paxlib/tp/tp.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 2004-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped

/*
 * pax tp format
 */

#include <paxlib.h>
#include <ccode.h>
#include <tm.h>

#define TP_BLOCK    512

#define DIRDEC      192
#define DIRMAG      496

typedef  uint8_t ui1;
typedef uint16_t ui2;
typedef uint32_t ui4;

typedef struct Dir_s
{
    char    pathname[32];
    ui1 mode[2];
    ui1 uid;
    ui1 gid;
    ui1 unused1;
    ui1 size[3];
    ui1 modtime[4];
    ui1 tapeaddr[2];
    ui1 unused2[16];
    ui1 checksum[2];
} Dir_t;

typedef struct Ar_s
{
    Pax_t*          pax;
    Paxarchive_t*       ap;
    off_t           offset;
    Dir_t*          dp;
    Dir_t*          ep;
    Dir_t           dir[1];
} Ar_t;

static int
tp_done(Pax_t* pax, register Paxarchive_t* ap)
{
    register Ar_t*  ar = (Ar_t*)ap->data;

    if (!ar)
        return -1;
    ap->io->eof = 1;
    free(ar);
    ap->data = 0;
    return 0;
}

static int
tp_getprologue(Pax_t* pax, Paxformat_t* fp, register Paxarchive_t* ap, Paxfile_t* f, unsigned char* buf, size_t size)
{
    register Ar_t*      ar;
    register ui1*       s;
    register ui1*       e;
    int16_t         w;
    size_t          n;

    if (size < 2 * TP_BLOCK)
        return 0;
    w = 0;
    for (e = (s = (ui1*)buf + TP_BLOCK) + TP_BLOCK; s < e; s += 2)
        w += s[0] + (s[1]<<8);
    if (w)
        return 0;
    w = ((Dir_t*)buf)->checksum[0] + (((Dir_t*)buf)->checksum[1]<<8);
    if (w < 0 || w > DIRMAG)
        w = DIRMAG;
    n = (size_t)w * sizeof(Dir_t);
    if (!(ar = newof(0, Ar_t, 1, n - sizeof(Dir_t))))
        return paxnospace(pax);
    if (paxread(pax, ap, NiL, PAX_BLOCK, 0, 0) != PAX_BLOCK || paxread(pax, ap, ar->dir, n, 0, 0) != n)
    {
        error(2, "%s: %s format directory read error", ap->name, fp->name);
        free(ar);
        return -1;
    }
    ar->dp = ar->dir;
    ar->ep = ar->dir + w;
    ar->pax = pax;
    ar->ap = ap;
    ap->data = ar;
    return 1;
}

static int
tp_getheader(Pax_t* pax, register Paxarchive_t* ap, register Paxfile_t* f)
{
    register Ar_t*      ar = (Ar_t*)ap->data;
    register Dir_t*     dp;
    register ui1*       s;
    register ui1*       e;
    int16_t         w;

    do
    {
        if (ar->dp >= ar->ep)
            return 0;
        dp = ar->dp++;
    } while (!*dp->pathname);
    w = 0;
    for (e = (s = (ui1*)ar->dir) + sizeof(Dir_t); s < e; s += 2)
        w += s[0] + (s[1]<<8);
    if (w)
    {
        error(2, "%s: %s format directory entry %d checksum error", ap->name, ap->format->name, ar->dp - ar->dir);
        return -1;
    }
    if (CC_NATIVE != CC_ASCII)
        ccmaps(dp->pathname,  sizeof(dp->pathname), CC_ASCII, CC_NATIVE);
    f->name = dp->pathname;
    f->linktype = PAX_NOLINK;
    f->linkpath = 0;
    f->st->st_mode = X_IFREG | ((dp->mode[0] + (dp->mode[1]<<8)) & 07777);
    f->st->st_uid = dp->uid;
    f->st->st_gid = dp->gid;
    f->st->st_size = (dp->size[0]<<16) + dp->size[1] + (dp->size[2]<<8);
    f->st->st_mtime = dp->modtime[2] + (dp->modtime[3]<<8) + (dp->modtime[0]<<16) + (dp->modtime[1]<<24);
    f->st->st_nlink = 1;
    ar->offset = (off_t)(dp->tapeaddr[0] + (dp->tapeaddr[1]<<8)) * TP_BLOCK;
    return 1;
}

static int
tp_getdata(Pax_t* pax, register Paxarchive_t* ap, register Paxfile_t* f, int fd)
{
    Sfio_t*     sp;
    off_t       skip;
    ssize_t     n;
    int     r;

    if (!(n = f->st->st_size))
        return 1;
    skip = roundof(f->st->st_size, TP_BLOCK);
    r = -1;
    if (fd < 0)
        r = 1;
    else if (sp = paxpart(pax, ap, f->st->st_size))
        for (;;)
        {
            if ((n = sfread(sp, pax->buf, sizeof(pax->buf))) < 0)
            {
                (*pax->errorf)(NiL, pax, 2, "%s: %s: unexpected EOF", ap->name, f->name);
                break;
            }
            else if (n == 0)
            {
                r = 1;
                break;
            }
            skip -= n;
            if (paxdata(pax, ap, f, fd, pax->buf, n))
                break;
        }
    if (skip && paxread(pax, ap, NiL, skip, 0, 0) != skip)
    {
        (*pax->errorf)(NiL, pax, 2, "%s: %s: cannot skip past %s format data", ap->name, f->name, ap->format->name);
        r = -1;
    }
    return r;
}

Paxformat_t pax_tp_format =
{
    "tp",
    0,
    "unix 4th-7th edition PDP-11 tp archive",
    0,
    PAX_ARCHIVE|PAX_NOHARDLINKS|PAX_IN,
    PAX_DEFBUFFER,
    PAX_DEFBLOCKS,
    PAX_BLOCK,
    PAXNEXT(tp),
    0,
    tp_done,
    tp_getprologue,
    tp_getheader,
    tp_getdata,
};

PAXLIB(tp)