1/*	$NetBSD: getnetconfig.c,v 1.3 2000/07/06 03:10:34 christos Exp $	*/
2
3/*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2009, Sun Microsystems, Inc.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * - Redistributions of source code must retain the above copyright notice,
12 *   this list of conditions and the following disclaimer.
13 * - Redistributions in binary form must reproduce the above copyright notice,
14 *   this list of conditions and the following disclaimer in the documentation
15 *   and/or other materials provided with the distribution.
16 * - Neither the name of Sun Microsystems, Inc. nor the names of its
17 *   contributors may be used to endorse or promote products derived
18 *   from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * Copyright (c) 1989 by Sun Microsystems, Inc.
35 */
36
37#include "namespace.h"
38#include "reentrant.h"
39#include <stdio.h>
40#include <errno.h>
41#include <netconfig.h>
42#include <stddef.h>
43#include <stdlib.h>
44#include <string.h>
45#include <rpc/rpc.h>
46#include <unistd.h>
47#include "un-namespace.h"
48#include "rpc_com.h"
49
50/*
51 * The five library routines in this file provide application access to the
52 * system network configuration database, /etc/netconfig.  In addition to the
53 * netconfig database and the routines for accessing it, the environment
54 * variable NETPATH and its corresponding routines in getnetpath.c may also be
55 * used to specify the network transport to be used.
56 */
57
58
59/*
60 * netconfig errors
61 */
62
63#define NC_NONETCONFIG	ENOENT
64#define NC_NOMEM	ENOMEM
65#define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */
66#define NC_BADFILE	EBADF	    /* format for netconfig file is bad */
67#define NC_NOTFOUND	ENOPROTOOPT /* specified netid was not found */
68
69/*
70 * semantics as strings (should be in netconfig.h)
71 */
72#define NC_TPI_CLTS_S	    "tpi_clts"
73#define	NC_TPI_COTS_S	    "tpi_cots"
74#define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"
75#define	NC_TPI_RAW_S        "tpi_raw"
76
77/*
78 * flags as characters (also should be in netconfig.h)
79 */
80#define	NC_NOFLAG_C	'-'
81#define	NC_VISIBLE_C	'v'
82#define	NC_BROADCAST_C	'b'
83
84/*
85 * Character used to indicate there is no name-to-address lookup library
86 */
87#define NC_NOLOOKUP	"-"
88
89static const char * const _nc_errors[] = {
90    "Netconfig database not found",
91    "Not enough memory",
92    "Not initialized",
93    "Netconfig database has invalid format",
94    "Netid not found in netconfig database"
95};
96
97struct netconfig_info {
98    int		eof;	/* all entries has been read */
99    int		ref;	/* # of times setnetconfig() has been called */
100    struct netconfig_list	*head;	/* head of the list */
101    struct netconfig_list	*tail;	/* last of the list */
102};
103
104struct netconfig_list {
105    char			*linep;	/* hold line read from netconfig */
106    struct netconfig		*ncp;
107    struct netconfig_list	*next;
108};
109
110struct netconfig_vars {
111    int   valid;	/* token that indicates a valid netconfig_vars */
112    int   flag;		/* first time flag */
113    struct netconfig_list *nc_configs;  /* pointer to the current netconfig entry */
114};
115
116#define NC_VALID	0xfeed
117#define NC_STORAGE	0xf00d
118#define NC_INVALID	0
119
120
121static int *__nc_error(void);
122static int parse_ncp(char *, struct netconfig *);
123static struct netconfig *dup_ncp(struct netconfig *);
124
125
126static FILE *nc_file;		/* for netconfig db */
127static mutex_t nc_file_lock = MUTEX_INITIALIZER;
128
129static struct netconfig_info	ni = { 0, 0, NULL, NULL};
130static mutex_t ni_lock = MUTEX_INITIALIZER;
131
132static thread_key_t nc_key;
133static once_t nc_once = ONCE_INITIALIZER;
134static int nc_key_error;
135
136static void
137nc_key_init(void)
138{
139
140	nc_key_error = thr_keycreate(&nc_key, free);
141}
142
143#define MAXNETCONFIGLINE    1000
144
145static int *
146__nc_error(void)
147{
148	static int nc_error = 0;
149	int *nc_addr;
150
151	/*
152	 * Use the static `nc_error' if we are the main thread
153	 * (including non-threaded programs), or if an allocation
154	 * fails.
