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 BF6155A0269 for ; Tue, 18 Oct 2022 10:40:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666082404; 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=4zSy/ilxDvnzMHlRs41qn2dVsp9A9FNfdaRo7DMNRcg=; b=J2wx6BFS/EyF4MTQWGjOuxX/MmpB4JKfgIlvxou0nJxxi5OHLS7N1k/mCqjxjiNJ4LFCxU XKVuIZqb9i5Zch6sTl3tV0fun6UVg6dyY6oz/Iu82t5nUebduWJ25Dj/42qqWTDOtIsR5l 6DirwDWpX4Hwsx8b2mSaV4fss3IusLY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-375-27KfU9_RNIu3czWJap-W4w-1; Tue, 18 Oct 2022 04:40:01 -0400 X-MC-Unique: 27KfU9_RNIu3czWJap-W4w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E06F03C0CD51; Tue, 18 Oct 2022 08:40:00 +0000 (UTC) Received: from maya.cloud.tilaa.com (ovpn-208-31.brq.redhat.com [10.40.208.31]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7342A2027061; Tue, 18 Oct 2022 08:40:00 +0000 (UTC) Date: Tue, 18 Oct 2022 05:06:11 +0200 From: Stefano Brivio To: David Gibson Subject: Re: [PATCH 09/14] Split tap_ip_send() into IPv4 and IPv6 specific functions Message-ID: <20221018050611.02d79478@elisabeth> In-Reply-To: <20221017085807.473470-10-david@gibson.dropbear.id.au> References: <20221017085807.473470-1-david@gibson.dropbear.id.au> <20221017085807.473470-10-david@gibson.dropbear.id.au> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: VLWG7E3YOQ4F3BRWWEQUP2S32HU32LXL X-Message-ID-Hash: VLWG7E3YOQ4F3BRWWEQUP2S32HU32LXL X-MailFrom: sbrivio@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: 3.3.3 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 Mon, 17 Oct 2022 19:58:02 +1100 David Gibson wrote: > The IPv4 and IPv6 paths in tap_ip_send() have very little in common, and > it turns out that every caller (statically) knows if it is using IPv4 or > IPv6. So split into separate tap_ip4_send() and tap_ip6_send() functions. > Use a new tap_l2_hdr() function for the very small common part. > > While we're there, make some minor cleanups: > - We were double writing some fields in the IPv6 header, so that it > temporary matched the pseudo-header for checksum calculation. With > recent checksum reworks, this isn't neccessary any more. > - We don't use any IPv4 header options, so use some sizeof() constructs > instead of some open coded values for header length. > - The comment used to say that the flow label was for TCP over IPv6, but > in fact the only thing we used it for was ICMPv6 ...right, this used to be the data path. > > Signed-off-by: David Gibson > --- > dhcpv6.c | 6 +- > icmp.c | 10 +--- > tap.c | 176 +++++++++++++++++++++++++++++-------------------------- > tap.h | 6 +- > 4 files changed, 102 insertions(+), 96 deletions(-) > > diff --git a/dhcpv6.c b/dhcpv6.c > index e7640ce..7829968 100644 > --- a/dhcpv6.c > +++ b/dhcpv6.c > @@ -531,8 +531,8 @@ int dhcpv6(struct ctx *c, const struct pool *p, > > resp_not_on_link.hdr.xid = mh->xid; > > - tap_ip_send(c, src, IPPROTO_UDP, > - (char *)&resp_not_on_link, n, mh->xid); > + tap_ip6_send(c, src, IPPROTO_UDP, > + (char *)&resp_not_on_link, n, mh->xid); > > return 1; > } > @@ -580,7 +580,7 @@ int dhcpv6(struct ctx *c, const struct pool *p, > > resp.hdr.xid = mh->xid; > > - tap_ip_send(c, src, IPPROTO_UDP, (char *)&resp, n, mh->xid); > + tap_ip6_send(c, src, IPPROTO_UDP, (char *)&resp, n, mh->xid); > c->ip6.addr_seen = c->ip6.addr; > > return 1; > diff --git a/icmp.c b/icmp.c > index 21ea2d7..61c2d90 100644 > --- a/icmp.c > +++ b/icmp.c > @@ -69,10 +69,6 @@ static uint8_t icmp_act[IP_VERSIONS][DIV_ROUND_UP(ICMP_NUM_IDS, 8)]; > void icmp_sock_handler(const struct ctx *c, union epoll_ref ref, > uint32_t events, const struct timespec *now) > { > - struct in6_addr a6 = { .s6_addr = { 0, 0, 0, 0, > - 0, 0, 0, 0, > - 0, 0, 0xff, 0xff, > - 0, 0, 0, 0 } }; > union icmp_epoll_ref *iref = &ref.r.p.icmp; > struct sockaddr_storage sr; > socklen_t sl = sizeof(sr); > @@ -109,7 +105,7 @@ void icmp_sock_handler(const struct ctx *c, union epoll_ref ref, > icmp_id_map[V6][id].seq = seq; > } > > - tap_ip_send(c, &sr6->sin6_addr, IPPROTO_ICMPV6, buf, n, 0); > + tap_ip6_send(c, &sr6->sin6_addr, IPPROTO_ICMPV6, buf, n, 0); > } else { > struct sockaddr_in *sr4 = (struct sockaddr_in *)&sr; > struct icmphdr *ih = (struct icmphdr *)buf; > @@ -127,9 +123,7 @@ void icmp_sock_handler(const struct ctx *c, union epoll_ref ref, > icmp_id_map[V4][id].seq = seq; > } > > - memcpy(&a6.s6_addr[12], &sr4->sin_addr, sizeof(sr4->sin_addr)); > - > - tap_ip_send(c, &a6, IPPROTO_ICMP, buf, n, 0); > + tap_ip4_send(c, sr4->sin_addr.s_addr, IPPROTO_ICMP, buf, n); > } > } > > diff --git a/tap.c b/tap.c > index ae75fac..45547ac 100644 > --- a/tap.c > +++ b/tap.c > @@ -109,100 +109,110 @@ const struct in6_addr *tap_ip6_daddr(const struct ctx *c, > } > > /** > - * tap_ip_send() - Send IP packet, with L2 headers, calculating L3/L4 checksums > + * tap_l2_hdr() - Build an L2 header for an inbound packet > * @c: Execution context > - * @src: IPv6 source address, IPv4-mapped for IPv4 sources > - * @proto: L4 protocol number > - * @in: Payload > - * @len: L4 payload length > - * @flow: Flow label for TCP over IPv6 > + * @buf: Buffer address at which to generate header > + * @proto: Ethernet protocol number for L3 > + * > + * Returns a pointer at which to write the packet's payload * Return: ... -- Stefano