Clean up {DAG, Septel, Myricom SNF}-only builds.

In the core code, treat them similarly to other builds.  In the
configure script, ensure that no other pcap-XXX.c file is built, so we
have only the entries for the capture mechanism in question in the
tables for pcap_findalldevs() and pcap_create(), so that those routines
are the only ones called.  If XXX_ONLY is defined in pcap-XXX.c, define
a stub pcap_platform_finddevs() that finds no regular interfaces and a
stub pcap_create_interface() that fails with a "we only support XXX"
error message.

1 files changed, 28 insertions, 0 deletions

diff --git a/pcap-snf.c b/pcap-snf.c
index a72fdd88..207c4959 100644
--- a/pcap-snf.c
+++ b/pcap-snf.c
@@ -490,3 +490,31 @@ snf_create(const char *device, char *ebuf, int *is_ours)
 	ps->snf_boardnum = boardnum;
 	return p;
 }
+
+#ifdef SNF_ONLY
+/*
+ * This libpcap build supports only SNF cards, not regular network
+ * interfaces..
+ */
+
+/*
+ * There are no regular interfaces, just DAG interfaces.
+ */
+int
+pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
+{
+	*alldevsp = NULL;
+	return (0);
+}
+
+/*
+ * Attempts to open a regular interface fail.
+ */
+pcap_t *
+pcap_create_interface(const char *device, char *errbuf)
+{
+	pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+	    "This version of libpcap only supports SNF cards");
+	return NULL;
+}
+#endif