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 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)getnetconfig.c 1.12 91/12/19 SMI";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 /*
40 * Copyright (c) 1989 by Sun Microsystems, Inc.
41 */
42
43 #include "namespace.h"
44 #include "reentrant.h"
45 #include <stdio.h>
46 #include <errno.h>
47 #include <netconfig.h>
48 #include <stddef.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <rpc/rpc.h>
52 #include <unistd.h>
53 #include "un-namespace.h"
54 #include "rpc_com.h"
55
56 /*
57 * The five library routines in this file provide application access to the
58 * system network configuration database, /etc/netconfig. In addition to the
59 * netconfig database and the routines for accessing it, the environment
60 * variable NETPATH and its corresponding routines in getnetpath.c may also be
61 * used to specify the network transport to be used.
62 */
63
64
65 /*
66 * netconfig errors
67 */
68
69 #define NC_NONETCONFIG ENOENT
70 #define NC_NOMEM ENOMEM
71 #define NC_NOTINIT EINVAL /* setnetconfig was not called first */
72 #define NC_BADFILE EBADF /* format for netconfig file is bad */
73 #define NC_NOTFOUND ENOPROTOOPT /* specified netid was not found */
74
75 /*
76 * semantics as strings (should be in netconfig.h)
77 */
78 #define NC_TPI_CLTS_S "tpi_clts"
79 #define NC_TPI_COTS_S "tpi_cots"
80 #define NC_TPI_COTS_ORD_S "tpi_cots_ord"
81 #define NC_TPI_RAW_S "tpi_raw"
82
83 /*
84 * flags as characters (also should be in netconfig.h)
85 */
86 #define NC_NOFLAG_C '-'
87 #define NC_VISIBLE_C 'v'
88 #define NC_BROADCAST_C 'b'
89
90 /*
91 * Character used to indicate there is no name-to-address lookup library
92 */
93 #define NC_NOLOOKUP "-"
94
95 static const char * const _nc_errors[] = {
96 "Netconfig database not found",
97 "Not enough memory",
98 "Not initialized",
99 "Netconfig database has invalid format",
100 "Netid not found in netconfig database"
101 };
102
103 struct netconfig_info {
104 int eof; /* all entries has been read */
105 int ref; /* # of times setnetconfig() has been called */
106 struct netconfig_list *head; /* head of the list */
107 struct netconfig_list *tail; /* last of the list */
108 };
109
110 struct netconfig_list {
111 char *linep; /* hold line read from netconfig */
112 struct netconfig *ncp;
113 struct netconfig_list *next;
114 };
115
116 struct netconfig_vars {
117 int valid; /* token that indicates a valid netconfig_vars */
118 int flag; /* first time flag */
119 struct netconfig_list *nc_configs; /* pointer to the current netconfig entry */
120 };
121
122 #define NC_VALID 0xfeed
123 #define NC_STORAGE 0xf00d
124 #define NC_INVALID 0
125
126
127 static int *__nc_error(void);
128 static int parse_ncp(char *, struct netconfig *);
129 static struct netconfig *dup_ncp(struct netconfig *);
130
131
132 static FILE *nc_file; /* for netconfig db */
133 static mutex_t nc_file_lock = MUTEX_INITIALIZER;
134
135 static struct netconfig_info ni = { 0, 0, NULL, NULL};
136 static mutex_t ni_lock = MUTEX_INITIALIZER;
137
138 static thread_key_t nc_key;
139 static once_t nc_once = ONCE_INITIALIZER;
140 static int nc_key_error;
141
142 static void
nc_key_init(void)143 nc_key_init(void)
144 {
145
146 nc_key_error = thr_keycreate(&nc_key, free);
147 }
148
149 #define MAXNETCONFIGLINE 1000
150
151 static int *
__nc_error(void)152 __nc_error(void)
153 {
154 static int nc_error = 0;
155 int *nc_addr;
156
157 /*
158 * Use the static `nc_error' if we are the main thread
159 * (including non-threaded programs), or if an allocation
160 * fails.
