1/*	$NetBSD: getnetconfig.c,v 1.19 2011/10/15 23:00:02 christos Exp $	*/
2
3/*
4 * Copyright (c) 2010, Oracle America, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 *     * Redistributions of source code must retain the above copyright
11 *       notice, this list of conditions and the following disclaimer.
12 *     * Redistributions in binary form must reproduce the above
13 *       copyright notice, this list of conditions and the following
14 *       disclaimer in the documentation and/or other materials
15 *       provided with the distribution.
16 *     * Neither the name of the "Oracle America, 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
21 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35#if defined(LIBC_SCCS) && !defined(lint)
36#if 0
37static        char sccsid[] = "@(#)getnetconfig.c	1.12 91/12/19 SMI";
38#else
39__RCSID("$NetBSD: getnetconfig.c,v 1.19 2011/10/15 23:00:02 christos Exp $");
40#endif
41#endif
42
43/*
44 * Copyright (c) 1989 by Sun Microsystems, Inc.
45 */
46
47#include "namespace.h"
48#include "reentrant.h"
49#include <stdio.h>
50#include <assert.h>
51#include <errno.h>
52#include <netconfig.h>
53#include <stddef.h>
54#include <stdlib.h>
55#include <string.h>
56#include <rpc/rpc.h>
57#include "rpc_internal.h"
58
59#ifdef __weak_alias
60__weak_alias(getnetconfig,_getnetconfig)
61__weak_alias(setnetconfig,_setnetconfig)
62__weak_alias(endnetconfig,_endnetconfig)
63__weak_alias(getnetconfigent,_getnetconfigent)
64__weak_alias(freenetconfigent,_freenetconfigent)
65__weak_alias(nc_perror,_nc_perror)
66__weak_alias(nc_sperror,_nc_sperror)
67#endif
68
69/*
70 * The five library routines in this file provide application access to the
71 * system network configuration database, /etc/netconfig.  In addition to the
72 * netconfig database and the routines for accessing it, the environment
73 * variable NETPATH and its corresponding routines in getnetpath.c may also be
74 * used to specify the network transport to be used.
75 */
76
77
78/*
79 * netconfig errors
80 */
81
82#define NC_NONETCONFIG	ENOENT
83#define NC_NOMEM	ENOMEM
84#define NC_NOTINIT	EINVAL	    /* setnetconfig was not called first */
85#define NC_BADFILE	EBADF	    /* format for netconfig file is bad */
86
87/*
88 * semantics as strings (should be in netconfig.h)
89 */
90#define NC_TPI_CLTS_S	    "tpi_clts"
91#define	NC_TPI_COTS_S	    "tpi_cots"
92#define	NC_TPI_COTS_ORD_S   "tpi_cots_ord"
93#define	NC_TPI_RAW_S        "tpi_raw"
94
95/*
96 * flags as characters (also should be in netconfig.h)
97 */
98#define	NC_NOFLAG_C	'-'
99#define	NC_VISIBLE_C	'v'
100#define	NC_BROADCAST_C	'b'
101
102/*
103 * Character used to indicate there is no name-to-address lookup library
104 */
105#define NC_NOLOOKUP	"-"
106
107static const char * const _nc_errors[] = {
108	"Netconfig database not found",
109	"Not enough memory",
110	"Not initialized",
111	"Netconfig database has invalid format"
112};
113
114struct netconfig_info {
115	int		eof;	/* all entries has been read */
116	int		ref;	/* # of times setnetconfig() has been called */
117	struct netconfig_list	*head;	/* head of the list */
118	struct netconfig_list	*tail;	/* last of the list */
119};
120
121struct netconfig_list {
122	char			*linep;	/* hold line read from netconfig */
123	struct netconfig	*ncp;
124	struct netconfig_list	*next;
125};
126
127struct netconfig_vars {
128	    int   valid;	/* token that indicates valid netconfig_vars */
129	    int   flag;		/* first time flag */
130	    struct netconfig_list *nc_configs;
131	   			 /* pointer to the current netconfig entry */
132};
133
134#define NC_VALID	0xfeed
135#define NC_STORAGE	0xf00d
136#define NC_INVALID	0
137
138
139static int *__nc_error __P((void));
140static int parse_ncp __P((char *, struct netconfig *));
