Basic wrapper around the libnl netlink library. More...

#include <Netlink.h>

Classes
struct	BridgePortDetails

Public Member Functions
bool	isValid () const

bool	ifaceUp (const std::string &ifaceName)
	Brings an interface up.

bool	ifaceDown (const std::string &ifaceName)
	Takes an interface down.

bool	ifaceIsUp (const std::string &ifaceName) const
	Queries the interface to determine if it's up or not.

bool	ifaceExists (const std::string &ifaceName) const
	Checks if an interface with a given name exists (interface could be either up or down)

bool	setIfaceAddress (const std::string &ifaceName, const in_addr_t address, const in_addr_t netmask)
	Sets the ip address and netmask of an interface (IPv4)

bool	setIfaceAddress (const std::string &ifaceName, const struct in6_addr address, const int netmask)
	Sets the ip address and netmask of an interface (IPv6)

bool	setIfaceForwarding (const std::string &ifaceName, bool enable)
	Enables or disables IPv4 forwarding on the given interface.

bool	setIfaceForwarding6 (const std::shared_ptr< DobbyRdkPluginUtils > &utils, const std::string &ifaceName, bool enable)
	Enables or disables IPv6 forwarding on the given interface.

bool	setIfaceRouteLocalNet (const std::string &ifaceName, bool enable)
	Sets the route_localnet flag on the interface.

bool	setIfaceAcceptRa (const std::shared_ptr< DobbyRdkPluginUtils > &utils, const std::string &ifaceName, int value)
	Sets the accept_ra flag on the interface.

bool	setIfaceMAC (const std::string &ifaceName, const std::array< uint8_t, 6 > &address)
	Sets the MAC address of the given interface.

std::array< uint8_t, 6 >	getIfaceMAC (const std::string &ifaceName)
	Gets the MAC address of the given interface.

std::list< BridgePortDetails >	getAttachedIfaces (const std::string &bridgeName)
	Gets the set of interfaces currently enslaved to a given bridge device.

bool	createBridge (const std::string &bridgeName)
	Creates a new bridge device.

bool	destroyBridge (const std::string &bridgeName)
	Deletes an existing bridge device.

bool	addIfaceToBridge (const std::string &bridgeName, const std::string &ifaceName)
	Adds an interface to the bridge device.

bool	delIfaceFromBridge (const std::string &bridgeName, const std::string &ifaceName)
	Removes an interface from a bridge.

std::string	createVeth (const std::string &peerVethName, pid_t peerPid, std::vector< std::string > &takenVeths)
	Creates a veth pair for the netns attached to the given pid.

bool	checkVeth (const std::string &vethName)

bool	addRoute (const std::string &iface, const in_addr_t destination, const in_addr_t netmask, const in_addr_t gateway)
	Adds a new route to the routing table (IPv4)

bool	addRoute (const std::string &iface, const struct in6_addr destination, const int netmask, const struct in6_addr gateway)
	Adds a new route to the routing table (IPv6)

bool	addArpEntry (const std::string &iface, in_addr_t address, const std::array< uint8_t, 6 > &mac)
	Sets an entry in the ARP table.

bool	delArpEntry (const std::string &iface, in_addr_t address)
	Removes (invalidates) an entry in the ARP table.

Private Member Functions
bool	applyChangesToLink (const std::string &ifaceName, const NlLink &changes)

bool	setLinkAddress (const NlLink &link, const in_addr_t address, const in_addr_t netmask)
	Sets the ip address and netmask of an interface (IPv4)

bool	setLinkAddress (const NlLink &link, const struct in6_addr address, const int netmask)
	Sets the ip address and netmask of an interface (IPv6)

bool	setIfaceConfig (const std::string &ifaceName, const unsigned int configId, const uint32_t value)
	Sets the config on a given interface.

std::string	getAvailableVethName (const int startIndex) const
	Returns the number of the next free veth device.

Private Attributes
struct nl_sock *	mSocket

int	mSysClassNetDirFd

std::mutex	mLock

Detailed Description

Basic wrapper around the libnl netlink library.

There is only expected to be one of these objects (i.e. a shared_ptr is passed around). The object represents a single netlink socket.

At construction time a new netlink socket is opened, on destruction it is closed.

Member Function Documentation

◆ addArpEntry()

bool Netlink::addArpEntry	(	const std::string &	iface,
		in_addr_t	address,
		const std::array< uint8_t, 6 > &	mac
	)

Sets an entry in the ARP table.

