On Tue, Jan 14, 2020 at 7:58 AM Eelco Chaudron <echaudro@xxxxxxxxxx>
wrote:
Add a test that will attach a FENTRY and FEXIT program to the XDP
test
program. It will also verify data from the XDP context on FENTRY and
verifies the return code on exit.
Signed-off-by: Eelco Chaudron <echaudro@xxxxxxxxxx>
---
v1 -> v2:
- Changed code to use the BPF skeleton
- Replace static volatile with global variable in eBPF code
.../testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c | 69
++++++++++++++++++++
.../testing/selftests/bpf/progs/test_xdp_bpf2bpf.c | 44
+++++++++++++
2 files changed, 113 insertions(+)
create mode 100644
tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
create mode 100644
tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
new file mode 100644
index 000000000000..e6e849df2632
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <net/if.h>
+#include "test_xdp.skel.h"
+#include "test_xdp_bpf2bpf.skel.h"
+
+void test_xdp_bpf2bpf(void)
+{
+
extra line
+ struct test_xdp *pkt_skel = NULL;
+ struct test_xdp_bpf2bpf *ftrace_skel = NULL;
something with indentation?
+ __u64 *ftrace_res;
+
variable declarations shouldn't be split, probably?
+ struct vip key4 = {.protocol = 6, .family = AF_INET};
+ struct iptnl_info value4 = {.family = AF_INET};
+ char buf[128];
+ struct iphdr *iph = (void *)buf + sizeof(struct ethhdr);
+ __u32 duration = 0, retval, size;
+ int err, pkt_fd, map_fd;
+
+ /* Load XDP program to introspect */
+ pkt_skel = test_xdp__open_and_load();
+ if (CHECK(!pkt_skel, "pkt_skel_load", "test_xdp skeleton
failed\n"))
+ return;
+
+ pkt_fd = bpf_program__fd(pkt_skel->progs._xdp_tx_iptunnel);
+
+ map_fd = bpf_map__fd(pkt_skel->maps.vip2tnl);
+ bpf_map_update_elem(map_fd, &key4, &value4, 0);
+
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .attach_prog_fd = pkt_fd,
+ );
DECLARE_LIBBPF_OPTS is a variable declaration, so should go together
with all other declarations. Compiler should complain about this, but
I guess selftests/bpf Makefile doesn't have necessary flags, that
other kernel code has. You can declare opts first and then initialize
some extra fields later:
DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
... later in code ...
opts.attach_prog_fd = pkt_fd;
+
+ ftrace_skel = test_xdp_bpf2bpf__open_opts(&opts);
+ if (CHECK(!ftrace_skel, "__open", "ftrace skeleton
failed\n"))
+ goto out;
+
+ if (CHECK(test_xdp_bpf2bpf__load(ftrace_skel), "__load",
"ftrace skeleton failed\n"))
+ goto out;
for consistency with attach check below and for readability, move out
load call into separate statement, it's easy to miss when it is inside
CHECK()
+
+ err = test_xdp_bpf2bpf__attach(ftrace_skel);
+ if (CHECK(err, "ftrace_attach", "ftrace attach failed: %d\n",
err))
+ goto out;
+
+ /* Run test program */
+ err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
+ buf, &size, &retval, &duration);
+
+ CHECK(err || retval != XDP_TX || size != 74 ||
+ iph->protocol != IPPROTO_IPIP, "ipv4",
+ "err %d errno %d retval %d size %d\n",
+ err, errno, retval, size);
should it goto out here as well?
+
+ /* Verify test results */
+ ftrace_res = (__u64 *)ftrace_skel->bss;
+
+ if (CHECK(ftrace_res[0] != if_nametoindex("lo"), "result",
+ "fentry failed err %llu\n", ftrace_res[0]))
+ goto out;
+
+ if (CHECK(ftrace_res[1] != XDP_TX, "result",
+ "fexit failed err %llu\n", ftrace_res[1]))
+ goto out;
why this casting? You can do access those variables much more
naturally with ftrace_skel->bss->test_result_fentry and
ftrace_skel->bss->test_result_fexit without making dangerous
assumptions about their offsets within data section.
+
+out:
+ test_xdp__destroy(pkt_skel);
+ test_xdp_bpf2bpf__destroy(ftrace_skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
new file mode 100644
index 000000000000..74c78b30ae07
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+#include "bpf_trace_helpers.h"
+
+struct net_device {
+ /* Structure does not need to contain all entries,
+ * as "preserve_access_index" will use BTF to fix this...
+ */
+ int ifindex;
+} __attribute__((preserve_access_index));
+
+struct xdp_rxq_info {
+ /* Structure does not need to contain all entries,
+ * as "preserve_access_index" will use BTF to fix this...
+ */
+ struct net_device *dev;
+ __u32 queue_index;
+} __attribute__((preserve_access_index));
+
+struct xdp_buff {
+ void *data;
+ void *data_end;
+ void *data_meta;
+ void *data_hard_start;
+ unsigned long handle;
+ struct xdp_rxq_info *rxq;
+} __attribute__((preserve_access_index));
+
+__u64 test_result_fentry = 0;
+BPF_TRACE_1("fentry/_xdp_tx_iptunnel", trace_on_entry,
+ struct xdp_buff *, xdp)
BPF_TRACE_x is no more, see BPF_PROG and how it's used for
fentry/fexit tests:
SEC("fentry/_xdp_tx_iptunnel")
int BPF_PROG(trace_on_entry, struct xdp_buff *xdp)
+{
+ test_result_fentry = xdp->rxq->dev->ifindex;
+ return 0;
+}
+
+__u64 test_result_fexit = 0;
+BPF_TRACE_2("fexit/_xdp_tx_iptunnel", trace_on_exit,
+ struct xdp_buff*, xdp, int, ret)
+{
+ test_result_fexit = ret;
+ return 0;
+}
