Added multicast udp, added callback for interrupt data arrival

Implemented begin multicast for receiving multicast udp.
Added ability to add a callback from the interrupt when udp
receive data (Usefull with FreeRTOS).
```
void EthernetUDP::onDataArrival( std::function<void()> onDataArrival_fn){
  _udp.onDataArrival = onDataArrival_fn;
}
```

Author: straccio

src/EthernetUdp.cpp

@@ -25,16 +25,23 @@
  *
  * [email protected] 12/30/2008
  */
-
 #include "STM32Ethernet.h"
 #include "Udp.h"
 #include "Dns.h"
 
+#include "lwip/igmp.h"
+#include "lwip/ip_addr.h"
+
 /* Constructor */
 EthernetUDP::EthernetUDP() {}
 
 /* Start EthernetUDP socket, listening at local port PORT */
 uint8_t EthernetUDP::begin(uint16_t port) {
+  return begin(Ethernet.localIP(), port);
+}
+
+/* Start EthernetUDP socket, listening at local IP ip and port PORT */
+uint8_t EthernetUDP::begin(IPAddress ip, uint16_t port, bool multicast) {
   // Can create a single udp connection per socket
   if(_udp.pcb != NULL) {
     return 0;
@@ -46,14 +53,25 @@ uint8_t EthernetUDP::begin(uint16_t port) {
     return 0;
   }
 
-  IPAddress ip = Ethernet.localIP();
   ip_addr_t ipaddr;
+  err_t err;
+  u8_to_ip_addr(rawIPAddress(ip), &ipaddr);
+  if (multicast) {
+    err = udp_bind(_udp.pcb, IP_ADDR_ANY, port);
+  } else {
+    err = udp_bind(_udp.pcb, &ipaddr, port);
+  }
 
-  if(ERR_OK != udp_bind(_udp.pcb, u8_to_ip_addr(rawIPAddress(ip), &ipaddr), port)) {
+  if(ERR_OK != err) {
     stop();
     return 0;
   }
 
+#if LWIP_IGMP
+  if ((multicast) && (ERR_OK != igmp_joingroup(IP_ADDR_ANY, &ipaddr))) {
+      return 0;
+  }
+#endif
   udp_recv(_udp.pcb, &udp_receive_callback, &_udp);
 
   _port = port;
@@ -104,8 +122,6 @@ int EthernetUDP::beginPacket(IPAddress ip, uint16_t port)
     return 0;
   }
 
-  ip_addr_t ipaddr;
-
   _sendtoIP = ip;
   _sendtoPort = port;
 
@@ -245,6 +261,11 @@ void EthernetUDP::flush()
 /* Start EthernetUDP socket, listening at local port PORT */
 uint8_t EthernetUDP::beginMulticast(IPAddress ip, uint16_t port)
 {
-  UNUSED(ip);
-  return begin(port);
+  return begin(ip, port, true);
+}
+
+#if LWIP_UDP
+void EthernetUDP::onDataArrival( std::function<void()> onDataArrival_fn){
+  _udp.onDataArrival = onDataArrival_fn;
 }
+#endif

src/EthernetUdp.h

@@ -38,10 +38,9 @@
 #define ethernetudp_h
 
 #include <Udp.h>
+#include <functional>
 
-extern "C" {
 #include "utility/stm32_eth.h"
-}
 
 #define UDP_TX_PACKET_MAX_SIZE 24
 
@@ -62,6 +61,7 @@ class EthernetUDP : public UDP {
 public:
   EthernetUDP();  // Constructor
   virtual uint8_t begin(uint16_t);	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
+  virtual uint8_t begin(IPAddress, uint16_t, bool multicast = false);	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
   virtual uint8_t beginMulticast(IPAddress, uint16_t);	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
   virtual void stop();  // Finish with the UDP socket
 
@@ -104,6 +104,7 @@ class EthernetUDP : public UDP {
   virtual IPAddress remoteIP() { return _remoteIP; };
   // Return the port of the host who sent the current incoming packet
   virtual uint16_t remotePort() { return _remotePort; };
+  virtual void onDataArrival( std::function<void()> onDataArrival_fn);
 };
 
