In preparation for testing GSO over UDP tunnels, enhance the test infrastructure to support a more complex data path involving a TUN device and a VXLAN tunnel.
This patch introduces a dedicated setup/teardown topology that creates both a VXLAN tunnel interface and a TUN interface. The TUN device acts as the VTEP (Virtual Tunnel Endpoint), allowing it to send and receive virtio-net packets. Note that after adding a new address to the UDP tunnel, we need to wait a bit until the associated route is available. This setup effectively tests the kernel's data path for encapsulated traffic.
Additionally, a new data structure is defined to manage test parameters. This structure is designed to be extensible, allowing different test data and configurations to be easily added in subsequent patches.
Signed-off-by: Xu Du xudu@redhat.com --- v1 -> v2: - Explicitly wait for successful target route lookup before transmitting the packets. - Add UDP connect() to verify remote reachability. - Abstract address assignment logic into helpers.
tools/testing/selftests/net/tun.c | 439 ++++++++++++++++++++++++++++++ 1 file changed, 439 insertions(+)
diff --git a/tools/testing/selftests/net/tun.c b/tools/testing/selftests/net/tun.c index 08e760fa5d15..add5e91df6c9 100644 --- a/tools/testing/selftests/net/tun.c +++ b/tools/testing/selftests/net/tun.c @@ -15,6 +15,78 @@ #include "kselftest_harness.h" #include "tuntap_helpers.h"
+static const char param_dev_vxlan_name[] = "vxlan1"; +static unsigned char param_hwaddr_outer_dst[] = { 0x00, 0xfe, 0x98, + 0x14, 0x22, 0x42 }; +static unsigned char param_hwaddr_outer_src[] = { 0x00, 0xfe, 0x98, + 0x94, 0xd2, 0x43 }; +static unsigned char param_hwaddr_inner_dst[] = { 0x00, 0xfe, 0x98, + 0x94, 0x22, 0xcc }; +static unsigned char param_hwaddr_inner_src[] = { 0x00, 0xfe, 0x98, + 0x94, 0xd2, 0xdd }; + +static struct in_addr param_ipaddr4_outer_dst = { + __constant_htonl(0xac100001), +}; + +static struct in_addr param_ipaddr4_outer_src = { + __constant_htonl(0xac100002), +}; + +static struct in_addr param_ipaddr4_inner_dst = { + __constant_htonl(0xac100101), +}; + +static struct in_addr param_ipaddr4_inner_src = { + __constant_htonl(0xac100102), +}; + +static struct in6_addr param_ipaddr6_outer_dst = { + { { 0x20, 0x02, 0x0d, 0xb8, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 } }, +}; + +static struct in6_addr param_ipaddr6_outer_src = { + { { 0x20, 0x02, 0x0d, 0xb8, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 } }, +}; + +static struct in6_addr param_ipaddr6_inner_dst = { + { { 0x20, 0x02, 0x0d, 0xb8, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 } }, +}; + +static struct in6_addr param_ipaddr6_inner_src = { + { { 0x20, 0x02, 0x0d, 0xb8, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 } }, +}; + +#define VN_ID 1 +#define VN_PORT 4789 +#define UDP_SRC_PORT 22 +#define UDP_DST_PORT 48878 +#define IPPREFIX_LEN 24 +#define IP6PREFIX_LEN 64 +#define TIMEOUT_SEC 10 +#define TIMEOUT_USEC 100000 +#define MAX_RETRIES 20 + +#define UDP_TUNNEL_VXLAN_4IN4 0x01 +#define UDP_TUNNEL_VXLAN_6IN4 0x02 +#define UDP_TUNNEL_VXLAN_4IN6 0x04 +#define UDP_TUNNEL_VXLAN_6IN6 0x08 + +#define UDP_TUNNEL_OUTER_IPV4 (UDP_TUNNEL_VXLAN_4IN4 | UDP_TUNNEL_VXLAN_6IN4) +#define UDP_TUNNEL_INNER_IPV4 (UDP_TUNNEL_VXLAN_4IN4 | UDP_TUNNEL_VXLAN_4IN6) + +#define TUN_VNET_TNL_SIZE sizeof(struct virtio_net_hdr_v1_hash_tunnel) + +struct vxlan_setup_config { + struct sockaddr_storage local_ip; + struct sockaddr_storage remote_ip; + __be32 vni; + int remote_ifindex; + __be16 dst_port; + unsigned char hwaddr[6]; + uint8_t csum; +}; + static int tun_attach(int fd, char *dev) { struct ifreq ifr; @@ -67,6 +139,198 @@ static int tun_delete(char *dev) return dev_delete(dev); }
