/*      $NetBSD: read.c,v 1.4 2009/03/14 21:04:06 dsl Exp $     */

/*
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Julian Coleman, Waldi Ravens and Leo Weppelman.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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 "privahdi.h"
#include <fcntl.h>
#ifdef DEBUG
#include <stdio.h>
#endif
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/dkio.h>
#include <sys/ioctl.h>

/*
 * Read AHDI partitions from disk.
 */
int
ahdi_readlabel (struct ahdi_ptable *ptable, char *diskname, int flags)
{
        int                      fd, rv;
        struct disklabel        *dl;

        if (!(fd = openraw (diskname, O_RDONLY)))
                return (-1);

        if ((dl = read_dl (fd)) == NULL) {
                close (fd);
                return (-1);
        }

        if (dl->d_secsize != AHDI_BSIZE) {
                close (fd);
                return (-2);
        }

        if ((rv = check_magic(fd, LABELSECTOR, flags)) < 0) {
                close (fd);
                return (rv);
        }

        bzero ((void *) ptable, sizeof (struct ahdi_ptable));

        if ((rv = read_rsec (fd, ptable, AHDI_BBLOCK, AHDI_BBLOCK, flags))
            < 0) {
                close (fd);
                return (rv);
        }

        if (dl->d_secperunit != ptable->secperunit) {
                if (flags & AHDI_IGN_SPU)
                        ptable->secperunit = dl->d_secperunit;
                else {
                        close (fd);
                        return (-6);
                }
        }

        ptable->nsectors = dl->d_nsectors;
        ptable->ntracks = dl->d_ntracks;
        ptable->ncylinders = dl->d_ncylinders;
        ptable->secpercyl = dl->d_secpercyl;

        assign_letters (ptable);

        close (fd);
        return (1);
}

/*
 * Read AHDI partitions from root sector/auxillary root sector.
 */
int
read_rsec (int fd, struct ahdi_ptable *ptable, u_int rsec, u_int esec, int flags)
{
        struct ahdi_part        *part, *end;
        struct ahdi_root        *root;
        u_int16_t                cksum, newcksum;
        int                      rv;

        if ((root = disk_read (fd, rsec, 1)) == NULL) {
                return (-1);
        }

        if (rsec == AHDI_BBLOCK) {
                end = &root->ar_parts[AHDI_MAXRPD];
                if (root->ar_checksum) {
                        cksum = root->ar_checksum;
                        root->ar_checksum = 0;
                        newcksum = ahdi_cksum (root);
                        if ((cksum != newcksum) && !(flags & AHDI_IGN_CKSUM)) {
                                free (root);
                                return (-4);
                        }
                }
                ptable->secperunit=root->ar_hdsize;
        } else
                end = &root->ar_parts[AHDI_MAXARPD];
        for (part = root->ar_parts; part < end; ++part) {
#ifdef DEBUG
                printf ("Found partitions at sector %u:\n", rsec);
                printf ("  flags : %02x\n", part->ap_flg);
                printf ("  id    : %c%c%c\n", part->ap_id[0], part->ap_id[1],
                    part->ap_id[2]);
                printf ("  start : %u\n", part->ap_st);
                printf ("  size  : %u\n", part->ap_size);
#endif
                if (!(part->ap_flg & 0x01)) {
                        if ((part->ap_id[0] || part->ap_id[1] ||
                            part->ap_id[2]) && (flags & AHDI_IGN_EXISTS))
                                part->ap_flg &= 0x01;
                        else
                                continue;
                }
                        
                if (AHDI_MKPID (part->ap_id[0], part->ap_id[1],
                    part->ap_id[2]) == AHDI_PID_XGM) {
                        u_int   offs = part->ap_st + esec;
                        if ((rv = read_rsec (fd, ptable, offs,
                            esec == AHDI_BBLOCK ? offs : esec, flags)) < 0) {
                                free (root);
                                return (rv);
                        }
                } else {
                        /* Attempt to check for junk values */
                        if (((part->ap_st + rsec) > ptable->secperunit ||
                            (part->ap_st + rsec + part->ap_size -1) >
                            ptable->secperunit)) {
                                if (flags & AHDI_IGN_EXT) {
                                        /* Fake previous partition */
                                        ptable->parts[ptable->nparts].id[0] =
                                            part->ap_id[0];
                                        ptable->parts[ptable->nparts].id[1] =
                                            part->ap_id[1];
                                        ptable->parts[ptable->nparts].id[2] =
                                            part->ap_id[2];
                                } else {
                                        free (root);
                                        return (-5);
                                }
                        }
                        ptable->parts[ptable->nparts].flag = part->ap_flg;
                        ptable->parts[ptable->nparts].id[0] = part->ap_id[0];
                        ptable->parts[ptable->nparts].id[1] = part->ap_id[1];
                        ptable->parts[ptable->nparts].id[2] = part->ap_id[2];
                        ptable->parts[ptable->nparts].root = rsec;
                        ptable->parts[ptable->nparts].start =
                            part->ap_st + rsec;
                        ptable->parts[ptable->nparts].size = part->ap_size;
                        ptable->nparts++;
                }
        }
        free (root);
        if (ptable->nparts || FORCE_AHDI)
                return (1);
        else
                return (-3);
}

/*
 * Read a sector from the disk.
 */
void *
disk_read (fd, start, count)
        int      fd;
        u_int    start,
                 count;
{
        void    *buffer;
        off_t   offset;
        size_t  size;


        size   = count * DEV_BSIZE;
        offset = start * DEV_BSIZE;

        if ((buffer = malloc (size)) == NULL)
                return (NULL);

        if (lseek (fd, offset, SEEK_SET) != offset) {
                free (buffer);
                return (NULL);
        }
        if (read (fd, buffer, size) != size) {
                free (buffer);
                return (NULL);
        }
        return (buffer);
}

/*
 * Assign NetBSD drive letters to partitions
 */
void
assign_letters (struct ahdi_ptable *ptable)
{
        int             i, have_root, pno;
        u_int32_t       pid;

#define ROOT_PART 0

        have_root = 0;
        pno = 0;
        
        for (i = 0; i < ptable->nparts; i++) {
                while (pno == ROOT_PART || pno == SWAP_PART || pno == RAW_PART)
                        pno++;
                pid = AHDI_MKPID (ptable->parts[i].id[0],
                    ptable->parts[i].id[1], ptable->parts[i].id[2]);
                if (!have_root && pid == AHDI_PID_NBD) {
                        ptable->parts[i].letter = ROOT_PART;
                        have_root = 1;
                } else if (pid == AHDI_PID_SWP)
                        ptable->parts[i].letter = SWAP_PART;
                else {
                        ptable->parts[i].letter = pno;
                        pno++;
                }
        }
}

/*
 * Read disklabel for disk.
 */
struct disklabel *
read_dl (int fd)
{
        struct disklabel        *dl;

        if ((dl = malloc (sizeof (struct disklabel))) == NULL) {
                return (NULL);
        }

        if (ioctl (fd, DIOCGDINFO, dl) < 0) {
                free (dl);
                return (NULL);
        }
        return (dl);
}