141static struct netconfig *dup_ncp __P((struct netconfig *));
142
143
144static FILE *nc_file;		/* for netconfig db */
145static struct netconfig_info	ni = { 0, 0, NULL, NULL};
146
147#define MAXNETCONFIGLINE    1000
148
149#ifdef _REENTRANT
150static thread_key_t nc_key;
151static once_t nc_once = ONCE_INITIALIZER;
152
153static void
154__nc_error_setup(void)
155{
156	thr_keycreate(&nc_key, free);
157}
158#endif
159
160static int *
161__nc_error()
162{
163#ifdef _REENTRANT
164	int *nc_addr = NULL;
165#endif
166	static int nc_error = 0;
167
168#ifdef _REENTRANT
169	if (__isthreaded == 0)
170		return &nc_error;
171	thr_once(&nc_once, __nc_error_setup);
172	nc_addr = thr_getspecific(nc_key) ;
173	if (nc_addr == NULL) {
174		nc_addr = malloc(sizeof (int));
175		if (nc_addr == NULL)
176			return &nc_error;
177		if (thr_setspecific(nc_key, (void *) nc_addr) != 0) {
178			if (nc_addr)
179				free(nc_addr);
180			return &nc_error;
181		}
182		*nc_addr = 0;
183	}
184	return nc_addr;
185#else
186	return &nc_error;
187#endif
188}
189
190#define nc_error        (*(__nc_error()))
191/*
192 * A call to setnetconfig() establishes a /etc/netconfig "session".  A session
193 * "handle" is returned on a successful call.  At the start of a session (after
194 * a call to setnetconfig()) searches through the /etc/netconfig database will
195 * proceed from the start of the file.  The session handle must be passed to
196 * getnetconfig() to parse the file.  Each call to getnetconfig() using the
197 * current handle will process one subsequent entry in /etc/netconfig.
198 * setnetconfig() must be called before the first call to getnetconfig().
199 * (Handles are used to allow for nested calls to setnetpath()).
200 *
201 * A new session is established with each call to setnetconfig(), with a new
202 * handle being returned on each call.  Previously established sessions remain
203 * active until endnetconfig() is called with that session's handle as an
204 * argument.
205 *
206 * setnetconfig() need *not* be called before a call to getnetconfigent().
207 * setnetconfig() returns a NULL pointer on failure (for example, if
208 * the netconfig database is not present).
209 */
210void *
211setnetconfig()
212{
213	struct netconfig_vars *nc_vars;
214
215	if ((nc_vars = malloc(sizeof(*nc_vars))) == NULL) {
216		return(NULL);
217	}
218
219	/*
220	 * For multiple calls, i.e. nc_file is not NULL, we just return the
221	 * handle without reopening the netconfig db.
222	 */
223	ni.ref++;
224	if ((nc_file != NULL) || (nc_file = fopen(NETCONFIG, "re")) != NULL) {
225		nc_vars->valid = NC_VALID;
226		nc_vars->flag = 0;
227		nc_vars->nc_configs = ni.head;
228		return ((void *)nc_vars);
229	}
230	ni.ref--;
231	nc_error = NC_NONETCONFIG;
232	free(nc_vars);
233	return (NULL);
234}
235
236
237/*
238 * When first called, getnetconfig() returns a pointer to the first entry in
239 * the netconfig database, formatted as a struct netconfig.  On each subsequent
240 * call, getnetconfig() returns a pointer to the next entry in the database.
241 * getnetconfig() can thus be used to search the entire netconfig file.
242 * getnetconfig() returns NULL at end of file.
243 */
244
245struct netconfig *
246getnetconfig(handlep)
247	void *handlep;
248{
249	struct netconfig_vars *ncp = (struct netconfig_vars *)handlep;
250	char *stringp;		/* tmp string pointer */
251	struct netconfig_list	*list;
252	struct netconfig *np;
253
254	/*
255	 * Verify that handle is valid
256	 */
257	if (ncp == NULL || nc_file == NULL) {
258		nc_error = NC_NOTINIT;
259		return (NULL);
260	}
261
262	switch (ncp->valid) {
263	case NC_VALID:
264		/*
265		 * If entry has already been read into the list,
266		 * we return the entry in the linked list.
