Commit Graph

11 Commits

Author SHA1 Message Date
Matteo Croce
b2e2922373 netns: make netns_{save,restore} static
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>
2019-06-20 14:30:41 -07:00
Matteo Croce
80a931d41c ip: reset netns after each command in batch mode
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>
2019-06-10 10:42:14 -07:00
Pavel Maltsev
e2f5ceccda Allow to configure /var/run/netns directory
Currently NETNS_RUN_DIR is hardcoded and refers to /var/run/netns.
However, some systems (e.g. Android) doesn't have /var
which results in error attempts to create network namespaces on these
systems.  This change makes NETNS_RUN_DIR configurable at build time
by allowing to pass environment variable to make command.
Also, this change makes /etc/netns directory configurable through
NETNS_ETC_DIR environment variable.

For example: ./configure && NETNS_RUN_DIR=/mnt/vendor/netns make

Tested: verified that iproute2 with configuration mentioned above
creates namespaces in /mnt/vendor/netns

Signed-off-by: Pavel Maltsev <pavelm@google.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
2018-05-23 15:16:53 -07:00
Stephen Hemminger
6054c1ebf7 SPDX license identifiers
For all files in iproute2 which do not have an obvious license
identification, mark them with SPDK GPL-2

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
2017-11-24 12:21:35 -08:00
Stephen Hemminger
892e21248c remove unnecessary extern
No need for extern on function prototypes.
2015-08-13 14:09:58 -07:00
Nicolas Dichtel
b765eda924 libnamespaces: fix warning about syscall()
The warning was:
In file included from namespace.c:14:0:
../include/namespace.h: In function ‘setns’:
../include/namespace.h:37:2: warning: implicit declaration of function ‘syscall’ [-Wimplicit-function-declaration]

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
2015-04-27 11:41:46 -07:00
Vadim Kochan
e998e118dd lib: Exec func on each netns
Added possibility to run some func on each netns.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
2015-02-05 10:28:19 -08:00
Nicolas Dichtel
1ff6b16e2d lib: fix setns() function when !HAVE_SETNS
When HAVE_SETNS is not set, iproute2 provides a local implementation of this
function based on __NR_setns.
This macro is defined in sys/syscall.h, which was not included, thus the local
implementation always returned -1.

CC: Vadim Kochan <vadim4j@gmail.com>
Fixes: eb67e4498a ("lib: Add netns_switch func for change network namespace")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
2015-02-05 10:11:51 -08:00
Nicolas Dichtel
ffff693130 lib: fix warning in namespace.h
Warning was:
In file included from bridge.c:16:0:
../include/namespace.h:33:12: warning: ‘setns’ defined but not used [-Wunused-function]

CC: Vadim Kochan <vadim4j@gmail.com>
Fixes: eb67e4498a ("lib: Add netns_switch func for change network namespace")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
2015-02-05 10:11:35 -08:00
Vadim Kochan
c3087c10f1 netns: Rename & move get_netns_fd to lib
Renamed get_netns_fd -> netns_get_fd and moved to
lib/namespace.c

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
2015-01-13 17:34:47 -08:00
Vadim Kochan
eb67e4498a lib: Add netns_switch func for change network namespace
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>
2014-12-27 10:22:27 -08:00