From nobody Fri Jan 9 18:19:47 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEFD32868B2 for ; Tue, 6 Jan 2026 01:35:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767663357; cv=none; b=MKY1cjB6PUxG8zLQ87cB+k5QEgUmPciTBazN1J9K+BL7JaRNZOuYZfruaCxWOfX42to8YF5bGRw1SmRSdieLako6f2TWl3yfVwvDjynB6O9dioGa+OOL/LAt7yDIzD5tyq8d6qmr97X9XHuj7EhpHnHqkSDtDy4YNkEKMph4rYo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767663357; c=relaxed/simple; bh=Zq1Setti4rHsB3+ThqaDAQ01swL11cF1fNxgGM0PHeo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GOXd0zIqZJYHlF/zSD4wBnZVRcSQRCBTcsbYe4qqRVwpgzLVkt2XBQs9ir8ieei1EtaitXjJOwdXQiXu2gwzeZBhTHAd5kjyxqbCkeRDlddIW0MdW7ArVmpUhqOkwlqGSpMPEauGAefEXtXJ5rk0WM8y6j8lK330vgs0SwieEes= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YAYFpxkN; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YAYFpxkN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767663354; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=LRz+JUHDJPTQK9o/T4QW/5UA/qmHHVcBln6aFBJ9uxQ=; b=YAYFpxkNTye3gkDRc2SNeUUr+IIDJFNpr0LDg7Jdi7K2LmLGw7WYopJHWeFtNb+AJjsliX LxrrrGu/ZicRcEMJvVuhkH7ZCuejK1KpO588eQB7BoiYQD4cyralFZ/veAWjgbajqI12vV 5lyjE2WzWc41iJdboCD/dmC+qNfqZxI= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-384-Frkikj4sMBun2xyuv6aUTg-1; Mon, 05 Jan 2026 20:35:49 -0500 X-MC-Unique: Frkikj4sMBun2xyuv6aUTg-1 X-Mimecast-MFC-AGG-ID: Frkikj4sMBun2xyuv6aUTg_1767663348 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CB8971800365; Tue, 6 Jan 2026 01:35:47 +0000 (UTC) Received: from xudu-thinkpadx1carbongen9.nay.csb (unknown [10.66.60.72]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D817018004D4; Tue, 6 Jan 2026 01:35:43 +0000 (UTC) From: Xu Du To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, shuah@kernel.org Cc: netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v4 4/8] selftest: tap: Refactor tap test to use tuntap_helpers Date: Tue, 6 Jan 2026 09:35:17 +0800 Message-ID: <02a1295475c7218510e9a808ad8f97bb6005cdfc.1767597114.git.xudu@redhat.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Refactor existing TAP test cases to use the previously introduced tuntap_helpers from tuntap_helpers.h for device setup, packet construction, and cleanup. This reduces code duplication, improves test maintainability, and ensures consistent behavior across test scenarios. Signed-off-by: Xu Du --- v1 -> v2: - Add mactap IFLA_ADDRESS attribute. - Fix incorrect argument order in build_eth and build_ipv4_header. tools/testing/selftests/net/tap.c | 281 +++++------------------------- 1 file changed, 41 insertions(+), 240 deletions(-) diff --git a/tools/testing/selftests/net/tap.c b/tools/testing/selftests/ne= t/tap.c index a0c9418132c8..6793e47d67a7 100644 --- a/tools/testing/selftests/net/tap.c +++ b/tools/testing/selftests/net/tap.c @@ -10,14 +10,13 @@ #include #include #include -#include -#include #include #include #include #include #include #include "kselftest_harness.h" +#include "tuntap_helpers.h" =20 static const char param_dev_tap_name[] =3D "xmacvtap0"; static const char param_dev_dummy_name[] =3D "xdummy0"; @@ -26,161 +25,36 @@ static unsigned char param_hwaddr_dest[] =3D { 0x00, 0xfe, 0x98, 0x94, 0xd2, 0x43 }; =20 -#define MAX_RTNL_PAYLOAD (2048) -#define PKT_DATA 0xCB -#define TEST_PACKET_SZ (sizeof(struct virtio_net_hdr) + ETH_HLEN + ETH_MAX= _MTU) - -static struct rtattr *rtattr_add(struct nlmsghdr *nh, unsigned short type, - unsigned short len) -{ - struct rtattr *rta =3D - (struct rtattr *)((uint8_t *)nh + RTA_ALIGN(nh->nlmsg_len)); - rta->rta_type =3D type; - rta->rta_len =3D RTA_LENGTH(len); - nh->nlmsg_len =3D RTA_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len); - return rta; -} - -static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short typ= e) -{ - return rtattr_add(nh, type, 0); -} - -static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr) -{ - uint8_t *end =3D (uint8_t *)nh + nh->nlmsg_len; - - attr->rta_len =3D end - (uint8_t *)attr; -} - -static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short t= ype, - const char *s) -{ - unsigned int strsz =3D strlen(s) + 1; - struct rtattr *rta; - - rta =3D rtattr_add(nh, type, strsz); - - memcpy(RTA_DATA(rta), s, strsz); - return rta; -} - -static struct rtattr *rtattr_add_any(struct nlmsghdr *nh, unsigned short t= ype, - const void *arr, size_t len) -{ - struct rtattr *rta =3D rtattr_add(nh, type, len); - - memcpy(RTA_DATA(rta), arr, len); - return rta; -} - -static int dev_create(const char *dev, const char *link_type, - int (*fill_rtattr)(struct nlmsghdr *nh), - int (*fill_info_data)(struct nlmsghdr *nh)) -{ - struct { - struct nlmsghdr nh; - struct ifinfomsg info; - unsigned char data[MAX_RTNL_PAYLOAD]; - } req; - struct rtattr *link_info, *info_data; - int ret, rtnl; - - rtnl =3D socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); - if (rtnl < 0) { - fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno)); - return 1; - } - - memset(&req, 0, sizeof(req)); - req.nh.nlmsg_len =3D NLMSG_LENGTH(sizeof(req.info)); - req.nh.nlmsg_flags =3D NLM_F_REQUEST | NLM_F_CREATE; - req.nh.nlmsg_type =3D RTM_NEWLINK; - - req.info.ifi_family =3D AF_UNSPEC; - req.info.ifi_type =3D 1; - req.info.ifi_index =3D 0; - req.info.ifi_flags =3D IFF_BROADCAST | IFF_UP; - req.info.ifi_change =3D 0xffffffff; - - rtattr_add_str(&req.nh, IFLA_IFNAME, dev); - - if (fill_rtattr) { - ret =3D fill_rtattr(&req.nh); - if (ret) - return ret; - } - - link_info =3D rtattr_begin(&req.nh, IFLA_LINKINFO); - - rtattr_add_str(&req.nh, IFLA_INFO_KIND, link_type); - - if (fill_info_data) { - info_data =3D rtattr_begin(&req.nh, IFLA_INFO_DATA); - ret =3D fill_info_data(&req.nh); - if (ret) - return ret; - rtattr_end(&req.nh, info_data); - } - - rtattr_end(&req.nh, link_info); - - ret =3D send(rtnl, &req, req.nh.nlmsg_len, 0); - if (ret < 0) - fprintf(stderr, "%s: send %s\n", __func__, strerror(errno)); - ret =3D (unsigned int)ret !