Import libarchive-2.4.17. See NEWS for details.

[dragonfly.git] / contrib / libarchive-2 / libarchive / archive_read_support_format_ar.c

/*-
 * 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_read_support_format_ar.c,v 1.8 2008/02/19 05:54:24 kientzle Exp $");

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#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_read_private.h"

struct ar {
        off_t    entry_bytes_remaining;
        off_t    entry_offset;
        off_t    entry_padding;
        char    *strtab;
        size_t   strtab_size;
};

/*
 * 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

#define isdigit(x)      (x) >= '0' && (x) <= '9'

static int      archive_read_format_ar_bid(struct archive_read *a);
static int      archive_read_format_ar_cleanup(struct archive_read *a);
static int      archive_read_format_ar_read_data(struct archive_read *a,
                    const void **buff, size_t *size, off_t *offset);
static int      archive_read_format_ar_skip(struct archive_read *a);
static int      archive_read_format_ar_read_header(struct archive_read *a,
                    struct archive_entry *e);
static uint64_t ar_atol8(const char *p, unsigned char_cnt);
static uint64_t ar_atol10(const char *p, unsigned char_cnt);
static int      ar_parse_gnu_filename_table(struct archive_read *, struct ar *,
                    const void *, size_t);
static int      ar_parse_common_header(struct ar *ar, struct archive_entry *,
                    const char *h);

int
archive_read_support_format_ar(struct archive *_a)
{
        struct archive_read *a = (struct archive_read *)_a;
        struct ar *ar;
        int r;

        ar = (struct ar *)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));
        ar->strtab = NULL;

        r = __archive_read_register_format(a,
            ar,
            archive_read_format_ar_bid,
            archive_read_format_ar_read_header,
            archive_read_format_ar_read_data,
            archive_read_format_ar_skip,
            archive_read_format_ar_cleanup);

        if (r != ARCHIVE_OK) {
                free(ar);
                return (r);
        }
        return (ARCHIVE_OK);
}

static int
archive_read_format_ar_cleanup(struct archive_read *a)
{
        struct ar *ar;

        ar = (struct ar *)(a->format->data);
        if (ar->strtab)
                free(ar->strtab);
        free(ar);
        (a->format->data) = NULL;
        return (ARCHIVE_OK);
}

static int
archive_read_format_ar_bid(struct archive_read *a)
{
        struct ar *ar;
        ssize_t bytes_read;
        const void *h;

        if (a->archive.archive_format != 0 &&
            (a->archive.archive_format & ARCHIVE_FORMAT_BASE_MASK) !=
            ARCHIVE_FORMAT_AR)
                return(0);

        ar = (struct ar *)(a->format->data);

        /*
         * Verify the 8-byte file signature.
         * TODO: Do we need to check more than this?
         */
        bytes_read = (a->decompressor->read_ahead)(a, &h, 8);
        if (bytes_read < 8)
                return (-1);
        if (strncmp((const char*)h, "!<arch>\n", 8) == 0) {
                return (64);
        }
        return (-1);
}

static int
archive_read_format_ar_read_header(struct archive_read *a,
    struct archive_entry *entry)
{
        char filename[AR_name_size + 1];
        struct ar *ar;
        uint64_t number; /* Used to hold parsed numbers before validation. */
        ssize_t bytes_read;
        size_t bsd_name_length, entry_size;
        char *p;
        const void *b;
        const char *h;
        int r;

        ar = (struct ar*)(a->format->data);

        if (a->archive.file_position == 0) {
                /*
                 * We are now at the beginning of the archive,
                 * so we need first consume the ar global header.
                 */
                (a->decompressor->consume)(a, 8);
                /* Set a default format code for now. */
                a->archive.archive_format = ARCHIVE_FORMAT_AR;
        }

        /* Read the header for the next file entry. */
        bytes_read = (a->decompressor->read_ahead)(a, &b, 60);
        if (bytes_read < 60) {
                /* Broken header. */
                return (ARCHIVE_EOF);
        }
        (a->decompressor->consume)(a, 60);
        h = (const char *)b;

        /* Verify the magic signature on the file header. */
        if (strncmp(h + AR_fmag_offset, "`\n", 2) != 0) {
                archive_set_error(&a->archive, EINVAL,
                    "Consistency check failed");
                return (ARCHIVE_WARN);
        }

        /* Copy filename into work buffer. */
        strncpy(filename, h + AR_name_offset, AR_name_size);
        filename[AR_name_size] = '\0';

