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=202508 header.b=baI2yPHF; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 3CD825A027B for ; Thu, 21 Aug 2025 04:04:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202508; t=1755741833; bh=BU5ZNMseuPIdkrnaxF5f/ghjvC1LsIxvRZ891TMcGjA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=baI2yPHFk2Yg7E08jfyD47gox8Wp6PlEMaL4iR55rItZ/5+Cz4Ds7M+qDFnbCr1QR RUbP8UciUgC2Fp1p9xarYe75s3Jp1eKqPwLjJsiApjsrtqFZyISn4hwENK1OFSJvpa lezfvi8bmips1S94iYBVk2/RiVNgaRRBvybBspjpe2EWMrJpxd98hd7KMBzDWXrLdb h4IgwIe7hDiEhC7A0kz/9Ra1hG0Tk3m9Ho96FTjwLj5JIDGriIj34H/GjRl1DO8ouv 0huENNmxePBa0jecxwMmTj8J3VbpxTZcS01oXUFiIHu6Dak6+11VtFTolFd361WI0m 1PlGznnh44y/A== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4c6mp12X8Lz4xQW; Thu, 21 Aug 2025 12:03:53 +1000 (AEST) Date: Thu, 21 Aug 2025 11:51:21 +1000 From: David Gibson To: Jon Maloy Subject: Re: [PATCH v4 8/9] icmp: let icmp use mac address from flowside structure Message-ID: References: <20250820031005.2725591-1-jmaloy@redhat.com> <20250820031005.2725591-9-jmaloy@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3hBMf/RDEWAHHav2" Content-Disposition: inline In-Reply-To: <20250820031005.2725591-9-jmaloy@redhat.com> Message-ID-Hash: GAAQEXKU67Z6A4FG754PPC2R5N7RE2RU X-Message-ID-Hash: GAAQEXKU67Z6A4FG754PPC2R5N7RE2RU 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: sbrivio@redhat.com, dgibson@redhat.com, passt-dev@passt.top 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: --3hBMf/RDEWAHHav2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 19, 2025 at 11:10:04PM -0400, Jon Maloy wrote: > Even ICMP needs to be updated to use the external MAC address instead > of just the own tap address when applicable. We do that here. >=20 > Signed-off-by: Jon Maloy > --- > icmp.c | 4 ++-- > ndp.c | 2 +- > tap.c | 10 ++++++---- > tap.h | 4 ++-- > udp.c | 12 ++++++++---- > 5 files changed, 19 insertions(+), 13 deletions(-) >=20 > diff --git a/icmp.c b/icmp.c > index 95f38c1..aa42cc3 100644 > --- a/icmp.c > +++ b/icmp.c > @@ -129,12 +129,12 @@ void icmp_sock_handler(const struct ctx *c, union e= poll_ref ref) > const struct in_addr *daddr =3D inany_v4(&ini->eaddr); > =20 > ASSERT(saddr && daddr); /* Must have IPv4 addresses */ > - tap_icmp4_send(c, *saddr, *daddr, buf, n); > + tap_icmp4_send(c, *saddr, *daddr, buf, pingf->f.tap_omac, n); > } else if (pingf->f.type =3D=3D FLOW_PING6) { > const struct in6_addr *saddr =3D &ini->oaddr.a6; > const struct in6_addr *daddr =3D &ini->eaddr.a6; > =20 > - tap_icmp6_send(c, saddr, daddr, buf, n); > + tap_icmp6_send(c, saddr, daddr, buf, pingf->f.tap_omac, n); > } > return; > =20 > diff --git a/ndp.c b/ndp.c > index 9912f80..19b9b28 100644 > --- a/ndp.c > +++ b/ndp.c > @@ -185,7 +185,7 @@ static void ndp_send(const struct ctx *c, const struc= t in6_addr *dst, > { > const struct in6_addr *src =3D &c->ip6.our_tap_ll; > =20 > - tap_icmp6_send(c, src, dst, buf, l4len); > + tap_icmp6_send(c, src, dst, buf, c->our_tap_mac, l4len); > } > =20 > /** > diff --git a/tap.c b/tap.c > index 0349835..443928a 100644 > --- a/tap.c > +++ b/tap.c > @@ -278,13 +278,14 @@ void