xref: /onnv-gate/usr/src/cmd/fs.d/nfs/mountd/rmtab.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * rmtab.c
24*0Sstevel@tonic-gate  *
25*0Sstevel@tonic-gate  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26*0Sstevel@tonic-gate  * Use is subject to license terms.
27*0Sstevel@tonic-gate  */
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate #include <stdio.h>
32*0Sstevel@tonic-gate #include <stdlib.h>
33*0Sstevel@tonic-gate #include <ctype.h>
34*0Sstevel@tonic-gate #include <sys/types.h>
35*0Sstevel@tonic-gate #include <string.h>
36*0Sstevel@tonic-gate #include <sys/param.h>
37*0Sstevel@tonic-gate #include <sys/stat.h>
38*0Sstevel@tonic-gate #include <sys/file.h>
39*0Sstevel@tonic-gate #include <sys/time.h>
40*0Sstevel@tonic-gate #include <errno.h>
41*0Sstevel@tonic-gate #include <rpcsvc/mount.h>
42*0Sstevel@tonic-gate #include <sys/pathconf.h>
43*0Sstevel@tonic-gate #include <sys/systeminfo.h>
44*0Sstevel@tonic-gate #include <sys/utsname.h>
45*0Sstevel@tonic-gate #include <signal.h>
46*0Sstevel@tonic-gate #include <locale.h>
47*0Sstevel@tonic-gate #include <unistd.h>
48*0Sstevel@tonic-gate #include <thread.h>
49*0Sstevel@tonic-gate #include <syslog.h>
50*0Sstevel@tonic-gate #include <sys/socket.h>
51*0Sstevel@tonic-gate #include <netinet/in.h>
52*0Sstevel@tonic-gate #include <arpa/inet.h>
53*0Sstevel@tonic-gate #include "../lib/sharetab.h"
54*0Sstevel@tonic-gate #include "hashset.h"
55*0Sstevel@tonic-gate #include "mountd.h"
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate static char RMTAB[] = "/etc/rmtab";
58*0Sstevel@tonic-gate static FILE *rmtabf = NULL;
59*0Sstevel@tonic-gate 
60*0Sstevel@tonic-gate /*
61*0Sstevel@tonic-gate  * There is nothing magic about the value selected here. Too low,
62*0Sstevel@tonic-gate  * and mountd might spend too much time rewriting the rmtab file.
63*0Sstevel@tonic-gate  * Too high, it won't do it frequently enough.
64*0Sstevel@tonic-gate  */
65*0Sstevel@tonic-gate static int rmtab_del_thresh = 250;
66*0Sstevel@tonic-gate 
67*0Sstevel@tonic-gate #define	RMTAB_TOOMANY_DELETED()	\
68*0Sstevel@tonic-gate 	((rmtab_deleted > rmtab_del_thresh) && (rmtab_deleted > rmtab_inuse))
69*0Sstevel@tonic-gate 
70*0Sstevel@tonic-gate /*
71*0Sstevel@tonic-gate  * mountd's version of a "struct mountlist". It is the same except
72*0Sstevel@tonic-gate  * for the added ml_pos field.
