pasta: make it possible to disable socket splicing

During testing it is sometimes useful to force traffic which would
normally be forwared by socket splicing through the tap interface.

In this commit, we add a command switch enabling such funtionality
for inbound local traffic.

For outbound local traffic this is much trickier, if even possible,
so leave that for a later commit.

Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/conf.c b/conf.c
index eaa7d99..97d8beb 100644
--- a/conf.c
+++ b/conf.c
@@ -977,7 +977,8 @@ pasta_opts:
 		"			Don't copy all routes to namespace\n"
 		"  --no-copy-addrs	DEPRECATED:\n"
 		"			Don't copy all addresses to namespace\n"
-		"  --ns-mac-addr ADDR	Set MAC address on tap interface\n");
+		"  --ns-mac-addr ADDR	Set MAC address on tap interface\n"
+		"  --no-splice		Disable inbound socket splicing\n");
 
 	exit(status);
 }
@@ -1319,6 +1320,7 @@ void conf(struct ctx *c, int argc, char **argv)
 		{"no-dhcpv6",	no_argument,		&c->no_dhcpv6,	1 },
 		{"no-ndp",	no_argument,		&c->no_ndp,	1 },
 		{"no-ra",	no_argument,		&c->no_ra,	1 },
+		{"no-splice",	no_argument,		&c->no_splice,	1 },
 		{"freebind",	no_argument,		&c->freebind,	1 },
 		{"no-map-gw",	no_argument,		&no_map_gw,	1 },
 		{"ipv4-only",	no_argument,		NULL,		'4' },
@@ -1756,6 +1758,9 @@ void conf(struct ctx *c, int argc, char **argv)
 		}
 	} while (name != -1);
 
+	if (c->mode != MODE_PASTA)
+		c->no_splice = 1;
+
 	if (c->mode == MODE_PASTA && !c->pasta_conf_ns) {
 		if (copy_routes_opt)
 			die("--no-copy-routes needs --config-net");