ctrl: fix deferred commands (and hence fix osmo-bts-sysmo 'clock-info' cmd)
The CTRL interface has a ctrl_cmd_def_* API that allows deferring a CTRL
command reply until later. However, the command handling currently fails to
acknowledge this and deallocates the struct ctrl_cmd anyway.
Fix: in struct ctrl_cmd, add a defer pointer to be populated by
ctrl_cmd_def_make(). A cmd thus marked as deferred is not deallocated at the
end of command handling. This fix needs no change in calling code.
(Another idea was to return a different code than CTRL_CMD_HANDLED when the
command is to be deferred, but that would require adjusting each user of
ctrl_cmd_def_make(). The implicit marking is safer and easier.)
Show that handling deferred commands is fixed by adjusting the expectations of
ctrl_test.c's test_deferred_cmd() and removing the now obsolete exit_early
label.
One symptom of the breakage is that osmo-bts-sysmo crashes when asked to report
a trx's clock-info, which is aggravated by the fact that the sysmobts-mgr does
ask osmo-bts-sysmo for a clock-info.
The crash appears since Id583b413f8b8bd16e5cf92a8a9e8663903646381 -- it looked
like just fixing an obvious memory leak, which it did as shown by the unit
test, but deferred ctrl commands actually relied on that leak. Both fixed now.
Related: OS#3120
Change-Id: I24232be7dcf7be79f4def91ddc8b8f8005b56318
diff --git a/src/ctrl/control_cmd.c b/src/ctrl/control_cmd.c
index c747e84..fb0cd2b 100644
--- a/src/ctrl/control_cmd.c
+++ b/src/ctrl/control_cmd.c
@@ -566,6 +566,7 @@
cd = talloc_zero(ctx, struct ctrl_cmd_def);
+ cmd->defer = cd;
cd->cmd = cmd;
cd->data = data;
diff --git a/src/ctrl/control_if.c b/src/ctrl/control_if.c
index 07de0d4..df8abbc 100644
--- a/src/ctrl/control_if.c
+++ b/src/ctrl/control_if.c
@@ -401,6 +401,13 @@
if (cmd->type != CTRL_TYPE_ERROR) {
cmd->ccon = ccon;
if (ctrl_cmd_handle(ctrl, cmd, ctrl->data) == CTRL_CMD_HANDLED) {
+
+ if (cmd->defer) {
+ /* The command is still stored as ctrl_cmd_def.cmd, in the def_cmds list.
+ * Just leave hanging for deferred handling. Reply will happen later. */
+ return 0;
+ }
+
/* On CTRL_CMD_HANDLED, no reply needs to be sent back. */
talloc_free(cmd);
cmd = NULL;