Before this patch "_libssh2_error" required the error message to be a
static string.
This patch adds a new function "_libssh2_error_flags" accepting an
additional "flags" argument and specifically the flag
"LIBSSH2_ERR_FLAG_DUP" indicating that the passed string must be
duplicated into the heap.
Then, the method "_libssh2_error" has been rewritten to use that new
function under the hood.
Signed-off-by: Salvador Fandino <sfandino@yahoo.com>
Signed-off-by: Salvador Fandiño <sfandino@yahoo.com>
A common novice programmer error (at least among those using the
wrapping Perl module Net::SSH2), is to try to reuse channels.
This patchs detects that incorrect usage and fails with a
LIBSSH2_ERROR_BAD_USE error instead of hanging.
Signed-off-by: Salvador Fandino <sfandino-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
Until now, the window size (channel->remote.window_size) was being
updated just after receiving the packet from the transport layer.
That behaviour is wrong because the channel queue may grow uncontrolled
when data arrives from the network faster that the upper layer consumes
it.
This patch adds a new counter, read_avail, which keeps a count of the
bytes available from the packet queue for reading. Also, now the window
size is adjusted when the data is actually read by an upper layer.
That way, if the upper layer stops reading data, the window will
eventually fill and the remote host will stop sending data. When the
upper layers reads enough data, a window adjust packet is delivered and
the transfer resumes.
The read_avail counter is used to detect the situation when the remote
server tries to send data surpassing the window size. In that case, the
extra data is discarded.
Signed-off-by: Salvador <sfandino@yahoo.com>
Add a "use_in_auth" flag to the LIBSSH2_COMP_METHOD struct and a
separate "zlib@openssh.com" method, along with checking session->state
for LIBSSH2_STATE_AUTHENTICATED. Appears to work on the OpenSSH servers
I've tried against, and it should work as before with normal zlib
compression.
Usually a format macro should hold the whole format, otherwise
it should be named a prefix. Also fixed usage of this macro in
scp.c for a signed var where it was used as prefix for unsigned.
Partly reverse 566894494b4972ae12 which was simplifying the code far too
much and ended up overflowing a buffer within the LIBSSH2_SESSION
struct. Back to allocating the buffer properly like it used to do.
Bug: http://www.libssh2.org/mail/libssh2-devel-archive-2011-06/0032.shtml
Reported by: Alfred Gebert
Added crypto.h that is the unified header to include when using crypto
functionality. It should be the only header that needs to adapt to the
underlying crypto library in use. It provides the set of prototypes that
are library agnostic.
The attempts made to have _libssh2_channel_write() accept larger pieces
of data and split up the data by itself into 32700 byte chunks and pass
them on to channel_write() in a loop as a way to do faster operations on
larger data blocks was a failed attempt.
The reason why it is difficult:
The API only allows EAGAIN or a length to be returned. When looping over
multiple blocks to get sent, one block can get sent and the next might
not. And yet: when transport_send() has returned EAGAIN we must not call
it again with new data until it has returned OK on the existing data it
is still working on. This makes it a mess and we do get a much easier
job by simply returning the bytes or EAGAIN at once, as in the EAGAIN
case we can assume that we will be called with the same arguments again
and transport_send() will be happy.
Unfortunately, I think we take a small performance hit by not being able
to do this.
Starting now, we unconditionally use the internal replacement functions
for send() and recv() - creatively named _libssh2_recv() and
_libssh2_send().
On errors, these functions return the negative 'errno' value instead of
the traditional -1. This design allows systems that have no "natural"
errno support to not have to invent it. It also means that no code
outside of these two transfer functions should use the errno variable.
When SCP send or recv fails, it gets a special message from the server
with a warning or error message included. We have no current API to
expose that message but the foundation is there. Removed unnecessary use
of session struct fields.
I added size checks in several places. I fixed the code flow to be easier
to read in some places.
I removed unnecessary zeroing of structs. I removed unused struct fields.
We don't like magic numbers in the code. Now the acceptable failure
codes sent in the SSH_MSG_CHANNEL_OPEN_FAILURE message are added as
defined values in the private header file.
The sftp_write function shouldn't assume that the buffer pointer will be
the same in subsequent calls, even if it assumes that the data already
passed in before haven't changed.
The sftp structs are now moved to sftp.h (which I forgot to add before)
sftp_write was rewritten to split up outgoing data into multiple packets
and deal with the acks in a more asynchronous manner. This is meant to
help overcome latency and round-trip problems with the SFTP protocol.
Neither _libssh2_channel_write nor sftp_write now have the 32500 size
limit anymore and instead the channel writing function now has its own
logic to send data in multiple calls until everything is sent.
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.
We now allow libssh2_session_flag() to enable compression with a new
flag and I added documentation for the previous LIBSSH2_FLAG_SIGPIPE
flag which I wasn't really aware of!
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.
The LIBSSH2_DEBUG macro, defined in libssh2_priv.h, incorrectly uses the
function variable ssh_msg_disconnect when it should use ssh_msg_debug.
This shows that the LIBSSH2_CALLBACK_DEBUG callback never has worked...
'last_errno' holds to the error code from the SFTP protocol and
since that is 32 bits on the wire there's no point in using a
long for this internally which is larger on some platforms.
