xref: /freebsd/lib/libc/rpc/getnetconfig.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /*	$NetBSD: getnetconfig.c,v 1.3 2000/07/06 03:10:34 christos Exp $	*/
2 /*	$FreeBSD$ */
3 
4 /*
5  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
6  * unrestricted use provided that this legend is included on all tape
7  * media and as a part of the software program in whole or part.  Users
8  * may copy or modify Sun RPC without charge, but are not authorized
9  * to license or distribute it to anyone else except as part of a product or
10  * program developed by the user or with the express written consent of
11  * Sun Microsystems, Inc.
12  *
13  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
14  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
15  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
16  *
17  * Sun RPC is provided with no support and without any obligation on the
18  * part of Sun Microsystems, Inc. to assist in its use, correction,
19  * modification or enhancement.
20  *
21  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
22  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
23  * OR ANY PART THEREOF.
24  *
25  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
26  * or profits or other special, indirect and consequential damages, even if
27  * Sun has been advised of the possibility of such damages.
28  *
29  * Sun Microsystems, Inc.
30  * 2550 Garcia Avenue
31  * Mountain View, California  94043
32  */
33 /*
34 #ifndef lint
35 static        char sccsid[] = "@(#)getnetconfig.c	1.12 91/12/19 SMI";
36 #endif
37 */
38 
39 /*
40  * Copyright (c) 1989 by Sun Microsystems, Inc.
41  */
42 
43 #include "namespace.h"
44 #include "reentrant.h"
45 #include <sys/cdefs.h>
46 #include <stdio.h>
47 #include <errno.h>
48 #include <netconfig.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <rpc/rpc.h>
52 #include "un-namespace.h"
53 #include "rpc_com.h"
54 
55 /*
56  * The five library routines in this file provide application access to the
57  * system network configuration database, /etc/netconfig.  In addition to the
58  * netconfig database and the routines for accessing it, the environment
59  * variable NETPATH and its corresponding routines in getnetpath.c may also be
60  * used to specify the network transport to be used.
61  */
62 
63 
64 /*
65  * netconfig errors
66  */
67 
68 #define NC_NONETCONFIG	ENOENT
69 #define NC_NOMEM	ENOMEM
70 #define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */
71 #define NC_BADFILE	EBADF	    /* format for netconfig file is bad */
72 #define NC_NOTFOUND	ENOPROTOOPT /* specified netid was not found */
73 
74 /*
75  * semantics as strings (should be in netconfig.h)
76  */
77 #define NC_TPI_CLTS_S	    "tpi_clts"
78 #define	NC_TPI_COTS_S	    "tpi_cots"
79 #define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"
80 #define	NC_TPI_RAW_S        "tpi_raw"
81 
82 /*
83  * flags as characters (also should be in netconfig.h)
84  */
85 #define	NC_NOFLAG_C	'-'
86 #define	NC_VISIBLE_C	'v'
87 #define	NC_BROADCAST_C	'b'
88 
89 /*
90  * Character used to indicate there is no name-to-address lookup library
91  */
92 #define NC_NOLOOKUP	"-"
93 
94 static const char * const _nc_errors[] = {
95     "Netconfig database not found",
96     "Not enough memory",
97     "Not initialized",
98     "Netconfig database has invalid format",
99     "Netid not found in netconfig database"
100 };
101 
102 struct netconfig_info {
103     int		eof;	/* all entries has been read */
104     int		ref;	/* # of times setnetconfig() has been called */
105     struct netconfig_list	*head;	/* head of the list */
106     struct netconfig_list	*tail;	/* last of the list */
107 };
108 
109 struct netconfig_list {
110     char			*linep;	/* hold line read from netconfig */
111     struct netconfig		*ncp;
112     struct netconfig_list	*next;
113 };
114 
115 struct netconfig_vars {
116     int   valid;	/* token that indicates a valid netconfig_vars */
117     int   flag;		/* first time flag */
118     struct netconfig_list *nc_configs;  /* pointer to the current netconfig entry */
119 };
120 
121 #define NC_VALID	0xfeed
122 #define NC_STORAGE	0xf00d
123 #define NC_INVALID	0
124 
125 
126 static int *__nc_error __P((void));
127 static int parse_ncp __P((char *, struct netconfig *));
128 static struct netconfig *dup_ncp __P((struct netconfig *));
129 
130 
131 static FILE *nc_file;		/* for netconfig db */
132 static struct netconfig_info	ni = { 0, 0, NULL, NULL};
133 
134 #define MAXNETCONFIGLINE    1000
135 
136 static int *
137 __nc_error()
138 {
139 	static pthread_mutex_t nc_lock = PTHREAD_MUTEX_INITIALIZER;
140 	static thread_key_t nc_key = 0;
141 	static int nc_error = 0;
142 	int error, *nc_addr;
143 
144 	/*
145 	 * Use the static `nc_error' if we are the main thread
146 	 * (including non-threaded programs), or if an allocation
147 	 * fails.
