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
73 11.3 prevent file overwriting
74 11.4 simultaneous parallel transfers
75 11.5 provide formpost headers
76 11.6 url-specific options
78 11.8 warning when setting an option
85 13.2 nicer lacking perl message
86 13.3 more protocols supported
87 13.4 more platforms supported
90 14.1 http-style HEAD output for ftp
91 14.2 combine error codes
92 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
94 15. Next major release
95 15.1 cleanup return codes
96 15.2 remove obsolete defines
98 15.4 remove several functions
99 15.5 remove CURLOPT_FAILONERROR
100 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
101 15.7 remove progress meter from libcurl
103 ==============================================================================
107 1.1 Zero-copy interface
109 Introduce another callback interface for upload/download that makes one less
110 copy of data and thus a faster operation.
111 [http://curl.haxx.se/dev/no_copy_callbacks.txt]
113 1.2 More data sharing
115 curl_share_* functions already exist and work, and they can be extended to
116 share more. For example, enable sharing of the ares channel and the
121 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
122 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
123 To support ipv6 interface addresses for network interfaces properly.
125 1.4 signal-based resolver timeouts
127 libcurl built without an asynchronous resolver library uses alarm() to time
128 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
129 signal handler back into the library with a sigsetjmp, which effectively
130 causes libcurl to continue running within the signal handler. This is
131 non-portable and could cause problems on some platforms. A discussion on the
132 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
134 Also, alarm() provides timeout resolution only to the nearest second. alarm
135 ought to be replaced by setitimer on systems that support it.
137 2. libcurl - multi interface
139 2.1 More non-blocking
141 Make sure we don't ever loop because of non-blocking sockets returning
142 EWOULDBLOCK or similar. Blocking cases include:
144 - Name resolves on non-windows unless c-ares is used
145 - NSS SSL connections
146 - Active FTP connections
147 - HTTP proxy CONNECT operations
148 - SOCKS proxy handshakes
151 - The "DONE" operation (post transfer protocol-specific actions) for the
152 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
154 2.2 Remove easy interface internally
156 Make curl_easy_perform() a wrapper-function that simply creates a multi
157 handle, adds the easy handle to it, runs curl_multi_perform() until the
158 transfer is done, then detach the easy handle, destroy the multi handle and
159 return the easy handle's return code. This will thus make everything
160 internally use and assume the multi interface. The select()-loop should use
163 2.3 Avoid having to remove/readd handles
165 curl_multi_handle_control() - this can control the easy handle (while) added
166 to a multi handle in various ways:
168 o RESTART, unconditionally restart this easy handle's transfer from the
169 start, re-init the state
171 o RESTART_COMPLETED, restart this easy handle's transfer but only if the
172 existing transfer has already completed and it is in a "finished state".
174 o STOP, just stop this transfer and consider it completed
180 2.4 Fix HTTP Pipelining for PUT
182 HTTP Pipelining can be a way to greatly enhance performance for multiple
183 serial requests and currently libcurl only supports that for HEAD and GET
184 requests but it should also be possible for PUT.
196 HOST is a suggested command in the works for a client to tell which host name
197 to use, to offer FTP servers named-based virtual hosting:
199 http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11
201 4.2 Alter passive/active on failure and retry
203 When trying to connect passively to a server which only supports active
204 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
205 connection. There could be a way to fallback to an active connection (and
206 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
208 4.3 Earlier bad letter detection
210 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
211 process to avoid doing a resolve and connect in vain.
213 4.4 REST for large files
215 REST fix for servers not behaving well on >2GB requests. This should fail if
216 the server doesn't set the pointer to the requested index. The tricky
217 (impossible?) part is to figure out if the server did the right thing or not.
