along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.24 2000/08/08 17:07:48 guus Exp $
+ $Id: protocol.c,v 1.28.4.25 2000/09/10 15:18:03 guus Exp $
*/
#include "config.h"
#include "system.h"
-char buffer[MAXBUFSIZE+1];
-int buflen;
+/* Generic outgoing request routine - takes care of logging and error detection as well */
-/* Outgoing request routines */
-
-int send_ack(conn_list_t *cl)
+int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
{
+ va_list args;
+ char *buffer = NULL;
cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Sending ACK to %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
+ if(debug_lvl >= DEBUG_PROTOCOL)
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), requestname[request], cl->id, cl->hostname);
+
+ va_start(args, format);
+ len = vasprintf(&buffer, format, args);
+ va_end(args);
- buflen = snprintf(buffer, MAXBUFSIZE, "%d\n", ACK);
+ if(len < 0 || !buffer)
+ {
+ syslog(LOG_ERR, _("Error during vasprintf(): %m"));
+ return -1;
+ }
+
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Sending meta data to %s (%s): %s"), cl->id, cl->hostname, buffer);
+
+ if(cl->status.encryptout)
+ {
+ /* FIXME: Do encryption */
+ }
if((write(cl->meta_socket, buffer, buflen)) < 0)
{
- syslog(LOG_ERR, _("Send failed: %d:%d: %m"), __FILE__, __LINE__);
+ syslog(LOG_ERR, _("Sending meta data failed: %m"));
return -1;
}
+cp
+}
+
+/* Connection protocol:
+
+ Client Server
+ send_id(*)
+ send_challenge
+ send_chal_reply(*)
+ send_id
+ send_challenge
+ send_chal_reply
+ send_ack
+ send_ack
+
+ (*) Unencrypted.
+*/
+
+int send_id(conn_list_t *cl)
+{
cp
- return 0;
+ return send_request(cl, "%d %s %d-%d %s", ID, myself->id, myself->min_version, myself->max_version, opt2str(myself->options));
+}
+
+int id_h(conn_list_t *cl)
+{
+ conn_list_t *old;
+ char *options;
+cp
+ if(sscanf(cl->buffer, "%*d %as %d-%d %as", &cl->id, &cl->min_version, &cl->max_version, &options) != 4)
+ {
+ syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
+ return -1;
+ }
+
+ /* Check if version ranges overlap */
+
+ if((cl->min_version > myself->max_version) || (cl->max_version < myself_min_version) || (cl->min_version > cl->max_version))
+ {
+ syslog(LOG_ERR, _("Peer %s uses incompatible version (%d-%d)"), cl->hostname, cl->min_version, cl->max_version);
+ return -1;
+ }
+
+ /* Check if option string is valid */
+
+ if(str2opt(options) == -1)
+ {
+ syslog(LOG_ERR, _("Peer %s uses invalid option string"), cl->hostname);
+ return -1;
+ }
+
+ /* Check if identity is a valid name */
+
+ if(!check_id(cl->id))
+ {
+ syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
+ return -1;
+ }
+
+ /* Load information about peer */
+
+ if(!read_id(cl))
+ {
+ syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->id);
+ 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->id)))
+ {
+ if(debug_lvl > DEBUG_CONNECTIONS)
+ syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->id, cl->hostname);
+ cl->status.outgoing = 0;
+ old->status.outgoing = 1;
+ terminate_connection(cl);
+ return 0;
+ }
+ }
+
+ /* Since we know the identity now, we can encrypt the meta channel */
+
+ cl->status.encryptout = 1;
+
+ /* Send a challenge to verify the identity */
+
+ cl->allow_request = CHAL_REPLY;
+cp
+ return send_challenge(cl);
+}
+
+int send_challenge(conn_list_t *cl)
+{
+ char *buffer;
+ int keylength;
+ int x;
+cp
