From: Stanislav Fomichev <sdf@google•com>
To: netdev@vger•kernel.org
Cc: davem@davemloft•net, ast@kernel•org, daniel@iogearbox•net,
simon.horman@netronome•com, willemb@google•com,
Stanislav Fomichev <sdf@google•com>
Subject: [RFC bpf-next 6/7] selftests/bpf: add flow dissector bpf_skb_load_bytes helper test
Date: Tue, 5 Feb 2019 09:36:28 -0800 [thread overview]
Message-ID: <20190205173629.160717-7-sdf@google.com> (raw)
In-Reply-To: <20190205173629.160717-1-sdf@google.com>
With the on-stack skb, we want to make sure we don't trigger any
shinfo access. Add small test which tries to read the data past
the packet boundary.
Signed-off-by: Stanislav Fomichev <sdf@google•com>
---
tools/testing/selftests/bpf/test_progs.c | 49 ++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index c52bd90fbb34..c12f61efc427 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1995,6 +1995,54 @@ static void test_flow_dissector(void)
bpf_object__close(obj);
}
+static void test_flow_dissector_load_bytes(void)
+{
+ struct bpf_flow_keys flow_keys;
+ __u32 duration, retval, size;
+ struct bpf_insn prog[] = {
+ // BPF_REG_1 - 1st argument: context
+ // BPF_REG_2 - 2nd argument: offset, start at last byte + 1
+ BPF_MOV64_IMM(BPF_REG_2, sizeof(pkt_v4)),
+ // BPF_REG_3 - 3rd argument: destination, reserve byte on stack
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_3, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -1),
+ // BPF_REG_4 - 4th argument: copy one byte
+ BPF_MOV64_IMM(BPF_REG_4, 1),
+ // bpf_skb_load_bytes(ctx, sizeof(pkt_v4), ptr, 1)
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_skb_load_bytes),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
+ // if (ret == 0) return BPF_DROP (2)
+ BPF_MOV64_IMM(BPF_REG_0, BPF_DROP),
+ BPF_EXIT_INSN(),
+ // if (ret != 0) return BPF_OK (0)
+ BPF_MOV64_IMM(BPF_REG_0, BPF_OK),
+ BPF_EXIT_INSN(),
+ };
+ int fd, err;
+
+ /* make sure bpf_skb_load_bytes helper doesn't cause any
+ * problems when used with the fake skb in the flow
+ * dissector (try to read past the last byte)
+ */
+ fd = bpf_load_program(BPF_PROG_TYPE_FLOW_DISSECTOR, prog,
+ ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
+ CHECK(fd < 0,
+ "flow_dissector-bpf_skb_load_bytes-load",
+ "fd %d errno %d\n",
+ fd, errno);
+
+ err = bpf_prog_test_run(fd, 1, &pkt_v4, sizeof(pkt_v4),
+ &flow_keys, &size, &retval, &duration);
+ CHECK(size != sizeof(flow_keys) || err || retval != 1,
+ "flow_dissector-bpf_skb_load_bytes",
+ "err %d errno %d retval %d duration %d size %u/%lu\n",
+ err, errno, retval, duration, size, sizeof(flow_keys));
+
+ if (fd >= -1)
+ close(fd);
+}
+
static void *test_spin_lock(void *arg)
{
__u32 duration, retval;
@@ -2136,6 +2184,7 @@ int main(void)
test_queue_stack_map(QUEUE);
test_queue_stack_map(STACK);
test_flow_dissector();
+ test_flow_dissector_load_bytes();
test_spinlock();
test_map_lock();
--
2.20.1.611.gfbb209baf1-goog
next prev parent reply other threads:[~2019-02-05 17:36 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-05 17:36 [RFC bpf-next 0/7] net: flow_dissector: trigger BPF hook when called from eth_get_headlen Stanislav Fomichev
2019-02-05 17:36 ` [RFC bpf-next 1/7] net: introduce __init_skb and __init_skb_shinfo helpers Stanislav Fomichev
2019-02-05 20:18 ` Willem de Bruijn
2019-02-05 17:36 ` [RFC bpf-next 2/7] net: introduce skb_net helper Stanislav Fomichev
2019-02-05 20:19 ` Willem de Bruijn
2019-02-05 20:42 ` Stanislav Fomichev
2019-02-05 17:36 ` [RFC bpf-next 3/7] net: plumb network namespace into __skb_flow_dissect Stanislav Fomichev
2019-02-05 20:19 ` Willem de Bruijn
2019-02-05 20:40 ` Stanislav Fomichev
2019-02-05 17:36 ` [RFC bpf-next 4/7] net: flow_dissector: handle no-skb use case Stanislav Fomichev
2019-02-05 20:19 ` Willem de Bruijn
2019-02-05 20:45 ` Stanislav Fomichev
2019-02-05 17:36 ` [RFC bpf-next 5/7] bpf: when doing BPF_PROG_TEST_RUN for flow dissector use no-skb mode Stanislav Fomichev
2019-02-05 20:19 ` Willem de Bruijn
2019-02-05 17:36 ` Stanislav Fomichev [this message]
2019-02-05 17:36 ` [RFC bpf-next 7/7] net: flow_dissector: pass net argument to the eth_get_headlen Stanislav Fomichev
2019-02-05 20:18 ` [RFC bpf-next 0/7] net: flow_dissector: trigger BPF hook when called from eth_get_headlen Willem de Bruijn
2019-02-05 20:40 ` Stanislav Fomichev
2019-02-06 0:47 ` Alexei Starovoitov
2019-02-06 0:59 ` Stanislav Fomichev
2019-02-06 3:12 ` Alexei Starovoitov
2019-02-06 3:56 ` Stanislav Fomichev
2019-02-06 4:11 ` Alexei Starovoitov
2019-02-06 5:49 ` Stanislav Fomichev
2019-02-12 17:02 ` Stanislav Fomichev
2019-02-14 4:39 ` Alexei Starovoitov
2019-02-14 5:57 ` Stanislav Fomichev
2019-02-14 6:38 ` Alexei Starovoitov
2019-02-14 17:35 ` Stanislav Fomichev
2019-02-25 20:33 ` Stanislav Fomichev
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