hier.7: Document some recently added directories.

[dragonfly.git] / contrib / libarchive / libarchive / archive_read_support_format_mtree.c

/*-
 * Copyright (c) 2003-2007 Tim Kientzle
 * Copyright (c) 2008 Joerg Sonnenberger
 * Copyright (c) 2011-2012 Michihiro NAKAJIMA
 * 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: head/lib/libarchive/archive_read_support_format_mtree.c 201165 2009-12-29 05:52:13Z kientzle $");

#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"
#include "archive_pack_dev.h"

#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC       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
#define MTREE_HAS_NOCHANGE      0x1000 /* FreeBSD specific */

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;
        int64_t                  offset;
        int                      fd;
        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;

        int64_t                  cur_size;
        char checkfs;
};

static int      bid_keycmp(const char *, const char *, ssize_t);
static int      cleanup(struct archive_read *);
static int      detect_form(struct archive_read *, int *);
static int      mtree_bid(struct archive_read *, int);
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, int64_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 **);

/*
 * There's no standard for TIME_T_MAX/TIME_T_MIN.  So we compute them
 * here.  TODO: Move this to configure time, but be careful
 * about cross-compile environments.
 */
static int64_t
get_time_t_max(void)
{
#if defined(TIME_T_MAX)
        return TIME_T_MAX;
#else
        /* ISO C allows time_t to be a floating-point type,
           but POSIX requires an integer type.  The following
           should work on any system that follows the POSIX
           conventions. */
        if (((time_t)0) < ((time_t)-1)) {
                /* Time_t is unsigned */
                return (~(time_t)0);
        } else {
                /* Time_t is signed. */
                /* Assume it's the same as int64_t or int32_t */
                if (sizeof(time_t) == sizeof(int64_t)) {
                        return (time_t)INT64_MAX;
                } else {
                        return (time_t)INT32_MAX;
                }
        }
#endif
}

static int64_t
get_time_t_min(void)
{
#if defined(TIME_T_MIN)
        return TIME_T_MIN;
#else
        if (((time_t)0) < ((time_t)-1)) {
                /* Time_t is unsigned */
                return (time_t)0;
        } else {
                /* Time_t is signed. */
                if (sizeof(time_t) == sizeof(int64_t)) {
                        return (time_t)INT64_MIN;
                } else {
                        return (time_t)INT32_MIN;
                }
        }
#endif
}

static int
archive_read_format_mtree_options(struct archive_read *a,
    const char *key, const char *val)
{
        struct mtree *mtree;

        mtree = (struct mtree *)(a->format->data);
        if (strcmp(key, "checkfs")  == 0) {
                /* Allows to read information missing from the mtree from the file system */
                if (val == NULL || val[0] == 0) {
                        mtree->checkfs = 0;
                } else {
                        mtree->checkfs = 1;
                }
                return (ARCHIVE_OK);
        }

        /* Note: The "warn" return is just to inform the options
         * supervisor that we didn't handle it.  It will generate
         * a suitable error if no one used this option. */
        return (ARCHIVE_WARN);
}

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;

        archive_check_magic(_a, ARCHIVE_READ_MAGIC,
            ARCHIVE_STATE_NEW, "archive_read_support_format_mtree");

        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, archive_read_format_mtree_options, read_header, read_data, skip, NULL, cleanup, NULL, NULL);

        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 ssize_t
get_line_size(const char *b, ssize_t avail, ssize_t *nlsize)
{
        ssize_t len;

        len = 0;
        while (len < avail) {
                switch (*b) {
                case '\0':/* Non-ascii character or control character. */
                        if (nlsize != NULL)
                                *nlsize = 0;
                        return (-1);
                case '\r':
                        if (avail-len > 1 && b[1] == '\n') {
                                if (nlsize != NULL)
                                        *nlsize = 2;
                                return (len+2);
                        }
                        /* FALL THROUGH */
                case '\n':
                        if (nlsize != NULL)
                                *nlsize = 1;
                        return (len+1);
                default:
                        b++;
                        len++;
                        break;
                }
        }
        if (nlsize != NULL)
                *nlsize = 0;
        return (avail);
}

