Re: [PATCH net-next v3 14/14] bpf: add simple bpf tests in the tx path for so_timstamping feature

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Jason Xing wrote:
> On Tue, Oct 29, 2024 at 9:27 AM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > Jason Xing wrote:
> > > From: Jason Xing <kernelxing@tencent.com>
> > >
> > > Only check if we pass those three key points after we enable the
> > > bpf extension for so_timestamping. During each point, we can choose
> > > whether to print the current timestamp.
> > >
> > > Signed-off-by: Jason Xing <kernelxing@tencent.com>
> > > ---
> > >  .../bpf/prog_tests/so_timestamping.c          |  98 ++++++++++++++
> > >  .../selftests/bpf/progs/so_timestamping.c     | 123 ++++++++++++++++++
> > >  2 files changed, 221 insertions(+)
> > >  create mode 100644 tools/testing/selftests/bpf/prog_tests/so_timestamping.c
> > >  create mode 100644 tools/testing/selftests/bpf/progs/so_timestamping.c
> > >
> > > diff --git a/tools/testing/selftests/bpf/prog_tests/so_timestamping.c b/tools/testing/selftests/bpf/prog_tests/so_timestamping.c
> > > new file mode 100644
> > > index 000000000000..dfb7588c246d
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/prog_tests/so_timestamping.c
> > > @@ -0,0 +1,98 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/* Copyright (c) 2024 Tencent */
> > > +
> > > +#define _GNU_SOURCE
> > > +#include <sched.h>
> > > +#include <linux/socket.h>
> > > +#include <linux/tls.h>
> > > +#include <net/if.h>
> > > +
> > > +#include "test_progs.h"
> > > +#include "cgroup_helpers.h"
> > > +#include "network_helpers.h"
> > > +
> > > +#include "so_timestamping.skel.h"
> > > +
> > > +#define CG_NAME "/so-timestamping-test"
> > > +
> > > +static const char addr4_str[] = "127.0.0.1";
> > > +static const char addr6_str[] = "::1";
> > > +static struct so_timestamping *skel;
> > > +static int cg_fd;
> > > +
> > > +static int create_netns(void)
> > > +{
> > > +     if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
> > > +             return -1;
> > > +
> > > +     if (!ASSERT_OK(system("ip link set dev lo up"), "set lo up"))
> > > +             return -1;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static void test_tcp(int family)
> > > +{
> > > +     struct so_timestamping__bss *bss = skel->bss;
> > > +     char buf[] = "testing testing";
> > > +     int sfd = -1, cfd = -1;
> > > +     int n;
> > > +
> > > +     memset(bss, 0, sizeof(*bss));
> > > +
> > > +     sfd = start_server(family, SOCK_STREAM,
> > > +                        family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
> > > +     if (!ASSERT_GE(sfd, 0, "start_server"))
> > > +             goto out;
> > > +
> > > +     cfd = connect_to_fd(sfd, 0);
> > > +     if (!ASSERT_GE(cfd, 0, "connect_to_fd_server")) {
> > > +             close(sfd);
> > > +             goto out;
> > > +     }
> > > +
> > > +     n = write(cfd, buf, sizeof(buf));
> > > +     if (!ASSERT_EQ(n, sizeof(buf), "send to server"))
> > > +             goto out;
> > > +
> > > +     ASSERT_EQ(bss->nr_active, 1, "nr_active");
> > > +     ASSERT_EQ(bss->nr_passive, 1, "nr_passive");
> > > +     ASSERT_EQ(bss->nr_sched, 1, "nr_sched");
> > > +     ASSERT_EQ(bss->nr_txsw, 1, "nr_txsw");
> > > +     ASSERT_EQ(bss->nr_ack, 1, "nr_ack");
> > > +
> > > +out:
> > > +     if (sfd >= 0)
> > > +             close(sfd);
> > > +     if (cfd >= 0)
> > > +             close(cfd);
> > > +}
> > > +
> > > +void test_so_timestamping(void)
> > > +{
> > > +     cg_fd = test__join_cgroup(CG_NAME);
> > > +     if (cg_fd < 0)
> > > +             return;
> > > +
> > > +     if (create_netns())
> > > +             goto done;
> > > +
> > > +     skel = so_timestamping__open();
> > > +     if (!ASSERT_OK_PTR(skel, "open skel"))
> > > +             goto done;
> > > +
> > > +     if (!ASSERT_OK(so_timestamping__load(skel), "load skel"))
> > > +             goto done;
> > > +
> > > +     skel->links.skops_sockopt =
> > > +             bpf_program__attach_cgroup(skel->progs.skops_sockopt, cg_fd);
> > > +     if (!ASSERT_OK_PTR(skel->links.skops_sockopt, "attach cgroup"))
> > > +             goto done;
> > > +
> > > +     test_tcp(AF_INET6);
> > > +     test_tcp(AF_INET);
> > > +
> > > +done:
> > > +     so_timestamping__destroy(skel);
> > > +     close(cg_fd);
> > > +}
> > > diff --git a/tools/testing/selftests/bpf/progs/so_timestamping.c b/tools/testing/selftests/bpf/progs/so_timestamping.c
> > > new file mode 100644
