From 752fddc0501c540214875b26bde2538f0a831811 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alexis=20Lothor=C3=A9=20=28eBPF=20Foundation=29?= Date: Wed, 20 Nov 2024 08:43:20 +0100 Subject: [PATCH] selftests/bpf: document pseudo-header checksum helpers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit network_helpers.h provides helpers to compute checksum for pseudo headers but no helpers to compute the global checksums. Before adding those, clarify csum_tcpudp_magic and csum_ipv6_magic purpose by adding some documentation. Signed-off-by: Alexis Lothoré (eBPF Foundation) Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20241120-flow_dissector-v3-10-45b46494f937@bootlin.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/network_helpers.h | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h index 0b2ed90c763f..00d6e7d52545 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -129,6 +129,21 @@ static inline __sum16 build_ip_csum(struct iphdr *iph) return csum_fold(sum); } +/** + * csum_tcpudp_magic - compute IP pseudo-header checksum + * + * Compute the IPv4 pseudo header checksum. The helper can take a + * accumulated sum from the transport layer to accumulate it and directly + * return the transport layer + * + * @saddr: IP source address + * @daddr: IP dest address + * @len: IP data size + * @proto: transport layer protocol + * @csum: The accumulated partial sum to add to the computation + * + * Returns the folded sum + */ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, __u8 proto, __wsum csum) @@ -144,6 +159,21 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, return csum_fold((__u32)s); } +/** + * csum_ipv6_magic - compute IPv6 pseudo-header checksum + * + * Compute the ipv6 pseudo header checksum. The helper can take a + * accumulated sum from the transport layer to accumulate it and directly + * return the transport layer + * + * @saddr: IPv6 source address + * @daddr: IPv6 dest address + * @len: IPv6 data size + * @proto: transport layer protocol + * @csum: The accumulated partial sum to add to the computation + * + * Returns the folded sum + */ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, __u8 proto, -- 2.25.1