zstream: consolidate shared code

zstream currently contains three identical copies of dump_record(),
which appear to all be drawn from libzfs_sendrecv.c. The original
is marked internal.

This PR adds zstream_util.[hc] and puts the shared code there along with
a couple of other items in common.

No functional changes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Garth Snyder <garth@garthsnyder.com>
Closes #18284

cmd/zstream/Makefile.am

@@ -11,7 +11,9 @@ zstream_SOURCES = \
 	%D%/zstream_dump.c \
 	%D%/zstream_recompress.c \
 	%D%/zstream_redup.c \
-	%D%/zstream_token.c
+	%D%/zstream_token.c \
+	%D%/zstream_util.c \
+	%D%/zstream_util.h
 
 zstream_LDADD = \
 	libzfs.la \

cmd/zstream/zstream.h

@@ -25,9 +25,6 @@
 extern "C" {
 #endif
 
-extern void *safe_calloc(size_t n);
-extern int sfread(void *buf, size_t size, FILE *fp);
-extern void *safe_malloc(size_t size);
 extern int zstream_do_redup(int, char *[]);
 extern int zstream_do_dump(int, char *[]);
 extern int zstream_do_decompress(int argc, char *argv[]);

cmd/zstream/zstream_decompress.c

@@ -37,31 +37,7 @@
 #include <sys/zstd/zstd.h>
 #include "zfs_fletcher.h"
 #include "zstream.h"
-
+#include "zstream_util.h"
-static int
-dump_record(dmu_replay_record_t *drr, void *payload, int payload_len,
-    zio_cksum_t *zc, int outfd)
-{
-	assert(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum)
-	    == sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
-	fletcher_4_incremental_native(drr,
-	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
-	if (drr->drr_type != DRR_BEGIN) {
-		assert(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
-		    drr_checksum.drr_checksum));
-		drr->drr_u.drr_checksum.drr_checksum = *zc;
-	}
-	fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
-	    sizeof (zio_cksum_t), zc);
-	if (write(outfd, drr, sizeof (*drr)) == -1)
-		return (errno);
-	if (payload_len != 0) {
-		fletcher_4_incremental_native(payload, payload_len, zc);
-		if (write(outfd, payload, payload_len) == -1)
-			return (errno);
-	}
-	return (0);
-}
 
 int
 zstream_do_decompress(int argc, char *argv[])

cmd/zstream/zstream_dump.c

@@ -44,6 +44,7 @@
 #include <sys/zio.h>
 #include <zfs_fletcher.h>
 #include "zstream.h"
+#include "zstream_util.h"
 
 /*
  * If dump mode is enabled, the number of bytes to print per line
@@ -60,18 +61,6 @@ static FILE *send_stream = 0;
 static boolean_t do_byteswap = B_FALSE;
 static boolean_t do_cksum = B_TRUE;
 
-void *
-safe_malloc(size_t size)
-{
-	void *rv = malloc(size);
-	if (rv == NULL) {
-		(void) fprintf(stderr, "ERROR; failed to allocate %zu bytes\n",
-		    size);
-		abort();
-	}
-	return (rv);
-}
-
 /*
  * ssread - send stream read.
  *

cmd/zstream/zstream_recompress.c

@@ -37,31 +37,7 @@
 #include <sys/zstd/zstd.h>
 #include "zfs_fletcher.h"
 #include "zstream.h"
-
+#include "zstream_util.h"
-static int
-dump_record(dmu_replay_record_t *drr, void *payload, int payload_len,
-    zio_cksum_t *zc, int outfd)
-{
-	assert(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum)
-	    == sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
-	fletcher_4_incremental_native(drr,
-	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
-	if (drr->drr_type != DRR_BEGIN) {
-		assert(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
-		    drr_checksum.drr_checksum));
-		drr->drr_u.drr_checksum.drr_checksum = *zc;
-	}
-	fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
-	    sizeof (zio_cksum_t), zc);
-	if (write(outfd, drr, sizeof (*drr)) == -1)
-		return (errno);
-	if (payload_len != 0) {
-		fletcher_4_incremental_native(payload, payload_len, zc);
-		if (write(outfd, payload, payload_len) == -1)
-			return (errno);
-	}
-	return (0);
-}
 
 int
 zstream_do_recompress(int argc, char *argv[])

cmd/zstream/zstream_redup.c

@@ -37,6 +37,7 @@
 #include <sys/zio_checksum.h>
 #include "zfs_fletcher.h"
 #include "zstream.h"
+#include "zstream_util.h"
 
 
 #define	MAX_RDT_PHYSMEM_PERCENT		20
@@ -57,34 +58,6 @@ typedef struct redup_table {
 	int		numhashbits;
 } redup_table_t;
 
-void *
-safe_calloc(size_t n)
-{
-	void *rv = calloc(1, n);
-	if (rv == NULL) {
-		fprintf(stderr,
-		    "Error: could not allocate %u bytes of memory\n",
-		    (int)n);
-		exit(1);
-	}
-	return (rv);
-}
-
-/*
- * Safe version of fread(), exits on error.
- */
-int
-sfread(void *buf, size_t size, FILE *fp)
-{
-	int rv = fread(buf, size, 1, fp);
-	if (rv == 0 && ferror(fp)) {
-		(void) fprintf(stderr, "Error while reading file: %s\n",
-		    strerror(errno));
-		exit(1);
-	}
-	return (rv);
-}
-
 /*
  * Safe version of pread(), exits on error.
  */
@@ -104,31 +77,6 @@ spread(int fd, void *buf, size_t count, off_t offset)
 	}
 }
 
