pen.c revision 21673 
1#ifndef lint
2static const char *rcsid = "$FreeBSD: head/usr.sbin/pkg_install/lib/pen.c 21673 1997-01-14 07:20:47Z jkh $";
3#endif
4
5/*
6 * FreeBSD install - a package for the installation and maintainance
7 * of non-core utilities.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * Jordan K. Hubbard
19 * 18 July 1993
20 *
21 * Routines for managing the "play pen".
22 *
23 */
24
25#include "lib.h"
26#include <sys/signal.h>
27#include <sys/param.h>
28#include <sys/mount.h>
29
30/* For keeping track of where we are */
31static char Current[FILENAME_MAX];
32static char Previous[FILENAME_MAX];
33
34char *
35where_playpen(void)
36{
37    return Current;
38}
39
40/* Find a good place to play. */
41static char *
42find_play_pen(char *pen, size_t sz)
43{
44    char *cp;
45    struct stat sb;
46
47    if (pen[0] && stat(pen, &sb) != FAIL && (min_free(pen) >= sz))
48	return pen;
49    else if ((cp = getenv("PKG_TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
50	sprintf(pen, "%s/instmp.XXXXXX", cp);
51    else if ((cp = getenv("TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
52	sprintf(pen, "%s/instmp.XXXXXX", cp);
53    else if (stat("/var/tmp", &sb) != FAIL && min_free("/var/tmp") >= sz)
54	strcpy(pen, "/var/tmp/instmp.XXXXXX");
55    else if (stat("/tmp", &sb) != FAIL && min_free("/tmp") >= sz)
56	strcpy(pen, "/tmp/instmp.XXXXXX");
57    else if ((stat("/usr/tmp", &sb) == SUCCESS || mkdir("/usr/tmp", 01777) == SUCCESS) && min_free("/usr/tmp") >= sz)
58	strcpy(pen, "/usr/tmp/instmp.XXXXXX");
59    else {
60	barf("Can't find enough temporary space to extract the files, please set\n"
61	     "your PKG_TMPDIR environment variable to a location with at least %d bytes\n"
62	     "free.", sz);
63	return NULL;
64    }
65    return pen;
66}
67
68/*
69 * Make a temporary directory to play in and chdir() to it, returning
70 * pathname of previous working directory.
71 */
72char *
73make_playpen(char *pen, size_t sz)
74{
75    if (!find_play_pen(pen, sz))
76	return NULL;
77
78    if (!mktemp(pen)) {
79	barf("Can't mktemp '%s'.", pen);
80	return NULL;
81    }
82    if (mkdir(pen, 0755) == FAIL) {
83	barf("Can't mkdir '%s'.", pen);
84	return NULL;
85    }
86    if (Verbose) {
87	if (sz)
88	    fprintf(stderr, "Requested space: %d bytes, free space: %qd bytes in %s\n", (int)sz, min_free(pen), pen);
89    }
90    if (min_free(pen) < sz) {
91	rmdir(pen);
92	barf("Not enough free space to create: `%s'\n"
93	     "Please set your PKG_TMPDIR environment variable to a location\n"
94	     "with more space and\ntry the command again.", pen);
95        return NULL;
96    }
97    if (Current[0])
98	strcpy(Previous, Current);
99    else if (!getcwd(Previous, FILENAME_MAX)) {
100	upchuck("getcwd");
101	return NULL;
102    }
103    if (chdir(pen) == FAIL)
104	barf("Can't chdir to '%s'.", pen);
105    strcpy(Current, pen);
106    return Previous;
107}
108
109/* Convenience routine for getting out of playpen */
110void
111leave_playpen(char *save)
112{
113    void (*oldsig)(int);
114
115    /* Don't interrupt while we're cleaning up */
116    oldsig = signal(SIGINT, SIG_IGN);
117    if (Previous[0] && chdir(Previous) == FAIL)
118	barf("Can't chdir back to '%s'.", Previous);
119    else if (Current[0] && strcmp(Current, Previous)) {
120	if (vsystem("rm -rf %s", Current))
121	    whinge("Couldn't remove temporary dir '%s'", Current);
122	strcpy(Current, Previous);
123    }
124    if (save)
125	strcpy(Previous, save);
126    else
127	Previous[0] = '\0';
128    signal(SIGINT, oldsig);
129}
130
131off_t
132min_free(char *tmpdir)
133{
134    struct statfs buf;
135
136    if (statfs(tmpdir, &buf) != 0) {
137	perror("Error in statfs");
138	return -1;
139    }
140    return (off_t)buf.f_bavail * (off_t)buf.f_bsize;
141}
142