219 4.5 FTP proxy support
221 Support the most common FTP proxies, Philip Newton provided a list allegedly
222 from ncftp. This is not a subject without debate, and is probably not really
223 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
227 FTP ASCII transfers do not follow RFC959. They don't convert the data
232 5.1 Better persistency for HTTP 1.0
234 "Better" support for persistent connections over HTTP 1.0
235 http://curl.haxx.se/bug/feature.cgi?id=1089001
237 5.2 support FF3 sqlite cookie files
239 Firefox 3 is changing from its former format to a a sqlite database instead.
240 We should consider how (lib)curl can/should support this.
241 http://curl.haxx.se/bug/feature.cgi?id=1871388
243 5.3 Rearrange request header order
245 Server implementors often make an effort to detect browser and to reject
246 clients it can detect to not match. One of the last details we cannot yet
247 control in libcurl's HTTP requests, which also can be exploited to detect
248 that libcurl is in fact used even when it tries to impersonate a browser, is
249 the order of the request headers. I propose that we introduce a new option in
250 which you give headers a value, and then when the HTTP request is built it
251 sorts the headers based on that number. We could then have internally created
252 headers use a default value so only headers that need to be moved have to be
260 Reading input (to send to the remote server) on stdin is a crappy solution for
261 library purposes. We need to invent a good way for the application to be able
262 to provide the data to send.
264 6.2 ditch telnet-specific select
266 Move the telnet support's network select() loop go away and merge the code
267 into the main transfer loop. Until this is done, the multi interface won't
270 6.3 feature negotiation debug data
272 Add telnet feature negotiation data to the debug callback as header data.
274 6.4 send data in chunks
276 Currently, telnet sends data one byte at a time. This is fine for interactive
277 use, but inefficient for any other. Sent data should be sent in larger
282 7.1 Disable specific versions
284 Provide an option that allows for disabling specific SSL versions, such as
285 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
287 7.2 Provide mutex locking API
289 Provide a libcurl API for setting mutex callbacks in the underlying SSL
290 library, so that the same application code can use mutex-locking
291 independently of OpenSSL or GnutTLS being used.
293 7.3 Evaluate SSL patches
295 Evaluate/apply Gertjan van Wingerde's SSL patches:
296 http://curl.haxx.se/mail/lib-2004-03/0087.html
298 7.4 Cache OpenSSL contexts
300 "Look at SSL cafile - quick traces look to me like these are done on every
301 request as well, when they should only be necessary once per ssl context (or
302 once per handle)". The major improvement we can rather easily do is to make
303 sure we don't create and kill a new SSL "context" for every request, but
304 instead make one for every connection and re-use that SSL context in the same
305 style connections are re-used. It will make us use slightly more memory but
306 it will libcurl do less creations and deletions of SSL contexts.
308 7.5 Export session ids
310 Add an interface to libcurl that enables "session IDs" to get
311 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
312 serialise the current SSL state to a buffer of your choice, and recover/reset
313 the state from such a buffer at a later date - this is used by mod_ssl for
314 apache to implement and SSL session ID cache".
316 7.6 Provide callback for cert verification
318 OpenSSL supports a callback for customised verification of the peer
319 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
320 it be? There's so much that could be done if it were!
322 7.7 Support other SSL libraries
324 Make curl's SSL layer capable of using other free SSL libraries. Such as
325 MatrixSSL (http://www.matrixssl.org/).
327 7.8 Support SRP on the TLS layer
329 Peter Sylvester's patch for SRP on the TLS layer. Awaits OpenSSL support for
330 this, no need to support this in libcurl before there's an OpenSSL release
333 7.9 improve configure --with-ssl
335 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
342 Is this even possible?
346 Work out a common method with Peter Sylvester's OpenSSL-patch for SRP on the
347 TLS to provide name and password. GnuTLS already supports it...
351 Add a way to check if the connection seems to be alive, to correspond to the
352 SSL_peak() way we use with OpenSSL.
356 libcurl assumes that there are gcrypt functions available when
359 GnuTLS can be built to use libnettle instead as crypto library,
360 which breaks the previously mentioned assumption
362 The correct fix would be to detect which crypto layer that is in use and
363 adapt our code to use that instead of blindly assuming gcrypt.
371 There's no RFC for protocol nor URI/URL format. An implementation should
372 most probably use an existing rsync library, such as librsync.
378 "curl --sync http://example.com/feed[1-100].rss" or
379 "curl --sync http://example.net/{index,calendar,history}.html"
381 Downloads a range or set of URLs using the remote name, but only if the
382 remote file is newer than the local file. A Last-Modified HTTP date header
383 should also be used to set the mod date on the downloaded file.
