tools/testing/selftests/bpf/prog_tests/probe_user.c

// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>

void test_probe_user(void)
{
#define kprobe_name "__sys_connect"
	const char *prog_name = "kprobe/" kprobe_name;
	const char *obj_file = "./test_probe_user.o";
	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, );
	int err, results_map_fd, sock_fd, duration = 0;
	struct sockaddr curr, orig, tmp;
	struct sockaddr_in *in = (struct sockaddr_in *)&curr;
	struct bpf_link *kprobe_link = NULL;
	struct bpf_program *kprobe_prog;
	struct bpf_object *obj;
	static const int zero = 0;

	obj = bpf_object__open_file(obj_file, &opts);
	if (CHECK(IS_ERR(obj), "obj_open_file", "err %ld\n", PTR_ERR(obj)))
		return;

	kprobe_prog = bpf_object__find_program_by_title(obj, prog_name);
	if (CHECK(!kprobe_prog, "find_probe",
		  "prog '%s' not found\n", prog_name))
		goto cleanup;

	err = bpf_object__load(obj);
	if (CHECK(err, "obj_load", "err %d\n", err))
		goto cleanup;

	results_map_fd = bpf_find_map(__func__, obj, "test_pro.bss");
	if (CHECK(results_map_fd < 0, "find_bss_map",
		  "err %d\n", results_map_fd))
		goto cleanup;

	kprobe_link = bpf_program__attach_kprobe(kprobe_prog, false,
						 kprobe_name);
	if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
		  "err %ld\n", PTR_ERR(kprobe_link))) {
		kprobe_link = NULL;
		goto cleanup;
	}

	memset(&curr, 0, sizeof(curr));
	in->sin_family = AF_INET;
	in->sin_port = htons(5555);
	in->sin_addr.s_addr = inet_addr("255.255.255.255");
	memcpy(&orig, &curr, sizeof(curr));

	sock_fd = socket(AF_INET, SOCK_STREAM, 0);
	if (CHECK(sock_fd < 0, "create_sock_fd", "err %d\n", sock_fd))
		goto cleanup;

	connect(sock_fd, &curr, sizeof(curr));
	close(sock_fd);

	err = bpf_map_lookup_elem(results_map_fd, &zero, &tmp);
	if (CHECK(err, "get_kprobe_res",
		  "failed to get kprobe res: %d\n", err))
		goto cleanup;

	in = (struct sockaddr_in *)&tmp;
	if (CHECK(memcmp(&tmp, &orig, sizeof(orig)), "check_kprobe_res",
		  "wrong kprobe res from probe read: %s:%u\n",
		  inet_ntoa(in->sin_addr), ntohs(in->sin_port)))
		goto cleanup;

	memset(&tmp, 0xab, sizeof(tmp));

	in = (struct sockaddr_in *)&curr;
	if (CHECK(memcmp(&curr, &tmp, sizeof(tmp)), "check_kprobe_res",
		  "wrong kprobe res from probe write: %s:%u\n",
		  inet_ntoa(in->sin_addr), ntohs(in->sin_port)))
		goto cleanup;
cleanup:
	bpf_link__destroy(kprobe_link);
	bpf_object__close(obj);
}