add_dns[46]() rely on the gateway address and c->no_map_gw being already initialised, in order to properly handle DNS servers which need NAT to be accessed from the guest. Usually these are called from get_dns() which is well after the addresses are configured, so that's fine. However, they can also be called earlier if an explicit -D command line option is given. In this case no_map_gw and/or c->ip[46].gw may not get be initialised properly, leading to this doing the wrong thing. Luckily we already have a second pass of option parsing for things which need addresses to already be configured. Move handling of -D to there. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- conf.c | 84 +++++++++++++++++++++++++++++++--------------------------- 1 file changed, 45 insertions(+), 39 deletions(-) diff --git a/conf.c b/conf.c index a79e7a66..76d37da0 100644 --- a/conf.c +++ b/conf.c @@ -1235,10 +1235,10 @@ void conf(struct ctx *c, int argc, char **argv) const char *logname = (c->mode == MODE_PASTA) ? "pasta" : "passt"; char userns[PATH_MAX] = { 0 }, netns[PATH_MAX] = { 0 }; bool copy_addrs_opt = false, copy_routes_opt = false; - struct in6_addr *dns6 = c->ip6.dns, dns6_tmp; - struct in_addr *dns4 = c->ip4.dns, dns4_tmp; enum fwd_ports_mode fwd_default = FWD_NONE; bool v4_only = false, v6_only = false; + struct in6_addr *dns6 = c->ip6.dns; + struct in_addr *dns4 = c->ip4.dns; struct fqdn *dnss = c->dns_search; unsigned int ifi4 = 0, ifi6 = 0; const char *logfile = NULL; @@ -1545,40 +1545,6 @@ void conf(struct ctx *c, int argc, char **argv) die("Invalid or redundant outbound address: %s", optarg); break; - case 'D': - if (!strcmp(optarg, "none")) { - c->no_dns = 1; - - dns4 = &c->ip4.dns[0]; - memset(c->ip4.dns, 0, sizeof(c->ip4.dns)); - c->ip4.dns[0] = (struct in_addr){ 0 }; - c->ip4.dns_match = (struct in_addr){ 0 }; - c->ip4.dns_host = (struct in_addr){ 0 }; - - dns6 = &c->ip6.dns[0]; - memset(c->ip6.dns, 0, sizeof(c->ip6.dns)); - c->ip6.dns_match = (struct in6_addr){ 0 }; - c->ip6.dns_host = (struct in6_addr){ 0 }; - - break; - } - - c->no_dns = 0; - - if (dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) && - inet_pton(AF_INET, optarg, &dns4_tmp)) { - add_dns4(c, &dns4_tmp, &dns4); - break; - } - - if (dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) && - inet_pton(AF_INET6, optarg, &dns6_tmp)) { - add_dns6(c, &dns6_tmp, &dns6); - break; - } - - die("Cannot use DNS address %s", optarg); - break; case 'S': if (!strcmp(optarg, "none")) { c->no_dns_search = 1; @@ -1620,6 +1586,7 @@ void conf(struct ctx *c, int argc, char **argv) case 'u': case 'T': case 'U': + case 'D': /* Handle these later, once addresses are configured */ break; case 'h': @@ -1677,16 +1644,55 @@ void conf(struct ctx *c, int argc, char **argv) if (c->ifi6 && IN6_IS_ADDR_UNSPECIFIED(&c->ip6.gw)) c->no_map_gw = 1; - /* Inbound port options can be parsed now (after IPv4/IPv6 settings) */ + /* Inbound port options & DNS can be parsed now (after IPv4/IPv6 + * settings) + */ udp_portmap_clear(); optind = 1; do { name = getopt_long(argc, argv, optstring, options, NULL); - if (name == 't') + if (name == 't') { conf_ports(c, name, optarg, &c->tcp.fwd_in); - else if (name == 'u') + } else if (name == 'u') { conf_ports(c, name, optarg, &c->udp.fwd_in); + } else if (name == 'D') { + struct in6_addr dns6_tmp; + struct in_addr dns4_tmp; + + if (!strcmp(optarg, "none")) { + c->no_dns = 1; + + dns4 = &c->ip4.dns[0]; + memset(c->ip4.dns, 0, sizeof(c->ip4.dns)); + c->ip4.dns[0] = (struct in_addr){ 0 }; + c->ip4.dns_match = (struct in_addr){ 0 }; + c->ip4.dns_host = (struct in_addr){ 0 }; + + dns6 = &c->ip6.dns[0]; + memset(c->ip6.dns, 0, sizeof(c->ip6.dns)); + c->ip6.dns_match = (struct in6_addr){ 0 }; + c->ip6.dns_host = (struct in6_addr){ 0 }; + + continue; + } + + c->no_dns = 0; + + if (dns4 - &c->ip4.dns[0] < ARRAY_SIZE(c->ip4.dns) && + inet_pton(AF_INET, optarg, &dns4_tmp)) { + add_dns4(c, &dns4_tmp, &dns4); + break; + } + + if (dns6 - &c->ip6.dns[0] < ARRAY_SIZE(c->ip6.dns) && + inet_pton(AF_INET6, optarg, &dns6_tmp)) { + add_dns6(c, &dns6_tmp, &dns6); + break; + } + + die("Cannot use DNS address %s", optarg); + } } while (name != -1); if (c->mode == MODE_PASTA) -- 2.46.0