+/*
+ protocol.c -- handle the meta-protocol, basic functions
+ Copyright (C) 1999-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
+ 2000,2001 Guus Sliepen <guus@sliepen.warande.net>
+
+ 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 1.1 2002/04/28 12:46:26 zarq Exp $
+*/
+
+#include "config.h"
+
+#include <sys/types.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include <utils.h>
+#include <xalloc.h>
+
+#include "conf.h"
+#include "protocol.h"
+#include "meta.h"
+#include "connection.h"
+#include "interface.h"
+#include "logging.h"
+
+#include "system.h"
+
+avl_tree_t *past_request_tree;
+
+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 *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)
+ {
+ syslog(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"), c->name, c->hostname);
+ return -1;
+ }
+
+ if(debug_lvl >= DEBUG_PROTOCOL)
+ {
+ sscanf(buffer, "%d", &request);
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], c->name, c->hostname, buffer);
+ else
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], c->name, c->hostname);
+ }
+
+ buffer[len++] = '\n';
+cp
+ return send_meta(c, buffer, len);
+}
+
+int receive_request(connection_t *c)
+{
+ int request;
+cp
+ if(sscanf(c->buffer, "%d", &request) == 1)
+ {
+ if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL))
+ {
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Unknown request from %s (%s): %s"),
+ c->name, c->hostname, c->buffer);
+ else
+ syslog(LOG_ERR, _("Unknown request from %s (%s)"),
+ c->name, c->hostname);
+
+ return -1;
+ }
+ else
+ {
+ if(debug_lvl >= DEBUG_PROTOCOL)
+ {
+ if(debug_lvl >= DEBUG_META)
+ syslog(LOG_DEBUG, _("Got %s from %s (%s): %s"),
+ request_name[request], c->name, c->hostname, c->buffer);
+ else
+ syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
+ request_name[request], c->name, c->hostname);
+ }
+ }
+
+ if((c->allow_request != ALL) && (c->allow_request != request))
+ {
+ syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), c->name, c->hostname);
+ return -1;
+ }
+
+ if(request_handlers[request](c))
+ /* Something went wrong. Probably scriptkiddies. Terminate. */
+ {
+ syslog(LOG_ERR, _("Error while processing %s from %s (%s)"),
+ request_name[request], c->name, c->hostname);
+ return -1;
+ }
+ }
+ else
+ {
+ syslog(LOG_ERR, _("Bogus data received from %s (%s)"),
+ c->name, c->hostname);
+ return -1;
+ }
+cp
+ return 0;
+}
+
+int past_request_compare(past_request_t *a, past_request_t *b)
+{
+cp
+ return strcmp(a->request, b->request);
+}
+
+void free_past_request(past_request_t *r)
+{
+cp
+ if(r->request)
+ free(r->request);
+ free(r);
+cp
+}
+
+void init_requests(void)
+{
+cp
+ past_request_tree = avl_alloc_tree((avl_compare_t)past_request_compare, (avl_action_t)free_past_request);
+cp
+}
+
+void exit_requests(void)
+{
+cp
+ avl_delete_tree(past_request_tree);
+cp
+}
+
+int seen_request(char *request)
+{
+ past_request_t p, *new;
+cp
+ p.request = request;
+
+ if(avl_search(past_request_tree, &p))
+ {
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ syslog(LOG_DEBUG, _("Already seen request"));
+ return 1;
+ }
+ else
+ {
+ new = (past_request_t *)xmalloc(sizeof(*new));
+ new->request = xstrdup(request);
+ new->firstseen = now;
+ avl_insert(past_request_tree, new);
+ return 0;
+ }
+cp
+}
+
+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 = (past_request_t *)node->data;
+ if(p->firstseen + pingtimeout < now)
+ avl_delete_node(past_request_tree, node), deleted++;
+ else
+ left++;
+ }
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS && left + deleted)
+ syslog(LOG_DEBUG, _("Aging past requests: deleted %d, left %d\n"), deleted, left);
+cp
+}
+
+/* Jumptable for the request handlers */
+
+int (*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_node_h, del_node_h,
+ add_subnet_h, del_subnet_h,
+ add_edge_h, del_edge_h,
+ key_changed_h, req_key_h, ans_key_h,
+};
+
+/* Request names */
+
+char (*request_name[]) = {
+ "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK",
+ "STATUS", "ERROR", "TERMREQ",
+ "PING", "PONG",
+// "ADD_NODE", "DEL_NODE",
+ "ADD_SUBNET", "DEL_SUBNET",
+ "ADD_EDGE", "DEL_EDGE",
+ "KEY_CHANGED", "REQ_KEY", "ANS_KEY",
+};