lib/efi_selftest/efi_selftest_snp.c - github/trini/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * efi_selftest_snp
  *
  * Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
  *
  * This unit test covers the Simple Network Protocol as well as
  * the CopyMem and SetMem boottime services.
  *
  * A DHCP discover message is sent. The test is successful if a
  * DHCP reply is received.
  *
  * TODO: Once ConnectController and DisconnectController are implemented
  *	 we should connect our code as controller.
  */

 #include <efi_selftest.h>
 #include <net.h>

 /*
  * MAC address for broadcasts
  */
 static const u8 BROADCAST_MAC[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

 struct dhcp_hdr {
 	u8 op;
 #define BOOTREQUEST 1
 #define BOOTREPLY 2
 	u8 htype;
 # define HWT_ETHER 1
 	u8 hlen;
 # define HWL_ETHER 6
 	u8 hops;
 	u32 xid;
 	u16 secs;
 	u16 flags;
 #define DHCP_FLAGS_UNICAST	0x0000
 #define DHCP_FLAGS_BROADCAST	0x0080
 	u32 ciaddr;
 	u32 yiaddr;
 	u32 siaddr;
 	u32 giaddr;
 	u8 chaddr[16];
 	u8 sname[64];
 	u8 file[128];
 };

 /*
  * Message type option.
  */
 #define DHCP_MESSAGE_TYPE	0x35
 #define DHCPDISCOVER		1
 #define DHCPOFFER		2
 #define DHCPREQUEST		3
 #define DHCPDECLINE		4
 #define DHCPACK			5
 #define DHCPNAK			6
 #define DHCPRELEASE		7

 struct dhcp {
 	struct ethernet_hdr eth_hdr;
 	struct ip_udp_hdr ip_udp;
 	struct dhcp_hdr dhcp_hdr;
 	u8 opt[128];
 } __packed;

 static struct efi_boot_services *boottime;
 static struct efi_simple_network *net;
 static struct efi_event *timer;
 static const efi_guid_t efi_net_guid = EFI_SIMPLE_NETWORK_PROTOCOL_GUID;
 /* IP packet ID */
 static unsigned int net_ip_id;

 /*
  * Compute the checksum of the IP header. We cover even values of length only.
  * We cannot use net/checksum.c due to different CFLAGS values.
  *
  * @buf:	IP header
  * @len:	length of header in bytes
  * @return:	checksum
  */
 static unsigned int efi_ip_checksum(const void *buf, size_t len)
 {
 	size_t i;
 	u32 sum = 0;
 	const u16 *pos = buf;

 	for (i = 0; i < len; i += 2)
 		sum += *pos++;

 	sum = (sum >> 16) + (sum & 0xffff);
 	sum += sum >> 16;
 	sum = ~sum & 0xffff;

 	return sum;
 }

 /*
  * Transmit a DHCPDISCOVER message.
  */
 static efi_status_t send_dhcp_discover(void)
 {
 	efi_status_t ret;
 	struct dhcp p = {};

 	/*
 	 * Fill Ethernet header
 	 */
 	boottime->copy_mem(p.eth_hdr.et_dest, (void *)BROADCAST_MAC, ARP_HLEN);
 	boottime->copy_mem(p.eth_hdr.et_src, &net->mode->current_address,
 			   ARP_HLEN);
 	p.eth_hdr.et_protlen = htons(PROT_IP);
 	/*
 	 * Fill IP header
 	 */
 	p.ip_udp.ip_hl_v	= 0x45;
 	p.ip_udp.ip_len		= htons(sizeof(struct dhcp) -
 					sizeof(struct ethernet_hdr));
 	p.ip_udp.ip_id		= htons(++net_ip_id);
 	p.ip_udp.ip_off		= htons(IP_FLAGS_DFRAG);
 	p.ip_udp.ip_ttl		= 0xff; /* time to live */
 	p.ip_udp.ip_p		= IPPROTO_UDP;
 	boottime->set_mem(&p.ip_udp.ip_dst, 4, 0xff);
 	p.ip_udp.ip_sum		= efi_ip_checksum(&p.ip_udp, IP_HDR_SIZE);

