//! A zero allocation supporting library for parsing & writing a bunch of packet based protocols (EthernetII, IPv4, IPv6, UDP, TCP ...).
//!
//! Currently supported are:
//! * Ethernet II
//! * IEEE 802.1Q VLAN Tagging Header
//! * ARP
//! * IPv4
//! * IPv6 (supporting the most common extension headers, but not all)
//! * UDP
//! * TCP
//! * ICMP & ICMPv6 (not all message types are supported)
//!
//! Reconstruction of fragmented IP packets is also supported, but requires allocations.
//!
//! # Usage
//!
//! Add the following to your `Cargo.toml`:
//!
//! ```toml
//! [dependencies]
//! etherparse = "0.17"
//! ```
//!
//! # What is etherparse?
//!
//! Etherparse is intended to provide the basic network parsing functions that allow for easy analysis, transformation or generation of recorded network data.
//!
//! Some key points are:
//!
//! * It is completely written in Rust and thoroughly tested.
//! * Special attention has been paid to not use allocations or syscalls.
//! * The package is still in development and can & will still change.
//! * The current focus of development is on the most popular protocols in the internet & transport layer.
//!
//! # How to parse network packages?
//! Etherparse gives you two options for parsing network packages automatically:
//!
//! ## Slicing the packet
//! Here the different components in a packet are separated without parsing all their fields. For each header a slice is generated that allows access to the fields of a header.
//! ```
//! # use etherparse::{SlicedPacket, PacketBuilder};
//! # let builder = PacketBuilder::
//! #    ethernet2([1,2,3,4,5,6],     //source mac
//! #               [7,8,9,10,11,12]) //destination mac
//! #    .ipv4([192,168,1,1], //source ip
//! #          [192,168,1,2], //destination ip
//! #          20)            //time to life
//! #    .udp(21,    //source port
//! #         1234); //destination port
//! #    //payload of the udp packet
//! #    let payload = [1,2,3,4,5,6,7,8];
//! #    //get some memory to store the serialized data
//! #    let mut packet = Vec::<u8>::with_capacity(
//! #                            builder.size(payload.len()));
//! #    builder.write(&mut packet, &payload).unwrap();
//! match SlicedPacket::from_ethernet(&packet) {
//!     Err(value) => println!("Err {:?}", value),
//!     Ok(value) => {
//!         println!("link: {:?}", value.link);
//!         println!("vlan: {:?}", value.vlan);
//!         println!("net: {:?}", value.net); // contains ip & arp
//!         println!("transport: {:?}", value.transport);
//!     }
//! }
//! ```
//! This is the faster option if your code is not interested in all fields of all the headers. It is a good choice if you just want filter or find packages based on a subset of the headers and/or their fields.
//!
//! Depending from which point downward you want to slice a package check out the functions:
//!
//! * [`SlicedPacket::from_ethernet`] for parsing from an Ethernet II header downwards
//! * [`SlicedPacket::from_linux_sll`] for parsing from a Linux Cooked Capture v1 (SLL) downwards
//! * [`SlicedPacket::from_ether_type`] for parsing a slice starting after an Ethernet II header
//! * [`SlicedPacket::from_ip`] for parsing from an IPv4 or IPv6 downwards
//!
//! In case you want to parse cut off packets (e.g. packets returned in in ICMP message) you can use the "lax" parsing methods:
//!
//! * [`LaxSlicedPacket::from_ethernet`] for parsing from an Ethernet II header downwards
//! * [`LaxSlicedPacket::from_ether_type`] for parsing a slice starting after an Ethernet II header
//! * [`LaxSlicedPacket::from_ip`] for parsing from an IPv4 or IPv6 downwards
//!
//! ## Deserializing all headers into structs
//!
//! This option deserializes all known headers and transfers their contents to header structs.
//! ```rust
//! # use etherparse::{PacketHeaders, PacketBuilder};
