[net] Add Ethernet lengths and Header/Address types

rust/kernel/net.rs

@@ -9,6 +9,7 @@
 use crate::{bindings, str::CStr, to_result, ARef, AlwaysRefCounted, Error, Result};
 use core::{cell::UnsafeCell, ptr::NonNull};
 
+pub mod ethernet;
 #[cfg(CONFIG_NETFILTER)]
 pub mod filter;
 

rust/kernel/net/ethernet.rs

@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Ethernet Module
+//!
+//! C headers: [`include/uapi/linux/if_ether.h`](../../../../include/uapi/linux/if_ether.h)
+
+use crate::bindings;
+
+// IEEE 802.3 Ethernet magic constants
+//
+// Taken from the original tree at `include/uapi/linux/if_ether.h`.
+
+/// Octets in one ethernet address
+pub const ALEN: usize = bindings::ETH_ALEN as usize;
+
+/// Octets in ethernet type field
+pub const TLEN: usize = bindings::ETH_TLEN as usize;
+
+/// Total octets in header
+pub const HLEN: usize = bindings::ETH_HLEN as usize;
+
+/// Minimal octet count in frame without the FCS
+pub const ZLEN: usize = bindings::ETH_ZLEN as usize;
+
+/// Maximal octet count in payload
+pub const DATA_LEN: usize = bindings::ETH_DATA_LEN as usize;
+
+/// Maximal octet count in frame without the FCS
+pub const FRAME_LEN: usize = bindings::ETH_FRAME_LEN as usize;
+
+/// Octets in the Frame Check Sum (FCS)
+pub const FCS_LEN: usize = bindings::ETH_FCS_LEN as usize;
+
+/// Minimal MTU
+///
+/// RFC791 fixes it to be at 68 octets for IPv4
+pub const MIN_MTU: usize = bindings::ETH_MIN_MTU as usize;
+
+/// Maximal MTU
+pub const MAX_MTU: usize = bindings::ETH_MAX_MTU as usize;
+
+/// Ethernet Protocol Identifiers
+///
+/// These were taken from the original tree at `include/uapi/linux/if_ether.h`.
+/// Memory-wise, they are represented as machine-endian `u16`. That size is
+/// convenient because it corresponds to the ethertype size in Ethernet II
+/// headers.
+#[derive(Copy, Clone, Debug)]
+#[repr(u16)]
+pub enum Proto {
+    /// Ethernet loopback protocol
+    Loop = bindings::ETH_P_LOOP as u16,
+    /// Xerox PUP Packet
+    Pup = bindings::ETH_P_PUP as u16,
+    /// Xexor PUP Address Transfer packet
+    PupAddrTrans = bindings::ETH_P_PUPAT as u16,
+    /// TSN (IEEE 1722) packet
+    Tsn = bindings::ETH_P_TSN as u16,
+    /// ERSPAN version 2 (type III)
+    Erspan2 = bindings::ETH_P_ERSPAN2 as u16,
+    /// Internet Protocol v4 packet
+    Ip = bindings::ETH_P_IP as u16,
+    /// CCITT X.25
+    X25 = bindings::ETH_P_X25 as u16,
+    /// Address resolution protocol
+    Arp = bindings::ETH_P_ARP as u16,
+    /// G8BPQ AX.25 Ethernet Packet *[ NOT AN OFFICIALLY REGISTERED ID ]*
+    Bpq = bindings::ETH_P_BPQ as u16,
+    /// Xerox IEEE802.3 PUP packet
+    IeeePup = bindings::ETH_P_IEEEPUP as u16,
+    /// Xerox IEEE802.3 PUP Address Transfer packet
