From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTP id 8DC315A004E for ; Tue, 11 Jun 2024 13:42:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718106145; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=qsEKX8EGXY9p48kq2VLU7EpmdtjdosPqzswDAklsjDE=; b=bYSu2MjCjlxWrhV2MVdiuHaqTVFu4S8Z916CYCwT3Qf5WAeFChmvMtmUhKF5uQzdFAsph0 EED2jo9aGajUZKNivIsv0JStDcozdNBga2I9zhy6KHt1f8UxBfeDaYHaK8o1da/vxRWvPE vxBQDoy/3m6+N7VunFZF9SIvtB41nfY= Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-82-hwPXQVvtMGOXgc7urbEIqg-1; Tue, 11 Jun 2024 07:42:23 -0400 X-MC-Unique: hwPXQVvtMGOXgc7urbEIqg-1 Received: by mail-qk1-f198.google.com with SMTP id af79cd13be357-797a7e8473dso176077385a.0 for ; Tue, 11 Jun 2024 04:42:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718106143; x=1718710943; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=qsEKX8EGXY9p48kq2VLU7EpmdtjdosPqzswDAklsjDE=; b=k5vgmjcwHtpdXHXac/heFvm5xr8rVLFJ/4hA44Y9iqVvzenmWmMFYz8BDe+Q85wRcE lUFWhNOAaOCVr7rdyAw6VUDjbMAmeNmwFY2VX2779p3yR8ALLUI8XBcsIzSmVXEYdjE6 5b3/FzyHw60o/ZhA+6NPQiYXlnYTwqTrRY4mqG8LBQLdfB7bYrW9S4w+D9AWrXgemDjm HEyMR9eJido2HLgjtF7EE7MCacRazo0ciXnjfjEHpmGhrqx5ZWZEaWxb7S6/TT3hL/oe BGFcZxy8N7PM7XQgXK4DCeexZBKaHP+SIGVZ+QXjExod6tP0Hh8YbTzMLqqOlJx8JGzN Ge7g== X-Gm-Message-State: AOJu0YyOlA7nTDRjc80TM4EMo+pp+su0eaoejidDDgbFRHKZckoiYtOY KaD1JNQn943qtOwYr/uaF/0293sIBgji3+1ODIk8fnjRph+99P2apd5uP+TtsR3nruF5ZSxsHMn /mn43nKlnKJCxc2CGcPNuuDPC1ngatohMjxwIU8X7slVpCOOOLOFSg3c6Sw== X-Received: by 2002:a05:620a:6207:b0:792:ea76:133c with SMTP id af79cd13be357-7953c319b96mr1079388485a.24.1718106143262; Tue, 11 Jun 2024 04:42:23 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEMEX6h+rUT6xKooRmhR41FnfdPr6vhGnSgrVLlKpPTaq/X8iO2bzO5+i+nHl+lGQ0w6LpOZw== X-Received: by 2002:a05:620a:6207:b0:792:ea76:133c with SMTP id af79cd13be357-7953c319b96mr1079387185a.24.1718106142752; Tue, 11 Jun 2024 04:42:22 -0700 (PDT) Received: from ?IPV6:2a01:e0a:e10:ef90:8e19:3414:44f0:befd? ([2a01:e0a:e10:ef90:8e19:3414:44f0:befd]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7954850e6aesm380890885a.55.2024.06.11.04.42.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 Jun 2024 04:42:22 -0700 (PDT) Message-ID: Date: Tue, 11 Jun 2024 13:42:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 1/8] tcp: extract buffer management from tcp_send_flag() To: David Gibson References: <20240605152129.1641658-1-lvivier@redhat.com> <20240605152129.1641658-2-lvivier@redhat.com> From: Laurent Vivier Autocrypt: addr=lvivier@redhat.com; keydata= xsFNBFYFJhkBEAC2me7w2+RizYOKZM+vZCx69GTewOwqzHrrHSG07MUAxJ6AY29/+HYf6EY2 WoeuLWDmXE7A3oJoIsRecD6BXHTb0OYS20lS608anr3B0xn5g0BX7es9Mw+hV/pL+63EOCVm