+ if(cl->chal_hash)
+ free(cl->chal_hash);
+
+ /* Allocate buffers for the challenge and the hash */
+
+ cl->chal_hash = xmalloc(SHA_DIGEST_LEN);
+ keylength = BN_num_bytes(cl->metakey.n);
+ buffer = xmalloc(keylength*2);
+
+ /* Copy random data and the public key to the buffer */
+
+ RAND_bytes(buffer, keylength);
+ BN_bn2bin(cl->metakey.n, buffer+keylength);
+
+ /* Calculate the hash from that */
+
+ SHA1(buffer, keylength*2, cl->chal_hash);
+
+ /* Convert the random data to a hexadecimal formatted string */
+
+ bin2hex(buffer,buffer,keylength);
+ buffer[keylength*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(conn_list_t *cl)
+{
+ char *challenge;
+cp
+ if(sscanf(cl->buffer, "%*d %as", &cl->id, &challenge) != 1)
+ {
+ syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->id, cl->hostname);
+ return -1;
+ }
+
+ /* Rest is done by send_chal_reply() */
+
+ x = send_chal_reply(cl, challenge);
+ free(challenge);
+cp
+ return x;
+}
+
+int send_chal_reply(conn_list_t *cl, char *challenge)
+{
+ char *buffer;
+ int keylength;
+ char *hash;
+ int x;
+cp
+ keylength = BN_num_bytes(myself->meyakey.n);
+
+ /* Check if the length of the challenge is all right */
+
+ if(strlen(challenge) != keylength*2)
+ {
+ syslog(LOG_ERROR, _("Intruder: wrong challenge length from %s (%s)"), cl->id, cl->hostname);
+ return -1;
+ }
+
+ /* Allocate buffers for the challenge and the hash */
+
+ buffer = xmalloc(keylength*2);
+ hash = xmalloc(SHA_DIGEST_LEN*2+1);
+
+ /* Copy the incoming random data and our public key to the buffer */
+
+ hex2bin(challenge, buffer, keylength);
+ BN_bn2bin(myself->metakey.n, buffer+keylength);
+
+ /* Calculate the hash from that */
+
+ SHA1(buffer, keylength*2, hash);
+ free(buffer);
+
+ /* Convert the hash to a hexadecimal formatted string */
+
+ bin2hex(hash,hash,SHA_DIGEST_LEN);
+ hash[SHA_DIGEST_LEN*2] = '\0';
+
+ /* Send the reply */
+
+ if(cl->status.outgoing)
+ cl->allow_resuest = ID;
+ else
+ cl->allow_request = ACK;
+
+ x = send_request(cl, "%d %s", CHAL_REPLY, hash);
+ free(hash);
+cp
+ return x;
+}
+
+int chal_reply_h(conn_list_t *cl)
+{
+ char *hash;
+cp
+ if(sscanf(cl->buffer, "%*d %as", &cl->id, &hash) != 2)
+ {
+ syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->id, cl->hostname);
+ return -1;
+ }
+
+ /* Check if the length of the hash is all right */
+
+ if(strlen(hash) != SHA_DIGEST_LEN*2)
+ {
+ syslog(LOG_ERROR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->id, cl->hostname);
+ return -1;
+ }
+
+ /* Convert the hash to binary format */
+
+ hex2bin(hash, hash, SHA_DIGEST_LEN);
+
+ /* Verify the incoming hash with the calculated hash */
+
+ if{!memcmp(hash, cl->chal_hash, SHA_DIGEST_LEN)}
+ {
+ syslog(LOG_ERROR, _("Intruder: wrong challenge reply from %s (%s)"), cl->id, cl->hostname);
+ 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.
+ */
+
+ free(hash);
+ free(cl->chal_hash);
+
+cp
+ if(cl->status.outgoing)
+ {
+ cl->allow_request = ACK;
+ return send_ack(cl);
+ }
+ else
+ {
+ cl->allow_request = CHALLENGE;
+ return send_id(cl);
+ }
+}
+
+int send_ack(conn_list_t *cl)
+{
+cp
+ return send_request(cl, "%d", ACK);
+}
+
+int ack_h(conn_list_t *cl)
+{
+cp
+ /* Okay, before we active the connection, we check if there is another entry
+ in the connection list with the same vpn_ip. If so, it presumably is an
+ old connection that has timed out but we don't know it yet.
