CMake/Utilities/cmlibarchive/libarchive/archive_read_support_format_mtree.c

/*-
 * Copyright (c) 2003-2007 Tim Kientzle
 * Copyright (c) 2008 Joerg Sonnenberger
 * 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.
 *
 * 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_mtree.c,v 1.11 2008/12/06 06:45:15 kientzle Exp $");

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <stddef.h>
/* #include <stdint.h> */ /* See archive_platform.h */
#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"
#include "archive_string.h"

#ifndef O_BINARY
#define O_BINARY 0
#endif

#define MTREE_HAS_DEVICE    0x0001
#define MTREE_HAS_FFLAGS    0x0002
#define MTREE_HAS_GID       0x0004
#define MTREE_HAS_GNAME     0x0008
#define MTREE_HAS_MTIME     0x0010
#define MTREE_HAS_NLINK     0x0020
#define MTREE_HAS_PERM      0x0040
#define MTREE_HAS_SIZE      0x0080
#define MTREE_HAS_TYPE      0x0100
#define MTREE_HAS_UID       0x0200
#define MTREE_HAS_UNAME     0x0400

#define MTREE_HAS_OPTIONAL  0x0800

struct mtree_option {
    struct mtree_option *next;
    char *value;
};

struct mtree_entry {
    struct mtree_entry *next;
    struct mtree_option *options;
    char *name;
    char full;
    char used;
};

struct mtree {
    struct archive_string    line;
    size_t           buffsize;
    char            *buff;
    off_t            offset;
    int          fd;
    int          filetype;
    int          archive_format;
    const char      *archive_format_name;
    struct mtree_entry  *entries;
    struct mtree_entry  *this_entry;
    struct archive_string    current_dir;
    struct archive_string    contents_name;

    struct archive_entry_linkresolver *resolver;

    off_t            cur_size, cur_offset;
};

static int  cleanup(struct archive_read *);
static int  mtree_bid(struct archive_read *);
static int  parse_file(struct archive_read *, struct archive_entry *,
            struct mtree *, struct mtree_entry *, int *);
static void parse_escapes(char *, struct mtree_entry *);
static int  parse_line(struct archive_read *, struct archive_entry *,
            struct mtree *, struct mtree_entry *, int *);
static int  parse_keyword(struct archive_read *, struct mtree *,
            struct archive_entry *, struct mtree_option *, int *);
static int  read_data(struct archive_read *a,
            const void **buff, size_t *size, off_t *offset);
static ssize_t  readline(struct archive_read *, struct mtree *, char **, ssize_t);
static int  skip(struct archive_read *a);
static int  read_header(struct archive_read *,
            struct archive_entry *);
static int64_t  mtree_atol10(char **);
static int64_t  mtree_atol8(char **);
static int64_t  mtree_atol(char **);

static void
free_options(struct mtree_option *head)
{
    struct mtree_option *next;

    for (; head != NULL; head = next) {
        next = head->next;
        free(head->value);
        free(head);
    }
}

int
archive_read_support_format_mtree(struct archive *_a)
{
    struct archive_read *a = (struct archive_read *)_a;
    struct mtree *mtree;
    int r;

    mtree = (struct mtree *)malloc(sizeof(*mtree));
    if (mtree == NULL) {
        archive_set_error(&a->archive, ENOMEM,
            "Can't allocate mtree data");
        return (ARCHIVE_FATAL);
    }
    memset(mtree, 0, sizeof(*mtree));
    mtree->fd = -1;

    r = __archive_read_register_format(a, mtree, "mtree",
        mtree_bid, NULL, read_header, read_data, skip, cleanup);

    if (r != ARCHIVE_OK)
        free(mtree);
    return (ARCHIVE_OK);
}

static int
cleanup(struct archive_read *a)
{
    struct mtree *mtree;
    struct mtree_entry *p, *q;

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

    p = mtree->entries;
    while (p != NULL) {
        q = p->next;
        free(p->name);
        free_options(p->options);
        free(p);
        p = q;
    }
    archive_string_free(&mtree->line);
    archive_string_free(&mtree->current_dir);
    archive_string_free(&mtree->contents_name);
    archive_entry_linkresolver_free(mtree->resolver);

    free(mtree->buff);
    free(mtree);
    (a->format->data) = NULL;
    return (ARCHIVE_OK);
}


static int
mtree_bid(struct archive_read *a)
{
    const char *signature = "#mtree";
    const char *p;

    /* Now let's look at the actual header and see if it matches. */
    p = __archive_read_ahead(a, strlen(signature), NULL);
    if (p == NULL)
        return (-1);

    if (strncmp(p, signature, strlen(signature)) == 0)
        return (8 * strlen(signature));
    return (0);
}