161 */
162 if (thr_main())
163 return (&nc_error);
164 if (thr_once(&nc_once, nc_key_init) != 0 || nc_key_error != 0)
165 return (&nc_error);
166 if ((nc_addr = (int *)thr_getspecific(nc_key)) == NULL) {
167 nc_addr = (int *)malloc(sizeof (int));
168 if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {
169 free(nc_addr);
170 return (&nc_error);
171 }
172 *nc_addr = 0;
173 }
174 return (nc_addr);
175 }
176
177 #define nc_error (*(__nc_error()))
178 /*
179 * A call to setnetconfig() establishes a /etc/netconfig "session". A session
180 * "handle" is returned on a successful call. At the start of a session (after
181 * a call to setnetconfig()) searches through the /etc/netconfig database will
182 * proceed from the start of the file. The session handle must be passed to
183 * getnetconfig() to parse the file. Each call to getnetconfig() using the
184 * current handle will process one subsequent entry in /etc/netconfig.
185 * setnetconfig() must be called before the first call to getnetconfig().
186 * (Handles are used to allow for nested calls to setnetpath()).
187 *
188 * A new session is established with each call to setnetconfig(), with a new
189 * handle being returned on each call. Previously established sessions remain
190 * active until endnetconfig() is called with that session's handle as an
191 * argument.
192 *
193 * setnetconfig() need *not* be called before a call to getnetconfigent().
194 * setnetconfig() returns a NULL pointer on failure (for example, if
195 * the netconfig database is not present).
196 */
197 void *
setnetconfig(void)198 setnetconfig(void)
199 {
200 struct netconfig_vars *nc_vars;
201
202 if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
203 (struct netconfig_vars))) == NULL) {
204 return(NULL);
205 }
206
207 /*
208 * For multiple calls, i.e. nc_file is not NULL, we just return the
209 * handle without reopening the netconfig db.
210 */
211 mutex_lock(&ni_lock);
212 ni.ref++;
213 mutex_unlock(&ni_lock);
214
215 mutex_lock(&nc_file_lock);
216 if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {
217 nc_vars->valid = NC_VALID;
218 nc_vars->flag = 0;
219 nc_vars->nc_configs = ni.head;
220 mutex_unlock(&nc_file_lock);
221 return ((void *)nc_vars);
222 }
223 mutex_unlock(&nc_file_lock);
224
225 mutex_lock(&ni_lock);
226 ni.ref--;
227 mutex_unlock(&ni_lock);
228
229 nc_error = NC_NONETCONFIG;
230 free(nc_vars);
231 return (NULL);
232 }
233
234
235 /*
236 * When first called, getnetconfig() returns a pointer to the first entry in
237 * the netconfig database, formatted as a struct netconfig. On each subsequent
238 * call, getnetconfig() returns a pointer to the next entry in the database.
239 * getnetconfig() can thus be used to search the entire netconfig file.
240 * getnetconfig() returns NULL at end of file.
241 */
242
243 struct netconfig *
getnetconfig(void * handlep)244 getnetconfig(void *handlep)
245 {
246 struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
247 char *stringp; /* tmp string pointer */
248 struct netconfig_list *list;
249 struct netconfig *np;
250 struct netconfig *result;
251
252 /*
253 * Verify that handle is valid
254 */
255 mutex_lock(&nc_file_lock);
256 if (ncp == NULL || nc_file == NULL) {
257 nc_error = NC_NOTINIT;
258 mutex_unlock(&nc_file_lock);
259 return (NULL);
260 }
261 mutex_unlock(&nc_file_lock);
262
263 switch (ncp->valid) {
264 case NC_VALID:
265 /*
266 * If entry has already been read into the list,
267 * we return the entry in the linked list.
268 * If this is the first time call, check if there are any entries in
269 * linked list. If no entries, we need to read the netconfig db.
270 * If we have been here and the next entry is there, we just return
271 * it.
272 */
273 if (ncp->flag == 0) { /* first time */
274 ncp->flag = 1;
275 mutex_lock(&ni_lock);
276 ncp->nc_configs = ni.head;
277 mutex_unlock(&ni_lock);
278 if (ncp->nc_configs != NULL) /* entry already exist */
279 return(ncp->nc_configs->ncp);
280 }
281 else if (ncp->nc_configs != NULL && ncp->nc_configs->next != NULL) {
282 ncp->nc_configs = ncp->nc_configs->next;
283 return(ncp->nc_configs->ncp);
284 }
285
286 /*
287 * If we cannot find the entry in the list and is end of file,
288 * we give up.
