freebsd-dev/sys/net/if_epair.c
Robert Watson 530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00

897 lines
23 KiB
C

/*-
* Copyright (c) 2008 The FreeBSD Foundation
* Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org>
* All rights reserved.
*
* This software was developed by CK Software GmbH under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* A pair of virtual back-to-back connected ethernet like interfaces
* (``two interfaces with a virtual cross-over cable'').
*
* This is mostly intended to be used to provide connectivity between
* different virtual network stack instances.
*/
/*
* Things to re-think once we have more experience:
* - ifp->if_reassign function once we can test with vimage. Depending on
* how if_vmove() is going to be improved.
* - Real random etheraddrs that are checked to be uniquish; we would need
* to re-do them in case we move the interface between network stacks
* in a private if_reassign function.
* In case we bridge to a real interface/network or between indepedent
* epairs on multiple stacks/machines, we may need this.
* For now let the user handle that case.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/smp.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_clone.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/vnet.h>
#define EPAIRNAME "epair"
SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW, 0, "epair sysctl");
#ifdef EPAIR_DEBUG
static int epair_debug = 0;
SYSCTL_XINT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW,
&epair_debug, 0, "if_epair(4) debugging.");
#define DPRINTF(fmt, arg...) \
if (epair_debug) \
printf("[%s:%d] " fmt, __func__, __LINE__, ##arg)
#else
#define DPRINTF(fmt, arg...)
#endif
static void epair_nh_sintr(struct mbuf *);
static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *);
static void epair_nh_drainedcpu(u_int);
static void epair_start_locked(struct ifnet *);
static int epair_clone_match(struct if_clone *, const char *);
static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t);
static int epair_clone_destroy(struct if_clone *, struct ifnet *);
/* Netisr realted definitions and sysctl. */
static struct netisr_handler epair_nh = {
.nh_name = EPAIRNAME,
.nh_proto = NETISR_EPAIR,
.nh_policy = NETISR_POLICY_CPU,
.nh_handler = epair_nh_sintr,
.nh_m2cpuid = epair_nh_m2cpuid,
.nh_drainedcpu = epair_nh_drainedcpu,
};
static int
sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
{
int error, qlimit;
netisr_getqlimit(&epair_nh, &qlimit);
error = sysctl_handle_int(oidp, &qlimit, 0, req);
if (error || !req->newptr)
return (error);
if (qlimit < 1)
return (EINVAL);
return (netisr_setqlimit(&epair_nh, qlimit));
}
SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen, CTLTYPE_INT|CTLFLAG_RW,
0, 0, sysctl_epair_netisr_maxqlen, "I",
"Maximum if_epair(4) netisr \"hw\" queue length");
struct epair_softc {
struct ifnet *ifp; /* This ifp. */
struct ifnet *oifp; /* other ifp of pair. */
u_int refcount; /* # of mbufs in flight. */
u_int cpuid; /* CPU ID assigned upon creation. */
void (*if_qflush)(struct ifnet *);
/* Original if_qflush routine. */
};
/*
* Per-CPU list of ifps with data in the ifq that needs to be flushed
* to the netisr ``hw'' queue before we allow any further direct queuing
* to the ``hw'' queue.
*/
struct epair_ifp_drain {
STAILQ_ENTRY(epair_ifp_drain) ifp_next;
struct ifnet *ifp;
};
STAILQ_HEAD(eid_list, epair_ifp_drain);
#define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \
"if_epair", NULL, MTX_DEF)
#define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx)
#define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \
MA_OWNED)
#define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx)
#define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx)
#ifdef INVARIANTS
#define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v))
#define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r))
#define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r))
#define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p)
#else
#define EPAIR_REFCOUNT_INIT(r, v)
#define EPAIR_REFCOUNT_AQUIRE(r)
#define EPAIR_REFCOUNT_RELEASE(r)
#define EPAIR_REFCOUNT_ASSERT(a, p)
#endif
static MALLOC_DEFINE(M_EPAIR, EPAIRNAME,
"Pair of virtual cross-over connected Ethernet-like interfaces");
static struct if_clone epair_cloner = IFC_CLONE_INITIALIZER(
EPAIRNAME, NULL, IF_MAXUNIT,
NULL, epair_clone_match, epair_clone_create, epair_clone_destroy);
/*
* DPCPU area and functions.
