From 2266742c3315c40fee07a6d12be3c39190cd5f1c Mon Sep 17 00:00:00 2001
From: Emil M George <emilmgeorge@gmail.com>
Date: Thu, 31 May 2018 11:58:25 +0530
Subject: [PATCH] Add Ping frame handling

---
 wsclient.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/wsclient.c b/wsclient.c
index 4847a9f..3d73273 100644
--- a/wsclient.c
+++ b/wsclient.c
@@ -173,6 +173,36 @@ void libwsclient_handle_control_frame(wsclient *c, wsclient_frame *ctl_frame) {
 			}
 			c->flags |= CLIENT_SHOULD_CLOSE;
 			break;
+		case 0x9:
+			// Received ping frame
+			if((c->flags & CLIENT_SHOULD_CLOSE) == 0) {
+				// Server sent ping.  Send pong frame as acknowledgement.
+				for(i=0;i<ctl_frame->payload_len;i++)
+					*(ctl_frame->rawdata + ctl_frame->payload_offset + i) ^= (mask[i % 4] & 0xff); //mask payload
+				*(ctl_frame->rawdata + 1) |= 0x80; //turn mask bit on
+				i = 0;
+				// change opcode to 0xA (Pong Frame)
+				*(ctl_frame->rawdata) = (*(ctl_frame->rawdata) & 0xf0) | 0xA;
+				pthread_mutex_lock(&c->send_lock);
+				while(i < ctl_frame->payload_offset + ctl_frame->payload_len && n >= 0) {
+					n = _libwsclient_write(c, ctl_frame->rawdata + i, ctl_frame->payload_offset + ctl_frame->payload_len - i);
+					i += n;
+				}
+				pthread_mutex_unlock(&c->send_lock);
+				if(n < 0) {
+					if(c->onerror) {
+						err = libwsclient_new_error(WS_HANDLE_CTL_FRAME_SEND_ERR);
+						err->extra_code = n;
+						c->onerror(c, err);
+						free(err);
+						err = NULL;
+					}
+				}
+			}
+			break;
+		case 0xA:
+			// Received pong frame. Nothing to do.
+			break;
 		default:
 			fprintf(stderr, "Unhandled control frame received.  Opcode: %d\n", ctl_frame->opcode);
 			break;