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Fix and add a workaround on an issue of EtherIP packet with reversed

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version field sent via gif(4)+if_bridge(4).  The EtherIP
implementation found on FreeBSD 6.1, 6.2, 6.3, 7.0, 7.1, and 7.2 had
an interoperability issue because it sent the incorrect EtherIP
packets and discarded the correct ones.

This change introduces the following two flags to gif(4):

 accept_rev_ethip_ver: accepts both correct EtherIP packets and ones
    with reversed version field, if enabled.  If disabled, the gif
    accepts the correct packets only.  This flag is enabled by
    default.

 send_rev_ethip_ver: sends EtherIP packets with reversed version field
    intentionally, if enabled.  If disabled, the gif sends the correct
    packets only.  This flag is disabled by default.

These flags are stored in struct gif_softc and can be set by
ifconfig(8) on per-interface basis.

Note that this is an incompatible change of EtherIP with the older
FreeBSD releases.  If you need to interoperate older FreeBSD boxes and
new versions after this commit, setting "send_rev_ethip_ver" is
needed.

Reviewed by:	thompsa and rwatson
Spotted by:	Shunsuke SHINOMIYA
PR:		kern/125003
MFC after:	2 weeks
This commit is contained in:
Hiroki Sato 2009-06-07 23:00:40 +00:00
parent 385432acf8
commit dbe5926046
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=193664
9 changed files with 264 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sbin/ifconfig/Makefile
View File

@ -24,6 +24,7 @@ SRCS+= ifmac.c # MAC support
SRCS+= ifmedia.c # SIOC[GS]IFMEDIA support
SRCS+= ifvlan.c # SIOC[GS]ETVLAN support
SRCS+= ifgre.c # GRE keys etc
SRCS+= ifgif.c # GIF reversed header workaround
SRCS+= ifieee80211.c regdomain.c # SIOC[GS]IEEE80211 support
DPADD+= ${LIBBSDXML} ${LIBSBUF}

132
sbin/ifconfig/ifgif.c Normal file
View File

@ -0,0 +1,132 @@
/*-
* Copyright (c) 2009 Hiroki Sato. 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 ``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 HIS RELATIVES 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 MIND, 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.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <stdlib.h>
#include <unistd.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_gif.h>
#include <net/route.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <err.h>
#include <errno.h>
#include "ifconfig.h"
static void gif_status(int);
static struct {
const char *label;
u_int mask;
} gif_opts[] = {
{ "ACCEPT_REV_ETHIP_VER", GIF_ACCEPT_REVETHIP },
{ "SEND_REV_ETHIP_VER", GIF_SEND_REVETHIP },
};
static void
gif_status(int s)
{
int opts;
int nopts = 0;
int i;
ifr.ifr_data = (caddr_t)&opts;
if (ioctl(s, GIFGOPTS, &ifr) == -1)
return;
printf("\toptions=%d<", opts);
for (i=0; i < sizeof(gif_opts)/sizeof(gif_opts[0]); i++) {
if (opts & gif_opts[i].mask) {
if (nopts++)
printf(",");
printf("%s", gif_opts[i].label);
}
}
printf(">\n");
}
static void
setgifopts(const char *val,
int d, int s, const struct afswtch *afp)
{
int opts;
ifr.ifr_data = (caddr_t)&opts;
if (ioctl(s, GIFGOPTS, &ifr) == -1) {
warn("ioctl(GIFGOPTS)");
return;
}
if (d < 0)
opts &= ~(-d);
else
opts |= d;
if (ioctl(s, GIFSOPTS, &ifr) == -1) {
warn("ioctl(GIFSOPTS)");
return;
}
}
static struct cmd gif_cmds[] = {
DEF_CMD("accept_rev_ethip_ver", GIF_ACCEPT_REVETHIP, setgifopts),
DEF_CMD("-accept_rev_ethip_ver",-GIF_ACCEPT_REVETHIP, setgifopts),
DEF_CMD("send_rev_ethip_ver", GIF_SEND_REVETHIP, setgifopts),
DEF_CMD("-send_rev_ethip_ver", -GIF_SEND_REVETHIP, setgifopts),
};
static struct afswtch af_gif = {
.af_name = "af_gif",
.af_af = AF_UNSPEC,
.af_other_status = gif_status,
};
static __constructor void
gif_ctor(void)
{
#define N(a) (sizeof(a) / sizeof(a[0]))
int i;
for (i = 0; i < N(gif_cmds); i++)
cmd_register(&gif_cmds[i]);
af_register(&af_gif);
#undef N
}

