/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 *      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T
 *        All Rights Reserved
 */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * chgrp [-fhR] gid file ...
 * chgrp -R [-f] [-H|-L|-P] gid file ...
 * chgrp -s [-fhR] groupsid file ...
 * chgrp -s -R [-f] [-H|-L|-P] groupsid file ...
 */

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/avl.h>
#include <grp.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <locale.h>
#include <libcmdutils.h>
#include <errno.h>
#include <strings.h>
#include <aclutils.h>

static struct group     *gr;
static struct stat      stbuf;
static struct stat      stbuf2;
static gid_t            gid;
static int              hflag = 0,
                        fflag = 0,
                        rflag = 0,
                        Hflag = 0,
                        Lflag = 0,
                        Pflag = 0,
                        sflag = 0;
static int              status = 0;     /* total number of errors received */

static avl_tree_t       *tree;          /* search tree to store inode data */

static void usage(void);
static int isnumber(char *);
static int Perror(char *);
static void chgrpr(char *, gid_t);

/*
 * Check to see if we are to follow symlinks specified on the command line.
 * This assumes we've already checked to make sure neither -h or -P was
 * specified, so we are just looking to see if -R -L, or -R -H was specified.
 */
#define FOLLOW_CL_LINKS (rflag && (Hflag || Lflag))

/*
 * Follow symlinks when traversing directories.  Only follow symlinks
 * to other parts of the file hierarchy if -L was specified.
 */
#define FOLLOW_D_LINKS  (Lflag)

#define CHOWN(f, u, g)  if (chown(f, u, g) < 0) { \
                                status += Perror(f); \
                        }

#define LCHOWN(f, u, g) if (lchown(f, u, g) < 0) { \
                                status += Perror(f); \
                        }
/*
 * We're ignoring errors here because preserving the SET[UG]ID bits is just
 * a courtesy.  This is only used on directories.
 */
#define SETUGID_PRESERVE(dir, mode) \
        if (((mode) & (S_ISGID|S_ISUID)) != 0) \
                (void) chmod((dir), (mode) & ~S_IFMT)

extern int              optind;


int
main(int argc, char *argv[])
{
        int             c;

        /* set the locale for only the messages system (all else is clean) */

        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)               /* Should be defined by cc -D */
#define TEXT_DOMAIN     "SYS_TEST"      /* Use this only if it weren't */
#endif
        (void) textdomain(TEXT_DOMAIN);

        while ((c = getopt(argc, argv, "RhfHLPs")) != EOF)
                switch (c) {
                        case 'R':
                                rflag++;
                                break;
                        case 'h':
                                hflag++;
                                break;
                        case 'f':
                                fflag++;
                                break;
                        case 'H':
                                /*
                                 * If more than one of -H, -L, and -P
                                 * are specified, only the last option
                                 * specified determines the behavior of
                                 * chgrp.  In addition, make [-H|-L]
                                 * mutually exclusive of -h.
                                 */
                                Lflag = Pflag = 0;
                                Hflag++;
                                break;
                        case 'L':
                                Hflag = Pflag = 0;
                                Lflag++;
                                break;
                        case 'P':
                                Hflag = Lflag = 0;
                                Pflag++;
                                break;
                        case 's':
                                sflag++;
                                break;
                        default:
                                usage();
                }
        /*
         * Set Pflag by default for recursive operations
         * if no other options were specified.
         */
        if (rflag && !(Lflag || Hflag || Pflag || hflag)) {
                Pflag = 1;
        }

        /*
         * Check for sufficient arguments
         * or a usage error.
         */
        argc -= optind;
        argv = &argv[optind];

        if ((argc < 2) ||
            ((Hflag || Lflag || Pflag) && !rflag) ||
            ((Hflag || Lflag || Pflag) && hflag)) {
                usage();
        }

        if (sflag) {
                if (sid_to_id(argv[0], B_FALSE, &gid)) {
                        (void) fprintf(stderr, gettext(
                            "chgrp: invalid group sid %s\n"), argv[0]);
                        exit(2);
                }
        } else if ((gr = getgrnam(argv[0])) != NULL) {
                gid = gr->gr_gid;
        } else {
                if (isnumber(argv[0])) {
                        errno = 0;
                        /* gid is an int */
                        gid = (gid_t)strtoul(argv[0], NULL, 10);
                        if (errno != 0) {
                                if (errno == ERANGE) {
                                        (void) fprintf(stderr, gettext(
                                        "chgrp: group id is too large\n"));
                                        exit(2);
                                } else {
                                        (void) fprintf(stderr, gettext(
                                        "chgrp: invalid group id\n"));
                                        exit(2);
                                }
                        }
                } else {
                        (void) fprintf(stderr, "chgrp: ");
                        (void) fprintf(stderr, gettext("unknown group: %s\n"),
                            argv[0]);
                        exit(2);
                }
        }

