/*
- protocol.c -- handle the meta-protocol
- Copyright (C) 1999,2000 Ivo Timmermans <itimmermans@bigfoot.com>,
- 2000 Guus Sliepen <guus@sliepen.warande.net>
+ protocol.c -- handle the meta-protocol, basic functions
+ Copyright (C) 1999-2001 Ivo Timmermans <ivo@o2w.nl>,
+ 2000,2001 Guus Sliepen <guus@sliepen.eu.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.67 2000/11/25 13:33:33 guus Exp $
+ $Id: protocol.c,v 1.28.4.144 2003/07/29 10:50:15 guus Exp $
*/
-#include "config.h"
-
-#include <sys/types.h>
-
-#include <stdlib.h>
-#include <string.h>
-#include <syslog.h>
-#include <sys/socket.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <stdarg.h>
-
-#include <utils.h>
-#include <xalloc.h>
-
-#include <netinet/in.h>
-
-#ifdef HAVE_OPENSSL_SHA_H
-# include <openssl/sha.h>
-#else
-# include <sha.h>
-#endif
-
-#ifdef HAVE_OPENSSL_RAND_H
-# include <openssl/rand.h>
-#else
-# include <rand.h>
-#endif
-
-#ifdef HAVE_OPENSSL_EVP_H
-# include <openssl/evp.h>
-#else
-# include <evp.h>
-#endif
-
+#include "system.h"
#include "conf.h"
-#include "net.h"
-#include "netutl.h"
-#include "protocol.h"
-#include "meta.h"
#include "connection.h"
+#include "logger.h"
+#include "meta.h"
+#include "protocol.h"
+#include "utils.h"
+#include "xalloc.h"
-#include "system.h"
-
-int check_id(char *id)
-{
- int i;
-
- for (i = 0; i < strlen(id); i++)
- if(!isalnum(id[i]) && id[i] != '_')
- return -1;
-
- return 0;
-}
-
-/* Generic request routines - takes care of logging and error detection as well */
-
-int send_request(connection_t *cl, const char *format, ...)
-{
- va_list args;
- char buffer[MAXBUFSIZE];
- int len, request;
-
-cp
- /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic,
- and there is a limit on the input buffer anyway */
-
- va_start(args, format);
- len = vsnprintf(buffer, MAXBUFSIZE, format, args);
- request = va_arg(args, int);
- va_end(args);
-
- if(len < 0 || len > MAXBUFSIZE-1)
- {
- syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
- return -1;
- }
-
- len++;
-
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
-
-cp
- return send_meta(cl, buffer, len);
-}
-
-int receive_request(connection_t *cl)
-{
- int request;
-cp
- if(sscanf(cl->buffer, "%d", &request) == 1)
- {
- if((request < 0) || (request > 255) || (request_handlers[request] == NULL))
- {
- syslog(LOG_ERR, _("Unknown request from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
- else
- {
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
- request_name[request], cl->name, cl->hostname);
- }
-
- if((cl->allow_request != ALL) && (cl->allow_request != request))
- {
- syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- if(request_handlers[request](cl))
- /* Something went wrong. Probably scriptkiddies. Terminate. */
- {
- syslog(LOG_ERR, _("Error while processing %s from %s (%s)"),
- request_name[request], cl->name, cl->hostname);
- return -1;
- }
- }
- else
- {
- syslog(LOG_ERR, _("Bogus data received from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
-cp
- return 0;
-}
-
-/* Connection protocol:
-
- Client Server
- send_id(u)
- send_challenge(R)
- send_chal_reply(H)
- send_id(u)
- send_challenge(R)
- send_chal_reply(H)
- ---------------------------------------
- send_metakey(R)
- send_metakey(R)
- ---------------------------------------
- send_ack(u)
- send_ack(u)
- ---------------------------------------
- Other requests(E)...
-
- (u) Unencrypted,
- (R) RSA,
- (H) SHA1,
- (E) Encrypted with symmetric cipher.
