From 09d0e99d5b60e5cbb2ccb0493dff2b516f2ee3eb Mon Sep 17 00:00:00 2001
From: Nick Moore <nick@zoic.org>
Date: Thu, 2 May 2019 14:41:37 +1000
Subject: [PATCH] assign variable socket number to DHCP

---
 shared-module/wiznet/wiznet5k.c | 44 ++++++++++++++++++++-------------
 shared-module/wiznet/wiznet5k.h |  2 +-
 2 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/shared-module/wiznet/wiznet5k.c b/shared-module/wiznet/wiznet5k.c
index 39b2bd3fed..660df90b75 100644
--- a/shared-module/wiznet/wiznet5k.c
+++ b/shared-module/wiznet/wiznet5k.c
@@ -93,6 +93,16 @@ int wiznet5k_gethostbyname(mp_obj_t nic, const char *name, mp_uint_t len, uint8_
     }
 }
 
+int get_available_socket(wiznet5k_obj_t *wiz) {
+    for (uint8_t sn = 0; sn < _WIZCHIP_SOCK_NUM_; sn++) {
+        if ((wiz->socket_used & (1 << sn)) == 0) {
+            wiz->socket_used |= (1 << sn);
+            return sn;
+        }
+    }
+    return -1;
+}
+
 int wiznet5k_socket_socket(mod_network_socket_obj_t *socket, int *_errno) {
     if (socket->u_param.domain != MOD_NETWORK_AF_INET) {
         *_errno = MP_EAFNOSUPPORT;
@@ -106,14 +116,8 @@ int wiznet5k_socket_socket(mod_network_socket_obj_t *socket, int *_errno) {
     }
 
     if (socket->u_param.fileno == -1) {
-        // get first unused socket number ... 0 is reserved for DHCP
-        for (mp_uint_t sn = 1; sn < _WIZCHIP_SOCK_NUM_; sn++) {
-            if ((wiznet5k_obj.socket_used & (1 << sn)) == 0) {
-                wiznet5k_obj.socket_used |= (1 << sn);
-                socket->u_param.fileno = sn;
-                break;
-            }
-        }
+        // get first unused socket number
+        socket->u_param.fileno = get_available_socket(&wiznet5k_obj);
         if (socket->u_param.fileno == -1) {
             // too many open sockets
             *_errno = MP_EMFILE;
@@ -318,33 +322,37 @@ int wiznet5k_socket_ioctl(mod_network_socket_obj_t *socket, mp_uint_t request, m
 }
 
 void wiznet5k_socket_timer_tick(mod_network_socket_obj_t *socket) {
-    if (wiznet5k_obj.dhcp_active) {
+    if (wiznet5k_obj.dhcp_socket >= 0) {
         DHCP_time_handler();
         DHCP_run();
     }
 }
 
 void wiznet5k_start_dhcp(void) {
+    // XXX this should throw an error if DHCP fails
     static DHCP_INIT_BUFFER_TYPE dhcp_buf[DHCP_INIT_BUFFER_SIZE];
 
-    if (!wiznet5k_obj.dhcp_active) {
+    if (wiznet5k_obj.dhcp_socket < 0) {
         // Set up the socket to listen on UDP 68 before calling DHCP_init
-        WIZCHIP_EXPORT(socket)(0, MOD_NETWORK_SOCK_DGRAM, DHCP_CLIENT_PORT, 0);
-        DHCP_init(0, dhcp_buf);
-        wiznet5k_obj.dhcp_active = 1;
+        wiznet5k_obj.dhcp_socket = get_available_socket(&wiznet5k_obj);
+        if (wiznet5k_obj.dhcp_socket < 0) return;
+
+        WIZCHIP_EXPORT(socket)(wiznet5k_obj.dhcp_socket, MOD_NETWORK_SOCK_DGRAM, DHCP_CLIENT_PORT, 0);
+        DHCP_init(wiznet5k_obj.dhcp_socket, dhcp_buf);
     }
 }
 
 void wiznet5k_stop_dhcp(void) {
-    if (wiznet5k_obj.dhcp_active) {
-        wiznet5k_obj.dhcp_active = 0;
+    if (wiznet5k_obj.dhcp_socket >= 0) {
         DHCP_stop();
-        WIZCHIP_EXPORT(close)(0);
+        WIZCHIP_EXPORT(close)(wiznet5k_obj.dhcp_socket);
+        wiznet5k_obj.socket_used &= ~(1 << wiznet5k_obj.dhcp_socket);
+        wiznet5k_obj.dhcp_socket = -1;
     }
 }
 
 bool wiznet5k_check_dhcp(void) {
-    return wiznet5k_obj.dhcp_active;
+    return wiznet5k_obj.dhcp_socket >= 0;
 }
 
 /// Create and return a WIZNET5K object.
@@ -357,6 +365,7 @@ mp_obj_t wiznet5k_create(mp_obj_t spi_in, mp_obj_t cs_in, mp_obj_t rst_in) {
     common_hal_digitalio_digitalinout_construct(&wiznet5k_obj.cs, cs_in);
     common_hal_digitalio_digitalinout_construct(&wiznet5k_obj.rst, rst_in);
     wiznet5k_obj.socket_used = 0;
+    wiznet5k_obj.dhcp_socket = -1;
 
     /*!< SPI configuration */
     // XXX probably should check if the provided SPI is already configured, and
@@ -394,6 +403,7 @@ mp_obj_t wiznet5k_create(mp_obj_t spi_in, mp_obj_t cs_in, mp_obj_t rst_in) {
     // seems we need a small delay after init
     mp_hal_delay_ms(250);
 
+    // dhcp is started by default
     wiznet5k_start_dhcp();
 
     // register with network module
diff --git a/shared-module/wiznet/wiznet5k.h b/shared-module/wiznet/wiznet5k.h
index 1284a44fd1..09f83df66f 100644
--- a/shared-module/wiznet/wiznet5k.h
+++ b/shared-module/wiznet/wiznet5k.h
@@ -39,7 +39,7 @@ typedef struct _wiznet5k_obj_t {
     digitalio_digitalinout_obj_t cs;
     digitalio_digitalinout_obj_t rst;
     uint8_t socket_used;
-    bool dhcp_active;
+    int8_t dhcp_socket;
 } wiznet5k_obj_t;
 
 int wiznet5k_gethostbyname(mp_obj_t nic, const char *name, mp_uint_t len, uint8_t *out_ip);