155	 */
156	if (thr_main())
157		return (&nc_error);
158	if (thr_once(&nc_once, nc_key_init) != 0 || nc_key_error != 0)
159		return (&nc_error);
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			free(nc_addr);
164			return (&nc_error);
165		}
166		*nc_addr = 0;
167	}
168	return (nc_addr);
169}
170
171#define nc_error        (*(__nc_error()))
172/*
173 * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
174 * "handle" is returned on a successful call.  At the start of a session (after
175 * a call to setnetconfig()) searches through the /etc/netconfig database will
176 * proceed from the start of the file.  The session handle must be passed to
177 * getnetconfig() to parse the file.  Each call to getnetconfig() using the
178 * current handle will process one subsequent entry in /etc/netconfig.
179 * setnetconfig() must be called before the first call to getnetconfig().
180 * (Handles are used to allow for nested calls to setnetpath()).
181 *
182 * A new session is established with each call to setnetconfig(), with a new
183 * handle being returned on each call.  Previously established sessions remain
184 * active until endnetconfig() is called with that session's handle as an
185 * argument.
186 *
187 * setnetconfig() need *not* be called before a call to getnetconfigent().
188 * setnetconfig() returns a NULL pointer on failure (for example, if
189 * the netconfig database is not present).
190 */
191void *
192setnetconfig(void)
193{
194    struct netconfig_vars *nc_vars;
195
196    if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
197		(struct netconfig_vars))) == NULL) {
198	return(NULL);
199    }
200
201    /*
202     * For multiple calls, i.e. nc_file is not NULL, we just return the
203     * handle without reopening the netconfig db.
204     */
205    mutex_lock(&ni_lock);
206    ni.ref++;
207    mutex_unlock(&ni_lock);
208
209    mutex_lock(&nc_file_lock);
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	mutex_unlock(&nc_file_lock);
215	return ((void *)nc_vars);
216    }
217    mutex_unlock(&nc_file_lock);
218
219    mutex_lock(&ni_lock);
220    ni.ref--;
221    mutex_unlock(&ni_lock);
222
223    nc_error = NC_NONETCONFIG;
224    free(nc_vars);
225    return (NULL);
226}
227
228
229/*
230 * When first called, getnetconfig() returns a pointer to the first entry in
231 * the netconfig database, formatted as a struct netconfig.  On each subsequent
232 * call, getnetconfig() returns a pointer to the next entry in the database.
233 * getnetconfig() can thus be used to search the entire netconfig file.
234 * getnetconfig() returns NULL at end of file.
235 */
236
237struct netconfig *
238getnetconfig(void *handlep)
239{
240    struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
241    char *stringp;		/* tmp string pointer */
242    struct netconfig_list	*list;
243    struct netconfig *np;
244    struct netconfig *result;
245
246    /*
247     * Verify that handle is valid
248     */
249    mutex_lock(&nc_file_lock);
250    if (ncp == NULL || nc_file == NULL) {
251	nc_error = NC_NOTINIT;
252	mutex_unlock(&nc_file_lock);
253	return (NULL);
254    }
255    mutex_unlock(&nc_file_lock);
256
257    switch (ncp->valid) {
258    case NC_VALID:
259	/*
260	 * If entry has already been read into the list,
261	 * we return the entry in the linked list.
262	 * If this is the first time call, check if there are any entries in
263	 * linked list.  If no entries, we need to read the netconfig db.
264	 * If we have been here and the next entry is there, we just return
265	 * it.
266	 */
267	if (ncp->flag == 0) {	/* first time */
268	    ncp->flag = 1;
269	    mutex_lock(&ni_lock);
270	    ncp->nc_configs = ni.head;
271	    mutex_unlock(&ni_lock);
272	    if (ncp->nc_configs != NULL)	/* entry already exist */
273		return(ncp->nc_configs->ncp);
274	}
275	else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {
276	    ncp->nc_configs = ncp->nc_configs->next;
277	    return(ncp->nc_configs->ncp);
278	}
279
280	/*
281	 * If we cannot find the entry in the list and is end of file,
282	 * we give up.
