bpf/prog_tests/kfree_skb.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <test_progs.h>
0003 #include <network_helpers.h>
0004 #include "kfree_skb.skel.h"
0005
0006 struct meta {
0007     int ifindex;
0008     __u32 cb32_0;
0009     __u8 cb8_0;
0010 };
0011
0012 static union {
0013     __u32 cb32[5];
0014     __u8 cb8[20];
0015 } cb = {
0016     .cb32[0] = 0x81828384,
0017 };
0018
0019 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
0020 {
0021     struct meta *meta = (struct meta *)data;
0022     struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
0023     int duration = 0;
0024
0025     if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
0026           size, 72 + sizeof(*meta)))
0027         return;
0028     if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
0029           "meta->ifindex = %d\n", meta->ifindex))
0030         /* spurious kfree_skb not on loopback device */
0031         return;
0032     if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
0033           meta->cb8_0, cb.cb8[0]))
0034         return;
0035     if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
0036           "cb32_0 %x != %x\n",
0037           meta->cb32_0, cb.cb32[0]))
0038         return;
0039     if (CHECK(pkt_v6->eth.h_proto != 0xdd86, "check_eth",
0040           "h_proto %x\n", pkt_v6->eth.h_proto))
0041         return;
0042     if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
0043           "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
0044         return;
0045     if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
0046           "tcp.doff %x\n", pkt_v6->tcp.doff))
0047         return;
0048
0049     *(bool *)ctx = true;
0050 }
0051
0052 /* TODO: fix kernel panic caused by this test in parallel mode */
0053 void serial_test_kfree_skb(void)
0054 {
0055     struct __sk_buff skb = {};
0056     LIBBPF_OPTS(bpf_test_run_opts, topts,
0057         .data_in = &pkt_v6,
0058         .data_size_in = sizeof(pkt_v6),
0059         .ctx_in = &skb,
0060         .ctx_size_in = sizeof(skb),
0061     );
0062     struct kfree_skb *skel = NULL;
0063     struct bpf_link *link;
0064     struct bpf_object *obj;
0065     struct perf_buffer *pb = NULL;
0066     int err, prog_fd;
0067     bool passed = false;
0068     __u32 duration = 0;
0069     const int zero = 0;
0070     bool test_ok[2];
0071
0072     err = bpf_prog_test_load("./test_pkt_access.o", BPF_PROG_TYPE_SCHED_CLS,
0073                  &obj, &prog_fd);
0074     if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
0075         return;
0076
0077     skel = kfree_skb__open_and_load();
0078     if (!ASSERT_OK_PTR(skel, "kfree_skb_skel"))
0079         goto close_prog;
0080
0081     link = bpf_program__attach_raw_tracepoint(skel->progs.trace_kfree_skb, NULL);
0082     if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
0083         goto close_prog;
0084     skel->links.trace_kfree_skb = link;
0085
0086     link = bpf_program__attach_trace(skel->progs.fentry_eth_type_trans);
0087     if (!ASSERT_OK_PTR(link, "attach fentry"))
0088         goto close_prog;
0089     skel->links.fentry_eth_type_trans = link;
0090
0091     link = bpf_program__attach_trace(skel->progs.fexit_eth_type_trans);
0092     if (!ASSERT_OK_PTR(link, "attach fexit"))
0093         goto close_prog;
0094     skel->links.fexit_eth_type_trans = link;
0095
0096     /* set up perf buffer */
0097     pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1,
0098                   on_sample, NULL, &passed, NULL);
0099     if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
0100         goto close_prog;
0101
0102     memcpy(skb.cb, &cb, sizeof(cb));
0103     err = bpf_prog_test_run_opts(prog_fd, &topts);
0104     ASSERT_OK(err, "ipv6 test_run");
0105     ASSERT_OK(topts.retval, "ipv6 test_run retval");
0106
0107     /* read perf buffer */
0108     err = perf_buffer__poll(pb, 100);
0109     if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
0110         goto close_prog;
0111
0112     /* make sure kfree_skb program was triggered
0113      * and it sent expected skb into ring buffer
0114      */
0115     ASSERT_TRUE(passed, "passed");
0116
0117     err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.bss), &zero, test_ok);
0118     if (CHECK(err, "get_result",
0119           "failed to get output data: %d\n", err))
0120         goto close_prog;
0121
0122     CHECK_FAIL(!test_ok[0] || !test_ok[1]);
0123 close_prog:
0124     perf_buffer__free(pb);
0125     bpf_object__close(obj);
0126     kfree_skb__destroy(skel);
0127 }