Copy ip_cloaking.c to ip_cloaking_3.0.c

diff --git a/extensions/ip_cloaking_3.0.c b/extensions/ip_cloaking_3.0.c
new file mode 100644 (file)
index 0000000..e80a19a
--- /dev/null
+++ b/extensions/ip_cloaking_3.0.c
@@ -0,0 +1,230 @@
+/* $Id: ip_cloaking.c 3526 2007-07-06 07:56:14Z nenolod $ */
+
+#include "stdinc.h"
+#include "modules.h"
+#include "hook.h"
+#include "client.h"
+#include "ircd.h"
+#include "send.h"
+#include "s_conf.h"
+#include "s_user.h"
+#include "s_serv.h"
+#include "numeric.h"
+
+/* if you're modifying this module, you'll probably to change this */
+#define KEY 0x13748cfa
+
+static int
+_modinit(void)
+{
+       /* add the usermode to the available slot */
+       user_modes['h'] = find_umode_slot();
+       construct_umodebuf();
+
+       return 0;
+}
+
+static void
+_moddeinit(void)
+{
+       /* disable the umode and remove it from the available list */
+       user_modes['h'] = 0;
+       construct_umodebuf();
+}
+
+static void check_umode_change(void *data);
+static void check_new_user(void *data);
+mapi_hfn_list_av1 ip_cloaking_hfnlist[] = {
+       { "umode_changed", (hookfn) check_umode_change },
+       { "new_local_user", (hookfn) check_new_user },
+       { NULL, NULL }
+};
+
+DECLARE_MODULE_AV1(ip_cloaking, _modinit, _moddeinit, NULL, NULL,
+                       ip_cloaking_hfnlist, "$Revision: 3526 $");
+
+static void
+distribute_hostchange(struct Client *client)
+{
+       if (irccmp(client->host, client->orighost))
+               sendto_one_numeric(client, RPL_HOSTHIDDEN, "%s :is now your hidden host",
+                       client->host);
+       else
+               sendto_one_numeric(client, RPL_HOSTHIDDEN, "%s :hostname reset",
+                       client->host);
+
+       sendto_server(NULL, NULL,
+               CAP_EUID | CAP_TS6, NOCAPS, ":%s CHGHOST %s :%s",
+               use_id(&me), use_id(client), client->host);
+       sendto_server(NULL, NULL,
+               CAP_TS6, CAP_EUID, ":%s ENCAP * CHGHOST %s :%s",
+               use_id(&me), use_id(client), client->host);
+       if (irccmp(client->host, client->orighost))
+               SetDynSpoof(client);
+       else
+               ClearDynSpoof(client);
+}
+
+#define Nval 0x8c3a48ac
+#define HOSTLEN 63
+#define INITDATA "98fwqefnoiqefv03f423t34gbv3vb89tg432t3b8" /* change this */
+
+static inline unsigned int
+get_string_entropy(const char *inbuf)
+{
+       unsigned int accum = 1;
+
+       while(*inbuf != '\0')
+               accum += *inbuf++;
+
+       return accum;
+}
+
+/* calls get_string_entropy() and toasts it against INITDATA */
+static inline unsigned int
+get_string_weighted_entropy(const char *inbuf)
+{
+       static int base_entropy = 0;
+        unsigned int accum = get_string_entropy(inbuf);
+
+       /* initialize the algorithm if it is not yet ready */
+       if (base_entropy == 0)
+               base_entropy = get_string_entropy(INITDATA);
+
+        return (Nval * accum) ^ base_entropy;
+}
+
+static void
+do_host_cloak_ip(const char *inbuf, char *outbuf)
+{
+       char *tptr;
+       unsigned int accum = get_string_weighted_entropy(inbuf);
+       char buf[HOSTLEN];
+       int ipv6 = 0;
+
+       strncpy(buf, inbuf, HOSTLEN);
+       tptr = strrchr(buf, '.');
+
+       if (tptr == NULL)
+       {
+               tptr = strrchr(buf, ':');
+               ipv6 = 1;
+       }
+
+       if (tptr == NULL)
+       {
+               strncpy(outbuf, inbuf, HOSTLEN);
+               return;
+       }
+
+       *tptr++ = '\0';
+
+       if(ipv6)
+       {
+           snprintf(outbuf, HOSTLEN, "%s:%x", buf, accum);
+       }
+       else
+       {
+           snprintf(outbuf, HOSTLEN, "%s.%x", buf, accum);
+       }
+}
+
+static void
+do_host_cloak_host(const char *inbuf, char *outbuf)
+{
+       char b26_alphabet[] = "abcdefghijklmnopqrstuvwxyz";
+       char *tptr;
+       unsigned int accum = get_string_weighted_entropy(inbuf);
+
+       strncpy(outbuf, inbuf, HOSTLEN);
+
+       /* pass 1: scramble first section of hostname using base26 
+        * alphabet toasted against the weighted entropy of the string.
+        *
+        * numbers are not changed at this time, only letters.
+        */
+       for (tptr = outbuf; *tptr != '\0'; tptr++)
+       {
+               if (*tptr == '.')
+                       break;
+
+               if (isdigit(*tptr) || *tptr == '-')
+                       continue;
+
+               *tptr = b26_alphabet[(*tptr * accum) % 26];
+       }
+
+       /* pass 2: scramble each number in the address */
+       for (tptr = outbuf; *tptr != '\0'; tptr++)
+       {
+               if (isdigit(*tptr))
+               {
+                       *tptr = 48 + ((*tptr * accum) % 10);
+               }
+       }       
+}
+
+static void
+check_umode_change(void *vdata)
+{
+       hook_data_umode_changed *data = (hook_data_umode_changed *)vdata;
+       struct Client *source_p = data->client;
+
+       if (!MyClient(source_p))
+               return;
+
+       /* didn't change +h umode, we don't need to do anything */
+       if (!((data->oldumodes ^ source_p->umodes) & user_modes['h']))
+               return;
+
+       if (source_p->umodes & user_modes['h'])
+       {
+               if (IsIPSpoof(source_p) || source_p->localClient->mangledhost == NULL || (IsDynSpoof(source_p) && strcmp(source_p->host, source_p->localClient->mangledhost)))
+               {
+                       source_p->umodes &= ~user_modes['h'];
+                       return;
+               }
+               if (strcmp(source_p->host, source_p->localClient->mangledhost))
+               {
+                       rb_strlcpy(source_p->host, source_p->localClient->mangledhost, HOSTLEN);
+                       distribute_hostchange(source_p);
+               }
+               else /* not really nice, but we need to send this numeric here */
+                       sendto_one_numeric(source_p, RPL_HOSTHIDDEN, "%s :is now your hidden host",
+                               source_p->host);
+       }
+       else if (!(source_p->umodes & user_modes['h']))
+       {
+               if (source_p->localClient->mangledhost != NULL &&
+                               !strcmp(source_p->host, source_p->localClient->mangledhost))
+               {
+                       rb_strlcpy(source_p->host, source_p->orighost, HOSTLEN);
+                       distribute_hostchange(source_p);
+               }
+       }
+}
+
+static void
+check_new_user(void *vdata)
+{
+       struct Client *source_p = (void *)vdata;
+
+       if (IsIPSpoof(source_p))
+       {
+               source_p->umodes &= ~user_modes['h'];
+               return;
+       }
+       source_p->localClient->mangledhost = rb_malloc(HOSTLEN);
+       if (!irccmp(source_p->orighost, source_p->sockhost))
+               do_host_cloak_ip(source_p->orighost, source_p->localClient->mangledhost);
+       else
+               do_host_cloak_host(source_p->orighost, source_p->localClient->mangledhost);
+       if (IsDynSpoof(source_p))
+               source_p->umodes &= ~user_modes['h'];
+       if (source_p->umodes & user_modes['h'])
+       {
+               rb_strlcpy(source_p->host, source_p->localClient->mangledhost, sizeof(source_p->host));
+               if (irccmp(source_p->host, source_p->orighost))
+                       SetDynSpoof(source_p);
+       }
+}