From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C6D71E521E; Fri, 16 May 2025 22:48:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747435703; cv=none; b=DDR5oM2xjwZ25ppmv7HSpYFfa8Ref45bAARTtYJTAI27yqFiZgLNqF0uSJi38k+42B5Bha6FffUbk9drXjxARxLvi0l1kHqOOpzoQmiuDTZCsyAzqb45nuqfgwtCiInLqm8kNHOWWcEIrpYiuptSwA7BDGLWQPt0C/D1aRgQ+lo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747435703; c=relaxed/simple; bh=yROJcUJUluTmvuWqH6sVnkz8MLzn1opuwX66hhGfvZ0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DzBb2o5V6gc66j/R96BihjMBbMkzw1Vz16MhDmKA9m6uv5xj79JGNWHyH2b5qlxho9chYMRTXienmrCctCT7Sq8nriHfceK/Uk6+AYxAqf5WCX4n93eKSpJyQU45VQebKL6iXlCOvDvMJ4NNB82NNMRACRJlytfby8EJA5yz4XE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=KNwAVyDa; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="KNwAVyDa" Message-ID: <98348a02-9f8b-4648-8abe-e6b802ae9a63@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1747435698; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/Kn3cw/i9KsqJM9UPHYhp9YQGkmyJhf1bZCm6cblBTo=; b=KNwAVyDaRahLcjoMm8xwTyaHlm9MPcGMHLoDln8yHLSBIqxlTtzfZwnuujgT4GATrhtffh RhfJhB/egVkLNs0LLLUmk/SbOYwe/w0CoxeA7ky0R4gG5jb6K4tAKB4MtJp8AZ8lVeiSpg 09De2x4kD27q72nQDt3G7AS10AHvtxE= Date: Fri, 16 May 2025 15:48:09 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next/net v3 4/5] selftests/bpf: Add mptcp_subflow bpf_iter subtest To: "Matthieu Baerts (NGI0)" Cc: mptcp@lists.linux.dev, Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20250320-bpf-next-net-mptcp-bpf_iter-subflows-v3-0-9abd22c2a7fd@kernel.org> <20250320-bpf-next-net-mptcp-bpf_iter-subflows-v3-4-9abd22c2a7fd@kernel.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau Content-Language: en-US In-Reply-To: <20250320-bpf-next-net-mptcp-bpf_iter-subflows-v3-4-9abd22c2a7fd@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 3/20/25 10:48 AM, Matthieu Baerts (NGI0) wrote: > From: Geliang Tang > > This patch adds a "cgroup/getsockopt" program "iters_subflow" to test the > newly added mptcp_subflow bpf_iter. > > Export mptcp_subflow helpers bpf_iter_mptcp_subflow_new/_next/_destroy > and other helpers into bpf_experimental.h. > > Use bpf_for_each() to walk the subflow list of an msk. From there, > future MPTCP-specific kfunc can be called in the loop. Because they are > not there yet, this test doesn't do anything very "useful" for the > moment, but it focuses on validating the 'bpf_iter' part and the basic > MPTCP kfunc. That's why it simply adds all subflow ids to local variable > local_ids to make sure all subflows have been seen, then invoke > mptcp_subflow_tcp_sock() in the loop to pick the subflow context. > > Out of the loop, use bpf_mptcp_subflow_ctx() to get the subflow context > of the picked subflow context and do some verifications. Finally, assign > local_ids to global variable ids so that the application can obtain this > value. > > A related subtest called test_iters_subflow is added to load and verify > the newly added mptcp_subflow type bpf_iter example in test_mptcp. The > endpoint_init() helper is used to add 3 new subflow endpoints. Then one > byte of message is sent to trigger the creation of new subflows. > getsockopt() is invoked once the subflows have been created to trigger > the "cgroup/getsockopt" test program "iters_subflow". skel->bss->ids is > then checked to make sure it equals 10, the sum of each subflow ID: we > should have 4 subflows: 1 + 2 + 3 + 4 = 10. If that's the case, the > bpf_iter loop did the job as expected. > > Signed-off-by: Geliang Tang > Reviewed-by: Matthieu Baerts (NGI0) > Signed-off-by: Matthieu Baerts (NGI0) > --- > Notes: > - v2: > - explicit sk protocol checks are no longer needed, implicitly done > in bpf_skc_to_mptcp_sock(). > - use