158843e06d
some trick is necessary to prevent further BSD geoms from attaching to that. Our old trick was to make sure we don't attach to a geom from the "BSD" class, but this doesn't work if an intermediary geom obscures this fact. Instead, calculate the MD5 checksum of the label we target and ask if anybody below us loves that label. If they do we don't. Coded by: gordon.
870 lines
24 KiB
C
870 lines
24 KiB
C
/*-
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* Copyright (c) 2002 Poul-Henning Kamp
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* Copyright (c) 2002 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project by Poul-Henning Kamp
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* and NAI Labs, the Security Research Division of Network Associates, Inc.
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* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
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* DARPA CHATS research program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The names of the authors may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*
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* This is the method for dealing with BSD disklabels. It has been
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* extensively (by my standards at least) commented, in the vain hope that
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* it will serve as the source in future copy&paste operations.
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*/
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#include <sys/param.h>
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#ifndef _KERNEL
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <signal.h>
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#include <err.h>
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#else
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/conf.h>
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#include <sys/bio.h>
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#include <sys/malloc.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#endif
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#include <sys/stdint.h>
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#include <sys/md5.h>
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#include <sys/errno.h>
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#include <sys/disklabel.h>
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#include <geom/geom.h>
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#include <geom/geom_slice.h>
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#define BSD_CLASS_NAME "BSD"
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#define ALPHA_LABEL_OFFSET 64
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/*
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* Our private data about one instance. All the rest is handled by the
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* slice code and stored in its softc, so this is just the stuff
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* specific to BSD disklabels.
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*/
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struct g_bsd_softc {
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off_t labeloffset;
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off_t mbroffset;
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off_t rawoffset;
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struct disklabel ondisk;
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struct disklabel inram;
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u_char labelsum[16];
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};
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/*
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* The next 4 functions isolate us from how the compiler lays out and pads
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* "struct disklabel". We treat what we read from disk as a bytestream and
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* explicitly convert it into a struct disklabel. This makes us compiler-
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* endianness- and wordsize- agnostic.
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* For now we only have little-endian formats to deal with.
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*/
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static void
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g_bsd_ledec_partition(u_char *ptr, struct partition *d)
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{
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d->p_size = g_dec_le4(ptr + 0);
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d->p_offset = g_dec_le4(ptr + 4);
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d->p_fsize = g_dec_le4(ptr + 8);
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d->p_fstype = ptr[12];
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d->p_frag = ptr[13];
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d->p_cpg = g_dec_le2(ptr + 14);
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}
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static void
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g_bsd_ledec_disklabel(u_char *ptr, struct disklabel *d)
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{
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int i;
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d->d_magic = g_dec_le4(ptr + 0);
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d->d_type = g_dec_le2(ptr + 4);
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d->d_subtype = g_dec_le2(ptr + 6);
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bcopy(ptr + 8, d->d_typename, 16);
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bcopy(ptr + 24, d->d_packname, 16);
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d->d_secsize = g_dec_le4(ptr + 40);
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d->d_nsectors = g_dec_le4(ptr + 44);
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d->d_ntracks = g_dec_le4(ptr + 48);
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d->d_ncylinders = g_dec_le4(ptr + 52);
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d->d_secpercyl = g_dec_le4(ptr + 56);
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d->d_secperunit = g_dec_le4(ptr + 60);
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d->d_sparespertrack = g_dec_le2(ptr + 64);
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d->d_sparespercyl = g_dec_le2(ptr + 66);
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d->d_acylinders = g_dec_le4(ptr + 68);
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d->d_rpm = g_dec_le2(ptr + 72);
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d->d_interleave = g_dec_le2(ptr + 74);
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d->d_trackskew = g_dec_le2(ptr + 76);
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d->d_cylskew = g_dec_le2(ptr + 78);
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d->d_headswitch = g_dec_le4(ptr + 80);
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d->d_trkseek = g_dec_le4(ptr + 84);
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d->d_flags = g_dec_le4(ptr + 88);
