like a good ol' List (see Knuth 1 or
76 * any decent Lisp manual), but with more information in the cons cells.
79 /* --- @netg__cons@ --- */
81 typedef struct netg__cons
{
84 struct netg__cons
*cons
;
85 struct netg__atom
*atom
;
87 struct netg__cons
*cdr
;
91 f_cons
= 1, /* The @car@ is a cons cell */
92 f_visit
= 2, /* Currently threaded on this cell */
93 f_uncycled
= 4 /* Cycles removed from here on in */
96 /* --- @netg__atom@ --- */
98 typedef struct netg__atom
{
99 char *n
; /* Unresolved netgroup reference */
100 char *h
; /* Matched hostname */
101 char *u
; /* Matched user name */
102 char *d
; /* Matched domain name */
105 /* --- @netg__sym@ --- */
107 typedef struct netg__sym
{
112 /* --- Token types for the netgroup parser --- */
119 /*----- Static variables --------------------------------------------------*/
121 static sym_table netg__table
; /* Netgroup table */
122 static sym_iter netg__iter
; /* Iterator object for users */
124 /*----- Main code ---------------------------------------------------------*/
126 /* --- @netg__lex@ --- *
128 * Arguments: @const char **p@ = pointer to next unscanned character
129 * @char *q@ = pointer to output buffer
131 * Returns: Token type (either character code or a magic number).
133 * Use: Lexes a netgroups line into tokens.
136 static int netg__lex(char **p
, char *q
)
138 /* --- Skip any leading whitespace --- */
140 while (isspace((unsigned char)**p
))
143 /* --- Now work out what we've got --- */
147 if (**p
== '(' || **p
== ')' || **p
== ',')
151 while (**p
!= 0 && **p
!= '(' && **p
!= ')' &&
152 **p
!= ',' && !isspace((unsigned char)**p
));
157 /* --- @netg__foreach@ --- *
159 * Arguments: @int st@ = YP protocol-level status code
160 * @char *k@ = pointer to string containing the key
161 * @int ksz@ = length of the key string
162 * @char *v@ = pointer to string containing the value
163 * @int vsz@ = length of the value string
164 * @char *data@ = pointer to my data information
166 * Returns: Zero to continue, nonzero for no more entries.
168 * Use: Handles each incoming netgroup, attaching it to the table.
171 static int netg__foreach(int st
, char *k
, int ksz
,
172 char *v
, int vsz
, char *data
)
177 netg__cons
*c
, **link
;
181 /* --- If something is amiss, then quit now --- */
186 /* --- Ignore empty lines from the original file --- */
191 /* --- Build my own trashable copies of the key and value --- *
193 * Note the oddness when I copy the value string. The extra byte at the
194 * beginning allows me to use the same area of memory as an output buffer
195 * for the lexer. It must be big enough; the lexer doesn't back up; and
196 * that extra byte gives me somewhere to put a terminating null byte.
199 kc
= xmalloc(ksz
+ 1);
203 vc
= xmalloc(vsz
+ 2);
204 memcpy(vc
+ 1, v
, vsz
);
207 T( trace(TRACE_DEBUG
, "debug: netgroup `%s': `%s'", kc
, vc
+ 1); )
209 /* --- Allocate a symbol in my table --- */
211 sng
= sym_find(&netg__table
, kc
, -1, sizeof(*sng
), &f
);
215 /* --- Run to the end of the list --- */
217 for (link
= &sng
->cons
; *link
; link
= &((*link
)->cdr
))
220 /* --- Now start the tricky bit --- *
222 * I have to start parsing the netgroup value string. Oh, well, it
225 * The parser is written so as to avoid saying things more often than
226 * necessary. This tends to involve @goto@s. You've been warned.
230 t
= netg__lex(&p
, vc
);
234 /* --- Start with a fresh cons cell, with an empty atom attached --- */
236 c
= xmalloc(sizeof(*c
));
237 c
->car
.atom
= xmalloc(sizeof(*c
->car
.atom
));
239 /* --- Restart here after an error --- *
241 * If I restart here, I can avoid freeing the cons cell reallocating
242 * it, which is a little silly.
