/*-
 * Copyright (c) 2007 Kai Wang
 * Copyright (c) 2007 Tim Kientzle
 * 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
 *    in this position and unchanged.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
 */

#include "archive_platform.h"
__FBSDID("$FreeBSD: src/lib/libarchive/archive_write_set_format_ar.c,v 1.8 2008/08/10 02:06:28 kientzle Exp $");

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif

#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
#include "archive_write_private.h"

struct ar_w {
    uint64_t     entry_bytes_remaining;
    uint64_t     entry_padding;
    int      is_strtab;
    int      has_strtab;
    char        *strtab;
};

/*
 * Define structure of the "ar" header.
 */
#define AR_name_offset 0
#define AR_name_size 16
#define AR_date_offset 16
#define AR_date_size 12
#define AR_uid_offset 28
#define AR_uid_size 6
#define AR_gid_offset 34
#define AR_gid_size 6
#define AR_mode_offset 40
#define AR_mode_size 8
#define AR_size_offset 48
#define AR_size_size 10
#define AR_fmag_offset 58
#define AR_fmag_size 2

static int       archive_write_set_format_ar(struct archive_write *);
static int       archive_write_ar_header(struct archive_write *,
                 struct archive_entry *);
static ssize_t       archive_write_ar_data(struct archive_write *,
                 const void *buff, size_t s);
static int       archive_write_ar_destroy(struct archive_write *);
static int       archive_write_ar_finish(struct archive_write *);
static int       archive_write_ar_finish_entry(struct archive_write *);
static const char   *ar_basename(const char *path);
static int       format_octal(int64_t v, char *p, int s);
static int       format_decimal(int64_t v, char *p, int s);

int
archive_write_set_format_ar_bsd(struct archive *_a)
{
    struct archive_write *a = (struct archive_write *)_a;
    int r = archive_write_set_format_ar(a);
    if (r == ARCHIVE_OK) {
        a->archive.archive_format = ARCHIVE_FORMAT_AR_BSD;
        a->archive.archive_format_name = "ar (BSD)";
    }
    return (r);
}

int
archive_write_set_format_ar_svr4(struct archive *_a)
{
    struct archive_write *a = (struct archive_write *)_a;
    int r = archive_write_set_format_ar(a);
    if (r == ARCHIVE_OK) {
        a->archive.archive_format = ARCHIVE_FORMAT_AR_GNU;
        a->archive.archive_format_name = "ar (GNU/SVR4)";
    }
    return (r);
}

/*
 * Generic initialization.
 */
static int
archive_write_set_format_ar(struct archive_write *a)
{
    struct ar_w *ar;

    /* If someone else was already registered, unregister them. */
    if (a->format_destroy != NULL)
        (a->format_destroy)(a);

    ar = (struct ar_w *)malloc(sizeof(*ar));
    if (ar == NULL) {
        archive_set_error(&a->archive, ENOMEM, "Can't allocate ar data");
        return (ARCHIVE_FATAL);
    }
    memset(ar, 0, sizeof(*ar));
    a->format_data = ar;

    a->format_name = "ar";
    a->format_write_header = archive_write_ar_header;
    a->format_write_data = archive_write_ar_data;
    a->format_finish = archive_write_ar_finish;
    a->format_destroy = archive_write_ar_destroy;
    a->format_finish_entry = archive_write_ar_finish_entry;
    return (ARCHIVE_OK);
}

static int
archive_write_ar_header(struct archive_write *a, struct archive_entry *entry)
{
    int ret, append_fn;
    char buff[60];
    char *ss, *se;
    struct ar_w *ar;
    const char *pathname;
    const char *filename;
    int64_t size;

    ret = 0;
    append_fn = 0;
    ar = (struct ar_w *)a->format_data;
    ar->is_strtab = 0;
    filename = NULL;
    size = archive_entry_size(entry);


    /*
     * Reject files with empty name.
     */
    pathname = archive_entry_pathname(entry);
    if (*pathname == '\0') {
        archive_set_error(&a->archive, EINVAL,
            "Invalid filename");
        return (ARCHIVE_WARN);
    }

    /*
     * If we are now at the beginning of the archive,
     * we need first write the ar global header.
     */
    if (a->archive.file_position == 0)
        (a->compressor.write)(a, "!<arch>\n", 8);

    memset(buff, ' ', 60);
    strncpy(&buff[AR_fmag_offset], "`\n", 2);

    if (strcmp(pathname, "/") == 0 ) {
        /* Entry is archive symbol table in GNU format */
        buff[AR_name_offset] = '/';
        goto stat;
    }
    if (strcmp(pathname, "__.SYMDEF") == 0) {
        /* Entry is archive symbol table in BSD format */
        strncpy(buff + AR_name_offset, "__.SYMDEF", 9);
        goto stat;
    }
    if (strcmp(pathname, "//") == 0) {
        /*
         * Entry is archive filename table, inform that we should
         * collect strtab in next _data call.
         */
        ar->is_strtab = 1;
        buff[AR_name_offset] = buff[AR_name_offset + 1] = '/';
        /*
         * For archive string table, only ar_size filed should
         * be set.
         */
        goto size;
    }

