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

   1 /* -*-c-*-
   2  *
   3  * $Id: class.c,v 1.1 1997/07/21 13:47:52 mdw Exp $
   4  *
   5  * Handling classes of things nicely
   6  *
   7  * (c) 1997 EBI
   8  */
   9
  10 /*----- Licencing 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
  26  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: class.c,v $
  32  * Revision 1.1  1997/07/21 13:47:52  mdw
  33  * Initial revision
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 /* --- ANSI headers --- */
  40
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 /* --- Unix headers --- */
  46
  47 #include <sys/types.h>
  48 #include <sys/socket.h>
  49
  50 #include <netinet/in.h>
  51
  52 #include <arpa/inet.h>
  53
  54 #include <netdb.h>
  55
  56 /* --- Local headers --- */
  57
  58 #include "class.h"
  59 #include "set.h"
  60 #include "sym.h"
  61 #include "utils.h"
  62
  63 /*----- Global variables --------------------------------------------------*/
  64
  65 static classdef class__all = { clType_all, -1, 0 };
  66 classdef *class_all = &class__all;
  67
  68 /*----- Wildcard matching -------------------------------------------------*/
  69
  70 /* --- @class__wildMatch@ --- *
  71  *
  72  * Arguments:   @const char *pat@ = pointer to pattern string
  73  *              @const char *p@ = pointer to target string
  74  *
  75  * Returns:     Zero if no match, nonzero if match.
  76  *
  77  * Use:         Wildcard-matches the pattern against the target string.
  78  */
  79
  80 static int class__wildMatch(const char *pat, const char *p)
  81 {
  82   for (;;) {
  83     if (*pat == 0 && *p == 0)
  84       return (42); /* For sadism's sake */
  85     else if (*pat == '*') {
  86       while (*pat == '*')
  87         pat++;
  88       do {
  89         if (class__wildMatch(pat, p))
  90           return (27); /* Nyahaha */
  91         p++;
  92       } while (*p);
  93       return (0);
  94     } else if (*pat == '?' || *pat == *p)
  95       p++, pat++;
  96     else
  97       return (0);
  98   }
  99 }
 100
 101 /*----- Main code ---------------------------------------------------------*/
 102
 103 /* --- @class_create@ --- *
 104  *
 105  * Arguments:   @unsigned type@ = type of the class to create
 106  *              @sym_table *t@ = pointer to symbol table which stores info
 107  *
 108  * Returns:     Pointer to a @classdef@ which maintains the class's info.
 109  *
 110  * Use:         Creates a new class definition.  The new definition has one
 111  *              reference attached to it (which is the one you get returned).
 112  */
 113
 114 classdef *class_create(unsigned type, sym_table *t)
 115 {
 116   classdef *c = xmalloc(sizeof(*c));
 117   c->type = type;
 118   c->ref = 1;
 119   c->t = t;
 120   return (c);
 121 }
 122
 123 /* --- @class_inc@ --- *
 124  *
 125  * Arguments:   @classdef *c@ = pointer to a class block
 126  *
 127  * Returns:     ---
 128  *
 129  * Use:         Adds a reference to the class definition.
 130  */
 131
 132 void class_inc(classdef *c)
 133 {
 134   if (c != class_all)
 135     c->ref++;
 136 }
 137
 138 /* --- @class_dec@ --- *
 139  *
 140  * Arguments:   @classdef *c@ = pointer to a class block
 141  *
 142  * Returns:     ---
 143  *
 144  * Use:         Removes a reference to a class block.
 145  */
 146
 147 void class_dec(classdef *c)
 148 {
 149   if (c != class_all && !--c->ref) {
 150     sym_destroyTable(c->t);
 151     free(c);
 152   }
 153 }
 154
 155 /* --- @class_userMatch@ --- *
 156  *
 157  * Arguments:   @classdef *c@ = pointer to a class block
 158  *              @int u@ = uid number to check against
 159  *
 160  * Returns:     Zero if no match, nonzero if it matched.
 161  *
 162  * Use:         Looks to see if a user is in a group.
 163  */
 164
 165 int class_userMatch(classdef *c, int u)
 166 {
 167   if (~c->type & clType_user)
 168     return (0);
 169   else if (c == class_all)
 170     return (1);
 171   else
 172     return (sym_find(c->t, (char *)&u, sizeof(u), 0, 0) != 0);
 173 }
 174
 175 /* --- @class_commandMatch@ --- *
 176  *
 177  * Arguments:   @classdef *c@ = pointer to a class block
 178  *              @const char *p@ = pointer to command string to match
 179  *
 180  * Returns:     Zero for no match, nonzero if it matched.
