xref: /dragonfly/lib/libc/rpc/getnetconfig.c (revision 9ddb8543)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user or with the express written consent of
8  * Sun Microsystems, Inc.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  *
30  * @(#)getnetconfig.c	1.12 91/12/19 SMI
31  * $NetBSD: getnetconfig.c,v 1.3 2000/07/06 03:10:34 christos Exp $
32  * $FreeBSD: src/lib/libc/rpc/getnetconfig.c,v 1.14 2007/09/20 22:35:24 matteo Exp $
33  */
34 
35 /*
36  * Copyright (c) 1989 by Sun Microsystems, Inc.
37  */
38 
39 #include "namespace.h"
40 #include "reentrant.h"
41 #include <stdio.h>
42 #include <errno.h>
43 #include <netconfig.h>
44 #include <stddef.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <rpc/rpc.h>
48 #include <unistd.h>
49 #include "un-namespace.h"
50 #include "rpc_com.h"
51 
52 /*
53  * The five library routines in this file provide application access to the
54  * system network configuration database, /etc/netconfig.  In addition to the
55  * netconfig database and the routines for accessing it, the environment
56  * variable NETPATH and its corresponding routines in getnetpath.c may also be
57  * used to specify the network transport to be used.
58  */
59 
60 
61 /*
62  * netconfig errors
63  */
64 
65 #define NC_NONETCONFIG	ENOENT
66 #define NC_NOMEM	ENOMEM
67 #define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */
68 #define NC_BADFILE	EBADF	    /* format for netconfig file is bad */
69 #define NC_NOTFOUND	ENOPROTOOPT /* specified netid was not found */
70 
71 /*
72  * semantics as strings (should be in netconfig.h)
73  */
74 #define NC_TPI_CLTS_S	    "tpi_clts"
75 #define	NC_TPI_COTS_S	    "tpi_cots"
76 #define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"
77 #define	NC_TPI_RAW_S        "tpi_raw"
78 
79 /*
80  * flags as characters (also should be in netconfig.h)
81  */
82 #define	NC_NOFLAG_C	'-'
83 #define	NC_VISIBLE_C	'v'
84 #define	NC_BROADCAST_C	'b'
85 
86 /*
87  * Character used to indicate there is no name-to-address lookup library
88  */
89 #define NC_NOLOOKUP	"-"
90 
91 static const char * const _nc_errors[] = {
92     "Netconfig database not found",
93     "Not enough memory",
94     "Not initialized",
95     "Netconfig database has invalid format",
96     "Netid not found in netconfig database"
97 };
98 
99 struct netconfig_info {
100     int		eof;	/* all entries has been read */
101     int		ref;	/* # of times setnetconfig() has been called */
102     struct netconfig_list	*head;	/* head of the list */
103     struct netconfig_list	*tail;	/* last of the list */
104 };
105 
106 struct netconfig_list {
107     char			*linep;	/* hold line read from netconfig */
108     struct netconfig		*ncp;
109     struct netconfig_list	*next;
110 };
111 
112 struct netconfig_vars {
113     int   valid;	/* token that indicates a valid netconfig_vars */
114     int   flag;		/* first time flag */
115     struct netconfig_list *nc_configs;  /* pointer to the current netconfig entry */
116 };
117 
118 #define NC_VALID	0xfeed
119 #define NC_STORAGE	0xf00d
120 #define NC_INVALID	0
121 
122 
123 static int *__nc_error(void);
124 static int parse_ncp(char *, struct netconfig *);
125 static struct netconfig *dup_ncp(struct netconfig *);
126 
127 
128 static FILE *nc_file;		/* for netconfig db */
129 static struct netconfig_info	ni = { 0, 0, NULL, NULL};
130 
131 #define MAXNETCONFIGLINE    1000
132 
133 static int *
134 __nc_error(void)
135 {
136 	static pthread_mutex_t nc_lock = PTHREAD_MUTEX_INITIALIZER;
137 	static thread_key_t nc_key = 0;
138 	static int nc_error = 0;
139 	int error, *nc_addr;
140 
141 	/*
142 	 * Use the static `nc_error' if we are the main thread
143 	 * (including non-threaded programs), or if an allocation
144 	 * fails.