> > > index 000000000000..a15317951786
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/progs/so_timestamping.c
> > > @@ -0,0 +1,123 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/* Copyright (c) 2024 Tencent */
> > > +
> > > +#include "vmlinux.h"
> > > +#include "bpf_tracing_net.h"
> > > +#include <bpf/bpf_core_read.h>
> > > +#include <bpf/bpf_helpers.h>
> > > +#include <bpf/bpf_tracing.h>
> > > +#include "bpf_misc.h"
> > > +
> > > +#define SO_TIMESTAMPING 37
> > > +#define SOF_TIMESTAMPING_BPF_SUPPPORTED_MASK (SOF_TIMESTAMPING_SOFTWARE | \
> > > +                                           SOF_TIMESTAMPING_TX_SCHED | \
> > > +                                           SOF_TIMESTAMPING_TX_SOFTWARE | \
> > > +                                           SOF_TIMESTAMPING_TX_ACK | \
> > > +                                           SOF_TIMESTAMPING_OPT_ID | \
> > > +                                           SOF_TIMESTAMPING_OPT_ID_TCP)
> > > +
> > > +extern unsigned long CONFIG_HZ __kconfig;
> > > +
> > > +int nr_active;
> > > +int nr_passive;
> > > +int nr_sched;
> > > +int nr_txsw;
> > > +int nr_ack;
> > > +
> > > +struct sockopt_test {
> > > +     int opt;
> > > +     int new;
> > > +     int expected;
> > > +};
> > > +
> > > +static const struct sockopt_test sol_socket_tests[] = {
> > > +     { .opt = SO_TIMESTAMPING, .new = SOF_TIMESTAMPING_TX_SCHED, .expected = 256, },
> > > +     { .opt = SO_TIMESTAMPING, .new = SOF_TIMESTAMPING_BPF_SUPPPORTED_MASK, .expected = 66450, },
> > > +     { .opt = 0, },
> > > +};
> > > +
> > > +struct loop_ctx {
> > > +     void *ctx;
> > > +     struct sock *sk;
> > > +};
> > > +
> > > +static int bpf_test_sockopt_int(void *ctx, struct sock *sk,
> > > +                             const struct sockopt_test *t,
> > > +                             int level)
> > > +{
> > > +     int tmp, new, expected, opt;
> > > +
> > > +     opt = t->opt;
> > > +     new = t->new;
> > > +     expected = t->expected;
> > > +
> > > +     if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
> > > +             return 1;
> > > +     if (bpf_getsockopt(ctx, level, opt, &tmp, sizeof(tmp)) ||
> > > +         tmp != expected)
> > > +             return 1;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int bpf_test_socket_sockopt(__u32 i, struct loop_ctx *lc)
> > > +{
> > > +     const struct sockopt_test *t;
> > > +
> > > +     if (i >= ARRAY_SIZE(sol_socket_tests))
> > > +             return 1;
> > > +
> > > +     t = &sol_socket_tests[i];
> > > +     if (!t->opt)
> > > +             return 1;
> > > +
> > > +     return bpf_test_sockopt_int(lc->ctx, lc->sk, t, SOL_SOCKET);
> > > +}
> > > +
> > > +static int bpf_test_sockopt(void *ctx, struct sock *sk)
> > > +{
> > > +     struct loop_ctx lc = { .ctx = ctx, .sk = sk, };
> > > +     int n;
> > > +
> > > +     n = bpf_loop(ARRAY_SIZE(sol_socket_tests), bpf_test_socket_sockopt, &lc, 0);
> > > +     if (n != ARRAY_SIZE(sol_socket_tests))
> > > +             return -1;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +SEC("sockops")
> > > +int skops_sockopt(struct bpf_sock_ops *skops)
> > > +{
> > > +     struct bpf_sock *bpf_sk = skops->sk;
> > > +     struct sock *sk;
> > > +
> > > +     if (!bpf_sk)
> > > +             return 1;
> > > +
> > > +     sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk);
> > > +     if (!sk)
> > > +             return 1;
> > > +
> > > +     switch (skops->op) {
> > > +     case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
> > > +             nr_active += !bpf_test_sockopt(skops, sk);
> > > +             break;
> > > +     case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
> > > +             nr_passive += !bpf_test_sockopt(skops, sk);
> > > +             break;
> > > +     case BPF_SOCK_OPS_TS_SCHED_OPT_CB:
> > > +             nr_sched += 1;
> > > +             break;
> > > +     case BPF_SOCK_OPS_TS_SW_OPT_CB:
> > > +             nr_txsw += 1;
> > > +             break;
> > > +     case BPF_SOCK_OPS_TS_ACK_OPT_CB:
> > > +             nr_ack += 1;
> > > +             break;
> >
> > Perhaps demonstrate what to do with the args on the new
> > TS_*_OPT_CB.
> 
> Roger that.
> 
> I would like to know if the current patch is too big to review? Should
> I split it into a few patches? But this series has 14 patches right
> now which could possibly exceed the maximum limit.

For a test patch, this looks fine to me. They often are a longer than
feature patches. But much of it is easy to grasp.