Re: [External] Re: [PATCH bpf-next v2 2/2] bpf, selftests: Add test case for cgroup skb to get net_cls classid helpers

[Feng Zhou <zhoufeng.zf@bytedance.com>]

在 2024/10/1 09:58, Martin KaFai Lau 写道:
> On 9/18/24 12:45 AM, Feng zhou wrote:
>> From: Feng Zhou <zhoufeng.zf@bytedance.com>
>>
>> This patch adds a test for cgroup skb to get classid.
>>
>> Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
>> ---
>>   .../bpf/prog_tests/cg_skb_get_classid.c       | 87 +++++++++++++++++++
>>   .../selftests/bpf/progs/cg_skb_get_classid.c  | 19 ++++
>>   2 files changed, 106 insertions(+)
>>   create mode 100644 
>> tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c
>>   create mode 100644 
>> tools/testing/selftests/bpf/progs/cg_skb_get_classid.c
>>
>> diff --git 
>> a/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c 
>> b/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c
>> new file mode 100644
>> index 000000000000..13a5943c387d
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c
>> @@ -0,0 +1,87 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +
>> +/*
>> + * Copyright 2024 Bytedance.
>> + */
>> +
>> +#include <test_progs.h>
>> +
>> +#include "cg_skb_get_classid.skel.h"
>> +
>> +#include "cgroup_helpers.h"
>> +#include "network_helpers.h"
>> +
>> +static int run_test(int cgroup_fd, int server_fd)
>> +{
>> +    struct cg_skb_get_classid *skel;
>> +    int fd, err = 0;
>> +
>> +    skel = cg_skb_get_classid__open_and_load();
>> +    if (!ASSERT_OK_PTR(skel, "skel_open"))
>> +        return -1;
>> +
>> +    skel->links.cg_skb_classid =
>> +        bpf_program__attach_cgroup(skel->progs.cg_skb_classid,
>> +                       cgroup_fd);
>> +    if (!ASSERT_OK_PTR(skel->links.cg_skb_classid, "prog_attach")) {
>> +        err = -1;
>> +        goto out;
>> +    }
>> +
>> +    if (!ASSERT_OK(join_classid(), "join_classid")) {
>> +        err = -1;
>> +        goto out;
>> +    }
>> +
>> +    errno = 0;
>> +    fd = connect_to_fd_opts(server_fd, NULL);
>> +    if (fd >= 0) {
>> +        if (skel->bss->classid != getpid()) {
>> +            log_err("Get unexpected classid");
>> +            err = -1;
>> +        }
>> +
>> +        close(fd);
>> +    } else {
>> +        log_err("Unexpected errno from connect to server");
>> +        err = -1;
>> +    }
>> +out:
>> +    cg_skb_get_classid__destroy(skel);
>> +    return err;
>> +}
>> +
>> +void test_cg_skb_get_classid(void)
>> +{
>> +    struct network_helper_opts opts = {};
>> +    int server_fd, client_fd, cgroup_fd;
>> +    static const int port = 60120;
> 
> Running a test with a specific port without netns could fail when 
> test_progs is run in parallel (-j). e.g. cgroup_v1v2 is using the same 
> port.
> 
>> +
>> +    /* Step 1: Check base connectivity works without any BPF. */
>> +    server_fd = start_server(AF_INET, SOCK_STREAM, NULL, port, 0);
>> +    if (!ASSERT_GE(server_fd, 0, "server_fd"))
>> +        return;
>> +    client_fd = connect_to_fd_opts(server_fd, &opts);
>> +    if (!ASSERT_GE(client_fd, 0, "client_fd")) {
>> +        close(server_fd);
>> +        return;
>> +    }
>> +    close(client_fd);
>> +    close(server_fd);
> 
> imo, this connection pre-test is unnecessary. I would remove it.
> 
>> +
>> +    /* Step 2: Check BPF prog attached to cgroups. */
>> +    cgroup_fd = test__join_cgroup("/cg_skb_get_classid");
>> +    if (!ASSERT_GE(cgroup_fd, 0, "cgroup_fd"))
>> +        return;
>> +    server_fd = start_server(AF_INET, SOCK_STREAM, NULL, port, 0);
>> +    if (!ASSERT_GE(server_fd, 0, "server_fd")) {
>> +        close(cgroup_fd);
>> +        return;
>> +    }
>> +    setup_classid_environment();
>> +    set_classid();
>> +    ASSERT_OK(run_test(cgroup_fd, server_fd), "cg_skb_get_classid");
> 
> Please run this test under a netns and without specifying a particular 
> port. connect_to_fd_opts will figure out the port used in server_fd.
> 
> Patch 1 lgtm.
> 
> Please add a few words to the cover letter also.
> 
> pw-bot: cr

Sorry for taking so long to reply.

Will do, thanks.