Commit 24e59f26 authored by Xu Du's avatar Xu Du Committed by Jakub Kicinski
Browse files

selftest: tun: Add helpers for GSO over UDP tunnel 



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 GENEVE udp tunnel.

This patch introduces a dedicated setup/teardown topology that creates
both a GENEVE 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. This setup effectively tests the kernel's data path
for encapsulated traffic.

Note that after adding a new address to the UDP tunnel, we need to wait
a bit until the associated route is available.

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: default avatarXu Du <xudu@redhat.com>
Link: https://patch.msgid.link/b5787b8c269f43ce11e1756f1691cc7fd9a1e901.1768979440.git.xudu@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 82cfdcfa

tools/testing/selftests/net/tun.c

+425 −0
Original line number Diff line number Diff line
@@ -15,6 +15,80 @@ 
#include "kselftest_harness.h"

#include "tuntap_helpers.h"



static const char param_dev_geneve_name[] = "geneve1";

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_GENEVE_4IN4 0x01

#define UDP_TUNNEL_GENEVE_6IN4 0x02

#define UDP_TUNNEL_GENEVE_4IN6 0x04

#define UDP_TUNNEL_GENEVE_6IN6 0x08



#define UDP_TUNNEL_OUTER_IPV4 (UDP_TUNNEL_GENEVE_4IN4 | UDP_TUNNEL_GENEVE_6IN4)

#define UDP_TUNNEL_INNER_IPV4 (UDP_TUNNEL_GENEVE_4IN4 | UDP_TUNNEL_GENEVE_4IN6)



#define TUN_VNET_TNL_SIZE sizeof(struct virtio_net_hdr_v1_hash_tunnel)



struct geneve_setup_config {

	int family;

	union {

		struct in_addr r4;

		struct in6_addr r6;

	} remote;

	__be32 vnid;

	__be16 vnport;

	unsigned char hwaddr[6];

	uint8_t csum;

};



static int tun_attach(int fd, char *dev)

{

	struct ifreq ifr;
@@ -67,6 +141,202 @@ static int tun_delete(char *dev) 
	return ip_link_del(dev);

}



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 size_t sockaddr_len(int family)

{

	return (family == AF_INET) ? sizeof(struct sockaddr_in) :

				     sizeof(struct sockaddr_in6);

}



static int geneve_fill_newlink(struct rt_link_newlink_req *req, void *data)

{

	struct geneve_setup_config *cfg = data;



#define SET_GENEVE_REMOTE rt_link_newlink_req_set_linkinfo_data_geneve_remote

#define SET_GENEVE_REMOTE6 rt_link_newlink_req_set_linkinfo_data_geneve_remote6



	rt_link_newlink_req_set_address(req, cfg->hwaddr, ETH_ALEN);

	rt_link_newlink_req_set_linkinfo_data_geneve_id(req, cfg->vnid);

	rt_link_newlink_req_set_linkinfo_data_geneve_port(req, cfg->vnport);

	rt_link_newlink_req_set_linkinfo_data_geneve_udp_csum(req, cfg->csum);



	if (cfg->family == AF_INET)

		SET_GENEVE_REMOTE(req, cfg->remote.r4.s_addr);

	else

		SET_GENEVE_REMOTE6(req, &cfg->remote.r6,

				   sizeof(cfg->remote.r6));



	return 0;

}



static int geneve_create(const char *dev, int family, void *remote,

			 void *hwaddr)

{

	struct geneve_setup_config geneve;



	memset(&geneve, 0, sizeof(geneve));

	geneve.vnid = VN_ID;

	geneve.vnport = htons(VN_PORT);

	geneve.csum = 1;

	geneve.family = family;

	if (family == AF_INET)

		memcpy(&geneve.remote.r4, remote, sizeof(struct in_addr));

	else

		memcpy(&geneve.remote.r6, remote, sizeof(struct in6_addr));

	memcpy(geneve.hwaddr, hwaddr, ETH_ALEN);



	return ip_link_add(dev, "geneve", geneve_fill_newlink, (void *)&geneve);

}



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 void parse_route_rsp(struct rt_route_getroute_rsp *rsp, void *rtm_type)

{

	*(uint8_t *)rtm_type = rsp->_hdr.rtm_type;

}



static int ip_route_check(const char *intf, int family, void *addr)

{

	uint8_t rtm_type, table = RT_TABLE_LOCAL;

	int retries = MAX_RETRIES;



	while (retries-- > 0) {

		if (ip_route_get(intf, family, table, addr, parse_route_rsp,

				 &rtm_type) == 0 &&

		    rtm_type == RTN_LOCAL)

			break;



		usleep(TIMEOUT_USEC);

