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authorMike Manning <mmanning@vyatta.att-mail.com>2018-11-07 16:36:05 +0100
committerDavid S. Miller <davem@davemloft.net>2018-11-08 01:12:38 +0100
commit6897445fb194c8ad046df4a13e1ee9f080a5a21e (patch)
tree0064e564646e9066a26230163ba453adb505fe8f /Documentation/networking
parentnet: ensure unbound datagram socket to be chosen when not in a VRF (diff)
downloadlinux-6897445fb194c8ad046df4a13e1ee9f080a5a21e.tar.xz
linux-6897445fb194c8ad046df4a13e1ee9f080a5a21e.zip
net: provide a sysctl raw_l3mdev_accept for raw socket lookup with VRFs
Add a sysctl raw_l3mdev_accept to control raw socket lookup in a manner similar to use of tcp_l3mdev_accept for stream and of udp_l3mdev_accept for datagram sockets. Have this default to enabled for reasons of backwards compatibility. This is so as to specify the output device with cmsg and IP_PKTINFO, but using a socket not bound to the corresponding VRF. This allows e.g. older ping implementations to be run with specifying the device but without executing it in the VRF. If the option is disabled, packets received in a VRF context are only handled by a raw socket bound to the VRF, and correspondingly packets in the default VRF are only handled by a socket not bound to any VRF. Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/ip-sysctl.txt12
-rw-r--r--Documentation/networking/vrf.txt13
2 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 32b21571adfe..aa9e6a331679 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -370,6 +370,7 @@ tcp_l3mdev_accept - BOOLEAN
derived from the listen socket to be bound to the L3 domain in
which the packets originated. Only valid when the kernel was
compiled with CONFIG_NET_L3_MASTER_DEV.
+ Default: 0 (disabled)
tcp_low_latency - BOOLEAN
This is a legacy option, it has no effect anymore.
@@ -773,6 +774,7 @@ udp_l3mdev_accept - BOOLEAN
being received regardless of the L3 domain in which they
originated. Only valid when the kernel was compiled with
CONFIG_NET_L3_MASTER_DEV.
+ Default: 0 (disabled)
udp_mem - vector of 3 INTEGERs: min, pressure, max
Number of pages allowed for queueing by all UDP sockets.
@@ -799,6 +801,16 @@ udp_wmem_min - INTEGER
total pages of UDP sockets exceed udp_mem pressure. The unit is byte.
Default: 4K
+RAW variables:
+
+raw_l3mdev_accept - BOOLEAN
+ Enabling this option allows a "global" bound socket to work
+ across L3 master domains (e.g., VRFs) with packets capable of
+ being received regardless of the L3 domain in which they
+ originated. Only valid when the kernel was compiled with
+ CONFIG_NET_L3_MASTER_DEV.
+ Default: 1 (enabled)
+
CIPSOv4 Variables:
cipso_cache_enable - BOOLEAN
diff --git a/Documentation/networking/vrf.txt b/Documentation/networking/vrf.txt
index d4b129402d57..a5f103b083a0 100644
--- a/Documentation/networking/vrf.txt
+++ b/Documentation/networking/vrf.txt
@@ -111,9 +111,22 @@ the same port if they bind to an l3mdev.
TCP & UDP services running in the default VRF context (ie., not bound
to any VRF device) can work across all VRF domains by enabling the
tcp_l3mdev_accept and udp_l3mdev_accept sysctl options:
+
sysctl -w net.ipv4.tcp_l3mdev_accept=1
sysctl -w net.ipv4.udp_l3mdev_accept=1
+These options are disabled by default so that a socket in a VRF is only
+selected for packets in that VRF. There is a similar option for RAW
+sockets, which is enabled by default for reasons of backwards compatibility.
+This is so as to specify the output device with cmsg and IP_PKTINFO, but
+using a socket not bound to the corresponding VRF. This allows e.g. older ping
+implementations to be run with specifying the device but without executing it
+in the VRF. This option can be disabled so that packets received in a VRF
+context are only handled by a raw socket bound to the VRF, and packets in the
+default VRF are only handled by a socket not bound to any VRF:
+
+ sysctl -w net.ipv4.raw_l3mdev_accept=0
+
netfilter rules on the VRF device can be used to limit access to services
running in the default VRF context as well.