Device driver supporting the vending of network access from this FreeBSD domain to other domains. More...

#include <sys/cdefs.h>
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#include <netinet/tcp.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <machine/in_cksum.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <machine/_inttypes.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xen_intr.h>
#include <contrib/xen/io/netif.h>
#include <xen/xenbus/xenbusvar.h>
#include "netback_unit_tests.c"

Include dependency graph for netback.c:

Go to the source code of this file.

Data Structures
struct	xnb_pkt

struct	xnb_ring_config
	Configuration data for a shared memory request ring used to communicate with the front-end client of this this driver. More...

struct	xnb_softc

Macros
#define	XNB_SG 1 /* netback driver supports feature-sg */

#define	XNB_GSO_TCPV4 0 /* netback driver supports feature-gso-tcpv4 */

#define	XNB_RX_COPY 1 /* netback driver supports feature-rx-copy */

#define	XNB_RX_FLIP 0 /* netback driver does not support feature-rx-flip */

#define	XNB_DEBUG /* hardcode on during development */

#define	DPRINTF(fmt, args...) printf("xnb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)

#define	GNTTAB_LEN (64)

#define	XNB_CSUM_FEATURES (CSUM_TCP \| CSUM_UDP)

#define	NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)

#define	NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)

#define	RING_HAS_UNCONSUMED_REQUESTS_2(_r, cons)

#define	virt_to_mfn(x) (vtophys(x) >> PAGE_SHIFT)

#define	virt_to_offset(x) ((x) & (PAGE_SIZE - 1))

Typedefs
typedef struct gnttab_copy	gnttab_copy_table[GNTTAB_LEN]

Enumerations
enum	xnb_flag_t { XNBF_RING_CONNECTED = 0x01 , XNBF_RESOURCE_SHORTAGE = 0x02 , XNBF_SHUTDOWN = 0x04 , XNBF_IN_SHUTDOWN = 0x08 }

enum	xnb_ring_type_t { XNB_RING_TYPE_TX = 0 , XNB_RING_TYPE_RX = 1 , XNB_NUM_RING_TYPES }

Functions
	__FBSDID ("$FreeBSD$")

static	MALLOC_DEFINE (M_XENNETBACK, "xnb", "Xen Net Back Driver Data")

static void	xnb_attach_failed (struct xnb_softc xnb, int err, const char fmt,...) __printflike(3

static void static int	xnb_shutdown (struct xnb_softc *xnb)

static int	create_netdev (device_t dev)

static int	xnb_detach (device_t dev)

static int	xnb_ifmedia_upd (struct ifnet *ifp)

static void	xnb_ifmedia_sts (struct ifnet ifp, struct ifmediareq ifmr)

static void	xnb_intr (void *arg)

static int	xnb_send (netif_rx_back_ring_t rxb, domid_t otherend, const struct mbuf mbufc, gnttab_copy_table gnttab)

static int	xnb_recv (netif_tx_back_ring_t txb, domid_t otherend, struct mbuf mbufc, struct ifnet ifnet, gnttab_copy_table gnttab)

static int	xnb_ring2pkt (struct xnb_pkt pkt, const netif_tx_back_ring_t tx_ring, RING_IDX start)

static void	xnb_txpkt2rsp (const struct xnb_pkt pkt, netif_tx_back_ring_t ring, int error)

static struct mbuf *	xnb_pkt2mbufc (const struct xnb_pkt pkt, struct ifnet ifp)

static int	xnb_txpkt2gnttab (const struct xnb_pkt pkt, struct mbuf mbufc, gnttab_copy_table gnttab, const netif_tx_back_ring_t *txb, domid_t otherend_id)

static void	xnb_update_mbufc (struct mbuf *mbufc, const gnttab_copy_table gnttab, int n_entries)

static int	xnb_mbufc2pkt (const struct mbuf mbufc, struct xnb_pkt pkt, RING_IDX start, int space)

static int	xnb_rxpkt2gnttab (const struct xnb_pkt pkt, const struct mbuf mbufc, gnttab_copy_table gnttab, const netif_rx_back_ring_t *rxb, domid_t otherend_id)

static int	xnb_rxpkt2rsp (const struct xnb_pkt pkt, const gnttab_copy_table gnttab, int n_entries, netif_rx_back_ring_t ring)

static void	xnb_stop (struct xnb_softc *)

static int	xnb_ioctl (struct ifnet *, u_long, caddr_t)

static void	xnb_start_locked (struct ifnet *)

static void	xnb_start (struct ifnet *)

static void	xnb_ifinit_locked (struct xnb_softc *)

static void	xnb_ifinit (void *)

static int	xnb_unit_test_main (SYSCTL_HANDLER_ARGS)

static int	xnb_dump_rings (SYSCTL_HANDLER_ARGS)

static void	xnb_pkt_initialize (struct xnb_pkt *pxnb)

static void	xnb_pkt_validate (struct xnb_pkt *pxnb)

static void	xnb_pkt_invalidate (struct xnb_pkt *pxnb)

static int	xnb_pkt_is_valid (const struct xnb_pkt *pxnb)

static void __unused	xnb_dump_pkt (const struct xnb_pkt *pkt)

static void	xnb_dump_txreq (RING_IDX idx, const struct netif_tx_request *txreq)

static void __unused	xnb_dump_gnttab_copy (const struct gnttab_copy *entry)

static void __unused	xnb_dump_mbuf (const struct mbuf *m)

static void	xnb_free_communication_mem (struct xnb_softc *xnb)

static int	xnb_disconnect (struct xnb_softc *xnb)

static int	xnb_connect_ring (struct xnb_softc *xnb, xnb_ring_type_t ring_type)

static int	xnb_connect_comms (struct xnb_softc *xnb)

static int	xnb_alloc_communication_mem (struct xnb_softc *xnb)

static int	xnb_collect_xenstore_info (struct xnb_softc *xnb)

static int	xnb_publish_backend_info (struct xnb_softc *xnb)

static void	xnb_connect (struct xnb_softc *xnb)

static int	xnb_probe (device_t dev)

static void	xnb_setup_sysctl (struct xnb_softc *xnb)

static int	xnb_attach (device_t dev)

static int	xnb_suspend (device_t dev)

static int	xnb_resume (device_t dev)

static void	xnb_frontend_changed (device_t dev, XenbusState frontend_state)

