Revert "TCP: Fix race condition in "proto_tcp.tcp_parallel_handling""

This reverts commit d279257.

Author: benceszigeti

modules/proto_tls/proto_tls.c

@@ -629,7 +629,7 @@ static int proto_tls_send(struct socket_info* send_sock,
 
 static int tls_read_req(struct tcp_connection* con, int* bytes_read)
 {
-	int ret, rc = 0;
+	int ret;
 	int bytes;
 	int total_bytes;
 	struct tcp_req* req;
@@ -733,7 +733,7 @@ static int tls_read_req(struct tcp_connection* con, int* bytes_read)
 	int max_chunks = tcp_attr_isset(con, TCP_ATTR_MAX_MSG_CHUNKS) ?
 			con->profile.attrs[TCP_ATTR_MAX_MSG_CHUNKS] : tls_max_msg_chunks;
 
-	switch ((rc = tcp_handle_req(req, con, max_chunks, 0))) {
+	switch (tcp_handle_req(req, con, max_chunks, 0) ) {
 		case 1:
 			goto again;
 		case -1:
@@ -743,9 +743,8 @@ static int tls_read_req(struct tcp_connection* con, int* bytes_read)
 	LM_DBG("tls_read_req end\n");
 done:
 	if (bytes_read) *bytes_read=total_bytes;
-
-	return rc == 2   ?  1  /* connection is already released! */
-	       /* 0,1? */:  0; /* connection will be released */
+	/* connection will be released */
+	return 0;
 error:
 	/* connection will be released as ERROR */
 	return -1;

net/api_proto_net.h

@@ -34,25 +34,6 @@
 
 
 typedef int (*proto_net_write_f)(void *src, int fd);
-
-/**
- * Read a complete SIP message from the network, including its body/payload and
- * also fully process it, through receive_msg() and opensips.cfg routing logic.
- *
- * The function must include sufficient parsing logic in order to overcome
- * the streaming protocol's inherent limitation of not having the data "split"
- * into individual application-layer messages.  For example, implementors may
- * want to block-READ until "Content-Length: " to obtain payload size, then
- * continue READ'ing until EOH, then a final READ for the full body.
- *
- * Possible return values:
- *   -1 :: error during reading, the @src connection is still valid and must be
- *         released by caller
- *    0 :: a complete request was read and processed; check @src->state for
- *         S_CONN_EOF and release @src connection if condition is true
- *    1 :: a complete request was read and processed; the @src ptr is *invalid*
- *         as the connection has already been released, to achieve parallelism
- */
 typedef int (*proto_net_read_f)(void *src, int *len);
 typedef int (*proto_net_conn_init_f)(struct tcp_connection *c);
 typedef void (*proto_net_conn_clean_f)(struct tcp_connection *c);

net/net_tcp_proc.c

@@ -344,9 +344,6 @@ inline static int handle_io(struct fd_map* fm, int idx,int event_type)
 						"handle read, err, resp: %d, att: %d",
 						resp, con->msg_attempts);
 					tcpconn_release_error(con, 0, "Read error");
-				} else if (resp == 1) {
-					/* the connection is already released */
-					break;
 				} else if (con->state==S_CONN_EOF) {
 					reactor_del_all( con->fd, idx, IO_FD_CLOSING );
 					tcpconn_check_del(con);

net/proto_tcp/proto_tcp.c

@@ -648,7 +648,7 @@ int tcp_read(struct tcp_connection *c,struct tcp_req *r)
  */
 static int tcp_read_req(struct tcp_connection* con, int* bytes_read)
 {
-	int bytes, rc;
+	int bytes;
 	int total_bytes;
 	struct tcp_req* req;
 
@@ -736,7 +736,7 @@ static int tcp_read_req(struct tcp_connection* con, int* bytes_read)
 	int max_chunks = tcp_attr_isset(con, TCP_ATTR_MAX_MSG_CHUNKS) ?
 			con->profile.attrs[TCP_ATTR_MAX_MSG_CHUNKS] : tcp_max_msg_chunks;
 
-	switch ((rc = tcp_handle_req(req,con,max_chunks,parallel_handling))){
+	switch (tcp_handle_req(req,con,max_chunks,parallel_handling)){
 		case 1:
 			goto again;
 		case -1:
@@ -746,9 +746,8 @@ static int tcp_read_req(struct tcp_connection* con, int* bytes_read)
 	LM_DBG("tcp_read_req end for conn %p, req is %p\n",con,con->con_req);
 done:
 	if (bytes_read) *bytes_read=total_bytes;
-
-	return rc == 2   ?  1  /* connection is already released! */
-	       /* 0,1? */:  0; /* connection will be released */
+	/* connection will be released */
+	return 0;
 error:
 	/* connection will be released as ERROR */
 	return -1;

net/proto_tcp/tcp_common.h

@@ -382,7 +382,6 @@ static inline int tcp_handle_req(struct tcp_req *req,
 
 		/* prepare for next request */
 		size=req->pos-req->parsed;
-		con->msg_attempts = 0;
 
 		if (req->state==H_PING_CRLFCRLF) {
 			/* we send the reply */
@@ -414,7 +413,6 @@ static inline int tcp_handle_req(struct tcp_req *req,
 					msg_buf_cpy[msg_len] = 0;
 					msg_buf = msg_buf_cpy;
 					tcp_done_reading( con );
-					con = NULL; /* having reached this, we MUST return 2 */
 				}
 
 			} else {
@@ -430,6 +428,8 @@ static inline int tcp_handle_req(struct tcp_req *req,
 				pkg_free(msg_buf_cpy);
 		}
 
+		con->msg_attempts = 0;
+
 		if (size) {
 			/* restoring the char only makes sense if there is something else to
 			 * process, otherwise we can leave it. This prevents us from accessing
@@ -450,8 +450,7 @@ static inline int tcp_handle_req(struct tcp_req *req,
 			/* if we no longer need this tcp_req
 			 * we can free it now */
 			shm_free(req);
-			if (con)
-				con->con_req = NULL;
+			con->con_req = NULL;
 		}
 	} else {
 		/* request not complete - check the if the thresholds are exceeded */
@@ -510,8 +509,8 @@ static inline int tcp_handle_req(struct tcp_req *req,
 		}
 	}
 
-	/* everything ok; if connection was returned already, use special rc 2 */
-	return con ? 0 : 2;
+	/* everything ok */
+	return 0;
 error:
 	/* report error */
 	return -1;