/*
 * The extended mtree format permits multiple lines specifying
 * attributes for each file.  For those entries, only the last line
 * is actually used.  Practically speaking, that means we have
 * to read the entire mtree file into memory up front.
 *
 * The parsing is done in two steps.  First, it is decided if a line
 * changes the global defaults and if it is, processed accordingly.
 * Otherwise, the options of the line are merged with the current
 * global options.
 */
static int
add_option(struct archive_read *a, struct mtree_option **global,
    const char *value, size_t len)
{
    struct mtree_option *option;

    if ((option = malloc(sizeof(*option))) == NULL) {
        archive_set_error(&a->archive, errno, "Can't allocate memory");
        return (ARCHIVE_FATAL);
    }
    if ((option->value = malloc(len + 1)) == NULL) {
        free(option);
        archive_set_error(&a->archive, errno, "Can't allocate memory");
        return (ARCHIVE_FATAL);
    }
    memcpy(option->value, value, len);
    option->value[len] = '\0';
    option->next = *global;
    *global = option;
    return (ARCHIVE_OK);
}

static void
remove_option(struct mtree_option **global, const char *value, size_t len)
{
    struct mtree_option *iter, *last;

    last = NULL;
    for (iter = *global; iter != NULL; last = iter, iter = iter->next) {
        if (strncmp(iter->value, value, len) == 0 &&
            (iter->value[len] == '\0' ||
             iter->value[len] == '='))
            break;
    }
    if (iter == NULL)
        return;
    if (last == NULL)
        *global = iter->next;
    else
        last->next = iter->next;

    free(iter->value);
    free(iter);
}

static int
process_global_set(struct archive_read *a,
    struct mtree_option **global, const char *line)
{
    const char *next, *eq;
    size_t len;
    int r;

    line += 4;
    for (;;) {
        next = line + strspn(line, " \t\r\n");
        if (*next == '\0')
            return (ARCHIVE_OK);
        line = next;
        next = line + strcspn(line, " \t\r\n");
        eq = strchr(line, '=');
        if (eq > next)
            len = next - line;
        else
            len = eq - line;

        remove_option(global, line, len);
        r = add_option(a, global, line, next - line);
        if (r != ARCHIVE_OK)
            return (r);
        line = next;
    }
}

static int
process_global_unset(struct archive_read *a,
    struct mtree_option **global, const char *line)
{
    const char *next;
    size_t len;

    line += 6;
    if (strchr(line, '=') != NULL) {
        archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
            "/unset shall not contain `='");
        return ARCHIVE_FATAL;
    }

    for (;;) {
        next = line + strspn(line, " \t\r\n");
        if (*next == '\0')
            return (ARCHIVE_OK);
        line = next;
        len = strcspn(line, " \t\r\n");

        if (len == 3 && strncmp(line, "all", 3) == 0) {
            free_options(*global);
            *global = NULL;
        } else {
            remove_option(global, line, len);
        }

        line += len;
    }
}

static int
process_add_entry(struct archive_read *a, struct mtree *mtree,
    struct mtree_option **global, const char *line,
    struct mtree_entry **last_entry)
{
    struct mtree_entry *entry;
    struct mtree_option *iter;
    const char *next, *eq;
    size_t len;
    int r;

    if ((entry = malloc(sizeof(*entry))) == NULL) {
        archive_set_error(&a->archive, errno, "Can't allocate memory");
        return (ARCHIVE_FATAL);
    }
    entry->next = NULL;
    entry->options = NULL;
    entry->name = NULL;
    entry->used = 0;
    entry->full = 0;

    /* Add this entry to list. */
    if (*last_entry == NULL)
        mtree->entries = entry;
    else
        (*last_entry)->next = entry;
    *last_entry = entry;

    len = strcspn(line, " \t\r\n");
    if ((entry->name = malloc(len + 1)) == NULL) {
        archive_set_error(&a->archive, errno, "Can't allocate memory");
        return (ARCHIVE_FATAL);
    }

    memcpy(entry->name, line, len);
    entry->name[len] = '\0';
    parse_escapes(entry->name, entry);

    line += len;
    for (iter = *global; iter != NULL; iter = iter->next) {
        r = add_option(a, &entry->options, iter->value,
            strlen(iter->value));
        if (r != ARCHIVE_OK)
            return (r);
    }

    for (;;) {
        next = line + strspn(line, " \t\r\n");
        if (*next == '\0')
            return (ARCHIVE_OK);
        line = next;
        next = line + strcspn(line, " \t\r\n");
        eq = strchr(line, '=');
        if (eq > next)
            len = next - line;
        else
            len = eq - line;

