Duplicate Address Detection (RFC 4862) is available only for IPv6
addresses. As a consequence, 'nodad' option, turning it off, should
be available only for IPv6, and is defined like that in the man page.
However it is possible to set nodad on IPv4 addresses, too:
$ ip link add dummy0 type dummy
$ ip -4 addr add 192.168.1.1 dev dummy0 nodad
$ ip a
1: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen
1000
link/ether 1a:6d:c6:96:ca:f8 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.1/32 scope global nodad dummy0
valid_lft forever preferred_lft forever
Fix this adding a check on the protocol family before setting
IFA_F_NODAD flag.
Fixes: bac735c53a36d ("enabled to manipulate the flags of IFA_F_HOMEADDRESS or
IFA_F_NODAD from ip.")
Signed-off-by: Andrea Claudi <acla...@redhat.com>
---
ip/ipaddress.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 47e5be7462fe7..38356cc929e7b 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -2250,7 +2250,10 @@ static int ipaddr_modify(int cmd, int flags, int argc,
char **argv)
} else if (strcmp(*argv, "home") == 0) {
ifa_flags |= IFA_F_HOMEADDRESS;
} else if (strcmp(*argv, "nodad") == 0) {
- ifa_flags |= IFA_F_NODAD;
+ if (req.ifa.ifa_family == AF_INET6)
+ ifa_flags |= IFA_F_NODAD;
+ else
+ invarg("nodad option can be set only for IPv6
addresses\n", *argv);
} else if (strcmp(*argv, "mngtmpaddr") == 0) {
ifa_flags |= IFA_F_MANAGETEMPADDR;
} else if (strcmp(*argv, "noprefixroute") == 0) {
--
2.20.1
