/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright 2017 OmniTI Computer Consulting, Inc.  All rights reserved.
 * Copyright 2017 Jason King
 * Copyright 2025 Edgecast Cloud LLC
 */

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

/*
 * du -- summarize disk usage
 *      du [-Adorx] [-a|-s] [-h|-k|-m] [-H|-L] [file...]
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/avl.h>
#include <sys/sysmacros.h>
#include <fcntl.h>
#include <dirent.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
#include <libcmdutils.h>


static int              aflg = 0;
static int              rflg = 0;
static int              sflg = 0;
static int              kflg = 0;
static int              mflg = 0;
static int              oflg = 0;
static int              dflg = 0;
static int              hflg = 0;
static int              Aflg = 0;
static int              Hflg = 0;
static int              Lflg = 0;
static int              cmdarg = 0;     /* Command line argument */
static char             *dot = ".";
static int              level = 0;      /* Level of recursion */

static char             *base;
static char             *name;
static size_t           base_len = PATH_MAX + 1;    /* # of chars for base */
static size_t           name_len = PATH_MAX + 1;    /* # of chars for name */

/*
 * Output formats. illumos uses a tab as separator, XPG4 a space.
 */
#ifdef XPG4
#define FORMAT1 "%s %s\n"
#define FORMAT2 "%llu %s\n"
#else
#define FORMAT1 "%s\t%s\n"
#define FORMAT2 "%llu\t%s\n"
#endif

/*
 * convert bytes to blocks
 */
#define DEV_BSHIFT      9
#define DEV_KSHIFT      10
#define DEV_MSHIFT      20

static u_longlong_t     descend(char *curname, int curfd, int *retcode,
                            dev_t device);
static void             printsize(blkcnt_t blocks, char *path);
static void             exitdu(int exitcode);

static avl_tree_t       *tree = NULL;

int
main(int argc, char **argv)
{
        blkcnt_t        blocks = 0;
        int             c;
        extern int      optind;
        char            *np;
        pid_t           pid, wpid;
        int             status, retcode = 0;
        setbuf(stderr, NULL);
        (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);

#ifdef XPG4
        rflg++;         /* "-r" is not an option but ON always */
#endif

        while ((c = getopt(argc, argv, "aAdhHkLmorsx")) != EOF)
                switch (c) {

                case 'a':
                        aflg++;
                        continue;

                case 'h':
                        hflg++;
                        kflg = 0;
                        mflg = 0;
                        continue;

                case 'r':
                        rflg++;
                        continue;

                case 's':
                        sflg++;
                        continue;

                case 'k':
                        kflg++;
                        hflg = 0;
                        mflg = 0;
                        continue;

                case 'm':
                        mflg++;
                        hflg = 0;
                        kflg = 0;
                        continue;

                case 'o':
                        oflg++;
                        continue;

                case 'd':
                        dflg++;
                        continue;

                case 'x':
                        dflg++;
                        continue;

                case 'A':
                        Aflg++;
                        continue;

                case 'H':
                        Hflg++;
                        /* -H and -L are mutually exclusive */
                        Lflg = 0;
                        cmdarg++;
                        continue;

                case 'L':
                        Lflg++;
                        /* -H and -L are mutually exclusive */
                        Hflg = 0;
                        cmdarg = 0;
                        continue;
                case '?':
                        (void) fprintf(stderr, gettext(
                            "usage: du [-Adorx] [-a|-s] [-h|-k|-m] [-H|-L] "
                            "[file...]\n"));
                        exit(2);
                }
        if (optind == argc) {
                argv = &dot;
                argc = 1;
                optind = 0;
        }

        /* "-o" and "-s" don't make any sense together. */
        if (oflg && sflg)
                oflg = 0;

        if ((base = (char *)calloc(base_len, sizeof (char))) == NULL) {
                perror("du");
                exit(1);
        }
        if ((name = (char *)calloc(name_len, sizeof (char))) == NULL) {
                perror("du");
                free(base);
                exit(1);
        }
        do {
                pid = (pid_t)-1;
                if (optind < argc - 1) {
                        pid = fork();
                        if (pid == (pid_t)-1) {
                                perror(gettext("du: No more processes"));
                                exitdu(1);
                        }
                        if (pid != 0) {
                                while ((wpid = wait(&status)) != pid &&
                                    wpid != (pid_t)-1)
                                        ;
                                if (pid != (pid_t)-1 && status != 0)
                                        retcode = 1;
                        }
                }
                if (optind == argc - 1 || pid == 0) {
                        while (base_len < (strlen(argv[optind]) + 1)) {
                                base_len = base_len * 2;
                                if ((base = (char *)realloc(base, base_len *
                                    sizeof (char))) == NULL) {
                                        if (rflg) {
                                                (void) fprintf(stderr, gettext(
                                                    "du: can't process %s"),
                                                    argv[optind]);
                                                perror("");
                                        }
                                        exitdu(1);
                                }
                        }
                        if (base_len > name_len) {
                                name_len = base_len;
                                if ((name = (char *)realloc(name, name_len *
                                    sizeof (char))) == NULL) {
                                        if (rflg) {
                                                (void) fprintf(stderr, gettext(
                                                    "du: can't process %s"),
                                                    argv[optind]);
                                                perror("");
                                        }
                                        exitdu(1);
                                }
                        }
                        (void) strcpy(base, argv[optind]);
                        (void) strcpy(name, argv[optind]);
                        np = strrchr(name, '/');
                        if (np != NULL) {
                                *np++ = '\0';
                                if (chdir(*name ? name : "/") < 0) {
                                        if (rflg) {
                                                (void) fprintf(stderr, "du: ");
                                                perror(*name ? name : "/");
                                                exitdu(1);
                                        }
                                        exitdu(0);
                                }
                        } else
                                np = base;
                        blocks = descend(*np ? np : ".", 0, &retcode,
                            (dev_t)0);
                        if (sflg)
                                printsize(blocks, base);
                        if (optind < argc - 1)
                                exitdu(retcode);
                }
                optind++;
        } while (optind < argc);
        exitdu(retcode);