 	/*
 	 * Fill UDP header
 	 */
 	p.ip_udp.udp_src	= htons(68);
 	p.ip_udp.udp_dst	= htons(67);
 	p.ip_udp.udp_len	= htons(sizeof(struct dhcp) -
 					sizeof(struct ethernet_hdr) -
 					sizeof(struct ip_hdr));
 	/*
 	 * Fill DHCP header
 	 */
 	p.dhcp_hdr.op		= BOOTREQUEST;
 	p.dhcp_hdr.htype	= HWT_ETHER;
 	p.dhcp_hdr.hlen		= HWL_ETHER;
 	p.dhcp_hdr.flags	= htons(DHCP_FLAGS_UNICAST);
 	boottime->copy_mem(&p.dhcp_hdr.chaddr,
 			   &net->mode->current_address, ARP_HLEN);
 	/*
 	 * Fill options
 	 */
 	p.opt[0]	= 0x63; /* DHCP magic cookie */
 	p.opt[1]	= 0x82;
 	p.opt[2]	= 0x53;
 	p.opt[3]	= 0x63;
 	p.opt[4]	= DHCP_MESSAGE_TYPE;
 	p.opt[5]	= 0x01; /* length */
 	p.opt[6]	= DHCPDISCOVER;
 	p.opt[7]	= 0x39; /* maximum message size */
 	p.opt[8]	= 0x02; /* length */
 	p.opt[9]	= 0x02; /* 576 bytes */
 	p.opt[10]	= 0x40;
 	p.opt[11]	= 0xff; /* end of options */

 	/*
 	 * Transmit DHCPDISCOVER message.
 	 */
 	ret = net->transmit(net, 0, sizeof(struct dhcp), &p, NULL, NULL, 0);
 	if (ret != EFI_SUCCESS)
 		efi_st_error("Sending a DHCP request failed\n");
 	else
 		efi_st_printf("DHCP Discover\n");
 	return ret;
 }

 /*
  * Setup unit test.
  *
  * Create a 1 s periodic timer.
  * Start the network driver.
  *
  * @handle:	handle of the loaded image
  * @systable:	system table
  * @return:	EFI_ST_SUCCESS for success
  */
 static int setup(const efi_handle_t handle,
 		 const struct efi_system_table *systable)
 {
 	efi_status_t ret;

 	boottime = systable->boottime;

 	/*
 	 * Create a timer event.
 	 */
 	ret = boottime->create_event(EVT_TIMER, TPL_CALLBACK, NULL, NULL,
 				     &timer);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("Failed to create event\n");
 		return EFI_ST_FAILURE;
 	}
 	/*
 	 * Set timer period to 1s.
 	 */
 	ret = boottime->set_timer(timer, EFI_TIMER_PERIODIC, 10000000);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("Failed to set timer\n");
 		return EFI_ST_FAILURE;
 	}
 	/*
 	 * Find an interface implementing the SNP protocol.
 	 */
 	ret = boottime->locate_protocol(&efi_net_guid, NULL, (void **)&net);
 	if (ret != EFI_SUCCESS) {
 		net = NULL;
 		efi_st_error("Failed to locate simple network protocol\n");
 		return EFI_ST_FAILURE;
 	}
 	/*
 	 * Check hardware address size.
 	 */
 	if (!net->mode) {
 		efi_st_error("Mode not provided\n");
 		return EFI_ST_FAILURE;
 	}
 	if (net->mode->hwaddr_size != ARP_HLEN) {
 		efi_st_error("HwAddressSize = %u, expected %u\n",
 			     net->mode->hwaddr_size, ARP_HLEN);
 		return EFI_ST_FAILURE;
 	}
 	/*
 	 * Check that WaitForPacket event exists.
 	 */
 	if (!net->wait_for_packet) {
 		efi_st_error("WaitForPacket event missing\n");
 		return EFI_ST_FAILURE;
 	}
 	if (net->mode->state == EFI_NETWORK_INITIALIZED) {
 		/*
 		 * Shut down network adapter.
 		 */
 		ret = net->shutdown(net);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to shut down network adapter\n");
 			return EFI_ST_FAILURE;
 		}
 	}
 	if (net->mode->state == EFI_NETWORK_STARTED) {
 		/*
 		 * Stop network adapter.
 		 */
 		ret = net->stop(net);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to stop network adapter\n");
 			return EFI_ST_FAILURE;
 		}
 	}
 	/*
 	 * Start network adapter.
 	 */
 	ret = net->start(net);
 	if (ret != EFI_SUCCESS && ret != EFI_ALREADY_STARTED) {
 		efi_st_error("Failed to start network adapter\n");
 		return EFI_ST_FAILURE;
 	}
 	if (net->mode->state != EFI_NETWORK_STARTED) {
 		efi_st_error("Failed to start network adapter\n");
 		return EFI_ST_FAILURE;
 	}
 	/*
 	 * Initialize network adapter.
 	 */
 	ret = net->initialize(net, 0, 0);
 	if (ret != EFI_SUCCESS) {
 		efi_st_error("Failed to initialize network adapter\n");
 		return EFI_ST_FAILURE;
 	}
 	if (net->mode->state != EFI_NETWORK_INITIALIZED) {
 		efi_st_error("Failed to initialize network adapter\n");
 		return EFI_ST_FAILURE;
 	}
 	return EFI_ST_SUCCESS;
 }