148 	 */
149 	if (thr_main())
150 		return (&nc_error);
151 	if (nc_key == 0) {
152 		error = 0;
153 		mutex_lock(&nc_lock);
154 		if (nc_key == 0)
155 			error = thr_keycreate(&nc_key, free);
156 		mutex_unlock(&nc_lock);
157 		if (error)
158 			return (&nc_error);
159 	}
160 	if ((nc_addr = (int *)thr_getspecific(nc_key)) == NULL) {
161 		nc_addr = (int *)malloc(sizeof (int));
162 		if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {
163 			if (nc_addr)
164 				free(nc_addr);
165 			return (&nc_error);
166 		}
167 		*nc_addr = 0;
168 	}
169 	return (nc_addr);
170 }
171 
172 #define nc_error        (*(__nc_error()))
173 /*
174  * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
175  * "handle" is returned on a successful call.  At the start of a session (after
176  * a call to setnetconfig()) searches through the /etc/netconfig database will
177  * proceed from the start of the file.  The session handle must be passed to
178  * getnetconfig() to parse the file.  Each call to getnetconfig() using the
179  * current handle will process one subsequent entry in /etc/netconfig.
180  * setnetconfig() must be called before the first call to getnetconfig().
181  * (Handles are used to allow for nested calls to setnetpath()).
182  *
183  * A new session is established with each call to setnetconfig(), with a new
184  * handle being returned on each call.  Previously established sessions remain
185  * active until endnetconfig() is called with that session's handle as an
186  * argument.
187  *
188  * setnetconfig() need *not* be called before a call to getnetconfigent().
189  * setnetconfig() returns a NULL pointer on failure (for example, if
190  * the netconfig database is not present).
191  */
192 void *
193 setnetconfig()
194 {
195     struct netconfig_vars *nc_vars;
196 
197     if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
198 		(struct netconfig_vars))) == NULL) {
199 	return(NULL);
200     }
201 
202     /*
203      * For multiple calls, i.e. nc_file is not NULL, we just return the
204      * handle without reopening the netconfig db.
205      */
206     ni.ref++;
207     if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {
208 	nc_vars->valid = NC_VALID;
209 	nc_vars->flag = 0;
210 	nc_vars->nc_configs = ni.head;
211 	return ((void *)nc_vars);
212     }
213     ni.ref--;
214     nc_error = NC_NONETCONFIG;
215     free(nc_vars);
216     return (NULL);
217 }
218 
219 
220 /*
221  * When first called, getnetconfig() returns a pointer to the first entry in
222  * the netconfig database, formatted as a struct netconfig.  On each subsequent
223  * call, getnetconfig() returns a pointer to the next entry in the database.
224  * getnetconfig() can thus be used to search the entire netconfig file.
225  * getnetconfig() returns NULL at end of file.
226  */
227 
228 struct netconfig *
229 getnetconfig(handlep)
230 void *handlep;
231 {
232     struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
233     char *stringp;		/* tmp string pointer */
234     struct netconfig_list	*list;
235     struct netconfig *np;
236 
237     /*
238      * Verify that handle is valid
239      */
240     if (ncp == NULL || nc_file == NULL) {
241 	nc_error = NC_NOTINIT;
242 	return (NULL);
243     }
244 
245     switch (ncp->valid) {
246     case NC_VALID:
247 	/*
248 	 * If entry has already been read into the list,
249 	 * we return the entry in the linked list.
250 	 * If this is the first time call, check if there are any entries in
251 	 * linked list.  If no entries, we need to read the netconfig db.
252 	 * If we have been here and the next entry is there, we just return
253 	 * it.