	DRIVER_MODULE (xnb, xenbusb_back, xnb_driver, xnb_devclass, 0, 0)

Variables
static device_method_t	xnb_methods []

static driver_t	xnb_driver

devclass_t	xnb_devclass

Detailed Description

Device driver supporting the vending of network access from this FreeBSD domain to other domains.

Definition in file netback.c.

Macro Definition Documentation

◆ DPRINTF

#define DPRINTF	(	fmt,
		args...
	)	printf("xnb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)

Definition at line 105 of file netback.c.

◆ GNTTAB_LEN

#define GNTTAB_LEN (64)

Definition at line 112 of file netback.c.

◆ NET_RX_RING_SIZE

#define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)

Definition at line 118 of file netback.c.

◆ NET_TX_RING_SIZE

#define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)

Definition at line 117 of file netback.c.

◆ RING_HAS_UNCONSUMED_REQUESTS_2

#define RING_HAS_UNCONSUMED_REQUESTS_2	(	_r,
		cons
	)

Value:

        ({                     \
        unsigned int req = (_r)->sring->req_prod - cons;                \
        unsigned int rsp = RING_SIZE(_r) -                              \
        (cons - (_r)->rsp_prod_pvt);                                    \
        req < rsp ? req : rsp;                                          \
})

Two argument version of the standard macro. Second argument is a tentative value of req_cons

Definition at line 124 of file netback.c.

◆ virt_to_mfn

#define virt_to_mfn ( x ) (vtophys(x) >> PAGE_SHIFT)

Definition at line 131 of file netback.c.

◆ virt_to_offset

#define virt_to_offset ( x ) ((x) & (PAGE_SIZE - 1))

Definition at line 132 of file netback.c.

◆ XNB_CSUM_FEATURES

#define XNB_CSUM_FEATURES (CSUM_TCP | CSUM_UDP)

Definition at line 115 of file netback.c.

◆ XNB_DEBUG

#define XNB_DEBUG /* hardcode on during development */

Definition at line 102 of file netback.c.

◆ XNB_GSO_TCPV4

#define XNB_GSO_TCPV4 0 /* netback driver supports feature-gso-tcpv4 */

Definition at line 97 of file netback.c.

◆ XNB_RX_COPY

#define XNB_RX_COPY 1 /* netback driver supports feature-rx-copy */

Definition at line 98 of file netback.c.

◆ XNB_RX_FLIP

#define XNB_RX_FLIP 0 /* netback driver does not support feature-rx-flip */

Definition at line 99 of file netback.c.

◆ XNB_SG

#define XNB_SG 1 /* netback driver supports feature-sg */

Definition at line 96 of file netback.c.

Typedef Documentation

◆ gnttab_copy_table

typedef struct gnttab_copy gnttab_copy_table[GNTTAB_LEN]

Predefined array type of grant table copy descriptors. Used to pass around statically allocated memory structures.

Definition at line 138 of file netback.c.

Enumeration Type Documentation

◆ xnb_flag_t

enum xnb_flag_t

Per-instance connection state flags.

Enumerator
XNBF_RING_CONNECTED	Communication with the front-end has been established.
XNBF_RESOURCE_SHORTAGE	Front-end requests exist in the ring and are waiting for xnb_xen_req objects to free up.
XNBF_SHUTDOWN	Connection teardown has started.
XNBF_IN_SHUTDOWN	A thread is already performing shutdown processing.

Definition at line 358 of file netback.c.

◆ xnb_ring_type_t

enum xnb_ring_type_t

Types of rings. Used for array indices and to identify a ring's control data structure type

Enumerator
XNB_RING_TYPE_TX
XNB_RING_TYPE_RX
XNB_NUM_RING_TYPES

Definition at line 380 of file netback.c.

Function Documentation

◆ __FBSDID()

__FBSDID ( "$FreeBSD$" )

◆ create_netdev()

int create_netdev ( device_t dev )

static

Create a network device.

Parameters

handle device handle

Definition at line 1181 of file netback.c.

References xnb_softc::carrier, xnb_softc::dev, xnb_softc::handle, xnb_softc::if_name, ifp, xnb_softc::mac, NET_RX_RING_SIZE, xnb_softc::rx_lock, xnb_softc::sc_lock, xnb_softc::sc_media, xnb_softc::tx_lock, XNB_CSUM_FEATURES, xnb_ifinit(), xnb_ifmedia_sts(), xnb_ifmedia_upd(), xnb_softc::xnb_ifp, xnb_ioctl(), xnb_start(), and xs_scanf().

Referenced by xnb_attach().

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◆ DRIVER_MODULE()

DRIVER_MODULE	(	xnb	,
		xenbusb_back	,
		xnb_driver	,
		xnb_devclass	,
		0	,
		0
	)

◆ MALLOC_DEFINE()

static MALLOC_DEFINE	(	M_XENNETBACK	,
		"xnb"	,
		"Xen Net Back Driver Data"
	)

static

Custom malloc type for all driver allocations.

