1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2020 Facebook */
  3#include <uapi/linux/if_link.h>
  4#include <test_progs.h>
  5#include "test_xdp_link.skel.h"
  6
  7#define IFINDEX_LO 1
  8
  9void serial_test_xdp_link(void)
 10{
 11	struct test_xdp_link *skel1 = NULL, *skel2 = NULL;
 12	__u32 id1, id2, id0 = 0, prog_fd1, prog_fd2;
 13	LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
 14	struct bpf_link_info link_info;
 15	struct bpf_prog_info prog_info;
 16	struct bpf_link *link;
 17	int err;
 18	__u32 link_info_len = sizeof(link_info);
 19	__u32 prog_info_len = sizeof(prog_info);
 20
 21	skel1 = test_xdp_link__open_and_load();
 22	if (!ASSERT_OK_PTR(skel1, "skel_load"))
 23		goto cleanup;
 24	prog_fd1 = bpf_program__fd(skel1->progs.xdp_handler);
 25
 26	skel2 = test_xdp_link__open_and_load();
 27	if (!ASSERT_OK_PTR(skel2, "skel_load"))
 28		goto cleanup;
 29	prog_fd2 = bpf_program__fd(skel2->progs.xdp_handler);
 30
 31	memset(&prog_info, 0, sizeof(prog_info));
 32	err = bpf_prog_get_info_by_fd(prog_fd1, &prog_info, &prog_info_len);
 33	if (!ASSERT_OK(err, "fd_info1"))
 34		goto cleanup;
 35	id1 = prog_info.id;
 36
 37	memset(&prog_info, 0, sizeof(prog_info));
 38	err = bpf_prog_get_info_by_fd(prog_fd2, &prog_info, &prog_info_len);
 39	if (!ASSERT_OK(err, "fd_info2"))
 40		goto cleanup;
 41	id2 = prog_info.id;
 42
 43	/* set initial prog attachment */
 44	err = bpf_xdp_attach(IFINDEX_LO, prog_fd1, XDP_FLAGS_REPLACE, &opts);
 45	if (!ASSERT_OK(err, "fd_attach"))
 46		goto cleanup;
 47
 48	/* validate prog ID */
 49	err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
 50	if (!ASSERT_OK(err, "id1_check_err") || !ASSERT_EQ(id0, id1, "id1_check_val"))
 51		goto cleanup;
 52
 53	/* BPF link is not allowed to replace prog attachment */
 54	link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO);
 55	if (!ASSERT_ERR_PTR(link, "link_attach_should_fail")) {
 56		bpf_link__destroy(link);
 57		/* best-effort detach prog */
 58		opts.old_prog_fd = prog_fd1;
 59		bpf_xdp_detach(IFINDEX_LO, XDP_FLAGS_REPLACE, &opts);
 60		goto cleanup;
 61	}
 62
 63	/* detach BPF program */
 64	opts.old_prog_fd = prog_fd1;
 65	err = bpf_xdp_detach(IFINDEX_LO, XDP_FLAGS_REPLACE, &opts);
 66	if (!ASSERT_OK(err, "prog_detach"))
 67		goto cleanup;
 68
 69	/* now BPF link should attach successfully */
 70	link = bpf_program__attach_xdp(skel1->progs.xdp_handler, IFINDEX_LO);
 71	if (!ASSERT_OK_PTR(link, "link_attach"))
 72		goto cleanup;
 73	skel1->links.xdp_handler = link;
 74
 75	/* validate prog ID */
 76	err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
 77	if (!ASSERT_OK(err, "id1_check_err") || !ASSERT_EQ(id0, id1, "id1_check_val"))
 78		goto cleanup;
 79
 80	/* BPF prog attach is not allowed to replace BPF link */
 81	opts.old_prog_fd = prog_fd1;
 82	err = bpf_xdp_attach(IFINDEX_LO, prog_fd2, XDP_FLAGS_REPLACE, &opts);
 83	if (!ASSERT_ERR(err, "prog_attach_fail"))
 84		goto cleanup;
 85
 86	/* Can't force-update when BPF link is active */
 87	err = bpf_xdp_attach(IFINDEX_LO, prog_fd2, 0, NULL);
 88	if (!ASSERT_ERR(err, "prog_update_fail"))
 89		goto cleanup;
 90
 91	/* Can't force-detach when BPF link is active */
 92	err = bpf_xdp_detach(IFINDEX_LO, 0, NULL);
 93	if (!ASSERT_ERR(err, "prog_detach_fail"))
 94		goto cleanup;
 95
 96	/* BPF link is not allowed to replace another BPF link */
 97	link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO);
 98	if (!ASSERT_ERR_PTR(link, "link_attach_should_fail")) {
 99		bpf_link__destroy(link);
100		goto cleanup;
101	}
102
103	bpf_link__destroy(skel1->links.xdp_handler);
104	skel1->links.xdp_handler = NULL;
105
106	/* new link attach should succeed */
107	link = bpf_program__attach_xdp(skel2->progs.xdp_handler, IFINDEX_LO);
108	if (!ASSERT_OK_PTR(link, "link_attach"))
109		goto cleanup;
110	skel2->links.xdp_handler = link;
111
112	err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
113	if (!ASSERT_OK(err, "id2_check_err") || !ASSERT_EQ(id0, id2, "id2_check_val"))
114		goto cleanup;
115
116	/* updating program under active BPF link works as expected */
117	err = bpf_link__update_program(link, skel1->progs.xdp_handler);
118	if (!ASSERT_OK(err, "link_upd"))
119		goto cleanup;
120
121	memset(&link_info, 0, sizeof(link_info));
122	err = bpf_link_get_info_by_fd(bpf_link__fd(link),
123				      &link_info, &link_info_len);
124	if (!ASSERT_OK(err, "link_info"))
125		goto cleanup;
126
127	ASSERT_EQ(link_info.type, BPF_LINK_TYPE_XDP, "link_type");
128	ASSERT_EQ(link_info.prog_id, id1, "link_prog_id");
129	ASSERT_EQ(link_info.xdp.ifindex, IFINDEX_LO, "link_ifindex");
130
131	/* updating program under active BPF link with different type fails */
132	err = bpf_link__update_program(link, skel1->progs.tc_handler);
133	if (!ASSERT_ERR(err, "link_upd_invalid"))
134		goto cleanup;
135
136	err = bpf_link__detach(link);
137	if (!ASSERT_OK(err, "link_detach"))
138		goto cleanup;
139
140	memset(&link_info, 0, sizeof(link_info));
141	err = bpf_link_get_info_by_fd(bpf_link__fd(link),
142				      &link_info, &link_info_len);
143
144	ASSERT_OK(err, "link_info");
145	ASSERT_EQ(link_info.prog_id, id1, "link_prog_id");
146	/* ifindex should be zeroed out */
147	ASSERT_EQ(link_info.xdp.ifindex, 0, "link_ifindex");
148
149cleanup:
150	test_xdp_link__destroy(skel1);
151	test_xdp_link__destroy(skel2);
152}