-
- Part of the challenge is directly used to set the symmetric cipher key and the initial vector.
- Since a man-in-the-middle cannot decrypt the RSA challenges, this means that he cannot get or
- forge the key for the symmetric cipher.
-*/
-
-int send_id(connection_t *cl)
-{
-cp
- cl->allow_request = CHALLENGE;
-cp
- return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port);
-}
-
-int id_h(connection_t *cl)
-{
- connection_t *old;
- config_t const *cfg;
- char name[MAX_STRING_SIZE];
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %d %lx %hd", name, &cl->protocol_version, &cl->options, &cl->port) != 4)
- {
- syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
- return -1;
- }
-
- /* Check if version matches */
-
- if(cl->protocol_version != myself->protocol_version)
- {
- syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"),
- cl->name, cl->hostname, cl->protocol_version);
- return -1;
- }
-
- /* Check if identity is a valid name */
-
- if(check_id(name))
- {
- syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
- return -1;
- }
-
- /* Copy string to cl */
-
- cl->name = xstrdup(name);
-
- /* Load information about peer */
-
- if(read_host_config(cl))
- {
- syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name);
- return -1;
- }
-
- /* First check if the host we connected to is already in our
- connection list. If so, we are probably making a loop, which
- is not desirable.
- */
-
- if(cl->status.outgoing)
- {
- if((old = lookup_id(cl->name)))
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->name, cl->hostname);
- cl->status.outgoing = 0;
- old->status.outgoing = 1;
- terminate_connection(cl);
- return 0;
- }
- }
-
- /* Now we can add the name to the id tree */
-
- id_add(cl);
-
- /* Read in the public key, so that we can send a challenge */
-
- if((cfg = get_config_val(cl->config, config_publickey)))
- {
- cl->rsa_key = RSA_new();
- BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
- BN_hex2bn(&cl->rsa_key->e, "FFFF");
- }
- else
- {
- syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-cp
- return send_challenge(cl);
-}
-
-int send_challenge(connection_t *cl)
-{
- char *buffer;
- int len, x;
-cp
- len = RSA_size(cl->rsa_key);
-
- /* Allocate buffers for the challenge */
-
- buffer = xmalloc(len*2+1);
-
- if(cl->hischallenge)
- free(cl->hischallenge);
-
- cl->hischallenge = xmalloc(len);
-cp
- /* Copy random data to the buffer */
-
- RAND_bytes(cl->hischallenge, len);
-
- cl->hischallenge[0] &= 0x7F; /* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->hischallenge, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer);
- }
-
- /* Encrypt the random data */
-
- if(RSA_public_encrypt(len, cl->hischallenge, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */
- {
- syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
- free(buffer);
- return -1;
- }
-cp
- /* Convert the encrypted random data to a hexadecimal formatted string */
-
- bin2hex(buffer, buffer, len);
- buffer[len*2] = '\0';
-
- /* Send the challenge */
-
- cl->allow_request = CHAL_REPLY;
- x = send_request(cl, "%d %s", CHALLENGE, buffer);
- free(buffer);
-cp
- return x;
-}
-
-int challenge_h(connection_t *cl)
-{
- char buffer[MAX_STRING_SIZE];
- int len;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1)
- {
- syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- len = RSA_size(myself->rsa_key);
-
- /* Check if the length of the challenge is all right */
-
- if(strlen(buffer) != len*2)
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Allocate buffers for the challenge */
-
- if(!cl->mychallenge)
- cl->mychallenge = xmalloc(len);
-
- /* Convert the challenge from hexadecimal back to binary */
-
- hex2bin(buffer,buffer,len);
-
- /* Decrypt the challenge */
-
- if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */
- {
- syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->mychallenge, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
- }
-
- /* Rest is done by send_chal_reply() */
-cp
- return send_chal_reply(cl);
-}
-
-int send_chal_reply(connection_t *cl)
-{
- char hash[SHA_DIGEST_LENGTH*2+1];
-cp
- if(!cl->mychallenge)
- {
- syslog(LOG_ERR, _("Trying to send CHAL_REPLY to %s (%s) without a valid CHALLENGE"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Calculate the hash from the challenge we received */
