[libvirt] [PATCH v2] remote: Print ssh stderr on connection failure

[Daniel Veillard]

On Thu, Feb 18, 2010 at 10:56:47AM -0500, Cole Robinson wrote:
> 
> Signed-off-by: Cole Robinson <crobinso at redhat.com>
> ---
>  src/remote/remote_driver.c |   38 +++++++++++++++++++++++++++++++++++---
>  1 files changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
> index 13534ce..8914c39 100644
> --- a/src/remote/remote_driver.c
> +++ b/src/remote/remote_driver.c
> @@ -154,6 +154,7 @@ struct private_data {
>      virMutex lock;
>  
>      int sock;                   /* Socket. */
> +    int errfd;                /* File handle connected to remote stderr */
>      int watch;                  /* File handle watch */
>      pid_t pid;                  /* PID of tunnel process */
>      int uses_tls;               /* TLS enabled on socket? */
> @@ -783,6 +784,7 @@ doRemoteOpen (virConnectPtr conn,
>      case trans_ext: {
>          pid_t pid;
>          int sv[2];
> +        int errfd[2];
>  
>          /* Fork off the external process.  Use socketpair to create a private
>           * (unnamed) Unix domain socket to the child process so we don't have
> @@ -794,14 +796,22 @@ doRemoteOpen (virConnectPtr conn,
>              goto failed;
>          }
>  
> +        if (pipe(errfd) == -1) {
> +            virReportSystemError(errno, "%s",
> +                                 _("unable to create socket pair"));
> +            goto failed;
> +        }
> +
>          if (virExec((const char**)cmd_argv, NULL, NULL,
> -                    &pid, sv[1], &(sv[1]), NULL,
> +                    &pid, sv[1], &(sv[1]), &(errfd[1]),
>                      VIR_EXEC_CLEAR_CAPS) < 0)
>              goto failed;
>  
>          /* Parent continues here. */
>          close (sv[1]);
> +        close (errfd[1]);
>          priv->sock = sv[0];
> +        priv->errfd = errfd[0];
>          priv->pid = pid;
>  
>          /* Do not set 'is_secure' flag since we can't guarentee
> @@ -827,6 +837,12 @@ doRemoteOpen (virConnectPtr conn,
>          goto failed;
>      }
>  
> +    if ((priv->errfd != -1) && virSetNonBlock(priv->errfd) < 0) {
> +        virReportSystemError(errno, "%s",
> +                             _("unable to make socket non-blocking"));
> +        goto failed;
> +    }
> +
>      if (pipe(wakeupFD) < 0) {
>          virReportSystemError(errno, "%s",
>                               _("unable to make pipe"));
> @@ -939,6 +955,9 @@ doRemoteOpen (virConnectPtr conn,
>  
>   failed:
>      /* Close the socket if we failed. */
> +    if (priv->errfd >= 0)
> +        close(priv->errfd);
> +
>      if (priv->sock >= 0) {
>          if (priv->uses_tls && priv->session) {
>              gnutls_bye (priv->session, GNUTLS_SHUT_RDWR);
> @@ -986,6 +1005,7 @@ remoteAllocPrivateData(virConnectPtr conn)
>      priv->localUses = 1;
>      priv->watch = -1;
>      priv->sock = -1;
> +    priv->errfd = -1;
>  
>      return priv;
>  }
> @@ -1408,6 +1428,7 @@ doRemoteClose (virConnectPtr conn, struct private_data *priv)
>          sasl_dispose (&priv->saslconn);
>  #endif
>      close (priv->sock);
> +    close (priv->errfd);
>  
>  #ifndef WIN32
>      if (priv->pid > 0) {
> @@ -7785,12 +7806,23 @@ remoteIOReadBuffer(virConnectPtr conn,
>                  if (errno == EWOULDBLOCK)
>                      return 0;
>  
> +                char errout[1024] = "\0";
> +                if (priv->errfd != -1) {
> +                    saferead(priv->errfd, errout, sizeof(errout));
> +                }
> +
>                  virReportSystemError(errno,
> -                                     "%s", _("cannot recv data"));
> +                                     _("cannot recv data: %s"), errout);
> +
>              } else {
> +                char errout[1024] = "\0";
> +                if (priv->errfd != -1) {
> +                    saferead(priv->errfd, errout, sizeof(errout));
> +                }
> +
>                  errorf (in_open ? NULL : conn,
>                          VIR_ERR_SYSTEM_ERROR,
> -                        "%s", _("server closed connection"));
> +                        _("server closed connection: %s"), errout);
>              }
>              return -1;
>          }

  It would be nice if we could have a function to read and allocate from
an fd instead of a static stack allocation, but it's not urgent,

  ACK,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
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