1/*
2 * FreeBSD install - a package for the installation and maintenance
3 * of non-core utilities.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * Jordan K. Hubbard
15 * 18 July 1993
16 *
17 * Routines for managing the "play pen".
18 *
19 */
20
21#include <sys/cdefs.h>
22__FBSDID("$FreeBSD: releng/10.3/usr.sbin/pkg_install/lib/pen.c 228990 2011-12-30 10:58:14Z uqs $");
23
24#include "lib.h"
25#include <err.h>
26#include <libutil.h>
27#include <libgen.h>
28#include <sys/signal.h>
29#include <sys/param.h>
30#include <sys/mount.h>
31
32/* For keeping track of where we are */
33static char PenLocation[FILENAME_MAX];
34
35char *
36where_playpen(void)
37{
38    return PenLocation;
39}
40
41/* Find a good place to play. */
42static char *
43find_play_pen(char *pen, off_t sz)
44{
45    char *cp;
46    struct stat sb;
47    char humbuf[6];
48
49    if (pen[0] && isdir(dirname(pen)) == TRUE && (min_free(dirname(pen)) >= sz))
50	return pen;
51    else if ((cp = getenv("PKG_TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
52	sprintf(pen, "%s/instmp.XXXXXX", cp);
53    else if ((cp = getenv("TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
54	sprintf(pen, "%s/instmp.XXXXXX", cp);
55    else if (stat("/var/tmp", &sb) != FAIL && min_free("/var/tmp") >= sz)
56	strcpy(pen, "/var/tmp/instmp.XXXXXX");
57    else if (stat("/tmp", &sb) != FAIL && min_free("/tmp") >= sz)
58	strcpy(pen, "/tmp/instmp.XXXXXX");
59    else if ((stat("/usr/tmp", &sb) == SUCCESS || mkdir("/usr/tmp", 01777) == SUCCESS) && min_free("/usr/tmp") >= sz)
60	strcpy(pen, "/usr/tmp/instmp.XXXXXX");
61    else {
62	cleanup(0);
63	humanize_number(humbuf, sizeof humbuf, sz, "", HN_AUTOSCALE,
64	    HN_NOSPACE);
65	errx(2,
66"%s: can't find enough temporary space to extract the files, please set your\n"
67"PKG_TMPDIR environment variable to a location with at least %s bytes\n"
68"free", __func__, humbuf);
69	return NULL;
70    }
71    return pen;
72}
73
74#define MAX_STACK	20
75static char *pstack[MAX_STACK];
76static int pdepth = -1;
77
78static const char *
79pushPen(const char *pen)
80{
81    if (++pdepth == MAX_STACK)
82	errx(2, "%s: stack overflow.\n", __func__);
83    pstack[pdepth] = strdup(pen);
84
85    return pstack[pdepth];
86}
87
88static void
89popPen(char *pen)
90{
91    if (pdepth == -1) {
92	pen[0] = '\0';
93	return;
94    }
95    strcpy(pen, pstack[pdepth]);
96    free(pstack[pdepth--]);
97}
98
99/*
100 * Make a temporary directory to play in and chdir() to it, returning
101 * pathname of previous working directory.
102 */
103const char *
104make_playpen(char *pen, off_t sz)
105{
106    char humbuf1[6], humbuf2[6];
107    char cwd[FILENAME_MAX];
108
109    if (!find_play_pen(pen, sz))
110	return NULL;
111
112    if (!mkdtemp(pen)) {
113	cleanup(0);
114	errx(2, "%s: can't mktemp '%s'", __func__, pen);
115    }
116
117    if (Verbose) {
118	if (sz) {
119	    humanize_number(humbuf1, sizeof humbuf1, sz, "", HN_AUTOSCALE,
120	        HN_NOSPACE);
121	    humanize_number(humbuf2, sizeof humbuf2, min_free(pen),
122	        "", HN_AUTOSCALE, HN_NOSPACE);
123	    fprintf(stderr, "Requested space: %s bytes, free space: %s bytes in %s\n", humbuf1, humbuf2, pen);
124	}
125    }
126
127    if (min_free(pen) < sz) {
128	rmdir(pen);
129	cleanup(0);
130	errx(2, "%s: not enough free space to create '%s'.\n"
131	     "Please set your PKG_TMPDIR environment variable to a location\n"
132	     "with more space and\ntry the command again", __func__, pen);
133    }
134
135    if (!getcwd(cwd, FILENAME_MAX)) {
136	upchuck("getcwd");
137	return NULL;
138    }
139
140    if (chdir(pen) == FAIL) {
141	cleanup(0);
142	errx(2, "%s: can't chdir to '%s'", __func__, pen);
143    }
144
145    strcpy(PenLocation, pen);
146    return pushPen(cwd);
147}
148
149/* Convenience routine for getting out of playpen */
150int
151leave_playpen()
152{
153    static char left[FILENAME_MAX];
154    void (*oldsig)(int);
155
156    if (!PenLocation[0])
157	return 0;
158
159    /* Don't interrupt while we're cleaning up */
160    oldsig = signal(SIGINT, SIG_IGN);
161    strcpy(left, PenLocation);
162    popPen(PenLocation);
163
164    if (chdir(PenLocation) == FAIL) {
165	cleanup(0);
166	errx(2, "%s: can't chdir back to '%s'", __func__, PenLocation);
167    }
168
169    if (left[0] == '/' && vsystem("/bin/rm -rf %s", left))
170	warnx("couldn't remove temporary dir '%s'", left);
171    signal(SIGINT, oldsig);
172
173    return 1;
174}
175
176off_t
177min_free(const char *tmpdir)
178{
179    struct statfs buf;
180
181    if (statfs(tmpdir, &buf) != 0) {
182	warn("statfs");
183	return -1;
184    }
185    return (off_t)buf.f_bavail * (off_t)buf.f_bsize;
186}
187