-
- SHA1(cl->mychallenge, RSA_size(myself->rsa_key), hash);
-
- /* Convert the hash to a hexadecimal formatted string */
-
- bin2hex(hash,hash,SHA_DIGEST_LENGTH);
- hash[SHA_DIGEST_LENGTH*2] = '\0';
-
- /* Send the reply */
-
- if(cl->status.outgoing)
- cl->allow_request = ID;
- else
- cl->allow_request = METAKEY;
-
-cp
- return send_request(cl, "%d %s", CHAL_REPLY, hash);
-}
-
-int chal_reply_h(connection_t *cl)
-{
- char hishash[MAX_STRING_SIZE];
- char myhash[SHA_DIGEST_LENGTH];
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING, hishash) != 1)
- {
- syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if the length of the hash is all right */
-
- if(strlen(hishash) != SHA_DIGEST_LENGTH*2)
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Convert the hash to binary format */
-
- hex2bin(hishash, hishash, SHA_DIGEST_LENGTH);
-
- /* Calculate the hash from the challenge we sent */
-
- SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash);
-
- /* Verify the incoming hash with the calculated hash */
-
- if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname);
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
- hishash[SHA_DIGEST_LENGTH*2] = '\0';
- syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
- }
- return -1;
- }
-
-
- /* Identity has now been positively verified.
- If we are accepting this new connection, then send our identity,
- if we are making this connecting, acknowledge.
- */
-cp
- if(cl->status.outgoing)
- return send_metakey(cl);
- else
- return send_id(cl);
-}
-
-int send_metakey(connection_t *cl)
-{
- char *buffer;
- int len, x;
-cp
- len = RSA_size(cl->rsa_key);
-
- /* Allocate buffers for the meta key */
-
- buffer = xmalloc(len*2+1);
-
- if(!cl->cipher_outkey)
- cl->cipher_outkey = xmalloc(len);
-
- if(!cl->cipher_outctx)
- cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx));
-cp
- /* Copy random data to the buffer */
-
- RAND_bytes(cl->cipher_outkey, len);
-
- cl->cipher_outkey[0] &= 0x7F; /* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->cipher_outkey, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
- }
-
- /* Encrypt the random data */
-
- if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */
- {
- syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
- free(buffer);
- return -1;
- }
-cp
- /* Convert the encrypted random data to a hexadecimal formatted string */
-
- bin2hex(buffer, buffer, len);
- buffer[len*2] = '\0';
-
- /* Send the meta key */
-
- if(cl->status.outgoing)
- cl->allow_request = METAKEY;
- else
- cl->allow_request = ACK;
-
- x = send_request(cl, "%d %s", METAKEY, buffer);
- free(buffer);
-
- EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len);
-cp
- return x;
-}
-
-int metakey_h(connection_t *cl)
-{
- char buffer[MAX_STRING_SIZE];
- int len;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1)
- {
- syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- len = RSA_size(myself->rsa_key);
-
- /* Check if the length of the meta key is all right */
-
- if(strlen(buffer) != len*2)
- {
- syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Allocate buffers for the meta key */
-
- if(!cl->cipher_inkey)
- cl->cipher_inkey = xmalloc(len);
-
- if(!cl->cipher_inctx)
- cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx));
-
- /* Convert the challenge from hexadecimal back to binary */
-
- hex2bin(buffer,buffer,len);
-
- /* Decrypt the meta key */
-
- if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */
- {
- syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->cipher_inkey, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
- }
-
- EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
-
-cp
- if(cl->status.outgoing)
- return send_ack(cl);
- else
- return send_metakey(cl);
-}
-
-int send_ack(connection_t *cl)
-{
- int x;
-cp
- if(cl->status.outgoing)
- cl->allow_request = ACK;
-
- x = send_request(cl, "%d", ACK);
- cl->status.encryptout = 1;
-cp
- return x;
-}
-
-int ack_h(connection_t *cl)
-{
- connection_t *old, *p;
- subnet_t *subnet;
- rbl_t *rbl, *rbl2;
-cp
- /* Okay, before we active the connection, we check if there is another entry
- in the connection list with the same name. If so, it presumably is an
- old connection that has timed out but we don't know it yet.