SUVTEQwbGQN62guOKnJJJfphbbv82glIC/Ei4Ky8BwZkUuXd7d5NFJKC9/GDrbWdj75cDNQx UZ9XXbXEKY9MHX83Uy7JFoiFDMOVHn55HnncflUncO0zDzY7CxFeQFwYRbsCXOUL9yBtqLer Ky8/yjBskIlNrp0uQSt9LMoMsdSjYLYhvk1StsNPg74+s4u0Q6z45+l8RAsgLw5OLtTa+ePM JyS7OIGNYxAX6eZk1+91a6tnqfyPcMbduxyBaYXn94HUG162BeuyBkbNoIDkB7pCByed1A7q q9/FbuTDwgVGVLYthYSfTtN0Y60OgNkWCMtFwKxRaXt1WFA5ceqinN/XkgA+vf2Ch72zBkJL RBIhfOPFv5f2Hkkj0MvsUXpOWaOjatiu0fpPo6Hw14UEpywke1zN4NKubApQOlNKZZC4hu6/ 8pv2t4HRi7s0K88jQYBRPObjrN5+owtI51xMaYzvPitHQ2053LmgsOdN9EKOqZeHAYG2SmRW LOxYWKX14YkZI5j/TXfKlTpwSMvXho+efN4kgFvFmP6WT+tPnwARAQABzSNMYXVyZW50IFZp dmllciA8bHZpdmllckByZWRoYXQuY29tPsLBeAQTAQIAIgUCVgVQgAIbAwYLCQgHAwIGFQgC CQoLBBYCAwECHgECF4AACgkQ8ww4vT8vvjwpgg//fSGy0Rs/t8cPFuzoY1cex4limJQfReLr SJXCANg9NOWy/bFK5wunj+h/RCFxIFhZcyXveurkBwYikDPUrBoBRoOJY/BHK0iZo7/WQkur 6H5losVZtrotmKOGnP/lJYZ3H6OWvXzdz8LL5hb3TvGOP68K8Bn8UsIaZJoeiKhaNR0sOJyI YYbgFQPWMHfVwHD/U+/gqRhD7apVysxv5by/pKDln1I5v0cRRH6hd8M8oXgKhF2+rAOL7gvh jEHSSWKUlMjC7YwwjSZmUkL+TQyE18e2XBk85X8Da3FznrLiHZFHQ/NzETYxRjnOzD7/kOVy gKD/o7asyWQVU65mh/ECrtjfhtCBSYmIIVkopoLaVJ/kEbVJQegT2P6NgERC/31kmTF69vn8 uQyW11Hk8tyubicByL3/XVBrq4jZdJW3cePNJbTNaT0d/bjMg5zCWHbMErUib2Nellnbg6bc 2HLDe0NLVPuRZhHUHM9hO/JNnHfvgiRQDh6loNOUnm9Iw2YiVgZNnT4soUehMZ7au8PwSl4I KYE4ulJ8RRiydN7fES3IZWmOPlyskp1QMQBD/w16o+lEtY6HSFEzsK3o0vuBRBVp2WKnssVH qeeV01ZHw0bvWKjxVNOksP98eJfWLfV9l9e7s6TaAeySKRRubtJ+21PRuYAxKsaueBfUE7ZT 7zfOwU0EVgUmGQEQALxSQRbl/QOnmssVDxWhHM5TGxl7oLNJms2zmBpcmlrIsn8nNz0rRyxT 460k2niaTwowSRK8KWVDeAW6ZAaWiYjLlTunoKwvF8vP3JyWpBz0diTxL5o+xpvy/Q6YU3BN efdq8Vy3rFsxgW7mMSrI/CxJ667y8ot5DVugeS2NyHfmZlPGE0Nsy7hlebS4liisXOrN3jFz asKyUws3VXek4V65lHwB23BVzsnFMn/bw/rPliqXGcwl8CoJu8dSyrCcd1Ibs0/Inq9S9+t0 VmWiQWfQkz4rvEeTQkp/VfgZ6z98JRW7S6l6eophoWs0/ZyRfOm+QVSqRfFZdxdP2PlGeIFM C3fXJgygXJkFPyWkVElr76JTbtSHsGWbt6xUlYHKXWo+xf9WgtLeby3cfSkEchACrxDrQpj+ Jt/JFP+q997dybkyZ5IoHWuPkn7uZGBrKIHmBunTco1+cKSuRiSCYpBIXZMHCzPgVDjk4viP brV9NwRkmaOxVvye0vctJeWvJ6KA7NoAURplIGCqkCRwg0MmLrfoZnK/gRqVJ/f6adhU1oo6 z4p2/z3PemA0C0ANatgHgBb90cd16AUxpdEQmOCmdNnNJF/3Zt3inzF+NFzHoM5Vwq6rc1JP jfC3oqRLJzqAEHBDjQFlqNR3IFCIAo4SYQRBdAHBCzkM4rWyRhuVABEBAAHCwV8EGAECAAkF AlYFJhkCGwwACgkQ8ww4vT8vvjwg9w//VQrcnVg3TsjEybxDEUBm8dBmnKqcnTBFmxN5FFtI WlEuY8+YMiWRykd8Ln9RJ/98/ghABHz9TN8TRo2b6WimV64FmlVn17Ri6FgFU3xNt9TTEChq AcNg88eYryKsYpFwegGpwUlaUaaGh1m9OrTzcQy+klVfZWaVJ9Nw0keoGRGb8j4XjVpL8+2x OhXKrM1fzzb8JtAuSbuzZSQPDwQEI5CKKxp7zf76J21YeRrEW4WDznPyVcDTa+tz++q2S/Bp P4W98bXCBIuQgs2m+OflERv5c3Ojldp04/S4NEjXEYRWdiCxN7ca5iPml5gLtuvhJMSy36gl U6IW9kn30IWuSoBpTkgV7rLUEhh9Ms82VWW/h2TxL8enfx40PrfbDtWwqRID3WY8jLrjKfTd R3LW8BnUDNkG+c4FzvvGUs8AvuqxxyHbXAfDx9o/jXfPHVRmJVhSmd+hC3mcQ+4iX5bBPBPM oDqSoLt5w9GoQQ6gDVP2ZjTWqwSRMLzNr37rJjZ1pt0DCMMTbiYIUcrhX8eveCJtY7NGWNyx