along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.86 2001/03/13 21:33:31 guus Exp $
+ $Id: protocol.c,v 1.28.4.107 2001/10/08 11:47:55 guus Exp $
*/
#include "config.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
+#include <openssl/sha.h>
+#include <openssl/rand.h>
+#include <openssl/evp.h>
-#ifdef HAVE_OPENSSL_EVP_H
-# include <openssl/evp.h>
-#else
-# include <evp.h>
+#ifndef HAVE_RAND_PSEUDO_BYTES
+#define RAND_pseudo_bytes RAND_bytes
#endif
-
#include "conf.h"
#include "net.h"
#include "netutl.h"
#include "system.h"
+int mykeyused = 0;
+
int check_id(char *id)
{
int i;
return -1;
}
- len++;
-
if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+ {
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], cl->name, cl->hostname, buffer);
+ else
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+ }
+ buffer[len++] = '\n';
cp
return send_meta(cl, buffer, len);
}
int receive_request(connection_t *cl)
{
int request;
-cp
+cp
if(sscanf(cl->buffer, "%d", &request) == 1)
{
if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL))
{
- syslog(LOG_ERR, _("Unknown request from %s (%s)"),
- cl->name, cl->hostname);
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Unknown request from %s (%s): %s"),
+ cl->name, cl->hostname, cl->buffer);
+ else
+ 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(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Got %s from %s (%s): %s"),
+ request_name[request], cl->name, cl->hostname, cl->buffer);
+ else
+ syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
+ request_name[request], cl->name, cl->hostname);
+ }
}
if((cl->allow_request != ALL) && (cl->allow_request != request))
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.
-*/
+/* The authentication protocol is described in detail in doc/SECURITY2,
+ the rest will be described in doc/PROTOCOL. */
int send_id(connection_t *cl)
{
int id_h(connection_t *cl)
{
- connection_t *old;
- unsigned short int port;
char name[MAX_STRING_SIZE];
- avl_node_t *node;
cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %d %lx %hd", name, &cl->protocol_version, &cl->options, &port) != 4)
+ 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;
/* Copy string to cl */
+ if(cl->name)
+ free(cl->name);
+
cl->name = xstrdup(name);
/* Load information about peer */
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);
-
- /* And uhr... cl->port just changed so we have to unlink it from the connection tree and re-insert... */
-
- node = avl_unlink(connection_tree, cl);
- cl->port = port;
- avl_insert_node(connection_tree, node);
-
/* Read in the public key, so that we can send a metakey */
if(read_rsa_public_key(cl))
old connection that has timed out but we don't know it yet.
*/
- while((old = lookup_id(cl->name)))
+ if((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);
+ syslog(LOG_NOTICE, _("Removing old connection for %s at %s in favour of new connection at %s"),
+ old->name, old->hostname, cl->hostname);
+ if(old->status.outgoing)
+ {
+ cl->status.outgoing = 1;
+ old->status.outgoing = 0;
+ }
+ terminate_connection(old, 0);
+ return 0;
}
-
+
+ /* Also check if no other tinc daemon uses the same IP and port for UDP traffic */
+
+ old = avl_search(active_tree, cl);
+ if(old)
+ {
+ syslog(LOG_ERR, _("%s is listening on %s:%hd, which is already in use by %s!"),
+ cl->name, cl->hostname, cl->port, old->name);
+ return -1;
+ }
+
/* Activate this connection */
cl->allow_request = ALL;
- cl->status.active = 1;
cl->nexthop = cl;
+ cl->prevhop = myself;
cl->cipher_pkttype = EVP_bf_cbc();
cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
+ active_add(cl);
+
if(debug_lvl >= DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
+ if(cl->status.outgoing)
+ seconds_till_retry = 5; /* Reset retry timeout */
cp
/* Check some options */
cl->options |= OPTION_TCPONLY;
}
+ if((myself->options | cl->options) & OPTION_INDIRECT)
+ cl->via = myself;
+ else
+ cl->via = cl;
+
/* Send him our subnets */
for(node = myself->subnet_tree->head; node; node = node->next)
/* And send him all the hosts and their subnets we know... */
- for(node = connection_tree->head; node; node = node->next)
+ for(node = active_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p != cl && p->status.active)
+ if(p != cl)
{
/* Notify others of this connection */
send_add_subnet(cl, subnet);
}
}
- }
+ }
cp
return 0;
}
char *netstr;
char *owner;
cp
- if((cl->options | myself->options | subnet->owner->options) & OPTION_INDIRECT)
