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
67 9.1 ditch ldap-specific select
75 11.1 Content-Disposition
78 11.4 prevent file overwriting
79 11.5 ftp wildcard download
80 11.6 simultaneous parallel transfers
81 11.7 provide formpost headers
82 11.8 url-specific options
84 11.10 warning when setting an option
91 13.2 nicer lacking perl message
92 13.3 more protocols supported
93 13.4 more platforms supported
96 14.1 http-style HEAD output for ftp
97 14.2 combine error codes
98 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
100 15. Next major release
101 15.1 cleanup return codes
102 15.2 remove obsolete defines
104 15.4 remove several functions
105 15.5 remove CURLOPT_FAILONERROR
106 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
107 15.7 remove progress meter from libcurl
109 ==============================================================================
113 1.1 Zero-copy interface
115 Introduce another callback interface for upload/download that makes one less
116 copy of data and thus a faster operation.
117 [http://curl.haxx.se/dev/no_copy_callbacks.txt]
119 1.2 More data sharing
121 curl_share_* functions already exist and work, and they can be extended to
122 share more. For example, enable sharing of the ares channel and the
127 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
128 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
129 To support ipv6 interface addresses for network interfaces properly.
131 1.4 signal-based resolver timeouts
133 libcurl built without an asynchronous resolver library uses alarm() to time
134 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
135 signal handler back into the library with a sigsetjmp, which effectively
136 causes libcurl to continue running within the signal handler. This is
137 non-portable and could cause problems on some platforms. A discussion on the
138 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
140 Also, alarm() provides timeout resolution only to the nearest second. alarm
141 ought to be replaced by setitimer on systems that support it.
143 2. libcurl - multi interface
145 2.1 More non-blocking
147 Make sure we don't ever loop because of non-blocking sockets returning
148 EWOULDBLOCK or similar. Blocking cases include:
150 - Name resolves on non-windows unless c-ares is used
151 - NSS SSL connections
152 - Active FTP connections
153 - HTTP proxy CONNECT operations
154 - SOCKS proxy handshakes
157 - The "DONE" operation (post transfer protocol-specific actions) for the
158 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
160 2.2 Remove easy interface internally
162 Make curl_easy_perform() a wrapper-function that simply creates a multi
163 handle, adds the easy handle to it, runs curl_multi_perform() until the
164 transfer is done, then detach the easy handle, destroy the multi handle and
165 return the easy handle's return code. This will thus make everything
166 internally use and assume the multi interface. The select()-loop should use
169 2.3 Avoid having to remove/readd handles
171 curl_multi_handle_control() - this can control the easy handle (while) added
172 to a multi handle in various ways:
174 o RESTART, unconditionally restart this easy handle's transfer from the
175 start, re-init the state
177 o RESTART_COMPLETED, restart this easy handle's transfer but only if the
178 existing transfer has already completed and it is in a "finished state".
180 o STOP, just stop this transfer and consider it completed
186 2.4 Fix HTTP Pipelining for PUT
188 HTTP Pipelining can be a way to greatly enhance performance for multiple
189 serial requests and currently libcurl only supports that for HEAD and GET
190 requests but it should also be possible for PUT.
203 PRET is a command that primarily "drftpd" supports, which could be useful
204 when using libcurl against such a server. It is a non-standard and a rather
205 oddly designed command, but...
206 http://curl.haxx.se/bug/feature.cgi?id=1729967
208 4.2 Alter passive/active on failure and retry
210 When trying to connect passively to a server which only supports active
211 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
212 connection. There could be a way to fallback to an active connection (and
213 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
215 4.3 Earlier bad letter detection
217 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
218 process to avoid doing a resolve and connect in vain.
220 4.4 REST for large files
222 REST fix for servers not behaving well on >2GB requests. This should fail if
223 the server doesn't set the pointer to the requested index. The tricky
224 (impossible?) part is to figure out if the server did the right thing or not.
226 4.5 FTP proxy support
228 Support the most common FTP proxies, Philip Newton provided a list allegedly
229 from ncftp. This is not a subject without debate, and is probably not really
230 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
234 FTP ASCII transfers do not follow RFC959. They don't convert the data
239 5.1 Better persistency for HTTP 1.0
241 "Better" support for persistent connections over HTTP 1.0
242 http://curl.haxx.se/bug/feature.cgi?id=1089001
244 5.2 support FF3 sqlite cookie files
246 Firefox 3 is changing from its former format to a a sqlite database instead.
247 We should consider how (lib)curl can/should support this.
248 http://curl.haxx.se/bug/feature.cgi?id=1871388
250 5.3 Rearrange request header order
252 Server implementors often make an effort to detect browser and to reject
253 clients it can detect to not match. One of the last details we cannot yet
254 control in libcurl's HTTP requests, which also can be exploited to detect
255 that libcurl is in fact used even when it tries to impersonate a browser, is
256 the order of the request headers. I propose that we introduce a new option in
257 which you give headers a value, and then when the HTTP request is built it
258 sorts the headers based on that number. We could then have internally created
259 headers use a default value so only headers that need to be moved have to be
267 Reading input (to send to the remote server) on stdin is a crappy solution for
268 library purposes. We need to invent a good way for the application to be able
269 to provide the data to send.
