Index: multicat.c
===================================================================
--- multicat.c	(revision 76)
+++ multicat.c	(working copy)
@@ -44,6 +44,10 @@
 #include <sys/ioctl.h>
 #include <syslog.h>
 
+#ifdef __FreeBSD__
+#	include <sys/uio.h>
+#endif
+
 #ifdef SIOCGSTAMPNS
 #   define HAVE_TIMESTAMPS
 #endif
@@ -276,12 +280,12 @@
     ssize_t i_ret;
     struct iovec iov[2];
 
-    #ifdef __FAVOR_BSD
+    #if defined(__FreeBSD__) || defined(__FAVOR_BSD)
     pktheader.udph.uh_ulen
     #else
     pktheader.udph.len
     #endif
-    = htons(sizeof(struct udphdr) + i_len);
+	= htons(sizeof(struct udphdr) + i_len);
 
     iov[0].iov_base = &pktheader;
     iov[0].iov_len = sizeof(struct udprawpkt);
Index: util.c
===================================================================
--- util.c	(revision 76)
+++ util.c	(working copy)
@@ -451,7 +451,11 @@
                         uint8_t ttl, uint8_t tos, uint16_t len)
 {
 #ifndef __APPLE__
+#	if defined(__FreeBSD__)
+    struct ip *iph = &(dgram->iph);
+#	else
     struct iphdr *iph = &(dgram->iph);
+#	endif
     struct udphdr *udph = &(dgram->udph);
 
 #ifdef DEBUG_SOCKET
@@ -464,7 +468,27 @@
     printf("Filling raw header (%p) (%s:%u -> %s:%u)\n", dgram, ipsrc_str, portsrc, ipdst_str, portdst);
 #endif
 
+    #if defined(__FreeBSD__) || defined(__FAVOR_BSD)
     // Fill ip header
+    iph->ip_hl    = 5;              // ip header with no specific option
+    iph->ip_v     = 4;
+    iph->ip_tos   = tos;
+    iph->ip_len   = sizeof(struct udprawpkt) + len; // auto-htoned ?
+    iph->ip_id    = htons(0);       // auto-generated if frag_off (flags) = 0 ?
+    iph->ip_off   = 0;
+    iph->ip_ttl   = ttl;
+    iph->ip_p     = IPPROTO_UDP;
+    iph->ip_sum   = 0;
+    iph->ip_src.s_addr = ipsrc;
+    iph->ip_dst.s_addr = ipdst;
+
+    // Fill udp header
+    udph->uh_sport = htons(portsrc);
+    udph->uh_dport = htons(portdst);
+    udph->uh_ulen  = htons(sizeof(struct udphdr) + len);
+    udph->uh_sum   = 0;
+    #else
+    // Fill ip header
     iph->ihl      = 5;              // ip header with no specific option
     iph->version  = 4;
     iph->tos      = tos;
@@ -478,12 +502,6 @@
     iph->daddr    = ipdst;
 
     // Fill udp header
-    #ifdef __FAVOR_BSD
-    udph->uh_sport = htons(portsrc);
-    udph->uh_dport = htons(portdst);
-    udph->uh_ulen  = htons(sizeof(struct udphdr) + len);
-    udph->uh_sum   = 0;
-    #else
     udph->source = htons(portsrc);
     udph->dest   = htons(portdst);
     udph->len    = htons(sizeof(struct udphdr) + len);
@@ -721,7 +739,7 @@
 
             if ( bind_addr.ss.ss_family != AF_UNSPEC )
             {
-                #ifndef __APPLE__
+                #if !defined(__APPLE__) && !defined(__FreeBSD__)
                 if ( IN6_IS_ADDR_MULTICAST( &bind_addr.sin6.sin6_addr ) )
                 {
                     struct ipv6_mreq imr;
Index: util.h
===================================================================
--- util.h	(revision 76)
+++ util.h	(working copy)
@@ -24,7 +24,7 @@
 #include <netinet/udp.h>
 #include <netinet/ip.h>
 
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(__FreeBSD__)
 #define POLLRDHUP 0
 /* uClibc may does not have clock_nanosleep() */
 #elif !defined (__UCLIBC__) || \
@@ -58,11 +58,15 @@
  * Raw udp packet structure with flexible-array payload
  *****************************************************************************/
 struct udprawpkt {
-#ifndef __APPLE__
+#if !defined(__APPLE__)
+#	if defined(__FreeBSD__)
+    struct  ip iph;
+#	else
     struct  iphdr iph;
+#	endif
     struct  udphdr udph;
+#endif
     uint8_t payload[];
-#endif
 } __attribute__((packed));