=3D req.nh.nlmsg_len; - - close(rtnl); - return ret; -} - -static int dev_delete(const char *dev) -{ - struct { - struct nlmsghdr nh; - struct ifinfomsg info; - unsigned char data[MAX_RTNL_PAYLOAD]; - } req; - int ret, rtnl; - - rtnl =3D socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); - if (rtnl < 0) { - fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno)); - return 1; - } - - memset(&req, 0, sizeof(req)); - req.nh.nlmsg_len =3D NLMSG_LENGTH(sizeof(req.info)); - req.nh.nlmsg_flags =3D NLM_F_REQUEST; - req.nh.nlmsg_type =3D RTM_DELLINK; - - req.info.ifi_family =3D AF_UNSPEC; - - rtattr_add_str(&req.nh, IFLA_IFNAME, dev); +static struct in_addr param_ipaddr_src =3D { + __constant_htonl(0xac110002), +}; =20 - ret =3D send(rtnl, &req, req.nh.nlmsg_len, 0); - if (ret < 0) - fprintf(stderr, "%s: send %s\n", __func__, strerror(errno)); +static struct in_addr param_ipaddr_dst =3D { + __constant_htonl(0xac110001), +}; =20 - ret =3D (unsigned int)ret !=3D req.nh.nlmsg_len; +#define UDP_SRC_PORT 22 +#define UDP_DST_PORT 58822 +#define TEST_PACKET_SZ (sizeof(struct virtio_net_hdr) + ETH_HLEN + ETH_MAX= _MTU) =20 - close(rtnl); - return ret; -} +struct mactap_setup_config { + char name[IFNAMSIZ]; + unsigned char hwaddr[ETH_ALEN]; +}; =20 -static int macvtap_fill_rtattr(struct nlmsghdr *nh) +static int macvtap_fill_rtattr(struct nlmsghdr *nh, void *data) { + struct mactap_setup_config *mactap =3D data; int ifindex; =20 - ifindex =3D if_nametoindex(param_dev_dummy_name); + ifindex =3D if_nametoindex(mactap->name); if (ifindex =3D=3D 0) { fprintf(stderr, "%s: ifindex %s\n", __func__, strerror(errno)); return -errno; } =20 rtattr_add_any(nh, IFLA_LINK, &ifindex, sizeof(ifindex)); - rtattr_add_any(nh, IFLA_ADDRESS, param_hwaddr_src, ETH_ALEN); - + rtattr_add_any(nh, IFLA_ADDRESS, mactap->hwaddr, ETH_ALEN); return 0; } =20 @@ -212,91 +86,6 @@ static int opentap(const char *devname) return fd; } =20 -size_t build_eth(uint8_t *buf, uint16_t proto) -{ - struct ethhdr *eth =3D (struct ethhdr *)buf; - - eth->h_proto =3D htons(proto); - memcpy(eth->h_source, param_hwaddr_src, ETH_ALEN); - memcpy(eth->h_dest, param_hwaddr_dest, ETH_ALEN); - - return ETH_HLEN; -} - -static uint32_t add_csum(const uint8_t *buf, int len) -{ - uint32_t sum =3D 0; - uint16_t *sbuf =3D (uint16_t *)buf; - - while (len > 1) { - sum +=3D *sbuf++; - len -=3D 2; - } - - if (len) - sum +=3D *(uint8_t *)sbuf; - - return sum; -} - -static uint16_t finish_ip_csum(uint32_t sum) -{ - uint16_t lo =3D sum & 0xffff; - uint16_t hi =3D sum >> 16; - - return ~(lo + hi); - -} - -static uint16_t build_ip_csum(const uint8_t *buf, int len, - uint32_t sum) -{ - sum +=3D add_csum(buf, len); - return finish_ip_csum(sum); -} - -static int build_ipv4_header(uint8_t *buf, int payload_len) -{ - struct iphdr *iph =3D (struct iphdr *)buf; - - iph->ihl =3D 5; - iph->version =3D 4; - iph->ttl =3D 8; - iph->tot_len =3D - htons(sizeof(*iph) + sizeof(struct udphdr) + payload_len); - iph->id =3D htons(1337); - iph->protocol =3D IPPROTO_UDP; - iph->saddr =3D htonl((172 << 24) | (17 << 16) | 2); - iph->daddr =3D htonl((172 << 24) | (17 << 16) | 1); - iph->check =3D build_ip_csum(buf, iph->ihl << 2, 0); - - return iph->ihl << 2; -} - -static int build_udp_packet(uint8_t *buf, int payload_len, bool csum_off) -{ - const int ip4alen =3D sizeof(uint32_t); - struct