conf: Delay handling -D option until after addresses are configured

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@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2024-08-12 19:53:54 +10:00 committed by Stefano Brivio
parent 86bdd968ea
commit f6d5a52392

84
conf.c
View file

@ -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)