From f643d39168aacc3d798f34f81d81957e7abc55ad Mon Sep 17 00:00:00 2001
From: Nicolas Van Wambeke <nicolasvw@free.fr>
Date: Fri, 3 Apr 2020 11:36:58 +0200
Subject: [PATCH] Changes to use random port numbers (depend on user's uid)
 rather than a static port. Allows all students to use the same machine (for
 Covid-19 mitigation)

---
 Makefile                  | 4 +++-
 include/api/mictcp_core.h | 9 ++++++---
 tsock_video               | 7 ++++---
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 18fd838..e8a02cb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,7 @@
 DATE := `date +'%Y%m%d'`
 TAG := moodle-$(USER)
+PORT := $(shell expr `id -u` % 2000 + 12487)
+PORT2 := $(shell expr $(PORT) + 1)
 
 ifneq ($(tag),)
         TAG := $(TAG)-$(tag)
@@ -25,7 +27,7 @@ vpath %.c $(SRC_DIR)
 
 define make-goal
 $1/%.o: %.c
-	$(CC) -std=gnu99 -Wall -g -I $(INCLUDES) -c $$< -o $$@
+	$(CC) -DAPI_CS_Port=$(PORT) -DAPI_SC_Port=$(PORT2) -std=gnu99 -Wall -g -I $(INCLUDES) -c $$< -o $$@
 endef
 
 .PHONY: all checkdirs clean
diff --git a/include/api/mictcp_core.h b/include/api/mictcp_core.h
index 234653c..0e61c95 100644
--- a/include/api/mictcp_core.h
+++ b/include/api/mictcp_core.h
@@ -22,9 +22,12 @@ unsigned long get_now_time_usec();
 /**********************************************************************
  * Private core functions, should not be used for implementing mictcp *
  **********************************************************************/
-
-#define API_CS_Port 8524
-#define API_SC_Port 8525
+#ifndef API_CS_Port
+  #define API_CS_Port 8524
+#endif
+#ifndef API_SC_Port
+  #define API_SC_Port 8525
+#endif
 #define API_HD_Size 15
 
 typedef struct ip_payload
diff --git a/tsock_video b/tsock_video
index 7a43230..320bb83 100755
--- a/tsock_video
+++ b/tsock_video
@@ -3,6 +3,7 @@
 puits=false
 sourc=false
 protocol="tcp"
+port=`expr \`id -u\` % 3000 + 14578`
 
 usage() { echo "Usage: $0 [[-p|-s] [-t (tcp|mictcp)]" 1>&2; exit 1; }
 
@@ -35,11 +36,11 @@ fi
 if [ "$puits" = true ]; then
 
     echo "Lancement du puits, protocole " $protocol
-    cvlc rtp://127.0.0.1:1234 > /dev/null 2>&1 &
+    cvlc rtp://127.0.0.1:$port > /dev/null 2>&1 &
 
     if [ "$protocol" = "mictcp" ]; then
         cd build
-        ./gateway -p -t $protocol 1234 &
+        ./gateway -p -t $protocol $port &
     cd ..
     fi
 fi
@@ -48,7 +49,7 @@ if [ "$sourc" = true ]; then
 
     echo "Lancement de la source, protocol " $protocol
     cd build
-    ./gateway -s -t $protocol 127.0.0.1 1234 &
+    ./gateway -s -t $protocol 127.0.0.1 $port &
     cd ..
 fi