_ _ ____ _ ___| | | | _ \| | / __| | | | |_) | | | (__| |_| | _ <| |___ \___|\___/|_| \_\_____| Things that could be nice to do in the future Things to do in project cURL. Please tell us what you think, contribute and send us patches that improve things! All bugs documented in the KNOWN_BUGS document are subject for fixing! 1. libcurl 1.1 Zero-copy interface 1.2 More data sharing 1.3 struct lifreq 1.4 signal-based resolver timeouts 2. libcurl - multi interface 2.1 More non-blocking 2.2 Remove easy interface internally 2.3 Avoid having to remove/readd handles 2.4 Fix HTTP Pipelining for PUT 3. Documentation 3.1 More and better 4. FTP 4.1 PRET 4.2 Alter passive/active on failure and retry 4.3 Earlier bad letter detection 4.4 REST for large files 4.5 FTP proxy support 4.6 ASCII support 5. HTTP 5.1 Better persistency for HTTP 1.0 5.2 support FF3 sqlite cookie files 5.3 Rearrange request header order 6. TELNET 6.1 ditch stdin 6.2 ditch telnet-specific select 6.3 feature negotiation debug data 6.4 send data in chunks 7. SSL 7.1 Disable specific versions 7.2 Provide mutex locking API 7.3 Evaluate SSL patches 7.4 Cache OpenSSL contexts 7.5 Export session ids 7.6 Provide callback for cert verification 7.7 Support other SSL libraries 7.8 Support SRP on the TLS layer 7.9 improve configure --with-ssl 7.10 Make NTLM work with other crypto functions 8. GnuTLS 8.1 SSL engine stuff 8.2 SRP 8.3 non-blocking 8.4 check connection 9. Other protocols 9.1 ditch ldap-specific select 10. New protocols 10.1 RTSP 10.2 RSYNC 10.3 RTMP 11. Client 11.1 Content-Disposition 11.2 sync 11.3 glob posts 11.4 prevent file overwriting 11.5 ftp wildcard download 11.6 simultaneous parallel transfers 11.7 provide formpost headers 11.8 url-specific options 11.9 metalink support 11.10 warning when setting an option 12. Build 12.1 roffit 13. Test suite 13.1 SSL tunnel 13.2 nicer lacking perl message 13.3 more protocols supported 13.4 more platforms supported 14. Next SONAME bump 14.1 http-style HEAD output for ftp 14.2 combine error codes 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype 15. Next major release 15.1 cleanup return codes 15.2 remove obsolete defines 15.3 size_t 15.4 remove several functions 15.5 remove CURLOPT_FAILONERROR 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE 15.7 remove progress meter from libcurl ============================================================================== 1. libcurl 1.1 Zero-copy interface Introduce another callback interface for upload/download that makes one less copy of data and thus a faster operation. [http://curl.haxx.se/dev/no_copy_callbacks.txt] 1.2 More data sharing curl_share_* functions already exist and work, and they can be extended to share more. For example, enable sharing of the ares channel and the connection cache. 1.3 struct lifreq Use 'struct lifreq' and SIOCGLIFADDR instead of 'struct ifreq' and SIOCGIFADDR on newer Solaris versions as they claim the latter is obsolete. To support ipv6 interface addresses for network interfaces properly. 1.4 signal-based resolver timeouts libcurl built without an asynchronous resolver library uses alarm() to time out DNS lookups. When a timeout occurs, this causes libcurl to jump from the signal handler back into the library with a sigsetjmp, which effectively causes libcurl to continue running within the signal handler. This is non-portable and could cause problems on some platforms. A discussion on the problem is available at http://curl.haxx.se/mail/lib-2008-09/0197.html Also, alarm() provides timeout resolution only to the nearest second. alarm ought to be replaced by setitimer on systems that support it. 2. libcurl - multi interface 2.1 More non-blocking Make sure we don't ever loop because of non-blocking sockets returning EWOULDBLOCK or similar. Blocking cases include: - Name resolves on non-windows unless c-ares is used - GnuTLS SSL connections - NSS SSL connections - Active FTP connections - HTTP proxy CONNECT operations - SOCKS proxy handshakes - file:// transfers - TELNET transfers - The "DONE" operation (post transfer protocol-specific actions) for the protocols SFTP, SMTP, FTP. Fixing Curl_done() for this is a worthy task. 2.2 Remove easy interface internally Make curl_easy_perform() a wrapper-function that simply creates a multi handle, adds the easy handle to it, runs curl_multi_perform() until the transfer is done, then detach the easy handle, destroy the multi handle and return the easy handle's return code. This will thus make everything internally use and assume the multi interface. The select()-loop should use curl_multi_socket(). 