The new function takes two data areas, combines them and sends them as a
single SSH packet. This allows several functions to allocate and copy
less data.
I also found and fixed a mixed up use of the compression function
arguments that I introduced in my rewrite in a recent commit.
In the transport functions we avoid a strcmp() now and just check a
boolean instead.
The compress/decompress function's return code is now acknowledged and
used as actual return code in case of failures.
LIBSSH2_SOCKET_NONE (-1) should no longer be used as error code as it is
(too) generic and we should instead use specific and dedicated error
codes to better describe the error.
To get the blocking vs non-blocking to work as smooth as possible
and behave better internally, we avoid using the external
interfaces when calling functions internally.
Renamed a few internal functions to use _libssh2 prefix when not
being private within a file, and removed the libssh2_ for one
that was private within the file.
I'll introduce a new internal function set named
_libssh2_store_u32
_libssh2_store_u64
_libssh2_store_str
That can be used all through the library to build binary outgoing
packets. Using these instead of the current approach removes
hundreds of lines from the library while at the same time greatly
enhances readability. I've not yet fully converted everything to
use these functions.
I've converted LOTS of 'unsigned long' to 'size_t' where
data/string lengths are dealt with internally. This is The Right
Thing and it will help us make the transition to our
size_t-polished API later on as well.
I'm removing the PACKET_* error codes. They were originally
introduced as a set of separate error codes from the transport
layer, but having its own set of errors turned out to be very
awkward and they were then converted into a set of #defines that
simply maps them to the global libssh2 error codes instead. Now,
I'l take the next logical step and simply replace the PACKET_*
defines with the actual LIBSSH2_ERROR_* defines. It will increase
readability and decrease confusion.
I also separated packet stuff into its own packet.h header file.
We reserve ^libssh2_ for public symbols and we use _libssh2 as
prefix for internal ones. I fixed the intendation of all these
edits with emacs afterwards, which then changed it slightly more
than just _libssh2_error() expressions but I didn't see any
obvious problems.
When we ignore the EAGAIN from the transport layer within channel_write, we
now drain the outgoing transport layer buffer so that remainders in that
won't cause any problems in the next invoke of _libssh2_transport_write()
commit 7317edab61d2179febc38a2c2c4da0b951d74cbc cleared the outbound
blocking bit when send_existing() returned PACKET_NONE and *ret=0, as
opposed to before even calling send_existing(), but because *ret=1 when
sending parts 2..n of an existing packet, the bit would only be cleared
when calling libssh2_transport_write() for a new packet.
Clear the direction flag after the final part of a packet has been sent.
libssh2_error() no longer allocates a string and only accepts a const
error string. I also made a lot of functions use the construct of
return libssh2_error(...) instead of having one call to
libssh2_error() and then a separate return call. In several of those
cases I then also changed the former -1 return code to a more
detailed one - something that I think will not change behaviors
anywhere but it's worth keeping an eye open for any such.
The libssh2_trace_sethandler() call allows the user to handle the output of libssh2 rather than having it written to stderr. This patch updates libssh2_trace_sethandler() to allow a user-defined void* context value to be passed back to the output handler.
Commit 683aa0f6b52fb1014873c961709102b5006372fc made send_existing() send
more than just the second part of a packet when the kernel did not accept
the full packet, but the function still overlooked the SSH protocol
overhead in each packet, often 48 bytes.
If only the last few bytes of a packet remained, then the packet would
erroneously be considered completely sent, and the next call to write
more data in the session would return a -39 error.
When libssh2_transport_write() is called to continue sending a
partially sent packet the write direction flag must not be cleared
until the previous packet has been completely sent, or the app would
hang if the packet still isn't sent completely, since select() gets
called by the internal blocking emulation layer in libssh2 but would
then not be watching the socket for writability.
Clear the flag only once processing of previous packet data is
complete and a new packet is about to be prepared.
The channel layer sends packets using the transport layer, possibly
calling _libssh2_transport_write() many times for each packet.
The transport layer uses the send_existing() helper to send out any
remaining parts of previous packets before a new packet is started.
The bug made send_existing() consider the entire packet sent as soon as it
successfully sent the second part of a packet, even if the packet was not
completely done yet.
I made this change just to easier grep for "return .*EAGAIN" cases
as they should be very rare or done wrongly. Already worked to find
a flaw, marked with "TODO FIXME THIS IS WRONG" in channel.c. I also
fixed a few cases to become more general returns now when we have
more unified return codes internally.
Alexander Lamaison tracked down that my previous commit broke SFTP
reads in some aspects. The reversion now gets back to always recv()
until EAGAIN is returned so that the code no longer treats a short
read as an indication that it is "enough for now".
The bad commit in particular had another independent change included,
which is to clear the direction-bits first in the transport read
and write functions, but this reversion does not revert that change.
Clearing those bits first is a good thing.
The anonymous bug report #2822910 pointed out that debugdump() was
stupidly called within the send_existing() function. At closer
inspection was the report not only right, but it also revealed
another problem to me: when the _libssh2_send() function returns
after sending only a part of the buffer, it would then misbehave.
This probably is very rare though, which must be the reason we
haven't seen a bigger problem with this.
as we're already doing the correct check further down anyway there's no point
in doing the (wrong) check further up as well. Paul Veldkamp pointed this out.
and introduced a transport.h header.
* Fixed the blocking mode to only change behavior not the actual underlying
socket mode so we now always work with non-blocking sockets. This also
introduces a new rule of thumb in libssh2 code: we don't call the
external function calls internally. We use the internal (non-blocking)
ones!
* libssh2_channel_receive_window_adjust2 was added and
libssh2_channel_receive_window_adjust is now deprecated
* Introduced "local" header files with prototypes etc for different parts
instead of cramming everything into libssh2_priv.h. channel.h is the
first.
properly after recv() and send() calls (that internally are now known as
_libssh2_recv() and _libssh2_send()) so that the API and more works fine on
windows too!
some tests:
* cut off "_ex" from several internal function names
* corrected some log outputs
* simplified libssh2_channel_read_ex() and made it much faster in the process
* cut out {{{ and }}} comments that were incorrect anyway
* fixed sftp_packet_ask() to return the correct packet by using memcmp() and
not strncmp()
* fixed mkdir()'s wait for packet to use the correct request_id - it
semi-worked previously because strncmp() in sftp_packet_ask() made it
match far too easily.
* took away the polling functionality from sftp_packet_ask() since it wasn't
used
libssh2_session_block_directions() which returns a bitmask for what
directions the connection blocks. It is to be used applications that use
non-blocking sockets and when a libssh2 function returns
LIBSSH2_ERROR_EAGAIN this function can be used to figure out in which
direction the socket would block and thus it can wait for the socket to
again be ready for communication in that direction before it calls libssh2
again.