271 6.2 ditch telnet-specific select
273 Move the telnet support's network select() loop go away and merge the code
274 into the main transfer loop. Until this is done, the multi interface won't
277 6.3 feature negotiation debug data
279 Add telnet feature negotiation data to the debug callback as header data.
281 6.4 send data in chunks
283 Currently, telnet sends data one byte at a time. This is fine for interactive
284 use, but inefficient for any other. Sent data should be sent in larger
289 7.1 Disable specific versions
291 Provide an option that allows for disabling specific SSL versions, such as
292 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
294 7.2 Provide mutex locking API
296 Provide a libcurl API for setting mutex callbacks in the underlying SSL
297 library, so that the same application code can use mutex-locking
298 independently of OpenSSL or GnutTLS being used.
300 7.3 Evaluate SSL patches
302 Evaluate/apply Gertjan van Wingerde's SSL patches:
303 http://curl.haxx.se/mail/lib-2004-03/0087.html
305 7.4 Cache OpenSSL contexts
307 "Look at SSL cafile - quick traces look to me like these are done on every
308 request as well, when they should only be necessary once per ssl context (or
309 once per handle)". The major improvement we can rather easily do is to make
310 sure we don't create and kill a new SSL "context" for every request, but
311 instead make one for every connection and re-use that SSL context in the same
312 style connections are re-used. It will make us use slightly more memory but
313 it will libcurl do less creations and deletions of SSL contexts.
315 7.5 Export session ids
317 Add an interface to libcurl that enables "session IDs" to get
318 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
319 serialise the current SSL state to a buffer of your choice, and recover/reset
320 the state from such a buffer at a later date - this is used by mod_ssl for
321 apache to implement and SSL session ID cache".
323 7.6 Provide callback for cert verification
325 OpenSSL supports a callback for customised verification of the peer
326 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
327 it be? There's so much that could be done if it were!
329 7.7 Support other SSL libraries
331 Make curl's SSL layer capable of using other free SSL libraries. Such as
332 MatrixSSL (http://www.matrixssl.org/).
334 7.8 Support SRP on the TLS layer
336 Peter Sylvester's patch for SRP on the TLS layer. Awaits OpenSSL support for
337 this, no need to support this in libcurl before there's an OpenSSL release
340 7.9 improve configure --with-ssl
342 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
345 7.10 Make NTLM work with other crypto functions
347 Get NTLM working using the functions provided by NSS etc. Not strictly
348 SSL/TLS related, but hey... Another option is to get available DES and MD4
349 source code from the cryptopp library. They are fine license-wise, but are
350 C++. NTLM currenly only works when libcurl is built with OpenSSL or GnuTLS
357 Is this even possible?
361 Work out a common method with Peter Sylvester's OpenSSL-patch for SRP on the
362 TLS to provide name and password. GnuTLS already supports it...
366 Fix the connection phase to be non-blocking when multi interface is used
370 Add a way to check if the connection seems to be alive, to correspond to the
371 SSL_peak() way we use with OpenSSL.
375 9.1 ditch ldap-specific select
377 * Look over the implementation. The looping will have to "go away" from the
378 lib/ldap.c source file and get moved to the main network code so that the
379 multi interface and friends will work for LDAP as well.
381 9.2 stop TFTP blocking
383 Stop TFTP from being blocking and doing its own read loop in tftp_do.
389 RFC2326 (protocol - very HTTP-like, also contains URL description)
393 There's no RFC for protocol nor URI/URL format. An implementation should
394 most probably use an existing rsync library, such as librsync.
