-#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(conn_list_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(conn_list_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(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;
- }
-}
-
-/* Connection protocol:
-
- Client Server
- send_id(u)
- send_challenge(R)
- send_chal_reply(H)
- send_id(u)
- send_challenge(R)
- send_chal_reply(H)
- ---------------------------------------
- Any negotations about the meta protocol
- encryption go here(u).
- ---------------------------------------
- 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(conn_list_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(conn_list_t *cl)
-{
- conn_list_t *old;
-cp
- if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->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(cl->name))
- {
- syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
- return -1;
- }
-
- /* 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;
- }
- }
-cp
- return send_challenge(cl);
-}
-
-int send_challenge(conn_list_t *cl)
-{
- char buffer[CHAL_LENGTH*2+1];
-cp
- /* Allocate buffers for the challenge */
-
- if(!cl->hischallenge)
- cl->hischallenge = xmalloc(CHAL_LENGTH);
-cp
- /* Copy random data to the buffer */
-
- RAND_bytes(cl->hischallenge, CHAL_LENGTH);
-cp
- /* Convert the random data to a hexadecimal formatted string */
-
- bin2hex(cl->hischallenge, buffer, CHAL_LENGTH);
- buffer[CHAL_LENGTH*2] = '\0';
-
- /* Send the challenge */
-
- cl->allow_request = CHAL_REPLY;
-cp
- return send_request(cl, "%d %s", CHALLENGE, buffer);
-}
-
-int challenge_h(conn_list_t *cl)
-{
- char *buffer;
-cp
- if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
- {
- syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Check if the length of the challenge is all right */
-
- if(strlen(buffer) != CHAL_LENGTH*2)
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname);
- free(buffer);
- return -1;
- }
-
- /* Allocate buffers for the challenge */
-
- if(!cl->mychallenge)
- cl->mychallenge = xmalloc(CHAL_LENGTH);
-
- /* Convert the challenge from hexadecimal back to binary */
-
- hex2bin(buffer,cl->mychallenge,CHAL_LENGTH);
- free(buffer);
-
- /* Rest is done by send_chal_reply() */
-cp
- return send_chal_reply(cl);
-}
-
-int send_chal_reply(conn_list_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, CHAL_LENGTH, 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 = ACK;
-
-cp
- return send_request(cl, "%d %s", CHAL_REPLY, hash);
-}
-
-int chal_reply_h(conn_list_t *cl)
-{
- char *hishash;
- char myhash[SHA_DIGEST_LENGTH];
-cp
- if(sscanf(cl->buffer, "%*d %as", &hishash) != 1)
- {
- syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
- free(hishash);
- 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);
- free(hishash);
- 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, CHAL_LENGTH, 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);
- free(hishash);
- return -1;
- }
-
- free(hishash);
-
- /* 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_ack(cl);
- else
- return send_id(cl);
-}
-
-int send_ack(conn_list_t *cl)
-{
-cp
- cl->allow_request = ACK;
-cp
- return send_request(cl, "%d", ACK);
-}
-
-int ack_h(conn_list_t *cl)
-{
- conn_list_t *old;
-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);
- 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->name, cl->hostname);
-
- /* Exchange information about other tinc daemons */
-
-/* FIXME: reprogram this.