//! # let builder = PacketBuilder::
//! #    ethernet2([1,2,3,4,5,6],     //source mac
//! #               [7,8,9,10,11,12]) //destination mac
//! #    .ipv4([192,168,1,1], //source ip
//! #          [192,168,1,2], //destination ip
//! #          20)            //time to life
//! #    .udp(21,    //source port
//! #         1234); //destination port
//! #    //payload of the udp packet
//! #    let payload = [1,2,3,4,5,6,7,8];
//! #    //get some memory to store the serialized data
//! #    let mut packet = Vec::<u8>::with_capacity(
//! #                            builder.size(payload.len()));
//! #    builder.write(&mut packet, &payload).unwrap();
//! match PacketHeaders::from_ethernet_slice(&packet) {
//!     Err(value) => println!("Err {:?}", value),
//!     Ok(value) => {
//!         println!("link: {:?}", value.link);
//!         println!("vlan: {:?}", value.vlan);
//!         println!("net: {:?}", value.net); // contains ip & arp
//!         println!("transport: {:?}", value.transport);
//!     }
//! }
//! ```
//! This option is slower then slicing when only few fields are accessed. But it can be the faster option or useful if you are interested in most fields anyways or if you want to re-serialize the headers with modified values.
//!
//! Depending from which point downward you want to unpack a package check out the functions
//!
//! * [`PacketHeaders::from_ethernet_slice`] for parsing from an Ethernet II header downwards
//! * [`PacketHeaders::from_ether_type`] for parsing a slice starting after an Ethernet II header
//! * [`PacketHeaders::from_ip_slice`] for parsing from an IPv4 or IPv6 downwards
//!
//! In case you want to parse cut off packets (e.g. packets returned in in ICMP message) you can use the "lax" parsing methods:
//!
//! * [`LaxPacketHeaders::from_ethernet`] for parsing from an Ethernet II header downwards
//! * [`LaxPacketHeaders::from_ether_type`] for parsing a slice starting after an Ethernet II header
//! * [`LaxPacketHeaders::from_ip`] for parsing from an IPv4 or IPv6 downwards
//!
//! ## Manually slicing only one packet layer
//!
//! It is also possible to only slice one packet layer:
//!
//! * [`Ethernet2Slice::from_slice_without_fcs`] & [`Ethernet2Slice::from_slice_with_crc32_fcs`]
//! * [`LinuxSllSlice::from_slice`]
//! * [`SingleVlanSlice::from_slice`] & [`DoubleVlanSlice::from_slice`]
//! * [`IpSlice::from_slice`] & [`LaxIpSlice::from_slice`]
//! * [`Ipv4Slice::from_slice`] & [`LaxIpv4Slice::from_slice`]
//! * [`Ipv6Slice::from_slice`] & [`LaxIpv6Slice::from_slice`]
//! * [`UdpSlice::from_slice`] & [`UdpSlice::from_slice_lax`]
//! * [`TcpSlice::from_slice`]
//! * [`Icmpv4Slice::from_slice`]
//! * [`Icmpv6Slice::from_slice`]
//!
//! The resulting data types allow access to both the header(s) and the payload of the layer
//! and will automatically limit the length of payload if the layer has a length field limiting the
//! payload (e.g. the payload of IPv6 packets will be limited by the "payload length" field in
//! an IPv6 header).
//!
//! ## Manually slicing & parsing only headers
//!
//! It is also possible just to parse headers. Have a look at the documentation for the
//! following \[NAME\]HeaderSlice.from_slice methods, if you want to just slice the header:
//!
//! * [`Ethernet2HeaderSlice::from_slice`]
//! * [`LinuxSllHeaderSlice::from_slice`]
//! * [`SingleVlanHeaderSlice::from_slice`]
//! * [`DoubleVlanHeaderSlice::from_slice`]
//! * [`ArpPacketSlice::from_slice`]
//! * [`Ipv4HeaderSlice::from_slice`]
//! * [`Ipv4ExtensionsSlice::from_slice`]
//! * [`Ipv6HeaderSlice::from_slice`]
//! * [`Ipv6ExtensionsSlice::from_slice`]
//! * [`Ipv6RawExtHeaderSlice::from_slice`]
//! * [`IpAuthHeaderSlice::from_slice`]
//! * [`Ipv6FragmentHeaderSlice::from_slice`]
//! * [`UdpHeaderSlice::from_slice`]
//! * [`TcpHeaderSlice::from_slice`]
