[PATCH 2/2] tools: console: pass stream/fd errors to user

[Nikolay Shirokovskiy <nshirokovskiy@xxxxxxxxxxxxx>]

If console disconnected due to connection problem or problem on server
side for example it is convinient to provide the cause to the user.
If error comes from API then error is saved in virsh global variable
but as we return success from virshRunConsole if we reach waiting
stage then error is never reported. Let's track for error in event loop!

Next after failure we do a cleanup and this cleanup can overwrite
root cause. Let's save root cause and then set it to virsh error
after all cleanup is done.

Let's also add missing error reports in code.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@xxxxxxxxxxxxx>
---
 tools/virsh-console.c | 59 +++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 50 insertions(+), 9 deletions(-)

diff --git a/tools/virsh-console.c b/tools/virsh-console.c
index c0c3f90..f1ad076 100644
--- a/tools/virsh-console.c
+++ b/tools/virsh-console.c
@@ -73,6 +73,7 @@ struct virConsole {
     struct virConsoleBuffer terminalToStream;
 
     char escapeChar;
+    virError error;
 };
 
 static virClassPtr virConsoleClass;
@@ -98,6 +99,11 @@ virConsoleHandleSignal(int sig ATTRIBUTE_UNUSED)
 static void
 virConsoleShutdown(virConsolePtr con)
 {
+    virErrorPtr err = virGetLastError();
+
+    if (con->error.code == VIR_ERR_OK && err && err->code != VIR_ERR_OK)
+        virCopyLastError(&con->error);
+
     if (con->st) {
         virStreamEventRemoveCallback(con->st);
         virStreamAbort(con->st);
@@ -126,6 +132,7 @@ virConsoleDispose(void *obj)
         virStreamFree(con->st);
 
     virCondDestroy(&con->cond);
+    virResetError(&con->error);
 }
 
 
@@ -162,7 +169,13 @@ virConsoleEventOnStream(virStreamPtr st,
                             avail);
         if (got == -2)
             goto cleanup; /* blocking */
-        if (got <= 0) {
+        if (got == 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("console stream EOF"));
+            virConsoleShutdown(con);
+            goto cleanup;
+        }
+        if (got < 0) {
             virConsoleShutdown(con);
             goto cleanup;
         }
@@ -245,11 +258,14 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED,
                    con->terminalToStream.offset,
                    avail);
         if (got < 0) {
-            if (errno != EAGAIN)
+            if (errno != EAGAIN) {
+                virReportSystemError(errno, "%s", _("can not read from stdin"));
                 virConsoleShutdown(con);
+            }
             goto cleanup;
         }
         if (got == 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdin"));
             virConsoleShutdown(con);
             goto cleanup;
         }
@@ -265,9 +281,16 @@ virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED,
                                          VIR_STREAM_EVENT_WRITABLE);
     }
 
-    if (events & VIR_EVENT_HANDLE_ERROR ||
-        events & VIR_EVENT_HANDLE_HANGUP) {
+    if (events & VIR_EVENT_HANDLE_ERROR) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error on stdin"));
         virConsoleShutdown(con);
+        goto cleanup;
+    }
+
+    if (events & VIR_EVENT_HANDLE_HANGUP) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdin"));
+        virConsoleShutdown(con);
+        goto cleanup;
     }
 
  cleanup:
@@ -297,8 +320,10 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED,
                      con->streamToTerminal.data,
                      con->streamToTerminal.offset);
         if (done < 0) {
-            if (errno != EAGAIN)
+            if (errno != EAGAIN) {
+                virReportSystemError(errno, "%s", _("can not write to stdout"));
                 virConsoleShutdown(con);
+            }
             goto cleanup;
         }
         memmove(con->streamToTerminal.data,
@@ -317,9 +342,16 @@ virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED,
     if (!con->streamToTerminal.offset)
         virEventUpdateHandle(con->stdoutWatch, 0);
 
-    if (events & VIR_EVENT_HANDLE_ERROR ||
-        events & VIR_EVENT_HANDLE_HANGUP) {
+    if (events & VIR_EVENT_HANDLE_ERROR) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("IO error stdout"));
         virConsoleShutdown(con);
+        goto cleanup;
+    }
+
+    if (events & VIR_EVENT_HANDLE_HANGUP) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("EOF on stdout"));
+        virConsoleShutdown(con);
+        goto cleanup;
     }
 
  cleanup:
@@ -447,15 +479,24 @@ virshRunConsole(vshControl *ctl,
 
     while (!con->quit) {
         if (virCondWait(&con->cond, &con->parent.lock) < 0) {
-            VIR_ERROR(_("unable to wait on console condition"));
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("unable to wait on console condition"));
             goto cleanup;
         }
     }
 
-    ret = 0;
+    if (con->error.code == VIR_ERR_OK)
+        ret = 0;
 
  cleanup:
     virConsoleShutdown(con);
+
+    if (ret < 0) {
+        vshResetLibvirtError();
+        virSetError(&con->error);
+        vshSaveLibvirtHelperError();
+    }
+
     virObjectUnlock(con);
     virObjectUnref(con);
 
-- 
1.8.3.1