Example program with HTTPServer and sensor data streaming over TCPSockets, using Donatien Garnier's Net APIs and services code on top of LWIP. Files StreamServer.h and .cpp encapsulate streaming over TCPSockets. Broadcast is done by sendToAll(), and all incoming data is echoed back to the client. Echo code can be replaced with some remote control of the streaming interface. See main() that shows how to periodically send some data to all subscribed clients. To subscribe, a client should open a socket at <mbed_ip> port 123. I used few lines in TCL code to set up a quick sink for the data. HTTP files are served on port 80 concurrently to the streaming.

Dependencies:   mbed

Revision:
0:e614f7875b60
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/drv/eth/eth_drv.cpp	Sat Jun 12 06:01:50 2010 +0000
@@ -0,0 +1,208 @@
+
+/*
+Copyright (c) 2010 Donatien Garnier (donatiengar [at] gmail [dot] com)
+ 
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+ 
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "netCfg.h"
+#if NET_ETH
+
+#include "mbed.h"
+
+Ethernet *pEth = NULL;
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "lwip/opt.h"
+
+#include "lwip/def.h"
+#include "lwip/pbuf.h"
+#include "lwip/sys.h"
+#include "lwip/stats.h"
+#include "netif/etharp.h"
+#include "string.h"
+
+//#include "eth_drv.h"
+
+#define IFNAME0 'E'
+#define IFNAME1 'X'
+
+#define min(x,y) (((x)<(y))?(x):(y))
+
+struct netif* eth_netif;
+
+static err_t eth_output(struct netif *netif, struct pbuf *p) {
+  #if ETH_PAD_SIZE
+    pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
+  #endif
+
+  do {
+    pEth->write((const char *)p->payload, p->len);
+  } while((p = p->next)!=NULL);
+
+  pEth->send();
+
+  #if ETH_PAD_SIZE
+    pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
+  #endif
+  
+  LINK_STATS_INC(link.xmit);
+  return ERR_OK;
+}
+
+/*
+void show(char *buf, int size) {
+    printf("Destination:  %02hx:%02hx:%02hx:%02hx:%02hx:%02hx\n",
+            buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
+    printf("Source: %02hx:%02hx:%02hx:%02hx:%02hx:%02hx\n",
+            buf[6], buf[7], buf[8], buf[9], buf[10], buf[11]);
+  
+    printf("Type %hd\n", htons((short)buf[12]));
+    
+   // hexview(buf, size);
+}
+*/
+
+void eth_poll() {
+  struct eth_hdr *ethhdr;
+  struct pbuf *frame, *p;
+  int len, read;
+
+  while((len = pEth->receive()) != 0) {
+      frame = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
+      if(frame == NULL) {
+          return;
+      }
+      p = frame;
+      /* no packet could be read, silently ignore this */
+      if (p == NULL) return;
+      do {
+         read = pEth->read((char *)p->payload, p->len);
+         p = p->next;
+      } while(p != NULL && read != 0);
+           
+      #if ETH_PAD_SIZE
+          pbuf_header(p, ETH_PAD_SIZE);
+      #endif
+
+      ethhdr = (struct eth_hdr *)(frame->payload);
+      
+     // show((char*)ethhdr, 13);
+      
+      /*
+      switch(htons(ethhdr->type)) {
+          
+          case ETHTYPE_IP:
+              etharp_ip_input(gnetif, frame);
+              pbuf_header(frame, -((s16_t) sizeof(struct eth_hdr)));
+              gnetif->input(frame, gnetif);
+              break;
+          
+          case ETHTYPE_ARP:
+              etharp_arp_input(gnetif, (struct eth_addr *)(gnetif->hwaddr), frame);
+              break;
+          
+          default:
+              break;
+      }*/
+      
+      
+      
+      //ethernet_input(frame, gnetif);
+      
+      switch (htons(ethhdr->type)) {
+      /* IP or ARP packet? */
+      case ETHTYPE_IP:
+      case ETHTYPE_ARP:
+      #if PPPOE_SUPPORT
+      /* PPPoE packet? */
+      case ETHTYPE_PPPOEDISC:
+      case ETHTYPE_PPPOE:
+      #endif /* PPPOE_SUPPORT */
+      /* full packet send to tcpip_thread to process */
+        //if (netif->input(p, gnetif)!=ERR_OK)
+        if (ethernet_input(frame, eth_netif)!=ERR_OK)
+        { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
+          pbuf_free(frame);
+          frame = NULL;
+        }
+        break;
+
+      default:
+        pbuf_free(frame);
+        frame = NULL;
+        break;
+      }
+      
+      /* pbuf_free(frame); */
+  }
+
+  
+ 
+  
+}
+
+err_t eth_init(struct netif *netif) {
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  
+  NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 0x2EA);
+  
+  /* maximum transfer unit */
+  netif->mtu = 0x2EA;
+  
+  /* device capabilities */
+  /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
+  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
+
+  netif->state = NULL;
+  eth_netif = netif;
+
+  netif->name[0] = IFNAME0;
+  netif->name[1] = IFNAME1;
+
+  /* We directly use etharp_output() here to save a function call.
+   * You can instead declare your own function an call etharp_output()
+   * from it if you have to do some checks before sending (e.g. if link
+   * is available...) */
+  netif->output          = etharp_output;
+  netif->linkoutput      = eth_output;
+
+  pEth = new Ethernet();
+
+  return ERR_OK;
+}
+
+void eth_free()
+{
+  if(pEth)
+    delete pEth;
+  pEth = NULL;
+}
+
+void eth_address(char* mac) {
+    pEth->address(mac);
+}
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif