Merge branch 'selftests-bpf-migrate-and-remove-cgroup-tracing-related-tests'

Daniel T. Lee says:

====================
selftests/bpf: migrate and remove cgroup/tracing related tests

The BPF testing framework has evolved significantly over time. However,
some legacy tests in the samples/bpf directory have not kept up with
these changes. These outdated tests can cause confusion and increase
maintenance efforts.

This patchset focuses on migrating outdated cgroup and tracing-related
tests from samples/bpf to selftests/bpf, ensuring the BPF test suite
remains current and efficient. Tests that are already covered by
selftests/bpf are removed, while those not yet covered are migrated.
This includes cgroup sock create tests for setting socket attributes
and blocking socket creation, as well as the removal of redundant
cgroup and tracing tests that have been replaced by newer tests.

This patchset covers the following cgroup/tracing tests:
- test_overhead: tests the overhead of BPF programs with task_rename,
  now covered by selftests and benchmark tests (rename-*). [1]

- test_override_return: tests the return override functionality, now
  handled by kprobe_multi_override in selftests.

- test_probe_write_user: tests the probe_write_user functionality,
  now replaced by the probe_user test in selftests.

- test_cgrp2_sock: tests cgroup BPF's ability to set sk_bound_dev_if,
  mark, and priority during socket creation. Migrated to selftests as
  'sock_create' since no existing tests fully cover this.

- test_cgrp2_sock2: tests blocking socket creation for specific types
  (AF_INET{6}, SOCK_DGRAM, IPPROTO_ICMP{V6}). Migrated to selftests
  in 'sock_create' test for coverage.

- test_current_task_under_cgroup: tests bpf_current_task_under_cgroup()
  to check if a task belongs to a cgroup. Already covered by
  task_under_cgroup at selftest and other cgroup ID tests.

- test_cgrp2_tc: tests bpf_skb_under_cgroup() to filter packets based
  on cgroup. This behavior is now validated by cgroup_skb_sk_lookup,
  which uses bpf_skb_cgroup_id, making this test redundant.

[1]: https://patchwork.kernel.org/cover/13759916
---
Changes in v2:
- commit message fix
Changes in v3:
- Makefile fix
====================

