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freebsd-dev/sys/dev/xen/netback/netback.c
Pedro F. Giffuni 718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags. 
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009-2011 Spectra Logic Corporation
* 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,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*
* Authors: Justin T. Gibbs (Spectra Logic Corporation)
* Alan Somers (Spectra Logic Corporation)
* John Suykerbuyk (Spectra Logic Corporation)
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/**
* \file netback.c
*
* \brief Device driver supporting the vending of network access
* from this FreeBSD domain to other domains.
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_sctp.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>
#if __FreeBSD_version >= 700000
#include <netinet/tcp.h>
#endif
#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 <xen/interface/io/netif.h>
#include <xen/xenbus/xenbusvar.h>
/*--------------------------- Compile-time Tunables --------------------------*/
/*---------------------------------- Macros ----------------------------------*/
/**
* Custom malloc type for all driver allocations.
*/
static MALLOC_DEFINE(M_XENNETBACK, "xnb", "Xen Net Back Driver Data");
#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 */
#undef XNB_DEBUG
#define XNB_DEBUG /* hardcode on during development */
#ifdef XNB_DEBUG
#define DPRINTF(fmt, args...) \
printf("xnb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
#else
#define DPRINTF(fmt, args...) do {} while (0)
#endif
/* Default length for stack-allocated grant tables */
#define GNTTAB_LEN (64)
/* Features supported by all backends. TSO and LRO can be negotiated */
#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)
/**
* Two argument version of the standard macro. Second argument is a tentative
* value of req_cons
*/
#define RING_HAS_UNCONSUMED_REQUESTS_2(_r, cons) ({ \
unsigned int req = (_r)->sring->req_prod - cons; \
unsigned int rsp = RING_SIZE(_r) - \
(cons - (_r)->rsp_prod_pvt); \
req < rsp ? req : rsp; \
})
#define virt_to_mfn(x) (vtophys(x) >> PAGE_SHIFT)
#define virt_to_offset(x) ((x) & (PAGE_SIZE - 1))
/**
* Predefined array type of grant table copy descriptors. Used to pass around
* statically allocated memory structures.
*/
typedef struct gnttab_copy gnttab_copy_table[GNTTAB_LEN];
/*--------------------------- Forward Declarations ---------------------------*/
struct xnb_softc;
struct xnb_pkt;
static void xnb_attach_failed(struct xnb_softc *xnb,
int err, const char *fmt, ...)
__printflike(3,4);
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*);
#ifdef XNB_DEBUG
static int xnb_unit_test_main(SYSCTL_HANDLER_ARGS);
static int xnb_dump_rings(SYSCTL_HANDLER_ARGS);
#endif
#if defined(INET) || defined(INET6)
static void xnb_add_mbuf_cksum(struct mbuf *mbufc);
#endif
/*------------------------------ Data Structures -----------------------------*/
/**
* Representation of a xennet packet. Simplified version of a packet as
* stored in the Xen tx ring. Applicable to both RX and TX packets
*/
struct xnb_pkt{
/**
* Array index of the first data-bearing (eg, not extra info) entry
* for this packet
*/
RING_IDX car;
/**
* Array index of the second data-bearing entry for this packet.
* Invalid if the packet has only one data-bearing entry. If the
* packet has more than two data-bearing entries, then the second
* through the last will be sequential modulo the ring size
*/
RING_IDX cdr;
/**
* Optional extra info. Only valid if flags contains
* NETTXF_extra_info. Note that extra.type will always be
* XEN_NETIF_EXTRA_TYPE_GSO. Currently, no known netfront or netback
* driver will ever set XEN_NETIF_EXTRA_TYPE_MCAST_*
*/
netif_extra_info_t extra;
/** Size of entire packet in bytes. */
uint16_t size;
/** The size of the first entry's data in bytes */
uint16_t car_size;
/**
* Either NETTXF_ or NETRXF_ flags. Note that the flag values are
* not the same for TX and RX packets
*/
uint16_t flags;
/**
* The number of valid data-bearing entries (either netif_tx_request's
* or netif_rx_response's) in the packet. If this is 0, it means the
* entire packet is invalid.
*/
uint16_t list_len;
/** There was an error processing the packet */
uint8_t error;
};
/** xnb_pkt method: initialize it */
static inline void
xnb_pkt_initialize(struct xnb_pkt *pxnb)
{
bzero(pxnb, sizeof(*pxnb));
}
/** xnb_pkt method: mark the packet as valid */
static inline void
xnb_pkt_validate(struct xnb_pkt *pxnb)
{
pxnb->error = 0;
};
/** xnb_pkt method: mark the packet as invalid */
static inline void
xnb_pkt_invalidate(struct xnb_pkt *pxnb)
{
pxnb->error = 1;
};
/** xnb_pkt method: Check whether the packet is valid */
static inline int
xnb_pkt_is_valid(const struct xnb_pkt *pxnb)
{
return (! pxnb->error);
}
#ifdef XNB_DEBUG
/** xnb_pkt method: print the packet's contents in human-readable format*/
static void __unused
xnb_dump_pkt(const struct xnb_pkt *pkt) {
if (pkt == NULL) {
DPRINTF("Was passed a null pointer.\n");
return;
}
DPRINTF("pkt address= %p\n", pkt);
DPRINTF("pkt->size=%d\n", pkt->size);
DPRINTF("pkt->car_size=%d\n", pkt->car_size);
DPRINTF("pkt->flags=0x%04x\n", pkt->flags);
DPRINTF("pkt->list_len=%d\n", pkt->list_len);
/* DPRINTF("pkt->extra"); TODO */
DPRINTF("pkt->car=%d\n", pkt->car);
DPRINTF("pkt->cdr=%d\n", pkt->cdr);
DPRINTF("pkt->error=%d\n", pkt->error);
}
#endif /* XNB_DEBUG */
static void
xnb_dump_txreq(RING_IDX idx, const struct netif_tx_request *txreq)
{
if (txreq != NULL) {
DPRINTF("netif_tx_request index =%u\n", idx);
DPRINTF("netif_tx_request.gref =%u\n", txreq->gref);
DPRINTF("netif_tx_request.offset=%hu\n", txreq->offset);
DPRINTF("netif_tx_request.flags =%hu\n", txreq->flags);
DPRINTF("netif_tx_request.id =%hu\n", txreq->id);
DPRINTF("netif_tx_request.size =%hu\n", txreq->size);
}
}
/**
* \brief Configuration data for a shared memory request ring
* used to communicate with the front-end client of this
* this driver.
*/
struct xnb_ring_config {
/**
* Runtime structures for ring access. Unfortunately, TX and RX rings
* use different data structures, and that cannot be changed since it
* is part of the interdomain protocol.
*/
union{
netif_rx_back_ring_t rx_ring;
netif_tx_back_ring_t tx_ring;
} back_ring;
/**
* The device bus address returned by the hypervisor when
* mapping the ring and required to unmap it when a connection
* is torn down.
*/
uint64_t bus_addr;
/** The pseudo-physical address where ring memory is mapped.*/
uint64_t gnt_addr;
/** KVA address where ring memory is mapped. */
vm_offset_t va;
/**
* Grant table handles, one per-ring page, returned by the
* hyperpervisor upon mapping of the ring and required to
* unmap it when a connection is torn down.
*/
grant_handle_t handle;
/** The number of ring pages mapped for the current connection. */
unsigned ring_pages;
/**
* The grant references, one per-ring page, supplied by the
* front-end, allowing us to reference the ring pages in the
* front-end's domain and to map these pages into our own domain.
*/
grant_ref_t ring_ref;
};
/**
* Per-instance connection state flags.
*/
typedef enum
{
/** Communication with the front-end has been established. */
XNBF_RING_CONNECTED = 0x01,
/**
* Front-end requests exist in the ring and are waiting for
* xnb_xen_req objects to free up.
*/
XNBF_RESOURCE_SHORTAGE = 0x02,
/** Connection teardown has started. */
XNBF_SHUTDOWN = 0x04,
/** A thread is already performing shutdown processing. */
XNBF_IN_SHUTDOWN = 0x08
} xnb_flag_t;
/**
* Types of rings. Used for array indices and to identify a ring's control
* data structure type
*/
typedef enum{
XNB_RING_TYPE_TX = 0, /* ID of TX rings, used for array indices */
XNB_RING_TYPE_RX = 1, /* ID of RX rings, used for array indices */
XNB_NUM_RING_TYPES
} xnb_ring_type_t;
/**
* Per-instance configuration data.
*/
struct xnb_softc {
/** NewBus device corresponding to this instance. */
device_t dev;
/* Media related fields */
/** Generic network media state */
struct ifmedia sc_media;
/** Media carrier info */
struct ifnet *xnb_ifp;
/** Our own private carrier state */
unsigned carrier;
/** Device MAC Address */
uint8_t mac[ETHER_ADDR_LEN];
/* Xen related fields */
/**
* \brief The netif protocol abi in effect.
