xref: /netbsd/external/bsd/am-utils/dist/libamu/mtab.c (revision 31bdb48a)
1 /*	$NetBSD: mtab.c,v 1.1.1.3 2015/01/17 16:34:18 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997-2014 Erez Zadok
5  * Copyright (c) 1989 Jan-Simon Pendry
6  * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
7  * Copyright (c) 1989 The Regents of the University of California.
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * Jan-Simon Pendry at Imperial College, London.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *
38  * File: am-utils/libamu/mtab.c
39  *
40  */
41 
42 #ifdef HAVE_CONFIG_H
43 # include <config.h>
44 #endif /* HAVE_CONFIG_H */
45 #include <am_defs.h>
46 #include <amu.h>
47 
48 
49 /*
50  * Firewall /etc/mtab entries
51  */
52 void
mnt_free(mntent_t * mp)53 mnt_free(mntent_t *mp)
54 {
55   XFREE(mp->mnt_fsname);
56   XFREE(mp->mnt_dir);
57   XFREE(mp->mnt_type);
58   XFREE(mp->mnt_opts);
59 
60 #ifdef HAVE_MNTENT_T_MNT_TIME
61 # ifdef HAVE_MNTENT_T_MNT_TIME_STRING
62   XFREE(mp->mnt_time);
63 # endif /* HAVE_MNTENT_T_MNT_TIME_STRING */
64 #endif /* HAVE_MNTENT_T_MNT_TIME */
65 
66   XFREE(mp);
67 }
68 
69 
70 /*
71  * Discard memory allocated for mount list
72  */
73 void
discard_mntlist(mntlist * mp)74 discard_mntlist(mntlist *mp)
75 {
76   mntlist *mp2;
77 
78   while ((mp2 = mp)) {
79     mp = mp->mnext;
80     if (mp2->mnt)
81       mnt_free(mp2->mnt);
82     XFREE(mp2);
83   }
84 }
85 
86 
87 /*
88  * Throw away a mount list
89  */
90 void
free_mntlist(mntlist * mp)91 free_mntlist(mntlist *mp)
92 {
93   discard_mntlist(mp);
94 #ifdef MOUNT_TABLE_ON_FILE
95   unlock_mntlist();
96 #endif /* MOUNT_TABLE_ON_FILE */
97 }
98 
99 
100 /*
101  * Utility routine which returns a pointer to whatever follows an = in a
102  * string.  Returns null if = is not found in the string.
103  */
104 char *
haseq(char * instr)105 haseq(char *instr)
106 {
107   if (instr) {
108     char *eq = strchr(instr, '=');
109     if (eq) return ++eq;
110   }
111   return NULL;
112 }
113 
114 
115 /*
116  * Utility routine which returns a pointer to whatever
117  * follows an = in a mount option.  Returns null if option
118  * doesn't exist or doesn't have an '='.  Won't fail for opt,foo=.
119  */
120 char *
hasmnteq(mntent_t * mnt,char * opt)121 hasmnteq(mntent_t *mnt, char *opt)
122 {
123   if (mnt && opt) {		/* disallow null input pointers */
124     if ( *opt ) {		/* disallow the null string as an opt */
125       char *str = amu_hasmntopt(mnt, opt);
126       if ( str ) {		/* option was there */
127 	char *eq = str + strlen(opt); /* Look at char just after option */
128 	if (*eq == '=')		/* Is it '=' ? */
129 	  return ++eq;		/* If so, return pointer to remaining str */
130       }
131     }
132   }
133   return NULL;
134 }
135 
136 
137 /*
138  * Wrapper around hasmntvalerr(), which retains backwards compatibiliy with
139  * older use of hasmntval().
140  *
141  * XXX: eventually, all use of hasmntval() should be replaced with
142  * hasmntvalerr().
143  */
144 int
hasmntval(mntent_t * mnt,char * opt)145 hasmntval(mntent_t *mnt, char *opt)
146 {
147   int err, val = 0;
148 
149   err = hasmntvalerr(mnt, opt, &val);
150   if (err)	   /* if there was an error (hasmntvalerr returned 1) */
151     return 0;	   /* redundant: val==0 above, but leave here for clarity */
152   /* otherwise there was no error */
153   return val;
154 }
155 
156 
157 /*
158  * Utility routine which determines the value of a numeric option in the
159  * mount options (such as port=%d), and fills in the value in the argument
160  * valp (argument won't be touched if no value is set, for example due to an
161  * error).
162  *
163  * Returns non-zero (1) on error; returns 0 on success.
164  *
165  * XXX: eventually, all use of hasmntval() should be replaced with
166  * hasmntvalerr().
167  */
168 unsigned int
hasmntvalerr(mntent_t * mnt,char * opt,int * valp)169 hasmntvalerr(mntent_t *mnt, char *opt, int *valp)
170 {
171   char *str = amu_hasmntopt(mnt, opt);
172   int err = 1;		     /* 1 means no good value was set (an error) */
173   char *eq, *endptr;
174   long int i;
175 
176   /* exit if no option specificed */
177   if (!str) {
178     goto out;
179   }
180 
181   eq = hasmnteq(mnt, opt);
182 
183   if (!eq) {		  /* no argument to option ('=' sign was missing) */
184     plog(XLOG_MAP, "numeric option to \"%s\" missing", opt);
185     goto out;
186   }
187 
188   /* if got here, then we had an '=' after option name */
189   endptr = NULL;
190   i = strtol(eq, &endptr, 0); /* hex and octal allowed ;-) */
191   if (!endptr ||
192       (endptr != eq && (*endptr == ',' || *endptr == '\0'))) {
193       /*
194        * endptr set means strtol saw a non-digit.  If the non-digit is a
195        * comma, it's probably the start of the next option.  If the comma is
196        * the first char though, complain about it (foo=,bar is made
197        * noticeable by this).
198        *
199        * Similar reasoning for '\0' instead of comma, it's the end of the
200        * string.
201        */
202     *valp = (int) i;		/* set good value */
203     err = 0;			/* no error */
204   } else {
205     /* whatever was after the '=' sign wasn't a number */
206     plog(XLOG_MAP, "invalid numeric option in \"%s\": \"%s\"", opt, str);
207     /* fall through to error/exit processing */
208   }
209 
210  out:
211   return err;
212 }
213 
214 
215 /*
216  * Utility routine which returns the string value of
217  * an option in the mount options (such as proto=udp).
218  * Returns NULL if the option is not specified.
219  * Returns malloc'ed string (caller must free!)
220  */
221 char *
hasmntstr(mntent_t * mnt,char * opt)222 hasmntstr(mntent_t *mnt, char *opt)
223 {
224   char *str = amu_hasmntopt(mnt, opt);
225 
226   if (str) { /* The option was there */
227 
228     char *eq = hasmnteq(mnt, opt);
229 
230     if (eq) { /* and had an = after it */
231 
232       char *endptr = strchr(eq, ',');
233 
234       /* if saw no comma, return xstrdup'd string */
235       if (!endptr)
236 	return xstrdup(eq);
237       else {
238 	/* else we need to copy only the chars needed */
239 	int len = endptr - eq;
240 	char *buf = xmalloc(len + 1);
241 	strncpy(buf, eq, len);
242 	buf[len] = '\0';
243 	return buf;
244       }
245     }
246   }
247   return NULL;
248 }
249