        remove_option(&entry->options, line, len);
        r = add_option(a, &entry->options, line, next - line);
        if (r != ARCHIVE_OK)
            return (r);
        line = next;
    }
}

static int
read_mtree(struct archive_read *a, struct mtree *mtree)
{
    ssize_t len;
    uintmax_t counter;
    char *p;
    struct mtree_option *global;
    struct mtree_entry *last_entry;
    int r;

    mtree->archive_format = ARCHIVE_FORMAT_MTREE;
    mtree->archive_format_name = "mtree";

    global = NULL;
    last_entry = NULL;
    r = ARCHIVE_OK;

    for (counter = 1; ; ++counter) {
        len = readline(a, mtree, &p, 256);
        if (len == 0) {
            mtree->this_entry = mtree->entries;
            free_options(global);
            return (ARCHIVE_OK);
        }
        if (len < 0) {
            free_options(global);
            return (len);
        }
        /* Leading whitespace is never significant, ignore it. */
        while (*p == ' ' || *p == '\t') {
            ++p;
            --len;
        }
        /* Skip content lines and blank lines. */
        if (*p == '#')
            continue;
        if (*p == '\r' || *p == '\n' || *p == '\0')
            continue;
        if (*p != '/') {
            r = process_add_entry(a, mtree, &global, p,
                &last_entry);
        } else if (strncmp(p, "/set", 4) == 0) {
            if (p[4] != ' ' && p[4] != '\t')
                break;
            r = process_global_set(a, &global, p);
        } else if (strncmp(p, "/unset", 6) == 0) {
            if (p[6] != ' ' && p[6] != '\t')
                break;
            r = process_global_unset(a, &global, p);
        } else
            break;

        if (r != ARCHIVE_OK) {
            free_options(global);
            return r;
        }
    }

    archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
        "Can't parse line %ju", counter);
    free_options(global);
    return (ARCHIVE_FATAL);
}

/*
 * Read in the entire mtree file into memory on the first request.
 * Then use the next unused file to satisfy each header request.
 */
static int
read_header(struct archive_read *a, struct archive_entry *entry)
{
    struct mtree *mtree;
    char *p;
    int r, use_next;

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

    if (mtree->fd >= 0) {
        close(mtree->fd);
        mtree->fd = -1;
    }

    if (mtree->entries == NULL) {
        mtree->resolver = archive_entry_linkresolver_new();
        if (mtree->resolver == NULL)
            return ARCHIVE_FATAL;
        archive_entry_linkresolver_set_strategy(mtree->resolver,
            ARCHIVE_FORMAT_MTREE);
        r = read_mtree(a, mtree);
        if (r != ARCHIVE_OK)
            return (r);
    }

    a->archive.archive_format = mtree->archive_format;
    a->archive.archive_format_name = mtree->archive_format_name;

    for (;;) {
        if (mtree->this_entry == NULL)
            return (ARCHIVE_EOF);
        if (strcmp(mtree->this_entry->name, "..") == 0) {
            mtree->this_entry->used = 1;
            if (archive_strlen(&mtree->current_dir) > 0) {
                /* Roll back current path. */
                p = mtree->current_dir.s
                    + mtree->current_dir.length - 1;
                while (p >= mtree->current_dir.s && *p != '/')
                    --p;
                if (p >= mtree->current_dir.s)
                    --p;
                mtree->current_dir.length
                    = p - mtree->current_dir.s + 1;
            }
        }
        if (!mtree->this_entry->used) {
            use_next = 0;
            r = parse_file(a, entry, mtree, mtree->this_entry, &use_next);
            if (use_next == 0)
                return (r);
        }
        mtree->this_entry = mtree->this_entry->next;
    }
}

/*
 * A single file can have multiple lines contribute specifications.
 * Parse as many lines as necessary, then pull additional information
 * from a backing file on disk as necessary.
 */
static int
parse_file(struct archive_read *a, struct archive_entry *entry,
    struct mtree *mtree, struct mtree_entry *mentry, int *use_next)
{
    const char *path;
    struct stat st_storage, *st;
    struct mtree_entry *mp;
    struct archive_entry *sparse_entry;
    int r = ARCHIVE_OK, r1, parsed_kws, mismatched_type;

    mentry->used = 1;

    /* Initialize reasonable defaults. */
    mtree->filetype = AE_IFREG;
    archive_entry_set_size(entry, 0);