246 c
->car
.atom
->n
= c
->car
.atom
->h
= c
->car
.atom
->u
= c
->car
.atom
->d
= 0;
250 /* --- Handle end-of-line --- */
255 /* --- Handle a netgroup reference --- */
257 if (t
== tok_string
) {
258 T( trace(TRACE_DEBUG
, "debug: add reference to `%s'", vc
); )
259 c
->car
.atom
->n
= xstrdup(vc
);
262 t
= netg__lex(&p
, vc
);
266 /* --- Parse our merry way through the host--user--domain triple --- */
270 t
= netg__lex(&p
, vc
);
272 if (t
== tok_string
) {
273 T( trace(TRACE_DEBUG
, "debug: add host `%s'", vc
); )
274 c
->car
.atom
->h
= xstrdup(vc
);
275 t
= netg__lex(&p
, vc
);
280 t
= netg__lex(&p
, vc
);
282 if (t
== tok_string
) {
283 T( trace(TRACE_DEBUG
, "debug: add user `%s'", vc
); )
284 c
->car
.atom
->u
= xstrdup(vc
);
285 t
= netg__lex(&p
, vc
);
290 t
= netg__lex(&p
, vc
);
292 if (t
== tok_string
) {
293 T( trace(TRACE_DEBUG
, "debug: add domain `%s'", vc
); )
294 c
->car
.atom
->d
= xstrdup(vc
);
295 t
= netg__lex(&p
, vc
);
300 t
= netg__lex(&p
, vc
);
302 /* --- Finished that, so insert this cons cell into the list --- */
308 /* --- Tidy up during scanning of a triple --- *
310 * I'll search for the closing paren, and hope that I won't miss out too
315 while (t
!= tok_eof
&& t
!= ')')
316 t
= netg__lex(&p
, vc
);
318 /* --- Other syntax oddnesses come out here --- *
320 * Snarf the token which caused the error.
324 moan("syntax error in netgroups line for `%s'", kc
);
325 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
326 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
327 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
328 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
329 t
= netg__lex(&p
, vc
);
340 /* --- @netg__dumpGroup@ --- *
342 * Arguments: @netg__cons *c@ = pointer to a list head
343 * @int lev@ = indentation level
347 * Use: Dumps the netgroup given.
352 static void netg__dumpGroup(netg__cons
*c
, int lev
)
359 /* --- Check for a cycle --- */
361 if (c
->f
& f_visit
) {
362 trace(TRACE_DEBUG
, "debug: %*scycle!", lev
* 2, "");
366 /* --- Dump the netgroup --- */
370 for (cc
= c
; cc
; cc
= cc
->cdr
) {
371 if (cc
->f
& f_cons
) {
372 trace(TRACE_DEBUG
, "debug: %*ssubnetgroup...", lev
* 2, "");
373 netg__dumpGroup(cc
->car
.cons
, lev
+ 1);
374 } else if (cc
->car
.atom
->n
) {
375 trace(TRACE_DEBUG
, "debug: %*sunresolved subgroup `%s'",
376 lev
* 2, "", cc
->car
.atom
->n
);
378 trace(TRACE_DEBUG
, "debug: %*s(%s, %s, %s)", lev
* 2, "",
379 cc
->car
.atom
->h ? cc
->car
.atom
->h
: "<all-hosts>",
380 cc
->car
.atom
->u ? cc
->car
.atom
->u
: "<all-users>",
381 cc
->car
.atom
->d ? cc
->car
.atom
->d
: "<all-domains>");
390 /* --- @netg__dump@ --- *
396 * Use: Dumps the netgroups table.
401 static void netg__dump(void)
406 trace(TRACE_DEBUG
, "debug: dumping netgroups file");
407 for (sym_mkiter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
408 trace(TRACE_DEBUG
, "debug: netgroup `%s'...", sng
->_base
.name
);
409 sng
->cons
->f
&= ~f_visit
;
410 netg__dumpGroup(sng
->cons
, 1);
416 /* --- @netg_iterate@, @netg_iterate_r@ --- *
418 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
422 * Use: Starts iterating over the netgroups.
425 void netg_iterate(void) { netg_iterate_r(&netg__iter
); }
426 void netg_iterate_r(netg_iter
*i
) { sym_mkiter(i
, &netg__table
); }
428 /* --- @netg_next@, @netg_next_r@ --- *
430 * Arguments: @netg_iter *i@ = pointer to a netgroup iterator object
432 * Returns: An opaque pointer to the next item, or null.
434 * Use: Returns the next netgroup.
437 netg
*netg_next(void) { return (netg_next_r(&netg__iter
)); }
438 netg
*netg_next_r(netg_iter
*i
) { return (sym_next(i
)); }
440 /* --- @netg_name@ --- *
442 * Arguments: @netg *n@ = netgroup handle returned by @netg_next@.
444 * Returns: A pointer to the name; you may not modify this string.
446 * Use: Returns the name of a netgroup.
449 const char *netg_name(netg
*n
) { return (n
->_base
.name
); }
451 /* --- @netg_scan@ --- *
453 * Arguments: @netg *n@ = a netgroup handle returned by @netg_next@
454 * @int (*proc)(netg *n, const char *host, const char *user,@
455 * @const char *domain, void *ctx)@ = function to call
457 * @void *ctx@ = context pointer to pass to @proc@.