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d->d_drivedata[0] = g_dec_le4(ptr + 92);
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d->d_drivedata[1] = g_dec_le4(ptr + 96);
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d->d_drivedata[2] = g_dec_le4(ptr + 100);
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d->d_drivedata[3] = g_dec_le4(ptr + 104);
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d->d_drivedata[4] = g_dec_le4(ptr + 108);
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d->d_spare[0] = g_dec_le4(ptr + 112);
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d->d_spare[1] = g_dec_le4(ptr + 116);
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d->d_spare[2] = g_dec_le4(ptr + 120);
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d->d_spare[3] = g_dec_le4(ptr + 124);
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d->d_spare[4] = g_dec_le4(ptr + 128);
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d->d_magic2 = g_dec_le4(ptr + 132);
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d->d_checksum = g_dec_le2(ptr + 136);
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d->d_npartitions = g_dec_le2(ptr + 138);
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d->d_bbsize = g_dec_le4(ptr + 140);
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d->d_sbsize = g_dec_le4(ptr + 144);
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for (i = 0; i < MAXPARTITIONS; i++)
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g_bsd_ledec_partition(ptr + 148 + 16 * i, &d->d_partitions[i]);
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}
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static void
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g_bsd_leenc_partition(u_char *ptr, struct partition *d)
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{
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g_enc_le4(ptr + 0, d->p_size);
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g_enc_le4(ptr + 4, d->p_offset);
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g_enc_le4(ptr + 8, d->p_fsize);
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ptr[12] = d->p_fstype;
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ptr[13] = d->p_frag;
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g_enc_le2(ptr + 14, d->p_cpg);
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}
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static void
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g_bsd_leenc_disklabel(u_char *ptr, struct disklabel *d)
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{
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int i;
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g_enc_le4(ptr + 0, d->d_magic);
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g_enc_le2(ptr + 4, d->d_type);
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g_enc_le2(ptr + 6, d->d_subtype);
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bcopy(d->d_typename, ptr + 8, 16);
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bcopy(d->d_packname, ptr + 24, 16);
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g_enc_le4(ptr + 40, d->d_secsize);
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g_enc_le4(ptr + 44, d->d_nsectors);
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g_enc_le4(ptr + 48, d->d_ntracks);
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g_enc_le4(ptr + 52, d->d_ncylinders);
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g_enc_le4(ptr + 56, d->d_secpercyl);
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g_enc_le4(ptr + 60, d->d_secperunit);
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g_enc_le2(ptr + 64, d->d_sparespertrack);
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g_enc_le2(ptr + 66, d->d_sparespercyl);
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g_enc_le4(ptr + 68, d->d_acylinders);
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g_enc_le2(ptr + 72, d->d_rpm);
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g_enc_le2(ptr + 74, d->d_interleave);
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g_enc_le2(ptr + 76, d->d_trackskew);
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g_enc_le2(ptr + 78, d->d_cylskew);
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g_enc_le4(ptr + 80, d->d_headswitch);
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g_enc_le4(ptr + 84, d->d_trkseek);
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g_enc_le4(ptr + 88, d->d_flags);
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g_enc_le4(ptr + 92, d->d_drivedata[0]);
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g_enc_le4(ptr + 96, d->d_drivedata[1]);
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g_enc_le4(ptr + 100, d->d_drivedata[2]);
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g_enc_le4(ptr + 104, d->d_drivedata[3]);
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g_enc_le4(ptr + 108, d->d_drivedata[4]);
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g_enc_le4(ptr + 112, d->d_spare[0]);
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g_enc_le4(ptr + 116, d->d_spare[1]);
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g_enc_le4(ptr + 120, d->d_spare[2]);
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g_enc_le4(ptr + 124, d->d_spare[3]);
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g_enc_le4(ptr + 128, d->d_spare[4]);
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g_enc_le4(ptr + 132, d->d_magic2);
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g_enc_le2(ptr + 136, d->d_checksum);
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g_enc_le2(ptr + 138, d->d_npartitions);
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g_enc_le4(ptr + 140, d->d_bbsize);
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g_enc_le4(ptr + 144, d->d_sbsize);
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for (i = 0; i < MAXPARTITIONS; i++)
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g_bsd_leenc_partition(ptr + 148 + 16 * i, &d->d_partitions[i]);
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}
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static int
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g_bsd_ondisk_size(void)
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{
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return (148 + 16 * MAXPARTITIONS);
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}
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/*
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* For reasons which were valid and just in their days, FreeBSD/i386 uses
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* absolute disk-addresses in disklabels. The way it works is that the
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* p_offset field of all partitions have the first sector number of the
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* disk slice added to them. This was hidden kernel-magic, userland did
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* not see these offsets. These two functions subtract and add them
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* while converting from the "ondisk" to the "inram" labels and vice
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* versa.
