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

   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
   9 void 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_obj_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_obj_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_obj_get_info_by_fd(bpf_link__fd(link), &link_info, &link_info_len);
 123         if (!ASSERT_OK(err, "link_info"))
 124                 goto cleanup;
 125
 126         ASSERT_EQ(link_info.type, BPF_LINK_TYPE_XDP, "link_type");
 127         ASSERT_EQ(link_info.prog_id, id1, "link_prog_id");
 128         ASSERT_EQ(link_info.xdp.ifindex, IFINDEX_LO, "link_ifindex");
 129
 130         /* updating program under active BPF link with different type fails */
 131         err = bpf_link__update_program(link, skel1->progs.tc_handler);
 132         if (!ASSERT_ERR(err, "link_upd_invalid"))
 133                 goto cleanup;
 134
 135         err = bpf_link__detach(link);
 136         if (!ASSERT_OK(err, "link_detach"))
 137                 goto cleanup;
 138
 139         memset(&link_info, 0, sizeof(link_info));
 140         err = bpf_obj_get_info_by_fd(bpf_link__fd(link), &link_info, &link_info_len);
 141
 142         ASSERT_OK(err, "link_info");
 143         ASSERT_EQ(link_info.prog_id, id1, "link_prog_id");
 144         /* ifindex should be zeroed out */
 145         ASSERT_EQ(link_info.xdp.ifindex, 0, "link_ifindex");
 146
 147 cleanup:
 148         test_xdp_link__destroy(skel1);
 149         test_xdp_link__destroy(skel2);
 150 }