Introducing a number of options to the multi interface that
allows for multiple pipelines to the same host, in order to
optimize the balance between the penalty for opening new
connections and the potential pipelining latency.
Two new options for limiting the number of connections:
CURLMOPT_MAX_HOST_CONNECTIONS - Limits the number of running connections
to the same host. When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished, so we can reuse the connection.
CURLMOPT_MAX_TOTAL_CONNECTIONS - Limits the number of connections in total.
When adding a handle that exceeds this limit,
that handle will be put in a pending state until another handle is
finished. The free connection will then be reused, if possible, or
closed if the pending handle can't reuse it.
Several new options for pipelining:
CURLMOPT_MAX_PIPELINE_LENGTH - Limits the pipeling length. If a
pipeline is "full" when a connection is to be reused, a new connection
will be opened if the CURLMOPT_MAX_xxx_CONNECTIONS limits allow it.
If not, the handle will be put in a pending state until a connection is
ready (either free or a pipe got shorter).
CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a transfer with a content
length that is larger than this.
CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE - A pipelined connection will not
be reused if it is currently processing a chunk larger than this.
CURLMOPT_PIPELINING_SITE_BL - A blacklist of hosts that don't allow
pipelining.
CURLMOPT_PIPELINING_SERVER_BL - A blacklist of server types that don't allow
pipelining.
See the curl_multi_setopt() man page for details.
Allow an appliction to set libcurl specific SSL options. The first and
only options supported right now is CURLSSLOPT_ALLOW_BEAST.
It will make libcurl to disable any work-arounds the underlying SSL
library may have to address a known security flaw in the SSL3 and TLS1.0
protocol versions.
This is a reaction to us unconditionally removing that behavior after
this security advisory:
http://curl.haxx.se/docs/adv_20120124B.html
... it did however cause a lot of programs to fail because of old
servers not liking this work-around. Now programs can opt to decrease
the security in order to interoperate with old servers better.
This adds three new options to control the behavior of TCP keepalives:
- CURLOPT_TCP_KEEPALIVE: enable/disable probes
- CURLOPT_TCP_KEEPIDLE: idle time before sending first probe
- CURLOPT_TCP_KEEPINTVL: delay between successive probes
While not all operating systems support the TCP_KEEPIDLE and
TCP_KEEPINTVL knobs, the library will still allow these options to be
set by clients, silently ignoring the values.
1- Two new error codes are introduced.
CURLE_FTP_ACCEPT_FAILED to be set whenever ACCEPTing fails because of
FTP server connected.
CURLE_FTP_ACCEPT_TIMEOUT to be set whenever ACCEPTing timeouts.
Neither of these errors are considered fatal and control connection
remains OK because it could just be a firewall blocking server to
connect to the client.
2- One new setopt option was introduced.
CURLOPT_ACCEPTTIMEOUT_MS
It sets the maximum amount of time FTP client is going to wait for a
server to connect. Internal default accept timeout is 60 seconds.
Don't even declare the struct members for disabled features
Introducing the CURLSHE_NOT_BUILT_IN return code for the share interface
when trying to set a sharing option that has been disabled (or not
enabled) in the library.
Allow (*curl_write_callback) write callbacks to return
CURL_WRITEFUNC_OUT_OF_MEMORY to properly indicate libcurl of OOM conditions
inside the callback itself.
Added CURLOPT_TRANSFER_ENCODING as the option to set to request Transfer
Encoding in HTTP requests (if built zlib enabled). I also renamed
CURLOPT_ENCODING to CURLOPT_ACCEPT_ENCODING (while keeping the old name
around) to reduce the confusion when we have to encoding options for
HTTP.
--tr-encoding is now the new command line option for curl to request
this, and thus I updated the test cases accordingly.
Stop the abuse of CURLE_FAILED_INIT as return code for things not being
init related by introducing two new return codes:
CURLE_NOT_BUILT_IN and CURLE_UNKNOWN_OPTION
CURLE_NOT_BUILT_IN replaces return code 4 that has been obsoleted for
several years. It is used for returning error when something is
attempted to be used but the feature/option was not enabled or
explictitly disabled at build-time. Getting this error mostly means that
libcurl needs to be rebuilt.
CURLE_FAILED_INIT is now saved and used strictly for init
failures. Getting this problem means something went seriously wrong,
like a resource shortage or similar.
CURLE_UNKNOWN_OPTION is the option formerly known as
CURLE_UNKNOWN_TELNET_OPTION (and the old name is still present,
separately defined to be removed in a very distant future). This error
code is meant to be used to return when an option is given to libcurl
that isn't known. This problem would mostly indicate a problem in the
program that uses libcurl.
On second thought, I think CURLE_TLSAUTH_FAILED should be eliminated. It
was only being raised when an internal error occurred while allocating
or setting the GnuTLS SRP client credentials struct. For TLS
authentication failures, the general CURLE_SSL_CONNECT_ERROR seems
appropriate; its error string already includes "passwords" as a possible
cause. Having a separate TLS auth error code might also cause people to
think that a TLS auth failure means the wrong username or password was
entered, when it could also be a sign of a man-in-the-middle attack.
This is a meta symbol. OR this value together with a single specific
auth value to force libcurl to probe for un-restricted auth and if not,
only that single auth algorithm is acceptable.
For example you can use CURLAUTH_DIGEST|CURLAUTH_ONLY to make libcurl
first probe for what method to use, but yet only consider Digest to be
acceptable.
Using _only_ CURLAUTH_DIGEST without the CURLAUTH_ONLY field, will make
libcurl explicitly use Digest right away and not do any probing.
I've developed a script I call symbol-scan.pl that scans the curl.h and
multi.h header files and compare the symbols it finds in there with the
symbols symbols-in-versions documents and outputs a report on the
differences. Using this I've dug through the history to fill up
symbols-in-versions with all the symbols my script found mismatches for.
I will commit symbol-scan.pl separatly and think of a way to put it to
use in the build/tests so that we from now on will get this in-sync
check automatically.
With the curl memory tracking feature decoupled from the debug build feature,
CURLDEBUG and DEBUGBUILD preprocessor symbol definitions are used as follows:
CURLDEBUG used for curl debug memory tracking specific code (--enable-curldebug)
DEBUGBUILD used for debug enabled specific code (--enable-debug)