bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter

This patch adds tests for the batching and bpf_(get|set)sockopt in
bpf tcp iter.

It first creates:
a) 1 non SO_REUSEPORT listener in lhash2.
b) 256 passive and active fds connected to the listener in (a).
c) 256 SO_REUSEPORT listeners in one of the lhash2 bucket.

The test sets all listeners and connections to bpf_cubic before
running the bpf iter.

The bpf iter then calls setsockopt(TCP_CONGESTION) to switch
each listener and connection from bpf_cubic to bpf_dctcp.

The bpf iter has a random_retry mode such that it can return EAGAIN
to the usespace in the middle of a batch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210701200625.1036874-1-kafai@fb.com

1 files changed, 4 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 5e0d51c07b63..d60bc2897770 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -36,6 +36,10 @@ extern struct ipv6_packet pkt_v6;
 int settimeo(int fd, int timeout_ms);
 int start_server(int family, int type, const char *addr, __u16 port,
 		 int timeout_ms);
+int *start_reuseport_server(int family, int type, const char *addr_str,
+			    __u16 port, int timeout_ms,
+			    unsigned int nr_listens);
+void free_fds(int *fds, unsigned int nr_close_fds);
 int connect_to_fd(int server_fd, int timeout_ms);
 int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms);
 int fastopen_connect(int server_fd, const char *data, unsigned int data_len,