283	 */
284	mutex_lock(&ni_lock);
285	if (ni.eof == 1) {
286		mutex_unlock(&ni_lock);
287		return(NULL);
288	}
289	mutex_unlock(&ni_lock);
290
291	break;
292    default:
293	nc_error = NC_NOTINIT;
294	return (NULL);
295    }
296
297    stringp = (char *) malloc(MAXNETCONFIGLINE);
298    if (stringp == NULL)
299    	return (NULL);
300
301#ifdef MEM_CHK
302    if (malloc_verify() == 0) {
303	fprintf(stderr, "memory heap corrupted in getnetconfig\n");
304	exit(1);
305    }
306#endif
307
308    /*
309     * Read a line from netconfig file.
310     */
311    mutex_lock(&nc_file_lock);
312    do {
313	if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
314	    free(stringp);
315	    mutex_lock(&ni_lock);
316	    ni.eof = 1;
317	    mutex_unlock(&ni_lock);
318	    mutex_unlock(&nc_file_lock);
319	    return (NULL);
320        }
321    } while (*stringp == '#');
322    mutex_unlock(&nc_file_lock);
323
324    list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));
325    if (list == NULL) {
326    	free(stringp);
327    	return(NULL);
328    }
329    np = (struct netconfig *) malloc(sizeof (struct netconfig));
330    if (np == NULL) {
331    	free(stringp);
332	free(list);
333    	return(NULL);
334    }
335    list->ncp = np;
336    list->next = NULL;
337    list->ncp->nc_lookups = NULL;
338    list->linep = stringp;
339    if (parse_ncp(stringp, list->ncp) == -1) {
340	free(stringp);
341	free(np);
342	free(list);
343	return (NULL);
344    }
345    else {
346	/*
347	 * If this is the first entry that's been read, it is the head of
348	 * the list.  If not, put the entry at the end of the list.
349	 * Reposition the current pointer of the handle to the last entry
350	 * in the list.
351	 */
352	mutex_lock(&ni_lock);
353	if (ni.head == NULL) {	/* first entry */
354	    ni.head = ni.tail = list;
355	}
356    	else {
357    	    ni.tail->next = list;
358    	    ni.tail = ni.tail->next;
359    	}
360	ncp->nc_configs = ni.tail;
361	result = ni.tail->ncp;
362	mutex_unlock(&ni_lock);
363	return(result);
364    }
365}
366
367/*
368 * endnetconfig() may be called to "unbind" or "close" the netconfig database
369 * when processing is complete, releasing resources for reuse.  endnetconfig()
370 * may not be called before setnetconfig().  endnetconfig() returns 0 on
371 * success and -1 on failure (for example, if setnetconfig() was not called
372 * previously).
373 */
374int
375endnetconfig(void *handlep)
376{
377    struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
378
379    struct netconfig_list *q, *p;
380
381    /*
382     * Verify that handle is valid
383     */
384    if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
385	    nc_handlep->valid != NC_STORAGE)) {
386	nc_error = NC_NOTINIT;
387	return (-1);
388    }
389
390    /*
391     * Return 0 if anyone still needs it.
392     */
393    nc_handlep->valid = NC_INVALID;
394    nc_handlep->flag = 0;
395    nc_handlep->nc_configs = NULL;
396    mutex_lock(&ni_lock);
397    if (--ni.ref > 0) {
398	mutex_unlock(&ni_lock);
399    	free(nc_handlep);
400	return(0);
401    }
402
403    /*
404     * No one needs these entries anymore, then frees them.
405     * Make sure all info in netconfig_info structure has been reinitialized.
406     */
407    q = ni.head;
408    ni.eof = ni.ref = 0;
409    ni.head = NULL;
410    ni.tail = NULL;
411    mutex_unlock(&ni_lock);
412
413    while (q != NULL) {
414	p = q->next;
415	free(q->ncp->nc_lookups);
416	free(q->ncp);
417	free(q->linep);
418	free(q);
419	q = p;
420    }
421    free(nc_handlep);
422
423    mutex_lock(&nc_file_lock);
424    fclose(nc_file);
425    nc_file = NULL;
426    mutex_unlock(&nc_file_lock);
427
428    return (0);
429}
430
431/*
432 * getnetconfigent(netid) returns a pointer to the struct netconfig structure
433 * corresponding to netid.  It returns NULL if netid is invalid (that is, does
434 * not name an entry in the netconfig database).  It returns NULL and sets
435 * errno in case of failure (for example, if the netconfig database cannot be
436 * opened).
