/*
 * 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.
 */

/*
 * Copyright 2024-2025 RackTop Systems, Inc.
 */

#include "libcmdutils.h"

/*
 * Helper for mv/cp/ln (see $SRC/cmd/mv)
 * Copy a file "in" to "out" where
 *      fi is a file descriptor open for read on "in"
 *      fo is a file descriptor open for write on "out"
 *      infile is a name used for error messages re. "in"
 *      outfile is a name used for error messages re. "out"
 *      asfile is an attr. name on "in" if copying an attr, else NULL
 *      atfile is an attr. name on "out" if copying an attr, else NULL
 *      s1p points to stat info for "in"
 *      s2p points to stat info for "out"
 *
 * Returns 0 on success.  Returns 1 on failure AND closes fi, fo!
 *
 * Closing fi, fo on error may be surprising as an interface design
 * but callers expect this behavior.
 */
int
writefile(int fi, int fo, const char *infile, const char *outfile,
    const char *asfile, const char *atfile, struct stat *s1p, struct stat *s2p)
{
        int mapsize, munmapsize;
        caddr_t cp;
        off_t filesize = s1p->st_size;
        off_t offset;
        int nbytes;
        int remains;
        int n;
        size_t src_size;
        size_t targ_size;
        char *srcbuf;
        char *targbuf;

        if (asfile != NULL) {
                src_size = strlen(infile) + strlen(asfile) +
                    strlen(dgettext(TEXT_DOMAIN, " attribute ")) + 1;
        } else {
                src_size = strlen(infile) + 1;
        }
        srcbuf = malloc(src_size);
        if (srcbuf == NULL) {
                (void) fprintf(stderr,
                    dgettext(TEXT_DOMAIN, "could not allocate memory"
                    " for path buffer\n"));
                (void) close(fi);
                (void) close(fo);
                return (1);
        }
        if (asfile != NULL) {
                (void) snprintf(srcbuf, src_size, "%s%s%s",
                    infile, dgettext(TEXT_DOMAIN, " attribute "), asfile);
        } else {
                (void) snprintf(srcbuf, src_size, "%s", infile);
        }

        if (atfile != NULL) {
                targ_size = strlen(outfile) + strlen(atfile) +
                    strlen(dgettext(TEXT_DOMAIN, " attribute ")) + 1;
        } else {
                targ_size = strlen(outfile) + 1;
        }
        targbuf = malloc(targ_size);
        if (targbuf == NULL) {
                (void) fprintf(stderr,
                    dgettext(TEXT_DOMAIN, "could not allocate memory"
                    " for path buffer\n"));
                free(srcbuf);
                (void) close(fi);
                (void) close(fo);
                return (1);
        }
        if (atfile != NULL) {
                (void) snprintf(targbuf, targ_size, "%s%s%s",
                    outfile, dgettext(TEXT_DOMAIN, " attribute "), atfile);
        } else {
                (void) snprintf(targbuf, targ_size, "%s", outfile);
        }

        if (S_ISREG(s1p->st_mode) && s1p->st_size > SMALLFILESIZE) {
                /*
                 * Determine size of initial mapping.  This will determine the
                 * size of the address space chunk we work with.  This initial
                 * mapping size will be used to perform munmap() in the future.
                 */
                mapsize = MAXMAPSIZE;
                if (s1p->st_size < mapsize) mapsize = s1p->st_size;
                munmapsize = mapsize;

                /*
                 * Mmap time!
                 */
                if ((cp = mmap((caddr_t)NULL, mapsize, PROT_READ,
                    MAP_SHARED, fi, (off_t)0)) == MAP_FAILED)
                        mapsize = 0;   /* can't mmap today */
        } else
                mapsize = 0;

        if (mapsize != 0) {
                offset = 0;

                for (;;) {
                        nbytes = write(fo, cp, mapsize);
                        /*
                         * if we write less than the mmaped size it's due to a
                         * media error on the input file or out of space on
                         * the output file.  So, try again, and look for errno.
                         */
                        if ((nbytes >= 0) && (nbytes != (int)mapsize)) {
                                remains = mapsize - nbytes;
                                while (remains > 0) {
                                        nbytes = write(fo,
                                            cp + mapsize - remains, remains);
                                        if (nbytes < 0) {
                                                if (errno == ENOSPC)
                                                        perror(targbuf);
                                                else
                                                        perror(srcbuf);
                                                (void) close(fi);
                                                (void) close(fo);
                                                (void) munmap(cp, munmapsize);
                                                if (S_ISREG(s2p->st_mode))
                                                        (void) unlink(targbuf);
                                                free(srcbuf);
                                                free(targbuf);
                                                return (1);
                                        }
                                        remains -= nbytes;
                                        if (remains == 0)
                                                nbytes = mapsize;
                                }
                        }
                        /*
                         * although the write manual page doesn't specify this
                         * as a possible errno, it is set when the nfs read
                         * via the mmap'ed file is accessed, so report the
                         * problem as a source access problem, not a target file
                         * problem
                         */
                        if (nbytes < 0) {
                                if (errno == EACCES)
                                        perror(srcbuf);
                                else
                                        perror(targbuf);
                                (void) close(fi);
                                (void) close(fo);
                                (void) munmap(cp, munmapsize);
                                if (S_ISREG(s2p->st_mode))
                                        (void) unlink(targbuf);
                                free(srcbuf);
                                free(targbuf);
                                return (1);
                        }
                        filesize -= nbytes;
                        if (filesize == 0)
                                break;
                        offset += nbytes;
                        if (filesize < mapsize)
                                mapsize = filesize;
                        if (mmap(cp, mapsize, PROT_READ, MAP_SHARED |
                            MAP_FIXED, fi, offset) == MAP_FAILED) {
                                perror(srcbuf);
                                (void) close(fi);
                                (void) close(fo);
                                (void) munmap(cp, munmapsize);
                                if (S_ISREG(s2p->st_mode))
                                        (void) unlink(targbuf);
                                free(srcbuf);
                                free(targbuf);
                                return (1);
                        }
                }
                (void) munmap(cp, munmapsize);
        } else {
                char buf[SMALLFILESIZE];
                for (;;) {
                        n = read(fi, buf, sizeof (buf));
                        if (n == 0) {
                                free(srcbuf);
                                free(targbuf);
                                return (0);
                        } else if (n < 0) {
                                (void) close(fi);
                                (void) close(fo);
                                if (S_ISREG(s2p->st_mode))
                                        (void) unlink(targbuf);
                                free(srcbuf);
                                free(targbuf);
                                return (1);
                        } else if (write(fo, buf, n) != n) {
                                (void) close(fi);
                                (void) close(fo);
                                if (S_ISREG(s2p->st_mode))
                                        (void) unlink(targbuf);
                                free(srcbuf);
                                free(targbuf);
                                return (1);
                        }
                }
        }
        free(srcbuf);
        free(targbuf);
        return (0);
}