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b076458c | 1 | /* $Id: ip_cloaking.c 3526 2007-07-06 07:56:14Z nenolod $ */ |
212380e3 | 2 | |
3 | #include "stdinc.h" | |
4 | #include "modules.h" | |
5 | #include "hook.h" | |
6 | #include "client.h" | |
7 | #include "ircd.h" | |
8 | #include "send.h" | |
9 | #include "s_conf.h" | |
10 | #include "s_user.h" | |
11 | #include "s_serv.h" | |
212380e3 | 12 | #include "numeric.h" |
13 | ||
14 | /* if you're modifying this module, you'll probably to change this */ | |
15 | #define KEY 0x13748cfa | |
16 | ||
17 | static int | |
18 | _modinit(void) | |
19 | { | |
20 | /* add the usermode to the available slot */ | |
21 | user_modes['h'] = find_umode_slot(); | |
22 | construct_umodebuf(); | |
23 | ||
24 | return 0; | |
25 | } | |
26 | ||
27 | static void | |
28 | _moddeinit(void) | |
29 | { | |
30 | /* disable the umode and remove it from the available list */ | |
31 | user_modes['h'] = 0; | |
32 | construct_umodebuf(); | |
33 | } | |
34 | ||
35 | static void check_umode_change(void *data); | |
36 | static void check_new_user(void *data); | |
37 | mapi_hfn_list_av1 ip_cloaking_hfnlist[] = { | |
38 | { "umode_changed", (hookfn) check_umode_change }, | |
39 | { "new_local_user", (hookfn) check_new_user }, | |
40 | { NULL, NULL } | |
41 | }; | |
42 | ||
43 | DECLARE_MODULE_AV1(ip_cloaking, _modinit, _moddeinit, NULL, NULL, | |
b076458c | 44 | ip_cloaking_hfnlist, "$Revision: 3526 $"); |
212380e3 | 45 | |
46 | static void | |
47 | distribute_hostchange(struct Client *client) | |
48 | { | |
49 | if (irccmp(client->host, client->orighost)) | |
50 | sendto_one_numeric(client, RPL_HOSTHIDDEN, "%s :is now your hidden host", | |
51 | client->host); | |
52 | else | |
53 | sendto_one_numeric(client, RPL_HOSTHIDDEN, "%s :hostname reset", | |
54 | client->host); | |
55 | ||
56 | sendto_server(NULL, NULL, | |
57 | CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s :%s", | |
58 | use_id(&me), use_id(client), client->host); | |
59 | sendto_server(NULL, NULL, | |
60 | CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s", | |
61 | use_id(&me), use_id(client), client->host); | |
62 | sendto_server(NULL, NULL, | |
63 | NOCAPS, CAP_TS6, ":%s ENCAP * CHGHOST %s :%s", | |
64 | me.name, client->name, client->host); | |
65 | if (irccmp(client->host, client->orighost)) | |
66 | SetDynSpoof(client); | |
67 | else | |
68 | ClearDynSpoof(client); | |
69 | } | |
70 | ||
762cc38c | 71 | #define Nval 0x8c3a48ac |
72 | #define HOSTLEN 63 | |
73 | #define INITDATA "98fwqefnoiqefv03f423t34gbv3vb89tg432t3b8" /* change this */ | |
74 | ||
75 | static inline unsigned int | |
76 | get_string_entropy(const char *inbuf) | |
77 | { | |
78 | unsigned int accum = 1; | |
79 | ||
80 | while(*inbuf != '\0') | |
81 | accum += *inbuf++; | |
82 | ||
83 | return accum; | |
84 | } | |
85 | ||
86 | /* calls get_string_entropy() and toasts it against INITDATA */ | |
87 | static inline unsigned int | |
88 | get_string_weighted_entropy(const char *inbuf) | |
89 | { | |
90 | static int base_entropy = 0; | |
91 | unsigned int accum = get_string_entropy(inbuf); | |
92 | ||
93 | /* initialize the algorithm if it is not yet ready */ | |
94 | if (base_entropy == 0) | |
95 | base_entropy = get_string_entropy(INITDATA); | |
96 | ||
97 | return (Nval * accum) ^ base_entropy; | |
98 | } | |
99 | ||
212380e3 | 100 | static void |
762cc38c | 101 | do_host_cloak_ip(const char *inbuf, char *outbuf) |
212380e3 | 102 | { |
762cc38c | 103 | char *tptr; |
104 | unsigned int accum = get_string_weighted_entropy(inbuf); | |
105 | char buf[HOSTLEN]; | |
106 | ||
107 | strncpy(buf, inbuf, HOSTLEN); | |
108 | tptr = strrchr(buf, '.'); | |
514235a7 | 109 | |
110 | if (tptr == NULL) | |
b076458c | 111 | { |
112 | strncpy(outbuf, inbuf, HOSTLEN); | |
514235a7 | 113 | return; |