bpf_skc_to_mptcp_sock() instead of bpf_mptcp_sk(), and > mptcp_subflow_tcp_sock() instead of bpf_mptcp_subflow_tcp_sock(). > - bpf_mptcp_subflow_ctx() can now return NULL. > - v3: > - Use bpf_core_cast to get the msk instead of bpf_skc_to_mptcp_sock. > - Drop bpf_mptcp_sock_acquire and bpf_mptcp_sock_release (Martin). > - Adapt the commit message accordingly. > - Remove no longer needed export to the mptcp_bpf.h file and adapt > bpf_iter_mptcp_subflow_new parameter in bpf_experimental.h. > --- > tools/testing/selftests/bpf/bpf_experimental.h | 8 +++ > tools/testing/selftests/bpf/prog_tests/mptcp.c | 73 ++++++++++++++++++++++ > tools/testing/selftests/bpf/progs/mptcp_bpf.h | 4 ++ > .../testing/selftests/bpf/progs/mptcp_bpf_iters.c | 59 +++++++++++++++++ > 4 files changed, 144 insertions(+) > > diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h > index cd8ecd39c3f3c68d40c6e3e1465b42ed66537027..6a96c56f0725a86ab6e83675ca0e474c3d668b10 100644 > --- a/tools/testing/selftests/bpf/bpf_experimental.h > +++ b/tools/testing/selftests/bpf/bpf_experimental.h > @@ -575,6 +575,14 @@ extern int bpf_iter_css_new(struct bpf_iter_css *it, > extern struct cgroup_subsys_state *bpf_iter_css_next(struct bpf_iter_css *it) __weak __ksym; > extern void bpf_iter_css_destroy(struct bpf_iter_css *it) __weak __ksym; > > +struct bpf_iter_mptcp_subflow; > +extern int bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *it, > + struct sock *sk) __weak __ksym; > +extern struct mptcp_subflow_context * > +bpf_iter_mptcp_subflow_next(struct bpf_iter_mptcp_subflow *it) __weak __ksym; > +extern void > +bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it) __weak __ksym; > + > extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym; > extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym; > extern int bpf_wq_set_callback_impl(struct bpf_wq *wq, > diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c > index 85f3d4119802a85c86cde7b74a0b857252bad8b8..f37574b5ef68d8f32f8002df317869dfdf1d4b2d 100644 > --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c > +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c > @@ -11,6 +11,7 @@ > #include "mptcp_sock.skel.h" > #include "mptcpify.skel.h" > #include "mptcp_subflow.skel.h" > +#include "mptcp_bpf_iters.skel.h" > > #define NS_TEST "mptcp_ns" > #define ADDR_1 "10.0.1.1" > @@ -33,6 +34,9 @@ > #ifndef MPTCP_INFO > #define MPTCP_INFO 1 > #endif > +#ifndef TCP_IS_MPTCP > +#define TCP_IS_MPTCP 43 /* Is MPTCP being used? */ > +#endif > #ifndef MPTCP_INFO_FLAG_FALLBACK > #define MPTCP_INFO_FLAG_FALLBACK _BITUL(0) > #endif > @@ -480,6 +484,73 @@ static void test_subflow(void) > close(cgroup_fd); > } > > +static void run_iters_subflow(void) > +{ > + int server_fd, client_fd; > + int is_mptcp, err; > + socklen_t len; > + > + server_fd = start_mptcp_server(AF_INET, ADDR_1, PORT_1, 0); > + if (!ASSERT_OK_FD(server_fd, "start_mptcp_server")) > + return; > + > + client_fd = connect_to_fd(server_fd, 0); > + if (!ASSERT_OK_FD(client_fd, "connect_to_fd")) > + goto close_server; > + > + send_byte(client_fd); > + wait_for_new_subflows(client_fd); > + > + len = sizeof(is_mptcp); > + /* mainly to trigger the BPF program */ > + err = getsockopt(client_fd, SOL_TCP, TCP_IS_MPTCP, &is_mptcp, &len); > + if (ASSERT_OK(err, "getsockopt(client_fd, TCP_IS_MPTCP)")) > + ASSERT_EQ(is_mptcp, 1, "is_mptcp"); > + > + close(client_fd); > +close_server: > + close(server_fd); > +} > + > +static void test_iters_subflow(void) > +{ > + struct mptcp_bpf_iters *skel; > + struct netns_obj *netns; > + int cgroup_fd; > + > + cgroup_fd = test__join_cgroup("/iters_subflow"); > + if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup: iters_subflow")) > + return; > + > + skel = mptcp_bpf_iters__open_and_load(); > + if (!ASSERT_OK_PTR(skel, "skel_open_load: iters_subflow")) > + goto close_cgroup; > + > + skel->links.iters_subflow = bpf_program__attach_cgroup(skel->progs.iters_subflow, > + cgroup_fd); > + if (!ASSERT_OK_PTR(skel->links.iters_subflow, "attach getsockopt")) > + goto skel_destroy; > + > + netns = netns_new(NS_TEST, true); > + if (!ASSERT_OK_PTR(netns, "netns_new: iters_subflow")) > + goto skel_destroy; > + > + if (endpoint_init("subflow", 4) < 0) > + goto close_netns; > + > + run_iters_subflow(); > + > + /* 1 + 2 + 3 + 4 = 10 */ > + ASSERT_EQ(skel->bss->ids, 10, "subflow ids"); > + > +close_netns: > + netns_free(netns); > +skel_destroy: > + mptcp_bpf_iters__destroy(skel); > +close_cgroup: > + close(cgroup_fd); > +} > + > void test_mptcp(void) > { > if (test__start_subtest("base")) > @@ -488,4 +559,6 @@ void test_mptcp(void) > test_mptcpify(); > if (test__start_subtest("subflow")) > test_subflow(); > + if (test__start_subtest("iters_subflow")) > + test_iters_subflow(); > } > diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/selftests/bpf/progs/mptcp_bpf.h > index 3b188ccdcc4041acb4f7ed38ae8ddf5a7305466a..aa897074de6f377e8cddc859c3b2dc3751f14381 100644 > --- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h > +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h > @@ -39,4 +39,8 @@ mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) > return subflow->tcp_sock; > } > > +/* ksym */ > +extern struct mptcp_subflow_context * > +bpf_mptcp_subflow_ctx(const struct sock *sk) __ksym; > + > #endif > diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c > new file mode 100644 > index 0000000000000000000000000000000000000000..a1d8f9b20259a9cbdc46d58e0d18157564fa5acd > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_iters.c > @@ -0,0 +1,59 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2024, Kylin Software */ > + > +/* vmlinux.h, bpf_helpers.h and other 'define' */ > +#include "bpf_tracing_net.h" > +#include "mptcp_bpf.h" > + > +char _license[] SEC("license") = "GPL"; > +int ids; > + > +#ifndef TCP_IS_MPTCP > +#define TCP_IS_MPTCP 43 /* Is MPTCP being used? */ > +#endif > + > +SEC("cgroup/getsockopt") > +int iters_subflow(struct bpf_sockopt *ctx) > +{ > + struct mptcp_subflow_context *subflow; > + struct bpf_sock *sk = ctx->sk; > + struct sock *ssk = NULL; > + struct mptcp_sock *msk; > + int local_ids = 0; > + > + if (ctx->level != SOL_TCP || ctx->optname != TCP_IS_MPTCP) > + return 1; > + > + msk = bpf_core_cast(sk, struct mptcp_sock); > + if (!msk || msk->pm.server_side || !msk->pm.subflows) > + return 1; > + > + bpf_for_each(mptcp_subflow, subflow, (struct sock *)sk) { > + /* Here MPTCP-specific packet scheduler kfunc can be called: > + * this test is not doing anything really useful, only to Lets fold the bpf_iter_mptcp_subflow addition into the future "mptcp_sched_ops" set (the github link that you mentioned in patch 2). Post them as one set to have a more practical example. > + * verify the iteration works. > + */ > + > + local_ids += subflow->subflow_id; > + > + /* only to check the following helper works */ > + ssk = mptcp_subflow_tcp_sock(subflow); > + } > + > + if (!ssk) > + goto out; > + > + /* assert: if not OK, something wrong on the kernel side */ > + if (ssk->sk_dport != ((struct sock *)msk)->sk_dport) > + goto out; > + > + /* only to check the following kfunc works */ > + subflow = bpf_mptcp_subflow_ctx(ssk); bpf_core_cast should be as good instead of adding a new bpf_mptcp_subflow_ctx() kfunc, so patch 1 should not be needed. > + if (!subflow || subflow->token != msk->token) > + goto out; > + > + ids = local_ids; > + > +out: > + return 1; > +} >