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
21 2. libcurl - multi interface
23 2.2 Remove easy interface internally
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 7.9 improve configure --with-ssl
71 11.3 prevent file overwriting
72 11.4 simultaneous parallel transfers
73 11.5 provide formpost headers
74 11.6 url-specific options
76 11.8 warning when setting an option
77 11.9 IPv6 addresses with globbing
84 13.2 nicer lacking perl message
85 13.3 more protocols supported
86 13.4 more platforms supported
89 14.1 http-style HEAD output for ftp
90 14.2 combine error codes
91 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
93 15. Next major release
94 15.1 cleanup return codes
95 15.2 remove obsolete defines
97 15.4 remove several functions
98 15.5 remove CURLOPT_FAILONERROR
99 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
100 15.7 remove progress meter from libcurl
101 15.8 remove 'curl_httppost' from public
102 15.9 have form functions use CURL handle argument
104 ==============================================================================
108 1.2 More data sharing
110 curl_share_* functions already exist and work, and they can be extended to
111 share more. For example, enable sharing of the ares channel and the
116 Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and
117 SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete.
118 To support ipv6 interface addresses for network interfaces properly.
120 1.4 signal-based resolver timeouts
122 libcurl built without an asynchronous resolver library uses alarm() to time
123 out DNS lookups. When a timeout occurs, this causes libcurl to jump from the
124 signal handler back into the library with a sigsetjmp, which effectively
125 causes libcurl to continue running within the signal handler. This is
126 non-portable and could cause problems on some platforms. A discussion on the
127 problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html
129 Also, alarm() provides timeout resolution only to the nearest second. alarm
130 ought to be replaced by setitimer on systems that support it.
132 1.5 get rid of PATH_MAX
134 Having code use and rely on PATH_MAX is not nice:
135 http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
137 Currently the SSH based code uses it a bit, but to remove PATH_MAX from there
138 we need libssh2 to properly tell us when we pass in a too small buffer and
139 its current API (as of libssh2 1.2.7) doesn't.
141 1.6 progress callback without doubles
143 The progress callback was introduced way back in the days and the choice to
144 use doubles in the arguments was possibly good at the time. Today the doubles
145 only confuse users and make the amounts less precise. We should introduce
146 another progress callback option that take precedence over the old one and
147 have both co-exist for a forseeable time until we can remove the double-using
150 2. libcurl - multi interface
152 2.1 More non-blocking
154 Make sure we don't ever loop because of non-blocking sockets returning
155 EWOULDBLOCK or similar. Blocking cases include:
157 - Name resolves on non-windows unless c-ares is used
158 - NSS SSL connections
159 - HTTP proxy CONNECT operations
160 - SOCKS proxy handshakes
163 - The "DONE" operation (post transfer protocol-specific actions) for the
164 protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task.
166 2.2 Remove easy interface internally
168 Make curl_easy_perform() a wrapper-function that simply creates a multi
169 handle, adds the easy handle to it, runs curl_multi_perform() until the
170 transfer is done, then detach the easy handle, destroy the multi handle and
171 return the easy handle's return code. This will thus make everything
172 internally use and assume the multi interface. The select()-loop should use
175 2.4 Fix HTTP Pipelining for PUT
177 HTTP Pipelining can be a way to greatly enhance performance for multiple
178 serial requests and currently libcurl only supports that for HEAD and GET
179 requests but it should also be possible for PUT.
191 HOST is a suggested command in the works for a client to tell which host name
192 to use, to offer FTP servers named-based virtual hosting:
194 http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11
196 4.2 Alter passive/active on failure and retry
198 When trying to connect passively to a server which only supports active
199 connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the
200 connection. There could be a way to fallback to an active connection (and
201 vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793
203 4.3 Earlier bad letter detection
205 Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the
206 process to avoid doing a resolve and connect in vain.
208 4.4 REST for large files
210 REST fix for servers not behaving well on >2GB requests. This should fail if
211 the server doesn't set the pointer to the requested index. The tricky
212 (impossible?) part is to figure out if the server did the right thing or not.