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*/
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static void
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ondisk2inram(struct g_bsd_softc *sc)
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{
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struct partition *ppp;
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struct disklabel *dl;
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int i;
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sc->inram = sc->ondisk;
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dl = &sc->inram;
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/* Basic sanity-check needed to avoid mistakes. */
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if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC)
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return;
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if (dl->d_npartitions > MAXPARTITIONS)
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return;
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sc->rawoffset = dl->d_partitions[RAW_PART].p_offset;
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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if (ppp->p_size != 0 && ppp->p_offset < sc->rawoffset)
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sc->rawoffset = 0;
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}
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if (sc->rawoffset > 0) {
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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if (ppp->p_offset != 0)
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ppp->p_offset -= sc->rawoffset;
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}
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}
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dl->d_checksum = 0;
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dl->d_checksum = dkcksum(&sc->inram);
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}
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static void
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inram2ondisk(struct g_bsd_softc *sc)
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{
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struct partition *ppp;
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int i;
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sc->ondisk = sc->inram;
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if (sc->mbroffset != 0)
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sc->rawoffset = sc->mbroffset / sc->inram.d_secsize;
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if (sc->rawoffset != 0) {
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for (i = 0; i < sc->inram.d_npartitions; i++) {
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ppp = &sc->ondisk.d_partitions[i];
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if (ppp->p_size > 0)
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ppp->p_offset += sc->rawoffset;
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else
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ppp->p_offset = 0;
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}
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}
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sc->ondisk.d_checksum = 0;
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sc->ondisk.d_checksum = dkcksum(&sc->ondisk);
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}
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/*
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* Check that this looks like a valid disklabel, but be prepared
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* to get any kind of junk. The checksum must be checked only
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* after this function returns success to prevent a bogus d_npartitions
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* value from tripping us up.
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*/
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static int
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g_bsd_checklabel(struct disklabel *dl)
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{
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struct partition *ppp;
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int i;
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if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC)
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return (EINVAL);
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/*
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* If the label specifies more partitions than we can handle
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* we have to reject it: If people updated the label they would
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* trash it, and that would break the checksum.
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*/
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if (dl->d_npartitions > MAXPARTITIONS)
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return (EINVAL);
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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/* Cannot extend past unit. */
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if (ppp->p_size != 0 &&
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ppp->p_offset + ppp->p_size > dl->d_secperunit) {
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return (EINVAL);
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}
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}
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return (0);
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}
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/*
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* Modify our slicer to match proposed disklabel, if possible.
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* First carry out all the simple checks, then lock topology
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* and check that no open providers are affected negatively
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* then carry out all the changes.
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*
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* NB: Returns with topology held only if successful return.
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*/
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static int
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g_bsd_modify(struct g_geom *gp, struct disklabel *dl)
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{
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int i, error;
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struct partition *ppp;
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struct g_slicer *gsp;
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struct g_consumer *cp;
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u_int secsize, u;
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off_t mediasize;
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/* Basic check that this is indeed a disklabel. */
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error = g_bsd_checklabel(dl);
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if (error)
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return (error);
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/* Make sure the checksum is OK. */
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if (dkcksum(dl) != 0)
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return (EINVAL);
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/* Get dimensions of our device. */
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cp = LIST_FIRST(&gp->consumer);
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secsize = cp->provider->sectorsize;
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mediasize = cp->provider->mediasize;
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#ifdef nolonger
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/*
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* The raw-partition must start at zero. We do not check that the
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* size == mediasize because this is overly restrictive. We have
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* already tested in g_bsd_checklabel() that it is not longer.