- */
-
- while((old = lookup_id(cl->name)))
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
- cl->name, old->hostname, cl->hostname);
-
- terminate_connection(old);
- }
-
- /* Activate this connection */
-
- cl->allow_request = ALL;
- cl->status.active = 1;
- cl->status.decryptin = 1;
- cl->nexthop = cl;
- cl->cipher_pkttype = EVP_bf_cfb();
- cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
-
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
-
-cp
- if(!cl->status.outgoing)
- send_ack(cl);
-
- /* Send him our subnets */
-
- RBL_FOREACH(myself->subnet_tree, rbl)
- {
- subnet = (subnet_t *)rbl->data;
- send_add_subnet(cl, subnet);
- }
- /* And send him all the hosts and their subnets we know... */
-
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
-
- if(p != cl && p->status.active)
- {
- /* Notify others of this connection */
-
- if(p->status.meta)
- send_add_host(p, cl);
-
- /* Notify new connection of everything we know */
-
- send_add_host(cl, p);
-
- RBL_FOREACH(p->subnet_tree, rbl2)
- {
- subnet = (subnet_t *)rbl2->data;
- send_add_subnet(cl, subnet);
- }
- }
- }
-cp
- return 0;
-}
-
-/* Address and subnet information exchange */
-
-int send_add_subnet(connection_t *cl, subnet_t *subnet)
-{
- int x;
- char *netstr;
-cp
- x = send_request(cl, "%d %s %s", ADD_SUBNET,
- subnet->owner->name, netstr = net2str(subnet));
- free(netstr);
-cp
- return x;
-}
-
-int add_subnet_h(connection_t *cl)
-{
- char subnetstr[MAX_STRING_SIZE];
- char name[MAX_STRING_SIZE];
- connection_t *owner, *p;
- subnet_t *subnet;
- rbl_t *rbl;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 2)
- {
- syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if owner name is a valid */
-
- if(check_id(name))
- {
- syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if subnet string is valid */
-
- if(!(subnet = str2net(subnetstr)))
- {
- syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if somebody tries to add a subnet of ourself */
-
- if(!strcmp(name, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"),
- cl->name, cl->hostname);
- sighup = 1;
- return 0;
- }
-
- /* Check if the owner of the new subnet is in the connection list */
-
- if(!(owner = lookup_id(name)))
- {
- syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
- name, cl->name, cl->hostname);
- return -1;
- }
-
- /* If everything is correct, add the subnet to the list of the owner */
-
- subnet_add(owner, subnet);
-
- /* Tell the rest */
-
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p->status.meta && p->status.active && p!= cl)
- send_add_subnet(p, subnet);
- }
-cp
- return 0;
-}
-
-int send_del_subnet(connection_t *cl, subnet_t *subnet)
-{
- int x;
- char *netstr;
-cp
- netstr = net2str(subnet);
- x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr);
- free(netstr);
-cp
- return x;
-}
-
-int del_subnet_h(connection_t *cl)
-{
- char subnetstr[MAX_STRING_SIZE];
- char name[MAX_STRING_SIZE];
- connection_t *owner, *p;
- subnet_t *subnet;
- rbl_t *rbl;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 3)
- {
- syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if owner name is a valid */
-
- if(check_id(name))
- {
- syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if subnet string is valid */
-
- if(!(subnet = str2net(subnetstr)))
- {
- syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
- return -1;
- }
-
- free(subnetstr);
-
- /* Check if somebody tries to add a subnet of ourself */
-
- if(!strcmp(name, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"),
- cl->name, cl->hostname);
- sighup = 1;
- return 0;
- }
-
