From mboxrd@z Thu Jan 1 00:00:00 1970 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 AF9F61E515 for ; Tue, 29 Apr 2025 11:17:25 +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=1745925445; cv=none; b=KknRYdgwxlxOutbYpKsClBBzg9D2SPQ4bOMIqlBdsm8ktyZcVbXTFD3ccmu1oYZND1NXwMzFmmLGvJZK3YOfx/zSWK1GLKhEBCMYRtUDkqDQFxB6YxgYvnsxqUXmHlYgcldkQw2GAVdi/EwgLxh1wqdrpAbo1Km+R/Nkq1qdtlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745925445; c=relaxed/simple; bh=oaUpCyQX5XLDZBYxX0hoQSAzBfEwYh3JtkC0ewPqaoQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RU5dlYO/mbqtaOHHsO/MMOkO8Hz1l16nDoMNgVSxbDfZ9AWKVXlOdjxq3eLp+qbqjpNhJTC1l4bKBedbatvhNkQqBWHEHyB1qckB2ltx6fzI5v9bD1yLk+YuuDm98s89b5chAKO/lsntfY0xIe2GmrJJet+OeAnlu15ZblN12y8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cx/q19Ho; 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="Cx/q19Ho" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7133BC4CEE3; Tue, 29 Apr 2025 11:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745925445; bh=oaUpCyQX5XLDZBYxX0hoQSAzBfEwYh3JtkC0ewPqaoQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Cx/q19Ho8N1NYdBdmWztWLbjxKiLqHDCOxclwjblP7Sn3TPQsipaa14uvExeEKtuA u8B/ZjM8QIcECve+u+DGPE/kqta0R1npOUh+pc075s9yhfP1mrkNqvfRbWCQJ8yZQy 6IuOBByZG7vWi3zitvDDlfL+6GdDT/9K66ciW3axcy2IqU3OTmOrVPoPedoOstmoKC j9o03wc7rA4IvY02NO4w23qdNrVyZ5iO8bv+TghQCc/OMPNhBo41vMMh0DAFqHlnDB qLOA4Qqq+lVIQ55vBFsB0Wlg2jEHtIcuWO+p+nVl7SgqVrSYAYfTSExpRJOh5TnS2Y HT8OMPqwG7+Mg== Message-ID: Date: Tue, 29 Apr 2025 13:17:22 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp-next v2 1/3] tcp: add tcp_sock_set_maxseg Content-Language: en-GB, fr-BE To: Geliang Tang , mptcp@lists.linux.dev Cc: Geliang Tang References: From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Geliang, On 23/04/2025 11:40, Geliang Tang wrote: > From: Geliang Tang > > Add a helper tcp_sock_set_maxseg() to directly set the TCP_MAXSEG sockopt > from kernel space. Probably clearer to add: This new helper will be used in the following patch. > > Signed-off-by: Geliang Tang > --- > include/linux/tcp.h | 1 + > net/ipv4/tcp.c | 24 +++++++++++++++--------- > 2 files changed, 16 insertions(+), 9 deletions(-) > > diff --git a/include/linux/tcp.h b/include/linux/tcp.h > index 1669d95bb0f9..0041bc0aaee9 100644 > --- a/include/linux/tcp.h > +++ b/include/linux/tcp.h > @@ -623,6 +623,7 @@ void tcp_sock_set_nodelay(struct sock *sk); > void tcp_sock_set_quickack(struct sock *sk, int val); > int tcp_sock_set_syncnt(struct sock *sk, int val); > int tcp_sock_set_user_timeout(struct sock *sk, int val); > +int tcp_sock_set_maxseg(struct sock *sk, int val); > > static inline bool dst_tcp_usec_ts(const struct dst_entry *dst) > { > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 4516f93f6cd2..402f4a9b3fd1 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -3725,6 +3725,20 @@ int tcp_set_window_clamp(struct sock *sk, int val) > return 0; > } > > +int tcp_sock_set_maxseg(struct sock *sk, int val) > +{ > + /* Values greater than interface MTU won't take effect. However > + * at the point when this call is done we typically don't yet > + * know which interface is going to be used > + */ > + if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) > + return -EINVAL; > + > + tcp_sk(sk)->rx_opt.user_mss = val; > + return 0; > +} > +EXPORT_SYMBOL(tcp_sock_set_maxseg); This export is not needed: it is only needed when used from a module. The rest looks OK to me: Acked-by: Matthieu Baerts (NGI0) > + > /* > * Socket option code for TCP. > */ > @@ -3857,15 +3871,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, > > switch (optname) { > case TCP_MAXSEG: > - /* Values greater than interface MTU won't take effect. However > - * at the point when this call is done we typically don't yet > - * know which interface is going to be used > - */ > - if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { > - err = -EINVAL; > - break; > - } > - tp->rx_opt.user_mss = val; > + tcp_sock_set_maxseg(sk, val); > break; > > case TCP_NODELAY: Cheers, Matt -- Sponsored by the NGI0 Core fund.