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:
  15  *  Returns true iff the supplied nick* matches the supplied ban*
  16  */
  17
  18 int nickmatchban(nick *np, chanban *bp) {
  19   const char *ipstring;
  20   char fakehost[HOSTLEN+1];
  21
  22   /* nick/ident section: return 0 (no match) if they don't match */
  23
  24   if (bp->flags & CHANBAN_INVALID)
  25     return 0;
  26
  27   if (bp->flags & CHANBAN_USEREXACT &&
  28       ircd_strcmp(np->ident,bp->user->content) &&
  29       (!IsSetHost(np) || !np->shident ||
  30        ircd_strcmp(np->shident->content,bp->user->content)))
  31     return 0;
  32
  33   if (bp->flags & CHANBAN_NICKEXACT && ircd_strcmp(np->nick,bp->nick->content))
  34     return 0;
  35
  36   if (bp->flags & CHANBAN_USERMASK &&
  37       !match2strings(bp->user->content,np->ident) &&
  38       (!IsSetHost(np) || !np->shident ||
  39        !match2strings(bp->user->content, np->shident->content)))
  40     return 0;
  41
  42   if (bp->flags & CHANBAN_NICKMASK && !match2strings(bp->nick->content,np->nick))
  43      return 0;
  44
  45   /* host section.  Return 1 (match) if they do match
  46    * Note that if user or ident was specified, they've already been checked
  47    */
  48
  49   if (bp->flags & CHANBAN_HOSTANY)
  50     return 1;
  51
  52   if ((bp->flags & CHANBAN_CIDR) && (bp->flags & CHANBAN_HOSTEXACT)) {
  53     unsigned int cip;
  54     unsigned char *ch;
  55
  56     /* CIDR bans don't match IPv6 hosts */
  57     if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
  58       return 0;
  59
  60     /* Extract the client's IP address into a usable format */
  61     ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
  62     cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
  63
  64     if ((cip & bp->mask) == bp->ipaddr)
  65       return 1;
  66
  67     return 0; /* A CIDR ban won't match any other way */
  68   }
  69
  70   if (bp->flags & CHANBAN_IP) {
  71     if (bp->flags & CHANBAN_HOSTEXACT) {
  72       /* If it's an exact IP ban we can compare it numerically */
  73       unsigned int cip;
  74       unsigned char *ch;
  75
  76       /* Well, it won't match if it's not an IPv4 host */
  77       if (!irc_in_addr_is_ipv4(&(np->p_ipaddr)))
  78         return 0;
  79
  80       /* Extract the client's IP address into a usable format */
  81       ch=(unsigned char *)&(np->p_ipaddr.in6_16[6]);
  82       cip=(ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | (ch[3]);
  83
  84       if (cip==bp->ipaddr)
  85         return 1;
  86     } else {
  87       /* It's not an exact IP ban so let's generate the string */
  88       ipstring=IPtostr(np->p_ipaddr);
  89
  90       if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,ipstring))
  91         return 1;
  92     }
  93   } else {
  94     /* Hostname bans need to be checked against +x host, +h host (if set)
  95      * and actual host.  Note that the +x host is only generated (and checked) if it's
  96      * possible for the ban to match a hidden host.. */
  97
  98     if ((bp->flags & CHANBAN_HIDDENHOST) && IsAccount(np)) {
  99       sprintf(fakehost,"%s.%s",np->authname, HIS_HIDDENHOST);
 100
 101       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 102           !ircd_strcmp(fakehost, bp->host->content))
 103         return 1;
 104
 105       if ((bp->flags & CHANBAN_HOSTMASK) &&
 106           match2strings(bp->host->content, fakehost))
 107         return 1;
 108     }
 109
 110     if (IsSetHost(np)) {
 111       if ((bp->flags & CHANBAN_HOSTEXACT) &&
 112           !ircd_strcmp(np->sethost->content, bp->host->content))
 113         return 1;
 114
 115       if ((bp->flags & CHANBAN_HOSTMASK) &&
 116           match2strings(bp->host->content, np->sethost->content))
 117         return 1;
 118     }
 119
 120     if (bp->flags & CHANBAN_HOSTEXACT && !ircd_strcmp(np->host->name->content,bp->host->content))
 121       return 1;
 122
 123     if (bp->flags & CHANBAN_HOSTMASK && match2strings(bp->host->content,np->host->name->content))
 124       return 1;
 125   }
 126
 127   return 0;
 128 }
 129
 130 /*
 131  * nickbanned:
 132  *  Returns true iff the supplied nick* is banned on the supplied chan*
 133  */
 134
 135 int nickbanned(nick *np, channel *cp) {
 136   chanban *cbp;
 137
 138   for (cbp=cp->bans;cbp;cbp=cbp->next) {
 139     if (nickmatchban(np,cbp))
 140       return 1;
 141   }
 142
 143   return 0;
 144 }
 145
 146 /*
 147  * setban:
 148  *  Set the specified ban; if it completely encloses any existing bans
 149  *  then remove them.
