- Fix connection reuse for when the proposed new conn 'needle' has a
specified local port but does not have a specified device interface.
Bug: https://curl.haxx.se/mail/lib-2016-11/0137.html
Reported-by: bjt3[at]hotmail.com
Visual C++ now complains about implicitly casting time_t (64-bit) to
long (32-bit). Fix this by changing some variables from long to time_t,
or explicitly casting to long where the public interface would be
affected.
Closes#1131
Previously, the [host] part was just ignored which made libcurl accept
strange URLs misleading users. like "file://etc/passwd" which might've
looked like it refers to "/etc/passwd" but is just "/passwd" since the
"etc" is an ignored host name.
Reported-by: Mike Crowe
Assisted-by: Kamil Dudka
- Call Curl_initinfo on init and duphandle.
Prior to this change the statistical and informational variables were
simply zeroed by calloc on easy init and duphandle. While zero is the
correct default value for almost all info variables, there is one where
it isn't (filetime initializes to -1).
Bug: https://github.com/curl/curl/issues/1103
Reported-by: Neal Poole
... to make it less likely that we forget that the function actually
does case insentive compares. Also replaced several invokes of the
function with a plain strcmp when case sensitivity is not an issue (like
comparing with "-").
Curl_select_ready() was the former API that was replaced with
Curl_select_check() a while back and the former arg setup was provided
with a define (in order to leave existing code unmodified).
Now we instead offer SOCKET_READABLE and SOCKET_WRITABLE for the most
common shortcuts where only one socket is checked. They're also more
visibly macros.
- Change back behavior so that pipelining is considered possible for
connections that have not yet reached the protocol level.
This is a follow-up to e5f0b1a which had changed the behavior of
checking if pipelining is possible to ignore connections that had
'bits.close' set. Connections that have not yet reached the protocol
level also have that bit set, and we need to consider pipelining
possible on those connections.
No longer attempt to use "doomed" to-be-closed connections when
pipelining. Prior to this change connections marked for deletion (e.g.
timeout) would be erroneously used, resulting in sporadic crashes.
As originally reported and fixed by Carlo Wood (origin unknown).
Bug: https://github.com/curl/curl/issues/627
Reported-by: Rider Linden
Closes https://github.com/curl/curl/pull/1075
Participation-by: nopjmp@users.noreply.github.com
Add the new option CURLOPT_KEEP_SENDING_ON_ERROR to control whether
sending the request body shall be completed when the server responds
early with an error status code.
This is suitable for manual NTLM authentication.
Reviewed-by: Jay Satiro
Closes https://github.com/curl/curl/pull/904
With HTTP/2 each transfer is made in an indivial logical stream over the
connection, making most previous errors that caused the connection to get
forced-closed now instead just kill the stream and not the connection.
Fixes#941
I discovered some people have been using "https://example.com" style
strings as proxy and it "works" (curl doesn't complain) because curl
ignores unknown schemes and then assumes plain HTTP instead.
I think this misleads users into believing curl uses HTTPS to proxies
when it doesn't. Now curl rejects proxy strings using unsupported
schemes instead of just ignoring and defaulting to HTTP.
After a few wasted hours hunting down the reason for slowness during a
TLS handshake that turned out to be because of TCP_NODELAY not being
set, I think we have enough motivation to toggle the default for this
option. We now enable TCP_NODELAY by default and allow applications to
switch it off.
This also makes --tcp-nodelay unnecessary, but --no-tcp-nodelay can be
used to disable it.
Thanks-to: Tim Rühsen
Bug: https://curl.haxx.se/mail/lib-2016-06/0143.html
Previously, passing a timeout of zero to Curl_expire() was a magic code
for clearing all timeouts for the handle. That is now instead made with
the new Curl_expire_clear() function and thus a 0 timeout is fine to set
and will trigger a timeout ASAP.
This will help removing short delays, in particular notable when doing
HTTP/2.
Mostly in order to support broken web sites that redirect to broken URLs
that are accepted by browsers.
Browsers are typically even more leniant than this as the WHATWG URL
spec they should allow an _infinite_ amount. I tested 8000 slashes with
Firefox and it just worked.
Added test case 1141, 1142 and 1143 to verify the new parser.
Closes#791
The proper FTP wildcard init is now more properly done in Curl_pretransfer()
and the corresponding cleanup in Curl_close().