-static int
-dump_record(dmu_replay_record_t *drr, void *payload, int payload_len,
-    zio_cksum_t *zc, int outfd)
-{
-	assert(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum)
-	    == sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
-	fletcher_4_incremental_native(drr,
-	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
-	if (drr->drr_type != DRR_BEGIN) {
-		assert(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
-		    drr_checksum.drr_checksum));
-		drr->drr_u.drr_checksum.drr_checksum = *zc;
-	}
-	fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
-	    sizeof (zio_cksum_t), zc);
-	if (write(outfd, drr, sizeof (*drr)) == -1)
-		return (errno);
-	if (payload_len != 0) {
-		fletcher_4_incremental_native(payload, payload_len, zc);
-		if (write(outfd, payload, payload_len) == -1)
-			return (errno);
-	}
-	return (0);
-}
-
 static void
 rdt_insert(redup_table_t *rdt,
     uint64_t guid, uint64_t object, uint64_t offset, uint64_t stream_offset)

cmd/zstream/zstream_util.c

@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
+ * Copyright (c) 2012, Joyent, Inc. All rights reserved.
+ * Copyright (c) 2012 Pawel Jakub Dawidek <pawel@dawidek.net>.
+ * All rights reserved
+ * Copyright (c) 2013 Steven Hartland. All rights reserved.
+ * Copyright 2015, OmniTI Computer Consulting, Inc. All rights reserved.
+ * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
+ * Copyright (c) 2018, loli10K <ezomori.nozomu@gmail.com>. All rights reserved.
+ * Copyright (c) 2019 Datto Inc.
+ * Copyright (c) 2024, Klara, Inc.
+ */
+
+#include <sys/debug.h>
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <zfs_fletcher.h>
+#include "zstream_util.h"
+
+/*
+ * From libzfs_sendrecv.c
+ */
+int
+dump_record(dmu_replay_record_t *drr, void *payload, size_t payload_len,
+    zio_cksum_t *zc, int outfd)
+{
+	ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
+	    ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
+	fletcher_4_incremental_native(drr,
+	    offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
+	if (drr->drr_type != DRR_BEGIN) {
+		ASSERT(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
+		    drr_checksum.drr_checksum));
+		drr->drr_u.drr_checksum.drr_checksum = *zc;
+	}
+	fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
+	    sizeof (zio_cksum_t), zc);
+	if (write(outfd, drr, sizeof (*drr)) == -1)
+		return (errno);
+	if (payload_len != 0) {
+		fletcher_4_incremental_native(payload, payload_len, zc);
+		if (write(outfd, payload, payload_len) == -1)
+			return (errno);
+	}
+	return (0);
+}
+
+void *
+safe_malloc(size_t size)
+{
+	void *rv = malloc(size);
+	if (rv == NULL) {
+		(void) fprintf(stderr, "Error: failed to allocate %zu bytes\n",
+		    size);
+		exit(1);
+	}
+	return (rv);
+}
+
+void *
+safe_calloc(size_t size)
+{
+	void *rv = calloc(1, size);
+	if (rv == NULL) {
+		(void) fprintf(stderr,
+		    "Error: failed to allocate %zu bytes\n", size);
+		exit(1);
+	}
+	return (rv);
+}
+
+/*
+ * Safe version of fread(), exits on error.
+ */
+int
+sfread(void *buf, size_t size, FILE *fp)
+{
+	int rv = fread(buf, size, 1, fp);
+	if (rv == 0 && ferror(fp)) {
+		(void) fprintf(stderr, "Error while reading file: %s\n",
+		    strerror(errno));
+		exit(1);
+	}
+	return (rv);
+}

cmd/zstream/zstream_util.h

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2026 by Garth Snyder. All rights reserved.
+ */
+
+#ifndef	_ZSTREAM_UTIL_H
+#define	_ZSTREAM_UTIL_H
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+#include <sys/zfs_ioctl.h>
+#include <sys/zio_checksum.h>
+
+/*
+ * The safe_ versions of the functions below terminate the process if the
+ * operation doesn't succeed instead of returning an error.
+ */
+extern void *
+safe_malloc(size_t size);
+
+extern void *
+safe_calloc(size_t n);
+
+extern int
+sfread(void *buf, size_t size, FILE *fp);
+
+/*
+ * 1) Update checksum with the record header up to drr_checksum.
+ * 2) Update checksum field in the record header.
+ * 3) Update checksum with the checksum field in the record header.
+ * 4) Update checksum with the contents of the payload.
+ * 5) Write header and payload to fd.
+ */
+extern int
+dump_record(dmu_replay_record_t *drr, void *payload, size_t payload_len,
+	zio_cksum_t *zc, int outfd);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* _ZSTREAM_UTIL_H */