xref: /freebsd/stand/efi/libefi/efinet.c (revision 6413a870fa0721ac509e38f24d5dd5204c603288)

/*-
 * Copyright (c) 2001 Doug Rabson
 * Copyright (c) 2002, 2006 Marcel Moolenaar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>

#include <stand.h>
#include <net.h>
#include <netif.h>
#include <bootp.h>

#include <efi.h>
#include <efilib.h>
#include <Protocol/SimpleNetwork.h>
#include <Protocol/PxeBaseCode.h>

#include "dev_net.h"

static EFI_GUID sn_guid = EFI_SIMPLE_NETWORK_PROTOCOL_GUID;
static EFI_GUID pxe_guid = EFI_PXE_BASE_CODE_PROTOCOL_GUID;

/*
 * Snapshot of the UEFI PXE Base Code Protocol's cached DhcpAck taken
 * at device enumeration time, before efinet_probe() opens the Simple
 * Network Protocol with EFI_OPEN_PROTOCOL_EXCLUSIVE.  The EXCLUSIVE
 * open forces the firmware to disconnect any driver holding the SNP
 * handle BY_DRIVER (including the UEFI PXE stack), which uninstalls
 * the PXE Base Code Protocol from that handle.  We capture the ACK
 * here so it survives that disconnect.
 *
 * Per PXE 2.1, ProxyOffer's siaddr is the authoritative PXE boot
 * server and overrides any siaddr in the primary DhcpAck.  We splice
 * it into dhcp_ack.Dhcpv4.BootpSiAddr at snapshot time, so downstream
 * only sees one merged packet — no need to store ProxyOffer separately.
 *
 * Indexed by netif unit; allocated in efi_pxe_snapshot_all().
 */
struct pxe_cache_entry {
	bool				valid;
	EFI_PXE_BASE_CODE_PACKET	dhcp_ack;
};

static struct pxe_cache_entry *pxe_cache;

static void efinet_end(struct netif *);
static ssize_t efinet_get(struct iodesc *, void **, time_t);
static void efinet_init(struct iodesc *, void *);
static int efinet_match(struct netif *, void *);
static int efinet_probe(struct netif *, void *);
static ssize_t efinet_put(struct iodesc *, void *, size_t);

struct netif_driver efinetif = {
	.netif_bname = "efinet",
	.netif_match = efinet_match,
	.netif_probe = efinet_probe,
	.netif_init = efinet_init,
	.netif_get = efinet_get,
	.netif_put = efinet_put,
	.netif_end = efinet_end,
	.netif_ifs = NULL,
	.netif_nifs = 0
};

#ifdef EFINET_DEBUG
static void
dump_mode(EFI_SIMPLE_NETWORK_MODE *mode)
{
	int i;

	printf("State                 = %x\n", mode->State);
	printf("HwAddressSize         = %u\n", mode->HwAddressSize);
	printf("MediaHeaderSize       = %u\n", mode->MediaHeaderSize);
	printf("MaxPacketSize         = %u\n", mode->MaxPacketSize);
	printf("NvRamSize             = %u\n", mode->NvRamSize);
	printf("NvRamAccessSize       = %u\n", mode->NvRamAccessSize);
	printf("ReceiveFilterMask     = %x\n", mode->ReceiveFilterMask);
	printf("ReceiveFilterSetting  = %u\n", mode->ReceiveFilterSetting);
	printf("MaxMCastFilterCount   = %u\n", mode->MaxMCastFilterCount);
	printf("MCastFilterCount      = %u\n", mode->MCastFilterCount);
	printf("MCastFilter           = {");
	for (i = 0; i < mode->MCastFilterCount; i++)
		printf(" %s", ether_sprintf(mode->MCastFilter[i].Addr));
	printf(" }\n");
	printf("CurrentAddress        = %s\n",
	    ether_sprintf(mode->CurrentAddress.Addr));
	printf("BroadcastAddress      = %s\n",
	    ether_sprintf(mode->BroadcastAddress.Addr));
	printf("PermanentAddress      = %s\n",
	    ether_sprintf(mode->PermanentAddress.Addr));
	printf("IfType                = %u\n", mode->IfType);
	printf("MacAddressChangeable  = %d\n", mode->MacAddressChangeable);
	printf("MultipleTxSupported   = %d\n", mode->MultipleTxSupported);
	printf("MediaPresentSupported = %d\n", mode->MediaPresentSupported);
	printf("MediaPresent          = %d\n", mode->MediaPresent);
}
#endif

