samples/bpf: remove obsolete cgroup related tests

This patch removes the obsolete cgroup related tests. These tests are
now redundant because their functionality is already covered by more
modern and comprehensive tests under selftests/bpf.

The following files are removed:
- 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.

By removing these outdated tests, this patch helps streamline and
modernize the test suite, avoiding duplication of test coverage.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20241011044847.51584-4-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 0 insertions, 177 deletions

diff --git a/samples/bpf/test_cgrp2_attach.c b/samples/bpf/test_cgrp2_attach.c
deleted file mode 100644
index 68ce69457afe..000000000000
--- a/samples/bpf/test_cgrp2_attach.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/* eBPF example program:
- *
- * - Creates arraymap in kernel with 4 bytes keys and 8 byte values
- *
- * - Loads eBPF program
- *
- *   The eBPF program accesses the map passed in to store two pieces of
- *   information. The number of invocations of the program, which maps
- *   to the number of packets received, is stored to key 0. Key 1 is
- *   incremented on each iteration by the number of bytes stored in
- *   the skb.
- *
- * - Attaches the new program to a cgroup using BPF_PROG_ATTACH
- *
- * - Every second, reads map[0] and map[1] to see how many bytes and
- *   packets were seen on any socket of tasks in the given cgroup.
- */
-
-#define _GNU_SOURCE
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stddef.h>
-#include <string.h>
-#include <unistd.h>
-#include <assert.h>
-#include <errno.h>
-#include <fcntl.h>
-
-#include <linux/bpf.h>
-#include <bpf/bpf.h>
-
-#include "bpf_insn.h"
-#include "bpf_util.h"
-
-enum {
-	MAP_KEY_PACKETS,
-	MAP_KEY_BYTES,
-};
-
-char bpf_log_buf[BPF_LOG_BUF_SIZE];
-
-static int prog_load(int map_fd, int verdict)
-{
-	struct bpf_insn prog[] = {
-		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), /* save r6 so it's not clobbered by BPF_CALL */
-
-		/* Count packets */
-		BPF_MOV64_IMM(BPF_REG_0, MAP_KEY_PACKETS), /* r0 = 0 */
-		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
-		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
-		BPF_LD_MAP_FD(BPF_REG_1, map_fd), /* load map fd to r1 */
-		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
-		BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */
-		BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0),
-
-		/* Count bytes */
-		BPF_MOV64_IMM(BPF_REG_0, MAP_KEY_BYTES), /* r0 = 1 */
-		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
-		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
-		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
-		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
-		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, offsetof(struct __sk_buff, len)), /* r1 = skb->len */
-
-		BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0),
-
-		BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
-		BPF_EXIT_INSN(),
-	};
-	size_t insns_cnt = ARRAY_SIZE(prog);
-	LIBBPF_OPTS(bpf_prog_load_opts, opts,
-		.log_buf = bpf_log_buf,
-		.log_size = BPF_LOG_BUF_SIZE,
-	);
-
-	return bpf_prog_load(BPF_PROG_TYPE_CGROUP_SKB, NULL, "GPL",
-			     prog, insns_cnt, &opts);
-}
-
-static int usage(const char *argv0)
-{
-	printf("Usage: %s [-d] [-D] <cg-path> <egress|ingress>\n", argv0);
-	printf("	-d	Drop Traffic\n");
-	printf("	-D	Detach filter, and exit\n");
-	return EXIT_FAILURE;
-}
-
-static int attach_filter(int cg_fd, int type, int verdict)
-{
-	int prog_fd, map_fd, ret, key;
-	long long pkt_cnt, byte_cnt;
-
-	map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL,
-				sizeof(key), sizeof(byte_cnt),
-				256, NULL);
-	if (map_fd < 0) {
-		printf("Failed to create map: '%s'\n", strerror(errno));
-		return EXIT_FAILURE;
-	}
-
-	prog_fd = prog_load(map_fd, verdict);
-	printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
-
-	if (prog_fd < 0) {
-		printf("Failed to load prog: '%s'\n", strerror(errno));
-		return EXIT_FAILURE;
-	}
-
-	ret = bpf_prog_attach(prog_fd, cg_fd, type, 0);
-	if (ret < 0) {
-		printf("Failed to attach prog to cgroup: '%s'\n",
-		       strerror(errno));
-		return EXIT_FAILURE;
-	}
-	while (1) {
-		key = MAP_KEY_PACKETS;
-		assert(bpf_map_lookup_elem(map_fd, &key, &pkt_cnt) == 0);
-
-		key = MAP_KEY_BYTES;
-		assert(bpf_map_lookup_elem(map_fd, &key, &byte_cnt) == 0);
-
-		printf("cgroup received %lld packets, %lld bytes\n",
-		       pkt_cnt, byte_cnt);
-		sleep(1);
-	}
-
-	return EXIT_SUCCESS;
-}
-
-int main(int argc, char **argv)
-{
-	int detach_only = 0, verdict = 1;
-	enum bpf_attach_type type;
-	int opt, cg_fd, ret;
-
-	while ((opt = getopt(argc, argv, "Dd")) != -1) {
-		switch (opt) {
-		case 'd':
-			verdict = 0;
-			break;
-		case 'D':
-			detach_only = 1;
-			break;
-		default:
-			return usage(argv[0]);
-		}
-	}
-
-	if (argc - optind < 2)
-		return usage(argv[0]);
-
-	if (strcmp(argv[optind + 1], "ingress") == 0)
-		type = BPF_CGROUP_INET_INGRESS;
-	else if (strcmp(argv[optind + 1], "egress") == 0)
-		type = BPF_CGROUP_INET_EGRESS;
-	else
-		return usage(argv[0]);
-
-	cg_fd = open(argv[optind], O_DIRECTORY | O_RDONLY);
-	if (cg_fd < 0) {
-		printf("Failed to open cgroup path: '%s'\n", strerror(errno));
-		return EXIT_FAILURE;
-	}
-
-	if (detach_only) {
-		ret = bpf_prog_detach(cg_fd, type);
-		printf("bpf_prog_detach() returned '%s' (%d)\n",
-		       strerror(errno), errno);
-	} else
-		ret = attach_filter(cg_fd, type, verdict);
-
-	return ret;
-}