Since commit 9516823051ce ("ipaddress: Improve print_linkinfo()") we
return -1 instead of 0 when ip-address(8) label does not match network
device name as we did before change. This causes regression when trying
to output ip address matching label:
# ip addr add 192.168.192.1/24 dev lo label lo:1
# ip addr show label lo:1
<no output>
This is special case and return 0 from print_linkinfo() earlier to match
only filter.ifindex and filter.up if given, but not rest fields in
@filter. Then call print_selected_addrinfo() without calling
print_link_stats() in ipaddr_list_flush_or_save().
Later print_selected_addrinfo() calls print_addrinfo() that finally
matches IFA_LABEL attribute in netlink buffer with filter.label using
ifa_label_match_rta().
On the other hand there is three conditions checked in print_linkinfo()
to determine label special case:
1) filter.label != NULL
2) filter.family == AF_UNSPEC || filter.family == AF_PACKET
3) fnmatch(filter.label, name, 0)
With 1) it is ok to check if filtering by label is on by given pattern
in @filter.label.
Since label is IPv4 specific and AF_PACKET is for printing ip-link(8)
information (see ipaddr_link_list()::ipaddress.c as example) checking
for AF_PACKET in 2) doesn't take much sense: better to defer these
checks to print_addrinfo() determine valid combinations before calling
ifa_label_match_rta() to finally match IFA_LABEL to pattern in
filter.label.
For 3) we have following call for test case:
fnmatch(pattern, string, flags) ->
fnmatch(filter.label, name, 0) ->
fnmatch("lo:1", "lo", 0) == FNM_NOMATCH (1) or non-zero on error
To support special case in print_linkinfo() for filtering by label we
only need to check if label pattern is given in filter.label and return
0 to skip print_link_stats() in ipaddr_list_flush_or_save(): actual
filtering will be done in print_addrinfo().
Before commit 9516823051ce ("ipaddress: Improve print_linkinfo()"):
-------------------------------------------------------------------
$ ip addr sh label lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN \
group default qlen 1000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
fnmatch("lo", "lo", 0) == 0
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
$ ip addr show label 'lo:*'
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
$ ip addr sh label lo:1
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
$ ip -4 addr sh label lo:1
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN \
group default qlen 1000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
filter.family == AF_INET
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
After this change applied:
--------------------------
$ ip/ip addr show label lo
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
$ ip/ip addr show label 'lo:*'
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
$ ip/ip addr show label lo:1
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
$ ip/ip -4 addr show label lo:1
inet 192.168.192.1/24 scope global lo:1
valid_lft forever preferred_lft forever
Note that we no longer show link information as we did previously:
we are filtering by "label" pattern, not showing by "dev".
Fixes: commit 9516823051ce ("ipaddress: Improve print_linkinfo()")
Reported-by: Vincent Bernat <vinc...@bernat.im>
Signed-off-by: Serhey Popovych <serhe.popov...@gmail.com>
---
ip/ipaddress.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 5009bfe..ea8211c 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -837,10 +837,8 @@ int print_linkinfo(const struct sockaddr_nl *who,
if (!name)
return -1;
- if (filter.label &&
- (!filter.family || filter.family == AF_PACKET) &&
- fnmatch(filter.label, name, 0))
- return -1;
+ if (filter.label)
+ return 0;
if (tb[IFLA_GROUP]) {
int group = rta_getattr_u32(tb[IFLA_GROUP]);
--
1.7.10.4