+static size_t sockaddr_len(int family) +{ + return (family == AF_INET) ? sizeof(struct sockaddr_in) : + sizeof(struct sockaddr_in6); +} + +static int tun_open(char *dev, const int flags, const int hdrlen, + const int features, const unsigned char *mac_addr) +{ + struct ifreq ifr = { 0 }; + int fd, sk = -1; + + fd = open("/dev/net/tun", O_RDWR); + if (fd < 0) { + perror("open"); + return -1; + } + + ifr.ifr_flags = flags; + if (ioctl(fd, TUNSETIFF, (void *)&ifr) < 0) { + perror("ioctl(TUNSETIFF)"); + goto err; + } + strcpy(dev, ifr.ifr_name); + + if (hdrlen > 0) { + if (ioctl(fd, TUNSETVNETHDRSZ, &hdrlen) < 0) { + perror("ioctl(TUNSETVNETHDRSZ)"); + goto err; + } + } + + if (features) { + if (ioctl(fd, TUNSETOFFLOAD, features) < 0) { + perror("ioctl(TUNSETOFFLOAD)"); + goto err; + } + } + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) { + perror("socket"); + goto err; + } + + if (ioctl(sk, SIOCGIFFLAGS, &ifr) < 0) { + perror("ioctl(SIOCGIFFLAGS)"); + goto err; + } + + ifr.ifr_flags |= (IFF_UP | IFF_RUNNING); + if (ioctl(sk, SIOCSIFFLAGS, &ifr) < 0) { + perror("ioctl(SIOCSIFFLAGS)"); + goto err; + } + + if (mac_addr && flags & IFF_TAP) { + ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; + memcpy(ifr.ifr_hwaddr.sa_data, mac_addr, ETH_ALEN); + + if (ioctl(sk, SIOCSIFHWADDR, &ifr) < 0) { + perror("ioctl(SIOCSIFHWADDR)"); + goto err; + } + } + +out: + if (sk >= 0) + close(sk); + return fd; + +err: + close(fd); + fd = -1; + goto out; +} + +static int vxlan_fill_rtattr(struct nlmsghdr *nh, void *data) +{ + struct vxlan_setup_config *vxlan = data; + + rtattr_add_any(nh, IFLA_ADDRESS, vxlan->hwaddr, ETH_ALEN); + return 0; +} + +static int vxlan_fill_info_data(struct nlmsghdr *nh, void *data) +{ + struct vxlan_setup_config *vxlan = data; + + rtattr_add_any(nh, IFLA_VXLAN_LINK, &vxlan->remote_ifindex, + sizeof(vxlan->remote_ifindex)); + rtattr_add_any(nh, IFLA_VXLAN_ID, &vxlan->vni, sizeof(vxlan->vni)); + rtattr_add_any(nh, IFLA_VXLAN_PORT, &vxlan->dst_port, + sizeof(vxlan->dst_port)); + rtattr_add_any(nh, IFLA_VXLAN_UDP_CSUM, &vxlan->csum, + sizeof(vxlan->csum)); + + if (vxlan->remote_ip.ss_family == AF_INET) { + struct sockaddr_in *r = (struct sockaddr_in *)&vxlan->remote_ip; + struct sockaddr_in *l = (struct sockaddr_in *)&vxlan->local_ip; + + rtattr_add_any(nh, IFLA_VXLAN_GROUP, &r->sin_addr, + sizeof(struct in_addr)); + rtattr_add_any(nh, IFLA_VXLAN_LOCAL, &l->sin_addr, + sizeof(struct in_addr)); + } else { + struct sockaddr_in6 *r6 = + (struct sockaddr_in6 *)&vxlan->remote_ip; + struct sockaddr_in6 *l6 = + (struct sockaddr_in6 *)&vxlan->local_ip; + + rtattr_add_any(nh, IFLA_VXLAN_GROUP6, &r6->sin6_addr, + sizeof(struct in6_addr)); + rtattr_add_any(nh, IFLA_VXLAN_LOCAL6, &l6->sin6_addr, + sizeof(struct in6_addr)); + } + + return 0; +} + +static int set_pmtu_discover(int fd, bool is_ipv4) +{ + int level, name, val; + + if (is_ipv4) { + level = SOL_IP; + name = IP_MTU_DISCOVER; + val = IP_PMTUDISC_DO; + } else { + level = SOL_IPV6; + name = IPV6_MTU_DISCOVER; + val = IPV6_PMTUDISC_DO; + } + + return setsockopt(fd, level, name, &val, sizeof(val)); +} + +static int udp_socket_open(struct sockaddr_storage *ssa, bool do_frag, + bool do_connect, struct sockaddr_storage *dsa) +{ + struct timeval to = { .tv_sec = TIMEOUT_SEC }; + int fd, family = ssa->ss_family; + int salen = sockaddr_len(family); + + fd = socket(family, SOCK_DGRAM, 0); + if (fd < 0) + return -1; + + if (bind(fd, (struct sockaddr *)ssa, salen) < 0) { + perror("bind"); + goto err; + } + + if (do_connect && connect(fd, (struct sockaddr *)dsa, salen) < 0) { + perror("connect"); + goto err; + } + + if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &to, sizeof(to)) < 0) { + perror("setsockopt(SO_RCVTIMEO)"); + goto err; + } + + if (!do_frag && set_pmtu_discover(fd, family == AF_INET) < 0) { + perror("set_pmtu_discover"); + goto err; + } + return fd; + +err: + close(fd); + return -1; +} + +static int ip_route_check(const char *intf, int family, void *addr) +{ + int len = ip_addr_len(family) * 8; + int retries = MAX_RETRIES; + + while (retries-- > 0) { + if (ip_route_get(intf, family, addr, len, RTN_LOCAL, + RT_TABLE_LOCAL) > 0) + break; + usleep(TIMEOUT_USEC); + } + + if (retries < 0) + return -1; + + return 0; +} + FIXTURE(tun) { char ifname[IFNAMSIZ]; @@ -129,4 +393,179 @@ TEST_F(tun, reattach_close_delete) EXPECT_EQ(tun_delete(self->ifname), 0); }
+FIXTURE(tun_vnet_udptnl) +{ + char ifname[IFNAMSIZ]; + int fd, sock; +}; + +FIXTURE_VARIANT(tun_vnet_udptnl) +{ + int tunnel_type; + bool is_tap; +}; + +/* clang-format off */ +#define TUN_VNET_UDPTNL_VARIANT_ADD(type, desc) \ + FIXTURE_VARIANT_ADD(tun_vnet_udptnl, desc##udptnl) { \ + .tunnel_type = type, \ + .is_tap = true, \ + } +/* clang-format on */ + +TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_VXLAN_4IN4, 4in4); +TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_VXLAN_6IN4, 6in4); +TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_VXLAN_4IN6, 4in6); +TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_VXLAN_6IN6, 6in6); + +static void assign_ifaddr_vars(int family, int is_outer, void **srcip, + void **dstip, void **lladdr, int *prefix) +{ + if (is_outer) { + if (family == AF_INET) { + *srcip = (void *)¶m_ipaddr4_outer_src; + *dstip = (void *)¶m_ipaddr4_outer_dst; + } else { + *srcip = (void *)¶m_ipaddr6_outer_src; + *dstip = (void *)¶m_ipaddr6_outer_dst; + } + *lladdr = param_hwaddr_outer_dst; + } else { + if (family == AF_INET) { + *srcip = (void *)¶m_ipaddr4_inner_src; + *dstip = (void *)¶m_ipaddr4_inner_dst; + } else { + *srcip = (void *)¶m_ipaddr6_inner_src; + *dstip = (void *)¶m_ipaddr6_inner_dst; + } + *lladdr = param_hwaddr_inner_dst; + } + *prefix = (family == AF_INET) ? IPPREFIX_LEN : IP6PREFIX_LEN; +} + +static void assign_sockaddr_vars(int family, int is_outer, + struct sockaddr_storage *src, + struct sockaddr_storage *dst) +{ + struct sockaddr_in6 *s6, *d6; + struct sockaddr_in *s4, *d4; + + if (is_outer) { + if (family == AF_INET) { + s4 = (struct sockaddr_in *)src; + d4 = (struct sockaddr_in *)dst; + s4->sin_family = AF_INET; + d4->sin_family = AF_INET; + s4->sin_addr = param_ipaddr4_outer_src; + d4->sin_addr = param_ipaddr4_outer_dst; + } else { + s6 = (struct sockaddr_in6 *)src; + d6 = (struct sockaddr_in6 *)dst; + s6->sin6_family = AF_INET6; + d6->sin6_family = AF_INET6; + s6->sin6_addr = param_ipaddr6_outer_src; + d6->sin6_addr = param_ipaddr6_outer_dst; + } + } else { + if (family == AF_INET) { + s4 = (struct sockaddr_in *)src; + d4 = (struct sockaddr_in *)dst; + s4->sin_family = AF_INET; + d4->sin_family = AF_INET; + s4->sin_addr = param_ipaddr4_inner_src; + d4->sin_addr = param_ipaddr4_inner_dst; + s4->sin_port = htons(UDP_SRC_PORT); + d4->sin_port = htons(UDP_DST_PORT); + } else { + s6 = (struct sockaddr_in6 *)src; + d6 = (struct sockaddr_in6 *)dst; + s6->sin6_family = AF_INET6; + d6->sin6_family = AF_INET6; + s6->sin6_addr = param_ipaddr6_inner_src; + d6->sin6_addr = param_ipaddr6_inner_dst; + s6->sin6_port = htons(UDP_SRC_PORT); + d6->sin6_port = htons(UDP_DST_PORT); + } + } +} + +FIXTURE_SETUP(tun_vnet_udptnl) +{ + int ret, family, prefix, flags, features; + int tunnel_type = variant->tunnel_type; + struct sockaddr_storage ssa, dsa; + struct vxlan_setup_config vxlan; + void *srcip, *dstip, *lladdr; + + flags = (variant->is_tap ? IFF_TAP : IFF_TUN) | IFF_VNET_HDR | + IFF_MULTI_QUEUE | IFF_NO_PI; + features = TUN_F_CSUM | TUN_F_UDP_TUNNEL_GSO | + TUN_F_UDP_TUNNEL_GSO_CSUM | TUN_F_USO4 | TUN_F_USO6; + self->fd = tun_open(self->ifname, flags, TUN_VNET_TNL_SIZE, features, + param_hwaddr_outer_src); + ASSERT_GE(self->fd, 0); + + family = (tunnel_type & UDP_TUNNEL_OUTER_IPV4) ? AF_INET : AF_INET6; + assign_ifaddr_vars(family, 1, &srcip, &dstip, &lladdr, &prefix); + + ret = ip_addr_add(self->ifname, family, srcip, prefix); + ASSERT_EQ(ret, 0); + ret = ip_neigh_add(self->ifname, family, dstip, lladdr); + ASSERT_EQ(ret, 0); + ret = ip_route_check(self->ifname, family, srcip); + ASSERT_EQ(ret, 0); + + assign_sockaddr_vars(family, 1, &ssa, &dsa); + memset(&vxlan, 0, sizeof(vxlan)); + vxlan.vni = VN_ID; + vxlan.dst_port = htons(VN_PORT); + vxlan.csum = 1; + vxlan.remote_ifindex = if_nametoindex(self->ifname); + vxlan.local_ip = ssa; + vxlan.remote_ip = dsa; + memcpy(vxlan.hwaddr, param_hwaddr_inner_src, ETH_ALEN); + + ret = dev_create(param_dev_vxlan_name, "vxlan", vxlan_fill_rtattr, + vxlan_fill_info_data, (void *)&vxlan); + ASSERT_EQ(ret, 0); + + family = (tunnel_type & UDP_TUNNEL_INNER_IPV4) ? AF_INET : AF_INET6; + assign_ifaddr_vars(family, 0, &srcip, &dstip, &lladdr, &prefix); + + ret = ip_addr_add(param_dev_vxlan_name, family, srcip, prefix); + ASSERT_EQ(ret, 0); + ret = ip_neigh_add(param_dev_vxlan_name, family, dstip, lladdr); + ASSERT_EQ(ret, 0); + ret = ip_route_check(param_dev_vxlan_name, family, srcip); + ASSERT_EQ(ret, 0); + + assign_sockaddr_vars(family, 0, &ssa, &dsa); + self->sock = udp_socket_open(&ssa, false, true, &dsa); + ASSERT_GE(self->sock, 0); +} + +FIXTURE_TEARDOWN(tun_vnet_udptnl) +{ + int ret; + + if (self->sock != -1) + close(self->sock); + + ret = dev_delete(param_dev_vxlan_name); + EXPECT_EQ(ret, 0); + + ret = tun_delete(self->ifname); + EXPECT_EQ(ret, 0); +} + +TEST_F(tun_vnet_udptnl, basic) +{ + int ret; + char cmd[256] = { 0 }; + + sprintf(cmd, "ip addr show %s > /dev/null 2>&1", param_dev_vxlan_name); + ret = system(cmd); + ASSERT_EQ(ret, 0); +} + TEST_HARNESS_MAIN