From 1ed9c137140a4896cb0aa07f48dcb7182c8271d3 Mon Sep 17 00:00:00 2001
From: SS Roop <sairoop@elear.solutions>
Date: Fri, 15 Feb 2019 10:57:32 +0530
Subject: [PATCH] Add utcp_abort_all_connections function.

This adds a function to abort all open connections without invalidating
the utcp_connection_t handles. Its main purposes is when the application
knows communication with the peer is definitely not possible/desired anymore.
A RST packet will be sent to each connection's remote end, and the
receive callback will be invoked to indicate an error on each
connection.
---
 utcp.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++------------
 utcp.h |  2 ++
 2 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/utcp.c b/utcp.c
index 7c4e563..7591e19 100644
--- a/utcp.c
+++ b/utcp.c
@@ -624,8 +624,9 @@ ssize_t utcp_send(struct utcp_connection *c, const void *data, size_t len) {
 
 	// Don't send anything yet if the connection has not fully established yet
 
-	if (c->state == SYN_SENT || c->state == SYN_RECEIVED)
+	if(c->state == SYN_SENT || c->state == SYN_RECEIVED) {
 		return len;
+	}
 
 	ack(c, false);
 
@@ -1356,12 +1357,14 @@ skip_ack:
 
 			c->rcv.irs = hdr.seq;
 			c->rcv.nxt = hdr.seq;
+
 			if(c->shut_wr) {
 				c->snd.last++;
 				set_state(c, FIN_WAIT_1);
 			} else {
 				set_state(c, ESTABLISHED);
 			}
+
 			// TODO: notify application of this somehow.
 			break;
 
@@ -1550,8 +1553,9 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 	}
 
 	// Only process shutting down writes once.
-	if (c->shut_wr)
+	if(c->shut_wr) {
 		return 0;
+	}
 
 	c->shut_wr = true;
 
@@ -1594,18 +1598,29 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 	return 0;
 }
 
-int utcp_close(struct utcp_connection *c) {
-	if(utcp_shutdown(c, SHUT_RDWR) && errno != ENOTCONN) {
-		return -1;
+// Closes all the opened connections
+void utcp_abort_all_connections(struct utcp *utcp) {
+	if(!utcp) {
+		return;
 	}
 
-	c->recv = NULL;
-	c->poll = NULL;
-	c->reapable = true;
-	return 0;
+	for(int i = 0; i < utcp->nconnections; i++) {
+		struct utcp_connection *c = utcp->connections[i];
+
+		if(c->recv) {
+			errno = 0;
+			c->recv(c, NULL, 0);
+		}
+
+		if(utcp_reset_connection(c) != -1) {
+			c->reapable = false;
+		}
+	}
+
+	return;
 }
 
-int utcp_abort(struct utcp_connection *c) {
+int utcp_reset_connection(struct utcp_connection *c) {
 	if(!c) {
 		errno = EFAULT;
 		return -1;
@@ -1619,7 +1634,6 @@ int utcp_abort(struct utcp_connection *c) {
 
 	c->recv = NULL;
 	c->poll = NULL;
-	c->reapable = true;
 
 	switch(c->state) {
 	case CLOSED:
@@ -1658,6 +1672,29 @@ int utcp_abort(struct utcp_connection *c) {
 	return 0;
 }
 
+int utcp_close(struct utcp_connection *c) {
+	if(utcp_shutdown(c, SHUT_RDWR) && errno != ENOTCONN) {
+		return -1;
+	}
+
+	c->recv = NULL;
+	c->poll = NULL;
+	c->reapable = true;
+	return 0;
+}
+
+int utcp_abort(struct utcp_connection *c) {
+	int utcp_reset_return;
+
+	utcp_reset_return = utcp_reset_connection(c);
+
+	if(utcp_reset_return != -1) {
+		c->reapable = true;
+	}
+
+	return utcp_reset_return;
+}
+
 /* Handle timeouts.
  * One call to this function will loop through all connections,
  * checking if something needs to be resent or not.
@@ -1839,8 +1876,9 @@ size_t utcp_get_sndbuf(struct utcp_connection *c) {
 }
 
 size_t utcp_get_sndbuf_free(struct utcp_connection *c) {
-	if (!c)
+	if(!c) {
 		return 0;
+	}
 
 	switch(c->state) {
 	case SYN_SENT:
diff --git a/utcp.h b/utcp.h
index f8fad0c..0cad458 100644
--- a/utcp.h
+++ b/utcp.h
@@ -77,6 +77,8 @@ extern void utcp_set_recv_cb(struct utcp_connection *connection, utcp_recv_t rec
 extern void utcp_set_poll_cb(struct utcp_connection *connection, utcp_poll_t poll);
 extern void utcp_set_accept_cb(struct utcp *utcp, utcp_accept_t accept, utcp_pre_accept_t pre_accept);
 extern bool utcp_is_active(struct utcp *utcp);
+extern void utcp_abort_all_connections(struct utcp *utcp);
+extern int utcp_reset_connection(struct utcp_connection *c);
 
 // Global socket options
 
-- 
2.39.2