static ssize_t
next_line(struct archive_read *a,
    const char **b, ssize_t *avail, ssize_t *ravail, ssize_t *nl)
{
        ssize_t len;
        int quit;
        
        quit = 0;
        if (*avail == 0) {
                *nl = 0;
                len = 0;
        } else
                len = get_line_size(*b, *avail, nl);
        /*
         * Read bytes more while it does not reach the end of line.
         */
        while (*nl == 0 && len == *avail && !quit) {
                ssize_t diff = *ravail - *avail;
                size_t nbytes_req = (*ravail+1023) & ~1023U;
                ssize_t tested;

                /* Increase reading bytes if it is not enough to at least
                 * new two lines. */
                if (nbytes_req < (size_t)*ravail + 160)
                        nbytes_req <<= 1;

                *b = __archive_read_ahead(a, nbytes_req, avail);
                if (*b == NULL) {
                        if (*ravail >= *avail)
                                return (0);
                        /* Reading bytes reaches the end of file. */
                        *b = __archive_read_ahead(a, *avail, avail);
                        quit = 1;
                }
                *ravail = *avail;
                *b += diff;
                *avail -= diff;
                tested = len;/* Skip some bytes we already determinated. */
                len = get_line_size(*b, *avail, nl);
                if (len >= 0)
                        len += tested;
        }
        return (len);
}

/*
 * Compare characters with a mtree keyword.
 * Returns the length of a mtree keyword if matched.
 * Returns 0 if not matched.
 */
static int
bid_keycmp(const char *p, const char *key, ssize_t len)
{
        int match_len = 0;

        while (len > 0 && *p && *key) {
                if (*p == *key) {
                        --len;
                        ++p;
                        ++key;
                        ++match_len;
                        continue;
                }
                return (0);/* Not match */
        }
        if (*key != '\0')
                return (0);/* Not match */

        /* A following character should be specified characters */
        if (p[0] == '=' || p[0] == ' ' || p[0] == '\t' ||
            p[0] == '\n' || p[0] == '\r' ||
           (p[0] == '\\' && (p[1] == '\n' || p[1] == '\r')))
                return (match_len);
        return (0);/* Not match */
}

/*
 * Test whether the characters 'p' has is mtree keyword.
 * Returns the length of a detected keyword.
 * Returns 0 if any keywords were not found.
 */
static int
bid_keyword(const char *p,  ssize_t len)
{
        static const char *keys_c[] = {
                "content", "contents", "cksum", NULL
        };
        static const char *keys_df[] = {
                "device", "flags", NULL
        };
        static const char *keys_g[] = {
                "gid", "gname", NULL
        };
        static const char *keys_il[] = {
                "ignore", "inode", "link", NULL
        };
        static const char *keys_m[] = {
                "md5", "md5digest", "mode", NULL
        };
        static const char *keys_no[] = {
                "nlink", "nochange", "optional", NULL
        };
        static const char *keys_r[] = {
                "resdevice", "rmd160", "rmd160digest", NULL
        };
        static const char *keys_s[] = {
                "sha1", "sha1digest",
                "sha256", "sha256digest",
                "sha384", "sha384digest",
                "sha512", "sha512digest",
                "size", NULL
        };
        static const char *keys_t[] = {
                "tags", "time", "type", NULL
        };
        static const char *keys_u[] = {
                "uid", "uname", NULL
        };
        const char **keys;
        int i;

        switch (*p) {
        case 'c': keys = keys_c; break;
        case 'd': case 'f': keys = keys_df; break;
        case 'g': keys = keys_g; break;
        case 'i': case 'l': keys = keys_il; break;
        case 'm': keys = keys_m; break;
        case 'n': case 'o': keys = keys_no; break;
        case 'r': keys = keys_r; break;
        case 's': keys = keys_s; break;
        case 't': keys = keys_t; break;
        case 'u': keys = keys_u; break;
        default: return (0);/* Unknown key */
        }

        for (i = 0; keys[i] != NULL; i++) {
                int l = bid_keycmp(p, keys[i], len);
                if (l > 0)
                        return (l);
        }
        return (0);/* Unknown key */
}

