FreeBSD needs netinet/in.h with struct sockaddr_in for src/net.cpp
to be included explicitly. See man ip(4).

--- configure.in.orig	2024-08-31 18:10:20 UTC
+++ configure.in
@@ -71,7 +71,7 @@ string.h stdlib.h stdio.h sys/stat.h unistd.h stdarg.h
 [ \
 pthread.h \
 string.h stdlib.h stdio.h sys/stat.h unistd.h stdarg.h sys/ioctl.h arpa/inet.h \
-locale.h malloc.h sys/socket.h netdb.h signal.h ctype.h \
+locale.h malloc.h sys/socket.h netinet/in.h netdb.h signal.h ctype.h \
 algorithm string list vector queue stack sstream \
 expat.h \
 ] ,  , [AC_MSG_ERROR([Couldn't find some headers])] )