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