dhcp: normalize DHCP host and domain names from leases

Previoulsy, we just checked whether the domain names specified in
incoming DHCP leases are valid. Given that validation code actually
internally normalizes anyway, it's a good idea to simply do the full
normalization and store that in the lease structure. This allows us to
remove the manual removal of a trailing dot, if there is one.

1 files changed, 26 insertions, 33 deletions

diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index f2e6cb0ddc..37e187c738 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -489,59 +489,52 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option, v
                 lease_parse_u16(option, len, &lease->boot_file_size, 0);
                 break;
 
-        case DHCP_OPTION_DOMAIN_NAME:
-        {
-                _cleanup_free_ char *domainname = NULL;
-                char *e;
+        case DHCP_OPTION_DOMAIN_NAME: {
+                _cleanup_free_ char *domainname = NULL, *normalized = NULL;
 
                 r = lease_parse_string(option, len, &domainname);
                 if (r < 0)
                         return r;
 
-                /* Chop off trailing dot of domain name that some DHCP
-                 * servers send us back. Internally we want to store
-                 * host names without trailing dots and
-                 * host_name_is_valid() doesn't accept them. */
-                e = endswith(domainname, ".");
-                if (e)
-                        *e = 0;
-
-                if (is_localhost(domainname))
-                        break;
+                r = dns_name_normalize(domainname, &normalized);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to normalize domain name '%s': %m", domainname);
+                        return 0;
+                }
 
-                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);
+                if (is_localhost(normalized)) {
+                        log_debug_errno(r, "Detected 'localhost' as suggested hostname, ignoring.");
                         break;
                 }
 
                 free(lease->domainname);
-                lease->domainname = domainname;
-                domainname = NULL;
+                lease->domainname = normalized;
+                normalized = NULL;
 
                 break;
         }
-        case DHCP_OPTION_HOST_NAME:
-        {
-                _cleanup_free_ char *hostname = NULL;
-                char *e;
+
+        case DHCP_OPTION_HOST_NAME: {
+                _cleanup_free_ char *hostname = NULL, *normalized = NULL;
 
                 r = lease_parse_string(option, len, &hostname);
                 if (r < 0)
                         return r;
 
-                e = endswith(hostname, ".");
-                if (e)
-                        *e = 0;
+                r = dns_name_normalize(hostname, &normalized);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to normalize host name '%s': %m", hostname);
+                        return 0;
+                }
 
-                if (!hostname_is_valid(hostname, false) || is_localhost(hostname))
-                        break;
+                if (is_localhost(normalized)) {
+                        log_debug_errno(r, "Detected 'localhost' as suggested hostname, ignoring.");
+                        return 0;
+                }
 
-                free_and_replace(&lease->hostname, hostname);
-                hostname = NULL;
+                free(lease->hostname);
+                lease->hostname = normalized;
+                normalized = NULL;
 
                 break;
         }