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* XXX: RAW_PART is archaic anyway, and we should drop it.
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*/
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if (dl->d_partitions[RAW_PART].p_offset != 0)
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return (EINVAL);
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#endif
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#ifdef notyet
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/*
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* Indications are that the d_secperunit is not correctly
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* initialized in many cases, and since we don't need it
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* for anything, we dont strictly need this test.
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* Preemptive action to avoid confusing people in disklabel(8)
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* may be in order.
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*/
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/* The label cannot claim a larger size than the media. */
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if ((off_t)dl->d_secperunit * dl->d_secsize > mediasize)
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return (EINVAL);
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#endif
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/* ... or a smaller sector size. */
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if (dl->d_secsize < secsize)
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return (EINVAL);
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/* ... or a non-multiple sector size. */
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if (dl->d_secsize % secsize != 0)
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return (EINVAL);
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g_topology_lock();
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/* Don't munge open partitions. */
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gsp = gp->softc;
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for (i = 0; i < dl->d_npartitions; i++) {
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ppp = &dl->d_partitions[i];
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error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
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(off_t)ppp->p_offset * dl->d_secsize,
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(off_t)ppp->p_size * dl->d_secsize,
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dl->d_secsize,
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"%s%c", gp->name, 'a' + i);
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if (error) {
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g_topology_unlock();
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return (error);
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}
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}
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/* Look good, go for it... */
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for (u = 0; u < gsp->nslice; u++) {
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ppp = &dl->d_partitions[u];
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g_slice_config(gp, u, G_SLICE_CONFIG_SET,
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(off_t)ppp->p_offset * dl->d_secsize,
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(off_t)ppp->p_size * dl->d_secsize,
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dl->d_secsize,
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"%s%c", gp->name, 'a' + u);
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}
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return (0);
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}
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/*
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* Calculate a disklabel checksum for a little-endian byte-stream.
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* We need access to the decoded disklabel because the checksum only
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* covers the partition data for the first d_npartitions.
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*/
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static int
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g_bsd_lesum(struct disklabel *dl, u_char *p)
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{
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u_char *pe;
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uint16_t sum;
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pe = p + 148 + 16 * dl->d_npartitions;
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sum = 0;
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while (p < pe) {
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sum ^= g_dec_le2(p);
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p += 2;
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}
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return (sum);
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}
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/*
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* This is an internal helper function, called multiple times from the taste
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* function to try to locate a disklabel on the disk. More civilized formats
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* will not need this, as there is only one possible place on disk to look
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* for the magic spot.
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*/
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static int
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g_bsd_try(struct g_geom *gp, struct g_slicer *gsp, struct g_consumer *cp, int secsize, struct g_bsd_softc *ms, off_t offset)
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{
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int error;
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u_char *buf;
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struct disklabel *dl;
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off_t secoff;
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/*
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* We need to read entire aligned sectors, and we assume that the
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* disklabel does not span sectors, so one sector is enough.