        return (retcode);
}

/*
 * descend recursively, adding up the allocated blocks.
 * If curname is NULL, curfd is used.
 */
static u_longlong_t
descend(char *curname, int curfd, int *retcode, dev_t device)
{
        static DIR              *dirp = NULL;
        char                    *ebase0, *ebase;
        struct stat             stb, stb1;
        int                     i, j, ret, fd, tmpflg;
        int                     follow_symlinks;
        blkcnt_t                blocks = 0;
        off_t                   curoff = 0;
        ptrdiff_t               offset;
        ptrdiff_t               offset0;
        struct dirent           *dp;
        char                    dirbuf[PATH_MAX + 1];
        u_longlong_t            retval;

        ebase0 = ebase = strchr(base, 0);
        if (ebase > base && ebase[-1] == '/')
                ebase--;
        offset = ebase - base;
        offset0 = ebase0 - base;

        if (curname)
                curfd = AT_FDCWD;

        /*
         * If neither a -L or a -H was specified, don't follow symlinks.
         * If a -H was specified, don't follow symlinks if the file is
         * not a command line argument.
         */
        follow_symlinks = (Lflg || (Hflg && cmdarg));
        if (follow_symlinks) {
                i = fstatat(curfd, curname, &stb, 0);
                j = fstatat(curfd, curname, &stb1, AT_SYMLINK_NOFOLLOW);

                /*
                 * Make sure any files encountered while traversing the
                 * hierarchy are not considered command line arguments.
                 */
                if (Hflg) {
                        cmdarg = 0;
                }
        } else {
                i = fstatat(curfd, curname, &stb, AT_SYMLINK_NOFOLLOW);
                j = 0;
        }

        if ((i < 0) || (j < 0)) {
                if (rflg) {
                        (void) fprintf(stderr, "du: ");
                        perror(base);
                }

                /*
                 * POSIX states that non-zero status codes are only set
                 * when an error message is printed out on stderr
                 */
                *retcode = (rflg ? 1 : 0);
                *ebase0 = 0;
                return (0);
        }
        if (device) {
                if (dflg && stb.st_dev != device) {
                        *ebase0 = 0;
                        return (0);
                }
        }
        else
                device = stb.st_dev;

        /*
         * If following links (-L) we need to keep track of all inodes
         * visited so they are only visited/reported once and cycles
         * are avoided.  Otherwise, only keep track of files which are
         * hard links so they only get reported once, and of directories
         * so we don't report a directory and its hierarchy more than
         * once in the special case in which it lies under the
         * hierarchy of a directory which is a hard link.
         * Note:  Files with multiple links should only be counted
         * once.  Since each inode could possibly be referenced by a
         * symbolic link, we need to keep track of all inodes when -L
         * is specified.
         */
        if (Lflg || ((stb.st_mode & S_IFMT) == S_IFDIR) ||
            (stb.st_nlink > 1)) {
                int rc;
                if ((rc = add_tnode(&tree, stb.st_dev, stb.st_ino)) != 1) {
                        if (rc == 0) {
                                /*
                                 * This hierarchy, or file with multiple
                                 * links, has already been visited/reported.
                                 */
                                return (0);
                        } else {
                                /*
                                 * An error occurred while trying to add the
                                 * node to the tree.
                                 */
                                if (rflg) {
                                        perror("du");
                                }
                                exitdu(1);
                        }
                }
        }
        blocks = Aflg ? stb.st_size : stb.st_blocks;

