login/utmp_daemon.c

   1 /* Copyright (C) 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/socket.h>
  25 #include <sys/un.h>
  26 #include <unistd.h>
  27 #include <utmp.h>
  28
  29 #include "utmp-private.h"
  30 #include "programs/utmpd.h"
  31
  32
  33 /* Descriptor for the socket.  */
  34 static int daemon_sock = -1;
  35
  36
  37 /* Functions defined here.  */
  38 static int setutent_daemon (void);
  39 static int getutent_r_daemon (struct utmp *buffer, struct utmp **result);
  40 static int getutid_r_daemon (const struct utmp *line, struct utmp *buffer,
  41                              struct utmp **result);
  42 static int getutline_r_daemon (const struct utmp *id, struct utmp *buffer,
  43                                struct utmp **result);
  44 static struct utmp *pututline_daemon (const struct utmp *utmp);
  45 static void endutent_daemon (void);
  46 static int updwtmp_daemon (const char *file, const struct utmp *utmp);
  47
  48 /* Jump table for daemon functions.  */
  49 struct utfuncs __libc_utmp_daemon_functions =
  50 {
  51   setutent_daemon,
  52   getutent_r_daemon,
  53   getutid_r_daemon,
  54   getutline_r_daemon,
  55   pututline_daemon,
  56   endutent_daemon,
  57   updwtmp_daemon
  58 };
  59
  60 static int do_setutent (int sock);
  61 static int do_getutent (int sock, struct utmp *buffer);
  62 static int do_getutid (int sock, const struct utmp *id,
  63                             struct utmp *buffer);
  64 static int do_pututline (int sock, const struct utmp *utmp);
  65 static int do_getutline (int sock, const struct utmp *line,
  66                          struct utmp *buffer);
  67 static int do_pututline (int sock, const struct utmp *utmp);
  68 static int do_endutent (int sock);
  69 static int do_updwtmp (int sock, const char *file,
  70                        const struct utmp *utmp);
  71
  72 static int open_socket (const char *name);
  73 static int send_request (int sock, const request_header *request,
  74                          reply_header *reply);
  75
  76
  77 static int
  78 setutent_daemon (void)
  79 {
  80   if (access (_PATH_UTMPD_RW, F_OK) == -1
  81       && access (_PATH_UTMPD_RO, F_OK) == -1)
  82     return 0;
  83
  84   if (daemon_sock < 0)
  85     {
  86       daemon_sock = open_socket (_PATH_UTMPD_RW);
  87       if (daemon_sock < 0)
  88         {
  89           /* Hhm, read-write access did not work.  Try read-only.  */
  90           daemon_sock = open_socket (_PATH_UTMPD_RO);
  91           if (daemon_sock < 0)
  92             return 0;
  93         }
  94     }
  95
  96   /* Send request to the daemon.  */
  97   if (do_setutent (daemon_sock) < 0)
  98     return 0;
  99
 100   return 1;
 101 }
 102
 103
 104 static int
 105 getutent_r_daemon (struct utmp *buffer, struct utmp **result)
 106 {
 107   assert (daemon_sock >= 0);
 108
 109   /* Send request to the daemon.  */
 110   if (do_getutent (daemon_sock, buffer) < 0)
 111     {
 112       *result = NULL;
 113       return -1;;
 114     }
 115
 116   *result = buffer;
 117   return 0;
 118 }
 119
 120
 121 static int
 122 getutid_r_daemon (const struct utmp *id, struct utmp *buffer,
 123                   struct utmp **result)
 124 {
 125   assert (daemon_sock >= 0);
 126
 127   /* Send request to the daemon.  */
 128   if (do_getutid (daemon_sock, id, buffer) < 0)
 129     {
 130       *result = NULL;
 131       return -1;
 132     }
 133
 134   *result = buffer;
 135   return 0;
 136 }
 137
 138
 139 static int
 140 getutline_r_daemon (const struct utmp *line, struct utmp *buffer,
 141                     struct utmp **result)
 142 {
 143   assert (daemon_sock >= 0);
 144
 145   /* Send request to the daemon.  */
 146   if (do_getutline (daemon_sock, line, buffer) < 0)
 147     {
 148       *result = NULL;
 149       return -1;
 150     }
 151
 152   *result = buffer;
 153   return 0;
 154 }
 155
 156
 157 static struct utmp *
 158 pututline_daemon (const struct utmp *utmp)
 159 {
 160   assert (daemon_sock >= 0);
