1 /* $NetBSD: getnetconfig.c,v 1.3 2000/07/06 03:10:34 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #if defined(LIBC_SCCS) && !defined(lint)
32 static char sccsid[] = "@(#)getnetconfig.c 1.12 91/12/19 SMI";
33 #endif
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 /*
38 * Copyright (c) 1989 by Sun Microsystems, Inc.
39 */
40
41 #include "namespace.h"
42 #include "reentrant.h"
43 #include <stdio.h>
44 #include <errno.h>
45 #include <netconfig.h>
46 #include <stddef.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <rpc/rpc.h>
50 #include <unistd.h>
51 #include "un-namespace.h"
52 #include "rpc_com.h"
53
54 /*
55 * The five library routines in this file provide application access to the
56 * system network configuration database, /etc/netconfig. In addition to the
57 * netconfig database and the routines for accessing it, the environment
58 * variable NETPATH and its corresponding routines in getnetpath.c may also be
59 * used to specify the network transport to be used.
60 */
61
62
63 /*
64 * netconfig errors
65 */
66
67 #define NC_NONETCONFIG ENOENT
68 #define NC_NOMEM ENOMEM
69 #define NC_NOTINIT EINVAL /* setnetconfig was not called first */
70 #define NC_BADFILE EBADF /* format for netconfig file is bad */
71 #define NC_NOTFOUND ENOPROTOOPT /* specified netid was not found */
72
73 /*
74 * semantics as strings (should be in netconfig.h)
75 */
76 #define NC_TPI_CLTS_S "tpi_clts"
77 #define NC_TPI_COTS_S "tpi_cots"
78 #define NC_TPI_COTS_ORD_S "tpi_cots_ord"
79 #define NC_TPI_RAW_S "tpi_raw"
80
81 /*
82 * flags as characters (also should be in netconfig.h)
83 */
84 #define NC_NOFLAG_C '-'
85 #define NC_VISIBLE_C 'v'
86 #define NC_BROADCAST_C 'b'
87
88 /*
89 * Character used to indicate there is no name-to-address lookup library
90 */
91 #define NC_NOLOOKUP "-"
92
93 static const char * const _nc_errors[] = {
94 "Netconfig database not found",
95 "Not enough memory",
96 "Not initialized",
97 "Netconfig database has invalid format",
98 "Netid not found in netconfig database"
99 };
100
101 struct netconfig_info {
102 int eof; /* all entries has been read */
103 int ref; /* # of times setnetconfig() has been called */
104 struct netconfig_list *head; /* head of the list */
105 struct netconfig_list *tail; /* last of the list */
106 };
107
108 struct netconfig_list {
109 char *linep; /* hold line read from netconfig */
110 struct netconfig *ncp;
111 struct netconfig_list *next;
112 };
113
114 struct netconfig_vars {
115 int valid; /* token that indicates a valid netconfig_vars */
116 int flag; /* first time flag */
117 struct netconfig_list *nc_configs; /* pointer to the current netconfig entry */
118 };
119
120 #define NC_VALID 0xfeed
121 #define NC_STORAGE 0xf00d
122 #define NC_INVALID 0
123
124
125 static int *__nc_error(void);
126 static int parse_ncp(char *, struct netconfig *);
127 static struct netconfig *dup_ncp(struct netconfig *);
128
129
130 static FILE *nc_file; /* for netconfig db */
131 static mutex_t nc_file_lock = MUTEX_INITIALIZER;
132
133 static struct netconfig_info ni = { 0, 0, NULL, NULL};
134 static mutex_t ni_lock = MUTEX_INITIALIZER;
135
136 static thread_key_t nc_key;
137 static once_t nc_once = ONCE_INITIALIZER;
138 static int nc_key_error;
139
140 static void
nc_key_init(void)141 nc_key_init(void)
142 {
143
144 nc_key_error = thr_keycreate(&nc_key, free);
145 }
146
147 #define MAXNETCONFIGLINE 1000
148
149 static int *
__nc_error()150 __nc_error()
151 {
152 static int nc_error = 0;
153 int *nc_addr;
154
155 /*
156 * Use the static `nc_error' if we are the main thread
157 * (including non-threaded programs), or if an allocation
158 * fails.
