From a74712241b4675175cd8e3310fa206d8756ad5a1 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 15 Jan 2024 12:55:14 -0800 Subject: selftest: bpf: Test bpf_sk_assign_tcp_reqsk(). This commit adds a sample selftest to demonstrate how we can use bpf_sk_assign_tcp_reqsk() as the backend of SYN Proxy. The test creates IPv4/IPv6 x TCP connections and transfer messages over them on lo with BPF tc prog attached. The tc prog will process SYN and returns SYN+ACK with the following ISN and TS. In a real use case, this part will be done by other hosts. MSB LSB ISN: | 31 ... 8 | 7 6 | 5 | 4 | 3 2 1 0 | | Hash_1 | MSS | ECN | SACK | WScale | TS: | 31 ... 8 | 7 ... 0 | | Random | Hash_2 | WScale in SYN is reused in SYN+ACK. The client returns ACK, and tc prog will recalculate ISN and TS from ACK and validate SYN Cookie. If it's valid, the prog calls kfunc to allocate a reqsk for skb and configure the reqsk based on the argument created from SYN Cookie. Later, the reqsk will be processed in cookie_v[46]_check() to create a connection. Signed-off-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20240115205514.68364-7-kuniyu@amazon.com Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/progs/bpf_tracing_net.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'tools/testing/selftests/bpf/progs/bpf_tracing_net.h') diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index e8bd4b7b5ef7..7001965d1cc3 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -51,9 +51,25 @@ #define ICSK_TIME_LOSS_PROBE 5 #define ICSK_TIME_REO_TIMEOUT 6 +#define ETH_ALEN 6 #define ETH_HLEN 14 +#define ETH_P_IP 0x0800 #define ETH_P_IPV6 0x86DD +#define NEXTHDR_TCP 6 + +#define TCPOPT_NOP 1 +#define TCPOPT_EOL 0 +#define TCPOPT_MSS 2 +#define TCPOPT_WINDOW 3 +#define TCPOPT_TIMESTAMP 8 +#define TCPOPT_SACK_PERM 4 + +#define TCPOLEN_MSS 4 +#define TCPOLEN_WINDOW 3 +#define TCPOLEN_TIMESTAMP 10 +#define TCPOLEN_SACK_PERM 2 + #define CHECKSUM_NONE 0 #define CHECKSUM_PARTIAL 3 -- cgit v1.2.3