2.3 Avoid having to remove/readd handles curl_multi_handle_control() - this can control the easy handle (while) added to a multi handle in various ways: o RESTART, unconditionally restart this easy handle's transfer from the start, re-init the state o RESTART_COMPLETED, restart this easy handle's transfer but only if the existing transfer has already completed and it is in a "finished state". o STOP, just stop this transfer and consider it completed o PAUSE? o RESUME? 2.4 Fix HTTP Pipelining for PUT HTTP Pipelining can be a way to greatly enhance performance for multiple serial requests and currently libcurl only supports that for HEAD and GET requests but it should also be possible for PUT. 3. Documentation 3.1 More and better Exactly 4. FTP 4.1 PRET PRET is a command that primarily "drftpd" supports, which could be useful when using libcurl against such a server. It is a non-standard and a rather oddly designed command, but... http://curl.haxx.se/bug/feature.cgi?id=1729967 4.2 Alter passive/active on failure and retry When trying to connect passively to a server which only supports active connections, libcurl returns CURLE_FTP_WEIRD_PASV_REPLY and closes the connection. There could be a way to fallback to an active connection (and vice versa). http://curl.haxx.se/bug/feature.cgi?id=1754793 4.3 Earlier bad letter detection Make the detection of (bad) %0d and %0a codes in FTP url parts earlier in the process to avoid doing a resolve and connect in vain. 4.4 REST for large files REST fix for servers not behaving well on >2GB requests. This should fail if the server doesn't set the pointer to the requested index. The tricky (impossible?) part is to figure out if the server did the right thing or not. 4.5 FTP proxy support Support the most common FTP proxies, Philip Newton provided a list allegedly from ncftp. This is not a subject without debate, and is probably not really suitable for libcurl. http://curl.haxx.se/mail/archive-2003-04/0126.html 4.6 ASCII support FTP ASCII transfers do not follow RFC959. They don't convert the data accordingly. 5. HTTP 5.1 Better persistency for HTTP 1.0 "Better" support for persistent connections over HTTP 1.0 http://curl.haxx.se/bug/feature.cgi?id=1089001 5.2 support FF3 sqlite cookie files Firefox 3 is changing from its former format to a a sqlite database instead. We should consider how (lib)curl can/should support this. http://curl.haxx.se/bug/feature.cgi?id=1871388 5.3 Rearrange request header order Server implementors often make an effort to detect browser and to reject clients it can detect to not match. One of the last details we cannot yet control in libcurl's HTTP requests, which also can be exploited to detect that libcurl is in fact used even when it tries to impersonate a browser, is the order of the request headers. I propose that we introduce a new option in which you give headers a value, and then when the HTTP request is built it sorts the headers based on that number. We could then have internally created headers use a default value so only headers that need to be moved have to be specified. 6. TELNET 6.1 ditch stdin Reading input (to send to the remote server) on stdin is a crappy solution for library purposes. We need to invent a good way for the application to be able to provide the data to send. 6.2 ditch telnet-specific select Move the telnet support's network select() loop go away and merge the code into the main transfer loop. Until this is done, the multi interface won't work for telnet. 6.3 feature negotiation debug data Add telnet feature negotiation data to the debug callback as header data. 6.4 send data in chunks Currently, telnet sends data one byte at a time. This is fine for interactive use, but inefficient for any other. Sent data should be sent in larger chunks. 7. SSL 7.1 Disable specific versions Provide an option that allows for disabling specific SSL versions, such as SSLv2 http://curl.haxx.se/bug/feature.cgi?id=1767276 7.2 Provide mutex locking API Provide a libcurl API for setting mutex callbacks in the underlying SSL library, so that the same application code can use mutex-locking independently of OpenSSL or GnutTLS being used. 7.3 Evaluate SSL patches Evaluate/apply Gertjan van Wingerde's SSL patches: http://curl.haxx.se/mail/lib-2004-03/0087.html 7.4 Cache OpenSSL contexts "Look at SSL cafile - quick traces look to me like these are done on every request as well, when they should only be necessary once per ssl context (or once per handle)". The major improvement we can rather easily do is to make sure we don't create and kill a new SSL "context" for every request, but instead make one for every connection and re-use that SSL context in the same style connections are re-used. It will make us use slightly more memory but it will libcurl do less creations and deletions of SSL contexts. 