Files
CoreUtils/IMFHeader.cpp
T
Brad ArantandClaude Sonnet 5 bf6810b781 Rebuild CGIFormData on Parser/StreamReader, fix a 2-byte-lookahead bug
CGIFormData now inherits Parser instead of MString and parses a CGI
request body (urlencoded or multipart/form-data) resumably against the
shared StreamReader, exposing the result via operator[] - matching every
other Parser in this redesign. multipart/form-data reuses IMFBoundary and
IMFHeader via checkParse() (chained through the same StreamReader) for
each part's boundary line and header block; urlencoded bodies wait for
the full Content-Length before delegating to the existing
CGIFormattedData parser. File-upload parts (Content-Disposition with a
filename= parameter) are recognized and skipped, matching this
codebase's convention that uploads get a separate mechanism.

Values are stored under an indexed "name:N" key (N = 0-based occurrence
count for that name), matching the :N-suffix convention JetCore's
Tag::getVariable already applies to its $[:name] CGI variable syntax
(defaulting to :0) - this also naturally supports repeated field names
(checkboxes, multi-select). operator[] applies the same :0 default so a
bare name still works when called directly, not just through that
convention layer.

Two real resumability bugs found and fixed via a byte-at-a-time test
(feeding one byte per StreamReader::feed() call, the harshest possible
fragmentation):
- CGIFormData's opening boundary marker ("--boundary", no leading CRLF
  per RFC 2046 for the first boundary) crammed "find+consume the marker"
  and "disambiguate -- vs CRLF" into one state; when the disambiguation
  needed more data, INCOMPLETE was returned without recording that the
  marker was already consumed, so retrying re-searched for it past where
  it had already been consumed, silently skipping content forever. Split
  into two states (INIT / OPENING_TAIL), the same fix already applied
  once to IMFBoundary's PREFIX/TAIL split.
- IMFHeader's FIELD state checked eod() (a 1-byte availability check)
  immediately before an ifNext("\r\n") call that needs 2 bytes - a lone
  trailing \r with no \n yet available was wrongly treated as malformed
  instead of "wait for more data". Fixed to check getLength() < 2.

Verified via a dedicated test (64 assertions total across this and the
earlier Parser/StreamReader test) covering urlencoded, multipart with a
skipped file upload, and the byte-at-a-time stress case - plus a real
end-to-end run through jet-2.0 with a simulated CGI multipart POST
request (see the matching JetCore commit).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-23 15:07:09 -07:00

82 lines
2.6 KiB
C++

#include "IMFHeader.h"
#include "Exception.h"
namespace coreutils {
IMFHeader::IMFHeader(StreamReader &reader) : Parser(reader) {}
Parser::Status IMFHeader::parse() {
MString &buffer = reader.getBuffer();
switch (state) {
case NAME: {
if (buffer.eod())
return Status::INCOMPLETE;
if (buffer.getChar() == '\r') {
// ZString::getLength() is already cursor-relative.
if (buffer.getLength() < 2)
return Status::INCOMPLETE;
if (!buffer.ifNext(ZString("\r\n")))
throw coreutils::Exception("IMFHeader: expected CRLF at end of header block.");
return Status::COMPLETE;
}
name << buffer.getTokenInclude("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-0123456789");
if (buffer.eod())
return Status::INCOMPLETE;
if (!buffer.ifNext(ZString(":")))
throw coreutils::Exception("IMFHeader: expected ':' in header name.");
state = SKIP_SPACE;
return Status::DATA_AVAIL;
}
case SKIP_SPACE:
while (!buffer.eod() && buffer.getChar() == ' ')
buffer.nextChar();
if (buffer.eod())
return Status::INCOMPLETE;
state = FIELD;
return Status::DATA_AVAIL;
case FIELD:
field << buffer.getTokenExclude("\r\n");
// Need 2 bytes buffered to reliably test for "\r\n" - eod() (a
// 1-byte check) would wrongly treat a lone trailing \r as
// malformed instead of "wait for the \n". Same bug class already
// fixed once in IMFBoundary's TAIL state.
if (buffer.getLength() < 2)
return Status::INCOMPLETE;
if (!buffer.ifNext(ZString("\r\n")))
throw coreutils::Exception("IMFHeader: expected CRLF at end of header field.");
state = FOLD_CHECK;
return Status::DATA_AVAIL;
case FOLD_CHECK:
if (buffer.eod())
return Status::INCOMPLETE;
if (buffer.getChar() == ' ' || buffer.getChar() == '\t') {
buffer.nextChar();
field << " ";
state = SKIP_SPACE;
return Status::DATA_AVAIL;
}
commitField();
state = NAME;
return Status::DATA_AVAIL;
}
throw coreutils::Exception("IMFHeader: unreachable state.");
}
void IMFHeader::commitField() {
headers[name] = field;
name = MString();
field = MString();
}
std::map<MString, MString> &IMFHeader::getHeaders() {
return headers;
}
}