/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License, Version 1.0 only

 * (the "License").  You may not use this file except in compliance

 * with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * This file contains code to support better NFS error messages.  Death to

 * integer codes in user error messages!

 *

 * XXX Ideally this code should be more general and available to the entire

 * kernel (see RFE 1101936).  When this happens, this file can go away.

 */

#include <nfs/nfs.h>

#include <sys/systm.h>

#include <sys/cmn_err.h>

#include <sys/errno.h>

#include <sys/varargs.h>

#ifndef NULL

#define	NULL	0

#endif

/* size of a temporary printf format buffer. */

#define	FMT_BUF_SIZE	1024

static void expand_format_string(int, const char *, char *, int);

static char *nfs_strerror(int);

/*

 * nfs_perror: Works like printf (format string and variable args) except

 * that it will substitute an error message for a "%m" string (like

 * syslog), using the given errno value.

 */

void

nfs_perror(int error, char *fmt, ...)

{

	va_list ap;

	char buf[FMT_BUF_SIZE];		/* massaged version of fmt */

	/* Expand %m */

	expand_format_string(error, fmt, buf, FMT_BUF_SIZE);

	/*

	 * Now pass the massaged format string and its arguments off to

	 * printf.

	 */

	va_start(ap, fmt);

	(void) vzprintf(getzoneid(), buf, ap);

	va_end(ap);

}

/*

 * nfs_cmn_err: Works like cmn_err (error level, format string, and

 * variable args) except that it will substitute an error message for a

 * "%m" string (like syslog), using the given errno value.

 */

void

nfs_cmn_err(int error, int level, char *fmt, ...)

{

	va_list ap;

	char buf[FMT_BUF_SIZE];		/* massaged version of fmt */

	/* Expand %m */

	expand_format_string(error, fmt, buf, FMT_BUF_SIZE);

	/*

	 * Now pass the massaged format string and its arguments off to

	 * cmn_err.

	 */

	va_start(ap, fmt);

	(void) vzcmn_err(getzoneid(), level, buf, ap);

	va_end(ap);

}

/*

 * expand_format_string: copy the printf format string from "fmt" to "buf",

 * expanding %m to the error string for "error".

 */

static void

expand_format_string(int error, const char *fmt, char *buf, int buf_chars)

{

	const char *from;		/* pointer into fmt */

	char *to;			/* pointer into buf */

	char *errmsg;			/* expansion for %m */

	char *trunc_msg = "Truncated NFS error message: ";

	zoneid_t zoneid = getzoneid();

	/*

	 * Copy the given format string into the result buffer, expanding

	 * %m as we go.  If the result buffer is too short, complain and

	 * truncate the message.  (We don't expect this to ever happen,

	 * though.)

	 */

	for (from = fmt, to = buf; *from; from++) {

		if (to >= buf + buf_chars - 1) {

			zprintf(zoneid, trunc_msg);

			break;

		}

		if (*from == '%' && *(from+1) == 'm') {

			errmsg = nfs_strerror(error);

			/*

			 * If there's an error message and room to display

			 * it, copy it in.  If there's no message or not

			 * enough room, try just printing an error number.

			 * (We assume that the error value is in a

			 * reasonable range.)  If there's no room for

			 * anything, bail out.

			 */

			if (errmsg != NULL &&

			    strlen(buf) + strlen(errmsg) < buf_chars) {

				(void) strcpy(to, errmsg);

				to += strlen(errmsg);

			} else if (strlen(buf) + strlen("error XXX") <

			    buf_chars) {

				(void) sprintf(to, "error %d", error);

				/*

				 * Don't try to guess how many characters

				 * were laid down.

				 */

				to = buf + strlen(buf);

			} else {

				zprintf(zoneid, trunc_msg);

				break;

			}

			from++;

		} else {

			*to++ = *from;

		}

	}

	*to = '\0';

}

/*

 * nfs_strerror: map an errno value to a string.  Not all possible errno

 * values are supported.

 *

 * If there is no string for the given errno value, return NULL.

 */

static char *

nfs_strerror(int errcode)

{

	char *result;

	switch (errcode) {

	case EPERM:

		result = "Not owner";

		break;

	case ENOENT:

		result = "No such file or directory";

		break;

	case EIO:

		result = "I/O error";

		break;

	case EACCES:

		result = "Permission denied";

		break;

	case EEXIST:

		result = "File exists";

		break;

	case ENOTDIR:

		result = "Not a directory";

		break;

	case EISDIR:

		result = "Is a directory";

		break;

	case EINVAL:

		result = "Invalid argument";

		break;

	case EFBIG:

		result = "File too large";

		break;

	case ENOSPC:

		result = "No space left on device";

		break;

	case EROFS:

		result = "Read-only file system";

		break;

	case EDQUOT:

		result = "Disc quota exceeded";

		break;

	case ENOTEMPTY:

		result = "Directory not empty";

		break;

	case ESTALE:

		result = "Stale NFS file handle";

		break;

	case ENOMEM:

		result = "Not enough memory";

		break;

	default:

		result = NULL;

		break;

	}

	return (result);

}