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!
17 1.4 signal-based resolver timeouts
18 1.5 get rid of PATH_MAX
19 1.6 progress callback without doubles
20 1.7 Happy Eyeball dual stack connect
22 2. libcurl - multi interface
24 2.2 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
51 7.3 Graceful base64 decoding failure
52 7.4 Enhanced capability support
57 8.3 Graceful base64 decoding failure
58 8.4 Enhanced capability support
61 9.1 Graceful base64 decoding failure
62 9.2 Enhanced capability support
65 10.1 SASL based authentication mechanisms
71 12.1 Disable specific versions
72 12.2 Provide mutex locking API
73 12.3 Evaluate SSL patches
74 12.4 Cache OpenSSL contexts
75 12.5 Export session ids
76 12.6 Provide callback for cert verification
77 12.7 Support other SSL libraries
78 12.8 improve configure --with-ssl
86 14.1 Other authentication mechanisms
91 15.3 prevent file overwriting
92 15.4 simultaneous parallel transfers
93 15.5 provide formpost headers
94 15.6 url-specific options
95 15.7 warning when setting an option
96 15.8 IPv6 addresses with globbing
103 17.2 nicer lacking perl message
104 17.3 more protocols supported
105 17.4 more platforms supported
108 18.1 http-style HEAD output for ftp
109 18.2 combine error codes
110 18.3 extend CURLOPT_SOCKOPTFUNCTION prototype
112 19. Next major release
113 19.1 cleanup return codes
114 19.2 remove obsolete defines
116 19.4 remove several functions
117 19.5 remove CURLOPT_FAILONERROR
118 19.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
119 19.7 remove progress meter from libcurl
120 19.8 remove 'curl_httppost' from public
121 19.9 have form functions use CURL handle argument
122 19.10 Add CURLOPT_MAIL_CLIENT option
124 ==============================================================================
128 1.2 More data sharing
130 curl_share_* functions already exist and work, and they can be extended to
131 share more. For example, enable sharing of the ares channel and the
136 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
137 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
138 To support ipv6 interface addresses for network interfaces properly.
140 1.4 signal-based resolver timeouts
142 libcurl built without an asynchronous resolver library uses alarm() to time
143 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
144 signal handler back into the library with a sigsetjmp, which effectively
145 causes libcurl to continue running within the signal handler. This is
146 non-portable and could cause problems on some platforms. A discussion on the
147 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
149 Also, alarm() provides timeout resolution only to the nearest second. alarm
150 ought to be replaced by setitimer on systems that support it.
152 1.5 get rid of PATH_MAX
154 Having code use and rely on PATH_MAX is not nice:
155 http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
157 Currently the SSH based code uses it a bit, but to remove PATH_MAX from there
158 we need libssh2 to properly tell us when we pass in a too small buffer and
159 its current API (as of libssh2 1.2.7) doesn't.
161 1.6 progress callback without doubles
163 The progress callback was introduced way back in the days and the choice to
164 use doubles in the arguments was possibly good at the time. Today the doubles
165 only confuse users and make the amounts less precise. We should introduce
166 another progress callback option that take precedence over the old one and
167 have both co-exist for a forseeable time until we can remove the double-using
170 1.7 Happy Eyeball dual stack connect
172 In order to make alternative technologies not suffer when transitioning, like
173 when introducing IPv6 as an alternative to IPv4 and there are more than one
174 option existing simultaneously there are reasons to reconsider internal
177 To make libcurl do blazing fast IPv6 in a dual-stack configuration, this needs
180 http://tools.ietf.org/html/rfc6555
182 2. libcurl - multi interface
184 2.1 More non-blocking
186 Make sure we don't ever loop because of non-blocking sockets returning
187 EWOULDBLOCK or similar. Blocking cases include:
189 - Name resolves on non-windows unless c-ares is used
190 - NSS SSL connections
191 - HTTP proxy CONNECT operations
192 - SOCKS proxy handshakes
195 - The "DONE" operation (post transfer protocol-specific actions) for the
196 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
198 2.2 Fix HTTP Pipelining for PUT
200 HTTP Pipelining can be a way to greatly enhance performance for multiple
201 serial requests and currently libcurl only supports that for HEAD and GET
202 requests but it should also be possible for PUT.