 /*
  * Execute unit test.
  *
  * A DHCP discover message is sent. The test is successful if a
  * DHCP reply is received within 10 seconds.
  *
  * @return:	EFI_ST_SUCCESS for success
  */
 static int execute(void)
 {
 	efi_status_t ret;
 	struct efi_event *events[2];
 	efi_uintn_t index;
 	union {
 		struct dhcp p;
 		u8 b[PKTSIZE];
 	} buffer;
 	struct efi_mac_address srcaddr;
 	struct efi_mac_address destaddr;
 	size_t buffer_size;
 	u8 *addr;

 	/*
 	 * The timeout is to occur after 10 s.
 	 */
 	unsigned int timeout = 10;

 	/* Setup may have failed */
 	if (!net || !timer) {
 		efi_st_error("Cannot execute test after setup failure\n");
 		return EFI_ST_FAILURE;
 	}

 	/*
 	 * Send DHCP discover message
 	 */
 	ret = send_dhcp_discover();
 	if (ret != EFI_SUCCESS)
 		return EFI_ST_FAILURE;

 	/*
 	 * If we would call WaitForEvent only with the WaitForPacket event,
 	 * our code would block until a packet is received which might never
 	 * occur. By calling WaitFor event with both a timer event and the
 	 * WaitForPacket event we can escape this blocking situation.
 	 *
 	 * If the timer event occurs before we have received a DHCP reply
 	 * a further DHCP discover message is sent.
 	 */
 	events[0] = timer;
 	events[1] = net->wait_for_packet;
 	for (;;) {
 		u32 int_status;

 		/*
 		 * Wait for packet to be received or timer event.
 		 */
 		boottime->wait_for_event(2, events, &index);
 		if (index == 0) {
 			/*
 			 * The timer event occurred. Check for timeout.
 			 */
 			--timeout;
 			if (!timeout) {
 				efi_st_error("Timeout occurred\n");
 				return EFI_ST_FAILURE;
 			}
 			/*
 			 * Send further DHCP discover message
 			 */
 			ret = send_dhcp_discover();
 			if (ret != EFI_SUCCESS)
 				return EFI_ST_FAILURE;
 			continue;
 		}
 		/*
 		 * Receive packet
 		 */
 		buffer_size = sizeof(buffer);
 		ret = net->get_status(net, &int_status, NULL);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to get status");
 			return EFI_ST_FAILURE;
 		}
 		if (!(int_status & EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT)) {
 			efi_st_error("RX interrupt not set");
 			return EFI_ST_FAILURE;
 		}
 		ret = net->receive(net, NULL, &buffer_size, &buffer,
 				   &srcaddr, &destaddr, NULL);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to receive packet");
 			return EFI_ST_FAILURE;
 		}
 		/*
 		 * Check the packet is meant for this system.
 		 * Unfortunately QEMU ignores the broadcast flag.
 		 * So we have to check for broadcasts too.
 		 */
 		if (memcmp(&destaddr, &net->mode->current_address, ARP_HLEN) &&
 		    memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
 			continue;
 		/*
 		 * Check this is a DHCP reply
 		 */
 		if (buffer.p.eth_hdr.et_protlen != ntohs(PROT_IP) ||
 		    buffer.p.ip_udp.ip_hl_v != 0x45 ||
 		    buffer.p.ip_udp.ip_p != IPPROTO_UDP ||
 		    buffer.p.ip_udp.udp_src != ntohs(67) ||
 		    buffer.p.ip_udp.udp_dst != ntohs(68) ||
 		    buffer.p.dhcp_hdr.op != BOOTREPLY)
 			continue;
 		/*
 		 * We successfully received a DHCP reply.
 		 */
 		break;
 	}

