source/nsswitch/wb_common.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    winbind client common code
   5
   6    Copyright (C) Tim Potter 2000
   7    Copyright (C) Andrew Tridgell 2000
   8
   9    This library is free software; you can redistribute it and/or
  10    modify it under the terms of the GNU Library General Public
  11    License as published by the Free Software Foundation; either
  12    version 2 of the License, or (at your option) any later version.
  13
  14    This library 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 GNU
  17    Library General Public License for more details.
  18
  19    You should have received a copy of the GNU Library General Public
  20    License along with this library; if not, write to the
  21    Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22    Boston, MA  02111-1307, USA.
  23 */
  24
  25 #include "winbind_nss_config.h"
  26 #include "winbindd_nss.h"
  27
  28 /* Global variables.  These are effectively the client state information */
  29
  30 int winbindd_fd = -1;           /* fd for winbindd socket */
  31 static char *excluded_domain;
  32
  33 /* Free a response structure */
  34
  35 void free_response(struct winbindd_response *response)
  36 {
  37         /* Free any allocated extra_data */
  38
  39         if (response)
  40                 SAFE_FREE(response->extra_data);
  41 }
  42
  43 /*
  44   smbd needs to be able to exclude lookups for its own domain
  45 */
  46 void winbind_exclude_domain(const char *domain)
  47 {
  48         SAFE_FREE(excluded_domain);
  49         excluded_domain = strdup(domain);
  50 }
  51
  52
  53 /* Initialise a request structure */
  54
  55 void init_request(struct winbindd_request *request, int request_type)
  56 {
  57         static char *domain_env;
  58         static BOOL initialised;
  59
  60         request->length = sizeof(struct winbindd_request);
  61
  62         request->cmd = (enum winbindd_cmd)request_type;
  63         request->pid = getpid();
  64         request->domain[0] = '\0';
  65
  66         if (!initialised) {
  67                 initialised = True;
  68                 domain_env = getenv(WINBINDD_DOMAIN_ENV);
  69         }
  70
  71         if (domain_env) {
  72                 strncpy(request->domain, domain_env,
  73                         sizeof(request->domain) - 1);
  74                 request->domain[sizeof(request->domain) - 1] = '\0';
  75         }
  76 }
  77
  78 /* Initialise a response structure */
  79
  80 void init_response(struct winbindd_response *response)
  81 {
  82         /* Initialise return value */
  83
  84         response->result = WINBINDD_ERROR;
  85 }
  86
  87 /* Close established socket */
  88
  89 void close_sock(void)
  90 {
  91         if (winbindd_fd != -1) {
  92                 close(winbindd_fd);
  93                 winbindd_fd = -1;
  94         }
  95 }
  96
  97 /* Connect to winbindd socket */
  98
  99 int winbind_open_pipe_sock(void)
 100 {
 101         struct sockaddr_un sunaddr;
 102         static pid_t our_pid;
 103         struct stat st;
 104         pstring path;
 105
 106         if (our_pid != getpid()) {
 107                 close_sock();
 108                 our_pid = getpid();
 109         }
 110
 111         if (winbindd_fd != -1) {
 112                 return winbindd_fd;
 113         }
 114
 115         /* Check permissions on unix socket directory */
 116
 117         if (lstat(WINBINDD_SOCKET_DIR, &st) == -1) {
 118                 return -1;
 119         }
 120
 121         if (!S_ISDIR(st.st_mode) ||
 122             (st.st_uid != 0 && st.st_uid != geteuid())) {
 123                 return -1;
 124         }
 125
 126         /* Connect to socket */
 127
 128         strncpy(path, WINBINDD_SOCKET_DIR, sizeof(path) - 1);
 129         path[sizeof(path) - 1] = '\0';
 130
 131         strncat(path, "/", sizeof(path) - 1);
 132         path[sizeof(path) - 1] = '\0';
 133
 134         strncat(path, WINBINDD_SOCKET_NAME, sizeof(path) - 1);
 135         path[sizeof(path) - 1] = '\0';
 136
 137         ZERO_STRUCT(sunaddr);
 138         sunaddr.sun_family = AF_UNIX;
 139         strncpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path) - 1);
 140
 141         /* If socket file doesn't exist, don't bother trying to connect
 142            with retry.  This is an attempt to make the system usable when
 143            the winbindd daemon is not running. */
 144
 145         if (lstat(path, &st) == -1) {
 146                 return -1;
 147         }
 148
 149         /* Check permissions on unix socket file */
 150
 151         if (!S_ISSOCK(st.st_mode) ||
 152             (st.st_uid != 0 && st.st_uid != geteuid())) {
 153                 return -1;
 154         }
 155
 156         /* Connect to socket */
 157
 158         if ((winbindd_fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 159                 return -1;
 160         }
 161
 162         if (connect(winbindd_fd, (struct sockaddr *)&sunaddr,
 163                     sizeof(sunaddr)) == -1) {
 164                 close_sock();
 165                 return -1;
 166         }
 167
 168         return winbindd_fd;
 169 }
 170
 171 /* Write data to winbindd socket */
 172
 173 int write_sock(void *buffer, int count)
 174 {
 175         int result, nwritten;
 176
 177         /* Open connection to winbind daemon */
 178
 179  restart:
 180
 181         if (winbind_open_pipe_sock() == -1) {
 182                 return -1;
 183         }
 184
 185         /* Write data to socket */
 186
 187         nwritten = 0;
 188
 189         while(nwritten < count) {
 190                 struct timeval tv;
 191                 fd_set r_fds;
 192
 193                 /* Catch pipe close on other end by checking if a read()
 194                    call would not block by calling select(). */
 195
 196                 FD_ZERO(&r_fds);
 197                 FD_SET(winbindd_fd, &r_fds);
 198                 ZERO_STRUCT(tv);
 199
