5 \___|\___/|_| \_\_____|
7 Things that could be nice to do in the future
9 Things to do in project cURL. Please tell us what you think, contribute and
10 send us patches that improve things!
12 All bugs documented in the KNOWN_BUGS document are subject for fixing!
15 1.1 Zero-copy interface
18 1.4 signal-based resolver timeouts
20 2. libcurl - multi interface
22 2.2 Remove easy interface internally
23 2.3 Avoid having to remove/readd handles
24 2.4 Fix HTTP Pipelining for PUT
31 4.2 Alter passive/active on failure and retry
32 4.3 Earlier bad letter detection
33 4.4 REST for large files
38 5.1 Better persistency for HTTP 1.0
39 5.2 support FF3 sqlite cookie files
40 5.3 Rearrange request header order
44 6.2 ditch telnet-specific select
45 6.3 feature negotiation debug data
46 6.4 send data in chunks
49 7.1 Disable specific versions
50 7.2 Provide mutex locking API
51 7.3 Evaluate SSL patches
52 7.4 Cache OpenSSL contexts
53 7.5 Export session ids
54 7.6 Provide callback for cert verification
55 7.7 Support other SSL libraries
56 7.8 Support SRP on the TLS layer
57 7.9 improve configure --with-ssl
58 7.10 Make NTLM work with other crypto functions
66 9.1 ditch ldap-specific select
75 11.3 prevent file overwriting
76 11.4 simultaneous parallel transfers
77 11.5 provide formpost headers
78 11.6 url-specific options
80 11.8 warning when setting an option
87 13.2 nicer lacking perl message
88 13.3 more protocols supported
89 13.4 more platforms supported
92 14.1 http-style HEAD output for ftp
93 14.2 combine error codes
94 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
96 15. Next major release
97 15.1 cleanup return codes
98 15.2 remove obsolete defines
100 15.4 remove several functions
101 15.5 remove CURLOPT_FAILONERROR
102 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
103 15.7 remove progress meter from libcurl
105 ==============================================================================
109 1.1 Zero-copy interface
111 Introduce another callback interface for upload/download that makes one less
112 copy of data and thus a faster operation.
113 [http://curl.haxx.se/dev/no_copy_callbacks.txt]
115 1.2 More data sharing
117 curl_share_* functions already exist and work, and they can be extended to
118 share more. For example, enable sharing of the ares channel and the
123 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
124 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
125 To support ipv6 interface addresses for network interfaces properly.
127 1.4 signal-based resolver timeouts
129 libcurl built without an asynchronous resolver library uses alarm() to time
130 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
131 signal handler back into the library with a sigsetjmp, which effectively
132 causes libcurl to continue running within the signal handler. This is
133 non-portable and could cause problems on some platforms. A discussion on the
134 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
136 Also, alarm() provides timeout resolution only to the nearest second. alarm
137 ought to be replaced by setitimer on systems that support it.
139 2. libcurl - multi interface
141 2.1 More non-blocking
143 Make sure we don't ever loop because of non-blocking sockets returning
144 EWOULDBLOCK or similar. Blocking cases include:
146 - Name resolves on non-windows unless c-ares is used
147 - NSS SSL connections
148 - Active FTP connections
149 - HTTP proxy CONNECT operations
150 - SOCKS proxy handshakes
153 - The "DONE" operation (post transfer protocol-specific actions) for the
154 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
156 2.2 Remove easy interface internally
158 Make curl_easy_perform() a wrapper-function that simply creates a multi
159 handle, adds the easy handle to it, runs curl_multi_perform() until the
160 transfer is done, then detach the easy handle, destroy the multi handle and
161 return the easy handle's return code. This will thus make everything
162 internally use and assume the multi interface. The select()-loop should use
165 2.3 Avoid having to remove/readd handles
167 curl_multi_handle_control() - this can control the easy handle (while) added
168 to a multi handle in various ways:
170 o RESTART, unconditionally restart this easy handle's transfer from the
171 start, re-init the state
173 o RESTART_COMPLETED, restart this easy handle's transfer but only if the
174 existing transfer has already completed and it is in a "finished state".
176 o STOP, just stop this transfer and consider it completed
182 2.4 Fix HTTP Pipelining for PUT
184 HTTP Pipelining can be a way to greatly enhance performance for multiple
185 serial requests and currently libcurl only supports that for HEAD and GET
186 requests but it should also be possible for PUT.
199 HOST is a suggested command in the works for a client to tell which host name
200 to use, to offer FTP servers named-based virtual hosting:
202 http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11
204 4.2 Alter passive/active on failure and retry
206 When trying to connect passively to a server which only supports active
207 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
208 connection. There could be a way to fallback to an active connection (and
209 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
211 4.3 Earlier bad letter detection
213 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
214 process to avoid doing a resolve and connect in vain.
