From 7d8417774f5afef2da5e377751ca57ab4d54e7ab Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Sat, 7 Jan 2017 09:13:39 +1100
Subject: [PATCH] Properly drop subclients when the parent dies by testing
 whether the parent exists instead of the masked subclient id.

---
 src/ckpool.h     |  7 +++++++
 src/connector.c  | 20 ++++++++++++--------
 src/stratifier.c | 21 +--------------------
 3 files changed, 20 insertions(+), 28 deletions(-)

diff --git a/src/ckpool.h b/src/ckpool.h
index 32792308..c5f48158 100644
--- a/src/ckpool.h
+++ b/src/ckpool.h
@@ -390,4 +390,11 @@ static inline json_t *json_encode_errormsg(json_error_t __maybe_unused *err_val)
 static inline json_t *json_errormsg(const char __maybe_unused *fmt, ...) { return NULL; };
 static inline void send_api_response(json_t __maybe_unused *val, const int __maybe_unused sockd) {};
 
+/* Subclients have client_ids in the high bits. Returns the value of the parent
+ * client if one exists. */
+static inline int64_t subclient(const int64_t client_id)
+{
+	return (client_id >> 32);
+}
+
 #endif /* CKPOOL_H */
diff --git a/src/connector.c b/src/connector.c
index 8616f7b3..17683f8b 100644
--- a/src/connector.c
+++ b/src/connector.c
@@ -958,6 +958,7 @@ static void send_client(ckpool_t *ckp, cdata_t *cdata, const int64_t id, char *b
 	sender_send_t *sender_send;
 	client_instance_t *client;
 	bool redirect = false;
+	int64_t pass_id;
 	int len;
 
 	if (unlikely(!buf)) {
@@ -980,11 +981,9 @@ static void send_client(ckpool_t *ckp, cdata_t *cdata, const int64_t id, char *b
 
 	/* Grab a reference to this client until the sender_send has
 	 * completed processing. Is this a passthrough subclient ? */
-	if (id > 0xffffffffll) {
-		int64_t client_id, pass_id;
+	if ((pass_id = subclient(id))) {
+		int64_t client_id = id & 0xffffffffll;
 
-		client_id = id & 0xffffffffll;
-		pass_id = id >> 32;
 		/* Make sure the passthrough exists for passthrough subclients */
 		client = ref_client_by_id(cdata, pass_id);
 		if (unlikely(!client)) {
@@ -1057,10 +1056,16 @@ static void send_client_json(ckpool_t *ckp, cdata_t *cdata, int64_t client_id, j
 	json_decref(json_msg);
 }
 
-static bool client_exists(cdata_t *cdata, const int64_t id)
+/* When testing if a client exists, passthrough clients don't exist when their
+ * parent no longer exists. */
+static bool client_exists(cdata_t *cdata, int64_t id)
 {
+	int64_t parent_id = subclient(id);
 	client_instance_t *client;
 
+	if (parent_id)
+		id = parent_id;
+
 	ck_rlock(&cdata->lock);
 	HASH_FIND_I64(cdata->clients, &id, client);
 	ck_runlock(&cdata->lock);
@@ -1300,7 +1305,7 @@ static void client_message_processor(ckpool_t *ckp, json_t *json_msg)
 	json_object_del(json_msg, "client_id");
 	/* Put client_id back in for a passthrough subclient, passing its
 	 * upstream client_id instead of the passthrough's. */
-	if (client_id > 0xffffffffll)
+	if (subclient(client_id))
 		json_object_set_new_nocheck(json_msg, "client_id", json_integer(client_id & 0xffffffffll));
 
 	/* Flag redirector clients once they've been authorised */
@@ -1455,7 +1460,7 @@ retry:
 			goto retry;
 		}
 		/* A passthrough client */
-		if (client_id > 0xffffffffll) {
+		if (subclient(client_id)) {
 			drop_passthrough_client(ckp, cdata, client_id);
 			goto retry;
 		}
@@ -1474,7 +1479,6 @@ retry:
 			LOGDEBUG("Connector failed to parse testclient command: %s", buf);
 			goto retry;
 		}
-		client_id &= 0xffffffffll;
 		if (client_exists(cdata, client_id))
 			goto retry;
 		LOGINFO("Connector detected non-existent client id: %"PRId64, client_id);
diff --git a/src/stratifier.c b/src/stratifier.c
index 997e8fc3..f108f178 100644
--- a/src/stratifier.c
+++ b/src/stratifier.c
@@ -1938,13 +1938,6 @@ share_diff(char *coinbase, const uchar *enonce1bin, const workbase_t *wb, const
 	return diff_from_target(hash);
 }
 
-/* Subclients have client_ids in the high bits. Returns the value of the parent
- * client if one exists. */
-static inline int64_t subclient(const int64_t client_id)
-{
-	return (client_id >> 32);
-}
-
 /* Note recursive lock here - entered with workbase lock held, grabs instance lock */
 static void send_node_block(sdata_t *sdata, const char *enonce1, const char *nonce,
 			    const char *nonce2, const uint32_t ntime32, const int64_t jobid,
@@ -3160,18 +3153,6 @@ static void __drop_client(sdata_t *sdata, stratum_instance_t *client, bool lazil
 	} else if (unlikely(client->passthrough))
 		parent = true;
 
-	/* Tag any subclients of this parent to be dropped lazily */
-	if (parent) {
-		stratum_instance_t *tmp;
-
-		for (tmp = sdata->stratum_instances; tmp; tmp = tmp->hh.next) {
-			int64_t subid = subclient(tmp->id);
-
-			if (subid && subid == client->id)
-				tmp->dropped = true;
-		}
-	}
-
 	if (client->workername) {
 		if (user) {
 			ASPRINTF(msg, "Dropped client %s %s %suser %s worker %s %s",
@@ -3183,7 +3164,7 @@ static void __drop_client(sdata_t *sdata, stratum_instance_t *client, bool lazil
 				 lazily ? "lazily" : "");
 		}
 	} else {
-		ASPRINTF(msg, "Dropped workerless client %s %s %s",
+		ASPRINTF(msg, "Dropped %sworkerless client %s %s %s", parent ? "parent " : "",
 			 client->identity, client->address, lazily ? "lazily" : "");
 	}
 	__del_client(sdata, client);