freebsd-nq/sys/net/if_dead.c
Robert Watson 111c6b617b During if_detach(), invoke if_dead() to set the ifnet's function
pointers to "dead" implementations that no-op rather than invoking
the device driver.  This would generally be unexpected and
possibly quite badly handled by most device drivers after
if_detach() has completed.

Reviewed by:	bms
MFC after:	3 weeks
2009-04-23 11:51:53 +00:00

115 lines
2.7 KiB
C

/*-
* Copyright (c) 2009 Robert N. M. Watson
* 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.
*/
/*
* When an interface has been detached but not yet freed, we set the various
* ifnet function pointers to "ifdead" versions. This prevents unexpected
* calls from the network stack into the device driver after if_detach() has
* returned.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
static int
ifdead_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa,
struct route *ro)
{
m_freem(m);
return (ENXIO);
}
static void
ifdead_input(struct ifnet *ifp, struct mbuf *m)
{
m_freem(m);
}
static void
ifdead_start(struct ifnet *ifp)
{
}
static int
ifdead_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
return (ENXIO);
}
static void
ifdead_watchdog(struct ifnet *ifp)
{
}
static int
ifdead_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
struct sockaddr *sa)
{
*llsa = NULL;
return (ENXIO);
}
static void
ifdead_qflush(struct ifnet *ifp)
{
}
static int
ifdead_transmit(struct ifnet *ifp, struct mbuf *m)
{
m_freem(m);
return (ENXIO);
}
void
if_dead(struct ifnet *ifp)
{
ifp->if_output = ifdead_output;
ifp->if_input = ifdead_input;
ifp->if_start = ifdead_start;
ifp->if_ioctl = ifdead_ioctl;
ifp->if_watchdog = ifdead_watchdog;
ifp->if_resolvemulti = ifdead_resolvemulti;
ifp->if_qflush = ifdead_qflush;
ifp->if_transmit = ifdead_transmit;
}