*/
struct epair_dpcpu {
struct mtx if_epair_mtx; /* Per-CPU locking. */
int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */
struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with
* data in the ifq. */
};
DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu);
static void
epair_dpcpu_init(void)
{
struct epair_dpcpu *epair_dpcpu;
struct eid_list *s;
u_int cpuid;
for (cpuid = 0; cpuid <= mp_maxid; cpuid++) {
if (CPU_ABSENT(cpuid))
continue;
epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
/* Initialize per-cpu lock. */
EPAIR_LOCK_INIT(epair_dpcpu);
/* Driver flags are per-cpu as are our netisr "hw" queues. */
epair_dpcpu->epair_drv_flags = 0;
/*
* Initialize per-cpu drain list.
* Manually do what STAILQ_HEAD_INITIALIZER would do.
*/
s = &epair_dpcpu->epair_ifp_drain_list;
s->stqh_first = NULL;
s->stqh_last = &s->stqh_first;
}
}
static void
epair_dpcpu_detach(void)
{
struct epair_dpcpu *epair_dpcpu;
u_int cpuid;
for (cpuid = 0; cpuid <= mp_maxid; cpuid++) {
if (CPU_ABSENT(cpuid))
continue;
epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
/* Destroy per-cpu lock. */
EPAIR_LOCK_DESTROY(epair_dpcpu);
}
}
/*
* Helper functions.
*/
static u_int
cpuid_from_ifp(struct ifnet *ifp)
{
struct epair_softc *sc;
if (ifp == NULL)
return (0);
sc = ifp->if_softc;
return (sc->cpuid);
}
/*
* Netisr handler functions.
*/
static void
epair_nh_sintr(struct mbuf *m)
{
struct ifnet *ifp;
struct epair_softc *sc;
ifp = m->m_pkthdr.rcvif;
(*ifp->if_input)(ifp, m);
sc = ifp->if_softc;
EPAIR_REFCOUNT_RELEASE(&sc->refcount);
DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount);
}
static struct mbuf *
epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
{
*cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
return (m);
}
static void
epair_nh_drainedcpu(u_int cpuid)
{
struct epair_dpcpu *epair_dpcpu;
struct epair_ifp_drain *elm, *tvar;
struct ifnet *ifp;
epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
EPAIR_LOCK(epair_dpcpu);
/*
* Assume our "hw" queue and possibly ifq will be emptied
* again. In case we will overflow the "hw" queue while
* draining, epair_start_locked will set IFF_DRV_OACTIVE
* again and we will stop and return.
*/
STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
ifp_next, tvar) {
ifp = elm->ifp;
epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
epair_start_locked(ifp);
IFQ_LOCK(&ifp->if_snd);
if (IFQ_IS_EMPTY(&ifp->if_snd)) {
STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list,
elm, epair_ifp_drain, ifp_next);
free(elm, M_EPAIR);
}
IFQ_UNLOCK(&ifp->if_snd);
if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) {
/* Our "hw"q overflew again. */
epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE
DPRINTF("hw queue length overflow at %u\n",
epair_nh.nh_qlimit);
break;
}
}
EPAIR_UNLOCK(epair_dpcpu);
}
/*
* Network interface (`if') related functions.
*/
static int
epair_add_ifp_for_draining(struct ifnet *ifp)
{
struct epair_dpcpu *epair_dpcpu;
struct epair_softc *sc = sc = ifp->if_softc;
struct epair_ifp_drain *elm = NULL;
epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next)
if (elm->ifp == ifp)
break;
/* If the ipf is there already, return success. */
if (elm != NULL)
return (0);
elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO);
if (elm == NULL)
return (ENOMEM);
elm->ifp = ifp;
STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next);
return (0);
}
static void
epair_start_locked(struct ifnet *ifp)
{
struct epair_dpcpu *epair_dpcpu;
struct mbuf *m;
struct epair_softc *sc;
struct ifnet *oifp;
int error;
DPRINTF("ifp=%p\n", ifp);
sc = ifp->if_softc;
epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
EPAIR_LOCK_ASSERT(epair_dpcpu);
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
return;
if ((ifp->if_flags & IFF_UP) == 0)
return;
/*
* We get patckets here from ether_output via if_handoff()
* and ned to put them into the input queue of the oifp
* and call oifp->if_input() via netisr/epair_sintr().
*/
oifp = sc->oifp;
sc = oifp->if_softc;
for (;;) {
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == NULL)
break;
BPF_MTAP(ifp, m);
/*
* In case the outgoing interface is not usable,
* drop the packet.
*/
if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
(oifp->if_flags & IFF_UP) ==0) {
ifp->if_oerrors++;
m_freem(m);
continue;
}
DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
/*
* Add a reference so the interface cannot go while the
* packet is in transit as we rely on rcvif to stay valid.