- 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 */
-
-int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
-{
- int x;
- char *netstr;
-cp
- x = send_request(cl, "%d %s %s", ADD_SUBNET,
- other->name, netstr = net2str(subnet));
- free(netstr);
-cp
- return x;
-}
-
-int add_subnet_h(conn_list_t *cl)
-{
- char *subnetstr;
- char *name;
- conn_list_t *owner;
- subnet_t *subnet, *old;
-cp
- if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
- {
- syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
- free(name); free(subnetstr);
- 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);
- free(name); free(subnetstr);
- 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);
- free(name); free(subnetstr);
- return -1;
- }
-
- free(subnetstr);
-
- /* 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);
- free(name);
- 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);
- free(name);
- return -1;
- }
-
- /* If everything is correct, add the subnet to the list of the owner */
-
- subnet_add(owner, subnet);
-cp
- return 0;
-}
-
-int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
-{
-cp
- return send_request(cl, "%d %s %s", DEL_SUBNET, other->name, net2str(subnet));
-}
-
-int del_subnet_h(conn_list_t *cl)
-{
- char *subnetstr;
- char *name;
- conn_list_t *owner;
- subnet_t *subnet, *old;
-cp
- if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
- {
- syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
- free(name); free(subnetstr);
- 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);
- free(name); free(subnetstr);
- 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);
- free(name); free(subnetstr);
- 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);
- free(name);
- 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);
- free(name);
- return -1;
- }
-
- /* If everything is correct, delete the subnet from the list of the owner */
-
- subnet_del(subnet);
-cp
- return 0;
-}
-
-/* New and closed connections notification */
-
-int send_add_host(conn_list_t *cl, conn_list_t *other)
-{
-cp
- return send_request(cl, "%d %s %s %lx:%d %lx", ADD_HOST,
- myself->name, other->name, other->address, other->port, other->options);
-}
-
-int add_host_h(conn_list_t *cl)
-{
- char *sender;
- conn_list_t *old, *new, *hisuplink;
-cp
- new = new_conn_list();
-
- if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &new->name, &new->address, &new->port, &new->options) != 5)
- {
- 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(new->name) || check_id(sender))
- {
- syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- free(sender);
- return -1;
- }
-
- /* Check if somebody tries to add ourself */
-
- if(!strcmp(new->name, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
- sighup = 1;
- free(sender);
- return 0;
- }
-
- /* We got an ADD_HOST from ourself!? */
-
- if(!strcmp(sender, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname);
- sighup = 1;
- free(sender);
- return 0;
- }
-
- /* Lookup his uplink */
-
- if(!(new->hisuplink = lookup_id(sender)))
- {
- syslog(LOG_ERR, _("Got ADD_HOST from %s (%s) with origin %s which is not in our connection list"),
- sender, cl->name, cl->hostname);
- free(sender);
- return -1;
- }
-
- free(sender);
-
- /* Fill in more of the new conn_list structure */
-
- new->hostname = hostlookup(htonl(new->address));
-
- /* Check if the new host already exists in the connnection list */
-
- if((old = lookup_id(new->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, new->name, new->hostname);
- return 0;
- }
- else
- {
- if(debug_lvl > DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"),
- old->name, old->hostname);
- old->status.active = 0;
- terminate_connection(old);
- }
- }
-
- /* Fill in rest of conn_list structure */
-
- new->myuplink = cl;
- new->status.active = 1;
-
- /* Hook it up into the conn_list */
-
- conn_list_add(conn_list, new);
-
- /* Tell the rest about the new host */
-/* FIXME: reprogram this.
- notify_others(new, cl, send_add_host);
-*/
-cp
- return 0;
-}
-
-int send_del_host(conn_list_t *cl, conn_list_t *other)
-{
-cp
- return send_request(cl, "%d %s %s %lx:%d %lx", DEL_HOST,
- myself->name, other->name, other->address, other->port, other->options);
-}
-
-int del_host_h(conn_list_t *cl)
-{
- char *name;
- char *sender;
- ip_t address;
- port_t port;
- int options;
- conn_list_t *old, *hisuplink;
-
-cp
- if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &name, &address, &port, &options) != 5)
- {
- 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) || check_id(sender))
- {
- syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- free(name); free(sender);
- 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"),
- cl->name, cl->hostname);
- free(name); free(sender);
- sighup = 1;
- return 0;
- }
-
- /* We got an ADD_HOST from ourself!? */
-
- if(!strcmp(sender, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname);
- sighup = 1;
- free(name); free(sender);
- return 0;
- }
-
- /* Lookup his uplink */
-
- if(!(hisuplink = lookup_id(sender)))
- {
- syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) with origin %s which is not in our connection list"),
- cl->name, cl->hostname, sender);
- free(name); free(sender);
- return -1;
- }
-
- free(sender);
-
- /* Check if the new 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);
- free(name);
- return -1;
- }
-
- /* Check if the rest matches */
-
- if(address!=old->address || port!=old->port || options!=old->options || hisuplink!=old->hisuplink || cl!=old->myuplink)
- {
- 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 */