From 3fff88186f047627bb128d65155f42517f8e448f Mon Sep 17 00:00:00 2001 From: Matthieu Baerts Date: Fri, 9 Dec 2022 16:28:08 -0800 Subject: [PATCH] mptcp: remove MPTCP 'ifdef' in TCP SYN cookies To ease the maintenance, it is often recommended to avoid having #ifdef preprocessor conditions. Here the section related to CONFIG_MPTCP was quite short but the next commit needs to add more code around. It is then cleaner to move specific MPTCP code to functions located in net/mptcp directory. Now that mptcp_subflow_request_sock_ops structure can be static, it can also be marked as "read only after init". Suggested-by: Paolo Abeni Reviewed-by: Mat Martineau Cc: stable@vger.kernel.org Signed-off-by: Matthieu Baerts Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- include/net/mptcp.h | 12 ++++++++++-- net/ipv4/syncookies.c | 7 +++---- net/mptcp/subflow.c | 12 +++++++++++- 3 files changed, 24 insertions(+), 7 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 412479e..3c5c686 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -97,8 +97,6 @@ struct mptcp_out_options { }; #ifdef CONFIG_MPTCP -extern struct request_sock_ops mptcp_subflow_request_sock_ops; - void mptcp_init(void); static inline bool sk_is_mptcp(const struct sock *sk) @@ -188,6 +186,9 @@ void mptcp_seq_show(struct seq_file *seq); int mptcp_subflow_init_cookie_req(struct request_sock *req, const struct sock *sk_listener, struct sk_buff *skb); +struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, + struct sock *sk_listener, + bool attach_listener); __be32 mptcp_get_reset_option(const struct sk_buff *skb); @@ -274,6 +275,13 @@ static inline int mptcp_subflow_init_cookie_req(struct request_sock *req, return 0; /* TCP fallback */ } +static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, + struct sock *sk_listener, + bool attach_listener) +{ + return NULL; +} + static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); } #endif /* CONFIG_MPTCP */ diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 942d2df..26fb97d 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -288,12 +288,11 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, struct tcp_request_sock *treq; struct request_sock *req; -#ifdef CONFIG_MPTCP if (sk_is_mptcp(sk)) - ops = &mptcp_subflow_request_sock_ops; -#endif + req = mptcp_subflow_reqsk_alloc(ops, sk, false); + else + req = inet_reqsk_alloc(ops, sk, false); - req = inet_reqsk_alloc(ops, sk, false); if (!req) return NULL; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 2159b5f..3f670f2 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -529,7 +529,7 @@ static int subflow_v6_rebuild_header(struct sock *sk) } #endif -struct request_sock_ops mptcp_subflow_request_sock_ops; +static struct request_sock_ops mptcp_subflow_request_sock_ops __ro_after_init; static struct tcp_request_sock_ops subflow_request_sock_ipv4_ops __ro_after_init; static int subflow_v4_conn_request(struct sock *sk, struct sk_buff *skb) @@ -582,6 +582,16 @@ drop: } #endif +struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops, + struct sock *sk_listener, + bool attach_listener) +{ + ops = &mptcp_subflow_request_sock_ops; + + return inet_reqsk_alloc(ops, sk_listener, attach_listener); +} +EXPORT_SYMBOL(mptcp_subflow_reqsk_alloc); + /* validate hmac received in third ACK */ static bool subflow_hmac_valid(const struct request_sock *req, const struct mptcp_options_received *mp_opt) -- 2.7.4