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From: Zygo Blaxell <umsfalfb@umail.furryterror.org>
To: linux-crypto@nl.linux.org, linux-kernel@vger.kernel.org,
hvr@kernel.org
Subject: Cryptoapi on 2.4.17 (2 patches)
Date: Wed, 26 Dec 2001 17:03:58 -0500
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I have two patches, one for cryptoAPI (current CVS) and one for the
Linux kernel (2.4.17). =20
The cryptoapi patch fixes a silly symbol name bug. The
patch for the Linux kernel changes the default lo_iv_mode to
LO_IV_MODE_SECTOR--otherwise, the patch is just a straightforward port
of the patch in cryptoapi/doc in cryptoavi CVS.
I noticed that there doesn't seem to be a way to set lo_iv_mode from
user-space, not even with a module or kernel command-line parameter.
Is this just one of those features that isn't implemented yet, or did
I miss something?
The patches seem to work: I can swap on an rc6 encrypted partition
using the patches, and I can create an ext2 filesystem on an rc6 loopback
file, copy some data to it, unmount, losetup -d, losetup -e, mount it
again, and _still access the data afterwards_. Whee!
This still doesn't completely work for encrypted swap because somebody
(who shall remain nameless, but whose name rhymes with socks) seems to
have "lost" the kreclaimd kernel thread. I thought I would try to get=20
someone else to look at this before tackling that problem...
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? tests/.deps
? tests/Makefile
? tests/Makefile.in
Index: api/cryptoloop.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/cryptoapi/cryptoapi/api/cryptoloop.c,v
retrieving revision 1.4
diff -u -r1.4 cryptoloop.c
--- api/cryptoloop.c 2001/12/14 23:38:49 1.4
+++ api/cryptoloop.c 2001/12/26 21:30:57
@@ -44,7 +44,7 @@
# error you need at least kernel 2.4.3 -- unless you know exacty what you =
are doing
#endif
=20
-#if !defined(LOOP_IV_SECTOR_SIZE)
+#if !defined(LO_IV_SECTOR_SIZE)
# error you need to to patch your loop.c driver
#endif
=20
@@ -85,10 +85,10 @@
struct cipher_context *cx;
=20
/* encryption breaks for non sector aligned offsets */
- if (info->lo_offset % LOOP_IV_SECTOR_SIZE)=20
+ if (info->lo_offset % LO_IV_SECTOR_SIZE)=20
goto out;
=20
- lx->blocksize =3D LOOP_IV_SECTOR_SIZE;
+ lx->blocksize =3D LO_IV_SECTOR_SIZE;
lx->debug =3D 0;
=20
strncpy(cipher, info->lo_name, LO_NAME_SIZE);
@@ -163,7 +163,7 @@
out =3D raw_buf;
}
=20
- IV /=3D blocksize / LOOP_IV_SECTOR_SIZE;
+ IV /=3D blocksize / LO_IV_SECTOR_SIZE;
=20
#if defined(CRYPTOLOOP_DEBUG)
if (lx->debug)
@@ -203,7 +203,7 @@
switch (cmd) {
case CRYPTOLOOP_SET_BLKSIZE:
printk (KERN_DEBUG "cryptoloop: switch to blocksize %d requested\n", *=
arg_int);
- if (*arg_int >=3D 0 && (*arg_int % LOOP_IV_SECTOR_SIZE =3D=3D 0))
+ if (*arg_int >=3D 0 && (*arg_int % LO_IV_SECTOR_SIZE =3D=3D 0))
{
lx->blocksize =3D *arg_int;
err =3D 0;
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--- /home/zblaxell/linux/p3-laptop/kernel-source-2.4.17-zb-p3-laptop-zb2001=
122605/drivers/block/loop.c Fri Dec 21 12:41:53 2001
+++ drivers/block/loop.c Wed Dec 26 13:59:05 2001
@@ -36,6 +36,9 @@
* Al Viro too.
