bans/bans.c

   1 /* channelbans.c */
   2
   3 #include <assert.h>
   4 #include <string.h>
   5 #include <stdio.h>
   6 #include "bans.h"
   7
   8 #include "../nick/nick.h"
   9 #include "../lib/irc_string.h"
  10 #include "../irc/irc_config.h"
  11 #include "../core/nsmalloc.h"
  12 #include "../lib/flags.h"
  13 #include "../lib/version.h"
  14
  15 MODULE_VERSION("")
  16
  17 #define ALLOCUNIT 100
  18
  19 chanban *freebans;
  20
  21 void _init() {
  22   freebans=NULL;
  23 }
  24
  25 void _fini() {
  26   nsfreeall(POOL_BANS);
  27 }
  28
  29 chanban *getchanban() {
  30   int i;
  31   chanban *cbp;
  32
  33   if (freebans==NULL) {
  34     freebans=(chanban *)nsmalloc(POOL_BANS, ALLOCUNIT*sizeof(chanban));
  35     for (i=0;i<ALLOCUNIT-1;i++) {
  36       freebans[i].next=(struct chanban *)&(freebans[i+1]);
  37     }
  38     freebans[ALLOCUNIT-1].next=NULL;
  39   }
  40
  41   cbp=freebans;
  42   freebans=cbp->next;
  43
  44   cbp->nick=NULL;
  45   cbp->user=NULL;
  46   cbp->host=NULL;
  47
  48   return cbp;
  49 }
  50
  51 void freechanban(chanban *cbp) {
  52   cbp->next=(struct chanban *)freebans;
  53
  54   if (cbp->nick)
  55     freesstring(cbp->nick);
  56   if (cbp->user)
  57     freesstring(cbp->user);
  58   if (cbp->host)
  59     freesstring(cbp->host);
  60
  61   freebans=cbp;
  62 }
  63
  64 /*
  65  * makeban:
  66  *  Converts the specified ban into a ban structure
  67  */
  68
  69 chanban *makeban(const char *mask) {
  70   int len;
  71   int foundat=-1,foundbang=-1;
  72   int dotcount=0;
  73   int notip=0;
  74   int foundwild=0;
  75   int foundslash=0;
  76   int i;
  77   int checklen;
  78   chanban *cbp;
  79   char tmpbuf[512];
  80
  81   cbp=getchanban();
  82   len=strlen(mask);
  83
  84   cbp->flags=0;
  85
  86   /* Let's catch a silly case first */
  87   if (!strcmp(mask,"*")) {
  88     cbp->flags=CHANBAN_HOSTANY | CHANBAN_USERANY | CHANBAN_NICKANY;
  89     cbp->nick=NULL;
  90     cbp->user=NULL;
  91     cbp->host=NULL;
  92     cbp->timeset=time(NULL);
  93     return cbp;
  94   }
  95
  96   for (i=(len-1);i>=0;i--) {
  97     if (mask[i]=='@') {
  98       /* Got @ sign: everything after here is host */
  99       if ((len-i)-1 > HOSTLEN) {
 100         /* This is too long, we need to truncate it */
 101         strncpy(tmpbuf,&mask[len-HOSTLEN],HOSTLEN);
 102         tmpbuf[HOSTLEN]='\0';
 103         tmpbuf[0]='*';
 104         cbp->host=getsstring(tmpbuf,HOSTLEN);
 105         cbp->flags |= CHANBAN_HOSTMASK;
 106       } else if (i==(len-1)) {
 107         /* Ban ending with @, just mark it invalid */
 108         /* Note that "moo@*" overrides "moo@", so mark it as having a host too */
 109         cbp->flags |= (CHANBAN_INVALID | CHANBAN_HOSTNULL);
 110         cbp->host=NULL;
 111       } else if (i==(len-2) && mask[i+1]=='*') {
 112         /* Special case: "@*" */
 113         cbp->flags |= CHANBAN_HOSTANY;
 114         cbp->host=NULL;
 115       } else if (foundslash) {
 116         /* If we found a slash (/), this can only be a CIDR ban */
 117         /* However, it might be broken, so we need to retain the exact string
 118          * to track it accurately */
 119         cbp->host=getsstring(&mask[i+1],HOSTLEN);
 120         if ((notip || dotcount!=3) && !foundwild) {