159 */
160 if (thr_main())
161 return (&nc_error);
162 if (thr_once(&nc_once, nc_key_init) != 0 || nc_key_error != 0)
163 return (&nc_error);
164 if ((nc_addr = (int *)thr_getspecific(nc_key)) == NULL) {
165 nc_addr = (int *)malloc(sizeof (int));
166 if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {
167 if (nc_addr)
168 free(nc_addr);
169 return (&nc_error);
170 }
171 *nc_addr = 0;
172 }
173 return (nc_addr);
174 }
175
176 #define nc_error (*(__nc_error()))
177 /*
178 * A call to setnetconfig() establishes a /etc/netconfig "session". A session
179 * "handle" is returned on a successful call. At the start of a session (after
180 * a call to setnetconfig()) searches through the /etc/netconfig database will
181 * proceed from the start of the file. The session handle must be passed to
182 * getnetconfig() to parse the file. Each call to getnetconfig() using the
183 * current handle will process one subsequent entry in /etc/netconfig.
184 * setnetconfig() must be called before the first call to getnetconfig().
185 * (Handles are used to allow for nested calls to setnetpath()).
186 *
187 * A new session is established with each call to setnetconfig(), with a new
188 * handle being returned on each call. Previously established sessions remain
189 * active until endnetconfig() is called with that session's handle as an
190 * argument.
191 *
192 * setnetconfig() need *not* be called before a call to getnetconfigent().
193 * setnetconfig() returns a NULL pointer on failure (for example, if
194 * the netconfig database is not present).
195 */
196 void *
setnetconfig()197 setnetconfig()
198 {
199 struct netconfig_vars *nc_vars;
200
201 if ((nc_vars = (struct netconfig_vars *)malloc(sizeof
202 (struct netconfig_vars))) == NULL) {
203 return(NULL);
204 }
205
206 /*
207 * For multiple calls, i.e. nc_file is not NULL, we just return the
208 * handle without reopening the netconfig db.
209 */
210 mutex_lock(&ni_lock);
211 ni.ref++;
212 mutex_unlock(&ni_lock);
213
214 mutex_lock(&nc_file_lock);
215 if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "r")) != NULL) {
216 nc_vars->valid = NC_VALID;
217 nc_vars->flag = 0;
218 nc_vars->nc_configs = ni.head;
219 mutex_unlock(&nc_file_lock);
220 return ((void *)nc_vars);
221 }
222 mutex_unlock(&nc_file_lock);
223
224 mutex_lock(&ni_lock);
225 ni.ref--;
226 mutex_unlock(&ni_lock);
227
228 nc_error = NC_NONETCONFIG;
229 free(nc_vars);
230 return (NULL);
231 }
232
233
234 /*
235 * When first called, getnetconfig() returns a pointer to the first entry in
236 * the netconfig database, formatted as a struct netconfig. On each subsequent
237 * call, getnetconfig() returns a pointer to the next entry in the database.
238 * getnetconfig() can thus be used to search the entire netconfig file.
239 * getnetconfig() returns NULL at end of file.
240 */
241
242 struct netconfig *
getnetconfig(handlep)243 getnetconfig(handlep)
244 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(handlep)381 endnetconfig(handlep)
382 void *handlep;
383 {
384 struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
385
386 struct netconfig_list *q, *p;
387
388 /*
389 * Verify that handle is valid
390 */
391 if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
392 nc_handlep->valid != NC_STORAGE)) {
393 nc_error = NC_NOTINIT;
394 return (-1);
395 }
396
397 /*
398 * Return 0 if anyone still needs it.
399 */
400 nc_handlep->valid = NC_INVALID;
401 nc_handlep->flag = 0;
402 nc_handlep->nc_configs = NULL;
403 mutex_lock(&ni_lock);
404 if (--ni.ref > 0) {
405 mutex_unlock(&ni_lock);
406 free(nc_handlep);
407 return(0);
408 }
409
410 /*
411 * Noone needs these entries anymore, then frees them.
412 * Make sure all info in netconfig_info structure has been reinitialized.
413 */
414 q = ni.head;
415 ni.eof = ni.ref = 0;
416 ni.head = NULL;
417 ni.tail = NULL;
418 mutex_unlock(&ni_lock);
419
420 while (q != NULL) {
421 p = q->next;
422 if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);
423 free(q->ncp);
424 free(q->linep);
425 free(q);
426 q = p;
427 }
428 free(nc_handlep);
429
430 mutex_lock(&nc_file_lock);
431 fclose(nc_file);
432 nc_file = NULL;
433 mutex_unlock(&nc_file_lock);
434
435 return (0);
436 }
437
438 /*
439 * getnetconfigent(netid) returns a pointer to the struct netconfig structure
440 * corresponding to netid. It returns NULL if netid is invalid (that is, does
441 * not name an entry in the netconfig database). It returns NULL and sets
442 * errno in case of failure (for example, if the netconfig database cannot be
443 * opened).
