Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 404 insertions, 0 deletions

diff --git a/Documentation/networking/vrf.txt b/Documentation/networking/vrf.txt
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+Virtual Routing and Forwarding (VRF)
+====================================
+The VRF device combined with ip rules provides the ability to create virtual
+routing and forwarding domains (aka VRFs, VRF-lite to be specific) in the
+Linux network stack. One use case is the multi-tenancy problem where each
+tenant has their own unique routing tables and in the very least need
+different default gateways.
+
+Processes can be "VRF aware" by binding a socket to the VRF device. Packets
+through the socket then use the routing table associated with the VRF
+device. An important feature of the VRF device implementation is that it
+impacts only Layer 3 and above so L2 tools (e.g., LLDP) are not affected
+(ie., they do not need to be run in each VRF). The design also allows
+the use of higher priority ip rules (Policy Based Routing, PBR) to take
+precedence over the VRF device rules directing specific traffic as desired.
+
+In addition, VRF devices allow VRFs to be nested within namespaces. For
+example network namespaces provide separation of network interfaces at the
+device layer, VLANs on the interfaces within a namespace provide L2 separation
+and then VRF devices provide L3 separation.
+
+Design
+------
+A VRF device is created with an associated route table. Network interfaces
+are then enslaved to a VRF device:
+
+         +-----------------------------+
+         |           vrf-blue          |  ===> route table 10
+         +-----------------------------+
+            |        |            |
+         +------+ +------+     +-------------+
+         | eth1 | | eth2 | ... |    bond1    |
+         +------+ +------+     +-------------+
+                                  |       |
+                              +------+ +------+
+                              | eth8 | | eth9 |
+                              +------+ +------+
+
+Packets received on an enslaved device and are switched to the VRF device
+in the IPv4 and IPv6 processing stacks giving the impression that packets
+flow through the VRF device. Similarly on egress routing rules are used to
+send packets to the VRF device driver before getting sent out the actual
+interface. This allows tcpdump on a VRF device to capture all packets into
+and out of the VRF as a whole.[1] Similarly, netfilter[2] and tc rules can be
+applied using the VRF device to specify rules that apply to the VRF domain
+as a whole.
+
+[1] Packets in the forwarded state do not flow through the device, so those
+    packets are not seen by tcpdump. Will revisit this limitation in a
+    future release.
+
+[2] Iptables on ingress supports PREROUTING with skb->dev set to the real
+    ingress device and both INPUT and PREROUTING rules with skb->dev set to
+    the VRF device. For egress POSTROUTING and OUTPUT rules can be written
+    using either the VRF device or real egress device.
+
+Setup
+-----
+1. VRF device is created with an association to a FIB table.
+   e.g, ip link add vrf-blue type vrf table 10
+        ip link set dev vrf-blue up
+
+2. An l3mdev FIB rule directs lookups to the table associated with the device.
+   A single l3mdev rule is sufficient for all VRFs. The VRF device adds the
+   l3mdev rule for IPv4 and IPv6 when the first device is created with a
+   default preference of 1000. Users may delete the rule if desired and add
+   with a different priority or install per-VRF rules.
+
+   Prior to the v4.8 kernel iif and oif rules are needed for each VRF device:
+       ip ru add oif vrf-blue table 10
+       ip ru add iif vrf-blue table 10
+
+3. Set the default route for the table (and hence default route for the VRF).
+       ip route add table 10 unreachable default metric 4278198272
+
+   This high metric value ensures that the default unreachable route can
+   be overridden by a routing protocol suite.  FRRouting interprets
+   kernel metrics as a combined admin distance (upper byte) and priority
+   (lower 3 bytes).  Thus the above metric translates to [255/8192].
+
+4. Enslave L3 interfaces to a VRF device.
+       ip link set dev eth1 master vrf-blue
+
+   Local and connected routes for enslaved devices are automatically moved to
+   the table associated with VRF device. Any additional routes depending on
+   the enslaved device are dropped and will need to be reinserted to the VRF
+   FIB table following the enslavement.
