/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (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 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Buffer manipulation routines. These routines can be used to format
* data within a data buffer without worrying about overrunning the
* buffer.
*
* A ctxbuf_t structure is used to track the current location within
* the buffer. The ctxbuf_init() must be called first to initialize the
* context structure. ctxbuf_printf() can then be called to fill the buffer.
* ctxbuf_printf will discard any data that would overrun the buffer and
* the buffer will always be null terminated.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdio.h>
#include <stdarg.h>
#include <smbsrv/libsmb.h>
/*
* smb_ctxbuf_init
*
* Initialize the buffer context structure.
* This must be called before any of the other
* buffer routines can be used.
*
* Returns -1 if invalid parameters, 0 otherwise
*/
int
smb_ctxbuf_init(smb_ctxbuf_t *ctx, unsigned char *buf, size_t buflen)
{
if (ctx == 0 || buf == 0 || buflen == 0)
return (-1);
buf[0] = '\0';
ctx->basep = buf;
ctx->curp = buf;
ctx->endp = &buf[buflen];
return (0);
}
/*
* smb_ctxbuf_len
*
* Return the amount of data stored in the buffer,
* excluding the terminating null character. Similar
* to strlen()
*
* Returns 0 if the ctx is invalid.
*/
int
smb_ctxbuf_len(smb_ctxbuf_t *ctx)
{
if (ctx == 0 || ctx->basep == 0 ||
ctx->curp == 0 || ctx->endp == 0)
return (0);
else
/*LINTED E_PTRDIFF_OVERFLOW*/
return (ctx->curp - ctx->basep);
}
/*
* smb_ctxbuf_printf
*
* Move formatted output (based on fmt string) to the buffer
* identified in ctxbuf. Any output characters beyond the buffer
* are discarded and a null character is written at the end of the
* characters actually written.
*
* Returns
* Always return the number of bytes actually written (excluding the
* terminating null).
*/
int
smb_ctxbuf_printf(smb_ctxbuf_t *ctx, const char *fmt, ...)
{
int n;
va_list args;
if (ctx == 0 || ctx->basep == 0 ||
ctx->curp == 0 || ctx->endp == 0)
return (-1);
va_start(args, fmt);
/*LINTED E_PTRDIFF_OVERFLOW*/
n = vsnprintf((char *)ctx->curp, ctx->endp-ctx->curp, fmt, args);
ctx->curp += n;
va_end(args);
/*
* return the number of bytes moved into the buffer.
*/
return (n);
}