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- Implement loopback probing state in enhanced DAD algorithm.

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- Add no_dad and ignoreloop per-IF knob.  no_dad disables DAD completely,
  and ignoreloop is to prevent infinite loop in loopback probing state when
  loopback is permanently expected.
This commit is contained in:
Hiroki Sato 2015-03-05 21:27:49 +00:00
parent f5f4836d62
commit 23e9ffb0e1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=279676
6 changed files with 73 additions and 12 deletions
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4
sbin/ifconfig/af_inet6.c
View File

@ -485,6 +485,10 @@ static struct cmd inet6_cmds[] = {
DEF_CMD("-auto_linklocal",-ND6_IFF_AUTO_LINKLOCAL,setnd6flags),
DEF_CMD("no_prefer_iface",ND6_IFF_NO_PREFER_IFACE,setnd6flags),
DEF_CMD("-no_prefer_iface",-ND6_IFF_NO_PREFER_IFACE,setnd6flags),
DEF_CMD("no_dad", ND6_IFF_NO_DAD, setnd6flags),
DEF_CMD("-no_dad", -ND6_IFF_NO_DAD, setnd6flags),
DEF_CMD("ignoreloop", ND6_IFF_IGNORELOOP, setnd6flags),
DEF_CMD("-ignoreloop", -ND6_IFF_IGNORELOOP, setnd6flags),
DEF_CMD_ARG("pltime", setip6pltime),
DEF_CMD_ARG("vltime", setip6vltime),
DEF_CMD("eui64", 0, setip6eui64),

3
sbin/ifconfig/af_nd6.c
View File

@ -58,7 +58,8 @@ static const char rcsid[] =
#define MAX_SYSCTL_TRY 5
#define ND6BITS "\020\001PERFORMNUD\002ACCEPT_RTADV\003PREFER_SOURCE" \
"\004IFDISABLED\005DONT_SET_IFROUTE\006AUTO_LINKLOCAL" \
"\007NO_RADR\010NO_PREFER_IFACE\020DEFAULTIF"
"\007NO_RADR\010NO_PREFER_IFACE\011IGNORELOOP\012NO_DAD" \
"\020DEFAULTIF"
static int isnd6defif(int);
void setnd6flags(const char *, int, int, const struct afswtch *);

16
sbin/ifconfig/ifconfig.8
View File

@ -28,7 +28,7 @@
.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94
.\" $FreeBSD$
.\"
.Dd December 16, 2014
.Dd March 6, 2015
.Dt IFCONFIG 8
.Os
.Sh NAME
@ -687,6 +687,20 @@ policy table, configurable with
.It Cm -no_prefer_iface
Clear a flag
.Cm no_prefer_iface .
.It Cm no_dad
Set a flag to disable Duplicate Address Detection.
.It Cm -no_dad
Clear a flag
.Cm no_dad .
.It Cm ignoreloop
Set a flag to disable loopback detection in Enhanced Duplicate Address
Detection Algorithm.
When this flag is set,
Duplicate Address Detection will stop in a finite number of probings
even if a loopback configuration is detected.
.It Cm -ignoreloop
Clear a flag
.Cm ignoreloop .
.El
.Pp
The following parameters are specific for IPv6 addresses.

3
sys/netinet6/in6.c
View File

@ -1910,7 +1910,8 @@ in6if_do_dad(struct ifnet *ifp)
if ((ifp->if_flags & IFF_LOOPBACK) != 0)
return (0);
if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) ||
(ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD))
return (0);
/*

2
sys/netinet6/nd6.h
View File

@ -87,6 +87,8 @@ struct nd_ifinfo {
#define ND6_IFF_AUTO_LINKLOCAL 0x20
#define ND6_IFF_NO_RADR 0x40
#define ND6_IFF_NO_PREFER_IFACE 0x80 /* XXX: not related to ND. */
#define ND6_IFF_IGNORELOOP 0x100
#define ND6_IFF_NO_DAD 0x200
#define ND6_CREATE LLE_CREATE
#define ND6_EXCLUSIVE LLE_EXCLUSIVE

