/* protocol.c -- handle the meta-protocol, basic functions Copyright (C) 1999-2001 Ivo Timmermans , 2000,2001 Guus Sliepen 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 the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. $Id: protocol.c,v 1.28.4.148 2003/11/17 15:30:17 guus Exp $ */ #include "system.h" #include "conf.h" #include "connection.h" #include "logger.h" #include "meta.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" bool tunnelserver = false; /* Jumptable for the request handlers */ 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, }; /* Request names */ 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", }; static avl_tree_t *past_request_tree; bool check_id(const char *id) { for(; *id; id++) if(!isalnum(*id) && *id != '_') return false; return true; } /* Generic request routines - takes care of logging and error detection as well */ bool send_request(connection_t *c, 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); va_end(args); if(len < 0 || len > MAXBUFSIZE - 1) { logger(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"), c->name, c->hostname); return false; } 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); } buffer[len++] = '\n'; if(c == broadcast) { broadcast_meta(NULL, buffer, len); return true; } else return send_meta(c, buffer, len); } void forward_request(connection_t *from) { int request; cp(); 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); } 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; } return true; } static int past_request_compare(const past_request_t *a, const past_request_t *b) { return strcmp(a->request, b->request); } static void free_past_request(past_request_t *r) { cp(); if(r->request) free(r->request); free(r); } void init_requests(void) { cp(); past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request); } void exit_requests(void) { cp(); avl_delete_tree(past_request_tree); } bool seen_request(char *request) { past_request_t *new, p = {0}; cp(); p.request = request; if(avl_search(past_request_tree, &p)) { ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Already seen request")); return true; } else { new = xmalloc(sizeof(*new)); new->request = xstrdup(request); new->firstseen = now; avl_insert(past_request_tree, new); return false; } } void age_past_requests(void) { avl_node_t *node, *next; past_request_t *p; int left = 0, deleted = 0; cp(); for(node = past_request_tree->head; node; node = next) { next = node->next; p = node->data; if(p->firstseen + pingtimeout < now) avl_delete_node(past_request_tree, node), deleted++; else left++; } if(left || deleted) ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Aging past requests: deleted %d, left %d"), deleted, left); }