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
  61         if (*host == '\0' || *host == ':')
  62                 return 0;
  63
  64         for(; *host; host++)
  65         {
  66                 len++;
  67
  68                 if(!IsHostChar(*host))
  69                         return 0;
  70         }
  71
  72         if(len > HOSTLEN)
  73                 return 0;
  74
  75         return 1;
  76 }
  77
  78 /*
  79  * me_realhost
  80  * parv[1] = real host
  81  *
  82  * Yes this contains a little race condition if someone does a whois
  83  * in between the UID and REALHOST and use_whois_actually is enabled.
  84  * I don't think that's a big problem as the whole thing is a
  85  * race condition.
  86  */
  87 static int
  88 me_realhost(struct Client *client_p, struct Client *source_p,
  89         int parc, const char *parv[])
  90 {
  91         if (!IsPerson(source_p))
  92                 return 0;
  93
  94         del_from_hostname_hash(source_p->orighost, source_p);
  95         rb_strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
  96         if (irccmp(source_p->host, source_p->orighost))
  97                 SetDynSpoof(source_p);
  98         else
  99                 ClearDynSpoof(source_p);
 100         add_to_hostname_hash(source_p->orighost, source_p);
 101         return 0;
 102 }
 103
 104 static int
 105 do_chghost(struct Client *source_p, struct Client *target_p,
 106                 const char *newhost, int is_encap)
 107 {
 108         if (!clean_host(newhost))
 109         {
 110                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 111                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 112                                 target_p->name, newhost);
 113                 /* sending this remotely may disclose important
 114                  * routing information -- jilles */
 115                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 116                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 117                                         source_p->name, newhost);
 118                 return 0;
 119         }
 120         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 121         if (irccmp(target_p->host, target_p->orighost))
 122         {
 123                 SetDynSpoof(target_p);
 124                 if (MyClient(target_p))
 125                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 126         }
 127         else
 128         {
 129                 ClearDynSpoof(target_p);
 130                 if (MyClient(target_p))
 131                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 132         }
 133         if (MyClient(source_p))
 134                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 135         if (!IsServer(source_p) && !IsService(source_p))
 136                 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);
 137         return 1;
 138 }
 139
 140 /*
 141  * ms_chghost
 142  * parv[1] = target
 143  * parv[2] = host
 144  */
 145 static int
 146 ms_chghost(struct Client *client_p, struct Client *source_p,
 147         int parc, const char *parv[])
 148 {
 149         struct Client *target_p;
 150
 151         if (!(target_p = find_person(parv[1])))
 152                 return -1;
 153
 154         if (do_chghost(source_p, target_p, parv[2], 0))
 155         {
 156                 sendto_server(client_p, NULL,
 157                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 158                         use_id(source_p), use_id(target_p), parv[2]);
 159                 sendto_server(client_p, NULL,
 160                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 161                         use_id(source_p), use_id(target_p), parv[2]);
 162         }
 163
 164         return 0;
 165 }
 166
 167 /*
 168  * me_chghost
 169  * parv[1] = target
 170  * parv[2] = host
 171  */
 172 static int
 173 me_chghost(struct Client *client_p, struct Client *source_p,
 174         int parc, const char *parv[])
 175 {
 176         struct Client *target_p;
 177
 178         if (!(target_p = find_person(parv[1])))
 179                 return -1;
 180
 181         do_chghost(source_p, target_p, parv[2], 1);
 182
 183         return 0;
 184 }
 185
 186 /*
 187  * mo_chghost
 188  * parv[1] = target
 189  * parv[2] = host
 190  */
 191 /* Disable this because of the abuse potential -- jilles
 192  * No, make it toggleable via ./configure. --nenolod
 193  */
 194 static int
 195 mo_chghost(struct Client *client_p, struct Client *source_p,
 196         int parc, const char *parv[])
 197 {
 198 #ifdef ENABLE_OPER_CHGHOST
 199         struct Client *target_p;
 200
 201         if(!IsOperAdmin(source_p))
 202         {
 203                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 204                            me.name, source_p->name, "admin");
 205                 return 0;
 206         }
 207
 208         if (!(target_p = find_named_person(parv[1])))
 209         {
 210                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 211                                 form_str(ERR_NOSUCHNICK), parv[1]);
 212                 return 0;
 213         }
 214
 215         if (!clean_host(parv[2]))
 216         {
 217                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 218                 return 0;
 219         }
 220
 221         do_chghost(source_p, target_p, parv[2], 0);
 222
 223         sendto_server(NULL, NULL,
 224                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 225                 use_id(source_p), use_id(target_p), parv[2]);
 226         sendto_server(NULL, NULL,
 227                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 228                 use_id(source_p), use_id(target_p), parv[2]);
 229 #else
 230         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 231                         "CHGHOST");
 232 #endif
 233
 234         return 0;
 235 }
 236