267		 * If this is the first time call, check if there are any
268		 * entries in linked list.  If no entries, we need to read the
269		 * netconfig db.
270		 * If we have been here and the next entry is there, we just
271		 * return it.
272		 */
273		if (ncp->flag == 0) {	/* first time */
274			ncp->flag = 1;
275			ncp->nc_configs = ni.head;
276			if (ncp->nc_configs != NULL) /* entry already exist */
277				return(ncp->nc_configs->ncp);
278		}
279		else if (ncp->nc_configs != NULL &&
280		    ncp->nc_configs->next != NULL) {
281			ncp->nc_configs = ncp->nc_configs->next;
282			return(ncp->nc_configs->ncp);
283		}
284
285		/*
286		 * If we cannot find the entry in the list and is end of file,
287		 * we give up.
288		 */
289		if (ni.eof == 1)
290			return(NULL);
291		break;
292	default:
293		nc_error = NC_NOTINIT;
294		return (NULL);
295	}
296
297	stringp = 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	do {
312		if (fgets(stringp, MAXNETCONFIGLINE, nc_file) == NULL) {
313			free(stringp);
314			ni.eof = 1;
315			return (NULL);
316		}
317	} while (*stringp == '#');
318
319	list = malloc(sizeof(*list));
320	if (list == NULL) {
321		free(stringp);
322		return(NULL);
323	}
324	np = malloc(sizeof(*np));
325	if (np == NULL) {
326		free(stringp);
327		free(list);
328		return(NULL);
329	}
330	list->ncp = np;
331	list->next = NULL;
332	list->ncp->nc_lookups = NULL;
333	list->linep = stringp;
334	if (parse_ncp(stringp, list->ncp) == -1) {
335		free(stringp);
336		free(np);
337		free(list);
338		return (NULL);
339	} else {
340		/*
341		 * If this is the first entry that's been read, it is the
342		 * head of the list.  If not, put the entry at the end of
343		 * the list.  Reposition the current pointer of the handle to
344		 * the last entry in the list.
345		 */
346		if (ni.head == NULL)		/* first entry */
347			ni.head = ni.tail = list;
348		else {
349			ni.tail->next = list;
350			ni.tail = ni.tail->next;
351		}
352		ncp->nc_configs = ni.tail;
353		return(ni.tail->ncp);
354	}
355}
356
357/*
358 * endnetconfig() may be called to "unbind" or "close" the netconfig database
359 * when processing is complete, releasing resources for reuse.  endnetconfig()
360 * may not be called before setnetconfig().  endnetconfig() returns 0 on
361 * success and -1 on failure (for example, if setnetconfig() was not called
362 * previously).
363 */
364int
365endnetconfig(handlep)
366	void *handlep;
367{
368	struct netconfig_vars *nc_handlep = (struct netconfig_vars *)handlep;
369
370	struct netconfig_list *q, *p;
371
372	/*
373	 * Verify that handle is valid
374	 */
375	if (nc_handlep == NULL || (nc_handlep->valid != NC_VALID &&
376	    nc_handlep->valid != NC_STORAGE)) {
377		nc_error = NC_NOTINIT;
378		return (-1);
379	}
380
381	/*
382	 * Return 0 if anyone still needs it.
383	 */
384	nc_handlep->valid = NC_INVALID;
385	nc_handlep->flag = 0;
386	nc_handlep->nc_configs = NULL;
387	if (--ni.ref > 0) {
388		free(nc_handlep);
389		return(0);
390	}
391
392	/*
393	 * Noone needs these entries anymore, then frees them.
394	 * Make sure all info in netconfig_info structure has been
395	 * reinitialized.
396	 */
397	q = p = ni.head;
398	ni.eof = ni.ref = 0;
399	ni.head = NULL;
400	ni.tail = NULL;
401	while (q) {
402		p = q->next;
403		if (q->ncp->nc_lookups != NULL) free(q->ncp->nc_lookups);
404		free(q->ncp);
405		free(q->linep);
406		free(q);
407		q = p;
408	}
409	free(nc_handlep);
410
411	fclose(nc_file);
412	nc_file = NULL;
413	return (0);
414}
415
416/*
417 * getnetconfigent(netid) returns a pointer to the struct netconfig structure
418 * corresponding to netid.  It returns NULL if netid is invalid (that is, does
419 * not name an entry in the netconfig database).  It returns NULL and sets
420 * errno in case of failure (for example, if the netconfig database cannot be
421 * opened).
