1 /*	$NetBSD: mtab_aix.c,v 1.1.1.3 2015/01/17 16:34:16 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1997-2014 Erez Zadok
5  * Copyright (c) 1990 Jan-Simon Pendry
6  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
7  * Copyright (c) 1990 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/conf/mtab/mtab_aix.c
39  *
40  */
41 
42 /*
43  * AIX systems don't write their mount tables on a file.  Instead, they
44  * use a (better) system where the kernel keeps this state, and you access
45  * the mount tables via a known interface.
46  */
47 
48 #ifdef HAVE_CONFIG_H
49 # include <config.h>
50 #endif /* HAVE_CONFIG_H */
51 #include <am_defs.h>
52 #include <amu.h>
53 
54 /*
55  * These were missing external definitions from old AIX's headers.  They
56  * appear to be available in <sys/vmount.h> on AIX 5.3, and possibly
57  * earlier. Hence I commented this out.
58  */
59 #ifndef HAVE_EXTERN_MNTCTL
60 extern int mntctl(int cmd, int size, voidp buf);
61 #endif /* not HAVE_EXTERN_MNTCTL */
62 
63 
64 static mntent_t *
mnt_dup(struct vmount * mp)65 mnt_dup(struct vmount *mp)
66 {
67   mntent_t *new_mp = ALLOC(mntent_t);
68   char *ty;
69   char *fsname = xstrdup(vmt2dataptr(mp, VMT_OBJECT));
70 
71   new_mp->mnt_dir = strdup(vmt2dataptr(mp, VMT_STUB));
72   new_mp->mnt_opts = strdup(vmt2dataptr(mp, VMT_ARGS));
73 
74   switch (mp->vmt_gfstype) {
75 
76   case MOUNT_TYPE_UFS:
77     ty = MNTTAB_TYPE_UFS;
78     new_mp->mnt_fsname = xstrdup(fsname);
79     break;
80 
81   case MOUNT_TYPE_NFS:
82     ty = MNTTAB_TYPE_NFS;
83     new_mp->mnt_fsname = str3cat((char *) NULL,
84 				 vmt2dataptr(mp, VMT_HOSTNAME), ":",
85 				 fsname);
86     break;
87 
88 #ifdef HAVE_FS_NFS3
89   case MOUNT_TYPE_NFS3:
90     ty = MNTTAB_TYPE_NFS3;
91     new_mp->mnt_fsname = str3cat((char *) NULL,
92 				 vmt2dataptr(mp, VMT_HOSTNAME), ":",
93 				 fsname);
94     break;
95 #endif /* HAVE_FS_NFS3 */
96 
97   default:
98     ty = "unknown";
99     new_mp->mnt_fsname = xstrdup(fsname);
100     break;
101 
102   }
103 
104   new_mp->mnt_type = xstrdup(ty);
105   /* store the VFS ID for uvmount() */
106   new_mp->mnt_passno = mp->vmt_vfsnumber;
107   new_mp->mnt_freq = 0;
108 
109   XFREE(fsname);
110 
111   return new_mp;
112 }
113 
114 
115 /*
116  * Read a mount table into memory
117  */
118 mntlist *
read_mtab(char * fs,const char * mnttabname)119 read_mtab(char *fs, const char *mnttabname)
120 {
121   mntlist **mpp, *mhp;
122   int i;
123   char *mntinfo = NULL, *cp;
124   struct vmount *vp;
125   int ret;
126   int maxtry = 10;		/* maximum number of times to try mntctl */
127 
128   /*
129    * Figure out size of mount table and allocate space for a copy.  Then get
130    * mount table for real.  We repeat this loop at most 10 times to minimze
131    * the chance of a race condition (something gets un/mounted in between
132    * calls to mntctl()
133    */
134   i = sizeof(int);
135   do {
136     if (mntinfo)
137       XFREE(mntinfo);
138     mntinfo = xmalloc(i);
139     ret = mntctl(MCTL_QUERY, i, mntinfo);
140     if (ret == 0)
141       i = *(int*) mntinfo;
142     if (--maxtry <= 0) {
143       plog(XLOG_ERROR, "mntctl: could not get a stable result");
144       ret = -1;
145       errno = EINVAL;
146       break;
147     }
148   } while (ret == 0);
149   if (ret < 0) {
150     plog(XLOG_ERROR, "mntctl: %m");
151     goto out;
152   }
153 
154   mpp = &mhp;
155   for (i = 0, cp = mntinfo; i < ret; i++, cp += vp->vmt_length) {
156     vp = (struct vmount *) cp;
157 
158     /*
159      * Allocate a new slot
160      */
161     *mpp = ALLOC(struct mntlist);
162 
163     /*
164      * Copy the data returned by mntctl
165      */
166     (*mpp)->mnt = mnt_dup(vp);
167 
168     /*
169      * Move to next pointer
170      */
171     mpp = &(*mpp)->mnext;
172   }
173 
174   *mpp = NULL;
175 
176 out:
177   if (mntinfo)
178     XFREE(mntinfo);
179   return mhp;
180 }
181