text: // SPDX-License-Identifier: GPL-2.0
  
  #include <test_progs.h>
  
  #include "cgroup_helpers.h"
  
  #define FOO		"/foo"
  #define BAR		"/foo/bar/"
  #define PING_CMD	"ping -q -c1 -w1 127.0.0.1 > /dev/null"
  
  static char bpf_log_buf[BPF_LOG_BUF_SIZE];
  
  static int prog_load(int verdict)
  {
  	struct bpf_insn prog[] = {
  		BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
  		BPF_EXIT_INSN(),
  	};
  	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
  
  	return bpf_test_load_program(BPF_PROG_TYPE_CGROUP_SKB,
  			       prog, insns_cnt, "GPL", 0,
  			       bpf_log_buf, BPF_LOG_BUF_SIZE);
  }
  
  void serial_test_cgroup_attach_override(void)
  {
  	int drop_prog = -1, allow_prog = -1, foo = -1, bar = -1;
  	__u32 duration = 0;
  
  	allow_prog = prog_load(1);
  	if (CHECK(allow_prog < 0, "prog_load_allow",
  		  "verifier output:\n%s\n-------\n", bpf_log_buf))
  		goto err;
  
  	drop_prog = prog_load(0);
  	if (CHECK(drop_prog < 0, "prog_load_drop",
  		  "verifier output:\n%s\n-------\n", bpf_log_buf))
  		goto err;
  
  	foo = test__join_cgroup(FOO);
  	if (CHECK(foo < 0, "cgroup_join_foo", "cgroup setup failed\n"))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS,
  				  BPF_F_ALLOW_OVERRIDE),
  		  "prog_attach_drop_foo_override",
  		  "attach prog to %s failed, errno=%d\n", FOO, errno))
  		goto err;
  
  	if (CHECK(!system(PING_CMD), "ping_fail",
  		  "ping unexpectedly succeeded\n"))
  		goto err;
  
  	bar = test__join_cgroup(BAR);
  	if (CHECK(bar < 0, "cgroup_join_bar", "cgroup setup failed\n"))
  		goto err;
  
  	if (CHECK(!system(PING_CMD), "ping_fail",
  		  "ping unexpectedly succeeded\n"))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
  				  BPF_F_ALLOW_OVERRIDE),
  		  "prog_attach_allow_bar_override",
  		  "attach prog to %s failed, errno=%d\n", BAR, errno))
  		goto err;
  
  	if (CHECK(system(PING_CMD), "ping_ok", "ping failed\n"))
  		goto err;
  
  	if (CHECK(bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS),
  		  "prog_detach_bar",
  		  "detach prog from %s failed, errno=%d\n", BAR, errno))
  		goto err;
  
  	if (CHECK(!system(PING_CMD), "ping_fail",
  		  "ping unexpectedly succeeded\n"))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
  				  BPF_F_ALLOW_OVERRIDE),
  		  "prog_attach_allow_bar_override",
  		  "attach prog to %s failed, errno=%d\n", BAR, errno))
  		goto err;
  
  	if (CHECK(bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS),
  		  "prog_detach_foo",
  		  "detach prog from %s failed, errno=%d\n", FOO, errno))
  		goto err;
  
  	if (CHECK(system(PING_CMD), "ping_ok", "ping failed\n"))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
  				  BPF_F_ALLOW_OVERRIDE),
  		  "prog_attach_allow_bar_override",
  		  "attach prog to %s failed, errno=%d\n", BAR, errno))
  		goto err;
  
  	if (CHECK(!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0),
  		  "fail_prog_attach_allow_bar_none",
  		  "attach prog to %s unexpectedly succeeded\n", BAR))
  		goto err;
  
  	if (CHECK(bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS),
  		  "prog_detach_bar",
  		  "detach prog from %s failed, errno=%d\n", BAR, errno))
  		goto err;
  
  	if (CHECK(!bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS),
  		  "fail_prog_detach_foo",
  		  "double detach from %s unexpectedly succeeded\n", FOO))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS, 0),
  		  "prog_attach_allow_foo_none",
  		  "attach prog to %s failed, errno=%d\n", FOO, errno))
  		goto err;
  
  	if (CHECK(!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0),
  		  "fail_prog_attach_allow_bar_none",
  		  "attach prog to %s unexpectedly succeeded\n", BAR))
  		goto err;
  
  	if (CHECK(!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
  				   BPF_F_ALLOW_OVERRIDE),
  		  "fail_prog_attach_allow_bar_override",
  		  "attach prog to %s unexpectedly succeeded\n", BAR))
  		goto err;
  
  	if (CHECK(!bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS,
  				   BPF_F_ALLOW_OVERRIDE),
  		  "fail_prog_attach_allow_foo_override",
  		  "attach prog to %s unexpectedly succeeded\n", FOO))
  		goto err;
  
  	if (CHECK(bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS, 0),
  		  "prog_attach_drop_foo_none",
  		  "attach prog to %s failed, errno=%d\n", FOO, errno))
  		goto err;
  
  err:
  	close(foo);
  	close(bar);
  	close(allow_prog);
  	close(drop_prog);
  }
  