mdw@git.distorted.org.uk Git - become/blob - src/name.c

   1 /* -*-c-*-
   2  *
   3  * $Id: name.c,v 1.4 1997/08/20 16:17:59 mdw Exp $
   4  *
   5  * Looking up of names in symbol tables
   6  *
   7  * (c) 1997 EBI
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of `become'
  13  *
  14  * `Become' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `Become' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `become'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: name.c,v $
  32  * Revision 1.4  1997/08/20 16:17:59  mdw
  33  * Replace `name_reinit' by `name_end' for more sensible restart.
  34  *
  35  * Revision 1.3  1997/08/07 09:49:39  mdw
  36  * Extensive modifications to handle netgroups.  Also sanitise user and group
  37  * names before adding them to the symbol table.
  38  *
  39  * Revision 1.2  1997/08/04 10:24:24  mdw
  40  * Sources placed under CVS control.
  41  *
  42  * Revision 1.1  1997/07/21  13:47:46  mdw
  43  * Initial revision
  44  *
  45  */
  46
  47 /*----- Header files ------------------------------------------------------*/
  48
  49 /* --- ANSI headers --- */
  50
  51 #include <ctype.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55
  56 /* --- Unix headers --- */
  57
  58 #include <sys/types.h>
  59 #include <sys/socket.h>
  60
  61 #include <netinet/in.h>
  62
  63 #include <arpa/inet.h>
  64
  65 #include <netdb.h>
  66 #include <grp.h>
  67 #include <pwd.h>
  68
  69 /* --- Local headers --- */
  70
  71 #include "config.h"
  72
  73 #include "become.h"
  74 #include "class.h"
  75 #include "name.h"
  76 #include "netg.h"
  77 #include "sym.h"
  78 #include "userdb.h"
  79 #include "utils.h"
  80
  81 /*----- Static variables --------------------------------------------------*/
  82
  83 static sym_table name__table;           /* Symbol table for everything */
  84
  85 /*----- Main code ---------------------------------------------------------*/
  86
  87 /* --- @name__get@ --- *
  88  *
  89  * Arguments:   @const char *p@ = pointer to the name we want
  90  *              @unsigned type@ = type of class it should have
  91  *
  92  * Returns:     A pointer to a name ready to use, or zero if there's a type
  93  *              conflict.
  94  *
  95  * Use:         Creates a name of the appropriate type all ready to use.
  96  */
  97
  98 static name *name__get(const char *p, unsigned type)
  99 {
 100   unsigned f;
 101   name *n = sym_find(&name__table, p, -1, sizeof(*n), &f);
 102   if (!f) {
 103     sym_table *t = xmalloc(sizeof(*t));
 104     sym_createTable(t);
 105     n->c = class_create(type, t);
 106   }
 107   return (n->c->type == type ? n : 0);
 108 }
 109
 110 /* --- @name__sanitise@ --- *
 111  *
 112  * Arguments:   @const char *n@ = pointer to a name
 113  *              @char *buf@ = pointer to a buffer of space
 114  *              @size_t sz@ = size of the buffer
 115  *
 116  * Returns:     A pointer to the transformed name in the buffer, or null
 117  *              if there wasn't enough space.
 118  *
 119  * Use:         Transforms a name so that it only contains nice characters.
 120  */
 121
 122 static char *name__sanitise(const char *n, char *buf, size_t sz)
 123 {
 124   char *p = buf;
 125
 126   if (strlen(n) + 1 > sz)
 127     return (0);
 128
 129   while (*n) {
 130     if (isalnum((unsigned char)*n))
 131       *p++ = *n;
 132     else
 133       *p++ = '_';
 134     n++;
 135   }
 136   *p++ = 0;
 137   return (buf);
 138 }
 139
 140 /* --- @name__users@ --- *
 141  *
 142  * Arguments:   ---
 143  *
 144  * Returns:     ---
 145  *
 146  * Use:         Adds all of the users registered with the user database to
 147  *              the name table.  Also adds the users' primary groups.
 148  */
 149
 150 static void name__users(void)
 151 {
 152   struct passwd *pw;
 153   struct group *gr;
 154   char buf[32];
 155
 156   userdb_iterateUsers();
 157   while ((pw = userdb_nextUser()) != 0) {
 158     name *n;
 159     int u = pw->pw_uid;
 160
 161     /* --- First, add the user to the table --- */
 162
 163     if (name__sanitise(pw->pw_name, buf, sizeof(buf)) &&
 164         (n = name__get(buf, clType_user)) != 0)
 165       sym_find(n->c->t, (char *)&u, sizeof(u), sizeof(sym_base), 0);
 166
 167     /* --- Now handle the user's default group --- */
 168
 169     if ((gr = userdb_groupById(pw->pw_gid)) != 0 &&
 170         name__sanitise(gr->gr_name, buf, sizeof(buf)) &&
 171         (n = name__get(buf, clType_user)) != 0)
 172       sym_find(n->c->t, (char *)&u, sizeof(u), sizeof(sym_base), 0);
 173   }
 174 }
 175
 176 /* --- @name__groups@ --- *
 177  *
 178  * Arguments:   ---
 179  *
 180  * Returns:     ---
 181  *
 182  * Use:         Adds users into all of their supplementary groups.
