s4-dns: Reload DNS zones from dsdb when zones are modified through RPC or DRS
[obnox/samba/samba-obnox.git] / source4 / dns_server / dns_server.c
index d9851b1566927f382675507025b0a5b8debaf557..3e18287bfa1b8747c29d6bd852bee9a0f3bf8ec5 100644 (file)
 #include "lib/util/tevent_werror.h"
 #include "auth/auth.h"
 #include "auth/credentials/credentials.h"
+#include "librpc/gen_ndr/ndr_irpc.h"
+#include "lib/messaging/irpc.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_DNS
 
 NTSTATUS server_service_dns_init(void);
 
@@ -117,11 +122,12 @@ static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
        struct dns_process_state *state;
        enum ndr_err_code ndr_err;
        WERROR ret;
-
+       const char *forwarder = lpcfg_dns_forwarder(dns->task->lp_ctx);
        req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
        if (req == NULL) {
                return NULL;
        }
+       state->state.mem_ctx = state;
        state->in = in;
 
        state->dns = dns;
@@ -130,7 +136,7 @@ static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
                tevent_req_werror(req, WERR_INVALID_PARAM);
                return tevent_req_post(req, ev);
        }
-       dump_data(8, in->data, in->length);
+       dump_data_dbgc(DBGC_DNS, 8, in->data, in->length);
 
        ndr_err = ndr_pull_struct_blob(
                in, state, &state->in_packet,
@@ -141,22 +147,29 @@ static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }
-       if (DEBUGLVL(8)) {
-               NDR_PRINT_DEBUG(dns_name_packet, &state->in_packet);
+       if (DEBUGLVLC(DBGC_DNS, 8)) {
+               NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->in_packet);
        }
 
        ret = dns_verify_tsig(dns, state, &state->state, &state->in_packet, in);
        if (!W_ERROR_IS_OK(ret)) {
-               DEBUG(0, ("Bailing out early!\n"));
+               DEBUG(1, ("Failed to verify TSIG!\n"));
                state->dns_err = werr_to_dns_err(ret);
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }
 
+       if (state->in_packet.operation & DNS_FLAG_REPLY) {
+               DEBUG(1, ("Won't reply to replies.\n"));
+               tevent_req_werror(req, WERR_INVALID_PARAM);
+               return tevent_req_post(req, ev);
+       }
+
        state->state.flags = state->in_packet.operation;
        state->state.flags |= DNS_FLAG_REPLY;
 
-       if (lpcfg_dns_recursive_queries(dns->task->lp_ctx)) {
+       
+       if (forwarder && *forwarder) {
                state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
        }
 
@@ -235,6 +248,10 @@ static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                }
        }
 
+       if (DEBUGLVLC(DBGC_DNS, 8)) {
+               NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->out_packet);
+       }
+
        ndr_err = ndr_push_struct_blob(
                out, mem_ctx, &state->out_packet,
                (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
@@ -565,10 +582,9 @@ static void dns_udp_call_sendto_done(struct tevent_req *subreq)
 {
        struct dns_udp_call *call = tevent_req_callback_data(subreq,
                                       struct dns_udp_call);
-       ssize_t ret;
        int sys_errno;
 
-       ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
+       tdgram_sendto_queue_recv(subreq, &sys_errno);
 
        /* We don't care about errors */
 
@@ -650,7 +666,7 @@ static NTSTATUS dns_add_socket(struct dns_server *dns,
 /*
   setup our listening sockets on the configured network interfaces
 */
-static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
+static NTSTATUS dns_startup_interfaces(struct dns_server *dns,
                                       struct interface *ifaces)
 {
        const struct model_ops *model_ops;
@@ -668,13 +684,36 @@ static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_c
                return NT_STATUS_INTERNAL_ERROR;
        }
 
-       num_interfaces = iface_list_count(ifaces);
+       if (ifaces != NULL) {
+               num_interfaces = iface_list_count(ifaces);
 
-       for (i=0; i<num_interfaces; i++) {
-               const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
+               for (i=0; i<num_interfaces; i++) {
+                       const char *address = talloc_strdup(tmp_ctx,
+                                                           iface_list_n_ip(ifaces, i));
 
