samples/bpf: split common macros to net_shared.h

Currently, many programs under sample/bpf often include individual
macros by directly including the header under "linux/" rather than
using the "vmlinux.h" header.

However, there are some problems with migrating to "vmlinux.h" because
there is no definition for utility functions such as endianness
conversion (ntohs/htons). Fortunately, the xdp_sample program already
has a function that can be replaced to solve this problem.

Therefore, this commit attempts to separate these functions into a file
called net_shared.h to make them universally available. Additionally,
this file includes network-related macros that are not defined in
"vmlinux.h". (inspired by 'selftests' bpf_tracing_net.h)

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-8-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Daniel T. Lee 2023-01-15 16:16:10 +09:00 committed by Alexei Starovoitov
parent a1f93c8fb0
commit e69fe84595
2 changed files with 27 additions and 21 deletions

26
samples/bpf/net_shared.h Normal file
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@ -0,0 +1,26 @@
// SPDX-License-Identifier: GPL-2.0
#ifndef _NET_SHARED_H
#define _NET_SHARED_H
#define ETH_ALEN 6
#define ETH_P_802_3_MIN 0x0600
#define ETH_P_8021Q 0x8100
#define ETH_P_8021AD 0x88A8
#define ETH_P_IP 0x0800
#define ETH_P_IPV6 0x86DD
#define ETH_P_ARP 0x0806
#define IPPROTO_ICMPV6 58
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define bpf_ntohs(x) __builtin_bswap16(x)
#define bpf_htons(x) __builtin_bswap16(x)
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define bpf_ntohs(x) (x)
#define bpf_htons(x) (x)
#else
# error "Endianness detection needs to be set up for your compiler?!"
#endif
#endif

View File

@ -7,17 +7,9 @@
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_helpers.h>
#include "net_shared.h"
#include "xdp_sample_shared.h"
#define ETH_ALEN 6
#define ETH_P_802_3_MIN 0x0600
#define ETH_P_8021Q 0x8100
#define ETH_P_8021AD 0x88A8
#define ETH_P_IP 0x0800
#define ETH_P_IPV6 0x86DD
#define ETH_P_ARP 0x0806
#define IPPROTO_ICMPV6 58
#define EINVAL 22
#define ENETDOWN 100
#define EMSGSIZE 90
@ -55,18 +47,6 @@ static __always_inline void swap_src_dst_mac(void *data)
p[5] = dst[2];
}
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define bpf_ntohs(x) __builtin_bswap16(x)
#define bpf_htons(x) __builtin_bswap16(x)
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define bpf_ntohs(x) (x)
#define bpf_htons(x) (x)
#else
# error "Endianness detection needs to be set up for your compiler?!"
#endif
/*
* Note: including linux/compiler.h or linux/kernel.h for the macros below
* conflicts with vmlinux.h include in BPF files, so we define them here.