145 	 */
146 	if (thr_main())
147 		return (&nc_error);
148 	if (nc_key == 0) {
149 		error = 0;
150 		mutex_lock(&nc_lock);
151 		if (nc_key == 0)
152 			error = thr_keycreate(&nc_key, free);
153 		mutex_unlock(&nc_lock);
154 		if (error)
155 			return (&nc_error);
156 	}
157 	if ((nc_addr = (int *)thr_getspecific(nc_key)) == NULL) {
158 		nc_addr = (int *)malloc(sizeof (int));
159 		if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {
160 			if (nc_addr)
161 				free(nc_addr);
162 			return (&nc_error);
163 		}
164 		*nc_addr = 0;
165 	}
166 	return (nc_addr);
167 }
168 
169 #define nc_error        (*(__nc_error()))
170 /*
171  * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
172  * "handle" is returned on a successful call.  At the start of a session (after
173  * a call to setnetconfig()) searches through the /etc/netconfig database will
174  * proceed from the start of the file.  The session handle must be passed to
175  * getnetconfig() to parse the file.  Each call to getnetconfig() using the
176  * current handle will process one subsequent entry in /etc/netconfig.
177  * setnetconfig() must be called before the first call to getnetconfig().
178  * (Handles are used to allow for nested calls to setnetpath()).
179  *
180  * A new session is established with each call to setnetconfig(), with a new
181  * handle being returned on each call.  Previously established sessions remain
182  * active until endnetconfig() is called with that session's handle as an
183  * argument.
184  *
185  * setnetconfig() need *not* be called before a call to getnetconfigent().
186  * setnetconfig() returns a NULL pointer on failure (for example, if
187  * the netconfig database is not present).
188  */
189 void *
190 setnetconfig(void)
191 {
192     struct netconfig_vars *nc_vars;
193 
194     if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
195 		(struct netconfig_vars))) == NULL) {
196 	return(NULL);
197     }
198 
199     /*
200      * For multiple calls, i.e. nc_file is not NULL, we just return the
201      * handle without reopening the netconfig db.
202      */
203     ni.ref++;
204     if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {
205 	nc_vars->valid = NC_VALID;
206 	nc_vars->flag = 0;
207 	nc_vars->nc_configs = ni.head;
208 	return ((void *)nc_vars);
209     }
210     ni.ref--;
211     nc_error = NC_NONETCONFIG;
212     free(nc_vars);
213     return (NULL);
214 }
215 
216 
217 /*
218  * When first called, getnetconfig() returns a pointer to the first entry in
219  * the netconfig database, formatted as a struct netconfig.  On each subsequent
220  * call, getnetconfig() returns a pointer to the next entry in the database.
221  * getnetconfig() can thus be used to search the entire netconfig file.
222  * getnetconfig() returns NULL at end of file.
223  */
224 
225 struct netconfig *
226 getnetconfig(void *handlep)
227 {
228     struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
229     char *stringp;		/* tmp string pointer */
230     struct netconfig_list	*list;
231     struct netconfig *np;
232 
233     /*
234      * Verify that handle is valid
235      */
236     if (ncp == NULL || nc_file == NULL) {
237 	nc_error = NC_NOTINIT;
238 	return (NULL);
239     }
240 
241     switch (ncp->valid) {
242     case NC_VALID:
243 	/*
244 	 * If entry has already been read into the list,
245 	 * we return the entry in the linked list.
246 	 * If this is the first time call, check if there are any entries in
247 	 * linked list.  If no entries, we need to read the netconfig db.
248 	 * If we have been here and the next entry is there, we just return
249 	 * it.
250 	 */
251 	if (ncp->flag == 0) {	/* first time */
252 	    ncp->flag = 1;
253 	    ncp->nc_configs = ni.head;
254 	    if (ncp->nc_configs != NULL)	/* entry already exist */
255 		return(ncp->nc_configs->ncp);
256 	}
257 	else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {
258 	    ncp->nc_configs = ncp->nc_configs->next;
259 	    return(ncp->nc_configs->ncp);
260 	}
261 
262 	/*
263 	 * If we cannot find the entry in the list and is end of file,
264 	 * we give up.