73*0Sstevel@tonic-gate  */
74*0Sstevel@tonic-gate struct mntentry {
75*0Sstevel@tonic-gate 	char  *m_host;
76*0Sstevel@tonic-gate 	char  *m_path;
77*0Sstevel@tonic-gate 	long   m_pos;
78*0Sstevel@tonic-gate };
79*0Sstevel@tonic-gate 
80*0Sstevel@tonic-gate static HASHSET mntlist;
81*0Sstevel@tonic-gate 
82*0Sstevel@tonic-gate static int mntentry_equal(const void *, const void *);
83*0Sstevel@tonic-gate static uint32_t mntentry_hash(const void *);
84*0Sstevel@tonic-gate static int mntlist_contains(char *, char *);
85*0Sstevel@tonic-gate static void rmtab_delete(long);
86*0Sstevel@tonic-gate static long rmtab_insert(char *, char *);
87*0Sstevel@tonic-gate static void rmtab_rewrite(void);
88*0Sstevel@tonic-gate static void rmtab_parse(char *buf);
89*0Sstevel@tonic-gate static bool_t xdr_mntlistencode(XDR * xdrs, HASHSET * mntlist);
90*0Sstevel@tonic-gate 
91*0Sstevel@tonic-gate #define	exstrdup(s) \
92*0Sstevel@tonic-gate 	strcpy(exmalloc(strlen(s)+1), s)
93*0Sstevel@tonic-gate 
94*0Sstevel@tonic-gate 
95*0Sstevel@tonic-gate static int rmtab_inuse;
96*0Sstevel@tonic-gate static int rmtab_deleted;
97*0Sstevel@tonic-gate 
98*0Sstevel@tonic-gate static rwlock_t rmtab_lock;	/* lock to protect rmtab list */
99*0Sstevel@tonic-gate 
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate /*
102*0Sstevel@tonic-gate  * Check whether the given client/path combination
103*0Sstevel@tonic-gate  * already appears in the mount list.
104*0Sstevel@tonic-gate  */
105*0Sstevel@tonic-gate 
106*0Sstevel@tonic-gate static int
107*0Sstevel@tonic-gate mntlist_contains(char *host, char *path)
108*0Sstevel@tonic-gate {
109*0Sstevel@tonic-gate 	struct mntentry m;
110*0Sstevel@tonic-gate 
111*0Sstevel@tonic-gate 	m.m_host = host;
112*0Sstevel@tonic-gate 	m.m_path = path;
113*0Sstevel@tonic-gate 
114*0Sstevel@tonic-gate 	return (h_get(mntlist, &m) != NULL);
115*0Sstevel@tonic-gate }
116*0Sstevel@tonic-gate 
117*0Sstevel@tonic-gate 
118*0Sstevel@tonic-gate /*
119*0Sstevel@tonic-gate  *  Add an entry to the mount list.
120*0Sstevel@tonic-gate  *  First check whether it's there already - the client
121*0Sstevel@tonic-gate  *  may have crashed and be rebooting.
122*0Sstevel@tonic-gate  */
123*0Sstevel@tonic-gate 
124*0Sstevel@tonic-gate static void
125*0Sstevel@tonic-gate mntlist_insert(char *host, char *path)
126*0Sstevel@tonic-gate {
127*0Sstevel@tonic-gate 	if (!mntlist_contains(host, path)) {
128*0Sstevel@tonic-gate 		struct mntentry *m;
129*0Sstevel@tonic-gate 
130*0Sstevel@tonic-gate 		m = exmalloc(sizeof (struct mntentry));
131*0Sstevel@tonic-gate 
132*0Sstevel@tonic-gate 		m->m_host = exstrdup(host);
133*0Sstevel@tonic-gate 		m->m_path = exstrdup(path);
134*0Sstevel@tonic-gate 		m->m_pos = rmtab_insert(host, path);
135*0Sstevel@tonic-gate 		(void) h_put(mntlist, m);
136*0Sstevel@tonic-gate 	}
137*0Sstevel@tonic-gate }
138*0Sstevel@tonic-gate 
139*0Sstevel@tonic-gate void
140*0Sstevel@tonic-gate mntlist_new(char *host, char *path)
141*0Sstevel@tonic-gate {
142*0Sstevel@tonic-gate 	(void) rw_wrlock(&rmtab_lock);
143*0Sstevel@tonic-gate 	mntlist_insert(host, path);
144*0Sstevel@tonic-gate 	(void) rw_unlock(&rmtab_lock);
145*0Sstevel@tonic-gate }
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate /*
148*0Sstevel@tonic-gate  * Delete an entry from the mount list.
