banevade/banevade.c

   1 #include <stdio.h>
   2 #include "../irc/irc.h"
   3 #include "../lib/version.h"
   4 #include "../lib/irc_string.h"
   5 #include "../channel/channel.h"
   6 #include "../bans/bans.h"
   7 #include "../control/control.h"
   8 #include "../localuser/localuser.h"
   9 #include "../localuser/localuserchannel.h"
  10
  11 #define BANEVADE_SPAM
  12
  13 MODULE_VERSION("")
  14
  15 int ircdbanned(nick *n, channel *c);
  16
  17 static chanban *nickbanned2(nick *np, channel *cp, int visibleonly) {
  18         chanban *cbp;
  19
  20         for (cbp=cp->bans;cbp;cbp=cbp->next) {
  21                 if (nickmatchban(np,cbp,visibleonly))
  22                         return cbp;
  23         }
  24
  25         return NULL;
  26 }
  27
  28 void be_onjoin(int hooknum, void *arg) {
  29         void **arglist = (void **)arg;
  30         channel *c = ((channel *)arglist[0]);
  31         nick *np = arglist[1];
  32
  33         /* Verify both are valid */
  34         if(!c || !np)
  35                 return;
  36
  37         /* Services, opers and extended opers can bypass bans */
  38         if (IsService(np) || IsOper(np) || IsXOper(np) || NickOnServiceServer(np))
  39                 return;
  40
  41         int ircd_banned = ircdbanned(np, c);
  42         chanban *ns_banned = nickbanned2(np, c, 0);
  43
  44 #ifdef BANEVADE_SPAM
  45         Error("banevade", ERR_INFO, "Ban status ircd_banned=%d newserv_banned=%s", ircd_banned, (ns_banned ? "here" : "(null)"));
  46 #endif
  47
  48         /* If we're not considered banned as per the ircd code,
  49          but banned according to newserv - trigger the hook */
  50         if(!ircd_banned && ns_banned) {
  51                 /* We kinda dont need this hook anymore - but we'll trigger it anyway for future scripts/modules */
  52                 triggerhook(HOOK_CHANNEL_JOIN_BYPASS_BAN, arg);
  53
  54                 channel *cp = findchannel("#qnet.banevade");
  55                 if(cp)
  56                         controlchanmsg(cp, "banevade: bad user in %s: %s!%s@%s vs. %s", c->index->name->content, np->nick, np->ident, np->host->name->content, bantostring(ns_banned));
  57
  58                 if(IsAccount(np)) {
  59                         /* Reset host to [cc].HIS_HIDDENHOST */
  60                         char host[HOSTLEN+1] = "";
  61                         snprintf(host, sizeof(host), "%s.%s", np->authname, HIS_HIDDENHOST);
  62
  63                         /* I didnt find a function for this, so we're doing it R A W */
  64                         irc_send("%s SH %s %s %s", mynumeric->content, longtonumeric(np->numeric, 5), np->ident, host);
  65
  66                         /* Also remove them from the channel they're not supposed to be in */
  67                         /* We're gonna go with the generic default-Q-kick-reason since we don't know the real reason for the kick */
  68                         localkickuser(NULL, c, np, "Banned.");
  69                 } else {
  70                         /* Honest to god, this should never happen since the IRCD is in a state where it
  71                          * checks EITHER the sethost or the authname. So people shouldn't be able to avoid bans
  72                          * unauthed. But we still need to handle it, incase shit hits the fan. */
  73
  74                         /* User has a spoofed host but isn't authed, most likely a s:line (for some reason I want to write an s:line). Send them flying. */
  75                         /* We're not gonna kill the user because they'll most likely just reconnect and rejoin, causing a buttload of spam. */
  76                         /* So just trigger an extra line of spam into qnet.banevade so we'll investigate manually! */
  77                         //killuser(NULL, np, "Please don't avoid bans on QuakeNet");
  78
  79                         /* Also send an additional spam line to the amazing OGs in qnet.banevade */
  80                         if(cp) controlchanmsg(cp, "banevade: user %s appears to be un-authed, this might be a s:line!", np->nick);
  81                 }
  82         }
  83
  84 }
  85 void _init() {
  86         registerhook(HOOK_CHANNEL_JOIN, &be_onjoin);
  87         registerhook(HOOK_CHANNEL_CREATE, &be_onjoin);
  88 }
  89
  90 void _fini() {
  91         deregisterhook(HOOK_CHANNEL_JOIN, &be_onjoin);
  92         deregisterhook(HOOK_CHANNEL_CREATE, &be_onjoin);
  93 }
  94
  95 /* This code is based on snircd 1.3.4a, which has the bug where authed users with +h
  96  could bypass *!*@[account].users.quakenet.org bans.