b076458c | 114 | } |
514235a7 | 115 | |
762cc38c | 116 | *tptr++ = '\0'; |
212380e3 | 117 | |
762cc38c | 118 | snprintf(outbuf, HOSTLEN, "%s.%x", buf, accum); |
119 | } | |
120 | ||
121 | static void | |
122 | do_host_cloak_host(const char *inbuf, char *outbuf) | |
123 | { | |
124 | char b26_alphabet[] = "abcdefghijklmnopqrstuvwxyz"; | |
125 | char *tptr; | |
126 | unsigned int accum = get_string_weighted_entropy(inbuf); | |
127 | ||
128 | strncpy(outbuf, inbuf, HOSTLEN); | |
129 | ||
130 | /* pass 1: scramble first section of hostname using base26 | |
131 | * alphabet toasted against the weighted entropy of the string. | |
132 | * | |
133 | * numbers are not changed at this time, only letters. | |
134 | */ | |
135 | for (tptr = outbuf; *tptr != '\0'; tptr++) | |
212380e3 | 136 | { |
762cc38c | 137 | if (*tptr == '.') |
138 | break; | |
139 | ||
140 | if (isdigit(*tptr) || *tptr == '-') | |
141 | continue; | |
142 | ||
143 | *tptr = b26_alphabet[(*tptr * accum) % 26]; | |
212380e3 | 144 | } |
762cc38c | 145 | |
146 | /* pass 2: scramble each number in the address */ | |
147 | for (tptr = outbuf; *tptr != '\0'; tptr++) | |
148 | { | |
149 | if (isdigit(*tptr)) | |
150 | { | |
151 | *tptr = 48 + ((*tptr * accum) % 10); | |
152 | } | |
153 | } | |
212380e3 | 154 | } |
155 | ||
156 | static void | |
157 | check_umode_change(void *vdata) | |
158 | { | |
159 | hook_data_umode_changed *data = (hook_data_umode_changed *)vdata; | |
160 | struct Client *source_p = data->client; | |
161 | ||
162 | if (!MyClient(source_p)) | |
163 | return; | |
164 | ||
165 | /* didn't change +h umode, we don't need to do anything */ | |
166 | if (!((data->oldumodes ^ source_p->umodes) & user_modes['h'])) | |
167 | return; | |
168 | ||
169 | if (source_p->umodes & user_modes['h']) | |
170 | { | |
171 | if (IsIPSpoof(source_p) || source_p->localClient->mangledhost == NULL || (IsDynSpoof(source_p) && strcmp(source_p->host, source_p->localClient->mangledhost))) | |
172 | { | |
173 | source_p->umodes &= ~user_modes['h']; | |
174 | return; | |
175 | } | |
176 | if (strcmp(source_p->host, source_p->localClient->mangledhost)) | |
177 | { | |
178 | strlcpy(source_p->host, source_p->localClient->mangledhost, HOSTLEN); | |
179 | distribute_hostchange(source_p); | |
180 | } | |
181 | else /* not really nice, but we need to send this numeric here */ | |
182 | sendto_one_numeric(source_p, RPL_HOSTHIDDEN, "%s :is now your hidden host", | |
183 | source_p->host); | |
184 | } | |
185 | else if (!(source_p->umodes & user_modes['h'])) | |
186 | { | |
187 | if (source_p->localClient->mangledhost != NULL && | |
188 | !strcmp(source_p->host, source_p->localClient->mangledhost)) | |
189 | { | |
190 | strlcpy(source_p->host, source_p->orighost, HOSTLEN); | |
191 | distribute_hostchange(source_p); | |
192 | } | |
193 | } | |
194 | } | |
195 | ||
196 | static void | |
197 | check_new_user(void *vdata) | |
198 | { | |
199 | struct Client *source_p = (void *)vdata; | |
200 | ||
201 | if (IsIPSpoof(source_p)) | |
202 | { | |
203 | source_p->umodes &= ~user_modes['h']; | |
204 | return; | |
205 | } | |
c51d32ba | 206 | source_p->localClient->mangledhost = rb_malloc(HOSTLEN); |
212380e3 | 207 | if (!irccmp(source_p->orighost, source_p->sockhost)) |
762cc38c | 208 | do_host_cloak_ip(source_p->orighost, source_p->localClient->mangledhost); |
212380e3 | 209 | else |
762cc38c | 210 | do_host_cloak_host(source_p->orighost, source_p->localClient->mangledhost); |
212380e3 | 211 | if (IsDynSpoof(source_p)) |
212 | source_p->umodes &= ~user_modes['h']; | |
213 | if (source_p->umodes & user_modes['h']) | |
214 | { | |
215 | strlcpy(source_p->host, source_p->localClient->mangledhost, sizeof(source_p->host)); | |
216 | if (irccmp(source_p->host, source_p->orighost)) | |
217 | SetDynSpoof(source_p); | |
218 | } | |
219 | } |