The previous place of init/cleanup code made the internal pointer to be NULL
when this feature was used with the multi_socket() API, as it was made within
the curl_multi_perform() function.
Reported-by: Jonathan Cardoso Machado
Fixes#800
Only protocols that actually have a protocol registered for ALPN and NPN
should try to get that negotiated in the TLS handshake. That is only
HTTPS (well, http/1.1 and http/2) right now. Previously ALPN and NPN
would wrongly be used in all handshakes if libcurl was built with it
enabled.
Reported-by: Jay Satiro
Fixes#789
curl_printf.h defines printf to curl_mprintf, etc. This can cause
problems with external headers which may use
__attribute__((format(printf, ...))) markers etc.
To avoid that they cause problems with system includes, we include
curl_printf.h after any system headers. That makes the three last
headers to always be, and we keep them in this order:
curl_printf.h
curl_memory.h
memdebug.h
None of them include system headers, they all do funny #defines.
Reported-by: David Benjamin
Fixes#743
WinSock destroys recv() buffer if send() is failed. As result - server
response may be lost if server sent it while curl is still sending
request. This behavior noticeable on HTTP server short replies if
libcurl use several send() for request (usually for POST request).
To workaround this problem, libcurl use recv() before every send() and
keeps received data in intermediate buffer for further processing.
Fixes: #657Closes: #668
As these two options provide identical functionality, the former for
SOCK5 proxies and the latter for HTTP proxies, merged the two options
together.
As such CURLOPT_SOCKS5_GSSAPI_SERVICE is marked as deprecated as of
7.49.0.
Calculate the service name and proxy service names locally, rather than
in url.c which will allow for us to support overriding the service name
for other protocols such as FTP, IMAP, POP3 and SMTP.
Renamed the header and source files for this module as they are HTTP
specific and as such, they should use the naming convention as other
HTTP authentication source files do - this revert commit 260ee6b7bf.
Note: We could also rename curl_ntlm_wb.[c|h], however, the Winbind
code needs separating from the HTTP protocol and migrating into the
vauth directory, thus adding support for Winbind to the SASL based
protocols such as IMAP, POP3 and SMTP.
libidn's tld_check_lz returns an error offset of the first character
that it failed to process, however that offset is not a byte offset and
may not even be in the locale encoding therefore we can't use it to show
the user the character that failed to process.
Bug: https://github.com/curl/curl/issues/731
Reported-by: Karlson2k
I got a crash with this stack:
curl/lib/url.c:2873 (Curl_removeHandleFromPipeline)
curl/lib/url.c:2919 (Curl_getoff_all_pipelines)
curl/lib/multi.c:561 (curl_multi_remove_handle)
curl/lib/url.c:415 (Curl_close)
curl/lib/easy.c:859 (curl_easy_cleanup)
Closes#704
Prevent a crash if 2 (or more) requests are made to the same host and
pipelining is enabled and the connection does not complete.
Bug: https://github.com/curl/curl/pull/690
Some TFTP server implementations ignore the "TFTP Option extension"
(RFC 1782-1784, 2347-2349), or implement it in a flawed way, causing
problems with libcurl. Another switch for curl_easy_setopt
"CURLOPT_TFTP_NO_OPTIONS" is introduced which prevents libcurl from
sending TFTP option requests to a server, avoiding many problems caused
by faulty implementations.
Bug: https://github.com/curl/curl/issues/481
When an HTTP/2 upgrade request fails (no protocol switch), it would
previously detect that as still possible to pipeline on (which is
acorrect) and do that when PIPEWAIT was enabled even if pipelining was
not explictily enabled.
It should only pipelined if explicitly asked to.
Closes#584
Before this patch, if a URL does not start with the protocol
name/scheme, effective URLs would be prefixed with upper-case protocol
names/schemes. This behavior might not be expected by library users or
end users.
For example, if `CURLOPT_DEFAULT_PROTOCOL` is set to "https". And the
URL is "hostname/path". The effective URL would be
"HTTPS://hostname/path" instead of "https://hostname/path".
After this patch, effective URLs would be prefixed with a lower-case
protocol name/scheme.
Closes#597
Signed-off-by: Mohammad AlSaleh <CE.Mohammad.AlSaleh@gmail.com>
To make sure curl doesn't allow multiplexing before a connection is
upgraded to HTTP/2 (like when Upgrade: h2c fails), we must make sure the
connection uses HTTP/2 as well and not only check what's wanted.