    /*
     * Otherwise, entry is a normal archive member.
     * Strip leading paths from filenames, if any.
     */
    if ((filename = ar_basename(pathname)) == NULL) {
        /* Reject filenames with trailing "/" */
        archive_set_error(&a->archive, EINVAL,
            "Invalid filename");
        return (ARCHIVE_WARN);
    }

    if (a->archive.archive_format == ARCHIVE_FORMAT_AR_GNU) {
        /*
         * SVR4/GNU variant use a "/" to mark then end of the filename,
         * make it possible to have embedded spaces in the filename.
         * So, the longest filename here (without extension) is
         * actually 15 bytes.
         */
        if (strlen(filename) <= 15) {
            strncpy(&buff[AR_name_offset], 
                filename, strlen(filename));
            buff[AR_name_offset + strlen(filename)] = '/';
        } else {
            /*
             * For filename longer than 15 bytes, GNU variant
             * makes use of a string table and instead stores the
             * offset of the real filename to in the ar_name field.
             * The string table should have been written before.
             */
            if (ar->has_strtab <= 0) {
                archive_set_error(&a->archive, EINVAL,
                    "Can't find string table");
                return (ARCHIVE_WARN);
            }

            se = (char *)malloc(strlen(filename) + 3);
            if (se == NULL) {
                archive_set_error(&a->archive, ENOMEM,
                    "Can't allocate filename buffer");
                return (ARCHIVE_FATAL);
            }

            strncpy(se, filename, strlen(filename));
            strcpy(se + strlen(filename), "/\n");

            ss = strstr(ar->strtab, se);
            free(se);

            if (ss == NULL) {
                archive_set_error(&a->archive, EINVAL,
                    "Invalid string table");
                return (ARCHIVE_WARN);
            }

            /*
             * GNU variant puts "/" followed by digits into
             * ar_name field. These digits indicates the real
             * filename string's offset to the string table.
             */
            buff[AR_name_offset] = '/';
            if (format_decimal(ss - ar->strtab,
                buff + AR_name_offset + 1,
                AR_name_size - 1)) {
                archive_set_error(&a->archive, ERANGE,
                    "string table offset too large");
                return (ARCHIVE_WARN);
            }
        }
    } else if (a->archive.archive_format == ARCHIVE_FORMAT_AR_BSD) {
        /*
         * BSD variant: for any file name which is more than
         * 16 chars or contains one or more embedded space(s), the
         * string "#1/" followed by the ASCII length of the name is
         * put into the ar_name field. The file size (stored in the
         * ar_size field) is incremented by the length of the name.
         * The name is then written immediately following the
         * archive header.
         */
        if (strlen(filename) <= 16 && strchr(filename, ' ') == NULL) {
            strncpy(&buff[AR_name_offset], filename, strlen(filename));
            buff[AR_name_offset + strlen(filename)] = ' ';
        }
        else {
            strncpy(buff + AR_name_offset, "#1/", 3);
            if (format_decimal(strlen(filename),
                buff + AR_name_offset + 3,
                AR_name_size - 3)) {
                archive_set_error(&a->archive, ERANGE,
                    "File name too long");
                return (ARCHIVE_WARN);
            }
            append_fn = 1;
            size += strlen(filename);
        }
    }

stat:
    if (format_decimal(archive_entry_mtime(entry), buff + AR_date_offset, AR_date_size)) {
        archive_set_error(&a->archive, ERANGE,
            "File modification time too large");
        return (ARCHIVE_WARN);
    }
    if (format_decimal(archive_entry_uid(entry), buff + AR_uid_offset, AR_uid_size)) {
        archive_set_error(&a->archive, ERANGE,
            "Numeric user ID too large");
        return (ARCHIVE_WARN);
    }
    if (format_decimal(archive_entry_gid(entry), buff + AR_gid_offset, AR_gid_size)) {
        archive_set_error(&a->archive, ERANGE,
            "Numeric group ID too large");
        return (ARCHIVE_WARN);
    }
    if (format_octal(archive_entry_mode(entry), buff + AR_mode_offset, AR_mode_size)) {
        archive_set_error(&a->archive, ERANGE,
            "Numeric mode too large");
        return (ARCHIVE_WARN);
    }
    /*
     * Sanity Check: A non-pseudo archive member should always be
     * a regular file.
     */
    if (filename != NULL && archive_entry_filetype(entry) != AE_IFREG) {
        archive_set_error(&a->archive, EINVAL,
            "Regular file required for non-pseudo member");
        return (ARCHIVE_WARN);
    }

size:
    if (format_decimal(size, buff + AR_size_offset, AR_size_size)) {
        archive_set_error(&a->archive, ERANGE,
            "File size out of range");
        return (ARCHIVE_WARN);
    }