 	/*
 	 * Write a log message.
 	 */
 	addr = (u8 *)&buffer.p.ip_udp.ip_src;
 	efi_st_printf("DHCP reply received from %u.%u.%u.%u (%pm) ",
 		      addr[0], addr[1], addr[2], addr[3], &srcaddr);
 	if (!memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
 		efi_st_printf("as broadcast message.\n");
 	else
 		efi_st_printf("as unicast message.\n");

 	return EFI_ST_SUCCESS;
 }

 /*
  * Tear down unit test.
  *
  * Close the timer event created in setup.
  * Shut down the network adapter.
  *
  * @return:	EFI_ST_SUCCESS for success
  */
 static int teardown(void)
 {
 	efi_status_t ret;
 	int exit_status = EFI_ST_SUCCESS;

 	if (timer) {
 		/*
 		 * Stop timer.
 		 */
 		ret = boottime->set_timer(timer, EFI_TIMER_STOP, 0);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to stop timer");
 			exit_status = EFI_ST_FAILURE;
 		}
 		/*
 		 * Close timer event.
 		 */
 		ret = boottime->close_event(timer);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to close event");
 			exit_status = EFI_ST_FAILURE;
 		}
 	}
 	if (net) {
 		/*
 		 * Shut down network adapter.
 		 */
 		ret = net->shutdown(net);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to shut down network adapter\n");
 			exit_status = EFI_ST_FAILURE;
 		}
 		if (net->mode->state != EFI_NETWORK_STARTED) {
 			efi_st_error("Failed to shutdown network adapter\n");
 			return EFI_ST_FAILURE;
 		}
 		/*
 		 * Stop network adapter.
 		 */
 		ret = net->stop(net);
 		if (ret != EFI_SUCCESS) {
 			efi_st_error("Failed to stop network adapter\n");
 			exit_status = EFI_ST_FAILURE;
 		}
 		if (net->mode->state != EFI_NETWORK_STOPPED) {
 			efi_st_error("Failed to stop network adapter\n");
 			return EFI_ST_FAILURE;
 		}
 	}

 	return exit_status;
 }

 EFI_UNIT_TEST(snp) = {
 	.name = "simple network protocol",
 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
 	.setup = setup,
 	.execute = execute,
 	.teardown = teardown,
 #ifdef CONFIG_SANDBOX
 	/*
 	 * Running this test on the sandbox requires setting environment
 	 * variable ethact to a network interface connected to a DHCP server and
 	 * ethrotate to 'no'.
 	 */
 	.on_request = true,
 #endif
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* efi_selftest_snp
	*
	* Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
	*
	* This unit test covers the Simple Network Protocol as well as
	* the CopyMem and SetMem boottime services.
	*
	* A DHCP discover message is sent. The test is successful if a
	* DHCP reply is received.
	*
	* TODO: Once ConnectController and DisconnectController are implemented
	* we should connect our code as controller.
	*/

	#include <efi_selftest.h>
	#include <net.h>

	/*
	* MAC address for broadcasts
	*/
	static const u8 BROADCAST_MAC[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

	struct dhcp_hdr {
	u8 op;
	#define BOOTREQUEST 1
	#define BOOTREPLY 2
	u8 htype;
	# define HWT_ETHER 1
	u8 hlen;
	# define HWL_ETHER 6
	u8 hops;
	u32 xid;
	u16 secs;
	u16 flags;
	#define DHCP_FLAGS_UNICAST 0x0000
	#define DHCP_FLAGS_BROADCAST 0x0080
	u32 ciaddr;
	u32 yiaddr;
	u32 siaddr;
	u32 giaddr;
	u8 chaddr[16];
	u8 sname[64];
	u8 file[128];
	};

