From 80e24d22267597b2ace54686735e3c4cb26a523f Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 22 May 2023 19:56:17 -0700 Subject: [PATCH] bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops When BPF program drops pkts the sockmap logic 'eats' the packet and updates copied_seq. In the PASS case where the sk_buff is accepted we update copied_seq from recvmsg path so we need a new test to handle the drop case. Original patch series broke this resulting in test_sockmap_skb_verdict_fionread:PASS:ioctl(FIONREAD) error 0 nsec test_sockmap_skb_verdict_fionread:FAIL:ioctl(FIONREAD) unexpected ioctl(FIONREAD): actual 1503041772 != expected 256 After updated patch with fix. Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20230523025618.113937-14-john.fastabend@gmail.com --- .../selftests/bpf/prog_tests/sockmap_basic.c | 47 ++++++++++++++----- .../bpf/progs/test_sockmap_drop_prog.c | 32 +++++++++++++ 2 files changed, 66 insertions(+), 13 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_drop_prog.c diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index fe56049f6568..064cc5e8d9ad 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -11,6 +11,7 @@ #include "test_sockmap_skb_verdict_attach.skel.h" #include "test_sockmap_progs_query.skel.h" #include "test_sockmap_pass_prog.skel.h" +#include "test_sockmap_drop_prog.skel.h" #include "bpf_iter_sockmap.skel.h" #include "sockmap_helpers.h" @@ -410,19 +411,31 @@ out: test_sockmap_pass_prog__destroy(skel); } -static void test_sockmap_skb_verdict_fionread(void) +static void test_sockmap_skb_verdict_fionread(bool pass_prog) { + int expected, zero = 0, sent, recvd, avail; int err, map, verdict, s, c0, c1, p0, p1; - struct test_sockmap_pass_prog *skel; - int zero = 0, sent, recvd, avail; + struct test_sockmap_pass_prog *pass; + struct test_sockmap_drop_prog *drop; char buf[256] = "0123456789"; - skel = test_sockmap_pass_prog__open_and_load(); - if (!ASSERT_OK_PTR(skel, "open_and_load")) - return; + if (pass_prog) { + pass = test_sockmap_pass_prog__open_and_load(); + if (!ASSERT_OK_PTR(pass, "open_and_load")) + return; + verdict = bpf_program__fd(pass->progs.prog_skb_verdict); + map = bpf_map__fd(pass->maps.sock_map_rx); + expected = sizeof(buf); + } else { + drop = test_sockmap_drop_prog__open_and_load(); + if (!ASSERT_OK_PTR(drop, "open_and_load")) + return; + verdict = bpf_program__fd(drop->progs.prog_skb_verdict); + map = bpf_map__fd(drop->maps.sock_map_rx); + /* On drop data is consumed immediately and copied_seq inc'd */ + expected = 0; + } - verdict = bpf_program__fd(skel->progs.prog_skb_verdict); - map = bpf_map__fd(skel->maps.sock_map_rx); err = bpf_prog_attach(verdict, map, BPF_SK_SKB_STREAM_VERDICT, 0); if (!ASSERT_OK(err, "bpf_prog_attach")) @@ -443,9 +456,12 @@ static void test_sockmap_skb_verdict_fionread(void) ASSERT_EQ(sent, sizeof(buf), "xsend(p0)"); err = ioctl(c1, FIONREAD, &avail); ASSERT_OK(err, "ioctl(FIONREAD) error"); - ASSERT_EQ(avail, sizeof(buf), "ioctl(FIONREAD)"); - recvd = recv_timeout(c1, &buf, sizeof(buf), SOCK_NONBLOCK, IO_TIMEOUT_SEC); - ASSERT_EQ(recvd, sizeof(buf), "recv_timeout(c0)"); + ASSERT_EQ(avail, expected, "ioctl(FIONREAD)"); + /* On DROP test there will be no data to read */ + if (pass_prog) { + recvd = recv_timeout(c1, &buf, sizeof(buf), SOCK_NONBLOCK, IO_TIMEOUT_SEC); + ASSERT_EQ(recvd, sizeof(buf), "recv_timeout(c0)"); + } out_close: close(c0); @@ -453,7 +469,10 @@ out_close: close(c1); close(p1); out: - test_sockmap_pass_prog__destroy(skel); + if (pass_prog) + test_sockmap_pass_prog__destroy(pass); + else + test_sockmap_drop_prog__destroy(drop); } void test_sockmap_basic(void) @@ -493,5 +512,7 @@ void test_sockmap_basic(void) if (test__start_subtest("sockmap skb_verdict shutdown")) test_sockmap_skb_verdict_shutdown(); if (test__start_subtest("sockmap skb_verdict fionread")) - test_sockmap_skb_verdict_fionread(); + test_sockmap_skb_verdict_fionread(true); + if (test__start_subtest("sockmap skb_verdict fionread on drop")) + test_sockmap_skb_verdict_fionread(false); } diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_drop_prog.c b/tools/testing/selftests/bpf/progs/test_sockmap_drop_prog.c new file mode 100644 index 000000000000..29314805ce42 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sockmap_drop_prog.c @@ -0,0 +1,32 @@ +#include +#include +#include + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 20); + __type(key, int); + __type(value, int); +} sock_map_rx SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 20); + __type(key, int); + __type(value, int); +} sock_map_tx SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 20); + __type(key, int); + __type(value, int); +} sock_map_msg SEC(".maps"); + +SEC("sk_skb") +int prog_skb_verdict(struct __sk_buff *skb) +{ + return SK_DROP; +} + +char _license[] SEC("license") = "GPL";