 121           cbp->flags |= (CHANBAN_INVALID | CHANBAN_HOSTEXACT);
 122         } else if (foundwild) {
 123           cbp->flags |= (CHANBAN_INVALID | CHANBAN_HOSTMASK);
 124         } else {
 125           unsigned int a,b,c,d,l;
 126           /* CIDR bans have to match this pattern.  */
 127           if ((sscanf(&mask[i+1], "%u.%u.%u.%u/%u",&a,&b,&c,&d,&l) != 5) ||
 128                (a>255) || (b>255) || (c>255) || (d>255) || (l>32) ) {
 129             cbp->flags |= (CHANBAN_HOSTEXACT | CHANBAN_INVALID);
 130           } else {
 131             /* Save the IP address and mask for later */
 132             cbp->ipaddr=(a<<24)|(b<<16)|(c<<8)|d;
 133             cbp->mask=0xffffffff;
 134             if (l==0) {
 135               cbp->mask=0;
 136             } else if (l<32) {
 137               cbp->mask<<=(32-l);
 138             }
 139             /* pre-AND the IP with the mask here. */
 140             cbp->ipaddr &= cbp->mask;
 141             cbp->flags |= (CHANBAN_HOSTEXACT | CHANBAN_CIDR);
 142           }
 143         }
 144       } else {
 145         /* We have some string with between 1 and HOSTLEN characters.. */
 146         cbp->host=getsstring(&mask[i+1],HOSTLEN);
 147         if (foundwild) {
 148           /* We check all characters after the last wildcard (if any).. if they match
 149            * the corresponding bits of the hidden host string we mark it accordingly */
 150           if (!(checklen=len-foundwild-1)) { /* Ban ends in *, mark it anyway.. */
 151             cbp->flags |= CHANBAN_HIDDENHOST;
 152           } else {
 153             if (checklen>=strlen(HIS_HIDDENHOST)) {
 154               if (!ircd_strcmp(cbp->host->content+(cbp->host->length-strlen(HIS_HIDDENHOST)), HIS_HIDDENHOST))
 155                 cbp->flags |= CHANBAN_HIDDENHOST;
 156             } else {
 157               if (!ircd_strcmp(cbp->host->content+(cbp->host->length-checklen),
 158                                (HIS_HIDDENHOST)+strlen(HIS_HIDDENHOST)-checklen))
 159                 cbp->flags |= CHANBAN_HIDDENHOST;
 160             }
 161           }
 162           cbp->flags |= CHANBAN_HOSTMASK;
 163           if (!notip && dotcount<=3)
 164             cbp->flags |= CHANBAN_IP;
 165         } else {
 166           /* Exact host: see if it ends with the "hidden host" string */
 167           cbp->flags |= CHANBAN_HOSTEXACT;
 168           if ((cbp->host->length > (strlen(HIS_HIDDENHOST)+1)) &&
 169               !ircd_strcmp(cbp->host->content+(cbp->host->length-strlen(HIS_HIDDENHOST)), HIS_HIDDENHOST)) {
 170             cbp->flags |= CHANBAN_HIDDENHOST;
 171           } else if (!notip && dotcount==3) {
 172             unsigned int a,b,c,d;
 173             if ((sscanf(&mask[i+1], "%u.%u.%u.%u",&a,&b,&c,&d) != 4) ||
 174                   (a > 255) || (b > 255) || (c > 255) || (d > 255) ) {
 175               /* Something with only numbers and exactly 3 dots that isn't an IP address can't match anything. */
 176               cbp->flags |= CHANBAN_INVALID;
 177             } else {
 178               cbp->ipaddr=(a<<24)|(b<<16)|(c<<8)|d;
 179               cbp->flags |= CHANBAN_IP;
 180             }
 181           }
 182         }
 183       }
 184       foundat=i;
 185       break;
 186     } else if (mask[i]=='/') {
 187       foundslash=1;