254 	 */
255 	if (ncp->flag == 0) {	/* first time */
256 	    ncp->flag = 1;
257 	    ncp->nc_configs = ni.head;
258 	    if (ncp->nc_configs != NULL)	/* entry already exist */
259 		return(ncp->nc_configs->ncp);
260 	}
261 	else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {
262 	    ncp->nc_configs = ncp->nc_configs->next;
263 	    return(ncp->nc_configs->ncp);
264 	}
265 
266 	/*
267 	 * If we cannot find the entry in the list and is end of file,
268 	 * we give up.
269 	 */
270 	if (ni.eof == 1)	return(NULL);
271 	break;
272     default:
273 	nc_error = NC_NOTINIT;
274 	return (NULL);
275     }
276 
277     stringp = (char *) malloc(MAXNETCONFIGLINE);
278     if (stringp == NULL)
279     	return (NULL);
280 
281 #ifdef MEM_CHK
282     if (malloc_verify() == 0) {
283 	fprintf(stderr, "memory heap corrupted in getnetconfig\n");
284 	exit(1);
285     }
286 #endif
287 
288     /*
289      * Read a line from netconfig file.
290      */
291     do {
292 	if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
293 	    free(stringp);
294 	    ni.eof = 1;
295 	    return (NULL);
296         }
297     } while (*stringp == '#');
298 
299     list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));
300     if (list == NULL) {
301     	free(stringp);
302     	return(NULL);
303     }
304     np = (struct netconfig *) malloc(sizeof (struct netconfig));
305     if (np == NULL) {
306     	free(stringp);
307 	free(list);
308     	return(NULL);
309     }
310     list->ncp = np;
311     list->next = NULL;
312     list->ncp->nc_lookups = NULL;
313     list->linep = stringp;
314     if (parse_ncp(stringp, list->ncp) == -1) {
315 	free(stringp);
316 	free(np);
317 	free(list);
318 	return (NULL);
319     }
320     else {
321 	/*
322 	 * If this is the first entry that's been read, it is the head of
323 	 * the list.  If not, put the entry at the end of the list.
324 	 * Reposition the current pointer of the handle to the last entry
325 	 * in the list.
326 	 */
327 	if (ni.head == NULL) {	/* first entry */
328 	    ni.head = ni.tail = list;
329 	}
330     	else {
331     	    ni.tail->next = list;
332     	    ni.tail = ni.tail->next;
333     	}
334 	ncp->nc_configs = ni.tail;
335 	return(ni.tail->ncp);
336     }
337 }
338 
339 /*
340  * endnetconfig() may be called to "unbind" or "close" the netconfig database
341  * when processing is complete, releasing resources for reuse.  endnetconfig()
342  * may not be called before setnetconfig().  endnetconfig() returns 0 on
343  * success and -1 on failure (for example, if setnetconfig() was not called
344  * previously).
345  */
346 int
347 endnetconfig(handlep)
348 void *handlep;
349 {
350     struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
351 
352     struct netconfig_list *q, *p;
353 
354     /*
355      * Verify that handle is valid
356      */
357     if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
358 	    nc_handlep->valid != NC_STORAGE)) {
359 	nc_error = NC_NOTINIT;
360 	return (-1);
361     }
362 
363     /*
364      * Return 0 if anyone still needs it.
365      */
366     nc_handlep->valid = NC_INVALID;
367     nc_handlep->flag = 0;
368     nc_handlep->nc_configs = NULL;
369     if (--ni.ref > 0) {
370     	free(nc_handlep);
371 	return(0);
372     }
373 
374     /*
375      * Noone needs these entries anymore, then frees them.
376      * Make sure all info in netconfig_info structure has been reinitialized.
377      */
378     q = p = ni.head;
379     ni.eof = ni.ref = 0;
380     ni.head = NULL;
381     ni.tail = NULL;
382     while (q) {
383 	p = q->next;
384 	if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);
385 	free(q->ncp);
386 	free(q->linep);
387 	free(q);
388 	q = p;
389     }
390     free(nc_handlep);
391 
392     fclose(nc_file);
393     nc_file = NULL;
394     return (0);
395 }
396 
397 /*
398  * getnetconfigent(netid) returns a pointer to the struct netconfig structure
399  * corresponding to netid.  It returns NULL if netid is invalid (that is, does
400  * not name an entry in the netconfig database).  It returns NULL and sets
401  * errno in case of failure (for example, if the netconfig database cannot be
402  * opened).