265 	 */
266 	if (ni.eof == 1)	return(NULL);
267 	break;
268     default:
269 	nc_error = NC_NOTINIT;
270 	return (NULL);
271     }
272 
273     stringp = (char *) malloc(MAXNETCONFIGLINE);
274     if (stringp == NULL)
275 	return (NULL);
276 
277 #ifdef MEM_CHK
278     if (malloc_verify() == 0) {
279 	fprintf(stderr, "memory heap corrupted in getnetconfig\n");
280 	exit(1);
281     }
282 #endif
283 
284     /*
285      * Read a line from netconfig file.
286      */
287     do {
288 	if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
289 	    free(stringp);
290 	    ni.eof = 1;
291 	    return (NULL);
292         }
293     } while (*stringp == '#');
294 
295     list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));
296     if (list == NULL) {
297 	free(stringp);
298 	return(NULL);
299     }
300     np = (struct netconfig *) malloc(sizeof (struct netconfig));
301     if (np == NULL) {
302 	free(stringp);
303 	free(list);
304 	return(NULL);
305     }
306     list->ncp = np;
307     list->next = NULL;
308     list->ncp->nc_lookups = NULL;
309     list->linep = stringp;
310     if (parse_ncp(stringp, list->ncp) == -1) {
311 	free(stringp);
312 	free(np);
313 	free(list);
314 	return (NULL);
315     }
316     else {
317 	/*
318 	 * If this is the first entry that's been read, it is the head of
319 	 * the list.  If not, put the entry at the end of the list.
320 	 * Reposition the current pointer of the handle to the last entry
321 	 * in the list.
322 	 */
323 	if (ni.head == NULL) {	/* first entry */
324 	    ni.head = ni.tail = list;
325 	}
326 	else {
327 	    ni.tail->next = list;
328 	    ni.tail = ni.tail->next;
329 	}
330 	ncp->nc_configs = ni.tail;
331 	return(ni.tail->ncp);
332     }
333 }
334 
335 /*
336  * endnetconfig() may be called to "unbind" or "close" the netconfig database
337  * when processing is complete, releasing resources for reuse.  endnetconfig()
338  * may not be called before setnetconfig().  endnetconfig() returns 0 on
339  * success and -1 on failure (for example, if setnetconfig() was not called
340  * previously).
341  */
342 int
343 endnetconfig(void *handlep)
344 {
345     struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
346 
347     struct netconfig_list *q, *p;
348 
349     /*
350      * Verify that handle is valid
351      */
352     if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
353 	    nc_handlep->valid != NC_STORAGE)) {
354 	nc_error = NC_NOTINIT;
355 	return (-1);
356     }
357 
358     /*
359      * Return 0 if anyone still needs it.
360      */
361     nc_handlep->valid = NC_INVALID;
362     nc_handlep->flag = 0;
363     nc_handlep->nc_configs = NULL;
364     if (--ni.ref > 0) {
365 	free(nc_handlep);
366 	return(0);
367     }
368 
369     /*
370      * Noone needs these entries anymore, then frees them.
371      * Make sure all info in netconfig_info structure has been reinitialized.
372      */
373     q = p = ni.head;
374     ni.eof = ni.ref = 0;
375     ni.head = NULL;
376     ni.tail = NULL;
377     while (q) {
378 	p = q->next;
379 	if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);
380 	free(q->ncp);
381 	free(q->linep);
382 	free(q);
383 	q = p;
384     }
385     free(nc_handlep);
386 
387     fclose(nc_file);
388     nc_file = NULL;
389     return (0);
390 }
391 
392 /*
393  * getnetconfigent(netid) returns a pointer to the struct netconfig structure
394  * corresponding to netid.  It returns NULL if netid is invalid (that is, does
395  * not name an entry in the netconfig database).  It returns NULL and sets
396  * errno in case of failure (for example, if the netconfig database cannot be
397  * opened).
398  */
399 
400 struct netconfig *
401 getnetconfigent(const char *netid)
402 {
403     FILE *file;		/* NETCONFIG db's file pointer */
404     char *linep;	/* holds current netconfig line */
405     char *stringp;	/* temporary string pointer */
406     struct netconfig *ncp = NULL;   /* returned value */
407     struct netconfig_list *list;	/* pointer to cache list */
408 
409     nc_error = NC_NOTFOUND;	/* default error. */
410     if (netid == NULL || strlen(netid) == 0) {
411 	return (NULL);
412     }
413 
414     if (strcmp(netid, "unix") == 0) {
415 	fprintf(stderr, "The local transport is called \"unix\" ");
416 	fprintf(stderr, "in /etc/netconfig.\n");
417 	fprintf(stderr, "Please change this to \"local\" manually ");
418 	fprintf(stderr, "or run mergemaster(8).\n");
419 	fprintf(stderr, "See UPDATING entry 20021216 for details.\n");
420 	fprintf(stderr, "Continuing in 10 seconds\n\n");
421 	fprintf(stderr, "This warning will be removed 20030301\n");
422 	sleep(10);
423 
424     }
425 
426     /*
427      * Look up table if the entries have already been read and parsed in
428      * getnetconfig(), then copy this entry into a buffer and return it.