+    IeeePupAddrTrans = bindings::ETH_P_IEEEPUPAT as u16,
+    /// B.A.T.M.A.N. - advanced packet *[ NOT AN OFFICIALLY REGISTERED ID ]*
+    Batman = bindings::ETH_P_BATMAN as u16,
+
+    /// DEC Assigned Protocol
+    Dec = bindings::ETH_P_DEC as u16,
+    /// DEC DNA Dump/Load
+    DNADumpLoad = bindings::ETH_P_DNA_DL as u16,
+    /// DEC DNA Remote Control
+    DNARemoteControl = bindings::ETH_P_DNA_RC as u16,
+    /// DEC DNA Routing
+    DNARouting = bindings::ETH_P_DNA_RT as u16,
+    /// DEC LAT
+    Lat = bindings::ETH_P_LAT as u16,
+    /// DEC Diagnostics
+    Diag = bindings::ETH_P_DIAG as u16,
+    /// DEC Customer Use
+    Cust = bindings::ETH_P_CUST as u16,
+    /// DEC Systems Comms Arch
+    Sca = bindings::ETH_P_SCA as u16,
+
+    /// Trans Ethernet Bridging
+    Teb = bindings::ETH_P_TEB as u16,
+    /// Reverse Address Resolution Packet
+    Rarp = bindings::ETH_P_RARP as u16,
+
+    /// Appletalk DDP
+    ATalk = bindings::ETH_P_ATALK as u16,
+    /// Appletakl AARP
+    AArp = bindings::ETH_P_AARP as u16,
+
+    /// 802.1Q VLAN Extended Header
+    IEEE8021Q = bindings::ETH_P_8021Q as u16,
+    /// ERSPAN Type II
+    Erspan = bindings::ETH_P_ERSPAN as u16,
+    /// IPX over IDX
+    Ipx = bindings::ETH_P_IPX as u16,
+    /// Internet Protocol v6
+    IpV6 = bindings::ETH_P_IPV6 as u16,
+
+    /// IEEE Pause frames. See 802.3 31B
+    Pause = bindings::ETH_P_PAUSE as u16,
+    /// Slow protocol, see 802.3ad 43B
+    Slow = bindings::ETH_P_SLOW as u16,
+
+    /// Web Cache Coordination Protocol
+    /// Defined in draft-wilson-wrec-wccp-v2-00.txt
+    Wccp = bindings::ETH_P_WCCP as u16,
+
+    /// MPLS Unicast Traffic
+    MplsUnicast = bindings::ETH_P_MPLS_UC as u16,
+    /// MPLS Multicast Traffic
+    MplsMulticast = bindings::ETH_P_MPLS_MC as u16,
+
+    /// Multi-Protocol over ATM
+    AtmMpOa = bindings::ETH_P_ATMMPOA as u16,
+
+    /// PPPoE Discovery Message
+    PppDisc = bindings::ETH_P_PPP_DISC as u16,
+    /// PPPoE Session Messages
+    PppSes = bindings::ETH_P_PPP_SES as u16,
+
+    /// HPNA, wlan link-local tunnel
+    LinkCtl = bindings::ETH_P_LINK_CTL as u16,
+    /// Frame-based ATM Transport over Ethernet
+    AtmFate = bindings::ETH_P_ATMFATE as u16,
+    /// Port Access Entity (IEEE 802.1X)
+    Pae = bindings::ETH_P_PAE as u16,
+    /// PROFINET
+    Profinet = bindings::ETH_P_PROFINET as u16,
+    /// Multiple Proprietary Protocols
+    Realtek = bindings::ETH_P_REALTEK as u16,
+    /// ATA Over Ethernet
+    Aoe = bindings::ETH_P_AOE as u16,
+    /// EtherCat
+    EtherCat = bindings::ETH_P_ETHERCAT as u16,
+    /// 802.1ad Service VLAN
+    _8021ad = bindings::ETH_P_8021AD as u16,
+    /// 802.1 Local Experimental 1
+    _802Ex1 = bindings::ETH_P_802_EX1 as u16,