/*
 * Test whether there is a set of mtree keywords.
 * Returns the number of keyword.
 * Returns -1 if we got incorrect sequence.
 * This function expects a set of "<space characters>keyword=value".
 * When "unset" is specified, expects a set of "<space characters>keyword".
 */
static int
bid_keyword_list(const char *p,  ssize_t len, int unset, int last_is_path)
{
        int l;
        int keycnt = 0;

        while (len > 0 && *p) {
                int blank = 0;

                /* Test whether there are blank characters in the line. */
                while (len >0 && (*p == ' ' || *p == '\t')) {
                        ++p;
                        --len;
                        blank = 1;
                }
                if (*p == '\n' || *p == '\r')
                        break;
                if (p[0] == '\\' && (p[1] == '\n' || p[1] == '\r'))
                        break;
                if (!blank && !last_is_path) /* No blank character. */
                        return (-1);
                if (last_is_path && len == 0)
                                return (keycnt);

                if (unset) {
                        l = bid_keycmp(p, "all", len);
                        if (l > 0)
                                return (1);
                }
                /* Test whether there is a correct key in the line. */
                l = bid_keyword(p, len);
                if (l == 0)
                        return (-1);/* Unknown keyword was found. */
                p += l;
                len -= l;
                keycnt++;

                /* Skip value */
                if (*p == '=') {
                        int value = 0;
                        ++p;
                        --len;
                        while (len > 0 && *p != ' ' && *p != '\t') {
                                ++p;
                                --len;
                                value = 1;
                        }
                        /* A keyword should have a its value unless
                         * "/unset" operation. */ 
                        if (!unset && value == 0)
                                return (-1);
                }
        }
        return (keycnt);
}

static int
bid_entry(const char *p, ssize_t len, ssize_t nl, int *last_is_path)
{
        int f = 0;
        static const unsigned char safe_char[256] = {
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 00 - 0F */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 10 - 1F */
                /* !"$%&'()*+,-./  EXCLUSION:( )(#) */
                0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 20 - 2F */
                /* 0123456789:;<>?  EXCLUSION:(=) */
                1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, /* 30 - 3F */
                /* @ABCDEFGHIJKLMNO */
                1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 40 - 4F */
                /* PQRSTUVWXYZ[\]^_  */
                1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 50 - 5F */
                /* `abcdefghijklmno */
                1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 60 - 6F */
                /* pqrstuvwxyz{|}~ */
                1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, /* 70 - 7F */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 80 - 8F */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 90 - 9F */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* A0 - AF */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* B0 - BF */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* C0 - CF */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* D0 - DF */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* E0 - EF */
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* F0 - FF */
        };
        ssize_t ll;
        const char *pp = p;
        const char * const pp_end = pp + len;

        *last_is_path = 0;
        /*
         * Skip the path-name which is quoted.
         */
        for (;pp < pp_end; ++pp) {
                if (!safe_char[*(const unsigned char *)pp]) {
                        if (*pp != ' ' && *pp != '\t' && *pp != '\r'
                            && *pp != '\n')
                                f = 0;
                        break;
                }
                f = 1;
        }
        ll = pp_end - pp;

        /* If a path-name was not found at the first, try to check
         * a mtree format(a.k.a form D) ``NetBSD's mtree -D'' creates,
         * which places the path-name at the last. */
        if (f == 0) {
                const char *pb = p + len - nl;
                int name_len = 0;
                int slash;

