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 "sprintf_irc.h"
  29 #include "whowas.h"
  30 #include "monitor.h"
  31
  32 static int me_realhost(struct Client *, struct Client *, int, const char **);
  33 static int ms_chghost(struct Client *, struct Client *, int, const char **);
  34 static int me_chghost(struct Client *, struct Client *, int, const char **);
  35 static int mo_chghost(struct Client *, struct Client *, int, const char **);
  36
  37 struct Message realhost_msgtab = {
  38         "REALHOST", 0, 0, 0, MFLG_SLOW,
  39         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_realhost, 2}, mg_ignore}
  40 };
  41
  42 struct Message chghost_msgtab = {
  43         "CHGHOST", 0, 0, 0, MFLG_SLOW,
  44         {mg_ignore, mg_not_oper, {ms_chghost, 3}, {ms_chghost, 3}, {me_chghost, 3}, {mo_chghost, 3}}
  45 };
  46
  47 mapi_clist_av1 chghost_clist[] = { &chghost_msgtab, &realhost_msgtab, NULL };
  48
  49 DECLARE_MODULE_AV1(chghost, NULL, NULL, chghost_clist, NULL, NULL, "$Revision: 3424 $");
  50
  51 /* clean_host()
  52  *
  53  * input        - host to check
  54  * output       - 0 if erroneous, else 0
  55  * side effects -
  56  */
  57 static int
  58 clean_host(const char *host)
  59 {
  60         int len = 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         }
  72
  73         if(len > HOSTLEN)
  74                 return 0;
  75
  76         return 1;
  77 }
  78
  79 /*
  80  * me_realhost
  81  * parv[0] = origin
  82  * parv[1] = real host
  83  *
  84  * Yes this contains a little race condition if someone does a whois
  85  * in between the UID and REALHOST and use_whois_actually is enabled.
  86  * I don't think that's a big problem as the whole thing is a
  87  * race condition.
  88  */
  89 static int
  90 me_realhost(struct Client *client_p, struct Client *source_p,
  91         int parc, const char *parv[])
  92 {
  93         if (!IsPerson(source_p))
  94                 return 0;
  95
  96         del_from_hostname_hash(source_p->orighost, source_p);
  97         strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
  98         if (irccmp(source_p->host, source_p->orighost))
  99                 SetDynSpoof(source_p);
 100         else
 101                 ClearDynSpoof(source_p);
 102         add_to_hostname_hash(source_p->orighost, source_p);
 103         return 0;
 104 }
 105
 106 static int
 107 do_chghost(struct Client *source_p, struct Client *target_p,
 108                 const char *newhost, int is_encap)
 109 {
 110         if (!clean_host(newhost))
 111         {
 112                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 113                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 114                                 target_p->name, newhost);
 115                 /* sending this remotely may disclose important
 116                  * routing information -- jilles */
 117                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 118                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 119                                         source_p->name, newhost);
 120                 return 0;
 121         }
 122         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 123         if (irccmp(target_p->host, target_p->orighost))
 124         {
 125                 SetDynSpoof(target_p);
 126                 if (MyClient(target_p))
 127                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 128         }
 129         else
 130         {
 131                 ClearDynSpoof(target_p);
 132                 if (MyClient(target_p))
 133                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 134         }
 135         if (MyClient(source_p))
 136                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 137         if (!IsServer(source_p) && !IsService(source_p))
 138                 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);
 139         return 1;
 140 }
 141
 142 /*
 143  * ms_chghost
 144  * parv[0] = origin
 145  * parv[1] = target
 146  * parv[2] = host
 147  */
 148 static int
 149 ms_chghost(struct Client *client_p, struct Client *source_p,
 150         int parc, const char *parv[])
 151 {
 152         struct Client *target_p;
 153
 154         if (!(target_p = find_person(parv[1])))
 155                 return -1;
 156
 157         if (do_chghost(source_p, target_p, parv[2], 0))
 158         {
 159                 sendto_server(client_p, NULL,
 160                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 161                         use_id(source_p), use_id(target_p), parv[2]);
 162                 sendto_server(client_p, NULL,
 163                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 164                         use_id(source_p), use_id(target_p), parv[2]);
 165                 sendto_server(client_p, NULL,
 166                         NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 167                         source_p->name, target_p->name, parv[2]);
 168         }
 169
 170         return 0;
 171 }
 172
 173 /*
 174  * me_chghost
 175  * parv[0] = origin
 176  * parv[1] = target
 177  * parv[2] = host
 178  */
 179 static int
 180 me_chghost(struct Client *client_p, struct Client *source_p,
 181         int parc, const char *parv[])
 182 {
 183         struct Client *target_p;
 184
 185         if (!(target_p = find_person(parv[1])))
 186                 return -1;
 187
 188         do_chghost(source_p, target_p, parv[2], 1);
 189
 190         return 0;
 191 }
 192
 193 /*
 194  * mo_chghost
 195  * parv[0] = origin
 196  * parv[1] = target
 197  * parv[2] = host
 198  */
 199 /* Disable this because of the abuse potential -- jilles
 200  * No, make it toggleable via ./configure. --nenolod
 201  */
 202 static int
 203 mo_chghost(struct Client *client_p, struct Client *source_p,
 204         int parc, const char *parv[])
 205 {
 206 #ifdef ENABLE_OPER_CHGHOST
 207         struct Client *target_p;
 208
 209         if(!IsOperAdmin(source_p))
 210         {
 211                 sendto_one(source_p, form_str(ERR_NOPRIVS),
 212                            me.name, source_p->name, "admin");
 213                 return 0;
 214         }
 215
 216         if (!(target_p = find_named_person(parv[1])))
 217         {
 218                 sendto_one_numeric(source_p, ERR_NOSUCHNICK,
 219                                 form_str(ERR_NOSUCHNICK), parv[1]);
 220                 return 0;
 221         }
 222
 223         if (!clean_host(parv[2]))
 224         {
 225                 sendto_one_notice(source_p, ":Hostname %s is invalid", parv[2]);
 226                 return 0;
 227         }
 228
 229         do_chghost(source_p, target_p, parv[2], 0);
 230
 231         sendto_server(NULL, NULL,
 232                 CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 233                 use_id(source_p), use_id(target_p), parv[2]);
 234         sendto_server(NULL, NULL,
 235                 CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 236                 use_id(source_p), use_id(target_p), parv[2]);
 237         sendto_server(NULL, NULL,
 238                 NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s",
 239                 source_p->name, target_p->name, parv[2]);
 240 #else
 241         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 242                         "CHGHOST");
 243 #endif
 244
 245         return 0;
 246 }
 247