From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f169.google.com (mail-yw1-f169.google.com [209.85.128.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 301CE2D543A for ; Tue, 12 Aug 2025 00:30:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754958623; cv=none; b=M52QHh2ooUv3xQpjUcMRjcQpDpNlAYUW8MUNqIiZZ8+q8WC3hPwY7+UtnN2DDFT3kN0z2+fvrq3LGlxoPWSEyDo+M6+baVDnizx/HAQyIzL/ii5sMSs+icsDxt5gJa2BV7xFXSA1/avL12a6je3BeYneriktWpQHpERo5yU8B4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754958623; c=relaxed/simple; bh=ZjZ+9XSRdL1NNJWECE4bR3b8xUgqec2jVVaXuyLs4mI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kLCfvMD36eV0TidCIvhtQPF4fxgXgSsTiWWTs+eOWK+5bMnwPbfoyIsgTINdgJw6ausfCem/kpCXvvBUpVwptUgOHHAQUtVvfpaSpiqZ2TLRvC7M40AHB2XJ2RC2mhno6NGT5WeKvFEsOnbN1trvExAustZ4f0qHZUt7GpVKkc4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ioy8qfTS; arc=none smtp.client-ip=209.85.128.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ioy8qfTS" Received: by mail-yw1-f169.google.com with SMTP id 00721157ae682-712be7e034cso50503057b3.0 for ; Mon, 11 Aug 2025 17:30:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1754958621; x=1755563421; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=mCS3+f7av+InabTMNNCT7TnhPsUOD+ix7EtCirdhXZI=; b=ioy8qfTSI7hCaG/DCklA2vP/LIRjf0nO9701IuVbcPaPCOSnqpMM4waNdrzggG3XHv ne6abTSGpsmuqzbK25Q47wpWLksluEpvlKIY2AnZ1TzU/fMWmfCSvWQDx53MQ79nXxMl DwRQHyf0XygZjWJtwtaaiMZudgdHfZv5uwWcC8k63TqAewju1rt6AlhdxnE+yS4S+udZ EqU7G6TrsJuEXtFJ3q6T7Fd24j4kiCHk43tJ1YReGZ/mRNaRv6+SWXlGzWy4Hhye6gBl aYBQDrES1o/ySfqhDQBqwPVuGIZWwIIHdnSC6yRSds6yuWLr4b3UgoJ+8zoaJc+m/k+w s89Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754958621; x=1755563421; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mCS3+f7av+InabTMNNCT7TnhPsUOD+ix7EtCirdhXZI=; b=f+oAbiqtKAjAMJb9d/PeeK99glICjMoLMpCdjHvbzuWcxIXctTtSc9MNrxBf2BtMgq +sejs72Sv/tSf12/U6cw0gjkvO8X7/tM7BhoffLQoyDWoczTxrTlTl7WkoS+6bI2zVYm RHSHzR2nY1o1NfWOG0Aq+sthSwBIIVBGL0wSD1V9JQFWuImrGyGsCAuB3P0l0bEwDTjj R7PcSRDiju/mYTVBEcDoA9Ccv4pCrkKae7KgX5ChNmDrAn43QTBiLw+EFqwadsw2DZ2w 35GWdKjjcoXjCAg2h3AovcCEZfTl/TcvFTxmtj6xAjKBHTykaPECp+t8Egu9MYJTLs02 SUig== X-Forwarded-Encrypted: i=1; AJvYcCUJXE1//YBN9ZyG+Mp3Mssx6oXD6jVJCfTYZ2VLbkfQKIKURGUWJ61EZ1OEjiUyAVl2+fN/0fI=@vger.kernel.org X-Gm-Message-State: AOJu0YzBdIBGGFX0sUk3wgR8E+i+GHLBKGSEaZr0Z1OkmQ8Ws2G/tguf JZo6Itny9MWp4mUz7X1rd4GfmEqwQaQwbfvDnDyGKVEVGeX677PQ9mxW X-Gm-Gg: ASbGncuJBZniRX5+G6pYvEX5YPmjPQlXfvigfEq/qelRF4Y1Yl+GZxfxJaD6q51rtg4 5NcIQFQTBHr13grUm4qpVWwON3m1EpT1TWRjf+KigJ56QAQyMRIlEXNbaujGxN7Zy8UZ3OdgWCK 7E23YHH2VpEZyXAtpVXTmFpTfZm0MtHoTjiVtvgl3ynlX26WEEuzTtYtDukWBHK9opzORkqG+Mb iohMCkGATpfV6MskirISsOjmFnIWqtpQmJM1NgFKl0o//k6/V/wHd1sxpHQA+09irkYMZS+0h9N FKBPQ291uxTBqbsnQDUv+PQiDtOfXGAtFN9fgiBc9xzaqkPRyPL05LeuiZzd2AJAs8+/hHCiVhB uFEaTwRDLk4MV3gH61Lo= X-Google-Smtp-Source: AGHT+IE1YTmfG0SY7DtnD3yC4eqGGsmDbKE65KNGVmilbZ3SesnQrCGWMt4jfZVikVGj/BMdfAiOJg== X-Received: by 2002:a05:690c:7001:b0:71a:4325:a182 with SMTP id 00721157ae682-71c42a5c9c5mr26720457b3.24.1754958621026; Mon, 11 Aug 2025 17:30:21 -0700 (PDT) Received: from localhost ([2a03:2880:25ff:a::]) by smtp.gmail.com with ESMTPSA id 00721157ae682-71c44458bc4sm2086097b3.14.2025.08.11.17.30.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Aug 2025 17:30:20 -0700 (PDT) From: Daniel Zahka To: Donald Hunter , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Jonathan Corbet , Andrew Lunn Cc: Saeed Mahameed , Leon Romanovsky , Tariq Toukan , Boris Pismenny , Kuniyuki Iwashima , Willem de Bruijn , David Ahern , Neal Cardwell , Patrisious Haddad , Raed Salem , Jianbo Liu , Dragos Tatulea , Rahul Rameshbabu , Stanislav Fomichev , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Alexander Lobakin , Kiran Kella , Jacob Keller , netdev@vger.kernel.org Subject: [PATCH net-next v6 09/19] net: psp: update the TCP MSS to reflect PSP packet overhead Date: Mon, 11 Aug 2025 17:29:56 -0700 Message-ID: <20250812003009.2455540-10-daniel.zahka@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20250812003009.2455540-1-daniel.zahka@gmail.com> References: <20250812003009.2455540-1-daniel.zahka@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jakub Kicinski PSP eats 32B of header space. Adjust MSS appropriately. We can either modify tcp_mtu_to_mss() / tcp_mss_to_mtu() or reuse icsk_ext_hdr_len. The former option is more TCP specific and has runtime overhead. The latter is a bit of a hack as PSP is not an ext_hdr. If one squints hard enough, UDP encap is just a more practical version of IPv6 exthdr, so go with the latter. Happy to change. Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Signed-off-by: Daniel Zahka --- Notes: v6: - make psp_sk_overhead() add 40B of encapsulation overhead. v1: - https://lore.kernel.org/netdev/20240510030435.120935-8-kuba@kernel.org/ include/net/psp/functions.h | 14 ++++++++++++++ include/net/psp/types.h | 3 +++ net/ipv4/tcp_ipv4.c | 4 ++-- net/ipv6/ipv6_sockglue.c | 6 +++++- net/ipv6/tcp_ipv6.c | 6 +++--- net/psp/psp_sock.c | 5 +++++ 6 files changed, 32 insertions(+), 6 deletions(-) diff --git a/include/net/psp/functions.h b/include/net/psp/functions.h index bf703dcf353f..958c50dad34d 100644 --- a/include/net/psp/functions.h +++ b/include/net/psp/functions.h @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -139,6 +140,14 @@ static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb) return psp_sk_get_assoc_rcu(skb->sk); } + +static inline unsigned int psp_sk_overhead(const struct sock *sk) +{ + int psp_encap = sizeof(struct udphdr) + PSP_HDR_SIZE + PSP_TRL_SIZE; + bool has_psp = rcu_access_pointer(sk->psp_assoc); + + return has_psp ? psp_encap : 0; +} #else static inline void psp_sk_assoc_free(struct sock *sk) { } static inline void @@ -178,6 +187,11 @@ static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb) { return NULL; } + +static inline unsigned int psp_sk_overhead(const struct sock *sk) +{ + return 0; +} #endif static inline unsigned long diff --git a/include/net/psp/types.h b/include/net/psp/types.h index b0e32e7165a3..f93ad0e6c04f 100644 --- a/include/net/psp/types.h +++ b/include/net/psp/types.h @@ -93,6 +93,9 @@ struct psp_dev_caps { #define PSP_MAX_KEY 32 +#define PSP_HDR_SIZE 16 /* We don't support optional fields, yet */ +#define PSP_TRL_SIZE 16 /* AES-GCM/GMAC trailer size */ + struct psp_skb_ext { __be32 spi; u16 dev_id; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 35e2a1ce87b8..3c3e8760f89b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -293,9 +293,9 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_dport = usin->sin_port; sk_daddr_set(sk, daddr); - inet_csk(sk)->icsk_ext_hdr_len = 0; + inet_csk(sk)->icsk_ext_hdr_len = psp_sk_overhead(sk); if (inet_opt) - inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; + inet_csk(sk)->icsk_ext_hdr_len += inet_opt->opt.optlen; tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index e66ec623972e..a61e742794f9 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -49,6 +49,7 @@ #include #include #include +#include #include @@ -107,7 +108,10 @@ struct ipv6_txoptions *ipv6_update_options(struct sock *sk, !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) && inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) { struct inet_connection_sock *icsk = inet_csk(sk); - icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen; + + icsk->icsk_ext_hdr_len = + psp_sk_overhead(sk) + + opt->opt_flen + opt->opt_nflen; icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie); } } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 6a89edda31c7..adf83ec25b66 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -302,10 +302,10 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, sk->sk_gso_type = SKB_GSO_TCPV6; ip6_dst_store(sk, dst, NULL, NULL); - icsk->icsk_ext_hdr_len = 0; + icsk->icsk_ext_hdr_len = psp_sk_overhead(sk); if (opt) - icsk->icsk_ext_hdr_len = opt->opt_flen + - opt->opt_nflen; + icsk->icsk_ext_hdr_len += opt->opt_flen + + opt->opt_nflen; tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); diff --git a/net/psp/psp_sock.c b/net/psp/psp_sock.c index 9b761d186e80..66abf160e16c 100644 --- a/net/psp/psp_sock.c +++ b/net/psp/psp_sock.c @@ -180,6 +180,7 @@ int psp_sock_assoc_set_tx(struct sock *sk, struct psp_dev *psd, u32 version, struct psp_key_parsed *key, struct netlink_ext_ack *extack) { + struct inet_connection_sock *icsk; struct psp_assoc *pas, *dummy; int err; @@ -236,6 +237,10 @@ int psp_sock_assoc_set_tx(struct sock *sk, struct psp_dev *psd, tcp_write_collapse_fence(sk); pas->upgrade_seq = tcp_sk(sk)->rcv_nxt; + icsk = inet_csk(sk); + icsk->icsk_ext_hdr_len += psp_sk_overhead(sk); + icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie); + exit_free_dummy: kfree(dummy); exit_unlock: -- 2.47.3