xref: /netbsd-src/lib/libc/rpc/getnetconfig.c (revision 481fca6e59249d8ffcf24fef7cfbe7b131bfb080)
1 /*	$NetBSD: getnetconfig.c,v 1.3 2000/07/06 03:10:34 christos Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user or with the express written consent of
10  * Sun Microsystems, Inc.
11  *
12  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
13  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
14  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
15  *
16  * Sun RPC is provided with no support and without any obligation on the
17  * part of Sun Microsystems, Inc. to assist in its use, correction,
18  * modification or enhancement.
19  *
20  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
21  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
22  * OR ANY PART THEREOF.
23  *
24  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
25  * or profits or other special, indirect and consequential damages, even if
26  * Sun has been advised of the possibility of such damages.
27  *
28  * Sun Microsystems, Inc.
29  * 2550 Garcia Avenue
30  * Mountain View, California  94043
31  */
32 /*
33 #ifndef lint
34 static        char sccsid[] = "@(#)getnetconfig.c	1.12 91/12/19 SMI";
35 #endif
36 */
37 
38 /*
39  * Copyright (c) 1989 by Sun Microsystems, Inc.
40  */
41 
42 #include "namespace.h"
43 #include <sys/cdefs.h>
44 #include <stdio.h>
45 #include <errno.h>
46 #include <netconfig.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <rpc/rpc.h>
50 #include "rpc_com.h"
51 
52 #ifdef __weak_alias
53 __weak_alias(getnetconfig,_getnetconfig)
54 __weak_alias(setnetconfig,_setnetconfig)
55 __weak_alias(endnetconfig,_endnetconfig)
56 __weak_alias(getnetconfigent,_getnetconfigent)
57 __weak_alias(freenetconfigent,_freenetconfigent)
58 __weak_alias(nc_perror,_nc_perror)
59 __weak_alias(nc_sperror,_nc_sperror)
60 #endif
61 
62 /*
63  * The five library routines in this file provide application access to the
64  * system network configuration database, /etc/netconfig.  In addition to the
65  * netconfig database and the routines for accessing it, the environment
66  * variable NETPATH and its corresponding routines in getnetpath.c may also be
67  * used to specify the network transport to be used.
68  */
69 
70 
71 /*
72  * netconfig errors
73  */
74 
75 #define NC_NONETCONFIG	ENOENT
76 #define NC_NOMEM	ENOMEM
77 #define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */
78 #define NC_BADFILE	EBADF	    /* format for netconfig file is bad */
79 
80 /*
81  * semantics as strings (should be in netconfig.h)
82  */
83 #define NC_TPI_CLTS_S	    "tpi_clts"
84 #define	NC_TPI_COTS_S	    "tpi_cots"
85 #define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"
86 #define	NC_TPI_RAW_S        "tpi_raw"
87 
88 /*
89  * flags as characters (also should be in netconfig.h)
90  */
91 #define	NC_NOFLAG_C	'-'
92 #define	NC_VISIBLE_C	'v'
93 #define	NC_BROADCAST_C	'b'
94 
95 /*
96  * Character used to indicate there is no name-to-address lookup library
97  */
98 #define NC_NOLOOKUP	"-"
99 
100 static char *_nc_errors[] = {
101     "Netconfig database not found",
102     "Not enough memory",
103     "Not initialized",
104     "Netconfig database has invalid format"
105 };
106 
107 struct netconfig_info {
108     int		eof;	/* all entries has been read */
109     int		ref;	/* # of times setnetconfig() has been called */
110     struct netconfig_list	*head;	/* head of the list */
111     struct netconfig_list	*tail;	/* last of the list */
112 };
113 
114 struct netconfig_list {
115     char			*linep;	/* hold line read from netconfig */
116     struct netconfig		*ncp;
117     struct netconfig_list	*next;
118 };
119 
120 struct netconfig_vars {
121     int   valid;	/* token that indicates a valid netconfig_vars */
122     int   flag;		/* first time flag */
123     struct netconfig_list *nc_configs;  /* pointer to the current netconfig entry */
124 };
125 
126 #define NC_VALID	0xfeed
127 #define NC_STORAGE	0xf00d