- /* Check if the owner of the new subnet is in the connection list */
-
- if(!(owner = lookup_id(name)))
- {
- syslog(LOG_ERR, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"),
- name, cl->name, cl->hostname);
- return -1;
- }
-
- /* If everything is correct, delete the subnet from the list of the owner */
+/* Jumptable for the request handlers */
- subnet_del(subnet);
+static bool (*request_handlers[])(connection_t *) = {
+ id_h, metakey_h, challenge_h, chal_reply_h, ack_h,
+ status_h, error_h, termreq_h,
+ ping_h, pong_h,
+ add_subnet_h, del_subnet_h,
+ add_edge_h, del_edge_h,
+ key_changed_h, req_key_h, ans_key_h, tcppacket_h,
+};
- /* Tell the rest */
-
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p->status.meta && p->status.active && p!= cl)
- send_del_subnet(p, subnet);
- }
-cp
- return 0;
-}
+/* Request names */
-/* New and closed connections notification */
+static char (*request_name[]) = {
+ "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK",
+ "STATUS", "ERROR", "TERMREQ",
+ "PING", "PONG",
+ "ADD_SUBNET", "DEL_SUBNET",
+ "ADD_EDGE", "DEL_EDGE", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", "PACKET",
+};
-int send_add_host(connection_t *cl, connection_t *other)
-{
-cp
- return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
- other->name, other->address, other->port, other->options);
-}
+static avl_tree_t *past_request_tree;
-int add_host_h(connection_t *cl)
+bool check_id(const char *id)
{
- connection_t *old, *new, *p;
- char name[MAX_STRING_SIZE];
- rbl_t *rbl;
-cp
- new = new_connection();
-
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &new->address, &new->port, &new->options) != 4)
- {
- syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if identity is a valid name */
-
- if(check_id(name))
- {
- syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- free_connection(new);
- return -1;
- }
-
- /* Check if somebody tries to add ourself */
-
- if(!strcmp(name, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
- sighup = 1;
- free_connection(new);
- return 0;
- }
-
- /* Fill in more of the new connection structure */
-
- new->hostname = hostlookup(htonl(new->address));
-
- /* Check if the new host already exists in the connnection list */
-
- if((old = lookup_id(name)))
- {
- if((new->address == old->address) && (new->port == old->port))
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"),
- old->name, old->hostname, name, new->hostname);
- free_connection(new);
- return 0;
- }
- else
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Removing old entry for %s (%s) in favour of new connection"),
- old->name, old->hostname);
-
- terminate_connection(old);
- }
- }
-
- /* Hook it up into the connection */
+ for(; *id; id++)
+ if(!isalnum(*id) && *id != '_')
+ return false;
- new->name = xstrdup(name);
- connection_add(new);
- id_add(new);
-
- /* Tell the rest about the new host */
-
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p->status.meta && p->status.active && p!=cl)
- send_add_host(p, new);
- }
-
- /* Fill in rest of connection structure */
-
- new->nexthop = cl;
- new->status.active = 1;
- new->cipher_pkttype = EVP_bf_cfb();
- new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
-cp
- return 0;
+ return true;
}
-int send_del_host(connection_t *cl, connection_t *other)
-{
-cp
- return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
- other->name, other->address, other->port, other->options);
-}
+/* Generic request routines - takes care of logging and error
+ detection as well */
-int del_host_h(connection_t *cl)
+bool send_request(connection_t *c, const char *format, ...)
