libsystemd-network: use domain validation instead of hostname validation for dhcp domain option

previously hostname_is_valid was used to validate domain names, which
would silently drop perfectly valid dns names that were longer than a
single dns label.

2 files changed, 22 insertions, 6 deletions

diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index 8a4220621b..d8bc76edda 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -32,6 +32,7 @@
 #include "dhcp-lease-internal.h"
 #include "sd-dhcp-lease.h"
 #include "network-internal.h"
+#include "dns-domain.h"
 
 int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
         assert_return(lease, -EINVAL);
@@ -504,9 +505,18 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
                 if (e)
                         *e = 0;
 
-                if (!hostname_is_valid(domainname) || is_localhost(domainname))
+                if (is_localhost(domainname))
                         break;
 
+                r = dns_name_is_valid(domainname);
+                if (r <= 0) {
+                        if (r < 0)
+                                log_error_errno(r, "Failed to validate domain name: %s: %m", domainname);
+                        if (r == 0)
+                                log_warning("Domain name is not valid, ignoring: %s", domainname);
+                        break;
+                }
+
                 free(lease->domainname);
                 lease->domainname = domainname;
                 domainname = NULL;
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 5947084106..6f32e5f4a4 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -30,6 +30,7 @@
 #include "networkd-netdev.h"
 #include "networkd-link.h"
 #include "network-internal.h"
+#include "dns-domain.h"
 
 static int network_load_one(Manager *manager, const char *filename) {
         _cleanup_network_free_ Network *network = NULL;
@@ -466,11 +467,16 @@ int config_parse_domains(const char *unit,
         STRV_FOREACH(domain, *domains) {
                 if (is_localhost(*domain))
                         log_syntax(unit, LOG_ERR, filename, line, EINVAL, "'localhost' domain names may not be configured, ignoring assignment: %s", *domain);
-                else if (!hostname_is_valid(*domain)) {
-                        if (!streq(*domain, "*"))
-                                log_syntax(unit, LOG_ERR, filename, line, EINVAL, "domain name is not valid, ignoring assignment: %s", *domain);
-                } else
-                        continue;
+                else {
+                        r = dns_name_is_valid(*domain);
+                        if (r <= 0 && !streq(*domain, "*")) {
+                                if (r < 0)
+                                        log_error_errno(r, "Failed to validate domain name: %s: %m", *domain);
+                                if (r == 0)
+                                        log_warning("Domain name is not valid, ignoring assignment: %s", *domain);
+                        } else
+                                continue;
+                }
 
                 strv_remove(*domains, *domain);