Teach varnishtest about SO_RCVBUF

For now the varnishd handling of SO_SNDBUF lives in vmod-debug but could
be promoted to vmod-vtc to be usable out of tree too.

bin/varnishtest/tests/s00010.vtc

+varnishtest "client h1 send timeouts"
+
+server s1 {
+	rxreq
+	txresp -bodylen 100000
+} -start
+
+varnish v1 -vcl+backend {
+	import debug;
+
+	sub vcl_deliver {
+		debug.sndbuf(128b);
+	}
+} -start
+
+varnish v1 -cliok "param.set send_timeout 1"
+
+logexpect l1 -v v1 {
+	expect * * Debug "Hit total send timeout"
+} -start
+
+client c1 -rcvbuf 128 {
+	txreq
+	rxresphdrs
+	# keep the session open for 2 seconds
+	delay 2
+} -run
+
+logexpect l1 -wait
+
+feature SO_RCVTIMEO_WORKS
+varnish v1 -cliok "param.set idle_send_timeout 1"
+varnish v1 -cliok "param.reset send_timeout"
+
+logexpect l2 -v v1 {
+	expect * * Debug "Hit idle send timeout"
+} -start
+
+client c2 -rcvbuf 128 {
+	txreq
+	rxresphdrs
+	# keep the session open for 2 seconds
+	delay 2
+} -run
+
+logexpect l2 -wait

bin/varnishtest/vtc.h

@@ -88,7 +88,7 @@ void init_server(void);
 void init_syslog(void);
 
 int http_process(struct vtclog *vl, const char *spec, int sock, int *sfd,
-		 const char *addr);
+    const char *addr, int rcvbuf);
 
 char * synth_body(const char *len, int rnd);
 

bin/varnishtest/vtc_client.c

@@ -54,6 +54,7 @@ struct client {
 	char			*spec;
 
 	char			connect[256];
+	int			rcvbuf;
 
 	char			*proxy_spec;
 	int			proxy_version;
@@ -233,10 +234,12 @@ client_thread(void *priv)
 		if (c->proxy_spec != NULL)
 			client_proxy(vl, fd, c->proxy_version, c->proxy_spec);
 		if (! c->keepalive)
-			fd = http_process(vl, c->spec, fd, NULL, addr);
+			fd = http_process(vl, c->spec, fd, NULL, addr,
+			    c->rcvbuf);
 		else
 			while (fd >= 0 && u++ < c->repeat)
-				fd = http_process(vl, c->spec, fd, NULL, addr);
+				fd = http_process(vl, c->spec, fd, NULL, addr,
+				    c->rcvbuf);
 		vtc_log(vl, 3, "closing fd %d", fd);
 		VTCP_close(&fd);
 	}
@@ -402,6 +405,11 @@ cmd_client(CMD_ARGS)
 			c->keepalive = 1;
 			continue;
 		}
+		if (!strcmp(*av, "-rcvbuf")) {
+			c->rcvbuf = atoi(av[1]);
+			av++;
+			continue;
+		}
 		if (!strcmp(*av, "-start")) {
 			client_start(c);
 			continue;

bin/varnishtest/vtc_http.c

 /*-
- * Copyright (c) 2008-2015 Varnish Software AS
+ * Copyright (c) 2008-2019 Varnish Software AS
  * All rights reserved.
  *
  * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
@@ -1905,10 +1905,11 @@ http_process_cleanup(void *arg)
 
 int
 http_process(struct vtclog *vl, const char *spec, int sock, int *sfd,
-	     const char *addr)
+    const char *addr, int rcvbuf)
 {
 	struct http *hp;
-	int retval;
+	int retval, oldbuf;
+	socklen_t intlen = sizeof(int);
 
 	(void)sfd;
 	ALLOC_OBJ(hp, HTTP_MAGIC);
@@ -1916,6 +1917,18 @@ http_process(struct vtclog *vl, const char *spec, int sock, int *sfd,
 	hp->fd = sock;
 	hp->timeout = vtc_maxdur * 1000 / 2;
 
+	if (rcvbuf) {
+		hp->rcvbuf = rcvbuf;
+
+		oldbuf = 0;
+		AZ(getsockopt(hp->fd, SOL_SOCKET, SO_RCVBUF, &oldbuf, &intlen));
+		AZ(setsockopt(hp->fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, intlen));
+		AZ(getsockopt(hp->fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &intlen));
+
+		vtc_log(vl, 3, "-rcvbuf fd=%d old=%d new=%d actual=%d",
+		    hp->fd, oldbuf, hp->rcvbuf, rcvbuf);
+	}
+
 	hp->nrxbuf = 2048*1024;
 	hp->rx_b = malloc(hp->nrxbuf);
 	AN(hp->rx_b);

bin/varnishtest/vtc_http.h

@@ -38,6 +38,7 @@ struct http {
 
 	struct vsb		*vsb;
 