{
- char name[MAX_STRING_SIZE];
- ip_t address;
- port_t port;
- long int options;
- connection_t *old, *p;
- rbl_t *rbl;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &address, &port, &options) != 4)
- {
- syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if identity is a valid name */
-
- if(check_id(name))
- {
- syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if somebody tries to delete ourself */
+ va_list args;
+ char buffer[MAXBUFSIZE];
+ int len, request;
- if(!strcmp(name, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
- cl->name, cl->hostname);
- sighup = 1;
- return 0;
- }
+ cp();
- /* Check if the new host already exists in the connnection list */
+ /* Use vsnprintf instead of vasprintf: faster, no memory
+ fragmentation, cleanup is automatic, and there is a limit on the
+ input buffer anyway */
- if(!(old = lookup_id(name)))
- {
- syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for %s which is not in our connection list"),
- name, cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if the rest matches */
-
- if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop)
- {
- syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name);
- return 0;
- }
+ va_start(args, format);
+ len = vsnprintf(buffer, MAXBUFSIZE, format, args);
+ va_end(args);
- /* Ok, since EVERYTHING seems to check out all right, delete it */
-
- old->status.active = 0;
- terminate_connection(old);
-
- /* Tell the rest about the new host */
-
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p->status.meta && p->status.active && p!=cl)
- send_del_host(p, old);
- }
-cp
- return 0;
-}
-
-/* Status and error notification routines */
-
-int send_status(connection_t *cl, int statusno, char *statusstring)
-{
-cp
- if(!statusstring)
- statusstring = status_text[statusno];
-cp
- return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
-}
+ if(len < 0 || len > MAXBUFSIZE - 1) {
+ logger(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"),
+ c->name, c->hostname);
+ return false;
+ }
-int status_h(connection_t *cl)
-{
- int statusno;
- char statusstring[MAX_STRING_SIZE];
-cp
- if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &statusno, statusstring) != 2)
- {
- syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
+ ifdebug(PROTOCOL) {
+ sscanf(buffer, "%d", &request);
+ ifdebug(META)
+ logger(LOG_DEBUG, _("Sending %s to %s (%s): %s"),
+ request_name[request], c->name, c->hostname, buffer);
+ else
+ logger(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request],
+ c->name, c->hostname);
+ }
- if(debug_lvl >= DEBUG_STATUS)
- {
- syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"),
- cl->name, cl->hostname, status_text[statusno], statusstring);
- }
+ buffer[len++] = '\n';
-cp
- return 0;
+ if(c == broadcast) {
+ broadcast_meta(NULL, buffer, len);
+ return true;
+ } else
+ return send_meta(c, buffer, len);
}
-int send_error(connection_t *cl, int errno, char *errstring)
+void forward_request(connection_t *from)
{
-cp
- if(!errstring)
- errstring = strerror(errno);
- return send_request(cl, "%d %d %s", ERROR, errno, errstring);
-}
+ int request;
-int error_h(connection_t *cl)
-{
- int errno;
- char errorstring[MAX_STRING_SIZE];
-cp
- if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &errno, errorstring) != 2)
- {
- syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
+ cp();
- if(debug_lvl >= DEBUG_ERROR)
- {
- syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
- cl->name, cl->hostname, strerror(errno), errorstring);
- }
+ ifdebug(PROTOCOL) {
+ sscanf(from->buffer, "%d", &request);
+ ifdebug(META)
+ logger(LOG_DEBUG, _("Forwarding %s from %s (%s): %s"),
+ request_name[request], from->name, from->hostname,
+ from->buffer);
+ else
+ logger(LOG_DEBUG, _("Forwarding %s from %s (%s)"),
