# SPDX-License-Identifier: GPL-2.0-only # # Network configuration # menuconfig NET bool "Networking support" select NLATTR select GENERIC_NET_UTILS select BPF ---help--- Unless you really know what you are doing, you should say Y here. The reason is that some programs need kernel networking support even when running on a stand-alone machine that isn't connected to any other computer. If you are upgrading from an older kernel, you should consider updating your networking tools too because changes in the kernel and the tools often go hand in hand. The tools are contained in the package net-tools, the location and version number of which are given in <file:Documentation/Changes>. For a general introduction to Linux networking, it is highly recommended to read the NET-HOWTO, available from <http://www.tldp.org/docs.html#howto>. if NET config WANT_COMPAT_NETLINK_MESSAGES bool help This option can be selected by other options that need compat netlink messages. config COMPAT_NETLINK_MESSAGES def_bool y depends on COMPAT depends on WEXT_CORE || WANT_COMPAT_NETLINK_MESSAGES help This option makes it possible to send different netlink messages to tasks depending on whether the task is a compat task or not. To achieve this, you need to set skb_shinfo(skb)->frag_list to the compat skb before sending the skb, the netlink code will sort out which message to actually pass to the task. Newly written code should NEVER need this option but do compat-independent messages instead! config NET_INGRESS bool config NET_EGRESS bool config NET_REDIRECT bool config SKB_EXTENSIONS bool menu "Networking options" source "net/packet/Kconfig" source "net/unix/Kconfig" source "net/tls/Kconfig" source "net/xfrm/Kconfig" source "net/iucv/Kconfig" source "net/smc/Kconfig" source "net/xdp/Kconfig" config INET bool "TCP/IP networking" ---help--- These are the protocols used on the Internet and on most local Ethernets. It is highly recommended to say Y here (this will enlarge your kernel by about 400 KB), since some programs (e.g. the X window system) use TCP/IP even if your machine is not connected to any other computer. You will get the so-called loopback device which allows you to ping yourself (great fun, that!). For an excellent introduction to Linux networking, please read the Linux Networking HOWTO, available from <http://www.tldp.org/docs.html#howto>. If you say Y here and also to "/proc file system support" and "Sysctl support" below, you can change various aspects of the behavior of the TCP/IP code by writing to the (virtual) files in /proc/sys/net/ipv4/*; the options are explained in the file <file:Documentation/networking/ip-sysctl.txt>. Short answer: say Y. if INET source "net/ipv4/Kconfig" source "net/ipv6/Kconfig" source "net/netlabel/Kconfig" source "net/mptcp/Kconfig" endif # if INET config NETWORK_SECMARK bool "Security Marking" help This enables security marking of network packets, similar to nfmark, but designated for security purposes. If you are unsure how to answer this question, answer N. config NET_PTP_CLASSIFY def_bool n config NETWORK_PHY_TIMESTAMPING bool "Timestamping in PHY devices" select NET_PTP_CLASSIFY help This allows timestamping of network packets by PHYs (or other MII bus snooping devices) with hardware timestamping capabilities. This option adds some overhead in the transmit and receive paths. If you are unsure how to answer this question, answer N. menuconfig NETFILTER bool "Network packet filtering framework (Netfilter)" ---help--- Netfilter is a framework for filtering and mangling network packets that pass through your Linux box. The most common use of packet filtering is to run your Linux box as a firewall protecting a local network from the Internet. The type of firewall provided by this kernel support is called a "packet filter", which means that it can reject individual network packets based on type, source, destination etc. The other kind of firewall, a "proxy-based" one, is more secure but more intrusive and more bothersome to set up; it inspects the network traffic much more closely, modifies it and has knowledge about the higher level protocols, which a packet filter lacks. Moreover, proxy-based firewalls often require changes to the programs running on the local clients. Proxy-based firewalls don't need support by the kernel, but they are often combined with a packet filter, which only works if you say Y here. You should also say Y here if you intend to use your Linux box as the gateway to the Internet for a local network of machines without globally valid IP addresses. This is called "masquerading": if