When ip -all netns {del,exec} are called and no netns is present, ip
exit with status 0. However this does not happen if no netns has been
created since boot time: in that case, indeed, the NETNS_RUN_DIR is not
present and netns_foreach() exit with code 1.
$ ls /var/run/netns
ls: cannot access '/var/run/netns': No such file or directory
$ ip -all netns exec ip link show
$ echo $?
1
$ ip -all netns del
$ echo $?
1
$ ip netns add test
$ ip netns del test
$ ip -all netns del
$ echo $?
0
$ ls -a /var/run/netns
. ..
This leaves us in the unpleasant situation where the same command, when
no netns is present, does the same stuff (in this case, nothing), but
exit with two different statuses.
Fix this treating ENOENT in a different way from other errors, similarly
to what we already do in ipnetns.c netns_identify_pid()
Fixes: e998e118dd ("lib: Exec func on each netns")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
The netns_{save,restore} functions are only used in ipnetns.c now, since
the restore is not needed anymore after the netns exec command.
Move them in ipnetns.c, and make them static.
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
When creating a new netns or executing a program into an existing one,
the unshare() or setns() calls will change the current netns.
In batch mode, this can run commands on the wrong interfaces, as the
ifindex value is meaningful only in the current netns. For example, this
command fails because veth-c doesn't exists in the init netns:
# ip -b - <<-'EOF'
netns add client
link add name veth-c type veth peer veth-s netns client
addr add 192.168.2.1/24 dev veth-c
EOF
Cannot find device "veth-c"
Command failed -:7
But if there are two devices with the same name in the init and new netns,
ip will build a wrong ll_map with indexes belonging to the new netns,
and will execute actions in the init netns using this wrong mapping.
This script will flush all eth0 addresses and bring it down, as it has
the same ifindex of veth0 in the new netns:
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.76/24 brd 192.168.122.255 scope global dynamic eth0
valid_lft 3598sec preferred_lft 3598sec
# ip -b - <<-'EOF'
netns add client
link add name veth0 type veth peer name veth1
link add name veth-ns type veth peer name veth0 netns client
link set veth0 down
address flush veth0
EOF
# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
3: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether c2:db:d0:34:13:4a brd ff:ff:ff:ff:ff:ff
4: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether ca:9d:6b:5f:5f:8f brd ff:ff:ff:ff:ff:ff
5: veth-ns@if2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 32:ef:22:df:51:0a brd ff:ff:ff:ff:ff:ff link-netns client
The same issue can be triggered by the netns exec subcommand with a
sligthy different script:
# ip netns add client
# ip -b - <<-'EOF'
netns exec client true
link add name veth0 type veth peer name veth1
link add name veth-ns type veth peer name veth0 netns client
link set veth0 down
address flush veth0
EOF
Fix this by adding two netns_{save,reset} functions, which are used
to get a file descriptor for the init netns, and restore it after
each batch command.
netns_save() is called before the unshare() or setns(),
while netns_restore() is called after each command.
Fixes: 0dc34c7713 ("iproute2: Add processless network namespace support")
Reviewed-and-tested-by: Andrea Claudi <aclaudi@redhat.com>
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
This partly reverts 8f0807023d, bringing
back the umount(/sys) attempt.
In a LXC container we're unable to umount the sysfs instance, nor mount
a read-write one. We still are able to create a new read-only instance.
Nevertheless, it still makes sense to attempt the umount() even though
the sysfs is mounted read-only. Otherwise we may end up attempting to
mount a sysfs with the same flags as is already mounted, resulting in
an EBUSY error (meaning "Already mounted").
Perhaps this is not a very likely scenario in real world, but we hit
it in NetworkManager test suite and makes netns_switch() somewhat more
robust. It also fixes the case, when /sys wasn't mounted at all.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
It will fail with EPERM on Linux 4.15.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
My previous patch 5950ba9 ("lib/namespace: don't leak fd in error case")
was a step in the wrong direction. Instead of closing the opened file
descriptor in error case only, follow a better approach here and close
the fd as soon as it is not used anymore. This way the inelegant goto
statements can be dropped, and the fd leak in non-error case is fixed as
well.
Fixes: 5950ba9 ("lib/namespace: don't leak fd in error case")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Prefer using the POSIX constant PATH_MAX instead of the legacy BSD
derived MAXPATHLEN. The necessary includes for MAXPATHLEN and PATH_MAX
are <sys/param.h> and <limits.h>, respectively.
Signed-off-by: Felix Janda <felix.janda@posteo.de>
Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
New netns_switch func moved to the lib/namespace.c from ip/ipnetns.c
so it can be used from the other tools for fast switching
network namespace.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
