git: 2d7f27a4fb4c - stable/13 - opencrypto: Add a routine to copy a crypto buffer cursor

The branch stable/13 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=2d7f27a4fb4c1c67c48fad9c73b1f3eec60195d5

commit 2d7f27a4fb4c1c67c48fad9c73b1f3eec60195d5
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2022-02-16 02:45:32 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2022-03-18 15:31:33 +0000

    opencrypto: Add a routine to copy a crypto buffer cursor
    
    This was useful in converting armv8crypto to use buffer cursors.  There
    are some cases where one wants to make two passes over data, and this
    provides a way to "reset" a cursor.
    
    Reviewed by:    jhb
    
    (cherry picked from commit 09bfa5cf16a37509a136367431472f9169a173ad)
---
 share/man/man9/crypto_buffer.9 | 13 ++++++++++++-
 sys/opencrypto/cryptodev.h     |  7 +++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/share/man/man9/crypto_buffer.9 b/share/man/man9/crypto_buffer.9
index a16206e8e607..064c6fbc12e3 100644
--- a/share/man/man9/crypto_buffer.9
+++ b/share/man/man9/crypto_buffer.9
@@ -30,7 +30,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 25, 2021
+.Dd Feburary 11, 2022
 .Dt CRYPTO_BUFFER 9
 .Os
 .Sh NAME
@@ -99,6 +99,11 @@
 .Fn crypto_cursor_segbase "struct crypto_buffer_cursor *cc"
 .Ft size_t
 .Fn crypto_cursor_seglen "struct crypto_buffer_cursor *cc"
+.Ft void
+.Fo crypto_cursor_copy
+.Fa "const struct crypto_buffer_cursor *fromc"
+.Fa "struct crypto_buffer_cursor *toc"
+.Fc
 .Ft bool
 .Fn CRYPTO_HAS_OUTPUT_BUFFER "struct cryptop *crp"
 .Sh DESCRIPTION
@@ -327,6 +332,12 @@ returns the length of a buffer in bytes.
 .Fn crypto_cursor_seglen
 returns the length in bytes of a contiguous segment.
 .Pp
+.Fn crypto_cursor_copy
+makes a deep copy of the cursor
+.Fa fromc .
+The two copies do not share any state and can thus be used
+independently.
+.Pp
 .Fn CRYPTO_HAS_OUTPUT_BUFFER
 returns true if the request uses a separate output buffer.
 .Sh SEE ALSO
diff --git a/sys/opencrypto/cryptodev.h b/sys/opencrypto/cryptodev.h
index 1aa11c34d8ba..b127f4ee6b38 100644
--- a/sys/opencrypto/cryptodev.h
+++ b/sys/opencrypto/cryptodev.h
@@ -741,6 +741,13 @@ void	crypto_cursor_copydata(struct crypto_buffer_cursor *cc, int size,
 void	crypto_cursor_copydata_noadv(struct crypto_buffer_cursor *cc, int size,
 	    void *vdst);
 
+static __inline void
+crypto_cursor_copy(const struct crypto_buffer_cursor *fromc,
+    struct crypto_buffer_cursor *toc)
+{
+	memcpy(toc, fromc, sizeof(*toc));
+}
+
 static __inline void
 crypto_read_iv(struct cryptop *crp, void *iv)
 {