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
  74         status = socket_pending(kdc_socket->sock, &dsize);
  75         if (!NT_STATUS_IS_OK(status)) {
  76                 talloc_free(tmp_ctx);
  77                 return;
  78         }
  79
  80         blob = data_blob_talloc(kdc_socket, NULL, dsize);
  81         if (blob.data == NULL) {
  82                 /* hope this is a temporary low memory condition */
  83                 talloc_free(tmp_ctx);
  84                 return;
  85         }
  86
  87         status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
  88                                  &src_addr, &src_port);
  89         if (!NT_STATUS_IS_OK(status)) {
  90                 talloc_free(tmp_ctx);
  91                 return;
  92         }
  93         talloc_steal(tmp_ctx, src_addr);
  94         blob.length = nread;
  95
  96         DEBUG(2,("Received krb5 packet of length %d from %s:%d\n",
  97                  blob.length, src_addr, src_port));
  98
  99         /* TODO:  This really should be in a utility function somewhere */
 100         ZERO_STRUCT(src_sock_addr);
 101 #ifdef HAVE_SOCK_SIN_LEN
 102         src_sock_addr.sin_len         = sizeof(src_sock_addr);
 103 #endif
 104         addr                     = interpret_addr2(src_addr);
 105         src_sock_addr.sin_addr.s_addr = addr.addr;
 106         src_sock_addr.sin_port        = htons(src_port);
 107         src_sock_addr.sin_family      = PF_INET;
 108
 109         /* Call krb5 */
 110         if (krb5_kdc_process_krb5_request(kdc_socket->kdc->smb_krb5_context->krb5_context,
 111                                           kdc_socket->kdc->config,
 112                                           blob.data, blob.length,
 113                                           &reply,
 114                                           src_addr,
 115                                           (struct sockaddr *)&src_sock_addr) == -1) {
 116                 talloc_free(tmp_ctx);
 117                 return;
 118         }
 119
 120         /* queue a pending reply */
 121         rep = talloc(kdc_socket, struct kdc_reply);
 122         if (rep == NULL) {
 123                 talloc_free(tmp_ctx);
 124                 return;
 125         }
 126         rep->dest_address = talloc_steal(rep, src_addr);
 127         rep->dest_port    = src_port;
 128         rep->packet       = data_blob_talloc(rep, reply.data, reply.length);
 129         if (rep->packet.data == NULL) {
 130                 talloc_free(rep);
 131                 talloc_free(tmp_ctx);
 132                 return;
 133         }
 134
 135         DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
 136         EVENT_FD_WRITEABLE(kdc_socket->fde);
 137         talloc_free(tmp_ctx);
 138 }
 139
 140 /*
 141   handle fd events on a KDC socket
 142 */
 143 static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
 144                                uint16_t flags, void *private)
 145 {
 146         struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
 147         if (flags & EVENT_FD_WRITE) {
 148                 kdc_send_handler(kdc_socket);
 149         } else if (flags & EVENT_FD_READ) {
 150                 kdc_recv_handler(kdc_socket);
 151         }
 152 }
 153
 154
 155 /*
 156   start listening on the given address
 157 */
 158 static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
 159 {
 160         struct kdc_socket *kdc_socket;
 161         NTSTATUS status;
 162
 163         kdc_socket = talloc(kdc, struct kdc_socket);
 164         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 165
 166         status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
 167         if (!NT_STATUS_IS_OK(status)) {
 168                 talloc_free(kdc_socket);
 169                 return status;
 170         }
 171
 172         kdc_socket->kdc = kdc;
 173         kdc_socket->send_queue = NULL;
 174
 175         talloc_steal(kdc_socket, kdc_socket->sock);
 176
 177         kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
 178                                        socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
 179                                        kdc_socket_handler, kdc_socket);
 180
 181         status = socket_listen(kdc_socket->sock, address, lp_krb5_port(), 0, 0);
