From 073ef8aa62fc9909d1fe7b9a711f651951e9fbc5 Mon Sep 17 00:00:00 2001
From: Jan-Piet Mens <jpmens@gmail.com>
Date: Thu, 10 Sep 2015 21:04:10 +0200
Subject: [PATCH] new feature: round-trip monitoring, aka "pingping" 	closes
 #17

---
 Makefile      |  4 ++++
 README.md     |  5 +++++
 config.mk.in  |  1 +
 ocat.c        |  3 +++
 ot-recorder.c | 21 ++++++++++++++-------
 5 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 581021d..f5508d0 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,10 @@ OTR_OBJS = json.o \
 	   util.o \
 	   storage.o
 
+ifeq ($(HAVE_PING),yes)
+	CFLAGS += -DHAVE_PING=1
+endif
+
 ifeq ($(HAVE_LMDB),yes)
 	CFLAGS += -DHAVE_LMDB=1 -Imdb/
 	OTR_OBJS += gcache.o
diff --git a/README.md b/README.md
index 630ed62..fdaf92e 100644
--- a/README.md
+++ b/README.md
@@ -84,6 +84,11 @@ The `monitor` file is located relative to STORE and contains a single line, the
 1439738692 owntracks/jjolie/ipad
 ```
 
+
+If _recorder_ is built with `HAVE_PING` (default), a location publish to `owntracks/ping/ping` (i.e. username is `ping` and device is `ping`) can be  used to round-trip-test the recorder. For this particular username/device combination, _recorder_ will store LAST position, but it will not keep a .REC file for it. This can be used to verify, say, via your favorite monitoring system, that the _recorder_ is still operational.
+
+After sending a _pingping_, query the REST interface and deterrmine the difference in time.
+
 ## `ocat`
 
 _ocat_ is a CLI driver for _recorder_: it prints data stored by the _recorder_ in a variety of output formats.
diff --git a/config.mk.in b/config.mk.in
index f01b834..bf6bbab 100644
--- a/config.mk.in
+++ b/config.mk.in
@@ -1,6 +1,7 @@
 # Select features
 HAVE_HTTP ?= yes
 HAVE_LMDB ?= yes
+HAVE_PING ?= yes
 
 STORAGEDEFAULT = "./store"
 
diff --git a/ocat.c b/ocat.c
index 991804a..d212a6a 100644
--- a/ocat.c
+++ b/ocat.c
@@ -164,6 +164,9 @@ void print_versioninfo()
 #endif
 #ifdef HAVE_HTTP
 	printf("\tHAVE_HTTP = yes\n");
+#endif
+#ifdef HAVE_PING
+	printf("\tHAVE_PING = yes\n");
 #endif
 	printf("\tSTORAGEDEFAULT = \"%s\"\n", STORAGEDEFAULT);
 	printf("\tGEOHASH_PREC = %d\n", GEOHASH_PREC);
diff --git a/ot-recorder.c b/ot-recorder.c
index 1cf1967..ce269f0 100644
--- a/ot-recorder.c
+++ b/ot-recorder.c
@@ -371,6 +371,7 @@ void on_message(struct mosquitto *mosq, void *userdata, const struct mosquitto_m
 	static UT_string *reltopic = NULL;
 	char *jsonstring;
 	time_t now;
+	int pingping = FALSE;
 
 	/*
 	 * mosquitto_message->
@@ -411,6 +412,12 @@ void on_message(struct mosquitto *mosq, void *userdata, const struct mosquitto_m
 	utstring_printf(username, "%s", topics[1]);
 	utstring_printf(device, "%s", topics[2]);
 
+#ifdef HAVE_PING
+	if (!strcmp(utstring_body(username), "ping") && !strcmp(utstring_body(device), "ping")) {
+		pingping = TRUE;
+	}
+#endif
+
 	if ((count == TOPIC_PARTS) && (strcmp(topics[count-1], TOPIC_SUFFIX) == 0)) {
 		if (do_info(ud, username, device, m->payload) == TRUE) {  /* this was a card */
 			return;
@@ -546,7 +553,7 @@ void on_message(struct mosquitto *mosq, void *userdata, const struct mosquitto_m
 	 */
 
 #ifdef HAVE_HTTP
-	if (ud->mgserver) {
+	if (ud->mgserver && !pingping) {
 
 		/*
 		 * Create a new location object containing all the bits and
@@ -595,13 +602,13 @@ void on_message(struct mosquitto *mosq, void *userdata, const struct mosquitto_m
 		}
 #endif
 
-		if ((fp = pathn("a", "rec", username, device, "rec")) != NULL) {
-
-			fprintf(fp, RECFORMAT, isotime(now), "*", jsonstring);
-			fclose(fp);
+		if (!pingping) {
+			if ((fp = pathn("a", "rec", username, device, "rec")) != NULL) {
+				fprintf(fp, RECFORMAT, isotime(now), "*", jsonstring);
+				fclose(fp);
+			}
 		}
 
-
 		/* Keep track of original username & device name in LAST. */
 		json_append_member(json, "username",    json_mkstring(utstring_body(username)));
 		json_append_member(json, "device",    json_mkstring(utstring_body(device)));
@@ -740,7 +747,7 @@ int main(int argc, char **argv)
 	udata.gc		= NULL;
 #endif
 #ifdef HAVE_HTTP
-	udata.mgserver = NULL;
+	udata.mgserver		= NULL;
 #endif
 
 	if ((p = getenv("OTR_HOST")) != NULL) {