Closes#584
Patch-by: c0ff
Try harder to prevent libcurl from opening up an additional socket when
CURLOPT_PIPEWAIT is set. Accomplished by letting ongoing TCP and TLS
handshakes complete first before the decision is made.
Closes#575
It would previously be skipped if an existing error was returned, but
would lead to a previous value being left there and later used.
CURLINFO_TOTAL_TIME for example.
Still it avoids that final progress update if we reached DONE as the
result of a callback abort to avoid another callback to be called after
an abort-by-callback.
Reported-by: Lukas Ruzicka
Closes#538
They tend to never get updated anyway so they're frequently inaccurate
and we never go back to revisit them anyway. We document issues to work
on properly in KNOWN_BUGS and TODO instead.
... and assign it from the set.fread_func_set pointer in the
Curl_init_CONNECT function. This A) avoids that we have code that
assigns fields in the 'set' struct (which we always knew was bad) and
more importantly B) it makes it impossibly to accidentally leave the
wrong value for when the handle is re-used etc.
Introducing a state-init functionality in multi.c, so that we can set a
specific function to get called when we enter a state. The
Curl_init_CONNECT is thus called when switching to the CONNECT state.
Bug: https://github.com/bagder/curl/issues/346Closes#346
If the port number in the proxy string ended weirdly or the number is
too large, skip it. Mostly as a means to bail out early if a "bare" IPv6
numerical address is used without enclosing brackets.
Also mention the bracket requirement for IPv6 numerical addresses to the
man page for CURLOPT_PROXY.
Closes#415
Reported-by: Marcel Raad
- Add new option CURLOPT_DEFAULT_PROTOCOL to allow specifying a default
protocol for schemeless URLs.
- Add new tool option --proto-default to expose
CURLOPT_DEFAULT_PROTOCOL.
In the case of schemeless URLs libcurl will behave in this way:
When the option is used libcurl will use the supplied default.
When the option is not used, libcurl will follow its usual plan of
guessing from the hostname and falling back to 'http'.
New tool option --ssl-no-revoke.
New value CURLSSLOPT_NO_REVOKE for CURLOPT_SSL_OPTIONS.
Currently this option applies only to WinSSL where we have automatic
certificate revocation checking by default. According to the
ssl-compared chart there are other backends that have automatic checking
(NSS, wolfSSL and DarwinSSL) so we could possibly accommodate them at
some later point.
Bug: https://github.com/bagder/curl/issues/264
Reported-by: zenden2k <zenden2k@gmail.com>
With many easy handles using the same connection for multiplexing, it is
important we store and keep the transfer-oriented stuff in the
SessionHandle so that callbacks and callback data work fine even when
many easy handles share the same physical connection.
to allow code to act differently on the situation.
Also added some more info message for the connection re-use function to
make it clearer when connections are not re-used.
All the existing Curl_bundle* functions were only ever used from within
the conncache.c file, so I moved them over and made them static (and
removed the Curl_ prefix).
This avoids unnecessary dynamic allocs and as this also removed the last
users of *hash_alloc() and *hash_destroy(), those two functions are now
removed.
Make the HTTP headers separated by default for improved security and
reduced risk for information leakage.
Bug: http://curl.haxx.se/docs/adv_20150429.html
Reported-by: Yehezkel Horowitz, Oren Souroujon
If a URL is given with a zero-length host name, like in "http://:80" or
just ":80", `fix_hostname()` will index the host name pointer with a -1
offset (as it blindly assumes a non-zero length) and both read and
assign that address.
CVE-2015-3144
Bug: http://curl.haxx.se/docs/adv_20150422D.html
Reported-by: Hanno Böck
Since we just started make use of free(NULL) in order to simplify code,
this change takes it a step further and:
- converts lots of Curl_safefree() calls to good old free()
- makes Curl_safefree() not check the pointer before free()
The (new) rule of thumb is: if you really want a function call that
frees a pointer and then assigns it to NULL, then use Curl_safefree().
But we will prefer just using free() from now on.
The following functions return immediately if a null pointer was passed.
* Curl_cookie_cleanup
* curl_formfree
It is therefore not needed that a function caller repeats a corresponding check.
This issue was fixed by using the software Coccinelle 1.0.0-rc24.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
The function "free" is documented in the way that no action shall occur for
a passed null pointer. It is therefore not needed that a function caller
repeats a corresponding check.
http://stackoverflow.com/questions/18775608/free-a-null-pointer-anyway-or-check-first
This issue was fixed by using the software Coccinelle 1.0.0-rc24.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
When checking for a connection to re-use, a proxy-using request must
check for and use a proxy connection and not one based on the host
name!