437 */
438
439struct netconfig *
440getnetconfigent(const char *netid)
441{
442    FILE *file;		/* NETCONFIG db's file pointer */
443    char *linep;	/* holds current netconfig line */
444    char *stringp;	/* temporary string pointer */
445    struct netconfig *ncp = NULL;   /* returned value */
446    struct netconfig_list *list;	/* pointer to cache list */
447
448    nc_error = NC_NOTFOUND;	/* default error. */
449    if (netid == NULL || strlen(netid) == 0) {
450	return (NULL);
451    }
452
453    /*
454     * Look up table if the entries have already been read and parsed in
455     * getnetconfig(), then copy this entry into a buffer and return it.
456     * If we cannot find the entry in the current list and there are more
457     * entries in the netconfig db that has not been read, we then read the
458     * db and try find the match netid.
459     * If all the netconfig db has been read and placed into the list and
460     * there is no match for the netid, return NULL.
461     */
462    mutex_lock(&ni_lock);
463    if (ni.head != NULL) {
464	for (list = ni.head; list; list = list->next) {
465	    if (strcmp(list->ncp->nc_netid, netid) == 0) {
466		mutex_unlock(&ni_lock);
467	        return(dup_ncp(list->ncp));
468	    }
469	}
470	if (ni.eof == 1) {	/* that's all the entries */
471		mutex_unlock(&ni_lock);
472		return(NULL);
473	}
474    }
475    mutex_unlock(&ni_lock);
476
477
478    if ((file = fopen(NETCONFIG, "r")) == NULL) {
479	nc_error = NC_NONETCONFIG;
480	return (NULL);
481    }
482
483    if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
484	fclose(file);
485	nc_error = NC_NOMEM;
486	return (NULL);
487    }
488    do {
489	ptrdiff_t len;
490	char *tmpp;	/* tmp string pointer */
491
492	do {
493	    if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {
494		break;
495	    }
496	} while (*stringp == '#');
497	if (stringp == NULL) {	    /* eof */
498	    break;
499	}
500	if ((tmpp = strpbrk(stringp, "\t ")) == NULL) {	/* can't parse file */
501	    nc_error = NC_BADFILE;
502	    break;
503	}
504	if (strlen(netid) == (size_t) (len = tmpp - stringp) &&	/* a match */
505		strncmp(stringp, netid, (size_t)len) == 0) {
506	    if ((ncp = (struct netconfig *)
507		    malloc(sizeof (struct netconfig))) == NULL) {
508		break;
509	    }
510	    ncp->nc_lookups = NULL;
511	    if (parse_ncp(linep, ncp) == -1) {
512		free(ncp);
513		ncp = NULL;
514	    }
515	    break;
516	}
517    } while (stringp != NULL);
518    if (ncp == NULL) {
519	free(linep);
520    }
521    fclose(file);
522    return(ncp);
523}
524
525/*
526 * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
527 * netconfigp (previously returned by getnetconfigent()).
528 */
529
530void
531freenetconfigent(struct netconfig *netconfigp)
532{
533    if (netconfigp != NULL) {
534	free(netconfigp->nc_netid);	/* holds all netconfigp's strings */
535	free(netconfigp->nc_lookups);
536	free(netconfigp);
537    }
538    return;
539}
540
541/*
542 * Parse line and stuff it in a struct netconfig
543 * Typical line might look like:
544 *	udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
545 *
546 * We return -1 if any of the tokens don't parse, or malloc fails.
547 *
548 * Note that we modify stringp (putting NULLs after tokens) and
549 * we set the ncp's string field pointers to point to these tokens within
550 * stringp.