214 HOST is a suggested command in the works for a client to tell which host name
215 to use, to offer FTP servers named-based virtual hosting:
217 http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11
219 4.2 Alter passive/active on failure and retry
221 When trying to connect passively to a server which only supports active
222 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
223 connection. There could be a way to fallback to an active connection (and
224 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
226 4.3 Earlier bad letter detection
228 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
229 process to avoid doing a resolve and connect in vain.
231 4.4 REST for large files
233 REST fix for servers not behaving well on >2GB requests. This should fail if
234 the server doesn't set the pointer to the requested index. The tricky
235 (impossible?) part is to figure out if the server did the right thing or not.
237 4.5 FTP proxy support
239 Support the most common FTP proxies, Philip Newton provided a list allegedly
240 from ncftp. This is not a subject without debate, and is probably not really
241 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
245 FTP ASCII transfers do not follow RFC959. They don't convert the data
250 5.1 Better persistency for HTTP 1.0
252 "Better" support for persistent connections over HTTP 1.0
253 http://curl.haxx.se/bug/feature.cgi?id=1089001
255 5.2 support FF3 sqlite cookie files
257 Firefox 3 is changing from its former format to a a sqlite database instead.
258 We should consider how (lib)curl can/should support this.
259 http://curl.haxx.se/bug/feature.cgi?id=1871388
261 5.3 Rearrange request header order
263 Server implementors often make an effort to detect browser and to reject
264 clients it can detect to not match. One of the last details we cannot yet
265 control in libcurl's HTTP requests, which also can be exploited to detect
266 that libcurl is in fact used even when it tries to impersonate a browser, is
267 the order of the request headers. I propose that we introduce a new option in
268 which you give headers a value, and then when the HTTP request is built it
269 sorts the headers based on that number. We could then have internally created
270 headers use a default value so only headers that need to be moved have to be
277 Reading input (to send to the remote server) on stdin is a crappy solution for
278 library purposes. We need to invent a good way for the application to be able
279 to provide the data to send.
281 6.2 ditch telnet-specific select
283 Move the telnet support's network select() loop go away and merge the code
284 into the main transfer loop. Until this is done, the multi interface won't
287 6.3 feature negotiation debug data
289 Add telnet feature negotiation data to the debug callback as header data.
291 6.4 send data in chunks
293 Currently, telnet sends data one byte at a time. This is fine for interactive
294 use, but inefficient for any other. Sent data should be sent in larger
301 Add the ability for the user to specify whether the initial response is
302 included in the AUTH command. Some email servers, such as Microsoft
303 Exchange, can work with either whilst others need to have the initial
304 response sent separately:
306 http://curl.haxx.se/mail/lib-2012-03/0114.html
310 Add support for pipelining emails.
312 7.3 Graceful base64 decoding failure
314 Rather than shutting down the session and returning an error when the
315 decoding of a base64 encoded authentication response fails, we should
316 gracefully shutdown the authentication process by sending a * response to the
317 server as per RFC4954.
319 7.4 Enhanced capability support
321 Add the ability, for an application that uses libcurl, to obtain the list of
322 capabilities returned from the EHLO command.
328 Add the ability for the user to specify whether the initial response is
329 included in the AUTH command as per RFC5034.
333 Add support for pipelining commands.
335 8.3 Graceful base64 decoding failure
337 Rather than shutting down the session and returning an error when the
338 decoding of a base64 encoded authentication response fails, we should
339 gracefully shutdown the authentication process by sending a * response to the
340 server as per RFC5034.
342 8.4 Enhanced capability support
344 Add the ability, for an application that uses libcurl, to obtain the list of
345 capabilities returned from the CAPA command.
349 9.1 Graceful base64 decoding failure
351 Rather than shutting down the session and returning an error when the
352 decoding of a base64 encoded authentication response fails, we should
353 gracefully shutdown the authentication process by sending a * response to the
354 server as per RFC3501.
356 8.2 Enhanced capability support
358 Add the ability, for an application that uses libcurl, to obtain the list of
359 capabilities returned from the CAPABILITY command.