tap_udp4_send(const struct ctx *c, struct in_a= ddr src, in_port_t sport, > * @src: IPv4 source address > * @dst: IPv4 destination address > * @in: ICMP packet, including ICMP header > + * @src_mac: MAC address to be used as source for message > * @l4len: ICMP packet length, including ICMP header > */ > void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_a= ddr dst, > - const void *in, size_t l4len) > + const void *in, const void *src_mac, size_t l4len) > { > char buf[USHRT_MAX]; > - struct iphdr *ip4h =3D tap_push_l2h(c, buf, NULL, ETH_P_IP); > + struct iphdr *ip4h =3D tap_push_l2h(c, buf, src_mac, ETH_P_IP); > struct icmphdr *icmp4h =3D tap_push_ip4h(ip4h, src, dst, > l4len, IPPROTO_ICMP); > =20 > @@ -385,14 +386,15 @@ void tap_udp6_send(const struct ctx *c, > * @src: IPv6 source address > * @dst: IPv6 destination address > * @in: ICMP packet, including ICMP header > + * @src_mac: MAC address to be used as source for message > * @l4len: ICMP packet length, including ICMP header > */ > void tap_icmp6_send(const struct ctx *c, > const struct in6_addr *src, const struct in6_addr *dst, > - const void *in, size_t l4len) > + const void *in, const void *src_mac, size_t l4len) > { > char buf[USHRT_MAX]; > - struct ipv6hdr *ip6h =3D tap_push_l2h(c, buf, NULL, ETH_P_IPV6); > + struct ipv6hdr *ip6h =3D tap_push_l2h(c, buf, src_mac, ETH_P_IPV6); > struct icmp6hdr *icmp6h =3D tap_push_ip6h(ip6h, src, dst, l4len, > IPPROTO_ICMPV6, 0); > =20 > diff --git a/tap.h b/tap.h > index 6ec171d..ce0b9a6 100644 > --- a/tap.h > +++ b/tap.h > @@ -91,7 +91,7 @@ void tap_udp4_send(const struct ctx *c, struct in_addr = src, in_port_t sport, > struct in_addr dst, in_port_t dport, > const void *in, size_t dlen); > void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_a= ddr dst, > - const void *in, size_t l4len); > + const void *in, const void *src_mac, size_t l4len); > const struct in6_addr *tap_ip6_daddr(const struct ctx *c, > const struct in6_addr *src); > void *tap_push_ip6h(struct ipv6hdr *ip6h, > @@ -103,7 +103,7 @@ void tap_udp6_send(const struct ctx *c, > uint32_t flow, void *in, size_t dlen); > void tap_icmp6_send(const struct ctx *c, > const struct in6_addr *src, const struct in6_addr *dst, > - const void *in, size_t l4len); > + const void *in, const void *src_mac, size_t l4len); > void tap_send_single(const struct ctx *c, const void *data, size_t l2len= ); > size_t tap_send_frames(const struct ctx *c, const struct iovec *iov, > size_t bufs_per_frame, size_t nframes); > diff --git a/udp.c b/udp.c > index 30937dd..8d43646 100644 > --- a/udp.c > +++ b/udp.c > @@ -385,6 +385,7 @@ static void udp_tap_prepare(const struct mmsghdr *mmh, > * udp_send_tap_icmp4() - Construct and send ICMPv4 to local peer > * @c: Execution context > * @ee: Extended error descriptor > + * @uflow: UDP flow > * @toside: Destination side of flow > * @saddr: Address of ICMP generating node > * @in: First bytes (max 8) of original UDP message body > @@ -392,6 +393,7 @@ static void udp_tap_prepare(const struct mmsghdr *mmh, > */ > static void udp_send_tap_icmp4(const struct ctx *c, > const struct sock_extended_err *ee, > + const