+ request_name[request], from->name, from->hostname);
+ }
- terminate_connection(cl);
-cp
- return 0;
-}
+ from->buffer[from->reqlen - 1] = '\n';
+
+ broadcast_meta(from, from->buffer, from->reqlen);
+}
+
+bool receive_request(connection_t *c)
+{
+ int request;
+
+ cp();
+
+ if(sscanf(c->buffer, "%d", &request) == 1) {
+ if((request < 0) || (request >= LAST) || !request_handlers[request]) {
+ ifdebug(META)
+ logger(LOG_DEBUG, _("Unknown request from %s (%s): %s"),
+ c->name, c->hostname, c->buffer);
+ else
+ logger(LOG_ERR, _("Unknown request from %s (%s)"),
+ c->name, c->hostname);
+
+ return false;
+ } else {
+ ifdebug(PROTOCOL) {
+ ifdebug(META)
+ logger(LOG_DEBUG, _("Got %s from %s (%s): %s"),
+ request_name[request], c->name, c->hostname,
+ c->buffer);
+ else
+ logger(LOG_DEBUG, _("Got %s from %s (%s)"),
+ request_name[request], c->name, c->hostname);
+ }
+ }
+
+ if((c->allow_request != ALL) && (c->allow_request != request)) {
+ logger(LOG_ERR, _("Unauthorized request from %s (%s)"), c->name,
+ c->hostname);
+ return false;
+ }
+
+ if(!request_handlers[request](c)) {
+ /* Something went wrong. Probably scriptkiddies. Terminate. */
+
+ logger(LOG_ERR, _("Error while processing %s from %s (%s)"),
+ request_name[request], c->name, c->hostname);
+ return false;
+ }
+ } else {
+ logger(LOG_ERR, _("Bogus data received from %s (%s)"),
+ c->name, c->hostname);
+ return false;
+ }
-int send_termreq(connection_t *cl)
-{
-cp
- return send_request(cl, "%d", TERMREQ);
+ return true;
}
-int termreq_h(connection_t *cl)
+static int past_request_compare(const past_request_t *a, const past_request_t *b)
{
-cp
- terminate_connection(cl);
-cp
- return 0;
+ return strcmp(a->request, b->request);
}
-/* Keepalive routines - FIXME: needs a closer look */
-
-int send_ping(connection_t *cl)
+static void free_past_request(past_request_t *r)
{
-cp
- cl->status.pinged = 1;
- cl->last_ping_time = time(NULL);
-cp
- return send_request(cl, "%d", PING);
-}
+ cp();
-int ping_h(connection_t *cl)
-{
-cp
- return send_pong(cl);
-}
+ if(r->request)
+ free(r->request);
-int send_pong(connection_t *cl)
-{
-cp
- return send_request(cl, "%d", PONG);
+ free(r);
}
-int pong_h(connection_t *cl)
+void init_requests(void)
{
-cp
- cl->status.pinged = 0;
-cp
- return 0;
-}
-
-/* Key exchange */
+ cp();
-int send_key_changed(connection_t *from, connection_t *cl)
-{
- connection_t *p;
- rbl_t *rbl;
-cp
- RBL_FOREACH(connection_tree, rbl)
- {
- p = (connection_t *)rbl->data;
- if(p != cl && p->status.meta && p->status.active)
- send_request(p, "%d %s", KEY_CHANGED, from->name);
- }
-cp
- return 0;
+ past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request);
}
-int key_changed_h(connection_t *cl)
+void exit_requests(void)
{
- char from_id[MAX_STRING_SIZE];
- connection_t *from;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING, from_id) != 1)
- {
- syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
-
- if(!(from = lookup_id(from_id)))
- {
- syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
- return -1;
- }
-
- from->status.validkey = 0;
- from->status.waitingforkey = 0;
+ cp();
- send_key_changed(from, cl);
-cp
- return 0;
+ avl_delete_tree(past_request_tree);
}
-int send_req_key(connection_t *from, connection_t *to)
+bool seen_request(char *request)
{
-cp
- return send_request(to->nexthop, "%d %s %s", REQ_KEY,
- from->name, to->name);
-}
+ past_request_t p = {
+ .request = request,
+ };
+ past_request_t *new;
-int req_key_h(connection_t *cl)
-{
- char from_id[MAX_STRING_SIZE];
- char to_id[MAX_STRING_SIZE];
- connection_t *from, *to;
- char pktkey[129];
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, from_id, to_id) != 2)
- {
- syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
+ cp();
- if(!(from = lookup_id(from_id)))
