On Tue, Dec 20, 2022 at 5:49 PM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
>
> From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
>
> When the bpf_skb_adjust_room() shrinks the skb such that
> its csum_start is invalid, the skb->ip_summed should
> be reset from CHECKSUM_PARTIAL to CHECKSUM_NONE.
>
> The commit 54c3f1a81421 ("bpf: pull before calling skb_postpull_rcsum()")
> fixed it.
>
> This patch adds a test to ensure the skb->ip_summed changed
> from CHECKSUM_PARTIAL to CHECKSUM_NONE after bpf_skb_adjust_room().
>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
> ---
> v2: Add test to DENYLIST.s390x due to kfunc usage
>
> tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
> .../selftests/bpf/prog_tests/decap_sanity.c | 83 +++++++++++++++++++
> .../selftests/bpf/progs/bpf_tracing_net.h | 6 ++
> .../selftests/bpf/progs/decap_sanity.c | 68 +++++++++++++++
> 4 files changed, 158 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/decap_sanity.c
> create mode 100644 tools/testing/selftests/bpf/progs/decap_sanity.c
>
> diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
> index 585fcf73c731..dba6c027920d 100644
> --- a/tools/testing/selftests/bpf/DENYLIST.s390x
> +++ b/tools/testing/selftests/bpf/DENYLIST.s390x
> @@ -86,3 +86,4 @@ xdp_bpf2bpf # failed to auto-attach program 'trace_
> xdp_do_redirect # prog_run_max_size unexpected error: -22 (errno 22)
> xdp_synproxy # JIT does not support calling kernel function (kfunc)
> xfrm_info # JIT does not support calling kernel function (kfunc)
> +decap_sanity # JIT does not support calling kernel function (kfunc)
let's keep this list sorted?
> \ No newline at end of file
> diff --git a/tools/testing/selftests/bpf/prog_tests/decap_sanity.c b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c
> new file mode 100644
> index 000000000000..2fbb3017b740
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/decap_sanity.c
> @@ -0,0 +1,83 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
> +
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +#include <net/if.h>
> +#include <linux/in6.h>
> +
> +#include "test_progs.h"
> +#include "network_helpers.h"
> +#include "decap_sanity.skel.h"
> +
> +#define SYS(fmt, ...) \
> + ({ \
> + char cmd[1024]; \
> + snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \
> + if (!ASSERT_OK(system(cmd), cmd)) \
> + goto fail; \
> + })
> +
> +#define NS_TEST "decap_sanity_ns"
> +#define IPV6_IFACE_ADDR "face::1"
> +#define UDP_TEST_PORT 7777
> +
> +void test_decap_sanity(void)
> +{
> + LIBBPF_OPTS(bpf_tc_hook, qdisc_hook, .attach_point = BPF_TC_EGRESS);
> + LIBBPF_OPTS(bpf_tc_opts, tc_attach);
> + struct nstoken *nstoken = NULL;
> + struct decap_sanity *skel;
> + struct sockaddr_in6 addr;
> + socklen_t addrlen;
> + char buf[128] = {};
> + int sockfd, err;
> +
> + skel = decap_sanity__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "skel open_and_load"))
> + return;
> +
> + SYS("ip netns add %s", NS_TEST);
> + SYS("ip -net %s -6 addr add %s/128 dev lo nodad", NS_TEST, IPV6_IFACE_ADDR);
> + SYS("ip -net %s link set dev lo up", NS_TEST);
> +
> + nstoken = open_netns(NS_TEST);
> + if (!ASSERT_OK_PTR(nstoken, "open_netns"))
> + goto fail;
> +
> + qdisc_hook.ifindex = if_nametoindex("lo");
> + if (!ASSERT_GT(qdisc_hook.ifindex, 0, "if_nametoindex lo"))
> + goto fail;
> +
> + err = bpf_tc_hook_create(&qdisc_hook);
> + if (!ASSERT_OK(err, "create qdisc hook"))
> + goto fail;
you seem to be missing bpf_tc_hook_destroy() for clean up
> +
> + tc_attach.prog_fd = bpf_program__fd(skel->progs.decap_sanity);
> + err = bpf_tc_attach(&qdisc_hook, &tc_attach);
> + if (!ASSERT_OK(err, "attach filter"))
> + goto fail;
> +
> + addrlen = sizeof(addr);
> + err = make_sockaddr(AF_INET6, IPV6_IFACE_ADDR, UDP_TEST_PORT,
> + (void *)&addr, &addrlen);
> + if (!ASSERT_OK(err, "make_sockaddr"))
> + goto fail;
> + sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
> + if (!ASSERT_NEQ(sockfd, -1, "socket"))
> + goto fail;
> + err = sendto(sockfd, buf, sizeof(buf), 0, (void *)&addr, addrlen);
> + close(sockfd);
> + if (!ASSERT_EQ(err, sizeof(buf), "send"))
> + goto fail;
> +
> + ASSERT_EQ(skel->bss->init_csum_partial, true, "init_csum_partial");
> + ASSERT_EQ(skel->bss->final_csum_none, true, "final_csum_none");
> + ASSERT_EQ(skel->bss->broken_csum_start, false, "broken_csum_start");
ASSERT_TRUE and ASSERT_FALSE ?
> +
> +fail:
> + if (nstoken)
> + close_netns(nstoken);
> + system("ip netns del " NS_TEST " >& /dev/null");
> + decap_sanity__destroy(skel);
> +}
[...]