    /* Parse options from this line. */
    parsed_kws = 0;
    r = parse_line(a, entry, mtree, mentry, &parsed_kws);

    if (mentry->full) {
        archive_entry_copy_pathname(entry, mentry->name);
        /*
         * "Full" entries are allowed to have multiple lines
         * and those lines aren't required to be adjacent.  We
         * don't support multiple lines for "relative" entries
         * nor do we make any attempt to merge data from
         * separate "relative" and "full" entries.  (Merging
         * "relative" and "full" entries would require dealing
         * with pathname canonicalization, which is a very
         * tricky subject.)
         */
        for (mp = mentry->next; mp != NULL; mp = mp->next) {
            if (mp->full && !mp->used
                && strcmp(mentry->name, mp->name) == 0) {
                /* Later lines override earlier ones. */
                mp->used = 1;
                r1 = parse_line(a, entry, mtree, mp,
                    &parsed_kws);
                if (r1 < r)
                    r = r1;
            }
        }
    } else {
        /*
         * Relative entries require us to construct
         * the full path and possibly update the
         * current directory.
         */
        size_t n = archive_strlen(&mtree->current_dir);
        if (n > 0)
            archive_strcat(&mtree->current_dir, "/");
        archive_strcat(&mtree->current_dir, mentry->name);
        archive_entry_copy_pathname(entry, mtree->current_dir.s);
        if (archive_entry_filetype(entry) != AE_IFDIR)
            mtree->current_dir.length = n;
    }

    /*
     * Try to open and stat the file to get the real size
     * and other file info.  It would be nice to avoid
     * this here so that getting a listing of an mtree
     * wouldn't require opening every referenced contents
     * file.  But then we wouldn't know the actual
     * contents size, so I don't see a really viable way
     * around this.  (Also, we may want to someday pull
     * other unspecified info from the contents file on
     * disk.)
     */
    mtree->fd = -1;
    if (archive_strlen(&mtree->contents_name) > 0)
        path = mtree->contents_name.s;
    else
        path = archive_entry_pathname(entry);

    if (archive_entry_filetype(entry) == AE_IFREG ||
        archive_entry_filetype(entry) == AE_IFDIR) {
        mtree->fd = open(path, O_RDONLY | O_BINARY);
        if (mtree->fd == -1 &&
            (errno != ENOENT ||
             archive_strlen(&mtree->contents_name) > 0)) {
            archive_set_error(&a->archive, errno,
                "Can't open %s", path);
            r = ARCHIVE_WARN;
        }
    }

    st = &st_storage;
    if (mtree->fd >= 0) {
        if (fstat(mtree->fd, st) == -1) {
            archive_set_error(&a->archive, errno,
                "Could not fstat %s", path);
            r = ARCHIVE_WARN;
            /* If we can't stat it, don't keep it open. */
            close(mtree->fd);
            mtree->fd = -1;
            st = NULL;
        }
    } else if (lstat(path, st) == -1) {
        st = NULL;
    }

    /*
     * If there is a contents file on disk, use that size;
     * otherwise leave it as-is (it might have been set from
     * the mtree size= keyword).
     */
    if (st != NULL) {
        mismatched_type = 0;
        if ((st->st_mode & S_IFMT) == S_IFREG &&
            archive_entry_filetype(entry) != AE_IFREG)
            mismatched_type = 1;
        if ((st->st_mode & S_IFMT) == S_IFLNK &&
            archive_entry_filetype(entry) != AE_IFLNK)
            mismatched_type = 1;
        if ((st->st_mode & S_IFSOCK) == S_IFSOCK &&
            archive_entry_filetype(entry) != AE_IFSOCK)
            mismatched_type = 1;
        if ((st->st_mode & S_IFMT) == S_IFCHR &&
            archive_entry_filetype(entry) != AE_IFCHR)
            mismatched_type = 1;
        if ((st->st_mode & S_IFMT) == S_IFBLK &&
            archive_entry_filetype(entry) != AE_IFBLK)
            mismatched_type = 1;
        if ((st->st_mode & S_IFMT) == S_IFDIR &&
            archive_entry_filetype(entry) != AE_IFDIR)
            mismatched_type = 1;
        if ((st->st_mode & S_IFMT) == S_IFIFO &&
            archive_entry_filetype(entry) != AE_IFIFO)
            mismatched_type = 1;

        if (mismatched_type) {
            if ((parsed_kws & MTREE_HAS_OPTIONAL) == 0) {
                archive_set_error(&a->archive,
                    ARCHIVE_ERRNO_MISC,
                    "mtree specification has different type for %s",
                    archive_entry_pathname(entry));
                r = ARCHIVE_WARN;
            } else {
                *use_next = 1;
            }
            /* Don't hold a non-regular file open. */
            if (mtree->fd >= 0)
                close(mtree->fd);
            mtree->fd = -1;
            st = NULL;
            return r;
        }
    }