- {
- syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
- return -1;
- }
-
- /* Check if this key request is for us */
-
- if(!strcmp(to_id, myself->name))
- {
- bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
- pktkey[myself->cipher_pktkeylength*2] = '\0';
- send_ans_key(myself, from, pktkey);
- }
- else
- {
- if(!(to = lookup_id(to_id)))
- {
- syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"),
- cl->name, cl->hostname, to_id);
- return -1;
- }
-
- if(to->status.validkey) /* Proxy keys */
- {
- bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength);
- pktkey[to->cipher_pktkeylength*2] = '\0';
- send_ans_key(to, from, pktkey);
- }
- else
- send_req_key(from, to);
- }
-
-cp
- return 0;
-}
-
-int send_ans_key(connection_t *from, connection_t *to, char *pktkey)
-{
-cp
- return send_request(to->nexthop, "%d %s %s %s", ANS_KEY,
- from->name, to->name, pktkey);
+ if(avl_search(past_request_tree, &p)) {
+ ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Already seen request"));
+ return true;
+ } else {
+ new = (past_request_t *) xmalloc(sizeof(*new));
+ new->request = xstrdup(request);
+ new->firstseen = now;
+ avl_insert(past_request_tree, new);
+ return false;
+ }
}
-int ans_key_h(connection_t *cl)
+void age_past_requests(void)
{
- char from_id[MAX_STRING_SIZE];
- char to_id[MAX_STRING_SIZE];
- char pktkey[MAX_STRING_SIZE];
- int keylength;
- connection_t *from, *to;
-cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING, from_id, to_id, pktkey) != 3)
- {
- syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"),
- cl->name, cl->hostname);
- return -1;
- }
-
- if(!(from = lookup_id(from_id)))
- {
- syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
- return -1;
- }
-
- /* Check correctness of packet key */
-
- keylength = strlen(pktkey);
-
- if(keylength != from->cipher_pktkeylength*2)
- {
- syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"),
- cl->name, cl->hostname, from->name);
- return -1;
- }
-
- /* Forward it if necessary */
+ avl_node_t *node, *next;
+ past_request_t *p;
+ int left = 0, deleted = 0;
- if(strcmp(to_id, myself->name))
- {
- if(!(to = lookup_id(to_id)))
- {
- syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"),
- cl->name, cl->hostname, to_id);
- return -1;
- }
- send_ans_key(from, to, pktkey);
- }
+ cp();
- /* Update our copy of the origin's packet key */
+ for(node = past_request_tree->head; node; node = next) {
+ next = node->next;
+ p = (past_request_t *) node->data;
- if(from->cipher_pktkey)
- free(from->cipher_pktkey);
-
- from->cipher_pktkey = xstrdup(pktkey);
- keylength /= 2;
- hex2bin(from->cipher_pktkey, from->cipher_pktkey, keylength);
- from->cipher_pktkey[keylength] = '\0';
+ if(p->firstseen + pingtimeout < now)
+ avl_delete_node(past_request_tree, node), deleted++;
+ else
+ left++;
+ }
- from->status.validkey = 1;
- from->status.waitingforkey = 0;
-cp
- return 0;
+ if(left || deleted)
+ ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Aging past requests: deleted %d, left %d\n"),
+ deleted, left);
}
-
-/* Jumptable for the request handlers */
-
-int (*request_handlers[])(connection_t*) = {
- id_h, challenge_h, chal_reply_h, metakey_h, ack_h,
- status_h, error_h, termreq_h,
- ping_h, pong_h,
- add_host_h, del_host_h,
- add_subnet_h, del_subnet_h,
- key_changed_h, req_key_h, ans_key_h,
-};
-
-/* Request names */
-
-char (*request_name[]) = {
- "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK",
- "STATUS", "ERROR", "TERMREQ",
- "PING", "PONG",
- "ADD_HOST", "DEL_HOST",
- "ADD_SUBNET", "DEL_SUBNET",
- "KEY_CHANGED", "REQ_KEY", "ANS_KEY",
-};
-
-/* Status strings */
-
-char (*status_text[]) = {
- "Warning",
-};
-
-/* Error strings */
-
-char (*error_text[]) = {
- "Error",
-};
projects / tinc / blobdiff