From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793737893; b=ojDAv0Mi1FwwrTdM0cZHcJoy4ZJ0SD8Wy+DR+CIoJqJOvNEuen8fut+WCKrSYASmLLH4 0rJRcD3svfWn4YTpAt2LJElnneXo1TRMe/Xxitl82OM9lJBBkv9YsCX2XyOLaqqcHkNQF gO7Lwn0RrIIisqtmiGGiNZPtuTvoB0J8eO0Mk/FsZBeoAFokkneb3Vd2fyQPEiqy77nM9 Iq7CODT3EwbdgCLG5izGGMDauSTEoIBMxmywsLA48nhfZWT1kYa3+crHI3huUNPM+xcbK TTlaR+5rp/ZyQW6M3vnSwTYdiSIvsq+DH6HxW3H4NbfzAMuE0M7LDXdfu2BkWlrbIWA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793737893; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=tAuteYskstdeBpCYH9CcsGKkJ76cGxAdPzEGscpfTvM=; b=UoDnGTZXIMIbSOk6hIuaDu6s7qjG3itIVBKX1AV6ja1AirdAk9tUQw+Zo+N1qRE7JKJ/ ACTJ08Sx3LUmo3wKKHvXy3DnLHkCdF5bmjNEWLqsNjACYf6dBkb9vIzcBkT2PhfJzsV7s +AsTnaLwW3ReLfiGRXs4xBNKVGq8RAnA5Fx1pQphIZ5NrLKbQCUCjwTQ3oDPLG1NH8lOr Tq57OnS7edM1z6a+qpKakhx35xvZKbDgwDDZ+iIaqrBTAamoxlQfMAHRPOhCfWsYG+IA8 hJriFOJTUSm3zqAtj+P21VgDzKzJQA76kDfysZwUYzuIXBZFs89Yc8o3yZZTI0O200A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="GeYJtY/C"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A9CFF606A331; Tue, 3 Nov 2026 20:31:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GeYJtY/C Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFD2F1F000C1; Tue, 3 Nov 2026 20:31:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793737892; bh=tAuteYskstdeBpCYH9CcsGKkJ76cGxAdPzEGscpfTvM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GeYJtY/C6ti6m79Gf7a1ihXUA6vPheWq6Xj3tkMSbteES91jzl0CX4+8nGCkFxJs/ gr4wnCZEnvyCP2FnXkMlPF2qgdDTeHtFkn6tlP9PvquiMYwVMwONkSmvqsvK3p1tpu dhQtepYqYBgQvI/BhdL0OSj49MDn9W6nLgxRSgGhxiQEBbUYynaowrZ2QlvSow5UX2 JUJhmOBNQGSyc1R7xybMk+nLn3ielMCO/SGR/PWte7Qxgy3s0q7Hjai5v5RixwZCnX PimQKSierhtJCcs84+TGW/DcHlo31pM4HMDMBRE2KhVpG2jVO2SOQu001YOdXjeMFs b98UGeBxLuMhA== From: Eric Dumazet To: netdev@vger.kernel.org, "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: Eric Dumazet , Simon Horman , Willem de Bruijn , "Michael S. Tsirkin" , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Hassan Sultan , virtualization@lists.linux.dev Subject: [PATCH net 3/3] selftests: net: tun: test outer protocol of UDP tunnel GSO packets Date: Tue, 3 Nov 2026 21:31:13 +0100 Message-ID: <20261103203113.550604-4-edumazet@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261103203113.550604-1-edumazet@kernel.org> References: <20261103203113.550604-1-edumazet@kernel.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a tun_vnet_udptnl_proto fixture writing single 4in4 Geneve GSO frames to a tap device with UDP tunnel offloads enabled: - outer_proto_ok: an outer IPv4 header, with or without an 802.1Q tag, is accepted. - outer_proto_bad: an outer ethertype that does not match the declared tunnel type (IPv6 on an IPv4 tunnel, or NSH, with or without a VLAN tag) is rejected with EINVAL. Without the previous virtio_net patch, outer_proto_bad fails because the kernel accepts the frames. Signed-off-by: Eric Dumazet --- tools/testing/selftests/net/tun.c | 130 ++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) diff --git a/tools/testing/selftests/net/tun.c b/tools/testing/selftests/net/tun.c index 34de2580e32e..47a24b9c477b 100644 --- a/tools/testing/selftests/net/tun.c +++ b/tools/testing/selftests/net/tun.c @@ -683,6 +683,136 @@ TEST_F(tun_vnet_gso, vlan_tcpv4_gso_no_csum_64k) ASSERT_EQ(ret, len); } +#ifndef ETH_P_NSH +#define ETH_P_NSH 0x894F +#endif + +FIXTURE(tun_vnet_udptnl_proto) +{ + char ifname[IFNAMSIZ]; + uint8_t *pkt; + int fd; +}; + +FIXTURE_SETUP(tun_vnet_udptnl_proto) +{ + int flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR; + int features = TUN_F_CSUM | TUN_F_UDP_TUNNEL_GSO | + TUN_F_UDP_TUNNEL_GSO_CSUM | TUN_F_USO4 | TUN_F_USO6; + + self->fd = -1; + if (unshare(CLONE_NEWNET)) + SKIP(return, "Cannot create network namespace: %s", + strerror(errno)); + + self->pkt = calloc(1, MAX_VNET_TUNNEL_PACKET_SZ); + ASSERT_NE(self->pkt, NULL); + + memset(self->ifname, 0, sizeof(self->ifname)); + self->fd = tun_open(self->ifname, flags, TUN_VNET_TNL_SIZE, features, + param_hwaddr_outer_src); + ASSERT_GE(self->fd, 0); +} + +FIXTURE_TEARDOWN(tun_vnet_udptnl_proto) +{ + if (self->fd >= 0) + close(self->fd); + free(self->pkt); +} + +/* Build a 4in4 Geneve GSO frame whose outer ethertype is @l3proto, + * optionally behind an 802.1Q tag. + */ +static int build_udptnl_frame(uint8_t *buf, bool vlan, uint16_t l3proto, + int payload_len) +{ + struct virtio_net_hdr_v1_hash_tunnel *vh = (void *)buf; + int vlan_len = vlan ? 4 : 0; + int hlen = ETH_HLEN + vlan_len + UDP_TUNNEL_GENEVE_4IN4_HDRLEN; + uint8_t *outer_udph, *cur = buf; + int pktlen; + + cur += build_virtio_net_hdr_v1_hash_tunnel(cur, true, hlen, 1400, + AF_INET, AF_INET); + vh->outer_th_offset += vlan_len; + vh->inner_nh_offset += vlan_len; + vh->hash_hdr.hdr.csum_start += vlan_len; + + if (vlan) { + uint16_t vlan_tag[2] = { htons(100), htons(l3proto) }; + + cur += build_eth(cur, ETH_P_8021Q, param_hwaddr_outer_dst, + param_hwaddr_outer_src); + memcpy(cur, vlan_tag, sizeof(vlan_tag)); + cur += sizeof(vlan_tag); + } else { + cur += build_eth(cur, l3proto, param_hwaddr_outer_dst, + param_hwaddr_outer_src); + } + + pktlen = UDP_TUNNEL_GENEVE_4IN4_HDRLEN - sizeof(struct iphdr) + + payload_len; + cur += build_ipv4_header(cur, IPPROTO_UDP, pktlen, + ¶m_ipaddr4_outer_dst, + ¶m_ipaddr4_outer_src); + + outer_udph = cur; + cur += build_udp_header(cur, UDP_SRC_PORT, VN_PORT, + pktlen - sizeof(struct udphdr)); + cur += build_geneve_header(cur, VN_ID); + cur += build_eth(cur, ETH_P_IP, param_hwaddr_inner_dst, + param_hwaddr_inner_src); + cur += build_ipv4_header(cur, IPPROTO_UDP, + sizeof(struct udphdr) + payload_len, + ¶m_ipaddr4_inner_dst, + ¶m_ipaddr4_inner_src); + cur += build_udp_packet(cur, UDP_DST_PORT, UDP_SRC_PORT, payload_len, + AF_INET, false); + build_udp_packet_csum(outer_udph, AF_INET, false); + + return cur - buf; +} + +TEST_F(tun_vnet_udptnl_proto, outer_proto_ok) +{ + uint8_t *pkt = self->pkt; + int len, ret; + + len = build_udptnl_frame(pkt, false, ETH_P_IP, 2800); + ret = write(self->fd, pkt, len); + ASSERT_EQ(ret, len); + + /* The outer IPv4 header can follow a VLAN tag. */ + len = build_udptnl_frame(pkt, true, ETH_P_IP, 2800); + ret = write(self->fd, pkt, len); + ASSERT_EQ(ret, len); +} + +TEST_F(tun_vnet_udptnl_proto, outer_proto_bad) +{ + uint8_t *pkt = self->pkt; + int len, ret; + + /* Outer ethertype does not match the declared IPv4 tunnel. */ + len = build_udptnl_frame(pkt, false, ETH_P_IPV6, 2800); + ret = write(self->fd, pkt, len); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, EINVAL); + + /* Outer header is not IP at all. */ + len = build_udptnl_frame(pkt, false, ETH_P_NSH, 2800); + ret = write(self->fd, pkt, len); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, EINVAL); + + /* Same, behind a VLAN tag. */ + len = build_udptnl_frame(pkt, true, ETH_P_NSH, 2800); + ret = write(self->fd, pkt, len); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, EINVAL); +} + FIXTURE(tun_vnet_udptnl) { char ifname[IFNAMSIZ]; -- 2.53.0