-               status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
-               NT_STATUS_NOT_OK_RETURN(status);
+                       status = dns_add_socket(dns, model_ops, "dns", address,
+                                               DNS_SERVICE_PORT);
+                       NT_STATUS_NOT_OK_RETURN(status);
+               }
+       } else {
+               int num_binds = 0;
+               char **wcard;
+               wcard = iface_list_wildcard(tmp_ctx);
+               if (wcard == NULL) {
+                       DEBUG(0, ("No wildcard address available\n"));
+                       return NT_STATUS_INTERNAL_ERROR;
+               }
+               for (i = 0; wcard[i] != NULL; i++) {
+                       status = dns_add_socket(dns, model_ops, "dns", wcard[i],
+                                               DNS_SERVICE_PORT);
+                       if (NT_STATUS_IS_OK(status)) {
+                               num_binds++;
+                       }
+               }
+               if (num_binds == 0) {
+                       talloc_free(tmp_ctx);
+                       return NT_STATUS_INVALID_PARAMETER_MIX;
+               }
        }
 
        talloc_free(tmp_ctx);
@@ -724,15 +763,93 @@ static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
        return buffer;
 }
 
+static NTSTATUS dns_server_reload_zones(struct dns_server *dns)
+{
+       int ret;
+       static const char * const attrs[] = { "name", NULL};
+       struct ldb_result *res;
+       int i;
+       struct dns_server_zone *new_list = NULL;
+       struct dns_server_zone *old_list = NULL;
+       struct dns_server_zone *old_zone;
+
+       // TODO: this search does not work against windows
+       ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
+                         attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
+       if (ret != LDB_SUCCESS) {
+               return NT_STATUS_INTERNAL_DB_CORRUPTION;
+       }
+
+       TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
+
+       for (i=0; i < res->count; i++) {
+               struct dns_server_zone *z;
+
+               z = talloc_zero(dns, struct dns_server_zone);
+               if (z == NULL) {
+                       return NT_STATUS_NO_MEMORY;
+               }
+
+               z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
+               z->dn = talloc_move(z, &res->msgs[i]->dn);
+               /*
+                * Ignore the RootDNSServers zone and zones that we don't support yet
+                * RootDNSServers should never be returned (Windows DNS server don't)
+                * ..TrustAnchors should never be returned as is, (Windows returns
+                * TrustAnchors) and for the moment we don't support DNSSEC so we'd better
+                * not return this zone.
+                */
+               if ((strcmp(z->name, "RootDNSServers") == 0) ||
+                   (strcmp(z->name, "..TrustAnchors") == 0))
+               {
+                       DEBUG(10, ("Ignoring zone %s\n", z->name));
+                       talloc_free(z);
+                       continue;
+               }
+               DLIST_ADD_END(new_list, z, NULL);
+       }
+
+       old_list = dns->zones;
+       dns->zones = new_list;
+       while ((old_zone = DLIST_TAIL(old_list)) != NULL) {
+               DLIST_REMOVE(old_list, old_zone);
+               talloc_free(old_zone);
+       }
+
+       return NT_STATUS_OK;
+}
+
+/**
+ * Called when the internal DNS server should reload the zones from DB, for
+ * example, when zones are added or deleted through RPC or replicated by
+ * inbound DRS.
+ */
+static NTSTATUS dns_reload_zones(struct irpc_message *msg,
+                                struct dnssrv_reload_dns_zones *r)
+{
+       struct dns_server *dns;
+
+       dns = talloc_get_type(msg->private_data, struct dns_server);
+       if (dns == NULL) {
+               r->out.result = NT_STATUS_INTERNAL_ERROR;
+               return NT_STATUS_INTERNAL_ERROR;
+       }
+
+       r->out.result = dns_server_reload_zones(dns);
+
+       return NT_STATUS_OK;
+}
+
 static void dns_task_init(struct task_server *task)
 {
        struct dns_server *dns;
        NTSTATUS status;
-       struct interface *ifaces;
+       struct interface *ifaces = NULL;
        int ret;
-       struct ldb_result *res;
-       static const char * const attrs[] = { "name", NULL};
-       unsigned int i;
+       static const char * const attrs_none[] = { NULL};
+       struct ldb_message *dns_acc;
+       char *hostname_lower;
+       char *dns_spn;
 
        switch (lpcfg_server_role(task->lp_ctx)) {
        case ROLE_STANDALONE:
@@ -746,11 +863,13 @@ static void dns_task_init(struct task_server *task)
                break;
        }
 
-       load_interface_list(task, task->lp_ctx, &ifaces);
+       if (lpcfg_interfaces(task->lp_ctx) && lpcfg_bind_interfaces_only(task->lp_ctx)) {
+               load_interface_list(task, task->lp_ctx, &ifaces);
 