 161
 162   /* Send request to the daemon.  */
 163   if (do_pututline (daemon_sock, utmp) < 0)
 164     return NULL;
 165
 166   return (struct utmp *)utmp;
 167 }
 168
 169
 170 static void
 171 endutent_daemon (void)
 172 {
 173   assert (daemon_sock >= 0);
 174
 175   /* Send request to the daemon.  */
 176   do_endutent (daemon_sock);
 177
 178   close (daemon_sock);
 179   daemon_sock = -1;
 180 }
 181
 182
 183 static int
 184 updwtmp_daemon (const char *file, const struct utmp *utmp)
 185 {
 186   int sock;
 187
 188   /* Only try to open for both reading and writing.  */
 189   sock = open_socket (_PATH_UTMPD_RW);
 190   if (sock < 0)
 191     return -1;
 192
 193   /* Send request to the daemon.  */
 194   if (do_updwtmp (sock, file, utmp) < 0)
 195     {
 196       close (sock);
 197       return -1;
 198     }
 199
 200   close (sock);
 201   return 0;
 202 }
 203
 204
 205 static int
 206 do_setutent (int sock)
 207 {
 208   setutent_request *request;
 209   setutent_reply reply;
 210   size_t size;
 211   size_t name_len;
 212
 213   name_len = strlen (__libc_utmp_file_name) + 1;
 214   size = sizeof (setutent_request) + name_len;
 215
 216   request = malloc (size);
 217   if (request == NULL)
 218     return -1;
 219
 220   request->header.version = UTMPD_VERSION;
 221   request->header.size = size;
 222   request->header.type = UTMPD_REQ_SETUTENT;
 223   memcpy (request->file, __libc_utmp_file_name, name_len);
 224
 225   reply.header.version = UTMPD_VERSION;
 226   reply.header.size = sizeof (setutent_reply);
 227   reply.header.type = UTMPD_REQ_SETUTENT;
 228
 229   if (send_request (sock, &request->header, &reply.header) < 0)
 230     {
 231       free (request);
 232       return -1;
 233     }
 234
 235   if (reply.result < 0)
 236     __set_errno (reply.errnum);
 237
 238   free (request);
 239   return reply.result;
 240 }
 241
 242 static int
 243 do_getutent (int sock, struct utmp *buffer)
 244 {
 245   getutent_request request;
 246   getutent_reply reply;
 247
 248   request.header.version = UTMPD_VERSION;
 249   request.header.size = sizeof (getutent_request);
 250   request.header.type = UTMPD_REQ_GETUTENT;
 251
 252   reply.header.version = UTMPD_VERSION;
 253   reply.header.size = sizeof (getutent_reply);
 254   reply.header.type = UTMPD_REQ_GETUTENT;
 255
 256   if (send_request (sock, &request.header, &reply.header) < 0)
 257     return -1;
 258
 259   if (reply.result < 0)
 260     __set_errno (reply.errnum);
 261   else
 262     memcpy (buffer, &reply.entry, sizeof (struct utmp));
 263
 264   return reply.result;
 265 }
 266
 267 static int
 268 do_getutid (int sock, const struct utmp *id, struct utmp *buffer)
 269 {
 270   getutid_request request;
 271   getutid_reply reply;
 272
 273   request.header.version = UTMPD_VERSION;
 274   request.header.size = sizeof (getutid_request);
 275   request.header.type = UTMPD_REQ_GETUTID;
 276   memcpy (&request.id, id, sizeof (struct utmp));
 277
 278   reply.header.version = UTMPD_VERSION;
 279   reply.header.size = sizeof (getutid_reply);
 280   reply.header.type = UTMPD_REQ_GETUTID;
 281
 282   if (send_request (sock, &request.header, &reply.header) < 0)
 283     return -1;
 284
 285   if (reply.result < 0)
 286     __set_errno (reply.errnum);
 287   else
 288     memcpy (buffer, &reply.entry, sizeof (struct utmp));
 289
 290   return reply.result;
 291 }
 292
 293 static int
 294 do_getutline (int sock, const struct utmp *line, struct utmp *buffer)
 295 {
 296   getutline_request request;
 297   getutline_reply reply;
 298
 299   request.header.version = UTMPD_VERSION;
 300   request.header.size = sizeof (getutline_request);
 301   request.header.type = UTMPD_REQ_GETUTLINE;
 302   memcpy (&request.line, line, sizeof (struct utmp));
 303
 304   reply.header.version = UTMPD_VERSION;
 305   reply.header.size = sizeof (getutline_reply);
 306   reply.header.type = UTMPD_REQ_GETUTLINE;
 307
 308   if (send_request (sock, &request.header, &reply.header) < 0)