*
* There are situations where the back and front ends can
* have a different, native abi (e.g. intel x86_64 and
* 32bit x86 domains on the same machine). The back-end
* always accommodates the front-end's native abi. That
* value is pulled from the XenStore and recorded here.
*/
int abi;
/**
* Name of the bridge to which this VIF is connected, if any
* This field is dynamically allocated by xenbus and must be free()ed
* when no longer needed
*/
char *bridge;
/** The interrupt driven even channel used to signal ring events. */
evtchn_port_t evtchn;
/** Xen device handle.*/
long handle;
/** Handle to the communication ring event channel. */
xen_intr_handle_t xen_intr_handle;
/**
* \brief Cached value of the front-end's domain id.
*
* This value is used at once for each mapped page in
* a transaction. We cache it to avoid incuring the
* cost of an ivar access every time this is needed.
*/
domid_t otherend_id;
/**
* Undocumented frontend feature. Has something to do with
* scatter/gather IO
*/
uint8_t can_sg;
/** Undocumented frontend feature */
uint8_t gso;
/** Undocumented frontend feature */
uint8_t gso_prefix;
/** Can checksum TCP/UDP over IPv4 */
uint8_t ip_csum;
/* Implementation related fields */
/**
* Preallocated grant table copy descriptor for RX operations.
* Access must be protected by rx_lock
*/
gnttab_copy_table rx_gnttab;
/**
* Preallocated grant table copy descriptor for TX operations.
* Access must be protected by tx_lock
*/
gnttab_copy_table tx_gnttab;
/**
* Resource representing allocated physical address space
* associated with our per-instance kva region.
*/
struct resource *pseudo_phys_res;
/** Resource id for allocated physical address space. */
int pseudo_phys_res_id;
/** Ring mapping and interrupt configuration data. */
struct xnb_ring_config ring_configs[XNB_NUM_RING_TYPES];
/**
* Global pool of kva used for mapping remote domain ring
* and I/O transaction data.
*/
vm_offset_t kva;
/** Psuedo-physical address corresponding to kva. */
uint64_t gnt_base_addr;
/** Various configuration and state bit flags. */
xnb_flag_t flags;
/** Mutex protecting per-instance data in the receive path. */
struct mtx rx_lock;
/** Mutex protecting per-instance data in the softc structure. */
struct mtx sc_lock;
/** Mutex protecting per-instance data in the transmit path. */
struct mtx tx_lock;
/** The size of the global kva pool. */
int kva_size;
/** Name of the interface */
char if_name[IFNAMSIZ];
};
/*---------------------------- Debugging functions ---------------------------*/
#ifdef XNB_DEBUG
static void __unused
xnb_dump_gnttab_copy(const struct gnttab_copy *entry)
{
if (entry == NULL) {
printf("NULL grant table pointer\n");
return;
}
if (entry->flags & GNTCOPY_dest_gref)
printf("gnttab dest ref=\t%u\n", entry->dest.u.ref);
else
printf("gnttab dest gmfn=\t%"PRI_xen_pfn"\n",
entry->dest.u.gmfn);
printf("gnttab dest offset=\t%hu\n", entry->dest.offset);
printf("gnttab dest domid=\t%hu\n", entry->dest.domid);
if (entry->flags & GNTCOPY_source_gref)
printf("gnttab source ref=\t%u\n", entry->source.u.ref);
else
printf("gnttab source gmfn=\t%"PRI_xen_pfn"\n",
entry->source.u.gmfn);
printf("gnttab source offset=\t%hu\n", entry->source.offset);
printf("gnttab source domid=\t%hu\n", entry->source.domid);
printf("gnttab len=\t%hu\n", entry->len);
printf("gnttab flags=\t%hu\n", entry->flags);
printf("gnttab status=\t%hd\n", entry->status);
}
static int
xnb_dump_rings(SYSCTL_HANDLER_ARGS)
{
static char results[720];
struct xnb_softc const* xnb = (struct xnb_softc*)arg1;
netif_rx_back_ring_t const* rxb =
&xnb->ring_configs[XNB_RING_TYPE_RX].back_ring.rx_ring;
netif_tx_back_ring_t const* txb =
&xnb->ring_configs[XNB_RING_TYPE_TX].back_ring.tx_ring;
/* empty the result strings */
results[0] = 0;
if ( !txb || !txb->sring || !rxb || !rxb->sring )
return (SYSCTL_OUT(req, results, strnlen(results, 720)));
snprintf(results, 720,
"\n\t%35s %18s\n" /* TX, RX */
"\t%16s %18d %18d\n" /* req_cons */
"\t%16s %18d %18d\n" /* nr_ents */
"\t%16s %18d %18d\n" /* rsp_prod_pvt */
"\t%16s %18p %18p\n" /* sring */
"\t%16s %18d %18d\n" /* req_prod */
"\t%16s %18d %18d\n" /* req_event */
"\t%16s %18d %18d\n" /* rsp_prod */
"\t%16s %18d %18d\n", /* rsp_event */
"TX", "RX",
"req_cons", txb->req_cons, rxb->req_cons,
"nr_ents", txb->nr_ents, rxb->nr_ents,
"rsp_prod_pvt", txb->rsp_prod_pvt, rxb->rsp_prod_pvt,
"sring", txb->sring, rxb->sring,
"sring->req_prod", txb->sring->req_prod, rxb->sring->req_prod,
"sring->req_event", txb->sring->req_event, rxb->sring->req_event,
"sring->rsp_prod", txb->sring->rsp_prod, rxb->sring->rsp_prod,
"sring->rsp_event", txb->sring->rsp_event, rxb->sring->rsp_event);
return (SYSCTL_OUT(req, results, strnlen(results, 720)));
}
static void __unused
xnb_dump_mbuf(const struct mbuf *m)
{
int len;
uint8_t *d;
if (m == NULL)
return;
printf("xnb_dump_mbuf:\n");
if (m->m_flags & M_PKTHDR) {
printf(" flowid=%10d, csum_flags=%#8x, csum_data=%#8x, "
"tso_segsz=%5hd\n",
m->m_pkthdr.flowid, (int)m->m_pkthdr.csum_flags,
m->m_pkthdr.csum_data, m->m_pkthdr.tso_segsz);
printf(" rcvif=%16p, len=%19d\n",
m->m_pkthdr.rcvif, m->m_pkthdr.len);
}
printf(" m_next=%16p, m_nextpk=%16p, m_data=%16p\n",
m->m_next, m->m_nextpkt, m->m_data);
printf(" m_len=%17d, m_flags=%#15x, m_type=%18u\n",
m->m_len, m->m_flags, m->m_type);
len = m->m_len;
d = mtod(m, uint8_t*);
while (len > 0) {
int i;
printf(" ");
for (i = 0; (i < 16) && (len > 0); i++, len--) {
printf("%02hhx ", *(d++));
}
printf("\n");
}
}
#endif /* XNB_DEBUG */
/*------------------------ Inter-Domain Communication ------------------------*/
/**
* Free dynamically allocated KVA or pseudo-physical address allocations.
*
* \param xnb Per-instance xnb configuration structure.
*/
static void
xnb_free_communication_mem(struct xnb_softc *xnb)
{
if (xnb->kva != 0) {
if (xnb->pseudo_phys_res != NULL) {
xenmem_free(xnb->dev, xnb->pseudo_phys_res_id,
xnb->pseudo_phys_res);
xnb->pseudo_phys_res = NULL;
}
}
xnb->kva = 0;
xnb->gnt_base_addr = 0;
}
/**
* Cleanup all inter-domain communication mechanisms.
*
* \param xnb Per-instance xnb configuration structure.
*/
static int
xnb_disconnect(struct xnb_softc *xnb)
{
struct gnttab_unmap_grant_ref gnts[XNB_NUM_RING_TYPES];
int error;
int i;
if (xnb->xen_intr_handle != NULL)
xen_intr_unbind(&xnb->xen_intr_handle);
/*
* We may still have another thread currently processing requests. We
* must acquire the rx and tx locks to make sure those threads are done,
* but we can release those locks as soon as we acquire them, because no
* more interrupts will be arriving.
*/
mtx_lock(&xnb->tx_lock);
mtx_unlock(&xnb->tx_lock);
mtx_lock(&xnb->rx_lock);
mtx_unlock(&xnb->rx_lock);
/* Free malloc'd softc member variables */
if (xnb->bridge != NULL) {
free(xnb->bridge, M_XENSTORE);
xnb->bridge = NULL;
}
/* All request processing has stopped, so unmap the rings */
for (i=0; i < XNB_NUM_RING_TYPES; i++) {
gnts[i].host_addr = xnb->ring_configs[i].gnt_addr;
gnts[i].dev_bus_addr = xnb->ring_configs[i].bus_addr;
gnts[i].handle = xnb->ring_configs[i].handle;
}
error = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, gnts,
XNB_NUM_RING_TYPES);
KASSERT(error == 0, ("Grant table unmap op failed (%d)", error));
xnb_free_communication_mem(xnb);
/*
* Zero the ring config structs because the pointers, handles, and
* grant refs contained therein are no longer valid.