363 10.1 SASL based authentication mechanisms
365 Currently the LDAP module only supports ldap_simple_bind_s() in order to bind
366 to an LDAP server. However, this function sends username and password details
367 using the simple authentication mechanism (as clear text). However, it should
368 be possible to use ldap_bind_s() instead specifing the security context
369 information ourselves.
375 There's no RFC for the protocol or an URI/URL format. An implementation
376 should most probably use an existing rsync library, such as librsync.
380 12.1 Disable specific versions
382 Provide an option that allows for disabling specific SSL versions, such as
383 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
385 12.2 Provide mutex locking API
387 Provide a libcurl API for setting mutex callbacks in the underlying SSL
388 library, so that the same application code can use mutex-locking
389 independently of OpenSSL or GnutTLS being used.
391 12.3 Evaluate SSL patches
393 Evaluate/apply Gertjan van Wingerde's SSL patches:
394 http://curl.haxx.se/mail/lib-2004-03/0087.html
396 12.4 Cache OpenSSL contexts
398 "Look at SSL cafile - quick traces look to me like these are done on every
399 request as well, when they should only be necessary once per ssl context (or
400 once per handle)". The major improvement we can rather easily do is to make
401 sure we don't create and kill a new SSL "context" for every request, but
402 instead make one for every connection and re-use that SSL context in the same
403 style connections are re-used. It will make us use slightly more memory but
404 it will libcurl do less creations and deletions of SSL contexts.
406 12.5 Export session ids
408 Add an interface to libcurl that enables "session IDs" to get
409 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
410 serialise the current SSL state to a buffer of your choice, and recover/reset
411 the state from such a buffer at a later date - this is used by mod_ssl for
412 apache to implement and SSL session ID cache".
414 12.6 Provide callback for cert verification
416 OpenSSL supports a callback for customised verification of the peer
417 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
418 it be? There's so much that could be done if it were!
420 12.7 Support other SSL libraries
422 Make curl's SSL layer capable of using other free SSL libraries. Such as
423 MatrixSSL (http://www.matrixssl.org/).
425 12.8 improve configure --with-ssl
427 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
432 DNS-Based Authentication of Named Entities (DANE) is a way to provide SSL
433 keys and certs over DNS using DNSSEC as an alternative to the CA model.
434 http://www.rfc-editor.org/rfc/rfc6698.txt
438 13.1 SSL engine stuff
440 Is this even possible?
442 13.2 check connection
444 Add a way to check if the connection seems to be alive, to correspond to the
445 SSL_peak() way we use with OpenSSL.
449 14.1 Other authentication mechanisms
451 Add support for GSSAPI to SMTP, POP3 and IMAP.
457 "curl --sync http://example.com/feed[1-100].rss" or
458 "curl --sync http://example.net/{index,calendar,history}.html"
460 Downloads a range or set of URLs using the remote name, but only if the
461 remote file is newer than the local file. A Last-Modified HTTP date header
462 should also be used to set the mod date on the downloaded file.
466 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
467 This is easily scripted though.
469 15.3 prevent file overwriting
471 Add an option that prevents cURL from overwriting existing local files. When
472 used, and there already is an existing file with the target file name
473 (either -O or -o), a number should be appended (and increased if already
474 existing). So that index.html becomes first index.html.1 and then
477 15.4 simultaneous parallel transfers
479 The client could be told to use maximum N simultaneous parallel transfers and
480 then just make sure that happens. It should of course not make more than one
481 connection to the same remote host. This would require the client to use the
482 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
484 15.5 provide formpost headers
486 Extending the capabilities of the multipart formposting. How about leaving
487 the ';type=foo' syntax as it is and adding an extra tag (headers) which
488 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
489 fil1.hdr contains extra headers like
491 Content-Type: text/plain; charset=KOI8-R"
492 Content-Transfer-Encoding: base64
493 X-User-Comment: Please don't use browser specific HTML code
495 which should overwrite the program reasonable defaults (plain/text,
498 15.6 url-specific options
500 Provide a way to make options bound to a specific URL among several on the
501 command line. Possibly by letting ':' separate options between URLs,
504 curl --data foo --url url.com : \
506 --url url3.com --data foo3
508 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
510 The example would do a POST-GET-POST combination on a single command line.
512 15.7 warning when setting an option
514 Display a warning when libcurl returns an error when setting an option.
515 This can be useful to tell when support for a particular feature hasn't been
516 compiled into the library.
