From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202410 header.b=ByvFB+T5; dkim-atps=neutral Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by passt.top (Postfix) with ESMTPS id 651D55A061C for ; Mon, 28 Oct 2024 10:41:09 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202410; t=1730108451; bh=4xgIOdhA4u2Z4fhM/qf2HSfcNB+Vq7uH07u5UJhz71g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ByvFB+T5Xk09ayc5TkZkpLumuhcstrrcfR33tOcglY7Q/6+MoVHu58M3g6RCEqfEy dizy9PVxCnXQyb102jnZLoVHHiledFrRgdinFBguXMM8CG8SWPT6bKLS0GbvJfJILs gXEcU8CO4UaKi05LxK/kqIn/32HJ/Yj/GXbXNz/SU5/opkC2Opp5y9dSSQT3M8iWXD p4k9DdOilt739XWY6F3aAgkLGfIFvMRPJIhBCw0xFHZh2QNf6XqKOxl1dYVdcyHyxl F3ev5LXWgMWhP0kXU8zuL4hz2GKL53cMh3RxunXWrTAj3dz8vCTY4Usv3GSvQHtNHD daMki3N60EvjA== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4XcT0M2K3Gz4x8R; Mon, 28 Oct 2024 20:40:51 +1100 (AEDT) From: David Gibson To: Stefano Brivio , Laurent Vivier , passt-dev@passt.top Subject: [PATCH 4/7] tcp: Don't use return value from tcp_fill_headers[46] to adjust iov_len Date: Mon, 28 Oct 2024 20:40:47 +1100 Message-ID: <20241028094050.1609090-5-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028094050.1609090-1-david@gibson.dropbear.id.au> References: <20241028094050.1609090-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: K3MOHVLFRERBHXF52BWUMV5HO5LTAYF6 X-Message-ID-Hash: K3MOHVLFRERBHXF52BWUMV5HO5LTAYF6 X-MailFrom: dgibson@gandalf.ozlabs.org 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: David Gibson 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: Currently tcp_fill_headers[46] return the size of the IP payload, which we use to adjust the size of the last IOV entry for the frame, so that it only includes the expected data. This was originally done to isolate knowledge of the header layout to the header building functions. However, we since reorganized from a single buffer for the frame to an IO vector of pieces, which means we already know something about the layout in the caller. Use that knowledge to adjust iov_len *before* we call tcp_fill_headers*(). This means that the header building functions are called with the IOV containing the frame and only the frame, which will be useful later on. Signed-off-by: David Gibson --- tcp.c | 24 ++++++++---------------- tcp_buf.c | 13 ++++++------- tcp_internal.h | 17 +++++++++-------- 3 files changed, 23 insertions(+), 31 deletions(-) diff --git a/tcp.c b/tcp.c index 7c6f51a..d1e71ec 100644 --- a/tcp.c +++ b/tcp.c @@ -919,13 +919,11 @@ static void tcp_fill_header(struct tcphdr *th, * @check: Checksum, if already known * @seq: Sequence number for this segment * @no_tcp_csum: Do not set TCP checksum - * - * Return: The IPv4 payload length, host order */ -size_t tcp_fill_headers4(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct iphdr *iph, - struct tcp_payload_t *bp, size_t dlen, - const uint16_t *check, uint32_t seq, bool no_tcp_csum) +void tcp_fill_headers4(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct iphdr *iph, + struct tcp_payload_t *bp, size_t dlen, + const uint16_t *check, uint32_t seq, bool no_tcp_csum) { const struct flowside *tapside = TAPFLOW(conn); const struct in_addr *src4 = inany_v4(&tapside->oaddr); @@ -956,8 +954,6 @@ size_t tcp_fill_headers4(const struct tcp_tap_conn *conn, } tap_hdr_update(taph, l3len + sizeof(struct ethhdr)); - - return l4len; } /** @@ -970,13 +966,11 @@ size_t tcp_fill_headers4(const struct tcp_tap_conn *conn, * @check: Checksum, if already known * @seq: Sequence number for this segment * @no_tcp_csum: Do not set TCP checksum - * - * Return: The IPv6 payload length, host order */ -size_t tcp_fill_headers6(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct ipv6hdr *ip6h, - struct tcp_payload_t *bp, size_t dlen, - uint32_t seq, bool no_tcp_csum) +void tcp_fill_headers6(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct ipv6hdr *ip6h, + struct tcp_payload_t *bp, size_t dlen, + uint32_t seq, bool no_tcp_csum) { const struct flowside *tapside = TAPFLOW(conn); size_t l4len = dlen + sizeof(bp->th); @@ -1007,8 +1001,6 @@ size_t tcp_fill_headers6(const struct tcp_tap_conn *conn, } tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr)); - - return l4len; } /** diff --git a/tcp_buf.c b/tcp_buf.c index deb7be4..b2d806a 100644 --- a/tcp_buf.c +++ b/tcp_buf.c @@ -274,21 +274,20 @@ static void tcp_buf_make_frame(const struct tcp_tap_conn *conn, struct tap_hdr *taph = iov[TCP_IOV_TAP].iov_base; const struct flowside *tapside = TAPFLOW(conn); const struct in_addr *a4 = inany_v4(&tapside->oaddr); - size_t l4len; + + iov[TCP_IOV_PAYLOAD].iov_len = dlen + sizeof(struct tcphdr); if (a4) { struct iphdr *iph = iov[TCP_IOV_IP].iov_base; - l4len = tcp_fill_headers4(conn, taph, iph, payload, dlen, - check, seq, no_tcp_csum); + tcp_fill_headers4(conn, taph, iph, payload, dlen, + check, seq, no_tcp_csum); } else { struct ipv6hdr *ip6h = iov[TCP_IOV_IP].iov_base; - l4len = tcp_fill_headers6(conn, taph, ip6h, payload, dlen, - seq, no_tcp_csum); + tcp_fill_headers6(conn, taph, ip6h, payload, dlen, + seq, no_tcp_csum); } - - iov[TCP_IOV_PAYLOAD].iov_len = l4len; } /** diff --git a/tcp_internal.h b/tcp_internal.h index 0034b22..6cf5ad6 100644 --- a/tcp_internal.h +++ b/tcp_internal.h @@ -177,14 +177,15 @@ void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn); struct tcp_info_linux; -size_t tcp_fill_headers4(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct iphdr *iph, - struct tcp_payload_t *bp, size_t dlen, - const uint16_t *check, uint32_t seq, bool no_tcp_csum); -size_t tcp_fill_headers6(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct ipv6hdr *ip6h, - struct tcp_payload_t *bp, size_t dlen, - uint32_t seq, bool no_tcp_csum); +void tcp_fill_headers4(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct iphdr *iph, + struct tcp_payload_t *bp, size_t dlen, + const uint16_t *check, uint32_t seq, bool no_tcp_csum); +void tcp_fill_headers6(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, struct ipv6hdr *ip6h, + struct tcp_payload_t *bp, size_t dlen, + uint32_t seq, bool no_tcp_csum); + int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn, bool force_seq, struct tcp_info_linux *tinfo); int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn, -- 2.47.0