128 #define NC_INVALID	0
129 
130 
131 static int *__nc_error __P((void));
132 static int parse_ncp __P((char *, struct netconfig *));
133 static struct netconfig *dup_ncp __P((struct netconfig *));
134 
135 
136 static FILE *nc_file;		/* for netconfig db */
137 static struct netconfig_info	ni = { 0, 0, NULL, NULL};
138 
139 #define MAXNETCONFIGLINE    1000
140 
141 static int *
142 __nc_error()
143 {
144 #ifdef __REENT
145 	static thread_key_t nc_key = 0;
146 	int *nc_addr = NULL;
147 #endif
148 	static int nc_error = 0;
149 
150 #ifdef __REENT
151 	if (_thr_getspecific(nc_key, (void **) &nc_addr) != 0) {
152 		mutex_lock(&nc_lock);
153 		if (_thr_keycreate(&rce_key, free) != 0) {
154 			mutex_unlock(&nc_lock);
155 			return nc_addr;
156 		}
157 		mutex_unlock(&nc_lock);
158 	}
159 	if (nc_addr == NULL) {
160 		nc_addr = (int *)malloc(sizeof (int));
161 		if (_thr_setspecific(nc_key, (void *) nc_addr) != 0) {
162 			if (nc_addr)
163 				free(nc_addr);
164 			return &nc_error;
165 		}
166 		*nc_addr = 0;
167 		return nc_addr;
168 	}
169 	return nc_addr;
170 #else
171 	return &nc_error;
172 #endif
173 }
174 
175 #define nc_error        (*(__nc_error()))
176 /*
177  * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
178  * "handle" is returned on a successful call.  At the start of a session (after
179  * a call to setnetconfig()) searches through the /etc/netconfig database will
180  * proceed from the start of the file.  The session handle must be passed to
181  * getnetconfig() to parse the file.  Each call to getnetconfig() using the
182  * current handle will process one subsequent entry in /etc/netconfig.
183  * setnetconfig() must be called before the first call to getnetconfig().
184  * (Handles are used to allow for nested calls to setnetpath()).
185  *
186  * A new session is established with each call to setnetconfig(), with a new
187  * handle being returned on each call.  Previously established sessions remain
188  * active until endnetconfig() is called with that session's handle as an
189  * argument.
190  *
191  * setnetconfig() need *not* be called before a call to getnetconfigent().
192  * setnetconfig() returns a NULL pointer on failure (for example, if
193  * the netconfig database is not present).
194  */
195 void *
196 setnetconfig()
197 {
198     struct netconfig_vars *nc_vars;
199 
200     if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
201 		(struct netconfig_vars))) == NULL) {
202 	return(NULL);
203     }
204 
205     /*
206      * For multiple calls, i.e. nc_file is not NULL, we just return the
207      * handle without reopening the netconfig db.
208      */
209     ni.ref++;
210     if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {
211 	nc_vars->valid = NC_VALID;
212 	nc_vars->flag = 0;
213 	nc_vars->nc_configs = ni.head;
214 	return ((void *)nc_vars);
215     }
216     ni.ref--;
217     nc_error = NC_NONETCONFIG;
218     free(nc_vars);
219     return (NULL);
220 }
221 
222 
223 /*
224  * When first called, getnetconfig() returns a pointer to the first entry in
225  * the netconfig database, formatted as a struct netconfig.  On each subsequent
226  * call, getnetconfig() returns a pointer to the next entry in the database.
227  * getnetconfig() can thus be used to search the entire netconfig file.
228  * getnetconfig() returns NULL at end of file.
229  */
230 
231 struct netconfig *
232 getnetconfig(handlep)
233 void *handlep;
234 {
235     struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
236     char *stringp;		/* tmp string pointer */
237     struct netconfig_list	*list;
238     struct netconfig *np;
239 
240     /*
241      * Verify that handle is valid
242      */
243     if (ncp == NULL || nc_file == NULL) {
244 	nc_error = NC_NOTINIT;
245 	return (NULL);
246     }
247 
248     switch (ncp->valid) {
249     case NC_VALID:
250 	/*
251 	 * If entry has already been read into the list,
252 	 * we return the entry in the linked list.
