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(a)gibson.dropbear.id.au>
Signed-off-by: Jon Maloy <jmaloy(a)redhat.com>
---
v2: Some minor changes based on feedback from PASST team
---
conf.c | 5 +++++
fwd.c | 2 +-
passt.h | 2 ++
3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/conf.c b/conf.c
index 5107549..fe6fa04 100644
--- a/conf.c
+++ b/conf.c
@@ -846,6 +846,7 @@ static void usage(const char *name, FILE *f, int status)
" --no-ndp Disable NDP responses\n"
" --no-dhcpv6 Disable DHCPv6 server\n"
" --no-ra Disable router advertisements\n"
+ " --no-splice Disable inbound socket splicing\n"
" --freebind Bind to any address for forwarding\n"
" --no-map-gw Don't map gateway address to host\n"
" -4, --ipv4-only Enable IPv4 operation only\n"
@@ -1274,6 +1275,7 @@ 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' },
@@ -1701,6 +1703,9 @@ void conf(struct ctx *c, int argc, char **argv)
}
} while (name != -1);
+ if (c->mode == MODE_PASST)
+ c->no_splice = 1;
+
if (c->mode == MODE_PASTA && !c->pasta_conf_ns) {
if (copy_routes_opt)
die("--no-copy-routes needs --config-net");
diff --git a/fwd.c b/fwd.c
index 0b7f8b1..2829cd2 100644
--- a/fwd.c
+++ b/fwd.c
@@ -443,7 +443,7 @@ uint8_t fwd_nat_from_host(const struct ctx *c, uint8_t proto,
else if (proto == IPPROTO_UDP)
tgt->eport += c->udp.fwd_in.delta[tgt->eport];
- if (c->mode == MODE_PASTA && inany_is_loopback(&ini->eaddr)
&&
+ if (!c->no_splice && inany_is_loopback(&ini->eaddr) &&
(proto == IPPROTO_TCP || proto == IPPROTO_UDP)) {
/* spliceable */
diff --git a/passt.h b/passt.h
index 72c7f72..45ad26a 100644
--- a/passt.h
+++ b/passt.h
@@ -225,6 +225,7 @@ struct ip6_ctx {
* @no_dhcpv6: Disable DHCPv6 server
* @no_ndp: Disable NDP handler altogether
* @no_ra: Disable router advertisements
+ * @no_splice: Disable socket splicing for inbound traffic
* @host_lo_to_ns_lo: Map host loopback addresses to ns loopback addresses
* @freebind: Allow binding of non-local addresses for forwarding
* @low_wmem: Low probed net.core.wmem_max
@@ -286,6 +287,7 @@ struct ctx {
int no_dhcpv6;
int no_ndp;
int no_ra;
+ int no_splice;
int host_lo_to_ns_lo;
int freebind;
--
2.45.2