	}



	if (retries < 0)

		return -1;



	return 0;

}



FIXTURE(tun)

{

	char ifname[IFNAMSIZ];
@@ -129,4 +399,159 @@ 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_GENEVE_4IN4, 4in4);

TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_GENEVE_6IN4, 6in4);

TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_GENEVE_4IN6, 4in6);

TUN_VNET_UDPTNL_VARIANT_ADD(UDP_TUNNEL_GENEVE_6IN6, 6in6);



static void assign_ifaddr_vars(int family, int is_outer, void **srcip,

			       void **dstip, void **srcmac, void **dstmac)

{

	if (is_outer) {

		if (family == AF_INET) {

			*srcip = (void *)&param_ipaddr4_outer_src;

			*dstip = (void *)&param_ipaddr4_outer_dst;

		} else {

			*srcip = (void *)&param_ipaddr6_outer_src;

			*dstip = (void *)&param_ipaddr6_outer_dst;

		}

		*srcmac = param_hwaddr_outer_src;

		*dstmac = param_hwaddr_outer_dst;

	} else {

		if (family == AF_INET) {

			*srcip = (void *)&param_ipaddr4_inner_src;

			*dstip = (void *)&param_ipaddr4_inner_dst;

		} else {

			*srcip = (void *)&param_ipaddr6_inner_src;

			*dstip = (void *)&param_ipaddr6_inner_dst;

		}

		*srcmac = param_hwaddr_inner_src;

		*dstmac = param_hwaddr_inner_dst;

	}

}



static void assign_sockaddr_vars(int family, int is_outer,

				 struct sockaddr_storage *src,

				 struct sockaddr_storage *dst)

{

	src->ss_family = family;

	dst->ss_family = family;



	if (family == AF_INET) {

		struct sockaddr_in *s4 = (struct sockaddr_in *)src;

		struct sockaddr_in *d4 = (struct sockaddr_in *)dst;



		s4->sin_addr = is_outer ? param_ipaddr4_outer_src :

					  param_ipaddr4_inner_src;

		d4->sin_addr = is_outer ? param_ipaddr4_outer_dst :

					  param_ipaddr4_inner_dst;

		if (!is_outer) {

			s4->sin_port = htons(UDP_SRC_PORT);

			d4->sin_port = htons(UDP_DST_PORT);

		}

	} else {

		struct sockaddr_in6 *s6 = (struct sockaddr_in6 *)src;

		struct sockaddr_in6 *d6 = (struct sockaddr_in6 *)dst;



		s6->sin6_addr = is_outer ? param_ipaddr6_outer_src :

					   param_ipaddr6_inner_src;

		d6->sin6_addr = is_outer ? param_ipaddr6_outer_dst :

					   param_ipaddr6_inner_dst;

		if (!is_outer) {

			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;

	void *sip, *dip, *smac, *dmac;



	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;

	prefix = (family == AF_INET) ? IPPREFIX_LEN : IP6PREFIX_LEN;

	assign_ifaddr_vars(family, 1, &sip, &dip, &smac, &dmac);



	ret = ip_addr_add(self->ifname, family, sip, prefix);

	ASSERT_EQ(ret, 0);

	ret = ip_neigh_add(self->ifname, family, dip, dmac);

	ASSERT_EQ(ret, 0);

	ret = ip_route_check(self->ifname, family, sip);

	ASSERT_EQ(ret, 0);



	ret = geneve_create(param_dev_geneve_name, family, dip,

			    param_hwaddr_inner_src);

	ASSERT_EQ(ret, 0);



	family = (tunnel_type & UDP_TUNNEL_INNER_IPV4) ? AF_INET : AF_INET6;

	prefix = (family == AF_INET) ? IPPREFIX_LEN : IP6PREFIX_LEN;

	assign_ifaddr_vars(family, 0, &sip, &dip, &smac, &dmac);



	ret = ip_addr_add(param_dev_geneve_name, family, sip, prefix);

	ASSERT_EQ(ret, 0);

	ret = ip_neigh_add(param_dev_geneve_name, family, dip, dmac);

	ASSERT_EQ(ret, 0);

	ret = ip_route_check(param_dev_geneve_name, family, sip);

	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 = ip_link_del(param_dev_geneve_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_geneve_name);

	ret = system(cmd);

	ASSERT_EQ(ret, 0);

}



TEST_HARNESS_MAIN