/*
 * Copyright (c) 1987, 1993
 *      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.
 * 3. 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.
 *
 * @(#) Copyright (c) 1987, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)xinstall.c       8.1 (Berkeley) 7/21/93
 */

#include <sys/param.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <libgen.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <utime.h>
#include <vis.h>

#include "mtree.h"

/* Bootstrap aid - this doesn't exist in most older releases */
#ifndef MAP_FAILED
#define MAP_FAILED ((void *)-1) /* from <sys/mman.h> */
#endif
#ifndef UF_NOHISTORY
#define UF_NOHISTORY    0
#endif

#define MAX_CMP_SIZE    (16 * 1024 * 1024)

#define LN_ABSOLUTE     0x01
#define LN_RELATIVE     0x02
#define LN_HARD         0x04
#define LN_SYMBOLIC     0x08
#define LN_MIXED        0x10

#define DIRECTORY       0x01            /* Tell install it's a directory. */
#define SETFLAGS        0x02            /* Tell install to set flags. */
#define NOCHANGEBITS    (UF_IMMUTABLE | UF_APPEND | SF_IMMUTABLE | SF_APPEND)
#define BACKUP_SUFFIX   ".old"

static gid_t gid;
static uid_t uid;
static int dobackup, docompare, dodir, dolink, dopreserve, dostrip, dounpriv,
    nommap, safecopy, verbose;
static int haveopt_f, haveopt_g, haveopt_m, haveopt_o;
static mode_t mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
static const char *group, *owner;
static const char *suffix = BACKUP_SUFFIX;
static char *destdir, *fflags;

static int      compare(int, const char *, size_t, int, const char *, size_t);
static void     copy(int, const char *, int, const char *, off_t);
static int      create_newfile(const char *, int, struct stat *);
static int      create_tempfile(const char *, char *, size_t);
static int      do_link(const char *, const char *, const struct stat *);
static void     do_symlink(const char *, const char *, const struct stat *);
static void     makelink(const char *, const char *, const struct stat *);
static void     install(const char *, const char *, u_long, u_long, u_int);
static void     install_dir(char *);
static int      parseid(const char *, id_t *);
static void     strip(const char *);
static int      trymmap(int);
static void     usage(void);

int
main(int argc, char *argv[])
{
        struct stat from_sb, to_sb;
        mode_t *set;
        u_long fset;
        u_long fclr;
        int ch, no_target;
        u_int iflags;
        char *p;
        const char *to_name;

        fclr = 0;
        fset = 0;
        iflags = 0;
        group = NULL;
        owner = NULL;

        /* NOTE: please also update 'tools/install.sh' */
        while ((ch = getopt(argc, argv, "B:bCcD:df:g:L:l:M:m:N:o:pSsUv")) != -1)
                switch((char)ch) {
                case 'B':
                        suffix = optarg;
                        /* FALLTHROUGH */
                case 'b':
                        dobackup = 1;
                        break;
                case 'C':
                        docompare = 1;
                        break;
                case 'c':
                        /* For backwards compatibility. */
                        break;
                case 'D':
                        destdir = optarg;
                        break;
                case 'd':
                        dodir = 1;
                        break;
                case 'f':
#ifdef _ST_FLAGS_PRESENT_
                        haveopt_f = 1;
                        fflags = optarg;
#endif
                        break;
                case 'g':
                        haveopt_g = 1;
                        group = optarg;
                        break;
                case 'l':
                        for (p = optarg; *p; p++)
                                switch (*p) {
                                case 's':
                                        dolink &= ~(LN_HARD|LN_MIXED);
                                        dolink |= LN_SYMBOLIC;
                                        break;
                                case 'h':
                                        dolink &= ~(LN_SYMBOLIC|LN_MIXED);
                                        dolink |= LN_HARD;
                                        break;
                                case 'm':
                                        dolink &= ~(LN_SYMBOLIC|LN_HARD);
                                        dolink |= LN_MIXED;
                                        break;
                                case 'a':
                                        dolink &= ~LN_RELATIVE;
                                        dolink |= LN_ABSOLUTE;
                                        break;
                                case 'r':
                                        dolink &= ~LN_ABSOLUTE;
                                        dolink |= LN_RELATIVE;
                                        break;
                                default:
                                        errx(EXIT_FAILURE, "%c: invalid link type", *p);
                                        /* NOTREACHED */
                                }
                        break;
                case 'M':
                        nommap = 1;
                        break;
                case 'm':
                        haveopt_m = 1;
                        if (!(set = setmode(optarg)))
                                errx(EX_USAGE, "invalid file mode: %s",
                                     optarg);
                        mode = getmode(set, 0);
                        free(set);
                        break;
                case 'L':
                        /* -L kept for compatibility with pre-5.4 DragonFly */
                        warnx("Option -L is deprecated, use -N instead");
                        /* FALLTHROUGH */
                case 'N':
                        if (!setup_getid(optarg))
                                err(EX_OSERR, "Unable to use user and group "
                                    "databases in `%s'", optarg);
                        break;
                case 'o':
                        haveopt_o = 1;
                        owner = optarg;
                        break;
                case 'p':
                        docompare = dopreserve = 1;
                        break;
                case 'S':
                        safecopy = 1;
                        break;
                case 's':
                        dostrip = 1;
                        break;
                case 'U':
                        dounpriv = 1;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /* some options make no sense when creating directories */
        if (dostrip && dodir) {
                warnx("-d and -s may not be specified together");
                usage();
        }

