From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=none 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=B/QhMd6A; dkim-atps=neutral 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 249C25A004C for ; Tue, 17 Sep 2024 09:31:06 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726558264; 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=iq+ScrlgfPtN1GdCeCy8HsXh9D2zm0rmRnPr/XgeIAQ=; b=B/QhMd6AXvA32pPUikaIGlnlj9OdpQ8A4DPDuoOSf9HW401U8+VjmsJbd+v7h2ZaCFk2QT zN/REIuKC3W09ep+y7Z+68Png3I3IcINYAO/43+vya8ADyrK0CtjT29l8AUeQDcHUQa/Oh 9eKiWweBw/Z24IyNIJNTDR3lL3coN8s= 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-73-mXVEAcGvPtatpF-JEC1v9A-1; Tue, 17 Sep 2024 03:31:03 -0400 X-MC-Unique: mXVEAcGvPtatpF-JEC1v9A-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 CCDC01955F3C for ; Tue, 17 Sep 2024 07:31:02 +0000 (UTC) Received: from lenovo-t14s.redhat.com (unknown [10.39.193.4]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D8A3419560A3; Tue, 17 Sep 2024 07:31:01 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH v2 1/2] udp: Allow checksum to be disabled Date: Tue, 17 Sep 2024 09:30:57 +0200 Message-ID: <20240917073058.3666887-2-lvivier@redhat.com> In-Reply-To: <20240917073058.3666887-1-lvivier@redhat.com> References: <20240917073058.3666887-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 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: LXZGUF5ZIBBD4ZEHJUIXYK3MVKZS5HHV X-Message-ID-Hash: LXZGUF5ZIBBD4ZEHJUIXYK3MVKZS5HHV 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: We can need not to set the UDP checksum. Add a parameter to udp_update_hdr4() and udp_update_hdr6() to disable it. Signed-off-by: Laurent Vivier --- Notes: v2: s/UPD/UDP/ udp.c | 41 +++++++++++++++++++++++++++++++---------- 1 file changed, 31 insertions(+), 10 deletions(-) diff --git a/udp.c b/udp.c index 2ba00c9c20a8..95151efb9c46 100644 --- a/udp.c +++ b/udp.c @@ -298,11 +298,13 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n, * @bp: Pointer to udp_payload_t to update * @toside: Flowside for destination side * @dlen: Length of UDP payload + * @no_udp_csum: Do not set UDP checksum * * Return: size of IPv4 payload (UDP header + data) */ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp, - const struct flowside *toside, size_t dlen) + const struct flowside *toside, size_t dlen, + bool no_udp_csum) { const struct in_addr *src = inany_v4(&toside->oaddr); const struct in_addr *dst = inany_v4(&toside->eaddr); @@ -319,7 +321,10 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp, bp->uh.source = htons(toside->oport); bp->uh.dest = htons(toside->eport); bp->uh.len = htons(l4len); - csum_udp4(&bp->uh, *src, *dst, bp->data, dlen); + if (no_udp_csum) + bp->uh.check = 0; + else + csum_udp4(&bp->uh, *src, *dst, bp->data, dlen); return l4len; } @@ -330,11 +335,13 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp, * @bp: Pointer to udp_payload_t to update * @toside: Flowside for destination side * @dlen: Length of UDP payload + * @no_udp_csum: Do not set UDP checksum * * Return: size of IPv6 payload (UDP header + data) */ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp, - const struct flowside *toside, size_t dlen) + const struct flowside *toside, size_t dlen, + bool no_udp_csum) { uint16_t l4len = dlen + sizeof(bp->uh); @@ -348,7 +355,16 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp, bp->uh.source = htons(toside->oport); bp->uh.dest = htons(toside->eport); bp->uh.len = ip6h->payload_len; - csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, bp->data, dlen); + if (no_udp_csum) { + /* O is an invalid checksum for UDP IPv6 and dropped by + * the kernel stack, even if the checksum is disabled by virtio + * flags. We need to put any non-zero value here. + */ + bp->uh.check = 0xffff; + } else { + csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, + bp->data, dlen); + } return l4len; } @@ -358,9 +374,11 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp, * @mmh: Receiving mmsghdr array * @idx: Index of the datagram to prepare * @toside: Flowside for destination side + * @no_udp_csum: Do not set UDP checksum */ -static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx, - const struct flowside *toside) +static void udp_tap_prepare(const struct mmsghdr *mmh, + unsigned idx, const struct flowside *toside, + bool no_udp_csum) { struct iovec (*tap_iov)[UDP_NUM_IOVS] = &udp_l2_iov[idx]; struct udp_payload_t *bp = &udp_payload[idx]; @@ -368,13 +386,15 @@ static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx, size_t l4len; if (!inany_v4(&toside->eaddr) || !inany_v4(&toside->oaddr)) { - l4len = udp_update_hdr6(&bm->ip6h, bp, toside, mmh[idx].msg_len); + l4len = udp_update_hdr6(&bm->ip6h, bp, toside, + mmh[idx].msg_len, no_udp_csum); tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) + sizeof(udp6_eth_hdr)); (*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp6_eth_hdr); (*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip6h); } else { - l4len = udp_update_hdr4(&bm->ip4h, bp, toside, mmh[idx].msg_len); + l4len = udp_update_hdr4(&bm->ip4h, bp, toside, + mmh[idx].msg_len, no_udp_csum); tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) + sizeof(udp4_eth_hdr)); (*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp4_eth_hdr); @@ -565,7 +585,8 @@ void udp_listen_sock_handler(const struct ctx *c, union epoll_ref ref, udp_splice_prepare(udp_mh_recv, i); } else if (batchpif == PIF_TAP) { udp_tap_prepare(udp_mh_recv, i, - flowside_at_sidx(batchsidx)); + flowside_at_sidx(batchsidx), + false); } if (++i >= n) @@ -636,7 +657,7 @@ void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref, if (pif_is_socket(topif)) udp_splice_prepare(udp_mh_recv, i); else if (topif == PIF_TAP) - udp_tap_prepare(udp_mh_recv, i, toside); + udp_tap_prepare(udp_mh_recv, i, toside, false); /* Restore sockaddr length clobbered by recvmsg() */ udp_mh_recv[i].msg_hdr.msg_namelen = sizeof(udp_meta[i].s_in); } -- 2.46.0