398 There exists a patch that claims to introduce this protocol:
399 http://osdir.com/ml/gnu.gnash.devel2/2006-11/msg00278.html, further details
400 in the feature-request: http://curl.haxx.se/bug/feature.cgi?id=1843469
404 11.1 Content-Disposition
406 Add option that is similar to -O but that takes the output file name from the
407 Content-Disposition: header, and/or uses the local file name used in
408 redirections for the cases the server bounces the request further to a
409 different file (name): http://curl.haxx.se/bug/feature.cgi?id=1364676
413 "curl --sync http://example.com/feed[1-100].rss" or
414 "curl --sync http://example.net/{index,calendar,history}.html"
416 Downloads a range or set of URLs using the remote name, but only if the
417 remote file is newer than the local file. A Last-Modified HTTP date header
418 should also be used to set the mod date on the downloaded file.
422 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
423 This is easily scripted though.
425 11.4 prevent file overwriting
427 Add an option that prevents cURL from overwriting existing local files. When
428 used, and there already is an existing file with the target file name
429 (either -O or -o), a number should be appended (and increased if already
430 existing). So that index.html becomes first index.html.1 and then
433 11.5 ftp wildcard download
435 "curl ftp://site.com/*.txt"
437 11.6 simultaneous parallel transfers
439 The client could be told to use maximum N simultaneous parallel transfers and
440 then just make sure that happens. It should of course not make more than one
441 connection to the same remote host. This would require the client to use the
442 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
444 11.7 provide formpost headers
446 Extending the capabilities of the multipart formposting. How about leaving
447 the ';type=foo' syntax as it is and adding an extra tag (headers) which
448 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
449 fil1.hdr contains extra headers like
451 Content-Type: text/plain; charset=KOI8-R"
452 Content-Transfer-Encoding: base64
453 X-User-Comment: Please don't use browser specific HTML code
455 which should overwrite the program reasonable defaults (plain/text,
458 11.8 url-specific options
460 Provide a way to make options bound to a specific URL among several on the
461 command line. Possibly by letting ':' separate options between URLs,
464 curl --data foo --url url.com : \
466 --url url3.com --data foo3
468 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
470 The example would do a POST-GET-POST combination on a single command line.
472 11.9 metalink support
474 Add metalink support to curl (http://www.metalinker.org/). This is most useful
475 with simultaneous parallel transfers (11.6) but not necessary.
477 11.10 warning when setting an option
479 Display a warning when libcurl returns an error when setting an option.
480 This can be useful to tell when support for a particular feature hasn't been
481 compiled into the library.
487 Consider extending 'roffit' to produce decent ASCII output, and use that
488 instead of (g)nroff when building src/hugehelp.c
494 Make our own version of stunnel for simple port forwarding to enable HTTPS
495 and FTP-SSL tests without the stunnel dependency, and it could allow us to
496 provide test tools built with either OpenSSL or GnuTLS
498 13.2 nicer lacking perl message
500 If perl wasn't found by the configure script, don't attempt to run the tests
501 but explain something nice why it doesn't.
503 13.3 more protocols supported
505 Extend the test suite to include more protocols. The telnet could just do ftp
506 or http operations (for which we have test servers).
508 13.4 more platforms supported
510 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
511 fork()s and it should become even more portable.
515 14.1 http-style HEAD output for ftp
517 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
518 from being output in NOBODY requests over ftp
520 14.2 combine error codes
522 Combine some of the error codes to remove duplicates. The original
523 numbering should not be changed, and the old identifiers would be
524 macroed to the new ones in an CURL_NO_OLDIES section to help with
525 backward compatibility.
527 Candidates for removal and their replacements:
529 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
530 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
531 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
532 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
533 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
534 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
535 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
536 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
538 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
540 The current prototype only provides 'purpose' that tells what the
541 connection/socket is for, but not any protocol or similar. It makes it hard
542 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
545 15. Next major release
547 15.1 cleanup return codes
549 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
550 CURLMcode. These should be changed to be the same.
552 15.2 remove obsolete defines
554 remove obsolete defines from curl/curl.h
558 make several functions use size_t instead of int in their APIs
560 15.4 remove several functions
562 remove the following functions from the public API:
566 curl_mprintf (and variations)
572 They will instead become curlx_ - alternatives. That makes the curl app
573 still capable of using them, by building with them from source.
575 These functions have no purpose anymore:
579 curl_multi_socket_all
581 15.5 remove CURLOPT_FAILONERROR
583 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
584 internally. Let the app judge success or not for itself.
586 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
588 Remove support for a global DNS cache. Anything global is silly, and we
589 already offer the share interface for the same functionality but done
592 15.7 remove progress meter from libcurl
594 The internally provided progress meter output doesn't belong in the library.
595 Basically no application wants it (apart from curl) but instead applications
596 can and should do their own progress meters using the progress callback.
598 The progress callback should then be bumped as well to get proper 64bit
599 variable types passed to it instead of doubles so that big files work