 188     } else if (mask[i]=='.') {
 189       dotcount++;
 190     } else if (mask[i]=='?' || mask[i]=='*') {
 191       if (!foundwild)  /* Mark last wildcard in string */
 192         foundwild=i;
 193     } else if (mask[i]<'0' || mask[i]>'9') {
 194       notip=1;
 195     }
 196   }
 197
 198   if (foundat<0) {
 199     /* If there wasn't an @, this ban matches any host */
 200     cbp->host=NULL;
 201     cbp->flags |= CHANBAN_HOSTANY;
 202   }
 203
 204   foundwild=0;
 205
 206   for (i=0;i<foundat;i++) {
 207     if (mask[i]=='!') {
 208       if (i==0) {
 209         /* Invalid mask: nick is empty */
 210         cbp->flags |= CHANBAN_NICKNULL;
 211         cbp->nick=NULL;
 212       } else if (i==1 && mask[0]=='*') {
 213         /* matches any nick */
 214         cbp->flags |= CHANBAN_NICKANY;
 215         cbp->nick=NULL;
 216       } else {
 217         if (i>NICKLEN) {
 218           /* too long: just take the first NICKLEN chars */
 219           cbp->nick=getsstring(mask,NICKLEN);
 220         } else {
 221           cbp->nick=getsstring(mask,i);
 222         }
 223         if (foundwild)
 224           cbp->flags |= CHANBAN_NICKMASK;
 225         else
 226           cbp->flags |= CHANBAN_NICKEXACT;
 227       }
 228       foundbang=i;
 229       break;
 230     } else if (mask[i]=='?' || mask[i]=='*') {
 231       if (i<NICKLEN) {
 232         foundwild=1;
 233       }
 234     }
 235   }
 236
 237   if (foundbang<0) {
 238     /* We didn't find a !, what we do now depends on what happened
 239      * with the @ */
 240     if (foundat<0) {
 241       /* A ban with no ! or @ is treated as a nick ban only */
 242       /* Note that we've special-cased "*" at the top, so we can only
 243        * hit the MASK or EXACT case here. */
 244       if (len>NICKLEN)
 245         cbp->nick=getsstring(mask,NICKLEN);
 246       else
 247         cbp->nick=getsstring(mask,len);
 248
 249       if (foundwild)
 250         cbp->flags |= CHANBAN_NICKMASK;
 251       else
 252         cbp->flags |= CHANBAN_NICKEXACT;
 253
 254       cbp->flags |= (CHANBAN_USERANY | CHANBAN_HOSTANY);
 255       cbp->host=NULL;
 256       cbp->user=NULL;
 257     } else {
 258       /* A ban with @ only is treated as user@host */
 259       cbp->nick=NULL;
 260       cbp->flags |= CHANBAN_NICKANY;
 261     }
 262   }
 263
 264   if (foundat>=0) {
 265     /* We found an @, so everything between foundbang+1 and foundat-1 is supposed to be ident */
 266     /* This is true even if there was no !.. */
 267     if (foundat==(foundbang+1)) {
 268       /* empty ident matches nothing */
 269       cbp->flags |= (CHANBAN_INVALID | CHANBAN_USERNULL);
 270       cbp->user=NULL;
 271     } else if (foundat - foundbang - 1 > USERLEN) {
 272       /* It's too long.. */
 273       strncpy(tmpbuf,&mask[foundat-USERLEN],USERLEN);
 274       tmpbuf[USERLEN]='\0';
 275       tmpbuf[0]='*';
 276       cbp->user=getsstring(tmpbuf,USERLEN);
 277       cbp->flags |= CHANBAN_USERMASK;
 278     } else if ((foundat - foundbang - 1 == 1) && mask[foundbang+1]=='*') {
 279       cbp->user=NULL;
 280       cbp->flags |= CHANBAN_USERANY;
 281     } else {
 282       cbp->user=getsstring(&mask[foundbang+1],(foundat-foundbang-1));
 283       if (strchr(cbp->user->content,'*') || strchr(cbp->user->content,'?'))