Added test 1421 to verify
Bug: http://curl.haxx.se/bug/view.cgi?id=1492
SSL_CTX_load_verify_locations by default (and if given non-Null
parameters) searches the CAfile first and falls back to CApath. This
allows for CAfile to be a basis (e.g. installed by the package manager)
and CApath to be a user configured directory.
This wasn't reflected by the previous configure constraint which this
patch fixes.
Bug: https://github.com/bagder/curl/pull/139
This option can be used to enable/disable certificate status verification using
the "Certificate Status Request" TLS extension defined in RFC6066 section 8.
This also adds the CURLE_SSL_INVALIDCERTSTATUS error, to be used when the
certificate status verification fails, and the Curl_ssl_cert_status_request()
function, used to check whether the SSL backend supports the status_request
extension.
There was a confusion between these: this commit tries to disambiguate them.
- Scope can be computed from the address itself.
- Scope id is scope dependent: it is currently defined as 1-based local
interface index for link-local scoped addresses, and as a site index(?) for
(obsolete) site-local addresses. Linux only supports it for link-local
addresses.
The URL parser properly parses a scope id as an interface index, but stores it
in a field named "scope": confusion. The field has been renamed into "scope_id".
Curl_if2ip() used the scope id as it was a scope. This caused failures
to bind to an interface.
Scope is now computed from the addresses and Curl_if2ip() matches them.
If redundantly specified in the URL, scope id is check for mismatch with
the interface index.
This commit should fix SF bug #1451.
This fixes the test 506 torture test. The internal cookie API really
ought to be improved to separate cookie parsing errors (which may be
ignored) with OOM errors (which should be fatal).
As Windows based autoconf builds don't yet define USE_WIN32_CRYPTO
either explicitly through --enable-win32-cypto or automatically on
_WIN32 based platforms, subsequent builds broke with the following
error message:
"Can't compile NTLM support without a crypto library."
The ability to do HTTP requests over a UNIX domain socket has been
requested before, in Apr 2008 [0][1] and Sep 2010 [2]. While a
discussion happened, no patch seems to get through. I decided to give it
a go since I need to test a nginx HTTP server which listens on a UNIX
domain socket.
One patch [3] seems to make it possible to use the
CURLOPT_OPENSOCKETFUNCTION function to gain a UNIX domain socket.
Another person wrote a Go program which can do HTTP over a UNIX socket
for Docker[4] which uses a special URL scheme (though the name contains
cURL, it has no relation to the cURL library).
This patch considers support for UNIX domain sockets at the same level
as HTTP proxies / IPv6, it acts as an intermediate socket provider and
not as a separate protocol. Since this feature affects network
operations, a new feature flag was added ("unix-sockets") with a
corresponding CURL_VERSION_UNIX_SOCKETS macro.
A new CURLOPT_UNIX_SOCKET_PATH option is added and documented. This
option enables UNIX domain sockets support for all requests on the
handle (replacing IP sockets and skipping proxies).
A new configure option (--enable-unix-sockets) and CMake option
(ENABLE_UNIX_SOCKETS) can disable this optional feature. Note that I
deliberately did not mark this feature as advanced, this is a
feature/component that should easily be available.
[0]: http://curl.haxx.se/mail/lib-2008-04/0279.html
[1]: http://daniel.haxx.se/blog/2008/04/14/http-over-unix-domain-sockets/
[2]: http://sourceforge.net/p/curl/feature-requests/53/
[3]: http://curl.haxx.se/mail/lib-2008-04/0361.html
[4]: https://github.com/Soulou/curl-unix-socket
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
USE_NTLM would only be defined if: HTTP support was enabled, NTLM and
cryptography weren't disabled, and either a supporting cryptography
library or Windows SSPI was being compiled against.
This means it was not possible to build libcurl without HTTP support
and use NTLM for other protocols such as IMAP, POP3 and SMTP. Rather
than introduce a new SASL pre-processor definition, removed the HTTP
prerequisite just like USE_SPNEGO and USE_KRB5.
Note: Winbind support still needs to be dependent on CURL_DISABLE_HTTP
as it is only available to HTTP at present.
This bug dates back to August 2011 when I started to add support for
NTLM to SMTP.
