From 950410d4748cc1e108ae8295d707462ba1d0c206 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Tue, 25 Feb 2025 05:52:38 +0000 Subject: [PATCH] bpf: Extend bpf_skc_to_mptcp_sock to MPTCP sock Currently, bpf_skc_to_mptcp_sock() can only be used with sockets that are MPTCP subflows: TCP sockets with tp->is_mptcp, created by the kernel from an MPTCP socket (IPPROTO_MPTCP). Typically used with BPF sock_ops operators. Here, this helper is extended to support MPTCP sockets, the ones created by the userspace (IPPROTO_MPTCP). This is useful for BPF hooks involving these sockets, e.g. [gs]etsocktopt. bpf_skc_to_mptcp_sock() uses bpf_mptcp_sock_from_subflow(). The former suggests any MPTCP type/subtype can be used, but the latter only accepts subflow ones. So bpf_mptcp_sock_from_subflow is modified here to support MPTCP socket, and renamed to avoid confusions. Signed-off-by: Geliang Tang Reviewed-by: Matthieu Baerts (NGI0) --- include/net/mptcp.h | 4 ++-- net/core/filter.c | 2 +- net/mptcp/bpf.c | 10 ++++++++-- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 2c85ca92bb1c3..72d6e6597add8 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -323,9 +323,9 @@ static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } #endif #if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) -struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); +struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk); #else -static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } +static inline struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk) { return NULL; } #endif #if !IS_ENABLED(CONFIG_MPTCP) diff --git a/net/core/filter.c b/net/core/filter.c index a0867c5b32b37..3a910ada9bbce 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -11884,7 +11884,7 @@ const struct bpf_func_proto bpf_skc_to_unix_sock_proto = { BPF_CALL_1(bpf_skc_to_mptcp_sock, struct sock *, sk) { BTF_TYPE_EMIT(struct mptcp_sock); - return (unsigned long)bpf_mptcp_sock_from_subflow(sk); + return (unsigned long)bpf_mptcp_sock_from_sock(sk); } const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto = { diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 8a16672b94e23..988b22a06331a 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -12,9 +12,15 @@ #include #include "protocol.h" -struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) +struct mptcp_sock *bpf_mptcp_sock_from_sock(struct sock *sk) { - if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk)) + if (unlikely(!sk || !sk_fullsock(sk))) + return NULL; + + if (sk->sk_protocol == IPPROTO_MPTCP) + return mptcp_sk(sk); + + if (sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk)) return mptcp_sk(mptcp_subflow_ctx(sk)->conn); return NULL;