429      * If we cannot find the entry in the current list and there are more
430      * entries in the netconfig db that has not been read, we then read the
431      * db and try find the match netid.
432      * If all the netconfig db has been read and placed into the list and
433      * there is no match for the netid, return NULL.
434      */
435     if (ni.head != NULL) {
436 	for (list = ni.head; list; list = list->next) {
437 	    if (strcmp(list->ncp->nc_netid, netid) == 0) {
438 	        return(dup_ncp(list->ncp));
439 	    }
440 	}
441 	if (ni.eof == 1)	/* that's all the entries */
442 		return(NULL);
443     }
444 
445 
446     if ((file = fopen(NETCONFIG, "r")) == NULL) {
447 	nc_error = NC_NONETCONFIG;
448 	return (NULL);
449     }
450 
451     if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
452 	fclose(file);
453 	nc_error = NC_NOMEM;
454 	return (NULL);
455     }
456     do {
457 	ptrdiff_t len;
458 	char *tmpp;	/* tmp string pointer */
459 
460 	do {
461 	    if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {
462 		break;
463 	    }
464 	} while (*stringp == '#');
465 	if (stringp == NULL) {	    /* eof */
466 	    break;
467 	}
468 	if ((tmpp = strpbrk(stringp, "\t ")) == NULL) {	/* can't parse file */
469 	    nc_error = NC_BADFILE;
470 	    break;
471 	}
472 	if (strlen(netid) == (size_t) (len = tmpp - stringp) &&	/* a match */
473 		strncmp(stringp, netid, (size_t)len) == 0) {
474 	    if ((ncp = (struct netconfig *)
475 		    malloc(sizeof (struct netconfig))) == NULL) {
476 		break;
477 	    }
478 	    ncp->nc_lookups = NULL;
479 	    if (parse_ncp(linep, ncp) == -1) {
480 		free(ncp);
481 		ncp = NULL;
482 	    }
483 	    break;
484 	}
485     } while (stringp != NULL);
486     if (ncp == NULL) {
487 	free(linep);
488     }
489     fclose(file);
490     return(ncp);
491 }
492 
493 /*
494  * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
495  * netconfigp (previously returned by getnetconfigent()).
496  */
497 
498 void
499 freenetconfigent(struct netconfig *netconfigp)
500 {
501     if (netconfigp != NULL) {
502 	free(netconfigp->nc_netid);	/* holds all netconfigp's strings */
503 	if (netconfigp->nc_lookups != NULL)
504 	    free(netconfigp->nc_lookups);
505 	free(netconfigp);
506     }
507     return;
508 }
509 
510 /*
511  * Parse line and stuff it in a struct netconfig
512  * Typical line might look like:
513  *	udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
514  *
515  * We return -1 if any of the tokens don't parse, or malloc fails.
516  *
517  * Note that we modify stringp (putting NULLs after tokens) and
518  * we set the ncp's string field pointers to point to these tokens within
519  * stringp.