//!
//! And for deserialization into the corresponding header structs have a look at:
//!
//! * [`Ethernet2Header::read`] & [`Ethernet2Header::from_slice`]
//! * [`LinuxSllHeader::read`] & [`LinuxSllHeader::from_slice`]
//! * [`SingleVlanHeader::read`] & [`SingleVlanHeader::from_slice`]
//! * [`DoubleVlanHeader::read`] & [`DoubleVlanHeader::from_slice`]
//! * [`ArpPacket::read`] & [`ArpPacket::from_slice`]
//! * [`IpHeaders::read`] & [`IpHeaders::from_slice`]
//! * [`Ipv4Header::read`] & [`Ipv4Header::from_slice`]
//! * [`Ipv4Extensions::read`] & [`Ipv4Extensions::from_slice`]
//! * [`Ipv6Header::read`] & [`Ipv6Header::from_slice`]
//! * [`Ipv6Extensions::read`] & [`Ipv6Extensions::from_slice`]
//! * [`Ipv6RawExtHeader::read`] & [`Ipv6RawExtHeader::from_slice`]
//! * [`IpAuthHeader::read`] & [`IpAuthHeader::from_slice`]
//! * [`Ipv6FragmentHeader::read`] & [`Ipv6FragmentHeader::from_slice`]
//! * [`UdpHeader::read`] & [`UdpHeader::from_slice`]
//! * [`TcpHeader::read`] & [`TcpHeader::from_slice`]
//! * [`Icmpv4Header::read`] & [`Icmpv4Header::from_slice`]
//! * [`Icmpv6Header::read`] & [`Icmpv6Header::from_slice`]
//!
//! # How to generate fake packet data?
//!
//! ## Packet Builder
//!
//! The PacketBuilder struct provides a high level interface for quickly creating network packets. The PacketBuilder will automatically set fields which can be deduced from the content and compositions of the packet itself (e.g. checksums, lengths, ethertype, ip protocol number).
//!
//! [Example:](https://github.com/JulianSchmid/etherparse/blob/0.14.3/examples/write_udp.rs)
//! ```rust
//! use etherparse::PacketBuilder;
//!
//! let builder = PacketBuilder::
//!     ethernet2([1,2,3,4,5,6],     //source mac
//!                [7,8,9,10,11,12]) //destination mac
//!     .ipv4([192,168,1,1], //source ip
//!           [192,168,1,2], //destination ip
//!           20)            //time to life
//!     .udp(21,    //source port
//!          1234); //destination port
//!
//! //payload of the udp packet
//! let payload = [1,2,3,4,5,6,7,8];
//!
//! //get some memory to store the result
//! let mut result = Vec::<u8>::with_capacity(builder.size(payload.len()));
//!
//! //serialize
//! //this will automatically set all length fields, checksums and identifiers (ethertype & protocol)
//! //before writing the packet out to "result"
//! builder.write(&mut result, &payload).unwrap();
//! ```
//!
//! There is also an [example for TCP packets](https://github.com/JulianSchmid/etherparse/blob/0.14.3/examples/write_tcp.rs) available.
//!
//! Check out the [PacketBuilder documentation](struct.PacketBuilder.html) for more information.
//!
//! ## Manually serializing each header
//!
//! Alternatively it is possible to manually build a packet
//! ([example](https://github.com/JulianSchmid/etherparse/blob/0.14.3/examples/write_ipv4_udp.rs)).
//! Generally each struct representing a header has a "write" method that allows it to be
//! serialized. These write methods sometimes automatically calculate checksums and fill them
//! in. In case this is unwanted behavior (e.g. if you want to generate a packet with an invalid
//! checksum), it is also possible to call a "write_raw" method that will simply serialize the data
//! without doing checksum calculations.
//!
//! Read the documentations of the different methods for a more details:
//!
//! * [`Ethernet2Header::to_bytes`] & [`Ethernet2Header::write`]
//! * [`LinuxSllHeader::to_bytes`] & [`LinuxSllHeader::write`]
//! * [`SingleVlanHeader::to_bytes`] & [`SingleVlanHeader::write`]
//! * [`DoubleVlanHeader::to_bytes`] & [`DoubleVlanHeader::write`]
//! * [`ArpPacket::to_bytes`] & [`ArpPacket::write`]
//! * [`ArpEthIpv4Packet::to_bytes`]
//! * [`Ipv4Header::to_bytes`] & [`Ipv4Header::write`] & [`Ipv4Header::write_raw`]
//! * [`Ipv4Extensions::write`]
