multipart.nx

multipart.nx -- parse multipart/form-data bodies (RFC 7578). HTML <form enctype="multipart/form-data"> encodes each field as a separate "part" delimited by a boundary string announced in the Content-Type header: Content-Type: multipart/form-data; boundary=----WebKitFormBoundary Body structure (MIME): --BOUNDARY\r\n Content-Disposition: form-data; name="field1"\r\n \r\n value bytes\r\n --BOUNDARY\r\n Content-Disposition: form-data; name="file"; filename="a.txt"\r\n Content-Type: text/plain\r\n \r\n file bytes\r\n --BOUNDARY--\r\n (closing delimiter) We split the body into parts and surface each part's header block + body byte range. Callers parse the Content-Disposition line with content_type.nx to extract field name + filename. Invariants: MP1 Boundary string (without leading --) comes from the Content-Type parse; caller supplies it here. MP2 Final "--BOUNDARY--" delimiter stops parsing; parts after are ignored. MP3 Parts are surfaced with offsets into the caller's buffer; zero copies. MP4 \r\n between header and body must be present; malformed parts (missing blank line) are skipped.