static int
efinet_match(struct netif *nif, void *machdep_hint)
{
	struct devdesc *dev = machdep_hint;

	if (dev->d_unit == nif->nif_unit)
		return (1);
	return(0);
}

static int
efinet_probe(struct netif *nif, void *machdep_hint)
{
	EFI_SIMPLE_NETWORK *net;
	EFI_HANDLE h;
	EFI_STATUS status;

	h = nif->nif_driver->netif_ifs[nif->nif_unit].dif_private;
	/*
	 * Open the network device in exclusive mode. Without this
	 * we will be racing with the UEFI network stack. It will
	 * pull packets off the network leading to lost packets.
	 */
	status = BS->OpenProtocol(h, &sn_guid, (void **)&net,
	    IH, NULL, EFI_OPEN_PROTOCOL_EXCLUSIVE);
	if (status != EFI_SUCCESS) {
		printf("Unable to open network interface %d for "
		    "exclusive access: %lu\n", nif->nif_unit,
		    DECODE_ERROR(status));
		return (efi_status_to_errno(status));
	}

	return (0);
}

static ssize_t
efinet_put(struct iodesc *desc, void *pkt, size_t len)
{
	struct netif *nif = desc->io_netif;
	EFI_SIMPLE_NETWORK *net;
	EFI_STATUS status;
	void *buf;

	net = nif->nif_devdata;
	if (net == NULL)
		return (-1);

	status = net->Transmit(net, 0, len, pkt, NULL, NULL, NULL);
	if (status != EFI_SUCCESS)
		return (-1);

	/* Wait for the buffer to be transmitted */
	do {
		buf = NULL;	/* XXX Is this needed? */
		status = net->GetStatus(net, NULL, &buf);
		/*
		 * XXX EFI1.1 and the E1000 card returns a different
		 * address than we gave.  Sigh.
		 */
	} while (status == EFI_SUCCESS && buf == NULL);

	/* XXX How do we deal with status != EFI_SUCCESS now? */
	return ((status == EFI_SUCCESS) ? len : -1);
}

static ssize_t
efinet_get(struct iodesc *desc, void **pkt, time_t timeout)
{
	struct netif *nif = desc->io_netif;
	EFI_SIMPLE_NETWORK *net;
	EFI_STATUS status;
	UINTN bufsz;
	time_t t;
	char *buf, *ptr;
	ssize_t ret = -1;

	net = nif->nif_devdata;
	if (net == NULL)
		return (ret);

	bufsz = net->Mode->MaxPacketSize + ETHER_HDR_LEN + ETHER_CRC_LEN;
	buf = malloc(bufsz + ETHER_ALIGN);
	if (buf == NULL)
		return (ret);
	ptr = buf + ETHER_ALIGN;

	t = getsecs();
	while ((getsecs() - t) < timeout) {
		status = net->Receive(net, NULL, &bufsz, ptr, NULL, NULL, NULL);
		if (status == EFI_SUCCESS) {
			*pkt = buf;
			ret = (ssize_t)bufsz;
			break;
		}
		if (status != EFI_NOT_READY)
			break;
	}

	if (ret == -1)
		free(buf);
	return (ret);
}

/*
 * Snapshot the UEFI PXE Base Code Protocol's cached DhcpAck for handle
 * h (which must carry EFI_PXE_BASE_CODE_PROTOCOL) into pce, splicing
 * ProxyOffer's siaddr into it if present (per PXE 2.1, ProxyOffer's
 * siaddr is the authoritative boot server and overrides DhcpAck's).
 *
 * Silently leaves pce->valid = false if the protocol is absent, the
 * PXE base code is not Started on this handle (i.e. it wasn't the
 * interface used to network-boot), or no DhcpAck was received.
 */
static void
efi_pxe_snapshot(EFI_HANDLE h, struct pxe_cache_entry *pce)
{
	EFI_PXE_BASE_CODE_PROTOCOL *pxe;
	EFI_PXE_BASE_CODE_MODE *mode;
	EFI_STATUS status;