+ */
+
+ while((old = lookup_conn(cl->vpn_ip)))
+ {
+ if(debug_lvl > 1)
+ syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
+ cl->vpn_hostname, old->real_hostname, cl->real_hostname);
+ old->status.active = 0;
+ terminate_connection(old);
+ }
+
+ /* Activate this connection */
+
+ cl->allow_request = ALL;
+ cl->status.active = 1;
+
+ if(debug_lvl > DEBUG_CONNECTIONS)
+ syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->id, cl->hostname);
+
+ /* Exchange information about other tinc daemons */
+
+ notify_others(cl, NULL, send_add_host);
+ notify_one(cl);
+
+ upstreamindex = 0;
+
+cp
+ if(cl->status.outgoing)
+ return 0;
+ else
+ return send_ack(cl);
}
+/* Address and subnet information exchange */
+
+/* New and closed connections notification */
+
+/* Status and error notification routines */
+
+int send_status(conn_list_t *cl, int statusno, char *statusstring)
+{
+cp
+ return send_request(cl, "%d %d %s", STATUS, statusno, statusstring);
+}
+
+int send_error(conn_list_t *cl, int errno, char *errstring)
+{
+cp
+ return send_request(cl, "%d %d %s", ERROR, errno, errstring);
+}
+
+/* Old routines */
+
+
int send_termreq(conn_list_t *cl)
{
cp
return 0;
}
-/* Evil hack - TCP tunneling is bad */
int send_tcppacket(conn_list_t *cl, void *data, int len)
{
cp
cp
}
-int send_basic_info(conn_list_t *cl)
-{
-cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Sending BASIC_INFO to %s"),
- cl->real_hostname);
-
- buflen = snprintf(buffer, MAXBUFSIZE, "%d %d %lx/%lx:%x %d\n", BASIC_INFO, PROT_CURRENT, myself->vpn_ip, myself->vpn_mask, myself->port, myself->flags);
-
- if((write(cl->meta_socket, buffer, buflen)) < 0)
- {
- syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
- return -1;
- }
-cp
- return 0;
-}
-
-int send_passphrase(conn_list_t *cl)
-{
- passphrase_t tmp;
-cp
- encrypt_passphrase(&tmp);
-
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Sending PASSPHRASE to %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
-
- buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PASSPHRASE, tmp.phrase);
-
- if((write(cl->meta_socket, buffer, buflen)) < 0)
- {
- syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
- return -1;
- }
-cp
- return 0;
-}
-
-int send_public_key(conn_list_t *cl)
-{
-cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Sending PUBLIC_KEY to %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
-
- buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", PUBLIC_KEY, my_public_key_base36);
-
- if((write(cl->meta_socket, buffer, buflen)) < 0)
- {
- syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
- return -1;
- }
-cp
- return 0;
-}
-
-/* WDN doet deze functie? (GS)
-int send_calculate(conn_list_t *cl, char *k)
-{
-cp
- buflen = snprintf(buffer, MAXBUFSIZE, "%d %s\n", CALCULATE, k);
-
- if((write(cl->meta_socket, buffer, buflen)) < 0)
- {
- syslog(LOG_ERR, _("Send failed: %s:%d: %m"), __FILE__, __LINE__);
- return -1;
- }
-cp
- return 0;
-}
-*/
int send_key_request(ip_t to)
{
The incoming request handlers
*/
-int basic_info_h(conn_list_t *cl)
-{
- conn_list_t *old;
-cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Got BASIC_INFO from %s"), cl->real_hostname);
-
- if(sscanf(cl->buffer, "%*d %d %lx/%lx:%hx %d", &cl->protocol_version, &cl->vpn_ip, &cl->vpn_mask, &cl->port, &cl->flags) != 5)
- {
- syslog(LOG_ERR, _("Got bad BASIC_INFO from %s"),
- cl->real_hostname);
- return -1;
- }
-
- cl->vpn_hostname = hostlookup(htonl(cl->vpn_ip));
-
- if(cl->protocol_version != PROT_CURRENT)
- {
- syslog(LOG_ERR, _("Peer uses incompatible protocol version %d"),
- cl->protocol_version);
- return -1;
- }
-
- if(cl->status.outgoing)