214 4.5 FTP proxy support
216 Support the most common FTP proxies, Philip Newton provided a list allegedly
217 from ncftp. This is not a subject without debate, and is probably not really
218 suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html
222 FTP ASCII transfers do not follow RFC959. They don't convert the data
227 5.1 Better persistency for HTTP 1.0
229 "Better" support for persistent connections over HTTP 1.0
230 http://curl.haxx.se/bug/feature.cgi?id=1089001
232 5.2 support FF3 sqlite cookie files
234 Firefox 3 is changing from its former format to a a sqlite database instead.
235 We should consider how (lib)curl can/should support this.
236 http://curl.haxx.se/bug/feature.cgi?id=1871388
238 5.3 Rearrange request header order
240 Server implementors often make an effort to detect browser and to reject
241 clients it can detect to not match. One of the last details we cannot yet
242 control in libcurl's HTTP requests, which also can be exploited to detect
243 that libcurl is in fact used even when it tries to impersonate a browser, is
244 the order of the request headers. I propose that we introduce a new option in
245 which you give headers a value, and then when the HTTP request is built it
246 sorts the headers based on that number. We could then have internally created
247 headers use a default value so only headers that need to be moved have to be
255 Reading input (to send to the remote server) on stdin is a crappy solution for
256 library purposes. We need to invent a good way for the application to be able
257 to provide the data to send.
259 6.2 ditch telnet-specific select
261 Move the telnet support's network select() loop go away and merge the code
262 into the main transfer loop. Until this is done, the multi interface won't
265 6.3 feature negotiation debug data
267 Add telnet feature negotiation data to the debug callback as header data.
269 6.4 send data in chunks
271 Currently, telnet sends data one byte at a time. This is fine for interactive
272 use, but inefficient for any other. Sent data should be sent in larger
277 7.1 Disable specific versions
279 Provide an option that allows for disabling specific SSL versions, such as
280 SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276
282 7.2 Provide mutex locking API
284 Provide a libcurl API for setting mutex callbacks in the underlying SSL
285 library, so that the same application code can use mutex-locking
286 independently of OpenSSL or GnutTLS being used.
288 7.3 Evaluate SSL patches
290 Evaluate/apply Gertjan van Wingerde's SSL patches:
291 http://curl.haxx.se/mail/lib-2004-03/0087.html
293 7.4 Cache OpenSSL contexts
295 "Look at SSL cafile - quick traces look to me like these are done on every
296 request as well, when they should only be necessary once per ssl context (or
297 once per handle)". The major improvement we can rather easily do is to make
298 sure we don't create and kill a new SSL "context" for every request, but
299 instead make one for every connection and re-use that SSL context in the same
300 style connections are re-used. It will make us use slightly more memory but
301 it will libcurl do less creations and deletions of SSL contexts.
303 7.5 Export session ids
305 Add an interface to libcurl that enables "session IDs" to get
306 exported/imported. Cris Bailiff said: "OpenSSL has functions which can
307 serialise the current SSL state to a buffer of your choice, and recover/reset
308 the state from such a buffer at a later date - this is used by mod_ssl for
309 apache to implement and SSL session ID cache".
311 7.6 Provide callback for cert verification
313 OpenSSL supports a callback for customised verification of the peer
314 certificate, but this doesn't seem to be exposed in the libcurl APIs. Could
315 it be? There's so much that could be done if it were!
317 7.7 Support other SSL libraries
319 Make curl's SSL layer capable of using other free SSL libraries. Such as
320 MatrixSSL (http://www.matrixssl.org/).
322 7.9 improve configure --with-ssl
324 make the configure --with-ssl option first check for OpenSSL, then GnuTLS,
331 Is this even possible?
335 Add a way to check if the connection seems to be alive, to correspond to the
336 SSL_peak() way we use with OpenSSL.
340 libcurl assumes that there are gcrypt functions available when
343 GnuTLS can be built to use libnettle instead as crypto library,
344 which breaks the previously mentioned assumption
346 The correct fix would be to detect which crypto layer that is in use and
347 adapt our code to use that instead of blindly assuming gcrypt.
355 There's no RFC for protocol nor URI/URL format. An implementation should
356 most probably use an existing rsync library, such as librsync.
362 "curl --sync http://example.com/feed[1-100].rss" or
363 "curl --sync http://example.net/{index,calendar,history}.html"
365 Downloads a range or set of URLs using the remote name, but only if the
366 remote file is newer than the local file. A Last-Modified HTTP date header
367 should also be used to set the mod date on the downloaded file.