253 	 * If this is the first time call, check if there are any entries in
254 	 * linked list.  If no entries, we need to read the netconfig db.
255 	 * If we have been here and the next entry is there, we just return
256 	 * it.
257 	 */
258 	if (ncp->flag == 0) {	/* first time */
259 	    ncp->flag = 1;
260 	    ncp->nc_configs = ni.head;
261 	    if (ncp->nc_configs != NULL)	/* entry already exist */
262 		return(ncp->nc_configs->ncp);
263 	}
264 	else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {
265 	    ncp->nc_configs = ncp->nc_configs->next;
266 	    return(ncp->nc_configs->ncp);
267 	}
268 
269 	/*
270 	 * If we cannot find the entry in the list and is end of file,
271 	 * we give up.
272 	 */
273 	if (ni.eof == 1)	return(NULL);
274 	break;
275     default:
276 	nc_error = NC_NOTINIT;
277 	return (NULL);
278     }
279 
280     stringp = (char *) malloc(MAXNETCONFIGLINE);
281     if (stringp == NULL)
282     	return (NULL);
283 
284 #ifdef MEM_CHK
285     if (malloc_verify() == 0) {
286 	fprintf(stderr, "memory heap corrupted in getnetconfig\n");
287 	exit(1);
288     }
289 #endif
290 
291     /*
292      * Read a line from netconfig file.
293      */
294     do {
295 	if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
296 	    free(stringp);
297 	    ni.eof = 1;
298 	    return (NULL);
299         }
300     } while (*stringp == '#');
301 
302     list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));
303     if (list == NULL) {
304     	free(stringp);
305     	return(NULL);
306     }
307     np = (struct netconfig *) malloc(sizeof (struct netconfig));
308     if (np == NULL) {
309     	free(stringp);
310 	free(list);
311     	return(NULL);
312     }
313     list->ncp = np;
314     list->next = NULL;
315     list->ncp->nc_lookups = NULL;
316     list->linep = stringp;
317     if (parse_ncp(stringp, list->ncp) == -1) {
318 	free(stringp);
319 	free(np);
320 	free(list);
321 	return (NULL);
322     }
323     else {
324 	/*
325 	 * If this is the first entry that's been read, it is the head of
326 	 * the list.  If not, put the entry at the end of the list.
327 	 * Reposition the current pointer of the handle to the last entry
328 	 * in the list.
329 	 */
330 	if (ni.head == NULL) {	/* first entry */
331 	    ni.head = ni.tail = list;
332 	}
333     	else {
334     	    ni.tail->next = list;
335     	    ni.tail = ni.tail->next;
336     	}
337 	ncp->nc_configs = ni.tail;
338 	return(ni.tail->ncp);
339     }
340 }
341 
342 /*
343  * endnetconfig() may be called to "unbind" or "close" the netconfig database
344  * when processing is complete, releasing resources for reuse.  endnetconfig()
345  * may not be called before setnetconfig().  endnetconfig() returns 0 on
346  * success and -1 on failure (for example, if setnetconfig() was not called
347  * previously).
348  */
349 int
350 endnetconfig(handlep)
351 void *handlep;
352 {
353     struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
354 
355     struct netconfig_list *q, *p;
356 
357     /*
358      * Verify that handle is valid
359      */
360     if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
361 	    nc_handlep->valid != NC_STORAGE)) {
362 	nc_error = NC_NOTINIT;
363 	return (-1);
364     }
365 
366     /*
367      * Return 0 if anyone still needs it.
368      */
369     nc_handlep->valid = NC_INVALID;
370     nc_handlep->flag = 0;
371     nc_handlep->nc_configs = NULL;
372     if (--ni.ref > 0) {
373     	free(nc_handlep);
374 	return(0);
375     }
376 
377     /*
378      * Noone needs these entries anymore, then frees them.