        if (getenv("DONTSTRIP") != NULL) {
                warnx("DONTSTRIP set - will not strip installed binaries");
                dostrip = 0;
        }

        /* must have at least two arguments, except when creating directories */
        if (argc == 0 || (argc == 1 && !dodir))
                usage();

        /* need to make a temp copy so we can compare stripped version */
        if (docompare && dostrip)
                safecopy = 1;

        /* get group and owner id's */
        if (group != NULL && !dounpriv) {
                if (gid_from_group(group, &gid) == -1) {
                        id_t id;
                        if (!parseid(group, &id))
                                errx(1, "unknown group %s", group);
                        gid = id;
                }
        } else
                gid = (gid_t)-1;

        if (owner != NULL && !dounpriv) {
                if (uid_from_user(owner, &uid) == -1) {
                        id_t id;
                        if (!parseid(owner, &id))
                                errx(1, "unknown user %s", owner);
                        uid = id;
                }
        } else
                uid = (uid_t)-1;

#ifdef _ST_FLAGS_PRESENT_
        if (fflags != NULL && !dounpriv) {
                if (strtofflags(&fflags, &fset, &fclr))
                        errx(EX_USAGE, "%s: invalid flag", fflags);
                iflags |= SETFLAGS;
        }
#endif

        if (dodir) {
                for (; *argv != NULL; ++argv)
                        install_dir(*argv);
                exit(EX_OK);
                /* NOTREACHED */
        }

        to_name = argv[argc - 1];
        no_target = stat(to_name, &to_sb);
        if (!no_target && S_ISDIR(to_sb.st_mode)) {
                if (dolink & LN_SYMBOLIC) {
                        if (lstat(to_name, &to_sb) != 0)
                                err(EX_OSERR, "%s vanished", to_name);
                        if (S_ISLNK(to_sb.st_mode)) {
                                if (argc != 2) {
                                        errno = ENOTDIR;
                                        err(EX_USAGE, "%s", to_name);
                                }
                                install(*argv, to_name, fset, fclr, iflags);
                                exit(EX_OK);
                        }
                }
                for (; *argv != to_name; ++argv)
                        install(*argv, to_name, fset, fclr, iflags | DIRECTORY);
                exit(EX_OK);
                /* NOTREACHED */
        }

        /* can't do file1 file2 directory/file */
        if (argc != 2) {
                if (no_target)
                        warnx("target directory `%s' does not exist",
                            argv[argc - 1]);
                else
                        warnx("target `%s' is not a directory",
                            argv[argc - 1]);
                usage();
        }

        if (!no_target && !dolink) {
                if (stat(*argv, &from_sb))
                        err(EX_OSERR, "%s", *argv);
                if (!S_ISREG(to_sb.st_mode)) {
                        errno = EFTYPE;
                        err(EX_OSERR, "%s", to_name);
                }
                if (to_sb.st_dev == from_sb.st_dev &&
                    to_sb.st_ino == from_sb.st_ino)
                        errx(EX_USAGE, 
                            "%s and %s are the same file", *argv, to_name);
        }
        install(*argv, to_name, fset, fclr, iflags);
        exit(EX_OK);
        /* NOTREACHED */
}

/*
 * parseid --
 *      parse uid or gid from arg into id, returning non-zero if successful
 */
static int
parseid(const char *name, id_t *id)
{
        char    *ep;
        errno = 0;
        *id = (id_t)strtoul(name, &ep, 10);
        if (errno || *ep != '\0')
                return (0);
        return (1);
}

