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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); | |
212380e3 | 62 | if (irccmp(client->host, client->orighost)) |
63 | SetDynSpoof(client); | |
64 | else | |
65 | ClearDynSpoof(client); | |
66 | } | |
67 | ||
762cc38c | 68 | #define Nval 0x8c3a48ac |
69 | #define HOSTLEN 63 | |
70 | #define INITDATA "98fwqefnoiqefv03f423t34gbv3vb89tg432t3b8" /* change this */ | |
71 | ||
72 | static inline unsigned int | |
73 | get_string_entropy(const char *inbuf) | |
74 | { | |
75 | unsigned int accum = 1; | |
76 | ||
77 | while(*inbuf != '\0') | |
78 | accum += *inbuf++; | |
79 | ||
80 | return accum; | |
81 | } | |
82 | ||
83 | /* calls get_string_entropy() and toasts it against INITDATA */ | |
84 | static inline unsigned int | |
85 | get_string_weighted_entropy(const char *inbuf) | |
86 | { | |
87 | static int base_entropy = 0; | |
88 | unsigned int accum = get_string_entropy(inbuf); | |
89 | ||
90 | /* initialize the algorithm if it is not yet ready */ | |
91 | if (base_entropy == 0) | |
92 | base_entropy = get_string_entropy(INITDATA); | |
93 | ||
94 | return (Nval * accum) ^ base_entropy; | |
95 | } | |
96 | ||
212380e3 | 97 | static void |
762cc38c | 98 | do_host_cloak_ip(const char *inbuf, char *outbuf) |
212380e3 | 99 | { |
762cc38c | 100 | char *tptr; |
101 | unsigned int accum = get_string_weighted_entropy(inbuf); | |
102 | char buf[HOSTLEN]; | |
103 | ||
104 | strncpy(buf, inbuf, HOSTLEN); | |
105 | tptr = strrchr(buf, '.'); | |
514235a7 | 106 | |
107 | if (tptr == NULL) | |
b076458c | 108 | { |
109 | strncpy(outbuf, inbuf, HOSTLEN); | |
514235a7 | 110 | return; |
b076458c | 111 | } |
514235a7 | 112 | |
762cc38c | 113 | *tptr++ = '\0'; |
212380e3 | 114 | |
762cc38c | 115 | snprintf(outbuf, HOSTLEN, "%s.%x", buf, accum); |
116 | } | |
117 | ||
118 | static void | |
119 | do_host_cloak_host(const char *inbuf, char *outbuf) | |
120 | { | |
121 | char b26_alphabet[] = "abcdefghijklmnopqrstuvwxyz"; | |
122 | char *tptr; | |
123 | unsigned int accum = get_string_weighted_entropy(inbuf); | |
124 | ||
125 | strncpy(outbuf, inbuf, HOSTLEN); | |
126 | ||
127 | /* pass 1: scramble first section of hostname using base26 | |
128 | * alphabet toasted against the weighted entropy of the string. | |
129 | * | |
130 | * numbers are not changed at this time, only letters. | |
131 | */ | |
132 | for (tptr = outbuf; *tptr != '\0'; tptr++) | |
212380e3 | 133 | { |
762cc38c | 134 | if (*tptr == '.') |
135 | break; | |
136 | ||
137 | if (isdigit(*tptr) || *tptr == '-') | |
138 | continue; | |
139 | ||
140 | *tptr = b26_alphabet[(*tptr * accum) % 26]; | |
212380e3 | 141 | } |
762cc38c | 142 | |
143 | /* pass 2: scramble each number in the address */ | |
144 | for (tptr = outbuf; *tptr != '\0'; tptr++) | |
145 | { | |
146 | if (isdigit(*tptr)) | |
147 | { | |
148 | *tptr = 48 + ((*tptr * accum) % 10); | |
149 | } | |
150 | } | |
212380e3 | 151 | } |
152 | ||
153 | static void | |
154 | check_umode_change(void *vdata) | |
155 | { | |
156 | hook_data_umode_changed *data = (hook_data_umode_changed *)vdata; | |
157 | struct Client *source_p = data->client; | |
158 | ||
159 | if (!MyClient(source_p)) | |
160 | return; | |
161 | ||
162 | /* didn't change +h umode, we don't need to do anything */ | |
163 | if (!((data->oldumodes ^ source_p->umodes) & user_modes['h'])) | |
164 | return; | |
165 | ||
166 | if (source_p->umodes & user_modes['h']) | |
167 | { | |
168 | if (IsIPSpoof(source_p) || source_p->localClient->mangledhost == NULL || (IsDynSpoof(source_p) && strcmp(source_p->host, source_p->localClient->mangledhost))) | |
169 | { | |
170 | source_p->umodes &= ~user_modes['h']; | |
171 | return; | |
172 | } | |
173 | if (strcmp(source_p->host, source_p->localClient->mangledhost)) | |
174 | { | |
907468c4 | 175 | rb_strlcpy(source_p->host, source_p->localClient->mangledhost, HOSTLEN); |
212380e3 | 176 | distribute_hostchange(source_p); |
177 | } | |
178 | else /* not really nice, but we need to send this numeric here */ | |
179 | sendto_one_numeric(source_p, RPL_HOSTHIDDEN, "%s :is now your hidden host", | |
180 | source_p->host); | |
181 | } | |
182 | else if (!(source_p->umodes & user_modes['h'])) | |
183 | { | |
184 | if (source_p->localClient->mangledhost != NULL && | |
185 | !strcmp(source_p->host, source_p->localClient->mangledhost)) | |
186 | { | |
907468c4 | 187 | rb_strlcpy(source_p->host, source_p->orighost, HOSTLEN); |
212380e3 | 188 | distribute_hostchange(source_p); |
189 | } | |
190 | } | |
191 | } | |
192 | ||
193 | static void | |
194 | check_new_user(void *vdata) | |
195 | { | |
196 | struct Client *source_p = (void *)vdata; | |
197 | ||
198 | if (IsIPSpoof(source_p)) | |
199 | { | |
200 | source_p->umodes &= ~user_modes['h']; | |
201 | return; | |
202 | } | |
c51d32ba | 203 | source_p->localClient->mangledhost = rb_malloc(HOSTLEN); |
212380e3 | 204 | if (!irccmp(source_p->orighost, source_p->sockhost)) |
762cc38c | 205 | do_host_cloak_ip(source_p->orighost, source_p->localClient->mangledhost); |
212380e3 | 206 | else |
762cc38c | 207 | do_host_cloak_host(source_p->orighost, source_p->localClient->mangledhost); |
212380e3 | 208 | if (IsDynSpoof(source_p)) |
209 | source_p->umodes &= ~user_modes['h']; | |
210 | if (source_p->umodes & user_modes['h']) | |
211 | { | |
907468c4 | 212 | rb_strlcpy(source_p->host, source_p->localClient->mangledhost, sizeof(source_p->host)); |
212380e3 | 213 | if (irccmp(source_p->host, source_p->orighost)) |
214 | SetDynSpoof(source_p); | |
215 | } | |
216 | } |