* Jens Axboe <axboe@suse.de>, Nov 2000
*
+ * Fixed and made IV calculation customizable by lo_iv_mode
+ * Herbert Valerio Riedel <hvr@gnu.org>, Apr 2001
+ *
* Still To Fix:
* - Advisory locking is ignored here.=20
* - Should use an own CAP_* category instead of CAP_SYS_ADMIN=20
@@ -168,6 +171,43 @@
lo->lo_device);
}
=20
+static inline int loop_get_bs(struct loop_device *lo)
+{
+ int bs =3D 0;
+
+ if (blksize_size[MAJOR(lo->lo_device)])
+ bs =3D blksize_size[MAJOR(lo->lo_device)][MINOR(lo->lo_device)];
+ if (!bs)
+ bs =3D BLOCK_SIZE;=09
+
+ return bs;
+}
+
+static inline unsigned long loop_get_iv(struct loop_device *lo,
+ unsigned long sector)
+{
+ unsigned long offset, IV;
+ int bs;
+
+ switch (lo->lo_iv_mode) {
+ case LO_IV_MODE_SECTOR:
+ IV =3D sector + (lo->lo_offset >> LO_IV_SECTOR_BITS);
+ break;
+
+ default:
+ printk (KERN_WARNING "loop: unexpected lo_iv_mode\n");
+ case LO_IV_MODE_DEFAULT:
+ bs =3D loop_get_bs(lo);
+ IV =3D sector / (bs >> 9) + lo->lo_offset / bs;
+ offset =3D ((sector % (bs >> 9)) << 9) + lo->lo_offset % bs;
+ if (offset >=3D bs)
+ IV++;
+ break;
+ }
+
+ return IV;
+}
+
static int lo_send(struct loop_device *lo, struct buffer_head *bh, int bsi=
ze,
loff_t pos)
{
@@ -186,7 +226,7 @@
len =3D bh->b_size;
data =3D bh->b_data;
while (len > 0) {
- int IV =3D index * (PAGE_CACHE_SIZE/bsize) + offset/bsize;
+ unsigned long IV =3D loop_get_iv(lo, (pos - lo->lo_offset)=
>> LO_IV_SECTOR_BITS);
int transfer_result;
=20
size =3D PAGE_CACHE_SIZE - offset;
@@ -244,7 +284,10 @@
unsigned long count =3D desc->count;
struct lo_read_data *p =3D (struct lo_read_data*)desc->buf;
struct loop_device *lo =3D p->lo;
- int IV =3D page->index * (PAGE_CACHE_SIZE/p->bsize) + offset/p->bsize;
+ unsigned long IV =3D loop_get_iv(lo,
+ ((page->index << (PAGE_CACHE_SHIFT - LO_IV_SECTOR_BITS))
+ + (offset >> LO_IV_SECTOR_BITS)
+ - (lo->lo_offset >> LO_IV_SECTOR_BITS)));
=20
if (size > count)
size =3D count;
@@ -284,32 +327,6 @@
return desc.error;
}
=20
-static inline int loop_get_bs(struct loop_device *lo)
-{
- int bs =3D 0;
-
- if (blksize_size[MAJOR(lo->lo_device)])
- bs =3D blksize_size[MAJOR(lo->lo_device)][MINOR(lo->lo_device)];
- if (!bs)
- bs =3D BLOCK_SIZE;=09
-
- return bs;
-}
-
-static inline unsigned long loop_get_iv(struct loop_device *lo,
- unsigned long sector)
-{
- int bs =3D loop_get_bs(lo);
- unsigned long offset, IV;
-
- IV =3D sector / (bs >> 9) + lo->lo_offset / bs;
- offset =3D ((sector % (bs >> 9)) << 9) + lo->lo_offset % bs;
- if (offset >=3D bs)
- IV++;
-
- return IV;
-}
-
static int do_bh_filebacked(struct loop_device *lo, struct buffer_head *bh=
, int rw)
{
loff_t pos;
@@ -677,6 +694,7 @@
lo->lo_backing_file =3D file;
lo->transfer =3D NULL;
lo->ioctl =3D NULL;
+ lo->lo_iv_mode =3D LO_IV_MODE_SECTOR;
figure_loop_size(lo);
lo->old_gfp_mask =3D inode->i_mapping->gfp_mask;
inode->i_mapping->gfp_mask =3D GFP_NOIO;
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