/*
 * quiet_mktemp --
 *      mktemp implementation used mkstemp to avoid mktemp warnings.  We
 *      really do need mktemp semantics here as we will be creating a link.
 */
static char *
quiet_mktemp(char *template)
{
        int fd;

        if ((fd = mkstemp(template)) == -1)
                return (NULL);
        close (fd);
        if (unlink(template) == -1)
                err(EX_OSERR, "unlink %s", template);
        return (template);
}

/*
 * do_link --
 *      make a hard link, obeying dorename if set
 *      return -1 on failure
 */
static int
do_link(const char *from_name, const char *to_name,
    const struct stat *target_sb)
{
        char tmpl[MAXPATHLEN];
        int ret;

        if (safecopy && target_sb != NULL) {
                (void)snprintf(tmpl, sizeof(tmpl), "%s.inst.XXXXXX", to_name);
                /* This usage is safe. */
                if (quiet_mktemp(tmpl) == NULL)
                        err(EX_OSERR, "%s: mktemp", tmpl);
                ret = link(from_name, tmpl);
                if (ret == 0) {
                        if (target_sb->st_mode & S_IFDIR && rmdir(to_name) ==
                            -1) {
                                unlink(tmpl);
                                err(EX_OSERR, "%s", to_name);
                        }
#ifdef _ST_FLAGS_PRESENT_
                        if (target_sb->st_flags & NOCHANGEBITS)
                                (void)chflags(to_name, target_sb->st_flags &
                                     ~NOCHANGEBITS);
#endif
                        if (verbose)
                                printf("install: link %s -> %s\n",
                                    from_name, to_name);
                        ret = rename(tmpl, to_name);
                        /*
                         * If rename has posix semantics, then the temporary
                         * file may still exist when from_name and to_name point
                         * to the same file, so unlink it unconditionally.
                         */
                        (void)unlink(tmpl);
                }
                return (ret);
        } else {
                if (verbose)
                        printf("install: link %s -> %s\n",
                            from_name, to_name);
                return (link(from_name, to_name));
        }
}

/*
 * do_symlink --
 *      Make a symbolic link, obeying dorename if set. Exit on failure.
 */
static void
do_symlink(const char *from_name, const char *to_name,
    const struct stat *target_sb)
{
        char tmpl[MAXPATHLEN];

        if (safecopy && target_sb != NULL) {
                (void)snprintf(tmpl, sizeof(tmpl), "%s.inst.XXXXXX", to_name);
                /* This usage is safe. */
                if (quiet_mktemp(tmpl) == NULL)
                        err(EX_OSERR, "%s: mktemp", tmpl);

                if (symlink(from_name, tmpl) == -1)
                        err(EX_OSERR, "symlink %s -> %s", from_name, tmpl);

                if (target_sb->st_mode & S_IFDIR && rmdir(to_name) == -1) {
                        (void)unlink(tmpl);
                        err(EX_OSERR, "%s", to_name);
                }
#ifdef _ST_FLAGS_PRESENT_
                if (target_sb->st_flags & NOCHANGEBITS)
                        (void)chflags(to_name, target_sb->st_flags &
                             ~NOCHANGEBITS);
#endif
                if (verbose)
                        printf("install: symlink %s -> %s\n",
                            from_name, to_name);
                if (rename(tmpl, to_name) == -1) {
                        /* Remove temporary link before exiting. */
                        (void)unlink(tmpl);
                        err(EX_OSERR, "%s: rename", to_name);
                }
        } else {
                if (verbose)
                        printf("install: symlink %s -> %s\n",
                            from_name, to_name);
                if (symlink(from_name, to_name) == -1)
                        err(EX_OSERR, "symlink %s -> %s", from_name, to_name);
        }
}

/*
 * makelink --
 *      make a link from source to destination
 */
static void
makelink(const char *from_name, const char *to_name,
    const struct stat *target_sb)
{
        char    src[MAXPATHLEN], dst[MAXPATHLEN], lnk[MAXPATHLEN];
        struct stat     to_sb;

        /* Try hard links first. */
        if (dolink & (LN_HARD|LN_MIXED)) {
                if (do_link(from_name, to_name, target_sb) == -1) {
                        if ((dolink & LN_HARD) || errno != EXDEV)
                                err(EX_OSERR, "link %s -> %s", from_name, to_name);
                } else {
                        if (stat(to_name, &to_sb))
                                err(EX_OSERR, "%s: stat", to_name);
                        if (S_ISREG(to_sb.st_mode)) {
                                /*
                                 * XXX: hard links to anything other than
                                 * plain files are not metalogged
                                 */
                                int omode;
                                const char *oowner, *ogroup;
                                char *offlags;