*/
EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
m->m_pkthdr.rcvif = oifp;
CURVNET_SET_QUIET(oifp->if_vnet);
error = netisr_queue(NETISR_EPAIR, m);
CURVNET_RESTORE();
if (!error) {
ifp->if_opackets++;
/* Someone else received the packet. */
oifp->if_ipackets++;
} else {
epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
ifp->if_drv_flags |= IFF_DRV_OACTIVE;
if (epair_add_ifp_for_draining(ifp)) {
ifp->if_oerrors++;
m_freem(m);
}
EPAIR_REFCOUNT_RELEASE(&sc->refcount);
}
}
}
static void
epair_start(struct ifnet *ifp)
{
struct epair_dpcpu *epair_dpcpu;
epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
EPAIR_LOCK(epair_dpcpu);
epair_start_locked(ifp);
EPAIR_UNLOCK(epair_dpcpu);
}
static int
epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
{
struct epair_dpcpu *epair_dpcpu;
struct epair_softc *sc;
struct ifnet *oifp;
int error, len;
short mflags;
DPRINTF("ifp=%p m=%p\n", ifp, m);
sc = ifp->if_softc;
epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
EPAIR_LOCK_ASSERT(epair_dpcpu);
if (m == NULL)
return (0);
/*
* We are not going to use the interface en/dequeue mechanism
* on the TX side. We are called from ether_output_frame()
* and will put the packet into the incoming queue of the
* other interface of our pair via the netsir.
*/
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
m_freem(m);
return (ENXIO);
}
if ((ifp->if_flags & IFF_UP) == 0) {
m_freem(m);
return (ENETDOWN);
}
BPF_MTAP(ifp, m);
/*
* In case the outgoing interface is not usable,
* drop the packet.
*/
oifp = sc->oifp;
if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
(oifp->if_flags & IFF_UP) ==0) {
ifp->if_oerrors++;
m_freem(m);
return (0);
}
len = m->m_pkthdr.len;
mflags = m->m_flags;
DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
#ifdef ALTQ
/* Support ALTQ via the clasic if_start() path. */
IF_LOCK(&ifp->if_snd);
if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
ALTQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
if (error)
ifp->if_snd.ifq_drops++;
IF_UNLOCK(&ifp->if_snd);
if (!error) {
ifp->if_obytes += len;
if (mflags & (M_BCAST|M_MCAST))
ifp->if_omcasts++;
if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
epair_start_locked(ifp);
else
(void)epair_add_ifp_for_draining(ifp);
}
return (error);
}
IF_UNLOCK(&ifp->if_snd);
#endif
if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) {
/*
* Our hardware queue is full, try to fall back
* queuing to the ifq but do not call ifp->if_start.
* Either we are lucky or the packet is gone.
*/
IFQ_ENQUEUE(&ifp->if_snd, m, error);
if (!error)
(void)epair_add_ifp_for_draining(ifp);
return (error);
}
sc = oifp->if_softc;
/*
* Add a reference so the interface cannot go while the
* packet is in transit as we rely on rcvif to stay valid.
*/
EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
m->m_pkthdr.rcvif = oifp;
CURVNET_SET_QUIET(oifp->if_vnet);
error = netisr_queue(NETISR_EPAIR, m);
CURVNET_RESTORE();
if (!error) {
ifp->if_opackets++;
/*
* IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
* but as we bypass all this we have to duplicate
* the logic another time.
*/
ifp->if_obytes += len;
if (mflags & (M_BCAST|M_MCAST))
ifp->if_omcasts++;
/* Someone else received the packet. */
oifp->if_ipackets++;
} else {
/* The packet was freed already. */
EPAIR_REFCOUNT_RELEASE(&sc->refcount);
epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
ifp->if_drv_flags |= IFF_DRV_OACTIVE;
}
return (error);
}
static int
epair_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct epair_dpcpu *epair_dpcpu;
int error;
epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
EPAIR_LOCK(epair_dpcpu);
error = epair_transmit_locked(ifp, m);
EPAIR_UNLOCK(epair_dpcpu);
return (error);
}
static void
epair_qflush(struct ifnet *ifp)
{
struct epair_dpcpu *epair_dpcpu;
struct epair_softc *sc;
struct ifaltq *ifq;
sc = ifp->if_softc;
epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
EPAIR_LOCK(epair_dpcpu);
ifq = &ifp->if_snd;
DPRINTF("ifp=%p sc refcnt=%u ifq_len=%u\n",
ifp, sc->refcount, ifq->ifq_len);
/*
* Instead of calling EPAIR_REFCOUNT_RELEASE(&sc->refcount);
* n times, just subtract for the cleanup.