+
+   The IPv6 sysctl option keep_addr_on_down can be enabled to keep IPv6 global
+   addresses as VRF enslavement changes.
+       sysctl -w net.ipv6.conf.all.keep_addr_on_down=1
+
+5. Additional VRF routes are added to associated table.
+       ip route add table 10 ...
+
+
+Applications
+------------
+Applications that are to work within a VRF need to bind their socket to the
+VRF device:
+
+    setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, dev, strlen(dev)+1);
+
+or to specify the output device using cmsg and IP_PKTINFO.
+
+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
+
+netfilter rules on the VRF device can be used to limit access to services
+running in the default VRF context as well.
+
+The default VRF does not have limited scope with respect to port bindings.
+That is, if a process does a wildcard bind to a port in the default VRF it
+owns the port across all VRF domains within the network namespace.
+
+################################################################################
+
+Using iproute2 for VRFs
+=======================
+iproute2 supports the vrf keyword as of v4.7. For backwards compatibility this
+section lists both commands where appropriate -- with the vrf keyword and the
+older form without it.
+
+1. Create a VRF
+
+   To instantiate a VRF device and associate it with a table:
+       $ ip link add dev NAME type vrf table ID
+
+   As of v4.8 the kernel supports the l3mdev FIB rule where a single rule
+   covers all VRFs. The l3mdev rule is created for IPv4 and IPv6 on first
+   device create.
+
+2. List VRFs
+
+   To list VRFs that have been created:
+       $ ip [-d] link show type vrf
+         NOTE: The -d option is needed to show the table id
+
+   For example:
+   $ ip -d link show type vrf
+   11: mgmt: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+       link/ether 72:b3:ba:91:e2:24 brd ff:ff:ff:ff:ff:ff promiscuity 0
+       vrf table 1 addrgenmode eui64
+   12: red: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+       link/ether b6:6f:6e:f6:da:73 brd ff:ff:ff:ff:ff:ff promiscuity 0
+       vrf table 10 addrgenmode eui64
+   13: blue: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+       link/ether 36:62:e8:7d:bb:8c brd ff:ff:ff:ff:ff:ff promiscuity 0
+       vrf table 66 addrgenmode eui64
+   14: green: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+       link/ether e6:28:b8:63:70:bb brd ff:ff:ff:ff:ff:ff promiscuity 0
+       vrf table 81 addrgenmode eui64
+
+
+   Or in brief output:
+
+   $ ip -br link show type vrf
+   mgmt         UP             72:b3:ba:91:e2:24 <NOARP,MASTER,UP,LOWER_UP>
+   red          UP             b6:6f:6e:f6:da:73 <NOARP,MASTER,UP,LOWER_UP>
+   blue         UP             36:62:e8:7d:bb:8c <NOARP,MASTER,UP,LOWER_UP>
+   green        UP             e6:28:b8:63:70:bb <NOARP,MASTER,UP,LOWER_UP>
+
+
+3. Assign a Network Interface to a VRF
+
+   Network interfaces are assigned to a VRF by enslaving the netdevice to a
+   VRF device:
+       $ ip link set dev NAME master NAME
+
+   On enslavement connected and local routes are automatically moved to the
+   table associated with the VRF device.