*/
bzero(&xnb->ring_configs[XNB_RING_TYPE_TX],
sizeof(struct xnb_ring_config));
bzero(&xnb->ring_configs[XNB_RING_TYPE_RX],
sizeof(struct xnb_ring_config));
xnb->flags &= ~XNBF_RING_CONNECTED;
return (0);
}
/**
* Map a single shared memory ring into domain local address space and
* initialize its control structure
*
* \param xnb Per-instance xnb configuration structure
* \param ring_type Array index of this ring in the xnb's array of rings
* \return An errno
*/
static int
xnb_connect_ring(struct xnb_softc *xnb, xnb_ring_type_t ring_type)
{
struct gnttab_map_grant_ref gnt;
struct xnb_ring_config *ring = &xnb->ring_configs[ring_type];
int error;
/* TX ring type = 0, RX =1 */
ring->va = xnb->kva + ring_type * PAGE_SIZE;
ring->gnt_addr = xnb->gnt_base_addr + ring_type * PAGE_SIZE;
gnt.host_addr = ring->gnt_addr;
gnt.flags = GNTMAP_host_map;
gnt.ref = ring->ring_ref;
gnt.dom = xnb->otherend_id;
error = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &gnt, 1);
if (error != 0)
panic("netback: Ring page grant table op failed (%d)", error);
if (gnt.status != 0) {
ring->va = 0;
error = EACCES;
xenbus_dev_fatal(xnb->dev, error,
"Ring shared page mapping failed. "
"Status %d.", gnt.status);
} else {
ring->handle = gnt.handle;
ring->bus_addr = gnt.dev_bus_addr;
if (ring_type == XNB_RING_TYPE_TX) {
BACK_RING_INIT(&ring->back_ring.tx_ring,
(netif_tx_sring_t*)ring->va,
ring->ring_pages * PAGE_SIZE);
} else if (ring_type == XNB_RING_TYPE_RX) {
BACK_RING_INIT(&ring->back_ring.rx_ring,
(netif_rx_sring_t*)ring->va,
ring->ring_pages * PAGE_SIZE);
} else {
xenbus_dev_fatal(xnb->dev, error,
"Unknown ring type %d", ring_type);
}
}
return error;
}
/**
* Setup the shared memory rings and bind an interrupt to the event channel
* used to notify us of ring changes.
*
* \param xnb Per-instance xnb configuration structure.
*/
static int
xnb_connect_comms(struct xnb_softc *xnb)
{
int error;
xnb_ring_type_t i;
if ((xnb->flags & XNBF_RING_CONNECTED) != 0)
return (0);
/*
* Kva for our rings are at the tail of the region of kva allocated
* by xnb_alloc_communication_mem().
*/
for (i=0; i < XNB_NUM_RING_TYPES; i++) {
error = xnb_connect_ring(xnb, i);
if (error != 0)
return error;
}
xnb->flags |= XNBF_RING_CONNECTED;
error = xen_intr_bind_remote_port(xnb->dev,
xnb->otherend_id,
xnb->evtchn,
/*filter*/NULL,
xnb_intr, /*arg*/xnb,
INTR_TYPE_BIO | INTR_MPSAFE,
&xnb->xen_intr_handle);
if (error != 0) {
(void)xnb_disconnect(xnb);
xenbus_dev_fatal(xnb->dev, error, "binding event channel");
return (error);
}
DPRINTF("rings connected!\n");
return (0);
}
/**
* 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.
*
* \param xnb Per-instance xnb configuration structure.
*
* These address spaces are used to dynamically map pages in the
* front-end's domain into our own.
*/
static int
xnb_alloc_communication_mem(struct xnb_softc *xnb)
{
xnb_ring_type_t i;
xnb->kva_size = 0;
for (i=0; i < XNB_NUM_RING_TYPES; i++) {
xnb->kva_size += xnb->ring_configs[i].ring_pages * PAGE_SIZE;
}
/*
* Reserve a range of pseudo physical memory that we can map
* into kva. These pages will only be backed by machine
* pages ("real memory") during the lifetime of front-end requests
* via grant table operations. We will map the netif tx and rx rings
* into this space.
*/
xnb->pseudo_phys_res_id = 0;
xnb->pseudo_phys_res = xenmem_alloc(xnb->dev, &xnb->pseudo_phys_res_id,
xnb->kva_size);
if (xnb->pseudo_phys_res == NULL) {
xnb->kva = 0;
return (ENOMEM);
}
xnb->kva = (vm_offset_t)rman_get_virtual(xnb->pseudo_phys_res);
xnb->gnt_base_addr = rman_get_start(xnb->pseudo_phys_res);
return (0);
}
/**
* Collect information from the XenStore related to our device and its frontend
*
* \param xnb Per-instance xnb configuration structure.
*/
static int
xnb_collect_xenstore_info(struct xnb_softc *xnb)
{
/**
* \todo Linux collects the following info. We should collect most
* of this, too:
* "feature-rx-notify"
*/
const char *otherend_path;
const char *our_path;
int err;
unsigned int rx_copy, bridge_len;
uint8_t no_csum_offload;
otherend_path = xenbus_get_otherend_path(xnb->dev);
our_path = xenbus_get_node(xnb->dev);
/* Collect the critical communication parameters */
err = xs_gather(XST_NIL, otherend_path,
"tx-ring-ref", "%l" PRIu32,
&xnb->ring_configs[XNB_RING_TYPE_TX].ring_ref,
"rx-ring-ref", "%l" PRIu32,
&xnb->ring_configs[XNB_RING_TYPE_RX].ring_ref,
"event-channel", "%" PRIu32, &xnb->evtchn,
NULL);
if (err != 0) {
xenbus_dev_fatal(xnb->dev, err,
"Unable to retrieve ring information from "
"frontend %s. Unable to connect.",
otherend_path);
return (err);
}
/* Collect the handle from xenstore */
err = xs_scanf(XST_NIL, our_path, "handle", NULL, "%li", &xnb->handle);
if (err != 0) {
xenbus_dev_fatal(xnb->dev, err,
"Error reading handle from frontend %s. "
"Unable to connect.", otherend_path);
}
/*
* Collect the bridgename, if any. We do not need bridge_len; we just
* throw it away
*/
err = xs_read(XST_NIL, our_path, "bridge", &bridge_len,
(void**)&xnb->bridge);
if (err != 0)
xnb->bridge = NULL;
/*
* Does the frontend request that we use rx copy? If not, return an
* error because this driver only supports rx copy.
*/
err = xs_scanf(XST_NIL, otherend_path, "request-rx-copy", NULL,
"%" PRIu32, &rx_copy);
if (err == ENOENT) {
err = 0;
rx_copy = 0;
}
if (err < 0) {
xenbus_dev_fatal(xnb->dev, err, "reading %s/request-rx-copy",
otherend_path);
return err;
}
/**
* \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
*/
/* if (!rx_copy)*/
/* return EOPNOTSUPP;*/
/** \todo Collect the rx notify feature */
/* Collect the feature-sg. */
if (xs_scanf(XST_NIL, otherend_path, "feature-sg", NULL,
"%hhu", &xnb->can_sg) < 0)
xnb->can_sg = 0;
/* Collect remaining frontend features */
if (xs_scanf(XST_NIL, otherend_path, "feature-gso-tcpv4", NULL,
"%hhu", &xnb->gso) < 0)
xnb->gso = 0;
if (xs_scanf(XST_NIL, otherend_path, "feature-gso-tcpv4-prefix", NULL,
"%hhu", &xnb->gso_prefix) < 0)
xnb->gso_prefix = 0;
if (xs_scanf(XST_NIL, otherend_path, "feature-no-csum-offload", NULL,
"%hhu", &no_csum_offload) < 0)
no_csum_offload = 0;
xnb->ip_csum = (no_csum_offload == 0);
return (0);
}
/**
* Supply information about the physical device to the frontend
* via XenBus.
*
* \param xnb Per-instance xnb configuration structure.
*/
static int
xnb_publish_backend_info(struct xnb_softc *xnb)
{
struct xs_transaction xst;
const char *our_path;
int error;
our_path = xenbus_get_node(xnb->dev);
do {
error = xs_transaction_start(&xst);
if (error != 0) {
xenbus_dev_fatal(xnb->dev, error,
"Error publishing backend info "
"(start transaction)");
break;
}
error = xs_printf(xst, our_path, "feature-sg",
"%d", XNB_SG);
if (error != 0)
break;
error = xs_printf(xst, our_path, "feature-gso-tcpv4",
"%d", XNB_GSO_TCPV4);
if (error != 0)
break;
error = xs_printf(xst, our_path, "feature-rx-copy",
"%d", XNB_RX_COPY);
if (error != 0)
break;
error = xs_printf(xst, our_path, "feature-rx-flip",
"%d", XNB_RX_FLIP);
if (error != 0)
break;
error = xs_transaction_end(xst, 0);
if (error != 0 && error != EAGAIN) {
xenbus_dev_fatal(xnb->dev, error, "ending transaction");
break;
}
} while (error == EAGAIN);
return (error);
}
/**
* Connect to our netfront peer now that it has completed publishing
* its configuration into the XenStore.
