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
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 7.9 improve configure --with-ssl
64 9.1 Specify the preferred authentication mechanism
73 11.1 SASL based authentication mechanisms
81 14.1 Other authentication mechanisms
86 15.3 prevent file overwriting
87 15.4 simultaneous parallel transfers
88 15.5 provide formpost headers
89 15.6 url-specific options
90 15.7 warning when setting an option
91 15.8 IPv6 addresses with globbing
98 17.2 nicer lacking perl message
99 17.3 more protocols supported
100 17.4 more platforms supported
103 18.1 http-style HEAD output for ftp
104 18.2 combine error codes
105 18.3 extend CURLOPT_SOCKOPTFUNCTION prototype
107 19. Next major release
108 19.1 cleanup return codes
109 19.2 remove obsolete defines
111 19.4 remove several functions
112 19.5 remove CURLOPT_FAILONERROR
113 19.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
114 19.7 remove progress meter from libcurl
115 19.8 remove 'curl_httppost' from public
116 19.9 have form functions use CURL handle argument
117 19.10 Add CURLOPT_MAIL_CLIENT option
119 ==============================================================================
123 1.2 More data sharing
125 curl_share_* functions already exist and work, and they can be extended to
126 share more. For example, enable sharing of the ares channel and the
131 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
132 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
133 To support ipv6 interface addresses for network interfaces properly.
135 1.4 signal-based resolver timeouts
137 libcurl built without an asynchronous resolver library uses alarm() to time
138 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
139 signal handler back into the library with a sigsetjmp, which effectively
140 causes libcurl to continue running within the signal handler. This is
141 non-portable and could cause problems on some platforms. A discussion on the
142 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
144 Also, alarm() provides timeout resolution only to the nearest second. alarm
145 ought to be replaced by setitimer on systems that support it.
147 1.5 get rid of PATH_MAX
149 Having code use and rely on PATH_MAX is not nice:
150 http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
152 Currently the SSH based code uses it a bit, but to remove PATH_MAX from there
153 we need libssh2 to properly tell us when we pass in a too small buffer and
154 its current API (as of libssh2 1.2.7) doesn't.
156 1.6 progress callback without doubles
158 The progress callback was introduced way back in the days and the choice to
159 use doubles in the arguments was possibly good at the time. Today the doubles
160 only confuse users and make the amounts less precise. We should introduce
161 another progress callback option that take precedence over the old one and
162 have both co-exist for a forseeable time until we can remove the double-using
165 1.7 Happy Eyeball dual stack connect
167 In order to make alternative technologies not suffer when transitioning, like
168 when introducing IPv6 as an alternative to IPv4 and there are more than one
169 option existing simultaneously there are reasons to reconsider internal
172 To make libcurl do blazing fast IPv6 in a dual-stack configuration, this needs
175 http://tools.ietf.org/html/rfc6555
178 2. libcurl - multi interface
180 2.1 More non-blocking
182 Make sure we don't ever loop because of non-blocking sockets returning
183 EWOULDBLOCK or similar. Blocking cases include:
185 - Name resolves on non-windows unless c-ares is used
186 - NSS SSL connections
187 - HTTP proxy CONNECT operations
188 - SOCKS proxy handshakes
191 - The "DONE" operation (post transfer protocol-specific actions) for the
192 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
194 2.2 Fix HTTP Pipelining for PUT
196 HTTP Pipelining can be a way to greatly enhance performance for multiple
197 serial requests and currently libcurl only supports that for HEAD and GET
198 requests but it should also be possible for PUT.
210 HOST is a suggested command in the works for a client to tell which host name
211 to use, to offer FTP servers named-based virtual hosting:
213 http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11
215 4.2 Alter passive/active on failure and retry
217 When trying to connect passively to a server which only supports active
218 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
219 connection. There could be a way to fallback to an active connection (and
220 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
222 4.3 Earlier bad letter detection
224 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
225 process to avoid doing a resolve and connect in vain.
227 4.4 REST for large files
229 REST fix for servers not behaving well on >2GB requests. This should fail if
230 the server doesn't set the pointer to the requested index. The tricky
231 (impossible?) part is to figure out if the server did the right thing or not.
233 4.5 FTP proxy support
235 Support the most common FTP proxies, Philip Newton provided a list allegedly
236 from ncftp. This is not a subject without debate, and is probably not really
237 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
241 FTP ASCII transfers do not follow RFC959. They don't convert the data
246 5.1 Better persistency for HTTP 1.0
248 "Better" support for persistent connections over HTTP 1.0
249 http://curl.haxx.se/bug/feature.cgi?id=1089001
251 5.2 support FF3 sqlite cookie files
253 Firefox 3 is changing from its former format to a a sqlite database instead.
254 We should consider how (lib)curl can/should support this.
255 http://curl.haxx.se/bug/feature.cgi?id=1871388
257 5.3 Rearrange request header order
259 Server implementors often make an effort to detect browser and to reject
260 clients it can detect to not match. One of the last details we cannot yet
261 control in libcurl's HTTP requests, which also can be exploited to detect
262 that libcurl is in fact used even when it tries to impersonate a browser, is
263 the order of the request headers. I propose that we introduce a new option in
264 which you give headers a value, and then when the HTTP request is built it
265 sorts the headers based on that number. We could then have internally created
266 headers use a default value so only headers that need to be moved have to be
274 Reading input (to send to the remote server) on stdin is a crappy solution for
275 library purposes. We need to invent a good way for the application to be able
276 to provide the data to send.