  97  It has been somewhat rewritten to fit the NewServ ban flags and structure
  98 */
  99
 100 /* The ircd checks 4 things:
 101  *
 102  * The clients nick!username (where username is current, original usernames are not checked)
 103  * The clients real ip towards IP bans
 104  * The real host (if client is using a cloaked host)
 105  * The current host of the client
 106  *
 107  * This causes the bug that [account].HIS_HIDDENHOST is never checked towards the banlist
 108  * if they have +h set.
 109  * We need to replicate that check in this code
 110 */
 111
 112 #ifdef BANEVADE_SPAM
 113 #define IFNULLELSE(x, y) (x ? y : "(null)")
 114 #endif
 115
 116 int ircdbanned(nick *n, channel *c) {
 117         char    *nick = n->nick;
 118         char    *ident = n->ident;
 119         char    tmphost[HOSTLEN + 1];
 120         char    *sr;
 121         chanban *cb = NULL;
 122
 123         /* Here is the bug in the ircd.
 124          * In a perfect world we'd have one more variable to save both sethost and authhost
 125         */
 126         if (!IsAccount(n))
 127                 sr = NULL;
 128         else if (IsSetHost(n))
 129                 sr = n->sethost->content;
 130         else {
 131                 snprintf(tmphost, sizeof(tmphost), "%s.%s", n->authname, HIS_HIDDENHOST);
 132                 sr = tmphost;
 133         }
 134
 135 #ifdef BANEVADE_SPAM
 136         Error("banevade", ERR_INFO, "---------------------------");
 137         Error("banevade", ERR_INFO, "User %s has joined %s.", nick, c->index->name->content);
 138         Error("banevade", ERR_INFO, "We will be checking the following:");
 139         Error("banevade", ERR_INFO, " nick=%s ident=%s iphost=%s sr=%s host=%s", nick, ident, IPtostr(n->ipaddress), IFNULLELSE(sr, sr), n->host->name->content);
 140 #endif
 141
 142         /* Walk through ban list. */
 143         for (cb = c->bans; cb; cb = cb->next) {
 144 #ifdef BANEVADE_SPAM
 145                 Error("banevade", ERR_INFO, "Ban for: %s!%s@%s", IFNULLELSE(cb->nick, cb->nick->content), IFNULLELSE(cb->user, cb->user->content), IFNULLELSE(cb->host, cb->host->content));
 146 #endif
 147
 148                 /* Compare nick and user portion of ban. */
 149                 /* ircd code:
 150                  banlist->banstr[banlist->nu_len] = '\0';
 151                  res = match(banlist->banstr, nu);
 152                  banlist->banstr[banlist->nu_len] = '@';
 153                 */
 154
 155                 /* Our code - since we don't save nick!user in our ban structure - we need to check it using other tools!
 156                  * I've only used match2strings, I've not used the flags for CHANBAN_NICKEXACT etc.
 157                  * The only issue I could think of is the lack of irc_compare for {[]} etc.
 158                  * But the ircd uses match, so I went with this to be somewhat 1:1 close to it.
 159                  * Give me a poke if you want this to be more like nickbanned() with those checks.
 160                 */
 161                 if(cb->nick) {
 162                         if(!match2strings(cb->nick->content, nick)) {
 163 #ifdef BANEVADE_SPAM
 164                                 Error("banevade", ERR_INFO, " nick is present but not matching");
 165 #endif
 166                                 continue;
 167                         }
 168                 }
 169                 if(cb->user) {
 170                         if(!match2strings(cb->user->content, ident)) {
 171 #ifdef BANEVADE_SPAM
 172                                 Error("banevade", ERR_INFO, " user is present but not matching");
 173 #endif
 174                                 continue;
 175                         }
 176                 }
 177
 178                 /* Compare host portion of ban. */
 179                 /* ircd code:
 180                  if (!((cb->flags & BAN_IPMASK)
 181                         && ipmask_check(&cli_ip(cptr), &cb->address, cb->addrbits))
 182                         && match(hostmask, cli_user(cptr)->host)
 183                         && !(sr && !match(hostmask, sr)))
 184                                 continue;
 185                 */
 186                 if(cb->host) {
 187                         if(
 188                                 /* Check current host */
 189                                 !match2strings(cb->host->content, n->host->name->content)
 190                                 /* Check IP if ip-ban */
 191                                 && !((cb->flags & CHANBAN_IP) && ipmask_check(&(n->ipnode->prefix->sin), &(cb->ipaddr), cb->prefixlen))
 192                                 /* Check our real host (if +h/+x) */
 193                                 && !(sr && match2strings(cb->host->content, sr))
 194                         ) {
 195 #ifdef BANEVADE_SPAM
 196                                 Error("banevade", ERR_INFO, " host is present but not matching.");
 197 #endif
 198                                 continue;
 199                         }
 200                 }
 201
 202                 /* If we got this far, everything that exists in the ban matches! */
 203 #ifdef BANEVADE_SPAM
 204                 Error("banevade", ERR_INFO, " -- Ban appears to hit the user.");
 205 #endif
 206                 return 1;
 207         }
 208
 209         return 0;
 210 }