Added an additional option LWIP_ETHERNET to support ethernet without ARP (necessary for pure PPPoE) - no changes in the ppp code yet

src/api/tcpip.c

@@ -272,11 +272,11 @@ tcpip_thread(void *arg)
 
     case TCPIP_MSG_INPKT:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: PACKET %p\n", (void *)msg));
-#if LWIP_ARP
+#if LWIP_ETHERNET
       if (msg->msg.inp.netif->flags & NETIF_FLAG_ETHARP) {
         ethernet_input(msg->msg.inp.p, msg->msg.inp.netif);
       } else
-#endif /* LWIP_ARP */
+#endif /* LWIP_ETHERNET */
       { ip_input(msg->msg.inp.p, msg->msg.inp.netif);
       }
       memp_free(MEMP_TCPIP_MSG_INPKT, msg);

src/core/init.c

@@ -171,6 +171,9 @@
 #if PPP_SUPPORT && !PPPOS_SUPPORT & !PPPOE_SUPPORT
   #error "PPP_SUPPORT needs either PPPOS_SUPPORT or PPPOE_SUPPORT turned on"
 #endif
+#if !LWIP_ETHERNET && (LWIP_ARP || PPPOE_SUPPORT)
+  #error "LWIP_ETHERNET needs to be turned on for LWIP_ARP or PPPOE_SUPPORT"
+#endif
 
 
 /* Compile-time checks for deprecated options.

src/include/lwip/opt.h

@@ -376,6 +376,13 @@
 #define ETHARP_SUPPORT_VLAN             0
 #endif
 
+/** LWIP_ETHERNET==1: enable ethernet support for PPPoE even though ARP
+ * might be disabled
+ */
+#ifndef LWIP_ETHERNET
+#define LWIP_ETHERNET                   (LWIP_ARP || PPPOE_SUPPORT)
+#endif
+
 /*
    --------------------------------
    ---------- IP options ----------

src/include/netif/etharp.h

@@ -37,7 +37,7 @@
 
 #include "lwip/opt.h"
 
-#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
+#if LWIP_ARP || LWIP_ETHERNET /* don't build if not configured for use in lwipopts.h */
 
 #include "lwip/pbuf.h"
 #include "lwip/ip_addr.h"
@@ -139,6 +139,8 @@ PACK_STRUCT_END
 #define ETHTYPE_PPPOEDISC 0x8863  /* PPP Over Ethernet Discovery Stage */
 #define ETHTYPE_PPPOE     0x8864  /* PPP Over Ethernet Session Stage */
 
+#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
+
 /** ARP message types (opcodes) */
 #define ARP_REQUEST 1
 #define ARP_REPLY   2
@@ -169,8 +171,6 @@ err_t etharp_request(struct netif *netif, struct ip_addr *ipaddr);
  *  From RFC 3220 "IP Mobility Support for IPv4" section 4.6. */
 #define etharp_gratuitous(netif) etharp_request((netif), &(netif)->ip_addr)
 
-err_t ethernet_input(struct pbuf *p, struct netif *netif);
-
 #if LWIP_AUTOIP
 err_t etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr,
                  const struct eth_addr *ethdst_addr,
@@ -179,14 +179,18 @@ err_t etharp_raw(struct netif *netif, const struct eth_addr *ethsrc_addr,
                  const u16_t opcode);
 #endif /* LWIP_AUTOIP */
 
+#endif /* LWIP_ARP */
+
+err_t ethernet_input(struct pbuf *p, struct netif *netif);
+
 #define eth_addr_cmp(addr1, addr2) (memcmp((addr1)->addr, (addr2)->addr, ETHARP_HWADDR_LEN) == 0)
 
 extern const struct eth_addr ethbroadcast, ethzero;
 
+#endif /* LWIP_ARP || LWIP_ETHERNET */
+
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* LWIP_ARP */
-
 #endif /* __NETIF_ARP_H__ */

src/netif/etharp.c

@@ -45,7 +45,7 @@
  
 #include "lwip/opt.h"
 
-#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
+#if LWIP_ARP || LWIP_ETHERNET
 
 #include "lwip/inet.h"
 #include "lwip/ip.h"
@@ -61,6 +61,11 @@
 
 #include <string.h>
 
+const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
+const struct eth_addr ethzero = {{0,0,0,0,0,0}};
+
+#if LWIP_ARP /* don't build if not configured for use in lwipopts.h */
+
 /** the time an ARP entry stays valid after its last update,
  *  for ARP_TMR_INTERVAL = 5000, this is
  *  (240 * 5) seconds = 20 minutes.
@@ -103,8 +108,6 @@ struct etharp_entry {
   struct netif *netif;
 };
 
-const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
-const struct eth_addr ethzero = {{0,0,0,0,0,0}};
 static struct etharp_entry arp_table[ARP_TABLE_SIZE];
 #if !LWIP_NETIF_HWADDRHINT
 static u8_t etharp_cached_entry;
@@ -1134,6 +1137,7 @@ etharp_request(struct netif *netif, struct ip_addr *ipaddr)
                     (struct eth_addr *)netif->hwaddr, &netif->ip_addr, &ethzero,
                     ipaddr, ARP_REQUEST);
 }
+#endif /* LWIP_ARP */
 
 /**
  * Process received ethernet frames. Using this function instead of directly
@@ -1175,6 +1179,7 @@ ethernet_input(struct pbuf *p, struct netif *netif)
 #endif /* ETHARP_SUPPORT_VLAN */
 
   switch (type) {
+#if LWIP_ARP
     /* IP packet? */
     case ETHTYPE_IP:
 #if ETHARP_TRUST_IP_MAC
@@ -1196,7 +1201,7 @@ ethernet_input(struct pbuf *p, struct netif *netif)
       /* pass p to ARP module */
       etharp_arp_input(netif, (struct eth_addr*)(netif->hwaddr), p);
       break;
-
+#endif /* LWIP_ARP */
 #if PPPOE_SUPPORT
     case ETHTYPE_PPPOEDISC: /* PPP Over Ethernet Discovery Stage */
       pppoe_disc_input(netif, p);
@@ -1219,4 +1224,4 @@ ethernet_input(struct pbuf *p, struct netif *netif)
      so the caller doesn't have to free it again */
   return ERR_OK;
 }
-#endif /* LWIP_ARP */
+#endif /* LWIP_ARP || LWIP_ETHERNET */