	status = BS->OpenProtocol(h, &pxe_guid, (void **)&pxe,
	    IH, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
	if (EFI_ERROR(status))
		return;

	mode = pxe->Mode;
	if (mode->Started && mode->DhcpAckReceived) {
		memcpy(&pce->dhcp_ack, &mode->DhcpAck, sizeof(pce->dhcp_ack));

		if (mode->ProxyOfferReceived) {
			uint32_t proxy_siaddr = 0;

			memcpy(&proxy_siaddr,
			    mode->ProxyOffer.Dhcpv4.BootpSiAddr, 4);
			if (proxy_siaddr != 0)
				memcpy(pce->dhcp_ack.Dhcpv4.BootpSiAddr,
				    &proxy_siaddr, 4);
		}
		pce->valid = true;
	}

	BS->CloseProtocol(h, &pxe_guid, IH, NULL);
}

/*
 * Walk a device path looking for the first MSG_MAC_ADDR_DP node and
 * copy its 6-byte Ethernet MAC into out.  Returns true on success,
 * e.g. false if dp has no NIC node at all.
 */
bool
efi_devpath_get_mac(EFI_DEVICE_PATH *dp, uint8_t out[6])
{
	MAC_ADDR_DEVICE_PATH *mac;

	if (dp == NULL)
		return (false);
	while (!IsDevicePathEnd(dp)) {
		if (DevicePathType(dp) == MESSAGING_DEVICE_PATH &&
		    DevicePathSubType(dp) == MSG_MAC_ADDR_DP) {
			mac = (MAC_ADDR_DEVICE_PATH *)dp;
			memcpy(out, &mac->MacAddress, 6);
			return (true);
		}
		dp = NextDevicePathNode(dp);
	}
	return (false);
}

/*
 * Populate the pxe_cache[] array for all nifs SNP units.  Runs during
 * efinet_dev_init() before any SNP is opened EXCLUSIVE, so the UEFI
 * PXE driver is still bound and its Mode data is intact.
 *
 * Per the UEFI 2.x network-stack architecture, EFI_PXE_BASE_CODE_PROTOCOL
 * lives on an upper-layer child handle whose device path extends the
 * SNP's MAC-terminated path with Ipv4()/Ipv6() nodes.  Enumerate all
 * handles carrying PXE Base Code Protocol via LocateHandle() and match
 * each back to an SNP unit by MAC address extracted from the handle's
 * device path.  This also transparently covers the legacy single-handle
 * case where PXE Base Code is installed on the SNP handle itself:
 * LocateHandle() returns that handle, whose device path ends in a MAC
 * node that trivially matches the same SNP unit.
 */
static void
efi_pxe_snapshot_all(int nifs)
{
	EFI_HANDLE *pxe_handles;
	EFI_STATUS status;
	UINTN sz;
	int i, j, npxe;

	sz = 0;
	status = BS->LocateHandle(ByProtocol, &pxe_guid, NULL, &sz, NULL);
	if (status != EFI_BUFFER_TOO_SMALL)
		return;
	pxe_handles = malloc(sz);
	if (pxe_handles == NULL)
		return;
	status = BS->LocateHandle(ByProtocol, &pxe_guid, NULL, &sz,
	    pxe_handles);
	if (EFI_ERROR(status)) {
		free(pxe_handles);
		return;
	}
	npxe = sz / sizeof(EFI_HANDLE);

	/*
	 * PXE is present on this system; allocate the per-unit cache
	 * only now.  Non-PXE UEFI boots pay nothing for this feature.
	 */
	pxe_cache = calloc(nifs, sizeof(struct pxe_cache_entry));
	if (pxe_cache == NULL) {
		free(pxe_handles);
		return;
	}

	for (i = 0; i < npxe; i++) {
		EFI_DEVICE_PATH *dp;
		uint8_t pxe_mac[6];

		dp = efi_lookup_devpath(pxe_handles[i]);
		if (!efi_devpath_get_mac(dp, pxe_mac))
			continue;

		for (j = 0; j < nifs; j++) {
			EFI_DEVICE_PATH *snp_dp, *node;
			MAC_ADDR_DEVICE_PATH *snp_mac;