149*0Sstevel@tonic-gate  */
150*0Sstevel@tonic-gate 
151*0Sstevel@tonic-gate void
152*0Sstevel@tonic-gate mntlist_delete(char *host, char *path)
153*0Sstevel@tonic-gate {
154*0Sstevel@tonic-gate 	struct mntentry *m, mm;
155*0Sstevel@tonic-gate 
156*0Sstevel@tonic-gate 	mm.m_host = host;
157*0Sstevel@tonic-gate 	mm.m_path = path;
158*0Sstevel@tonic-gate 
159*0Sstevel@tonic-gate 	(void) rw_wrlock(&rmtab_lock);
160*0Sstevel@tonic-gate 
161*0Sstevel@tonic-gate 	if (m = (struct mntentry *)h_get(mntlist, &mm)) {
162*0Sstevel@tonic-gate 		rmtab_delete(m->m_pos);
163*0Sstevel@tonic-gate 
164*0Sstevel@tonic-gate 		(void) h_delete(mntlist, m);
165*0Sstevel@tonic-gate 
166*0Sstevel@tonic-gate 		free(m->m_path);
167*0Sstevel@tonic-gate 		free(m->m_host);
168*0Sstevel@tonic-gate 		free(m);
169*0Sstevel@tonic-gate 
170*0Sstevel@tonic-gate 		if (RMTAB_TOOMANY_DELETED())
171*0Sstevel@tonic-gate 			rmtab_rewrite();
172*0Sstevel@tonic-gate 	}
173*0Sstevel@tonic-gate 	(void) rw_unlock(&rmtab_lock);
174*0Sstevel@tonic-gate }
175*0Sstevel@tonic-gate 
176*0Sstevel@tonic-gate /*
177*0Sstevel@tonic-gate  * Delete all entries for a host from the mount list
178*0Sstevel@tonic-gate  */
179*0Sstevel@tonic-gate 
180*0Sstevel@tonic-gate void
181*0Sstevel@tonic-gate mntlist_delete_all(char *host)
182*0Sstevel@tonic-gate {
183*0Sstevel@tonic-gate 	HASHSET_ITERATOR iterator;
184*0Sstevel@tonic-gate 	struct mntentry *m;
185*0Sstevel@tonic-gate 
186*0Sstevel@tonic-gate 	(void) rw_wrlock(&rmtab_lock);
187*0Sstevel@tonic-gate 
188*0Sstevel@tonic-gate 	iterator = h_iterator(mntlist);
189*0Sstevel@tonic-gate 
190*0Sstevel@tonic-gate 	while (m = (struct mntentry *)h_next(iterator)) {
191*0Sstevel@tonic-gate 		if (strcasecmp(m->m_host, host))
192*0Sstevel@tonic-gate 			continue;
193*0Sstevel@tonic-gate 
194*0Sstevel@tonic-gate 		rmtab_delete(m->m_pos);
195*0Sstevel@tonic-gate 
196*0Sstevel@tonic-gate 		(void) h_delete(mntlist, m);
197*0Sstevel@tonic-gate 
198*0Sstevel@tonic-gate 		free(m->m_path);
199*0Sstevel@tonic-gate 		free(m->m_host);
200*0Sstevel@tonic-gate 		free(m);
201*0Sstevel@tonic-gate 	}
202*0Sstevel@tonic-gate 
203*0Sstevel@tonic-gate 	if (RMTAB_TOOMANY_DELETED())
204*0Sstevel@tonic-gate 		rmtab_rewrite();
205*0Sstevel@tonic-gate 
206*0Sstevel@tonic-gate 	(void) rw_unlock(&rmtab_lock);
207*0Sstevel@tonic-gate 
208*0Sstevel@tonic-gate 	if (iterator != NULL)
209*0Sstevel@tonic-gate 		free(iterator);
210*0Sstevel@tonic-gate }
211*0Sstevel@tonic-gate 
212*0Sstevel@tonic-gate /*
213*0Sstevel@tonic-gate  * Equivalent to xdr_mountlist from librpcsvc but for HASHSET
214*0Sstevel@tonic-gate  * rather that for a linked list. It is used only to encode data
215*0Sstevel@tonic-gate  * from HASHSET before sending it over the wire.