                /* The form D accepts only a single line for an entry. */
                if (pb-2 >= p &&
                    pb[-1] == '\\' && (pb[-2] == ' ' || pb[-2] == '\t'))
                        return (-1);
                if (pb-1 >= p && pb[-1] == '\\')
                        return (-1);

                slash = 0;
                while (p <= --pb && *pb != ' ' && *pb != '\t') {
                        if (!safe_char[*(const unsigned char *)pb])
                                return (-1);
                        name_len++;
                        /* The pathname should have a slash in this
                         * format. */
                        if (*pb == '/')
                                slash = 1;
                }
                if (name_len == 0 || slash == 0)
                        return (-1);
                /* If '/' is placed at the first in this field, this is not
                 * a valid filename. */
                if (pb[1] == '/')
                        return (-1);
                ll = len - nl - name_len;
                pp = p;
                *last_is_path = 1;
        }

        return (bid_keyword_list(pp, ll, 0, *last_is_path));
}

#define MAX_BID_ENTRY   3

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

        (void)best_bid; /* UNUSED */

        /* 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 (memcmp(p, signature, strlen(signature)) == 0)
                return (8 * (int)strlen(signature));

        /*
         * There is not a mtree signature. Let's try to detect mtree format.
         */
        return (detect_form(a, NULL));
}

static int
detect_form(struct archive_read *a, int *is_form_d)
{
        const char *p;
        ssize_t avail, ravail;
        ssize_t detected_bytes = 0, len, nl;
        int entry_cnt = 0, multiline = 0;
        int form_D = 0;/* The archive is generated by `NetBSD mtree -D'
                        * (In this source we call it `form D') . */

        if (is_form_d != NULL)
                *is_form_d = 0;
        p = __archive_read_ahead(a, 1, &avail);
        if (p == NULL)
                return (-1);
        ravail = avail;
        for (;;) {
                len = next_line(a, &p, &avail, &ravail, &nl);
                /* The terminal character of the line should be
                 * a new line character, '\r\n' or '\n'. */
                if (len <= 0 || nl == 0)
                        break;
                if (!multiline) {
                        /* Leading whitespace is never significant,
                         * ignore it. */
                        while (len > 0 && (*p == ' ' || *p == '\t')) {
                                ++p;
                                --avail;
                                --len;
                        }
                        /* Skip comment or empty line. */ 
                        if (p[0] == '#' || p[0] == '\n' || p[0] == '\r') {
                                p += len;
                                avail -= len;
                                continue;
                        }
                } else {
                        /* A continuance line; the terminal
                         * character of previous line was '\' character. */
                        if (bid_keyword_list(p, len, 0, 0) <= 0)
                                break;
                        if (multiline == 1)
                                detected_bytes += len;
                        if (p[len-nl-1] != '\\') {
                                if (multiline == 1 &&
                                    ++entry_cnt >= MAX_BID_ENTRY)
                                        break;
                                multiline = 0;
                        }
                        p += len;
                        avail -= len;
                        continue;
                }
                if (p[0] != '/') {
                        int last_is_path, keywords;

                        keywords = bid_entry(p, len, nl, &last_is_path);
                        if (keywords >= 0) {
                                detected_bytes += len;
                                if (form_D == 0) {
                                        if (last_is_path)
                                                form_D = 1;
                                        else if (keywords > 0)
                                                /* This line is not `form D'. */
                                                form_D = -1;
                                } else if (form_D == 1) {
                                        if (!last_is_path && keywords > 0)
                                                /* This this is not `form D'
                                                 * and We cannot accept mixed
                                                 * format. */
                                                break;
                                }
                                if (!last_is_path && p[len-nl-1] == '\\')
                                        /* This line continues. */
                                        multiline = 1;
                                else {
                                        /* We've got plenty of correct lines
                                         * to assume that this file is a mtree
                                         * format. */
                                        if (++entry_cnt >= MAX_BID_ENTRY)
                                                break;
                                }
                        } else
                                break;
                } else if (strncmp(p, "/set", 4) == 0) {
                        if (bid_keyword_list(p+4, len-4, 0, 0) <= 0)
                                break;
                        /* This line continues. */
                        if (p[len-nl-1] == '\\')
                                multiline = 2;
                } else if (strncmp(p, "/unset", 6) == 0) {
                        if (bid_keyword_list(p+6, len-6, 1, 0) <= 0)
                                break;
                        /* This line continues. */
                        if (p[len-nl-1] == '\\')
                                multiline = 2;
                } else
                        break;

