OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: Richard Lowe <richlowe@richlowe.net>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported by: Tony Hutter <hutter2@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/4185
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/45818ee

Porting Notes:
This code is ported on top of the Illumos Crypto Framework code:

    https://github.com/zfsonlinux/zfs/pull/4329/commits/b5e030c8dbb9cd393d313571dee4756fbba8c22d

The list of porting changes includes:

- Copied module/icp/include/sha2/sha2.h directly from illumos

- Removed from module/icp/algs/sha2/sha2.c:
	#pragma inline(SHA256Init, SHA384Init, SHA512Init)

- Added 'ctx' to lib/libzfs/libzfs_sendrecv.c:zio_checksum_SHA256() since
  it now takes in an extra parameter.

- Added CTASSERT() to assert.h from for module/zfs/edonr_zfs.c

- Added skein & edonr to libicp/Makefile.am

- Added sha512.S.  It was generated from sha512-x86_64.pl in Illumos.

- Updated ztest.c with new fletcher_4_*() args; used NULL for new CTX argument.

- In icp/algs/edonr/edonr_byteorder.h, Removed the #if defined(__linux) section
  to not #include the non-existant endian.h.

- In skein_test.c, renane NULL to 0 in "no test vector" array entries to get
  around a compiler warning.

- Fixup test files:
	- Rename <sys/varargs.h> -> <varargs.h>, <strings.h> -> <string.h>,
	- Remove <note.h> and define NOTE() as NOP.
	- Define u_longlong_t
	- Rename "#!/usr/bin/ksh" -> "#!/bin/ksh -p"
	- Rename NULL to 0 in "no test vector" array entries to get around a
	  compiler warning.
	- Remove "for isa in $($ISAINFO); do" stuff
	- Add/update Makefiles
	- Add some userspace headers like stdio.h/stdlib.h in places of
	  sys/types.h.

- EXPORT_SYMBOL *_Init/*_Update/*_Final... routines in ICP modules.

- Update scripts/zfs2zol-patch.sed

- include <sys/sha2.h> in sha2_impl.h

- Add sha2.h to include/sys/Makefile.am

- Add skein and edonr dirs to icp Makefile

- Add new checksums to zpool_get.cfg

- Move checksum switch block from zfs_secpolicy_setprop() to
  zfs_check_settable()

- Fix -Wuninitialized error in edonr_byteorder.h on PPC

- Fix stack frame size errors on ARM32
  	- Don't unroll loops in Skein on 32-bit to save stack space
  	- Add memory barriers in sha2.c on 32-bit to save stack space

- Add filetest_001_pos.ksh checksum sanity test

- Add option to write psudorandom data in file_write utility

module/zfs/zfs_ioctl.c

@@ -185,6 +185,7 @@
 #include <sys/dsl_bookmark.h>
 #include <sys/dsl_userhold.h>
 #include <sys/zfeature.h>
+#include <sys/zio_checksum.h>
 
 #include <linux/miscdevice.h>
 #include <linux/slab.h>
@@ -3809,11 +3810,6 @@ zfs_check_settable(const char *dsname, nvpair_t *pair, cred_t *cr)
 			return (SET_ERROR(ENOTSUP));
 		break;
 
-	case ZFS_PROP_DEDUP:
-		if (zfs_earlier_version(dsname, SPA_VERSION_DEDUP))
-			return (SET_ERROR(ENOTSUP));
-		break;
-
 	case ZFS_PROP_VOLBLOCKSIZE:
 	case ZFS_PROP_RECORDSIZE:
 		/* Record sizes above 128k need the feature to be enabled */
@@ -3893,6 +3889,47 @@ zfs_check_settable(const char *dsname, nvpair_t *pair, cred_t *cr)
 				return (SET_ERROR(ENOTSUP));
 		}
 		break;
+	case ZFS_PROP_CHECKSUM:
+	case ZFS_PROP_DEDUP:
+	{
+		spa_feature_t feature;
+		spa_t *spa;
+		uint64_t intval;
+		int err;
+
+		/* dedup feature version checks */
+		if (prop == ZFS_PROP_DEDUP &&
+		    zfs_earlier_version(dsname, SPA_VERSION_DEDUP))
+			return (SET_ERROR(ENOTSUP));
+
+		if (nvpair_value_uint64(pair, &intval) != 0)
+			return (SET_ERROR(EINVAL));
+
+		/* check prop value is enabled in features */
+		feature = zio_checksum_to_feature(intval);
+		if (feature == SPA_FEATURE_NONE)
+			break;
+
+		if ((err = spa_open(dsname, &spa, FTAG)) != 0)
+			return (err);
+		/*
+		 * Salted checksums are not supported on root pools.
+		 */
+		if (spa_bootfs(spa) != 0 &&
+		    intval < ZIO_CHECKSUM_FUNCTIONS &&
+		    (zio_checksum_table[intval].ci_flags &
+		    ZCHECKSUM_FLAG_SALTED)) {
+			spa_close(spa, FTAG);
+			return (SET_ERROR(ERANGE));
+		}
+		if (!spa_feature_is_enabled(spa, feature)) {
+			spa_close(spa, FTAG);
+			return (SET_ERROR(ENOTSUP));
+		}
+		spa_close(spa, FTAG);
+		break;
+	}
+
 	default:
 		break;
 	}