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linux-next/net/Kconfig
Tom Herbert 43a0c6751a strparser: Stream parser for messages
This patch introduces a utility for parsing application layer protocol
messages in a TCP stream. This is a generalization of the mechanism
implemented of Kernel Connection Multiplexor.

The API includes a context structure, a set of callbacks, utility
functions, and a data ready function.

A stream parser instance is defined by a strparse structure that
is bound to a TCP socket. The function to initialize the structure
is:

int strp_init(struct strparser *strp, struct sock *csk,
              struct strp_callbacks *cb);

csk is the TCP socket being bound to and cb are the parser callbacks.

The upper layer calls strp_tcp_data_ready when data is ready on the lower
socket for strparser to process. This should be called from a data_ready
callback that is set on the socket:

void strp_tcp_data_ready(struct strparser *strp);

A parser is bound to a TCP socket by setting data_ready function to
strp_tcp_data_ready so that all receive indications on the socket
go through the parser. This is assumes that sk_user_data is set to
the strparser structure.

There are four callbacks.
 - parse_msg is called to parse the message (returns length or error).
 - rcv_msg is called when a complete message has been received
 - read_sock_done is called when data_ready function exits
 - abort_parser is called to abort the parser

The input to parse_msg is an skbuff which contains next message under
construction. The backend processing of parse_msg will parse the
application layer protocol headers to determine the length of
the message in the stream. The possible return values are:

   >0 : indicates length of successfully parsed message
   0  : indicates more data must be received to parse the message
   -ESTRPIPE : current message should not be processed by the
      kernel, return control of the socket to userspace which
      can proceed to read the messages itself
   other < 0 : Error is parsing, give control back to userspace
      assuming that synchronzation is lost and the stream
      is unrecoverable (application expected to close TCP socket)

In the case of error return (< 0) strparse will stop the parser
and report and error to userspace. The application must deal
with the error. To handle the error the strparser is unbound
from the TCP socket. If the error indicates that the stream
TCP socket is at recoverable point (ESTRPIPE) then the application
can read the TCP socket to process the stream. Once the application
has dealt with the exceptions in the stream, it may again bind the
socket to a strparser to continue data operations.

Note that ENODATA may be returned to the application. In this case
parse_msg returned -ESTRPIPE, however strparser was unable to maintain
synchronization of the stream (i.e. some of the message in question
was already read by the parser).

strp_pause and strp_unpause are used to provide flow control. For
instance, if rcv_msg is called but the upper layer can't immediately
consume the message it can hold the message and pause strparser.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-17 19:36:23 -04:00

438 lines
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#
# 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
menu "Networking options"
source "net/packet/Kconfig"
source "net/unix/Kconfig"
source "net/xfrm/Kconfig"
source "net/iucv/Kconfig"
config INET
bool "TCP/IP networking"
select CRYPTO
select CRYPTO_AES
---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"
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 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_DEBUG
bool "Network packet filtering debugging"
depends on NETFILTER
help
You can say Y here if you want to get additional messages useful in
debugging the netfilter code.
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
default m
---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/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 "net/ipx/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/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 SOCK_CGROUP_DATA
bool
default n
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)
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_TCPPROBE
tristate "TCP connection probing"
depends on INET && PROC_FS && KPROBES
---help---
This module allows for capturing the changes to TCP connection
state in response to incoming packets. It is used for debugging
TCP congestion avoidance modules. If you don't understand
what was just said, you don't need it: say N.
Documentation on how to use TCP connection probing can be found
at:
http://www.linuxfoundation.org/collaborate/workgroups/networking/tcpprobe
To compile this code as a module, choose M here: the
module will be called tcp_probe.
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/irda/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"
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 DST_CACHE
bool
default n
config NET_DEVLINK
tristate "Network physical/parent device Netlink interface"
help
Network physical/parent device Netlink interface provides
infrastructure to support access to physical chip-wide config and
monitoring.
config MAY_USE_DEVLINK
tristate
default m if NET_DEVLINK=m
default y if NET_DEVLINK=y || NET_DEVLINK=n
help
Drivers using the devlink infrastructure should have a dependency
on MAY_USE_DEVLINK to ensure they do not cause link errors when
devlink is a loadable module and the driver using it is built-in.
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