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*/
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error = 0;
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secoff = offset % secsize;
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buf = g_read_data(cp, offset - secoff, secsize, &error);
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if (buf == NULL || error != 0)
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return (ENOENT);
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/* Decode into our native format. */
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dl = &ms->ondisk;
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|
g_bsd_ledec_disklabel(buf + secoff, dl);
|
|
|
|
ondisk2inram(ms);
|
|
|
|
dl = &ms->inram;
|
|
/* Does it look like a label at all? */
|
|
if (g_bsd_checklabel(dl))
|
|
error = ENOENT;
|
|
/* ... and does the raw data have a good checksum? */
|
|
if (error == 0 && g_bsd_lesum(dl, buf + secoff) != 0)
|
|
error = ENOENT;
|
|
|
|
/* Remember to free the buffer g_read_data() gave us. */
|
|
g_free(buf);
|
|
|
|
/* If we had a label, record it properly. */
|
|
if (error == 0) {
|
|
gsp->frontstuff = 16 * secsize; /* XXX */
|
|
ms->labeloffset = offset;
|
|
g_topology_lock();
|
|
g_slice_conf_hot(gp, 0, offset, g_bsd_ondisk_size());
|
|
g_topology_unlock();
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Implement certain ioctls to modify disklabels with. This function
|
|
* is called by the event handler thread with topology locked as result
|
|
* of the g_call_me() in g_bsd_start(). It is not necessary to keep
|
|
* topology locked all the time but make sure to return with topology
|
|
* locked as well.
|
|
*/
|
|
|
|
static void
|
|
g_bsd_ioctl(void *arg)
|
|
{
|
|
struct bio *bp;
|
|
struct g_geom *gp;
|
|
struct g_slicer *gsp;
|
|
struct g_bsd_softc *ms;
|
|
struct disklabel *dl;
|
|
struct g_ioctl *gio;
|
|
struct g_consumer *cp;
|
|
u_char *buf;
|
|
off_t secoff;
|
|
u_int secsize;
|
|
int error, i;
|
|
uint64_t sum;
|
|
|
|
/* We don't need topology for now. */
|
|
g_topology_unlock();
|
|
|
|
/* Get hold of the interesting bits from the bio. */
|
|
bp = arg;
|
|
gp = bp->bio_to->geom;
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
gio = (struct g_ioctl *)bp->bio_data;
|
|
|
|
/* The disklabel to set is the ioctl argument. */
|
|
dl = gio->data;
|
|
|
|
/* Validate and modify our slice instance to match. */
|
|
error = g_bsd_modify(gp, dl); /* Picks up topology lock on success. */
|
|
if (error) {
|
|
g_topology_lock();
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
/* Update our copy of the disklabel. */
|
|
ms->inram = *dl;
|
|
inram2ondisk(ms);
|
|
|
|
if (gio->cmd == DIOCSDINFO) {
|
|
g_io_deliver(bp, 0);
|
|
return;
|
|
}
|
|
KASSERT(gio->cmd == DIOCWDINFO, ("Unknown ioctl in g_bsd_ioctl"));
|
|
cp = LIST_FIRST(&gp->consumer);
|
|
/* Get sector size, we need it to read data. */
|
|
secsize = cp->provider->sectorsize;
|
|
secoff = ms->labeloffset % secsize;
|
|
buf = g_read_data(cp, ms->labeloffset - secoff, secsize, &error);
|
|
if (buf == NULL || error != 0) {
|
|
g_io_deliver(bp, error);
|
|
return;
|
|
}
|
|
dl = &ms->ondisk;
|
|
g_bsd_leenc_disklabel(buf + secoff, dl);
|
|
if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
|
|
sum = 0;
|
|
for (i = 0; i < 63; i++)
|
|
sum += g_dec_le8(buf + i * 8);
|
|
g_enc_le8(buf + 504, sum);
|
|
}
|
|
error = g_write_data(cp, ms->labeloffset - secoff, buf, secsize);
|
|
g_free(buf);
|
|
g_io_deliver(bp, error);
|
|
}
|
|
|
|
/*
|
|
* If the user tries to overwrite our disklabel through an open partition
|
|
* or via a magicwrite config call, we end up here and try to prevent
|
|
* footshooting as best we can.