 #endif

src/utility/ethernetif.c renamed to src/utility/ethernetif.cpp

@@ -51,6 +51,7 @@
 #include "ethernetif.h"
 #include <string.h>
 #include "PeripheralPins.h"
+#include "lwip/igmp.h"
 #include "stm32_eth.h"
 #if !defined(STM32_CORE_VERSION) || (STM32_CORE_VERSION  <= 0x01050000)
 #include "variant.h"
@@ -92,6 +93,11 @@ static ETH_HandleTypeDef EthHandle;
 
 static uint8_t macaddress[6]= { MAC_ADDR0, MAC_ADDR1, MAC_ADDR2, MAC_ADDR3, MAC_ADDR4, MAC_ADDR5 };
 
+#if LWIP_IGMP
+uint32_t ETH_HashTableHigh=0x0;
+uint32_t ETH_HashTableLow=0x0;
+#endif
+
 /* Private function prototypes -----------------------------------------------*/
 /* Private functions ---------------------------------------------------------*/
 /*******************************************************************************
@@ -205,7 +211,9 @@ static void low_level_init(struct netif *netif)
 
   /* Enable MAC and DMA transmission and reception */
   HAL_ETH_Start(&EthHandle);
-
+#if LWIP_IGMP
+  netif_set_igmp_mac_filter(netif, igmp_mac_filter);
+#endif
   /**** Configure PHY to generate an interrupt when Eth Link state changes ****/
   /* Read Register Configuration */
   HAL_ETH_ReadPHYRegister(&EthHandle, PHY_IMR, &regvalue);
@@ -214,6 +222,10 @@ static void low_level_init(struct netif *netif)
 
   /* Enable Interrupt on change of link status */
   HAL_ETH_WritePHYRegister(&EthHandle, PHY_IMR, regvalue );
+#if LWIP_IGMP
+  ETH_HashTableHigh=EthHandle.Instance->MACHTHR;
+  ETH_HashTableLow=EthHandle.Instance->MACHTLR;
+#endif
 }
 
 /**
@@ -510,6 +522,13 @@ void ethernetif_set_link(struct netif *netif)
   HAL_ETH_ReadPHYRegister(&EthHandle, PHY_BSR, &regvalue);
 
   if((regvalue & PHY_LINKED_STATUS) != (uint16_t)RESET) {
+#if LWIP_IGMP
+    if (!(netif->flags & NETIF_FLAG_IGMP)) {
+       netif->flags |= NETIF_FLAG_IGMP;
+       igmp_init();
+       igmp_start(netif);
+    }
+#endif
     netif_set_link_up(netif);
   }
 }
@@ -628,6 +647,72 @@ void ethernetif_set_mac_addr(const uint8_t *mac) {
   }
 }
 
+#if LWIP_IGMP
+err_t igmp_mac_filter( struct netif *netif, const ip4_addr_t *ip4_addr, netif_mac_filter_action action )
+{
+  uint8_t mac[6];
+  const uint8_t *p = (const uint8_t *)ip4_addr;
+
+  mac[0] = 0x01;
+  mac[1] = 0x00;
+  mac[2] = 0x5E;
+  mac[3] = *(p+1) & 0x7F;
+  mac[4] = *(p+2);
+  mac[5] = *(p+3);
+
+  register_multicast_address(mac);
+
+  return 0;
+}
+
+#ifndef HASH_BITS
+#define HASH_BITS 6 /* #bits in hash */
+#endif
+
+uint32_t ethcrc(const uint8_t *data, size_t length)
+{
+  uint32_t crc = 0xffffffff;
+  size_t i;
+  int j;
+
+  for (i = 0; i < length; i++) {
+    for (j = 0; j < 8; j++) {
+      if (((crc >> 31) ^ (data[i] >> j)) & 0x01) {
+        /* x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1 */
+        crc = (crc << 1) ^ 0x04C11DB7;
+      } else {
+        crc = crc << 1;
+      }
+    } 
+  }
+  return ~crc;
+}
+
+void register_multicast_address(const uint8_t *mac)
+{
+  uint32_t crc;
+  uint8_t hash;
+
+  /* Calculate crc32 value of mac address */
+  crc = ethcrc(mac, HASH_BITS);
+
+  /* 
+   * Only upper HASH_BITS are used
+   * which point to specific bit in the hash registers
+   */
+  hash = (crc >> 26) & 0x3F;
+
+	if (hash > 31) {
+    ETH_HashTableHigh |= 1 << (hash - 32);
+    EthHandle.Instance->MACHTHR = ETH_HashTableHigh;
+  }	else {
+    ETH_HashTableLow |= 1 << hash;
+    EthHandle.Instance->MACHTLR =ETH_HashTableLow;
+  }
+}
+#endif /* LWIP_IGMP */
+
+
 #ifdef ETH_INPUT_USE_IT
 /**
   * @brief  Ethernet Rx Transfer completed callback

