channel/channelbans.c

   1 /* channelbans.c */
   2
   3 #include <assert.h>
   4 #include <string.h>
   5 #include <stdio.h>
   6
   7 #include "channel.h"
   8 #include "../nick/nick.h"
   9 #include "../lib/irc_string.h"
  10 #include "../irc/irc_config.h"
  11 #include "../irc/irc.h"
  12
  13 /*
  14  * nickmatchban_visible:
  15  *  Returns true iff the supplied nick* matches the supplied ban*
  16  *  Doesn't check "invisible" things like true hosts and IPs for
  17  *  +x/+h users.
  18  *
  19  * copy & pasted this, touch and go whether this was a good idea.
  20  */
  21
  22 int nickmatchban_visible(nick *np, chanban *bp) {
  23   const char *ipstring;
  24   char fakehost[HOSTLEN+1];
  25   char *visibleident;
  26
  27   /* Don't waste time on invalid bans */
  28   if (bp->flags & CHANBAN_INVALID)
  29     return 0;
  30
  31   /* nick/ident section: return 0 (no match) if they don't match */
  32
  33   /* Determine the visible ident for sethost users.  Don't test the real one. */
  34   if (IsSetHost(np) && np->shident && *np->shident->content)
  35     visibleident=np->shident->content;
  36   else
  37     visibleident=np->ident;
  38
  39   if (bp->flags & CHANBAN_USEREXACT && ircd_strcmp(visibleident,bp->user->content))
  40     return 0;
  41
  42   if (bp->flags & CHANBAN_NICKEXACT && ircd_strcmp(np->nick,bp->nick->content))
  43     return 0;
  44
  45   if (bp->flags & CHANBAN_USERMASK && !match2strings(bp->user->content,visibleident))
  46     return 0;
  47
  48   if (bp->flags & CHANBAN_NICKMASK && !match2strings(bp->nick->content,np->nick))
  49     return 0;
  50
  51   /* host section.  Return 1 (match) if they do match
  52    * Note that if user or ident was specified, they've already been checked
  53    */
  54
  55   if (bp->flags & CHANBAN_HOSTANY)
  56     return 1;
  57
  58   if ((bp->flags & CHANBAN_CIDR) && (bp->flags & CHANBAN_HOSTEXACT)) {
  59     unsigned int cip;
  60     unsigned char *ch;
  61
  62     /* CIDR bans don't visibly match sethosted users */
  63     if (IsSetHost(np) || (IsAccount(np) && IsHideHost(np)))
  64       return 0;
  65
  66     /* CIDR bans don't match IPv6 hosts */
  67     if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
  68       return 0;
  69
  70     /* Extract the client's IP address into a usable format */
  71     ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
  72     cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
  73
  74     if ((cip & bp->mask) == bp->ipaddr)
  75       return 1;
  76
  77     return 0; /* A CIDR ban won't match any other way */
  78   }
  79
  80   if (bp->flags & CHANBAN_IP) {
  81     /* IP bans don't match sethosted users */
  82     if (IsSetHost(np) || (IsAccount(np) && IsHideHost(np)))
  83       return 0;
  84
  85     if (bp->flags & CHANBAN_HOSTEXACT) {
  86       /* If it's an exact IP ban we can compare it numerically */
  87       unsigned int cip;
  88       unsigned char *ch;
  89
  90       /* Well, it won't match if it's not an IPv4 host */
  91       if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
  92         return 0;
  93
  94       /* Extract the client's IP address into a usable format */
  95       ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
  96       cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
  97
  98       if (cip==bp->ipaddr)
  99         return 1;
 100     } else {
 101       /* It's not an exact IP ban so let's generate the string */
 102       ipstring=IPtostr(np->p_ipaddr);
 103
 104       if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,ipstring))
 105         return 1;
 106     }
 107   } else {
 108     /* Hostname bans need to be checked against +x host, +h host (if set)
 109      * and actual host.  Note that the +x host is only generated (and checked) if it's
 110      * possible for the ban to match a hidden host.. */
 111
 112     if ((bp->flags & CHANBAN_HIDDENHOST) && IsAccount(np)) {
 113       sprintf(fakehost,"%s.%s",np->authname, HIS_HIDDENHOST);
 114
 115       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 116           !ircd_strcmp(fakehost, bp->host->content))
 117         return 1;
 118
 119       if ((bp->flags & CHANBAN_HOSTMASK) &&
 120           match2strings(bp->host->content, fakehost))
 121         return 1;
 122     }
 123
 124     if (IsSetHost(np)) {
 125       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 126           !ircd_strcmp(np->sethost->content, bp->host->content))
 127         return 1;
 128
 129       if ((bp->flags & CHANBAN_HOSTMASK) &&
 130           match2strings(bp->host->content, np->sethost->content))
 131         return 1;
 132     }
 133
 134     /* If the user is +h or +rx don't check their real host */
 135     if (IsSetHost(np) || (IsHideHost(np) && IsAccount(np)))
 136       return 0;
 137
 138     if (bp->flags & CHANBAN_HOSTEXACT && !ircd_strcmp(np->host->name->content,bp->host->content))
 139       return 1;
 140
 141     if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,np->host->name->content))
 142       return 1;
 143   }
 144
 145   return 0;
 146 }
 147
 148 /*
 149  * nickmatchban:
 150  *  Returns true iff the supplied nick* matches the supplied ban*
 151  */
 152
 153 int nickmatchban(nick *np, chanban *bp) {
 154   const char *ipstring;
 155   char fakehost[HOSTLEN+1];
 156
 157   /* nick/ident section: return 0 (no match) if they don't match */
 158
 159   if (bp->flags & CHANBAN_INVALID)
 160     return 0;
 161
 162   if (bp->flags & CHANBAN_USEREXACT &&
 163       ircd_strcmp(np->ident,bp->user->content) &&
 164       (!IsSetHost(np) || !np->shident ||
 165        ircd_strcmp(np->shident->content,bp->user->content)))
 166     return 0;
 167
 168   if (bp->flags & CHANBAN_NICKEXACT && ircd_strcmp(np->nick,bp->nick->content))
 169     return 0;
 170
 171   if (bp->flags & CHANBAN_USERMASK &&
 172       !match2strings(bp->user->content,np->ident) &&
 173       (!IsSetHost(np) || !np->shident ||
 174        !match2strings(bp->user->content, np->shident->content)))
 175     return 0;
 176
 177   if (bp->flags & CHANBAN_NICKMASK && !match2strings(bp->nick->content,np->nick))
 178      return 0;
 179
 180   /* host section.  Return 1 (match) if they do match
 181    * Note that if user or ident was specified, they've already been checked
 182    */
 183
 184   if (bp->flags & CHANBAN_HOSTANY)
 185     return 1;
 186
 187   if ((bp->flags & CHANBAN_CIDR) && (bp->flags & CHANBAN_HOSTEXACT)) {
 188     unsigned int cip;
 189     unsigned char *ch;
 190
 191     /* CIDR bans don't match IPv6 hosts */
 192     if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
 193       return 0;
 194
 195     /* Extract the client's IP address into a usable format */
 196     ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
 197     cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
 198
 199     if ((cip & bp->mask) == bp->ipaddr)
 200       return 1;
 201
 202     return 0; /* A CIDR ban won't match any other way */
 203   }
 204
 205   if (bp->flags & CHANBAN_IP) {
 206     if (bp->flags & CHANBAN_HOSTEXACT) {
 207       /* If it's an exact IP ban we can compare it numerically */
 208       unsigned int cip;
 209       unsigned char *ch;
 210
 211       /* Well, it won't match if it's not an IPv4 host */
 212       if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
 213         return 0;
 214
 215       /* Extract the client's IP address into a usable format */
 216       ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
 217       cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
 218
 219       if (cip==bp->ipaddr)
 220         return 1;
 221     } else {
 222       /* It's not an exact IP ban so let's generate the string */
 223       ipstring=IPtostr(np->p_ipaddr);
 224
 225       if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,ipstring))
 226         return 1;
 227     }
 228   } else {
 229     /* Hostname bans need to be checked against +x host, +h host (if set)
 230      * and actual host.  Note that the +x host is only generated (and checked) if it's
 231      * possible for the ban to match a hidden host.. */
 232
 233     if ((bp->flags & CHANBAN_HIDDENHOST) && IsAccount(np)) {
 234       sprintf(fakehost,"%s.%s",np->authname, HIS_HIDDENHOST);
 235
 236       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 237           !ircd_strcmp(fakehost, bp->host->content))
 238         return 1;
 239
 240       if ((bp->flags & CHANBAN_HOSTMASK) &&
 241           match2strings(bp->host->content, fakehost))
 242         return 1;
 243     }
 244
 245     if (IsSetHost(np)) {
 246       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 247           !ircd_strcmp(np->sethost->content, bp->host->content))
 248         return 1;
 249
 250       if ((bp->flags & CHANBAN_HOSTMASK) &&
 251           match2strings(bp->host->content, np->sethost->content))
 252         return 1;
 253     }
 254
 255     if (bp->flags & CHANBAN_HOSTEXACT && !ircd_strcmp(np->host->name->content,bp->host->content))
 256       return 1;
 257
 258     if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,np->host->name->content))
 259       return 1;
 260   }
 261
 262   return 0;
 263 }
 264
 265 /*
 266  * nickbanned:
 267  *  Returns true iff the supplied nick* is banned on the supplied chan*
 268  *
 269  * Also nickbanned_visible - doesn't violate privacy by checking hidden
 270  * hosts and idents.  Factored into one function to reduce copy&paste.
 271  */
 272 static int nickbanned_real(nick *np, channel *cp, int (*cmpfunc)(nick *, chanban *)) {
 273   chanban *cbp;
 274
 275   for (cbp=cp->bans;cbp;cbp=cbp->next) {
 276     if (cmpfunc(np,cbp))
 277       return 1;
 278   }
 279
 280   return 0;
 281 }
 282
 283 int nickbanned(nick *np, channel *cp) {
 284   return nickbanned_real(np,cp,nickmatchban);
 285 }
 286
 287 int nickbanned_visible(nick *np, channel *cp) {
 288   return nickbanned_real(np,cp,nickmatchban_visible);
 289 }
 290
 291 /*
 292  * setban:
 293  *  Set the specified ban; if it completely encloses any existing bans
 294  *  then remove them.
 295  *
 296  * Returns 1 if the ban was set, or 0 if the ban was not set because an
 297  * existing ban overlapped it.
 298  */
 299
 300 int setban(channel *cp, const char *ban) {
 301   chanban **cbh,*cbp,*cbp2;
 302
 303   cbp=makeban(ban);
 304
 305   /* Don't set our ban if something encloses it */
 306   for (cbp2=cp->bans;cbp2;cbp2=cbp2->next) {
 307     if (banoverlap(cbp2, cbp)) {
 308       /* This ban overlaps the one we are adding.  Abort. */
 309       freechanban(cbp);
 310       return 0;
 311     }
 312   }
 313
 314   /* Remove enclosed bans first */
 315   for (cbh=&(cp->bans);*cbh;) {
 316     if (banoverlap(cbp,*cbh)) {
 317       cbp2=(*cbh);
 318       (*cbh)=cbp2->next;
 319       freechanban(cbp2);
 320       /* Break out of the loop if we just deleted the last ban */
 321       if ((*cbh)==NULL) {
 322         break;
 323       }
 324     } else {
 325       cbh=(chanban **)&((*cbh)->next);
 326     }
 327   }
 328
 329   /* Now set the new ban */
 330   cbp->next=(struct chanban *)cp->bans;
 331   cp->bans=cbp;
 332
 333   return 1;
 334 }
 335
 336 /*
 337  * clearban:
 338  *  Remove the specified ban iff an exact match is found
 339  *  Returns 1 if the ban was cleared, 0 if the ban didn't exist.
 340  *  If "optional" is 0 and the ban didn't exist, flags an error
 341  */
 342
 343 int clearban(channel *cp, const char *ban, int optional) {
 344   chanban **cbh,*cbp,*cbp2;
 345   int found=0;
 346   int i=0;
 347
 348   if (!cp)
 349     return 0;
 350
 351   cbp=makeban(ban);
 352
 353   for (cbh=&(cp->bans);*cbh;cbh=(chanban **)&((*cbh)->next)) {
 354     if (banequal(cbp,*cbh)) {
 355       cbp2=(*cbh);
 356       (*cbh)=cbp2->next;
 357       freechanban(cbp2);
 358       found=1;
 359       break;
 360     }
 361   }
 362
 363   if (!found && !optional) {
 364     Error("channel",ERR_DEBUG,"Couldn't remove ban %s from %s.  Dumping banlist:",ban,cp->index->name->content);
 365     for (cbp2=cp->bans;cbp2;cbp2=cbp2->next) {
 366       Error("channel",ERR_DEBUG,"%s %d %s",cp->index->name->content, i++, bantostringdebug(cbp2));
 367     }
 368   }
 369
 370   freechanban(cbp);
 371
 372   return found;
 373 }
 374
 375 /*
 376  * clearallbans:
 377  *  Just free all the bans on the channel
 378  */
 379
 380 void clearallbans(channel *cp) {
 381   chanban *cbp,*ncbp;
 382
 383   for (cbp=cp->bans;cbp;cbp=ncbp) {
 384     ncbp=(chanban *)cbp->next;
 385     freechanban(cbp);
 386   }
 387
 388   cp->bans=NULL;
 389 }