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=202502 header.b=jVhM7uCP; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 1292E5A0274 for ; Mon, 17 Feb 2025 05:53:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202502; t=1739768007; bh=WHOUXA51Ya8TupSX2zavDYYgeVVlVq31JFSyfuC0iAM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jVhM7uCPxjm0icLMe2CchhvV7vrKPXK99U83xRDevsguG2CxAbLR44ZwvmhdAzDYq f6gCvNMdrrgtwu5htxa6Z9PexBOdDdKgelab/zZNXMzH3tuhk8lB6+DNTLpz133p6D 4u7ylymkhtstgCRjyFgotAQ7FC3BRB9JytH5LHjGw7apF3mzznZGJU4kiL5AL2waml PlEXSUIALWk3eYDmE2Vpgalqasmm26YXjimduEmB8RKHsxu9LX5zmtPzad7oJvkWvA O+iqszhzTAHLotWEWD1lT6sNdepifSTk35a4V2av8x4+7F4acLwWZIbwZwi4AvpEjL o4733LE6IbtBQ== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4Yx9K335fqz4wd0; Mon, 17 Feb 2025 15:53:27 +1100 (AEDT) Date: Mon, 17 Feb 2025 15:07:26 +1100 From: David Gibson To: Jon Maloy Subject: Re: [PATCH v2 1/2] tap: break out building of udp header from tap_udp4_send function Message-ID: References: <20250214222943.1030954-1-jmaloy@redhat.com> <20250214222943.1030954-2-jmaloy@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wyYY8L+ZrX3xxQXe" Content-Disposition: inline In-Reply-To: <20250214222943.1030954-2-jmaloy@redhat.com> Message-ID-Hash: DYRD4AYSGYUD3BB3QBDD6HWEGJWOYROT X-Message-ID-Hash: DYRD4AYSGYUD3BB3QBDD6HWEGJWOYROT 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: passt-dev@passt.top, sbrivio@redhat.com, lvivier@redhat.com, dgibson@redhat.com 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: --wyYY8L+ZrX3xxQXe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 14, 2025 at 05:29:42PM -0500, Jon Maloy wrote: > We will need to build the UDP header at other locations than in function > tap_udp4_send(), so we break that part out to a separate function. >=20 > Signed-off-by: Jon Maloy Reviewed-by: David Gibson > --- > tap.c | 32 +++++++++++++++++++++++++------- > tap.h | 6 +++++- > 2 files changed, 30 insertions(+), 8 deletions(-) >=20 > diff --git a/tap.c b/tap.c > index cd32a90..8087779 100644 > --- a/tap.c > +++ b/tap.c > @@ -162,7 +162,7 @@ static void *tap_push_ip4h(struct iphdr *ip4h, struct= in_addr src, > } > =20 > /** > - * tap_udp4_send() - Send UDP over IPv4 packet > + * tap_push_uh4() - Build UDPv4 header with checksum > * @c: Execution context > * @src: IPv4 source address > * @sport: UDP source port > @@ -171,15 +171,11 @@ static void *tap_push_ip4h(struct iphdr *ip4h, stru= ct in_addr src, > * @in: UDP payload contents (not including UDP header) > * @dlen: UDP payload length (not including UDP header) > */ > -void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sp= ort, > +void *tap_push_uh4(struct udphdr *uh, struct in_addr src, in_port_t spor= t, > struct in_addr dst, in_port_t dport, > const void *in, size_t dlen) > { > size_t l4len =3D dlen + sizeof(struct udphdr); > - char buf[USHRT_MAX]; > - struct iphdr *ip4h =3D tap_push_l2h(c, buf, ETH_P_IP); > - struct udphdr *uh =3D