                                /*
                                 * XXX: use underlying perms, unless
                                 * overridden on command line.
                                 */
                                omode = mode;
                                if (!haveopt_m)
                                        mode = (to_sb.st_mode & 0777);
                                oowner = owner;
                                if (!haveopt_o)
                                        owner = NULL;
                                ogroup = group;
                                if (!haveopt_g)
                                        group = NULL;
                                offlags = fflags;
                                if (!haveopt_f)
                                        fflags = NULL;
                                mode = omode;
                                owner = oowner;
                                group = ogroup;
                                fflags = offlags;
                        }
                        return;
                }
        }

        /* Symbolic links. */
        if (dolink & LN_ABSOLUTE) {
                /* Convert source path to absolute. */
                if (realpath(from_name, src) == NULL)
                        err(EX_OSERR, "%s: realpath", from_name);
                do_symlink(src, to_name, target_sb);
                /* XXX: src may point outside of destdir */
                return;
        }

        if (dolink & LN_RELATIVE) {
                char *to_name_copy, *cp, *d, *s;

                if (*from_name != '/') {
                        /* this is already a relative link */
                        do_symlink(from_name, to_name, target_sb);
                        /* XXX: from_name may point outside of destdir. */
                        return;
                }

                /* Resolve pathnames. */
                if (realpath(from_name, src) == NULL)
                        err(EX_OSERR, "%s: realpath", from_name);

                /*
                 * The last component of to_name may be a symlink,
                 * so use realpath to resolve only the directory.
                 */
                to_name_copy = strdup(to_name);
                if (to_name_copy == NULL)
                        err(EX_OSERR, "%s: strdup", to_name);
                cp = dirname(to_name_copy);
                if (realpath(cp, dst) == NULL)
                        err(EX_OSERR, "%s: realpath", cp);
                /* .. and add the last component. */
                if (strcmp(dst, "/") != 0) {
                        if (strlcat(dst, "/", sizeof(dst)) > sizeof(dst))
                                errx(1, "resolved pathname too long");
                }
                strcpy(to_name_copy, to_name);
                cp = basename(to_name_copy);
                if (strlcat(dst, cp, sizeof(dst)) > sizeof(dst))
                        errx(1, "resolved pathname too long");
                free(to_name_copy);

                /* Trim common path components. */
                for (s = src, d = dst; *s == *d; s++, d++)
                        continue;
                while (*s != '/')
                        s--, d--;

                /* Count the number of directories we need to backtrack. */
                for (++d, lnk[0] = '\0'; *d; d++)
                        if (*d == '/')
                                (void)strlcat(lnk, "../", sizeof(lnk));

                (void)strlcat(lnk, ++s, sizeof(lnk));

                do_symlink(lnk, to_name, target_sb);
                /* XXX: Link may point outside of destdir. */
                return;
        }

        /*
         * If absolute or relative was not specified, try the names the
         * user provided.
         */
        do_symlink(from_name, to_name, target_sb);
        /* XXX: from_name may point outside of destdir. */
}

/*
 * install --
 *      build a path name and install the file
 */
static void
install(const char *from_name, const char *to_name, u_long fset, u_long fclr,
        u_int flags)
{
        struct stat from_sb, temp_sb, to_sb;
        struct utimbuf utb;
        int devnull, files_match, from_fd, serrno, target;
        int tempcopy, temp_fd, to_fd;
#ifdef _ST_FLAGS_PRESENT_
        u_long nfset;
#endif
        char backup[MAXPATHLEN], *p, pathbuf[MAXPATHLEN], tempfile[MAXPATHLEN];

        files_match = 0;
        from_fd = -1;
        to_fd = -1;

        /* If try to install NULL file to a directory, fails. */
        if (flags & DIRECTORY || strcmp(from_name, _PATH_DEVNULL)) {
                if (!dolink) {
                        if (stat(from_name, &from_sb))
                                err(EX_OSERR, "%s", from_name);
                        if (!S_ISREG(from_sb.st_mode)) {
                                errno = EFTYPE;
                                err(EX_OSERR, "%s", from_name);
                        }
                }
                /* Build the target path. */
                if (flags & DIRECTORY) {
                        (void)snprintf(pathbuf, sizeof(pathbuf), "%s%s%s",
                            to_name,
                            to_name[strlen(to_name) - 1] == '/' ? "" : "/",
                            (p = strrchr(from_name, '/')) ? ++p : from_name);
                        to_name = pathbuf;
                }
                devnull = 0;
        } else {
                devnull = 1;
        }

