_ _ ____ _ ___| | | | _ \| | / __| | | | |_) | | | (__| |_| | _ <| |___ \___|\___/|_| \_\_____| 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 1.2 More data sharing 1.3 struct lifreq 1.4 signal-based resolver timeouts 1.5 get rid of PATH_MAX 1.6 progress callback without doubles 1.7 Happy Eyeball dual stack connect 2. libcurl - multi interface 2.1 More non-blocking 2.2 Remove easy interface internally 2.4 Fix HTTP Pipelining for PUT 3. Documentation 3.1 More and better 4. FTP 4.1 HOST 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 7.9 improve configure --with-ssl 8. GnuTLS 8.1 SSL engine stuff 8.3 check connection 8.4 non-gcrypt 9. SMTP 9.1 Other authentication mechanims 9.2 Specify the preferred authentication mechanism 9.3 Initial response 9.4 Pipelining 10. POP3 10.1 APOP Authentication 10.2 Other authentication mechanims 10.3 auth= in URLs 11. Other protocols 12. New protocols 12.1 RSYNC 13. Client 13.1 sync 13.2 glob posts 13.3 prevent file overwriting 13.4 simultaneous parallel transfers 13.5 provide formpost headers 13.6 url-specific options 13.7 metalink support 13.8 warning when setting an option 13.9 IPv6 addresses with globbing 14. Build 14.1 roffit 15. Test suite 15.1 SSL tunnel 15.2 nicer lacking perl message 15.3 more protocols supported 15.4 more platforms supported 16. Next SONAME bump 16.1 http-style HEAD output for ftp 16.2 combine error codes 16.3 extend CURLOPT_SOCKOPTFUNCTION prototype 17. Next major release 17.1 cleanup return codes 17.2 remove obsolete defines 17.3 size_t 17.4 remove several functions 17.5 remove CURLOPT_FAILONERROR 17.6 remove CURLOPT_DNS_USE_GLOBAL_CACHE 17.7 remove progress meter from libcurl 17.8 remove 'curl_httppost' from public 17.9 have form functions use CURL handle argument ============================================================================== 1. libcurl 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. 1.5 get rid of PATH_MAX Having code use and rely on PATH_MAX is not nice: http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html Currently the SSH based code uses it a bit, but to remove PATH_MAX from there we need libssh2 to properly tell us when we pass in a too small buffer and its current API (as of libssh2 1.2.7) doesn't. 1.6 progress callback without doubles The progress callback was introduced way back in the days and the choice to use doubles in the arguments was possibly good at the time. Today the doubles only confuse users and make the amounts less precise. We should introduce another progress callback option that take precedence over the old one and have both co-exist for a forseeable time until we can remove the double-using one. 1.7 Happy Eyeball dual stack connect In order to make alternative technologies not suffer when transitioning, like when introducing IPv6 as an alternative to IPv4 and there are more than one option existing simultaneously there are reasons to reconsider internal choices. To make libcurl do blazing fast IPv6 in a dual-stack configuration, this needs to be addressed: http://tools.ietf.org/html/draft-ietf-v6ops-happy-eyeballs-07 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 - NSS SSL 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(). 2.4 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 HOST HOST is a suggested command in the works for a client to tell which host name to use, to offer FTP servers named-based virtual hosting: http://tools.ietf.org/html/draft-hethmon-mcmurray-ftp-hosts-11 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/). 7.9 improve configure --with-ssl make the configure --with-ssl option first check for OpenSSL, then GnuTLS, then NSS... 8. GnuTLS 8.1 SSL engine stuff Is this even possible? 8.3 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. 8.4 non-gcrypt libcurl assumes that there are gcrypt functions available when GnuTLS is. GnuTLS can be built to use libnettle instead as crypto library, which breaks the previously mentioned assumption The correct fix would be to detect which crypto layer that is in use and adapt our code to use that instead of blindly assuming gcrypt. 9. SMTP 9.1 Other authentication mechanims Add support for other authentication mechanisms such as digest-md5 and gssapi. 9.2 Specify the preferred authentication mechanism Add the ability to specify the preferred authentication mechanism or a list of mechanims that should be used. Not only that, but the order that is returned by the server during the EHLO response should be honored by curl. 9.3 Initial response Add the ability for the user to specify whether the initial response is included in the AUTH command. Some email servers, such as Microsoft Exchange, can work with either whilst others need to have the initial response sent separately: http://curl.haxx.se/mail/lib-2012-03/0114.html 9.4 Pipelining Add support for pipelining emails. 10. POP3 10.1 APOP Authentication Add support for the APOP command rather than using plain text authentication (USER and PASS) as this is very week security wise. Note: The APOP command is specified as "APOP <username> <md5 password>", however, it isn't supported by all mail servers. 10.2 Other authentication mechanims SASL offers support for additional authentication mechanisms via the AUTH command. Detection of an email server's support for SASL authentication can be detected via the CAPA command whilst a list of supported mechanisms can be retrieved with an empty AUTH command. 10.3 auth= in URLs Being able to specify the preferred authentication mechanim in the URL as per RFC-2384 (http://tools.ietf.org/html/rfc2384). 11. Other protocols 12. New protocols 12.1 RSYNC There's no RFC for the protocol or an URI/URL format. An implementation should most probably use an existing rsync library, such as librsync. 13. Client 13.1 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. 13.2 glob posts Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'. This is easily scripted though. 13.3 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. 13.4 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 13.5 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...) 13.6 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. 13.7 metalink support Add metalink support to curl (http://www.metalinker.org/). This is most useful with simultaneous parallel transfers (11.6) but not necessary. 13.8 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. 13.9 IPv6 addresses with globbing Currently the command line client needs to get url globbing disabled (with -g) for it to support IPv6 numerical addresses. This is a rather silly flaw that should be corrected. It probably involves a smarter detection of the '[' and ']' letters. 14. Build 14.1 roffit Consider extending 'roffit' to produce decent ASCII output, and use that instead of (g)nroff when building src/hugehelp.c 15. Test suite 15.1 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 15.2 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. 15.3 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). 15.4 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. 16. Next SONAME bump 16.1 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 16.2 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 16.3 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. 17. Next major release 17.1 cleanup return codes curl_easy_cleanup() returns void, but curl_multi_cleanup() returns a CURLMcode. These should be changed to be the same. 17.2 remove obsolete defines remove obsolete defines from curl/curl.h 17.3 size_t make several functions use size_t instead of int in their APIs 17.4 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 17.5 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. 17.6 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". 17.7 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. 17.8 remove 'curl_httppost' from public curl_formadd() was made to fill in a public struct, but the fact that the struct is public is never really used by application for their own advantage but instead often restricts how the form functions can or can't be modified. Changing them to return a private handle will benefit the implementation and allow us much greater freedoms while still maintining a solid API and ABI. 17.9 have form functions use CURL handle argument curl_formadd() and curl_formget() both currently have no CURL handle argument, but both can use a callback that is set in the easy handle, and thus curl_formget() with callback cannot function without first having curl_easy_perform() (or similar) called - which is hard to grasp and a design mistake.