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