422 */
423
424struct netconfig *
425getnetconfigent(netid)
426	const char *netid;
427{
428	FILE *file;			/* NETCONFIG db's file pointer */
429	char *linep;			/* holds current netconfig line */
430	char *stringp;			/* temporary string pointer */
431	struct netconfig *ncp = NULL;   /* returned value */
432	struct netconfig_list *list;	/* pointer to cache list */
433
434	if (netid == NULL || strlen(netid) == 0)
435		return (NULL);
436
437	/*
438	 * Look up table if the entries have already been read and parsed in
439	 * getnetconfig(), then copy this entry into a buffer and return it.
440	 * If we cannot find the entry in the current list and there are more
441	 * entries in the netconfig db that has not been read, we then read the
442	 * db and try find the match netid.
443	 * If all the netconfig db has been read and placed into the list and
444	 * there is no match for the netid, return NULL.
445	 */
446	if (ni.head != NULL) {
447		for (list = ni.head; list; list = list->next) {
448			if (strcmp(list->ncp->nc_netid, netid) == 0)
449			    return(dup_ncp(list->ncp));
450		}
451		if (ni.eof == 1)	/* that's all the entries */
452			return(NULL);
453	}
454
455	if ((file = fopen(NETCONFIG, "r")) == NULL)
456	    return (NULL);
457
458	if ((linep = malloc(MAXNETCONFIGLINE)) == NULL) {
459		fclose(file);
460		return (NULL);
461	}
462	do {
463		ptrdiff_t len;
464		char *tmpp;	/* tmp string pointer */
465
466		do {
467			if ((stringp = fgets(linep, MAXNETCONFIGLINE, file))
468			    == NULL)
469				break;
470		} while (*stringp == '#');
471		if (stringp == NULL)	/* eof */
472			break;
473		if ((tmpp = strpbrk(stringp, "\t ")) == NULL) {
474					/* can't parse file */
475			nc_error = NC_BADFILE;
476			break;
477		}
478		if (strlen(netid) == (size_t) (len = tmpp - stringp) &&	/* a match */
479		    strncmp(stringp, netid, (size_t)len) == 0) {
480			if ((ncp = malloc(sizeof(*ncp))) == NULL)
481				break;
482			ncp->nc_lookups = NULL;
483			if (parse_ncp(linep, ncp) == -1) {
484				free(ncp);
485				ncp = NULL;
486			}
487			break;
488		}
489	} while (stringp != NULL);
490	if (ncp == NULL)
491		free(linep);
492	fclose(file);
493	return(ncp);
494}
495
496/*
497 * freenetconfigent(netconfigp) frees the netconfig structure pointed to by
498 * netconfigp (previously returned by getnetconfigent()).
499 */
500
501void
502freenetconfigent(netconfigp)
503	struct netconfig *netconfigp;
504{
505	if (netconfigp != NULL) {
506				/* holds all netconfigp's strings */
507		free(netconfigp->nc_netid);
508		if (netconfigp->nc_lookups != NULL)
509			free(netconfigp->nc_lookups);
510		free(netconfigp);
511	}
512}
513
514/*
515 * Parse line and stuff it in a struct netconfig
516 * Typical line might look like:
517 *	udp tpi_cots vb inet udp /dev/udp /usr/lib/ip.so,/usr/local/ip.so
518 *
519 * We return -1 if any of the tokens don't parse, or malloc fails.
520 *
521 * Note that we modify stringp (putting NULLs after tokens) and
522 * we set the ncp's string field pointers to point to these tokens within
523 * stringp.