*
* \param xnb Per-instance xnb configuration structure.
*/
static void
xnb_connect(struct xnb_softc *xnb)
{
int error;
if (xenbus_get_state(xnb->dev) == XenbusStateConnected)
return;
if (xnb_collect_xenstore_info(xnb) != 0)
return;
xnb->flags &= ~XNBF_SHUTDOWN;
/* Read front end configuration. */
/* Allocate resources whose size depends on front-end configuration. */
error = xnb_alloc_communication_mem(xnb);
if (error != 0) {
xenbus_dev_fatal(xnb->dev, error,
"Unable to allocate communication memory");
return;
}
/*
* Connect communication channel.
*/
error = xnb_connect_comms(xnb);
if (error != 0) {
/* Specific errors are reported by xnb_connect_comms(). */
return;
}
xnb->carrier = 1;
/* Ready for I/O. */
xenbus_set_state(xnb->dev, XenbusStateConnected);
}
/*-------------------------- Device Teardown Support -------------------------*/
/**
* Perform device shutdown functions.
*
* \param 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.
*/
static int
xnb_shutdown(struct xnb_softc *xnb)
{
/*
* Due to the need to drop our mutex during some
* xenbus operations, it is possible for two threads
* to attempt to close out shutdown processing at
* the same time. Tell the caller that hits this
* race to try back later.
*/
if ((xnb->flags & XNBF_IN_SHUTDOWN) != 0)
return (EAGAIN);
xnb->flags |= XNBF_SHUTDOWN;
xnb->flags |= XNBF_IN_SHUTDOWN;
mtx_unlock(&xnb->sc_lock);
/* Free the network interface */
xnb->carrier = 0;
if (xnb->xnb_ifp != NULL) {
ether_ifdetach(xnb->xnb_ifp);
if_free(xnb->xnb_ifp);
xnb->xnb_ifp = NULL;
}
mtx_lock(&xnb->sc_lock);
xnb_disconnect(xnb);
mtx_unlock(&xnb->sc_lock);
if (xenbus_get_state(xnb->dev) < XenbusStateClosing)
xenbus_set_state(xnb->dev, XenbusStateClosing);
mtx_lock(&xnb->sc_lock);
xnb->flags &= ~XNBF_IN_SHUTDOWN;
/* Indicate to xnb_detach() that is it safe to proceed. */
wakeup(xnb);
return (0);
}
/**
* Report an attach time error to the console and Xen, and cleanup
* this instance by forcing immediate detach processing.
*
* \param xnb Per-instance xnb configuration structure.
* \param err Errno describing the error.
* \param fmt Printf style format and arguments
*/
static void
xnb_attach_failed(struct xnb_softc *xnb, int err, const char *fmt, ...)
{
va_list ap;
va_list ap_hotplug;
va_start(ap, fmt);
va_copy(ap_hotplug, ap);
xs_vprintf(XST_NIL, xenbus_get_node(xnb->dev),
"hotplug-error", fmt, ap_hotplug);
va_end(ap_hotplug);
(void)xs_printf(XST_NIL, xenbus_get_node(xnb->dev),
"hotplug-status", "error");
xenbus_dev_vfatal(xnb->dev, err, fmt, ap);
va_end(ap);
(void)xs_printf(XST_NIL, xenbus_get_node(xnb->dev), "online", "0");
xnb_detach(xnb->dev);
}
/*---------------------------- NewBus Entrypoints ----------------------------*/
/**
* Inspect a XenBus device and claim it if is of the appropriate type.
*
* \param dev NewBus device object representing a candidate XenBus device.
*
* \return 0 for success, errno codes for failure.
*/
static int
xnb_probe(device_t dev)
{
if (!strcmp(xenbus_get_type(dev), "vif")) {
DPRINTF("Claiming device %d, %s\n", device_get_unit(dev),
devclass_get_name(device_get_devclass(dev)));
device_set_desc(dev, "Backend Virtual Network Device");
device_quiet(dev);
return (0);
}
return (ENXIO);
}
/**
* Setup sysctl variables to control various Network Back parameters.
*
* \param xnb Xen Net Back softc.
*
*/
static void
xnb_setup_sysctl(struct xnb_softc *xnb)
{
struct sysctl_ctx_list *sysctl_ctx = NULL;
struct sysctl_oid *sysctl_tree = NULL;
sysctl_ctx = device_get_sysctl_ctx(xnb->dev);
if (sysctl_ctx == NULL)
return;
sysctl_tree = device_get_sysctl_tree(xnb->dev);
if (sysctl_tree == NULL)
return;
#ifdef XNB_DEBUG
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree),
OID_AUTO,
"unit_test_results",
CTLTYPE_STRING | CTLFLAG_RD,
xnb,
0,
xnb_unit_test_main,
"A",
"Results of builtin unit tests");
SYSCTL_ADD_PROC(sysctl_ctx,
SYSCTL_CHILDREN(sysctl_tree),
OID_AUTO,
"dump_rings",
CTLTYPE_STRING | CTLFLAG_RD,
xnb,
0,
xnb_dump_rings,
"A",
"Xennet Back Rings");
#endif /* XNB_DEBUG */
}
/**
* Create a network device.
* @param handle device handle
*/
int
create_netdev(device_t dev)
{
struct ifnet *ifp;
struct xnb_softc *xnb;
int err = 0;
uint32_t handle;
xnb = device_get_softc(dev);
mtx_init(&xnb->sc_lock, "xnb_softc", "xen netback softc lock", MTX_DEF);
mtx_init(&xnb->tx_lock, "xnb_tx", "xen netback tx lock", MTX_DEF);
mtx_init(&xnb->rx_lock, "xnb_rx", "xen netback rx lock", MTX_DEF);
xnb->dev = dev;
ifmedia_init(&xnb->sc_media, 0, xnb_ifmedia_upd, xnb_ifmedia_sts);
ifmedia_add(&xnb->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
ifmedia_set(&xnb->sc_media, IFM_ETHER|IFM_MANUAL);
/*
* Set the MAC address to a dummy value (00:00:00:00:00),
* if the MAC address of the host-facing interface is set
* to the same as the guest-facing one (the value found in
* xenstore), the bridge would stop delivering packets to
* us because it would see that the destination address of
* the packet is the same as the interface, and so the bridge
* would expect the packet has already been delivered locally
* (and just drop it).
*/
bzero(&xnb->mac[0], sizeof(xnb->mac));
/* The interface will be named using the following nomenclature:
*
* xnb<domid>.<handle>
*
* Where handle is the oder of the interface referred to the guest.
*/
err = xs_scanf(XST_NIL, xenbus_get_node(xnb->dev), "handle", NULL,
"%" PRIu32, &handle);
if (err != 0)
return (err);
snprintf(xnb->if_name, IFNAMSIZ, "xnb%" PRIu16 ".%" PRIu32,
xenbus_get_otherend_id(dev), handle);
if (err == 0) {
/* Set up ifnet structure */
ifp = xnb->xnb_ifp = if_alloc(IFT_ETHER);
ifp->if_softc = xnb;
if_initname(ifp, xnb->if_name, IF_DUNIT_NONE);
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_ioctl = xnb_ioctl;
ifp->if_start = xnb_start;
ifp->if_init = xnb_ifinit;
ifp->if_mtu = ETHERMTU;
ifp->if_snd.ifq_maxlen = NET_RX_RING_SIZE - 1;
ifp->if_hwassist = XNB_CSUM_FEATURES;
ifp->if_capabilities = IFCAP_HWCSUM;
ifp->if_capenable = IFCAP_HWCSUM;
ether_ifattach(ifp, xnb->mac);
xnb->carrier = 0;
}
return err;
}
/**
* Attach to a XenBus device that has been claimed by our probe routine.
*
* \param dev NewBus device object representing this Xen Net Back instance.
*
* \return 0 for success, errno codes for failure.
*/
static int
xnb_attach(device_t dev)
{
struct xnb_softc *xnb;
int error;
xnb_ring_type_t i;
error = create_netdev(dev);
if (error != 0) {
xenbus_dev_fatal(dev, error, "creating netdev");
return (error);
}
DPRINTF("Attaching to %s\n", xenbus_get_node(dev));
/*
* Basic initialization.
* After this block it is safe to call xnb_detach()
* to clean up any allocated data for this instance.
*/
xnb = device_get_softc(dev);
xnb->otherend_id = xenbus_get_otherend_id(dev);
for (i=0; i < XNB_NUM_RING_TYPES; i++) {
xnb->ring_configs[i].ring_pages = 1;
}
/*
* Setup sysctl variables.
*/
xnb_setup_sysctl(xnb);
/* Update hot-plug status to satisfy xend. */
error = xs_printf(XST_NIL, xenbus_get_node(xnb->dev),
"hotplug-status", "connected");
if (error != 0) {
xnb_attach_failed(xnb, error, "writing %s/hotplug-status",
xenbus_get_node(xnb->dev));
return (error);
}
if ((error = xnb_publish_backend_info(xnb)) != 0) {
/*
* If we can't publish our data, we cannot participate
* in this connection, and waiting for a front-end state
* change will not help the situation.