31
share/man/man4/gif.4
View File

@ -29,7 +29,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd April 10, 1999
.Dd June 8, 2009
.Dt GIF 4
.Os
.Sh NAME
@ -256,3 +256,32 @@ had a multi-destination behavior, configurable via
.Dv IFF_LINK0
flag.
The behavior is obsolete and is no longer supported.
.Pp
On
.Fx
6.1, 6.2, 6.3, 7.0, 7.1, and 7.2
the
.Nm
sends and receives incorrect EtherIP packets with reversed version
field when
.Xr if_bridge 4
is used together. As a workaround on this interoperability issue, the
following two
.Xr ifconfig 8
flags can be used:
.Bl -tag -width "accept_rev_ethip_ver" -offset indent
.It accept_rev_ethip_ver
accepts both correct EtherIP packets and ones with reversed version
field, if enabled. If disabled, the
.Nm
accepts the correct packets only. This flag is enabled by default.
.It send_rev_ethip_ver
sends EtherIP packets with reversed version field intentionally, if
enabled. If disabled, the
.Nm
sends the correct packets only. This flag is disabled by default.
.El
.Pp
If interoperability with the older
.Fx
machines is needed, both of these two flags must be enabled.

8
share/man/man4/if_bridge.4
View File

@ -35,7 +35,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd September 17, 2007
.Dd June 8, 2009
.Dt IF_BRIDGE 4
.Os
.Sh NAME
@ -406,6 +406,12 @@ ifconfig gif0 tunnel 1.2.3.4 5.6.7.8 up
ifconfig bridge0 create
ifconfig bridge0 addm fxp0 addm gif0 up
.Ed
.Pp
Note that
.Fx
6.1, 6.2, 6.3, 7.0, 7.1, and 7.2 have a bug in the EtherIP protocol.
For more details and workaround, see
.Xr gif 4 manual page.
.Sh SEE ALSO
.Xr gif 4 ,
.Xr ipf 4 ,

46
sys/net/if_gif.c
View File

@ -45,6 +45,7 @@
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/conf.h>
@ -198,6 +199,7 @@ gif_clone_create(ifc, unit, params)
if_initname(GIF2IFP(sc), ifc->ifc_name, unit);
sc->encap_cookie4 = sc->encap_cookie6 = NULL;
sc->gif_options = GIF_ACCEPT_REVETHIP;
GIF2IFP(sc)->if_addrlen = 0;
GIF2IFP(sc)->if_mtu = GIF_MTU;
@ -534,6 +536,7 @@ gif_input(m, af, ifp)
struct ifnet *ifp;
{
int isr, n;
struct gif_softc *sc = ifp->if_softc;
struct etherip_header *eip;
struct ether_header *eh;
struct ifnet *oldifp;
@ -594,11 +597,25 @@ gif_input(m, af, ifp)
}
eip = mtod(m, struct etherip_header *);
if (eip->eip_ver !=
(ETHERIP_VERSION & ETHERIP_VER_VERS_MASK)) {
/* discard unknown versions */
m_freem(m);
return;
/*
* GIF_ACCEPT_REVETHIP (enabled by default) intentionally
* accepts an EtherIP packet with revered version field in
* the header. This is a knob for backward compatibility
* with FreeBSD 7.2R or prior.
*/
if (sc->gif_options & GIF_ACCEPT_REVETHIP) {
if (eip->eip_resvl != ETHERIP_VERSION
&& eip->eip_ver != ETHERIP_VERSION) {
/* discard unknown versions */
m_freem(m);
return;
}
} else {
if (eip->eip_ver != ETHERIP_VERSION) {
/* discard unknown versions */
m_freem(m);
return;
}
}
m_adj(m, sizeof(struct etherip_header));
@ -653,6 +670,7 @@ gif_ioctl(ifp, cmd, data)
struct gif_softc *sc = ifp->if_softc;
struct ifreq *ifr = (struct ifreq*)data;
int error = 0, size;
u_int options;
struct sockaddr *dst, *src;
#ifdef SIOCSIFMTU /* xxx */
u_long mtu;
@ -887,6 +905,24 @@ gif_ioctl(ifp, cmd, data)
/* if_ioctl() takes care of it */
break;
case GIFGOPTS:
options = sc->gif_options;
error = copyout(&options, ifr->ifr_data,
sizeof(options));
break;
case GIFSOPTS:
if ((error = priv_check(curthread, PRIV_NET_GIF)) != 0)
break;
if ((error = copyin(&options, &sc->gif_options,
sizeof(sc->gif_options)))) {
if ((options | GIF_FULLOPTS) == GIF_FULLOPTS)
ifr->ifr_data = (caddr_t)options;
else
error = EINVAL;
}
break;
default:
error = EINVAL;
break;

