Req.uncacheable

bin/varnishd/cache/cache_req.c

@@ -251,6 +251,7 @@ Req_Cleanup(struct sess *sp, struct worker *wrk, struct req *req)
 	req->t_req = NAN;
 	req->req_body_status = NULL;
 
+	req->uncacheable = 0;
 	req->hash_always_miss = 0;
 	req->hash_ignore_busy = 0;
 	req->esi_level = 0;

bin/varnishd/cache/cache_req_fsm.c

@@ -871,6 +871,7 @@ cnt_recv_prep(struct req *req, const char *ci)
 		req->hash_always_miss = 0;
 		req->hash_ignore_busy = 0;
 		req->client_identity = NULL;
+		req->uncacheable = 0;
 		req->storage = NULL;
 	}
 
@@ -949,6 +950,10 @@ cnt_recv(struct worker *wrk, struct req *req)
 		return (REQ_FSM_DONE);
 	}
 
+	if (wrk->handling == VCL_RET_HASH && req->uncacheable) {
+		wrk->handling = VCL_RET_PASS;
+	}
+
 	recv_handling = wrk->handling;
 
 	/* We wash the A-E header here for the sake of VRY */

bin/varnishtest/tests/c00105.vtc

@@ -0,0 +1,47 @@
+varnishtest "req.uncacheable"
+
+server s1 {
+	rxreq
+	txresp -body "1"
+
+	rxreq
+	txresp -body "2"
+
+	rxreq
+	txresp -body "3"
+} -start
+
+varnish v1 -syntax 4.0 -arg "-smysteve=malloc,1m" -vcl+backend {
+	sub vcl_recv {
+		if (req.http.uncacheable) {
+			set req.uncacheable = true;
+		}
+	}
+} -start
+
+client c1 {
+	# insert object in cache
+	txreq
+	rxresp
+	expect resp.body == "1"
+
+	# hit the cached object
+	txreq
+	rxresp
+	expect resp.body == "1"
+
+	# bypass the cache
+	txreq -hdr "uncacheable: true"
+	rxresp
+	expect resp.body == "2"
+
+	# again
+	txreq -hdr "uncacheable: true"
+	rxresp
+	expect resp.body == "3"
+
+	# hit the cached object
+	txreq
+	rxresp
+	expect resp.body == "1"
+} -run

doc/sphinx/reference/vcl_var.rst

@@ -368,6 +368,22 @@ req.hash_always_miss
 	This is useful to force-update the cache without invalidating
 	existing entries in case the fetch fails.
 
+req.uncacheable
+
+	Type: BOOL
+
+	Readable from: client
+
+	Writable from: client
+
+	Default: ``false``.
+
+	Force a cache pass for this request, even if perfectly
+	good matching objects are in the cache.
+
+        This allows to flag a request as uncacheable in ``vcl_recv`` without
+        immediately returning from the subroutine.
+
 req.is_hitmiss
 
 	Type: BOOL
@@ -569,7 +585,8 @@ bereq.uncacheable
 
 
 	Indicates whether this request is uncacheable due to a
-	`pass` in the client side or a hit on an hit-for-pass object.
+	`pass` or `req.uncacheable` in the client side or a hit on an
+        hit-for-pass object.
 
 
 bereq.connect_timeout

include/tbl/req_flags.h

@@ -41,6 +41,7 @@ REQ_FLAG(is_hitpass,		1, 0, "")
 REQ_FLAG(waitinglist,		0, 0, "")
 REQ_FLAG(want100cont,		0, 0, "")
 REQ_FLAG(late100cont,		0, 0, "")
+REQ_FLAG(uncacheable,		1, 1, "")
 #undef REQ_FLAG
 
 /*lint -restore */