			if (pxe_cache[j].valid)
				continue;
			snp_dp = efi_lookup_devpath(
			    efinetif.netif_ifs[j].dif_private);
			if ((node = efi_devpath_last_node(snp_dp)) == NULL)
				continue;
			snp_mac = (MAC_ADDR_DEVICE_PATH *)node;
			if (memcmp(&snp_mac->MacAddress, pxe_mac, 6) != 0)
				continue;
			efi_pxe_snapshot(pxe_handles[i], &pxe_cache[j]);
			break;
		}
	}

	free(pxe_handles);
}

/*
 * Publish the UEFI PXE Base Code snapshot to the shared bootp_response
 * global so that the loader's DHCP client (stand/libsa/bootp.c) can
 * pick it up and enter RFC 2131 INIT-REBOOT instead of running a full
 * DISCOVER/OFFER/REQUEST/ACK cycle.  Also seed servip from the
 * ProxyOffer's siaddr, which is the authoritative PXE boot server on
 * setups where the primary DHCP is not PXE-aware (its DhcpAck siaddr
 * is zero).  bootp()'s post-processing preserves this pre-set servip
 * when the INIT-REBOOT ACK arrives with siaddr == 0.
 */
static void
efi_pxe_publish_cache(int unit)
{
	const struct pxe_cache_entry *pce;

	if (pxe_cache == NULL)
		return;
	pce = &pxe_cache[unit];
	if (!pce->valid)
		return;

	free(bootp_response);
	bootp_response_size = 0;
	bootp_response = malloc(sizeof(pce->dhcp_ack));
	if (bootp_response == NULL)
		return;
	memcpy(bootp_response, &pce->dhcp_ack, sizeof(pce->dhcp_ack));
	bootp_response_size = sizeof(pce->dhcp_ack);

	DEBUG_PRINTF(1, ("%s: bootp_response=%p size=%zu\n",
	    __func__, bootp_response, bootp_response_size));
}

/*
 * Loader uses BOOTP/DHCP and also uses RARP as a fallback to populate
 * network parameters and problems with DHCP servers can cause the loader
 * to fail to populate them. Allow the device to ask about the basic
 * network parameters and if present use them.
 */
static void
efi_env_net_params(struct iodesc *desc)
{
	char *envstr;
	in_addr_t ipaddr, mask, gwaddr, serveraddr;
	n_long rootaddr;

	if ((envstr = getenv("rootpath")) != NULL)
		strlcpy(rootpath, envstr, sizeof(rootpath));

	/*
	 * Get network parameters.
	 */
	envstr = getenv("ipaddr");
	ipaddr = (envstr != NULL) ? inet_addr(envstr) : 0;

	envstr = getenv("netmask");
	mask = (envstr != NULL) ? inet_addr(envstr) : 0;

	envstr = getenv("gatewayip");
	gwaddr = (envstr != NULL) ? inet_addr(envstr) : 0;

	envstr = getenv("serverip");
	serveraddr = (envstr != NULL) ? inet_addr(envstr) : 0;

	/* No network params. */
	if (ipaddr == 0 && mask == 0 && gwaddr == 0 && serveraddr == 0)
		return;

	/* Partial network params. */
	if (ipaddr == 0 || mask == 0 || gwaddr == 0 || serveraddr == 0) {
		printf("Incomplete network settings from U-Boot\n");
		return;
	}

	/*
	 * Set network parameters.
	 */
	myip.s_addr = ipaddr;
	netmask = mask;
	gateip.s_addr = gwaddr;
	servip.s_addr = serveraddr;

	/*
	 * There must be a rootpath. It may be ip:/path or it may be just the
	 * path in which case the ip needs to be serverip.
	 */
#ifdef LOADER_NET_SUPPORT
	rootaddr = net_parse_rootpath();
	if (rootaddr == INADDR_NONE)
		rootaddr = serveraddr;
#else
	rootaddr = serveraddr;
#endif
	rootip.s_addr = rootaddr;

