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 */
50void
51mnt_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 */
71void
72discard_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 */
88void
89free_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 */
102char *
103haseq(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 */
118char *
119hasmnteq(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 */
142int
143hasmntval(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 */
166unsigned int
167hasmntvalerr(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 */
219char *
220hasmntstr(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