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| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-01-15 23:55:14 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-01-24 01:40:24 +0300 |
| commit | a74712241b4675175cd8e3310fa206d8756ad5a1 (patch) | |
| tree | e9af2ccb810881632330d014ecc83b1726537a16 /tools/testing/selftests/bpf/bpf_kfuncs.h | |
| parent | e472f88891abbc535a5e16a68a104073985f6061 (diff) | |
| download | linux-a74712241b4675175cd8e3310fa206d8756ad5a1.tar.xz | |
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 <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240115205514.68364-7-kuniyu@amazon.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/bpf_kfuncs.h')
| -rw-r--r-- | tools/testing/selftests/bpf/bpf_kfuncs.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/bpf_kfuncs.h b/tools/testing/selftests/bpf/bpf_kfuncs.h index b4e78c1eb37b..23c24f852f4f 100644 --- a/tools/testing/selftests/bpf/bpf_kfuncs.h +++ b/tools/testing/selftests/bpf/bpf_kfuncs.h @@ -51,6 +51,16 @@ extern int bpf_dynptr_clone(const struct bpf_dynptr *ptr, struct bpf_dynptr *clo extern int bpf_sock_addr_set_sun_path(struct bpf_sock_addr_kern *sa_kern, const __u8 *sun_path, __u32 sun_path__sz) __ksym; +/* Description + * Allocate and configure a reqsk and link it with a listener and skb. + * Returns + * Error code + */ +struct sock; +struct bpf_tcp_req_attrs; +extern int bpf_sk_assign_tcp_reqsk(struct __sk_buff *skb, struct sock *sk, + struct bpf_tcp_req_attrs *attrs, int attrs__sz) __ksym; + void *bpf_cast_to_kern_ctx(void *) __ksym; void *bpf_rdonly_cast(void *obj, __u32 btf_id) __ksym; |