◆ xnb_alloc_communication_mem()

static int xnb_alloc_communication_mem ( struct xnb_softc * xnb )

static

Size KVA and pseudo-physical address allocations based on negotiated values for the size and number of I/O requests, and the size of our communication ring.

Parameters

xnb	Per-instance xnb configuration structure.

These address spaces are used to dynamically map pages in the front-end's domain into our own.

Definition at line 803 of file netback.c.

References xnb_softc::dev, xnb_softc::gnt_base_addr, xnb_softc::kva, xnb_softc::kva_size, xnb_softc::pseudo_phys_res, xnb_softc::pseudo_phys_res_id, xnb_softc::ring_configs, xnb_ring_config::ring_pages, xenmem_alloc(), and XNB_NUM_RING_TYPES.

Referenced by xnb_connect().

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◆ xnb_attach()

static int xnb_attach ( device_t dev )

static

Attach to a XenBus device that has been claimed by our probe routine.

Parameters

dev	NewBus device object representing this Xen Net Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 1255 of file netback.c.

References create_netdev(), xnb_softc::dev, DPRINTF, xnb_softc::otherend_id, xnb_softc::ring_configs, xnb_ring_config::ring_pages, xnb_attach_failed(), XNB_NUM_RING_TYPES, xnb_publish_backend_info(), xnb_setup_sysctl(), and xs_printf().

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◆ xnb_attach_failed()

static void xnb_attach_failed	(	struct xnb_softc *	xnb,
		int	err,
		const char *	fmt,
			...
	)

static

Report an attach time error to the console and Xen, and cleanup this instance by forcing immediate detach processing.

Parameters

xnb	Per-instance xnb configuration structure.
err	Errno describing the error.
fmt	Printf style format and arguments

Definition at line 1090 of file netback.c.

References xnb_softc::dev, xnb_detach(), xs_printf(), and xs_vprintf().

Referenced by xnb_attach().

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◆ xnb_collect_xenstore_info()

static int xnb_collect_xenstore_info ( struct xnb_softc * xnb )

static

Collect information from the XenStore related to our device and its frontend

Parameters

xnb	Per-instance xnb configuration structure.

Todo:: Linux collects the following info. We should collect most of this, too: "feature-rx-notify"

Todo:: : figure out the exact meaning of this feature, and when the frontend will set it to true. It should be set to true at some point

Todo:: Collect the rx notify feature

Definition at line 837 of file netback.c.

References xnb_softc::bridge, xnb_softc::can_sg, xnb_softc::dev, xnb_softc::evtchn, xnb_softc::gso, xnb_softc::gso_prefix, xnb_softc::handle, xnb_softc::ip_csum, xnb_softc::ring_configs, xnb_ring_config::ring_ref, XNB_RING_TYPE_RX, XNB_RING_TYPE_TX, xs_gather(), xs_read(), and xs_scanf().

Referenced by xnb_connect().

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◆ xnb_connect()

static void xnb_connect ( struct xnb_softc * xnb )

static

Connect to our netfront peer now that it has completed publishing its configuration into the XenStore.

Parameters

xnb	Per-instance xnb configuration structure.

Definition at line 995 of file netback.c.

References xnb_softc::carrier, xnb_softc::dev, xnb_softc::flags, xnb_alloc_communication_mem(), xnb_collect_xenstore_info(), and xnb_connect_comms().

Referenced by xnb_frontend_changed().

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◆ xnb_connect_comms()

static int xnb_connect_comms ( struct xnb_softc * xnb )

static

Setup the shared memory rings and bind an interrupt to the event channel used to notify us of ring changes.

Parameters

xnb	Per-instance xnb configuration structure.

Definition at line 754 of file netback.c.

References xnb_softc::dev, DPRINTF, xnb_softc::evtchn, xnb_softc::flags, xnb_softc::otherend_id, xnb_softc::xen_intr_handle, xnb_connect_ring(), xnb_disconnect(), xnb_intr(), XNB_NUM_RING_TYPES, and XNBF_RING_CONNECTED.

Referenced by xnb_connect().

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◆ xnb_connect_ring()

static int xnb_connect_ring	(	struct xnb_softc *	xnb,
		xnb_ring_type_t	ring_type
	)

static

Map a single shared memory ring into domain local address space and initialize its control structure

Parameters

xnb	Per-instance xnb configuration structure
ring_type	Array index of this ring in the xnb's array of rings

Returns: An errno

Definition at line 701 of file netback.c.

References xnb_ring_config::back_ring, xnb_ring_config::bus_addr, xnb_softc::dev, xnb_ring_config::gnt_addr, xnb_softc::gnt_base_addr, xnb_ring_config::handle, xnb_softc::kva, xnb_softc::otherend_id, xnb_softc::ring_configs, xnb_ring_config::ring_pages, xnb_ring_config::ring_ref, xnb_ring_config::rx_ring, xnb_ring_config::tx_ring, xnb_ring_config::va, XNB_RING_TYPE_RX, and XNB_RING_TYPE_TX.

Referenced by xnb_connect_comms().

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◆ xnb_detach()

static int xnb_detach ( device_t dev )

static

Detach from a net back device instance.

Parameters

dev	NewBus device object representing this Xen Net Back instance.

Returns: 0 for success, errno codes for failure.

Note: A net back device may be detached at any time in its life-cycle, including part way through the attach process. For this reason, initialization order and the initialization state checks in this routine must be carefully coupled so that attach time failures are gracefully handled.