444 */
445
446 struct netconfig *
getnetconfigent(netid)447 getnetconfigent(netid)
448 const char *netid;
449 {
450 FILE *file; /* NETCONFIG db's file pointer */
451 char *linep; /* holds current netconfig line */
452 char *stringp; /* temporary string pointer */
453 struct netconfig *ncp = NULL; /* returned value */
454 struct netconfig_list *list; /* pointer to cache list */
455
456 nc_error = NC_NOTFOUND; /* default error. */
457 if (netid == NULL || strlen(netid) == 0) {
458 return (NULL);
459 }
460
461 /*
462 * Look up table if the entries have already been read and parsed in
463 * getnetconfig(), then copy this entry into a buffer and return it.
464 * If we cannot find the entry in the current list and there are more
465 * entries in the netconfig db that has not been read, we then read the
466 * db and try find the match netid.
467 * If all the netconfig db has been read and placed into the list and
468 * there is no match for the netid, return NULL.
469 */
470 mutex_lock(&ni_lock);
471 if (ni.head != NULL) {
472 for (list = ni.head; list; list = list->next) {
473 if (strcmp(list->ncp->nc_netid, netid) == 0) {
474 mutex_unlock(&ni_lock);
475 return(dup_ncp(list->ncp));
476 }
477 }
478 if (ni.eof == 1) { /* that's all the entries */
479 mutex_unlock(&ni_lock);
480 return(NULL);
481 }
482 }
483 mutex_unlock(&ni_lock);
484
485
486 if ((file = fopen(NETCONFIG, "r")) == NULL) {
487 nc_error = NC_NONETCONFIG;
488 return (NULL);
489 }
490
491 if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
492 fclose(file);
493 nc_error = NC_NOMEM;
494 return (NULL);
495 }
496 do {
497 ptrdiff_t len;
498 char *tmpp; /* tmp string pointer */
499
500 do {
501 if ((stringp = fgets(linep, MAXNETCONFIGLINE, file)) == NULL) {
502 break;
503 }
504 } while (*stringp == '#');
505 if (stringp == NULL) { /* eof */
506 break;
507 }
508 if ((tmpp = strpbrk(stringp, "\t ")) == NULL) { /* can't parse file */
509 nc_error = NC_BADFILE;
510 break;
511 }
512 if (strlen(netid) == (size_t) (len = tmpp - stringp) && /* a match */
513 strncmp(stringp, netid, (size_t)len) == 0) {
514 if ((ncp = (struct netconfig *)
515 malloc(sizeof (struct netconfig))) == NULL) {
516 break;
517 }
518 ncp->nc_lookups = NULL;
519 if (parse_ncp(linep, ncp) == -1) {
520 free(ncp);
521 ncp = NULL;
522 }
523 break;
524 }
525 } while (stringp != NULL);
526 if (ncp == NULL) {
527 free(linep);
528 }
529 fclose(file);
530 return(ncp);
531 }
532
533 /*
534 * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
535 * netconfigp (previously returned by getnetconfigent()).
536 */
537
538 void
freenetconfigent(netconfigp)539 freenetconfigent(netconfigp)
540 struct netconfig *netconfigp;
541 {
542 if (netconfigp != NULL) {
543 free(netconfigp->nc_netid); /* holds all netconfigp's strings */
544 if (netconfigp->nc_lookups != NULL)
545 free(netconfigp->nc_lookups);
546 free(netconfigp);
547 }
548 return;
549 }
550
551 /*
552 * Parse line and stuff it in a struct netconfig
553 * Typical line might look like:
554 * udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
555 *
556 * We return -1 if any of the tokens don't parse, or malloc fails.
557 *
558 * Note that we modify stringp (putting NULLs after tokens) and
559 * we set the ncp's string field pointers to point to these tokens within
560 * stringp.
