Re: libssh: 0.5 ssh_connect hangs if you connect your own socket

["Oliver Stöneberg" <oliverst@xxxxxxxxx>]

Could you try using the latest version from the repository? You can 
download it from 
http://git.libssh.org/projects/libssh.git/snapshot/libssh-v0-5.zip

I expereinced similar issues and submitted some fixes. Apparently it 
broke something with nonblocking sessions, which I still have to look 
into, but I haven't seen any hangs in ssh_connect() with those.

> I'm attempting to switch over from libssh 0.4.8 to 0.5 (RC), and I'm having
> a problem when I try to connect the socket myself instead of relying on
> ssh_connect to do so:
> ssh_connect never returns.  On Windows, it chews up 100% of the CPU; on
> Linux, it just hangs.  
> 
> This works under 0.4.8.
> 
> Here's a test program:
> --------------------
> // libsshmrr2.cpp - Program to test hang in libssh's ssh_connect when
> // you use your own socket.
> // Mark Riordan  2011-05-17
> 
> #include <stdio.h>
> #include <string>
> #ifdef WIN32
> #else
> #include <sys/socket.h>
> #include <netinet/in.h>
> #include <arpa/inet.h>
> #include <errno.h>
> #define SOCKET int
> #endif
> #include "libssh/libssh.h"
> 
> using namespace std;
> 
> int doSSH()
> {
>    ssh_session session;
>    session=ssh_new();
> 
>    struct struct_settings {
>       string host;
>       int port;
>       string user;
>       int verbosity;
>    } settings;
>    settings.host="172.16.22.182";
>    settings.port = 22;
>    settings.user="mrr";
>    settings.verbosity=SSH_LOG_FUNCTIONS;
> 
>    printf("libssh version: %s\n", ssh_version(0));
> 
>    if (ssh_options_set(session, SSH_OPTIONS_USER, settings.user.c_str()) <
> 0) {
>       printf("Could not set user\n");
>       return 22;
>    }
> 
>    bool bUsingOwnSocket=true;
>    if(bUsingOwnSocket) {
> #ifdef WIN32
>       WSADATA         wsadata;
>       WSAStartup(MAKEWORD(2, 0), &wsadata);
> #endif
>       SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);
> 
>       unsigned long hostaddr = inet_addr(settings.host.c_str());
> 
>       struct sockaddr_in sin;
>       sin.sin_family = AF_INET;
>       sin.sin_port = htons(settings.port);
>       sin.sin_addr.s_addr = hostaddr;
>       if (connect(sock, (struct sockaddr *) (&sin),
>          sizeof(struct sockaddr_in)) != 0) {
> #ifdef WIN32
>          int err = WSAGetLastError();
> #else
>          int err = errno;
> #endif
>          printf("Failed to connect: error %d\n", err);
>         return 20;
>       } else {
>          printf("Connected our own socket to %s\n", settings.host.c_str());
>       }
>       if (ssh_options_set(session, SSH_OPTIONS_FD, &sock) < 0) {
>          return 21;
>       }
>    } else {
>       if (ssh_options_set(session, SSH_OPTIONS_HOST, settings.host.c_str())
> < 0) {
>          printf("Could not set host\n");
>          return 23;
>       }
>    }
>    ssh_options_set(session, SSH_OPTIONS_LOG_VERBOSITY, &settings.verbosity);
> 
>    if(ssh_connect(session)){
>       fprintf(stderr,"Connection failed : %s\n",ssh_get_error(session));
>       ssh_disconnect(session);
>       return 24;
>    } else {
>       printf("ssh_connect succeeded.\n");
>    }
> 
>    return 0;
> }
> 
> int main(int argc, char* argv[])
> {
>    int retval = doSSH();
>    printf("Press Enter to exit: ");
>    getchar();
>    return retval;
> }
> --------------------
> ssh_connect succeeds if I set bUsingOwnSocket to false.  
> If I set it to true, I get output like this on Linux:
> 
> Connected our own socket to 172.16.22.182
> [func] entering function ssh_connect line 628 in
> /home/mrr/dist/master/src/client.c
> [1] libssh 0.5.0 (c) 2003-2010 Aris Adamantiadis (aris@xxxxxxxxxxxx)
> Distributed under the LGPL, please refer to COPYING file for information
> about your rights, using threading threads_noop
> [2] Socket connecting, now waiting for the callbacks to work
> [func]  entering function ssh_handle_packets line 420 in
> /home/mrr/dist/master/src/session.c
> (then nothing)
> 
> On Windows, I get:
> Connected our own socket to 172.16.22.182
> [func] entering function ssh_connect line 628 in ..\..\src\client.c
> [1] libssh 0.5.0 (c) 2003-2010 Aris Adamantiadis (aris@xxxxxxxxxxxx)
> Distributed
> under the LGPL, please refer to COPYING file for information about your
> rights,
> using threading threads_noop
> [2] Socket connecting, now waiting for the callbacks to work
> [func] entering function ssh_handle_packets line 436 in ..\..\src\session.c
> [func] leaving function ssh_handle_packets line 449 in ..\..\src\session.c
> [func] entering function ssh_handle_packets line 436 in ..\..\src\session.c
> [func] leaving function ssh_handle_packets line 449 in ..\..\src\session.c
> ... (endless loop of last two lines)
> 
> I think that the problem under Windows is that in poll.c's bsd_poll,
> ssh_pollfd_t events==0, and hence bsd_poll is returning an error without
> even bothering to call select().
> 
> I get the same symptoms with both 0.4.91 from 2011-03-23, and today's
> version from git.
> 
> Any ideas?
> 
> Thanks,
> 
> Mark R
> 
> 
> 
> 
>