Definition at line 1326 of file netback.c.

References xnb_softc::dev, DPRINTF, xnb_softc::rx_lock, xnb_softc::sc_lock, xnb_softc::tx_lock, and xnb_shutdown().

Referenced by xnb_attach_failed().

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◆ xnb_disconnect()

static int xnb_disconnect ( struct xnb_softc * xnb )

static

Cleanup all inter-domain communication mechanisms.

Parameters

xnb	Per-instance xnb configuration structure.

Definition at line 639 of file netback.c.

References xnb_softc::bridge, xnb_ring_config::bus_addr, xnb_softc::flags, xnb_ring_config::gnt_addr, xnb_ring_config::handle, xnb_softc::ring_configs, xnb_softc::rx_lock, xnb_softc::sc_lock, xnb_softc::tx_lock, xnb_softc::xen_intr_handle, xnb_free_communication_mem(), XNB_NUM_RING_TYPES, XNB_RING_TYPE_RX, and XNB_RING_TYPE_TX.

Referenced by xnb_connect_comms(), and xnb_shutdown().

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◆ xnb_dump_gnttab_copy()

static void __unused xnb_dump_gnttab_copy ( const struct gnttab_copy * entry )

static

Definition at line 513 of file netback.c.

◆ xnb_dump_mbuf()

static void __unused xnb_dump_mbuf ( const struct mbuf * m )

static

Definition at line 579 of file netback.c.

◆ xnb_dump_pkt()

static void __unused xnb_dump_pkt ( const struct xnb_pkt * pkt )

static

xnb_pkt method: print the packet's contents in human-readable format

Definition at line 278 of file netback.c.

References xnb_pkt::car, xnb_pkt::car_size, xnb_pkt::cdr, DPRINTF, xnb_pkt::error, xnb_pkt::flags, xnb_pkt::list_len, and xnb_pkt::size.

◆ xnb_dump_rings()

static int xnb_dump_rings ( SYSCTL_HANDLER_ARGS )

static

Definition at line 540 of file netback.c.

References xnb_ring_config::back_ring, xnb_softc::ring_configs, xnb_ring_config::rx_ring, rxb, xnb_ring_config::tx_ring, txb, XNB_RING_TYPE_RX, and XNB_RING_TYPE_TX.

Referenced by xnb_setup_sysctl().

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◆ xnb_dump_txreq()

static void xnb_dump_txreq	(	RING_IDX	idx,
		const struct netif_tx_request *	txreq
	)

static

Definition at line 296 of file netback.c.

References DPRINTF.

Referenced by xnb_ring2pkt().

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◆ xnb_free_communication_mem()

static void xnb_free_communication_mem ( struct xnb_softc * xnb )

static

Free dynamically allocated KVA or pseudo-physical address allocations.

Parameters

xnb	Per-instance xnb configuration structure.

Definition at line 620 of file netback.c.

References xnb_softc::dev, xnb_softc::gnt_base_addr, xnb_softc::kva, xnb_softc::pseudo_phys_res, xnb_softc::pseudo_phys_res_id, and xenmem_free().

Referenced by xnb_disconnect().

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◆ xnb_frontend_changed()

static void xnb_frontend_changed	(	device_t	dev,
		XenbusState	frontend_state
	)

static

Handle state changes expressed via the XenStore by our front-end peer.

Parameters

dev	NewBus device object representing this Xen Net Back instance.
frontend_state	The new state of the front-end.

Returns: 0 for success, errno codes for failure.

Definition at line 1383 of file netback.c.

References xnb_softc::dev, DPRINTF, xnb_softc::sc_lock, xnb_connect(), and xnb_shutdown().

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◆ xnb_ifinit()

static void xnb_ifinit ( void * xsc )

static

Definition at line 2448 of file netback.c.

References xnb_softc::sc_lock, and xnb_ifinit_locked().

Referenced by create_netdev(), and xnb_ioctl().

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◆ xnb_ifinit_locked()

static void xnb_ifinit_locked ( struct xnb_softc * xnb )

static

Definition at line 2429 of file netback.c.

References ifp, xnb_softc::sc_lock, xnb_softc::xnb_ifp, and xnb_stop().

Referenced by xnb_ifinit(), and xnb_ioctl().

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◆ xnb_ifmedia_sts()

static void xnb_ifmedia_sts	(	struct ifnet *	ifp,
		struct ifmediareq *	ifmr
	)

static

Callback used by the generic networking code to ask us what our carrier state is. Since we don't have a physical carrier, this is very simple

Definition at line 2472 of file netback.c.

Referenced by create_netdev().

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◆ xnb_ifmedia_upd()

static int xnb_ifmedia_upd ( struct ifnet * ifp )

static

Callback used by the generic networking code to tell us when our carrier state has changed. Since we don't have a physical carrier, we don't care

Definition at line 2462 of file netback.c.

Referenced by create_netdev().

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◆ xnb_intr()

static void xnb_intr ( void * arg )

static

Interrupt handler bound to the shared ring's event channel. Entry point for the xennet transmit path in netback Transfers packets from the Xen ring to the host's generic networking stack

Parameters

arg	Callback argument registerd during event channel binding - the xnb_softc for this instance.

Definition at line 1425 of file netback.c.

References xnb_ring_config::back_ring, ifp, notify(), xnb_softc::otherend_id, xnb_softc::ring_configs, xnb_softc::tx_gnttab, xnb_softc::tx_lock, xnb_ring_config::tx_ring, txb, xnb_softc::xen_intr_handle, xnb_softc::xnb_ifp, xnb_recv(), XNB_RING_TYPE_TX, and xnb_start().

