From: Guus Sliepen <guus@meshlink.io>
Date: Thu, 29 Apr 2021 16:59:18 +0000 (+0200)
Subject: Clear send and receive buffers before channel close/error callbacks.
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=32ab3f06ce82167e2670bd9c7c58a0c21a2550c2;p=meshlink

Clear send and receive buffers before channel close/error callbacks.

When there is an error that would cause the poll callback to be called
with length zero, make sure we drop the buffers first, so that calls to
meshlink_channel_get_sendq() will also return zero. This allows poll
callbacks that wait for the send buffer to be emptied to work correctly.
---

diff --git a/src/utcp.c b/src/utcp.c
index 11a9eead..fa45e9c6 100644
--- a/src/utcp.c
+++ b/src/utcp.c
@@ -1600,6 +1600,8 @@ synack:
 			// The peer has aborted our connection.
 			set_state(c, CLOSED);
 			errno = ECONNRESET;
+			buffer_clear(&c->sndbuf);
+			buffer_clear(&c->rcvbuf);
 
 			if(c->recv) {
 				c->recv(c, NULL, 0);
@@ -2208,6 +2210,8 @@ struct timespec utcp_timeout(struct utcp *utcp) {
 		if(timespec_isset(&c->conn_timeout) && timespec_lt(&c->conn_timeout, &now)) {
 			errno = ETIMEDOUT;
 			c->state = CLOSED;
+			buffer_clear(&c->sndbuf);
+			buffer_clear(&c->rcvbuf);
 
 			if(c->recv) {
 				c->recv(c, NULL, 0);
@@ -2310,6 +2314,9 @@ void utcp_exit(struct utcp *utcp) {
 		struct utcp_connection *c = utcp->connections[i];
 
 		if(!c->reapable) {
+			buffer_clear(&c->sndbuf);
+			buffer_clear(&c->rcvbuf);
+
 			if(c->recv) {
 				c->recv(c, NULL, 0);
 			}