	/*
	* Message type option.
	*/
	#define DHCP_MESSAGE_TYPE 0x35
	#define DHCPDISCOVER 1
	#define DHCPOFFER 2
	#define DHCPREQUEST 3
	#define DHCPDECLINE 4
	#define DHCPACK 5
	#define DHCPNAK 6
	#define DHCPRELEASE 7

	struct dhcp {
	struct ethernet_hdr eth_hdr;
	struct ip_udp_hdr ip_udp;
	struct dhcp_hdr dhcp_hdr;
	u8 opt[128];
	} __packed;

	static struct efi_boot_services *boottime;
	static struct efi_simple_network *net;
	static struct efi_event *timer;
	static const efi_guid_t efi_net_guid = EFI_SIMPLE_NETWORK_PROTOCOL_GUID;
	/* IP packet ID */
	static unsigned int net_ip_id;

	/*
	* Compute the checksum of the IP header. We cover even values of length only.
	* We cannot use net/checksum.c due to different CFLAGS values.
	*
	* @buf: IP header
	* @len: length of header in bytes
	* @return: checksum
	*/
	static unsigned int efi_ip_checksum(const void *buf, size_t len)
	{
	size_t i;
	u32 sum = 0;
	const u16 *pos = buf;

	for (i = 0; i < len; i += 2)
	sum += *pos++;

	sum = (sum >> 16) + (sum & 0xffff);
	sum += sum >> 16;
	sum = ~sum & 0xffff;

	return sum;
	}

	/*
	* Transmit a DHCPDISCOVER message.
	*/
	static efi_status_t send_dhcp_discover(void)
	{
	efi_status_t ret;
	struct dhcp p = {};

	/*
	* Fill Ethernet header
	*/
	boottime->copy_mem(p.eth_hdr.et_dest, (void *)BROADCAST_MAC, ARP_HLEN);
	boottime->copy_mem(p.eth_hdr.et_src, &net->mode->current_address,
	ARP_HLEN);
	p.eth_hdr.et_protlen = htons(PROT_IP);
	/*
	* Fill IP header
	*/
	p.ip_udp.ip_hl_v = 0x45;
	p.ip_udp.ip_len = htons(sizeof(struct dhcp) -
	sizeof(struct ethernet_hdr));
	p.ip_udp.ip_id = htons(++net_ip_id);
	p.ip_udp.ip_off = htons(IP_FLAGS_DFRAG);
	p.ip_udp.ip_ttl = 0xff; /* time to live */
	p.ip_udp.ip_p = IPPROTO_UDP;
	boottime->set_mem(&p.ip_udp.ip_dst, 4, 0xff);
	p.ip_udp.ip_sum = efi_ip_checksum(&p.ip_udp, IP_HDR_SIZE);

	/*
	* Fill UDP header
	*/
	p.ip_udp.udp_src = htons(68);
	p.ip_udp.udp_dst = htons(67);
	p.ip_udp.udp_len = htons(sizeof(struct dhcp) -
	sizeof(struct ethernet_hdr) -
	sizeof(struct ip_hdr));
	/*
	* Fill DHCP header
	*/
	p.dhcp_hdr.op = BOOTREQUEST;
	p.dhcp_hdr.htype = HWT_ETHER;
	p.dhcp_hdr.hlen = HWL_ETHER;
	p.dhcp_hdr.flags = htons(DHCP_FLAGS_UNICAST);
	boottime->copy_mem(&p.dhcp_hdr.chaddr,
	&net->mode->current_address, ARP_HLEN);
	/*
	* Fill options
	*/
	p.opt[0] = 0x63; /* DHCP magic cookie */
	p.opt[1] = 0x82;
	p.opt[2] = 0x53;
	p.opt[3] = 0x63;
	p.opt[4] = DHCP_MESSAGE_TYPE;
	p.opt[5] = 0x01; /* length */
	p.opt[6] = DHCPDISCOVER;
	p.opt[7] = 0x39; /* maximum message size */
	p.opt[8] = 0x02; /* length */
	p.opt[9] = 0x02; /* 576 bytes */
	p.opt[10] = 0x40;
	p.opt[11] = 0xff; /* end of options */

	/*
	* Transmit DHCPDISCOVER message.
	*/
	ret = net->transmit(net, 0, sizeof(struct dhcp), &p, NULL, NULL, 0);
	if (ret != EFI_SUCCESS)
	efi_st_error("Sending a DHCP request failed\n");
	else
	efi_st_printf("DHCP Discover\n");
	return ret;
	}