    ret = (a->compressor.write)(a, buff, 60);
    if (ret != ARCHIVE_OK)
        return (ret);

    ar->entry_bytes_remaining = size;
    ar->entry_padding = ar->entry_bytes_remaining % 2;

    if (append_fn > 0) {
        ret = (a->compressor.write)(a, filename, strlen(filename));
        if (ret != ARCHIVE_OK)
            return (ret);
        ar->entry_bytes_remaining -= strlen(filename);
    }

    return (ARCHIVE_OK);
}

static ssize_t
archive_write_ar_data(struct archive_write *a, const void *buff, size_t s)
{
    struct ar_w *ar;
    int ret;

    ar = (struct ar_w *)a->format_data;
    if (s > ar->entry_bytes_remaining)
        s = ar->entry_bytes_remaining;

    if (ar->is_strtab > 0) {
        if (ar->has_strtab > 0) {
            archive_set_error(&a->archive, EINVAL,
                "More than one string tables exist");
            return (ARCHIVE_WARN);
        }

        ar->strtab = (char *)malloc(s);
        if (ar->strtab == NULL) {
            archive_set_error(&a->archive, ENOMEM,
                "Can't allocate strtab buffer");
            return (ARCHIVE_FATAL);
        }
        strncpy(ar->strtab, buff, s);
        ar->has_strtab = 1;
    }

    ret = (a->compressor.write)(a, buff, s);
    if (ret != ARCHIVE_OK)
        return (ret);

    ar->entry_bytes_remaining -= s;
    return (s);
}

static int
archive_write_ar_destroy(struct archive_write *a)
{
    struct ar_w *ar;

    ar = (struct ar_w *)a->format_data;

    if (ar == NULL)
        return (ARCHIVE_OK);

    if (ar->has_strtab > 0) {
        free(ar->strtab);
        ar->strtab = NULL;
    }

    free(ar);
    a->format_data = NULL;
    return (ARCHIVE_OK);
}

static int
archive_write_ar_finish(struct archive_write *a)
{
    int ret;

    /*
     * If we haven't written anything yet, we need to write
     * the ar global header now to make it a valid ar archive.
     */
    if (a->archive.file_position == 0) {
        ret = (a->compressor.write)(a, "!<arch>\n", 8);
        return (ret);
    }

    return (ARCHIVE_OK);
}

static int
archive_write_ar_finish_entry(struct archive_write *a)
{
    struct ar_w *ar;
    int ret;

    ar = (struct ar_w *)a->format_data;

    if (ar->entry_bytes_remaining != 0) {
        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
            "Entry remaining bytes larger than 0");
        return (ARCHIVE_WARN);
    }

    if (ar->entry_padding == 0) {
        return (ARCHIVE_OK);
    }

    if (ar->entry_padding != 1) {
        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
            "Padding wrong size: %d should be 1 or 0",
            ar->entry_padding);
        return (ARCHIVE_WARN);
    }

    ret = (a->compressor.write)(a, "\n", 1);
    return (ret);
}

/*
 * Format a number into the specified field using base-8.
 * NB: This version is slightly different from the one in
 * _ustar.c
 */
static int
format_octal(int64_t v, char *p, int s)
{
    int len;
    char *h;

    len = s;
    h = p;

    /* Octal values can't be negative, so use 0. */
    if (v < 0) {
        while (len-- > 0)
            *p++ = '0';
        return (-1);
    }

    p += s;     /* Start at the end and work backwards. */
    do {
        *--p = (char)('0' + (v & 7));
        v >>= 3;
    } while (--s > 0 && v > 0);

    if (v == 0) {
        memmove(h, p, len - s);
        p = h + len - s;
        while (s-- > 0)
            *p++ = ' ';
        return (0);
    }
    /* If it overflowed, fill field with max value. */
    while (len-- > 0)
        *p++ = '7';

    return (-1);
}

/*
 * Format a number into the specified field using base-10.
 */
static int
format_decimal(int64_t v, char *p, int s)
{
    int len;
    char *h;

    len = s;
    h = p;

    /* Negative values in ar header are meaningless , so use 0. */
    if (v < 0) {
        while (len-- > 0)
            *p++ = '0';
        return (-1);
    }

    p += s;
    do {
        *--p = (char)('0' + (v % 10));
        v /= 10;
    } while (--s > 0 && v > 0);

    if (v == 0) {
        memmove(h, p, len - s);
        p = h + len - s;
        while (s-- > 0)
            *p++ = ' ';
        return (0);
    }
    /* If it overflowed, fill field with max value. */
    while (len-- > 0)
        *p++ = '9';

    return (-1);
}

static const char *
ar_basename(const char *path)
{
    const char *endp, *startp;

    endp = path + strlen(path) - 1;
    /*
     * For filename with trailing slash(es), we return
     * NULL indicating an error.
     */
    if (*endp == '/')
        return (NULL);

    /* Find the start of the base */
    startp = endp;
    while (startp > path && *(startp - 1) != '/')
        startp--;
    
    return (startp);
}