7.5 Export session ids Add an interface to libcurl that enables "session IDs" to get exported/imported. Cris Bailiff said: "OpenSSL has functions which can serialise the current SSL state to a buffer of your choice, and recover/reset the state from such a buffer at a later date - this is used by mod_ssl for apache to implement and SSL session ID cache". 7.6 Provide callback for cert verification OpenSSL supports a callback for customised verification of the peer certificate, but this doesn't seem to be exposed in the libcurl APIs. Could it be? There's so much that could be done if it were! 7.7 Support other SSL libraries Make curl's SSL layer capable of using other free SSL libraries. Such as MatrixSSL (http://www.matrixssl.org/). 7.8 Support SRP on the TLS layer Peter Sylvester's patch for SRP on the TLS layer. Awaits OpenSSL support for this, no need to support this in libcurl before there's an OpenSSL release that does it. 7.9 improve configure --with-ssl make the configure --with-ssl option first check for OpenSSL, then GnuTLS, then NSS... 7.10 Make NTLM work with other crypto functions Get NTLM working using the functions provided by NSS etc. Not strictly SSL/TLS related, but hey... Another option is to get available DES and MD4 source code from the cryptopp library. They are fine license-wise, but are C++. NTLM currenly only works when libcurl is built with OpenSSL or GnuTLS support. 8. GnuTLS 8.1 SSL engine stuff Is this even possible? 8.2 SRP Work out a common method with Peter Sylvester's OpenSSL-patch for SRP on the TLS to provide name and password. GnuTLS already supports it... 8.3 non-blocking Fix the connection phase to be non-blocking when multi interface is used 8.4 check connection Add a way to check if the connection seems to be alive, to correspond to the SSL_peak() way we use with OpenSSL. 9. Other protocols 9.1 ditch ldap-specific select * Look over the implementation. The looping will have to "go away" from the lib/ldap.c source file and get moved to the main network code so that the multi interface and friends will work for LDAP as well. 9.2 stop TFTP blocking Stop TFTP from being blocking and doing its own read loop in tftp_do. 10. New protocols 10.1 RTSP RFC2326 (protocol - very HTTP-like, also contains URL description) 10.2 RSYNC There's no RFC for protocol nor URI/URL format. An implementation should most probably use an existing rsync library, such as librsync. 10.3 RTMP There exists a patch that claims to introduce this protocol: http://osdir.com/ml/gnu.gnash.devel2/2006-11/msg00278.html, further details in the feature-request: http://curl.haxx.se/bug/feature.cgi?id=1843469 11. Client 11.1 Content-Disposition Add option that is similar to -O but that takes the output file name from the Content-Disposition: header, and/or uses the local file name used in redirections for the cases the server bounces the request further to a different file (name): http://curl.haxx.se/bug/feature.cgi?id=1364676 11.2 sync "curl --sync http://example.com/feed[1-100].rss" or "curl --sync http://example.net/{index,calendar,history}.html" Downloads a range or set of URLs using the remote name, but only if the remote file is newer than the local file. A Last-Modified HTTP date header should also be used to set the mod date on the downloaded file. 11.3 glob posts Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'. This is easily scripted though. 11.4 prevent file overwriting Add an option that prevents cURL from overwriting existing local files. When used, and there already is an existing file with the target file name (either -O or -o), a number should be appended (and increased if already existing). So that index.html becomes first index.html.1 and then index.html.2 etc. 11.5 ftp wildcard download "curl ftp://site.com/*.txt" 11.6 simultaneous parallel transfers The client could be told to use maximum N simultaneous parallel transfers and then just make sure that happens. It should of course not make more than one connection to the same remote host. This would require the client to use the multi interface. http://curl.haxx.se/bug/feature.cgi?id=1558595 11.7 provide formpost headers Extending the capabilities of the multipart formposting. How about leaving the ';type=foo' syntax as it is and adding an extra