+    /// 802.11 Pre Authentication
+    PreAuth = bindings::ETH_P_PREAUTH as u16,
+    /// TIPC
+    Tipc = bindings::ETH_P_TIPC as u16,
+    /// Link Layer Discovery Protocol (LLDP)
+    Lldp = bindings::ETH_P_LLDP as u16,
+    /// Media Redundancy Protocol
+    Mrp = bindings::ETH_P_MRP as u16,
+    /// 802.1ae MACSec
+    MacSec = bindings::ETH_P_MACSEC as u16,
+    /// 802.1ah Backbone Service Tag
+    _8021ah = bindings::ETH_P_8021AH as u16,
+    /// 802.1Q Multiple Vlan Registration Protocol
+    Mvrp = bindings::ETH_P_MVRP as u16,
+    /// IEEE 1588 Timesync
+    _1588 = bindings::ETH_P_1588 as u16,
+    /// NCSI Protocol
+    Ncsi = bindings::ETH_P_NCSI as u16,
+    /// IEC 62439-3 PRP/HSRv0
+    Prp = bindings::ETH_P_PRP as u16,
+    /// Connectivity Fault Management
+    Cfm = bindings::ETH_P_CFM as u16,
+    /// Fiber Channel over Ethernet
+    FcoE = bindings::ETH_P_FCOE as u16,
+    /// InfiniBand over Ethernet
+    IboE = bindings::ETH_P_IBOE as u16,
+    /// TDLS
+    Tdls = bindings::ETH_P_TDLS as u16,
+    /// FCoE Initialization protocol
+    Fip = bindings::ETH_P_FIP as u16,
+    /// 802.21 Media Independant Handover Protocol
+    _80221 = bindings::ETH_P_80221 as u16,
+    /// IEC 62439-3 HSRv1
+    Hsr = bindings::ETH_P_HSR as u16,
+    /// Network Service Header
+    Nsh = bindings::ETH_P_NSH as u16,
+    /// Ethernet Loopback Packet (per IEEE 802.3)
+    Loopback = bindings::ETH_P_LOOPBACK as u16,
+
+    /// Deprecated QinQ VLAN 1 [ NOT AN OFFICIALLY REGISTERED ID ]
+    QinQ1 = bindings::ETH_P_QINQ1 as u16,
+    /// Deprecated QinQ VLAN 2 [ NOT AN OFFICIALLY REGISTERED ID ]
+    QinQ2 = bindings::ETH_P_QINQ2 as u16,
+    /// Deprecated QinQ VLAN 3 [ NOT AN OFFICIALLY REGISTERED ID ]
+    QinQ3 = bindings::ETH_P_QINQ3 as u16,
+
+    /// Ethertype DSA [ NOT AN OFFICIALLY REGISTERED ID ]
+    Edsa = bindings::ETH_P_EDSA as u16,
+    /// Fake VLAN Header Tag for DSA [ NOT AN OFFICIALLY REGISTERED ID ]
+    Dsa8021Q = bindings::ETH_P_DSA_8021Q as u16,
+    /// A5PSW Tag Value [ NOT AN OFFICIALLY REGISTERED ID ]
+    DsaA5Psw = bindings::ETH_P_DSA_A5PSW as u16,
+    /// ForCES inter-FE LFB type
+    Ife = bindings::ETH_P_IFE as u16,
+    /// IBM af_iucv [ NOT AN OFFICIALLY REGISTERED ID ]
+    AfIucv = bindings::ETH_P_AF_IUCV as u16,
+    /// Minimal Ethernet II protocol value
+    /// Any protocol value below that is 802.3
+    Min8023 = bindings::ETH_P_802_3_MIN as u16,
+
+    // Starting here it's just non DIX types.
+    // They won't clash for 1500 types.
+    /// Dummy type for 802.3 frames
+    _8023 = bindings::ETH_P_802_3 as u16,
+    /// Dummy protocol id for AX25
+    Ax25 = bindings::ETH_P_AX25 as u16,
+    /// Every packet (be careful!)