 284         cbp->flags |= CHANBAN_USERMASK;
 285       else
 286         cbp->flags |= CHANBAN_USEREXACT;
 287     }
 288     /* Username part can't contain an @ */
 289     if (cbp->user && strchr(cbp->user->content,'@')) {
 290       cbp->flags |= CHANBAN_INVALID;
 291     }
 292   }
 293
 294   assert(cbp->flags & (CHANBAN_USEREXACT | CHANBAN_USERMASK | CHANBAN_USERANY | CHANBAN_USERNULL));
 295   assert(cbp->flags & (CHANBAN_NICKEXACT | CHANBAN_NICKMASK | CHANBAN_NICKANY | CHANBAN_NICKNULL));
 296   assert(cbp->flags & (CHANBAN_HOSTEXACT | CHANBAN_HOSTMASK | CHANBAN_HOSTANY | CHANBAN_HOSTNULL));
 297
 298   cbp->timeset=time(NULL);
 299
 300   cbp->next=NULL;
 301
 302   return cbp;
 303 }
 304
 305 /* banoverlap:
 306  *  Returns nonzero iff bana is a SUPERSET of banb
 307  */
 308
 309 int banoverlap(const chanban *bana, const chanban *banb) {
 310   /* This function works by looking for cases where bana DOESN'T overlap banb */
 311
 312   /* NICK section */
 313   /* If bana has CHANBAN_NICKANY then it clearly overlaps
 314    * in the nick section so there are no checks */
 315
 316   if ((bana->flags & CHANBAN_NICKNULL) && !(banb->flags & CHANBAN_NICKNULL)) {
 317     return 0;
 318   }
 319
 320   if (bana->flags & CHANBAN_NICKMASK) {
 321     if (banb->flags & (CHANBAN_NICKANY | CHANBAN_NICKNULL)) {
 322       return 0;
 323     }
 324     if ((banb->flags & CHANBAN_NICKMASK) && !match2patterns(bana->nick->content, banb->nick->content)) {
 325       return 0;
 326     }
 327     if ((banb->flags & CHANBAN_NICKEXACT) && !match2strings(bana->nick->content, banb->nick->content)) {
 328       return 0;
 329     }
 330   }
 331
 332   if (bana->flags & CHANBAN_NICKEXACT) {
 333     if (banb->flags & (CHANBAN_NICKANY | CHANBAN_NICKMASK | CHANBAN_NICKNULL)) {
 334       return 0;
 335     }
 336     if ((!bana->nick && banb->nick) || (bana->nick && !banb->nick)) {
 337       return 0;
 338     }
 339     if (bana->nick && ircd_strcmp(bana->nick->content,banb->nick->content)) {
 340       return 0;
 341     }
 342   }
 343
 344   /* USER section */
 345   /* If bana has CHANBAN_USERANY then it clearly overlaps
 346    * in the user section so there are no checks */
 347
 348   if ((bana->flags & CHANBAN_USERNULL) && !(banb->flags & CHANBAN_USERNULL)) {
 349     return 0;
 350   }
 351
 352   if (bana->flags & CHANBAN_USERMASK) {
 353     if (banb->flags & (CHANBAN_USERANY | CHANBAN_USERNULL)) {
 354       return 0;
 355     }
 356     if ((banb->flags & CHANBAN_USERMASK) && !match2patterns(bana->user->content, banb->user->content)) {
 357       return 0;
 358     }
 359     if ((banb->flags & CHANBAN_USEREXACT) && !match2strings(bana->user->content, banb->user->content)) {
 360       return 0;
 361     }
 362   }
 363
 364   if (bana->flags & CHANBAN_USEREXACT) {
 365     if (banb->flags & (CHANBAN_USERANY | CHANBAN_USERMASK | CHANBAN_USERNULL)) {
 366       return 0;
 367     }
 368     if ((!bana->user && banb->user) || (bana->user && !banb->user)) {
 369       return 0;
 370     }
 371     if (bana->user && ircd_strcmp(bana->user->content,banb->user->content)) {
 372       return 0;
 373     }
 374   }
 375
 376   /* HOST section */
 377   /* If bana has CHANBAN_HOSTANY then it clearly overlaps
 378    * in the host section so there are no checks */
 379
 380   if ((bana->flags & CHANBAN_HOSTNULL) && !(banb->flags & CHANBAN_HOSTNULL)) {
 381     return 0;
 382   }
 383
 384   if (bana->flags & CHANBAN_HOSTMASK) {
