From 29f24c43cbe09b83162776a370848d5a782dc3b7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Date: Fri, 6 Aug 2021 14:28:54 +0200 Subject: [PATCH 1/2] samples/bpf: xdpsock: Make the sample more useful outside the tree MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The xdpsock sample application is a useful base for experiment's around AF_XDP sockets. Compiling the sample outside of the kernel tree is made harder then it has to be as the sample includes two headers and that are not installed by 'make install_header' nor are usually part of distributions kernel headers. The first header asm/barrier.h is not used and can just be dropped. The second linux/compiler.h are only needed for the decorator __force and are only used in ip_fast_csum(), csum_fold() and csum_tcpudp_nofold(). These functions are copied verbatim from include/asm-generic/checksum.h and lib/checksum.c. While it's fine to copy and use these functions in the sample application the decorator brings no value and can be dropped together with the include. With this change it's trivial to compile the xdpsock sample outside the kernel tree from xdpsock_user.c and xdpsock.h. $ gcc -o xdpsock xdpsock_user.c -lbpf -lpthread Signed-off-by: Niklas Söderlund Signed-off-by: Simon Horman Signed-off-by: Andrii Nakryiko Reviewed-by: Louis Peens Link: https://lore.kernel.org/bpf/20210806122855.26115-2-simon.horman@corigine.com --- samples/bpf/xdpsock_user.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 33d0bdebbed8..7c56a7a784e1 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1,12 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2017 - 2018 Intel Corporation. */ -#include #include #include #include #include -#include #include #include #include @@ -663,7 +661,7 @@ __sum16 ip_fast_csum(const void *iph, unsigned int ihl); */ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) { - return (__force __sum16)~do_csum(iph, ihl * 4); + return (__sum16)~do_csum(iph, ihl * 4); } /* @@ -673,11 +671,11 @@ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) */ static inline __sum16 csum_fold(__wsum csum) { - u32 sum = (__force u32)csum; + u32 sum = (u32)csum; sum = (sum & 0xffff) + (sum >> 16); sum = (sum & 0xffff) + (sum >> 16); - return (__force __sum16)~sum; + return (__sum16)~sum; } /* @@ -703,16 +701,16 @@ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, __u8 proto, __wsum sum) { - unsigned long long s = (__force u32)sum; + unsigned long long s = (u32)sum; - s += (__force u32)saddr; - s += (__force u32)daddr; + s += (u32)saddr; + s += (u32)daddr; #ifdef __BIG_ENDIAN__ s += proto + len; #else s += (proto + len) << 8; #endif - return (__force __wsum)from64to32(s); + return (__wsum)from64to32(s); } /* From f4700a62c27161e364f66fdce527e8b04083c444 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Date: Fri, 6 Aug 2021 14:28:55 +0200 Subject: [PATCH 2/2] samples/bpf: xdpsock: Remove forward declaration of ip_fast_csum() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a forward declaration of ip_fast_csum() just before its implementation, remove the unneeded forward declaration. While at it mark the implementation as static inline. Signed-off-by: Niklas Söderlund Signed-off-by: Simon Horman Signed-off-by: Andrii Nakryiko Reviewed-by: Louis Peens Link: https://lore.kernel.org/bpf/20210806122855.26115-3-simon.horman@corigine.com --- samples/bpf/xdpsock_user.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 7c56a7a784e1..49d7a6ad7e39 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -651,15 +651,13 @@ out: return result; } -__sum16 ip_fast_csum(const void *iph, unsigned int ihl); - /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * This function code has been taken from * Linux kernel lib/checksum.c */ -__sum16 ip_fast_csum(const void *iph, unsigned int ihl) +static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) { return (__sum16)~do_csum(iph, ihl * 4); }