//! * [`Ipv6Header::to_bytes`] & [`Ipv6Header::write`]
//! * [`Ipv6Extensions::write`]
//! * [`Ipv6RawExtHeader::to_bytes`] & [`Ipv6RawExtHeader::write`]
//! * [`IpAuthHeader::to_bytes`] & [`IpAuthHeader::write`]
//! * [`Ipv6FragmentHeader::to_bytes`] & [`Ipv6FragmentHeader::write`]
//! * [`UdpHeader::to_bytes`] & [`UdpHeader::write`]
//! * [`TcpHeader::to_bytes`] & [`TcpHeader::write`]
//! * [`Icmpv4Header::to_bytes`] & [`Icmpv4Header::write`]
//! * [`Icmpv6Header::to_bytes`] & [`Icmpv6Header::write`]
//!
//! # References
//! * Darpa Internet Program Protocol Specification [RFC 791](https://tools.ietf.org/html/rfc791)
//! * Internet Protocol, Version 6 (IPv6) Specification [RFC 8200](https://tools.ietf.org/html/rfc8200)
//! * [IANA 802 EtherTypes](https://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml)
//! * [IANA Protocol Numbers](https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml)
//! * [Internet Protocol Version 6 (IPv6) Parameters](https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml)
//! * [Wikipedia IEEE_802.1Q](https://en.wikipedia.org/w/index.php?title=IEEE_802.1Q&oldid=820983900)
//! * User Datagram Protocol (UDP) [RFC 768](https://tools.ietf.org/html/rfc768)
//! * Transmission Control Protocol [RFC 793](https://tools.ietf.org/html/rfc793)
//! * TCP Extensions for High Performance [RFC 7323](https://tools.ietf.org/html/rfc7323)
//! * The Addition of Explicit Congestion Notification (ECN) to IP [RFC 3168](https://tools.ietf.org/html/rfc3168)
//! * Robust Explicit Congestion Notification (ECN) Signaling with Nonces [RFC 3540](https://tools.ietf.org/html/rfc3540)
//! * IP Authentication Header [RFC 4302](https://tools.ietf.org/html/rfc4302)
//! * Mobility Support in IPv6 [RFC 6275](https://tools.ietf.org/html/rfc6275)
//! * Host Identity Protocol Version 2 (HIPv2) [RFC 7401](https://tools.ietf.org/html/rfc7401)
//! * Shim6: Level 3 Multihoming Shim Protocol for IPv6 [RFC 5533](https://tools.ietf.org/html/rfc5533)
//! * Computing the Internet Checksum [RFC 1071](https://datatracker.ietf.org/doc/html/rfc1071)
//! * Internet Control Message Protocol [RFC 792](https://datatracker.ietf.org/doc/html/rfc792)
//! * [IANA Internet Control Message Protocol (ICMP) Parameters](https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml)
//! * Requirements for Internet Hosts -- Communication Layers [RFC 1122](https://datatracker.ietf.org/doc/html/rfc1122)
//! * Requirements for IP Version 4 Routers [RFC 1812](https://datatracker.ietf.org/doc/html/rfc1812)
//! * Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification [RFC 4443](https://datatracker.ietf.org/doc/html/rfc4443)
//! * ICMP Router Discovery Messages [RFC 1256](https://datatracker.ietf.org/doc/html/rfc1256)
//! * [Internet Control Message Protocol version 6 (ICMPv6) Parameters](https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml)
//! * Multicast Listener Discovery (MLD) for IPv6 [RFC 2710](https://datatracker.ietf.org/doc/html/rfc2710)
//! * Neighbor Discovery for IP version 6 (IPv6) [RFC 4861](https://datatracker.ietf.org/doc/html/rfc4861)
//! * [LINKTYPE_LINUX_SLL](https://www.tcpdump.org/linktypes/LINKTYPE_LINUX_SLL.html) on tcpdump
//! * LINUX_SLL [header definition](https://github.com/the-tcpdump-group/libpcap/blob/a932566fa1f6df16176ac702b1762ea1cd9ed9a3/pcap/sll.h) on libpcap
//! * [Linux packet types definitions](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/include/uapi/linux/if_packet.h?id=e33c4963bf536900f917fb65a687724d5539bc21) on the Linux kernel
//! * Address Resolution Protocol (ARP) Parameters [Harware Types](https://www.iana.org/assignments/arp-parameters/arp-parameters.xhtml#arp-parameters-2)
//! * [Arp hardware identifiers definitions](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/include/uapi/linux/if_arp.h?id=e33c4963bf536900f917fb65a687724d5539bc21) on the Linux kernel

// # Reason for 'bool_comparison' disable:
//
// Clippy triggers triggers errors like the following if the warning stays enabled:
//
//   warning: equality checks against false can be replaced by a negation
//     --> src/packet_decoder.rs:131:20
//      |
//  131 |                 if false == fragmented {
//      |                    ^^^^^^^^^^^^^^^^^^^ help: try simplifying it as shown: `!fragmented`
//
//
// I prefer to write `false == value` instead of `!value` as it
// is more visually striking and is not as easy to overlook as the single
// character '!'.
#![allow(clippy::bool_comparison)]
// Removes all std and alloc default imports & enables "non std" support.
#![no_std]
// enables https://doc.rust-lang.org/beta/unstable-book/language-features/doc-cfg.html
// for docs.rs
#![cfg_attr(docsrs, feature(doc_cfg))]

#[cfg(test)]
extern crate alloc;
#[cfg(test)]
extern crate proptest;
#[cfg(any(feature = "std", test))]
extern crate std;

/// Module containing error types that can be triggered.
pub mod err;

/// Module containing helpers to re-assemble fragmented packets (contains allocations).
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
pub mod defrag;

mod link;
pub use link::*;

#[cfg(test)]
pub(crate) mod test_gens;

mod net;
pub use net::*;

#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
pub mod io;

mod transport;
pub use transport::*;

/// Helpers for calculating checksums.
pub mod checksum;

#[cfg(test)]
mod compositions_tests;

mod helpers;
pub(crate) use helpers::*;

mod lax_packet_headers;
pub use lax_packet_headers::*;

mod lax_payload_slice;
pub use lax_payload_slice::*;

mod lax_sliced_packet;
pub use lax_sliced_packet::*;

mod lax_sliced_packet_cursor;
pub(crate) use lax_sliced_packet_cursor::*;

mod len_source;
pub use len_source::*;

#[cfg(feature = "std")]
mod packet_builder;
#[cfg(feature = "std")]
pub use crate::packet_builder::*;

mod packet_headers;
pub use crate::packet_headers::*;

mod payload_slice;
pub use crate::payload_slice::*;

mod sliced_packet;
pub use crate::sliced_packet::*;

mod sliced_packet_cursor;
pub(crate) use sliced_packet_cursor::*;

#[cfg(test)]
pub(crate) mod test_packet;

/// Deprecated use [err::ReadError] instead or use the specific error type returned by operation you are using.
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[deprecated(
    since = "0.14.0",
    note = "Please use the type err::ReadError instead or use the specific error type returned by operation you are using."
)]
pub type ReadError = err::ReadError;

/// Deprecated use [err::ReadError] instead or use the specific error type returned by operation you are using.
#[cfg(feature = "std")]
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
#[deprecated(since = "0.14.0", note = "Please use the type err::Field instead.")]
pub type ErrorField = err::ValueType;