bugfix: ambiguous error message 'connection in dubious state' when connection is closed. (openresty#2016)

Author: zhuizhuhaomeng

src/ngx_http_lua_socket_tcp.c

@@ -5188,7 +5188,12 @@ ngx_http_lua_socket_tcp_setkeepalive(lua_State *L)
     pc = &u->peer;
     c = pc->connection;
 
-    if (c == NULL || u->read_closed || u->write_closed) {
+    /* When the server closes the connection,
+     * epoll will return EPOLLRDHUP event and nginx will set pending_eof.
+     */
+    if (c == NULL || u->read_closed || u->write_closed
+        || c->read->eof || c->read->pending_eof)
+    {
         lua_pushnil(L);
         lua_pushliteral(L, "closed");
         return 2;
@@ -5218,8 +5223,7 @@ ngx_http_lua_socket_tcp_setkeepalive(lua_State *L)
         return 2;
     }
 
-    if (c->read->eof
-        || c->read->error
+    if (c->read->error
         || c->read->timedout
         || c->write->error
         || c->write->timedout)

t/058-tcp-socket.t

@@ -4,7 +4,7 @@ use Test::Nginx::Socket::Lua;
 
 repeat_each(2);
 
-plan tests => repeat_each() * 231;
+plan tests => repeat_each() * (blocks() * 3 + 21);
 
 our $HtmlDir = html_dir;
 
@@ -4367,3 +4367,69 @@ connect failed: missing the port number
 finish
 --- no_error_log
 [error]
+
+
+
+=== TEST 73: reset the buffer pos when keepalive
+--- config
+    server_tokens off;
+    location /t {
+        set $port $TEST_NGINX_SERVER_PORT;
+
+        content_by_lua_block {
+            for i = 1, 10
+            do
+                local sock = ngx.socket.tcp()
+                local port = ngx.var.port
+                local ok, err = sock:connect("127.0.0.1", port)
+                if not ok then
+                    ngx.say("failed to connect: ", err)
+                    return
+                end
+
+                local req = "GET /hi HTTP/1.1\r\nHost: localhost\r\n\r\n"
+
+                local bytes, err = sock:send(req)
+                if not bytes then
+                    ngx.say("failed to send request: ", err)
+                    return
+                end
+
+                local line, err, part = sock:receive()
+                if not line then
+                    ngx.say("receive err: ", err)
+                    return
+                end
+
+                data, err = sock:receiveany(4096)
+                if not data then
+                    ngx.say("receiveany er: ", err)
+                    return
+                end
+
+                ok, err = sock:setkeepalive(10000, 32)
+                if not ok then
+                    ngx.say("reused times: ", i, ", setkeepalive err: ", err)
+                    return
+                end
+            end
+            ngx.say("END")
+        }
+    }
+
+    location /hi {
+        keepalive_requests 3;
+        content_by_lua_block {
+            ngx.say("Hello")
+        }
+
+        more_clear_headers Date;
+    }
+
+--- request
+GET /t
+--- response_body
+reused times: 3, setkeepalive err: closed
+--- no_error_log
+[error]
+--- skip_eval: 3: $ENV{TEST_NGINX_EVENT_TYPE} && $ENV{TEST_NGINX_EVENT_TYPE} ne 'epoll'

t/071-idle-socket.t

@@ -367,7 +367,7 @@ Transfer-Encoding: chunked\r
 Connection: close\r
 \r
 6\r
-failed to set keepalive: (?:unread data in buffer|connection in dubious state)
+failed to set keepalive: (?:unread data in buffer|closed|connection in dubious state)
 }
 --- no_error_log
 [error]