403  */
404 
405 struct netconfig *
406 getnetconfigent(netid)
407 	const char *netid;
408 {
409     FILE *file;		/* NETCONFIG db's file pointer */
410     char *linep;	/* holds current netconfig line */
411     char *stringp;	/* temporary string pointer */
412     struct netconfig *ncp = NULL;   /* returned value */
413     struct netconfig_list *list;	/* pointer to cache list */
414 
415     nc_error = NC_NOTFOUND;	/* default error. */
416     if (netid == NULL || strlen(netid) == 0) {
417 	return (NULL);
418     }
419 
420     /*
421      * Look up table if the entries have already been read and parsed in
422      * getnetconfig(), then copy this entry into a buffer and return it.
423      * If we cannot find the entry in the current list and there are more
424      * entries in the netconfig db that has not been read, we then read the
425      * db and try find the match netid.
426      * If all the netconfig db has been read and placed into the list and
427      * there is no match for the netid, return NULL.
428      */
429     if (ni.head != NULL) {
430 	for (list = ni.head; list; list = list->next) {
431 	    if (strcmp(list->ncp->nc_netid, netid) == 0) {
432 	        return(dup_ncp(list->ncp));
433 	    }
434 	}
435 	if (ni.eof == 1)	/* that's all the entries */
436 		return(NULL);
437     }
438 
439 
440     if ((file = fopen(NETCONFIG, "r")) == NULL) {
441 	nc_error = NC_NONETCONFIG;
442 	return (NULL);
443     }
444 
445     if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
446 	fclose(file);
447 	nc_error = NC_NOMEM;
448 	return (NULL);
449     }
450     do {
451 	int len;
452 	char *tmpp;	/* tmp string pointer */
453 
454 	do {
455 	    if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {
456 		break;
457 	    }
458 	} while (*stringp == '#');
459 	if (stringp == NULL) {	    /* eof */
460 	    break;
461 	}
462 	if ((tmpp = strpbrk(stringp, "\t ")) == NULL) {	/* can't parse file */
463 	    nc_error = NC_BADFILE;
464 	    break;
465 	}
466 	if (strlen(netid) == (len = tmpp - stringp) &&	/* a match */
467 		strncmp(stringp, netid, (size_t)len) == 0) {
468 	    if ((ncp = (struct netconfig *)
469 		    malloc(sizeof (struct netconfig))) == NULL) {
470 		break;
471 	    }
472 	    ncp->nc_lookups = NULL;
473 	    if (parse_ncp(linep, ncp) == -1) {
474 		free(ncp);
475 		ncp = NULL;
476 	    }
477 	    break;
478 	}
479     } while (stringp != NULL);
480     if (ncp == NULL) {
481 	free(linep);
482     }
483     fclose(file);
484     return(ncp);
485 }
486 
487 /*
488  * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
489  * netconfigp (previously returned by getnetconfigent()).
490  */
491 
492 void
493 freenetconfigent(netconfigp)
494 	struct netconfig *netconfigp;
495 {
496     if (netconfigp != NULL) {
497 	free(netconfigp->nc_netid);	/* holds all netconfigp's strings */
498 	if (netconfigp->nc_lookups != NULL)
499 	    free(netconfigp->nc_lookups);
500 	free(netconfigp);
501     }
502     return;
503 }
504 
505 /*
506  * Parse line and stuff it in a struct netconfig
507  * Typical line might look like:
508  *	udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
509  *
510  * We return -1 if any of the tokens don't parse, or malloc fails.
511  *
512  * Note that we modify stringp (putting NULLs after tokens) and
513  * we set the ncp's string field pointers to point to these tokens within
514  * stringp.