524 */
525
526static int
527parse_ncp(stringp, ncp)
528	char *stringp;		/* string to parse */
529	struct netconfig *ncp;	/* where to put results */
530{
531	char    *tokenp;	/* for processing tokens */
532	char    *lasts;
533
534	_DIAGASSERT(stringp != NULL);
535	_DIAGASSERT(ncp != NULL);
536
537	nc_error = NC_BADFILE;
538			/* nearly anything that breaks is for this reason */
539	stringp[strlen(stringp)-1] = '\0';	/* get rid of newline */
540	/* netid */
541	if ((ncp->nc_netid = strtok_r(stringp, "\t ", &lasts)) == NULL)
542		return (-1);
543
544	/* semantics */
545	if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL)
546		return (-1);
547	if (strcmp(tokenp, NC_TPI_COTS_ORD_S) == 0)
548		ncp->nc_semantics = NC_TPI_COTS_ORD;
549	else if (strcmp(tokenp, NC_TPI_COTS_S) == 0)
550		ncp->nc_semantics = NC_TPI_COTS;
551	else if (strcmp(tokenp, NC_TPI_CLTS_S) == 0)
552		ncp->nc_semantics = NC_TPI_CLTS;
553	else if (strcmp(tokenp, NC_TPI_RAW_S) == 0)
554		ncp->nc_semantics = NC_TPI_RAW;
555	else
556		return (-1);
557
558	/* flags */
559	if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL)
560		return (-1);
561	for (ncp->nc_flag = NC_NOFLAG; *tokenp != '\0'; tokenp++) {
562		switch (*tokenp) {
563		case NC_NOFLAG_C:
564			break;
565		case NC_VISIBLE_C:
566			ncp->nc_flag |= NC_VISIBLE;
567			break;
568		case NC_BROADCAST_C:
569			ncp->nc_flag |= NC_BROADCAST;
570			break;
571		default:
572			return (-1);
573		}
574	}
575	/* protocol family */
576	if ((ncp->nc_protofmly = strtok_r(NULL, "\t ", &lasts)) == NULL)
577		return (-1);
578	/* protocol name */
579	if ((ncp->nc_proto = strtok_r(NULL, "\t ", &lasts)) == NULL)
580		return (-1);
581	/* network device */
582	if ((ncp->nc_device = strtok_r(NULL, "\t ", &lasts)) == NULL)
583		return (-1);
584	if ((tokenp = strtok_r(NULL, "\t ", &lasts)) == NULL)
585		return (-1);
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		/* preallocate one string pointer */
595		ncp->nc_lookups = malloc(sizeof(*ncp->nc_lookups));
596		ncp->nc_nlookups = 0;
597		while ((cp = tokenp) != NULL) {
598			tokenp = _get_next_token(cp, ',');
599			ncp->nc_lookups[(size_t)ncp->nc_nlookups++] = cp;
600			ncp->nc_lookups = (char **)
601			    realloc(ncp->nc_lookups,
602			    (size_t)(ncp->nc_nlookups+1) *sizeof(char *));
603						/* for next loop */
604		}
605	}
606	return (0);
607}
608
609/*
610 * Returns a string describing the reason for failure.
611 */
612char *
613nc_sperror()
614{
615	const char *message;
616
617	switch(nc_error) {
618	case NC_NONETCONFIG:
619		message = _nc_errors[0];
620		break;
621	case NC_NOMEM:
622		message = _nc_errors[1];
623		break;
624	case NC_NOTINIT:
625		message = _nc_errors[2];
626		break;
627	case NC_BADFILE:
628		message = _nc_errors[3];
629		break;
630	default:
631		message = "Unknown network selection error";
632	}
633	return __UNCONST(message);
634}
635
636/*
637 * Prints a message onto standard error describing the reason for failure.
638 */
639void
640nc_perror(s)
641	const char *s;
642{
643
644	_DIAGASSERT(s != NULL);
645
646	fprintf(stderr, "%s: %s", s, nc_sperror());
647}
648
649/*
650 * Duplicates the matched netconfig buffer.
651 */
652static struct netconfig *
653	dup_ncp(ncp)
654	struct netconfig	*ncp;
655{
656	struct netconfig	*p;
657	char	*tmp;
658	u_int	i;
659
660	_DIAGASSERT(ncp != NULL);
661
662	if ((tmp = malloc(MAXNETCONFIGLINE)) == NULL)
663		return(NULL);
664	if ((p = malloc(sizeof(*p))) == 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 = 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] = strcpy(tmp,ncp->nc_lookups[i]);
694	}
695	return(p);
696}
697