From 4f1333c03a7f065c5c078fe2b7a3fec38896e517 Mon Sep 17 00:00:00 2001
From: Arnaud MASSERANN <arnaud1602@gmail.com>
Date: Wed, 9 Jan 2019 11:00:00 +0100
Subject: [PATCH] Added custom network ports

Makes it possible to run multiple devices on the same computer.
For debug purposes only.
---
 artnet/artnet.c   |  7 +++++++
 artnet/artnet.h   |  5 +++++
 artnet/network.c  | 11 +++++++----
 artnet/private.h  |  2 ++
 artnet/transmit.c |  2 +-
 5 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/artnet/artnet.c b/artnet/artnet.c
index fc016ad..6a39731 100644
--- a/artnet/artnet.c
+++ b/artnet/artnet.c
@@ -116,6 +116,8 @@ artnet_node artnet_new(const char *ip, int verbose) {
   n->state.report_code = ARTNET_RCPOWEROK;
   n->state.reply_addr.s_addr = 0;
   n->state.mode = ARTNET_STANDBY;
+  n->receive_port = ARTNET_PORT;
+  n->send_port = ARTNET_PORT;
 
   // set all ports to MERGE HTP mode and disable
   for (i=0; i < ARTNET_MAX_PORTS; i++) {
@@ -220,6 +222,11 @@ int artnet_destroy(artnet_node vn) {
   return ARTNET_EOK;
 }
 
+void artnet_set_network_ports(artnet_node vn, uint16_t receive_port, uint16_t send_port) {
+    node n = (node)vn;
+    n->receive_port = receive_port;
+    n->send_port = send_port;
+}
 
 /*
  * Set the OEM code
diff --git a/artnet/artnet.h b/artnet/artnet.h
index 2b79134..db7eb15 100644
--- a/artnet/artnet.h
+++ b/artnet/artnet.h
@@ -225,6 +225,11 @@ EXTERN int artnet_start(artnet_node n);
 EXTERN int artnet_read(artnet_node n, int timeout);
 EXTERN int artnet_stop(artnet_node n);
 EXTERN int artnet_destroy(artnet_node n);
+// Changes the network ports used by the node. This function is useful for debugging
+// (it makes it possible to run multiple devices on the same computer), but must not
+// be used in production, because the network port is fixed by the spec.
+// Must be called before artnet_start().
+EXTERN void artnet_set_network_ports(artnet_node n, uint16_t receive_port, uint16_t send_port);
 
 int artnet_join(artnet_node vn1, artnet_node vn2);
 
diff --git a/artnet/network.c b/artnet/network.c
index 1653f91..fc5f727 100644
--- a/artnet/network.c
+++ b/artnet/network.c
@@ -508,7 +508,7 @@ int artnet_net_start(node n) {
 
     memset(&servAddr, 0x00, sizeof(servAddr));
     servAddr.sin_family = AF_INET;
-    servAddr.sin_port = htons(ARTNET_PORT);
+    servAddr.sin_port = htons(n->receive_port);
     servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
 
     if (n->state.verbose)
@@ -628,8 +628,11 @@ int artnet_net_recv(node n, artnet_packet p, int delay) {
     return ARTNET_ENET;
   }
 
-  if (cliAddr.sin_addr.s_addr == n->state.ip_addr.s_addr ||
-      ntohl(cliAddr.sin_addr.s_addr) == LOOPBACK_IP) {
+  // Prevent receiving our own messages, except if using non-standard ports,
+  // in which case the user is running several nodes on the same machine for debugging.
+  if ((cliAddr.sin_addr.s_addr == n->state.ip_addr.s_addr ||
+      ntohl(cliAddr.sin_addr.s_addr) == LOOPBACK_IP) &&
+      n->send_port == n->receive_port ) {
     p->length = 0;
     return ARTNET_EOK;
   }
@@ -652,7 +655,7 @@ int artnet_net_send(node n, artnet_packet p) {
     return ARTNET_EACTION;
 
   addr.sin_family = AF_INET;
-  addr.sin_port = htons(ARTNET_PORT);
+  addr.sin_port = htons(n->send_port);
   addr.sin_addr = p->to;
   p->from = n->state.ip_addr;
 
diff --git a/artnet/private.h b/artnet/private.h
index cc1be11..4706d26 100644
--- a/artnet/private.h
+++ b/artnet/private.h
@@ -457,6 +457,8 @@ typedef struct artnet_node_s{
   node_list_t node_list;        // node list
   firmware_transfer_t firmware; // firmware details
   node_peering_t peering;       // peer if we've joined a group
+  uint16_t receive_port;        // The network port on which we receive data.
+  uint16_t send_port;           // The network port on which we send data.
 } artnet_node_t;
 
 
diff --git a/artnet/transmit.c b/artnet/transmit.c
index ce19b11..9f4c277 100644
--- a/artnet/transmit.c
+++ b/artnet/transmit.c
@@ -365,7 +365,7 @@ int artnet_tx_build_art_poll_reply(node n) {
   memcpy(&ar->id, ARTNET_STRING, ARTNET_STRING_SIZE);
   ar->opCode = htols(ARTNET_REPLY);
   memcpy(&ar->ip, &n->state.ip_addr.s_addr, 4);
-  ar->port = htols(ARTNET_PORT);
+  ar->port = htols(n->send_port);
   ar->verH = 0;
   ar->ver = 0;
   ar->subH = 0;