modules/m_chghost.c

   1 /*
   2  * Copyright (c) 2005 William Pitcock <nenolod -at- nenolod.net>
   3  * and Jilles Tjoelker <jilles -at- stack.nl>
   4  * All rights reserved.
   5  *
   6  * Redistribution in both source and binary forms are permitted
   7  * provided that the above copyright notice remains unchanged.
   8  *
   9  * m_chghost.c: A module for handling spoofing dynamically.
  10  */
  11
  12 #include "stdinc.h"
  13 #include "send.h"
  14 #include "channel.h"
  15 #include "client.h"
  16 #include "common.h"
  17 #include "config.h"
  18 #include "ircd.h"
  19 #include "numeric.h"
  20 #include "s_conf.h"
  21 #include "s_newconf.h"
  22 #include "s_serv.h"
  23 #include "s_user.h"
  24 #include "hash.h"
  25 #include "msg.h"
  26 #include "parse.h"
  27 #include "modules.h"
  28 #include "whowas.h"
  29 #include "monitor.h"
  30
  31 static int me_realhost(struct Client *, struct Client *, int, const char **);
  32 static int ms_chghost(struct Client *, struct Client *, int, const char **);
  33 static int me_chghost(struct Client *, struct Client *, int, const char **);
  34 static int mo_chghost(struct Client *, struct Client *, int, const char **);
  35
  36 struct Message realhost_msgtab = {
  37         "REALHOST", 0, 0, 0, MFLG_SLOW,
  38         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_realhost, 2}, mg_ignore}
  39 };
  40
  41 struct Message chghost_msgtab = {
  42         "CHGHOST", 0, 0, 0, MFLG_SLOW,
  43         {mg_ignore, mg_not_oper, {ms_chghost, 3}, {ms_chghost, 3}, {me_chghost, 3}, {mo_chghost, 3}}
  44 };
  45
  46 mapi_clist_av1 chghost_clist[] = { &chghost_msgtab, &realhost_msgtab, NULL };
  47
  48 DECLARE_MODULE_AV1(chghost, NULL, NULL, chghost_clist, NULL, NULL, "$Revision: 3424 $");
  49
  50 /* clean_host()
  51  *
  52  * input        - host to check
  53  * output       - 0 if erroneous, else 0
  54  * side effects -
  55  */
  56 static int
  57 clean_host(const char *host)
  58 {
  59         int len = 0;
  60         const char *last_slash = 0;
  61
  62         if (*host == '\0' || *host == ':')
  63                 return 0;
  64
  65         for(; *host; host++)
  66         {
  67                 len++;
  68
  69                 if(!IsHostChar(*host))
  70                         return 0;
  71                 if(*host == '/')
  72                         last_slash = host;
  73         }
  74
  75         if(len > HOSTLEN)
  76                 return 0;
  77
  78         if(last_slash && IsDigit(last_slash[1]))
  79                 return 0;
  80
  81         return 1;
  82 }
  83
  84 /*
  85  * me_realhost
  86  * parv[1] = real host
  87  *
  88  * Yes this contains a little race condition if someone does a whois
  89  * in between the UID and REALHOST and use_whois_actually is enabled.
  90  * I don't think that's a big problem as the whole thing is a
  91  * race condition.
  92  */
  93 static int
  94 me_realhost(struct Client *client_p, struct Client *source_p,
  95         int parc, const char *parv[])
  96 {
  97         if (!IsPerson(source_p))
  98                 return 0;
  99
 100         del_from_hostname_hash(source_p->orighost, source_p);
 101         rb_strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
 102         if (irccmp(source_p->host, source_p->orighost))
 103                 SetDynSpoof(source_p);
 104         else
 105                 ClearDynSpoof(source_p);
 106         add_to_hostname_hash(source_p->orighost, source_p);
 107         return 0;
 108 }
 109
 110 static int
 111 do_chghost(struct Client *source_p, struct Client *target_p,
 112                 const char *newhost, int is_encap)
 113 {
 114         if (!clean_host(newhost))
 115         {
 116                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 117                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 118                                 target_p->name, newhost);
 119                 /* sending this remotely may disclose important
 120                  * routing information -- jilles */
 121                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 122                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 123                                         source_p->name, newhost);
 124                 return 0;
 125         }
 126         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 127         if (irccmp(target_p->host, target_p->orighost))
 128         {
 129                 SetDynSpoof(target_p);
 130                 if (MyClient(target_p))
 131                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 132         }
 133         else
 134         {
 135                 ClearDynSpoof(target_p);
 136                 if (MyClient(target_p))
 137                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 138         }
 139         if (MyClient(source_p))
 140                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 141         if (!IsServer(source_p) && !IsService(source_p))
 142                 sendto_realops_snomask(SNO_GENERAL, L_ALL, "%s changed hostname for %s to %s", get_oper_name(source_p), target_p->name, target_p->host);
 143         return 1;
 144 }
 145
 146 /*
 147  * ms_chghost
 148  * parv[1] = target
 149  * parv[2] = host
 150  */
 151 static int
 152 ms_chghost(struct Client *client_p, struct Client *source_p,
 153         int parc, const char *parv[])
 154 {
 155         struct Client *target_p;
 156
 157         if (!(target_p = find_person(parv[1])))
 158                 return -1;
 159
 160         if (do_chghost(source_p, target_p, parv[2], 0))
 161         {
 162                 sendto_server(client_p, NULL,
 163                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 164                         use_id(source_p), use_id(target_p), parv[2]);
 165                 sendto_server(client_p, NULL,
 166                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 167                         use_id(source_p), use_id(target_p), parv[2]);
 168         }
 169
 170         return 0;
 171 }
 172
 173 /*
 174  * me_chghost
 175  * parv[1] = target
 176  * parv[2] = host
 177  */
 178 static int
 179 me_chghost(struct Client *client_p, struct Client *source_p,
 180         int parc, const char *parv[])
 181 {
 182         struct Client *target_p;
 183
 184         if (!(target_p = find_person(parv[1])))
 185                 return -1;
 186
 187         do_chghost(source_p, target_p, parv[2], 1);
 188
 189         return 0;
 190 }
 191
 192 /*
 193  * mo_chghost
 194  * parv[1] = target
 195  * parv[2] = host
 196  */
 197 /* Disable this because of the abuse potential -- jilles
 198  * No, make it toggleable via ./configure. --nenolod
 199  */
 200 static int
 201 mo_chghost(struct Client *client_p, struct Client *source_p,
 202         int parc, const char *parv[])
 203 {
 204 #ifdef ENABLE_OPER_CHGHOST
 205         struct Client *target_p;
 206
 207         if(!IsOperAdmin(source_p))
 208         {
 209                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 210                            me.name, source_p->name, "admin");
 211                 return 0;
 212         }
 213
 214         if (!(target_p = find_named_person(parv[1])))
 215         {
 216                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 217                                 form_str(ERR_NOSUCHNICK), parv[1]);
 218                 return 0;
 219         }
 220
 221         if (!clean_host(parv[2]))
 222         {
 223                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 224                 return 0;
 225         }
 226
 227         do_chghost(source_p, target_p, parv[2], 0);
 228
 229         sendto_server(NULL, NULL,
 230                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 231                 use_id(source_p), use_id(target_p), parv[2]);
 232         sendto_server(NULL, NULL,
 233                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 234                 use_id(source_p), use_id(target_p), parv[2]);
 235 #else
 236         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 237                         "CHGHOST");
 238 #endif
 239
 240         return 0;
 241 }
 242