- {
- /* 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((old=lookup_conn(cl->vpn_ip)))
- {
- if(debug_lvl>0)
- syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"),
- cl->vpn_hostname, cl->real_hostname);
- cl->status.outgoing = 0;
- old->status.outgoing = 1;
- terminate_connection(cl);
- return 0;
- }
-
- if(setup_vpn_connection(cl) < 0)
- return -1;
- send_basic_info(cl);
- }
- else
- {
-
- if(setup_vpn_connection(cl) < 0)
- return -1;
- send_passphrase(cl);
- }
-cp
- return 0;
-}
-
-int passphrase_h(conn_list_t *cl)
-{
-cp
- cl->pp = xmalloc(sizeof(*(cl->pp)));
-
- if(sscanf(cl->buffer, "%*d %as", &(cl->pp->phrase)) != 1)
- {
- syslog(LOG_ERR, _("Got bad PASSPHRASE from %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
- return -1;
- }
- cl->pp->len = strlen(cl->pp->phrase);
-
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Got PASSPHRASE from %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
-
- if(cl->status.outgoing)
- send_passphrase(cl);
- else
- send_public_key(cl);
-cp
- return 0;
-}
-
-int public_key_h(conn_list_t *cl)
-{
- char *g_n;
- conn_list_t *old;
-cp
- if(sscanf(cl->buffer, "%*d %as", &g_n) != 1)
- {
- syslog(LOG_ERR, _("Got bad PUBLIC_KEY from %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
- return -1;
- }
-
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Got PUBLIC_KEY from %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
-
- if(verify_passphrase(cl, g_n))
- {
- /* intruder! */
- syslog(LOG_ERR, _("Intruder from %s: passphrase for %s does not match!"),
- cl->real_hostname, cl->vpn_hostname);
- return -1;
- }
-
- if(cl->status.outgoing)
- send_public_key(cl);
- else
- {
- send_ack(cl);
-
- /* Okay, before we active the connection, we check if there is another entry
- in the connection list with the same vpn_ip. If so, it presumably is an
- old connection that has timed out but we don't know it yet.
- */
-
- while((old = lookup_conn(cl->vpn_ip)))
- {
- if(debug_lvl > 1)
- syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
- cl->vpn_hostname, old->real_hostname, cl->real_hostname);
- old->status.active = 0;
- terminate_connection(old);
- }
-
- cl->status.active = 1;
-
- if(debug_lvl > 0)
- syslog(LOG_NOTICE, _("Connection with %s (%s) activated"),
- cl->vpn_hostname, cl->real_hostname);
-
- notify_others(cl, NULL, send_add_host);
- notify_one(cl);
- }
-cp
- return 0;
-}
-
-int ack_h(conn_list_t *cl)
-{
-cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, _("Got ACK from %s (%s)"),
- cl->vpn_hostname, cl->real_hostname);
-
- cl->status.active = 1;
-
- if(debug_lvl > 0)
- syslog(LOG_NOTICE, _("Connection with %s (%s) activated"),
- cl->vpn_hostname, cl->real_hostname);
-
- notify_others(cl, NULL, send_add_host);
- notify_one(cl);
-
- upstreamindex = 0;
-cp
- return 0;
-}
int termreq_h(conn_list_t *cl)
{
return 0;
}
-int (*request_handlers[256])(conn_list_t*) = {
- 0, ack_h, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- termreq_h, timeout_h, del_host_h, 0, 0, 0, 0, 0, 0, 0,
- ping_h, pong_h, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- add_host_h, basic_info_h, passphrase_h, public_key_h, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- tcppacket_h, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- req_key_h, ans_key_h, key_changed_h, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0, 0, 0, 0
+/* "Complete overhaul". */
+
+int (*request_handlers[6])(conn_list_t*) = {
+ id_h, challenge_h, chal_reply_h, ack_h,
+ status_h, error_h,
+};
+
+char (*request_name[6]) = {
+ "ID", "CHALLENGE", "CHAL_REPLY", "ACK",
+ "STATUS", "ERROR",
};
projects / tinc / commitdiff