When duplicating a handle, the data to post was duplicated using
strdup() when it could be binary and contain zeroes and it was not even
zero terminated! This caused read out of bounds crashes/segfaults.
Since the lib/strdup.c file no longer is easily shared with the curl
tool with this change, it now uses its own version instead.
Bug: http://curl.haxx.se/docs/adv_20141105.html
CVE: CVE-2014-3707
Reported-By: Symeon Paraschoudis
... for the local variable name in functions holding the return
code. Using the same name universally makes code easier to read and
follow.
Also, unify code for checking for CURLcode errors with:
if(result) or if(!result)
instead of
if(result == CURLE_OK), if(CURLE_OK == result) or if(result != CURLE_OK)
Option --pinnedpubkey takes a path to a public key in DER format and
only connect if it matches (currently only implemented with OpenSSL).
Provides CURLOPT_PINNEDPUBLICKEY for curl_easy_setopt().
Extract a public RSA key from a website like so:
openssl s_client -connect google.com:443 2>&1 < /dev/null | \
sed -n '/-----BEGIN/,/-----END/p' | openssl x509 -noout -pubkey \
| openssl rsa -pubin -outform DER > google.com.der
Coverity CID 1202836. If the proxy environment variable returned an empty
string, it would be leaked. While an empty string is not really a proxy, other
logic in this function already allows a blank string to be returned so allow
that here to avoid the leak.
This was done to make sure NTLM state that is bound to a connection
doesn't survive and gets used for the subsequent request - but
disconnects can also be done to for example make room in the connection
cache and thus that connection is not strictly related to the easy
handle's current operation.
The http authentication state is still kept in the easy handle since all
http auth _except_ NTLM is connection independent and thus survive over
multiple connections.
Bug: http://curl.haxx.se/mail/lib-2014-08/0148.html
Reported-by: Paras S
Problem: if CURLOPT_FORBID_REUSE is set, requests using NTLM failed
since NTLM requires multiple requests that re-use the same connection
for the authentication to work
Solution: Ignore the forbid reuse flag in case the NTLM authentication
handshake is in progress, according to the NTLM state flag.
Fixed known bug #77.
The URL is not a property of the connection so it should not be freed in
the connection disconnect but in the Curl_close() that frees the easy
handle.
Bug: http://curl.haxx.se/mail/lib-2014-08/0148.html
Reported-by: Paras S
Bringing back the old functionality that was mistakenly removed when the
connection cache was remade. When creating a new connection, all the
existing ones are checked and those that are known to be dead get
disconnected for real and removed from the connection cache. It helps
the cache from holding on to very many stale connections and aids in
keeping down the number of system sockets in wait states.
Help-by: Jonatan Vela <jonatan.vela@ergon.ch>
Bug: http://curl.haxx.se/mail/lib-2014-06/0189.html
- Replace CURLAUTH_GSSNEGOTIATE with CURLAUTH_NEGOTIATE
- CURL_VERSION_GSSNEGOTIATE is deprecated which
is served by CURL_VERSION_SSPI, CURL_VERSION_GSSAPI and
CURUL_VERSION_SPNEGO now.
- Remove display of feature 'GSS-Negotiate'
When an error has been detected, skip the final forced call to the
progress callback by making sure to pass the current return code
variable in the Curl_done() call in the CURLM_STATE_DONE state.
This avoids the "extra" callback that could occur even if you returned
error from the progress callback.
Bug: http://curl.haxx.se/mail/lib-2014-06/0062.html
Reported by: Jonathan Cardoso Machado
The static connection counter caused a race condition. Moving the
connection id counter into conncache solves it, as well as simplifying
the related logic.
Make all code use connclose() and connkeep() when changing the "close
state" for a connection. These two macros take a string argument with an
explanation, and debug builds of curl will include that in the debug
output. Helps tracking connection re-use/close issues.
Depending on compiler line 3505 could generate the following warning or
error:
* warning: ISO C90 forbids mixed declarations and code
* A declaration cannot appear after an executable statement in a block
* error C2275: 'size_t' : illegal use of this type as an expression
set.infilesize in this case was modified in several places, which could
lead to repeated requests using the same handle to get unintendent/wrong
consequences based on what the previous request did!
This makes the findprotocol() function work as intended so that libcurl
can properly be restricted to not support HTTP while still supporting
HTTPS - since the HTTPS handler previously set both the HTTP and HTTPS
bits in the protocol field.