struct udp_flow *uflow, > const struct flowside *toside, > struct in_addr saddr, > const void *in, size_t dlen) > @@ -421,7 +423,7 @@ static void udp_send_tap_icmp4(const struct ctx *c, > tap_push_uh4(&msg.uh, eaddr, eport, oaddr, oport, in, dlen); > memcpy(&msg.data, in, dlen); > =20 > - tap_icmp4_send(c, saddr, eaddr, &msg, msglen); > + tap_icmp4_send(c, saddr, eaddr, &msg, uflow->f.tap_omac, msglen); This is only correct when saddr =3D=3D toside->oaddr; i.e. when the ICMP is coming from the flow peer. An ICMP can come from an intermediate node, which we'd need a separate MAC lookup for. > } > =20 > =20 > @@ -429,6 +431,7 @@ static void udp_send_tap_icmp4(const struct ctx *c, > * udp_send_tap_icmp6() - Construct and send ICMPv6 to local peer > * @c: Execution context > * @ee: Extended error descriptor > + * @uflow: UDP flow > * @toside: Destination side of flow > * @saddr: Address of ICMP generating node > * @in: First bytes (max 1232) of original UDP message body > @@ -437,6 +440,7 @@ static void udp_send_tap_icmp4(const struct ctx *c, > */ > static void udp_send_tap_icmp6(const struct ctx *c, > const struct sock_extended_err *ee, > + const struct udp_flow *uflow, > const struct flowside *toside, > const struct in6_addr *saddr, > void *in, size_t dlen, uint32_t flow) > @@ -466,7 +470,7 @@ static void udp_send_tap_icmp6(const struct ctx *c, > tap_push_uh6(&msg.uh, eaddr, eport, oaddr, oport, in, dlen); > memcpy(&msg.data, in, dlen); > =20 > - tap_icmp6_send(c, saddr, eaddr, &msg, msglen); > + tap_icmp6_send(c, saddr, eaddr, &msg, uflow->f.tap_omac, msglen); Ditto. > } > =20 > /** > @@ -626,12 +630,12 @@ static int udp_sock_recverr(const struct ctx *c, in= t s, flow_sidx_t sidx, > if (hdr->cmsg_level =3D=3D IPPROTO_IP && > (o4 =3D inany_v4(&otap)) && inany_v4(&toside->eaddr)) { > dlen =3D MIN(dlen, ICMP4_MAX_DLEN); > - udp_send_tap_icmp4(c, ee, toside, *o4, data, dlen); > + udp_send_tap_icmp4(c, ee, uflow, toside, *o4, data, dlen); > return 1; > } > =20 > if (hdr->cmsg_level =3D=3D IPPROTO_IPV6 && !inany_v4(&toside->eaddr)) { > - udp_send_tap_icmp6(c, ee, toside, &otap.a6, data, dlen, > + udp_send_tap_icmp6(c, ee, uflow, toside, &otap.a6, data, dlen, > FLOW_IDX(uflow)); > return 1; > } --=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 --3hBMf/RDEWAHHav2 Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmime5kACgkQzQJF27ox 2GdW/g/9GReZJ42GplWE0tAhc3AAjgiL710XEqHupcUns3bMfIz/4DEigO/sbCQZ YU5Sq+TmVofTj3lCCiWjwVHHJ8UUCQtDcHoJx8uHiiskdi+iTJDkG/w5RY6tlM4r zpGyLW4EqFqY2ZHYewylWucF9oZUgfDBJnjvCR0gefUl5YI9P6TEu8wNeg5/AJvi FR/DXERmwBdfm5+3mwldo7oknmKDFo0W0LvwKP0u2jSEmitPQA39JzcTJd6HyX5G 0Bn9F56FSBys9NUi1LhrA0Xb/y0FLkh5zjAVpNu2F5s0Bk7pU/Gti3LXcGV+3RBV qviaRRuP3KNS+5yGNNlbvdyLRUkpI0J3/qWCo1SaaGwmgTKDCau2HJC8p+0Zklqp qAczrhu8vRw3zwuKSIk95DXJ9bvNtdiqyAsm1g8xH8uJmH44kN7X3KnZE/JRZKL2 UwKm0GPZ/RWbLVyVCJ/voJHSDcDY/HrcaKGXS5tItFmMYuorrhelAgQIpvLVUnq3 +i/ESgKWpiUsuHkDe4uiIdHDgUzY7kNj6PEjs9Yzu/QPZX7kvHb/QAGF850sNPGd EzSrwEckB2H9FZat9C8plxnZHM1pfH48iHAF38tvVJdx/n2P+Hh64/I/X8T37ztn U9FAaGTKzODYtWoNNffu56cWYe9yUXxF4fxIJnaLHFJ2Hbv/WGM= =GY9w -----END PGP SIGNATURE----- --3hBMf/RDEWAHHav2--