551 *
552 * stringp - string to parse
553 * ncp     - where to put results
554 */
555
556static int
557parse_ncp(char *stringp, struct netconfig *ncp)
558{
559    char    *tokenp;	/* for processing tokens */
560    char    *lasts;
561    char    **nc_lookups;
562
563    nc_error = NC_BADFILE;	/* nearly anything that breaks is for this reason */
564    stringp[strlen(stringp)-1] = '\0';	/* get rid of newline */
565    /* netid */
566    if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {
567	return (-1);
568    }
569
570    /* semantics */
571    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
572	return (-1);
573    }
574    if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
575	ncp->nc_semantics = NC_TPI_COTS_ORD;
576    else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
577	ncp->nc_semantics = NC_TPI_COTS;
578    else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
579	ncp->nc_semantics = NC_TPI_CLTS;
580    else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
581	ncp->nc_semantics = NC_TPI_RAW;
582    else
583	return (-1);
584
585    /* flags */
586    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
587	return (-1);
588    }
589    for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';
590	    tokenp++) {
591	switch (*tokenp) {
592	case NC_NOFLAG_C:
593	    break;
594	case NC_VISIBLE_C:
595	    ncp->nc_flag |= NC_VISIBLE;
596	    break;
597	case NC_BROADCAST_C:
598	    ncp->nc_flag |= NC_BROADCAST;
599	    break;
600	default:
601	    return (-1);
602	}
603    }
604    /* protocol family */
605    if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {
606	return (-1);
607    }
608    /* protocol name */
609    if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {
610	return (-1);
611    }
612    /* network device */
613    if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {
614	return (-1);
615    }
616    if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
617	return (-1);
618    }
619    if (strcmp(tokenp, NC_NOLOOKUP) == 0) {
620	ncp->nc_nlookups = 0;
621	ncp->nc_lookups = NULL;
622    } else {
623	char *cp;	    /* tmp string */
624
625	free(ncp->nc_lookups); /* from last visit */
626	ncp->nc_lookups = NULL;
627	ncp->nc_nlookups = 0;
628	while ((cp = tokenp) != NULL) {
629	    if ((nc_lookups = reallocarray(ncp->nc_lookups,
630		ncp->nc_nlookups + 1, sizeof(*ncp->nc_lookups))) == NULL) {
631		    free(ncp->nc_lookups);
632		    ncp->nc_lookups = NULL;
633		    return (-1);
634	    }
635	    tokenp = _get_next_token(cp, ',');
636	    ncp->nc_lookups = nc_lookups;
637	    ncp->nc_lookups[ncp->nc_nlookups++] = cp;
638	}
639    }
640    return (0);
641}
642
643
644/*
645 * Returns a string describing the reason for failure.
646 */
647char *
648nc_sperror(void)
649{
650    const char *message;
651
652    switch(nc_error) {
653    case NC_NONETCONFIG:
654	message = _nc_errors[0];
655	break;
656    case NC_NOMEM:
657	message = _nc_errors[1];
658	break;
659    case NC_NOTINIT:
660	message = _nc_errors[2];
661	break;
662    case NC_BADFILE:
663	message = _nc_errors[3];
664	break;
665    case NC_NOTFOUND:
666	message = _nc_errors[4];
667	break;
668    default:
669	message = "Unknown network selection error";
670    }
671    /* LINTED const castaway */
672    return ((char *)message);
673}
674
675/*
676 * Prints a message onto standard error describing the reason for failure.
677 */
678void
679nc_perror(const char *s)
680{
681    fprintf(stderr, "%s: %s\n", s, nc_sperror());
682}
683
684/*
685 * Duplicates the matched netconfig buffer.
686 */
687static struct netconfig *
688dup_ncp(struct netconfig *ncp)
689{
690    struct netconfig	*p;
691    char	*tmp;
692    u_int	i;
693
694    if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
695	return(NULL);
696    if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
697	free(tmp);
698	return(NULL);
699    }
700    /*
701     * First we dup all the data from matched netconfig buffer.  Then we
702     * adjust some of the member pointer to a pre-allocated buffer where
703     * contains part of the data.
704     * To follow the convention used in parse_ncp(), we store all the
705     * necessary information in the pre-allocated buffer and let each
706     * of the netconfig char pointer member point to the right address
707     * in the buffer.
708     */
709    *p = *ncp;
710    p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
711    tmp = strchr(tmp, '\0') + 1;
712    p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
713    tmp = strchr(tmp, '\0') + 1;
714    p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
715    tmp = strchr(tmp, '\0') + 1;
716    p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
717    p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
718    if (p->nc_lookups == NULL) {
719	free(p->nc_netid);
720	free(p);
721	return(NULL);
722    }
723    for (i=0; i < p->nc_nlookups; i++) {
724    	tmp = strchr(tmp, '\0') + 1;
725    	p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
726    }
727    return(p);
728}
729