*/
sc->refcount -= ifq->ifq_len;
EPAIR_UNLOCK(epair_dpcpu);
if (sc->if_qflush)
sc->if_qflush(ifp);
}
static int
epair_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr;
int error;
ifr = (struct ifreq *)data;
switch (cmd) {
case SIOCSIFFLAGS:
case SIOCADDMULTI:
case SIOCDELMULTI:
error = 0;
break;
case SIOCSIFMTU:
/* We basically allow all kinds of MTUs. */
ifp->if_mtu = ifr->ifr_mtu;
error = 0;
break;
default:
/* Let the common ethernet handler process this. */
error = ether_ioctl(ifp, cmd, data);
break;
}
return (error);
}
static void
epair_init(void *dummy __unused)
{
}
/*
* Interface cloning functions.
* We use our private ones so that we can create/destroy our secondary
* device along with the primary one.
*/
static int
epair_clone_match(struct if_clone *ifc, const char *name)
{
const char *cp;
DPRINTF("name='%s'\n", name);
/*
* Our base name is epair.
* Our interfaces will be named epair<n>[ab].
* So accept anything of the following list:
* - epair
* - epair<n>
* but not the epair<n>[ab] versions.
*/
if (strncmp(EPAIRNAME, name, sizeof(EPAIRNAME)-1) != 0)
return (0);
for (cp = name + sizeof(EPAIRNAME) - 1; *cp != '\0'; cp++) {
if (*cp < '0' || *cp > '9')
return (0);
}
return (1);
}
static int
epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
{
struct epair_softc *sca, *scb;
struct ifnet *ifp;
char *dp;
int error, unit, wildcard;
uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
/*
* We are abusing params to create our second interface.
* Actually we already created it and called if_clone_createif()
* for it to do the official insertion procedure the moment we knew
* it cannot fail anymore. So just do attach it here.
*/
if (params) {
scb = (struct epair_softc *)params;
ifp = scb->ifp;
/* Assign a hopefully unique, locally administered etheraddr. */
eaddr[0] = 0x02;
eaddr[3] = (ifp->if_index >> 8) & 0xff;
eaddr[4] = ifp->if_index & 0xff;
eaddr[5] = 0x0b;
ether_ifattach(ifp, eaddr);
/* Correctly set the name for the cloner list. */
strlcpy(name, scb->ifp->if_xname, len);
return (0);
}
/* Try to see if a special unit was requested. */
error = ifc_name2unit(name, &unit);
if (error != 0)
return (error);
wildcard = (unit < 0);
error = ifc_alloc_unit(ifc, &unit);
if (error != 0)
return (error);
/*
* If no unit had been given, we need to adjust the ifName.
* Also make sure there is space for our extra [ab] suffix.
*/
for (dp = name; *dp != '\0'; dp++);
if (wildcard) {
error = snprintf(dp, len - (dp - name), "%d", unit);
if (error > len - (dp - name) - 1) {
/* ifName too long. */
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
dp += error;
}
if (len - (dp - name) - 1 < 1) {
/* No space left for our [ab] suffix. */
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
*dp = 'a';
/* Must not change dp so we can replace 'a' by 'b' later. */
*(dp+1) = '\0';
/* Allocate memory for both [ab] interfaces */
sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
EPAIR_REFCOUNT_INIT(&sca->refcount, 1);
sca->ifp = if_alloc(IFT_ETHER);
if (sca->ifp == NULL) {
free(sca, M_EPAIR);
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
EPAIR_REFCOUNT_INIT(&scb->refcount, 1);
scb->ifp = if_alloc(IFT_ETHER);
if (scb->ifp == NULL) {
free(scb, M_EPAIR);
if_free(sca->ifp);
free(sca, M_EPAIR);
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
/*
* Cross-reference the interfaces so we will be able to free both.
*/
sca->oifp = scb->ifp;
scb->oifp = sca->ifp;
/*
* Calculate the cpuid for netisr queueing based on the
* ifIndex of the interfaces. As long as we cannot configure
* this or use cpuset information easily we cannot guarantee
* cache locality but we can at least allow parallelism.