    if (st != NULL) {
        if ((parsed_kws & MTREE_HAS_DEVICE) == 0 &&
            (archive_entry_filetype(entry) == AE_IFCHR ||
             archive_entry_filetype(entry) == AE_IFBLK))
            archive_entry_set_rdev(entry, st->st_rdev);
        if ((parsed_kws & (MTREE_HAS_GID | MTREE_HAS_GNAME)) == 0)
            archive_entry_set_gid(entry, st->st_gid);
        if ((parsed_kws & (MTREE_HAS_UID | MTREE_HAS_UNAME)) == 0)
            archive_entry_set_uid(entry, st->st_uid);
        if ((parsed_kws & MTREE_HAS_MTIME) == 0) {
#if HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC
            archive_entry_set_mtime(entry, st->st_mtime,
                st->st_mtimespec.tv_nsec);
#elif HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
            archive_entry_set_mtime(entry, st->st_mtime,
                st->st_mtim.tv_nsec);
#elif HAVE_STRUCT_STAT_ST_MTIME_N
            archive_entry_set_mtime(entry, st->st_mtime,
                st->st_mtime_n);
#elif HAVE_STRUCT_STAT_ST_UMTIME
            archive_entry_set_mtime(entry, st->st_mtime,
                st->st_umtime*1000);
#elif HAVE_STRUCT_STAT_ST_MTIME_USEC
            archive_entry_set_mtime(entry, st->st_mtime,
                st->st_mtime_usec*1000);
#else
            archive_entry_set_mtime(entry, st->st_mtime, 0);
#endif
        }
        if ((parsed_kws & MTREE_HAS_NLINK) == 0)
            archive_entry_set_nlink(entry, st->st_nlink);
        if ((parsed_kws & MTREE_HAS_PERM) == 0)
            archive_entry_set_perm(entry, st->st_mode);
        if ((parsed_kws & MTREE_HAS_SIZE) == 0)
            archive_entry_set_size(entry, st->st_size);
        archive_entry_set_ino(entry, st->st_ino);
        archive_entry_set_dev(entry, st->st_dev);

        archive_entry_linkify(mtree->resolver, &entry, &sparse_entry);
    } else if (parsed_kws & MTREE_HAS_OPTIONAL) {
        /*
         * Couldn't open the entry, stat it or the on-disk type
         * didn't match.  If this entry is optional, just ignore it
         * and read the next header entry.
         */
        *use_next = 1;
        return ARCHIVE_OK;
    }

    mtree->cur_size = archive_entry_size(entry);
    mtree->offset = 0;

    return r;
}

/*
 * Each line contains a sequence of keywords.
 */
static int
parse_line(struct archive_read *a, struct archive_entry *entry,
    struct mtree *mtree, struct mtree_entry *mp, int *parsed_kws)
{
    struct mtree_option *iter;
    int r = ARCHIVE_OK, r1;

    for (iter = mp->options; iter != NULL; iter = iter->next) {
        r1 = parse_keyword(a, mtree, entry, iter, parsed_kws);
        if (r1 < r)
            r = r1;
    }
    if ((*parsed_kws & MTREE_HAS_TYPE) == 0) {
        archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
            "Missing type keyword in mtree specification");
        return (ARCHIVE_WARN);
    }
    return (r);
}

/*
 * Device entries have one of the following forms:
 * raw dev_t
 * format,major,minor[,subdevice]
 *
 * Just use major and minor, no translation etc is done
 * between formats.
 */
static int
parse_device(struct archive *a, struct archive_entry *entry, char *val)
{
    char *comma1, *comma2;

    comma1 = strchr(val, ',');
    if (comma1 == NULL) {
        archive_entry_set_dev(entry, mtree_atol10(&val));
        return (ARCHIVE_OK);
    }
    ++comma1;
    comma2 = strchr(comma1, ',');
    if (comma2 == NULL) {
        archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
            "Malformed device attribute");
        return (ARCHIVE_WARN);
    }
    ++comma2;
    archive_entry_set_rdevmajor(entry, mtree_atol(&comma1));
    archive_entry_set_rdevminor(entry, mtree_atol(&comma2));
    return (ARCHIVE_OK);
}

/*
 * Parse a single keyword and its value.
 */
static int
parse_keyword(struct archive_read *a, struct mtree *mtree,
    struct archive_entry *entry, struct mtree_option *option, int *parsed_kws)
{
    char *val, *key;

    key = option->value;

    if (*key == '\0')
        return (ARCHIVE_OK);

    if (strcmp(key, "optional") == 0) {
        *parsed_kws |= MTREE_HAS_OPTIONAL;
        return (ARCHIVE_OK);
    }
    if (strcmp(key, "ignore") == 0) {
        /*
         * The mtree processing is not recursive, so
         * recursion will only happen for explicitly listed
         * entries.
         */
        return (ARCHIVE_OK);
    }

    val = strchr(key, '=');
    if (val == NULL) {
        archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
            "Malformed attribute \"%s\" (%d)", key, key[0]);
        return (ARCHIVE_WARN);
    }

