diplodocus.org Git - nmh/blob - uip/aliasbr.c

   1
   2 /*
   3  * aliasbr.c -- new aliasing mechanism
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11 #include <h/aliasbr.h>
  12 #include <h/utils.h>
  13 #include <grp.h>
  14 #include <pwd.h>
  15
  16 static int akvis;
  17 static char *akerrst;
  18
  19 struct aka *akahead = NULL;
  20 struct aka *akatail = NULL;
  21
  22 struct home *homehead = NULL;
  23 struct home *hometail = NULL;
  24
  25 /*
  26  * prototypes
  27  */
  28 int alias (char *);
  29 int akvisible (void);
  30 void init_pw (void);
  31 char *akresult (struct aka *);
  32 char *akvalue (char *);
  33 char *akerror (int);
  34
  35 static  char *akval (struct aka *, char *);
  36 static int aleq (char *, char *);
  37 static char *scanp (unsigned char *);
  38 static char *getp (char *);
  39 static char *seekp (char *, char *, char **);
  40 static int addfile (struct aka *, char *);
  41 static int addgroup (struct aka *, char *);
  42 static int addmember (struct aka *, char *);
  43 static int addall (struct aka *);
  44 static char *getalias (char *);
  45 static void add_aka (struct aka *, char *);
  46 static struct aka *akalloc (char *);
  47 static struct home *hmalloc (struct passwd *);
  48 struct home *seek_home (char *);
  49
  50
  51 /* Do mh alias substitution on 's' and return the results. */
  52 char *
  53 akvalue (char *s)
  54 {
  55     register char *v;
  56
  57     if (akahead == NULL)
  58         alias (AliasFile);
  59
  60     akvis = -1;
  61     v = akval (akahead, s);
  62     if (akvis == -1)
  63         akvis = 0;
  64     return v;
  65 }
  66
  67
  68 int
  69 akvisible (void)
  70 {
  71     return akvis;
  72 }
  73
  74
  75 char *
  76 akresult (struct aka *ak)
  77 {
  78     register char *cp = NULL, *dp, *pp;
  79     register struct adr *ad;
  80
  81     for (ad = ak->ak_addr; ad; ad = ad->ad_next) {
  82         pp = ad->ad_local ? akval (ak->ak_next, ad->ad_text)
  83             : getcpy (ad->ad_text);
  84
  85         if (cp) {
  86             dp = cp;
  87             cp = concat (cp, ",", pp, NULL);
  88             free (dp);
  89             free (pp);
  90         }
  91         else
  92             cp = pp;
  93     }
  94
  95     if (akvis == -1)
  96         akvis = ak->ak_visible;
  97     return cp;
  98 }
  99
 100
 101 static  char *
 102 akval (struct aka *ak, char *s)
 103 {
 104     if (!s)
 105         return s;                       /* XXX */
 106
 107     for (; ak; ak = ak->ak_next)
 108         if (aleq (s, ak->ak_name))
 109             return akresult (ak);
 110
 111     return getcpy (s);
 112 }
 113
 114
 115 static int
 116 aleq (char *string, char *aliasent)
 117 {
 118     register char c;
 119
 120     while ((c = *string++))
 121         if (*aliasent == '*')
 122             return 1;
 123         else
 124             if ((c | 040) != (*aliasent | 040))
 125                 return 0;
 126             else
 127                 aliasent++;
 128
 129     return (*aliasent == 0 || *aliasent == '*');
 130 }
 131
 132
 133 int
 134 alias (char *file)
 135 {
 136     int i;
 137     register char *bp, *cp, *pp;
 138     char lc, *ap;
 139     register struct aka *ak = NULL;
 140     register FILE *fp;
 141
 142     if (*file != '/'
 143             && (strncmp (file, "./", 2) && strncmp (file, "../", 3)))
 144         file = etcpath (file);
 145     if ((fp = fopen (file, "r")) == NULL) {
 146         akerrst = file;
 147         return AK_NOFILE;
 148     }
 149
 150     while (vfgets (fp, &ap) == OK) {