FCRkhxRuGcpwPmRVDwOl39MB3iTsRighiMnijkbLXiKoJ5CDVvX5yicNqYJPKh5MFXN1bvsB kmYiStMRbrD0HoY1kx5/VozBtc70OU0EB8Wrv9hZD+Ofp0T3KOr1RUHvCZoLURfFhSQ= In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Message-ID-Hash: G7644LLHH5CUBV27IMEHR2LCKE2P6A2T X-Message-ID-Hash: G7644LLHH5CUBV27IMEHR2LCKE2P6A2T X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 11/06/2024 07:31, David Gibson wrote: > On Wed, Jun 05, 2024 at 05:21:22PM +0200, Laurent Vivier wrote: >> This commit isolates the internal data structure management used for storing >> data (e.g., tcp4_l2_flags_iov[], tcp6_l2_flags_iov[], tcp4_flags_ip[], >> tcp4_flags[], ...) from the tcp_send_flag() function. The extracted >> functionality is relocated to a new function named tcp_fill_flag_header(). >> >> tcp_fill_flag_header() is now a generic function that accepts parameters such >> as struct tcphdr and a data pointer. tcp_send_flag() utilizes this parameter to >> pass memory pointers from tcp4_l2_flags_iov[] and tcp6_l2_flags_iov[]. >> >> This separation sets the stage for utilizing tcp_fill_flag_header() to >> set the memory provided by the guest via vhost-user in future developments. > > Thanks for the commit message, it makes this much clearer. > > I have a number of comments below, but they're basically all cosmetic. > >> Signed-off-by: Laurent Vivier >> --- >> tcp.c | 63 ++++++++++++++++++++++++++++++++++++----------------------- >> 1 file changed, 39 insertions(+), 24 deletions(-) >> >> diff --git a/tcp.c b/tcp.c >> index 06acb41e4d90..68d4afa05a36 100644 >> --- a/tcp.c >> +++ b/tcp.c >> @@ -1549,24 +1549,25 @@ static void tcp_update_seqack_from_tap(const struct ctx *c, >> } >> >> /** >> - * tcp_send_flag() - Send segment with flags to tap (no payload) >> + * tcp_fill_flag_header() - Prepare header for flags-only segment (no payload) > > I don't love the name tcp_fill_flag_header(), although it's not > terrible. Maybe tcp_prepare_flags() would be better? > >> * @c: Execution context >> * @conn: Connection pointer >> * @flags: TCP flags: if not set, send segment only if ACK is due >> + * @th: TCP header to update >> + * @data: buffer to store TCP option >> + * @optlen: size of the TCP option buffer > > Worth noting this is an output parameter here... > >> * >> - * Return: negative error code on connection reset, 0 otherwise >> + * Return: < 0 error code on connection reset, >> + * 0 if there is no flag to send >> + * 1 otherwise > > .. or, since optlen will always be positive on success cases, you > could just return it. > We cannot return optlen here as optlen can be 0 (it is not zero only with SYN), and 0 means no flags to send. We can have flags to send with optlen equal to 0. Thanks, Laurent