This is equivalent of the performing the following on the command line

arp -i <iface> -s <address> <mac>

Parameters

[in]	iface	The name of the iface containing the ARP cache
[in]	address	The destination ip address
[in]	mac	The hardware address of the destination

Returns: true on success, false on failure.

◆ addIfaceToBridge()

bool Netlink::addIfaceToBridge	(	const std::string &	bridgeName,
		const std::string &	ifaceName
	)

Adds an interface to the bridge device.

This is equivalent of the performing the following on the command line

brctl addif <bridgeName> <ifaceName>

Returns: true on success, false on failure.

◆ addRoute() [1/2]

bool Netlink::addRoute	(	const std::string &	iface,
		const in_addr_t	destination,
		const in_addr_t	netmask,
		const in_addr_t	gateway
	)

Adds a new route to the routing table (IPv4)

This is equivalent of the performing the following on the command line

ip route add <destination>/<netmask> via <gateway> dev <ifname>

Parameters

[in]	iface	The name of the iface to route to
[in]	destination	The destination ip address
[in]	netmask	The netmask for the destination ip address
[in]	gateway	The ip address of the gateway

Returns: true on success, false on failure.

◆ addRoute() [2/2]

bool Netlink::addRoute	(	const std::string &	iface,
		const struct in6_addr	destination,
		const int	netmask,
		const struct in6_addr	gateway
	)

Adds a new route to the routing table (IPv6)

This is equivalent of the performing the following on the command line

ip -6 route add <destination>/<netmask> via <gateway> dev <ifname>

Parameters

[in]	iface	The name of the iface to route to
[in]	destination	The destination ip address
[in]	netmask	The netmask for the destination ip address
[in]	gateway	The ip address of the gateway, if null, we don't set a gateway for the route.

Returns: true on success, false on failure.

◆ createBridge()

bool Netlink::createBridge ( const std::string & bridgeName )

Creates a new bridge device.

Note that it is not an error if a bridge device already exists with the same name, this method will return true in that case.

This is equivalent of the performing the following on the command line

brctl addbr <bridgeName>

Parameters

[in] bridgeName The name of the new bridge device.

Returns: true on success, false on failure.

◆ createVeth()

std::string Netlink::createVeth	(	const std::string &	peerVethName,
		pid_t	peerPid,
		std::vector< std::string > &	takenVeths
	)

Creates a veth pair for the netns attached to the given pid.

Parameters

[in]	peerVethName	The name of the veth interface inside the net namespace (container), typically this will be "eth0".
[in]	peerPid	The pid of the process which has the netns we want to create the veth in (i.e. the pid of init process within the container).
[in]	takenVeths	Veth devices reserved by other containers. We want to check that in case of races.

Returns: on success the interface name of the veth pair, this is the name outside the container and will be of the form vethd, ie veth0, veth1, etc. On failure an empty string is returned.

◆ delArpEntry()

bool Netlink::delArpEntry	(	const std::string &	iface,
		in_addr_t	address
	)

Removes (invalidates) an entry in the ARP table.

This is equivalent of the performing the following on the command line

arp -i <iface> -d <address>

Parameters

[in]	iface	The name of the iface containing the ARP cache
[in]	address	The destination ip address

Returns: true on success, false on failure.

◆ delIfaceFromBridge()

bool Netlink::delIfaceFromBridge	(	const std::string &	bridgeName,
		const std::string &	ifaceName
	)

Removes an interface from a bridge.

This is equivalent of the performing the following on the command line

brctl delif <bridgeName> <ifaceName>

Returns: true on success, false on failure.

◆ destroyBridge()

bool Netlink::destroyBridge ( const std::string & bridgeName )

Deletes an existing bridge device.

This is equivalent of the performing the following on the command line

brctl delbr <bridgeName>

Parameters

[in] bridgeName The name of the new bridge to delete.

Returns: true on success, false on failure.

◆ getAttachedIfaces()

std::list< Netlink::BridgePortDetails > Netlink::getAttachedIfaces ( const std::string & bridgeName )

Gets the set of interfaces currently enslaved to a given bridge device.

Parameters

[in] bridgeName The name of the bridge device

Returns: a list of interfaces attached to the bridge, or empty list on failure.

◆ getAvailableVethName()

std::string Netlink::getAvailableVethName ( const int startIndex ) const

private

Returns the number of the next free veth device.