Referenced by xnb_connect_comms().

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◆ xnb_ioctl()

static int xnb_ioctl	(	struct ifnet *	ifp,
		u_long	cmd,
		caddr_t	data
	)

static

Definition at line 2201 of file netback.c.

References ifp, xnb_softc::sc_lock, xnb_softc::sc_media, XNB_CSUM_FEATURES, xnb_ifinit(), xnb_ifinit_locked(), and xnb_stop().

Referenced by create_netdev().

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◆ xnb_mbufc2pkt()

static int xnb_mbufc2pkt	(	const struct mbuf *	mbufc,
		struct xnb_pkt *	pkt,
		RING_IDX	start,
		int	space
	)

static

Create an xnb_pkt based on the contents of an mbuf chain.

Parameters

[in]	mbufc	mbuf chain to transform into a packet
[out]	pkt	Storage for the newly generated xnb_pkt
[in]	start	The ring index of the first available slot in the rx ring
[in]	space	The number of free slots in the rx ring

Return values

0	Success
EINVAL	mbufc was corrupt or not convertible into a pkt
EAGAIN	There was not enough space in the ring to queue the packet

Definition at line 1879 of file netback.c.

References xnb_pkt::car, xnb_pkt::car_size, xnb_pkt::cdr, xnb_pkt::extra, xnb_pkt::flags, xnb_pkt::list_len, xnb_pkt::size, xnb_pkt_invalidate(), and xnb_pkt_validate().

Referenced by xnb_mbufc2pkt_1cluster(), xnb_mbufc2pkt_2short(), xnb_mbufc2pkt_empty(), xnb_mbufc2pkt_extra(), xnb_mbufc2pkt_long(), xnb_mbufc2pkt_nospace(), xnb_mbufc2pkt_short(), xnb_rxpkt2gnttab_2req(), xnb_rxpkt2gnttab_empty(), xnb_rxpkt2gnttab_short(), xnb_rxpkt2rsp_2short(), xnb_rxpkt2rsp_2slots(), xnb_rxpkt2rsp_copyerror(), xnb_rxpkt2rsp_empty(), xnb_rxpkt2rsp_extra(), xnb_rxpkt2rsp_short(), and xnb_send().

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◆ xnb_pkt2mbufc()

static struct mbuf * xnb_pkt2mbufc	(	const struct xnb_pkt *	pkt,
		struct ifnet *	ifp
	)

static

Create an mbuf chain to represent a packet. Initializes all of the headers in the mbuf chain, but does not copy the data. The returned chain must be free()'d when no longer needed

Parameters

[in] pkt A packet to model the mbuf chain after

Returns: A newly allocated mbuf chain, possibly with clusters attached. NULL on failure

Todo:: consider using a memory pool for mbufs instead of reallocating them for every packet

Todo:: handle extra data

Definition at line 1656 of file netback.c.

References xnb_pkt::flags, ifp, and xnb_pkt::size.

Referenced by xnb_pkt2mbufc_1cluster(), xnb_pkt2mbufc_2cluster(), xnb_pkt2mbufc_csum(), xnb_pkt2mbufc_empty(), xnb_pkt2mbufc_largecluster(), xnb_pkt2mbufc_short(), xnb_recv(), xnb_txpkt2gnttab_2cluster(), xnb_txpkt2gnttab_2req(), xnb_txpkt2gnttab_empty(), xnb_txpkt2gnttab_short(), xnb_update_mbufc_2cluster(), xnb_update_mbufc_2req(), and xnb_update_mbufc_short().

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◆ xnb_pkt_initialize()

static void xnb_pkt_initialize ( struct xnb_pkt * pxnb )

inlinestatic

xnb_pkt method: initialize it

Definition at line 249 of file netback.c.

Referenced by xnb_ring2pkt().

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◆ xnb_pkt_invalidate()

static void xnb_pkt_invalidate ( struct xnb_pkt * pxnb )

inlinestatic

xnb_pkt method: mark the packet as invalid

Definition at line 263 of file netback.c.

References xnb_pkt::error.

Referenced by xnb_mbufc2pkt(), and xnb_ring2pkt().

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◆ xnb_pkt_is_valid()

static int xnb_pkt_is_valid ( const struct xnb_pkt * pxnb )

inlinestatic

xnb_pkt method: Check whether the packet is valid

Definition at line 270 of file netback.c.

References xnb_pkt::error.

Referenced by xnb_mbufc2pkt_1cluster(), xnb_mbufc2pkt_2short(), xnb_mbufc2pkt_empty(), xnb_mbufc2pkt_extra(), xnb_mbufc2pkt_long(), xnb_mbufc2pkt_nospace(), xnb_mbufc2pkt_short(), xnb_recv(), xnb_ring2pkt_1req(), xnb_ring2pkt_2req(), xnb_ring2pkt_3req(), xnb_ring2pkt_extra(), xnb_ring2pkt_partial(), xnb_ring2pkt_wraps(), xnb_rxpkt2gnttab(), xnb_txpkt2rsp(), and xnb_txpkt2rsp_invalid().

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◆ xnb_pkt_validate()

static void xnb_pkt_validate ( struct xnb_pkt * pxnb )

inlinestatic

xnb_pkt method: mark the packet as valid

Definition at line 256 of file netback.c.

References xnb_pkt::error.

Referenced by xnb_mbufc2pkt().

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◆ xnb_probe()

static int xnb_probe ( device_t dev )

static

Inspect a XenBus device and claim it if is of the appropriate type.

