frameassembly 1.5.1

A DSL for creating custom .pcap/.pcapng captures and decompiling captures to .fasm for testing firewalls, IDS rules, SNMP traps, and pentesting.
Documentation 
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//! File Transfer Protocol (FTP) Layer 7 control channel field parser.
//!
//! This module implements the `winnow` parser combinator for RFC 959 `FTP` control connection
//! commands and replies in FrameAssembly `.fasm` specifications. It recognizes the `FTP` protocol
//! keyword, client command verbs (`CMD`, e.g., `"USER"`, `"PASS"`, `"RETR"`, `"PASV"`), command
//! arguments (`ARG`), 3-digit server status codes (`CODE`), and human-readable server reply text
//! (`REPLY`).

use winnow::ModalResult as PResult;
use winnow::combinator::{alt, cut_err};
use winnow::prelude::*;

use crate::ast::*;
use crate::lexer::Token;
use crate::parser::{parse_any_str, parse_str_val, parse_u32, tag, ParsedField, Stream};

/// Parses an FTP protocol declaration or command/reply field.
pub(crate) fn parse_ftp_field<'i, 'a>(input: &mut Stream<'i, 'a>) -> PResult<ParsedField<'a>> {
    alt((
        tag(Token::Ftp).map(|(_, s)| ParsedField::Protocol(Protocol::Ftp, (s.start, s.len()))),
        (tag(Token::Cmd), cut_err(parse_any_str))
            .map(|((_, s), v)| ParsedField::L7StringField("CMD", v, (s.start, s.end - s.start))),
        (tag(Token::Arg), cut_err(parse_str_val))
            .map(|((_, s), v)| ParsedField::L7StringField("ARG", v, (s.start, s.end - s.start))),
        (tag(Token::Code), parse_u32)
            .map(|((_, s), v)| ParsedField::L7U32Field("CODE", v, (s.start, s.end - s.start))),
        (tag(Token::Reply), parse_str_val)
            .map(|((_, s), v)| ParsedField::L7StringField("REPLY", v, (s.start, s.end - s.start))),
    ))
    .parse_next(input)
}