*/
xnb_attach_failed(xnb, error,
"Publishing backend status for %s",
xenbus_get_node(xnb->dev));
return error;
}
/* Tell the front end that we are ready to connect. */
xenbus_set_state(dev, XenbusStateInitWait);
return (0);
}
/**
* Detach from a net back device instance.
*
* \param dev NewBus device object representing this Xen Net Back instance.
*
* \return 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.
*/
static int
xnb_detach(device_t dev)
{
struct xnb_softc *xnb;
DPRINTF("\n");
xnb = device_get_softc(dev);
mtx_lock(&xnb->sc_lock);
while (xnb_shutdown(xnb) == EAGAIN) {
msleep(xnb, &xnb->sc_lock, /*wakeup prio unchanged*/0,
"xnb_shutdown", 0);
}
mtx_unlock(&xnb->sc_lock);
DPRINTF("\n");
mtx_destroy(&xnb->tx_lock);
mtx_destroy(&xnb->rx_lock);
mtx_destroy(&xnb->sc_lock);
return (0);
}
/**
* Prepare this net back device for suspension of this VM.
*
* \param dev NewBus device object representing this Xen net Back instance.
*
* \return 0 for success, errno codes for failure.
*/
static int
xnb_suspend(device_t dev)
{
return (0);
}
/**
* Perform any processing required to recover from a suspended state.
*
* \param dev NewBus device object representing this Xen Net Back instance.
*
* \return 0 for success, errno codes for failure.
*/
static int
xnb_resume(device_t dev)
{
return (0);
}
/**
* Handle state changes expressed via the XenStore by our front-end peer.
*
* \param dev NewBus device object representing this Xen
* Net Back instance.
* \param frontend_state The new state of the front-end.
*
* \return 0 for success, errno codes for failure.
*/
static void
xnb_frontend_changed(device_t dev, XenbusState frontend_state)
{
struct xnb_softc *xnb;
xnb = device_get_softc(dev);
DPRINTF("frontend_state=%s, xnb_state=%s\n",
xenbus_strstate(frontend_state),
xenbus_strstate(xenbus_get_state(xnb->dev)));
switch (frontend_state) {
case XenbusStateInitialising:
break;
case XenbusStateInitialised:
case XenbusStateConnected:
xnb_connect(xnb);
break;
case XenbusStateClosing:
case XenbusStateClosed:
mtx_lock(&xnb->sc_lock);
xnb_shutdown(xnb);
mtx_unlock(&xnb->sc_lock);
if (frontend_state == XenbusStateClosed)
xenbus_set_state(xnb->dev, XenbusStateClosed);
break;
default:
xenbus_dev_fatal(xnb->dev, EINVAL, "saw state %d at frontend",
frontend_state);
break;
}
}
/*---------------------------- Request Processing ----------------------------*/
/**
* 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
*
* \param arg Callback argument registerd during event channel
* binding - the xnb_softc for this instance.
*/
static void
xnb_intr(void *arg)
{
struct xnb_softc *xnb;
struct ifnet *ifp;
netif_tx_back_ring_t *txb;
RING_IDX req_prod_local;
xnb = (struct xnb_softc *)arg;
ifp = xnb->xnb_ifp;
txb = &xnb->ring_configs[XNB_RING_TYPE_TX].back_ring.tx_ring;
mtx_lock(&xnb->tx_lock);
do {
int notify;
req_prod_local = txb->sring->req_prod;
xen_rmb();
for (;;) {
struct mbuf *mbufc;
int err;
err = xnb_recv(txb, xnb->otherend_id, &mbufc, ifp,
xnb->tx_gnttab);
if (err || (mbufc == NULL))
break;
/* Send the packet to the generic network stack */
(*xnb->xnb_ifp->if_input)(xnb->xnb_ifp, mbufc);
}
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(txb, notify);
if (notify != 0)
xen_intr_signal(xnb->xen_intr_handle);
txb->sring->req_event = txb->req_cons + 1;
xen_mb();
} while (txb->sring->req_prod != req_prod_local) ;
mtx_unlock(&xnb->tx_lock);
xnb_start(ifp);
}
/**
* 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.
* \param[out] pkt The returned packet. If there is an error building
* the packet, pkt.list_len will be set to 0.
* \param[in] tx_ring Pointer to the Ring that is the input to this function
* \param[in] start The ring index of the first potential request
* \return The number of requests consumed to build this packet
*/
static int
xnb_ring2pkt(struct xnb_pkt *pkt, const netif_tx_back_ring_t *tx_ring,
RING_IDX start)
{
/*
* Outline:
* 1) Initialize pkt
* 2) Read the first request of the packet
* 3) Read the extras
* 4) Set cdr
* 5) Loop on the remainder of the packet
* 6) Finalize pkt (stuff like car_size and list_len)
*/
int idx = start;
int discard = 0; /* whether to discard the packet */
int more_data = 0; /* there are more request past the last one */
uint16_t cdr_size = 0; /* accumulated size of requests 2 through n */
xnb_pkt_initialize(pkt);
/* Read the first request */
if (RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
netif_tx_request_t *tx = RING_GET_REQUEST(tx_ring, idx);
pkt->size = tx->size;
pkt->flags = tx->flags & ~NETTXF_more_data;
more_data = tx->flags & NETTXF_more_data;
pkt->list_len++;
pkt->car = idx;
idx++;
}
/* Read the extra info */
if ((pkt->flags & NETTXF_extra_info) &&
RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
netif_extra_info_t *ext =
(netif_extra_info_t*) RING_GET_REQUEST(tx_ring, idx);
pkt->extra.type = ext->type;
switch (pkt->extra.type) {
case XEN_NETIF_EXTRA_TYPE_GSO:
pkt->extra.u.gso = ext->u.gso;
break;
default:
/*
* The reference Linux netfront driver will
* never set any other extra.type. So we don't
* know what to do with it. Let's print an
* error, then consume and discard the packet
*/
printf("xnb(%s:%d): Unknown extra info type %d."
" Discarding packet\n",
__func__, __LINE__, pkt->extra.type);
xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring,
start));
xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring,
idx));
discard = 1;
break;
}
pkt->extra.flags = ext->flags;
if (ext->flags & XEN_NETIF_EXTRA_FLAG_MORE) {
/*
* The reference linux netfront driver never sets this
* flag (nor does any other known netfront). So we
* will discard the packet.
*/
printf("xnb(%s:%d): Request sets "
"XEN_NETIF_EXTRA_FLAG_MORE, but we can't handle "
"that\n", __func__, __LINE__);
xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring, start));
xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring, idx));
discard = 1;
}
idx++;
}
/* Set cdr. If there is not more data, cdr is invalid */
pkt->cdr = idx;
/* Loop on remainder of packet */
while (more_data && RING_HAS_UNCONSUMED_REQUESTS_2(tx_ring, idx)) {
netif_tx_request_t *tx = RING_GET_REQUEST(tx_ring, idx);
pkt->list_len++;
cdr_size += tx->size;
if (tx->flags & ~NETTXF_more_data) {
/* There should be no other flags set at this point */
printf("xnb(%s:%d): Request sets unknown flags %d "
"after the 1st request in the packet.\n",
__func__, __LINE__, tx->flags);
xnb_dump_txreq(start, RING_GET_REQUEST(tx_ring, start));
xnb_dump_txreq(idx, RING_GET_REQUEST(tx_ring, idx));
}
more_data = tx->flags & NETTXF_more_data;
idx++;
}
/* Finalize packet */
if (more_data != 0) {
/* The ring ran out of requests before finishing the packet */
xnb_pkt_invalidate(pkt);
idx = start; /* tell caller that we consumed no requests */
} else {
/* Calculate car_size */
pkt->car_size = pkt->size - cdr_size;
}
if (discard != 0) {
xnb_pkt_invalidate(pkt);
}
return idx - start;
}
/**
* 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.
* \param[in] pkt the packet that needs a response
* \param[in] error true if there was an error handling the packet, such
* as in the hypervisor copy op or mbuf allocation
* \param[out] ring Responses go here
*/
static void
xnb_txpkt2rsp(const struct xnb_pkt *pkt, netif_tx_back_ring_t *ring,
int error)
{
/*
* Outline:
* 1) Respond to the first request
* 2) Respond to the extra info reques
* Loop through every remaining request in the packet, generating
* responses that copy those requests' ids and sets the status
* appropriately.
*/
netif_tx_request_t *tx;
netif_tx_response_t *rsp;
int i;
uint16_t status;
status = (xnb_pkt_is_valid(pkt) == 0) || error ?
