From de8ebc5dd9ce53d632390edf44cabeb04c7e2f98 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 10 Apr 2026 11:02:48 +1000 Subject: conf: Simplify handling of default forwarding mode For passt, the default forwarding mode is "none", which falls out naturally from the other handling: if we don't get any options, we get empty forwarding tables, which corresponds to "none" behaviour. However, for pasta the default is "auto". This is handled a bit oddly: in conf_ports() we set the mode variable, but don't set up the rules we need for "auto" mode. Instead we want until nearly the end of conf() and if the mode is FWD_MODE_AUTO or unset, we make conf_ports_range_except() calls to set up the "auto" rules. Simplify this a bit, by creating the rules within conf_ports() itself when we parse -[tuTU] auto. For the case of no forwarding options we call into conf_ports() itself with synthetic arguments. As well as making the code a little shorter, this makes it more obvious that giving no arguments really is equivalent to -[tuTU] auto. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- conf.c | 54 ++++++++++++++++++++++-------------------------------- 1 file changed, 22 insertions(+), 32 deletions(-) diff --git a/conf.c b/conf.c index e385afc..58edebc 100644 --- a/conf.c +++ b/conf.c @@ -345,6 +345,10 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg, die("'auto' port forwarding is only allowed for pasta"); *mode = FWD_MODE_AUTO; + + conf_ports_range_except(c, optname, optarg, fwd, NULL, NULL, + 1, NUM_PORTS - 1, NULL, 1, FWD_SCAN); + return; } @@ -1576,7 +1580,6 @@ void conf(struct ctx *c, int argc, char **argv) enum fwd_mode udp_out_mode = FWD_MODE_UNSET; enum fwd_mode tcp_in_mode = FWD_MODE_UNSET; enum fwd_mode udp_in_mode = FWD_MODE_UNSET; - enum fwd_mode fwd_default = FWD_MODE_NONE; bool v4_only = false, v6_only = false; unsigned dns4_idx = 0, dns6_idx = 0; unsigned long max_mtu = IP_MAX_MTU; @@ -1593,10 +1596,8 @@ void conf(struct ctx *c, int argc, char **argv) gid_t gid; - if (c->mode == MODE_PASTA) { + if (c->mode == MODE_PASTA) c->no_dhcp_dns = c->no_dhcp_dns_search = 1; - fwd_default = FWD_MODE_AUTO; - } if (tap_l2_max_len(c) - ETH_HLEN < max_mtu) max_mtu = tap_l2_max_len(c) - ETH_HLEN; @@ -2244,34 +2245,23 @@ void conf(struct ctx *c, int argc, char **argv) if_indextoname(c->ifi6, c->pasta_ifn); } - if (!tcp_in_mode) - tcp_in_mode = fwd_default; - if (!tcp_out_mode) - tcp_out_mode = fwd_default; - if (!udp_in_mode) - udp_in_mode = fwd_default; - if (!udp_out_mode) - udp_out_mode = fwd_default; - - if (tcp_in_mode == FWD_MODE_AUTO) { - conf_ports_range_except(c, 't', "auto", c->fwd[PIF_HOST], - NULL, NULL, 1, NUM_PORTS - 1, NULL, 1, - FWD_SCAN); - } - if (tcp_out_mode == FWD_MODE_AUTO) { - conf_ports_range_except(c, 'T', "auto", c->fwd[PIF_SPLICE], - NULL, "lo", 1, NUM_PORTS - 1, NULL, 1, - FWD_SCAN); - } - if (udp_in_mode == FWD_MODE_AUTO) { - conf_ports_range_except(c, 'u', "auto", c->fwd[PIF_HOST], - NULL, NULL, 1, NUM_PORTS - 1, NULL, 1, - FWD_SCAN); - } - if (udp_out_mode == FWD_MODE_AUTO) { - conf_ports_range_except(c, 'U', "auto", c->fwd[PIF_SPLICE], - NULL, "lo", 1, NUM_PORTS - 1, NULL, 1, - FWD_SCAN); + if (c->mode == MODE_PASTA) { + if (!tcp_in_mode) { + conf_ports(c, 't', "auto", + c->fwd[PIF_HOST], &tcp_in_mode); + } + if (!tcp_out_mode) { + conf_ports(c, 'T', "auto", + c->fwd[PIF_SPLICE], &tcp_out_mode); + } + if (!udp_in_mode) { + conf_ports(c, 'u', "auto", + c->fwd[PIF_HOST], &udp_in_mode); + } + if (!udp_out_mode) { + conf_ports(c, 'U', "auto", + c->fwd[PIF_SPLICE], &udp_out_mode); + } } if (!c->quiet) -- cgit v1.2.3