+
+   For example:
+   $ ip link set dev eth0 master mgmt
+
+
+4. Show Devices Assigned to a VRF
+
+   To show devices that have been assigned to a specific VRF add the master
+   option to the ip command:
+       $ ip link show vrf NAME
+       $ ip link show master NAME
+
+   For example:
+   $ ip link show vrf red
+   3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP mode DEFAULT group default qlen 1000
+       link/ether 02:00:00:00:02:02 brd ff:ff:ff:ff:ff:ff
+   4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP mode DEFAULT group default qlen 1000
+       link/ether 02:00:00:00:02:03 brd ff:ff:ff:ff:ff:ff
+   7: eth5: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master red state DOWN mode DEFAULT group default qlen 1000
+       link/ether 02:00:00:00:02:06 brd ff:ff:ff:ff:ff:ff
+
+
+   Or using the brief output:
+   $ ip -br link show vrf red
+   eth1             UP             02:00:00:00:02:02 <BROADCAST,MULTICAST,UP,LOWER_UP>
+   eth2             UP             02:00:00:00:02:03 <BROADCAST,MULTICAST,UP,LOWER_UP>
+   eth5             DOWN           02:00:00:00:02:06 <BROADCAST,MULTICAST>
+
+
+5. Show Neighbor Entries for a VRF
+
+   To list neighbor entries associated with devices enslaved to a VRF device
+   add the master option to the ip command:
+       $ ip [-6] neigh show vrf NAME
+       $ ip [-6] neigh show master NAME
+
+   For example:
+   $  ip neigh show vrf red
+   10.2.1.254 dev eth1 lladdr a6:d9:c7:4f:06:23 REACHABLE
+   10.2.2.254 dev eth2 lladdr 5e:54:01:6a:ee:80 REACHABLE
+
+   $ ip -6 neigh show vrf red
+   2002:1::64 dev eth1 lladdr a6:d9:c7:4f:06:23 REACHABLE
+
+
+6. Show Addresses for a VRF
+
+   To show addresses for interfaces associated with a VRF add the master
+   option to the ip command:
+       $ ip addr show vrf NAME
+       $ ip addr show master NAME
+
+   For example:
+   $ ip addr show vrf red
+   3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000
+       link/ether 02:00:00:00:02:02 brd ff:ff:ff:ff:ff:ff
+       inet 10.2.1.2/24 brd 10.2.1.255 scope global eth1
+          valid_lft forever preferred_lft forever
+       inet6 2002:1::2/120 scope global
+          valid_lft forever preferred_lft forever
+       inet6 fe80::ff:fe00:202/64 scope link
+          valid_lft forever preferred_lft forever
+   4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000
+       link/ether 02:00:00:00:02:03 brd ff:ff:ff:ff:ff:ff
+       inet 10.2.2.2/24 brd 10.2.2.255 scope global eth2
+          valid_lft forever preferred_lft forever
+       inet6 2002:2::2/120 scope global
+          valid_lft forever preferred_lft forever
+       inet6 fe80::ff:fe00:203/64 scope link
+          valid_lft forever preferred_lft forever
+   7: eth5: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master red state DOWN group default qlen 1000
+       link/ether 02:00:00:00:02:06 brd ff:ff:ff:ff:ff:ff
+
+   Or in brief format:
+   $ ip -br addr show vrf red
+   eth1             UP             10.2.1.2/24 2002:1::2/120 fe80::ff:fe00:202/64
+   eth2             UP             10.2.2.2/24 2002:2::2/120 fe80::ff:fe00:203/64
+   eth5             DOWN
+
+
+7. Show Routes for a VRF
+
+   To show routes for a VRF use the ip command to display the table associated
+   with the VRF device:
+       $ ip [-6] route show vrf NAME
+       $ ip [-6] route show table ID
+
+   For example:
+   $ ip route show vrf red
+   unreachable default  metric 4278198272
+   broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
+   10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
+   local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
+   broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2