Link: https://lore.kernel.org/r/20241011044847.51584-1-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 333 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/sock_create.c b/tools/testing/selftests/bpf/prog_tests/sock_create.c
new file mode 100644
index 000000000000..17a3713621dd
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/sock_create.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <test_progs.h>
+#include "cgroup_helpers.h"
+
+static char bpf_log_buf[4096];
+static bool verbose;
+
+enum sock_create_test_error {
+	OK = 0,
+	DENY_CREATE,
+};
+
+static struct sock_create_test {
+	const char			*descr;
+	const struct bpf_insn		insns[64];
+	enum bpf_attach_type		attach_type;
+	enum bpf_attach_type		expected_attach_type;
+
+	int				domain;
+	int				type;
+	int				protocol;
+
+	int				optname;
+	int				optval;
+	enum sock_create_test_error	error;
+} tests[] = {
+	{
+		.descr = "AF_INET set priority",
+		.insns = {
+			/* r3 = 123 (priority) */
+			BPF_MOV64_IMM(BPF_REG_3, 123),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, priority)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_PRIORITY,
+		.optval = 123,
+	},
+	{
+		.descr = "AF_INET6 set priority",
+		.insns = {
+			/* r3 = 123 (priority) */
+			BPF_MOV64_IMM(BPF_REG_3, 123),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, priority)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET6,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_PRIORITY,
+		.optval = 123,
+	},
+	{
+		.descr = "AF_INET set mark",
+		.insns = {
+			BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+			/* get uid of process */
+			BPF_EMIT_CALL(BPF_FUNC_get_current_uid_gid),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
+
+			/* if uid is 0, use given mark(666), else use uid as the mark */
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+			BPF_MOV64_IMM(BPF_REG_3, 666),
+
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, mark)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_MARK,
+		.optval = 666,
+	},
+	{
+		.descr = "AF_INET6 set mark",
+		.insns = {
+			BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+			/* get uid of process */
+			BPF_EMIT_CALL(BPF_FUNC_get_current_uid_gid),
+			BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
+
+			/* if uid is 0, use given mark(666), else use uid as the mark */
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+			BPF_MOV64_IMM(BPF_REG_3, 666),
+
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, mark)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET6,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_MARK,
+		.optval = 666,
+	},
+	{
+		.descr = "AF_INET bound to iface",
+		.insns = {
+			/* r3 = 1 (lo interface) */
+			BPF_MOV64_IMM(BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, bound_dev_if)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_BINDTOIFINDEX,
+		.optval = 1,
+	},
+	{
+		.descr = "AF_INET6 bound to iface",
+		.insns = {
+			/* r3 = 1 (lo interface) */
+			BPF_MOV64_IMM(BPF_REG_3, 1),
+			BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+				    offsetof(struct bpf_sock, bound_dev_if)),
+
+			/* return 1 */
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET6,
+		.type = SOCK_DGRAM,
+
+		.optname = SO_BINDTOIFINDEX,
+		.optval = 1,
+	},
+	{
+		.descr = "block AF_INET, SOCK_DGRAM, IPPROTO_ICMP socket",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),	/* r0 = verdict */
+
+			/* sock->family == AF_INET */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, family)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, AF_INET, 5),
+
+			/* sock->type == SOCK_DGRAM */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, type)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, SOCK_DGRAM, 3),
+
+			/* sock->protocol == IPPROTO_ICMP */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, protocol)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, IPPROTO_ICMP, 1),
+
+			/* return 0 (block) */
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET,
+		.type = SOCK_DGRAM,
+		.protocol = IPPROTO_ICMP,
+
+		.error = DENY_CREATE,
+	},
+	{
+		.descr = "block AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6 socket",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),	/* r0 = verdict */
+
+			/* sock->family == AF_INET6 */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, family)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, AF_INET6, 5),
+
+			/* sock->type == SOCK_DGRAM */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, type)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, SOCK_DGRAM, 3),
+
+			/* sock->protocol == IPPROTO_ICMPV6 */
+			BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct bpf_sock, protocol)),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_2, IPPROTO_ICMPV6, 1),
+
+			/* return 0 (block) */
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+		.attach_type = BPF_CGROUP_INET_SOCK_CREATE,
+
+		.domain = AF_INET,
+		.type = SOCK_DGRAM,
+		.protocol = IPPROTO_ICMPV6,
+
+		.error = DENY_CREATE,
+	},
+};
+
+static int load_prog(const struct bpf_insn *insns,
+		     enum bpf_attach_type expected_attach_type)
+{
+	LIBBPF_OPTS(bpf_prog_load_opts, opts,
+		    .expected_attach_type = expected_attach_type,
+		    .log_level = 2,
+		    .log_buf = bpf_log_buf,
+		    .log_size = sizeof(bpf_log_buf),
+	);
+	int fd, insns_cnt = 0;
+
+	for (;
+	     insns[insns_cnt].code != (BPF_JMP | BPF_EXIT);
+	     insns_cnt++) {
+	}
+	insns_cnt++;
+
+	fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns,
+			   insns_cnt, &opts);
+	if (verbose && fd < 0)
+		fprintf(stderr, "%s\n", bpf_log_buf);
+
+	return fd;
+}
+
+static int run_test(int cgroup_fd, struct sock_create_test *test)
+{
+	int sock_fd, err, prog_fd, optval, ret = -1;
+	socklen_t optlen = sizeof(optval);
+
+	prog_fd = load_prog(test->insns, test->expected_attach_type);
+	if (prog_fd < 0) {
+		log_err("Failed to load BPF program");
+		return -1;
+	}
+
+	err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
+	if (err < 0) {
+		log_err("Failed to attach BPF program");
+		goto close_prog_fd;
+	}
+
+	sock_fd = socket(test->domain, test->type, test->protocol);
+	if (sock_fd < 0) {
+		if (test->error == DENY_CREATE)
+			ret = 0;
+		else
+			log_err("Failed to create socket");
+
+		goto detach_prog;
+	}
+
+	err = getsockopt(sock_fd, SOL_SOCKET, test->optname, &optval, &optlen);
+	if (err) {
+		log_err("Failed to call getsockopt");
+		goto cleanup;
+	}
+
+	if (optval != test->optval) {
+		errno = 0;
+		log_err("getsockopt returned unexpected optval");
+		goto cleanup;
+	}
+
+	ret = test->error != OK;
+
+cleanup:
+	close(sock_fd);
+detach_prog:
+	bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
+close_prog_fd:
+	close(prog_fd);
+	return ret;
+}
+
+void test_sock_create(void)
+{
+	int cgroup_fd, i;
+
+	cgroup_fd = test__join_cgroup("/sock_create");
+	if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup"))
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		if (!test__start_subtest(tests[i].descr))
+			continue;
+
+		ASSERT_OK(run_test(cgroup_fd, &tests[i]), tests[i].descr);
+	}
+
+	close(cgroup_fd);
+}