    *val = '\0';
    ++val;

    switch (key[0]) {
    case 'c':
        if (strcmp(key, "content") == 0
            || strcmp(key, "contents") == 0) {
            parse_escapes(val, NULL);
            archive_strcpy(&mtree->contents_name, val);
            break;
        }
        if (strcmp(key, "cksum") == 0)
            break;
    case 'd':
        if (strcmp(key, "device") == 0) {
            *parsed_kws |= MTREE_HAS_DEVICE;
            return parse_device(&a->archive, entry, val);
        }
    case 'f':
        if (strcmp(key, "flags") == 0) {
            *parsed_kws |= MTREE_HAS_FFLAGS;
            archive_entry_copy_fflags_text(entry, val);
            break;
        }
    case 'g':
        if (strcmp(key, "gid") == 0) {
            *parsed_kws |= MTREE_HAS_GID;
            archive_entry_set_gid(entry, mtree_atol10(&val));
            break;
        }
        if (strcmp(key, "gname") == 0) {
            *parsed_kws |= MTREE_HAS_GNAME;
            archive_entry_copy_gname(entry, val);
            break;
        }
    case 'l':
        if (strcmp(key, "link") == 0) {
            archive_entry_copy_symlink(entry, val);
            break;
        }
    case 'm':
        if (strcmp(key, "md5") == 0 || strcmp(key, "md5digest") == 0)
            break;
        if (strcmp(key, "mode") == 0) {
            if (val[0] >= '0' && val[0] <= '9') {
                *parsed_kws |= MTREE_HAS_PERM;
                archive_entry_set_perm(entry,
                    mtree_atol8(&val));
            } else {
                archive_set_error(&a->archive,
                    ARCHIVE_ERRNO_FILE_FORMAT,
                    "Symbolic mode \"%s\" unsupported", val);
                return ARCHIVE_WARN;
            }
            break;
        }
    case 'n':
        if (strcmp(key, "nlink") == 0) {
            *parsed_kws |= MTREE_HAS_NLINK;
            archive_entry_set_nlink(entry, mtree_atol10(&val));
            break;
        }
    case 'r':
        if (strcmp(key, "rmd160") == 0 ||
            strcmp(key, "rmd160digest") == 0)
            break;
    case 's':
        if (strcmp(key, "sha1") == 0 || strcmp(key, "sha1digest") == 0)
            break;
        if (strcmp(key, "sha256") == 0 ||
            strcmp(key, "sha256digest") == 0)
            break;
        if (strcmp(key, "sha384") == 0 ||
            strcmp(key, "sha384digest") == 0)
            break;
        if (strcmp(key, "sha512") == 0 ||
            strcmp(key, "sha512digest") == 0)
            break;
        if (strcmp(key, "size") == 0) {
            archive_entry_set_size(entry, mtree_atol10(&val));
            break;
        }
    case 't':
        if (strcmp(key, "tags") == 0) {
            /*
             * Comma delimited list of tags.
             * Ignore the tags for now, but the interface
             * should be extended to allow inclusion/exclusion.
             */
            break;
        }
        if (strcmp(key, "time") == 0) {
            time_t m;
            long ns;

            *parsed_kws |= MTREE_HAS_MTIME;
            m = (time_t)mtree_atol10(&val);
            if (*val == '.') {
                ++val;
                ns = (long)mtree_atol10(&val);
            } else
                ns = 0;
            archive_entry_set_mtime(entry, m, ns);
            break;
        }
        if (strcmp(key, "type") == 0) {
            *parsed_kws |= MTREE_HAS_TYPE;
            switch (val[0]) {
            case 'b':
                if (strcmp(val, "block") == 0) {
                    mtree->filetype = AE_IFBLK;
                    break;
                }
            case 'c':
                if (strcmp(val, "char") == 0) {
                    mtree->filetype = AE_IFCHR;
                    break;
                }
            case 'd':
                if (strcmp(val, "dir") == 0) {
                    mtree->filetype = AE_IFDIR;
                    break;
                }
            case 'f':
                if (strcmp(val, "fifo") == 0) {
                    mtree->filetype = AE_IFIFO;
                    break;
                }
                if (strcmp(val, "file") == 0) {
                    mtree->filetype = AE_IFREG;
                    break;
                }
            case 'l':
                if (strcmp(val, "link") == 0) {
                    mtree->filetype = AE_IFLNK;
                    break;
                }
            default:
                archive_set_error(&a->archive,
                    ARCHIVE_ERRNO_FILE_FORMAT,
                    "Unrecognized file type \"%s\"", val);
                return (ARCHIVE_WARN);
            }
            archive_entry_set_filetype(entry, mtree->filetype);
            break;
        }
    case 'u':
        if (strcmp(key, "uid") == 0) {
            *parsed_kws |= MTREE_HAS_UID;
            archive_entry_set_uid(entry, mtree_atol10(&val));
            break;
        }
        if (strcmp(key, "uname") == 0) {
            *parsed_kws |= MTREE_HAS_UNAME;
            archive_entry_copy_uname(entry, val);
            break;
        }
    default:
        archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
            "Unrecognized key %s=%s", key, val);
        return (ARCHIVE_WARN);
    }
    return (ARCHIVE_OK);
}

