M1: compat layer + pf.ko skeleton builds against Linux 7.3.4

- pfk.h: BSD types/ioctl encoding (OpenBSD bit layout), locks (NET_LOCK=rwsem),
  pools, timeouts, mbuf shim over sk_buff, ifnet registry, toeplitz/siphash
- pfk_mod/pfk_hooks: misc /dev/pf (0600), IPv4 netfilter hook skeleton,
  DIOCGETSTATUS answered (M1 skeleton; engine ioctls land with pf_ioctl.c)
- vendorize/stage-port scripts: deterministic upstream staging with seds
  (struct renames, IFF_*->PFIFF_*, sa_len drops) logged to docs/porting-notes
- fixes: modules_prepare+Module.symvers for out-of-tree builds

module/include/compat/crypto/sha2.h

@@ -0,0 +1,83 @@
+/*	$OpenBSD: sha2.h,v 1.5 2014/11/16 17:39:09 tedu Exp $	*/
+
+/*
+ * FILE:	sha2.h
+ * AUTHOR:	Aaron D. Gifford <me@aarongifford.com>
+ * 
+ * Copyright (c) 2000-2001, Aaron D. Gifford
+ * All rights reserved.
+ *
+ * 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.
+ * 3. Neither the name of the copyright holder nor the names of contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``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 AUTHOR OR CONTRIBUTOR(S) 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.
+ *
+ * $From: sha2.h,v 1.1 2001/11/08 00:02:01 adg Exp adg $
+ */
+
+#ifndef _SHA2_H
+#define _SHA2_H
+
+
+/*** SHA-256/384/512 Various Length Definitions ***********************/
+#define SHA256_BLOCK_LENGTH		64
+#define SHA256_DIGEST_LENGTH		32
+#define SHA256_DIGEST_STRING_LENGTH	(SHA256_DIGEST_LENGTH * 2 + 1)
+#define SHA384_BLOCK_LENGTH		128
+#define SHA384_DIGEST_LENGTH		48
+#define SHA384_DIGEST_STRING_LENGTH	(SHA384_DIGEST_LENGTH * 2 + 1)
+#define SHA512_BLOCK_LENGTH		128
+#define SHA512_DIGEST_LENGTH		64
+#define SHA512_DIGEST_STRING_LENGTH	(SHA512_DIGEST_LENGTH * 2 + 1)
+
+
+/*** SHA-256/384/512 Context Structure *******************************/
+typedef struct _SHA2_CTX {
+	union {
+		u_int32_t	st32[8];
+		u_int64_t	st64[8];
+	} state;
+	u_int64_t	bitcount[2];
+	u_int8_t	buffer[SHA512_BLOCK_LENGTH];
+} SHA2_CTX;
+
+__BEGIN_DECLS
+void SHA256Init(SHA2_CTX *);
+void SHA256Update(SHA2_CTX *, const void *, size_t)
+	__attribute__((__bounded__(__string__,2,3)));
+void SHA256Final(u_int8_t[SHA256_DIGEST_LENGTH], SHA2_CTX *)
+	__attribute__((__bounded__(__minbytes__,1,SHA256_DIGEST_LENGTH)));
+
+void SHA384Init(SHA2_CTX *);
+void SHA384Update(SHA2_CTX *, const void *, size_t)
+	__attribute__((__bounded__(__string__,2,3)));
+void SHA384Final(u_int8_t[SHA384_DIGEST_LENGTH], SHA2_CTX *)
+	__attribute__((__bounded__(__minbytes__,1,SHA384_DIGEST_LENGTH)));
+
+void SHA512Init(SHA2_CTX *);
+void SHA512Update(SHA2_CTX *, const void *, size_t)
+	__attribute__((__bounded__(__string__,2,3)));
+void SHA512Final(u_int8_t[SHA512_DIGEST_LENGTH], SHA2_CTX *)
+	__attribute__((__bounded__(__minbytes__,1,SHA512_DIGEST_LENGTH)));
+__END_DECLS
+
+#endif /* _SHA2_H */