From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTP id DC8DC5A004E for ; Thu, 13 Jun 2024 14:37:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718282222; 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; bh=B6FTBXJT80U/FCPymqwgKLxXu59fYu8ayftz5lhO6kQ=; b=YABaymrQ/QNnGMn2B+3j+vcNGzqFpM15XN1RJ9l9Riq2dAzA7QycDbT1fAtvE9uakeJPXz w3IgcdHofw0VgHzbf/dDyZrwdaihaNZ26VBpxACUjfDYCY3jb3LCT80pV0PNxI+77SK8X4 hg/BbkRws50c9mvJ1p9QUZps1DEPUrw= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-215-87sXzLOJPye6BGi6W8-N8g-1; Thu, 13 Jun 2024 08:37:00 -0400 X-MC-Unique: 87sXzLOJPye6BGi6W8-N8g-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 70A2519560AE for ; Thu, 13 Jun 2024 12:36:59 +0000 (UTC) Received: from lenovo-t14s.redhat.com (unknown [10.39.193.78]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 86D7919560AA; Thu, 13 Jun 2024 12:36:58 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH v7 1/8] tcp: extract buffer management from tcp_send_flag() Date: Thu, 13 Jun 2024 14:36:48 +0200 Message-ID: <20240613123655.1362065-2-lvivier@redhat.com> In-Reply-To: <20240613123655.1362065-1-lvivier@redhat.com> References: <20240613123655.1362065-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: NEI2P42GKC3HDTC2VYEQRPNWY7GNXH2I X-Message-ID-Hash: NEI2P42GKC3HDTC2VYEQRPNWY7GNXH2I 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: Laurent Vivier 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: 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. Signed-off-by: Laurent Vivier --- tcp.c | 78 +++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 54 insertions(+), 24 deletions(-) diff --git a/tcp.c b/tcp.c index dd8d46e08628..e40f42259451 100644 --- a/tcp.c +++ b/tcp.c @@ -1567,24 +1567,25 @@ static void tcp_update_seqack_from_tap(const struct ctx *c, } /** - * tcp_send_flag() - Send segment with flags to tap (no payload) + * tcp_prepare_flags() - Prepare header for flags-only segment (no payload) * @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 (output parameter) * - * 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 */ -static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags) +static int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, + int flags, struct tcphdr *th, char *data, + size_t *optlen) { - struct tcp_flags_t *payload; struct tcp_info tinfo = { 0 }; socklen_t sl = sizeof(tinfo); int s = conn->sock; - size_t optlen = 0; - struct tcphdr *th; - struct iovec *iov; - size_t l4len; - char *data; if (SEQ_GE(conn->seq_ack_to_tap, conn->seq_from_tap) && !flags && conn->wnd_to_tap) @@ -1606,20 +1607,12 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags) if (!tcp_update_seqack_wnd(c, conn, flags, &tinfo) && !flags) return 0; - if (CONN_V4(conn)) - iov = tcp4_l2_flags_iov[tcp4_flags_used++]; - else - iov = tcp6_l2_flags_iov[tcp6_flags_used++]; - - payload = iov[TCP_IOV_PAYLOAD].iov_base; - th = &payload->th; - data = payload->opts; - + *optlen = 0; if (flags & SYN) { int mss; /* Options: MSS, NOP and window scale (8 bytes) */ - optlen = OPT_MSS_LEN + 1 + OPT_WS_LEN; + *optlen = OPT_MSS_LEN + 1 + OPT_WS_LEN; *data++ = OPT_MSS; *data++ = OPT_MSS_LEN; @@ -1653,17 +1646,13 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags) flags |= ACK; } - th->doff = (sizeof(*th) + optlen) / 4; + th->doff = (sizeof(*th) + *optlen) / 4; th->ack = !!(flags & ACK); th->rst = !!(flags & RST); th->syn = !!(flags & SYN); th->fin = !!(flags & FIN); - l4len = tcp_l2_buf_fill_headers(c, conn, iov, optlen, NULL, - conn->seq_to_tap); - iov[TCP_IOV_PAYLOAD].iov_len = l4len; - if (th->ack) { if (SEQ_GE(conn->seq_ack_to_tap, conn->seq_from_tap)) conn_flag(c, conn, ~ACK_TO_TAP_DUE); @@ -1678,6 +1667,47 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags) if (th->fin || th->syn) conn->seq_to_tap++; + return 1; +} + +/** + * tcp_send_flag() - Send segment with flags to tap (no payload) + * @c: Execution context + * @conn: Connection pointer + * @flags: TCP flags: if not set, send segment only if ACK is due + * + * Return: negative error code on connection reset, 0 otherwise + */ +static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags) +{ + struct tcp_flags_t *payload; + struct iovec *iov; + size_t optlen; + size_t l4len; + uint32_t seq; + int ret; + + if (CONN_V4(conn)) + iov = tcp4_l2_flags_iov[tcp4_flags_used++]; + else + iov = tcp6_l2_flags_iov[tcp6_flags_used++]; + + payload = iov[TCP_IOV_PAYLOAD].iov_base; + + seq = conn->seq_to_tap; + ret = tcp_prepare_flags(c, conn, flags, &payload->th, + payload->opts, &optlen); + if (ret <= 0) { + if (CONN_V4(conn)) + tcp4_flags_used--; + else + tcp6_flags_used--; + return ret; + } + + l4len = tcp_l2_buf_fill_headers(c, conn, iov, optlen, NULL, seq); + iov[TCP_IOV_PAYLOAD].iov_len = l4len; + if (flags & DUP_ACK) { struct iovec *dup_iov; int i; -- 2.45.2