Add the unlink argument to ss_send() (#56)

This part of a series of changes to implement #56. The kernel is modified to not free SKBs that are still in Tempesta queues. That gives Tempesta control over SKBs. Request SKBs are kept until a corresponging response it received. However. when response is sent to a client, its SKBs are no longer needed. The new argument tells ss_send() if it needs to remove SKBs from a Tempesta queue.
tempesta-tech · Jul 28, 2015 · 1a8399b · 1a8399b
1 parent 7b6764f
commit 1a8399b
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Showing 6 changed files with 32 additions and 16 deletions.
diff --git a/tempesta_fw/connection.c b/tempesta_fw/connection.c
@@ -117,9 +117,9 @@ tfw_connection_destruct(TfwConnection *conn)
 }
 
 void
-tfw_connection_send(TfwConnection *conn, TfwMsg *msg)
+tfw_connection_send(TfwConnection *conn, TfwMsg *msg, int unlink)
 {
-	ss_send(conn->sk, &msg->skb_list);
+	ss_send(conn->sk, &msg->skb_list, unlink);
 }
 
 /*

diff --git a/tempesta_fw/connection.h b/tempesta_fw/connection.h
@@ -111,7 +111,19 @@ tfw_connection_validate_cleanup(TfwConnection *conn)
 }
 
 void tfw_connection_hooks_register(TfwConnHooks *hooks, int type);
-void tfw_connection_send(TfwConnection *conn, TfwMsg *msg);
+void tfw_connection_send(TfwConnection *conn, TfwMsg *msg, int unlink);
+
+static inline void
+tfw_connection_send_req(TfwConnection *conn, TfwMsg *msg)
+{
+	tfw_connection_send(conn, msg, 0);
+}
+
+static inline void
+tfw_connection_send_resp(TfwConnection *conn, TfwMsg *msg)
+{
+	tfw_connection_send(conn, msg, 1);
+}
 
 /* Generic helpers, used for both client and server connections. */
 void tfw_connection_init(TfwConnection *conn);

diff --git a/tempesta_fw/http.c b/tempesta_fw/http.c
@@ -449,7 +449,7 @@ tfw_http_send_404(TfwHttpMsg *hm)
 		return -1;
 	}
 	TFW_DBG("Send HTTP 404 response to the client\n");
-	tfw_connection_send(conn, (TfwMsg *)resp);
+	tfw_connection_send_resp(conn, (TfwMsg *)resp);
 	tfw_http_msg_free(resp);
 
 	return 0;
@@ -465,7 +465,7 @@ tfw_http_send_500(TfwHttpMsg *hm)
 		return -1;
 	}
 	TFW_DBG("Send HTTP 500 response to the client\n");
-	tfw_connection_send(conn, (TfwMsg *)resp);
+	tfw_connection_send_resp(conn, (TfwMsg *)resp);
 	tfw_http_msg_free(resp);
 
 	return 0;
@@ -1195,7 +1195,7 @@ tfw_http_req_cache_cb(TfwHttpReq *req, TfwHttpResp *resp, void *data)
 		 * We have prepared response, send it as is.
 		 * TODO should we adjust it somehow?
 		 */
-		tfw_connection_send(req->conn, (TfwMsg *)resp);
+		tfw_connection_send_resp(req->conn, (TfwMsg *)resp);
 	} else {
 		/* Dispatch request to an appropriate server. */
 		TfwConnection *conn = tfw_sched_get_srv_conn((TfwMsg *)req);
@@ -1218,7 +1218,7 @@ tfw_http_req_cache_cb(TfwHttpReq *req, TfwHttpResp *resp, void *data)
 		list_add_tail(&req->msg.msg_list, &conn->msg_queue);
 
 		/* Send request to the server. */
-		tfw_connection_send(conn, (TfwMsg *)req);
+		tfw_connection_send_req(conn, (TfwMsg *)req);
 	}
 	return;
 