+    All = bindings::ETH_P_ALL as u16,
+    /// 802.2 frames
+    _8022 = bindings::ETH_P_802_2 as u16,
+    /// Internal only
+    Snap = bindings::ETH_P_SNAP as u16,
+    /// DEC DDCMP: Internal Only
+    DDcmp = bindings::ETH_P_DDCMP as u16,
+    /// Dummy type for WAN PPP frames
+    WanPpp = bindings::ETH_P_WAN_PPP as u16,
+    /// Dummy type for PPP MP frames
+    PppMp = bindings::ETH_P_PPP_MP as u16,
+    /// Localtalk pseudo type
+    LocalTalk = bindings::ETH_P_LOCALTALK as u16,
+    /// CAN: Controlled Area Network
+    Can = bindings::ETH_P_CAN as u16,
+    /// CANFD: CAN Flexible Data Rate
+    CanFd = bindings::ETH_P_CANFD as u16,
+    /// CANXL: CAN eXtended Frame Length
+    CanXl = bindings::ETH_P_CANXL as u16,
+    /// Dummy type for Atalk over PPP
+    PppTalk = bindings::ETH_P_PPPTALK as u16,
+    /// 802.2 frames
+    Tr8022 = bindings::ETH_P_TR_802_2 as u16,
+    /// Mobitex (kaz@cafe.net)
+    Mobitex = bindings::ETH_P_MOBITEX as u16,
+    /// Card specific control frames
+    Control = bindings::ETH_P_CONTROL as u16,
+    /// Linux IrDA
+    Irda = bindings::ETH_P_IRDA as u16,
+    /// Acorn Econet
+    Econet = bindings::ETH_P_ECONET as u16,
+    /// HDLC frames
+    Hdlc = bindings::ETH_P_HDLC as u16,
+    /// 1A for ArcNet :-)
+    ArcNet = bindings::ETH_P_ARCNET as u16,
+    /// Distributed Switch Arch.
+    Dsa = bindings::ETH_P_DSA as u16,
+    /// Trailer Switch Tagging as u16,
+    Trailer = bindings::ETH_P_TRAILER as u16,
+    /// Nokia Phonet frames
+    Phonet = bindings::ETH_P_PHONET as u16,
+    /// IEEE802.15.4 frame
+    IEEE802154 = bindings::ETH_P_IEEE802154 as u16,
+    /// ST-Ericsson CAIF protocol
+    Caif = bindings::ETH_P_CAIF as u16,
+    /// Multiplexed DSA protocol
+    XDsa = bindings::ETH_P_XDSA as u16,
+    /// Qalcomm Multiplexing and Aggregation Protocol (MAP)
+    Map = bindings::ETH_P_MAP as u16,
+    /// Management Component Transport Protocol packets
+    Mctp = bindings::ETH_P_MCTP as u16,
+}
+
+impl From<Proto> for u16 {
+    fn from(p: Proto) -> u16 {
+        p as u16
+    }
+}
+
+/// Unknown Ethernet Protocol Number Error
+#[derive(Clone, Copy, Debug)]
+pub struct UnknownProtoError(u16);
+
+impl TryFrom<u16> for Proto {
+    type Error = UnknownProtoError;
+    fn try_from(u: u16) -> core::result::Result<Self, Self::Error> {
+        match u32::from(u) {
+            bindings::ETH_P_LOOP => Ok(Self::Loop),
+            bindings::ETH_P_PUP => Ok(Self::Pup),
+            bindings::ETH_P_PUPAT => Ok(Self::PupAddrTrans),
+            bindings::ETH_P_TSN => Ok(Self::Tsn),
+            bindings::ETH_P_ERSPAN2 => Ok(Self::Erspan2),
+            bindings::ETH_P_IP => Ok(Self::Ip),
+            bindings::ETH_P_X25 => Ok(Self::X25),
+            bindings::ETH_P_ARP => Ok(Self::Arp),
+            bindings::ETH_P_BPQ => Ok(Self::Bpq),
+            bindings::ETH_P_IEEEPUP => Ok(Self::IeeePup),
+            bindings::ETH_P_IEEEPUPAT => Ok(Self::IeeePupAddrTrans),
+            bindings::ETH_P_BATMAN => Ok(Self::Batman),
+            bindings::ETH_P_DEC => Ok(Self::Dec),
+            bindings::ETH_P_DNA_DL => Ok(Self::DNADumpLoad),