278 6.2 ditch telnet-specific select
280 Move the telnet support's network select() loop go away and merge the code
281 into the main transfer loop. Until this is done, the multi interface won't
284 6.3 feature negotiation debug data
286 Add telnet feature negotiation data to the debug callback as header data.
288 6.4 send data in chunks
290 Currently, telnet sends data one byte at a time. This is fine for interactive
291 use, but inefficient for any other. Sent data should be sent in larger
296 7.1 Disable specific versions
298 Provide an option that allows for disabling specific SSL versions, such as
299 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
301 7.2 Provide mutex locking API
303 Provide a libcurl API for setting mutex callbacks in the underlying SSL
304 library, so that the same application code can use mutex-locking
305 independently of OpenSSL or GnutTLS being used.
307 7.3 Evaluate SSL patches
309 Evaluate/apply Gertjan van Wingerde's SSL patches:
310 http://curl.haxx.se/mail/lib-2004-03/0087.html
312 7.4 Cache OpenSSL contexts
314 "Look at SSL cafile - quick traces look to me like these are done on every
315 request as well, when they should only be necessary once per ssl context (or
316 once per handle)". The major improvement we can rather easily do is to make
317 sure we don't create and kill a new SSL "context" for every request, but
318 instead make one for every connection and re-use that SSL context in the same
319 style connections are re-used. It will make us use slightly more memory but
320 it will libcurl do less creations and deletions of SSL contexts.
322 7.5 Export session ids
324 Add an interface to libcurl that enables "session IDs" to get
325 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
326 serialise the current SSL state to a buffer of your choice, and recover/reset
327 the state from such a buffer at a later date - this is used by mod_ssl for
328 apache to implement and SSL session ID cache".
330 7.6 Provide callback for cert verification
332 OpenSSL supports a callback for customised verification of the peer
333 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
334 it be? There's so much that could be done if it were!
336 7.7 Support other SSL libraries
338 Make curl's SSL layer capable of using other free SSL libraries. Such as
339 MatrixSSL (http://www.matrixssl.org/).
341 7.9 improve configure --with-ssl
343 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
348 DNS-Based Authentication of Named Entities (DANE) is a way to provide SSL
349 keys and certs over DNS using DNSSEC as an alternative to the CA model.
350 http://www.rfc-editor.org/rfc/rfc6698.txt
357 Is this even possible?
361 Add a way to check if the connection seems to be alive, to correspond to the
362 SSL_peak() way we use with OpenSSL.
367 9.1 Specify the preferred authentication mechanism
369 Add the ability to specify the preferred authentication mechanism or a list
370 of mechanisms that should be used. Not only that, but the order that is
371 returned by the server during the EHLO response should be honored by curl.
375 Add the ability for the user to specify whether the initial response is
376 included in the AUTH command. Some email servers, such as Microsoft
377 Exchange, can work with either whilst others need to have the initial
378 response sent separately:
380 http://curl.haxx.se/mail/lib-2012-03/0114.html
384 Add support for pipelining emails.
390 Being able to specify the preferred authentication mechanism in the URL as
393 10.2 Initial response
395 Add the ability for the user to specify whether the initial response is
396 included in the AUTH command as per RFC5034.
400 11.1 SASL based authentication mechanisms
402 Currently the LDAP module only supports ldap_simple_bind_s() in order to bind
403 to an LDAP server. However, this function sends username and password details
404 using the simple authentication mechanism (as clear text). However, it should
405 be possible to use ldap_bind_s() instead specifing the security context
406 information ourselves.
414 There's no RFC for the protocol or an URI/URL format. An implementation
415 should most probably use an existing rsync library, such as librsync.
419 14.1 Other authentication mechanisms
421 Add support for gssapi to SMTP, POP3 and IMAP.
427 "curl --sync http://example.com/feed[1-100].rss" or
428 "curl --sync http://example.net/{index,calendar,history}.html"
430 Downloads a range or set of URLs using the remote name, but only if the
431 remote file is newer than the local file. A Last-Modified HTTP date header
432 should also be used to set the mod date on the downloaded file.