        target = (lstat(to_name, &to_sb) == 0);

        if (dolink) {
                if (target && !safecopy) {
                        if (to_sb.st_mode & S_IFDIR && rmdir(to_name) == -1)
                                err(EX_OSERR, "%s", to_name);
#ifdef _ST_FLAGS_PRESENT_
                        if (to_sb.st_flags & NOCHANGEBITS)
                                (void)chflags(to_name,
                                    to_sb.st_flags & ~NOCHANGEBITS);
#endif
                        unlink(to_name);
                }
                makelink(from_name, to_name, target ? &to_sb : NULL);
                return;
        }

        if (target && !S_ISREG(to_sb.st_mode) && !S_ISLNK(to_sb.st_mode)) {
                errno = EFTYPE;
                warn("%s", to_name);
                return;
        }

        /* Only copy safe if the target exists. */
        tempcopy = safecopy && target;

        if (!devnull && (from_fd = open(from_name, O_RDONLY, 0)) < 0)
                err(EX_OSERR, "%s", from_name);

        /* If we don't strip, we can compare first. */
        if (docompare && !dostrip && target && S_ISREG(to_sb.st_mode)) {
                if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
                        err(EX_OSERR, "%s", to_name);
                if (devnull)
                        files_match = to_sb.st_size == 0;
                else
                        files_match = !(compare(from_fd, from_name,
                            (size_t)from_sb.st_size, to_fd,
                            to_name, (size_t)to_sb.st_size));

                /* Close "to" file unless we match. */
                if (!files_match)
                        (void)close(to_fd);
        }

        if (!files_match) {
                if (tempcopy) {
                        to_fd = create_tempfile(to_name, tempfile,
                            sizeof(tempfile));
                        if (to_fd < 0)
                                err(EX_OSERR, "%s", tempfile);
                } else {
                        if ((to_fd = create_newfile(to_name, target,
                            &to_sb)) < 0)
                                err(EX_OSERR, "%s", to_name);
                        if (verbose)
                                (void)printf("install: %s -> %s\n",
                                    from_name, to_name);
                }
                if (!devnull)
                        copy(from_fd, from_name, to_fd,
                             tempcopy ? tempfile : to_name, from_sb.st_size);
        }

        if (dostrip) {
                strip(tempcopy ? tempfile : to_name);

                /*
                 * Re-open our fd on the target, in case we used a strip
                 * that does not work in-place -- like GNU binutils strip.
                 */
                close(to_fd);
                to_fd = open(tempcopy ? tempfile : to_name, O_RDONLY, 0);
                if (to_fd < 0)
                        err(EX_OSERR, "stripping %s", to_name);
        }

        /*
         * Compare the stripped temp file with the target.
         */
        if (docompare && dostrip && target && S_ISREG(to_sb.st_mode)) {
                temp_fd = to_fd;

                /* Re-open to_fd using the real target name. */
                if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
                        err(EX_OSERR, "%s", to_name);

                if (fstat(temp_fd, &temp_sb)) {
                        serrno = errno;
                        (void)unlink(tempfile);
                        errno = serrno;
                        err(EX_OSERR, "%s", tempfile);
                }

                if (compare(temp_fd, tempfile, (size_t)temp_sb.st_size, to_fd,
                            to_name, (size_t)to_sb.st_size) == 0) {
                        /*
                         * If target has more than one link we need to
                         * replace it in order to snap the extra links.
                         * Need to preserve target file times, though.
                         */
                        if (to_sb.st_nlink != 1) {
                                utb.actime = to_sb.st_atime;
                                utb.modtime = to_sb.st_mtime;
                                utime(tempfile, &utb);
                        } else {
                                files_match = 1;
                                (void)unlink(tempfile);
                        }
                        (void) close(temp_fd);
                }
        }