216*0Sstevel@tonic-gate  */
217*0Sstevel@tonic-gate 
218*0Sstevel@tonic-gate static bool_t
219*0Sstevel@tonic-gate xdr_mntlistencode(XDR *xdrs, HASHSET *mntlist)
220*0Sstevel@tonic-gate {
221*0Sstevel@tonic-gate 	HASHSET_ITERATOR iterator = h_iterator(*mntlist);
222*0Sstevel@tonic-gate 
223*0Sstevel@tonic-gate 	for (;;) {
224*0Sstevel@tonic-gate 		struct mntentry *m = (struct mntentry *)h_next(iterator);
225*0Sstevel@tonic-gate 		bool_t more_data = (m != NULL);
226*0Sstevel@tonic-gate 
227*0Sstevel@tonic-gate 		if (!xdr_bool(xdrs, &more_data)) {
228*0Sstevel@tonic-gate 			if (iterator != NULL)
229*0Sstevel@tonic-gate 				free(iterator);
230*0Sstevel@tonic-gate 			return (FALSE);
231*0Sstevel@tonic-gate 		}
232*0Sstevel@tonic-gate 
233*0Sstevel@tonic-gate 		if (!more_data)
234*0Sstevel@tonic-gate 			break;
235*0Sstevel@tonic-gate 
236*0Sstevel@tonic-gate 		if ((!xdr_name(xdrs, &m->m_host)) ||
237*0Sstevel@tonic-gate 			(!xdr_dirpath(xdrs, &m->m_path))) {
238*0Sstevel@tonic-gate 			if (iterator != NULL)
239*0Sstevel@tonic-gate 				free(iterator);
240*0Sstevel@tonic-gate 			return (FALSE);
241*0Sstevel@tonic-gate 		}
242*0Sstevel@tonic-gate 
243*0Sstevel@tonic-gate 	}
244*0Sstevel@tonic-gate 
245*0Sstevel@tonic-gate 	if (iterator != NULL)
246*0Sstevel@tonic-gate 		free(iterator);
247*0Sstevel@tonic-gate 
248*0Sstevel@tonic-gate 	return (TRUE);
249*0Sstevel@tonic-gate }
250*0Sstevel@tonic-gate 
251*0Sstevel@tonic-gate void
252*0Sstevel@tonic-gate mntlist_send(SVCXPRT *transp)
253*0Sstevel@tonic-gate {
254*0Sstevel@tonic-gate 	(void) rw_rdlock(&rmtab_lock);
255*0Sstevel@tonic-gate 
256*0Sstevel@tonic-gate 	errno = 0;
257*0Sstevel@tonic-gate 	if (!svc_sendreply(transp, xdr_mntlistencode, (char *)&mntlist))
258*0Sstevel@tonic-gate 		log_cant_reply(transp);
259*0Sstevel@tonic-gate 
260*0Sstevel@tonic-gate 	(void) rw_unlock(&rmtab_lock);
261*0Sstevel@tonic-gate }
262*0Sstevel@tonic-gate 
263*0Sstevel@tonic-gate /*
264*0Sstevel@tonic-gate  * Compute a hash for an mntlist entry.
265*0Sstevel@tonic-gate  */
266*0Sstevel@tonic-gate #define	SPACE		(uchar_t)0x20
267*0Sstevel@tonic-gate #define	HASH_BITS	3	/* Num. of bits to shift the hash  */
268*0Sstevel@tonic-gate #define	HASH_MAXHOST	6	/* Max. number of characters from a hostname */
269*0Sstevel@tonic-gate #define	HASH_MAXPATH	3	/* Max. number of characters from a pathname */
270*0Sstevel@tonic-gate 
271*0Sstevel@tonic-gate /*
272*0Sstevel@tonic-gate  * Compute a 32 bit hash value for an mntlist entry.
273*0Sstevel@tonic-gate  * We consider only first HASH_MAXHOST characters from the host part.
274*0Sstevel@tonic-gate  * We skip the first character in the path part (usually /), and we
275*0Sstevel@tonic-gate  * consider at most HASH_MAXPATH following characters.
276*0Sstevel@tonic-gate  * We shift the hash value by HASH_BITS after each character.