379      * Make sure all info in netconfig_info structure has been reinitialized.
380      */
381     q = p = ni.head;
382     ni.eof = ni.ref = 0;
383     ni.head = NULL;
384     ni.tail = NULL;
385     while (q) {
386 	p = q->next;
387 	if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);
388 	free(q->ncp);
389 	free(q->linep);
390 	free(q);
391 	q = p;
392     }
393     free(nc_handlep);
394 
395     fclose(nc_file);
396     nc_file = NULL;
397     return (0);
398 }
399 
400 /*
401  * getnetconfigent(netid) returns a pointer to the struct netconfig structure
402  * corresponding to netid.  It returns NULL if netid is invalid (that is, does
403  * not name an entry in the netconfig database).  It returns NULL and sets
404  * errno in case of failure (for example, if the netconfig database cannot be
405  * opened).
406  */
407 
408 struct netconfig *
409 getnetconfigent(netid)
410 	char *netid;
411 {
412     FILE *file;		/* NETCONFIG db's file pointer */
413     char *linep;	/* holds current netconfig line */
414     char *stringp;	/* temporary string pointer */
415     struct netconfig *ncp = NULL;   /* returned value */
416     struct netconfig_list *list;	/* pointer to cache list */
417 
418     if (netid == NULL || strlen(netid) == 0) {
419 	return (NULL);
420     }
421 
422     /*
423      * Look up table if the entries have already been read and parsed in
424      * getnetconfig(), then copy this entry into a buffer and return it.
425      * If we cannot find the entry in the current list and there are more
426      * entries in the netconfig db that has not been read, we then read the
427      * db and try find the match netid.
428      * If all the netconfig db has been read and placed into the list and
429      * there is no match for the netid, return NULL.
430      */
431     if (ni.head != NULL) {
432 	for (list = ni.head; list; list = list->next) {
433 	    if (strcmp(list->ncp->nc_netid, netid) == 0) {
434 	        return(dup_ncp(list->ncp));
435 	    }
436 	}
437 	if (ni.eof == 1)	/* that's all the entries */
438 		return(NULL);
439     }
440 
441 
442     if ((file = fopen(NETCONFIG, "r")) == NULL) {
443 	return (NULL);
444     }
445 
446     if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
447 	fclose(file);
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     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     default:
625 	message = "Unknown network selection error";
626     }
627     return (message);
628 }
629 
630 /*
631  * Prints a message onto standard error describing the reason for failure.
632  */
633 void
634 nc_perror(s)
635 	const char *s;
636 {
637     fprintf(stderr, "%s: %s", s, nc_sperror());
638 }
639 
640 /*
641  * Duplicates the matched netconfig buffer.
642  */
643 static struct netconfig *
644 dup_ncp(ncp)
645 struct netconfig	*ncp;
646 {
647     struct netconfig	*p;
648     char	*tmp;
649     int	i;
650 
651     if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
652 	return(NULL);
653     if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
654 	free(tmp);
655 	return(NULL);
656     }
657     /*
658      * First we dup all the data from matched netconfig buffer.  Then we
659      * adjust some of the member pointer to a pre-allocated buffer where
660      * contains part of the data.
661      * To follow the convention used in parse_ncp(), we store all the
662      * neccessary information in the pre-allocated buffer and let each
663      * of the netconfig char pointer member point to the right address
664      * in the buffer.
665      */
666     *p = *ncp;
667     p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
668     tmp = strchr(tmp, NULL) + 1;
669     p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
670     tmp = strchr(tmp, NULL) + 1;
671     p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
672     tmp = strchr(tmp, NULL) + 1;
673     p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
674     p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
675     if (p->nc_lookups == NULL) {
676 	free(p->nc_netid);
677 	return(NULL);
678     }
679     for (i=0; i < p->nc_nlookups; i++) {
680     	tmp = strchr(tmp, NULL) + 1;
681     	p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
682     }
683     return(p);
684 }
685