289 */
290 mutex_lock(&ni_lock);
291 if (ni.eof == 1) {
292 mutex_unlock(&ni_lock);
293 return(NULL);
294 }
295 mutex_unlock(&ni_lock);
296
297 break;
298 default:
299 nc_error = NC_NOTINIT;
300 return (NULL);
301 }
302
303 stringp = (char *) malloc(MAXNETCONFIGLINE);
304 if (stringp == NULL)
305 return (NULL);
306
307 #ifdef MEM_CHK
308 if (malloc_verify() == 0) {
309 fprintf(stderr, "memory heap corrupted in getnetconfig\n");
310 exit(1);
311 }
312 #endif
313
314 /*
315 * Read a line from netconfig file.
316 */
317 mutex_lock(&nc_file_lock);
318 do {
319 if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
320 free(stringp);
321 mutex_lock(&ni_lock);
322 ni.eof = 1;
323 mutex_unlock(&ni_lock);
324 mutex_unlock(&nc_file_lock);
325 return (NULL);
326 }
327 } while (*stringp == '#');
328 mutex_unlock(&nc_file_lock);
329
330 list = (struct netconfig_list *) malloc(sizeof (struct netconfig_list));
331 if (list == NULL) {
332 free(stringp);
333 return(NULL);
334 }
335 np = (struct netconfig *) malloc(sizeof (struct netconfig));
336 if (np == NULL) {
337 free(stringp);
338 free(list);
339 return(NULL);
340 }
341 list->ncp = np;
342 list->next = NULL;
343 list->ncp->nc_lookups = NULL;
344 list->linep = stringp;
345 if (parse_ncp(stringp, list->ncp) == -1) {
346 free(stringp);
347 free(np);
348 free(list);
349 return (NULL);
350 }
351 else {
352 /*
353 * If this is the first entry that's been read, it is the head of
354 * the list. If not, put the entry at the end of the list.
355 * Reposition the current pointer of the handle to the last entry
356 * in the list.
357 */
358 mutex_lock(&ni_lock);
359 if (ni.head == NULL) { /* first entry */
360 ni.head = ni.tail = list;
361 }
362 else {
363 ni.tail->next = list;
364 ni.tail = ni.tail->next;
365 }
366 ncp->nc_configs = ni.tail;
367 result = ni.tail->ncp;
368 mutex_unlock(&ni_lock);
369 return(result);
370 }
371 }
372
373 /*
374 * endnetconfig() may be called to "unbind" or "close" the netconfig database
375 * when processing is complete, releasing resources for reuse. endnetconfig()
376 * may not be called before setnetconfig(). endnetconfig() returns 0 on
377 * success and -1 on failure (for example, if setnetconfig() was not called
378 * previously).
379 */
380 int
endnetconfig(void * handlep)381 endnetconfig(void *handlep)
382 {
383 struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
384
385 struct netconfig_list *q, *p;
386
387 /*
388 * Verify that handle is valid
389 */
390 if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
391 nc_handlep->valid != NC_STORAGE)) {
392 nc_error = NC_NOTINIT;
393 return (-1);
394 }
395
396 /*
397 * Return 0 if anyone still needs it.
398 */
399 nc_handlep->valid = NC_INVALID;
400 nc_handlep->flag = 0;
401 nc_handlep->nc_configs = NULL;
402 mutex_lock(&ni_lock);
403 if (--ni.ref > 0) {
404 mutex_unlock(&ni_lock);
405 free(nc_handlep);
406 return(0);
407 }
408
409 /*
410 * No one needs these entries anymore, then frees them.
411 * Make sure all info in netconfig_info structure has been reinitialized.
412 */
413 q = ni.head;
414 ni.eof = ni.ref = 0;
415 ni.head = NULL;
416 ni.tail = NULL;
417 mutex_unlock(&ni_lock);
418
419 while (q != NULL) {
420 p = q->next;
421 free(q->ncp->nc_lookups);
422 free(q->ncp);
423 free(q->linep);
424 free(q);
425 q = p;
426 }
427 free(nc_handlep);
428
429 mutex_lock(&nc_file_lock);
430 fclose(nc_file);
431 nc_file = NULL;
432 mutex_unlock(&nc_file_lock);
433
434 return (0);
435 }
436
437 /*
438 * getnetconfigent(netid) returns a pointer to the struct netconfig structure
439 * corresponding to netid. It returns NULL if netid is invalid (that is, does
440 * not name an entry in the netconfig database). It returns NULL and sets
441 * errno in case of failure (for example, if the netconfig database cannot be
442 * opened).
