xref: /freebsd-11-stable/contrib/amd/libamu/mtab.c (revision 0e313a07064cd3489a645b5a2e7b4895707591a3)
1 /*
2  * Copyright (c) 1997-2014 Erez Zadok
3  * Copyright (c) 1989 Jan-Simon Pendry
4  * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
5  * Copyright (c) 1989 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Jan-Simon Pendry at Imperial College, London.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *
36  * File: am-utils/libamu/mtab.c
37  *
38  */
39 
40 #ifdef HAVE_CONFIG_H
41 # include <config.h>
42 #endif /* HAVE_CONFIG_H */
43 #include <am_defs.h>
44 #include <amu.h>
45 
46 
47 /*
48  * Firewall /etc/mtab entries
49  */
50 void
mnt_free(mntent_t * mp)51 mnt_free(mntent_t *mp)
52 {
53   XFREE(mp->mnt_fsname);
54   XFREE(mp->mnt_dir);
55   XFREE(mp->mnt_type);
56   XFREE(mp->mnt_opts);
57 
58 #ifdef HAVE_MNTENT_T_MNT_TIME
59 # ifdef HAVE_MNTENT_T_MNT_TIME_STRING
60   XFREE(mp->mnt_time);
61 # endif /* HAVE_MNTENT_T_MNT_TIME_STRING */
62 #endif /* HAVE_MNTENT_T_MNT_TIME */
63 
64   XFREE(mp);
65 }
66 
67 
68 /*
69  * Discard memory allocated for mount list
70  */
71 void
discard_mntlist(mntlist * mp)72 discard_mntlist(mntlist *mp)
73 {
74   mntlist *mp2;
75 
76   while ((mp2 = mp)) {
77     mp = mp->mnext;
78     if (mp2->mnt)
79       mnt_free(mp2->mnt);
80     XFREE(mp2);
81   }
82 }
83 
84 
85 /*
86  * Throw away a mount list
87  */
88 void
free_mntlist(mntlist * mp)89 free_mntlist(mntlist *mp)
90 {
91   discard_mntlist(mp);
92 #ifdef MOUNT_TABLE_ON_FILE
93   unlock_mntlist();
94 #endif /* MOUNT_TABLE_ON_FILE */
95 }
96 
97 
98 /*
99  * Utility routine which returns a pointer to whatever follows an = in a
100  * string.  Returns null if = is not found in the string.
101  */
102 char *
haseq(char * instr)103 haseq(char *instr)
104 {
105   if (instr) {
106     char *eq = strchr(instr, '=');
107     if (eq) return ++eq;
108   }
109   return NULL;
110 }
111 
112 
113 /*
114  * Utility routine which returns a pointer to whatever
115  * follows an = in a mount option.  Returns null if option
116  * doesn't exist or doesn't have an '='.  Won't fail for opt,foo=.
117  */
118 char *
hasmnteq(mntent_t * mnt,char * opt)119 hasmnteq(mntent_t *mnt, char *opt)
120 {
121   if (mnt && opt) {		/* disallow null input pointers */
122     if ( *opt ) {		/* disallow the null string as an opt */
123       char *str = amu_hasmntopt(mnt, opt);
124       if ( str ) {		/* option was there */
125 	char *eq = str + strlen(opt); /* Look at char just after option */
126 	if (*eq == '=')		/* Is it '=' ? */
127 	  return ++eq;		/* If so, return pointer to remaining str */
128       }
129     }
130   }
131   return NULL;
132 }
133 
134 
135 /*
136  * Wrapper around hasmntvalerr(), which retains backwards compatibiliy with
137  * older use of hasmntval().
138  *
139  * XXX: eventually, all use of hasmntval() should be replaced with
140  * hasmntvalerr().
141  */
142 int
hasmntval(mntent_t * mnt,char * opt)143 hasmntval(mntent_t *mnt, char *opt)
144 {
145   int err, val = 0;
146 
147   err = hasmntvalerr(mnt, opt, &val);
148   if (err)	   /* if there was an error (hasmntvalerr returned 1) */
149     return 0;	   /* redundant: val==0 above, but leave here for clarity */
150   /* otherwise there was no error */
151   return val;
152 }
153 
154 
155 /*
156  * Utility routine which determines the value of a numeric option in the
157  * mount options (such as port=%d), and fills in the value in the argument
158  * valp (argument won't be touched if no value is set, for example due to an
159  * error).
160  *
161  * Returns non-zero (1) on error; returns 0 on success.
162  *
163  * XXX: eventually, all use of hasmntval() should be replaced with
164  * hasmntvalerr().
165  */
166 unsigned int
hasmntvalerr(mntent_t * mnt,char * opt,int * valp)167 hasmntvalerr(mntent_t *mnt, char *opt, int *valp)
168 {
169   char *str = amu_hasmntopt(mnt, opt);
170   int err = 1;		     /* 1 means no good value was set (an error) */
171   char *eq, *endptr;
172   long int i;
173 
174   /* exit if no option specificed */
175   if (!str) {
176     goto out;
177   }
178 
179   eq = hasmnteq(mnt, opt);
180 
181   if (!eq) {		  /* no argument to option ('=' sign was missing) */
182     plog(XLOG_MAP, "numeric option to \"%s\" missing", opt);
183     goto out;
184   }
185 
186   /* if got here, then we had an '=' after option name */
187   endptr = NULL;
188   i = strtol(eq, &endptr, 0); /* hex and octal allowed ;-) */
189   if (!endptr ||
190       (endptr != eq && (*endptr == ',' || *endptr == '\0'))) {
191       /*
192        * endptr set means strtol saw a non-digit.  If the non-digit is a
193        * comma, it's probably the start of the next option.  If the comma is
194        * the first char though, complain about it (foo=,bar is made
195        * noticeable by this).
196        *
197        * Similar reasoning for '\0' instead of comma, it's the end of the
198        * string.
199        */
200     *valp = (int) i;		/* set good value */
201     err = 0;			/* no error */
202   } else {
203     /* whatever was after the '=' sign wasn't a number */
204     plog(XLOG_MAP, "invalid numeric option in \"%s\": \"%s\"", opt, str);
205     /* fall through to error/exit processing */
206   }
207 
208  out:
209   return err;
210 }
211 
212 
213 /*
214  * Utility routine which returns the string value of
215  * an option in the mount options (such as proto=udp).
216  * Returns NULL if the option is not specified.
217  * Returns malloc'ed string (caller must free!)
218  */
219 char *
hasmntstr(mntent_t * mnt,char * opt)220 hasmntstr(mntent_t *mnt, char *opt)
221 {
222   char *str = amu_hasmntopt(mnt, opt);
223 
224   if (str) { /* The option was there */
225 
226     char *eq = hasmnteq(mnt, opt);
227 
228     if (eq) { /* and had an = after it */
229 
230       char *endptr = strchr(eq, ',');
231 
232       /* if saw no comma, return xstrdup'd string */
233       if (!endptr)
234 	return xstrdup(eq);
235       else {
236 	/* else we need to copy only the chars needed */
237 	int len = endptr - eq;
238 	char *buf = xmalloc(len + 1);
239 	strncpy(buf, eq, len);
240 	buf[len] = '\0';
241 	return buf;
242       }
243     }
244   }
245   return NULL;
246 }
247