Struct Decoder 

pub struct Decoder { /* private fields */ }

BER decoder that reads from a byte buffer.

Implementations

impl Decoder

pub fn new(data: Bytes) -> Self

Create a new decoder from bytes.

pub fn with_target(data: Bytes, target: SocketAddr) -> Self

Create a decoder from bytes with a target address for error context.

pub fn from_slice(data: &[u8]) -> Self

Create a decoder from a byte slice (copies the data).

pub fn offset(&self) -> usize

Get the current offset.

pub fn remaining(&self) -> usize

Get remaining bytes.

pub fn is_empty(&self) -> bool

Check if we’ve reached the end.

pub fn peek_byte(&self) -> Option<u8>

Peek at the next byte without consuming it.

pub fn peek_tag(&self) -> Option<u8>

Peek at the next tag without consuming it.

Returns None if the buffer is empty or if the next byte signals a multi-byte tag (low five bits all set, i.e. byte & 0x1F == 0x1F). Valid SNMP uses only single-byte tags (all defined tags are below 31).

pub fn read_byte(&mut self) -> Result<u8>

Read a single byte.

pub fn read_tag(&mut self) -> Result<u8>

Read a tag byte.

Returns an error if the tag byte signals a multi-byte tag (low five bits all set, i.e. byte & 0x1F == 0x1F). Valid SNMP uses only single-byte tags (all defined tags are below 31).

pub fn read_length(&mut self) -> Result<usize>

Read a length and return (length, bytes consumed).

pub fn read_bytes(&mut self, len: usize) -> Result<Bytes>

Read raw bytes without copying.

pub fn expect_tag(&mut self, expected: u8) -> Result<usize>

Read and expect a specific tag, returning the content length.

pub fn read_integer(&mut self) -> Result<i32>

Read a BER integer (signed).

pub fn read_integer_value(&mut self, len: usize) -> Result<i32>

Read integer value given the length.

pub fn read_integer64(&mut self, expected_tag: u8) -> Result<u64>

Read a 64-bit unsigned integer (Counter64).

pub fn read_integer64_value(&mut self, len: usize) -> Result<u64>

Read 64-bit unsigned integer value given the length.

pub fn read_unsigned32(&mut self, expected_tag: u8) -> Result<u32>

Read an unsigned 32-bit integer with specific tag.

pub fn read_unsigned32_value(&mut self, len: usize) -> Result<u32>

Read unsigned 32-bit integer value given length.

pub fn read_octet_string(&mut self) -> Result<Bytes>

Read an OCTET STRING.

pub fn read_null(&mut self) -> Result<()>

Read a NULL.

pub fn read_oid(&mut self) -> Result<Oid>

Read an OBJECT IDENTIFIER.

pub fn read_oid_value(&mut self, len: usize) -> Result<Oid>

Read an OID given a pre-read length.

pub fn read_sequence(&mut self) -> Result<Decoder>

Read a SEQUENCE, returning a decoder for its contents.

pub fn read_constructed(&mut self, expected_tag: u8) -> Result<Decoder>

Read a constructed type with a specific tag, returning a decoder for its contents.

pub fn read_ip_address(&mut self) -> Result<[u8; 4]>

Read an IP address.

pub fn skip_tlv(&mut self) -> Result<()>

Skip a TLV (tag-length-value) without parsing.

pub fn sub_decoder(&mut self, len: usize) -> Result<Decoder>

Create a sub-decoder for a portion of the remaining data.

pub fn as_bytes(&self) -> &Bytes

Get the underlying bytes for the entire buffer.

pub fn remaining_slice(&self) -> &[u8]

Get remaining data as a slice.