mirror of
https://gitlab.isc.org/isc-projects/dhcp
synced 2025-08-22 01:49:35 +00:00
77 lines
3.2 KiB
C
77 lines
3.2 KiB
C
/* buffer.h
|
|
|
|
Definitions for the object management API protocol buffering... */
|
|
|
|
/*
|
|
* Copyright (C) 2004-2022 Internet Systems Consortium, Inc. ("ISC")
|
|
* Copyright (c) 1996-2003 by Internet Software Consortium
|
|
*
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
|
|
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* Internet Systems Consortium, Inc.
|
|
* PO Box 360
|
|
* Newmarket, NH 03857 USA
|
|
* <info@isc.org>
|
|
* https://www.isc.org/
|
|
*
|
|
*/
|
|
|
|
/* OMAPI buffers are ring buffers, which means that the beginning of the
|
|
buffer and the end of the buffer chase each other around. As long as
|
|
the tail never catches up to the head, there's room in the buffer for
|
|
data.
|
|
|
|
- If the tail and the head are equal, the buffer is empty.
|
|
|
|
- If the tail is less than the head, the contents of the buffer
|
|
are the bytes from the head to the end of buffer, and in addition,
|
|
the bytes between the beginning of the buffer and the tail, not
|
|
including the byte addressed by the tail.
|
|
|
|
- If the tail is greater than the head, then the buffer contains
|
|
valid bytes starting with the byte addressed by the head, and
|
|
ending with the byte before the byte addressed by the tail.
|
|
|
|
There will always be at least one byte of waste, because the tail can't
|
|
increase so that it's equal to the head (that would represent an empty
|
|
buffer. */
|
|
#define OMAPI_BUF_SIZE 4048
|
|
typedef struct _omapi_buffer {
|
|
struct _omapi_buffer *next; /* Buffers can be chained. */
|
|
u_int32_t refcnt; /* Buffers are reference counted. */
|
|
u_int16_t head, tail; /* Buffers are organized in a ring. */
|
|
char buf [OMAPI_BUF_SIZE]; /* The actual buffer is included in
|
|
the buffer data structure. */
|
|
} omapi_buffer_t;
|
|
|
|
#define BUFFER_BYTES_FREE(x) \
|
|
((x) -> tail > (x) -> head \
|
|
? sizeof ((x) -> buf) - ((x) -> tail - (x) -> head) \
|
|
: (x) -> head - (x) -> tail)
|
|
|
|
#define BYTES_IN_BUFFER(x) \
|
|
((x) -> tail > (x) -> head \
|
|
? (x) -> tail - (x) -> head - 1 \
|
|
: sizeof ((x) -> buf) - ((x) -> head - (x) -> tail) - 1)
|
|
|
|
isc_result_t omapi_connection_require (omapi_object_t *, unsigned);
|
|
isc_result_t omapi_connection_copyout (unsigned char *,
|
|
omapi_object_t *, unsigned);
|
|
isc_result_t omapi_connection_copyin (omapi_object_t *,
|
|
const unsigned char *, unsigned);
|
|
isc_result_t omapi_connection_flush (omapi_object_t *);
|
|
isc_result_t omapi_connection_get_uint32 (omapi_object_t *, u_int32_t *);
|
|
isc_result_t omapi_connection_put_uint32 (omapi_object_t *, u_int32_t);
|
|
isc_result_t omapi_connection_get_uint16 (omapi_object_t *, u_int16_t *);
|
|
isc_result_t omapi_connection_put_uint16 (omapi_object_t *, u_int32_t);
|