443 */
444
445 struct netconfig *
getnetconfigent(const char * netid)446 getnetconfigent(const char *netid)
447 {
448 FILE *file; /* NETCONFIG db's file pointer */
449 char *linep; /* holds current netconfig line */
450 char *stringp; /* temporary string pointer */
451 struct netconfig *ncp = NULL; /* returned value */
452 struct netconfig_list *list; /* pointer to cache list */
453
454 nc_error = NC_NOTFOUND; /* default error. */
455 if (netid == NULL || strlen(netid) == 0) {
456 return (NULL);
457 }
458
459 /*
460 * Look up table if the entries have already been read and parsed in
461 * getnetconfig(), then copy this entry into a buffer and return it.
462 * If we cannot find the entry in the current list and there are more
463 * entries in the netconfig db that has not been read, we then read the
464 * db and try find the match netid.
465 * If all the netconfig db has been read and placed into the list and
466 * there is no match for the netid, return NULL.
467 */
468 mutex_lock(&ni_lock);
469 if (ni.head != NULL) {
470 for (list = ni.head; list; list = list->next) {
471 if (strcmp(list->ncp->nc_netid, netid) == 0) {
472 mutex_unlock(&ni_lock);
473 return(dup_ncp(list->ncp));
474 }
475 }
476 if (ni.eof == 1) { /* that's all the entries */
477 mutex_unlock(&ni_lock);
478 return(NULL);
479 }
480 }
481 mutex_unlock(&ni_lock);
482
483
484 if ((file = fopen(NETCONFIG, "r")) == NULL) {
485 nc_error = NC_NONETCONFIG;
486 return (NULL);
487 }
488
489 if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
490 fclose(file);
491 nc_error = NC_NOMEM;
492 return (NULL);
493 }
494 do {
495 ptrdiff_t len;
496 char *tmpp; /* tmp string pointer */
497
498 do {
499 if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {
500 break;
501 }
502 } while (*stringp == '#');
503 if (stringp == NULL) { /* eof */
504 break;
505 }
506 if ((tmpp = strpbrk(stringp, "\t ")) == NULL) { /* can't parse file */
507 nc_error = NC_BADFILE;
508 break;
509 }
510 if (strlen(netid) == (size_t) (len = tmpp - stringp) && /* a match */
511 strncmp(stringp, netid, (size_t)len) == 0) {
512 if ((ncp = (struct netconfig *)
513 malloc(sizeof (struct netconfig))) == NULL) {
514 break;
515 }
516 ncp->nc_lookups = NULL;
517 if (parse_ncp(linep, ncp) == -1) {
518 free(ncp);
519 ncp = NULL;
520 }
521 break;
522 }
523 } while (stringp != NULL);
524 if (ncp == NULL) {
525 free(linep);
526 }
527 fclose(file);
528 return(ncp);
529 }
530
531 /*
532 * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
533 * netconfigp (previously returned by getnetconfigent()).
534 */
535
536 void
freenetconfigent(struct netconfig * netconfigp)537 freenetconfigent(struct netconfig *netconfigp)
538 {
539 if (netconfigp != NULL) {
540 free(netconfigp->nc_netid); /* holds all netconfigp's strings */
541 free(netconfigp->nc_lookups);
542 free(netconfigp);
543 }
544 return;
545 }
546
547 /*
548 * Parse line and stuff it in a struct netconfig
549 * Typical line might look like:
550 * udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
551 *
552 * We return -1 if any of the tokens don't parse, or malloc fails.
553 *
554 * Note that we modify stringp (putting NULLs after tokens) and
555 * we set the ncp's string field pointers to point to these tokens within
556 * stringp.
