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/* $OpenBSD: pen.c,v 1.12 2003/04/04 08:56:01 avsm Exp $ */
#ifndef lint
static const char *rcsid = "$OpenBSD: pen.c,v 1.12 2003/04/04 08:56:01 avsm Exp $";
#endif
/*
* FreeBSD install - a package for the installation and maintainance
* of non-core utilities.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Jordan K. Hubbard
* 18 July 1993
*
* Routines for managing the "play pen".
*
*/
#include <err.h>
#include "lib.h"
#include <sys/signal.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <errno.h>
/* For keeping track of where we are */
static char Current[FILENAME_MAX];
static char Previous[FILENAME_MAX];
/* Backup Current and Previous into temp. strings that are later
* restored & freed by restore_dirs
* This is to make nested calls to makeplaypen/leave_playpen work
*/
void
save_dirs(char **c, char **p)
{
*c=strdup(Current);
*p=strdup(Previous);
}
/* Restore Current and Previous from temp strings that were created
* by safe_dirs.
* This is to make nested calls to makeplaypen/leave_playpen work
*/
void
restore_dirs(char *c, char *p)
{
strlcpy(Current, c, sizeof(Current)); free(c);
strlcpy(Previous, p, sizeof(Previous)); free(p);
}
char *
where_playpen(void)
{
return Current;
}
/* Find a good place to play. */
static char *
find_play_pen(char *pen, size_t pensize, size_t sz)
{
char *cp;
struct stat sb;
if (pen[0] && stat(pen, &sb) != FAIL && (min_free(pen) >= sz))
return pen;
else if ((cp = getenv("PKG_TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
(void) snprintf(pen, pensize, "%s/instmp.XXXXXXXXXX", cp);
else if ((cp = getenv("TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
(void) snprintf(pen, pensize, "%s/instmp.XXXXXXXXXX", cp);
else if (stat("/var/tmp", &sb) != FAIL && min_free("/var/tmp") >= sz)
strlcpy(pen, "/var/tmp/instmp.XXXXXXXXXX", pensize);
else if (stat("/tmp", &sb) != FAIL && min_free("/tmp") >= sz)
strlcpy(pen, "/tmp/instmp.XXXXXXXXXX", pensize);
else if ((stat("/usr/tmp", &sb) == SUCCESS || mkdir("/usr/tmp", 01777) == SUCCESS) && min_free("/usr/tmp") >= sz)
strlcpy(pen, "/usr/tmp/instmp.XXXXXXXXXX", pensize);
else {
cleanup(0);
errx(2,
"can't find enough temporary space to extract the files, please set your\n"
"PKG_TMPDIR environment variable to a location with at least %lu bytes\n"
"free", (u_long)sz);
return NULL;
}
return pen;
}
/*
* Make a temporary directory to play in and chdir() to it, returning
* pathname of previous working directory.
*/
char *
make_playpen(char *pen, size_t pensize, size_t sz)
{
if (!find_play_pen(pen, pensize, sz))
return NULL;
if (!mkdtemp(pen)) {
cleanup(0);
errx(2, "can't mkdtemp '%s'", pen);
}
if (Verbose) {
if (sz)
fprintf(stderr, "Requested space: %lu bytes, free space: %qd bytes in %s\n", (u_long)sz, (long long)min_free(pen), pen);
}
if (min_free(pen) < sz) {
rmdir(pen);
cleanup(0);
errx(2, "not enough free space to create '%s'.\n"
"Please set your PKG_TMPDIR environment variable to a location\n"
"with more space and\ntry the command again", pen);
}
if (Current[0])
strlcpy(Previous, Current, sizeof(Previous));
else if (!getcwd(Previous, FILENAME_MAX)) {
cleanup(0);
err(1, "fatal error during execution: getcwd");
}
if (chdir(pen) == FAIL) {
cleanup(0);
errx(2, "can't chdir to '%s'", pen);
}
strlcpy(Current, pen, sizeof(Current));
return Previous;
}
/* Convenience routine for getting out of playpen */
void
leave_playpen(char *save)
{
int save_errno = errno;
void (*oldsig)(int);
/* XXX big signal race! */
/* Don't interrupt while we're cleaning up */
oldsig = signal(SIGINT, SIG_IGN);
if (Previous[0] && chdir(Previous) == FAIL) {
cleanup(0); /* XXX */
warnx("can't chdir back to '%s'", Previous);
_exit(2);
} else if (Current[0] && strcmp(Current, Previous)) {
if (strcmp(Current,"/")==0) {
fprintf(stderr,"PANIC: About to rm -rf / (not doing so, aborting)\n");
abort(); /* XXX is abort safe? */
}
if (vsystem("rm -rf %s", Current))
pwarnx("couldn't remove temporary dir '%s'", Current);
strlcpy(Current, Previous, sizeof(Current)); /* XXX */
}
if (save)
strlcpy(Previous, save, sizeof(Previous)); /* XXX */
else
Previous[0] = '\0';
signal(SIGINT, oldsig);
errno = save_errno;
}
off_t
min_free(char *tmpdir)
{
struct statfs buf;
if (statfs(tmpdir, &buf) != 0) {
warn("statfs");
return -1;
}
return (off_t)buf.f_bavail * (off_t)buf.f_bsize;
}
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