[PATCH bpf-next v6 10/13] selftests/bpf: Add csum helpers
From: Stanislav Fomichev <hidden>
Date: 2023-11-27 19:03:40
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Shuah Khan, Linus Torvalds
Checksum helpers will be used to calculate pseudo-header checksum in AF_XDP metadata selftests. The helpers are mirroring existing kernel ones: - csum_tcpudp_magic : IPv4 pseudo header csum - csum_ipv6_magic : IPv6 pseudo header csum - csum_fold : fold csum and do one's complement Signed-off-by: Stanislav Fomichev <redacted> --- tools/testing/selftests/bpf/network_helpers.h | 43 +++++++++++++++++++ 1 file changed, 43 insertions(+)
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 34f1200a781b..94b9be24e39b 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h@@ -71,4 +71,47 @@ struct nstoken; */ struct nstoken *open_netns(const char *name); void close_netns(struct nstoken *token); + +static __u16 csum_fold(__u32 csum) +{ + csum = (csum & 0xffff) + (csum >> 16); + csum = (csum & 0xffff) + (csum >> 16); + + return (__u16)~csum; +} + +static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, + __u32 len, __u8 proto, + __wsum csum) +{ + __u64 s = csum; + + s += (__u32)saddr; + s += (__u32)daddr; + s += htons(proto + len); + s = (s & 0xffffffff) + (s >> 32); + s = (s & 0xffffffff) + (s >> 32); + + return csum_fold((__u32)s); +} + +static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, + __wsum csum) +{ + __u64 s = csum; + int i; + + for (i = 0; i < 4; i++) + s += (__u32)saddr->s6_addr32[i]; + for (i = 0; i < 4; i++) + s += (__u32)daddr->s6_addr32[i]; + s += htons(proto + len); + s = (s & 0xffffffff) + (s >> 32); + s = (s & 0xffffffff) + (s >> 32); + + return csum_fold((__u32)s); +} + #endif
--
2.43.0.rc1.413.gea7ed67945-goog