387 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
388 This is easily scripted though.
390 11.3 prevent file overwriting
392 Add an option that prevents cURL from overwriting existing local files. When
393 used, and there already is an existing file with the target file name
394 (either -O or -o), a number should be appended (and increased if already
395 existing). So that index.html becomes first index.html.1 and then
398 11.4 simultaneous parallel transfers
400 The client could be told to use maximum N simultaneous parallel transfers and
401 then just make sure that happens. It should of course not make more than one
402 connection to the same remote host. This would require the client to use the
403 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
405 11.5 provide formpost headers
407 Extending the capabilities of the multipart formposting. How about leaving
408 the ';type=foo' syntax as it is and adding an extra tag (headers) which
409 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
410 fil1.hdr contains extra headers like
412 Content-Type: text/plain; charset=KOI8-R"
413 Content-Transfer-Encoding: base64
414 X-User-Comment: Please don't use browser specific HTML code
416 which should overwrite the program reasonable defaults (plain/text,
419 11.6 url-specific options
421 Provide a way to make options bound to a specific URL among several on the
422 command line. Possibly by letting ':' separate options between URLs,
425 curl --data foo --url url.com : \
427 --url url3.com --data foo3
429 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
431 The example would do a POST-GET-POST combination on a single command line.
433 11.7 metalink support
435 Add metalink support to curl (http://www.metalinker.org/). This is most useful
436 with simultaneous parallel transfers (11.6) but not necessary.
438 11.8 warning when setting an option
440 Display a warning when libcurl returns an error when setting an option.
441 This can be useful to tell when support for a particular feature hasn't been
442 compiled into the library.
448 Consider extending 'roffit' to produce decent ASCII output, and use that
449 instead of (g)nroff when building src/hugehelp.c
455 Make our own version of stunnel for simple port forwarding to enable HTTPS
456 and FTP-SSL tests without the stunnel dependency, and it could allow us to
457 provide test tools built with either OpenSSL or GnuTLS
459 13.2 nicer lacking perl message
461 If perl wasn't found by the configure script, don't attempt to run the tests
462 but explain something nice why it doesn't.
464 13.3 more protocols supported
466 Extend the test suite to include more protocols. The telnet could just do ftp
467 or http operations (for which we have test servers).
469 13.4 more platforms supported
471 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
472 fork()s and it should become even more portable.
476 14.1 http-style HEAD output for ftp
478 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
479 from being output in NOBODY requests over ftp
481 14.2 combine error codes
483 Combine some of the error codes to remove duplicates. The original
484 numbering should not be changed, and the old identifiers would be
485 macroed to the new ones in an CURL_NO_OLDIES section to help with
486 backward compatibility.
488 Candidates for removal and their replacements:
490 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
491 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
492 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
493 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
494 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
495 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
496 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
497 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
499 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
501 The current prototype only provides 'purpose' that tells what the
502 connection/socket is for, but not any protocol or similar. It makes it hard
503 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
506 15. Next major release
508 15.1 cleanup return codes
510 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
511 CURLMcode. These should be changed to be the same.
513 15.2 remove obsolete defines
515 remove obsolete defines from curl/curl.h
519 make several functions use size_t instead of int in their APIs
521 15.4 remove several functions
523 remove the following functions from the public API:
527 curl_mprintf (and variations)
533 They will instead become curlx_ - alternatives. That makes the curl app
534 still capable of using them, by building with them from source.
536 These functions have no purpose anymore:
540 curl_multi_socket_all
542 15.5 remove CURLOPT_FAILONERROR
544 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
545 internally. Let the app judge success or not for itself.
547 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
549 Remove support for a global DNS cache. Anything global is silly, and we
550 already offer the share interface for the same functionality but done
553 15.7 remove progress meter from libcurl
555 The internally provided progress meter output doesn't belong in the library.
556 Basically no application wants it (apart from curl) but instead applications
557 can and should do their own progress meters using the progress callback.
559 The progress callback should then be bumped as well to get proper 64bit
560 variable types passed to it instead of doubles so that big files work