Parameters

dev	NewBus device object representing a candidate XenBus device.

Returns: 0 for success, errno codes for failure.

Definition at line 1119 of file netback.c.

References DPRINTF.

◆ xnb_publish_backend_info()

static int xnb_publish_backend_info ( struct xnb_softc * xnb )

static

Supply information about the physical device to the frontend via XenBus.

Parameters

xnb	Per-instance xnb configuration structure.

Definition at line 940 of file netback.c.

References xnb_softc::dev, XNB_GSO_TCPV4, XNB_RX_COPY, XNB_RX_FLIP, XNB_SG, xs_printf(), xs_transaction_end(), and xs_transaction_start().

Referenced by xnb_attach().

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◆ xnb_recv()

static int xnb_recv	(	netif_tx_back_ring_t *	txb,
		domid_t	otherend,
		struct mbuf **	mbufc,
		struct ifnet *	ifnet,
		gnttab_copy_table	gnttab
	)

static

Dequeue at most one packet from the shared ring

Parameters

[in,out]	txb	Netif tx ring. A packet will be removed from it, and its private indices will be updated. But the indices will not be pushed to the shared ring.
[in]	ifnet	Interface to which the packet will be sent
[in]	otherend	Domain ID of the other end of the ring
[out]	mbufc	The assembled mbuf chain, ready to send to the generic networking stack
[in,out]	gnttab	Pointer to enough memory for a grant table. We make this a function parameter so that we will take less stack space.

Returns: An error code

Definition at line 1807 of file netback.c.

References DPRINTF, gnttab, txb, xnb_pkt2mbufc(), xnb_pkt_is_valid(), xnb_ring2pkt(), xnb_txpkt2gnttab(), xnb_txpkt2rsp(), and xnb_update_mbufc().

Referenced by xnb_intr().

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◆ xnb_resume()

static int xnb_resume ( device_t dev )

static

Perform any processing required to recover from a suspended state.

Parameters

dev	NewBus device object representing this Xen Net Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 1368 of file netback.c.

◆ xnb_ring2pkt()

static int xnb_ring2pkt	(	struct xnb_pkt *	pkt,
		const netif_tx_back_ring_t *	tx_ring,
		RING_IDX	start
	)

static

Build a struct xnb_pkt based on netif_tx_request's from a netif tx ring. Will read exactly 0 or 1 packets from the ring; never a partial packet.

Parameters

[out]	pkt	The returned packet. If there is an error building the packet, pkt.list_len will be set to 0.
[in]	tx_ring	Pointer to the Ring that is the input to this function
[in]	start	The ring index of the first potential request

Returns: The number of requests consumed to build this packet

Definition at line 1477 of file netback.c.

References xnb_pkt::car, xnb_pkt::car_size, xnb_pkt::cdr, xnb_pkt::extra, xnb_pkt::flags, xnb_pkt::list_len, RING_HAS_UNCONSUMED_REQUESTS_2, xnb_pkt::size, xnb_dump_txreq(), xnb_pkt_initialize(), and xnb_pkt_invalidate().

Referenced by xnb_get1pkt(), xnb_pkt2mbufc_empty(), xnb_recv(), xnb_ring2pkt_1req(), xnb_ring2pkt_2req(), xnb_ring2pkt_3req(), xnb_ring2pkt_emptyring(), xnb_ring2pkt_extra(), xnb_ring2pkt_partial(), xnb_ring2pkt_wraps(), xnb_txpkt2gnttab_2cluster(), xnb_txpkt2gnttab_2req(), xnb_txpkt2gnttab_empty(), xnb_txpkt2gnttab_short(), xnb_txpkt2rsp_1req(), xnb_txpkt2rsp_emptypkt(), xnb_txpkt2rsp_error(), xnb_txpkt2rsp_extra(), xnb_txpkt2rsp_invalid(), xnb_txpkt2rsp_long(), xnb_txpkt2rsp_wraps(), xnb_update_mbufc_2cluster(), xnb_update_mbufc_2req(), and xnb_update_mbufc_short().

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◆ xnb_rxpkt2gnttab()

static int xnb_rxpkt2gnttab	(	const struct xnb_pkt *	pkt,
		const struct mbuf *	mbufc,
		gnttab_copy_table	gnttab,
		const netif_rx_back_ring_t *	rxb,
		domid_t	otherend_id
	)

static

Build a gnttab_copy table that can be used to copy data from an mbuf chain to the frontend's shared buffers. Does not actually perform the copy. Always uses gref's on the other end's side.

Parameters

[in]	pkt	pkt's associated responses form the dest for the copy operatoin
[in]	mbufc	The source for the copy operation
[out]	gnttab	Storage for the returned grant table
[in]	rxb	Pointer to the backend ring structure
[in]	otherend_id	The domain ID of the other end of the copy

Returns: The number of gnttab entries filled

Definition at line 1952 of file netback.c.

References xnb_pkt::car, xnb_pkt::cdr, gnttab, GNTTAB_LEN, rxb, xnb_pkt::size, virt_to_mfn, virt_to_offset, and xnb_pkt_is_valid().

Referenced by xnb_rxpkt2gnttab_2req(), xnb_rxpkt2gnttab_empty(), xnb_rxpkt2gnttab_short(), xnb_rxpkt2rsp_2short(), xnb_rxpkt2rsp_2slots(), xnb_rxpkt2rsp_copyerror(), xnb_rxpkt2rsp_empty(), xnb_rxpkt2rsp_extra(), xnb_rxpkt2rsp_short(), and xnb_send().

