From e001a021d5752db8926e7dc936a60b7f3f49689b Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Mon, 16 Feb 2009 20:24:29 +0000
Subject: [PATCH] patch #6539: (configurable) response to broadcast- and
 multicast pings

---
 CHANGELOG              |  8 ++++++--
 src/core/ipv4/icmp.c   | 29 +++++++++++++++++++++++------
 src/include/lwip/opt.h | 14 ++++++++++++++
 3 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 15342e82..93b64896 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -19,13 +19,17 @@ HISTORY
 
   ++ New features:
 
+  2009-02-16 Simon Goldschmidt (patch by Rishi Khan)
+  * icmp.c, opt.h: patch #6539: (configurable) response to broadcast- and multicast
+    pings
+
   2009-02-12 Simon Goldschmidt
   * init.h: Added LWIP_VERSION to get the current version of the stack
 
   2009-02-11 Simon Goldschmidt (suggested by Gottfried Spitaler)
   * opt.h, memp.h/.c: added MEMP_MEM_MALLOC to use mem_malloc/mem_free instead
-  of the pool allocator (can save code size with MEM_LIBC_MALLOC if libc-malloc
-  is otherwise used)
+    of the pool allocator (can save code size with MEM_LIBC_MALLOC if libc-malloc
+    is otherwise used)
 
   2009-01-28 Jonathan Larmour (suggested by Bill Bauerbach)
   * ipv4/inet_chksum.c, ipv4/lwip/inet_chksum.h: inet_chksum_pseudo_partial()
diff --git a/src/core/ipv4/icmp.c b/src/core/ipv4/icmp.c
index 6a72c780..b49d6598 100644
--- a/src/core/ipv4/icmp.c
+++ b/src/core/ipv4/icmp.c
@@ -94,13 +94,30 @@ icmp_input(struct pbuf *p, struct netif *inp)
 #endif /* LWIP_DEBUG */
   switch (type) {
   case ICMP_ECHO:
-    /* broadcast or multicast destination address? */
-    if (ip_addr_isbroadcast(&iphdr->dest, inp) || ip_addr_ismulticast(&iphdr->dest)) {
-      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast or broadcast pings\n"));
-      ICMP_STATS_INC(icmp.err);
-      pbuf_free(p);
-      return;
+#if !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
+    {
+      int accepted = 1;
+#if !LWIP_MULTICAST_PING
+      /* multicast destination address? */
+      if (ip_addr_ismulticast(&iphdr->dest)) {
+        accepted = 0;
+      }
+#endif /* LWIP_MULTICAST_PING */
+#if !LWIP_BROADCAST_PING
+      /* broadcast destination address? */
+      if (ip_addr_isbroadcast(&iphdr->dest, inp)) {
+        accepted = 0;
+      }
+#endif /* LWIP_BROADCAST_PING */
+      /* broadcast or multicast destination address not acceptd? */
+      if (!accepted) {
+        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast or broadcast pings\n"));
+        ICMP_STATS_INC(icmp.err);
+        pbuf_free(p);
+        return;
+      }
     }
+#endif /* !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
     LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
     if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
       LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 907a9582..17964f48 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -461,6 +461,20 @@
 #define ICMP_TTL                       (IP_DEFAULT_TTL)
 #endif
 
+/**
+ * LWIP_BROADCAST_PING==1: respond to broadcast pings (default is unicast only)
+ */
+#ifndef LWIP_BROADCAST_PING
+#define LWIP_BROADCAST_PING             0
+#endif
+
+/**
+ * LWIP_MULTICAST_PING==1: respond to multicast pings (default is unicast only)
+ */
+#ifndef LWIP_MULTICAST_PING
+#define LWIP_MULTICAST_PING             0
+#endif
+
 /*
    ---------------------------------
    ---------- RAW options ----------