From 846e952260278225b79de4062fff1f8f2145a544 Mon Sep 17 00:00:00 2001
From: José Bollo <jose.bollo@iot.bzh>
Date: Wed, 5 Jul 2017 13:39:27 +0200
Subject: afb-debug: add features for debugging
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When compiled with -DAGL_DEVEL or -DAFB_INSERT_DEBUG_FEATURES
afb-daemon interprets the environment variables
AFB_DEBUG_BREAK and AFB_DEBUG_WAIT.

The environment variable AFB_DEBUG_BREAK make afb-daemon emit
a break (SIGINT) that should be treated by the debugger.

The environment variable AFB_DEBUG_WAIT make afb-daemon wait
for a break (SIGINT) to continue. This can be used to attach
a debugger.

The content of the variables AFB_DEBUG_BREAK and AFB_DEBUG_WAIT
is a list of key names of the point where the action should
occur. The list is separated by spaces or commas ','.

Example:

 AFB_DEBUG_WAIT=main-entry,start-load

The defined points are: main-entry, main-args, main-start,
start-entry, start-load, start-start, start-http, start-call,
start-exec.

Here some of their characteristic:
 - main-entry: at the beginning befaore any other instruction
 - main-args: after parsing arguments
 - main-start: after daemonisation before starting
 - start-entry: at start entry
 - start-load: before loading bindings after initialisation of afb-daemon
 - start-start: after loading bindings befaore starting it
 - start-call: after init before starting HTTP server
 - start-http: after http server, before calling startup calls
 - start-exec: before running the --exec command

Change-Id: Id405e749c590fb95f32e30a7d37c30b6412cf0a5
Signed-off-by: José Bollo <jose.bollo@iot.bzh>
---
 src/afb-debug.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 src/afb-debug.c

(limited to 'src/afb-debug.c')

diff --git a/src/afb-debug.c b/src/afb-debug.c
new file mode 100644
index 00000000..5817f17e
--- /dev/null
+++ b/src/afb-debug.c
@@ -0,0 +1,86 @@
+/*
+ Copyright 2017 IoT.bzh
+
+ author: José Bollo <jose.bollo@iot.bzh>
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+#include "afb-debug.h"
+
+#if defined(AFB_INSERT_DEBUG_FEATURES)
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+
+#include "verbose.h"
+
+static char key_env_break[] = "AFB_DEBUG_BREAK";
+static char key_env_wait[] = "AFB_DEBUG_WAIT";
+static char separs[] = ", \t\n";
+
+static int has_key(const char *key, const char *list)
+{
+	if (list && key) {
+		list += strspn(list, separs);
+		while (*list) {
+			size_t s = strcspn(list, separs);
+			if (!strncasecmp(list, key, s) && !key[s])
+				return 1;
+			list += s;
+			list += strspn(list, separs);
+		}
+	}
+	return 0;
+}
+
+static void handler(int signum)
+{
+}
+
+void afb_debug(const char *key)
+{
+	enum { None, Break, Wait } action;
+
+	if (has_key(key, secure_getenv(key_env_break)))
+		action = Break;
+	else if (has_key(key, secure_getenv(key_env_wait)))
+		action = Wait;
+	else
+		action = None;
+
+	if (action != None) {
+		const char *a = action == Break ? "BREAK" : "WAIT";
+		struct sigaction sa, psa;
+		sigset_t ss;
+
+		NOTICE("DEBUG %s before %s", a, key);
+		memset(&sa, 0, sizeof sa);
+		sa.sa_handler = handler;
+		sigaction(SIGINT, &sa, &psa);
+		if (action == Break) {
+			raise(SIGINT);
+		} else {
+			sigemptyset(&ss);
+			sigaddset(&ss, SIGINT);
+			sigwaitinfo(&ss, NULL);
+		}
+		sigaction(SIGINT, &psa, NULL);
+		NOTICE("DEBUG %s after %s", a, key);
+	}
+}
+
+#endif
+
-- 
cgit 1.2.3-korg