515  */
516 
517 static int
518 parse_ncp(stringp, ncp)
519 char *stringp;		/* string to parse */
520 struct netconfig *ncp;	/* where to put results */
521 {
522     char    *tokenp;	/* for processing tokens */
523     char    *lasts;
524 
525     nc_error = NC_BADFILE;	/* nearly anything that breaks is for this reason */
526     stringp[strlen(stringp)-1] = '\0';	/* get rid of newline */
527     /* netid */
528     if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {
529 	return (-1);
530     }
531 
532     /* semantics */
533     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
534 	return (-1);
535     }
536     if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
537 	ncp->nc_semantics = NC_TPI_COTS_ORD;
538     else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
539 	ncp->nc_semantics = NC_TPI_COTS;
540     else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
541 	ncp->nc_semantics = NC_TPI_CLTS;
542     else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
543 	ncp->nc_semantics = NC_TPI_RAW;
544     else
545 	return (-1);
546 
547     /* flags */
548     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
549 	return (-1);
550     }
551     for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';
552 	    tokenp++) {
553 	switch (*tokenp) {
554 	case NC_NOFLAG_C:
555 	    break;
556 	case NC_VISIBLE_C:
557 	    ncp->nc_flag |= NC_VISIBLE;
558 	    break;
559 	case NC_BROADCAST_C:
560 	    ncp->nc_flag |= NC_BROADCAST;
561 	    break;
562 	default:
563 	    return (-1);
564 	}
565     }
566     /* protocol family */
567     if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {
568 	return (-1);
569     }
570     /* protocol name */
571     if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {
572 	return (-1);
573     }
574     /* network device */
575     if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {
576 	return (-1);
577     }
578     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
579 	return (-1);
580     }
581     if (strcmp(tokenp, NC_NOLOOKUP) == 0) {
582 	ncp->nc_nlookups = 0;
583 	ncp->nc_lookups = NULL;
584     } else {
585 	char *cp;	    /* tmp string */
586 
587 	if (ncp->nc_lookups != NULL)	/* from last visit */
588 	    free(ncp->nc_lookups);
589 	/* preallocate one string pointer */
590 	ncp->nc_lookups = (char **)malloc(sizeof (char *));
591 	ncp->nc_nlookups = 0;
592 	while ((cp = tokenp) != NULL) {
593 	    tokenp = _get_next_token(cp, ',');
594 	    ncp->nc_lookups[(size_t)ncp->nc_nlookups++] = cp;
595 	    ncp->nc_lookups = (char **)realloc(ncp->nc_lookups,
596 		(size_t)(ncp->nc_nlookups+1) *sizeof(char *));	/* for next loop */
597 	}
598     }
599     return (0);
600 }
601 
602 
603 /*
604  * Returns a string describing the reason for failure.
605  */
606 char *
607 nc_sperror()
608 {
609     const char *message;
610 
611     switch(nc_error) {
612     case NC_NONETCONFIG:
613 	message = _nc_errors[0];
614 	break;
615     case NC_NOMEM:
616 	message = _nc_errors[1];
617 	break;
618     case NC_NOTINIT:
619 	message = _nc_errors[2];
620 	break;
621     case NC_BADFILE:
622 	message = _nc_errors[3];
623 	break;
624     case NC_NOTFOUND:
625 	message = _nc_errors[4];
626 	break;
627     default:
628 	message = "Unknown network selection error";
629     }
630     /* LINTED const castaway */
631     return ((char *)message);
632 }
633 
634 /*
635  * Prints a message onto standard error describing the reason for failure.
636  */
637 void
638 nc_perror(s)
639 	const char *s;
640 {
641     fprintf(stderr, "%s: %s\n", s, nc_sperror());
642 }
643 
644 /*
645  * Duplicates the matched netconfig buffer.
646  */
647 static struct netconfig *
648 dup_ncp(ncp)
649 struct netconfig	*ncp;
650 {
651     struct netconfig	*p;
652     char	*tmp;
653     int	i;
654 
655     if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
656 	return(NULL);
657     if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
658 	free(tmp);
659 	return(NULL);
660     }
661     /*
662      * First we dup all the data from matched netconfig buffer.  Then we
663      * adjust some of the member pointer to a pre-allocated buffer where
664      * contains part of the data.
665      * To follow the convention used in parse_ncp(), we store all the
666      * neccessary information in the pre-allocated buffer and let each
667      * of the netconfig char pointer member point to the right address
668      * in the buffer.
669      */
670     *p = *ncp;
671     p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
672     tmp = strchr(tmp, NULL) + 1;
673     p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
674     tmp = strchr(tmp, NULL) + 1;
675     p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
676     tmp = strchr(tmp, NULL) + 1;
677     p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
678     p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
679     if (p->nc_lookups == NULL) {
680 	free(p->nc_netid);
681 	return(NULL);
682     }
683     for (i=0; i < p->nc_nlookups; i++) {
684     	tmp = strchr(tmp, NULL) + 1;
685     	p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
686     }
687     return(p);
688 }
689