|
|
*/
|
|
static void
|
|
g_bsd_hotwrite(void *arg)
|
|
{
|
|
struct bio *bp;
|
|
struct g_geom *gp;
|
|
struct g_slicer *gsp;
|
|
struct g_slice *gsl;
|
|
struct g_bsd_softc *ms;
|
|
struct g_bsd_softc fake;
|
|
u_char *p;
|
|
int error;
|
|
|
|
bp = arg;
|
|
gp = bp->bio_to->geom;
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
gsl = &gsp->slices[bp->bio_to->index];
|
|
p = (u_char*)bp->bio_data + ms->labeloffset
|
|
- (bp->bio_offset + gsl->offset);
|
|
g_bsd_ledec_disklabel(p, &fake.ondisk);
|
|
|
|
ondisk2inram(&fake);
|
|
if (g_bsd_checklabel(&fake.inram)) {
|
|
g_io_deliver(bp, EPERM);
|
|
return;
|
|
}
|
|
if (g_bsd_lesum(&fake.ondisk, p) != 0) {
|
|
g_io_deliver(bp, EPERM);
|
|
return;
|
|
}
|
|
g_topology_unlock();
|
|
error = g_bsd_modify(gp, &fake.inram); /* May pick up topology. */
|
|
if (error) {
|
|
g_io_deliver(bp, EPERM);
|
|
g_topology_lock();
|
|
return;
|
|
}
|
|
/* Update our copy of the disklabel. */
|
|
ms->inram = fake.inram;
|
|
inram2ondisk(ms);
|
|
g_bsd_leenc_disklabel(p, &ms->ondisk);
|
|
g_slice_finish_hot(bp);
|
|
}
|
|
|
|
/*-
|
|
* This start routine is only called for non-trivial requests, all the
|
|
* trivial ones are handled autonomously by the slice code.
|
|
* For requests we handle here, we must call the g_io_deliver() on the
|
|
* bio, and return non-zero to indicate to the slice code that we did so.
|
|
* This code executes in the "DOWN" I/O path, this means:
|
|
* * No sleeping.
|
|
* * Don't grab the topology lock.
|
|
* * Don't call biowait, g_getattr(), g_setattr() or g_read_data()
|
|
*/
|
|
|
|
static int
|
|
g_bsd_start(struct bio *bp)
|
|
{
|
|
struct g_geom *gp;
|
|
struct g_bsd_softc *ms;
|
|
struct g_slicer *gsp;
|
|
struct g_ioctl *gio;
|
|
int error;
|
|
|
|
gp = bp->bio_to->geom;
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
switch(bp->bio_cmd) {
|
|
case BIO_READ:
|
|
/* We allow reading of our hot spots */
|
|
return (0);
|
|
case BIO_DELETE:
|
|
/* We do not allow deleting our hot spots */
|
|
return (EPERM);
|
|
case BIO_WRITE:
|
|
g_call_me(g_bsd_hotwrite, bp);
|
|
return (EJUSTRETURN);
|
|
case BIO_GETATTR:
|
|
if (g_handleattr(bp, "BSD::labelsum", ms->labelsum,
|
|
sizeof(ms->labelsum)))
|
|
return (1);
|
|
break;
|
|
case BIO_SETATTR:
|
|
break;
|
|
default:
|
|
KASSERT(0 == 1, ("Unknown bio_cmd in g_bsd_start (%d)",
|
|
bp->bio_cmd));
|
|
}
|
|
|
|
/* We only handle ioctl(2) requests of the right format. */
|
|
if (strcmp(bp->bio_attribute, "GEOM::ioctl"))
|
|
return (0);
|
|
else if (bp->bio_length != sizeof(*gio))
|
|
return (0);
|
|
|
|
/* Get hold of the ioctl parameters. */
|
|
gio = (struct g_ioctl *)bp->bio_data;
|
|
|
|
switch (gio->cmd) {
|
|
case DIOCGDINFO:
|
|
/* Return a copy of the disklabel to userland. */
|
|
bcopy(&ms->inram, gio->data, sizeof(ms->inram));
|
|
g_io_deliver(bp, 0);
|
|
return (1);
|
|
case DIOCSDINFO:
|
|
case DIOCWDINFO:
|
|
/*
|
|
* These we cannot do without the topology lock and some
|
|
* some I/O requests. Ask the event-handler to schedule
|
|
* us in a less restricted environment.