*/
sca->cpuid =
netisr_get_cpuid(sca->ifp->if_index % netisr_get_cpucount());
scb->cpuid =
netisr_get_cpuid(scb->ifp->if_index % netisr_get_cpucount());
/* Finish initialization of interface <n>a. */
ifp = sca->ifp;
ifp->if_softc = sca;
strlcpy(ifp->if_xname, name, IFNAMSIZ);
ifp->if_dname = ifc->ifc_name;
ifp->if_dunit = unit;
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_start = epair_start;
ifp->if_ioctl = epair_ioctl;
ifp->if_init = epair_init;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
/* Assign a hopefully unique, locally administered etheraddr. */
eaddr[0] = 0x02;
eaddr[3] = (ifp->if_index >> 8) & 0xff;
eaddr[4] = ifp->if_index & 0xff;
eaddr[5] = 0x0a;
ether_ifattach(ifp, eaddr);
sca->if_qflush = ifp->if_qflush;
ifp->if_qflush = epair_qflush;
ifp->if_transmit = epair_transmit;
ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */
/* Swap the name and finish initialization of interface <n>b. */
*dp = 'b';
ifp = scb->ifp;
ifp->if_softc = scb;
strlcpy(ifp->if_xname, name, IFNAMSIZ);
ifp->if_dname = ifc->ifc_name;
ifp->if_dunit = unit;
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_start = epair_start;
ifp->if_ioctl = epair_ioctl;
ifp->if_init = epair_init;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
/* We need to play some tricks here for the second interface. */
strlcpy(name, EPAIRNAME, len);
error = if_clone_create(name, len, (caddr_t)scb);
if (error)
panic("%s: if_clone_createif() for our 2nd iface failed: %d",
__func__, error);
scb->if_qflush = ifp->if_qflush;
ifp->if_qflush = epair_qflush;
ifp->if_transmit = epair_transmit;
ifp->if_baudrate = IF_Gbps(10UL); /* arbitrary maximum */
/*
* Restore name to <n>a as the ifp for this will go into the
* cloner list for the initial call.
*/
strlcpy(name, sca->ifp->if_xname, len);
DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb);
/* Tell the world, that we are ready to rock. */
sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
return (0);
}
static int
epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
{
struct ifnet *oifp;
struct epair_softc *sca, *scb;
int unit, error;
DPRINTF("ifp=%p\n", ifp);
/*
* In case we called into if_clone_destroyif() ourselves
* again to remove the second interface, the softc will be
* NULL. In that case so not do anything but return success.
*/
if (ifp->if_softc == NULL)
return (0);
unit = ifp->if_dunit;
sca = ifp->if_softc;
oifp = sca->oifp;
scb = oifp->if_softc;
DPRINTF("ifp=%p oifp=%p\n", ifp, oifp);
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
ether_ifdetach(oifp);
ether_ifdetach(ifp);
/*
* Wait for all packets to be dispatched to if_input.
* The numbers can only go down as the interfaces are
* detached so there is no need to use atomics.
*/
DPRINTF("sca refcnt=%u scb refcnt=%u\n", sca->refcount, scb->refcount);
EPAIR_REFCOUNT_ASSERT(sca->refcount == 1 && scb->refcount == 1,
("%s: sca->refcount!=1: %d || scb->refcount!=1: %d",
__func__, sca->refcount, scb->refcount));
/*
* Get rid of our second half.
*/
oifp->if_softc = NULL;
error = if_clone_destroyif(ifc, oifp);
if (error)
panic("%s: if_clone_destroyif() for our 2nd iface failed: %d",
__func__, error);
/*
* Finish cleaning up. Free them and release the unit.
* As the other of the two interfaces my reside in a different vnet,
* we need to switch before freeing them.
*/
CURVNET_SET_QUIET(oifp->if_vnet);
if_free_type(oifp, IFT_ETHER);
CURVNET_RESTORE();
if_free_type(ifp, IFT_ETHER);
free(scb, M_EPAIR);
free(sca, M_EPAIR);
ifc_free_unit(ifc, unit);
return (0);
}
static int
epair_modevent(module_t mod, int type, void *data)
{
int qlimit;
switch (type) {
case MOD_LOAD:
/* For now limit us to one global mutex and one inq. */
epair_dpcpu_init();
epair_nh.nh_qlimit = 42 * ifqmaxlen; /* 42 shall be the number. */
if (TUNABLE_INT_FETCH("net.link.epair.netisr_maxqlen", &qlimit))
epair_nh.nh_qlimit = qlimit;
netisr_register(&epair_nh);
if_clone_attach(&epair_cloner);
if (bootverbose)
printf("%s initialized.\n", EPAIRNAME);
break;
case MOD_UNLOAD:
if_clone_detach(&epair_cloner);
netisr_unregister(&epair_nh);
epair_dpcpu_detach();
if (bootverbose)
printf("%s unloaded.\n", EPAIRNAME);
break;
default:
return (EOPNOTSUPP);
}
return (0);
}
static moduledata_t epair_mod = {
"if_epair",
epair_modevent,
0
};
DECLARE_MODULE(if_epair, epair_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_epair, 1);