+	int			rcvbuf;
 	int			nrxbuf;
 	char			*rx_b;
 	char			*rx_p;

bin/varnishtest/vtc_server.c

@@ -57,6 +57,7 @@ struct server {
 	int			depth;
 	int			sock;
 	int			fd;
+	int			rcvbuf;
 	char			listen[256];
 	char			aaddr[32];
 	char			aport[32];
@@ -248,11 +249,12 @@ server_thread(void *priv)
 		} else
 			vtc_log(vl, 3, "accepted fd %d 0.0.0.0 0", fd);
 		if (! s->keepalive)
-			fd = http_process(vl, s->spec, fd, &s->sock, s->listen);
+			fd = http_process(vl, s->spec, fd, &s->sock, s->listen,
+			    s->rcvbuf);
 		else
 			while (fd >= 0 && i++ < s->repeat)
 				fd = http_process(vl, s->spec, fd,
-				    &s->sock, s->listen);
+				    &s->sock, s->listen, s->rcvbuf);
 		vtc_log(vl, 3, "shutting fd %d", fd);
 		j = shutdown(fd, SHUT_WR);
 		if (!VTCP_Check(j))
@@ -300,7 +302,7 @@ server_dispatch_wrk(void *priv)
 	fd = s->fd;
 
 	vtc_log(vl, 3, "start with fd %d", fd);
-	fd = http_process(vl, s->spec, fd, &s->sock, s->listen);
+	fd = http_process(vl, s->spec, fd, &s->sock, s->listen, s->rcvbuf);
 	vtc_log(vl, 3, "shutting fd %d", fd);
 	j = shutdown(fd, SHUT_WR);
 	if (!VTCP_Check(j))
@@ -541,6 +543,11 @@ cmd_server(CMD_ARGS)
 			av++;
 			continue;
 		}
+		if (!strcmp(*av, "-rcvbuf")) {
+			s->rcvbuf = atoi(av[1]);
+			av++;
+			continue;
+		}
 		if (!strcmp(*av, "-start")) {
 			server_start(s);
 			continue;

lib/libvmod_debug/vmod.vcc

 #
-# Copyright (c) 2010-2015 Varnish Software AS
+# Copyright (c) 2010-2019 Varnish Software AS
 # All rights reserved.
 #
 # Author: Poul-Henning Kamp <phk@FreeBSD.org>
@@ -251,3 +251,5 @@ Prevent VCL from going cold
 $Function VOID release_vcl_busy()
 
 Allow VCL to go cold
+
+$Function VOID sndbuf(BYTES sndbuf)

lib/libvmod_debug/vmod_debug.c

 /*-
- * Copyright (c) 2012-2015 Varnish Software AS
+ * Copyright (c) 2012-2019 Varnish Software AS
  * All rights reserved.
  *
  * Author: Poul-Henning Kamp <phk@FreeBSD.org>
@@ -807,3 +807,39 @@ xyzzy_release_vcl_busy(VRT_CTX)
 
 	VRT_VCL_Unbusy(ctx);
 }
+
+VCL_VOID
+xyzzy_sndbuf(VRT_CTX, VCL_BYTES buflen)
+{
+	int fd = -1, oldbuf, newbuf;
+	socklen_t intlen = sizeof(int);
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+
+	if (ctx->bo) {
+		CHECK_OBJ(ctx->bo, BUSYOBJ_MAGIC);
+		INCOMPL();
+	}
+	else if (ctx->req) {
+		CHECK_OBJ(ctx->req, REQ_MAGIC);
+		CHECK_OBJ(ctx->req->sp, SESS_MAGIC);
+		fd = ctx->req->sp->fd;
+	}
+	else {
+		VRT_fail(ctx, "debug.sndbuf() called outside a transaction.");
+		return;
+	}
+
+	xxxassert(fd >= 0);
+
+	oldbuf = 0;
+	AZ(getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &oldbuf, &intlen));
+
+	newbuf = buflen;
+	AZ(setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &newbuf, intlen));
+	AZ(getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &newbuf, &intlen));
+
+	AN(ctx->vsl);
+	VSLb(ctx->vsl, SLT_Debug, "SO_SNDBUF fd=%d old=%d new=%ld actual=%d",
+	    fd, oldbuf, buflen, newbuf);
+}