#ifdef EFINET_DEBUG
	printf("%s: proto=%d\n", __func__, netproto);
	printf("%s: ip=%s\n", __func__, inet_ntoa(myip));
	printf("%s: mask=%s\n", __func__, intoa(netmask));
	printf("%s: gateway=%s\n", __func__, inet_ntoa(gateip));
	printf("%s: server=%s\n", __func__, inet_ntoa(servip));
#endif

	desc->myip = myip;
}

static void
efinet_init(struct iodesc *desc, void *machdep_hint)
{
	struct netif *nif = desc->io_netif;
	EFI_SIMPLE_NETWORK *net;
	EFI_HANDLE h;
	EFI_STATUS status;
	UINT32 mask;

	/* Attempt to get netboot params from env */
	efi_env_net_params(desc);

	if (nif->nif_driver->netif_ifs[nif->nif_unit].dif_unit < 0) {
		printf("Invalid network interface %d\n", nif->nif_unit);
		return;
	}

	h = nif->nif_driver->netif_ifs[nif->nif_unit].dif_private;
	if (rootip.s_addr == 0)
		efi_pxe_publish_cache(nif->nif_unit);
	status = OpenProtocolByHandle(h, &sn_guid, (void **)&nif->nif_devdata);
	if (status != EFI_SUCCESS) {
		printf("net%d: cannot fetch interface data (status=%lu)\n",
		    nif->nif_unit, DECODE_ERROR(status));
		return;
	}

	net = nif->nif_devdata;
	if (net->Mode->State == EfiSimpleNetworkStopped) {
		status = net->Start(net);
		if (status != EFI_SUCCESS) {
			printf("net%d: cannot start interface (status=%lu)\n",
			    nif->nif_unit, DECODE_ERROR(status));
			return;
		}
	}

	if (net->Mode->State != EfiSimpleNetworkInitialized) {
		status = net->Initialize(net, 0, 0);
		if (status != EFI_SUCCESS) {
			printf("net%d: cannot init. interface (status=%lu)\n",
			    nif->nif_unit, DECODE_ERROR(status));
			return;
		}
	}

	mask = EFI_SIMPLE_NETWORK_RECEIVE_UNICAST |
	    EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST;

	status = net->ReceiveFilters(net, mask, 0, FALSE, 0, NULL);
	if (status != EFI_SUCCESS)
		printf("net%d: cannot set rx. filters (status=%lu)\n",
		    nif->nif_unit, DECODE_ERROR(status));

#ifdef EFINET_DEBUG
	dump_mode(net->Mode);
#endif

	bcopy(net->Mode->CurrentAddress.Addr, desc->myea, 6);
}

static void
efinet_end(struct netif *nif)
{
	EFI_SIMPLE_NETWORK *net = nif->nif_devdata;
	EFI_HANDLE h;

	if (net == NULL)
		return;

	net->Shutdown(net);
	h = nif->nif_driver->netif_ifs[nif->nif_unit].dif_private;
	BS->CloseProtocol(h, &sn_guid, IH, NULL);
	nif->nif_devdata = NULL;
}

static int efinet_dev_init(void);
static int efinet_dev_print(int);

struct devsw efinet_dev = {
	.dv_name = "net",
	.dv_type = DEVT_NET,
	.dv_init = efinet_dev_init,
	.dv_strategy = NULL,		/* Will be set in efinet_dev_init */
	.dv_open = NULL,		/* Will be set in efinet_dev_init */
	.dv_close = NULL,		/* Will be set in efinet_dev_init */
	.dv_ioctl = noioctl,
	.dv_print = efinet_dev_print,
	.dv_cleanup = nullsys,
};

static int
efinet_dev_init(void)
{
	struct netif_dif *dif;
	struct netif_stats *stats;
	EFI_DEVICE_PATH *devpath, *node;
	EFI_HANDLE *handles, *handles2;
	EFI_STATUS status;
	UINTN sz;
	int err, i, nifs;
	extern struct devsw netdev;

