Struct pcarp::block::EnhancedPacket

pub struct EnhancedPacket<'a> {
    pub interface_id: InterfaceId,
    pub timestamp: u64,
    pub captured_len: u32,
    pub packet_len: u32,
    pub packet_data: Range<usize>,
    pub options: &'a [u8],
}

Contains a single captured packet, or a portion of it. It represents an evolution of the original, now obsolete, Packet Block. If this appears in a file, an Interface Description Block is also required, before this block.

An Enhanced Packet Block (EPB) is the standard container for storing the packets coming from the network. The Enhanced Packet Block is optional because packets can be stored either by means of this block or the Simple Packet Block, which can be used to speed up capture file generation; or a file may have no packets in it.

The Enhanced Packet Block is an improvement over the original, now obsolete, Packet Block:

• it stores the Interface Identifier as a 32-bit integer value. This is a requirement when a capture stores packets coming from a large number of interfaces
• unlike the Packet Block, the number of packets dropped by the capture system between this packet and the previous one is not stored in the header, but rather in an option of the block itself.

This documentation is copyright (c) 2018 IETF Trust and the persons identified as the authors of this document. All rights reserved. Please see the linked document for the full copyright notice.

Fields

interface_id: InterfaceId

Specifies the interface this packet comes from; the correct interface will be the one whose Interface Description Block (within the current Section of the file) is identified by the same number (see Section 4.2) of this field. The interface ID MUST be valid, which means that an matching interface description block MUST exist.

timestamp: u64

Upper 32 bits and lower 32 bits of a 64-bit timestamp. The timestamp is a single 64-bit unsigned integer that represents the number of units of time that have elapsed since 1970-01-01 00:00:00 UTC. The length of a unit of time is specified by the 'if_tsresol' option (see Figure 10) of the Interface Description block referenced by this packet. Note that, unlike timestamps in the libpcap file format, timestamps in Enhanced Packet Blocks are not saved as two 32-bit values that represent the seconds and microseconds that have elapsed since 1970-01-01 00:00:00 UTC. Timestamps in Enhanced Packet Blocks are saved as two 32-bit words that represent the upper and lower 32 bits of a single 64-bit quantity.

captured_len: u32

Number of octets captured from the packet (i.e. the length of the Packet Data field). It will be the minimum value among the Original Packet Length and the snapshot length for the interface (SnapLen, defined in Figure 10). The value of this field does not include the padding octets added at the end of the Packet Data field to align the Packet Data field to a 32-bit boundary.

packet_len: u32

Actual length of the packet when it was transmitted on the network. It can be different from Captured Packet Length if the packet has been truncated by the capture process.

packet_data: Range<usize>

The data coming from the network, including link-layer headers. The actual length of this field is Captured Packet Length plus the padding to a 32-bit boundary. The format of the link-layer headers depends on the LinkType field specified in the Interface Description Block (see Section 4.2) and it is specified in the entry for that format in the the tcpdump.org link-layer header types registry.

options: &'a [u8]

Optionally, a list of options (formatted according to the rules defined in Section 3.5) can be present.

Trait Implementations

impl<'a> Clone for EnhancedPacket<'a>

fn clone(&self) -> EnhancedPacket<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> From<EnhancedPacket<'a>> for Block<'a>

fn from(x: EnhancedPacket<'a>) -> Self

Performs the conversion.

impl<'a> PartialEq<EnhancedPacket<'a>> for EnhancedPacket<'a>

fn eq(&self, other: &EnhancedPacket<'a>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &EnhancedPacket<'a>) -> bool

This method tests for !=.

impl<'a> Debug for EnhancedPacket<'a>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.