NETIF_RSP_ERROR : NETIF_RSP_OKAY;
KASSERT((pkt->list_len == 0) || (ring->rsp_prod_pvt == pkt->car),
("Cannot respond to ring requests out of order"));
if (pkt->list_len >= 1) {
uint16_t id;
tx = RING_GET_REQUEST(ring, ring->rsp_prod_pvt);
id = tx->id;
rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
rsp->id = id;
rsp->status = status;
ring->rsp_prod_pvt++;
if (pkt->flags & NETRXF_extra_info) {
rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
rsp->status = NETIF_RSP_NULL;
ring->rsp_prod_pvt++;
}
}
for (i=0; i < pkt->list_len - 1; i++) {
uint16_t id;
tx = RING_GET_REQUEST(ring, ring->rsp_prod_pvt);
id = tx->id;
rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
rsp->id = id;
rsp->status = status;
ring->rsp_prod_pvt++;
}
}
/**
* 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
* \param[in] pkt A packet to model the mbuf chain after
* \return A newly allocated mbuf chain, possibly with clusters attached.
* NULL on failure
*/
static struct mbuf*
xnb_pkt2mbufc(const struct xnb_pkt *pkt, struct ifnet *ifp)
{
/**
* \todo consider using a memory pool for mbufs instead of
* reallocating them for every packet
*/
/** \todo handle extra data */
struct mbuf *m;
m = m_getm(NULL, pkt->size, M_NOWAIT, MT_DATA);
if (m != NULL) {
m->m_pkthdr.rcvif = ifp;
if (pkt->flags & NETTXF_data_validated) {
/*
* We lie to the host OS and always tell it that the
* checksums are ok, because the packet is unlikely to
* get corrupted going across domains.
*/
m->m_pkthdr.csum_flags = (
CSUM_IP_CHECKED |
CSUM_IP_VALID |
CSUM_DATA_VALID |
CSUM_PSEUDO_HDR
);
m->m_pkthdr.csum_data = 0xffff;
}
}
return m;
}
/**
* 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.
* \param[in] pkt pkt's associated requests form the src for
* the copy operation
* \param[in] mbufc mbufc's storage forms the dest for the copy operation
* \param[out] gnttab Storage for the returned grant table
* \param[in] txb Pointer to the backend ring structure
* \param[in] otherend_id The domain ID of the other end of the copy
* \return The number of gnttab entries filled
*/
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)
{
struct mbuf *mbuf = mbufc;/* current mbuf within the chain */
int gnt_idx = 0; /* index into grant table */
RING_IDX r_idx = pkt->car; /* index into tx ring buffer */
int r_ofs = 0; /* offset of next data within tx request's data area */
int m_ofs = 0; /* offset of next data within mbuf's data area */
/* size in bytes that still needs to be represented in the table */
uint16_t size_remaining = pkt->size;
while (size_remaining > 0) {
const netif_tx_request_t *txq = RING_GET_REQUEST(txb, r_idx);
const size_t mbuf_space = M_TRAILINGSPACE(mbuf) - m_ofs;
const size_t req_size =
r_idx == pkt->car ? pkt->car_size : txq->size;
const size_t pkt_space = req_size - r_ofs;
/*
* space is the largest amount of data that can be copied in the
* grant table's next entry
*/
const size_t space = MIN(pkt_space, mbuf_space);
/* TODO: handle this error condition without panicking */
KASSERT(gnt_idx < GNTTAB_LEN, ("Grant table is too short"));
gnttab[gnt_idx].source.u.ref = txq->gref;
gnttab[gnt_idx].source.domid = otherend_id;
gnttab[gnt_idx].source.offset = txq->offset + r_ofs;
gnttab[gnt_idx].dest.u.gmfn = virt_to_mfn(
mtod(mbuf, vm_offset_t) + m_ofs);
gnttab[gnt_idx].dest.offset = virt_to_offset(
mtod(mbuf, vm_offset_t) + m_ofs);
gnttab[gnt_idx].dest.domid = DOMID_SELF;
gnttab[gnt_idx].len = space;
gnttab[gnt_idx].flags = GNTCOPY_source_gref;
gnt_idx++;
r_ofs += space;
m_ofs += space;
size_remaining -= space;
if (req_size - r_ofs <= 0) {
/* Must move to the next tx request */
r_ofs = 0;
r_idx = (r_idx == pkt->car) ? pkt->cdr : r_idx + 1;
}
if (M_TRAILINGSPACE(mbuf) - m_ofs <= 0) {
/* Must move to the next mbuf */
m_ofs = 0;
mbuf = mbuf->m_next;
}
}
return gnt_idx;
}
/**
* Check the status of the grant copy operations, and update mbufs various
* non-data fields to reflect the data present.
* \param[in,out] mbufc mbuf chain to update. The chain must be valid and of
* the correct length, and data should already be present
* \param[in] gnttab A grant table for a just completed copy op
* \param[in] n_entries The number of valid entries in the grant table
*/
static void
xnb_update_mbufc(struct mbuf *mbufc, const gnttab_copy_table gnttab,
int n_entries)
{
struct mbuf *mbuf = mbufc;
int i;
size_t total_size = 0;
for (i = 0; i < n_entries; i++) {
KASSERT(gnttab[i].status == GNTST_okay,
("Some gnttab_copy entry had error status %hd\n",
gnttab[i].status));
mbuf->m_len += gnttab[i].len;
total_size += gnttab[i].len;
if (M_TRAILINGSPACE(mbuf) <= 0) {
mbuf = mbuf->m_next;
}
}
mbufc->m_pkthdr.len = total_size;
#if defined(INET) || defined(INET6)
xnb_add_mbuf_cksum(mbufc);
#endif
}
/**
* Dequeue at most one packet from the shared ring
* \param[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.
* \param[in] ifnet Interface to which the packet will be sent
* \param[in] otherend Domain ID of the other end of the ring
* \param[out] mbufc The assembled mbuf chain, ready to send to the generic
* networking stack
* \param[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 An error code
*/
static int
xnb_recv(netif_tx_back_ring_t *txb, domid_t otherend, struct mbuf **mbufc,
struct ifnet *ifnet, gnttab_copy_table gnttab)
{
struct xnb_pkt pkt;
/* number of tx requests consumed to build the last packet */
int num_consumed;
int nr_ents;
*mbufc = NULL;
num_consumed = xnb_ring2pkt(&pkt, txb, txb->req_cons);
if (num_consumed == 0)
return 0; /* Nothing to receive */
/* update statistics independent of errors */
if_inc_counter(ifnet, IFCOUNTER_IPACKETS, 1);
/*
* if we got here, then 1 or more requests was consumed, but the packet
* is not necessarily valid.
*/
if (xnb_pkt_is_valid(&pkt) == 0) {
/* got a garbage packet, respond and drop it */
xnb_txpkt2rsp(&pkt, txb, 1);
txb->req_cons += num_consumed;
DPRINTF("xnb_intr: garbage packet, num_consumed=%d\n",
num_consumed);
if_inc_counter(ifnet, IFCOUNTER_IERRORS, 1);
return EINVAL;
}
*mbufc = xnb_pkt2mbufc(&pkt, ifnet);
if (*mbufc == NULL) {
/*
* Couldn't allocate mbufs. Respond and drop the packet. Do
* not consume the requests
*/
xnb_txpkt2rsp(&pkt, txb, 1);
DPRINTF("xnb_intr: Couldn't allocate mbufs, num_consumed=%d\n",
num_consumed);
if_inc_counter(ifnet, IFCOUNTER_IQDROPS, 1);
return ENOMEM;
}
nr_ents = xnb_txpkt2gnttab(&pkt, *mbufc, gnttab, txb, otherend);
if (nr_ents > 0) {
int __unused hv_ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
gnttab, nr_ents);
KASSERT(hv_ret == 0,
("HYPERVISOR_grant_table_op returned %d\n", hv_ret));
xnb_update_mbufc(*mbufc, gnttab, nr_ents);
}
xnb_txpkt2rsp(&pkt, txb, 0);
txb->req_cons += num_consumed;
return 0;
}
/**
* Create an xnb_pkt based on the contents of an mbuf chain.
* \param[in] mbufc mbuf chain to transform into a packet
* \param[out] pkt Storage for the newly generated xnb_pkt
* \param[in] start The ring index of the first available slot in the rx
* ring
* \param[in] space The number of free slots in the rx ring
* \retval 0 Success
* \retval EINVAL mbufc was corrupt or not convertible into a pkt
* \retval EAGAIN There was not enough space in the ring to queue the
* packet
*/
static int
xnb_mbufc2pkt(const struct mbuf *mbufc, struct xnb_pkt *pkt,
RING_IDX start, int space)
{
int retval = 0;
if ((mbufc == NULL) ||
( (mbufc->m_flags & M_PKTHDR) == 0) ||
(mbufc->m_pkthdr.len == 0)) {
xnb_pkt_invalidate(pkt);
retval = EINVAL;
} else {
int slots_required;
xnb_pkt_validate(pkt);
pkt->flags = 0;
pkt->size = mbufc->m_pkthdr.len;
pkt->car = start;
pkt->car_size = mbufc->m_len;
if (mbufc->m_pkthdr.csum_flags & CSUM_TSO) {
pkt->flags |= NETRXF_extra_info;
pkt->extra.u.gso.size = mbufc->m_pkthdr.tso_segsz;
pkt->extra.u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
pkt->extra.u.gso.pad = 0;
pkt->extra.u.gso.features = 0;
pkt->extra.type = XEN_NETIF_EXTRA_TYPE_GSO;
pkt->extra.flags = 0;
pkt->cdr = start + 2;
} else {
pkt->cdr = start + 1;
}
if (mbufc->m_pkthdr.csum_flags & (CSUM_TSO | CSUM_DELAY_DATA)) {
pkt->flags |=
(NETRXF_csum_blank | NETRXF_data_validated);
}
/*
* Each ring response can have up to PAGE_SIZE of data.