@@ -1461,7 +1461,7 @@ tfw_http_resp_process(TfwConnection *conn, struct sk_buff *skb,
 	 * The cache frees the response and the request.
 	 * conn->msg will get NULLed in the process.
 	 */
-	tfw_connection_send(hmreq->conn, (TfwMsg *)hmresp);
+	tfw_connection_send_resp(hmreq->conn, (TfwMsg *)hmresp);
 	tfw_cache_add((TfwHttpResp *)hmresp, (TfwHttpReq *)hmreq);
 
 	return TFW_PASS;

diff --git a/tempesta_fw/http_sticky.c b/tempesta_fw/http_sticky.c
@@ -75,7 +75,7 @@ tfw_http_sticky_send_302(TfwHttpMsg *hm)
 	if ((resp = tfw_http_prep_302(hm, &cookie)) == NULL) {
 		return -1;
 	}
-	tfw_connection_send(conn, (TfwMsg *)resp);
+	tfw_connection_send_resp(conn, (TfwMsg *)resp);
 	tfw_http_msg_free(resp);
 
 	return 0;
@@ -90,7 +90,7 @@ tfw_http_sticky_send_502(TfwHttpMsg *hm)
 	if ((resp = tfw_http_prep_502(hm)) == NULL) {
 		return -1;
 	}
-	tfw_connection_send(conn, (TfwMsg *)resp);
+	tfw_connection_send_resp(conn, (TfwMsg *)resp);
 	tfw_http_msg_free(resp);
 
 	return 0;

diff --git a/tempesta_fw/sock.c b/tempesta_fw/sock.c
@@ -132,9 +132,9 @@ ss_skb_route(struct sk_buff *skb, struct tcp_sock *tp)
  * TODO use MSG_MORE untill we reach end of message.
  */
 void
-ss_send(struct sock *sk, const SsSkbList *skb_list)
+ss_send(struct sock *sk, SsSkbList *skb_list, int unlink)
 {
-	struct sk_buff *skb;
+	struct sk_buff *skb, *nskb;
 	struct tcp_skb_cb *tcb;
 	struct tcp_sock *tp = tcp_sk(sk);
 	int flags = MSG_DONTWAIT; /* we can't sleep */
@@ -143,15 +143,19 @@ ss_send(struct sock *sk, const SsSkbList *skb_list)
 	SS_DBG("%s: sk %p, sk->sk_socket %p, state (%s)\n",
 		__FUNCTION__, sk, sk->sk_socket, ss_statename[sk->sk_state]);
 
-	/* Synchronize concurrent socket writting in different softirqs. */
+	/* Synchronize concurrent socket writes in different softirqs. */
 	bh_lock_sock_nested(sk);
 
 	mss_now = tcp_send_mss(sk, &size_goal, flags);
 
 	BUG_ON(ss_skb_queue_empty(skb_list));
-	for (skb = ss_skb_peek(skb_list), tcb = TCP_SKB_CB(skb);
-	     skb; skb = ss_skb_next(skb_list, skb))
+	for (skb = ss_skb_peek(skb_list), tcb = TCP_SKB_CB(skb),
+	     nskb = ss_skb_next(skb_list, skb); skb;
+	     skb = nskb, nskb = nskb ? ss_skb_next(skb_list, nskb) : NULL)
 	{
+		if (unlink)
+			ss_skb_unlink(skb_list, skb);
+
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		skb_shinfo(skb)->gso_segs = 0;
 

diff --git a/tempesta_fw/sync_socket.h b/tempesta_fw/sync_socket.h
@@ -180,7 +180,7 @@ void ss_proto_init(SsProto *proto, const SsHooks *hooks, int type);
 void ss_proto_inherit(const SsProto *parent, SsProto *child, int child_type);
 void ss_set_callbacks(struct sock *sk);
 void ss_set_listen(struct sock *sk);
-void ss_send(struct sock *sk, const SsSkbList *skb_list);
+void ss_send(struct sock *sk, SsSkbList *skb_list, int unlink);
 void ss_close(struct sock *sk);
 int ss_sock_create(int family, int type, int protocol, struct sock **res);
 void ss_release(struct sock *sk);