kern/179473: Source code contribution of implementation about virtual ethernet interface
Henning Matyschok
henning.matyschok at stud.fh-flensburg.de
Thu Jun 20 05:20:01 UTC 2013
The following reply was made to PR kern/179473; it has been noted by GNATS.
From: "Henning Matyschok" <henning.matyschok at stud.fh-flensburg.de>
To: bug-followup at freebsd.org, henning.matyschok at stud.fh-flensburg.de
Cc:
Subject: Re: kern/179473: Source code contribution of implementation about
virtual ethernet interface
Date: Thu, 20 Jun 2013 05:21:20 -0000
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I apologize for my inexperiences of using the pr system and wrong spelling.
After code review, an hour ago, I've realized that there exists a similar
implementation of a virtual Ethernet interface by OpenBSD project since
2009. In avoidance of misunderstoodings, I've change namespace of source
code entirely and added copyright information on top of file.
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/*-
* Copyright (c) 2013 Henning Matyschok
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/*
* Copyright (c) 2009 Theo de Raadt
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/libkern.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <net/if.h>
#include <net/if_clone.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <net/if_bridgevar.h>
#include <net/if_vlan_var.h>
#include <net/if_dl.h>
#include <net/if_arp.h>
#include <net/bpf.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip_carp.h>
static const uint8_t ether_bcast_lla[ETHER_ADDR_LEN] =
{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
/*
* Declaration of reduced struct bridge_softc is needed to identify
* bridge(4) describing ifnet structure on the fly, when frame
* originates from ng_ether(4).
*
* See net/if_bridge.c and net/if_var.h for further
* details.
*/
struct bridge_softc {
struct ifnet *sc_ifp;
};
#define VETHERNAME "vether"
struct vether_softc {
struct ifnet *sc_ifp; /* It will be a network interface. */
LIST_ENTRY(vether_softc) vether_list;
struct mtx sc_mtx;
#define VETHER_LOCK_INIT(sc) mtx_init(&(sc)->sc_mtx, "vether softc", \
NULL, MTX_DEF)
#define VETHER_LOCK_DESTROY(sc) mtx_destroy(&(sc)->sc_mtx)
#define VETHER_LOCK(sc) mtx_lock(&(sc)->sc_mtx)
#define VETHER_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx)
#define VETHER_LOCK_ASSERT(sc) mtx_assert(&(sc)->sc_mtx, MA_OWNED)
/* Fake information about used transmission media. */
struct ifmedia sc_ifm;
int sc_status;
};
static LIST_HEAD(, vether_softc) vether_list;
static struct mtx vether_mtx;
static MALLOC_DEFINE(M_VETHER, VETHERNAME, "Virtual ethernet interface");
/* Ifc cloner specific subr. */
static int vether_clone_create(struct if_clone *, int, caddr_t);
static void vether_clone_destroy(struct ifnet *);
IFC_SIMPLE_DECLARE(vether, 0);
/* Interface specific methods. */
static void vether_init(void *);
static void vether_start(struct ifnet *);
static void vether_stop(struct ifnet *, int);
static int vether_media_change(struct ifnet *);
static void vether_media_status(struct ifnet *, struct ifmediareq *);
static int vether_ioctl(struct ifnet *, u_long, caddr_t);
/*
* Module event handler.
*/
static int
vether_mod_event(module_t mod, int event, void *data)
{
int error = 0;
switch (event) {
case MOD_LOAD:
mtx_init(&vether_mtx, "if_vether", NULL, MTX_DEF);
if_clone_attach(&vether_cloner);
break;
case MOD_UNLOAD:
if_clone_detach(&vether_cloner);
mtx_destroy(&vether_mtx);
break;
default:
error = EOPNOTSUPP;
}
return(error);
}
static moduledata_t vether_mod = {
"if_vether",
vether_mod_event,
0
};
DECLARE_MODULE(if_vether, vether_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
/*
* Instantiates vether interface.