277*0Sstevel@tonic-gate  */
278*0Sstevel@tonic-gate 
279*0Sstevel@tonic-gate static uint32_t
280*0Sstevel@tonic-gate mntentry_hash(const void *p)
281*0Sstevel@tonic-gate {
282*0Sstevel@tonic-gate 	struct mntentry *m = (struct mntentry *)p;
283*0Sstevel@tonic-gate 	uchar_t *s;
284*0Sstevel@tonic-gate 	uint_t i, sum = 0;
285*0Sstevel@tonic-gate 
286*0Sstevel@tonic-gate 	for (i = 0, s = (uchar_t *)m->m_host; *s && i < HASH_MAXHOST; i++) {
287*0Sstevel@tonic-gate 		uchar_t ls = tolower(*s);
288*0Sstevel@tonic-gate 		sum <<= HASH_BITS;
289*0Sstevel@tonic-gate 		sum += ls - SPACE;
290*0Sstevel@tonic-gate 		*s++;
291*0Sstevel@tonic-gate 	}
292*0Sstevel@tonic-gate 
293*0Sstevel@tonic-gate 	/*
294*0Sstevel@tonic-gate 	 * The first character is usually '/'.
295*0Sstevel@tonic-gate 	 * Start with the next character.
296*0Sstevel@tonic-gate 	 */
297*0Sstevel@tonic-gate 	for (i = 0, s = (uchar_t *)m->m_path+1; *s && i < HASH_MAXPATH; i++) {
298*0Sstevel@tonic-gate 		sum <<= HASH_BITS;
299*0Sstevel@tonic-gate 		sum += *s++ - SPACE;
300*0Sstevel@tonic-gate 	}
301*0Sstevel@tonic-gate 
302*0Sstevel@tonic-gate 	return (sum);
303*0Sstevel@tonic-gate }
304*0Sstevel@tonic-gate 
305*0Sstevel@tonic-gate /*
306*0Sstevel@tonic-gate  * Compare mntlist entries.
307*0Sstevel@tonic-gate  * The comparison ignores a value of m_pos.
308*0Sstevel@tonic-gate  */
309*0Sstevel@tonic-gate 
310*0Sstevel@tonic-gate static int
311*0Sstevel@tonic-gate mntentry_equal(const void *p1, const void *p2)
312*0Sstevel@tonic-gate {
313*0Sstevel@tonic-gate 	struct mntentry *m1 = (struct mntentry *)p1;
314*0Sstevel@tonic-gate 	struct mntentry *m2 = (struct mntentry *)p2;
315*0Sstevel@tonic-gate 
316*0Sstevel@tonic-gate 	return ((strcasecmp(m1->m_host, m2->m_host) ||
317*0Sstevel@tonic-gate 		strcmp(m1->m_path, m2->m_path)) ? 0 : 1);
318*0Sstevel@tonic-gate }
319*0Sstevel@tonic-gate 
320*0Sstevel@tonic-gate /*
321*0Sstevel@tonic-gate  * Rewrite /etc/rmtab with a current content of mntlist.
322*0Sstevel@tonic-gate  */
323*0Sstevel@tonic-gate static void
324*0Sstevel@tonic-gate rmtab_rewrite()
325*0Sstevel@tonic-gate {
326*0Sstevel@tonic-gate 	if (rmtabf)
327*0Sstevel@tonic-gate 		(void) fclose(rmtabf);
328*0Sstevel@tonic-gate 
329*0Sstevel@tonic-gate 	/* Rewrite the file. */
330*0Sstevel@tonic-gate 	if (rmtabf = fopen(RMTAB, "w+")) {
331*0Sstevel@tonic-gate 		HASHSET_ITERATOR iterator;
332*0Sstevel@tonic-gate 		struct mntentry *m;
333*0Sstevel@tonic-gate 
334*0Sstevel@tonic-gate 		(void) fchmod(fileno(rmtabf),
335*0Sstevel@tonic-gate 		    (S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH));
336*0Sstevel@tonic-gate 		rmtab_inuse = rmtab_deleted = 0;
337*0Sstevel@tonic-gate 
338*0Sstevel@tonic-gate 		iterator = h_iterator(mntlist);
339*0Sstevel@tonic-gate 
340*0Sstevel@tonic-gate 		while (m = (struct mntentry *)h_next(iterator))
341*0Sstevel@tonic-gate 			m->m_pos = rmtab_insert(m->m_host, m->m_path);
342*0Sstevel@tonic-gate 		if (iterator != NULL)
343*0Sstevel@tonic-gate 			free(iterator);
344*0Sstevel@tonic-gate 	}
345*0Sstevel@tonic-gate }
346*0Sstevel@tonic-gate 
347*0Sstevel@tonic-gate /*
348*0Sstevel@tonic-gate  * Parse the content of /etc/rmtab and insert the entries into mntlist.