                /* Test next line. */
                p += len;
                avail -= len;
        }
        if (entry_cnt >= MAX_BID_ENTRY || (entry_cnt > 0 && len == 0)) {
                if (is_form_d != NULL) {
                        if (form_D == 1)
                                *is_form_d = 1;
                }
                return (32);
        }

        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 *opt;

        if ((opt = malloc(sizeof(*opt))) == NULL) {
                archive_set_error(&a->archive, errno, "Can't allocate memory");
                return (ARCHIVE_FATAL);
        }
        if ((opt->value = malloc(len + 1)) == NULL) {
                free(opt);
                archive_set_error(&a->archive, errno, "Can't allocate memory");
                return (ARCHIVE_FATAL);
        }
        memcpy(opt->value, value, len);
        opt->value[len] = '\0';
        opt->next = *global;
        *global = opt;
        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, ssize_t line_len,
    struct mtree_entry **last_entry, int is_form_d)
{
        struct mtree_entry *entry;
        struct mtree_option *iter;
        const char *next, *eq, *name, *end;
        size_t name_len, len;
        int r, i;

        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;

        if (is_form_d) {
                /* Filename is last item on line. */
                /* Adjust line_len to trim trailing whitespace */
                while (line_len > 0) {
                        char last_character = line[line_len - 1];
                        if (last_character == '\r'
                            || last_character == '\n'
                            || last_character == '\t'
                            || last_character == ' ') {
                                line_len--;
                        } else {
                                break;
                        }
                }
                /* Name starts after the last whitespace separator */
                name = line;
                for (i = 0; i < line_len; i++) {
                        if (line[i] == '\r'
                            || line[i] == '\n'
                            || line[i] == '\t'
                            || line[i] == ' ') {
                                name = line + i + 1;
                        }
                }
                name_len = line + line_len - name;
                end = name;
        } else {
                /* Filename is first item on line */
                name_len = strcspn(line, " \t\r\n");
                name = line;
                line += name_len;
                end = line + line_len;
        }
        /* name/name_len is the name within the line. */
        /* line..end brackets the entire line except the name */

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

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

        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);
                if (next >= end)
                        return (ARCHIVE_OK);
                line = next;
                next = line + strcspn(line, " \t\r\n");
                eq = strchr(line, '=');
                if (eq == NULL || 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, is_form_d;

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

        global = NULL;
        last_entry = NULL;

        (void)detect_form(a, &is_form_d);

        for (counter = 1; ; ++counter) {
                len = readline(a, mtree, &p, 65536);
                if (len == 0) {
                        mtree->this_entry = mtree->entries;
                        free_options(global);
                        return (ARCHIVE_OK);
                }
                if (len < 0) {
                        free_options(global);
                        return ((int)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, len,
                            &last_entry, is_form_d);
                } 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;

        mentry->used = 1;

        /* Initialize reasonable defaults. */
        archive_entry_set_filetype(entry, AE_IFREG);
        archive_entry_set_size(entry, 0);
        archive_string_empty(&mtree->contents_name);

        /* 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;
        }

        if (mtree->checkfs) {
                /*
                 * 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 | O_CLOEXEC);
                        __archive_ensure_cloexec_flag(mtree->fd);
                        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;
                }