        /*
         * Move the new file into place if doing a safe copy
         * and the files are different (or just not compared).
         */
        if (tempcopy && !files_match) {
#ifdef _ST_FLAGS_PRESENT_
                /* Try to turn off the immutable bits. */
                if (to_sb.st_flags & NOCHANGEBITS)
                        (void)chflags(to_name, to_sb.st_flags & ~NOCHANGEBITS);
#endif
                if (dobackup) {
                        if ((size_t)snprintf(backup, MAXPATHLEN, "%s%s", to_name,
                            suffix) != strlen(to_name) + strlen(suffix)) {
                                unlink(tempfile);
                                errx(EX_OSERR, "%s: backup filename too long",
                                    to_name);
                        }
                        if (verbose)
                                (void)printf("install: %s -> %s\n", to_name, backup);
                        if (rename(to_name, backup) < 0) {
                                serrno = errno;
                                unlink(tempfile);
                                errno = serrno;
                                err(EX_OSERR, "rename: %s to %s", to_name,
                                     backup);
                        }
                }
                if (verbose)
                        (void)printf("install: %s -> %s\n", from_name, to_name);
                if (rename(tempfile, to_name) < 0) {
                        serrno = errno;
                        unlink(tempfile);
                        errno = serrno;
                        err(EX_OSERR, "rename: %s to %s",
                            tempfile, to_name);
                }

                /* Re-open to_fd so we aren't hosed by the rename(2). */
                (void) close(to_fd);
                if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
                        err(EX_OSERR, "%s", to_name);
        }

        /*
         * Preserve the timestamp of the source file if necessary.
         */
        if (dopreserve && !files_match && !devnull) {
                utb.actime = from_sb.st_atime;
                utb.modtime = from_sb.st_mtime;
                utime(to_name, &utb);
        }

        if (fstat(to_fd, &to_sb) == -1) {
                serrno = errno;
                (void)unlink(to_name);
                errno = serrno;
                err(EX_OSERR, "%s", to_name);
        }

        /*
         * Set owner, group, mode for target; do the chown first,
         * chown may lose the setuid bits.
         */
#ifdef _ST_FLAGS_PRESENT_
        if (!dounpriv && ((gid != (gid_t)-1 && gid != to_sb.st_gid) ||
            (uid != (uid_t)-1 && uid != to_sb.st_uid) ||
            (mode != to_sb.st_mode))) {
                /* Try to turn off the immutable bits. */
                if (to_sb.st_flags & NOCHANGEBITS)
                        (void)fchflags(to_fd, to_sb.st_flags & ~NOCHANGEBITS);
        }
#endif

        if (!dounpriv && (
            (gid != (gid_t)-1 && gid != to_sb.st_gid) ||
            (uid != (uid_t)-1 && uid != to_sb.st_uid)))
                if (fchown(to_fd, uid, gid) == -1) {
                        serrno = errno;
                        (void)unlink(to_name);
                        errno = serrno;
                        err(EX_OSERR,"%s: chown/chgrp", to_name);
                }

        if (mode != to_sb.st_mode) {
                if (fchmod(to_fd,
                     dounpriv ? mode & (S_IRWXU|S_IRWXG|S_IRWXO) : mode)) {
                        serrno = errno;
                        (void)unlink(to_name);
                        errno = serrno;
                        err(EX_OSERR, "%s: chmod", to_name);
                }
        }

        /*
         * If provided a set of flags, set them, otherwise, preserve the
         * flags, except for the dump and history flags.  The dump flag
         * is left clear on the target while the history flag from when
         * the target was created (which is inherited from the target's
         * parent directory) is retained.
         */
#ifdef _ST_FLAGS_PRESENT_
        if (flags & SETFLAGS) {
                nfset = (to_sb.st_flags | fset) & ~fclr;
        } else {
                nfset = (from_sb.st_flags & ~(UF_NODUMP | UF_NOHISTORY)) |
                        (to_sb.st_flags & UF_NOHISTORY);
        }

        /*
         * NFS does not support flags.  Ignore EOPNOTSUPP flags if we're just
         * trying to turn off UF_NODUMP.  If we're trying to set real flags,
         * then warn if the fs doesn't support it, otherwise fail.
         */
        if (!dounpriv && !devnull && fchflags(to_fd, nfset)) {
                if (flags & SETFLAGS) {
                        if (errno == EOPNOTSUPP)
                                warn("%s: chflags", to_name);
                        else {
                                serrno = errno;
                                (void)unlink(to_name);
                                errno = serrno;
                                err(EX_OSERR, "%s: chflags", to_name);
                        }
                }
        }
#endif

        (void)close(to_fd);
        if (!devnull)
                (void)close(from_fd);
}