This works by scanning /sys/class/net/ for devices with names "veth%d", the first one not found is returned.

Parameters

[in] startIndex Starting index for veth names

Returns: the name of a free veth device, if all names are used (possible?) we return an empty string.

◆ getIfaceMAC()

std::array< uint8_t, 6 > Netlink::getIfaceMAC ( const std::string & ifaceName )

Gets the MAC address of the given interface.

Parameters

[in] ifaceName The name of the interface to get.

Returns: the mac address.

◆ ifaceDown()

bool Netlink::ifaceDown ( const std::string & ifaceName )

Takes an interface down.

Parameters

[in] ifaceName The name of the interface to take down.

Returns: true on success, false on failure.

◆ ifaceExists()

bool Netlink::ifaceExists ( const std::string & ifaceName ) const

Checks if an interface with a given name exists (interface could be either up or down)

Parameters

[in] ifaceName The name of the interface to check

Returns: true if the interface exists, otherwise false.

◆ ifaceIsUp()

bool Netlink::ifaceIsUp ( const std::string & ifaceName ) const

Queries the interface to determine if it's up or not.

Parameters

[in] ifaceName The name of the interface to check

Returns: true if the interface is up, otherwise false.

◆ ifaceUp()

bool Netlink::ifaceUp ( const std::string & ifaceName )

Brings an interface up.

Parameters

[in] ifaceName The name of the interface to bring up.

Returns: true on success, false on failure.

◆ setIfaceAcceptRa()

bool Netlink::setIfaceAcceptRa	(	const std::shared_ptr< DobbyRdkPluginUtils > &	utils,
		const std::string &	ifaceName,
		int	value
	)

Sets the accept_ra flag on the interface.

This is the equivalent of the following on the command line

echo "2" > /proc/sys/net/ipv6/conf/<ifaceName>/accept_ra

Or echo "1" > /proc/sys/net/ipv6/conf/<ifaceName>/accept_ra Or echo "0" > /proc/sys/net/ipv6/conf/<ifaceName>/accept_ra

This is used to set accept_ra to "2" so that router advertisements are accepted on the interface even with forwarding enabled.

Parameters

[in]	utils	Instance of the DobbyRdkPluginUtils class.
[in]	ifaceName	The name of the interface to set the config on.
[in]	enable	true to enable, false to disable.

Returns: true on success, false on failure.

◆ setIfaceAddress() [1/2]

bool Netlink::setIfaceAddress	(	const std::string &	ifaceName,
		const in_addr_t	address,
		const in_addr_t	netmask
	)

Sets the ip address and netmask of an interface (IPv4)

This is the equivalent of the following on the command line

ifconfig <ifaceName> <address> netmask <netmask>

Parameters

[in]	ifaceName	The name of the interface to set the address on
[in]	address	The address to set, the netmask will be applied to this before setting on the iface
[in]	netmask	The netmask to apply.

Returns: true on success, false on failure.

◆ setIfaceAddress() [2/2]

bool Netlink::setIfaceAddress	(	const std::string &	ifaceName,
		const struct in6_addr	address,
		const int	netmask
	)

Sets the ip address and netmask of an interface (IPv6)

This is the equivalent of the following on the command line

ifconfig <ifaceName> inet6 add <address>/<netmask>

Parameters

[in]	ifaceName	The name of the interface to set the address on
[in]	address	The IPv6 address to set, the netmask will be applied to this before setting on the iface
[in]	netmask	The netmask to apply.

Returns: true on success, false on failure.

◆ setIfaceConfig()

bool Netlink::setIfaceConfig	(	const std::string &	ifaceName,
		const unsigned int	configId,
		const uint32_t	value
	)

private

Sets the config on a given interface.

Used by setIfaceForwarding() and setIfaceRouteLocalNet().

Parameters

[in]	ifaceName	The name of the interface to set the address on
[in]	configId	The config to set.
[in]	value	The value to set.

Returns: true on success, false on failure.

◆ setIfaceForwarding()

bool Netlink::setIfaceForwarding	(	const std::string &	ifaceName,
		bool	enable
	)

Enables or disables IPv4 forwarding on the given interface.

This is the equivalent of the following on the command line

echo "1" > /proc/sys/net/ipv4/conf/<ifaceName>/forwarding

Or echo "0" > /proc/sys/net/ipv4/conf/<ifaceName>/forwarding

Parameters

[in]	ifaceName	The name of the interface to set the config on
[in]	enable	true to enable, false to disable.

