Merge branch 'selftests-bpf-convert-test_tc_tunnel-sh-to-test_progs'

Alexis Lothoré says:

====================
Hello,
this is the v3 of test_tc_tunnel conversion into test_progs framework.
This new revision:
- fixes a few issues spotted by the bot reviewer
- removes any test ensuring connection failure (and so depending on a
  timout) to keep the execution time reasonable

test_tc_tunnel.sh tests a variety of tunnels based on BPF: packets are
encapsulated by a BPF program on the client egress. We then check that
those packets can be decapsulated on server ingress side, either thanks
to kernel-based or BPF-based decapsulation. Those tests are run thanks
to two veths in two dedicated namespaces.

- patches 1 and 2 are preparatory patches
- patch 3 introduce tc_tunnel test into test_progs
- patch 4 gets rid of the test_tc_tunnel.sh script

The new test has been executed both in some x86 local qemu machine, as
well as in CI:

  # ./test_progs -a tc_tunnel
  #454/1   tc_tunnel/ipip_none:OK
  #454/2   tc_tunnel/ipip6_none:OK
  #454/3   tc_tunnel/ip6tnl_none:OK
  #454/4   tc_tunnel/sit_none:OK
  #454/5   tc_tunnel/vxlan_eth:OK
  #454/6   tc_tunnel/ip6vxlan_eth:OK
  #454/7   tc_tunnel/gre_none:OK
  #454/8   tc_tunnel/gre_eth:OK
  #454/9   tc_tunnel/gre_mpls:OK
  #454/10  tc_tunnel/ip6gre_none:OK
  #454/11  tc_tunnel/ip6gre_eth:OK
  #454/12  tc_tunnel/ip6gre_mpls:OK
  #454/13  tc_tunnel/udp_none:OK
  #454/14  tc_tunnel/udp_eth:OK
  #454/15  tc_tunnel/udp_mpls:OK
  #454/16  tc_tunnel/ip6udp_none:OK
  #454/17  tc_tunnel/ip6udp_eth:OK
  #454/18  tc_tunnel/ip6udp_mpls:OK
  #454     tc_tunnel:OK
  Summary: 1/18 PASSED, 0 SKIPPED, 0 FAILED
====================

Link: https://patch.msgid.link/20251027-tc_tunnel-v3-0-505c12019f9d@bootlin.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Author: Martin KaFai Lau

tools/testing/selftests/bpf/Makefile

@@ -105,7 +105,6 @@ TEST_FILES = xsk_prereqs.sh $(wildcard progs/btf_dump_test_case_*.c)
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
 	test_lirc_mode2.sh \
-	test_tc_tunnel.sh \
 	test_tc_edt.sh \
 	test_xdping.sh \
 	test_bpftool_build.sh \

tools/testing/selftests/bpf/network_helpers.c

@@ -766,6 +766,50 @@ int send_recv_data(int lfd, int fd, uint32_t total_bytes)
 	return err;
 }
 
+int tc_prog_attach(const char *dev, int ingress_fd, int egress_fd)
+{
+	int ifindex, ret;
+
+	if (!ASSERT_TRUE(ingress_fd >= 0 || egress_fd >= 0,
+			 "at least one program fd is valid"))
+		return -1;
+
+	ifindex = if_nametoindex(dev);
+	if (!ASSERT_NEQ(ifindex, 0, "get ifindex"))
+		return -1;
+
+	DECLARE_LIBBPF_OPTS(bpf_tc_hook, hook, .ifindex = ifindex,
+			    .attach_point = BPF_TC_INGRESS | BPF_TC_EGRESS);
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts1, .handle = 1,
+			    .priority = 1, .prog_fd = ingress_fd);
+	DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts2, .handle = 1,
+			    .priority = 1, .prog_fd = egress_fd);
+
+	ret = bpf_tc_hook_create(&hook);
+	if (!ASSERT_OK(ret, "create tc hook"))
+		return ret;
+
+	if (ingress_fd >= 0) {
+		hook.attach_point = BPF_TC_INGRESS;
+		ret = bpf_tc_attach(&hook, &opts1);
+		if (!ASSERT_OK(ret, "bpf_tc_attach")) {
+			bpf_tc_hook_destroy(&hook);
+			return ret;
+		}
+	}
+
+	if (egress_fd >= 0) {
+		hook.attach_point = BPF_TC_EGRESS;
+		ret = bpf_tc_attach(&hook, &opts2);
+		if (!ASSERT_OK(ret, "bpf_tc_attach")) {
+			bpf_tc_hook_destroy(&hook);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 #ifdef TRAFFIC_MONITOR
 struct tmonitor_ctx {
 	pcap_t *pcap;

tools/testing/selftests/bpf/network_helpers.h

@@ -255,6 +255,22 @@ struct tmonitor_ctx;
 
 typedef int (*tm_print_fn_t)(const char *format, va_list args);
 
+/**
+ * tc_prog_attach - attach BPF program(s) to an interface
+ *
+ * Takes file descriptors pointing to at least one, at most two BPF
+ * programs, and attach those programs to an interface ingress, egress or
+ * both.
+ *
+ * @dev: string containing the interface name
+ * @ingress_fd: file descriptor of the program to attach to interface ingress
+ * @egress_fd: file descriptor of the program to attach to interface egress
+ *
+ * Returns 0 on success, -1 if no valid file descriptor has been found, if
+ * the interface name is invalid or if an error ocurred during attach.
+ */
+int tc_prog_attach(const char *dev, int ingress_fd, int egress_fd);
+
 #ifdef TRAFFIC_MONITOR
 struct tmonitor_ctx *traffic_monitor_start(const char *netns, const char *test_name,
 					   const char *subtest_name);