518 15.8 IPv6 addresses with globbing
520 Currently the command line client needs to get url globbing disabled (with
521 -g) for it to support IPv6 numerical addresses. This is a rather silly flaw
522 that should be corrected. It probably involves a smarter detection of the
529 Consider extending 'roffit' to produce decent ASCII output, and use that
530 instead of (g)nroff when building src/tool_hugehelp.c
536 Make our own version of stunnel for simple port forwarding to enable HTTPS
537 and FTP-SSL tests without the stunnel dependency, and it could allow us to
538 provide test tools built with either OpenSSL or GnuTLS
540 17.2 nicer lacking perl message
542 If perl wasn't found by the configure script, don't attempt to run the tests
543 but explain something nice why it doesn't.
545 17.3 more protocols supported
547 Extend the test suite to include more protocols. The telnet could just do ftp
548 or http operations (for which we have test servers).
550 17.4 more platforms supported
552 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
553 fork()s and it should become even more portable.
557 18.1 http-style HEAD output for ftp
559 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
560 from being output in NOBODY requests over ftp
562 18.2 combine error codes
564 Combine some of the error codes to remove duplicates. The original
565 numbering should not be changed, and the old identifiers would be
566 macroed to the new ones in an CURL_NO_OLDIES section to help with
567 backward compatibility.
569 Candidates for removal and their replacements:
571 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
573 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
575 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
577 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
579 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
581 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
583 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
585 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
587 18.3 extend CURLOPT_SOCKOPTFUNCTION prototype
589 The current prototype only provides 'purpose' that tells what the
590 connection/socket is for, but not any protocol or similar. It makes it hard
591 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
594 10. Next major release
596 19.1 cleanup return codes
598 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
599 CURLMcode. These should be changed to be the same.
601 19.2 remove obsolete defines
603 remove obsolete defines from curl/curl.h
607 make several functions use size_t instead of int in their APIs
609 19.4 remove several functions
611 remove the following functions from the public API:
615 curl_mprintf (and variations)
621 They will instead become curlx_ - alternatives. That makes the curl app
622 still capable of using them, by building with them from source.
624 These functions have no purpose anymore:
628 curl_multi_socket_all
630 19.5 remove CURLOPT_FAILONERROR
632 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
633 internally. Let the app judge success or not for itself.
635 19.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
637 Remove support for a global DNS cache. Anything global is silly, and we
638 already offer the share interface for the same functionality but done
641 19.7 remove progress meter from libcurl
643 The internally provided progress meter output doesn't belong in the library.
644 Basically no application wants it (apart from curl) but instead applications
645 can and should do their own progress meters using the progress callback.
647 The progress callback should then be bumped as well to get proper 64bit
648 variable types passed to it instead of doubles so that big files work
651 19.8 remove 'curl_httppost' from public
653 curl_formadd() was made to fill in a public struct, but the fact that the
654 struct is public is never really used by application for their own advantage
655 but instead often restricts how the form functions can or can't be modified.
657 Changing them to return a private handle will benefit the implementation and
658 allow us much greater freedoms while still maintining a solid API and ABI.
660 19.9 have form functions use CURL handle argument
662 curl_formadd() and curl_formget() both currently have no CURL handle
663 argument, but both can use a callback that is set in the easy handle, and
664 thus curl_formget() with callback cannot function without first having
665 curl_easy_perform() (or similar) called - which is hard to grasp and a design
668 19.10 Add CURLOPT_MAIL_CLIENT option
670 Rather than use the URL to specify the mail client string to present in the
671 HELO and EHLO commands, libcurl should support a new CURLOPT specifically for
672 specifing this data as the URL is non-standard and to be honest a bit of a
675 Please see the following thread for more information:
676 http://curl.haxx.se/mail/lib-2012-05/0178.html