 183  */
 184
 185 static void name__groups(void)
 186 {
 187   struct group *gr;
 188   struct passwd *pw;
 189   char **p;
 190   char buf[32];
 191
 192   userdb_iterateGroups();
 193   while ((gr = userdb_nextGroup()) != 0) {
 194     name *n;
 195     int u;
 196
 197     if (name__sanitise(gr->gr_name, buf, sizeof(buf)) &&
 198         (n = name__get(buf, clType_user)) != 0) {
 199
 200       /* --- Now add all of the members --- */
 201
 202       for (p = gr->gr_mem; *p; p++) {
 203         if ((pw = userdb_userByName(*p)) != 0) {
 204           u = pw->pw_uid;
 205           sym_find(n->c->t, (char *)&u, sizeof(u), sizeof(sym_base), 0);
 206         }
 207       }
 208     }
 209   }
 210 }
 211
 212 /* --- @name__scan@ --- *
 213  *
 214  * Arguments:   @netg *n@ = the netgroup handle we're scanning
 215  *              @const char *host@ = the host name
 216  *              @const char *user@ = the user name
 217  *              @const char *domain@ = the (NIS?) domain name
 218  *              @void *ctx@ = some context pointer
 219  *
 220  * Returns:     Zero to continue scanning.
 221  *
 222  * Use:         Scans a netgroup, adding items to the name table.
 223  */
 224
 225 /* --- A data type --- */
 226
 227 typedef struct name__scanctx {
 228   char *name;                           /* Netgroup name prefixed with `?_'*/
 229   unsigned f;                           /* Various interesting flags */
 230   name *h;                              /* Name entry for hosts */
 231   name *u;                              /* Name entry for users */
 232 } name__scanctx;
 233
 234 enum { f_host = 1, f_user = 2 };
 235
 236 /* --- And now for the real code --- */
 237
 238 static int name__scan(netg *n, const char *host, const char *user,
 239                       const char *domain, void *ctx)
 240 {
 241   name__scanctx *sc = ctx;
 242
 243   /* --- Add the host to the hosts class --- */
 244
 245   if (sc->f & f_host && host) {
 246     struct hostent *h;
 247     struct in_addr in;
 248     const char *a;
 249
 250     /* --- First ensure that I have a host class --- */
 251
 252     if (!sc->h) {
 253       sc->name[0] = 'h';
 254       sc->h = name__get(sc->name, clType_host);
 255       if (!sc->h) {
 256         sc->f &= ~f_host;
 257         goto done_host;
 258       }
 259     }
 260
 261     /* --- Now that I've done that, try to add the host --- *
 262      *
 263      * I'll turn it into an IP address.  There's less chance of confusion
 264      * that way.
 265      */
 266
 267     if ((h = gethostbyname(host)) == 0)
 268       goto done_host;
 269     memcpy(&in, h->h_addr, sizeof(in));
 270     if ((a = inet_ntoa(in)) == 0)
 271       goto done_host;
 272     sym_find(sc->h->c->t, a, -1, sizeof(sym_base), 0);
 273   done_host:;
 274   }
 275
 276   /* --- Add the user to the users class --- */
 277
 278   if (sc->f & f_user && user) {
 279     struct passwd *pw;
 280     int u;
 281
 282     /* --- First ensure that I have a user class --- */
 283
 284     if (!sc->u) {
 285       sc->name[0] = 'u';
 286       sc->u = name__get(sc->name, clType_user);
 287       if (!sc->u) {
 288         sc->f &= ~f_user;
 289         goto done_user;
 290       }
 291     }
 292
 293     /* --- Add the user to the list --- */
 294
 295     if ((pw = userdb_userByName(user)) == 0)
 296       goto done_user;
 297     u = pw->pw_uid;
 298     sym_find(sc->u->c->t, (char *)&u, sizeof(u), sizeof(sym_base), 0);
 299   done_user:;
 300   }
 301
 302   return (0);
 303 }
 304
 305 /* --- @name__netgroups@ --- *
 306  *
 307  * Arguments:   ---
 308  *
 309  * Returns:     ---
 310  *
 311  * Use:         Populates the name table with netgroup information.