Returns: true on success, false on failure.

◆ setIfaceForwarding6()

bool Netlink::setIfaceForwarding6	(	const std::shared_ptr< DobbyRdkPluginUtils > &	utils,
		const std::string &	ifaceName,
		bool	enable
	)

Enables or disables IPv6 forwarding on the given interface.

This is the equivalent of the following on the command line

echo "1" > /proc/sys/net/ipv6/conf/<ifaceName>/forwarding

Or echo "0" > /proc/sys/net/ipv6/conf/<ifaceName>/forwarding

Parameters

[in]	utils	Instance of the DobbyRdkPluginUtils class.
[in]	ifaceName	The name of the interface to set the config on.
[in]	enable	true to enable, false to disable.

Returns: true on success, false on failure.

◆ setIfaceMAC()

bool Netlink::setIfaceMAC	(	const std::string &	ifaceName,
		const std::array< uint8_t, 6 > &	address
	)

Sets the MAC address of the given interface.

This is primarily used to set a fixed MAC address for the bridge device.

Parameters

[in]	ifaceName	The name of the interface to set.
[in]	address	The MAC address to set.

Returns: true if successfully set.

◆ setIfaceRouteLocalNet()

bool Netlink::setIfaceRouteLocalNet	(	const std::string &	ifaceName,
		bool	enable
	)

Sets the route_localnet flag on the interface.

Which means: "Do not consider loopback addresses as martian source or destination while routing. This enables the use of 127/8 for local routing purposes. default FALSE"

This is the equivalent of the following on the command line

echo "1" > /proc/sys/net/ipv4/conf/<ifaceName>/route_localnet

Or echo "0" > /proc/sys/net/ipv4/conf/<ifaceName>/route_localnet

This is used so we can use iptables to route packets on the bridge interface to local host. The main usage is for connecting specific ports like dns, as to the localhost interface.

Parameters

[in]	ifaceName	The name of the interface to set the config on.
[in]	enable	true to enable, false to disable.

Returns: true on success, false on failure.

◆ setLinkAddress() [1/2]

bool Netlink::setLinkAddress	(	const NlLink &	link,
		const in_addr_t	address,
		const in_addr_t	netmask
	)

private

Sets the ip address and netmask of an interface (IPv4)

This is the equivalent of the following on the command line

ifconfig <ifaceName> <address> netmask <netmask>

Parameters

[in]	link	Instance of NlLink (rtnl_link wrapper)
[in]	address	The address to set, the netmask will be applied to this before setting on the iface
[in]	netmask	The netmask to apply.

Returns: true on success, false on failure.

◆ setLinkAddress() [2/2]

bool Netlink::setLinkAddress	(	const NlLink &	link,
		const struct in6_addr	address,
		const int	netmask
	)

private

Sets the ip address and netmask of an interface (IPv6)

This is the equivalent of the following on the command line

ifconfig <ifaceName> inet6 add <address>/<netmask>

Parameters

[in]	link	Instance of NlLink (rtnl_link wrapper)
[in]	address	The address to set, the netmask will be applied to this before setting on the iface
[in]	netmask	The netmask to apply.

Returns: true on success, false on failure.

The documentation for this class was generated from the following files:

rdkPlugins/Networking/include/Netlink.h
rdkPlugins/Networking/source/Netlink.cpp

Classes

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Function Documentation

◆ addArpEntry()

◆ addIfaceToBridge()

◆ addRoute() [1/2]

◆ addRoute() [2/2]

◆ createBridge()

◆ createVeth()

◆ delArpEntry()

◆ delIfaceFromBridge()

◆ destroyBridge()

◆ getAttachedIfaces()

◆ getAvailableVethName()

◆ getIfaceMAC()

◆ ifaceDown()

◆ ifaceExists()

◆ ifaceIsUp()

◆ ifaceUp()

◆ setIfaceAcceptRa()

◆ setIfaceAddress() [1/2]

◆ setIfaceAddress() [2/2]

◆ setIfaceConfig()

◆ setIfaceForwarding()

◆ setIfaceForwarding6()

◆ setIfaceMAC()

◆ setIfaceRouteLocalNet()

◆ setLinkAddress() [1/2]

◆ setLinkAddress() [2/2]