// SPDX-License-Identifier: GPL-2.0
#include <error.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <linux/filter.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_rlimit.h"
#include "bpf_util.h"
#include "cgroup_helpers.h"
static int prog_attach(struct bpf_object *obj, int cgroup_fd, const char *title)
{
enum bpf_attach_type attach_type;
enum bpf_prog_type prog_type;
struct bpf_program *prog;
int err;
err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
if (err) {
log_err("Failed to deduct types for %s BPF program", title);
return -1;
}
prog = bpf_object__find_program_by_title(obj, title);
if (!prog) {
log_err("Failed to find %s BPF program", title);
return -1;
}
err = bpf_prog_attach(bpf_program__fd(prog), cgroup_fd,
attach_type, BPF_F_ALLOW_MULTI);
if (err) {
log_err("Failed to attach %s BPF program", title);
return -1;
}
return 0;
}
static int prog_detach(struct bpf_object *obj, int cgroup_fd, const char *title)
{
enum bpf_attach_type attach_type;
enum bpf_prog_type prog_type;
struct bpf_program *prog;
int err;
err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
if (err)
return -1;
prog = bpf_object__find_program_by_title(obj, title);
if (!prog)
return -1;
err = bpf_prog_detach2(bpf_program__fd(prog), cgroup_fd,
attach_type);
if (err)
return -1;
return 0;
}
static int run_getsockopt_test(struct bpf_object *obj, int cg_parent,
int cg_child, int sock_fd)
{
socklen_t optlen;
__u8 buf;
int err;
/* Set IP_TOS to the expected value (0x80). */
buf = 0x80;
err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
if (err < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0x80) {
log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
err = -1;
goto detach;
}
/* Attach child program and make sure it returns new value:
* - kernel: -> 0x80
* - child: 0x80 -> 0x90
*/
err = prog_attach(obj, cg_child, "cgroup/getsockopt/child");
if (err)
goto detach;
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0x90) {
log_err("Unexpected getsockopt 0x%x != 0x90", buf);
err = -1;
goto detach;
}
/* Attach parent program and make sure it returns new value:
* - kernel: -> 0x80
* - child: 0x80 -> 0x90
* - parent: 0x90 -> 0xA0
*/
err = prog_attach(obj, cg_parent, "cgroup/getsockopt/parent");
if (err)
goto detach;
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0xA0) {
log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
err = -1;
goto detach;
}
/* Setting unexpected initial sockopt should return EPERM:
* - kernel: -> 0x40
* - child: unexpected 0x40, EPERM
* - parent: unexpected 0x40, EPERM
*/
buf = 0x40;
if (setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1) < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (!err) {
log_err("Unexpected success from getsockopt(IP_TOS)");
goto detach;
}
/* Detach child program and make sure we still get EPERM:
* - kernel: -> 0x40
* - parent: unexpected 0x40, EPERM
*/
err = prog_detach(obj, cg_child, "cgroup/getsockopt/child");
if (err) {
log_err("Failed to detach child program");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (!err) {
log_err("Unexpected success from getsockopt(IP_TOS)");
goto detach;
}
/* Set initial value to the one the parent program expects:
* - kernel: -> 0x90
* - parent: 0x90 -> 0xA0
*/
buf = 0x90;
err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
if (err < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0xA0) {
log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
err = -1;
goto detach;
}
detach:
prog_detach(obj, cg_child, "cgroup/getsockopt/child");
prog_detach(obj, cg_parent, "cgroup/getsockopt/parent");
return err;
}
static int run_setsockopt_test(struct bpf_object *obj, int cg_parent,
int cg_child, int sock_fd)
{
socklen_t optlen;
__u8 buf;
int err;
/* Set IP_TOS to the expected value (0x80). */
buf = 0x80;
err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
if (err < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0x80) {
log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
err = -1;
goto detach;
}
/* Attach child program and make sure it adds 0x10. */
err = prog_attach(obj, cg_child, "cgroup/setsockopt");
if (err)
goto detach;
buf = 0x80;
err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
if (err < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0x80 + 0x10) {
log_err("Unexpected getsockopt 0x%x != 0x80 + 0x10", buf);
err = -1;
goto detach;
}
/* Attach parent program and make sure it adds another 0x10. */
err = prog_attach(obj, cg_parent, "cgroup/setsockopt");
if (err)
goto detach;
buf = 0x80;
err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
if (err < 0) {
log_err("Failed to call setsockopt(IP_TOS)");
goto detach;
}
buf = 0x00;
optlen = 1;
err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto detach;
}
if (buf != 0x80 + 2 * 0x10) {
log_err("Unexpected getsockopt 0x%x != 0x80 + 2 * 0x10", buf);
err = -1;
goto detach;
}
detach:
prog_detach(obj, cg_child, "cgroup/setsockopt");
prog_detach(obj, cg_parent, "cgroup/setsockopt");
return err;
}
int main(int argc, char **argv)
{
struct bpf_prog_load_attr attr = {
.file = "./sockopt_multi.o",
};
int cg_parent = -1, cg_child = -1;
struct bpf_object *obj = NULL;
int sock_fd = -1;
int err = -1;
int ignored;
if (setup_cgroup_environment()) {
log_err("Failed to setup cgroup environment\n");
goto out;
}
cg_parent = create_and_get_cgroup("/parent");
if (cg_parent < 0) {
log_err("Failed to create cgroup /parent\n");
goto out;
}
cg_child = create_and_get_cgroup("/parent/child");
if (cg_child < 0) {
log_err("Failed to create cgroup /parent/child\n");
goto out;
}
if (join_cgroup("/parent/child")) {
log_err("Failed to join cgroup /parent/child\n");
goto out;
}
err = bpf_prog_load_xattr(&attr, &obj, &ignored);
if (err) {
log_err("Failed to load BPF object");
goto out;
}
sock_fd = socket(AF_INET, SOCK_STREAM, 0);
if (sock_fd < 0) {
log_err("Failed to create socket");
goto out;
}
if (run_getsockopt_test(obj, cg_parent, cg_child, sock_fd))
err = -1;
printf("test_sockopt_multi: getsockopt %s\n",
err ? "FAILED" : "PASSED");
if (run_setsockopt_test(obj, cg_parent, cg_child, sock_fd))
err = -1;
printf("test_sockopt_multi: setsockopt %s\n",
err ? "FAILED" : "PASSED");
out:
close(sock_fd);
bpf_object__close(obj);
close(cg_child);
close(cg_parent);
printf("test_sockopt_multi: %s\n", err ? "FAILED" : "PASSED");
return err ? EXIT_FAILURE : EXIT_SUCCESS;
}