        /*
         * If there are extended attributes on the current file, add their
         * block usage onto the block count.  Note: Since pathconf() always
         * follows symlinks, only test for extended attributes using pathconf()
         * if we are following symlinks or the current file is not a symlink.
         */
        if (curname && (follow_symlinks ||
            ((stb.st_mode & S_IFMT) != S_IFLNK)) &&
            pathconf(curname, _PC_XATTR_EXISTS) == 1) {
                if ((fd = attropen(curname, ".", O_RDONLY)) < 0) {
                        if (rflg)
                                perror(gettext(
                                    "du: can't access extended attributes"));
                }
                else
                {
                        tmpflg = sflg;
                        sflg = 1;
                        blocks += descend(NULL, fd, retcode, device);
                        sflg = tmpflg;
                }
        }
        if ((stb.st_mode & S_IFMT) != S_IFDIR) {
                /*
                 * Don't print twice: if sflg, file will get printed in main().
                 * Otherwise, level == 0 means this file is listed on the
                 * command line, so print here; aflg means print all files.
                 */
                if (sflg == 0 && (aflg || level == 0))
                        printsize(blocks, base);
                return (blocks);
        }
        if (dirp != NULL)
                /*
                 * Close the parent directory descriptor, we will reopen
                 * the directory when we pop up from this level of the
                 * recursion.
                 */
                (void) closedir(dirp);
        if (curname == NULL)
                dirp = fdopendir(curfd);
        else
                dirp = opendir(curname);
        if (dirp == NULL) {
                if (rflg) {
                        (void) fprintf(stderr, "du: ");
                        perror(base);
                }
                *retcode = 1;
                *ebase0 = 0;
                return (0);
        }
        level++;
        if (curname == NULL || (Lflg && S_ISLNK(stb1.st_mode))) {
                if (getcwd(dirbuf, PATH_MAX) == NULL) {
                        if (rflg) {
                                (void) fprintf(stderr, "du: ");
                                perror(base);
                        }
                        exitdu(1);
                }
        }
        if ((curname ? (chdir(curname) < 0) : (fchdir(curfd) < 0))) {
                if (rflg) {
                        (void) fprintf(stderr, "du: ");
                        perror(base);
                }
                *retcode = 1;
                *ebase0 = 0;
                (void) closedir(dirp);
                dirp = NULL;
                level--;
                return (0);
        }
        while ((dp = readdir(dirp)) != NULL) {
                if ((strcmp(dp->d_name, ".") == 0) ||
                    (strcmp(dp->d_name, "..") == 0))
                        continue;
                /*
                 * we're about to append "/" + dp->d_name
                 * onto end of base; make sure there's enough
                 * space
                 */
                while ((offset + strlen(dp->d_name) + 2) > base_len) {
                        base_len = base_len * 2;
                        if ((base = (char *)realloc(base,
                            base_len * sizeof (char))) == NULL) {
                                if (rflg) {
                                        perror("du");
                                }
                                exitdu(1);
                        }
                        ebase = base + offset;
                        ebase0 = base + offset0;
                }
                /* LINTED - unbounded string specifier */
                (void) sprintf(ebase, "/%s", dp->d_name);
                curoff = telldir(dirp);
                retval = descend(ebase + 1, 0, retcode, device);
                        /* base may have been moved via realloc in descend() */
                ebase = base + offset;
                ebase0 = base + offset0;
                *ebase = 0;
                blocks += retval;
                if (dirp == NULL) {
                        if ((dirp = opendir(".")) == NULL) {
                                if (rflg) {
                                        (void) fprintf(stderr,
                                            gettext("du: Can't reopen in "));
                                        perror(base);
                                }
                                *retcode = 1;
                                level--;
                                return (0);
                        }
                        seekdir(dirp, curoff);
                }
        }
        (void) closedir(dirp);
        level--;
        dirp = NULL;
        if (sflg == 0)
                printsize(blocks, base);
        if (curname == NULL || (Lflg && S_ISLNK(stb1.st_mode)))
                ret = chdir(dirbuf);
        else
                ret = chdir("..");
        if (ret < 0) {
                if (rflg) {
                        (void) sprintf(strchr(base, '\0'), "/..");
                        (void) fprintf(stderr,
                            gettext("du: Can't change dir to '..' in "));
                        perror(base);
                }
                exitdu(1);
        }
        *ebase0 = 0;
        if (oflg)
                return (0);
        else
                return (blocks);
}

static u_longlong_t
mkb(blkcnt_t n, size_t shift)
{
        u_longlong_t v = (u_longlong_t)n;

        /*
         * If hflg was not used, we need to output number of blocks
         * rounded up. Block sizes can be 1M, 1K or 512 bytes.
         * First, convert blocks to 1 byte units and then round up.
         */
        if (!Aflg)
                v <<= DEV_BSHIFT;

        return (P2ROUNDUP(v, 1 << shift) >> shift);
}

static void
printsize(blkcnt_t blocks, char *path)
{
        if (hflg) {
                u_longlong_t bsize = Aflg ? 1 : (1 << DEV_BSHIFT);

                char buf[NN_NUMBUF_SZ] = { 0 };

                nicenum_scale(blocks, bsize, buf, sizeof (buf), 0);
                (void) printf(FORMAT1, buf, path);
                return;
        }

        if (kflg) {
                (void) printf(FORMAT2, mkb(blocks, DEV_KSHIFT), path);
        } else if (mflg) {
                (void) printf(FORMAT2, mkb(blocks, DEV_MSHIFT), path);
        } else {
                (void) printf(FORMAT2, mkb(blocks, DEV_BSHIFT), path);
        }
}

static void
exitdu(int exitcode)
{
        free(base);
        free(name);
        exit(exitcode);
}