	/*
	* Setup unit test.
	*
	* Create a 1 s periodic timer.
	* Start the network driver.
	*
	* @handle: handle of the loaded image
	* @systable: system table
	* @return: EFI_ST_SUCCESS for success
	*/
	static int setup(const efi_handle_t handle,
	const struct efi_system_table *systable)
	{
	efi_status_t ret;

	boottime = systable->boottime;

	/*
	* Create a timer event.
	*/
	ret = boottime->create_event(EVT_TIMER, TPL_CALLBACK, NULL, NULL,
	&timer);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to create event\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Set timer period to 1s.
	*/
	ret = boottime->set_timer(timer, EFI_TIMER_PERIODIC, 10000000);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to set timer\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Find an interface implementing the SNP protocol.
	*/
	ret = boottime->locate_protocol(&efi_net_guid, NULL, (void **)&net);
	if (ret != EFI_SUCCESS) {
	net = NULL;
	efi_st_error("Failed to locate simple network protocol\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Check hardware address size.
	*/
	if (!net->mode) {
	efi_st_error("Mode not provided\n");
	return EFI_ST_FAILURE;
	}
	if (net->mode->hwaddr_size != ARP_HLEN) {
	efi_st_error("HwAddressSize = %u, expected %u\n",
	net->mode->hwaddr_size, ARP_HLEN);
	return EFI_ST_FAILURE;
	}
	/*
	* Check that WaitForPacket event exists.
	*/
	if (!net->wait_for_packet) {
	efi_st_error("WaitForPacket event missing\n");
	return EFI_ST_FAILURE;
	}
	if (net->mode->state == EFI_NETWORK_INITIALIZED) {
	/*
	* Shut down network adapter.
	*/
	ret = net->shutdown(net);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to shut down network adapter\n");
	return EFI_ST_FAILURE;
	}
	}
	if (net->mode->state == EFI_NETWORK_STARTED) {
	/*
	* Stop network adapter.
	*/
	ret = net->stop(net);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to stop network adapter\n");
	return EFI_ST_FAILURE;
	}
	}
	/*
	* Start network adapter.
	*/
	ret = net->start(net);
	if (ret != EFI_SUCCESS && ret != EFI_ALREADY_STARTED) {
	efi_st_error("Failed to start network adapter\n");
	return EFI_ST_FAILURE;
	}
	if (net->mode->state != EFI_NETWORK_STARTED) {
	efi_st_error("Failed to start network adapter\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Initialize network adapter.
	*/
	ret = net->initialize(net, 0, 0);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to initialize network adapter\n");
	return EFI_ST_FAILURE;
	}
	if (net->mode->state != EFI_NETWORK_INITIALIZED) {
	efi_st_error("Failed to initialize network adapter\n");
	return EFI_ST_FAILURE;
	}
	return EFI_ST_SUCCESS;
	}

	/*
	* Execute unit test.
	*
	* A DHCP discover message is sent. The test is successful if a
	* DHCP reply is received within 10 seconds.
	*
	* @return: EFI_ST_SUCCESS for success
	*/
	static int execute(void)
	{
	efi_status_t ret;
	struct efi_event *events[2];
	efi_uintn_t index;
	union {
	struct dhcp p;
	u8 b[PKTSIZE];
	} buffer;
	struct efi_mac_address srcaddr;
	struct efi_mac_address destaddr;
	size_t buffer_size;
	u8 *addr;

	/*
	* The timeout is to occur after 10 s.
	*/
	unsigned int timeout = 10;

	/* Setup may have failed */
	if (!net \|\| !timer) {
	efi_st_error("Cannot execute test after setup failure\n");
	return EFI_ST_FAILURE;
	}

	/*
	* Send DHCP discover message
	*/
	ret = send_dhcp_discover();
	if (ret != EFI_SUCCESS)
	return EFI_ST_FAILURE;

	/*
	* If we would call WaitForEvent only with the WaitForPacket event,
	* our code would block until a packet is received which might never
	* occur. By calling WaitFor event with both a timer event and the
	* WaitForPacket event we can escape this blocking situation.
	*
	* If the timer event occurs before we have received a DHCP reply
	* a further DHCP discover message is sent.
	*/
	events[0] = timer;
	events[1] = net->wait_for_packet;
	for (;;) {
	u32 int_status;