        /*
         * Guess the format variant based on the filename.
         */
        if (a->archive.archive_format == ARCHIVE_FORMAT_AR) {
                /* We don't already know the variant, so let's guess. */
                /*
                 * Biggest clue is presence of '/': GNU starts special
                 * filenames with '/', appends '/' as terminator to
                 * non-special names, so anything with '/' should be
                 * GNU except for BSD long filenames.
                 */
                if (strncmp(filename, "#1/", 3) == 0)
                        a->archive.archive_format = ARCHIVE_FORMAT_AR_BSD;
                else if (strchr(filename, '/') != NULL)
                        a->archive.archive_format = ARCHIVE_FORMAT_AR_GNU;
                else if (strncmp(filename, "__.SYMDEF", 9) == 0)
                        a->archive.archive_format = ARCHIVE_FORMAT_AR_BSD;
                /*
                 * XXX Do GNU/SVR4 'ar' programs ever omit trailing '/'
                 * if name exactly fills 16-byte field?  If so, we
                 * can't assume entries without '/' are BSD. XXX
                 */
        }

        /* Update format name from the code. */
        if (a->archive.archive_format == ARCHIVE_FORMAT_AR_GNU)
                a->archive.archive_format_name = "ar (GNU/SVR4)";
        else if (a->archive.archive_format == ARCHIVE_FORMAT_AR_BSD)
                a->archive.archive_format_name = "ar (BSD)";
        else
                a->archive.archive_format_name = "ar";

        /*
         * Remove trailing spaces from the filename.  GNU and BSD
         * variants both pad filename area out with spaces.
         * This will only be wrong if GNU/SVR4 'ar' implementations
         * omit trailing '/' for 16-char filenames and we have
         * a 16-char filename that ends in ' '.
         */
        p = filename + AR_name_size - 1;
        while (p >= filename && *p == ' ') {
                *p = '\0';
                p--;
        }

        /*
         * Remove trailing slash unless first character is '/'.
         * (BSD entries never end in '/', so this will only trim
         * GNU-format entries.  GNU special entries start with '/'
         * and are not terminated in '/', so we don't trim anything
         * that starts with '/'.)
         */
        if (filename[0] != '/' && *p == '/')
                *p = '\0';

        /*
         * '//' is the GNU filename table.
         * Later entries can refer to names in this table.
         */
        if (strcmp(filename, "//") == 0) {
                /* This must come before any call to _read_ahead. */
                ar_parse_common_header(ar, entry, h);
                archive_entry_copy_pathname(entry, filename);
                archive_entry_set_filetype(entry, AE_IFREG);
                /* Get the size of the filename table. */
                number = ar_atol10(h + AR_size_offset, AR_size_size);
                if (number > SIZE_MAX) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "Filename table too large");
                        return (ARCHIVE_FATAL);
                }
                entry_size = (size_t)number;
                /* Read the filename table into memory. */
                bytes_read = (a->decompressor->read_ahead)(a, &b, entry_size);
                if (bytes_read <= 0)
                        return (ARCHIVE_FATAL);
                if ((size_t)bytes_read < entry_size) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "Truncated input file");
                        return (ARCHIVE_FATAL);
                }
                /*
                 * Don't consume the contents, so the client will
                 * also get a shot at reading it.
                 */

                /* Parse the filename table. */
                return (ar_parse_gnu_filename_table(a, ar, b, entry_size));
        }

        /*
         * GNU variant handles long filenames by storing /<number>
         * to indicate a name stored in the filename table.
         */
        if (filename[0] == '/' && isdigit(filename[1])) {
                number = ar_atol10(h + AR_name_offset + 1, AR_name_size - 1);
                /*
                 * If we can't look up the real name, warn and return
                 * the entry with the wrong name.
                 */
                if (ar->strtab == NULL || number > ar->strtab_size) {
                        archive_set_error(&a->archive, EINVAL,
                            "Can't find long filename for entry");
                        archive_entry_copy_pathname(entry, filename);
                        /* Parse the time, owner, mode, size fields. */
                        ar_parse_common_header(ar, entry, h);
                        return (ARCHIVE_WARN);
                }

                archive_entry_copy_pathname(entry, &ar->strtab[(size_t)number]);
                /* Parse the time, owner, mode, size fields. */
                return (ar_parse_common_header(ar, entry, h));
        }