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◆ xnb_rxpkt2rsp()

static int xnb_rxpkt2rsp	(	const struct xnb_pkt *	pkt,
		const gnttab_copy_table	gnttab,
		int	n_entries,
		netif_rx_back_ring_t *	ring
	)

static

Generates responses for all the requests that constituted pkt. Builds responses and writes them to the ring, but doesn't push the shared ring indices.

Parameters

[in]	pkt	the packet that needs a response
[in]	gnttab	The grant copy table corresponding to this packet. Used to determine how many rsp->netif_rx_response_t's to generate.
[in]	n_entries	Number of relevant entries in the grant table
[out]	ring	Responses go here

Returns: The number of RX requests that were consumed to generate the responses

Definition at line 2027 of file netback.c.

References DPRINTF, xnb_pkt::extra, xnb_pkt::flags, and gnttab.

Referenced by xnb_rxpkt2rsp_2short(), xnb_rxpkt2rsp_2slots(), xnb_rxpkt2rsp_copyerror(), xnb_rxpkt2rsp_empty(), xnb_rxpkt2rsp_extra(), xnb_rxpkt2rsp_short(), and xnb_send().

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◆ xnb_send()

static int xnb_send	(	netif_rx_back_ring_t *	ring,
		domid_t	otherend,
		const struct mbuf *	mbufc,
		gnttab_copy_table	gnttab
	)

static

Sends one packet to the ring. Blocks until the packet is on the ring

Parameters

[in]	mbufc	Contains one packet to send. Caller must free
[in,out]	rxb	The packet will be pushed onto this ring, but the otherend will not be notified.
[in]	otherend	The domain ID of the other end of the connection

Return values

EAGAIN The ring did not have enough space for the packet. The ring has not been modified

Parameters

[in,out] gnttab Pointer to enough memory for a grant table. We make this a function parameter so that we will take less stack space.

Return values

EINVAL mbufc was corrupt or not convertible into a pkt

Definition at line 2392 of file netback.c.

References xnb_pkt::error, gnttab, xnb_mbufc2pkt(), xnb_rxpkt2gnttab(), and xnb_rxpkt2rsp().

Referenced by xnb_start_locked().

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◆ xnb_setup_sysctl()

static void xnb_setup_sysctl ( struct xnb_softc * xnb )

static

Setup sysctl variables to control various Network Back parameters.

Parameters

xnb	Xen Net Back softc.

Definition at line 1138 of file netback.c.

References xnb_softc::dev, xnb_dump_rings(), and xnb_unit_test_main().

Referenced by xnb_attach().

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◆ xnb_shutdown()

static int xnb_shutdown ( struct xnb_softc * xnb )

static

Perform device shutdown functions.

Parameters

xnb	Per-instance xnb configuration structure.

Mark this instance as shutting down, wait for any active requests to drain, disconnect from the front-end, and notify any waiters (e.g. a thread invoking our detach method) that detach can now proceed.

Definition at line 1042 of file netback.c.

References xnb_softc::carrier, xnb_softc::dev, xnb_softc::flags, xnb_softc::sc_lock, xnb_disconnect(), xnb_softc::xnb_ifp, XNBF_IN_SHUTDOWN, and XNBF_SHUTDOWN.

Referenced by xnb_detach(), and xnb_frontend_changed().

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◆ xnb_start()

static void xnb_start ( struct ifnet * ifp )

static

Definition at line 2417 of file netback.c.

References ifp, xnb_softc::rx_lock, and xnb_start_locked().

Referenced by create_netdev(), and xnb_intr().

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◆ xnb_start_locked()

static void xnb_start_locked ( struct ifnet * ifp )

static

Definition at line 2312 of file netback.c.

References xnb_ring_config::back_ring, xnb_softc::carrier, ifp, notify(), xnb_softc::otherend_id, xnb_softc::ring_configs, xnb_softc::rx_gnttab, xnb_ring_config::rx_ring, rxb, xnb_softc::xen_intr_handle, XNB_RING_TYPE_RX, and xnb_send().

Referenced by xnb_start().

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◆ xnb_stop()

static void xnb_stop ( struct xnb_softc * xnb )

static

Definition at line 2190 of file netback.c.

References ifp, xnb_softc::sc_lock, and xnb_softc::xnb_ifp.

Referenced by xnb_ifinit_locked(), and xnb_ioctl().

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◆ xnb_suspend()

static int xnb_suspend ( device_t dev )

static

Prepare this net back device for suspension of this VM.

Parameters

dev	NewBus device object representing this Xen net Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 1355 of file netback.c.

◆ xnb_txpkt2gnttab()

static int xnb_txpkt2gnttab	(	const struct xnb_pkt *	pkt,
		struct mbuf *	mbufc,
		gnttab_copy_table	gnttab,
		const netif_tx_back_ring_t *	txb,
		domid_t	otherend_id
	)

static

Build a gnttab_copy table that can be used to copy data from a pkt to an mbufc. Does not actually perform the copy. Always uses gref's on the packet side.

Parameters

[in]	pkt	pkt's associated requests form the src for the copy operation
[in]	mbufc	mbufc's storage forms the dest for the copy operation
[out]	gnttab	Storage for the returned grant table
[in]	txb	Pointer to the backend ring structure
[in]	otherend_id	The domain ID of the other end of the copy

Returns: The number of gnttab entries filled

Definition at line 1700 of file netback.c.

References xnb_pkt::car, xnb_pkt::car_size, xnb_pkt::cdr, gnttab, GNTTAB_LEN, xnb_pkt::size, txb, virt_to_mfn, and virt_to_offset.