tap_push_ip4h(ip4h, src, dst, l4len, IPPROTO_UDP); > - char *data =3D (char *)(uh + 1); > const struct iovec iov =3D { > .iov_base =3D (void *)in, > .iov_len =3D dlen > @@ -190,8 +186,30 @@ void tap_udp4_send(const struct ctx *c, struct in_ad= dr src, in_port_t sport, > uh->dest =3D htons(dport); > uh->len =3D htons(l4len); > csum_udp4(uh, src, dst, &payload); > - memcpy(data, in, dlen); > + return uh + 1; > +} > + > +/** > + * tap_udp4_send() - Send UDP over IPv4 packet > + * @c: Execution context > + * @src: IPv4 source address > + * @sport: UDP source port > + * @dst: IPv4 destination address > + * @dport: UDP destination port > + * @in: UDP payload contents (not including UDP header) > + * @dlen: UDP payload length (not including UDP header) > + */ > +void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sp= ort, > + struct in_addr dst, in_port_t dport, > + const void *in, size_t dlen) > +{ > + size_t l4len =3D dlen + sizeof(struct udphdr); > + char buf[USHRT_MAX]; > + struct iphdr *ip4h =3D tap_push_l2h(c, buf, ETH_P_IP); > + struct udphdr *uh =3D tap_push_ip4h(ip4h, src, dst, l4len, IPPROTO_UDP); > + char *data =3D tap_push_uh4(uh, src, sport, dst, dport, in, dlen); > =20 > + memcpy(data, in, dlen); > tap_send_single(c, buf, dlen + (data - buf)); > } > =20 > diff --git a/tap.h b/tap.h > index dfbd8b9..3451343 100644 > --- a/tap.h > +++ b/tap.h > @@ -8,6 +8,8 @@ > =20 > #define ETH_HDR_INIT(proto) { .h_proto =3D htons_constant(proto) } > =20 > +struct udphdr; > + > /** > * struct tap_hdr - tap backend specific headers > * @vnet_len: Frame length (for qemu socket transport) > @@ -43,7 +45,9 @@ static inline void tap_hdr_update(struct tap_hdr *thdr,= size_t l2len) > if (thdr) > thdr->vnet_len =3D htonl(l2len); > } > - > +void *tap_push_uh4(struct udphdr *uh, struct in_addr src, in_port_t spor= t, > + struct in_addr dst, in_port_t dport, > + const void *in, size_t dlen); > void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sp= ort, > struct in_addr dst, in_port_t dport, > const void *in, size_t dlen); --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --wyYY8L+ZrX3xxQXe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmeytf0ACgkQzQJF27ox 2GcKAQ/7BXNbQt+BuxoiyCfajy6KIV9u5aJzBaOQKpmcJbdCv/HDV/PkGcaJMhaX VS5TmhPlnfDbLQ/e/tzJ0e/BkMEO1S1OyDImOcapSCEmuaGjfzZGESGq3yD60O5i 2TQFLLnhPFEef/DSh4xCKB9yS6H9g3kFRaljJZJUBcxbzNk76K7XMdCgY0S9/Dfg OM1rkt5cH8vXE1OsasRC696TvvoMNOOVPj+msrN+oxHIO5jaM0ji4GGl/KOsnZ3i xTKdYNOC+7XAjLaxYaHYfJevVq8yuHGdIWXbZN8AbaLA3mmryonQNrXcc8P1TUeM xHuInVyp8e0nQZnWYwBvh08OnQF9+XZx9Yz7vQuCBK1zwXvB59w7UCAev7GvvyLo flMoiNX2qkR8Ulq5zfC0hc+/IpMNC7NZbAVrxneCtfoE23nyZ8rfj4LBZO6TvpMm VIFR5/Yg75zVUke+oTLJonIaPfxp2V5a1y9aOoLe1vDzYXfxfHbCfSzK5sOrchj7 tmCKZLsX5Ts5L9scoyRJCAfWoLrRyYcs5Nifne0UrWiykbwKVJtzL1dF++ozmtKN 1DDC69cG4Sw9g0FJXnI3VvYMQ2wzwo6Lo5wF67nfV0ucFe3LGCeLZI1F04pt2gub qnj0KtVFHkrPSycOfRrtJHW/UkoTXcEQn9VUpiYzh1zd5CuOJO8= =zal4 -----END PGP SIGNATURE----- --wyYY8L+ZrX3xxQXe--