* Assume that we can defragment the mbuf chain efficiently
* into responses so that each response but the last uses all
* PAGE_SIZE bytes.
*/
pkt->list_len = howmany(pkt->size, PAGE_SIZE);
if (pkt->list_len > 1) {
pkt->flags |= NETRXF_more_data;
}
slots_required = pkt->list_len +
(pkt->flags & NETRXF_extra_info ? 1 : 0);
if (slots_required > space) {
xnb_pkt_invalidate(pkt);
retval = EAGAIN;
}
}
return retval;
}
/**
* 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.
* \param[in] pkt pkt's associated responses form the dest for the copy
* operatoin
* \param[in] mbufc The source for the copy operation
* \param[out] gnttab Storage for the returned grant table
* \param[in] rxb Pointer to the backend ring structure
* \param[in] otherend_id The domain ID of the other end of the copy
* \return The number of gnttab entries filled
*/
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)
{
const struct mbuf *mbuf = mbufc;/* current mbuf within the chain */
int gnt_idx = 0; /* index into grant table */
RING_IDX r_idx = pkt->car; /* index into rx ring buffer */
int r_ofs = 0; /* offset of next data within rx request's data area */
int m_ofs = 0; /* offset of next data within mbuf's data area */
/* size in bytes that still needs to be represented in the table */
uint16_t size_remaining;
size_remaining = (xnb_pkt_is_valid(pkt) != 0) ? pkt->size : 0;
while (size_remaining > 0) {
const netif_rx_request_t *rxq = RING_GET_REQUEST(rxb, r_idx);
const size_t mbuf_space = mbuf->m_len - m_ofs;
/* Xen shared pages have an implied size of PAGE_SIZE */
const size_t req_size = PAGE_SIZE;
const size_t pkt_space = req_size - r_ofs;
/*
* space is the largest amount of data that can be copied in the
* grant table's next entry
*/
const size_t space = MIN(pkt_space, mbuf_space);
/* TODO: handle this error condition without panicing */
KASSERT(gnt_idx < GNTTAB_LEN, ("Grant table is too short"));
gnttab[gnt_idx].dest.u.ref = rxq->gref;
gnttab[gnt_idx].dest.domid = otherend_id;
gnttab[gnt_idx].dest.offset = r_ofs;
gnttab[gnt_idx].source.u.gmfn = virt_to_mfn(
mtod(mbuf, vm_offset_t) + m_ofs);
gnttab[gnt_idx].source.offset = virt_to_offset(
mtod(mbuf, vm_offset_t) + m_ofs);
gnttab[gnt_idx].source.domid = DOMID_SELF;
gnttab[gnt_idx].len = space;
gnttab[gnt_idx].flags = GNTCOPY_dest_gref;
gnt_idx++;
r_ofs += space;
m_ofs += space;
size_remaining -= space;
if (req_size - r_ofs <= 0) {
/* Must move to the next rx request */
r_ofs = 0;
r_idx = (r_idx == pkt->car) ? pkt->cdr : r_idx + 1;
}
if (mbuf->m_len - m_ofs <= 0) {
/* Must move to the next mbuf */
m_ofs = 0;
mbuf = mbuf->m_next;
}
}
return gnt_idx;
}
/**
* 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.
* \param[in] pkt the packet that needs a response
* \param[in] gnttab The grant copy table corresponding to this packet.
* Used to determine how many rsp->netif_rx_response_t's to
* generate.
* \param[in] n_entries Number of relevant entries in the grant table
* \param[out] ring Responses go here
* \return The number of RX requests that were consumed to generate
* the responses
*/
static int
xnb_rxpkt2rsp(const struct xnb_pkt *pkt, const gnttab_copy_table gnttab,
int n_entries, netif_rx_back_ring_t *ring)
{
/*
* This code makes the following assumptions:
* * All entries in gnttab set GNTCOPY_dest_gref
* * The entries in gnttab are grouped by their grefs: any two
* entries with the same gref must be adjacent
*/
int error = 0;
int gnt_idx, i;
int n_responses = 0;
grant_ref_t last_gref = GRANT_REF_INVALID;
RING_IDX r_idx;
KASSERT(gnttab != NULL, ("Received a null granttable copy"));
/*
* In the event of an error, we only need to send one response to the
* netfront. In that case, we musn't write any data to the responses
* after the one we send. So we must loop all the way through gnttab
* looking for errors before we generate any responses
*
* Since we're looping through the grant table anyway, we'll count the
* number of different gref's in it, which will tell us how many
* responses to generate
*/
for (gnt_idx = 0; gnt_idx < n_entries; gnt_idx++) {
int16_t status = gnttab[gnt_idx].status;
if (status != GNTST_okay) {
DPRINTF(
"Got error %d for hypervisor gnttab_copy status\n",
status);
error = 1;
break;
}
if (gnttab[gnt_idx].dest.u.ref != last_gref) {
n_responses++;
last_gref = gnttab[gnt_idx].dest.u.ref;
}
}
if (error != 0) {
uint16_t id;
netif_rx_response_t *rsp;
id = RING_GET_REQUEST(ring, ring->rsp_prod_pvt)->id;
rsp = RING_GET_RESPONSE(ring, ring->rsp_prod_pvt);
rsp->id = id;
rsp->status = NETIF_RSP_ERROR;
n_responses = 1;
} else {
gnt_idx = 0;
const int has_extra = pkt->flags & NETRXF_extra_info;
if (has_extra != 0)
n_responses++;
for (i = 0; i < n_responses; i++) {
netif_rx_request_t rxq;
netif_rx_response_t *rsp;
r_idx = ring->rsp_prod_pvt + i;
/*
* We copy the structure of rxq instead of making a
* pointer because it shares the same memory as rsp.
*/
rxq = *(RING_GET_REQUEST(ring, r_idx));
rsp = RING_GET_RESPONSE(ring, r_idx);
if (has_extra && (i == 1)) {
netif_extra_info_t *ext =
(netif_extra_info_t*)rsp;
ext->type = XEN_NETIF_EXTRA_TYPE_GSO;
ext->flags = 0;
ext->u.gso.size = pkt->extra.u.gso.size;
ext->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
ext->u.gso.pad = 0;
ext->u.gso.features = 0;
} else {
rsp->id = rxq.id;
rsp->status = GNTST_okay;
rsp->offset = 0;
rsp->flags = 0;
if (i < pkt->list_len - 1)
rsp->flags |= NETRXF_more_data;
if ((i == 0) && has_extra)
rsp->flags |= NETRXF_extra_info;
if ((i == 0) &&
(pkt->flags & NETRXF_data_validated)) {
rsp->flags |= NETRXF_data_validated;
rsp->flags |= NETRXF_csum_blank;
}
rsp->status = 0;
for (; gnttab[gnt_idx].dest.u.ref == rxq.gref;
gnt_idx++) {
rsp->status += gnttab[gnt_idx].len;
}
}
}
}
ring->req_cons += n_responses;
ring->rsp_prod_pvt += n_responses;
return n_responses;
}
#if defined(INET) || defined(INET6)
/**
* Add IP, TCP, and/or UDP checksums to every mbuf in a chain. The first mbuf
* in the chain must start with a struct ether_header.
*
* XXX This function will perform incorrectly on UDP packets that are split up
* into multiple ethernet frames.