+   broadcast 10.2.2.0 dev eth2  proto kernel  scope link  src 10.2.2.2
+   10.2.2.0/24 dev eth2  proto kernel  scope link  src 10.2.2.2
+   local 10.2.2.2 dev eth2  proto kernel  scope host  src 10.2.2.2
+   broadcast 10.2.2.255 dev eth2  proto kernel  scope link  src 10.2.2.2
+
+   $ ip -6 route show vrf red
+   local 2002:1:: dev lo  proto none  metric 0  pref medium
+   local 2002:1::2 dev lo  proto none  metric 0  pref medium
+   2002:1::/120 dev eth1  proto kernel  metric 256  pref medium
+   local 2002:2:: dev lo  proto none  metric 0  pref medium
+   local 2002:2::2 dev lo  proto none  metric 0  pref medium
+   2002:2::/120 dev eth2  proto kernel  metric 256  pref medium
+   local fe80:: dev lo  proto none  metric 0  pref medium
+   local fe80:: dev lo  proto none  metric 0  pref medium
+   local fe80::ff:fe00:202 dev lo  proto none  metric 0  pref medium
+   local fe80::ff:fe00:203 dev lo  proto none  metric 0  pref medium
+   fe80::/64 dev eth1  proto kernel  metric 256  pref medium
+   fe80::/64 dev eth2  proto kernel  metric 256  pref medium
+   ff00::/8 dev red  metric 256  pref medium
+   ff00::/8 dev eth1  metric 256  pref medium
+   ff00::/8 dev eth2  metric 256  pref medium
+   unreachable default dev lo  metric 4278198272  error -101 pref medium
+
+8. Route Lookup for a VRF
+
+   A test route lookup can be done for a VRF:
+       $ ip [-6] route get vrf NAME ADDRESS
+       $ ip [-6] route get oif NAME ADDRESS
+
+   For example:
+   $ ip route get 10.2.1.40 vrf red
+   10.2.1.40 dev eth1  table red  src 10.2.1.2
+       cache
+
+   $ ip -6 route get 2002:1::32 vrf red
+   2002:1::32 from :: dev eth1  table red  proto kernel  src 2002:1::2  metric 256  pref medium
+
+
+9. Removing Network Interface from a VRF
+
+   Network interfaces are removed from a VRF by breaking the enslavement to
+   the VRF device:
+       $ ip link set dev NAME nomaster
+
+   Connected routes are moved back to the default table and local entries are
+   moved to the local table.
+
+   For example:
+   $ ip link set dev eth0 nomaster
+
+--------------------------------------------------------------------------------
+
+Commands used in this example:
+
+cat >> /etc/iproute2/rt_tables.d/vrf.conf <<EOF
+1  mgmt
+10 red
+66 blue
+81 green
+EOF
+
+function vrf_create
+{
+    VRF=$1
+    TBID=$2
+
+    # create VRF device
+    ip link add ${VRF} type vrf table ${TBID}
+
+    if [ "${VRF}" != "mgmt" ]; then
+        ip route add table ${TBID} unreachable default metric 4278198272
+    fi
+    ip link set dev ${VRF} up
+}
+
+vrf_create mgmt 1
+ip link set dev eth0 master mgmt
+
+vrf_create red 10
+ip link set dev eth1 master red
+ip link set dev eth2 master red
+ip link set dev eth5 master red
+
+vrf_create blue 66
+ip link set dev eth3 master blue
+
+vrf_create green 81
+ip link set dev eth4 master green
+
+
+Interface addresses from /etc/network/interfaces:
+auto eth0
+iface eth0 inet static
+      address 10.0.0.2
+      netmask 255.255.255.0
+      gateway 10.0.0.254
+
+iface eth0 inet6 static
+      address 2000:1::2
+      netmask 120
+
+auto eth1
+iface eth1 inet static
+      address 10.2.1.2
+      netmask 255.255.255.0
+
+iface eth1 inet6 static
+      address 2002:1::2
+      netmask 120
+
+auto eth2
+iface eth2 inet static
+      address 10.2.2.2
+      netmask 255.255.255.0
+
+iface eth2 inet6 static
+      address 2002:2::2
+      netmask 120
+
+auto eth3
+iface eth3 inet static
+      address 10.2.3.2
+      netmask 255.255.255.0
+
+iface eth3 inet6 static
+      address 2002:3::2
+      netmask 120
+
+auto eth4
+iface eth4 inet static
+      address 10.2.4.2
+      netmask 255.255.255.0
+
+iface eth4 inet6 static
+      address 2002:4::2
+      netmask 120