26
sys/net/if_gif.h
View File

@ -71,6 +71,7 @@ struct gif_softc {
const struct encaptab *encap_cookie4;
const struct encaptab *encap_cookie6;
void *gif_netgraph; /* ng_gif(4) netgraph node info */
u_int gif_options;
LIST_ENTRY(gif_softc) gif_list; /* all gif's are linked */
};
#define GIF2IFP(sc) ((sc)->gif_ifp)
@ -94,12 +95,18 @@ struct gif_softc {
#define MTAG_GIF_CALLED 0
struct etherip_header {
u_int8_t eip_ver; /* version/reserved */
u_int8_t eip_pad; /* required padding byte */
};
#define ETHERIP_VER_VERS_MASK 0x0f
#define ETHERIP_VER_RSVD_MASK 0xf0
#define ETHERIP_VERSION 0x03
#if BYTE_ORDER == LITTLE_ENDIAN
u_int eip_resvl:4, /* reserved */
eip_ver:4; /* version */
#endif
#if BYTE_ORDER == BIG_ENDIAN
u_int eip_ver:4, /* version */
eip_resvl:4; /* reserved */
#endif
u_int8_t eip_resvh; /* reserved */
} __packed;
#define ETHERIP_VERSION 0x3
/* mbuf adjust factor to force 32-bit alignment of IP header */
#define ETHERIP_ALIGN 2
@ -143,4 +150,11 @@ extern struct vnet_gif vnet_gif_0;
#endif /* _KERNEL */
#define GIFGOPTS _IOR('i', 150, struct ifreq)
#define GIFSOPTS _IOW('i', 151, struct ifreq)
#define GIF_ACCEPT_REVETHIP 0x0001
#define GIF_SEND_REVETHIP 0x0010
#define GIF_FULLOPTS (GIF_ACCEPT_REVETHIP|GIF_SEND_REVETHIP)
#endif /* _NET_IF_GIF_H_ */

18
sys/netinet/in_gif.c
View File

@ -148,8 +148,22 @@ in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
#endif /* INET6 */
case AF_LINK:
proto = IPPROTO_ETHERIP;
eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
eiphdr.eip_pad = 0;
/*
* GIF_SEND_REVETHIP (disabled by default) intentionally
* sends an EtherIP packet with revered version field in
* the header. This is a knob for backward compatibility
* with FreeBSD 7.2R or prior.
*/
if ((sc->gif_options & GIF_SEND_REVETHIP)) {
eiphdr.eip_ver = 0;
eiphdr.eip_resvl = ETHERIP_VERSION;
eiphdr.eip_resvh = 0;
} else {
eiphdr.eip_ver = ETHERIP_VERSION;
eiphdr.eip_resvl = 0;
eiphdr.eip_resvh = 0;
}
/* prepend Ethernet-in-IP header */
M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
if (m && m->m_len < sizeof(struct etherip_header))

18
sys/netinet6/in6_gif.c
View File

@ -144,8 +144,22 @@ in6_gif_output(struct ifnet *ifp,
#endif
case AF_LINK:
proto = IPPROTO_ETHERIP;
eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
eiphdr.eip_pad = 0;
/*
* GIF_SEND_REVETHIP (disabled by default) intentionally
* sends an EtherIP packet with revered version field in
* the header. This is a knob for backward compatibility
* with FreeBSD 7.2R or prior.
*/
if ((sc->gif_options & GIF_SEND_REVETHIP)) {
eiphdr.eip_ver = 0;
eiphdr.eip_resvl = ETHERIP_VERSION;
eiphdr.eip_resvh = 0;
} else {
eiphdr.eip_ver = ETHERIP_VERSION;
eiphdr.eip_resvl = 0;
eiphdr.eip_resvh = 0;
}
/* prepend Ethernet-in-IP header */
M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
if (m && m->m_len < sizeof(struct etherip_header))

1
sys/sys/priv.h
View File

@ -324,6 +324,7 @@
#define PRIV_NET_ADDIFADDR 413 /* Add protocol addr to interface. */
#define PRIV_NET_DELIFADDR 414 /* Delete protocol addr on interface. */
#define PRIV_NET_LAGG 415 /* Administer lagg interface. */
#define PRIV_NET_GIF 416 /* Administer gif interface. */
/*
* 802.11-related privileges.