520  */
521 
522 static int
523 parse_ncp(char *stringp,		/* string to parse */
524 	  struct netconfig *ncp)	/* where to put results */
525 {
526     char    *tokenp;	/* for processing tokens */
527     char    *lasts;
528     char    **nc_lookups;
529 
530     nc_error = NC_BADFILE;	/* nearly anything that breaks is for this reason */
531     stringp[strlen(stringp)-1] = '\0';	/* get rid of newline */
532     /* netid */
533     if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {
534 	return (-1);
535     }
536 
537     /* semantics */
538     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
539 	return (-1);
540     }
541     if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
542 	ncp->nc_semantics = NC_TPI_COTS_ORD;
543     else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
544 	ncp->nc_semantics = NC_TPI_COTS;
545     else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
546 	ncp->nc_semantics = NC_TPI_CLTS;
547     else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
548 	ncp->nc_semantics = NC_TPI_RAW;
549     else
550 	return (-1);
551 
552     /* flags */
553     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
554 	return (-1);
555     }
556     for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';
557 	    tokenp++) {
558 	switch (*tokenp) {
559 	case NC_NOFLAG_C:
560 	    break;
561 	case NC_VISIBLE_C:
562 	    ncp->nc_flag |= NC_VISIBLE;
563 	    break;
564 	case NC_BROADCAST_C:
565 	    ncp->nc_flag |= NC_BROADCAST;
566 	    break;
567 	default:
568 	    return (-1);
569 	}
570     }
571     /* protocol family */
572     if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {
573 	return (-1);
574     }
575     /* protocol name */
576     if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {
577 	return (-1);
578     }
579     /* network device */
580     if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {
581 	return (-1);
582     }
583     if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
584 	return (-1);
585     }
586     if (strcmp(tokenp, NC_NOLOOKUP) == 0) {
587 	ncp->nc_nlookups = 0;
588 	ncp->nc_lookups = NULL;
589     } else {
590 	char *cp;	    /* tmp string */
591 
592 	if (ncp->nc_lookups != NULL)	/* from last visit */
593 	    free(ncp->nc_lookups);
594 	ncp->nc_lookups = NULL;
595 	ncp->nc_nlookups = 0;
596 	while ((cp = tokenp) != NULL) {
597 	    if ((nc_lookups = realloc(ncp->nc_lookups,
598 		(ncp->nc_nlookups + 1) * sizeof *ncp->nc_lookups)) == NULL) {
599 		    free(ncp->nc_lookups);
600 		    ncp->nc_lookups = NULL;
601 		    return (-1);
602 	    }
603 	    tokenp = _get_next_token(cp, ',');
604 	    ncp->nc_lookups = nc_lookups;
605 	    ncp->nc_lookups[ncp->nc_nlookups++] = cp;
606 	}
607     }
608     return (0);
609 }
610 
611 
612 /*
613  * Returns a string describing the reason for failure.
614  */
615 char *
616 nc_sperror(void)
617 {
618     const char *message;
619 
620     switch(nc_error) {
621     case NC_NONETCONFIG:
622 	message = _nc_errors[0];
623 	break;
624     case NC_NOMEM:
625 	message = _nc_errors[1];
626 	break;
627     case NC_NOTINIT:
628 	message = _nc_errors[2];
629 	break;
630     case NC_BADFILE:
631 	message = _nc_errors[3];
632 	break;
633     case NC_NOTFOUND:
634 	message = _nc_errors[4];
635 	break;
636     default:
637 	message = "Unknown network selection error";
638     }
639     /* LINTED const castaway */
640     return ((char *)message);
641 }
642 
643 /*
644  * Prints a message onto standard error describing the reason for failure.
645  */
646 void
647 nc_perror(const char *s)
648 {
649     fprintf(stderr, "%s: %s\n", s, nc_sperror());
650 }
651 
652 /*
653  * Duplicates the matched netconfig buffer.
654  */
655 static struct netconfig *
656 dup_ncp(struct netconfig *ncp)
657 {
658     struct netconfig	*p;
659     char	*tmp;
660     u_int	i;
661 
662     if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
663 	return(NULL);
664     if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
665 	free(tmp);
666 	return(NULL);
667     }
668     /*
669      * First we dup all the data from matched netconfig buffer.  Then we
670      * adjust some of the member pointer to a pre-allocated buffer where
671      * contains part of the data.
672      * To follow the convention used in parse_ncp(), we store all the
673      * necessary information in the pre-allocated buffer and let each
674      * of the netconfig char pointer member point to the right address
675      * in the buffer.
676      */
677     *p = *ncp;
678     p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
679     tmp = strchr(tmp, '\0') + 1;
680     p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
681     tmp = strchr(tmp, '\0') + 1;
682     p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
683     tmp = strchr(tmp, '\0') + 1;
684     p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
685     p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
686     if (p->nc_lookups == NULL) {
687 	free(p->nc_netid);
688 	free(p);
689 	return(NULL);
690     }
691     for (i=0; i < p->nc_nlookups; i++) {
692 	tmp = strchr(tmp, '\0') + 1;
693 	p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
694     }
695     return(p);
696 }
697