349*0Sstevel@tonic-gate  * The buffer s should be ended with a NUL char.
350*0Sstevel@tonic-gate  */
351*0Sstevel@tonic-gate 
352*0Sstevel@tonic-gate static void
353*0Sstevel@tonic-gate rmtab_parse(char *s)
354*0Sstevel@tonic-gate {
355*0Sstevel@tonic-gate 	char  *host;
356*0Sstevel@tonic-gate 	char  *path;
357*0Sstevel@tonic-gate 	char  *tmp;
358*0Sstevel@tonic-gate 	struct in6_addr ipv6addr;
359*0Sstevel@tonic-gate 
360*0Sstevel@tonic-gate host_part:
361*0Sstevel@tonic-gate 	if (*s == '#')
362*0Sstevel@tonic-gate 		goto skip_rest;
363*0Sstevel@tonic-gate 
364*0Sstevel@tonic-gate 	host = s;
365*0Sstevel@tonic-gate 	for (;;) {
366*0Sstevel@tonic-gate 		switch (*s++) {
367*0Sstevel@tonic-gate 		case '\0':
368*0Sstevel@tonic-gate 			return;
369*0Sstevel@tonic-gate 		case '\n':
370*0Sstevel@tonic-gate 			goto host_part;
371*0Sstevel@tonic-gate 		case ':':
372*0Sstevel@tonic-gate 			s[-1] = '\0';
373*0Sstevel@tonic-gate 			goto path_part;
374*0Sstevel@tonic-gate 		case '[':
375*0Sstevel@tonic-gate 			tmp = strchr(s, ']');
376*0Sstevel@tonic-gate 			if (tmp) {
377*0Sstevel@tonic-gate 				*tmp = '\0';
378*0Sstevel@tonic-gate 				if (inet_pton(AF_INET6, s, &ipv6addr) > 0) {
379*0Sstevel@tonic-gate 					host = s;
380*0Sstevel@tonic-gate 					s = ++tmp;
381*0Sstevel@tonic-gate 				} else
382*0Sstevel@tonic-gate 					*tmp = ']';
383*0Sstevel@tonic-gate 			}
384*0Sstevel@tonic-gate 		default:
385*0Sstevel@tonic-gate 			continue;
386*0Sstevel@tonic-gate 		}
387*0Sstevel@tonic-gate 	}
388*0Sstevel@tonic-gate 
389*0Sstevel@tonic-gate path_part:
390*0Sstevel@tonic-gate 	path = s;
391*0Sstevel@tonic-gate 	for (;;) {
392*0Sstevel@tonic-gate 		switch (*s++) {
393*0Sstevel@tonic-gate 		case '\n':
394*0Sstevel@tonic-gate 			s[-1] = '\0';
395*0Sstevel@tonic-gate 			if (*host && *path)
396*0Sstevel@tonic-gate 				mntlist_insert(host, path);
397*0Sstevel@tonic-gate 			goto host_part;
398*0Sstevel@tonic-gate 		case '\0':
399*0Sstevel@tonic-gate 			if (*host && *path)
400*0Sstevel@tonic-gate 				mntlist_insert(host, path);
401*0Sstevel@tonic-gate 			return;
402*0Sstevel@tonic-gate 		default:
403*0Sstevel@tonic-gate 			continue;
404*0Sstevel@tonic-gate 		}
405*0Sstevel@tonic-gate 	}
406*0Sstevel@tonic-gate 
407*0Sstevel@tonic-gate skip_rest:
408*0Sstevel@tonic-gate 	for (;;) {
409*0Sstevel@tonic-gate 		switch (*++s) {
410*0Sstevel@tonic-gate 		case '\n':
411*0Sstevel@tonic-gate 			goto host_part;
412*0Sstevel@tonic-gate 		case '\0':
413*0Sstevel@tonic-gate 			return;
414*0Sstevel@tonic-gate 		default:
415*0Sstevel@tonic-gate 			continue;
416*0Sstevel@tonic-gate 		}
417*0Sstevel@tonic-gate 	}
418*0Sstevel@tonic-gate }
419*0Sstevel@tonic-gate 
420*0Sstevel@tonic-gate /*
421*0Sstevel@tonic-gate  * Read in contents of rmtab.
