From nobody Mon Nov 25 08:14:23 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D65031A291 for ; Thu, 5 Sep 2024 02:27:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725503233; cv=none; b=GF2fngMKQOO++KGb29Mcn1HoT1GQUdZL+3dQKpK53IG5NbPbKpHyOoJskIZcSwgtBQfYF48vYyDG3YnFWH8mihB1nP05jb3KdlJHg51Ma/VLIMhO2p0UMEozsEbr9jPIWc422vlZVqftsMENXY9cMk9yEUzLM3Szh1AHZZQnFMw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725503233; c=relaxed/simple; bh=kF63BG1kfd4wi0jmp68mCE8dz2DQJPjq1voABtLVq38=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O/zBX1jko5ul7zs51+uaXNInd6QRn62la14CXDmBdqQCgu9Oh7SOBNk/9hV976it4cKMjQiAcmFOF/y7NDGxG44HwjY7edD0herg0PAtvvfv1IBTgqBuGUeoYnqqJaLl43DjQbkAloWqsft8j1QUagOfDAO3lZH3zFO+9GCjfLo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OFZwcGMq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OFZwcGMq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EECBAC4CEC6; Thu, 5 Sep 2024 02:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725503233; bh=kF63BG1kfd4wi0jmp68mCE8dz2DQJPjq1voABtLVq38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OFZwcGMqYS88Ip1gJFKXGJD9NVxfhcBNfKJYimtMpNSlTbAVScM6X+xaEjZZ2W3KB X4bFTbK3kujV4XTnoK3e20+TIMIOg7tVvL9LZP0ZlDxnV/xwZkQ9plmNfaz1LK2WjC prav5hUIOuJikxgL8vqopZEbnrx+BcpFqilea2VMJE8iaZsVY5rp9qaT9bBdsaNYm7 uPJakt8zN0J09c5OaOs3vOGtgGsEHT14iCOrDBsDGWjAxZkCMVPf6KL3zzYxQCH9Sz j3MF5RkWTAt4ii7vMHO3fohRp/oGJE/ceS8hT9Y9SBDYMSCdNob6c3FimYBbnWMnD5 2CYaeqKvEnyzw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , Martin KaFai Lau Subject: [PATCH mptcp-next v8 2/4] selftests/bpf: Add getsockopt to inspect mptcp subflow Date: Thu, 5 Sep 2024 10:26:57 +0800 Message-ID: <44ef8e395feddc3fe83c1ea043c3bc07f98c1042.1725502822.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang This patch adds a "cgroup/getsockopt" way to inspect the subflows of a mptcp socket. mptcp_for_each_stubflow() and other helpers related to list_dentry are added into progs/mptcp_bpf.h. Add an extra "cgroup/getsockopt" prog to walk the msk->conn_list and use bpf_core_cast to cast a pointer to tcp_sock for readonly. It will allow to inspect all the fields in a tcp_sock. Suggested-by: Martin KaFai Lau Signed-off-by: Geliang Tang --- tools/testing/selftests/bpf/progs/mptcp_bpf.h | 27 ++++++++ .../selftests/bpf/progs/mptcp_subflow.c | 69 +++++++++++++++++++ 2 files changed, 96 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf.h b/tools/testing/= selftests/bpf/progs/mptcp_bpf.h index 782f36ed027e..92d5deed0214 100644 --- a/tools/testing/selftests/bpf/progs/mptcp_bpf.h +++ b/tools/testing/selftests/bpf/progs/mptcp_bpf.h @@ -4,9 +4,36 @@ =20 #include #include +#include "bpf_experimental.h" =20 #define MPTCP_SUBFLOWS_MAX 8 =20 +static inline int list_is_head(const struct list_head *list, + const struct list_head *head) +{ + return list =3D=3D head; +} + +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +#define list_next_entry(pos, member) \ + list_entry((pos)->member.next, typeof(*(pos)), member) + +#define list_entry_is_head(pos, head, member) \ + list_is_head(&pos->member, (head)) + +#define list_for_each_entry(pos, head, member) \ + for (pos =3D list_first_entry(head, typeof(*pos), member); \ + cond_break, !list_entry_is_head(pos, head, member); \ + pos =3D list_next_entry(pos, member)) + +#define mptcp_for_each_subflow(__msk, __subflow) \ + list_for_each_entry(__subflow, &((__msk)->conn_list), node) + extern void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subf= low, bool scheduled) __ksym; =20 diff --git a/tools/testing/selftests/bpf/progs/mptcp_subflow.c b/tools/test= ing/selftests/bpf/progs/mptcp_subflow.c index 2e28f4a215b5..70302477e326 100644 --- a/tools/testing/selftests/bpf/progs/mptcp_subflow.c +++ b/tools/testing/selftests/bpf/progs/mptcp_subflow.c @@ -4,10 +4,12 @@ =20 /* vmlinux.h, bpf_helpers.h and other 'define' */ #include "bpf_tracing_net.h" +#include "mptcp_bpf.h" =20 char _license[] SEC("license") =3D "GPL"; =20 char cc[TCP_CA_NAME_MAX] =3D "reno"; +int pid; =20 /* Associate a subflow counter to each token */ struct { @@ -57,3 +59,70 @@ int mptcp_subflow(struct bpf_sock_ops *skops) =20 return 1; } + +static int _check_getsockopt_subflow_mark(struct mptcp_sock *msk, struct b= pf_sockopt *ctx) +{ + struct mptcp_subflow_context *subflow; + int i =3D 0; + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk; + + ssk =3D mptcp_subflow_tcp_sock(bpf_core_cast(subflow, + struct mptcp_subflow_context)); + + if (ssk->sk_mark !=3D ++i) { + ctx->retval =3D -2; + break; + } + } + + return 1; +} + +static int _check_getsockopt_subflow_cc(struct mptcp_sock *msk, struct bpf= _sockopt *ctx) +{ + struct mptcp_subflow_context *subflow; + + mptcp_for_each_subflow(msk, subflow) { + struct inet_connection_sock *icsk; + struct sock *ssk; + + ssk =3D mptcp_subflow_tcp_sock(bpf_core_cast(subflow, + struct mptcp_subflow_context)); + icsk =3D bpf_core_cast(ssk, struct inet_connection_sock); + + if (ssk->sk_mark =3D=3D 2 && + __builtin_memcmp(icsk->icsk_ca_ops->name, cc, TCP_CA_NAME_MAX)) { + ctx->retval =3D -2; + break; + } + } + + return 1; +} + +SEC("cgroup/getsockopt") +int _getsockopt_subflow(struct bpf_sockopt *ctx) +{ + struct bpf_sock *sk =3D ctx->sk; + struct mptcp_sock *msk; + + if (bpf_get_current_pid_tgid() >> 32 !=3D pid) + return 1; + + if (!sk || sk->protocol !=3D IPPROTO_MPTCP || + (!(ctx->level =3D=3D SOL_SOCKET && ctx->optname =3D=3D SO_MARK) && + !(ctx->level =3D=3D SOL_TCP && ctx->optname =3D=3D TCP_CONGESTION))) + return 1; + + msk =3D bpf_core_cast(sk, struct mptcp_sock); + if (msk->pm.subflows !=3D 1) { + ctx->retval =3D -1; + return 1; + } + + if (ctx->optname =3D=3D SO_MARK) + return _check_getsockopt_subflow_mark(msk, ctx); + return _check_getsockopt_subflow_cc(msk, ctx); +} --=20 2.43.0