Re: [PATCH bpf-next v2 2/3] selftests/bpf: Test for IPv6 ext header parsing

On Tue, Dec 7, 2021 at 2:58 PM Mathieu Jadin mathjadin@gmail.com wrote:

This test creates a client and a server exchanging a single byte with a Segment Routing Header and the eBPF program saves the inner segment in a sk_storage. The test program checks that the segment is correct.

Signed-off-by: Mathieu Jadin mathjadin@gmail.com

.../bpf/prog_tests/tcp_ipv6_exthdr_srh.c | 171 ++++++++++++++++++ .../selftests/bpf/progs/tcp_ipv6_exthdr_srh.c | 78 ++++++++ 2 files changed, 249 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/tcp_ipv6_exthdr_srh.c create mode 100644 tools/testing/selftests/bpf/progs/tcp_ipv6_exthdr_srh.c

diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_ipv6_exthdr_srh.c b/tools/testing/selftests/bpf/prog_tests/tcp_ipv6_exthdr_srh.c new file mode 100644 index 000000000000..70f7ee230975 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/tcp_ipv6_exthdr_srh.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <linux/seg6.h> +#include "cgroup_helpers.h" +#include "network_helpers.h"

+struct tcp_srh_storage {

•   struct in6_addr inner_segment;
  

+};

+static void send_byte(int fd) +{

•   char b = 0x55;
  

•   if (CHECK_FAIL(send(fd, &b, sizeof(b), 0) != 1))
  

•           perror("Failed to send single byte");
  

+}

+static int verify_srh(int map_fd, int server_fd, struct ipv6_sr_hdr *client_srh) +{

•   int err = 0;
  

•   struct tcp_srh_storage val;
  

•   if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &server_fd, &val) < 0)) {
  

please use ASSERT_XXX() macros instead of CHECK and especially instead of CHECK_FAIL

•           perror("Failed to read socket storage");
  

•           return -1;
  

•   }
  

•   if (memcmp(&val.inner_segment, &client_srh->segments[1],
  

•              sizeof(struct in6_addr))) {
  

•           log_err("The inner segment of the received SRH differs from the sent one");
  

•           err++;
  

•   }
  

•   return err;
  

+}

+static int run_test(int cgroup_fd, int listen_fd) +{

•   struct bpf_prog_load_attr attr = {
  

•           .prog_type = BPF_PROG_TYPE_SOCK_OPS,
  

•           .file = "./tcp_ipv6_exthdr_srh.o",
  

•           .expected_attach_type = BPF_CGROUP_SOCK_OPS,
  

•   };
  

•   size_t srh_size = sizeof(struct ipv6_sr_hdr) +
  

•           2 * sizeof(struct in6_addr);
  

•   struct ipv6_sr_hdr *client_srh;
  

•   struct bpf_object *obj;
  

•   struct bpf_map *map;
  

•   struct timeval tv;
  

•   int client_fd;
  

•   int server_fd;
  

•   int prog_fd;
  

•   int map_fd;
  

•   char byte;
  

•   int err;
  

•   err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
  

bpf_prog_load_xattr() is deprecated, please use BPF skeleton for the test

•   if (err) {
  

•           log_err("Failed to load BPF object");
  

•           return -1;
  

•   }
  

•   map = bpf_object__next_map(obj, NULL);
  

•   map_fd = bpf_map__fd(map);
  

[...]

+void test_tcp_ipv6_exthdr_srh(void) +{

•   int server_fd, cgroup_fd;
  

•   cgroup_fd = test__join_cgroup("/tcp_ipv6_exthdr_srh");
  

•   if (CHECK_FAIL(cgroup_fd < 0))
  

•           return;
  

•   server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
  

•   if (CHECK_FAIL(server_fd < 0))
  

•           goto close_cgroup_fd;
  

•   if (CHECK_FAIL(system("sysctl net.ipv6.conf.all.seg6_enabled=1")))
  

•           goto close_server;
  

•   if (CHECK_FAIL(system("sysctl net.ipv6.conf.lo.seg6_enabled=1")))
  

•           goto reset_sysctl;
  

•   CHECK_FAIL(run_test(cgroup_fd, server_fd));
  

•   if (CHECK_FAIL(system("sysctl net.ipv6.conf.lo.seg6_enabled=0")))
  

•           log_err("Cannot reset sysctl net.ipv6.conf.lo.seg6_enabled to 0");
  

+reset_sysctl:

•   if (CHECK_FAIL(system("sysctl net.ipv6.conf.all.seg6_enabled=0")))
  

•           log_err("Cannot reset sysctl net.ipv6.conf.all.seg6_enabled to 0");
  

same here, please no CHECK_FAIL()s

+close_server:

•   close(server_fd);
  

+close_cgroup_fd:

•   close(cgroup_fd);
  

+}

[...]