 385     if (banb->flags & (CHANBAN_HOSTANY | CHANBAN_HOSTNULL)) {
 386       return 0;
 387     }
 388     if ((banb->flags & CHANBAN_HOSTMASK) && !match2patterns(bana->host->content, banb->host->content)) {
 389       return 0;
 390     }
 391     if ((banb->flags & CHANBAN_HOSTEXACT) && !match2strings(bana->host->content, banb->host->content)) {
 392       return 0;
 393     }
 394   }
 395
 396   if (bana->flags & CHANBAN_HOSTEXACT) {
 397     if (banb->flags & (CHANBAN_HOSTANY | CHANBAN_HOSTMASK | CHANBAN_HOSTNULL)) {
 398       return 0;
 399     }
 400     if ((!bana->host && banb->host) || (bana->host && !banb->host)) {
 401       return 0;
 402     }
 403     if (bana->host && ircd_strcmp(bana->host->content,banb->host->content)) {
 404       return 0;
 405     }
 406   }
 407
 408   return 1;
 409 }
 410
 411 /*
 412  * banequal:
 413  *  Returns nonzero iff the bans are EXACTLY the same
 414  */
 415
 416 int banequal(chanban *bana, chanban *banb) {
 417   if (bana->flags != banb->flags)
 418     return 0;
 419
 420   if ((!bana->nick && banb->nick) || (bana->nick && !banb->nick))
 421     return 0;
 422
 423   if (bana->nick && ircd_strcmp(bana->nick->content,banb->nick->content))
 424     return 0;
 425
 426   if ((!bana->user && banb->user) || (bana->user && !banb->user))
 427     return 0;
 428
 429   if (bana->user && ircd_strcmp(bana->user->content,banb->user->content))
 430     return 0;
 431
 432   if ((!bana->host && banb->host) || (bana->host && !banb->host))
 433     return 0;
 434
 435   if (bana->host && ircd_strcmp(bana->host->content,banb->host->content))
 436     return 0;
 437
 438   return 1;
 439 }
 440
 441 /*
 442  * bantostring:
 443  *  Convert the specified ban to a string
 444  */
 445
 446 char *bantostring(chanban *bp) {
 447   static char outstring[NICKLEN+USERLEN+HOSTLEN+5];
 448   int strpos=0;
 449
 450   if (bp->flags & CHANBAN_NICKANY) {
 451     strpos += sprintf(outstring+strpos,"*");
 452   } else if (bp->nick) {
 453     strpos += sprintf(outstring+strpos,"%s",bp->nick->content);
 454   }
 455
 456   strpos += sprintf(outstring+strpos,"!");
 457
 458   if (bp->flags & CHANBAN_USERANY) {
 459     strpos += sprintf(outstring+strpos,"*");
 460   } else if (bp->user) {
 461     strpos += sprintf(outstring+strpos,"%s",bp->user->content);
 462   }
 463
 464   strpos += sprintf(outstring+strpos,"@");
 465
 466   if (bp->flags & CHANBAN_HOSTANY) {
 467     strpos += sprintf(outstring+strpos,"*");
 468   } else if (bp->host) {
 469     strpos += sprintf(outstring+strpos,"%s",bp->host->content);
 470   }
 471
 472   return outstring;
 473 }
 474
 475 /*
 476  * bantostringdebug:
 477  *  Convert the specified ban to a string (debugging version)
 478  */
 479
 480 char *bantostringdebug(chanban *bp) {
 481   static char outstring[NICKLEN+USERLEN+HOSTLEN+5];
 482   int strpos=0;
 483
 484   strpos += sprintf(outstring+strpos, "flags=%04x ",bp->flags);
 485
 486   if (bp->nick) {
 487     strpos += sprintf(outstring+strpos, "nick=%s ",bp->nick->content);
 488   } else {
 489     strpos += sprintf(outstring+strpos, "nonick ");
 490   }
 491
 492   if (bp->user) {
 493     strpos += sprintf(outstring+strpos, "user=%s ",bp->user->content);
 494   } else {
 495     strpos += sprintf(outstring+strpos, "nouser ");
 496   }
 497
 498   if (bp->host) {
 499     strpos += sprintf(outstring+strpos, "host=%s ",bp->host->content);
 500   } else {
 501     strpos += sprintf(outstring+strpos, "nohost ");
 502   }
 503
 504
 505   return outstring;
 506 }
 507