459 * Returns: Zero if all went well, or the nonzero return value from
462 * Use: Passes all the members of the netgroup to a given function.
463 * The function is given the names, directly from the NIS
464 * netgroup map, except that any empty entries are passed as
465 * null pointers rather than empty strings. You may not modify
466 * any of the strings. The enumeration function, @proc@, may
467 * return nonzero to stop itself from being called any more;
468 * if this happens, the value it returns becomes the result of
469 * this function. If all the items are enumerated OK, this
470 * function returns zero.
473 static int netg__doScan(netg__cons
*c
,
475 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
476 const char */
*user*/
,
477 const char */
*domain*/
, void */
*ctx*/
),
484 e
= netg__doScan(c
->car
.cons
, n
, proc
, ctx
);
486 e
= proc(n
, c
->car
.atom
->h
, c
->car
.atom
->u
, c
->car
.atom
->d
, ctx
);
494 int netg_scan(netg
*n
,
495 int (*proc
)(netg */
*n*/
, const char */
*host*/
,
496 const char */
*user*/
, const char */
*domain*/
,
500 return (netg__doScan(n
->cons
, n
, proc
, ctx
));
503 /* --- @netg__breakCycle@ --- *
505 * Arguments: @netg__cons *c@ = pointer to a list
509 * Use: Scans the given list (recursively) and breaks any cycles it
513 static void netg__breakCycle(netg__cons
*c
)
517 if (!c
|| c
->f
& f_uncycled
)
521 for (cc
= c
; cc
; cc
= cc
->cdr
) {
524 if (cc
->car
.cons
->f
& f_visit
) {
525 T( trace(TRACE_DEBUG
, "debug: cycle in netgroups"); )
528 netg__breakCycle(cc
->car
.cons
);
534 /* --- @netg_init@ --- *
540 * Use: Reads the netgroup database and turns it into something nice.
545 /* --- Initialise my symbol table --- */
547 sym_create(&netg__table
);
549 /* --- Bind myself unto a YP server --- */
555 /* --- Now try to read all the netgroup entries --- */
558 static struct ypall_callback ncb
= { netg__foreach
, 0 };
559 yp_all(yp_domain
, "netgroup", &ncb
);
562 /* --- Dump the table --- */
564 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
566 /* --- Now resolve all the remaining references --- */
574 for (sym_mkiter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
575 for (c
= sng
->cons
; c
; c
= c
->cdr
) {
576 if ((c
->f
& f_cons
) == 0 && c
->car
.atom
->n
) {
578 ng
= sym_find(&netg__table
, a
->n
, -1, 0, 0);
580 moan("undefined netgroup `%s' (ignored)", a
->n
);
583 c
->car
.cons
= ng
->cons
;
593 /* --- Remove cycles in the netgroups table --- */
599 for (sym_mkiter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
600 sng
->cons
->f
&= ~f_uncycled
;
601 for (sym_mkiter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; )
602 netg__breakCycle(sng
->cons
);
605 /* --- Dump the table again --- */
607 IF_TRACING(TRACE_DEBUG
, netg__dump(); )
610 /* --- @netg_end@ --- *
616 * Use: Empties the netgroups database.
625 /* --- Remove all the old netgroups rubbish --- */
627 for (sym_mkiter(&i
, &netg__table
); (sng
= sym_next(&i
)) != 0; ) {
631 if (~c
->f
& f_cons
) {
632 if (c
->car
.atom
->n
) free(c
->car
.atom
->n
);
633 if (c
->car
.atom
->h
) free(c
->car
.atom
->h
);
634 if (c
->car
.atom
->u
) free(c
->car
.atom
->u
);
635 if (c
->car
.atom
->d
) free(c
->car
.atom
->d
);
641 sym_remove(&netg__table
, sng
);
644 sym_destroy(&netg__table
);
647 /*----- Test driver -------------------------------------------------------*/
651 int scanner(netg
*n
, const char *h
, const char *u
, const char *d
, void *c
)
653 fprintf(stderr
, " %s, %s, %s\n",
654 h ? h
: "<any>", u ? u
: "<any>", d ? d
: "<any>");
662 trace_on(stderr
, TRACE_ALL
);
664 for (netg_iterate(); (n
= netg_next()) != 0; ) {
665 fprintf(stderr
, "netgroup %s\n", netg_name(n
));
666 netg_scan(n
, scanner
, 0);
673 /*----- That's all, folks -------------------------------------------------*/