422*0Sstevel@tonic-gate  * Call rmtab_parse to parse the file and store entries in mntlist.
423*0Sstevel@tonic-gate  * Rewrites the file to get rid of unused entries.
424*0Sstevel@tonic-gate  */
425*0Sstevel@tonic-gate 
426*0Sstevel@tonic-gate #define	RMTAB_LOADLEN	(16*2024)	/* Max bytes to read at a time */
427*0Sstevel@tonic-gate 
428*0Sstevel@tonic-gate void
429*0Sstevel@tonic-gate rmtab_load()
430*0Sstevel@tonic-gate {
431*0Sstevel@tonic-gate 	FILE *fp;
432*0Sstevel@tonic-gate 
433*0Sstevel@tonic-gate 	(void) rwlock_init(&rmtab_lock, USYNC_THREAD, NULL);
434*0Sstevel@tonic-gate 
435*0Sstevel@tonic-gate 	/*
436*0Sstevel@tonic-gate 	 * Don't need to lock the list at this point
437*0Sstevel@tonic-gate 	 * because there's only a single thread running.
438*0Sstevel@tonic-gate 	 */
439*0Sstevel@tonic-gate 	mntlist = h_create(mntentry_hash, mntentry_equal, 101, 0.75);
440*0Sstevel@tonic-gate 
441*0Sstevel@tonic-gate 	if (fp = fopen(RMTAB, "r")) {
442*0Sstevel@tonic-gate 		char buf[RMTAB_LOADLEN+1];
443*0Sstevel@tonic-gate 		size_t len;
444*0Sstevel@tonic-gate 
445*0Sstevel@tonic-gate 		/*
446*0Sstevel@tonic-gate 		 * Read at most RMTAB_LOADLEN bytes from /etc/rmtab.
447*0Sstevel@tonic-gate 		 * - if fread returns RMTAB_LOADLEN we can be in the middle
448*0Sstevel@tonic-gate 		 *   of a line so change the last newline character into NUL
449*0Sstevel@tonic-gate 		 *   and seek back to the next character after newline.
450*0Sstevel@tonic-gate 		 * - otherwise set NUL behind the last character read.
451*0Sstevel@tonic-gate 		 */
452*0Sstevel@tonic-gate 		while ((len = fread(buf, 1, RMTAB_LOADLEN, fp)) > 0) {
453*0Sstevel@tonic-gate 			if (len == RMTAB_LOADLEN) {
454*0Sstevel@tonic-gate 				int i;
455*0Sstevel@tonic-gate 
456*0Sstevel@tonic-gate 				for (i = 1; i < len; i++) {
457*0Sstevel@tonic-gate 					if (buf[len-i] == '\n') {
458*0Sstevel@tonic-gate 						buf[len-i] = '\0';
459*0Sstevel@tonic-gate 						(void) fseek(fp, -i+1,
460*0Sstevel@tonic-gate 							    SEEK_CUR);
461*0Sstevel@tonic-gate 						goto parse;
462*0Sstevel@tonic-gate 					}
463*0Sstevel@tonic-gate 				}
464*0Sstevel@tonic-gate 			}
465*0Sstevel@tonic-gate 
466*0Sstevel@tonic-gate 			/* Put a NUL character at the end of buffer */
467*0Sstevel@tonic-gate 			buf[len] = '\0';
468*0Sstevel@tonic-gate 	parse:
469*0Sstevel@tonic-gate 			rmtab_parse(buf);
470*0Sstevel@tonic-gate 		}
471*0Sstevel@tonic-gate 		(void) fclose(fp);
472*0Sstevel@tonic-gate 	}
473*0Sstevel@tonic-gate 	rmtab_rewrite();
474*0Sstevel@tonic-gate }
475*0Sstevel@tonic-gate 
476*0Sstevel@tonic-gate /*
477*0Sstevel@tonic-gate  * Write an entry at the current location in rmtab
478*0Sstevel@tonic-gate  * for the given client and path.