557 *
558 * stringp - string to parse
559 * ncp - where to put results
560 */
561
562 static int
parse_ncp(char * stringp,struct netconfig * ncp)563 parse_ncp(char *stringp, struct netconfig *ncp)
564 {
565 char *tokenp; /* for processing tokens */
566 char *lasts;
567 char **nc_lookups;
568
569 nc_error = NC_BADFILE; /* nearly anything that breaks is for this reason */
570 stringp[strlen(stringp)-1] = '\0'; /* get rid of newline */
571 /* netid */
572 if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {
573 return (-1);
574 }
575
576 /* semantics */
577 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
578 return (-1);
579 }
580 if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
581 ncp->nc_semantics = NC_TPI_COTS_ORD;
582 else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
583 ncp->nc_semantics = NC_TPI_COTS;
584 else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
585 ncp->nc_semantics = NC_TPI_CLTS;
586 else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
587 ncp->nc_semantics = NC_TPI_RAW;
588 else
589 return (-1);
590
591 /* flags */
592 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
593 return (-1);
594 }
595 for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';
596 tokenp++) {
597 switch (*tokenp) {
598 case NC_NOFLAG_C:
599 break;
600 case NC_VISIBLE_C:
601 ncp->nc_flag |= NC_VISIBLE;
602 break;
603 case NC_BROADCAST_C:
604 ncp->nc_flag |= NC_BROADCAST;
605 break;
606 default:
607 return (-1);
608 }
609 }
610 /* protocol family */
611 if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {
612 return (-1);
613 }
614 /* protocol name */
615 if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {
616 return (-1);
617 }
618 /* network device */
619 if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {
620 return (-1);
621 }
622 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
623 return (-1);
624 }
625 if (strcmp(tokenp, NC_NOLOOKUP) == 0) {
626 ncp->nc_nlookups = 0;
627 ncp->nc_lookups = NULL;
628 } else {
629 char *cp; /* tmp string */
630
631 free(ncp->nc_lookups); /* from last visit */
632 ncp->nc_lookups = NULL;
633 ncp->nc_nlookups = 0;
634 while ((cp = tokenp) != NULL) {
635 if ((nc_lookups = reallocarray(ncp->nc_lookups,
636 ncp->nc_nlookups + 1, sizeof(*ncp->nc_lookups))) == NULL) {
637 free(ncp->nc_lookups);
638 ncp->nc_lookups = NULL;
639 return (-1);
640 }
641 tokenp = _get_next_token(cp, ',');
642 ncp->nc_lookups = nc_lookups;
643 ncp->nc_lookups[ncp->nc_nlookups++] = cp;
644 }
645 }
646 return (0);
647 }
648
649
650 /*
651 * Returns a string describing the reason for failure.
652 */
653 char *
nc_sperror(void)654 nc_sperror(void)
655 {
656 const char *message;
657
658 switch(nc_error) {
659 case NC_NONETCONFIG:
660 message = _nc_errors[0];
661 break;
662 case NC_NOMEM:
663 message = _nc_errors[1];
664 break;
665 case NC_NOTINIT:
666 message = _nc_errors[2];
667 break;
668 case NC_BADFILE:
669 message = _nc_errors[3];
670 break;
671 case NC_NOTFOUND:
672 message = _nc_errors[4];
673 break;
674 default:
675 message = "Unknown network selection error";
676 }
677 /* LINTED const castaway */
678 return ((char *)message);
679 }
680
681 /*
682 * Prints a message onto standard error describing the reason for failure.
683 */
684 void
nc_perror(const char * s)685 nc_perror(const char *s)
686 {
687 fprintf(stderr, "%s: %s\n", s, nc_sperror());
688 }
689
690 /*
691 * Duplicates the matched netconfig buffer.
692 */
693 static struct netconfig *
dup_ncp(struct netconfig * ncp)694 dup_ncp(struct netconfig *ncp)
695 {
696 struct netconfig *p;
697 char *tmp;
698 u_int i;
699
700 if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
701 return(NULL);
702 if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
703 free(tmp);
704 return(NULL);
705 }
706 /*
707 * First we dup all the data from matched netconfig buffer. Then we
708 * adjust some of the member pointer to a pre-allocated buffer where
709 * contains part of the data.
710 * To follow the convention used in parse_ncp(), we store all the
711 * necessary information in the pre-allocated buffer and let each
712 * of the netconfig char pointer member point to the right address
713 * in the buffer.
714 */
715 *p = *ncp;
716 p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
717 tmp = strchr(tmp, '\0') + 1;
718 p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
719 tmp = strchr(tmp, '\0') + 1;
720 p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
721 tmp = strchr(tmp, '\0') + 1;
722 p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
723 p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
724 if (p->nc_lookups == NULL) {
725 free(p->nc_netid);
726 free(p);
727 return(NULL);
728 }
729 for (i=0; i < p->nc_nlookups; i++) {
730 tmp = strchr(tmp, '\0') + 1;
731 p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
732 }
733 return(p);
734 }
735