--- /dev/null
+From f369dbb9e67eb5ef336944af63039b6d8f838384 Mon Sep 17 00:00:00 2001
+From: Thomas Markwalder <tmark@isc.org>
+Date: Thu, 12 Sep 2019 10:35:46 -0400
+Subject: [PATCH 1/3] Ensure context is running prior to calling
+ isc_app_ctxsuspend
+
+Add a release note.
+
+includes/omapip/isclib.h
+ Added actx_running flag to global context, dhcp_gbl_ctx
+
+omapip/isclib.c
+ set_ctx_running() - new function used as the ctxonrun callback
+
+ dhcp_context_create() - installs set_ctx_running callback
+
+ dhcp_signal_handler() - modified to use act_running flag to
+ determine is context is running and should be suspended
+
+Upstream-Status: Backport [https://gitlab.isc.org/isc-projects/dhcp.git]
+
+Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
+---
+ RELNOTES | 7 +++++
+ includes/omapip/isclib.h | 3 ++-
+ omapip/isclib.c | 57 +++++++++++++++++++++++++++++++++-------
+ 3 files changed, 57 insertions(+), 10 deletions(-)
+
+diff --git a/RELNOTES b/RELNOTES
+index f10305d..1730473 100644
+--- a/RELNOTES
++++ b/RELNOTES
+@@ -6,6 +6,13 @@
+
+ NEW FEATURES
+
++- Closed a small window of time between the installation of graceful
++ shutdown signal handlers and application context startup, during which
++ the receipt of shutdown signal would cause a REQUIRE() assertion to
++ occur. Note this issue is only visible when compiling with
++ ENABLE_GENTLE_SHUTDOWN defined.
++ [Gitlab #53,!18 git TBD]
++
+ Please note that that ISC DHCP is now licensed under the Mozilla Public License,
+ MPL 2.0. Please see https://www.mozilla.org/en-US/MPL/2.0/ to read the MPL 2.0
+ license terms.
+diff --git a/includes/omapip/isclib.h b/includes/omapip/isclib.h
+index 6c20584..af6a6fc 100644
+--- a/includes/omapip/isclib.h
++++ b/includes/omapip/isclib.h
+@@ -94,7 +94,8 @@
+ typedef struct dhcp_context {
+ isc_mem_t *mctx;
+ isc_appctx_t *actx;
+- int actx_started;
++ int actx_started; // ISC_TRUE if ctxstart has been called
++ int actx_running; // ISC_TRUE if ctxrun has been called
+ isc_taskmgr_t *taskmgr;
+ isc_task_t *task;
+ isc_socketmgr_t *socketmgr;
+diff --git a/omapip/isclib.c b/omapip/isclib.c
+index ce4b4a1..73e017c 100644
+--- a/omapip/isclib.c
++++ b/omapip/isclib.c
+@@ -134,6 +134,35 @@ handle_signal(int sig, void (*handler)(int)) {
+ }
+ }
+
++/* Callback passed to isc_app_ctxonrun
++ *
++ * BIND9 context code will invoke this handler once the context has
++ * entered the running state. We use it to set a global marker so that
++ * we can tell if the context is running. Several of the isc_app_
++ * calls REQUIRE that the context is running and we need a way to
++ * know that.
++ *
++ * We also check to see if we received a shutdown signal prior to
++ * the context entering the run state. If we did, then we can just
++ * simply shut the context down now. This closes the relatively
++ * small window between start up and entering run via the call
++ * to dispatch().
++ *
++ */
++static void
++set_ctx_running(isc_task_t *task, isc_event_t *event) {
++ task = task; // unused;
++ dhcp_gbl_ctx.actx_running = ISC_TRUE;
++
++ if (shutdown_signal) {
++ // We got signaled shutdown before we entered running state.
++ // Now that we've reached running state, shut'er down.
++ isc_app_ctxsuspend(dhcp_gbl_ctx.actx);
++ }
++
++ isc_event_free(&event);
++}
++
+ isc_result_t
+ dhcp_context_create(int flags,
+ struct in_addr *local4,
+@@ -141,6 +170,9 @@ dhcp_context_create(int flags,
+ isc_result_t result;
+
+ if ((flags & DHCP_CONTEXT_PRE_DB) != 0) {
++ dhcp_gbl_ctx.actx_started = ISC_FALSE;
++ dhcp_gbl_ctx.actx_running = ISC_FALSE;
++
+ /*
+ * Set up the error messages, this isn't the right place
+ * for this call but it is convienent for now.
+@@ -204,15 +236,24 @@ dhcp_context_create(int flags,
+ if (result != ISC_R_SUCCESS)
+ goto cleanup;
+
+- result = isc_task_create(dhcp_gbl_ctx.taskmgr, 0, &dhcp_gbl_ctx.task);
++ result = isc_task_create(dhcp_gbl_ctx.taskmgr, 0,
++ &dhcp_gbl_ctx.task);
+ if (result != ISC_R_SUCCESS)
+ goto cleanup;
+
+ result = isc_app_ctxstart(dhcp_gbl_ctx.actx);
+ if (result != ISC_R_SUCCESS)
+- return (result);
++ goto cleanup;
++
+ dhcp_gbl_ctx.actx_started = ISC_TRUE;
+
++ // Install the onrun callback.
++ result = isc_app_ctxonrun(dhcp_gbl_ctx.actx, dhcp_gbl_ctx.mctx,
++ dhcp_gbl_ctx.task, set_ctx_running,
++ dhcp_gbl_ctx.actx);
++ if (result != ISC_R_SUCCESS)
++ goto cleanup;
++
+ /* Not all OSs support suppressing SIGPIPE through socket
+ * options, so set the sigal action to be ignore. This allows
+ * broken connections to fail gracefully with EPIPE on writes */
+@@ -335,19 +376,17 @@ isclib_make_dst_key(char *inname,
+ * @param signal signal code that we received
+ */
+ void dhcp_signal_handler(int signal) {
+- isc_appctx_t *ctx = dhcp_gbl_ctx.actx;
+- int prev = shutdown_signal;
+-
+- if (prev != 0) {
++ if (shutdown_signal != 0) {
+ /* Already in shutdown. */
+ return;
+ }
++
+ /* Possible race but does it matter? */
+ shutdown_signal = signal;
+
+- /* Use reload (aka suspend) for easier dispatch() reenter. */
+- if (ctx && ctx->methods && ctx->methods->ctxsuspend) {
+- (void) isc_app_ctxsuspend(ctx);
++ /* If the application context is running tell it to shut down */
++ if (dhcp_gbl_ctx.actx_running == ISC_TRUE) {
++ (void) isc_app_ctxsuspend(dhcp_gbl_ctx.actx);
+ }
+ }
+
+--
+2.23.0
+
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