479*0Sstevel@tonic-gate  *
480*0Sstevel@tonic-gate  * Returns the starting position of the entry
481*0Sstevel@tonic-gate  * or -1 if there was an error.
482*0Sstevel@tonic-gate  */
483*0Sstevel@tonic-gate 
484*0Sstevel@tonic-gate long
485*0Sstevel@tonic-gate rmtab_insert(char *host, char *path)
486*0Sstevel@tonic-gate {
487*0Sstevel@tonic-gate 	long   pos;
488*0Sstevel@tonic-gate 	struct in6_addr ipv6addr;
489*0Sstevel@tonic-gate 
490*0Sstevel@tonic-gate 	if (rmtabf == NULL || fseek(rmtabf, 0L, 2) == -1) {
491*0Sstevel@tonic-gate 		return (-1);
492*0Sstevel@tonic-gate 	}
493*0Sstevel@tonic-gate 	pos = ftell(rmtabf);
494*0Sstevel@tonic-gate 
495*0Sstevel@tonic-gate 	/*
496*0Sstevel@tonic-gate 	 * Check if host is an IPv6 literal
497*0Sstevel@tonic-gate 	 */
498*0Sstevel@tonic-gate 
499*0Sstevel@tonic-gate 	if (inet_pton(AF_INET6, host, &ipv6addr) > 0) {
500*0Sstevel@tonic-gate 		if (fprintf(rmtabf, "[%s]:%s\n", host, path) == EOF) {
501*0Sstevel@tonic-gate 			return (-1);
502*0Sstevel@tonic-gate 		}
503*0Sstevel@tonic-gate 	} else {
504*0Sstevel@tonic-gate 		if (fprintf(rmtabf, "%s:%s\n", host, path) == EOF) {
505*0Sstevel@tonic-gate 			return (-1);
506*0Sstevel@tonic-gate 		}
507*0Sstevel@tonic-gate 	}
508*0Sstevel@tonic-gate 	if (fflush(rmtabf) == EOF) {
509*0Sstevel@tonic-gate 		return (-1);
510*0Sstevel@tonic-gate 	}
511*0Sstevel@tonic-gate 	rmtab_inuse++;
512*0Sstevel@tonic-gate 	return (pos);
513*0Sstevel@tonic-gate }
514*0Sstevel@tonic-gate 
515*0Sstevel@tonic-gate /*
516*0Sstevel@tonic-gate  * Mark as unused the rmtab entry at the given offset in the file.
517*0Sstevel@tonic-gate  */
518*0Sstevel@tonic-gate 
519*0Sstevel@tonic-gate void
520*0Sstevel@tonic-gate rmtab_delete(long pos)
521*0Sstevel@tonic-gate {
522*0Sstevel@tonic-gate 	if (rmtabf != NULL && pos != -1 && fseek(rmtabf, pos, 0) == 0) {
523*0Sstevel@tonic-gate 		(void) fprintf(rmtabf, "#");
524*0Sstevel@tonic-gate 		(void) fflush(rmtabf);
525*0Sstevel@tonic-gate 
526*0Sstevel@tonic-gate 		rmtab_inuse--;
527*0Sstevel@tonic-gate 		rmtab_deleted++;
528*0Sstevel@tonic-gate 	}
529*0Sstevel@tonic-gate }
530