udphdr *udph =3D (struct udphdr *)buf; - int len =3D sizeof(*udph) + payload_len; - uint32_t sum =3D 0; - - udph->source =3D htons(22); - udph->dest =3D htons(58822); - udph->len =3D htons(len); - - memset(buf + sizeof(struct udphdr), PKT_DATA, payload_len); - - sum =3D add_csum(buf - 2 * ip4alen, 2 * ip4alen); - sum +=3D htons(IPPROTO_UDP) + udph->len; - - if (!csum_off) - sum +=3D add_csum(buf, len); - - udph->check =3D finish_ip_csum(sum); - - return sizeof(*udph) + payload_len; -} - size_t build_test_packet_valid_udp_gso(uint8_t *buf, size_t payload_len) { uint8_t *cur =3D buf; @@ -310,9 +99,12 @@ size_t build_test_packet_valid_udp_gso(uint8_t *buf, si= ze_t payload_len) vh->gso_size =3D ETH_DATA_LEN - sizeof(struct iphdr); cur +=3D sizeof(*vh); =20 - cur +=3D build_eth(cur, ETH_P_IP); - cur +=3D build_ipv4_header(cur, payload_len); - cur +=3D build_udp_packet(cur, payload_len, true); + cur +=3D build_eth(cur, ETH_P_IP, param_hwaddr_src, param_hwaddr_dest); + cur +=3D build_ipv4_header(cur, IPPROTO_UDP, + payload_len + sizeof(struct udphdr), + ¶m_ipaddr_src, ¶m_ipaddr_dst); + cur +=3D build_udp_packet(cur, UDP_SRC_PORT, UDP_DST_PORT, payload_len, + AF_INET, true); =20 return cur - buf; } @@ -326,9 +118,12 @@ size_t build_test_packet_valid_udp_csum(uint8_t *buf, = size_t payload_len) vh->gso_type =3D VIRTIO_NET_HDR_GSO_NONE; cur +=3D sizeof(*vh); =20 - cur +=3D build_eth(cur, ETH_P_IP); - cur +=3D build_ipv4_header(cur, payload_len); - cur +=3D build_udp_packet(cur, payload_len, false); + cur +=3D build_eth(cur, ETH_P_IP, param_hwaddr_src, param_hwaddr_dest); + cur +=3D build_ipv4_header(cur, IPPROTO_UDP, + payload_len + sizeof(struct udphdr), + ¶m_ipaddr_src, ¶m_ipaddr_dst); + cur +=3D build_udp_packet(cur, UDP_SRC_PORT, UDP_DST_PORT, payload_len, + AF_INET, false); =20 return cur - buf; } @@ -345,10 +140,13 @@ size_t build_test_packet_crash_tap_invalid_eth_proto(= uint8_t *buf, vh->gso_size =3D ETH_DATA_LEN - sizeof(struct iphdr); cur +=3D sizeof(*vh); =20 - cur +=3D build_eth(cur, 0); + cur +=3D build_eth(cur, ETH_P_IP, param_hwaddr_src, param_hwaddr_dest); cur +=3D sizeof(struct iphdr) + sizeof(struct udphdr); - cur +=3D build_ipv4_header(cur, payload_len); - cur +=3D build_udp_packet(cur, payload_len, true); + cur +=3D build_ipv4_header(cur, IPPROTO_UDP, + payload_len + sizeof(struct udphdr), + ¶m_ipaddr_src, ¶m_ipaddr_dst); + cur +=3D build_udp_packet(cur, UDP_SRC_PORT, UDP_DST_PORT, payload_len, + AF_INET, true); cur +=3D payload_len; =20 return cur - buf; @@ -362,12 +160,15 @@ FIXTURE(tap) FIXTURE_SETUP(tap) { int ret; + struct mactap_setup_config mactap_config; =20 - ret =3D dev_create(param_dev_dummy_name, "dummy", NULL, NULL); + ret =3D dev_create(param_dev_dummy_name, "dummy", NULL, NULL, NULL); EXPECT_EQ(ret, 0); =20 + strcpy(mactap_config.name, param_dev_dummy_name); + memcpy(mactap_config.hwaddr, param_hwaddr_src, ETH_ALEN); ret =3D dev_create(param_dev_tap_name, "macvtap", macvtap_fill_rtattr, - NULL); + NULL, &mactap_config); EXPECT_EQ(ret, 0); =20 self->fd =3D opentap(param_dev_tap_name); --=20 2.49.0