	/*
	 * Advertise our DHCP Client-System Architecture (RFC 4578).  Many
	 * x86_64 UEFI firmwares report themselves as "EFI BC" (0x0007)
	 * rather than "EFI x86-64" (0x0009); match that convention for
	 * best DHCP-server config compatibility.
	 */
#if defined(__amd64__)
	bootp_client_arch = 0x0007;	/* EFI BC */
#elif defined(__i386__)
	bootp_client_arch = 0x0006;	/* EFI IA32 */
#elif defined(__aarch64__)
	bootp_client_arch = 0x000b;	/* EFI 64-bit ARM */
#elif defined(__arm__)
	bootp_client_arch = 0x000a;	/* EFI 32-bit ARM */
#elif defined(__riscv)
	bootp_client_arch = 0x001b;	/* EFI 64-bit RISC-V */
#endif

	sz = 0;
	handles = NULL;
	status = BS->LocateHandle(ByProtocol, &sn_guid, NULL, &sz, NULL);
	if (status == EFI_BUFFER_TOO_SMALL) {
		handles = (EFI_HANDLE *)malloc(sz);
		if (handles == NULL)
			return (ENOMEM);
		status = BS->LocateHandle(ByProtocol, &sn_guid, NULL, &sz,
		    handles);
		if (EFI_ERROR(status))
			free(handles);
	}
	if (EFI_ERROR(status))
		return (efi_status_to_errno(status));
	handles2 = (EFI_HANDLE *)malloc(sz);
	if (handles2 == NULL) {
		free(handles);
		return (ENOMEM);
	}
	nifs = 0;
	for (i = 0; i < sz / sizeof(EFI_HANDLE); i++) {
		devpath = efi_lookup_devpath(handles[i]);
		if (devpath == NULL)
			continue;
		if ((node = efi_devpath_last_node(devpath)) == NULL)
			continue;

		if (DevicePathType(node) != MESSAGING_DEVICE_PATH ||
		    DevicePathSubType(node) != MSG_MAC_ADDR_DP)
			continue;

		handles2[nifs] = handles[i];
		nifs++;
	}
	free(handles);
	if (nifs == 0) {
		err = ENOENT;
		goto done;
	}

	err = efi_register_handles(&efinet_dev, handles2, NULL, nifs);
	if (err != 0)
		goto done;

	efinetif.netif_ifs = calloc(nifs, sizeof(struct netif_dif));
	stats = calloc(nifs, sizeof(struct netif_stats));
	if (efinetif.netif_ifs == NULL || stats == NULL) {
		free(efinetif.netif_ifs);
		free(stats);
		efinetif.netif_ifs = NULL;
		err = ENOMEM;
		goto done;
	}
	efinetif.netif_nifs = nifs;

	for (i = 0; i < nifs; i++) {

		dif = &efinetif.netif_ifs[i];
		dif->dif_unit = i;
		dif->dif_nsel = 1;
		dif->dif_stats = &stats[i];
		dif->dif_private = handles2[i];
	}

	/*
	 * Snapshot the PXE Base Code cache now, before any code path
	 * opens the SNP with EFI_OPEN_PROTOCOL_EXCLUSIVE (efinet_probe()).
	 * An EXCLUSIVE open causes the firmware to disconnect the UEFI
	 * PXE driver, which uninstalls the PXE Base Code Protocol and
	 * loses the cached DhcpAck/ProxyOffer packets.
	 */
	efi_pxe_snapshot_all(nifs);

#ifdef LOADER_NET_SUPPORT
	efinet_dev.dv_cleanup = netdev.dv_cleanup;
	efinet_dev.dv_open = netdev.dv_open;
	efinet_dev.dv_close = netdev.dv_close;
	efinet_dev.dv_strategy = netdev.dv_strategy;
#endif

done:
	free(handles2);
	return (err);
}

static int
efinet_dev_print(int verbose)
{
	CHAR16 *text;
	EFI_HANDLE h;
	int unit, ret = 0;

	printf("%s devices:", efinet_dev.dv_name);
	if ((ret = pager_output("\n")) != 0)
		return (ret);

	for (unit = 0, h = efi_find_handle(&efinet_dev, 0);
	    h != NULL; h = efi_find_handle(&efinet_dev, ++unit)) {
		printf("    %s%d:", efinet_dev.dv_name, unit);
		if (verbose) {
			text = efi_devpath_name(efi_lookup_devpath(h));
			if (text != NULL) {
				printf("    %S", text);
				efi_free_devpath_name(text);
			}
		}
		if ((ret = pager_output("\n")) != 0)
			break;
	}
	return (ret);
}