From fb9c2a7f25a12040ecbbcc7a21fa75e6f7387d5c Mon Sep 17 00:00:00 2001
From: Cody Cutrer <cody@instructure.com>
Date: Thu, 5 Sep 2013 16:05:52 -0600
Subject: [PATCH] detect server close due to synchronous callbacks

---
 src/client.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/client.c b/src/client.c
index d8bc5f2..5662f61 100644
--- a/src/client.c
+++ b/src/client.c
@@ -220,41 +220,42 @@ bool handle_auth_response(PgSocket *client, PktHdr *pkt) {
 	uint32_t length;
 	const char *username, *password;
 	PgUser user;
+	PgSocket *server = client->link;
 
 	switch(pkt->type) {
 	case 'T':	/* RowDescription */
 		if (!mbuf_get_uint16be(&pkt->data, &columns)) {
-			disconnect_server(client->link, false, "bad packet");
+			disconnect_server(server, false, "bad packet");
 			return false;
 		}
 		if (columns != 2u) {
-			disconnect_server(client->link, false, "expected 1 column from login query, not %hu", columns);
+			disconnect_server(server, false, "expected 1 column from login query, not %hu", columns);
 			return false;
 		}
 		break;
 	case 'D':	/* DataRow */
 		memset(&user, 0, sizeof(user));
 		if (!mbuf_get_uint16be(&pkt->data, &columns)) {
-			disconnect_server(client->link, false, "bad packet");
+			disconnect_server(server, false, "bad packet");
 			return false;
 		}
 		if (columns != 2u) {
-			disconnect_server(client->link, false, "expected 1 column from login query, not %hu", columns);
+			disconnect_server(server, false, "expected 1 column from login query, not %hu", columns);
 			return false;
 		}
 		if (!mbuf_get_uint32be(&pkt->data, &length)) {
-			disconnect_server(client->link, false, "bad packet");
+			disconnect_server(server, false, "bad packet");
 			return false;
 		}
 		if (!mbuf_get_chars(&pkt->data, length, &username)) {
-			disconnect_server(client->link, false, "bad packet");
+			disconnect_server(server, false, "bad packet");
 			return false;
 		}
 		if (sizeof(user.name) - 1 < length)
 			length = sizeof(user.name) - 1;
 		memcpy(user.name, username, length);
 		if (!mbuf_get_uint32be(&pkt->data, &length)) {
-			disconnect_server(client->link, false, "bad packet");
+			disconnect_server(server, false, "bad packet");
 			return false;
 		}
 		if (length == (uint32_t)-1) {
@@ -264,7 +265,7 @@ bool handle_auth_response(PgSocket *client, PktHdr *pkt) {
 			length = 3;
 		} else {
 			if (!mbuf_get_chars(&pkt->data, length, &password)) {
-				disconnect_server(client->link, false, "bad packet");
+				disconnect_server(server, false, "bad packet");
 				return false;
 			}
 		}
@@ -274,7 +275,7 @@ bool handle_auth_response(PgSocket *client, PktHdr *pkt) {
 
 		client->auth_user = add_db_user(client->db, user.name, user.passwd);
 		if (!client->auth_user) {
-			disconnect_server(client->link, false, "unable to allocate new user for auth");
+			disconnect_server(server, false, "unable to allocate new user for auth");
 			return false;
 		}
 		break;
@@ -291,12 +292,17 @@ bool handle_auth_response(PgSocket *client, PktHdr *pkt) {
 			client->link->resetting = true;
 			sbuf_continue(&client->sbuf);
 		}
+		// either sbuf_continue or disconnect_client could disconnect the server
+		// way down in their bowels of other callbacks. so check that, and
+		// return appropriately (similar to reuse_on_release)
+		if (server->state == SV_FREE || server->state == SV_JUSTFREE)
+			return false;
 		return true;
 	default:
-		disconnect_server(client->link, false, "unexpected response from login query");
+		disconnect_server(server, false, "unexpected response from login query");
 		return false;
 	}
-	sbuf_prepare_skip(&client->link->sbuf, pkt->len);
+	sbuf_prepare_skip(&server->sbuf, pkt->len);
 	return true;
 }
 
-- 
2.40.0