216 4.4 REST for large files
218 REST fix for servers not behaving well on >2GB requests. This should fail if
219 the server doesn't set the pointer to the requested index. The tricky
220 (impossible?) part is to figure out if the server did the right thing or not.
222 4.5 FTP proxy support
224 Support the most common FTP proxies, Philip Newton provided a list allegedly
225 from ncftp. This is not a subject without debate, and is probably not really
226 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
230 FTP ASCII transfers do not follow RFC959. They don't convert the data
235 5.1 Better persistency for HTTP 1.0
237 "Better" support for persistent connections over HTTP 1.0
238 http://curl.haxx.se/bug/feature.cgi?id=1089001
240 5.2 support FF3 sqlite cookie files
242 Firefox 3 is changing from its former format to a a sqlite database instead.
243 We should consider how (lib)curl can/should support this.
244 http://curl.haxx.se/bug/feature.cgi?id=1871388
246 5.3 Rearrange request header order
248 Server implementors often make an effort to detect browser and to reject
249 clients it can detect to not match. One of the last details we cannot yet
250 control in libcurl's HTTP requests, which also can be exploited to detect
251 that libcurl is in fact used even when it tries to impersonate a browser, is
252 the order of the request headers. I propose that we introduce a new option in
253 which you give headers a value, and then when the HTTP request is built it
254 sorts the headers based on that number. We could then have internally created
255 headers use a default value so only headers that need to be moved have to be
263 Reading input (to send to the remote server) on stdin is a crappy solution for
264 library purposes. We need to invent a good way for the application to be able
265 to provide the data to send.
267 6.2 ditch telnet-specific select
269 Move the telnet support's network select() loop go away and merge the code
270 into the main transfer loop. Until this is done, the multi interface won't
273 6.3 feature negotiation debug data
275 Add telnet feature negotiation data to the debug callback as header data.
277 6.4 send data in chunks
279 Currently, telnet sends data one byte at a time. This is fine for interactive
280 use, but inefficient for any other. Sent data should be sent in larger
285 7.1 Disable specific versions
287 Provide an option that allows for disabling specific SSL versions, such as
288 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
290 7.2 Provide mutex locking API
292 Provide a libcurl API for setting mutex callbacks in the underlying SSL
293 library, so that the same application code can use mutex-locking
294 independently of OpenSSL or GnutTLS being used.
296 7.3 Evaluate SSL patches
298 Evaluate/apply Gertjan van Wingerde's SSL patches:
299 http://curl.haxx.se/mail/lib-2004-03/0087.html
301 7.4 Cache OpenSSL contexts
303 "Look at SSL cafile - quick traces look to me like these are done on every
304 request as well, when they should only be necessary once per ssl context (or
305 once per handle)". The major improvement we can rather easily do is to make
306 sure we don't create and kill a new SSL "context" for every request, but
307 instead make one for every connection and re-use that SSL context in the same
308 style connections are re-used. It will make us use slightly more memory but
309 it will libcurl do less creations and deletions of SSL contexts.
311 7.5 Export session ids
313 Add an interface to libcurl that enables "session IDs" to get
314 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
315 serialise the current SSL state to a buffer of your choice, and recover/reset
316 the state from such a buffer at a later date - this is used by mod_ssl for
317 apache to implement and SSL session ID cache".
319 7.6 Provide callback for cert verification
321 OpenSSL supports a callback for customised verification of the peer
322 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
323 it be? There's so much that could be done if it were!
325 7.7 Support other SSL libraries
327 Make curl's SSL layer capable of using other free SSL libraries. Such as
328 MatrixSSL (http://www.matrixssl.org/).
330 7.8 Support SRP on the TLS layer
332 Peter Sylvester's patch for SRP on the TLS layer. Awaits OpenSSL support for
333 this, no need to support this in libcurl before there's an OpenSSL release
336 7.9 improve configure --with-ssl
338 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
341 7.10 Make NTLM work with other crypto functions
343 Get NTLM working using the functions provided by NSS etc. Not strictly
344 SSL/TLS related, but hey... Another option is to get available DES and MD4
345 source code from the cryptopp library. They are fine license-wise, but are
346 C++. NTLM currenly only works when libcurl is built with OpenSSL or GnuTLS
353 Is this even possible?
357 Work out a common method with Peter Sylvester's OpenSSL-patch for SRP on the
358 TLS to provide name and password. GnuTLS already supports it...
362 Add a way to check if the connection seems to be alive, to correspond to the
363 SSL_peak() way we use with OpenSSL.
367 9.1 ditch ldap-specific select
369 * Look over the implementation. The looping will have to "go away" from the
370 lib/ldap.c source file and get moved to the main network code so that the
371 multi interface and friends will work for LDAP as well.