one of the computers on your local network wants to send something to the outside, your box can "masquerade" as that computer, i.e. it forwards the traffic to the intended outside destination, but modifies the packets to make it look like they came from the firewall box itself. It works both ways: if the outside host replies, the Linux box will silently forward the traffic to the correct local computer. This way, the computers on your local net are completely invisible to the outside world, even though they can reach the outside and can receive replies. It is even possible to run globally visible servers from within a masqueraded local network using a mechanism called portforwarding. Masquerading is also often called NAT (Network Address Translation). Another use of Netfilter is in transparent proxying: if a machine on the local network tries to connect to an outside host, your Linux box can transparently forward the traffic to a local server, typically a caching proxy server. Yet another use of Netfilter is building a bridging firewall. Using a bridge with Network packet filtering enabled makes iptables "see" the bridged traffic. For filtering on the lower network and Ethernet protocols over the bridge, use ebtables (under bridge netfilter configuration). Various modules exist for netfilter which replace the previous masquerading (ipmasqadm), packet filtering (ipchains), transparent proxying, and portforwarding mechanisms. Please see <file:Documentation/Changes> under "iptables" for the location of these packages. if NETFILTER config NETFILTER_ADVANCED bool "Advanced netfilter configuration" depends on NETFILTER default y help If you say Y here you can select between all the netfilter modules. If you say N the more unusual ones will not be shown and the basic ones needed by most people will default to 'M'. If unsure, say Y. config BRIDGE_NETFILTER tristate "Bridged IP/ARP packets filtering" depends on BRIDGE depends on NETFILTER && INET depends on NETFILTER_ADVANCED select NETFILTER_FAMILY_BRIDGE select SKB_EXTENSIONS ---help--- Enabling this option will let arptables resp. iptables see bridged ARP resp. IP traffic. If you want a bridging firewall, you probably want this option enabled. Enabling or disabling this option doesn't enable or disable ebtables. If unsure, say N. source "net/netfilter/Kconfig" source "net/ipv4/netfilter/Kconfig" source "net/ipv6/netfilter/Kconfig" source "net/decnet/netfilter/Kconfig" source "net/bridge/netfilter/Kconfig" endif source "net/bpfilter/Kconfig" source "net/dccp/Kconfig" source "net/sctp/Kconfig" source "net/rds/Kconfig" source "net/tipc/Kconfig" source "net/atm/Kconfig" source "net/l2tp/Kconfig" source "net/802/Kconfig" source "net/bridge/Kconfig" source "net/dsa/Kconfig" source "net/8021q/Kconfig" source "net/decnet/Kconfig" source "net/llc/Kconfig" source "drivers/net/appletalk/Kconfig" source "net/x25/Kconfig" source "net/lapb/Kconfig" source "net/phonet/Kconfig" source "net/6lowpan/Kconfig" source "net/ieee802154/Kconfig" source "net/mac802154/Kconfig" source "net/sched/Kconfig" source "net/dcb/Kconfig" source "net/dns_resolver/Kconfig" source "net/batman-adv/Kconfig" source "net/openvswitch/Kconfig" source "net/vmw_vsock/Kconfig" source "net/netlink/Kconfig" source "net/mpls/Kconfig" source "net/nsh/Kconfig" source "net/hsr/Kconfig" source "net/switchdev/Kconfig" source "net/l3mdev/Kconfig" source "net/qrtr/Kconfig" source "net/ncsi/Kconfig" config RPS bool depends on SMP && SYSFS default y config RFS_ACCEL bool depends on RPS select CPU_RMAP default y config XPS bool depends on SMP default y config HWBM bool config CGROUP_NET_PRIO bool "Network priority cgroup" depends on CGROUPS select SOCK_CGROUP_DATA ---help--- Cgroup subsystem for use in assigning processes to network priorities on a per-interface basis. config CGROUP_NET_CLASSID bool "Network classid cgroup" depends on CGROUPS select SOCK_CGROUP_DATA ---help--- Cgroup subsystem for use as general purpose socket classid marker that is being used in cls_cgroup and for netfilter matching. config NET_RX_BUSY_POLL bool default y config BQL bool depends on SYSFS select DQL default y config BPF_JIT bool "enable BPF Just In Time compiler" depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT depends on MODULES ---help--- Berkeley Packet Filter filtering capabilities are normally handled by an interpreter. This option allows kernel to generate a native code when filter is loaded in memory. This should speedup packet sniffing (libpcap/tcpdump). Note, admin should enable this feature changing: /proc/sys/net/core/bpf_jit_enable /proc/sys/net/core/bpf_jit_harden (optional) /proc/sys/net/core/bpf_jit_kallsyms (optional) config BPF_STREAM_PARSER bool "enable BPF STREAM_PARSER" depends on INET depends on BPF_SYSCALL depends on CGROUP_BPF select STREAM_PARSER select NET_SOCK_MSG ---help--- Enabling this allows a stream parser to be used with BPF_MAP_TYPE_SOCKMAP. BPF_MAP_TYPE_SOCKMAP provides a map type to use with network sockets. It can be used to enforce socket policy, implement socket redirects, etc. config NET_FLOW_LIMIT bool depends on RPS default y ---help--- The network stack has to drop packets when a receive processing CPU's backlog reaches netdev_max_backlog. If a few out of many active flows generate the vast majority of load, drop their traffic earlier to maintain capacity for the other flows. This feature provides servers with many clients some protection against DoS by a single (spoofed) flow that greatly exceeds average workload. menu "Network testing" config NET_PKTGEN tristate "Packet Generator (USE WITH CAUTION)" depends on INET && PROC_FS ---help--- This module will inject preconfigured packets, at a configurable rate, out of a given interface. It is used for network interface stress testing and performance analysis. If you don't understand what was just said, you don't need it: say N. Documentation on how to use the packet generator can be found at <file:Documentation/networking/pktgen.txt>. To compile this code as a module, choose M here: the module will be called pktgen. config NET_DROP_MONITOR tristate "Network packet drop alerting service" depends on INET && TRACEPOINTS ---help--- This feature provides an alerting service to userspace in the event that packets are discarded in the network stack. Alerts are broadcast via netlink socket to any listening user space process. If you don't need network drop alerts, or if you are ok just checking the various proc files and other utilities for drop statistics, say N here. endmenu endmenu source "net/ax25/Kconfig" source "net/can/Kconfig" source "net/bluetooth/Kconfig" source "net/rxrpc/Kconfig" source "net/kcm/Kconfig" source "net/strparser/Kconfig" config FIB_RULES bool menuconfig WIRELESS bool "Wireless" depends on !S390 default y if WIRELESS source "net/wireless/Kconfig" source "net/mac80211/Kconfig" endif # WIRELESS source "net/wimax/Kconfig" source "net/rfkill/Kconfig" source "net/9p/Kconfig" source "net/caif/Kconfig" source "net/ceph/Kconfig" source "net/nfc/Kconfig" source "net/psample/Kconfig" source "net/ife/Kconfig" config LWTUNNEL bool "Network light weight tunnels" ---help--- This feature provides an infrastructure to support light weight tunnels like mpls. There is no netdevice associated with a light weight tunnel endpoint. Tunnel encapsulation parameters are stored with light weight tunnel state associated with fib routes. config LWTUNNEL_BPF bool "Execute BPF program as route nexthop action" depends on LWTUNNEL && INET default y if LWTUNNEL=y ---help--- Allows to run BPF programs as a nexthop action following a route lookup for incoming and outgoing packets. config DST_CACHE bool default n config GRO_CELLS bool default n config SOCK_VALIDATE_XMIT bool config NET_SOCK_MSG bool default n help The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or ULPs (upper layer modules, e.g. TLS) to process L7 application data with the help of BPF programs. config NET_DEVLINK bool default n imply NET_DROP_MONITOR config PAGE_POOL bool config FAILOVER tristate "Generic failover module" help The failover module provides a generic interface for paravirtual drivers to register a netdev and a set of ops with a failover instance. The ops are used as event handlers that get called to handle netdev register/unregister/link change/name change events on slave pci ethernet devices with the same mac address as the failover netdev. This enables paravirtual drivers to use a VF as an accelerated low latency datapath. It also allows live migration of VMs with direct attached VFs by failing over to the paravirtual datapath when the VF is unplugged. config ETHTOOL_NETLINK bool "Netlink interface for ethtool" default y help An alternative userspace interface for ethtool based on generic netlink. It provides better extensibility and some new features, e.g. notification messages. endif # if NET # Used by archs to tell that they support BPF JIT compiler plus which flavour. # Only one of the two can be selected for a specific arch since eBPF JIT supersedes # the cBPF JIT. # Classic BPF JIT (cBPF) config HAVE_CBPF_JIT bool # Extended BPF JIT (eBPF) config HAVE_EBPF_JIT bool