source/kdc/kdc.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    KDC Server startup
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   7    Copyright (C) Andrew Tridgell        2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "smbd/service_task.h"
  26 #include "lib/events/events.h"
  27 #include "lib/socket/socket.h"
  28 #include "kdc/kdc.h"
  29 #include "system/network.h"
  30 #include "dlinklist.h"
  31
  32 /*
  33   handle fd send events on a KDC socket
  34 */
  35 static void kdc_send_handler(struct kdc_socket *kdc_socket)
  36 {
  37         while (kdc_socket->send_queue) {
  38                 struct kdc_reply *rep = kdc_socket->send_queue;
  39                 NTSTATUS status;
  40                 size_t sendlen;
  41
  42                 status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, 0,
  43                                        rep->dest_address, rep->dest_port);
  44                 if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
  45                         break;
  46                 }
  47
  48                 DLIST_REMOVE(kdc_socket->send_queue, rep);
  49                 talloc_free(rep);
  50         }
  51
  52         if (kdc_socket->send_queue == NULL) {
  53                 EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
  54         }
  55 }
  56
  57
  58 /*
  59   handle fd recv events on a KDC socket
  60 */
  61 static void kdc_recv_handler(struct kdc_socket *kdc_socket)
  62 {
  63         NTSTATUS status;
  64         TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
  65         DATA_BLOB blob;
  66         struct kdc_reply *rep;
  67         krb5_data reply;
  68         size_t nread, dsize;
  69         const char *src_addr;
  70         int src_port;
  71         struct sockaddr_in src_sock_addr;
  72         struct ipv4_addr addr;
  73         int ret;
  74
  75         status = socket_pending(kdc_socket->sock, &dsize);
  76         if (!NT_STATUS_IS_OK(status)) {
  77                 talloc_free(tmp_ctx);
  78                 return;
  79         }
  80
  81         blob = data_blob_talloc(kdc_socket, NULL, dsize);
  82         if (blob.data == NULL) {
  83                 /* hope this is a temporary low memory condition */
  84                 talloc_free(tmp_ctx);
  85                 return;
  86         }
  87
  88         status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
  89                                  &src_addr, &src_port);
  90         if (!NT_STATUS_IS_OK(status)) {
  91                 talloc_free(tmp_ctx);
  92                 return;
  93         }
  94         talloc_steal(tmp_ctx, src_addr);
  95         blob.length = nread;
  96
  97         DEBUG(2,("Received krb5 packet of length %d from %s:%d\n",
  98                  blob.length, src_addr, src_port));
  99
 100         /* TODO:  This really should be in a utility function somewhere */
 101         ZERO_STRUCT(src_sock_addr);
 102 #ifdef HAVE_SOCK_SIN_LEN
 103         src_sock_addr.sin_len         = sizeof(src_sock_addr);
 104 #endif
 105         addr                     = interpret_addr2(src_addr);
 106         src_sock_addr.sin_addr.s_addr = addr.addr;
 107         src_sock_addr.sin_port        = htons(src_port);
 108         src_sock_addr.sin_family      = PF_INET;
 109
 110         /* Call krb5 */
 111         ret = krb5_kdc_process_krb5_request(kdc_socket->kdc->smb_krb5_context->krb5_context,
 112                                             kdc_socket->kdc->config,
 113                                             blob.data, blob.length,
 114                                             &reply,
 115                                             src_addr,
 116                                             (struct sockaddr *)&src_sock_addr);
 117         if (ret == -1) {
 118                 talloc_free(tmp_ctx);
 119                 return;
 120         }
 121
 122         /* queue a pending reply */
 123         rep = talloc(kdc_socket, struct kdc_reply);
 124         if (rep == NULL) {
 125                 krb5_data_free(&reply);
 126                 talloc_free(tmp_ctx);
 127                 return;
 128         }
 129         rep->dest_address = talloc_steal(rep, src_addr);
 130         rep->dest_port    = src_port;
 131         rep->packet       = data_blob_talloc(rep, reply.data, reply.length);
 132         krb5_data_free(&reply);
 133
 134         if (rep->packet.data == NULL) {
 135                 talloc_free(rep);
 136                 talloc_free(tmp_ctx);
 137                 return;
 138         }
 139
 140         DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
 141         EVENT_FD_WRITEABLE(kdc_socket->fde);
 142         talloc_free(tmp_ctx);
 143 }
 144
 145 /*
 146   handle fd events on a KDC socket
 147 */
 148 static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
 149                                uint16_t flags, void *private)
 150 {
 151         struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
 152         if (flags & EVENT_FD_WRITE) {
 153                 kdc_send_handler(kdc_socket);
 154         }
 155         if (flags & EVENT_FD_READ) {
 156                 kdc_recv_handler(kdc_socket);
 157         }
 158 }
 159
 160
 161 /*
 162   start listening on the given address
 163 */
 164 static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
