// SPDX-License-Identifier: CDDL-1.0
/*
 * 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
 * https://opensource.org/license/CDDL-1.0.
 */
/*
 * Copyright (c) 2025 by Lawrence Livermore National Security, LLC.
 */
/*
 * This file contains zfs_dbgmsg() specific functions that are not OS or
 * userspace specific.
 */
#include <sys/zfs_context.h>
#include <sys/zfs_debug.h>
#include <sys/nvpair.h>

/*
 * Given a multi-line string, print out one of the lines and return a pointer
 * to the next line. Lines are demarcated by '\n'.  Note: this modifies the
 * input string (buf[]).
 *
 * This function is meant to be used in a loop like:
 * 	while (buf != NULL)
 * 		buf = kernel_print_one_line(buf);
 *
 * This function is useful for printing large, multi-line text buffers.
 *
 * Returns the pointer to the beginning of the next line in buf[], or NULL
 * if it's the last line, or nothing more to print.
 */
static char *
zfs_dbgmsg_one_line(char *buf)
{
	char *nl;
	if (!buf)
		return (NULL);

	nl = strchr(buf, '\n');
	if (nl == NULL) {
		__zfs_dbgmsg(buf);
		return (NULL); /* done */
	}
	*nl = '\0';
	__zfs_dbgmsg(buf);

	return (nl + 1);
}

/*
 * Dump an nvlist tree to dbgmsg.
 *
 * This is the zfs_dbgmsg version of userspace's dump_nvlist() from libnvpair.
 */
void
__zfs_dbgmsg_nvlist(nvlist_t *nv)
{
	int len;
	char *buf;

	len = nvlist_snprintf(NULL, 0, nv, 4);
	len++; /* Add null terminator */

	buf = vmem_alloc(len, KM_SLEEP);
	if (buf == NULL)
		return;

	(void) nvlist_snprintf(buf, len, nv, 4);

	while (buf != NULL)
		buf = zfs_dbgmsg_one_line(buf);

	vmem_free(buf, len);
}

EXPORT_SYMBOL(__zfs_dbgmsg_nvlist);