Rather than disregard overflowing classification headers, fill up our buffer

completely (with up to UA_LIMIT characters)

Add a regression test with a 1025 byte long User-Agent Header

Fixes Assertion `w > uabuf' failed panics.

src/dcs_varnish.c

@@ -59,8 +59,11 @@ const char * const ua_prepend[DCS_VARNISH2_NHDRS] = {
 #define appnd(w, space, r, l)			\
 	l = strlen(r);				\
 	strncpy(w, r, space);			\
-	if (l > space)				\
+	if (l > space) {			\
+		w += space;			\
+		space = 0;			\
 		break;				\
+	}					\
 	space -= l;				\
 	w += l;
 

src/tests/dcs02_excessive_ua_length.vtc

+# $Id$
+
+varnishtest "Test dcs vmod excessively long ua"
+
+server s1 {
+	rxreq
+	txresp
+} -start
+
+varnish v1 -vcl+backend { 
+	import dcs from "${vmod_topbuild}/src/.libs/libvmod_dcs.so";
+
+	sub vcl_recv {
+	    # this code will classify 
+	    #
+	    # for best performance in production, only call classify
+	    # once or use inline-C to save the return value of
+	    # classify (int)
+	
+	    # exotic use cases
+	    set req.http.xx-entry-key     = dcs.entry_key(dcs.classify());
+	    set req.http.xx-type-id       = dcs.type_id(dcs.classify());
+
+	    # common use cases
+	    set req.http.x-nb-classified  = dcs.type_name(dcs.classify());
+	    set req.http.X-DeviceClass    = dcs.type_class(dcs.classify());
+
+	    error 200;
+	}
+
+	sub vcl_error {
+	    set obj.http.xx-entry-key     = req.http.xx-entry-key;
+	    set obj.http.xx-type-id       = req.http.xx-type-id;
+
+	    set obj.http.x-nb-classified  = req.http.x-nb-classified;
+	    set obj.http.X-DeviceClass    = req.http.X-DeviceClass;
+	    synthetic {"classified ad here
+"};
+	    return (deliver);
+	}
+
+} -start
+
+client c1 {
+	txreq -hdr "User-Agent: motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits" \
+	      -hdr "X-Goog-Source: even longer"
+	rxresp
+	expect resp.status == 200
+	expect resp.http.xx-entry-key == "motorokr z6/r60_g_80.xx.yyi mozilla/4.0 (compatible; msie 6.0 linux; motorokr z6;nnn) profile/midp-2.0 configuration/cldc-1.1 opera 8.50[yy] up.link/6.3.0.0.0 netbiscuits"
+	expect resp.http.xx-type-id == "11"
+	expect resp.http.x-nb-classified == "Mobile Phone"
+	expect resp.http.X-DeviceClass == "smartphone"
+} -run
+