2 * Charybdis: an advanced ircd
3 * ip_cloaking.c: provide user hostname cloaking
5 * Written originally by nenolod, altered to use FNV by Elizabeth in 2008
23 /* add the usermode to the available slot */
24 user_modes
['h'] = find_umode_slot();
33 /* disable the umode and remove it from the available list */
38 static void check_umode_change(void *data
);
39 static void check_new_user(void *data
);
40 mapi_hfn_list_av1 ip_cloaking_hfnlist
[] = {
41 { "umode_changed", (hookfn
) check_umode_change
},
42 { "new_local_user", (hookfn
) check_new_user
},
46 static const char ip_cloaking_desc
[] = "IP cloaking module that uses user mode +h";
48 DECLARE_MODULE_AV2(ip_cloaking
, _modinit
, _moddeinit
, NULL
, NULL
,
49 ip_cloaking_hfnlist
, NULL
, NULL
, ip_cloaking_desc
);
52 distribute_hostchange(struct Client
*client_p
, char *newhost
)
54 if (newhost
!= client_p
->orighost
)
55 sendto_one_numeric(client_p
, RPL_HOSTHIDDEN
, "%s :is now your hidden host",
58 sendto_one_numeric(client_p
, RPL_HOSTHIDDEN
, "%s :hostname reset",
61 sendto_server(NULL
, NULL
,
62 CAP_EUID
| CAP_TS6
, NOCAPS
, ":%s CHGHOST %s :%s",
63 use_id(&me
), use_id(client_p
), newhost
);
64 sendto_server(NULL
, NULL
,
65 CAP_TS6
, CAP_EUID
, ":%s ENCAP * CHGHOST %s :%s",
66 use_id(&me
), use_id(client_p
), newhost
);
68 change_nick_user_host(client_p
, client_p
->name
, client_p
->username
, newhost
, 0, "Changing host");
70 if (newhost
!= client_p
->orighost
)
71 SetDynSpoof(client_p
);
73 ClearDynSpoof(client_p
);
77 do_host_cloak_ip(const char *inbuf
, char *outbuf
)
79 /* None of the characters in this table can be valid in an IP */
80 char chartable
[] = "ghijklmnopqrstuvwxyz";
82 uint32_t accum
= fnv_hash((const unsigned char*) inbuf
, 32);
87 rb_strlcpy(outbuf
, inbuf
, HOSTLEN
+ 1);
89 if (strchr(outbuf
, ':'))
94 * We count the number of colons so we can calculate how much
95 * of the host to cloak. This is because some hostmasks may not
96 * have as many octets as we'd like.
98 * We have to do this ahead of time because doing this during
99 * the actual cloaking would get ugly
101 for (tptr
= outbuf
; *tptr
!= '\0'; tptr
++)
105 else if (!strchr(outbuf
, '.'))
108 for (tptr
= outbuf
; *tptr
!= '\0'; tptr
++)
110 if (*tptr
== ':' || *tptr
== '.')
116 if (ipv6
&& sepcount
< totalcount
/ 2)
119 if (!ipv6
&& sepcount
< 2)
122 *tptr
= chartable
[(*tptr
+ accum
) % 20];
123 accum
= (accum
<< 1) | (accum
>> 31);
128 do_host_cloak_host(const char *inbuf
, char *outbuf
)
130 char b26_alphabet
[] = "abcdefghijklmnopqrstuvwxyz";
132 uint32_t accum
= fnv_hash((const unsigned char*) inbuf
, 32);
134 rb_strlcpy(outbuf
, inbuf
, HOSTLEN
+ 1);
136 /* pass 1: scramble first section of hostname using base26
137 * alphabet toasted against the FNV hash of the string.
139 * numbers are not changed at this time, only letters.
141 for (tptr
= outbuf
; *tptr
!= '\0'; tptr
++)
146 if (isdigit((unsigned char)*tptr
) || *tptr
== '-')
149 *tptr
= b26_alphabet
[(*tptr
+ accum
) % 26];
151 /* Rotate one bit to avoid all digits being turned odd or even */
152 accum
= (accum
<< 1) | (accum
>> 31);
155 /* pass 2: scramble each number in the address */
156 for (tptr
= outbuf
; *tptr
!= '\0'; tptr
++)
158 if (isdigit((unsigned char)*tptr
))
159 *tptr
= '0' + (*tptr
+ accum
) % 10;
161 accum
= (accum
<< 1) | (accum
>> 31);
166 check_umode_change(void *vdata
)
168 hook_data_umode_changed
*data
= (hook_data_umode_changed
*)vdata
;
169 struct Client
*source_p
= data
->client
;
171 if (!MyClient(source_p
))
174 /* didn't change +h umode, we don't need to do anything */
175 if (!((data
->oldumodes
^ source_p
->umodes
) & user_modes
['h']))
178 if (source_p
->umodes
& user_modes
['h'])
180 if (IsIPSpoof(source_p
) || source_p
->localClient
->mangledhost
== NULL
|| (IsDynSpoof(source_p
) && strcmp(source_p
->host
, source_p
->localClient
->mangledhost
)))
182 source_p
->umodes
&= ~user_modes
['h'];
185 if (strcmp(source_p
->host
, source_p
->localClient
->mangledhost
))
187 distribute_hostchange(source_p
, source_p
->localClient
->mangledhost
);
189 else /* not really nice, but we need to send this numeric here */
190 sendto_one_numeric(source_p
, RPL_HOSTHIDDEN
, "%s :is now your hidden host",
193 else if (!(source_p
->umodes
& user_modes
['h']))
195 if (source_p
->localClient
->mangledhost
!= NULL
&&
196 !strcmp(source_p
->host
, source_p
->localClient
->mangledhost
))
198 distribute_hostchange(source_p
, source_p
->orighost
);
204 check_new_user(void *vdata
)
206 struct Client
*source_p
= (void *)vdata
;
208 if (IsIPSpoof(source_p
))
210 source_p
->umodes
&= ~user_modes
['h'];
213 source_p
->localClient
->mangledhost
= rb_malloc(HOSTLEN
+ 1);
214 if (!irccmp(source_p
->orighost
, source_p
->sockhost
))
215 do_host_cloak_ip(source_p
->orighost
, source_p
->localClient
->mangledhost
);
217 do_host_cloak_host(source_p
->orighost
, source_p
->localClient
->mangledhost
);
218 if (IsDynSpoof(source_p
))
219 source_p
->umodes
&= ~user_modes
['h'];
220 if (source_p
->umodes
& user_modes
['h'])
222 rb_strlcpy(source_p
->host
, source_p
->localClient
->mangledhost
, sizeof(source_p
->host
));
223 if (irccmp(source_p
->host
, source_p
->orighost
))
224 SetDynSpoof(source_p
);