From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=SdVHunfC; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id 6662A5A0271 for ; Fri, 27 Feb 2026 15:03:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772201025; 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=E1upqBW536u2L8eaehnPTAJn0sOmIRIgnL/c9bgnfhY=; b=SdVHunfCJ6iBLZrhCsmoPiqaYQcD7omzuLJqYijRYOJBYoCr8M/wSBS8V8YUluSijuyHct PwQD3LFnDHLYObqHNdtAiVKTiBkKagoMuSahySJEtGZQ66pQoZcyNLaCcftXc4pBY1BsQI 9N2N8fItn3k2+9tr5xTwSwlCkGR3C64= Received: from mx-prod-mc-03.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-448-x6qMRR2lPvyE4yCJmk-fjg-1; Fri, 27 Feb 2026 09:03:44 -0500 X-MC-Unique: x6qMRR2lPvyE4yCJmk-fjg-1 X-Mimecast-MFC-AGG-ID: x6qMRR2lPvyE4yCJmk-fjg_1772201023 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 73E0819560B7 for ; Fri, 27 Feb 2026 14:03:43 +0000 (UTC) Received: from lenovo-t14s.redhat.com (unknown [10.45.225.86]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7EC4930001B9; Fri, 27 Feb 2026 14:03:42 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH 07/12] udp_vu: Use iov_tail in udp_vu_prepare() Date: Fri, 27 Feb 2026 15:03:25 +0100 Message-ID: <20260227140330.2216753-8-lvivier@redhat.com> In-Reply-To: <20260227140330.2216753-1-lvivier@redhat.com> References: <20260227140330.2216753-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: LiXJeSL0NK2yt_TvNywQgFMpw2wY6Ss5PHnjt94qDs8_1772201023 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: VLXA2TPBZ57CHZOU4ECR3WRUEQLZEU5J X-Message-ID-Hash: VLXA2TPBZ57CHZOU4ECR3WRUEQLZEU5J 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: Rework udp_vu_prepare() to use IOV_REMOVE_HEADER() and IOV_PUT_HEADER() to walk through Ethernet, IP and UDP headers instead of the layout-specific helpers (vu_eth(), vu_ip(), vu_payloadv4(), vu_payloadv6()) that assume a contiguous buffer. The payload length is now implicit in the iov_tail, so drop the dlen parameter. Signed-off-by: Laurent Vivier --- iov.c | 1 - udp_vu.c | 63 ++++++++++++++++++++++++++++++-------------------------- 2 files changed, 34 insertions(+), 30 deletions(-) diff --git a/iov.c b/iov.c index 2cf23d284e4a..7c9641968271 100644 --- a/iov.c +++ b/iov.c @@ -304,7 +304,6 @@ void *iov_peek_header_(struct iov_tail *tail, void *v, size_t len, size_t align) * * Return: number of bytes written */ -/* cppcheck-suppress unusedFunction */ size_t iov_put_header_(struct iov_tail *tail, const void *v, size_t len) { size_t l = len; diff --git a/udp_vu.c b/udp_vu.c index dd8904d65a38..6d87f4872268 100644 --- a/udp_vu.c +++ b/udp_vu.c @@ -101,52 +101,54 @@ static ssize_t udp_vu_sock_recv(struct iov_tail *data, int s, bool v6) * @c: Execution context * @data: IO vector tail for the frame * @toside: Address information for one side of the flow - * @dlen: Packet data length * * Return: Layer-4 length */ static size_t udp_vu_prepare(const struct ctx *c, const struct iov_tail *data, - const struct flowside *toside, ssize_t dlen) + const struct flowside *toside) { - const struct iovec *iov = data->iov; - struct ethhdr *eh; + struct iov_tail current = *data; + struct ethhdr *eh, eh_storage; + struct udphdr *uh, uh_storage; size_t l4len; /* ethernet header */ - eh = vu_eth(iov[0].iov_base); + eh = IOV_REMOVE_HEADER(¤t, eh_storage); memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source)); /* initialize header */ if (inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)) { - struct iphdr *iph = vu_ip(iov[0].iov_base); - struct udp_payload_t *bp = vu_payloadv4(iov[0].iov_base); - const struct iovec payload_iov = { - .iov_base = bp->data, - .iov_len = dlen, - }; - struct iov_tail payload = IOV_TAIL(&payload_iov, 1, 0); + struct iphdr *iph, iph_storage; eh->h_proto = htons(ETH_P_IP); + iph = IOV_REMOVE_HEADER(¤t, iph_storage); *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_UDP); - l4len = udp_update_hdr4(iph, &bp->uh, &payload, toside, true); + uh = IOV_REMOVE_HEADER(¤t, uh_storage); + l4len = udp_update_hdr4(iph, uh, ¤t, toside, true); + + current = *data; + IOV_PUT_HEADER(¤t, eh); + IOV_PUT_HEADER(¤t, iph); + IOV_PUT_HEADER(¤t, uh); } else { - struct ipv6hdr *ip6h = vu_ip(iov[0].iov_base); - struct udp_payload_t *bp = vu_payloadv6(iov[0].iov_base); - const struct iovec payload_iov = { - .iov_base = bp->data, - .iov_len = dlen, - }; - struct iov_tail payload = IOV_TAIL(&payload_iov, 1, 0); + struct ipv6hdr *ip6h, ip6h_storage; eh->h_proto = htons(ETH_P_IPV6); + ip6h = IOV_REMOVE_HEADER(¤t, ip6h_storage); *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_UDP); - l4len = udp_update_hdr6(ip6h, &bp->uh, &payload, toside, true); + uh = IOV_REMOVE_HEADER(¤t, uh_storage); + l4len = udp_update_hdr6(ip6h, uh, ¤t, toside, true); + + current = *data; + IOV_PUT_HEADER(¤t, eh); + IOV_PUT_HEADER(¤t, ip6h); + IOV_PUT_HEADER(¤t, uh); } return l4len; @@ -165,9 +167,10 @@ static void udp_vu_csum(const struct flowside *toside, struct iov_tail payload = *data; struct udphdr *uh, uh_storage; bool ipv4 = src4 && dst4; + int hdrlen = sizeof(struct ethhdr) + + (ipv4 ? sizeof(struct iphdr) : sizeof(struct ipv6hdr)); - iov_drop_header(&payload, - udp_vu_hdrlen(!ipv4) - sizeof(struct udphdr)); + iov_drop_header(&payload, hdrlen); uh = IOV_REMOVE_HEADER(&payload, uh_storage); if (ipv4) @@ -208,8 +211,8 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) } for (i = 0; i < n; i++) { + int elem_cnt, elem_used; ssize_t dlen; - int elem_cnt; vu_init_elem(elem, iov_vu, ARRAY_SIZE(elem)); @@ -225,18 +228,20 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) vu_queue_rewind(vq, elem_cnt); continue; } + elem_used = data.cnt; /* release unused buffers */ - vu_queue_rewind(vq, elem_cnt - data.cnt); + vu_queue_rewind(vq, elem_cnt - elem_used); if (data.cnt > 0) { - vu_set_vnethdr(vdev, data.iov[0].iov_base, data.cnt); - udp_vu_prepare(c, &data, toside, dlen); + vu_set_vnethdr(vdev, data.iov[0].iov_base, elem_used); + iov_drop_header(&data, VNET_HLEN); + udp_vu_prepare(c, &data, toside); if (*c->pcap) { udp_vu_csum(toside, &data); - pcap_iov(data.iov, data.cnt, VNET_HLEN); + pcap_iov(data.iov, data.cnt, 0); } - vu_flush(vdev, vq, elem, data.cnt); + vu_flush(vdev, vq, elem, elem_used); } } } -- 2.53.0