This fixes --proto and --proto-redir for most SSL protocols.
This is done by adding a few new convenience defines that groups HTTP
and HTTPS, FTP and FTPS etc that should then be used when the code wants
to check for both protocols at once. PROTO_FAMILY_[protocol] style.
Bug: https://github.com/bagder/curl/pull/97
Reported-by: drizzt
In addition to FTP, other connection based protocols such as IMAP, POP3,
SMTP, SCP, SFTP and LDAP require a new connection when different log-in
credentials are specified. Fixed the detection logic to include these
other protocols.
Bug: http://curl.haxx.se/docs/adv_20140326A.html
Port number zero is perfectly allowed to connect to. I moved to storing
the remote port number in an int so that -1 means undefined and 0-65535
can be used for legitimate port numbers.
When allowing NTLM, the re-use connection logic was too focused on
finding an existing NTLM connection to use and didn't properly allow
re-use of other ones. This made the logic not re-use perfectly re-usable
connections.
Added test case 1418 and 1419 to verify.
Regression brought in 8ae35102c (curl 7.35.0)
Reported-by: Jeff King
Bug: http://thread.gmane.org/gmane.comp.version-control.git/242213
Make sure that the special NTLM magic we do is for HTTP+NTLM only since
that's where the authenticated connection is a weird non-standard
paradigm.
Regression brought in 8ae35102c (curl 7.35.0)
Bug: http://curl.haxx.se/mail/lib-2014-02/0100.html
Reported-by: Dan Fandrich
when using --http2 one can now selectively disable NPN or ALPN with
--no-alpn and --no-npn. for now honored with NSS only.
TODO: honor this option with GnuTLS and OpenSSL
Removed some of the infof() calls that were added with the recent
pipeline improvements but they're not useful to the vast majority of
readers and the pipelining seems to fundamentaly work - the debugging
outputs can easily be added there if debugging these functions is needed
again.
When the requested authentication bitmask includes NTLM, we cannot
re-use a connection for another username/password as we then risk
re-using NTLM (connection-based auth).
This has the unfortunate downside that if you include NTLM as a possible
auth, you cannot re-use connections for other usernames/passwords even
if NTLM doesn't end up the auth type used.
Reported-by: Paras S
Patched-by: Paras S
Bug: http://curl.haxx.se/mail/lib-2014-01/0046.html
Following commit 0aafd77fa4, replaced the internal usage of
FORMAT_OFF_T and FORMAT_OFF_TU with the external versions that we
expect API programmers to use.
This negates the need for separate definitions which were subtly
different under different platforms/compilers.
To avoid the regression when users pass in passwords containing semi-
colons, we now drop the ability to set the login options with the same
options. Support for login options in CURLOPT_USERPWD was added in
7.31.0.
Test case 83 was modified to verify that colons and semi-colons can be
used as part of the password when using -u (CURLOPT_USERPWD).
Bug: http://curl.haxx.se/bug/view.cgi?id=1311
Reported-by: Petr Bahula
Assisted-by: Steve Holme
Signed-off-by: Daniel Stenberg <daniel@haxx.se>
Rather than set the authentication options as part of the login details
specified in the URL, or via the older CURLOPT_USERPWD option, added a
new libcurl option to allow the login options to be set separately.
This patch adds a 200ms delay between the first and second address
family socket connection attempts.
It also iterates over IP addresses in the order returned by the
system, meaning most dual-stack systems will try IPv6 first.
Additionally, it refactors the connect code, removing most code that
handled synchronous connects. Since all sockets are now non-blocking,
the logic can be made simpler.
This patch invokes two socket connect()s nearly simultaneously, and
the socket that is first connected "wins" and is subsequently used for
the connection. The other is terminated.
There is a very slight IPv4 preference, in that if both sockets connect
simultaneously IPv4 is checked first and thus will win.
This is a regression since the switch to always-multi internally
c43127414d.
Test 1316 was modified since we now clearly call the Curl_client_write()
function when doing the LIST transfer part and then the
handler->protocol says FTP and ftpc.transfertype is 'A' which implies
text converting even though that the response is initially a HTTP
CONNECT response in this case.
Otherwise, the FTP protocol would unnecessarily hang 60 seconds if
aborted in the CURLOPT_HEADERFUNCTION callback.
Reported by: Tomas Mlcoch
Bug: https://bugzilla.redhat.com/1005686
