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 MsgBuf *, struct Client *, struct Client *, int, const char **);
  32 static int ms_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  33 static int me_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  34 static int mo_chghost(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  35
  36 struct Message realhost_msgtab = {
  37         "REALHOST", 0, 0, 0, 0,
  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, 0,
  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 static const char chghost_desc[] = "Provides commands used to change and retrieve client hostnames";
  49
  50 DECLARE_MODULE_AV2(chghost, NULL, NULL, chghost_clist, NULL, NULL, NULL, NULL, chghost_desc);
  51
  52 /* clean_host()
  53  *
  54  * input        - host to check
  55  * output       - 0 if erroneous, else 1
  56  * side effects -
  57  */
  58 static int
  59 clean_host(const char *host)
  60 {
  61         int len = 0;
  62         const char *last_slash = 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                 if(*host == '/')
  74                         last_slash = host;
  75         }
  76
  77         if(len > HOSTLEN)
  78                 return 0;
  79
  80         if(last_slash && IsDigit(last_slash[1]))
  81                 return 0;
  82
  83         return 1;
  84 }
  85
  86 /*
  87  * me_realhost
  88  * parv[1] = real host
  89  *
  90  * Yes this contains a little race condition if someone does a whois
  91  * in between the UID and REALHOST and use_whois_actually is enabled.
  92  * I don't think that's a big problem as the whole thing is a
  93  * race condition.
  94  */
  95 static int
  96 me_realhost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
  97         int parc, const char *parv[])
  98 {
  99         if (!IsPerson(source_p))
 100                 return 0;
 101
 102         del_from_hostname_hash(source_p->orighost, source_p);
 103         rb_strlcpy(source_p->orighost, parv[1], sizeof source_p->orighost);
 104         if (irccmp(source_p->host, source_p->orighost))
 105                 SetDynSpoof(source_p);
 106         else
 107                 ClearDynSpoof(source_p);
 108         add_to_hostname_hash(source_p->orighost, source_p);
 109         return 0;
 110 }
 111
 112 static int
 113 do_chghost(struct Client *source_p, struct Client *target_p,
 114                 const char *newhost, int is_encap)
 115 {
 116         if (!clean_host(newhost))
 117         {
 118                 sendto_realops_snomask(SNO_GENERAL, is_encap ? L_ALL : L_NETWIDE, "%s attempted to change hostname for %s to %s (invalid)",
 119                                 IsServer(source_p) ? source_p->name : get_oper_name(source_p),
 120                                 target_p->name, newhost);
 121                 /* sending this remotely may disclose important
 122                  * routing information -- jilles */
 123                 if (is_encap ? MyClient(target_p) : !ConfigServerHide.flatten_links)
 124                         sendto_one_notice(target_p, ":*** Notice -- %s attempted to change your hostname to %s (invalid)",
 125                                         source_p->name, newhost);
 126                 return 0;
 127         }
 128         change_nick_user_host(target_p, target_p->name, target_p->username, newhost, 0, "Changing host");
 129         if (irccmp(target_p->host, target_p->orighost))
 130         {
 131                 SetDynSpoof(target_p);
 132                 if (MyClient(target_p))
 133                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :is now your hidden host (set by %s)", target_p->host, source_p->name);
 134         }
 135         else
 136         {
 137                 ClearDynSpoof(target_p);
 138                 if (MyClient(target_p))
 139                         sendto_one_numeric(target_p, RPL_HOSTHIDDEN, "%s :hostname reset by %s", target_p->host, source_p->name);
 140         }
 141         if (MyClient(source_p))
 142                 sendto_one_notice(source_p, ":Changed hostname for %s to %s", target_p->name, target_p->host);
 143         if (!IsServer(source_p) && !IsService(source_p))
 144                 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);
 145         return 1;
 146 }
 147
 148 /*
 149  * ms_chghost
 150  * parv[1] = target
 151  * parv[2] = host
 152  */
 153 static int
 154 ms_chghost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 155         int parc, const char *parv[])
 156 {
 157         struct Client *target_p;
 158
 159         if (!(target_p = find_person(parv[1])))
 160                 return -1;
 161
 162         if (do_chghost(source_p, target_p, parv[2], 0))
 163         {
 164                 sendto_server(client_p, NULL,
 165                         CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s %s",
 166                         use_id(source_p), use_id(target_p), parv[2]);
 167                 sendto_server(client_p, NULL,
 168                         CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
 169                         use_id(source_p), use_id(target_p), parv[2]);
 170         }
 171
 172         return 0;
 173 }
 174
 175 /*
 176  * me_chghost
 177  * parv[1] = target
 178  * parv[2] = host
 179  */
 180 static int
 181 me_chghost(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 182         int parc, const char *parv[])
 183 {
 184         struct Client *target_p;
 185
 186         if (!(target_p = find_person(parv[1])))
 187                 return -1;
 188
 189         do_chghost(source_p, target_p, parv[2], 1);
 190
 191         return 0;
 192 }
 193
 194 /*
 195  * mo_chghost
 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 MsgBuf *msgbuf_p, 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 #else
 238         sendto_one_numeric(source_p, ERR_DISABLED, form_str(ERR_DISABLED),
 239                         "CHGHOST");
 240 #endif
 241
 242         return 0;
 243 }
 244