From 9c5ccc52abe3977be53e42af84a6e590b3e1db19 Mon Sep 17 00:00:00 2001
From: Daniel Xu <dxu@dxuuu.xyz>
Date: Wed, 22 Mar 2023 18:19:26 -0600
Subject: qga: Refactor guest-exec capture-output to take enum
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Previously capture-output was an optional boolean flag that either
captured all output or captured none. While this is OK in most cases, it
lacks flexibility for more advanced capture cases, such as wanting to
only capture stdout.

This commits refactors guest-exec qapi to take an enum for capture mode
instead while preserving backwards compatibility.

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
---
 qga/commands.c       | 37 ++++++++++++++++++++++++++++++++++---
 qga/qapi-schema.json | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 66 insertions(+), 4 deletions(-)

(limited to 'qga')

diff --git a/qga/commands.c b/qga/commands.c
index 172826f..01f68b4 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -379,11 +379,23 @@ close:
     return false;
 }
 
+static GuestExecCaptureOutputMode ga_parse_capture_output(
+        GuestExecCaptureOutput *capture_output)
+{
+    if (!capture_output)
+        return GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE;
+    else if (capture_output->type == QTYPE_QBOOL)
+        return capture_output->u.flag ? GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED
+                                      : GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE;
+    else
+        return capture_output->u.mode;
+}
+
 GuestExec *qmp_guest_exec(const char *path,
                        bool has_arg, strList *arg,
                        bool has_env, strList *env,
                        const char *input_data,
-                       bool has_capture_output, bool capture_output,
+                       GuestExecCaptureOutput *capture_output,
                        Error **errp)
 {
     GPid pid;
@@ -396,7 +408,8 @@ GuestExec *qmp_guest_exec(const char *path,
     gint in_fd, out_fd, err_fd;
     GIOChannel *in_ch, *out_ch, *err_ch;
     GSpawnFlags flags;
-    bool has_output = (has_capture_output && capture_output);
+    bool has_output = false;
+    GuestExecCaptureOutputMode output_mode;
     g_autofree uint8_t *input = NULL;
     size_t ninput = 0;
 
@@ -415,8 +428,26 @@ GuestExec *qmp_guest_exec(const char *path,
 
     flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD |
         G_SPAWN_SEARCH_PATH_FROM_ENVP;
-    if (!has_output) {
+
+    output_mode = ga_parse_capture_output(capture_output);
+    switch (output_mode) {
+    case GUEST_EXEC_CAPTURE_OUTPUT_MODE_NONE:
         flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL;
+        break;
+    case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDOUT:
+        has_output = true;
+        flags |= G_SPAWN_STDERR_TO_DEV_NULL;
+        break;
+    case GUEST_EXEC_CAPTURE_OUTPUT_MODE_STDERR:
+        has_output = true;
+        flags |= G_SPAWN_STDOUT_TO_DEV_NULL;
+        break;
+    case GUEST_EXEC_CAPTURE_OUTPUT_MODE_SEPARATED:
+        has_output = true;
+        break;
+    case GUEST_EXEC_CAPTURE_OUTPUT_MODE__MAX:
+        /* Silence warning; impossible branch */
+        break;
     }
 
     ret = g_spawn_async_with_pipes(NULL, argv, envp, flags,
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 6a20eeb..44e44c2 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -1201,6 +1201,37 @@
   'data': { 'pid': 'int'} }
 
 ##
+# @GuestExecCaptureOutputMode:
+#
+# An enumeration of guest-exec capture modes.
+#
+# @none: do not capture any output
+# @stdout: only capture stdout
+# @stderr: only capture stderr
+# @separated: capture both stdout and stderr, but separated into
+#             GuestExecStatus out-data and err-data, respectively
+#
+# Since: 8.0
+##
+ { 'enum': 'GuestExecCaptureOutputMode',
+   'data': [ 'none', 'stdout', 'stderr', 'separated' ] }
+
+##
+# @GuestExecCaptureOutput:
+#
+# Controls what guest-exec output gets captures.
+#
+# @flag: captures both stdout and stderr if true. Equivalent
+#        to GuestExecCaptureOutputMode::all. (since 2.5)
+# @mode: capture mode; preferred interface
+#
+# Since: 8.0
+##
+ { 'alternate': 'GuestExecCaptureOutput',
+   'data': { 'flag': 'bool',
+             'mode': 'GuestExecCaptureOutputMode'} }
+
+##
 # @guest-exec:
 #
 # Execute a command in the guest
@@ -1218,7 +1249,7 @@
 ##
 { 'command': 'guest-exec',
   'data':    { 'path': 'str', '*arg': ['str'], '*env': ['str'],
-               '*input-data': 'str', '*capture-output': 'bool' },
+               '*input-data': 'str', '*capture-output': 'GuestExecCaptureOutput' },
   'returns': 'GuestExec' }
 
 
-- 
cgit v1.1