freebsd-dev/usr.sbin/chown/chown.c
Brooks Davis 54404cfb13 In preparation for raising NGROUPS and NGROUPS_MAX, change base
system callers of getgroups(), getgrouplist(), and setgroups() to
allocate buffers dynamically.  Specifically, allocate a buffer of size
sysconf(_SC_NGROUPS_MAX)+1 (+2 in a few cases to allow for overflow).

This (or similar gymnastics) is required for the code to actually follow
the POSIX.1-2008 specification where {NGROUPS_MAX} may differ at runtime
and where getgroups may return {NGROUPS_MAX}+1 results on systems like
FreeBSD which include the primary group.

In id(1), don't pointlessly add the primary group to the list of all
groups, it is always the first result from getgroups().  In principle
the old code was more portable, but this was only done in one of the two
places where getgroups() was called to the overall effect was pointless.

Document the actual POSIX requirements in the getgroups(2) and
setgroups(2) manpages.  We do not yet support a dynamic NGROUPS, but we
may in the future.

MFC after:	2 weeks
2009-06-19 15:58:24 +00:00

312 lines
7.2 KiB
C

/*
* Copyright (c) 1988, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1988, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)chown.c 8.8 (Berkeley) 4/4/94";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <grp.h>
#include <libgen.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
void a_gid(const char *);
void a_uid(const char *);
void chownerr(const char *);
uid_t id(const char *, const char *);
void usage(void);
uid_t uid;
gid_t gid;
int ischown;
const char *gname;
int
main(int argc, char **argv)
{
FTS *ftsp;
FTSENT *p;
int Hflag, Lflag, Rflag, fflag, hflag, vflag;
int ch, fts_options, rval;
char *cp;
ischown = (strcmp(basename(argv[0]), "chown") == 0);
Hflag = Lflag = Rflag = fflag = hflag = vflag = 0;
while ((ch = getopt(argc, argv, "HLPRfhv")) != -1)
switch (ch) {
case 'H':
Hflag = 1;
Lflag = 0;
break;
case 'L':
Lflag = 1;
Hflag = 0;
break;
case 'P':
Hflag = Lflag = 0;
break;
case 'R':
Rflag = 1;
break;
case 'f':
fflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'v':
vflag++;
break;
case '?':
default:
usage();
}
argv += optind;
argc -= optind;
if (argc < 2)
usage();
if (Rflag) {
fts_options = FTS_PHYSICAL;
if (hflag && (Hflag || Lflag))
errx(1, "the -R%c and -h options may not be "
"specified together", Hflag ? 'H' : 'L');
if (Hflag)
fts_options |= FTS_COMFOLLOW;
else if (Lflag) {
fts_options &= ~FTS_PHYSICAL;
fts_options |= FTS_LOGICAL;
}
} else
fts_options = hflag ? FTS_PHYSICAL : FTS_LOGICAL;
uid = (uid_t)-1;
gid = (gid_t)-1;
if (ischown) {
if ((cp = strchr(*argv, ':')) != NULL) {
*cp++ = '\0';
a_gid(cp);
}
#ifdef SUPPORT_DOT
else if ((cp = strchr(*argv, '.')) != NULL) {
warnx("separation of user and group with a period is deprecated");
*cp++ = '\0';
a_gid(cp);
}
#endif
a_uid(*argv);
} else
a_gid(*argv);
if ((ftsp = fts_open(++argv, fts_options, 0)) == NULL)
err(1, NULL);
for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
switch (p->fts_info) {
case FTS_D: /* Change it at FTS_DP. */
if (!Rflag)
fts_set(ftsp, p, FTS_SKIP);
continue;
case FTS_DNR: /* Warn, chown. */
warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
rval = 1;
break;
case FTS_ERR: /* Warn, continue. */
case FTS_NS:
warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
rval = 1;
continue;
case FTS_SL:
case FTS_SLNONE:
/*
* The only symlinks that end up here are ones that
* don't point to anything and ones that we found
* doing a physical walk.
*/
if (hflag)
break;
else
continue;
default:
break;
}
if ((uid == (uid_t)-1 || uid == p->fts_statp->st_uid) &&
(gid == (gid_t)-1 || gid == p->fts_statp->st_gid))
continue;
if ((hflag ? lchown : chown)(p->fts_accpath, uid, gid) == -1) {
if (!fflag) {
chownerr(p->fts_path);
rval = 1;
}
} else {
if (vflag) {
printf("%s", p->fts_path);
if (vflag > 1) {
if (ischown) {
printf(": %ju:%ju -> %ju:%ju",
(uintmax_t)
p->fts_statp->st_uid,
(uintmax_t)
p->fts_statp->st_gid,
(uid == (uid_t)-1) ?
(uintmax_t)
p->fts_statp->st_uid :
(uintmax_t)uid,
(gid == (gid_t)-1) ?
(uintmax_t)
p->fts_statp->st_gid :
(uintmax_t)gid);
} else {
printf(": %ju -> %ju",
(uintmax_t)
p->fts_statp->st_gid,
(gid == (gid_t)-1) ?
(uintmax_t)
p->fts_statp->st_gid :
(uintmax_t)gid);
}
}
printf("\n");
}
}
}
if (errno)
err(1, "fts_read");
exit(rval);
}
void
a_gid(const char *s)
{
struct group *gr;
if (*s == '\0') /* Argument was "uid[:.]". */
return;
gname = s;
gid = ((gr = getgrnam(s)) != NULL) ? gr->gr_gid : id(s, "group");
}
void
a_uid(const char *s)
{
struct passwd *pw;
if (*s == '\0') /* Argument was "[:.]gid". */
return;
uid = ((pw = getpwnam(s)) != NULL) ? pw->pw_uid : id(s, "user");
}
uid_t
id(const char *name, const char *type)
{
uid_t val;
char *ep;
/*
* XXX
* We know that uid_t's and gid_t's are unsigned longs.
*/
errno = 0;
val = strtoul(name, &ep, 10);
if (errno)
err(1, "%s", name);
if (*ep != '\0')
errx(1, "%s: illegal %s name", name, type);
return (val);
}
void
chownerr(const char *file)
{
static uid_t euid = -1;
static int ngroups = -1;
static long ngroups_max;
gid_t *groups;
/* Check for chown without being root. */
if (errno != EPERM || (uid != (uid_t)-1 &&
euid == (uid_t)-1 && (euid = geteuid()) != 0)) {
warn("%s", file);
return;
}
/* Check group membership; kernel just returns EPERM. */
if (gid != (gid_t)-1 && ngroups == -1 &&
euid == (uid_t)-1 && (euid = geteuid()) != 0) {
ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
if ((groups = malloc(sizeof(gid_t) * ngroups_max)) == NULL)
err(1, "malloc");
ngroups = getgroups(ngroups_max, groups);
while (--ngroups >= 0 && gid != groups[ngroups]);
if (ngroups < 0) {
warnx("you are not a member of group %s", gname);
return;
}
}
warn("%s", file);
}
void
usage(void)
{
if (ischown)
(void)fprintf(stderr, "%s\n%s\n",
"usage: chown [-fhv] [-R [-H | -L | -P]] owner[:group]"
" file ...",
" chown [-fhv] [-R [-H | -L | -P]] :group file ...");
else
(void)fprintf(stderr, "%s\n",
"usage: chgrp [-fhv] [-R [-H | -L | -P]] group file ...");
exit(1);
}