 200                 if (select(winbindd_fd + 1, &r_fds, NULL, NULL, &tv) == -1) {
 201                         close_sock();
 202                         return -1;                   /* Select error */
 203                 }
 204
 205                 /* Write should be OK if fd not available for reading */
 206
 207                 if (!FD_ISSET(winbindd_fd, &r_fds)) {
 208
 209                         /* Do the write */
 210
 211                         result = write(winbindd_fd,
 212                                        (char *)buffer + nwritten,
 213                                        count - nwritten);
 214
 215                         if ((result == -1) || (result == 0)) {
 216
 217                                 /* Write failed */
 218
 219                                 close_sock();
 220                                 return -1;
 221                         }
 222
 223                         nwritten += result;
 224
 225                 } else {
 226
 227                         /* Pipe has closed on remote end */
 228
 229                         close_sock();
 230                         goto restart;
 231                 }
 232         }
 233
 234         return nwritten;
 235 }
 236
 237 /* Read data from winbindd socket */
 238
 239 static int read_sock(void *buffer, int count)
 240 {
 241         int result = 0, nread = 0;
 242
 243         /* Read data from socket */
 244
 245         while(nread < count) {
 246
 247                 result = read(winbindd_fd, (char *)buffer + nread,
 248                               count - nread);
 249
 250                 if ((result == -1) || (result == 0)) {
 251
 252                         /* Read failed.  I think the only useful thing we
 253                            can do here is just return -1 and fail since the
 254                            transaction has failed half way through. */
 255
 256                         close_sock();
 257                         return -1;
 258                 }
 259
 260                 nread += result;
 261         }
 262
 263         return result;
 264 }
 265
 266 /* Read reply */
 267
 268 int read_reply(struct winbindd_response *response)
 269 {
 270         int result1, result2 = 0;
 271
 272         if (!response) {
 273                 return -1;
 274         }
 275
 276         /* Read fixed length response */
 277
 278         if ((result1 = read_sock(response, sizeof(struct winbindd_response)))
 279             == -1) {
 280
 281                 return -1;
 282         }
 283
 284         /* We actually send the pointer value of the extra_data field from
 285            the server.  This has no meaning in the client's address space
 286            so we clear it out. */
 287
 288         response->extra_data = NULL;
 289
 290         /* Read variable length response */
 291
 292         if (response->length > sizeof(struct winbindd_response)) {
 293                 int extra_data_len = response->length -
 294                         sizeof(struct winbindd_response);
 295
 296                 /* Mallocate memory for extra data */
 297
 298                 if (!(response->extra_data = malloc(extra_data_len))) {
 299                         return -1;
 300                 }
 301
 302                 if ((result2 = read_sock(response->extra_data, extra_data_len))
 303                     == -1) {
 304                         free_response(response);
 305                         return -1;
 306                 }
 307         }
 308
 309         /* Return total amount of data read */
 310
 311         return result1 + result2;
 312 }
 313
 314 /*
 315  * send simple types of requests
 316  */
 317
 318 NSS_STATUS winbindd_send_request(int req_type, struct winbindd_request *request)
 319 {
 320         struct winbindd_request lrequest;
 321
 322         /* Check for our tricky environment variable */
 323
 324         if (getenv(WINBINDD_DONT_ENV)) {
 325                 return NSS_STATUS_NOTFOUND;
 326         }
 327
 328         /* smbd may have excluded this domain */
 329         if (excluded_domain &&
 330             strcasecmp(excluded_domain, request->domain) == 0) {
 331                 return NSS_STATUS_NOTFOUND;
 332         }
 333
 334         if (!request) {
 335                 ZERO_STRUCT(lrequest);
 336                 request = &lrequest;
 337         }
 338
 339         /* Fill in request and send down pipe */
 340
 341         init_request(request, req_type);
 342
 343         if (write_sock(request, sizeof(*request)) == -1) {
 344                 return NSS_STATUS_UNAVAIL;
 345         }
 346
 347         return NSS_STATUS_SUCCESS;
 348 }
 349
 350 /*
 351  * Get results from winbindd request
 352  */
 353
 354 NSS_STATUS winbindd_get_response(struct winbindd_response *response)
 355 {
 356         struct winbindd_response lresponse;
 357
 358         if (!response) {
 359                 ZERO_STRUCT(lresponse);
 360                 response = &lresponse;
 361         }
 362
 363         init_response(response);
 364
 365         /* Wait for reply */
 366         if (read_reply(response) == -1) {
 367                 return NSS_STATUS_UNAVAIL;
 368         }
 369
 370         /* Throw away extra data if client didn't request it */
 371         if (response == &lresponse) {
 372                 free_response(response);
 373         }
 374
 375         /* Copy reply data from socket */
 376         if (response->result != WINBINDD_OK) {
 377                 return NSS_STATUS_NOTFOUND;
 378         }
 379
 380         return NSS_STATUS_SUCCESS;
 381 }
 382
 383 /* Handle simple types of requests */
 384
 385 NSS_STATUS winbindd_request(int req_type,
 386                                  struct winbindd_request *request,
 387                                  struct winbindd_response *response)
 388 {
 389         NSS_STATUS status;
 390
 391         status = winbindd_send_request(req_type, request);
 392         if (status != NSS_STATUS_SUCCESS)
 393                 return(status);
 394         return winbindd_get_response(response);
 395 }