This change allows to exec some cmd on each
named netns (except default) by specifying '-all' option:
# ip -all netns exec ip link
Each command executes synchronously.
Exit status is not considered, so there might be a case
that some CMD can fail on some netns but success on the other.
EXAMPLES:
1) Show link info on all netns:
$ ip -all netns exec ip link
netns: test_net
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
4: tap0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 500
link/ether 1a:19:6f:25:eb:85 brd ff:ff:ff:ff:ff:ff
netns: home0
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
4: tap0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 500
link/ether ea:1a:59:40:d3:29 brd ff:ff:ff:ff:ff:ff
netns: lan0
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
4: tap0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 500
link/ether ce:49:d5:46:81:ea brd ff:ff:ff:ff:ff:ff
2) Set UP tap0 device for the all netns:
$ ip -all netns exec ip link set dev tap0 up
netns: test_net
netns: home0
netns: lan0
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
b13ba03f54