/*
 * compare --
 *      compare two files; non-zero means files differ
 */
static int
compare(int from_fd, const char *from_name __unused, size_t from_len,
        int to_fd, const char *to_name __unused, size_t to_len)
{
        char *p, *q;
        int rv;
        int done_compare;

        rv = 0;
        if (from_len != to_len)
                return 1;

        if (from_len <= MAX_CMP_SIZE) {
                done_compare = 0;
                if (trymmap(from_fd) && trymmap(to_fd)) {
                        p = mmap(NULL, from_len, PROT_READ, MAP_SHARED,
                            from_fd, (off_t)0);
                        if (p == (char *)MAP_FAILED)
                                goto out;
                        q = mmap(NULL, from_len, PROT_READ, MAP_SHARED,
                            to_fd, (off_t)0);
                        if (q == (char *)MAP_FAILED) {
                                munmap(p, from_len);
                                goto out;
                        }

                        rv = memcmp(p, q, from_len);
                        munmap(p, from_len);
                        munmap(q, from_len);
                        done_compare = 1;
                }
        out:
                if (!done_compare) {
                        char buf1[MAXBSIZE];
                        char buf2[MAXBSIZE];
                        int n1, n2;

                        rv = 0;
                        lseek(from_fd, 0, SEEK_SET);
                        lseek(to_fd, 0, SEEK_SET);
                        while (rv == 0) {
                                n1 = read(from_fd, buf1, sizeof(buf1));
                                if (n1 == 0)
                                        break;          /* EOF */
                                else if (n1 > 0) {
                                        n2 = read(to_fd, buf2, n1);
                                        if (n2 == n1)
                                                rv = memcmp(buf1, buf2, n1);
                                        else
                                                rv = 1; /* out of sync */
                                } else
                                        rv = 1;         /* read failure */
                        }
                        lseek(from_fd, 0, SEEK_SET);
                        lseek(to_fd, 0, SEEK_SET);
                }
        } else
                rv = 1; /* don't bother in this case */

        return rv;
}

/*
 * create_tempfile --
 *      create a temporary file based on path and open it
 */
static int
create_tempfile(const char *path, char *temp, size_t tsize)
{
        char *p;

        (void)strncpy(temp, path, tsize);
        temp[tsize - 1] = '\0';
        if ((p = strrchr(temp, '/')) != NULL)
                p++;
        else
                p = temp;
        (void)strncpy(p, "INS@XXXXXX", &temp[tsize - 1] - p);
        temp[tsize - 1] = '\0';
        return (mkstemp(temp));
}

/*
 * create_newfile --
 *      create a new file, overwriting an existing one if necessary
 */
static int
create_newfile(const char *path, int target, struct stat *sbp)
{
        char backup[MAXPATHLEN];

        if (target) {
                /*
                 * Unlink now... avoid ETXTBSY errors later.  Try to turn
                 * off the append/immutable bits -- if we fail, go ahead,
                 * it might work.
                 */
#ifdef _ST_FLAGS_PRESENT_
                if (sbp->st_flags & NOCHANGEBITS)
                        (void)chflags(path, sbp->st_flags & ~NOCHANGEBITS);
#endif

                if (dobackup) {
                        if ((size_t)snprintf(backup, MAXPATHLEN, "%s%s",
                            path, suffix) != strlen(path) + strlen(suffix))
                                errx(EX_OSERR, "%s: backup filename too long",
                                    path);
                        (void)snprintf(backup, MAXPATHLEN, "%s%s",
                            path, suffix);
                        if (verbose)
                                (void)printf("install: %s -> %s\n",
                                    path, backup);
                        if (rename(path, backup) < 0)
                                err(EX_OSERR, "rename: %s to %s", path, backup);
                } else
                        unlink(path);
        }

        return (open(path, O_CREAT | O_RDWR | O_TRUNC, S_IRUSR | S_IWUSR));
}

/*
 * copy --
 *      copy from one file to another
 */
static void
copy(int from_fd, const char *from_name, int to_fd,
     const char *to_name, off_t size)
{
        int nr, nw;
        int serrno;
        char *p;
        char buf[MAXBSIZE];
        int done_copy;

        /* Rewind file descriptors. */
        if (lseek(from_fd, (off_t)0, SEEK_SET) == (off_t)-1)
                err(EX_OSERR, "lseek: %s", from_name);
        if (lseek(to_fd, (off_t)0, SEEK_SET) == (off_t)-1)
                err(EX_OSERR, "lseek: %s", to_name);

