ETHER: Add build support leveraging libpcap shared object without pcap.h

Some host systems come with the libpcap shared object installed.  If that
is the case, since the default build behavior is to dynamically load libpcap,
builds can now potentially avoid a forced install of the libpcap-devel package.

makefile

@@ -998,6 +998,10 @@ ifeq (${WIN32},)  #*nix Environments (&& cygwin)
         endif
       endif
     else # pcap desired but pcap.h not found
+      ifneq (,$(call find_lib,$(PCAPLIB)))
+        PCAP_LIB_VERSION = $(shell strings $(call find_lib,$(PCAPLIB)) | grep 'libpcap version' | awk '{ print $$3}')
+        PCAP_LIB_BASE_VERSION = $(firstword $(subst ., ,$(PCAP_LIB_VERSION)))
+      endif
       NEEDED_PKGS += DPKG_PCAP
       # On non-Linux platforms, we'll still try to provide deprecated support for libpcap in /usr/local
       INCPATHSAVE := ${INCPATH}
@@ -1053,19 +1057,27 @@ ifeq (${WIN32},)  #*nix Environments (&& cygwin)
         LIBEXT = $(LIBEXTSAVE)
       else
         INCPATH = $(INCPATHSAVE)
-        $(info *** Warning ***)
+        ifeq (1,$(PCAP_LIB_BASE_VERSION))
-        $(info *** Warning *** $(BUILD_SINGLE)Simulator$(BUILD_MULTIPLE) $(BUILD_MULTIPLE_VERB) being built WITHOUT)
+          $(info using libpcap $(PCAP_LIB_VERSION) without an available pcap.h)
-        $(info *** Warning *** libpcap networking support)
+          NETWORK_CCDEFS = -DUSE_SHARED -DHAVE_PCAP_NETWORK -DPCAP_LIB_VERSION=$(PCAP_LIB_VERSION)
-        $(info *** Warning ***)
+          NETWORK_FEATURES = - dynamic networking support using libpcap components from www.tcpdump.org and locally installed libpcap.${LIBEXT}
-        $(info *** Warning *** To build simulator(s) with libpcap networking support you)
+          NETWORK_LAN_FEATURES += PCAP
-        $(info *** Warning *** should install the libpcap development components for)
+          NEEDED_PKGS := $(filter-out DPKG_PCAP,$(NEEDED_PKGS))
-        $(info *** Warning *** for your $(OSNAME) system.)
+        else
-        ifeq (,$(or $(findstring Linux,$(OSTYPE)),$(findstring OSX,$(OSNAME))))
+          $(info *** Warning ***)
-          $(info *** Warning *** You should read 0readme_ethernet.txt and follow the instructions)
+          $(info *** Warning *** $(BUILD_SINGLE)Simulator$(BUILD_MULTIPLE) $(BUILD_MULTIPLE_VERB) being built WITHOUT)
-          $(info *** Warning *** regarding the needed libpcap development components for your)
+          $(info *** Warning *** libpcap networking support)
-          $(info *** Warning *** $(OSNAME) platform.)
+          $(info *** Warning ***)
+          $(info *** Warning *** To build simulator(s) with libpcap networking support you)
+          $(info *** Warning *** should install the libpcap development components for)
+          $(info *** Warning *** for your $(OSNAME) system.)
+          ifeq (,$(or $(findstring Linux,$(OSTYPE)),$(findstring OSX,$(OSNAME))))
+            $(info *** Warning *** You should read 0readme_ethernet.txt and follow the instructions)
+            $(info *** Warning *** regarding the needed libpcap development components for your)
+            $(info *** Warning *** $(OSNAME) platform.)
+          endif
+          $(info *** Warning ***)
         endif
-        $(info *** Warning ***)
       endif
     endif
     # Consider other network connections

sim_ether.c

@@ -999,7 +999,7 @@ t_stat sim_ether_test (DEVICE *dptr, const char *cptr)
 #include <net/bpf.h>
 #endif
 
-#if defined (HAVE_PCAP_NETWORK)
+#if defined (HAVE_PCAP_NETWORK) && !defined (PCAP_LIB_VERSION)
 /*============================================================================*/
 /*      WIN32, Linux, and xBSD routines use WinPcap and libpcap packages      */
 /*        OpenVMS Alpha uses a WinPcap port and an associated execlet         */
@@ -1012,8 +1012,46 @@ struct pcap_pkthdr {
     uint32 len;     /* length this packet (off wire) */
 };
 #define PCAP_ERRBUF_SIZE 256
-typedef void * pcap_t;  /* Pseudo Type to avoid compiler errors */
+typedef void * pcap_t;          /* Pseudo Type to avoid compiler errors */
-#define DLT_EN10MB 1    /* Dummy Value to avoid compiler errors */
+#define DLT_EN10MB 1            /* Dummy Value to avoid compiler errors */
+#if defined (PCAP_LIB_VERSION) && defined (USE_SHARED)
+typedef uint32 bpf_u_int32;     /* Pseudo Type to avoid compiler errors */
+typedef struct pcap_if {
+        struct pcap_if *next;
+        char *name;             /* name to hand to "pcap_open_live()" */
+        char *description;      /* textual description of interface, or NULL */
+        struct pcap_addr *addresses;
+        bpf_u_int32 flags;      /* PCAP_IF_ interface flags */
+} pcap_if_t;       /* Pseudo Type to avoid compiler errors */
+#define PCAP_IF_LOOPBACK                                0x00000001      /* interface is loopback */
+struct bpf_program { void *pgm; };  /* Pseudo Type to avoid compiler errors */
+typedef void (*pcap_handler)(u_char *, const struct pcap_pkthdr *,
+                             const u_char *);
+
+void    pcap_close (pcap_t *);
+#define BPF_CONST_STRING 1
+int     pcap_compile (pcap_t *, struct bpf_program *, const char *, int, unsigned int);
+int     pcap_datalink (pcap_t *);
+int     pcap_dispatch (pcap_t *, int, pcap_handler, u_char *);
+int     pcap_findalldevs (pcap_if_t **, char *);
+void    pcap_freealldevs (pcap_if_t *);
+void    pcap_freecode (struct bpf_program *);
+char*   pcap_geterr (pcap_t *);
+int     pcap_lookupnet (const char *, bpf_u_int32 *, bpf_u_int32 *, char *);
+pcap_t* pcap_open_live (const char *, int, int, int, char *);
+#ifdef _WIN32
+int     pcap_setmintocopy (pcap_t* handle, int);
+HANDLE  pcap_getevent (pcap_t *);
+#else
+#ifdef MUST_DO_SELECT
+int     pcap_get_selectable_fd (pcap_t *);
+#endif
+int     pcap_fileno (pcap_t *);
+#endif
+int     pcap_sendpacket (pcap_t* handle, const u_char* msg, int len);
+int     pcap_setfilter (pcap_t *, struct bpf_program *);
+int     pcap_setnonblock(pcap_t* a, int nonblock, char *errbuf);
+#endif
 #endif /* HAVE_PCAP_NETWORK */
 
 /*