Referenced by xnb_recv(), xnb_txpkt2gnttab_2cluster(), xnb_txpkt2gnttab_2req(), xnb_txpkt2gnttab_empty(), xnb_txpkt2gnttab_short(), xnb_update_mbufc_2cluster(), xnb_update_mbufc_2req(), and xnb_update_mbufc_short().

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◆ xnb_txpkt2rsp()

static void xnb_txpkt2rsp	(	const struct xnb_pkt *	pkt,
		netif_tx_back_ring_t *	ring,
		int	error
	)

static

Respond to all the requests that constituted pkt. Builds the responses and writes them to the ring, but doesn't push them to the shared ring.

Parameters

[in]	pkt	the packet that needs a response
[in]	error	true if there was an error handling the packet, such as in the hypervisor copy op or mbuf allocation
[out]	ring	Responses go here

Definition at line 1599 of file netback.c.

References xnb_pkt::car, xnb_pkt::flags, xnb_pkt::list_len, and xnb_pkt_is_valid().

Referenced by xnb_recv(), xnb_txpkt2rsp_1req(), xnb_txpkt2rsp_emptypkt(), xnb_txpkt2rsp_error(), xnb_txpkt2rsp_extra(), xnb_txpkt2rsp_invalid(), xnb_txpkt2rsp_long(), and xnb_txpkt2rsp_wraps().

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◆ xnb_unit_test_main()

static int xnb_unit_test_main ( SYSCTL_HANDLER_ARGS )

static

Referenced by xnb_setup_sysctl().

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◆ xnb_update_mbufc()

static void xnb_update_mbufc	(	struct mbuf *	mbufc,
		const gnttab_copy_table	gnttab,
		int	n_entries
	)

static

Check the status of the grant copy operations, and update mbufs various non-data fields to reflect the data present.

Parameters

[in,out]	mbufc	mbuf chain to update. The chain must be valid and of the correct length, and data should already be present
[in]	gnttab	A grant table for a just completed copy op
[in]	n_entries	The number of valid entries in the grant table

Definition at line 1767 of file netback.c.

References gnttab.

Referenced by xnb_recv(), xnb_update_mbufc_2cluster(), xnb_update_mbufc_2req(), and xnb_update_mbufc_short().

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Variable Documentation

◆ xnb_devclass

devclass_t xnb_devclass

Definition at line 2498 of file netback.c.

◆ xnb_driver

driver_t xnb_driver

static

Initial value:

= {
        "xnb",
        xnb_methods,
        sizeof(struct xnb_softc),
}

Definition at line 2493 of file netback.c.

◆ xnb_methods

device_method_t xnb_methods[]

static

Initial value:

= {
        
        DEVMETHOD(device_probe,         xnb_probe),
        DEVMETHOD(device_attach,        xnb_attach),
        DEVMETHOD(device_detach,        xnb_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD(device_suspend,       xnb_suspend),
        DEVMETHOD(device_resume,        xnb_resume),
 
        
        DEVMETHOD(xenbus_otherend_changed, xnb_frontend_changed),
        { 0, 0 }
}

Definition at line 2479 of file netback.c.

Data Structures

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DPRINTF

◆ GNTTAB_LEN

◆ NET_RX_RING_SIZE

◆ NET_TX_RING_SIZE

◆ RING_HAS_UNCONSUMED_REQUESTS_2

◆ virt_to_mfn

◆ virt_to_offset

◆ XNB_CSUM_FEATURES

◆ XNB_DEBUG

◆ XNB_GSO_TCPV4

◆ XNB_RX_COPY

◆ XNB_RX_FLIP

◆ XNB_SG

Typedef Documentation

◆ gnttab_copy_table

Enumeration Type Documentation

◆ xnb_flag_t

◆ xnb_ring_type_t

Function Documentation

◆ __FBSDID()

◆ create_netdev()

◆ DRIVER_MODULE()

◆ MALLOC_DEFINE()

◆ xnb_alloc_communication_mem()

◆ xnb_attach()

◆ xnb_attach_failed()

◆ xnb_collect_xenstore_info()

◆ xnb_connect()

◆ xnb_connect_comms()

◆ xnb_connect_ring()

◆ xnb_detach()

◆ xnb_disconnect()

◆ xnb_dump_gnttab_copy()

◆ xnb_dump_mbuf()

◆ xnb_dump_pkt()

◆ xnb_dump_rings()

◆ xnb_dump_txreq()

◆ xnb_free_communication_mem()

◆ xnb_frontend_changed()

◆ xnb_ifinit()

◆ xnb_ifinit_locked()

◆ xnb_ifmedia_sts()

◆ xnb_ifmedia_upd()

◆ xnb_intr()

◆ xnb_ioctl()

◆ xnb_mbufc2pkt()

◆ xnb_pkt2mbufc()

◆ xnb_pkt_initialize()

◆ xnb_pkt_invalidate()

◆ xnb_pkt_is_valid()

◆ xnb_pkt_validate()

◆ xnb_probe()

◆ xnb_publish_backend_info()

◆ xnb_recv()

◆ xnb_resume()

◆ xnb_ring2pkt()

◆ xnb_rxpkt2gnttab()

◆ xnb_rxpkt2rsp()

◆ xnb_send()

◆ xnb_setup_sysctl()

◆ xnb_shutdown()

◆ xnb_start()

◆ xnb_start_locked()

◆ xnb_stop()

◆ xnb_suspend()

◆ xnb_txpkt2gnttab()

◆ xnb_txpkt2rsp()

◆ xnb_unit_test_main()

◆ xnb_update_mbufc()

Variable Documentation

◆ xnb_devclass

◆ xnb_driver