Write a request or response body from a stream too

bin/varnishtest/tests/a02024.vtc

+varnishtest "Write a body to a file"
+
+server s1 {
+	fatal
+	stream 1 {
+		rxreq
+		expect req.http.Content-Type == "text/plain"
+		write_body req.txt
+		txresp -hdr Content-Type text/plain -body response
+	} -run
+
+} -start
+
+client c1 -connect ${s1_sock} {
+	fatal
+	stream 1 {
+		txreq -req POST -hdr Content-Type text/plain -body request
+		rxresp
+		expect resp.http.Content-Type == "text/plain"
+		write_body resp.txt
+	} -run
+} -run
+
+server s1 -wait
+
+shell {grep -q request req.txt}
+shell {grep -q response resp.txt}

bin/varnishtest/vtc_http2.c

@@ -45,6 +45,7 @@
 #include "vtc_http.h"
 
 #include "vct.h"
+#include "vfil.h"
 #include "vgz.h"
 #include "vnum.h"
 #include "vre.h"
@@ -2467,6 +2468,28 @@ cmd_expect(CMD_ARGS)
 	AZ(pthread_mutex_unlock(&s->hp->mtx));
 }
 
+/* SECTION: stream.spec.write_body
+ *
+ * write_body STRING
+ *	Same as the ``write_body`` command for HTTP/1.
+ */
+static void
+cmd_write_body(CMD_ARGS)
+{
+	struct stream *s;
+
+	(void)cmd;
+	(void)vl;
+	CAST_OBJ_NOTNULL(s, priv, STREAM_MAGIC);
+	AN(av[0]);
+	AN(av[1]);
+	AZ(av[2]);
+	AZ(strcmp(av[0], "write_body"));
+	if (VFIL_writefile(NULL, av[1], s->body, s->bodylen) != 0)
+		vtc_log(s->hp->vl, 0, "failed to write body: %s (%d)",
+		    strerror(errno), errno);
+}
+
 /* SECTION: stream.spec Specification
  *
  * The specification of a stream follows the exact same rules as one for a
@@ -2502,6 +2525,7 @@ static const struct cmds stream_cmds[] = {
 	CMD_STREAM(txrst)
 	CMD_STREAM(txsettings)
 	CMD_STREAM(txwinup)
+	CMD_STREAM(write_body)
 
 	/* general purpose */
 	CMD(barrier)