+            bindings::ETH_P_DNA_RC => Ok(Self::DNARemoteControl),
+            bindings::ETH_P_DNA_RT => Ok(Self::DNARouting),
+            bindings::ETH_P_LAT => Ok(Self::Lat),
+            bindings::ETH_P_DIAG => Ok(Self::Diag),
+            bindings::ETH_P_CUST => Ok(Self::Cust),
+            bindings::ETH_P_SCA => Ok(Self::Sca),
+            bindings::ETH_P_TEB => Ok(Self::Teb),
+            bindings::ETH_P_RARP => Ok(Self::Rarp),
+            bindings::ETH_P_ATALK => Ok(Self::ATalk),
+            bindings::ETH_P_AARP => Ok(Self::AArp),
+            bindings::ETH_P_8021Q => Ok(Self::IEEE8021Q),
+            bindings::ETH_P_ERSPAN => Ok(Self::Erspan),
+            bindings::ETH_P_IPX => Ok(Self::Ipx),
+            bindings::ETH_P_IPV6 => Ok(Self::IpV6),
+            bindings::ETH_P_PAUSE => Ok(Self::Pause),
+            bindings::ETH_P_SLOW => Ok(Self::Slow),
+            bindings::ETH_P_WCCP => Ok(Self::Wccp),
+            bindings::ETH_P_MPLS_UC => Ok(Self::MplsUnicast),
+            bindings::ETH_P_MPLS_MC => Ok(Self::MplsMulticast),
+            bindings::ETH_P_ATMMPOA => Ok(Self::AtmMpOa),
+            bindings::ETH_P_PPP_DISC => Ok(Self::PppDisc),
+            bindings::ETH_P_PPP_SES => Ok(Self::PppSes),
+            bindings::ETH_P_LINK_CTL => Ok(Self::LinkCtl),
+            bindings::ETH_P_ATMFATE => Ok(Self::AtmFate),
+            bindings::ETH_P_PAE => Ok(Self::Pae),
+            bindings::ETH_P_PROFINET => Ok(Self::Profinet),
+            bindings::ETH_P_REALTEK => Ok(Self::Realtek),
+            bindings::ETH_P_AOE => Ok(Self::Aoe),
+            bindings::ETH_P_ETHERCAT => Ok(Self::EtherCat),
+            bindings::ETH_P_8021AD => Ok(Self::_8021ad),
+            bindings::ETH_P_802_EX1 => Ok(Self::_802Ex1),
+            bindings::ETH_P_PREAUTH => Ok(Self::PreAuth),
+            bindings::ETH_P_TIPC => Ok(Self::Tipc),
+            bindings::ETH_P_LLDP => Ok(Self::Lldp),
+            bindings::ETH_P_MRP => Ok(Self::Mrp),
+            bindings::ETH_P_MACSEC => Ok(Self::MacSec),
+            bindings::ETH_P_8021AH => Ok(Self::_8021ah),
+            bindings::ETH_P_MVRP => Ok(Self::Mvrp),
+            bindings::ETH_P_1588 => Ok(Self::_1588),
+            bindings::ETH_P_NCSI => Ok(Self::Ncsi),
+            bindings::ETH_P_PRP => Ok(Self::Prp),
+            bindings::ETH_P_CFM => Ok(Self::Cfm),
+            bindings::ETH_P_FCOE => Ok(Self::FcoE),
+            bindings::ETH_P_IBOE => Ok(Self::IboE),
+            bindings::ETH_P_TDLS => Ok(Self::Tdls),
+            bindings::ETH_P_FIP => Ok(Self::Fip),
+            bindings::ETH_P_80221 => Ok(Self::_80221),
+            bindings::ETH_P_HSR => Ok(Self::Hsr),
+            bindings::ETH_P_NSH => Ok(Self::Nsh),
+            bindings::ETH_P_LOOPBACK => Ok(Self::Loopback),
+            bindings::ETH_P_QINQ1 => Ok(Self::QinQ1),
+            bindings::ETH_P_QINQ2 => Ok(Self::QinQ2),
+            bindings::ETH_P_QINQ3 => Ok(Self::QinQ3),
+            bindings::ETH_P_EDSA => Ok(Self::Edsa),
+            bindings::ETH_P_DSA_8021Q => Ok(Self::Dsa8021Q),
+            bindings::ETH_P_DSA_A5PSW => Ok(Self::DsaA5Psw),
+            bindings::ETH_P_IFE => Ok(Self::Ife),
