usr/src/usr.sbin/chown/chown.c

/*
 * Copyright (c) 1988, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static 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     8.2 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>

#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void    a_gid __P((char *));
void    a_uid __P((char *));
void    chownerr __P((char *));
u_long  id __P((char *, char *));
void    usage __P((void));

uid_t uid;
gid_t gid;
int Rflag, ischown, fflag;
char *gname, *myname;

int
main(argc, argv)
        int argc;
        char *argv[];
{
        extern int optind;
        FTS *ftsp;
        FTSENT *p;
        int Hflag, Lflag, Pflag, ch, fts_options, hflag, rval;
        char *cp;

        myname = (cp = rindex(*argv, '/')) ? cp + 1 : *argv;
        ischown = myname[2] == 'o';

        Hflag = Lflag = Pflag = hflag = 0;
        while ((ch = getopt(argc, argv, "HLPRfh")) != EOF)
                switch (ch) {
                case 'H':
                        Hflag = 1;
                        Lflag = Pflag = 0;
                        break;
                case 'L':
                        Lflag = 1;
                        Hflag = Pflag = 0;
                        break;
                case 'P':
                        Pflag = 1;
                        Hflag = Lflag = 0;
                        break;
                case 'R':
                        Rflag = 1;
                        break;
                case 'f':
                        fflag = 1;
                        break;
                case 'h':
                        /*
                         * In System V (and probably POSIX.2) the -h option
                         * causes chown/chgrp to change the owner/group of
                         * the symbolic link.  4.4BSD's symbolic links don't
                         * have owners/groups, so it's an undocumented noop.
                         * Do syntax checking, though.
                         */
                        hflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;

        if (argc < 2)
                usage();

        fts_options = FTS_NOSTAT | FTS_PHYSICAL;
        if (Rflag) {
                if (hflag)
                        errx(1,
                "the -R and -h options may not be specified together.");
                if (Hflag)
                        fts_options |= FTS_COMFOLLOW;
                if (Lflag) {
                        fts_options &= ~FTS_PHYSICAL;
                        fts_options |= FTS_LOGICAL;
                }
        }

        uid = gid = -1;
        if (ischown) {
#ifdef SUPPORT_DOT
                if ((cp = strchr(*argv, '.')) != NULL) {
                        *cp++ = '\0';
                        a_gid(cp);
                } else
#endif
                if ((cp = strchr(*argv, ':')) != NULL) {
                        *cp++ = '\0';
                        a_gid(cp);
                }
                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:
                        if (Rflag)              /* Change it at FTS_DP. */
                                continue;
                        fts_set(ftsp, p, FTS_SKIP);
                        break;
                case FTS_DC:
                        warnx("tree cycle: %s", p->fts_path);
                        rval = 1;
                        continue;
                case FTS_ERR:
                        errno = p->fts_errno;
                        warn("%s", p->fts_path);
                        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.
                         */
                        continue;
                }
                if (chown(p->fts_accpath, uid, gid) && !fflag) {
                        chownerr(p->fts_path);
                        rval = 1;
                }
        }
        exit(rval);
}

void
a_gid(s)
        char *s;
{
        struct group *gr;

        if (*s == '\0')                 /* Argument was "uid[:.]". */
                return;
        gname = s;
        gid = ((gr = getgrnam(s)) == NULL) ? id(s, "group") : gr->gr_gid;
}

void
a_uid(s)
        char *s;
{
        struct passwd *pw;

        if (*s == '\0')                 /* Argument was "[:.]gid". */
                return;
        uid = ((pw = getpwnam(s)) == NULL) ? id(s, "user") : pw->pw_uid;
}

u_long
id(name, type)
        char *name, *type;
{
        u_long 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(file)
        char *file;
{
        static int euid = -1, ngroups = -1;
        int groups[NGROUPS];

        /* Check for chown without being root. */
        if (errno != EPERM ||
            uid != -1 && euid == -1 && (euid = geteuid()) != 0) {
                if (fflag)
                        exit(0);
                err(1, "%s", file);
        }

        /* Check group membership; kernel just returns EPERM. */
        if (gid != -1 && ngroups == -1) {
                ngroups = getgroups(NGROUPS, groups);
                while (--ngroups >= 0 && gid != groups[ngroups]);
                if (ngroups < 0) {
                        if (fflag)
                                exit(0);
                        errx(1, "you are not a member of group %s", gname);
                }
        }

        if (!fflag)
                warn("%s", file);
}

void
usage()
{
        (void)fprintf(stderr,
            "usage: %s [-R [-H | -L | -P]] [-f] %s file ...\n",
            myname, ischown ? "[owner][:group]" : "group");
        exit(1);
}