 181  *
 182  * Use:         Tries to match a string against the wildcard patterns in the
 183  *              given class.  Note that this involves examining all the
 184  *              items, so it's not too quick.  Then again, you don't have
 185  *              big command classes, do you...?
 186  */
 187
 188 int class_commandMatch(classdef *c, const char *p)
 189 {
 190   sym_iter i;
 191   sym_base *s;
 192
 193   if (~c->type & clType_command)
 194     return (0);
 195   else if (c == class_all)
 196     return (1);
 197   else {
 198     for (sym_createIter(&i, c->t); (s = sym_next(&i)) != 0; ) {
 199       if (class__wildMatch(s->name, p))
 200         return (1);
 201     }
 202     return (0);
 203   }
 204 }
 205
 206 /* --- @class_hostMatch@ --- *
 207  *
 208  * Arguments:   @classdef *c@ = pointer to class block
 209  *              @struct in_addr addr@ = IP address to match
 210  *
 211  * Returns:     Zero for no match, nonzero if it matched.
 212  *
 213  * Use:         Tries to match an IP address against the patterns and masks
 214  *              in the given class.
 215  */
 216
 217 int class_hostMatch(classdef *c, struct in_addr addr)
 218 {
 219   sym_iter i;
 220   sym_base *s;
 221   const char *a;
 222   struct hostent *he;
 223   char **p;
 224
 225   if (~c->type & clType_host)
 226     return (0);
 227   else if (c == class_all)
 228     return (1);
 229   else {
 230
 231     /* --- Get the dotted-quad and other names for the address --- */
 232
 233     if ((a = inet_ntoa(addr)) == 0)
 234       return (0);
 235     if ((he = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET)) == 0)
 236       return (0);
 237
 238     /* --- Now search the list for a match --- *
 239      *
 240      * This is almost infinitely slow, I'm afraid.
 241      */
 242
 243     for (sym_createIter(&i, c->t); (s = sym_next(&i)) != 0; ) {
 244
 245       /* --- Check the dotted-quad name first --- */
 246
 247       if (class__wildMatch(s->name, a))
 248         return (1);
 249
 250       /* --- Now try the host's main name --- */
 251
 252       if (class__wildMatch(s->name, he->h_name))
 253         return (1);
 254
 255       /* --- Now go through all the names --- */
 256
 257       for (p = he->h_aliases; *p; p++) {
 258         if (class__wildMatch(s->name, *p))
 259           return (1);
 260       }
 261     }
 262     return (0);
 263   }
 264 }
 265
 266 /* --- @class_dump@ --- *
 267  *
 268  * Arguments:   @classdef *c@ = pointer to a class block
 269  *              @FILE *fp@ = pointer to a stream object
 270  *
 271  * Returns:     ---
 272  *
 273  * Use:         Dumps the contents of a class to a stream.
 274  */
 275
 276 void class_dump(classdef *c, FILE *fp)
 277 {
 278   sym_iter i;
 279   sym_base *s;
 280
 281   /* --- Write a little header block --- */
 282
 283   {
 284     const char *typetbl[] = {
 285       "bad class",
 286       "user",
 287       "command",
 288       "user/command",
 289       "host",
 290       "host/user",
 291       "host/command",
 292       "all",
 293     };
 294
 295     fprintf(fp,
 296             "*** Type: %s\n"
 297             "*** Refs: %u\n"
 298             "*** \n"
 299             "*** Items:\n",
 300             c->type < clType__limit ? typetbl[c->type] : "bad class",
 301             c->ref);
 302   }
 303
 304   /* --- Dump the table --- */
 305
 306   if (c->type != clType_all) {
 307     for (sym_createIter(&i, c->t); (s = sym_next(&i)) != 0; ) {
 308       switch (c->type) {
 309         case clType_user:
 310           fprintf(fp, "***   %i\n", *(int *)s->name);
 311           break;
 312         case clType_command:
 313         case clType_host:
 314           fputs("***   ", fp);
 315           fwrite(s->name, s->len, 1, fp);
 316           putc('\n', fp);
 317           break;
 318       }
 319     }
 320   }
 321
 322   putc('\n', fp);
 323 }
 324
 325 /*----- That's all, folks -------------------------------------------------*/