*/
static void
xnb_add_mbuf_cksum(struct mbuf *mbufc)
{
struct ether_header *eh;
struct ip *iph;
uint16_t ether_type;
eh = mtod(mbufc, struct ether_header*);
ether_type = ntohs(eh->ether_type);
if (ether_type != ETHERTYPE_IP) {
/* Nothing to calculate */
return;
}
iph = (struct ip*)(eh + 1);
if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
iph->ip_sum = 0;
iph->ip_sum = in_cksum_hdr(iph);
}
switch (iph->ip_p) {
case IPPROTO_TCP:
if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
size_t tcplen = ntohs(iph->ip_len) - sizeof(struct ip);
struct tcphdr *th = (struct tcphdr*)(iph + 1);
th->th_sum = in_pseudo(iph->ip_src.s_addr,
iph->ip_dst.s_addr, htons(IPPROTO_TCP + tcplen));
th->th_sum = in_cksum_skip(mbufc,
sizeof(struct ether_header) + ntohs(iph->ip_len),
sizeof(struct ether_header) + (iph->ip_hl << 2));
}
break;
case IPPROTO_UDP:
if (mbufc->m_pkthdr.csum_flags & CSUM_IP_VALID) {
size_t udplen = ntohs(iph->ip_len) - sizeof(struct ip);
struct udphdr *uh = (struct udphdr*)(iph + 1);
uh->uh_sum = in_pseudo(iph->ip_src.s_addr,
iph->ip_dst.s_addr, htons(IPPROTO_UDP + udplen));
uh->uh_sum = in_cksum_skip(mbufc,
sizeof(struct ether_header) + ntohs(iph->ip_len),
sizeof(struct ether_header) + (iph->ip_hl << 2));
}
break;
default:
break;
}
}
#endif /* INET || INET6 */
static void
xnb_stop(struct xnb_softc *xnb)
{
struct ifnet *ifp;
mtx_assert(&xnb->sc_lock, MA_OWNED);
ifp = xnb->xnb_ifp;
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
if_link_state_change(ifp, LINK_STATE_DOWN);
}
static int
xnb_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct xnb_softc *xnb = ifp->if_softc;
struct ifreq *ifr = (struct ifreq*) data;
#ifdef INET
struct ifaddr *ifa = (struct ifaddr*)data;
#endif
int error = 0;
switch (cmd) {
case SIOCSIFFLAGS:
mtx_lock(&xnb->sc_lock);
if (ifp->if_flags & IFF_UP) {
xnb_ifinit_locked(xnb);
} else {
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
xnb_stop(xnb);
}
}
/*
* Note: netfront sets a variable named xn_if_flags
* here, but that variable is never read
*/
mtx_unlock(&xnb->sc_lock);
break;
case SIOCSIFADDR:
#ifdef INET
mtx_lock(&xnb->sc_lock);
if (ifa->ifa_addr->sa_family == AF_INET) {
ifp->if_flags |= IFF_UP;
if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
IFF_DRV_OACTIVE);
if_link_state_change(ifp,
LINK_STATE_DOWN);
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
if_link_state_change(ifp,
LINK_STATE_UP);
}
arp_ifinit(ifp, ifa);
mtx_unlock(&xnb->sc_lock);
} else {
mtx_unlock(&xnb->sc_lock);
#endif
error = ether_ioctl(ifp, cmd, data);
#ifdef INET
}
#endif
break;
case SIOCSIFCAP:
mtx_lock(&xnb->sc_lock);
if (ifr->ifr_reqcap & IFCAP_TXCSUM) {
ifp->if_capenable |= IFCAP_TXCSUM;
ifp->if_hwassist |= XNB_CSUM_FEATURES;
} else {
ifp->if_capenable &= ~(IFCAP_TXCSUM);
ifp->if_hwassist &= ~(XNB_CSUM_FEATURES);
}
if ((ifr->ifr_reqcap & IFCAP_RXCSUM)) {
ifp->if_capenable |= IFCAP_RXCSUM;
} else {
ifp->if_capenable &= ~(IFCAP_RXCSUM);
}
/*
* TODO enable TSO4 and LRO once we no longer need
* to calculate checksums in software
*/
#if 0
if (ifr->if_reqcap |= IFCAP_TSO4) {
if (IFCAP_TXCSUM & ifp->if_capenable) {
printf("xnb: Xen netif requires that "
"TXCSUM be enabled in order "
"to use TSO4\n");
error = EINVAL;
} else {
ifp->if_capenable |= IFCAP_TSO4;
ifp->if_hwassist |= CSUM_TSO;
}
} else {
ifp->if_capenable &= ~(IFCAP_TSO4);
ifp->if_hwassist &= ~(CSUM_TSO);
}
if (ifr->ifreqcap |= IFCAP_LRO) {
ifp->if_capenable |= IFCAP_LRO;
} else {
ifp->if_capenable &= ~(IFCAP_LRO);
}
#endif
mtx_unlock(&xnb->sc_lock);
break;
case SIOCSIFMTU:
ifp->if_mtu = ifr->ifr_mtu;
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
xnb_ifinit(xnb);
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCSIFMEDIA:
case SIOCGIFMEDIA:
error = ifmedia_ioctl(ifp, ifr, &xnb->sc_media, cmd);
break;
default:
error = ether_ioctl(ifp, cmd, data);
break;
}
return (error);
}
static void
xnb_start_locked(struct ifnet *ifp)
{
netif_rx_back_ring_t *rxb;
struct xnb_softc *xnb;
struct mbuf *mbufc;
RING_IDX req_prod_local;
xnb = ifp->if_softc;
rxb = &xnb->ring_configs[XNB_RING_TYPE_RX].back_ring.rx_ring;
if (!xnb->carrier)
return;
do {
int out_of_space = 0;
int notify;
req_prod_local = rxb->sring->req_prod;
xen_rmb();
for (;;) {
int error;
IF_DEQUEUE(&ifp->if_snd, mbufc);
if (mbufc == NULL)
break;
error = xnb_send(rxb, xnb->otherend_id, mbufc,
xnb->rx_gnttab);
switch (error) {
case EAGAIN:
/*
* Insufficient space in the ring.
* Requeue pkt and send when space is
* available.
*/
IF_PREPEND(&ifp->if_snd, mbufc);
/*
* Perhaps the frontend missed an IRQ
* and went to sleep. Notify it to wake
* it up.
*/
out_of_space = 1;
break;
case EINVAL:
/* OS gave a corrupt packet. Drop it.*/
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
/* FALLTHROUGH */
default:
/* Send succeeded, or packet had error.
* Free the packet */
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
if (mbufc)
m_freem(mbufc);
break;
}
if (out_of_space != 0)
break;
}
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(rxb, notify);
if ((notify != 0) || (out_of_space != 0))
xen_intr_signal(xnb->xen_intr_handle);
rxb->sring->req_event = req_prod_local + 1;
xen_mb();
} while (rxb->sring->req_prod != req_prod_local) ;
}
/**
* Sends one packet to the ring. Blocks until the packet is on the ring
* \param[in] mbufc Contains one packet to send. Caller must free
* \param[in,out] rxb The packet will be pushed onto this ring, but the
* otherend will not be notified.
* \param[in] otherend The domain ID of the other end of the connection
* \retval EAGAIN The ring did not have enough space for the packet.
* The ring has not been modified
* \param[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.
* \retval EINVAL mbufc was corrupt or not convertible into a pkt
*/
static int
xnb_send(netif_rx_back_ring_t *ring, domid_t otherend, const struct mbuf *mbufc,
gnttab_copy_table gnttab)
{
struct xnb_pkt pkt;
int error, n_entries, n_reqs;
RING_IDX space;
space = ring->sring->req_prod - ring->req_cons;
error = xnb_mbufc2pkt(mbufc, &pkt, ring->rsp_prod_pvt, space);
if (error != 0)
return error;
n_entries = xnb_rxpkt2gnttab(&pkt, mbufc, gnttab, ring, otherend);
if (n_entries != 0) {
int __unused hv_ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
gnttab, n_entries);
KASSERT(hv_ret == 0, ("HYPERVISOR_grant_table_op returned %d\n",
hv_ret));
}
n_reqs = xnb_rxpkt2rsp(&pkt, gnttab, n_entries, ring);
return 0;
}
static void
xnb_start(struct ifnet *ifp)
{
struct xnb_softc *xnb;
xnb = ifp->if_softc;
mtx_lock(&xnb->rx_lock);
xnb_start_locked(ifp);
mtx_unlock(&xnb->rx_lock);
}
/* equivalent of network_open() in Linux */
static void
xnb_ifinit_locked(struct xnb_softc *xnb)
{
struct ifnet *ifp;
ifp = xnb->xnb_ifp;
mtx_assert(&xnb->sc_lock, MA_OWNED);
if (ifp->if_drv_flags & IFF_DRV_RUNNING)
return;
xnb_stop(xnb);
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
if_link_state_change(ifp, LINK_STATE_UP);
}
static void
xnb_ifinit(void *xsc)
{
struct xnb_softc *xnb = xsc;
mtx_lock(&xnb->sc_lock);
xnb_ifinit_locked(xnb);
mtx_unlock(&xnb->sc_lock);
}
/**
* 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
*/
static int
xnb_ifmedia_upd(struct ifnet *ifp)
{
return (0);
}
/**
* 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
*/
static void
xnb_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
ifmr->ifm_status = IFM_AVALID|IFM_ACTIVE;
ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
}
/*---------------------------- NewBus Registration ---------------------------*/
static device_method_t xnb_methods[] = {
/* Device interface */
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),
/* Xenbus interface */
DEVMETHOD(xenbus_otherend_changed, xnb_frontend_changed),
{ 0, 0 }
};
static driver_t xnb_driver = {
"xnb",
xnb_methods,
sizeof(struct xnb_softc),
};
devclass_t xnb_devclass;
DRIVER_MODULE(xnb, xenbusb_back, xnb_driver, xnb_devclass, 0, 0);
/*-------------------------- Unit Tests -------------------------------------*/
#ifdef XNB_DEBUG
#include "netback_unit_tests.c"
#endif
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