d3594be653
This started out as regression tests for the `curl_ws_recv()` and
`curl_ws_send()` implementation and ended up with a bugfix, additional
protocol validation and minor logging improvements.
- Fix reset of fragmented message decoder state when a PING/PONG is
received in between message fragments.
- Fix undefined behavior (applying zero offset to null pointer) in
curl_ws_send() when the given buffer is NULL.
- Detect invalid overlong PING/PONG/CLOSE frames.
- Detect invalid fragmented PING/PONG/CLOSE frames.
- Detect invalid sequences of fragmented frames.
- a) A continuation frame (0x80...) is received without any ongoing
fragmented message.
- b) A new fragmented message is started (0x81/0x01/0x82/0x02...)
before the ongoing fragmented message has terminated.
- Made logs for invalid opcodes easier to understand.
- Moved noisy logs to the `CURL_TRC_WS` log level.
- Unified the prefixes for WebSocket log messages: `[WS] ...`
- Add env var `CURL_WS_FORCE_ZERO_MASK` in debug builds.
- If set, it forces the bit mask applied to outgoing payloads to
0x00000000, which effectively means the payload is not masked at
all. This drastically simplifies defining the expected `<protocol>`
data in test cases.
- 2700: Frame types
- 2701: Invalid opcode 0x3
- 2702: Invalid opcode 0xB
- 2703: Invalid reserved bit RSV1 _(replaces 2310)_
- 2704: Invalid reserved bit RSV2
- 2705: Invalid reserved bit RSV3
- 2706: Invalid masked server message
- 2707: Peculiar frame sizes _(part. replaces 2311)_
- 2708: Automatic PONG
- 2709: No automatic PONG _(replaces 2312)_
- 2710: Unsolicited PONG
- 2711: Empty PING/PONG/CLOSE
- 2712: Max sized PING/PONG/CLOSE
- 2713: Invalid oversized PING _(replaces 2307)_
- 2714: Invalid oversized PONG
- 2715: Invalid oversized CLOSE
- 2716: Invalid fragmented PING
- 2717: Invalid fragmented PONG
- 2718: Invalid fragmented CLOSE
- 2719: Fragmented messages _(part. replaces 2311)_
- 2720: Fragmented messages with empty fragments
- 2721: Fragmented messages with interleaved pong
- 2722: Invalid fragmented message without initial frame
- 2723: Invalid fragmented message without final frame
- 2305: curl_ws_recv() loop reading three larger frames
- This test involuntarily sent an invalid sequence of opcodes (0x01...,0x01...,0x81...) , but neither libcurl nor the test caught this! The correct sequence was tested in 2311 (0x01...,0x00...,0x80...). See below for 2311.
- Validation of the opcode sequence was added to libcurl and is now tested in 2723.
- Superseded by 2719 (fragmented message) and 2707 (large frames).
- 2307: overlong PING payload
- The tested PING payload length check was actually missing, but the test didn't catch this since it involuntarily sent an invalid opcode (0x19... instead of 0x89...) so that the expected error occurred, but for the wrong reason.
- Superseded by 2713.
- 2310: unknown reserved bit set in frame header
- Superseded by 2703 and extended by 2704 and 2705.
- 2311: curl_ws_recv() read fragmented message
- Superseded by 2719 (fragmented message) and 2707 (large frames).
- 2312: WebSockets no auto ping
- Superseded by 2709.
- No tests for `CURLOPT_WRITEFUNCTION`.
- No tests for sending of invalid frames/fragments.
Closes #17136
4.8 KiB
| c | SPDX-License-Identifier | Title | Section | Source | See-also | Protocol | Added-in | ||
|---|---|---|---|---|---|---|---|---|---|
| Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. | curl | libcurl-env-dbg | 3 | libcurl |
|
|
n/a |
NAME
libcurl-env-dbg - environment variables libcurl DEBUGBUILD understands
DESCRIPTION
This is a set of variables only recognized and used if libcurl was built "debug enabled", which should never be true for a library used in production. These variables are intended for internal use only, subject to change and have many effects on the behavior of libcurl. Refer to the source code to determine how exactly they are being used.
CURL_ALTSVC_HTTP
Bypass the AltSvc HTTPS protocol restriction if this variable exists.