        for (c = 1; c < argc; c++) {
                tree = NULL;
                if (lstat(argv[c], &stbuf) < 0) {
                        status += Perror(argv[c]);
                        continue;
                }
                if (rflag && ((stbuf.st_mode & S_IFMT) == S_IFLNK)) {
                        if (hflag || Pflag) {
                                /*
                                 * Change the group id of the symbolic link
                                 * specified on the command line.
                                 * Don't follow the symbolic link to
                                 * any other part of the file hierarchy.
                                 */
                                LCHOWN(argv[c], -1, gid);
                        } else {
                                if (stat(argv[c], &stbuf2) < 0) {
                                        status += Perror(argv[c]);
                                        continue;
                                }
                                /*
                                 * We know that we are to change the
                                 * group of the file referenced by the
                                 * symlink specified on the command line.
                                 * Now check to see if we are to follow
                                 * the symlink to any other part of the
                                 * file hierarchy.
                                 */
                                if (FOLLOW_CL_LINKS) {
                                        if ((stbuf2.st_mode & S_IFMT)
                                            == S_IFDIR) {
                                                /*
                                                 * We are following symlinks so
                                                 * traverse into the directory.
                                                 * Add this node to the search
                                                 * tree so we don't get into an
                                                 * endless loop.
                                                 */
                                                if (add_tnode(&tree,
                                                    stbuf2.st_dev,
                                                    stbuf2.st_ino) == 1) {
                                                        chgrpr(argv[c], gid);
                                                        /*
                                                         * Try to restore the
                                                         * SET[UG]ID bits.
                                                         */
                                                        SETUGID_PRESERVE(
                                                            argv[c],
                                                            stbuf2.st_mode &
                                                            ~S_IFMT);
                                                } else {
                                                        /*
                                                         * Error occurred.
                                                         * rc can't be 0
                                                         * as this is the first
                                                         * node to be added to
                                                         * the search tree.
                                                         */
                                                        status += Perror(
                                                            argv[c]);
                                                }
                                        } else {
                                                /*
                                                 * Change the group id of the
                                                 * file referenced by the
                                                 * symbolic link.
                                                 */
                                                CHOWN(argv[c], -1, gid);
                                        }
                                } else {
                                        /*
                                         * Change the group id of the file
                                         * referenced by the symbolic link.
                                         */
                                        CHOWN(argv[c], -1, gid);

                                        if ((stbuf2.st_mode & S_IFMT)
                                            == S_IFDIR) {
                                                /* Reset the SET[UG]ID bits. */
                                                SETUGID_PRESERVE(argv[c],
                                                    stbuf2.st_mode & ~S_IFMT);
                                        }
                                }
                        }
                } else if (rflag && ((stbuf.st_mode & S_IFMT) == S_IFDIR)) {
                        /*
                         * Add this node to the search tree so we don't
                         * get into a endless loop.
                         */
                        if (add_tnode(&tree, stbuf.st_dev,
                            stbuf.st_ino) == 1) {
                                chgrpr(argv[c], gid);

                                /* Restore the SET[UG]ID bits. */
                                SETUGID_PRESERVE(argv[c],
                                    stbuf.st_mode & ~S_IFMT);
                        } else {
                                /*
                                 * An error occurred while trying
                                 * to add the node to the tree.
                                 * Continue on with next file
                                 * specified.  Note: rc shouldn't
                                 * be 0 as this was the first node
                                 * being added to the search tree.
                                 */
                                status += Perror(argv[c]);
                        }
                } else {
                        if (hflag || Pflag) {
                                LCHOWN(argv[c], -1, gid);
                        } else {
                                CHOWN(argv[c], -1, gid);
                        }
                        /* If a directory, reset the SET[UG]ID bits. */
                        if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
                                SETUGID_PRESERVE(argv[c],
                                    stbuf.st_mode & ~S_IFMT);
                        }
                }
        }
        return (status);
}

/*
 * chgrpr() - recursive chown()
 *
 * Recursively chowns the input directory then its contents.  rflag must
 * have been set if chgrpr() is called.  The input directory should not
 * be a sym link (this is handled in the calling routine).  In
 * addition, the calling routine should have already added the input
 * directory to the search tree so we do not get into endless loops.
 * Note: chgrpr() doesn't need a return value as errors are reported
 * through the global "status" variable.
 */
static void
chgrpr(char *dir, gid_t gid)
{
        struct dirent *dp;
        DIR *dirp;
        struct stat st, st2;
        char savedir[1024];

        if (getcwd(savedir, 1024) == 0) {
                (void) fprintf(stderr, "chgrp: ");
                (void) fprintf(stderr, gettext("%s\n"), savedir);
                exit(255);
        }