                /*
                 * Check for a mismatch between the type in the specification
                 * and the type of the contents object on disk.
                 */
                if (st != NULL) {
                        if (((st->st_mode & S_IFMT) == S_IFREG &&
                              archive_entry_filetype(entry) == AE_IFREG)
#ifdef S_IFLNK
                          ||((st->st_mode & S_IFMT) == S_IFLNK &&
                              archive_entry_filetype(entry) == AE_IFLNK)
#endif
#ifdef S_IFSOCK
                          ||((st->st_mode & S_IFSOCK) == S_IFSOCK &&
                              archive_entry_filetype(entry) == AE_IFSOCK)
#endif
#ifdef S_IFCHR
                          ||((st->st_mode & S_IFMT) == S_IFCHR &&
                              archive_entry_filetype(entry) == AE_IFCHR)
#endif
#ifdef S_IFBLK
                          ||((st->st_mode & S_IFMT) == S_IFBLK &&
                              archive_entry_filetype(entry) == AE_IFBLK)
#endif
                          ||((st->st_mode & S_IFMT) == S_IFDIR &&
                              archive_entry_filetype(entry) == AE_IFDIR)
#ifdef S_IFIFO
                          ||((st->st_mode & S_IFMT) == S_IFIFO &&
                              archive_entry_filetype(entry) == AE_IFIFO)
#endif
                        ) {
                                /* Types match. */
                        } else {
                                /* Types don't match; bail out gracefully. */
                                if (mtree->fd >= 0)
                                        close(mtree->fd);
                                mtree->fd = -1;
                                if (parsed_kws & MTREE_HAS_OPTIONAL) {
                                        /* It's not an error for an optional
                                         * entry to not match disk. */
                                        *use_next = 1;
                                } else if (r == ARCHIVE_OK) {
                                        archive_set_error(&a->archive,
                                            ARCHIVE_ERRNO_MISC,
                                            "mtree specification has different"
                                            " type for %s",
                                            archive_entry_pathname(entry));
                                        r = ARCHIVE_WARN;
                                }
                                return (r);
                        }
                }

                /*
                 * If there is a contents file on disk, pick some of the
                 * metadata from that file.  For most of these, we only
                 * set it from the contents if it wasn't already parsed
                 * from the specification.
                 */
                if (st != NULL) {
                        if (((parsed_kws & MTREE_HAS_DEVICE) == 0 ||
                                (parsed_kws & MTREE_HAS_NOCHANGE) != 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 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 0)
                                archive_entry_set_gid(entry, st->st_gid);
                        if ((parsed_kws & (MTREE_HAS_UID | MTREE_HAS_UNAME))
                                == 0 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 0)
                                archive_entry_set_uid(entry, st->st_uid);
                        if ((parsed_kws & MTREE_HAS_MTIME) == 0 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 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 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 0)
                                archive_entry_set_nlink(entry, st->st_nlink);
                        if ((parsed_kws & MTREE_HAS_PERM) == 0 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 0)
                                archive_entry_set_perm(entry, st->st_mode);
                        if ((parsed_kws & MTREE_HAS_SIZE) == 0 ||
                            (parsed_kws & MTREE_HAS_NOCHANGE) != 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 (r == ARCHIVE_OK && (*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]
 * When parsing succeeded, `pdev' will contain the appropriate dev_t value.
 */

/* strsep() is not in C90, but strcspn() is. */
/* Taken from http://unixpapa.com/incnote/string.html */
static char *
la_strsep(char **sp, char *sep)
{
        char *p, *s;
        if (sp == NULL || *sp == NULL || **sp == '\0')
                return(NULL);
        s = *sp;
        p = s + strcspn(s, sep);
        if (*p != '\0')
                *p++ = '\0';
        *sp = p;
        return(s);
}

static int
parse_device(dev_t *pdev, struct archive *a, char *val)
{
#define MAX_PACK_ARGS 3
        unsigned long numbers[MAX_PACK_ARGS];
        char *p, *dev;
        int argc;
        pack_t *pack;
        dev_t result;
        const char *error = NULL;