 309     return -1;
 310
 311   if (reply.result < 0)
 312     __set_errno (reply.errnum);
 313   else
 314     memcpy (buffer, &reply.entry, sizeof (struct utmp));
 315
 316   return reply.result;
 317 }
 318
 319 static int
 320 do_pututline (int sock, const struct utmp *utmp)
 321 {
 322   pututline_request request;
 323   pututline_reply reply;
 324
 325   request.header.version = UTMPD_VERSION;
 326   request.header.size = sizeof (pututline_request);
 327   request.header.type = UTMPD_REQ_PUTUTLINE;
 328   memcpy (&request.utmp, utmp, sizeof (struct utmp));
 329
 330   reply.header.version = UTMPD_VERSION;
 331   reply.header.size = sizeof (pututline_reply);
 332   reply.header.type = UTMPD_REQ_PUTUTLINE;
 333
 334   if (send_request (sock, &request.header, &reply.header) < 0)
 335     return -1;
 336
 337   if (reply.result < 0)
 338     __set_errno (reply.errnum);
 339
 340   return reply.result;
 341 }
 342
 343 static int
 344 do_endutent (int sock)
 345 {
 346   endutent_request request;
 347   endutent_reply reply;
 348
 349   request.header.version = UTMPD_VERSION;
 350   request.header.size = sizeof (endutent_request);
 351   request.header.type = UTMPD_REQ_ENDUTENT;
 352
 353   reply.header.version = UTMPD_VERSION;
 354   reply.header.size = sizeof (endutent_reply);
 355   reply.header.type = UTMPD_REQ_ENDUTENT;
 356
 357   if (send_request (sock, &request.header, &reply.header) < 0)
 358     return -1;
 359
 360   if (reply.result < 0)
 361     __set_errno (reply.errnum);
 362
 363   return reply.result;
 364 }
 365
 366 static int
 367 do_updwtmp (int sock, const char *file, const struct utmp *utmp)
 368 {
 369   updwtmp_request *request;
 370   updwtmp_reply reply;
 371   size_t size;
 372   size_t file_len;
 373
 374   file_len = strlen (file) + 1;
 375   size = sizeof (updwtmp_request) + file_len;
 376
 377   request = malloc (size);
 378   if (request == NULL)
 379     return -1;
 380
 381   request->header.version = UTMPD_VERSION;
 382   request->header.size = size;
 383   request->header.type = UTMPD_REQ_UPDWTMP;
 384   memcpy (&request->utmp, utmp, sizeof (struct utmp));
 385   memcpy (request->file, file, file_len);
 386
 387   reply.header.version = UTMPD_VERSION;
 388   reply.header.size = sizeof (updwtmp_reply);
 389   reply.header.type = UTMPD_REQ_UPDWTMP;
 390
 391   if (send_request (sock, &request->header, &reply.header) < 0)
 392     {
 393       free (request);
 394       return -1;
 395     }
 396
 397   if (reply.result < 0)
 398     __set_errno (reply.errnum);
 399
 400   free (request);
 401   return reply.result;
 402 }
 403
 404
 405 /* Create a socket connected to NAME.  */
 406 static int
 407 open_socket (const char *name)
 408 {
 409   struct sockaddr_un addr;
 410   int sock;
 411
 412   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 413   if (sock < 0)
 414     return -1;
 415
 416   addr.sun_family = AF_UNIX;
 417   strcpy (addr.sun_path, name);
 418   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 419     {
 420       close (sock);
 421       return -1;
 422     }
 423
 424   return sock;
 425 }
 426
 427 /* Send REQUEST to SOCK, and wait for reply.  Returns 0 if successful,
 428    storing the reply in REPLY, and -1 if not.  */
 429 static int
 430 send_request (int sock, const request_header *request,
 431               reply_header *reply)
 432 {
 433   reply_header header;
 434   ssize_t nbytes;
 435
 436   nbytes = write (sock, request, request->size);
 437   if (nbytes != (ssize_t) request->size)
 438     return -1;
 439
 440   nbytes = read (sock, &header, sizeof (reply_header));
 441   if (nbytes != sizeof (reply_header))
 442     return -1;
 443
 444   if (reply->version != header.version
 445       || reply->size != header.size
 446       || reply->type != header.type)
 447     return -1;
 448
 449   nbytes = read (sock, reply + 1, reply->size - sizeof (reply_header));
 450   if (nbytes != (ssize_t) (reply->size - sizeof (reply_header)))
 451     return -1;
 452
 453   return 0;
 454 }