linux-stable/include/uapi/linux/if_arcnet.h
Gustavo A. R. Silva 94dfc73e7c treewide: uapi: Replace zero-length arrays with flexible-array members
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

-fstrict-flex-arrays=3 is coming and we need to land these changes
to prevent issues like these in the short future:

../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0,
but the source string has length 2 (including NUL byte) [-Wfortify-source]
		strcpy(de3->name, ".");
		^

Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If
this breaks anything, we can use a union with a new member name.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/
Acked-by: Dan Williams <dan.j.williams@intel.com> # For ndctl.h
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-06-28 21:26:05 +02:00

130 lines
3.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Global definitions for the ARCnet interface.
*
* Authors: David Woodhouse and Avery Pennarun
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _LINUX_IF_ARCNET_H
#define _LINUX_IF_ARCNET_H
#include <linux/types.h>
#include <linux/if_ether.h>
/*
* These are the defined ARCnet Protocol ID's.
*/
/* CAP mode */
/* No macro but uses 1-8 */
/* RFC1201 Protocol ID's */
#define ARC_P_IP 212 /* 0xD4 */
#define ARC_P_IPV6 196 /* 0xC4: RFC2497 */
#define ARC_P_ARP 213 /* 0xD5 */
#define ARC_P_RARP 214 /* 0xD6 */
#define ARC_P_IPX 250 /* 0xFA */
#define ARC_P_NOVELL_EC 236 /* 0xEC */
/* Old RFC1051 Protocol ID's */
#define ARC_P_IP_RFC1051 240 /* 0xF0 */
#define ARC_P_ARP_RFC1051 241 /* 0xF1 */
/* MS LanMan/WfWg "NDIS" encapsulation */
#define ARC_P_ETHER 232 /* 0xE8 */
/* Unsupported/indirectly supported protocols */
#define ARC_P_DATAPOINT_BOOT 0 /* very old Datapoint equipment */
#define ARC_P_DATAPOINT_MOUNT 1
#define ARC_P_POWERLAN_BEACON 8 /* Probably ATA-Netbios related */
#define ARC_P_POWERLAN_BEACON2 243 /* 0xF3 */
#define ARC_P_LANSOFT 251 /* 0xFB - what is this? */
#define ARC_P_ATALK 0xDD
/* Hardware address length */
#define ARCNET_ALEN 1
/*
* The RFC1201-specific components of an arcnet packet header.
*/
struct arc_rfc1201 {
__u8 proto; /* protocol ID field - varies */
__u8 split_flag; /* for use with split packets */
__be16 sequence; /* sequence number */
__u8 payload[]; /* space remaining in packet (504 bytes)*/
};
#define RFC1201_HDR_SIZE 4
/*
* The RFC1051-specific components.
*/
struct arc_rfc1051 {
__u8 proto; /* ARC_P_RFC1051_ARP/RFC1051_IP */
__u8 payload[]; /* 507 bytes */
};
#define RFC1051_HDR_SIZE 1
/*
* The ethernet-encap-specific components. We have a real ethernet header
* and some data.
*/
struct arc_eth_encap {
__u8 proto; /* Always ARC_P_ETHER */
struct ethhdr eth; /* standard ethernet header (yuck!) */
__u8 payload[]; /* 493 bytes */
};
#define ETH_ENCAP_HDR_SIZE 14
struct arc_cap {
__u8 proto;
__u8 cookie[sizeof(int)];
/* Actually NOT sent over the network */
union {
__u8 ack;
__u8 raw[0]; /* 507 bytes */
} mes;
};
/*
* The data needed by the actual arcnet hardware.
*
* Now, in the real arcnet hardware, the third and fourth bytes are the
* 'offset' specification instead of the length, and the soft data is at
* the _end_ of the 512-byte buffer. We hide this complexity inside the
* driver.
*/
struct arc_hardware {
__u8 source; /* source ARCnet - filled in automagically */
__u8 dest; /* destination ARCnet - 0 for broadcast */
__u8 offset[2]; /* offset bytes (some weird semantics) */
};
#define ARC_HDR_SIZE 4
/*
* This is an ARCnet frame header, as seen by the kernel (and userspace,
* when you do a raw packet capture).
*/
struct archdr {
/* hardware requirements */
struct arc_hardware hard;
/* arcnet encapsulation-specific bits */
union {
struct arc_rfc1201 rfc1201;
struct arc_rfc1051 rfc1051;
struct arc_eth_encap eth_encap;
struct arc_cap cap;
__u8 raw[0]; /* 508 bytes */
} soft;
};
#endif /* _LINUX_IF_ARCNET_H */