- owner = myself->name;
- else
- owner = subnet->owner->name;
+ owner = subnet->owner->name;
x = send_request(cl, "%d %s %s", ADD_SUBNET,
owner, netstr = net2str(subnet));
for(node = connection_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p->status.meta && p->status.active && p!= cl)
+ if(p->status.active && p!= cl)
send_add_subnet(p, subnet);
}
cp
char *netstr;
char *owner;
cp
- if(cl->options & OPTION_INDIRECT)
- owner = myself->name;
- else
- owner = subnet->owner->name;
+ owner = subnet->owner->name;
x = send_request(cl, "%d %s %s", DEL_SUBNET, owner, netstr = net2str(subnet));
free(netstr);
for(node = connection_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p->status.meta && p->status.active && p!= cl)
+ if(p->status.active && p!= cl)
send_del_subnet(p, subnet);
}
cp
int send_add_host(connection_t *cl, connection_t *other)
{
cp
- if(!((cl->options | myself->options | other->options) & OPTION_INDIRECT))
- return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
- other->name, other->address, other->port, other->options);
- else
- return 0;
+ return send_request(cl, "%d %s %lx:%d %lx %s", ADD_HOST,
+ other->name, other->address, other->port, other->options, other->prevhop->name);
}
int add_host_h(connection_t *cl)
{
connection_t *old, *new, *p;
- char name[MAX_STRING_SIZE];
+ char name[MAX_STRING_SIZE], prevhop[MAX_STRING_SIZE];
avl_node_t *node;
cp
new = new_connection();
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &new->address, &new->port, &new->options) != 4)
+ if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx "MAX_STRING, name, &new->address, &new->port, &new->options, prevhop) != 5)
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
return -1;
return -1;
}
+ if(check_id(prevhop))
+ {
+ syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid prevhop 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;
+ syslog(LOG_ERR, _("Got ADD_HOST from %s (%s) for ourself!"), cl->name, cl->hostname);
free_connection(new);
- return 0;
+ return -1;
}
/* Fill in more of the new connection structure */
new->hostname = hostlookup(htonl(new->address));
+ new->prevhop = lookup_id(prevhop);
+
+ if(!new->prevhop)
+ {
+ syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): unknown prevhop"), cl->name, cl->hostname);
+ free_connection(new);
+ return -1;
+ }
+
/* 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((new->address == old->address) && (new->port == old->port) && (cl->nexthop == old->nexthop))
{
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);
+ old->name, old->hostname, cl->name, cl->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);
+ syslog(LOG_NOTICE, _("Removing old entry for %s (%s) from %s in favour of new connection from %s"),
+ old->name, old->hostname, old->nexthop->name, cl->nexthop->name);
- terminate_connection(old);
+ terminate_connection(old, 0);
}
}
- /* Hook it up into the connection */
+ /* Hook it up into the active tree */
new->name = xstrdup(name);
- connection_add(new);
- id_add(new);
+ active_add(new);
/* Tell the rest about the new host */
for(node = connection_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p->status.meta && p->status.active && p!=cl)
+ if(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_cbc();
new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
+
+ if(new->options & OPTION_INDIRECT || new->prevhop->via != new->prevhop)
+ new->via = new->prevhop->via;
+ else
+ new->via = new;
cp
return 0;
}
int send_del_host(connection_t *cl, connection_t *other)
{
cp
- if(!((cl->options | myself->options) & OPTION_INDIRECT))
- return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
- other->name, other->address, other->port, other->options);
- else
- return 0;
+ return send_request(cl, "%d %s %lx:%d %lx %s", DEL_HOST,
+ other->name, other->address, other->port, other->options, other->prevhop->name);
}
int del_host_h(connection_t *cl)
{
- char name[MAX_STRING_SIZE];
- ip_t address;
+ char name[MAX_STRING_SIZE], prevhop[MAX_STRING_SIZE];
+ ipv4_t address;
port_t port;
long int options;
connection_t *old, *p;
avl_node_t *node;
cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &address, &port, &options) != 4)
+ if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx "MAX_STRING, name, &address, &port, &options, prevhop) != 5)
{
syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
cl->name, cl->hostname);
return -1;
}
+ if(check_id(prevhop))
+ {
+ syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid prevhop name"), cl->name, cl->hostname);
+ return -1;
+ }
+
/* Check if somebody tries to delete ourself */
if(!strcmp(name, myself->name))
{
- syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
+ syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for ourself!"),
cl->name, cl->hostname);
- sighup = 1;
- return 0;
+ return -1;
}
- /* Check if the new host already exists in the connnection list */
+ /* Check if the deleted host already exists in the connnection list */
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);
+ cl->name, cl->hostname, name);
return -1;
}
/* Check if the rest matches */
- if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop)
+ if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop || strcmp(prevhop, old->prevhop->name))
{
syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name);
return 0;
/* Ok, since EVERYTHING seems to check out all right, delete it */
- old->status.active = 0;
- terminate_connection(old);
+ terminate_connection(old, 0);
- /* Tell the rest about the new host */
+ /* Tell the rest about the deleted host */
for(node = connection_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p->status.meta && p->status.active && p!=cl)
+ if(p->status.active && p!=cl)
send_del_host(p, old);
}
cp
cl->name, cl->hostname, strerror(err), errorstring);
}
- terminate_connection(cl);
+ terminate_connection(cl, cl->status.meta);
cp
return 0;
}
int termreq_h(connection_t *cl)
{
cp
- terminate_connection(cl);
+ terminate_connection(cl, cl->status.meta);
cp
return 0;
}
int send_ping(connection_t *cl)
{
+ char salt[SALTLEN*2+1];
cp
cl->status.pinged = 1;
cl->last_ping_time = time(NULL);
+ RAND_pseudo_bytes(salt, SALTLEN);
+ bin2hex(salt, salt, SALTLEN);
+ salt[SALTLEN*2] = '\0';
cp
- return send_request(cl, "%d", PING);
+ return send_request(cl, "%d %s", PING, salt);
}
int ping_h(connection_t *cl)
int send_pong(connection_t *cl)
{
+ char salt[SALTLEN*2+1];
+cp
+ RAND_pseudo_bytes(salt, SALTLEN);
+ bin2hex(salt, salt, SALTLEN);
+ salt[SALTLEN*2] = '\0';
cp
- return send_request(cl, "%d", PONG);
+ return send_request(cl, "%d %s", PONG, salt);
}
int pong_h(connection_t *cl)
connection_t *p;
avl_node_t *node;
cp
+ /* Only send this message if some other daemon requested our key previously.
+ This reduces unnecessary key_changed broadcasts.
+ */
+
+ if(from==myself && !mykeyused)
+ return 0;
+
for(node = connection_tree->head; node; node = node->next)
{
p = (connection_t *)node->data;
- if(p != cl && p->status.meta && p->status.active)
- if(!(p->options & OPTION_INDIRECT) || from == myself)
- send_request(p, "%d %s", KEY_CHANGED, from->name);
+ if(p != cl && p->status.active)
+ send_request(p, "%d %s", KEY_CHANGED, from->name);
}
cp
return 0;
from->status.validkey = 0;
from->status.waitingforkey = 0;
- if(!(from->options | cl->options | myself->options) & OPTION_INDIRECT)
- send_key_changed(from, cl);
+ send_key_changed(from, cl);
cp
return 0;
}
/* Check if this key request is for us */
- if(!strcmp(to_id, myself->name))
+ if(!strcmp(to_id, myself->name)) /* Yes, send our own key back */
{
bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
pktkey[myself->cipher_pktkeylength*2] = '\0';
send_ans_key(myself, from, pktkey);
+ mykeyused = 1;
}
else
{
{
int x;
cp
+ /* Evil hack. */
+
x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len);
if(x)
return x;
-
- return send_meta(cl->nexthop, packet->data, packet->len);
+cp
+ return send_meta(cl, packet->data, packet->len);
}
int tcppacket_h(connection_t *cl)
{
- vpn_packet_t packet;
- char *p;
- int todo, x;
+ short int len;
cp
- if(sscanf(cl->buffer, "%*d %hd", &packet.len) != 1)
+ if(sscanf(cl->buffer, "%*d %hd", &len) != 1)
{
syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname);
return -1;
}
- /* Evil hack. */
-
- p = packet.data;
- todo = packet.len;
-
- while(todo)
- {
- x = read(cl->meta_socket, p, todo);
-
- if(x<=0)
- {
- if(x==0)
- syslog(LOG_NOTICE, _("Connection closed by %s (%s)"), cl->name, cl->hostname);
- else
- if(errno==EINTR || errno==EAGAIN) /* FIXME: select() or poll() or reimplement this evil hack */
- continue;
- else
- syslog(LOG_ERR, _("Error during reception of PACKET from %s (%s): %m"), cl->name, cl->hostname);
-
- return -1;
- }
-
- todo -= x;
- p += x;
- }
+ /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
- receive_packet(cl, &packet);
+ cl->tcplen = len;
cp
return 0;
}
projects / tinc / blobdiff