 151         bp = ap;
 152         switch (*(pp = scanp (bp))) {
 153             case '<':           /* recurse a level */
 154                 if (!*(cp = getp (pp + 1))) {
 155                     akerrst = "'<' without alias-file";
 156                     fclose (fp);
 157                     return AK_ERROR;
 158                 }
 159                 if ((i = alias (cp)) != AK_OK) {
 160                     fclose (fp);
 161                     return i;
 162                 }
 163
 164             case ':':           /* comment */
 165             case ';':
 166             case '#':
 167             case 0:
 168                 continue;
 169         }
 170
 171         akerrst = bp;
 172         if (!*(cp = seekp (pp, &lc, &ap))) {
 173             fclose (fp);
 174             return AK_ERROR;
 175         }
 176         if (!(ak = akalloc (cp))) {
 177             fclose (fp);
 178             return AK_LIMIT;
 179         }
 180         switch (lc) {
 181             case ':':
 182                 ak->ak_visible = 0;
 183                 break;
 184
 185             case ';':
 186                 ak->ak_visible = 1;
 187                 break;
 188
 189             default:
 190                 fclose (fp);
 191                 return AK_ERROR;
 192         }
 193
 194         switch (*(pp = scanp (ap))) {
 195             case 0:             /* EOL */
 196                 fclose (fp);
 197                 return AK_ERROR;
 198
 199             case '<':           /* read values from file */
 200                 if (!*(cp = getp (pp + 1))) {
 201                     fclose (fp);
 202                     return AK_ERROR;
 203                 }
 204                 if (!addfile (ak, cp)) {
 205                     fclose (fp);
 206                     return AK_NOFILE;
 207                 }
 208                 break;
 209
 210             case '=':           /* UNIX group */
 211                 if (!*(cp = getp (pp + 1))) {
 212                     fclose (fp);
 213                     return AK_ERROR;
 214                 }
 215                 if (!addgroup (ak, cp)) {
 216                     fclose (fp);
 217                     return AK_NOGROUP;
 218                 }
 219                 break;
 220
 221             case '+':           /* UNIX group members */
 222                 if (!*(cp = getp (pp + 1))) {
 223                     fclose (fp);
 224                     return AK_ERROR;
 225                 }
 226                 if (!addmember (ak, cp)) {
 227                     fclose (fp);
 228                     return AK_NOGROUP;
 229                 }
 230                 break;
 231
 232             case '*':           /* Everyone */
 233                 addall (ak);
 234                 break;
 235
 236             default:            /* list */
 237                 while ((cp = getalias (pp)))
 238                     add_aka (ak, cp);
 239                 break;
 240         }
 241     }
 242
 243     fclose (fp);
 244     return AK_OK;
 245 }
 246
 247
 248 char *
 249 akerror (int i)
 250 {
 251     static char buffer[BUFSIZ];
 252
 253     switch (i) {
 254         case AK_NOFILE:
 255             snprintf (buffer, sizeof(buffer), "unable to read '%s'", akerrst);
 256             break;
 257
 258         case AK_ERROR:
 259             snprintf (buffer, sizeof(buffer), "error in line '%s'", akerrst);
 260             break;
 261
 262         case AK_LIMIT:
 263             snprintf (buffer, sizeof(buffer), "out of memory while on '%s'", akerrst);
 264             break;
 265