 165 {
 166         struct kdc_socket *kdc_socket;
 167         NTSTATUS status;
 168
 169         kdc_socket = talloc(kdc, struct kdc_socket);
 170         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 171
 172         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
 173         if (!NT_STATUS_IS_OK(status)) {
 174                 talloc_free(kdc_socket);
 175                 return status;
 176         }
 177
 178         kdc_socket->kdc = kdc;
 179         kdc_socket->send_queue = NULL;
 180
 181         talloc_steal(kdc_socket, kdc_socket->sock);
 182
 183         kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 184                                        socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
 185                                        kdc_socket_handler, kdc_socket);
 186
 187         status = socket_listen(kdc_socket->sock, address, lp_krb5_port(), 0, 0);
 188         if (!NT_STATUS_IS_OK(status)) {
 189                 DEBUG(0,("Failed to bind to %s:%d - %s\n",
 190                          address, lp_krb5_port(), nt_errstr(status)));
 191                 talloc_free(kdc_socket);
 192                 return status;
 193         }
 194
 195         return NT_STATUS_OK;
 196 }
 197
 198
 199 /*
 200   setup our listening sockets on the configured network interfaces
 201 */
 202 NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
 203 {
 204         int num_interfaces = iface_count();
 205         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 206         NTSTATUS status;
 207
 208         /* if we are allowing incoming packets from any address, then
 209            we need to bind to the wildcard address */
 210         if (!lp_bind_interfaces_only()) {
 211                 status = kdc_add_socket(kdc, "0.0.0.0");
 212                 NT_STATUS_NOT_OK_RETURN(status);
 213         } else {
 214                 int i;
 215
 216                 for (i=0; i<num_interfaces; i++) {
 217                         const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
 218                         status = kdc_add_socket(kdc, address);
 219                         NT_STATUS_NOT_OK_RETURN(status);
 220                 }
 221         }
 222
 223         talloc_free(tmp_ctx);
 224
 225         return NT_STATUS_OK;
 226 }
 227
 228 /*
 229   startup the kdc task
 230 */
 231 static void kdc_task_init(struct task_server *task)
 232 {
 233         struct kdc_server *kdc;
 234         NTSTATUS status;
 235         krb5_error_code ret;
 236
 237         if (iface_count() == 0) {
 238                 task_terminate(task, "kdc: no network interfaces configured");
 239                 return;
 240         }
 241
 242         kdc = talloc(task, struct kdc_server);
 243         if (kdc == NULL) {
 244                 task_terminate(task, "kdc: out of memory");
 245                 return;
 246         }
 247
 248         kdc->task = task;
 249
 250         /* Setup the KDC configuration */
 251         kdc->config = talloc(kdc, struct krb5_kdc_configuration);
 252         if (!kdc->config) {
 253                 task_terminate(task, "kdc: out of memory");
 254                 return;
 255         }
 256         krb5_kdc_default_config(kdc->config);
 257
 258         /* NAT and the like make this pointless, and painful */
 259         kdc->config->check_ticket_addresses = FALSE;
 260
 261         initialize_krb5_error_table();
 262
 263         ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
 264         if (ret) {
 265                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 266                          error_message(ret)));
 267                 task_terminate(task, "kdc: krb5_init_context failed");
 268                 return;
 269         }
 270
 271         kdc->config->logf = kdc->smb_krb5_context->logf;
 272         kdc->config->db = talloc(kdc->config, struct HDB *);
 273         if (!kdc->config->db) {
 274                 task_terminate(task, "kdc: out of memory");
 275                 return;
 276         }
 277         kdc->config->num_db = 1;
 278
 279         ret = hdb_ldb_create(kdc->smb_krb5_context->krb5_context,
 280                              &kdc->config->db[0], lp_sam_url());
 281         if (ret != 0) {
 282                 DEBUG(1, ("kdc_task_init: hdb_ldb_create fails: %s\n",
 283                           smb_get_krb5_error_message(kdc->smb_krb5_context->krb5_context, ret, kdc)));
 284                 task_terminate(task, "kdc: hdb_ldb_create failed");
 285                 return;
 286         }
 287
 288         /* start listening on the configured network interfaces */
 289         status = kdc_startup_interfaces(kdc);
 290         if (!NT_STATUS_IS_OK(status)) {
 291                 task_terminate(task, "kdc failed to setup interfaces");
 292                 return;
 293         }
 294 }
 295
 296
 297 /*
 298   called on startup of the KDC service
 299 */
 300 static NTSTATUS kdc_init(struct event_context *event_ctx,
 301                          const struct model_ops *model_ops)
 302 {
 303         return task_server_startup(event_ctx, model_ops, kdc_task_init);
 304 }
 305
 306 /* called at smbd startup - register ourselves as a server service */
 307 NTSTATUS server_service_kdc_init(void)
 308 {
 309         return register_server_service("kdc", kdc_init);
 310 }