	/*
	* Wait for packet to be received or timer event.
	*/
	boottime->wait_for_event(2, events, &index);
	if (index == 0) {
	/*
	* The timer event occurred. Check for timeout.
	*/
	--timeout;
	if (!timeout) {
	efi_st_error("Timeout occurred\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Send further DHCP discover message
	*/
	ret = send_dhcp_discover();
	if (ret != EFI_SUCCESS)
	return EFI_ST_FAILURE;
	continue;
	}
	/*
	* Receive packet
	*/
	buffer_size = sizeof(buffer);
	ret = net->get_status(net, &int_status, NULL);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to get status");
	return EFI_ST_FAILURE;
	}
	if (!(int_status & EFI_SIMPLE_NETWORK_RECEIVE_INTERRUPT)) {
	efi_st_error("RX interrupt not set");
	return EFI_ST_FAILURE;
	}
	ret = net->receive(net, NULL, &buffer_size, &buffer,
	&srcaddr, &destaddr, NULL);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to receive packet");
	return EFI_ST_FAILURE;
	}
	/*
	* Check the packet is meant for this system.
	* Unfortunately QEMU ignores the broadcast flag.
	* So we have to check for broadcasts too.
	*/
	if (memcmp(&destaddr, &net->mode->current_address, ARP_HLEN) &&
	memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
	continue;
	/*
	* Check this is a DHCP reply
	*/
	if (buffer.p.eth_hdr.et_protlen != ntohs(PROT_IP) \|\|
	buffer.p.ip_udp.ip_hl_v != 0x45 \|\|
	buffer.p.ip_udp.ip_p != IPPROTO_UDP \|\|
	buffer.p.ip_udp.udp_src != ntohs(67) \|\|
	buffer.p.ip_udp.udp_dst != ntohs(68) \|\|
	buffer.p.dhcp_hdr.op != BOOTREPLY)
	continue;
	/*
	* We successfully received a DHCP reply.
	*/
	break;
	}

	/*
	* Write a log message.
	*/
	addr = (u8 *)&buffer.p.ip_udp.ip_src;
	efi_st_printf("DHCP reply received from %u.%u.%u.%u (%pm) ",
	addr[0], addr[1], addr[2], addr[3], &srcaddr);
	if (!memcmp(&destaddr, BROADCAST_MAC, ARP_HLEN))
	efi_st_printf("as broadcast message.\n");
	else
	efi_st_printf("as unicast message.\n");

	return EFI_ST_SUCCESS;
	}

	/*
	* Tear down unit test.
	*
	* Close the timer event created in setup.
	* Shut down the network adapter.
	*
	* @return: EFI_ST_SUCCESS for success
	*/
	static int teardown(void)
	{
	efi_status_t ret;
	int exit_status = EFI_ST_SUCCESS;

	if (timer) {
	/*
	* Stop timer.
	*/
	ret = boottime->set_timer(timer, EFI_TIMER_STOP, 0);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to stop timer");
	exit_status = EFI_ST_FAILURE;
	}
	/*
	* Close timer event.
	*/
	ret = boottime->close_event(timer);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to close event");
	exit_status = EFI_ST_FAILURE;
	}
	}
	if (net) {
	/*
	* Shut down network adapter.
	*/
	ret = net->shutdown(net);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to shut down network adapter\n");
	exit_status = EFI_ST_FAILURE;
	}
	if (net->mode->state != EFI_NETWORK_STARTED) {
	efi_st_error("Failed to shutdown network adapter\n");
	return EFI_ST_FAILURE;
	}
	/*
	* Stop network adapter.
	*/
	ret = net->stop(net);
	if (ret != EFI_SUCCESS) {
	efi_st_error("Failed to stop network adapter\n");
	exit_status = EFI_ST_FAILURE;
	}
	if (net->mode->state != EFI_NETWORK_STOPPED) {
	efi_st_error("Failed to stop network adapter\n");
	return EFI_ST_FAILURE;
	}
	}

	return exit_status;
	}

	EFI_UNIT_TEST(snp) = {
	.name = "simple network protocol",
	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
	.setup = setup,
	.execute = execute,
	.teardown = teardown,
	#ifdef CONFIG_SANDBOX
	/*
	* Running this test on the sandbox requires setting environment
	* variable ethact to a network interface connected to a DHCP server and
	* ethrotate to 'no'.
	*/
	.on_request = true,
	#endif
	};