fix #31

d-a-v · Mar 22, 2019 · 25d5e81 · 25d5e81
1 parent 2f481dc
commit 25d5e81
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diff --git a/glue-lwip/arduino/lwipopts.h b/glue-lwip/arduino/lwipopts.h
@@ -3529,6 +3529,12 @@
 #error LWIP_FEATURES must be defined
 #endif
 
+
+/**
+ * TCP_RANDOM_PORT: randomize port instead of simply increasing
+ */
+#define TCP_RANDOM_PORT 1
+
 /*
    --------------------------------------------------
    ------------------ SNTP options ------------------

diff --git a/patches/tcp-random-port.patch b/patches/tcp-random-port.patch
@@ -0,0 +1,19 @@
+diff --git a/src/core/tcp.c b/src/core/tcp.c
+index bd7d64ec..402fbd19 100644
+--- a/src/core/tcp.c
++++ b/src/core/tcp.c
+@@ -1015,9 +1015,14 @@ tcp_new_port(void)
+   struct tcp_pcb *pcb;
+
+ again:
++#if TCP_RANDOM_PORT && defined(LWIP_RAND)
++  tcp_port = (u16_t)(LWIP_RAND() % (TCP_LOCAL_PORT_RANGE_END - TCP_LOCAL_PORT_RANGE_START))
++             + TCP_LOCAL_PORT_RANGE_START;
++#else
+   tcp_port++;
+   if (tcp_port == TCP_LOCAL_PORT_RANGE_END) {
+     tcp_port = TCP_LOCAL_PORT_RANGE_START;
+   }
++#endif
+   /* Check all PCB lists. */
+   for (i = 0; i < NUM_TCP_PCB_LISTS; i++) {