        /*
         * Mmap and write if less than 8M (the limit is so we don't totally
         * trash memory on big files.  This is really a minor hack, but it
         * wins some CPU back.
         */
        done_copy = 0;
        if (size <= 8 * 1048576 && trymmap(from_fd) &&
            (p = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED,
                    from_fd, (off_t)0)) != (char *)MAP_FAILED) {
                nw = write(to_fd, p, size);
                if (nw != size) {
                        serrno = errno;
                        (void)unlink(to_name);
                        errno = nw > 0 ? EIO : serrno;
                        err(EX_OSERR, "%s", to_name);
                }
                done_copy = 1;
        }
        if (!done_copy) {
                while ((nr = read(from_fd, buf, sizeof(buf))) > 0) {
                        if ((nw = write(to_fd, buf, nr)) != nr) {
                                serrno = errno;
                                (void)unlink(to_name);
                                errno = nw > 0 ? EIO : serrno;
                                err(EX_OSERR, "%s", to_name);
                        }
                }
                if (nr != 0) {
                        serrno = errno;
                        (void)unlink(to_name);
                        errno = serrno;
                        err(EX_OSERR, "%s", from_name);
                }
        }
}

/*
 * strip --
 *      use strip(1) to strip the target file
 */
static void
strip(const char *to_name)
{
        const char *stripbin;
        int serrno, status;

        switch (fork()) {
        case -1:
                serrno = errno;
                (void)unlink(to_name);
                errno = serrno;
                err(EX_TEMPFAIL, "fork");
        case 0:
                stripbin = getenv("STRIPBIN");
                if (stripbin == NULL)
                        stripbin = "strip";
                execlp(stripbin, stripbin, to_name, NULL);
                err(EX_OSERR, "exec(%s)", stripbin);
        default:
                if (wait(&status) == -1 || status) {
                        serrno = errno;
                        (void)unlink(to_name);
                        errc(EX_SOFTWARE, serrno, "wait");
                        /* NOTREACHED */
                }
        }
}

/*
 * When doing a concurrent make -j N multiple install's can race the mkdir.
 */
static
int
mkdir_race(const char *path, int nmode)
{
        int res;
        struct stat sb;

        res = mkdir(path, nmode);
        if (res < 0 && errno == EEXIST) {
                if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode))
                        return(0);
                res = mkdir(path, nmode);
        }
        return (res);
}

/*
 * install_dir --
 *      build directory hierarchy
 */
static void
install_dir(char *path)
{
        char *p;
        struct stat sb;
        int ch;

        for (p = path;; ++p)
                if (!*p || (p != path && *p  == '/')) {
                        ch = *p;
                        *p = '\0';
                        if (stat(path, &sb)) {
                                if (errno != ENOENT ||
                                    mkdir_race(path, 0755) < 0) {
                                        err(EX_OSERR, "mkdir %s", path);
                                        /* NOTREACHED */
                                } else if (verbose)
                                        (void)printf("install: mkdir %s\n",
                                                     path);
                        } else if (!S_ISDIR(sb.st_mode))
                                errx(EX_OSERR, "%s exists but is not a directory", path);
                        if (!(*p = ch))
                                break;
                }

        if (!dounpriv) {
                if ((gid != (gid_t)-1 || uid != (uid_t)-1) &&
                    chown(path, uid, gid))
                        warn("chown %u:%u %s", uid, gid, path);
                /* XXXBED: should we do the chmod in the dounpriv case? */
                if (chmod(path, mode))
                        warn("chmod %o %s", mode, path);
        }
}

/*
 * usage --
 *      print a usage message and die
 */
static void
usage(void)
{
        fprintf(stderr,
"usage: install [-bCcpSsUv] [-f flags] [-g group] [-m mode] [-o owner]\n"
"               [-D dest] [-h hash]\n"
"               [-B suffix] [-l linkflags] [-N dbdir]\n"
"               file1 file2\n"
"       install [-bCcpSsUv] [-B suffix] [-D dest] [-f flags] [-g group]\n"
"               [-N dbdir] [-m mode] [-o owner] file1 ... fileN directory\n"
"       install -d [-lUv] [-D dest] [-g group] [-m mode] [-N dbdir] [-o owner]\n"
"               directory ...\n");
        exit(EX_USAGE);
        /* NOTREACHED */
}

/*
 * trymmap --
 *      return true (1) if mmap should be tried, false (0) if not.
 */
static int
trymmap(int fd)
{
/*
 * The ifdef is for bootstrapping - f_fstypename doesn't exist in
 * pre-Lite2-merge systems.
 */
#ifdef MFSNAMELEN
        struct statfs stfs;

        if (nommap || fstatfs(fd, &stfs) != 0)
                return (0);
        if (strcmp(stfs.f_fstypename, "ufs") == 0 ||
            strcmp(stfs.f_fstypename, "cd9660") == 0)
                return (1);
#endif
        return (0);
}