        memset(pdev, 0, sizeof(*pdev));
        if ((dev = strchr(val, ',')) != NULL) {
                /*
                 * Device's major/minor are given in a specified format.
                 * Decode and pack it accordingly.
                 */
                *dev++ = '\0';
                if ((pack = pack_find(val)) == NULL) {
                        archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
                            "Unknown format `%s'", val);
                        return ARCHIVE_WARN;
                }
                argc = 0;
                while ((p = la_strsep(&dev, ",")) != NULL) {
                        if (*p == '\0') {
                                archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
                                    "Missing number");
                                return ARCHIVE_WARN;
                        }
                        numbers[argc++] = (unsigned long)mtree_atol(&p);
                        if (argc > MAX_PACK_ARGS) {
                                archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
                                    "Too many arguments");
                                return ARCHIVE_WARN;
                        }
                }
                if (argc < 2) {
                        archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
                            "Not enough arguments");
                        return ARCHIVE_WARN;
                }
                result = (*pack)(argc, numbers, &error);
                if (error != NULL) {
                        archive_set_error(a, ARCHIVE_ERRNO_FILE_FORMAT,
                            "%s", error);
                        return ARCHIVE_WARN;
                }
        } else {
                /* file system raw value. */
                result = (dev_t)mtree_atol(&val);
        }
        *pdev = result;
        return ARCHIVE_OK;
#undef MAX_PACK_ARGS
}

/*
 * 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 *opt, int *parsed_kws)
{
        char *val, *key;

        key = opt->value;

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

        if (strcmp(key, "nochange") == 0) {
                *parsed_kws |= MTREE_HAS_NOCHANGE;
                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) {
                        /* stat(2) st_rdev field, e.g. the major/minor IDs
                         * of a char/block special file */
                        int r;
                        dev_t dev;

                        *parsed_kws |= MTREE_HAS_DEVICE;
                        r = parse_device(&dev, &a->archive, val);
                        if (r == ARCHIVE_OK)
                                archive_entry_set_rdev(entry, dev);
                        return r;
                }
        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 'i':
                if (strcmp(key, "inode") == 0) {
                        archive_entry_set_ino(entry, mtree_atol10(&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,
                                    (mode_t)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,
                                (unsigned int)mtree_atol10(&val));
                        break;
                }
        case 'r':
                if (strcmp(key, "resdevice") == 0) {
                        /* stat(2) st_dev field, e.g. the device ID where the
                         * inode resides */
                        int r;
                        dev_t dev;

                        r = parse_device(&dev, &a->archive, val);
                        if (r == ARCHIVE_OK)
                                archive_entry_set_dev(entry, dev);
                        return 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) {
                        int64_t m;
                        int64_t my_time_t_max = get_time_t_max();
                        int64_t my_time_t_min = get_time_t_min();
                        long ns = 0;

                        *parsed_kws |= MTREE_HAS_MTIME;
                        m = mtree_atol10(&val);
                        /* Replicate an old mtree bug:
                         * 123456789.1 represents 123456789
                         * seconds and 1 nanosecond. */
                        if (*val == '.') {
                                ++val;
                                ns = (long)mtree_atol10(&val);
                        } else
                                ns = 0;
                        if (m > my_time_t_max)
                                m = my_time_t_max;
                        else if (m < my_time_t_min)
                                m = my_time_t_min;
                        archive_entry_set_mtime(entry, (time_t)m, ns);
                        break;
                }
                if (strcmp(key, "type") == 0) {
                        switch (val[0]) {
                        case 'b':
                                if (strcmp(val, "block") == 0) {
                                        archive_entry_set_filetype(entry, AE_IFBLK);
                                        break;
                                }
                        case 'c':
                                if (strcmp(val, "char") == 0) {
                                        archive_entry_set_filetype(entry,
                                                AE_IFCHR);
                                        break;
                                }
                        case 'd':
                                if (strcmp(val, "dir") == 0) {
                                        archive_entry_set_filetype(entry,
                                                AE_IFDIR);
                                        break;
                                }
                        case 'f':
                                if (strcmp(val, "fifo") == 0) {
                                        archive_entry_set_filetype(entry,
                                                AE_IFIFO);
                                        break;
                                }
                                if (strcmp(val, "file") == 0) {
                                        archive_entry_set_filetype(entry,
                                                AE_IFREG);
                                        break;
                                }
                        case 'l':
                                if (strcmp(val, "link") == 0) {
                                        archive_entry_set_filetype(entry,
                                                AE_IFLNK);
                                        break;
                                }
                        default:
                                archive_set_error(&a->archive,
                                    ARCHIVE_ERRNO_FILE_FORMAT,
                                    "Unrecognized file type \"%s\"; "
                                    "assuming \"file\"", val);
                                archive_entry_set_filetype(entry, AE_IFREG);
                                return (ARCHIVE_WARN);
                        }
                        *parsed_kws |= MTREE_HAS_TYPE;
                        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,
    int64_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 ((int64_t)mtree->buffsize > mtree->cur_size - mtree->offset)
                bytes_to_read = (size_t)(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;