436 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
437 This is easily scripted though.
439 15.3 prevent file overwriting
441 Add an option that prevents cURL from overwriting existing local files. When
442 used, and there already is an existing file with the target file name
443 (either -O or -o), a number should be appended (and increased if already
444 existing). So that index.html becomes first index.html.1 and then
447 15.4 simultaneous parallel transfers
449 The client could be told to use maximum N simultaneous parallel transfers and
450 then just make sure that happens. It should of course not make more than one
451 connection to the same remote host. This would require the client to use the
452 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
454 15.5 provide formpost headers
456 Extending the capabilities of the multipart formposting. How about leaving
457 the ';type=foo' syntax as it is and adding an extra tag (headers) which
458 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
459 fil1.hdr contains extra headers like
461 Content-Type: text/plain; charset=KOI8-R"
462 Content-Transfer-Encoding: base64
463 X-User-Comment: Please don't use browser specific HTML code
465 which should overwrite the program reasonable defaults (plain/text,
468 15.6 url-specific options
470 Provide a way to make options bound to a specific URL among several on the
471 command line. Possibly by letting ':' separate options between URLs,
474 curl --data foo --url url.com : \
476 --url url3.com --data foo3
478 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
480 The example would do a POST-GET-POST combination on a single command line.
482 15.7 warning when setting an option
484 Display a warning when libcurl returns an error when setting an option.
485 This can be useful to tell when support for a particular feature hasn't been
486 compiled into the library.
488 15.8 IPv6 addresses with globbing
490 Currently the command line client needs to get url globbing disabled (with
491 -g) for it to support IPv6 numerical addresses. This is a rather silly flaw
492 that should be corrected. It probably involves a smarter detection of the
499 Consider extending 'roffit' to produce decent ASCII output, and use that
500 instead of (g)nroff when building src/tool_hugehelp.c
506 Make our own version of stunnel for simple port forwarding to enable HTTPS
507 and FTP-SSL tests without the stunnel dependency, and it could allow us to
508 provide test tools built with either OpenSSL or GnuTLS
510 17.2 nicer lacking perl message
512 If perl wasn't found by the configure script, don't attempt to run the tests
513 but explain something nice why it doesn't.
515 17.3 more protocols supported
517 Extend the test suite to include more protocols. The telnet could just do ftp
518 or http operations (for which we have test servers).
520 17.4 more platforms supported
522 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
523 fork()s and it should become even more portable.
527 18.1 http-style HEAD output for ftp
529 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
530 from being output in NOBODY requests over ftp
532 18.2 combine error codes
534 Combine some of the error codes to remove duplicates. The original
535 numbering should not be changed, and the old identifiers would be
536 macroed to the new ones in an CURL_NO_OLDIES section to help with
537 backward compatibility.
539 Candidates for removal and their replacements:
541 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
543 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
545 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
547 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
549 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
551 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
553 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
555 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
557 18.3 extend CURLOPT_SOCKOPTFUNCTION prototype
559 The current prototype only provides 'purpose' that tells what the
560 connection/socket is for, but not any protocol or similar. It makes it hard
561 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
564 10. Next major release
566 19.1 cleanup return codes
568 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
569 CURLMcode. These should be changed to be the same.
571 19.2 remove obsolete defines
573 remove obsolete defines from curl/curl.h
577 make several functions use size_t instead of int in their APIs
579 19.4 remove several functions
581 remove the following functions from the public API:
585 curl_mprintf (and variations)
591 They will instead become curlx_ - alternatives. That makes the curl app
592 still capable of using them, by building with them from source.
594 These functions have no purpose anymore:
598 curl_multi_socket_all
600 19.5 remove CURLOPT_FAILONERROR
602 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
603 internally. Let the app judge success or not for itself.
605 19.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
607 Remove support for a global DNS cache. Anything global is silly, and we
608 already offer the share interface for the same functionality but done
611 19.7 remove progress meter from libcurl
613 The internally provided progress meter output doesn't belong in the library.
614 Basically no application wants it (apart from curl) but instead applications
615 can and should do their own progress meters using the progress callback.
617 The progress callback should then be bumped as well to get proper 64bit
618 variable types passed to it instead of doubles so that big files work
621 19.8 remove 'curl_httppost' from public
623 curl_formadd() was made to fill in a public struct, but the fact that the
624 struct is public is never really used by application for their own advantage
625 but instead often restricts how the form functions can or can't be modified.
627 Changing them to return a private handle will benefit the implementation and
628 allow us much greater freedoms while still maintining a solid API and ABI.
630 19.9 have form functions use CURL handle argument
632 curl_formadd() and curl_formget() both currently have no CURL handle
633 argument, but both can use a callback that is set in the easy handle, and
634 thus curl_formget() with callback cannot function without first having
635 curl_easy_perform() (or similar) called - which is hard to grasp and a design
638 19.10 Add CURLOPT_MAIL_CLIENT option
640 Rather than use the URL to specify the mail client string to present in the
641 HELO and EHLO commands, libcurl should support a new CURLOPT specifically for
642 specifing this data as the URL is non-standard and to be honest a bit of a
645 Please see the following thread for more information:
646 http://curl.haxx.se/mail/lib-2012-05/0178.html