[master] bc46b11d2 vrt: Make client.identity readable in backend tasks

[Dridi Boukelmoune]

commit bc46b11d22088073e75554a07cc72912f834c69f
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Fri Oct 9 15:57:43 2020 +0200

    vrt: Make client.identity readable in backend tasks
    
    This puts client.identity at the same level as client.ip which happens
    to be its fall-back before being explicitly set.

diff --git a/bin/varnishd/cache/cache.h b/bin/varnishd/cache/cache.h
index 22acb7c7f..6a01cd5b5 100644
--- a/bin/varnishd/cache/cache.h
+++ b/bin/varnishd/cache/cache.h
@@ -440,6 +440,8 @@ struct busyobj {
 
 	uint16_t		err_code;
 	const char		*err_reason;
+
+	const char		*client_identity;
 };
 
 
diff --git a/bin/varnishd/cache/cache_busyobj.c b/bin/varnishd/cache/cache_busyobj.c
index 1e77272c0..d80bd1ecc 100644
--- a/bin/varnishd/cache/cache_busyobj.c
+++ b/bin/varnishd/cache/cache_busyobj.c
@@ -132,6 +132,11 @@ VBO_GetBusyObj(struct worker *wrk, const struct req *req)
 
 	bo->do_stream = 1;
 
+	if (req->client_identity != NULL) {
+		bo->client_identity = WS_Copy(bo->ws, req->client_identity, -1);
+		XXXAN(bo->client_identity);
+	}
+
 	bo->director_req = req->director_hint;
 	bo->vcl = req->vcl;
 	VCL_Ref(bo->vcl);
diff --git a/bin/varnishd/cache/cache_vrt_var.c b/bin/varnishd/cache/cache_vrt_var.c
index 1f3138e1c..957d49cdb 100644
--- a/bin/varnishd/cache/cache_vrt_var.c
+++ b/bin/varnishd/cache/cache_vrt_var.c
@@ -296,11 +296,19 @@ VRT_r_beresp_uncacheable(VRT_CTX)
 VCL_STRING
 VRT_r_client_identity(VRT_CTX)
 {
+	const char *id;
+
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	CHECK_OBJ_NOTNULL(ctx->req, REQ_MAGIC);
-	if (ctx->req->client_identity != NULL)
-		return (ctx->req->client_identity);
-	return (SES_Get_String_Attr(ctx->req->sp, SA_CLIENT_IP));
+	if (ctx->req != NULL) {
+		CHECK_OBJ(ctx->req, REQ_MAGIC);
+		id = ctx->req->client_identity;
+	} else {
+		CHECK_OBJ_NOTNULL(ctx->bo, BUSYOBJ_MAGIC);
+		id = ctx->bo->client_identity;
+	}
+	if (id != NULL)
+		return (id);
+	return (SES_Get_String_Attr(ctx->sp, SA_CLIENT_IP));
 }
 
 VCL_VOID
diff --git a/bin/varnishtest/tests/v00025.vtc b/bin/varnishtest/tests/v00025.vtc
index d3d0cf684..790f24873 100644
--- a/bin/varnishtest/tests/v00025.vtc
+++ b/bin/varnishtest/tests/v00025.vtc
@@ -2,8 +2,10 @@ varnishtest "More VCL coverage"
 
 server s1 {
 	rxreq
+	expect req.http.c_id == "Samuel B. Nobody"
 	txresp
 	rxreq
+	expect req.http.c_id == ${localhost}
 	txresp
 } -start
 
@@ -85,6 +87,7 @@ varnish v1 -syntax 4.0 -vcl+backend {
 	}
 
 	sub vcl_backend_fetch {
+		set bereq.http.c_id = client.identity;
 		if (bereq.between_bytes_timeout < 10s) {
 			set bereq.http.quick = "please";
 		}
@@ -147,6 +150,10 @@ varnish v1 -syntax 4.0 -errvcl {Symbol not found: 'local.socket' (Only available
 }
 
 varnish v1 -syntax 4.1 -vcl+backend {
+	sub vcl_backend_fetch {
+		set bereq.http.c_id = client.identity;
+	}
+
 	sub vcl_backend_response {
 		set beresp.http.B-Sess-XID = sess.xid;
 		set beresp.http.B-Endpoint = local.endpoint;
diff --git a/doc/sphinx/reference/vcl_var.rst b/doc/sphinx/reference/vcl_var.rst
index a6e67d2d2..72098379a 100644
--- a/doc/sphinx/reference/vcl_var.rst
+++ b/doc/sphinx/reference/vcl_var.rst
@@ -117,7 +117,7 @@ client.identity
 
 	Type: STRING
 
-	Readable from: client
+	Readable from: client, backend
 
 	Writable from: client