 266         case AK_NOGROUP:
 267             snprintf (buffer, sizeof(buffer), "no such group as '%s'", akerrst);
 268             break;
 269
 270         default:
 271             snprintf (buffer, sizeof(buffer), "unknown error (%d)", i);
 272             break;
 273     }
 274
 275     return buffer;
 276 }
 277
 278
 279 static char *
 280 scanp (unsigned char *p)
 281 {
 282     while (isspace (*p))
 283         p++;
 284     return p;
 285 }
 286
 287
 288 static char *
 289 getp (char *p)
 290 {
 291     register unsigned char  *cp = scanp (p);
 292
 293     p = cp;
 294     while (!isspace (*cp) && *cp)
 295         cp++;
 296     *cp = 0;
 297
 298     return p;
 299 }
 300
 301
 302 static char *
 303 seekp (char *p, char *c, char **a)
 304 {
 305     register unsigned char *cp;
 306
 307     p = cp = scanp (p);
 308     while (!isspace (*cp) && *cp && *cp != ':' && *cp != ';')
 309         cp++;
 310     *c = *cp;
 311     *cp++ = 0;
 312     *a = cp;
 313
 314     return p;
 315 }
 316
 317
 318 static int
 319 addfile (struct aka *ak, char *file)
 320 {
 321     register char *cp;
 322     char buffer[BUFSIZ];
 323     register FILE *fp;
 324
 325     if (!(fp = fopen (etcpath (file), "r"))) {
 326         akerrst = file;
 327         return 0;
 328     }
 329
 330     while (fgets (buffer, sizeof buffer, fp))
 331         while ((cp = getalias (buffer)))
 332             add_aka (ak, cp);
 333
 334     fclose (fp);
 335     return 1;
 336 }
 337
 338
 339 static int
 340 addgroup (struct aka *ak, char *grp)
 341 {
 342     register char *gp;
 343     register struct group *gr = getgrnam (grp);
 344     register struct home *hm = NULL;
 345
 346     if (!gr)
 347         gr = getgrgid (atoi (grp));
 348     if (!gr) {
 349         akerrst = grp;
 350         return 0;
 351     }
 352
 353     while ((gp = *gr->gr_mem++))
 354     {
 355         struct passwd *pw;
 356         for (hm = homehead; hm; hm = hm->h_next)
 357             if (!strcmp (hm->h_name, gp)) {
 358                 add_aka (ak, hm->h_name);
 359                 break;
 360             }
 361         if ((pw = getpwnam(gp)))
 362         {
 363                 hmalloc(pw);
 364                 add_aka (ak, gp);
 365         }
 366     }
 367
 368     return 1;
 369 }
 370
 371
 372 static int
 373 addmember (struct aka *ak, char *grp)
 374 {
 375     gid_t gid;
 376     register struct group *gr = getgrnam (grp);
 377     register struct home *hm = NULL;
 378
 379     if (gr)
 380         gid = gr->gr_gid;
 381     else {
 382         gid = atoi (grp);
 383         gr = getgrgid (gid);
 384     }
 385     if (!gr) {
 386         akerrst = grp;
 387         return 0;
 388     }
 389
 390     init_pw ();
 391
 392     for (hm = homehead; hm; hm = hm->h_next)
 393         if (hm->h_gid == gid)
 394             add_aka (ak, hm->h_name);
 395
 396     return 1;
 397 }
 398
 399
 400 static int
 401 addall (struct aka *ak)
 402 {
 403     int noshell = NoShell == NULL || *NoShell == 0;
 404     register struct home *hm;
 405
 406     init_pw ();
 407
 408     if (Everyone < 0)
 409         Everyone = EVERYONE;
 410
 411     for (hm = homehead; hm; hm = hm->h_next)
 412         if ((int) hm->h_uid > Everyone
 413                 && (noshell || strcmp (hm->h_shell, NoShell)))
 414             add_aka (ak, hm->h_name);
 415
 416     return homehead != NULL;
 417 }
 418
 419
 420 static char *
 421 getalias (char *addrs)
 422 {
 423     register unsigned char *pp, *qp;
 424     static char *cp = NULL;
 425
 426     if (cp == NULL)
 427         cp = addrs;
