3 * $Id: tmpdir.c,v 1.5 2004/04/08 01:36:22 mdw Exp $
5 * Choose and check temporary directories
7 * (c) 1999 Mark Wooding
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of chkpath.
14 * chkpath is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * chkpath is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with chkpath; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
36 #include <sys/types.h>
41 #include <mLib/alloc.h>
42 #include <mLib/dstr.h>
43 #include <mLib/mdwopt.h>
44 #include <mLib/quis.h>
45 #include <mLib/report.h>
47 #include "checkpath.h"
49 /*----- Static variables --------------------------------------------------*/
52 static struct checkpath cp
;
53 static struct passwd
*pw
;
55 /*----- Main code ---------------------------------------------------------*/
59 * Arguments: @const char *p@ = pathname to check
60 * @int *f@ = try-to-create flag
62 * Returns: Nonzero if the directory is OK
64 * Use: Ensures that a directory is OK. If @f@ is a real pointer,
65 * and @*f@ is set, then try to create the directory.
68 static int ok(const char *p
, int *f
)
72 /* --- Read the directory status --- */
76 /* --- Maybe create it if it doesn't exist --- */
78 if (errno
!= ENOENT
|| !f
|| !*f
)
85 /* --- Now read the new status --- *
87 * This fixes a race condition between the previous @lstat@ call and
95 /* --- Make sure the directory is good --- *
97 * It must be a genuine directory (not a link); it must be readable
98 * and writable only by its owner, and that owner must be me.
101 if (S_ISDIR(st
.st_mode
) && (st
.st_mode
& 0777) == 0700 && st
.st_uid
== me
)
106 /* --- @trytmp@ --- *
108 * Arguments: @const char *parent@ = parent directory name
109 * @const char *base@ = subdirectory base name
111 * Returns: Pointer to directory name, or null. (String needs freeing.)
113 * Use: Tries to find or create an appropriate temporary directory.
116 static char *trytmp(const char *parent
, const char *base
)
118 static char c
[] = { "0123456789"
119 "abcdefghijklmnopqrstuvwxyz"
120 "ABCDEFGHIJKLMNOPQRSTUVWXYZ" };
126 /* --- Make sure the parent directory is sane --- *
128 * Must make sure that all the lead-up to the temporary directory is safe.
129 * Otherwise other people can play with symlinks or rename directories
130 * after I've done all this careful work to make the endpoint directory
134 if (checkpath(parent
, &cp
))
137 /* --- See whether the trivial version will work --- */
139 dstr_putf(&d
, "%s/%s", parent
, base
);
140 if (ok(d
.buf
, &createflag
))
143 /* --- Now try with various suffixes --- */
149 for (p
= c
; *p
; p
++) {
152 if (ok(d
.buf
, &createflag
))
154 for (q
= c
; *q
; q
++) {
157 if (ok(d
.buf
, &createflag
))
173 /* --- @fullcheck@ --- *
175 * Arguments: @const char *p@ = pointer to path to check
177 * Returns: Zero if it's a bad directory.
179 * Use: Runs a thorough check on a directory.
182 static int fullcheck(const char *p
)
184 return (checkpath(p
, &cp
) == 0 && ok(p
, 0));
187 /* --- @goodtmp@ --- *
191 * Returns: Pointer to a known-good secure temporary directory, or
194 * Use: Finds a good place to store temporary files.
197 static char *goodtmp(void)
201 /* --- First of all, try the user's current choice --- */
203 if ((p
= getenv("TMPDIR")) != 0 && fullcheck(p
))
206 /* --- Try making a directory in `/tmp' --- */
208 if (!(q
= getenv("USER")) && !(q
= getenv("LOGNAME")))
210 if ((q
= trytmp("/tmp", q
)) != 0)
213 /* --- That failed: try a directory in the user's home --- */
215 if (!(q
= getenv("HOME")))
217 if ((q
= trytmp(q
, "tmp")) != 0)
220 /* --- Still no joy: give up --- *
222 * To be fair, if the user can't find a safe place in his own home
223 * directory then he's pretty stuffed.
229 /* --- @usage@ --- */
231 static void usage(FILE *fp
)
233 fprintf(fp
, "Usage: %s [-bc] [-v PATH]\n", QUIS
);
236 /* --- @version@ --- */
238 static void version(FILE *fp
)
240 fprintf(fp
, "%s version %s\n", QUIS
, VERSION
);
245 static void help(FILE *fp
)
251 Sets a suitable and secure temporary directory, or checks that a given\n\
252 directory is suitable for use with temporary files. A directory is\n\
253 considered good for a particular user if it's readable and writable only\n\
254 by that user, and if all its parents are modifiable only by the user or\n\
257 Options supported:\n\
259 -h, --help Display this help text.\n\
260 -V, --version Display the program's version number.\n\
261 -u, --usage Display a terse usage summary.\n\
263 -b, --bourne Output a `TMPDIR' setting for Bourne shell users.\n\
264 -c, --cshell Output a `TMPDIR' setting for C shell users.\n\
265 -v, --verify PATH Check whether PATH is good, setting exit status.\n\
267 The default action is to examine the caller's shell and output a suitable\n\
268 setting for that shell type.\n\
275 * Arguments: @int argc@ = number of command line arguments
276 * @char *argv[]@ = the actual argument strings
278 * Returns: Zero if all went well, else nonzero.
280 * Use: Performs helpful operations on temporary directories.
283 int main(int argc
, char *argv
[])
294 /* --- Initialize variables --- */
298 cp
.cp_what
= CP_WRWORLD
| CP_WRGRP
| CP_WROTHUSR
| CP_STICKYOK
;
301 checkpath_setids(&cp
);
304 die(1, "you don't exist");
306 /* --- Parse arguments --- */
309 static struct option opts
[] = {
310 { "help", 0, 0, 'h' },
311 { "version", 0, 0, 'V' },
312 { "usage", 0, 0, 'u' },
313 { "bourne", 0, 0, 'b' },
314 { "cshell", 0, 0, 'c' },
315 { "verify", OPTF_ARGREQ
, 0, 'v' },
318 int i
= mdwopt(argc
, argv
, "hVu bcv:", opts
, 0, 0, 0);
339 return (!fullcheck(optarg
));
347 if (duff
|| optind
!= argc
) {
352 /* --- Choose a shell --- */
356 if (!(p
= getenv("SHELL")))
358 if (strstr(p
, "csh"))
364 /* --- Start the checking --- */
369 die(1, "no good tmp directory");
372 printf("TMPDIR=\"%s\"; export TMPDIR\n", p
);
375 printf("setenv TMPDIR \"%s\"\n", p
);
383 /*----- That's all, folks -------------------------------------------------*/