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 "tools.h"
  14 #include "send.h"
  15 #include "channel.h"
  16 #include "client.h"
  17 #include "common.h"
  18 #include "config.h"
  19 #include "ircd.h"
  20 #include "numeric.h"
  21 #include "memory.h"
  22 #include "s_conf.h"
  23 #include "s_newconf.h"
  24 #include "s_serv.h"
  25 #include "s_user.h"
  26 #include "hash.h"
  27 #include "msg.h"
  28 #include "parse.h"
  29 #include "modules.h"
  30 #include "sprintf_irc.h"
  31 #include "whowas.h"
  32 #include "monitor.h"
  33
  34 static int me_realhost(struct Client *, struct Client *, int, const char **);
  35 static int ms_chghost(struct Client *, struct Client *, int, const char **);
  36 static int me_chghost(struct Client *, struct Client *, int, const char **);
  37 static int mo_chghost(struct Client *, struct Client *, int, const char **);
  38
  39 struct Message realhost_msgtab = {
  40         "REALHOST", 0, 0, 0, MFLG_SLOW,
  41         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_realhost, 2}, mg_ignore}
  42 };
  43
  44 struct Message chghost_msgtab = {
  45         "CHGHOST", 0, 0, 0, MFLG_SLOW,
  46         {mg_ignore, mg_not_oper, {ms_chghost, 3}, {ms_chghost, 3}, {me_chghost, 3}, {mo_chghost, 3}}
  47 };
  48
  49 mapi_clist_av1 chghost_clist[] = { &chghost_msgtab, &realhost_msgtab, NULL };
  50
  51 DECLARE_MODULE_AV1(chghost, NULL, NULL, chghost_clist, NULL, NULL, "$Revision: 1865 $");
  52
  53 /* clean_host()
  54  *
  55  * input        - host to check
  56  * output       - 0 if erroneous, else 0
  57  * side effects -
  58  */
  59 static int
  60 clean_host(const char *host)
  61 {
  62         int len = 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[0] = origin
  81  * parv[1] = real host
  82  *
  83  * Yes this contains a little race condition if someone does a whois
  84  * in between the UID and REALHOST and use_whois_actually is enabled.
  85  * I don't think that's a big problem as the whole thing is a
  86  * race condition.
  87  */
  88 static int
  89 me_realhost(struct Client *client_p, struct Client *source_p,
  90         int parc, const char *parv[])
  91 {
  92         if (!IsPerson(source_p))
  93                 return 0;
  94
  95         del_from_hostname_hash(source_p->orighost, source_p);
  96         strlcpy(source_p->orighost, parv[1], HOSTLEN);
  97         if (irccmp(source_p->host, source_p->orighost))
  98                 SetDynSpoof(source_p);
  99         else
 100                 ClearDynSpoof(source_p);
 101         add_to_hostname_hash(source_p->orighost, source_p);
 102         return 0;
 103 }
 104
 105 static int
 106 do_chghost(struct Client *source_p, struct Client *target_p,
 107                 const char *newhost, int is_encap)
 108 {
 109         if (!clean_host(newhost))
 110         {
 111                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 112                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 113                                 target_p->name, newhost);
 114                 /* sending this remotely may disclose important
 115                  * routing information -- jilles */
 116                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 117                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 118                                         source_p->name, newhost);
 119                 return 0;
 120         }
 121         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 122         if (irccmp(target_p->host, target_p->orighost))
 123         {
 124                 SetDynSpoof(target_p);
 125                 if (MyClient(target_p))
 126                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 127         }
 128         else
 129         {
 130                 ClearDynSpoof(target_p);
 131                 if (MyClient(target_p))
 132                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 133         }
 134         if (MyClient(source_p))
 135                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 136         if (!IsServer(source_p) && !IsService(source_p))
 137                 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);
 138         return 1;
 139 }
 140
 141 /*
 142  * ms_chghost
 143  * parv[0] = origin
 144  * parv[1] = target
 145  * parv[2] = host
 146  */
 147 static int
 148 ms_chghost(struct Client *client_p, struct Client *source_p,
 149         int parc, const char *parv[])
 150 {
 151         struct Client *target_p;
 152
 153         if (!(target_p = find_person(parv[1])))
 154                 return -1;
 155
 156         if (do_chghost(source_p, target_p, parv[2], 0))
 157         {
 158                 sendto_server(client_p, NULL,
 159                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 160                         use_id(source_p), use_id(target_p), parv[2]);
 161                 sendto_server(client_p, NULL,
 162                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 163                         use_id(source_p), use_id(target_p), parv[2]);
 164                 sendto_server(client_p, NULL,
 165                         NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 166                         source_p->name, target_p->name, parv[2]);
 167         }
 168
 169         return 0;
 170 }
 171
 172 /*
 173  * me_chghost
 174  * parv[0] = origin
 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[0] = origin
 195  * parv[1] = target
 196  * parv[2] = host
 197  */
 198 /* Disable this because of the abuse potential -- jilles
 199  * No, make it toggleable via ./configure. --nenolod
 200  */
 201 static int
 202 mo_chghost(struct Client *client_p, struct Client *source_p,
 203         int parc, const char *parv[])
 204 {
 205 #ifdef ENABLE_OPER_CHGHOST
 206         struct Client *target_p;
 207
 208         if(!IsOperAdmin(source_p))
 209         {
 210                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 211                            me.name, source_p->name, "admin");
 212                 return 0;
 213         }
 214
 215         if (!(target_p = find_named_person(parv[1])))
 216         {
 217                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 218                                 form_str(ERR_NOSUCHNICK), parv[1]);
 219                 return 0;
 220         }
 221
 222         if (!clean_host(parv[2]))
 223         {
 224                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 225                 return 0;
 226         }
 227
 228         do_chghost(source_p, target_p, parv[2], 0);
 229
 230         sendto_server(NULL, NULL,
 231                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 232                 use_id(source_p), use_id(target_p), parv[2]);
 233         sendto_server(NULL, NULL,
 234                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 235                 use_id(source_p), use_id(target_p), parv[2]);
 236         sendto_server(NULL, NULL,
 237                 NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 238                 source_p->name, target_p->name, parv[2]);
 239 #else
 240         sendto_one_notice(source_p, ":CHGHOST is disabled");
 241 #endif
 242
 243         return 0;
 244 }
 245