From a56795c1490d4c8d29dfdf69e48c094bff57f966 Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon>
Date: Sat, 15 May 2010 14:52:39 +0000
Subject: [PATCH] Added new option SO_REUSE_RXTOALL to pass received UDP
 broadcast/multicast packets to more than one pcb

---
 CHANGELOG              |  4 +++-
 src/core/udp.c         | 42 ++++++++++++++++++++++++++++++++++++++++++
 src/include/lwip/opt.h | 11 ++++++++++-
 3 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index fe3458e4..d6e2a2c1 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -14,7 +14,9 @@ HISTORY
   ++ New features:
 
   2010-05-13: Simon Goldschmidt
-  * tcp.c, udp.c: task #6995: Implement SO_REUSEADDR (correctly)
+  * tcp.c, udp.c: task #6995: Implement SO_REUSEADDR (correctly), added
+    new option SO_REUSE_RXTOALL to pass received UDP broadcast/multicast
+    packets to more than one pcb.
 
   2010-05-02: Simon Goldschmidt
   * netbuf.h/.c, sockets.c, api_msg.c: use checksum-on-copy for sending
diff --git a/src/core/udp.c b/src/core/udp.c
index 954e1c19..7b5d0492 100644
--- a/src/core/udp.c
+++ b/src/core/udp.c
@@ -276,6 +276,48 @@ udp_input(struct pbuf *p, struct netif *inp)
     }
     if (pcb != NULL) {
       snmp_inc_udpindatagrams();
+#if SO_REUSE_RXTOALL
+      if ((broadcast || ip_addr_ismulticast(&iphdr->dest)) &&
+          ((pcb->so_options & SOF_REUSEADDR) != 0)) {
+        /* pass broadcast- or multicast packets to all multicast pcbs
+           if SOF_REUSEADDR is set on the first match */
+        struct udp_pcb *mpcb;
+        /* for that, move payload to IP header again */
+        pbuf_header(p, (s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+        for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
+          if (mpcb != pcb) {
+            /* compare PCB local addr+port to UDP destination addr+port */
+            if ((mpcb->local_port == dest) &&
+                ((!broadcast && ip_addr_isany(&mpcb->local_ip)) ||
+                 ip_addr_cmp(&(mpcb->local_ip), &(iphdr->dest)) ||
+#if LWIP_IGMP
+                 ip_addr_ismulticast(&(iphdr->dest)) ||
+#endif /* LWIP_IGMP */
+#if IP_SOF_BROADCAST_RECV
+                 (broadcast && (mpcb->so_options & SOF_BROADCAST)))) {
+#else  /* IP_SOF_BROADCAST_RECV */
+                 (broadcast))) {
+#endif /* IP_SOF_BROADCAST_RECV */
+              /* pass a copy of the packet to all local matches */
+              if (mpcb->recv != NULL) {
+                struct pbuf *q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
+                if (q != NULL) {
+                  err_t err = pbuf_copy(q, p);
+                  if (err == ERR_OK) {
+                    /* move payload to UDP data */
+                    struct ip_hdr *q_iphdr = (struct ip_hdr *)q->payload;
+                    pbuf_header(q, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+                    mpcb->recv(mpcb->recv_arg, mpcb, q, &q_iphdr->src, src);
+                  }
+                }
+              }
+            }
+          }
+        }
+        /* and move payload to UDP data again */
+        pbuf_header(p, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+      }
+#endif /* SO_REUSE_RXTOALL */
       /* callback */
       if (pcb->recv != NULL) {
         /* now the recv function is responsible for freeing p */
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 81d98970..1aa2c400 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1388,12 +1388,21 @@
 #endif
 
 /**
- * SO_REUSE==1: Enable SO_REUSEADDR and SO_REUSEPORT options. DO NOT USE!
+ * SO_REUSE==1: Enable SO_REUSEADDR option.
  */
 #ifndef SO_REUSE
 #define SO_REUSE                        0
 #endif
 
+/**
+ * SO_REUSE_RXTOALL==1: Pass a copy of incoming broadcast/multicast packets
+ * to all local matches if SO_REUSEADDR is turned on.
+ * WARNING: Adds a memcpy for every packet if passing to more than one pcb!
+ */
+#ifndef SO_REUSE_RXTOALL
+#define SO_REUSE_RXTOALL                0
+#endif
+
 /*
    ----------------------------------------
    ---------- Statistics options ----------