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: 3424 $");
  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         if (*host == '\0' || *host == ':')
  65                 return 0;
  66
  67         for(; *host; host++)
  68         {
  69                 len++;
  70
  71                 if(!IsHostChar(*host))
  72                         return 0;
  73         }
  74
  75         if(len > HOSTLEN)
  76                 return 0;
  77
  78         return 1;
  79 }
  80
  81 /*
  82  * me_realhost
  83  * parv[0] = origin
  84  * parv[1] = real host
  85  *
  86  * Yes this contains a little race condition if someone does a whois
  87  * in between the UID and REALHOST and use_whois_actually is enabled.
  88  * I don't think that's a big problem as the whole thing is a
  89  * race condition.
  90  */
  91 static int
  92 me_realhost(struct Client *client_p, struct Client *source_p,
  93         int parc, const char *parv[])
  94 {
  95         if (!IsPerson(source_p))
  96                 return 0;
  97
  98         del_from_hostname_hash(source_p->orighost, source_p);
  99         strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
 100         if (irccmp(source_p->host, source_p->orighost))
 101                 SetDynSpoof(source_p);
 102         else
 103                 ClearDynSpoof(source_p);
 104         add_to_hostname_hash(source_p->orighost, source_p);
 105         return 0;
 106 }
 107
 108 static int
 109 do_chghost(struct Client *source_p, struct Client *target_p,
 110                 const char *newhost, int is_encap)
 111 {
 112         if (!clean_host(newhost))
 113         {
 114                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 115                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 116                                 target_p->name, newhost);
 117                 /* sending this remotely may disclose important
 118                  * routing information -- jilles */
 119                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 120                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 121                                         source_p->name, newhost);
 122                 return 0;
 123         }
 124         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 125         if (irccmp(target_p->host, target_p->orighost))
 126         {
 127                 SetDynSpoof(target_p);
 128                 if (MyClient(target_p))
 129                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 130         }
 131         else
 132         {
 133                 ClearDynSpoof(target_p);
 134                 if (MyClient(target_p))
 135                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 136         }
 137         if (MyClient(source_p))
 138                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 139         if (!IsServer(source_p) && !IsService(source_p))
 140                 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);
 141         return 1;
 142 }
 143
 144 /*
 145  * ms_chghost
 146  * parv[0] = origin
 147  * parv[1] = target
 148  * parv[2] = host
 149  */
 150 static int
 151 ms_chghost(struct Client *client_p, struct Client *source_p,
 152         int parc, const char *parv[])
 153 {
 154         struct Client *target_p;
 155
 156         if (!(target_p = find_person(parv[1])))
 157                 return -1;
 158
 159         if (do_chghost(source_p, target_p, parv[2], 0))
 160         {
 161                 sendto_server(client_p, NULL,
 162                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 163                         use_id(source_p), use_id(target_p), parv[2]);
 164                 sendto_server(client_p, NULL,
 165                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 166                         use_id(source_p), use_id(target_p), parv[2]);
 167                 sendto_server(client_p, NULL,
 168                         NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 169                         source_p->name, target_p->name, parv[2]);
 170         }
 171
 172         return 0;
 173 }
 174
 175 /*
 176  * me_chghost
 177  * parv[0] = origin
 178  * parv[1] = target
 179  * parv[2] = host
 180  */
 181 static int
 182 me_chghost(struct Client *client_p, struct Client *source_p,
 183         int parc, const char *parv[])
 184 {
 185         struct Client *target_p;
 186
 187         if (!(target_p = find_person(parv[1])))
 188                 return -1;
 189
 190         do_chghost(source_p, target_p, parv[2], 1);
 191
 192         return 0;
 193 }
 194
 195 /*
 196  * mo_chghost
 197  * parv[0] = origin
 198  * parv[1] = target
 199  * parv[2] = host
 200  */
 201 /* Disable this because of the abuse potential -- jilles
 202  * No, make it toggleable via ./configure. --nenolod
 203  */
 204 static int
 205 mo_chghost(struct Client *client_p, struct Client *source_p,
 206         int parc, const char *parv[])
 207 {
 208 #ifdef ENABLE_OPER_CHGHOST
 209         struct Client *target_p;
 210
 211         if(!IsOperAdmin(source_p))
 212         {
 213                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 214                            me.name, source_p->name, "admin");
 215                 return 0;
 216         }
 217
 218         if (!(target_p = find_named_person(parv[1])))
 219         {
 220                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 221                                 form_str(ERR_NOSUCHNICK), parv[1]);
 222                 return 0;
 223         }
 224
 225         if (!clean_host(parv[2]))
 226         {
 227                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 228                 return 0;
 229         }
 230
 231         do_chghost(source_p, target_p, parv[2], 0);
 232
 233         sendto_server(NULL, NULL,
 234                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 235                 use_id(source_p), use_id(target_p), parv[2]);
 236         sendto_server(NULL, NULL,
 237                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 238                 use_id(source_p), use_id(target_p), parv[2]);
 239         sendto_server(NULL, NULL,
 240                 NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 241                 source_p->name, target_p->name, parv[2]);
 242 #else
 243         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 244                         "CHGHOST");
 245 #endif
 246
 247         return 0;
 248 }
 249