tag (headers) which works like this: curl -F "coolfiles=@fil1.txt;headers=@fil1.hdr" where fil1.hdr contains extra headers like Content-Type: text/plain; charset=KOI8-R" Content-Transfer-Encoding: base64 X-User-Comment: Please don't use browser specific HTML code which should overwrite the program reasonable defaults (plain/text, 8bit...) 11.8 url-specific options Provide a way to make options bound to a specific URL among several on the command line. Possibly by letting ':' separate options between URLs, similar to this: curl --data foo --url url.com : \ --url url2.com : \ --url url3.com --data foo3 (More details: http://curl.haxx.se/mail/archive-2004-07/0133.html) The example would do a POST-GET-POST combination on a single command line. 11.9 metalink support Add metalink support to curl (http://www.metalinker.org/). This is most useful with simultaneous parallel transfers (11.6) but not necessary. 11.10 warning when setting an option Display a warning when libcurl returns an error when setting an option. This can be useful to tell when support for a particular feature hasn't been compiled into the library. 12. Build 12.1 roffit Consider extending 'roffit' to produce decent ASCII output, and use that instead of (g)nroff when building src/hugehelp.c 13. Test suite 13.1 SSL tunnel Make our own version of stunnel for simple port forwarding to enable HTTPS and FTP-SSL tests without the stunnel dependency, and it could allow us to provide test tools built with either OpenSSL or GnuTLS 13.2 nicer lacking perl message If perl wasn't found by the configure script, don't attempt to run the tests but explain something nice why it doesn't. 13.3 more protocols supported Extend the test suite to include more protocols. The telnet could just do ftp or http operations (for which we have test servers). 13.4 more platforms supported Make the test suite work on more platforms. OpenBSD and Mac OS. Remove fork()s and it should become even more portable. 14. Next SONAME bump 14.1 http-style HEAD output for ftp #undef CURL_FTP_HTTPSTYLE_HEAD in lib/ftp.c to remove the HTTP-style headers from being output in NOBODY requests over ftp 14.2 combine error codes Combine some of the error codes to remove duplicates. The original numbering should not be changed, and the old identifiers would be macroed to the new ones in an CURL_NO_OLDIES section to help with backward compatibility. Candidates for removal and their replacements: CURLE_FILE_COULDNT_READ_FILE => CURLE_REMOTE_FILE_NOT_FOUND CURLE_FTP_COULDNT_RETR_FILE => CURLE_REMOTE_FILE_NOT_FOUND CURLE_FTP_COULDNT_USE_REST => CURLE_RANGE_ERROR CURLE_FUNCTION_NOT_FOUND => CURLE_FAILED_INIT CURLE_LDAP_INVALID_URL => CURLE_URL_MALFORMAT CURLE_TFTP_NOSUCHUSER => CURLE_TFTP_ILLEGAL CURLE_TFTP_NOTFOUND => CURLE_REMOTE_FILE_NOT_FOUND CURLE_TFTP_PERM => CURLE_REMOTE_ACCESS_DENIED 14.3 extend CURLOPT_SOCKOPTFUNCTION prototype The current prototype only provides 'purpose' that tells what the connection/socket is for, but not any protocol or similar. It makes it hard for applications to differentiate on TCP vs UDP and even HTTP vs FTP and similar. 15. Next major release 15.1 cleanup return codes curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a CURLMcode. These should be changed to be the same. 15.2 remove obsolete defines remove obsolete defines from curl/curl.h 15.3 size_t make several functions use size_t instead of int in their APIs 15.4 remove several functions remove the following functions from the public API: curl_getenv curl_mprintf (and variations) curl_strequal curl_strnequal They will instead become curlx_ - alternatives. That makes the curl app still capable of using them, by building with them from source. These functions have no purpose anymore: curl_multi_socket curl_multi_socket_all 15.5 remove CURLOPT_FAILONERROR Remove support for CURLOPT_FAILONERROR, it has gotten too kludgy and weird internally. Let the app judge success or not for itself. 15.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE Remove support for a global DNS cache. Anything global is silly, and we already offer the share interface for the same functionality but done "right". 15.7 remove progress meter from libcurl The internally provided progress meter output doesn't belong in the library. Basically no application wants it (apart from curl) but instead applications can and should do their own progress meters using the progress callback. The progress callback should then be bumped as well to get proper 64bit variable types passed to it instead of doubles so that big files work correctly.