 182         if (!NT_STATUS_IS_OK(status)) {
 183                 DEBUG(0,("Failed to bind to %s:%d - %s\n",
 184                          address, lp_krb5_port(), nt_errstr(status)));
 185                 talloc_free(kdc_socket);
 186                 return status;
 187         }
 188
 189         return NT_STATUS_OK;
 190 }
 191
 192
 193 /*
 194   setup our listening sockets on the configured network interfaces
 195 */
 196 NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
 197 {
 198         int num_interfaces = iface_count();
 199         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 200         NTSTATUS status;
 201
 202         /* if we are allowing incoming packets from any address, then
 203            we need to bind to the wildcard address */
 204         if (!lp_bind_interfaces_only()) {
 205                 status = kdc_add_socket(kdc, "0.0.0.0");
 206                 NT_STATUS_NOT_OK_RETURN(status);
 207         } else {
 208                 int i;
 209
 210                 for (i=0; i<num_interfaces; i++) {
 211                         const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
 212                         status = kdc_add_socket(kdc, address);
 213                         NT_STATUS_NOT_OK_RETURN(status);
 214                 }
 215         }
 216
 217         talloc_free(tmp_ctx);
 218
 219         return NT_STATUS_OK;
 220 }
 221
 222 /*
 223   startup the kdc task
 224 */
 225 static void kdc_task_init(struct task_server *task)
 226 {
 227         struct kdc_server *kdc;
 228         NTSTATUS status;
 229         krb5_error_code ret;
 230
 231         if (iface_count() == 0) {
 232                 task_terminate(task, "kdc: no network interfaces configured");
 233                 return;
 234         }
 235
 236         kdc = talloc(task, struct kdc_server);
 237         if (kdc == NULL) {
 238                 task_terminate(task, "kdc: out of memory");
 239                 return;
 240         }
 241
 242         kdc->task = task;
 243
 244         /* Setup the KDC configuration */
 245         kdc->config = talloc(kdc, struct krb5_kdc_configuration);
 246         if (!kdc->config) {
 247                 task_terminate(task, "kdc: out of memory");
 248                 return;
 249         }
 250         krb5_kdc_default_config(kdc->config);
 251
 252         initialize_krb5_error_table();
 253
 254         ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
 255         if (ret) {
 256                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 257                          error_message(ret)));
 258                 task_terminate(task, "kdc: krb5_init_context failed");
 259                 return;
 260         }
 261
 262         kdc->config->logf = kdc->smb_krb5_context->logf;
 263         kdc->config->db = talloc(kdc->config, struct HDB *);
 264         if (!kdc->config->db) {
 265                 task_terminate(task, "kdc: out of memory");
 266                 return;
 267         }
 268         kdc->config->num_db = 1;
 269
 270         ret = hdb_ldb_create(kdc->smb_krb5_context->krb5_context,
 271                              &kdc->config->db[0], lp_sam_url());
 272         if (ret != 0) {
 273                 DEBUG(1, ("kdc_task_init: hdb_ldb_create fails: %s\n",
 274                           smb_get_krb5_error_message(kdc->smb_krb5_context->krb5_context, ret, kdc)));
 275                 task_terminate(task, "kdc: hdb_ldb_create failed");
 276                 return;
 277         }
 278
 279         /* start listening on the configured network interfaces */
 280         status = kdc_startup_interfaces(kdc);
 281         if (!NT_STATUS_IS_OK(status)) {
 282                 task_terminate(task, "kdc failed to setup interfaces");
 283                 return;
 284         }
 285 }
 286
 287
 288 /*
 289   called on startup of the KDC service
 290 */
 291 static NTSTATUS kdc_init(struct event_context *event_ctx,
 292                          const struct model_ops *model_ops)
 293 {
 294         return task_server_startup(event_ctx, model_ops, kdc_task_init);
 295 }
 296
 297 /* called at smbd startup - register ourselves as a server service */
 298 NTSTATUS server_service_kdc_init(void)
 299 {
 300         return register_server_service("kdc", kdc_init);
 301 }