|
|
*/
|
|
error = g_call_me(g_bsd_ioctl, bp);
|
|
if (error)
|
|
g_io_deliver(bp, error);
|
|
/*
|
|
* We must return non-zero to indicate that we will deal
|
|
* with this bio, even though we have not done so yet.
|
|
*/
|
|
return (1);
|
|
default:
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Dump configuration information in XML format.
|
|
* Notice that the function is called once for the geom and once for each
|
|
* consumer and provider. We let g_slice_dumpconf() do most of the work.
|
|
*/
|
|
static void
|
|
g_bsd_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
|
|
{
|
|
struct g_bsd_softc *ms;
|
|
struct g_slicer *gsp;
|
|
|
|
gsp = gp->softc;
|
|
ms = gsp->softc;
|
|
g_slice_dumpconf(sb, indent, gp, cp, pp);
|
|
if (indent != NULL && pp == NULL && cp == NULL) {
|
|
sbuf_printf(sb, "%s<labeloffset>%jd</labeloffset>\n",
|
|
indent, (intmax_t)ms->labeloffset);
|
|
sbuf_printf(sb, "%s<rawoffset>%jd</rawoffset>\n",
|
|
indent, (intmax_t)ms->rawoffset);
|
|
sbuf_printf(sb, "%s<mbroffset>%jd</mbroffset>\n",
|
|
indent, (intmax_t)ms->mbroffset);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The taste function is called from the event-handler, with the topology
|
|
* lock already held and a provider to examine. The flags are unused.
|
|
*
|
|
* If flags == G_TF_NORMAL, the idea is to take a bite of the provider and
|
|
* if we find valid, consistent magic on it, build a geom on it.
|
|
* any magic bits which indicate that we should automatically put a BSD
|
|
* geom on it.
|
|
*
|
|
* There may be cases where the operator would like to put a BSD-geom on
|
|
* providers which do not meet all of the requirements. This can be done
|
|
* by instead passing the G_TF_INSIST flag, which will override these
|
|
* checks.
|
|
*
|
|
* The final flags value is G_TF_TRANSPARENT, which instructs the method
|
|
* to put a geom on top of the provider and configure it to be as transparent
|
|
* as possible. This is not really relevant to the BSD method and therefore
|
|
* not implemented here.
|
|
*/
|
|
|
|
static struct g_geom *
|
|
g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags)
|
|
{
|
|
struct g_geom *gp;
|
|
struct g_consumer *cp;
|
|
int error, i;
|
|
struct g_bsd_softc *ms;
|
|
struct disklabel *dl;
|
|
u_int secsize;
|
|
struct g_slicer *gsp;
|
|
MD5_CTX md5sum;
|
|
u_char hash[16];
|
|
|
|
g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name);
|
|
g_topology_assert();
|
|
|
|
/* We don't implement transparent inserts. */
|
|
if (flags == G_TF_TRANSPARENT)
|
|
return (NULL);
|
|
|
|
/*
|
|
* BSD labels are a subclass of the general "slicing" topology so
|
|
* a lot of the work can be done by the common "slice" code.
|
|
* Create a geom with space for MAXPARTITIONS providers, one consumer
|
|
* and a softc structure for us. Specify the provider to attach
|
|
* the consumer to and our "start" routine for special requests.
|
|
* The provider is opened with mode (1,0,0) so we can do reads
|
|
* from it.
|
|
*/
|
|
gp = g_slice_new(mp, MAXPARTITIONS, pp, &cp, &ms,
|
|
sizeof(*ms), g_bsd_start);
|
|
if (gp == NULL)
|
|
return (NULL);
|
|
|
|
/*
|
|
* Now that we have attached to and opened our provider, we do
|
|
* not need the topology lock until we change the topology again
|
|
* next time.