 428     else
 429         if (*cp == 0)
 430             return (cp = NULL);
 431
 432     for (pp = cp; isspace (*pp); pp++)
 433         continue;
 434     if (*pp == 0)
 435         return (cp = NULL);
 436     for (qp = pp; *qp != 0 && *qp != ','; qp++)
 437         continue;
 438     if (*qp == ',')
 439         *qp++ = 0;
 440     for (cp = qp, qp--; qp > pp; qp--)
 441         if (*qp != 0) {
 442             if (isspace (*qp))
 443                 *qp = 0;
 444             else
 445                 break;
 446         }
 447
 448     return pp;
 449 }
 450
 451
 452 static void
 453 add_aka (struct aka *ak, char *pp)
 454 {
 455     register struct adr *ad, *ld;
 456
 457     for (ad = ak->ak_addr, ld = NULL; ad; ld = ad, ad = ad->ad_next)
 458         if (!strcmp (pp, ad->ad_text))
 459             return;
 460
 461     ad = (struct adr *) mh_xmalloc (sizeof(*ad));
 462     ad->ad_text = getcpy (pp);
 463     ad->ad_local = strchr(pp, '@') == NULL && strchr(pp, '!') == NULL;
 464     ad->ad_next = NULL;
 465     if (ak->ak_addr)
 466         ld->ad_next = ad;
 467     else
 468         ak->ak_addr = ad;
 469 }
 470
 471
 472 void
 473 init_pw (void)
 474 {
 475     register struct passwd  *pw;
 476     static int init;
 477
 478     if (!init)
 479     {
 480         /* if the list has yet to be initialized */
 481         /* zap the list, and rebuild from scratch */
 482         homehead=NULL;
 483         hometail=NULL;
 484         init++;
 485
 486         setpwent ();
 487
 488         while ((pw = getpwent ()))
 489             if (!hmalloc (pw))
 490                 break;
 491
 492         endpwent ();
 493     }
 494 }
 495
 496
 497 static struct aka *
 498 akalloc (char *id)
 499 {
 500     register struct aka *p;
 501
 502     p = (struct aka *) mh_xmalloc (sizeof(*p));
 503
 504     p->ak_name = getcpy (id);
 505     p->ak_visible = 0;
 506     p->ak_addr = NULL;
 507     p->ak_next = NULL;
 508     if (akatail != NULL)
 509         akatail->ak_next = p;
 510     if (akahead == NULL)
 511         akahead = p;
 512     akatail = p;
 513
 514     return p;
 515 }
 516
 517
 518 static struct home *
 519 hmalloc (struct passwd *pw)
 520 {
 521     register struct home *p;
 522
 523     p = (struct home *) mh_xmalloc (sizeof(*p));
 524
 525     p->h_name = getcpy (pw->pw_name);
 526     p->h_uid = pw->pw_uid;
 527     p->h_gid = pw->pw_gid;
 528     p->h_home = getcpy (pw->pw_dir);
 529     p->h_shell = getcpy (pw->pw_shell);
 530     p->h_ngrps = 0;
 531     p->h_next = NULL;
 532     if (hometail != NULL)
 533         hometail->h_next = p;
 534     if (homehead == NULL)
 535         homehead = p;
 536     hometail = p;
 537
 538     return p;
 539 }
 540
 541
 542 struct home *
 543 seek_home (char *name)
 544 {
 545     register struct home *hp;
 546     struct passwd *pw;
 547     char lname[32];
 548     unsigned char *c;
 549     char *c1;
 550
 551     for (hp = homehead; hp; hp = hp->h_next)
 552         if (!mh_strcasecmp (name, hp->h_name))
 553             return hp;
 554
 555     /*
 556      * The only place where there might be problems.
 557      * This assumes that ALL usernames are kept in lowercase.
 558      */
 559     for (c = name, c1 = lname;
 560          *c && (c1 - lname < (int) sizeof(lname) - 1);
 561          c++, c1++) {
 562         if (isalpha(*c) && isupper(*c))
 563             *c1 = tolower (*c);
 564         else
 565             *c1 = *c;
 566     }
 567     *c1 = '\0';
 568     if ((pw = getpwnam(lname)))
 569         return(hmalloc(pw));
 570
 571     return NULL;
 572 }