        /*
         * BSD handles long filenames by storing "#1/" followed by the
         * length of filename as a decimal number, then prepends the
         * the filename to the file contents.
         */
        if (strncmp(filename, "#1/", 3) == 0) {
                /* Parse the time, owner, mode, size fields. */
                /* This must occur before _read_ahead is called again. */
                ar_parse_common_header(ar, entry, h);

                /* Parse the size of the name, adjust the file size. */
                number = ar_atol10(h + AR_name_offset + 3, AR_name_size - 3);
                if ((off_t)number > ar->entry_bytes_remaining) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "Bad input file size");
                        return (ARCHIVE_FATAL);
                }
                bsd_name_length = (size_t)number;
                ar->entry_bytes_remaining -= bsd_name_length;
                /* Adjust file size reported to client. */
                archive_entry_set_size(entry, ar->entry_bytes_remaining);

                /* Read the long name into memory. */
                bytes_read = (a->decompressor->read_ahead)(a, &b, bsd_name_length);
                if (bytes_read <= 0)
                        return (ARCHIVE_FATAL);
                if ((size_t)bytes_read < bsd_name_length) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "Truncated input file");
                        return (ARCHIVE_FATAL);
                }
                (a->decompressor->consume)(a, bsd_name_length);

                /* Store it in the entry. */
                p = (char *)malloc(bsd_name_length + 1);
                if (p == NULL) {
                        archive_set_error(&a->archive, ENOMEM,
                            "Can't allocate fname buffer");
                        return (ARCHIVE_FATAL);
                }
                strncpy(p, b, bsd_name_length);
                p[bsd_name_length] = '\0';
                archive_entry_copy_pathname(entry, p);
                free(p);
                return (ARCHIVE_OK);
        }

        /*
         * "/" is the SVR4/GNU archive symbol table.
         */
        if (strcmp(filename, "/") == 0) {
                archive_entry_copy_pathname(entry, "/");
                /* Parse the time, owner, mode, size fields. */
                r = ar_parse_common_header(ar, entry, h);
                /* Force the file type to a regular file. */
                archive_entry_set_filetype(entry, AE_IFREG);
                return (r);
        }

        /*
         * "__.SYMDEF" is a BSD archive symbol table.
         */
        if (strcmp(filename, "__.SYMDEF") == 0) {
                archive_entry_copy_pathname(entry, filename);
                /* Parse the time, owner, mode, size fields. */
                return (ar_parse_common_header(ar, entry, h));
        }

        /*
         * Otherwise, this is a standard entry.  The filename
         * has already been trimmed as much as possible, based
         * on our current knowledge of the format.
         */
        archive_entry_copy_pathname(entry, filename);
        return (ar_parse_common_header(ar, entry, h));
}

static int
ar_parse_common_header(struct ar *ar, struct archive_entry *entry,
    const char *h)
{
        uint64_t n;

        /* Copy remaining header */
        archive_entry_set_mtime(entry,
            (time_t)ar_atol10(h + AR_date_offset, AR_date_size), 0L);
        archive_entry_set_uid(entry,
            (uid_t)ar_atol10(h + AR_uid_offset, AR_uid_size));
        archive_entry_set_gid(entry,
            (gid_t)ar_atol10(h + AR_gid_offset, AR_gid_size));
        archive_entry_set_mode(entry,
            (mode_t)ar_atol8(h + AR_mode_offset, AR_mode_size));
        n = ar_atol10(h + AR_size_offset, AR_size_size);

        ar->entry_offset = 0;
        ar->entry_padding = n % 2;
        archive_entry_set_size(entry, n);
        ar->entry_bytes_remaining = n;
        return (ARCHIVE_OK);
}

static int
archive_read_format_ar_read_data(struct archive_read *a,
    const void **buff, size_t *size, off_t *offset)
{
        ssize_t bytes_read;
        struct ar *ar;

        ar = (struct ar *)(a->format->data);

        if (ar->entry_bytes_remaining > 0) {
                bytes_read = (a->decompressor->read_ahead)(a, buff, 1);
                if (bytes_read == 0) {
                        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
                            "Truncated ar archive");
                        return (ARCHIVE_FATAL);
                }
                if (bytes_read < 0)
                        return (ARCHIVE_FATAL);
                if (bytes_read > ar->entry_bytes_remaining)
                        bytes_read = (ssize_t)ar->entry_bytes_remaining;
                *size = bytes_read;
                *offset = ar->entry_offset;
                ar->entry_offset += bytes_read;
                ar->entry_bytes_remaining -= bytes_read;
                (a->decompressor->consume)(a, (size_t)bytes_read);
                return (ARCHIVE_OK);
        } else {
                while (ar->entry_padding > 0) {
                        bytes_read = (a->decompressor->read_ahead)(a, buff, 1);
                        if (bytes_read <= 0)
                                return (ARCHIVE_FATAL);
                        if (bytes_read > ar->entry_padding)
                                bytes_read = (ssize_t)ar->entry_padding;
                        (a->decompressor->consume)(a, (size_t)bytes_read);
                        ar->entry_padding -= bytes_read;
                }
                *buff = NULL;
                *size = 0;
                *offset = ar->entry_offset;
                return (ARCHIVE_EOF);
        }
}