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

    mtree = (struct mtree *)(a->format->data);
    if (mtree->fd < 0) {
        *buff = NULL;
        *offset = 0;
        *size = 0;
        return (ARCHIVE_EOF);
    }
    if (mtree->buff == NULL) {
        mtree->buffsize = 64 * 1024;
        mtree->buff = malloc(mtree->buffsize);
        if (mtree->buff == NULL) {
            archive_set_error(&a->archive, ENOMEM,
                "Can't allocate memory");
            return (ARCHIVE_FATAL);
        }
    }

    *buff = mtree->buff;
    *offset = mtree->offset;
    if ((off_t)mtree->buffsize > mtree->cur_size - mtree->offset)
        bytes_to_read = mtree->cur_size - mtree->offset;
    else
        bytes_to_read = mtree->buffsize;
    bytes_read = read(mtree->fd, mtree->buff, bytes_to_read);
    if (bytes_read < 0) {
        archive_set_error(&a->archive, errno, "Can't read");
        return (ARCHIVE_WARN);
    }
    if (bytes_read == 0) {
        *size = 0;
        return (ARCHIVE_EOF);
    }
    mtree->offset += bytes_read;
    *size = bytes_read;
    return (ARCHIVE_OK);
}

/* Skip does nothing except possibly close the contents file. */
static int
skip(struct archive_read *a)
{
    struct mtree *mtree;

    mtree = (struct mtree *)(a->format->data);
    if (mtree->fd >= 0) {
        close(mtree->fd);
        mtree->fd = -1;
    }
    return (ARCHIVE_OK);
}

/*
 * Since parsing backslash sequences always makes strings shorter,
 * we can always do this conversion in-place.
 */
static void
parse_escapes(char *src, struct mtree_entry *mentry)
{
    char *dest = src;
    char c;

    /*
     * The current directory is somewhat special, it should be archived
     * only once as it will confuse extraction otherwise.
     */
    if (strcmp(src, ".") == 0)
        mentry->full = 1;

    while (*src != '\0') {
        c = *src++;
        if (c == '/' && mentry != NULL)
            mentry->full = 1;
        if (c == '\\') {
            switch (src[0]) {
            case '0':
                if (src[1] < '0' || src[1] > '7') {
                    c = 0;
                    ++src;
                    break;
                }
                /* FALLTHROUGH */
            case '1':
            case '2':
            case '3':
                if (src[1] >= '0' && src[1] <= '7' &&
                    src[2] >= '0' && src[2] <= '7') {
                    c = (src[0] - '0') << 6;
                    c |= (src[1] - '0') << 3;
                    c |= (src[2] - '0');
                    src += 3;
                }
                break;
            case 'a':
                c = '\a';
                ++src;
                break;
            case 'b':
                c = '\b';
                ++src;
                break;
            case 'f':
                c = '\f';
                ++src;
                break;
            case 'n':
                c = '\n';
                ++src;
                break;
            case 'r':
                c = '\r';
                ++src;
                break;
            case 's':
                c = ' ';
                ++src;
                break;
            case 't':
                c = '\t';
                ++src;
                break;
            case 'v':
                c = '\v';
                ++src;
                break;
            }
        }
        *dest++ = c;
    }
    *dest = '\0';
}

/*
 * Note that this implementation does not (and should not!) obey
 * locale settings; you cannot simply substitute strtol here, since
 * it does obey locale.
 */
static int64_t
mtree_atol8(char **p)
{
    int64_t l, limit, last_digit_limit;
    int digit, base;

    base = 8;
    limit = INT64_MAX / base;
    last_digit_limit = INT64_MAX % base;

    l = 0;
    digit = **p - '0';
    while (digit >= 0 && digit < base) {
        if (l>limit || (l == limit && digit > last_digit_limit)) {
            l = INT64_MAX; /* Truncate on overflow. */
            break;
        }
        l = (l * base) + digit;
        digit = *++(*p) - '0';
    }
    return (l);
}