377 There's no RFC for protocol nor URI/URL format. An implementation should
378 most probably use an existing rsync library, such as librsync.
382 There exists a patch that claims to introduce this protocol:
383 http://osdir.com/ml/gnu.gnash.devel2/2006-11/msg00278.html, further details
384 in the feature-request: http://curl.haxx.se/bug/feature.cgi?id=1843469
390 "curl --sync http://example.com/feed[1-100].rss" or
391 "curl --sync http://example.net/{index,calendar,history}.html"
393 Downloads a range or set of URLs using the remote name, but only if the
394 remote file is newer than the local file. A Last-Modified HTTP date header
395 should also be used to set the mod date on the downloaded file.
399 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
400 This is easily scripted though.
402 11.3 prevent file overwriting
404 Add an option that prevents cURL from overwriting existing local files. When
405 used, and there already is an existing file with the target file name
406 (either -O or -o), a number should be appended (and increased if already
407 existing). So that index.html becomes first index.html.1 and then
410 11.4 simultaneous parallel transfers
412 The client could be told to use maximum N simultaneous parallel transfers and
413 then just make sure that happens. It should of course not make more than one
414 connection to the same remote host. This would require the client to use the
415 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
417 11.5 provide formpost headers
419 Extending the capabilities of the multipart formposting. How about leaving
420 the ';type=foo' syntax as it is and adding an extra tag (headers) which
421 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
422 fil1.hdr contains extra headers like
424 Content-Type: text/plain; charset=KOI8-R"
425 Content-Transfer-Encoding: base64
426 X-User-Comment: Please don't use browser specific HTML code
428 which should overwrite the program reasonable defaults (plain/text,
431 11.6 url-specific options
433 Provide a way to make options bound to a specific URL among several on the
434 command line. Possibly by letting ':' separate options between URLs,
437 curl --data foo --url url.com : \
439 --url url3.com --data foo3
441 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
443 The example would do a POST-GET-POST combination on a single command line.
445 11.7 metalink support
447 Add metalink support to curl (http://www.metalinker.org/). This is most useful
448 with simultaneous parallel transfers (11.6) but not necessary.
450 11.8 warning when setting an option
452 Display a warning when libcurl returns an error when setting an option.
453 This can be useful to tell when support for a particular feature hasn't been
454 compiled into the library.
460 Consider extending 'roffit' to produce decent ASCII output, and use that
461 instead of (g)nroff when building src/hugehelp.c
467 Make our own version of stunnel for simple port forwarding to enable HTTPS
468 and FTP-SSL tests without the stunnel dependency, and it could allow us to
469 provide test tools built with either OpenSSL or GnuTLS
471 13.2 nicer lacking perl message
473 If perl wasn't found by the configure script, don't attempt to run the tests
474 but explain something nice why it doesn't.
476 13.3 more protocols supported
478 Extend the test suite to include more protocols. The telnet could just do ftp
479 or http operations (for which we have test servers).
481 13.4 more platforms supported
483 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
484 fork()s and it should become even more portable.
488 14.1 http-style HEAD output for ftp
490 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
491 from being output in NOBODY requests over ftp
493 14.2 combine error codes
495 Combine some of the error codes to remove duplicates. The original
496 numbering should not be changed, and the old identifiers would be
497 macroed to the new ones in an CURL_NO_OLDIES section to help with
498 backward compatibility.
500 Candidates for removal and their replacements:
502 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
503 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
504 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
505 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
506 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
507 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
508 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
509 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
511 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
513 The current prototype only provides 'purpose' that tells what the
514 connection/socket is for, but not any protocol or similar. It makes it hard
515 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
518 15. Next major release
520 15.1 cleanup return codes
522 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
523 CURLMcode. These should be changed to be the same.
525 15.2 remove obsolete defines
527 remove obsolete defines from curl/curl.h
531 make several functions use size_t instead of int in their APIs
533 15.4 remove several functions
535 remove the following functions from the public API:
539 curl_mprintf (and variations)
545 They will instead become curlx_ - alternatives. That makes the curl app
546 still capable of using them, by building with them from source.
548 These functions have no purpose anymore:
552 curl_multi_socket_all
554 15.5 remove CURLOPT_FAILONERROR
556 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
557 internally. Let the app judge success or not for itself.
559 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
561 Remove support for a global DNS cache. Anything global is silly, and we
562 already offer the share interface for the same functionality but done
565 15.7 remove progress meter from libcurl
567 The internally provided progress meter output doesn't belong in the library.
568 Basically no application wants it (apart from curl) but instead applications
569 can and should do their own progress meters using the progress callback.
571 The progress callback should then be bumped as well to get proper 64bit
572 variable types passed to it instead of doubles so that big files work