 150  *
 151  * Returns 1 if the ban was set, or 0 if the ban was not set because an
 152  * existing ban overlapped it.
 153  */
 154
 155 int setban(channel *cp, const char *ban) {
 156   chanban **cbh,*cbp,*cbp2;
 157
 158   cbp=makeban(ban);
 159
 160   /* Don't set our ban if something encloses it */
 161   for (cbp2=cp->bans;cbp2;cbp2=cbp2->next) {
 162     if (banoverlap(cbp2, cbp)) {
 163       /* This ban overlaps the one we are adding.  Abort. */
 164       freechanban(cbp);
 165       return 0;
 166     }
 167   }
 168
 169   /* Remove enclosed bans first */
 170   for (cbh=&(cp->bans);*cbh;) {
 171     if (banoverlap(cbp,*cbh)) {
 172       cbp2=(*cbh);
 173       (*cbh)=cbp2->next;
 174       freechanban(cbp2);
 175       /* Break out of the loop if we just deleted the last ban */
 176       if ((*cbh)==NULL) {
 177         break;
 178       }
 179     } else {
 180       cbh=(chanban **)&((*cbh)->next);
 181     }
 182   }
 183
 184   /* Now set the new ban */
 185   cbp->next=(struct chanban *)cp->bans;
 186   cp->bans=cbp;
 187
 188   return 1;
 189 }
 190
 191 /*
 192  * clearban:
 193  *  Remove the specified ban iff an exact match is found
 194  *  Returns 1 if the ban was cleared, 0 if the ban didn't exist.
 195  *  If "optional" is 0 and the ban didn't exist, flags an error
 196  */
 197
 198 int clearban(channel *cp, const char *ban, int optional) {
 199   chanban **cbh,*cbp,*cbp2;
 200   int found=0;
 201   int i=0;
 202
 203   if (!cp)
 204     return 0;
 205
 206   cbp=makeban(ban);
 207
 208   for (cbh=&(cp->bans);*cbh;cbh=(chanban **)&((*cbh)->next)) {
 209     if (banequal(cbp,*cbh)) {
 210       cbp2=(*cbh);
 211       (*cbh)=cbp2->next;
 212       freechanban(cbp2);
 213       found=1;
 214       break;
 215     }
 216   }
 217
 218   if (!found && !optional) {
 219     Error("channel",ERR_DEBUG,"Couldn't remove ban %s from %s.  Dumping banlist:",ban,cp->index->name->content);
 220     for (cbp2=cp->bans;cbp2;cbp2=cbp2->next) {
 221       Error("channel",ERR_DEBUG,"%s %d %s",cp->index->name->content, i++, bantostringdebug(cbp2));
 222     }
 223   }
 224
 225   freechanban(cbp);
 226
 227   return found;
 228 }
 229
 230 /*
 231  * clearallbans:
 232  *  Just free all the bans on the channel
 233  */
 234
 235 void clearallbans(channel *cp) {
 236   chanban *cbp,*ncbp;
 237
 238   for (cbp=cp->bans;cbp;cbp=ncbp) {
 239     ncbp=(chanban *)cbp->next;
 240     freechanban(cbp);
 241   }
 242
 243   cp->bans=NULL;
 244 }