+            bindings::ETH_P_AF_IUCV => Ok(Self::AfIucv),
+            bindings::ETH_P_802_3_MIN => Ok(Self::Min8023),
+            bindings::ETH_P_802_3 => Ok(Self::_8023),
+            bindings::ETH_P_AX25 => Ok(Self::Ax25),
+            bindings::ETH_P_ALL => Ok(Self::All),
+            bindings::ETH_P_802_2 => Ok(Self::_8022),
+            bindings::ETH_P_SNAP => Ok(Self::Snap),
+            bindings::ETH_P_DDCMP => Ok(Self::DDcmp),
+            bindings::ETH_P_WAN_PPP => Ok(Self::WanPpp),
+            bindings::ETH_P_PPP_MP => Ok(Self::PppMp),
+            bindings::ETH_P_LOCALTALK => Ok(Self::LocalTalk),
+            bindings::ETH_P_CAN => Ok(Self::Can),
+            bindings::ETH_P_CANFD => Ok(Self::CanFd),
+            bindings::ETH_P_CANXL => Ok(Self::CanXl),
+            bindings::ETH_P_PPPTALK => Ok(Self::PppTalk),
+            bindings::ETH_P_TR_802_2 => Ok(Self::Tr8022),
+            bindings::ETH_P_MOBITEX => Ok(Self::Mobitex),
+            bindings::ETH_P_CONTROL => Ok(Self::Control),
+            bindings::ETH_P_IRDA => Ok(Self::Irda),
+            bindings::ETH_P_ECONET => Ok(Self::Econet),
+            bindings::ETH_P_HDLC => Ok(Self::Hdlc),
+            bindings::ETH_P_ARCNET => Ok(Self::ArcNet),
+            bindings::ETH_P_DSA => Ok(Self::Dsa),
+            bindings::ETH_P_TRAILER => Ok(Self::Trailer),
+            bindings::ETH_P_PHONET => Ok(Self::Phonet),
+            bindings::ETH_P_IEEE802154 => Ok(Self::IEEE802154),
+            bindings::ETH_P_CAIF => Ok(Self::Caif),
+            bindings::ETH_P_XDSA => Ok(Self::XDsa),
+            bindings::ETH_P_MAP => Ok(Self::Map),
+            bindings::ETH_P_MCTP => Ok(Self::Mctp),
+            _ => Err(UnknownProtoError(u)),
+        }
+    }
+}
+
+/// Ethernet Address Type
+#[repr(transparent)]
+pub struct Address(pub [u8; ALEN]);
+
+impl Address {
+    /// Return the unspecified Ethernet address
+    pub const fn unspecified() -> Self {
+        Self([0x00; ALEN])
+    }
+
+    /// Return the broadcast Ethernet address
+    pub const fn broadcast() -> Self {
+        Self([0xff; ALEN])
+    }
+}
+
+/// Ethernet II protocol header
+#[repr(transparent)]
+pub struct Header(bindings::ethhdr);
+
+impl Header {
+    /// Build a new Ethernet header from all necessary information
+    ///
+    /// This method automatically handles conversion of the ethertype provided
+    /// into a network-endian u16.
+    pub fn new(dst: Address, src: Address, proto: Proto) -> Self {
+        Self(bindings::ethhdr {
+            h_dest: dst.0,
+            h_source: src.0,
+            h_proto: u16::to_be(u16::from(proto)),
+        })
+    }
+
+    /// Return the source address contained in the header
+    pub fn src_hwaddr(&self) -> Address {
+        Address(self.0.h_source)
+    }
+
+    /// Return the destination address contained in the header
+    pub fn dst_hwaddr(&self) -> Address {
+        Address(self.0.h_dest)
+    }
+
+    /// Return the protocol number contained in the header
+    ///
+    /// This method does not handle conversion from network endian.
+    pub fn proto_number(&self) -> u16 {
+        self.0.h_proto
+    }
+}