 312  */
 313
 314 void name__netgroups(void)
 315 {
 316   netg *n;
 317   char buf[32];
 318   const char *p;
 319   name__scanctx sc;
 320
 321   netg_iterate();
 322   buf[1] = '_';
 323   while ((n = netg_next()) != 0) {
 324     p = netg_name(n);
 325     if (name__sanitise(p, buf + 2, sizeof(buf) - 2) == 0)
 326       continue;
 327     sc.name = buf;
 328     sc.u = sc.h = 0;
 329     sc.f = f_host | f_user;
 330     netg_scan(n, name__scan, &sc);
 331   }
 332 }
 333
 334 /* --- @name_init@ --- *
 335  *
 336  * Arguments:   ---
 337  *
 338  * Returns:     ---
 339  *
 340  * Use:         Initialises the name table.  Requires the user database to
 341  *              be populated (see @userdb_local@ and @userdb_yp@, and
 342  *              @netg_init@).
 343  */
 344
 345 void name_init(void)
 346 {
 347   /* --- Initialise the name table --- */
 348
 349   sym_createTable(&name__table);
 350
 351   /* --- Add everyone into the table --- */
 352
 353   name__users();
 354   name__groups();
 355   name__netgroups();
 356
 357   /* --- Finally add in the `all' class --- *
 358    *
 359    * Do that now, to prevent it being overwritten by the above.
 360    */
 361
 362   {
 363     name *n;
 364     unsigned f;
 365
 366     n = sym_find(&name__table, "all", -1, sizeof(name), &f);
 367     if (f)
 368       class_dec(n->c);
 369     n->c = class_all;
 370   }
 371 }
 372
 373 /* --- @name_end@ --- *
 374  *
 375  * Arguments:   ---
 376  *
 377  * Returns:     ---
 378  *
 379  * Use:         Closes down the name database, so that it can be
 380  *              reinitialised.
 381  */
 382
 383 void name_end(void)
 384 {
 385   /* --- Empty the symbol table --- */
 386
 387   {
 388     sym_iter i;
 389     name *n;
 390
 391     for (sym_createIter(&i, &name__table); (n = sym_next(&i)) != 0; ) {
 392       if (n->c)
 393         class_dec(n->c);
 394     }
 395   }
 396
 397   /* --- Destroy and recreate the table --- */
 398
 399   sym_destroyTable(&name__table);
 400 }
 401
 402 /* --- @name_find@ --- *
 403  *
 404  * Arguments:   @const char *p@ = pointer to name to look up
 405  *              @unsigned create@ = whether to create the item
 406  *              @unsigned *f@ = whether the item was created
 407  *
 408  * Returns:     Pointer to a @name@ block containing the symbol, or
 409  *              zero if it wasn't found and we didn't want to create a
 410  *              new one.
 411  *
 412  * Use:         Looks up a name in the symbol table and returns the
 413  *              item so located.
 414  */
 415
 416 name *name_find(const char *p, unsigned create, unsigned *f)
 417 {
 418   /* --- This is a trivial veneer onto @sym_find@ --- */
 419
 420   return (sym_find(&name__table, p, -1, create ? sizeof(name) : 0, f));
 421 }
 422
 423 /* --- @name_dump@ --- *
 424  *
 425  * Arguments:   ---
 426  *
 427  * Returns:     ---
 428  *
 429  * Use:         Dumps a complete listing of the symbol table.
 430  */
 431
 432 void name_dump(void)
 433 {
 434 #ifdef TRACING
 435   sym_iter i;
 436   name *n;
 437
 438   trace(TRACE_DEBUG, "name: dumping names");
 439   for (sym_createIter(&i, &name__table); (n = sym_next(&i)) != 0; ) {
 440     trace(TRACE_DEBUG, "name: dumping `%s'", n->base.name);
 441     class_dump(n->c);
 442   }
 443 #endif
 444 }
 445
 446 /*----- Test driver -------------------------------------------------------*/
 447
 448 #ifdef TEST_RIG
 449
 450 int main(void)
 451 {
 452   ego("name-test");
 453   /* traceon(stdout, TRACE_ALL); */
 454   userdb_init();
 455   userdb_local();
 456   userdb_yp();
 457   netg_init();
 458   name_init();
 459   printf("loaded (%lu)\n", track_memused());
 460   getchar();
 461   for (;;) {
 462     name_end();
 463     netg_end();
 464     userdb_end();
 465     printf("cleared (%lu)\n", track_memused());
 466     track_memlist();
 467     userdb_init();
 468     userdb_local();
 469     userdb_yp();
 470     netg_init();
 471     name_init();
 472     printf("reloaded (%lu)\n", track_memused());
 473     getchar();
 474   }
 475   return (0);
 476 }
 477
 478 #endif