CURL_DBG_SOCK_RBLOCK
The percentage of recv() calls that should be answered with an EAGAIN at random. For TCP/UNIX sockets.
CURL_DBG_SOCK_RMAX
The maximum data that shall be received from the network in one recv() call. For TCP/UNIX sockets. This is applied to every recv.
Example: CURL_DBG_SOCK_RMAX=400 means recv buffer size is limited to a maximum of 400 bytes.
CURL_DBG_SOCK_WBLOCK
The percentage of send() calls that should be answered with an EAGAIN at random. For TCP/UNIX sockets.
CURL_DBG_SOCK_WPARTIAL
The percentage of data that shall be written to the network. For TCP/UNIX sockets. This is applied to every send.
Example: CURL_DBG_SOCK_WPARTIAL=80 means a send with 1000 bytes would only send 800.
CURL_DBG_QUIC_WBLOCK
The percentage of send() calls that should be answered with EAGAIN at random. QUIC only.
CURL_DEBUG
Trace logging behavior as an alternative to calling curl_global_trace(3).
Example: CURL_DEBUG=http/2 means trace details about HTTP/2 handling.
In the curl command line tool, built with --enable-debug, this environment
variable adds to arguments like --verbose, -vvv. At least a single -v
is needed to make the run emit trace output, but when it does, the contents
of CURL_DEBUG are added and can override existing options.
Example: CURL_DEBUG=tcp,-http/2 curl -vv url means trace protocol details,
triggered by -vv, add tracing of TCP in addition and remove tracing of
HTTP/2.
CURL_DEBUG_SIZE
Fake the size returned by CURLINFO_HEADER_SIZE and CURLINFO_REQUEST_SIZE.
CURL_DNS_SERVER
When built with c-ares for name resolving, setting this environment variable
to [IP:port] makes libcurl use that DNS server instead of the system
default. This is used by the curl test suite.
CURL_GETHOSTNAME
Fake the local machine's unqualified hostname for NTLM and SMTP.
CURL_HSTS_HTTP
Bypass the HSTS HTTPS protocol restriction if this variable exists.
CURL_FORCETIME
A time of 0 is used for AWS signatures and NTLM if this variable exists.
CURL_ENTROPY
A fixed faked value to use instead of a proper random number so that functions in libcurl that are otherwise getting random outputs can be tested for what they generate.
CURL_SMALLREQSEND
An alternative size of HTTP data to be sent at a time only if smaller than the current.
CURL_SMALLSENDS
An alternative size of socket data to be sent at a time only if smaller than the current.
CURL_TIME
Fake Unix timestamp to use for AltSvc, HSTS and CURLINFO variables that are time related.
This variable can also be used to fake the data returned by some CURLINFO variables that are not time-related (such as CURLINFO_LOCAL_PORT), and in that case the value is not a timestamp.
CURL_TRACE
LDAP tracing is enabled if this variable exists and its value is 1 or greater.
OpenLDAP tracing is separate. Refer to CURL_OPENLDAP_TRACE.
CURL_OPENLDAP_TRACE
OpenLDAP tracing is enabled if this variable exists and its value is 1 or greater. There is a number of debug levels, refer to openldap.c comments.
CURL_WS_CHUNK_SIZE
Used to influence the buffer chunk size used for WebSocket encoding and decoding.
CURL_WS_CHUNK_EAGAIN
Used to simulate blocking sends after this chunk size for WebSocket connections.
CURL_WS_FORCE_ZERO_MASK
Used to set the bitmask of all sent WebSocket frames to zero. The value of the environment variable does not matter.
CURL_FORBID_REUSE
Used to set the CURLOPT_FORBID_REUSE flag on each transfer initiated by the curl command line tool. The value of the environment variable does not matter.
CURL_GRACEFUL_SHUTDOWN
Make a blocking, graceful shutdown of all remaining connections when a multi handle is destroyed. This implicitly triggers for easy handles that are run via easy_perform. The value of the environment variable gives the shutdown timeout in milliseconds.
CURL_H2_STREAM_WIN_MAX
Set to a positive 32-bit number to override the HTTP/2 stream window's default of 10MB. Used in testing to verify correct window update handling.