[PATCH iproute2] ip-address: properly display zero IPv4 peer address
From: Thomas Haller <hidden>
Date: 2015-10-22 08:34:33
Subsystem:
the rest · Maintainer:
Linus Torvalds
Kernel allows for zero IPv4 peer addresses (IFA_ADDRESS):
ip address add 192.168.5.1 peer 0.0.0.0/24 dev dummy
which is distinct from a usual address like:
ip address add 192.168.5.1/24 dev dummy
ip address add 192.168.5.1 peer 192.168.5.1/24 dev dummy
For IPv4, a missing IFA_ADDRESS attribute means that the peer
is 0.0.0.0. See inet_fill_ifaddr(), which does:
if ((ifa->ifa_address &&
nla_put_in_addr(skb, IFA_ADDRESS, ifa->ifa_address)) ||
Signed-off-by: Thomas Haller <redacted>
---
ip/ipaddress.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index f290205..6fc4520 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c@@ -949,7 +949,8 @@ int print_addrinfo(const struct sockaddr_nl *who, struct nlmsghdr *n, if (!rta_tb[IFA_LOCAL]) rta_tb[IFA_LOCAL] = rta_tb[IFA_ADDRESS]; - if (!rta_tb[IFA_ADDRESS]) + if (!rta_tb[IFA_ADDRESS] && + ifa->ifa_family != AF_INET) rta_tb[IFA_ADDRESS] = rta_tb[IFA_LOCAL]; if (filter.ifindex && filter.ifindex != ifa->ifa_index)
@@ -1034,16 +1035,18 @@ int print_addrinfo(const struct sockaddr_nl *who, struct nlmsghdr *n, RTA_DATA(rta_tb[IFA_LOCAL]), abuf, sizeof(abuf))); - if (rta_tb[IFA_ADDRESS] == NULL || + if (rta_tb[IFA_ADDRESS] != NULL && memcmp(RTA_DATA(rta_tb[IFA_ADDRESS]), RTA_DATA(rta_tb[IFA_LOCAL]), ifa->ifa_family == AF_INET ? 4 : 16) == 0) { fprintf(fp, "/%d ", ifa->ifa_prefixlen); } else { fprintf(fp, " peer %s/%d ", - format_host(ifa->ifa_family, - RTA_PAYLOAD(rta_tb[IFA_ADDRESS]), - RTA_DATA(rta_tb[IFA_ADDRESS]), - abuf, sizeof(abuf)), + rta_tb[IFA_ADDRESS] + ? format_host(ifa->ifa_family, + RTA_PAYLOAD(rta_tb[IFA_ADDRESS]), + RTA_DATA(rta_tb[IFA_ADDRESS]), + abuf, sizeof(abuf)) + : "0.0.0.0", ifa->ifa_prefixlen); } }
--
2.4.3