        if (mentry != NULL && 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;
                        case '\\':
                                c = '\\';
                                ++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;

        if (**p == '-') {
                sign = -1;
                limit = ((uint64_t)(INT64_MAX) + 1) / base;
                last_digit_limit = ((uint64_t)(INT64_MAX) + 1) % base;
                ++(*p);
        } else {
                sign = 1;
                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))
                        return (sign < 0) ? INT64_MIN : INT64_MAX;
                l = (l * base) + digit;
                digit = *++(*p) - '0';
        }
        return (sign < 0) ? -l : l;
}

/* Parse a hex digit. */
static int
parsehex(char c)
{
        if (c >= '0' && c <= '9')
                return c - '0';
        else if (c >= 'a' && c <= 'f')
                return c - 'a';
        else if (c >= 'A' && c <= 'F')
                return c - 'A';
        else
                return -1;
}

/*
 * 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;

        if (**p == '-') {
                sign = -1;
                limit = ((uint64_t)(INT64_MAX) + 1) / base;
                last_digit_limit = ((uint64_t)(INT64_MAX) + 1) % base;
                ++(*p);
        } else {
                sign = 1;
                limit = INT64_MAX / base;
                last_digit_limit = INT64_MAX % base;
        }

        l = 0;
        digit = parsehex(**p);
        while (digit >= 0 && digit < base) {
                if (l > limit || (l == limit && digit > last_digit_limit))
                        return (sign < 0) ? INT64_MIN : INT64_MAX;
                l = (l * base) + digit;
                digit = parsehex(*++(*p));
        }
        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;
        void *nl;
        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);
                nl = memchr(t, '\n', bytes_read);
                /* If we found '\n', trim the read to end exactly there. */
                if (nl != NULL) {
                        bytes_read = ((const char *)nl) - ((const char *)t) + 1;
                }
                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);
                }
                /* Append new bytes to string. */
                memcpy(mtree->line.s + total_size, t, bytes_read);
                __archive_read_consume(a, bytes_read);
                total_size += bytes_read;
                mtree->line.s[total_size] = '\0';

                for (u = mtree->line.s + find_off; *u; ++u) {
                        if (u[0] == '\n') {
                                /* Ends with unescaped newline. */
                                *start = mtree->line.s;
                                return total_size;
                        } else if (u[0] == '#') {
                                /* Ends with comment sequence #...\n */
                                if (nl == NULL) {
                                        /* But we've not found the \n yet */
                                        break;
                                }
                        } else if (u[0] == '\\') {
                                if (u[1] == '\n') {
                                        /* Trim escaped newline. */
                                        total_size -= 2;
                                        mtree->line.s[total_size] = '\0';
                                        break;
                                } else if (u[1] != '\0') {
                                        /* Skip the two-char escape sequence */
                                        ++u;
                                }
                        }
                }
                find_off = u - mtree->line.s;
        }
}