src/utility/ethernetif.h

@@ -47,14 +47,11 @@
 
 #ifndef __ETHERNETIF_H__
 #define __ETHERNETIF_H__
-
-#include "lwip/err.h"
-#include "lwip/netif.h"
-
 #ifdef __cplusplus
  extern "C" {
 #endif
-
+#include "lwip/err.h"
+#include "lwip/netif.h"
 /* Exported types ------------------------------------------------------------*/
 uint8_t ethernetif_is_init(void);
 err_t ethernetif_init(struct netif *netif);
@@ -65,6 +62,11 @@ void ethernetif_notify_conn_changed(struct netif *netif);
 
 void ethernetif_set_mac_addr(const uint8_t *mac);
 
+#if LWIP_IGMP
+err_t igmp_mac_filter( struct netif *netif, const ip4_addr_t *ip4_addr, netif_mac_filter_action action );
+void register_multicast_address(const uint8_t *mac);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

src/utility/stm32_eth.cpp

@@ -47,10 +47,6 @@
 #include "lwip/prot/dhcp.h"
 #include "lwip/dns.h"
 
-#ifdef __cplusplus
- extern "C" {
-#endif
-
 /* Check ethernet link status every seconds */
 #define TIME_CHECK_ETH_LINK_STATE 500U
 
@@ -798,6 +794,10 @@ void udp_receive_callback(void *arg, struct udp_pcb *pcb, struct pbuf *p,
 
     ip_addr_copy(udp_arg->ip, *addr);
     udp_arg->port = port;
+
+    if(udp_arg->onDataArrival != NULL){
+      udp_arg->onDataArrival();
+    }
   } else {
     pbuf_free(p);
   }
@@ -1049,7 +1049,3 @@ void tcp_connection_close(struct tcp_pcb *tpcb, struct tcp_struct *tcp)
 }
 
 #endif /* LWIP_TCP */
-
-#ifdef __cplusplus
-}
-#endif

src/utility/stm32_eth.h

@@ -38,17 +38,14 @@
 #ifndef __STM32_ETH_H__
 #define __STM32_ETH_H__
 
-#ifdef __cplusplus
- extern "C" {
-#endif
-
 /* Includes ------------------------------------------------------------------*/
 #include "stm32_def.h"
 #include "lwip/ip_addr.h"
 #include "lwip/dhcp.h"
 #include "lwip/udp.h"
 #include "lwip/tcp.h"
 #include "lwip/opt.h"
+#include <functional>
 
 /* Exported types ------------------------------------------------------------*/
 /* TCP connection state */
@@ -74,6 +71,7 @@ struct udp_struct {
   struct pbuf_data data;
   ip_addr_t ip;       // the remote IP address from which the packet was received
   u16_t port;         // the remote port from which the packet was received
+  std::function<void()> onDataArrival;
 };
 
 /* TCP structure */
@@ -174,8 +172,4 @@ void tcp_connection_close(struct tcp_pcb *tpcb, struct tcp_struct *tcp);
 #error "LWIP_TCP must be enabled in lwipopts.h"
 #endif
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* __STM32_ETH_H__ */