-       if (iface_list_count(ifaces) == 0) {
-               task_server_terminate(task, "dns: no network interfaces configured", false);
-               return;
+               if (iface_list_count(ifaces) == 0) {
+                       task_server_terminate(task, "dns: no network interfaces configured", false);
+                       return;
+               }
        }
 
        task_server_set_title(task, "task[dns]");
@@ -762,6 +881,8 @@ static void dns_task_init(struct task_server *task)
        }
 
        dns->task = task;
+       /*FIXME: Make this a configurable option */
+       dns->max_payload = 4096;
 
        dns->server_credentials = cli_credentials_init(dns);
        if (!dns->server_credentials) {
@@ -769,57 +890,81 @@ static void dns_task_init(struct task_server *task)
                return;
        }
 
-       cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
-       status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
-       if (!NT_STATUS_IS_OK(status)) {
-               task_server_terminate(task,
-                       talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
-                                       nt_errstr(status)),
-                       true);
+       dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
+                             system_session(dns->task->lp_ctx), 0);
+       if (!dns->samdb) {
+               task_server_terminate(task, "dns: samdb_connect failed", true);
                return;
        }
 
+       cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
+
+       hostname_lower = strlower_talloc(dns, lpcfg_netbios_name(task->lp_ctx));
+       dns_spn = talloc_asprintf(dns, "DNS/%s.%s",
+                                 hostname_lower,
+                                 lpcfg_dnsdomain(task->lp_ctx));
+       TALLOC_FREE(hostname_lower);
+
+       ret = dsdb_search_one(dns->samdb, dns, &dns_acc,
+                             ldb_get_default_basedn(dns->samdb), LDB_SCOPE_SUBTREE,
+                             attrs_none, 0, "(servicePrincipalName=%s)",
+                             dns_spn);
+       if (ret == LDB_SUCCESS) {
+               TALLOC_FREE(dns_acc);
+               if (!dns_spn) {
+                       task_server_terminate(task, "dns: talloc_asprintf failed", true);
+                       return;
+               }
+               status = cli_credentials_set_stored_principal(dns->server_credentials, task->lp_ctx, dns_spn);
+               if (!NT_STATUS_IS_OK(status)) {
+                       task_server_terminate(task,
+                                             talloc_asprintf(task, "Failed to obtain server credentials for DNS, "
+                                                             "despite finding it in the samdb! %s\n",
+                                                             nt_errstr(status)),
+                                             true);
+                       return;
+               }
+       } else {
+               TALLOC_FREE(dns_spn);
+               status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
+               if (!NT_STATUS_IS_OK(status)) {
+                       task_server_terminate(task,
+                                             talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
+                                                             nt_errstr(status)),
+                                             true);
+                       return;
+               }
+       }
+
        dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
        if (!dns->tkeys) {
                task_server_terminate(task, "Failed to allocate tkey storage\n", true);
                return;
        }
 
-       dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
-                             system_session(dns->task->lp_ctx), 0);
-       if (!dns->samdb) {
-               task_server_terminate(task, "dns: samdb_connect failed", true);
+       status = dns_server_reload_zones(dns);
+       if (!NT_STATUS_IS_OK(status)) {
+               task_server_terminate(task, "dns: failed to load DNS zones", true);
                return;
        }
 
-       // TODO: this search does not work against windows
-       ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
-                         attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
-       if (ret != LDB_SUCCESS) {
-               task_server_terminate(task,
-                                     "dns: failed to look up root DNS zones",
-                                     true);
+       status = dns_startup_interfaces(dns, ifaces);
+       if (!NT_STATUS_IS_OK(status)) {
+               task_server_terminate(task, "dns failed to setup interfaces", true);
                return;
        }
 
-       TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
-
-       for (i=0; i < res->count; i++) {
-               struct dns_server_zone *z;
-
-               z = talloc_zero(dns, struct dns_server_zone);
-               if (z == NULL) {
-               }
-
-               z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
-               z->dn = talloc_move(z, &res->msgs[i]->dn);
-
-               DLIST_ADD_END(dns->zones, z, NULL);
+       /* Setup the IRPC interface and register handlers */
+       status = irpc_add_name(task->msg_ctx, "dnssrv");
+       if (!NT_STATUS_IS_OK(status)) {
+               task_server_terminate(task, "dns: failed to register IRPC name", true);
+               return;
        }
 
-       status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
+       status = IRPC_REGISTER(task->msg_ctx, irpc, DNSSRV_RELOAD_DNS_ZONES,
+                              dns_reload_zones, dns);
        if (!NT_STATUS_IS_OK(status)) {
-               task_server_terminate(task, "dns failed to setup interfaces", true);
+               task_server_terminate(task, "dns: failed to setup reload handler", true);
                return;
        }
 }