57
sys/netinet6/nd6_nbr.c
View File

@ -1182,6 +1182,7 @@ struct dadq {
int dad_ns_icount;
int dad_na_icount;
int dad_ns_lcount; /* looped back NS */
int dad_loopbackprobe; /* probing state for loopback detection */
struct callout dad_timer_ch;
struct vnet *dad_vnet;
u_int dad_refcnt;
@ -1223,7 +1224,6 @@ static struct dadq *
nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
{
struct dadq *dp;
char ip6buf[INET6_ADDRSTRLEN];
DADQ_RLOCK();
TAILQ_FOREACH(dp, &V_dadq, dad_list) {
@ -1238,10 +1238,6 @@ nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
ND_OPT_NONCE_LEN) == 0) {
log(LOG_ERR, "%s: a looped back NS message is "
"detected during DAD for %s.\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa)));
dp->dad_ns_lcount++;
continue;
}
@ -1357,7 +1353,7 @@ nd6_dad_start(struct ifaddr *ifa, int delay)
dp->dad_count = V_ip6_dad_count;
dp->dad_ns_icount = dp->dad_na_icount = 0;
dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
dp->dad_ns_lcount = 0;
dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
refcount_init(&dp->dad_refcnt, 1);
nd6_dad_add(dp);
if (delay == 0) {
@ -1432,8 +1428,10 @@ nd6_dad_timer(struct dadq *dp)
goto err;
}
/* timeouted with IFF_{RUNNING,UP} check */
if (dp->dad_ns_tcount > V_dad_maxtry) {
/* Stop DAD if the interface is down even after dad_maxtry attempts. */
if ((dp->dad_ns_tcount > V_dad_maxtry) &&
(((ifp->if_flags & IFF_UP) == 0) ||
((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
if_name(ifa->ifa_ifp)));
goto err;
@ -1456,7 +1454,42 @@ nd6_dad_timer(struct dadq *dp)
if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
/* We've seen NS or NA, means DAD has failed. */
nd6_dad_duplicated(ifa, dp);
else {
else if (V_dad_enhanced != 0 &&
dp->dad_ns_lcount > 0 &&
dp->dad_ns_lcount > dp->dad_loopbackprobe) {
/*
* A looped back probe is detected,
* Sec. 4.1 in draft-ietf-6man-enhanced-dad-13
* requires transmission of additional probes until
* the loopback condition becomes clear.
*/
log(LOG_ERR, "%s: a looped back NS message is "
"detected during DAD for %s. "
"Another DAD probes are being sent.\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa)));
dp->dad_loopbackprobe = dp->dad_ns_lcount;
/*
* An interface with IGNORELOOP is one which a
* loopback is permanently expected while regular
* traffic works. In that case, stop DAD after
* MAX_MULTICAST_SOLICIT number of NS messages
* regardless of the number of received loopback NS
* by increasing dad_loopbackprobe in advance.
*/
if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IGNORELOOP)
dp->dad_loopbackprobe += V_nd6_mmaxtries;
/*
* Send an NS immediately and increase dad_count by
* V_nd6_mmaxtries - 1.
*/
nd6_dad_ns_output(dp, ifa);
dp->dad_count =
dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
nd6_dad_starttimer(dp,
(long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
goto done;
} else {
/*
* We are done with DAD. No NA came, no NS came.
* No duplicate address found. Check IFDISABLED flag
@ -1470,6 +1503,12 @@ nd6_dad_timer(struct dadq *dp)
"%s: DAD complete for %s - no duplicates found\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
if (dp->dad_ns_lcount > 0)
log(LOG_ERR, "%s: DAD completed while "
"a looped back NS message is detected "
"during DAD for %s.\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa)));
}
}
err: