smoltcp/src/wire/mod.rs

/*! Low-level packet access and construction.

The `wire` module deals with the packet *representation*. It provides two levels
of functionality.

 * First, it provides functions to extract fields from sequences of octets,
   and to insert fields into sequences of octets. This happens `Packet` family of
   structures, e.g. [EthernetFrame] or [Ipv4Packet].
 * Second, in cases where the space of valid field values is much smaller than the space
   of possible field values, it provides a compact, high-level representation
   of packet data that can be parsed from and emitted into a sequence of octets.
   This happens through the `Repr` family of structs and enums, e.g. [ArpRepr] or [Ipv4Repr].

[EthernetFrame]: struct.EthernetFrame.html
[Ipv4Packet]: struct.Ipv4Packet.html
[ArpRepr]: enum.ArpRepr.html
[Ipv4Repr]: struct.Ipv4Repr.html

The functions in the `wire` module are designed for use together with `-Cpanic=abort`.

The `Packet` family of data structures guarantees that, if the `Packet::check_len()` method
returned `Ok(())`, then no accessor or setter method will panic; however, the guarantee
provided by `Packet::check_len()` may no longer hold after changing certain fields,
which are listed in the documentation for the specific packet.

The `Packet::new_checked` method is a shorthand for a combination of `Packet::new_unchecked`
and `Packet::check_len`.
When parsing untrusted input, it is *necessary* to use `Packet::new_checked()`;
so long as the buffer is not modified, no accessor will fail.
When emitting output, though, it is *incorrect* to use `Packet::new_checked()`;
the length check is likely to succeed on a zeroed buffer, but fail on a buffer
filled with data from a previous packet, such as when reusing buffers, resulting
in nondeterministic panics with some network devices but not others.
The buffer length for emission is not calculated by the `Packet` layer.

In the `Repr` family of data structures, the `Repr::parse()` method never panics
as long as `Packet::new_checked()` (or `Packet::check_len()`) has succeeded, and
the `Repr::emit()` method never panics as long as the underlying buffer is exactly
`Repr::buffer_len()` octets long.

# Examples

To emit an IP packet header into an octet buffer, and then parse it back:

```rust
# #[cfg(feature = "proto-ipv4")]
# {
use smoltcp::phy::ChecksumCapabilities;
use smoltcp::wire::*;
let repr = Ipv4Repr {
    src_addr:    Ipv4Address::new(10, 0, 0, 1),
    dst_addr:    Ipv4Address::new(10, 0, 0, 2),
    protocol:    IpProtocol::Tcp,
    payload_len: 10,
    hop_limit:   64
};
let mut buffer = vec![0; repr.buffer_len() + repr.payload_len];
{ // emission
    let mut packet = Ipv4Packet::new_unchecked(&mut buffer);
    repr.emit(&mut packet, &ChecksumCapabilities::default());
}
{ // parsing
    let packet = Ipv4Packet::new_checked(&buffer)
                            .expect("truncated packet");
    let parsed = Ipv4Repr::parse(&packet, &ChecksumCapabilities::default())
                          .expect("malformed packet");
    assert_eq!(repr, parsed);
}
# }
```
*/

mod field {
    pub type Field = ::core::ops::Range<usize>;
    pub type Rest = ::core::ops::RangeFrom<usize>;
}

pub mod pretty_print;

#[cfg(all(feature = "proto-ipv4", feature = "medium-ethernet"))]
mod arp;
#[cfg(feature = "proto-dhcpv4")]
pub(crate) mod dhcpv4;
#[cfg(feature = "medium-ethernet")]
mod ethernet;
#[cfg(any(feature = "proto-ipv4", feature = "proto-ipv6"))]
mod icmp;
#[cfg(feature = "proto-ipv4")]
mod icmpv4;
#[cfg(feature = "proto-ipv6")]
mod icmpv6;
#[cfg(feature = "proto-igmp")]
mod igmp;
pub(crate) mod ip;
#[cfg(feature = "proto-ipv4")]
mod ipv4;
#[cfg(feature = "proto-ipv6")]
mod ipv6;
#[cfg(feature = "proto-ipv6")]
mod ipv6fragment;
#[cfg(feature = "proto-ipv6")]
mod ipv6hopbyhop;
#[cfg(feature = "proto-ipv6")]
mod ipv6option;
#[cfg(feature = "proto-ipv6")]
mod ipv6routing;
#[cfg(feature = "proto-ipv6")]
mod mld;
#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
mod ndisc;
#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
mod ndiscoption;
mod tcp;
mod udp;

pub use self::pretty_print::PrettyPrinter;

#[cfg(feature = "medium-ethernet")]
pub use self::ethernet::{
    Address as EthernetAddress, EtherType as EthernetProtocol, Frame as EthernetFrame,
    Repr as EthernetRepr, HEADER_LEN as ETHERNET_HEADER_LEN,
};

#[cfg(all(feature = "proto-ipv4", feature = "medium-ethernet"))]
pub use self::arp::{
    Hardware as ArpHardware, Operation as ArpOperation, Packet as ArpPacket, Repr as ArpRepr,
};

pub use self::ip::{
    Address as IpAddress, Cidr as IpCidr, Endpoint as IpEndpoint, Protocol as IpProtocol,
    Repr as IpRepr, Version as IpVersion,
};

#[cfg(feature = "proto-ipv4")]
pub use self::ipv4::{
    Address as Ipv4Address, Cidr as Ipv4Cidr, Packet as Ipv4Packet, Repr as Ipv4Repr,
    HEADER_LEN as IPV4_HEADER_LEN, MIN_MTU as IPV4_MIN_MTU,
};

#[cfg(feature = "proto-ipv6")]
pub use self::ipv6::{
    Address as Ipv6Address, Cidr as Ipv6Cidr, Packet as Ipv6Packet, Repr as Ipv6Repr,
    HEADER_LEN as IPV6_HEADER_LEN, MIN_MTU as IPV6_MIN_MTU,
};

#[cfg(feature = "proto-ipv6")]
pub use self::ipv6option::{
    FailureType as Ipv6OptionFailureType, Ipv6Option, Repr as Ipv6OptionRepr,
    Type as Ipv6OptionType,
};

#[cfg(feature = "proto-ipv6")]
pub use self::ipv6hopbyhop::{Header as Ipv6HopByHopHeader, Repr as Ipv6HopByHopRepr};

#[cfg(feature = "proto-ipv6")]
pub use self::ipv6fragment::{Header as Ipv6FragmentHeader, Repr as Ipv6FragmentRepr};

#[cfg(feature = "proto-ipv6")]
pub use self::ipv6routing::{Header as Ipv6RoutingHeader, Repr as Ipv6RoutingRepr};

#[cfg(feature = "proto-ipv4")]
pub use self::icmpv4::{
    DstUnreachable as Icmpv4DstUnreachable, Message as Icmpv4Message, Packet as Icmpv4Packet,
    ParamProblem as Icmpv4ParamProblem, Redirect as Icmpv4Redirect, Repr as Icmpv4Repr,
    TimeExceeded as Icmpv4TimeExceeded,
};

#[cfg(feature = "proto-igmp")]
pub use self::igmp::{IgmpVersion, Packet as IgmpPacket, Repr as IgmpRepr};

#[cfg(feature = "proto-ipv6")]
pub use self::icmpv6::{
    DstUnreachable as Icmpv6DstUnreachable, Message as Icmpv6Message, Packet as Icmpv6Packet,
    ParamProblem as Icmpv6ParamProblem, Repr as Icmpv6Repr, TimeExceeded as Icmpv6TimeExceeded,
};

#[cfg(any(feature = "proto-ipv4", feature = "proto-ipv6"))]
pub use self::icmp::Repr as IcmpRepr;

#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
pub use self::ndisc::{
    NeighborFlags as NdiscNeighborFlags, Repr as NdiscRepr, RouterFlags as NdiscRouterFlags,
};

#[cfg(all(feature = "proto-ipv6", feature = "medium-ethernet"))]
pub use self::ndiscoption::{
    NdiscOption, PrefixInfoFlags as NdiscPrefixInfoFlags,
    PrefixInformation as NdiscPrefixInformation, RedirectedHeader as NdiscRedirectedHeader,
    Repr as NdiscOptionRepr, Type as NdiscOptionType,
};

#[cfg(feature = "proto-ipv6")]
pub use self::mld::{AddressRecord as MldAddressRecord, Repr as MldRepr};

pub use self::udp::{Packet as UdpPacket, Repr as UdpRepr, HEADER_LEN as UDP_HEADER_LEN};

pub use self::tcp::{
    Control as TcpControl, Packet as TcpPacket, Repr as TcpRepr, SeqNumber as TcpSeqNumber,
    TcpOption, HEADER_LEN as TCP_HEADER_LEN,
};

#[cfg(feature = "proto-dhcpv4")]
pub use self::dhcpv4::{
    MessageType as DhcpMessageType, Packet as DhcpPacket, Repr as DhcpRepr,
    CLIENT_PORT as DHCP_CLIENT_PORT, MAX_DNS_SERVER_COUNT as DHCP_MAX_DNS_SERVER_COUNT,
    SERVER_PORT as DHCP_SERVER_PORT,
};