561 */
562
563 static int
parse_ncp(stringp,ncp)564 parse_ncp(stringp, ncp)
565 char *stringp; /* string to parse */
566 struct netconfig *ncp; /* where to put results */
567 {
568 char *tokenp; /* for processing tokens */
569 char *lasts;
570 char **nc_lookups;
571
572 nc_error = NC_BADFILE; /* nearly anything that breaks is for this reason */
573 stringp[strlen(stringp)-1] = '\0'; /* get rid of newline */
574 /* netid */
575 if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL) {
576 return (-1);
577 }
578
579 /* semantics */
580 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
581 return (-1);
582 }
583 if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
584 ncp->nc_semantics = NC_TPI_COTS_ORD;
585 else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
586 ncp->nc_semantics = NC_TPI_COTS;
587 else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
588 ncp->nc_semantics = NC_TPI_CLTS;
589 else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
590 ncp->nc_semantics = NC_TPI_RAW;
591 else
592 return (-1);
593
594 /* flags */
595 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
596 return (-1);
597 }
598 for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0';
599 tokenp++) {
600 switch (*tokenp) {
601 case NC_NOFLAG_C:
602 break;
603 case NC_VISIBLE_C:
604 ncp->nc_flag |= NC_VISIBLE;
605 break;
606 case NC_BROADCAST_C:
607 ncp->nc_flag |= NC_BROADCAST;
608 break;
609 default:
610 return (-1);
611 }
612 }
613 /* protocol family */
614 if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL) {
615 return (-1);
616 }
617 /* protocol name */
618 if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL) {
619 return (-1);
620 }
621 /* network device */
622 if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL) {
623 return (-1);
624 }
625 if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL) {
626 return (-1);
627 }
628 if (strcmp(tokenp, NC_NOLOOKUP) == 0) {
629 ncp->nc_nlookups = 0;
630 ncp->nc_lookups = NULL;
631 } else {
632 char *cp; /* tmp string */
633
634 if (ncp->nc_lookups != NULL) /* from last visit */
635 free(ncp->nc_lookups);
636 ncp->nc_lookups = NULL;
637 ncp->nc_nlookups = 0;
638 while ((cp = tokenp) != NULL) {
639 if ((nc_lookups = realloc(ncp->nc_lookups,
640 (ncp->nc_nlookups + 1) * sizeof *ncp->nc_lookups)) == NULL) {
641 free(ncp->nc_lookups);
642 ncp->nc_lookups = NULL;
643 return (-1);
644 }
645 tokenp = _get_next_token(cp, ',');
646 ncp->nc_lookups = nc_lookups;
647 ncp->nc_lookups[ncp->nc_nlookups++] = cp;
648 }
649 }
650 return (0);
651 }
652
653
654 /*
655 * Returns a string describing the reason for failure.
656 */
657 char *
nc_sperror()658 nc_sperror()
659 {
660 const char *message;
661
662 switch(nc_error) {
663 case NC_NONETCONFIG:
664 message = _nc_errors[0];
665 break;
666 case NC_NOMEM:
667 message = _nc_errors[1];
668 break;
669 case NC_NOTINIT:
670 message = _nc_errors[2];
671 break;
672 case NC_BADFILE:
673 message = _nc_errors[3];
674 break;
675 case NC_NOTFOUND:
676 message = _nc_errors[4];
677 break;
678 default:
679 message = "Unknown network selection error";
680 }
681 /* LINTED const castaway */
682 return ((char *)message);
683 }
684
685 /*
686 * Prints a message onto standard error describing the reason for failure.
687 */
688 void
nc_perror(s)689 nc_perror(s)
690 const char *s;
691 {
692 fprintf(stderr, "%s: %s\n", s, nc_sperror());
693 }
694
695 /*
696 * Duplicates the matched netconfig buffer.
697 */
698 static struct netconfig *
dup_ncp(ncp)699 dup_ncp(ncp)
700 struct netconfig *ncp;
701 {
702 struct netconfig *p;
703 char *tmp;
704 u_int i;
705
706 if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
707 return(NULL);
708 if ((p=(struct netconfig *)malloc(sizeof(struct netconfig))) == NULL) {
709 free(tmp);
710 return(NULL);
711 }
712 /*
713 * First we dup all the data from matched netconfig buffer. Then we
714 * adjust some of the member pointer to a pre-allocated buffer where
715 * contains part of the data.
716 * To follow the convention used in parse_ncp(), we store all the
717 * necessary information in the pre-allocated buffer and let each
718 * of the netconfig char pointer member point to the right address
719 * in the buffer.
720 */
721 *p = *ncp;
722 p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
723 tmp = strchr(tmp, '\0') + 1;
724 p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
725 tmp = strchr(tmp, '\0') + 1;
726 p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
727 tmp = strchr(tmp, '\0') + 1;
728 p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
729 p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
730 if (p->nc_lookups == NULL) {
731 free(p->nc_netid);
732 free(p);
733 return(NULL);
734 }
735 for (i=0; i < p->nc_nlookups; i++) {
736 tmp = strchr(tmp, '\0') + 1;
737 p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
738 }
739 return(p);
740 }
741