/*
 * Note that this implementation does not (and should not!) obey
 * locale settings; you cannot simply substitute strtol here, since
 * it does obey locale.
 */
static int64_t
mtree_atol10(char **p)
{
    int64_t l, limit, last_digit_limit;
    int base, digit, sign;

    base = 10;
    limit = INT64_MAX / base;
    last_digit_limit = INT64_MAX % base;

    if (**p == '-') {
        sign = -1;
        ++(*p);
    } else
        sign = 1;

    l = 0;
    digit = **p - '0';
    while (digit >= 0 && digit < base) {
        if (l > limit || (l == limit && digit > last_digit_limit)) {
            l = INT64_MAX; /* Truncate on overflow. */
            break;
        }
        l = (l * base) + digit;
        digit = *++(*p) - '0';
    }
    return (sign < 0) ? -l : l;
}

/*
 * Note that this implementation does not (and should not!) obey
 * locale settings; you cannot simply substitute strtol here, since
 * it does obey locale.
 */
static int64_t
mtree_atol16(char **p)
{
    int64_t l, limit, last_digit_limit;
    int base, digit, sign;

    base = 16;
    limit = INT64_MAX / base;
    last_digit_limit = INT64_MAX % base;

    if (**p == '-') {
        sign = -1;
        ++(*p);
    } else
        sign = 1;

    l = 0;
    if (**p >= '0' && **p <= '9')
        digit = **p - '0';
    else if (**p >= 'a' && **p <= 'f')
        digit = **p - 'a' + 10;
    else if (**p >= 'A' && **p <= 'F')
        digit = **p - 'A' + 10;
    else
        digit = -1;
    while (digit >= 0 && digit < base) {
        if (l > limit || (l == limit && digit > last_digit_limit)) {
            l = INT64_MAX; /* Truncate on overflow. */
            break;
        }
        l = (l * base) + digit;
        if (**p >= '0' && **p <= '9')
            digit = **p - '0';
        else if (**p >= 'a' && **p <= 'f')
            digit = **p - 'a' + 10;
        else if (**p >= 'A' && **p <= 'F')
            digit = **p - 'A' + 10;
        else
            digit = -1;
    }
    return (sign < 0) ? -l : l;
}

static int64_t
mtree_atol(char **p)
{
    if (**p != '0')
        return mtree_atol10(p);
    if ((*p)[1] == 'x' || (*p)[1] == 'X') {
        *p += 2;
        return mtree_atol16(p);
    }
    return mtree_atol8(p);
}

/*
 * Returns length of line (including trailing newline)
 * or negative on error.  'start' argument is updated to
 * point to first character of line.
 */
static ssize_t
readline(struct archive_read *a, struct mtree *mtree, char **start, ssize_t limit)
{
    ssize_t bytes_read;
    ssize_t total_size = 0;
    ssize_t find_off = 0;
    const void *t;
    const char *s;
    void *p;
    char *u;

    /* Accumulate line in a line buffer. */
    for (;;) {
        /* Read some more. */
        t = __archive_read_ahead(a, 1, &bytes_read);
        if (t == NULL)
            return (0);
        if (bytes_read < 0)
            return (ARCHIVE_FATAL);
        s = t;  /* Start of line? */
        p = memchr(t, '\n', bytes_read);
        /* If we found '\n', trim the read. */
        if (p != NULL) {
            bytes_read = 1 + ((const char *)p) - s;
        }
        if (total_size + bytes_read + 1 > limit) {
            archive_set_error(&a->archive,
                ARCHIVE_ERRNO_FILE_FORMAT,
                "Line too long");
            return (ARCHIVE_FATAL);
        }
        if (archive_string_ensure(&mtree->line,
            total_size + bytes_read + 1) == NULL) {
            archive_set_error(&a->archive, ENOMEM,
                "Can't allocate working buffer");
            return (ARCHIVE_FATAL);
        }
        memcpy(mtree->line.s + total_size, t, bytes_read);
        __archive_read_consume(a, bytes_read);
        total_size += bytes_read;
        /* Null terminate. */
        mtree->line.s[total_size] = '\0';
        /* If we found an unescaped '\n', clean up and return. */
        for (u = mtree->line.s + find_off; *u; ++u) {
            if (u[0] == '\n') {
                *start = mtree->line.s;
                return total_size;
            }
            if (u[0] == '#') {
                if (p == NULL)
                    break;
                *start = mtree->line.s;
                return total_size;
            }
            if (u[0] != '\\')
                continue;
            if (u[1] == '\\') {
                ++u;
                continue;
            }
            if (u[1] == '\n') {
                memmove(u, u + 1,
                    total_size - (u - mtree->line.s) + 1);
                --total_size;
                ++u;
                break;
            }
            if (u[1] == '\0')
                break;
        }
        find_off = u - mtree->line.s;
    }
}