I've tested this on a different SFTP server and the problem doesn't exist. It appears that the SFTP server our company is using has this bug.
Thanks for your help, Bob -----Original Message----- From: libssh2-devel [mailto:libssh2-devel-boun...@cool.haxx.se] On Behalf Of Daniel Stenberg Sent: Wednesday, March 12, 2014 3:42 PM To: libssh2 development Subject: Re: SFTP read problems On Sat, 8 Mar 2014, Bob Kast wrote: > When doing a read a file that is about 12k, it fails partway through > with LIBSSH2_ERROR_SFTP_PROTOCOL. In looking closer, it is at this > point in > sftp.c: > > if(rc32 > chunk->len) { > /* A chunk larger than we requested was returned to us. > This is a protocol violation and we don't know how to > deal with it. Bail out! */ > return _libssh2_error(session, > LIBSSH2_ERROR_SFTP_PROTOCOL, > "FXP_READ response too big"); > } > > My code requests a block of 4096. It multiplies that by 4 (16,384), > then it starts doing packets requesting 2000 characters. After it's > done 8 of these, the 'count' goes down to 384, which is what > chunk->len is set to above. rc32 is set to 2000 so it fails. I assume you're trying with the latest libssh2 version? > I've found if I have the requested buffer at exactly a multiple of > 2000, it seems to work, although I'm somewhat nervous about it working for all cases. > > Is this expected? It is not documented. It is not expected. The check above is there to detect the error situation when a server returns a bigger chunk than what we asked for. libssh2 splits up data sizes into smaller chunks and ask for them one by one, so chunk->len is supposed to be the size of the chunk it asked for. -- / daniel.haxx.se _______________________________________________ libssh2-devel http://cool.haxx.se/cgi-bin/mailman/listinfo/libssh2-devel _______________________________________________ libssh2-devel http://cool.haxx.se/cgi-bin/mailman/listinfo/libssh2-devel