371 Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
372 This is easily scripted though.
374 11.3 prevent file overwriting
376 Add an option that prevents cURL from overwriting existing local files. When
377 used, and there already is an existing file with the target file name
378 (either -O or -o), a number should be appended (and increased if already
379 existing). So that index.html becomes first index.html.1 and then
382 11.4 simultaneous parallel transfers
384 The client could be told to use maximum N simultaneous parallel transfers and
385 then just make sure that happens. It should of course not make more than one
386 connection to the same remote host. This would require the client to use the
387 multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595
389 11.5 provide formpost headers
391 Extending the capabilities of the multipart formposting. How about leaving
392 the ';type=foo' syntax as it is and adding an extra tag (headers) which
393 works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where
394 fil1.hdr contains extra headers like
396 Content-Type: text/plain; charset=KOI8-R"
397 Content-Transfer-Encoding: base64
398 X-User-Comment: Please don't use browser specific HTML code
400 which should overwrite the program reasonable defaults (plain/text,
403 11.6 url-specific options
405 Provide a way to make options bound to a specific URL among several on the
406 command line. Possibly by letting ':' separate options between URLs,
409 curl --data foo --url url.com : \
411 --url url3.com --data foo3
413 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html)
415 The example would do a POST-GET-POST combination on a single command line.
417 11.7 metalink support
419 Add metalink support to curl (http://www.metalinker.org/). This is most useful
420 with simultaneous parallel transfers (11.6) but not necessary.
422 11.8 warning when setting an option
424 Display a warning when libcurl returns an error when setting an option.
425 This can be useful to tell when support for a particular feature hasn't been
426 compiled into the library.
428 11.9 IPv6 addresses with globbing
430 Currently the command line client needs to get url globbing disabled (with
431 -g) for it to support IPv6 numerical addresses. This is a rather silly flaw
432 that should be corrected. It probably involves a smarter detection of the
439 Consider extending 'roffit' to produce decent ASCII output, and use that
440 instead of (g)nroff when building src/hugehelp.c
446 Make our own version of stunnel for simple port forwarding to enable HTTPS
447 and FTP-SSL tests without the stunnel dependency, and it could allow us to
448 provide test tools built with either OpenSSL or GnuTLS
450 13.2 nicer lacking perl message
452 If perl wasn't found by the configure script, don't attempt to run the tests
453 but explain something nice why it doesn't.
455 13.3 more protocols supported
457 Extend the test suite to include more protocols. The telnet could just do ftp
458 or http operations (for which we have test servers).
460 13.4 more platforms supported
462 Make the test suite work on more platforms. OpenBSD and Mac OS. Remove
463 fork()s and it should become even more portable.
467 14.1 http-style HEAD output for ftp
469 #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers
470 from being output in NOBODY requests over ftp
472 14.2 combine error codes
474 Combine some of the error codes to remove duplicates. The original
475 numbering should not be changed, and the old identifiers would be
476 macroed to the new ones in an CURL_NO_OLDIES section to help with
477 backward compatibility.
479 Candidates for removal and their replacements:
481 CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND
482 CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND
483 CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR
484 CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT
485 CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT
486 CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL
487 CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND
488 CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED
490 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype
492 The current prototype only provides 'purpose' that tells what the
493 connection/socket is for, but not any protocol or similar. It makes it hard
494 for applications to differentiate on TCP vs UDP and even HTTP vs FTP and
497 15. Next major release
499 15.1 cleanup return codes
501 curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a
502 CURLMcode. These should be changed to be the same.
504 15.2 remove obsolete defines
506 remove obsolete defines from curl/curl.h
510 make several functions use size_t instead of int in their APIs
512 15.4 remove several functions
514 remove the following functions from the public API:
518 curl_mprintf (and variations)
524 They will instead become curlx_ - alternatives. That makes the curl app
525 still capable of using them, by building with them from source.
527 These functions have no purpose anymore:
531 curl_multi_socket_all
533 15.5 remove CURLOPT_FAILONERROR
535 Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird
536 internally. Let the app judge success or not for itself.
538 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE
540 Remove support for a global DNS cache. Anything global is silly, and we
541 already offer the share interface for the same functionality but done
544 15.7 remove progress meter from libcurl
546 The internally provided progress meter output doesn't belong in the library.
547 Basically no application wants it (apart from curl) but instead applications
548 can and should do their own progress meters using the progress callback.
550 The progress callback should then be bumped as well to get proper 64bit
551 variable types passed to it instead of doubles so that big files work
554 15.8 remove 'curl_httppost' from public
556 curl_formadd() was made to fill in a public struct, but the fact that the
557 struct is public is never really used by application for their own advantage
558 but instead often restricts how the form functions can or can't be modified.
560 Changing them to return a private handle will benefit the implementation and
561 allow us much greater freedoms while still maintining a solid API and ABI.
563 15.9 have form functions use CURL handle argument
565 curl_formadd() and curl_formget() both currently have no CURL handle
566 argument, but both can use a callback that is set in the easy handle, and
567 thus curl_formget() with callback cannot function without first having
568 curl_easy_perform() (or similar) called - which is hard to grasp and a design