|
|
*/
|
|
g_topology_unlock();
|
|
|
|
/*
|
|
* Fill in the optional details, in our case we have a dumpconf
|
|
* routine which the "slice" code should call at the right time
|
|
*/
|
|
gp->dumpconf = g_bsd_dumpconf;
|
|
|
|
/* Get the geom_slicer softc from the geom. */
|
|
gsp = gp->softc;
|
|
|
|
/*
|
|
* The do...while loop here allows us to have multiple escapes
|
|
* using a simple "break". This improves code clarity without
|
|
* ending up in deep nesting and without using goto or come from.
|
|
*/
|
|
do {
|
|
/*
|
|
* If the provider is an MBR we will only auto attach
|
|
* to type 165 slices in the G_TF_NORMAL case. We will
|
|
* attach to any other type.
|
|
*/
|
|
error = g_getattr("MBR::type", cp, &i);
|
|
if (!error) {
|
|
if (i != 165 && flags == G_TF_NORMAL)
|
|
break;
|
|
error = g_getattr("MBR::offset", cp, &ms->mbroffset);
|
|
if (error)
|
|
break;
|
|
}
|
|
|
|
/* Same thing if we are inside a PC98 */
|
|
error = g_getattr("PC98::type", cp, &i);
|
|
if (!error) {
|
|
if (i != 0xc494 && flags == G_TF_NORMAL)
|
|
break;
|
|
error = g_getattr("PC98::offset", cp, &ms->mbroffset);
|
|
if (error)
|
|
break;
|
|
}
|
|
|
|
/* Get sector size, we need it to read data. */
|
|
secsize = cp->provider->sectorsize;
|
|
if (secsize < 512)
|
|
break;
|
|
|
|
/* First look for a label at the start of the second sector. */
|
|
error = g_bsd_try(gp, gsp, cp, secsize, ms, secsize);
|
|
|
|
/* Next, look for alpha labels */
|
|
if (error)
|
|
error = g_bsd_try(gp, gsp, cp, secsize, ms,
|
|
ALPHA_LABEL_OFFSET);
|
|
|
|
/* If we didn't find a label, punt. */
|
|
if (error)
|
|
break;
|
|
|
|
/*
|
|
* In order to avoid recursively attaching to the same
|
|
* on-disk label (it's usually visible through the 'c'
|
|
* partition) we calculate an MD5 and ask if other BSD's
|
|
* below us love that label. If they do, we don't.
|
|
*/
|
|
|
|
dl = &ms->inram;
|
|
MD5Init(&md5sum);
|
|
MD5Update(&md5sum, (u_char *)dl, sizeof(dl));
|
|
MD5Final(ms->labelsum, &md5sum);
|
|
|
|
error = g_getattr("BSD::labelsum", cp, &hash);
|
|
if (!error && !strncmp(ms->labelsum, hash, sizeof(hash)))
|
|
break;
|
|
|
|
/*
|
|
* Process the found disklabel, and modify our "slice"
|
|
* instance to match it, if possible.
|
|
*/
|
|
error = g_bsd_modify(gp, dl); /* Picks up topology lock. */
|
|
if (!error)
|
|
g_topology_unlock();
|
|
break;
|
|
} while (0);
|
|
|
|
/* Success of failure, we can close our provider now. */
|
|
g_topology_lock();
|
|
error = g_access_rel(cp, -1, 0, 0);
|
|
|
|
/* If we have configured any providers, return the new geom. */
|
|
if (gsp->nprovider > 0)
|
|
return (gp);
|
|
/*
|
|
* ...else push the "self-destruct" button, by spoiling our own
|
|
* consumer. This triggers a call to g_std_spoiled which will
|
|
* dismantle what was setup.
|
|
*/
|
|
g_std_spoiled(cp);
|
|
return (NULL);
|
|
}
|
|
|
|
/* Finally, register with GEOM infrastructure. */
|
|
static struct g_class g_bsd_class = {
|
|
BSD_CLASS_NAME,
|
|
g_bsd_taste,
|
|
NULL,
|
|
G_CLASS_INITIALIZER
|
|
};
|
|
|
|
DECLARE_GEOM_CLASS(g_bsd_class, g_bsd);
|