*/
static int
vether_clone_create(struct if_clone *ifc, int unit, caddr_t data)
{
struct vether_softc *sc;
struct ifnet *ifp;
uint32_t randval;
uint8_t lla[ETHER_ADDR_LEN];
sc = malloc(sizeof(struct vether_softc), M_VETHER, M_WAITOK|M_ZERO);
ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
if (ifp == NULL) {
free(sc, M_VETHER);
return(ENOSPC);
}
VETHER_LOCK_INIT(sc);
ifp->if_softc = sc;
if_initname(ifp, ifc->ifc_name, unit);
/* Generates lla with randomized value. */
lla[0] = 0x0;
randval = arc4random();
memcpy(&lla[1], &randval, sizeof(uint32_t));
lla[5] = (uint8_t)unit; /* Interface major number */
ether_ifattach(ifp, lla);
ifp->if_init = vether_init;
ifp->if_ioctl = vether_ioctl;
ifp->if_start = vether_start;
ifp->if_capabilities = IFCAP_VLAN_MTU | IFCAP_JUMBO_MTU;
ifp->if_capenable = IFCAP_VLAN_MTU | IFCAP_JUMBO_MTU;
ifp->if_flags = (IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST);
ifp->if_snd.ifq_maxlen = ifqmaxlen;
ifmedia_init(&sc->sc_ifm, 0, vether_media_change, vether_media_status);
ifmedia_add(&sc->sc_ifm, IFM_ETHER | IFM_AUTO, 0, NULL);
ifmedia_set(&sc->sc_ifm, IFM_ETHER | IFM_AUTO);
sc->sc_status = IFM_AVALID;
ifp->if_baudrate = 0;
mtx_lock(&vether_mtx);
LIST_INSERT_HEAD(&vether_list, sc, vether_list);
mtx_unlock(&vether_mtx);
ifp->if_drv_flags |= IFF_DRV_RUNNING;
return(0);
}
/*
* Destroys vether interface.
*/
static void
vether_clone_destroy(struct ifnet *ifp)
{
struct vether_softc *sc;
sc = ifp->if_softc;
mtx_lock(&vether_mtx);
vether_stop(ifp, 1);
ifp->if_flags &= ~IFF_UP;
LIST_REMOVE(sc, vether_list);
ether_ifdetach(ifp);
VETHER_LOCK_DESTROY(sc);
mtx_unlock(&vether_mtx);
free(sc, M_VETHER);
}
/*
* Initializes vether interface.
*/
static void
vether_init(void *xsc)
{
struct vether_softc *sc;
struct ifnet *ifp;
sc = (struct vether_softc *)xsc;
ifp = sc->sc_ifp;
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
return;
}
VETHER_LOCK(sc);
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
VETHER_UNLOCK(sc);
}
/*
* Stops vether interface.
*/
static void
vether_stop(struct ifnet *ifp, int disable)
{
struct vether_softc *sc;
sc = ifp->if_softc;
VETHER_LOCK_ASSERT(sc);
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
return;
}
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
}
/*
* Dispatches transmissions of queued frames to bridge(4) or to
* itself when bridge(4) forwarded frames to this interface.
*/
static void
vether_start(struct ifnet *ifp)
{
struct mbuf *m;
struct bridge_softc *sc;
ifp->if_drv_flags |= IFF_DRV_OACTIVE;
for (;;) {
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == NULL) {
break;
}
if (ifp->if_bridge) {
sc = ifp->if_bridge;
if (m->m_pkthdr.rcvif == NULL) {
m->m_pkthdr.rcvif = ifp;
ETHER_BPF_MTAP(ifp, m);
ifp->if_obytes += m->m_pkthdr.len;
ifp->if_opackets++;
(sc->sc_ifp->if_transmit)(sc->sc_ifp, m);
} else if (m->m_pkthdr.rcvif == ifp) {
m_freem(m);
} else {
(ifp->if_input)(ifp, m);
}
} else {
m_freem(m);
}
}
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
}
static int
vether_media_change(struct ifnet *ifp)
{
return(0);
}
static void
vether_media_status(struct ifnet *ifp, struct ifmediareq *ifmr)
{
ifmr->ifm_status = IFM_AVALID | IFM_ACTIVE;
ifmr->ifm_active = IFM_ETHER | IFM_AUTO;
}
/*
* Handles ioctl requests. Media types can't changed,
* this is a virtual ethernet interface.
*/
static int
vether_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct vether_softc *sc = ifp->if_softc;
struct ifreq *ifr = (struct ifreq *)data;
int error = 0;
VETHER_LOCK(sc);
switch (cmd) {
case SIOCSIFMTU:
if (ifr->ifr_mtu > ETHER_MAX_LEN_JUMBO) {
error = EINVAL;
} else {
ifp->if_mtu = ifr->ifr_mtu;
}
break;
case SIOCSIFMEDIA:
case SIOCGIFMEDIA:
error = ifmedia_ioctl(ifp, ifr, &sc->sc_ifm, cmd);
break;
case SIOCSIFFLAGS:
case SIOCADDMULTI:
case SIOCDELMULTI:
break;
case SIOCSIFPHYS:
error = EOPNOTSUPP;
break;
default:
error = ether_ioctl(ifp, cmd, data);
break;
}
VETHER_UNLOCK(sc);
return(error);
}
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