        /*
         * Attempt to chown the directory, however don't return if we
         * can't as we still may be able to chown the contents of the
         * directory.  Note: the calling routine resets the SUID bits
         * on this directory so we don't have to perform an extra 'stat'.
         */
        CHOWN(dir, -1, gid);

        if (chdir(dir) < 0) {
                status += Perror(dir);
                return;
        }
        if ((dirp = opendir(".")) == NULL) {
                status += Perror(dir);
                return;
        }
        for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) {
                if ((strcmp(dp->d_name, ".") == 0) ||
                    (strcmp(dp->d_name, "..") == 0)) {
                        continue;       /* skip "." and ".." */
                }
                if (lstat(dp->d_name, &st) < 0) {
                        status += Perror(dp->d_name);
                        continue;
                }
                if ((st.st_mode & S_IFMT) == S_IFLNK) {
                        if (hflag || Pflag) {
                                /*
                                 * Change the group id of the symbolic link
                                 * encountered while traversing the
                                 * directory.  Don't follow the symbolic
                                 * link to any other part of the file
                                 * hierarchy.
                                 */
                                LCHOWN(dp->d_name, -1, gid);
                        } else {
                                if (stat(dp->d_name, &st2) < 0) {
                                        status += Perror(dp->d_name);
                                        continue;
                                }
                                /*
                                 * We know that we are to change the
                                 * group of the file referenced by the
                                 * symlink encountered while traversing
                                 * the directory.  Now check to see if we
                                 * are to follow the symlink to any other
                                 * part of the file hierarchy.
                                 */
                                if (FOLLOW_D_LINKS) {
                                        if ((st2.st_mode & S_IFMT) == S_IFDIR) {
                                                /*
                                                 * We are following symlinks so
                                                 * traverse into the directory.
                                                 * Add this node to the search
                                                 * tree so we don't get into an
                                                 * endless loop.
                                                 */
                                                int rc;
                                                if ((rc = add_tnode(&tree,
                                                    st2.st_dev,
                                                    st2.st_ino)) == 1) {
                                                        chgrpr(dp->d_name, gid);

                                                        /*
                                                         * Restore SET[UG]ID
                                                         * bits.
                                                         */
                                                        SETUGID_PRESERVE(
                                                            dp->d_name,
                                                            st2.st_mode &
                                                            ~S_IFMT);
                                                } else if (rc == 0) {
                                                        /* already visited */
                                                        continue;
                                                } else {
                                                        /*
                                                         * An error occurred
                                                         * while trying to add
                                                         * the node to the tree.
                                                         */
                                                        status += Perror(
                                                            dp->d_name);
                                                        continue;
                                                }
                                        } else {
                                                /*
                                                 * Change the group id of the
                                                 * file referenced by the
                                                 * symbolic link.
                                                 */
                                                CHOWN(dp->d_name, -1, gid);

                                        }
                                } else {
                                        /*
                                         * Change the group id of the file
                                         * referenced by the symbolic link.
                                         */
                                        CHOWN(dp->d_name, -1, gid);

                                        if ((st2.st_mode & S_IFMT) == S_IFDIR) {
                                                /* Restore SET[UG]ID bits. */
                                                SETUGID_PRESERVE(dp->d_name,
                                                    st2.st_mode & ~S_IFMT);
                                        }
                                }
                        }
                } else if ((st.st_mode & S_IFMT) == S_IFDIR) {
                        /*
                         * Add this node to the search tree so we don't
                         * get into a endless loop.
                         */
                        int rc;
                        if ((rc = add_tnode(&tree, st.st_dev,
                            st.st_ino)) == 1) {
                                chgrpr(dp->d_name, gid);

                                /* Restore the SET[UG]ID bits. */
                                SETUGID_PRESERVE(dp->d_name,
                                    st.st_mode & ~S_IFMT);
                        } else if (rc == 0) {
                                /* already visited */
                                continue;
                        } else {
                                /*
                                 * An error occurred while trying
                                 * to add the node to the search tree.
                                 */
                                status += Perror(dp->d_name);
                                continue;
                        }
                } else {
                        CHOWN(dp->d_name, -1, gid);
                }
        }
        (void) closedir(dirp);
        if (chdir(savedir) < 0) {
                (void) fprintf(stderr, "chgrp: ");
                (void) fprintf(stderr, gettext("can't change back to %s\n"),
                    savedir);
                exit(255);
        }
}

static int
isnumber(char *s)
{
        int c;

        while ((c = *s++) != '\0')
                if (!isdigit(c))
                        return (0);
        return (1);
}


static int
Perror(char *s)
{
        if (!fflag) {
                (void) fprintf(stderr, "chgrp: ");
                perror(s);
        }
        return (!fflag);
}


static void
usage(void)
{
        (void) fprintf(stderr, gettext(
            "usage:\n"
            "\tchgrp [-fhR] group file ...\n"
            "\tchgrp -R [-f] [-H|-L|-P] group file ...\n"
            "\tchgrp -s [-fhR] groupsid file ...\n"
            "\tchgrp -s -R [-f] [-H|-L|-P] groupsid file ...\n"));
        exit(2);
}