freebsd-nq/sys/net/if_llc.h
Warner Losh ff4323418b Move the __packed declarations. This makes sizeof(struct llc) 8 again
on the arm.  Add an assert to ensure that the size is 8 to prefent others
from falling into this trap (we should have more of these).

Why the construct:

	struct foo {
		union bar {
			struct {
				...
			} __packed fred;
			...
		} __packed wilma;
	} __packed;

has a different packing than:

	struct foo {
		union bar {
			struct {
				...
			} fred __packed;
			...
		} wilma __packed;
	} __packed;

is beyond my ability to ferret out of the gcc documentation.  Most
likely some subtle binding issue (eg before it says the struct itself
is packed, while after it means that the whole struct is packed into
the thing it is in).  Pointers to relevant documentation would be
appreciated.
2006-12-01 17:50:11 +00:00

162 lines
4.5 KiB
C

/* $NetBSD: if_llc.h,v 1.12 1999/11/19 20:41:19 thorpej Exp $ */
/*-
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)if_llc.h 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#ifndef _NET_IF_LLC_H_
#define _NET_IF_LLC_H_
/*
* IEEE 802.2 Link Level Control headers, for use in conjunction with
* 802.{3,4,5} media access control methods.
*
* Headers here do not use bit fields due to shortcommings in many
* compilers.
*/
struct llc {
u_int8_t llc_dsap;
u_int8_t llc_ssap;
union {
struct {
u_int8_t control;
u_int8_t format_id;
u_int8_t class;
u_int8_t window_x2;
} __packed type_u;
struct {
u_int8_t num_snd_x2;
u_int8_t num_rcv_x2;
} __packed type_i;
struct {
u_int8_t control;
u_int8_t num_rcv_x2;
} __packed type_s;
struct {
u_int8_t control;
/*
* We cannot put the following fields in a structure because
* the structure rounding might cause padding.
*/
u_int8_t frmr_rej_pdu0;
u_int8_t frmr_rej_pdu1;
u_int8_t frmr_control;
u_int8_t frmr_control_ext;
u_int8_t frmr_cause;
} __packed type_frmr;
struct {
u_int8_t control;
u_int8_t org_code[3];
u_int16_t ether_type;
} __packed type_snap;
struct {
u_int8_t control;
u_int8_t control_ext;
} __packed type_raw;
} __packed llc_un;
} __packed;
struct frmrinfo {
u_int8_t frmr_rej_pdu0;
u_int8_t frmr_rej_pdu1;
u_int8_t frmr_control;
u_int8_t frmr_control_ext;
u_int8_t frmr_cause;
} __packed;
#define llc_control llc_un.type_u.control
#define llc_control_ext llc_un.type_raw.control_ext
#define llc_fid llc_un.type_u.format_id
#define llc_class llc_un.type_u.class
#define llc_window llc_un.type_u.window_x2
#define llc_frmrinfo llc_un.type_frmr.frmr_rej_pdu0
#define llc_frmr_pdu0 llc_un.type_frmr.frmr_rej_pdu0
#define llc_frmr_pdu1 llc_un.type_frmr.frmr_rej_pdu1
#define llc_frmr_control llc_un.type_frmr.frmr_control
#define llc_frmr_control_ext llc_un.type_frmr.frmr_control_ext
#define llc_frmr_cause llc_un.type_frmr.frmr_cause
#define llc_snap llc_un.type_snap
/*
* Don't use sizeof(struct llc_un) for LLC header sizes
*/
#define LLC_ISFRAMELEN 4
#define LLC_UFRAMELEN 3
#define LLC_FRMRLEN 7
#define LLC_SNAPFRAMELEN 8
#ifdef CTASSERT
CTASSERT(sizeof (struct llc) == LLC_SNAPFRAMELEN);
#endif
/*
* Unnumbered LLC format commands
*/
#define LLC_UI 0x3
#define LLC_UI_P 0x13
#define LLC_DISC 0x43
#define LLC_DISC_P 0x53
#define LLC_UA 0x63
#define LLC_UA_P 0x73
#define LLC_TEST 0xe3
#define LLC_TEST_P 0xf3
#define LLC_FRMR 0x87
#define LLC_FRMR_P 0x97
#define LLC_DM 0x0f
#define LLC_DM_P 0x1f
#define LLC_XID 0xaf
#define LLC_XID_P 0xbf
#define LLC_SABME 0x6f
#define LLC_SABME_P 0x7f
/*
* Supervisory LLC commands
*/
#define LLC_RR 0x01
#define LLC_RNR 0x05
#define LLC_REJ 0x09
/*
* Info format - dummy only
*/
#define LLC_INFO 0x00
/*
* ISO PDTR 10178 contains among others
*/
#define LLC_8021D_LSAP 0x42
#define LLC_X25_LSAP 0x7e
#define LLC_SNAP_LSAP 0xaa
#define LLC_ISO_LSAP 0xfe
#endif /* _NET_IF_LLC_H_ */