static int
archive_read_format_ar_skip(struct archive_read *a)
{
        off_t bytes_skipped;
        struct ar* ar;
        int r = ARCHIVE_OK;
        const void *b;          /* Dummy variables */
        size_t s;
        off_t o;

        ar = (struct ar *)(a->format->data);
        if (a->decompressor->skip == NULL) {
                while (r == ARCHIVE_OK)
                        r = archive_read_format_ar_read_data(a, &b, &s, &o);
                return (r);
        }

        bytes_skipped = (a->decompressor->skip)(a, ar->entry_bytes_remaining +
            ar->entry_padding);
        if (bytes_skipped < 0)
                return (ARCHIVE_FATAL);

        ar->entry_bytes_remaining = 0;
        ar->entry_padding = 0;

        return (ARCHIVE_OK);
}

static int
ar_parse_gnu_filename_table(struct archive_read *a, struct ar *ar,
    const void *h, size_t size)
{
        char *p;

        if (ar->strtab != NULL) {
                archive_set_error(&a->archive, EINVAL,
                    "More than one string tables exist");
                return (ARCHIVE_WARN);
        }

        if (size == 0) {
                archive_set_error(&a->archive, EINVAL, "Invalid string table");
                return (ARCHIVE_WARN);
        }

        ar->strtab_size = size;
        ar->strtab = malloc(size);
        if (ar->strtab == NULL) {
                archive_set_error(&a->archive, ENOMEM,
                    "Can't allocate string table buffer");
                return (ARCHIVE_FATAL);
        }

        (void)memcpy(ar->strtab, h, size);
        for (p = ar->strtab; p < ar->strtab + size - 1; ++p) {
                if (*p == '/') {
                        *p++ = '\0';
                        if (*p != '\n')
                                goto bad_string_table;
                        *p = '\0';
                }
        }
        /*
         * Sanity check, last two chars must be `/\n' or '\n\n',
         * depending on whether the string table is padded by a '\n'
         * (string table produced by GNU ar always has a even size).
         */
        if (p != ar->strtab + size && *p != '\n')
                goto bad_string_table;

        /* Enforce zero termination. */
        ar->strtab[size - 1] = '\0';

        return (ARCHIVE_OK);

bad_string_table:
        archive_set_error(&a->archive, EINVAL,
            "Invalid string table");
        free(ar->strtab);
        ar->strtab = NULL;
        return (ARCHIVE_WARN);
}

static uint64_t
ar_atol8(const char *p, unsigned char_cnt)
{
        uint64_t l, limit, last_digit_limit;
        unsigned int digit, base;

        base = 8;
        limit = UINT64_MAX / base;
        last_digit_limit = UINT64_MAX % base;

        while ((*p == ' ' || *p == '\t') && char_cnt-- > 0)
                p++;

        l = 0;
        digit = *p - '0';
        while (*p >= '0' && digit < base  && char_cnt-- > 0) {
                if (l>limit || (l == limit && digit > last_digit_limit)) {
                        l = UINT64_MAX; /* Truncate on overflow. */
                        break;
                }
                l = (l * base) + digit;
                digit = *++p - '0';
        }
        return (l);
}

static uint64_t
ar_atol10(const char *p, unsigned char_cnt)
{
        uint64_t l, limit, last_digit_limit;
        unsigned int base, digit;

        base = 10;
        limit = UINT64_MAX / base;
        last_digit_limit = UINT64_MAX % base;

        while ((*p == ' ' || *p == '\t') && char_cnt-- > 0)
                p++;
        l = 0;
        digit = *p - '0';
        while (*p >= '0' && digit < base  && char_cnt-- > 0) {
                if (l > limit || (l == limit && digit > last_digit_limit)) {
                        l = UINT64_MAX; /* Truncate on overflow. */
                        break;
                }
                l = (l * base) + digit;
                digit = *++p - '0';
        }
        return (l);
}