tinc/src/protocol.c

207 lines
5.8 KiB
C
Raw Normal View History

2000-03-26 00:33:07 +00:00
/*
2002-02-10 21:57:54 +00:00
protocol.c -- handle the meta-protocol, basic functions
Copyright (C) 1999-2005 Ivo Timmermans,
2012-03-10 12:23:08 +00:00
2000-2012 Guus Sliepen <guus@tinc-vpn.org>
2000-03-26 00:33:07 +00:00
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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
2000-03-26 00:33:07 +00:00
*/
#include "system.h"
2000-03-26 00:33:07 +00:00
#include "conf.h"
2000-11-20 19:12:17 +00:00
#include "connection.h"
#include "logger.h"
#include "meta.h"
#include "protocol.h"
#include "utils.h"
#include "xalloc.h"
2000-05-29 21:01:26 +00:00
bool tunnelserver = false;
bool strictsubnets = false;
bool experimental = false;
/* Jumptable for the request handlers */
static bool (*request_handlers[])(connection_t *, const char *) = {
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, control_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", "CONTROL",
};
2007-05-18 10:05:26 +00:00
static splay_tree_t *past_request_tree;
2007-05-18 10:00:00 +00:00
bool check_id(const char *id) {
for(; *id; id++)
if(!isalnum(*id) && *id != '_')
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
2003-07-22 20:55:21 +00:00
return true;
2000-09-15 12:58:40 +00:00
}
2000-12-05 08:59:30 +00:00
/* Generic request routines - takes care of logging and error
detection as well */
2007-05-18 10:00:00 +00:00
bool send_request(connection_t *c, const char *format, ...) {
2002-09-09 21:25:28 +00:00
va_list args;
char request[MAXBUFSIZE];
int len;
2002-09-09 21:25:28 +00:00
2009-09-08 16:18:36 +00:00
/* Use vsnprintf instead of vxasprintf: faster, no memory
2002-09-09 21:25:28 +00:00
fragmentation, cleanup is automatic, and there is a limit on the
input buffer anyway */
va_start(args, format);
len = vsnprintf(request, MAXBUFSIZE, format, args);
2002-09-09 21:25:28 +00:00
va_end(args);
if(len < 0 || len > MAXBUFSIZE - 1) {
logger(DEBUG_ALWAYS, LOG_ERR, "Output buffer overflow while sending request to %s (%s)",
2002-09-09 21:25:28 +00:00
c->name, c->hostname);
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
}
logger(DEBUG_META, LOG_DEBUG, "Sending %s to %s (%s): %s", request_name[atoi(request)], c->name, c->hostname, request);
2002-09-09 21:25:28 +00:00
request[len++] = '\n';
2002-09-09 21:25:28 +00:00
if(c == everyone) {
broadcast_meta(NULL, request, len);
2003-07-22 20:55:21 +00:00
return true;
} else
return send_meta(c, request, len);
}
void forward_request(connection_t *from, const char *request) {
logger(DEBUG_META, LOG_DEBUG, "Forwarding %s from %s (%s): %s", request_name[atoi(request)], from->name, from->hostname, request);
2002-09-09 21:25:28 +00:00
// Create a temporary newline-terminated copy of the request
int len = strlen(request);
char tmp[len + 1];
memcpy(tmp, request, len);
tmp[len] = '\n';
broadcast_meta(from, tmp, sizeof tmp);
}
bool receive_request(connection_t *c, const char *request) {
int reqno = atoi(request);
2002-09-09 21:25:28 +00:00
if(reqno || *request == '0') {
if((reqno < 0) || (reqno >= LAST) || !request_handlers[reqno]) {
logger(DEBUG_META, LOG_DEBUG, "Unknown request from %s (%s): %s", c->name, c->hostname, request);
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
} else {
logger(DEBUG_META, LOG_DEBUG, "Got %s from %s (%s): %s", request_name[reqno], c->name, c->hostname, request);
2002-09-09 21:25:28 +00:00
}
if((c->allow_request != ALL) && (c->allow_request != reqno)) {
logger(DEBUG_ALWAYS, LOG_ERR, "Unauthorized request from %s (%s)", c->name, c->hostname);
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
}
if(!request_handlers[reqno](c, request)) {
2002-09-09 21:25:28 +00:00
/* Something went wrong. Probably scriptkiddies. Terminate. */
2003-07-22 20:55:21 +00:00
logger(DEBUG_ALWAYS, LOG_ERR, "Error while processing %s from %s (%s)", request_name[reqno], c->name, c->hostname);
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
}
} else {
logger(DEBUG_ALWAYS, LOG_ERR, "Bogus data received from %s (%s)", c->name, c->hostname);
2003-07-22 20:55:21 +00:00
return false;
}
2000-10-29 00:02:20 +00:00
2003-07-22 20:55:21 +00:00
return true;
}
2007-05-18 10:00:00 +00:00
static int past_request_compare(const past_request_t *a, const past_request_t *b) {
2002-09-09 21:25:28 +00:00
return strcmp(a->request, b->request);
}
2007-05-18 10:00:00 +00:00
static void free_past_request(past_request_t *r) {
2002-09-09 21:25:28 +00:00
if(r->request)
free((char *)r->request);
2002-09-09 21:25:28 +00:00
free(r);
}
2007-05-17 23:14:42 +00:00
static struct event past_request_event;
bool seen_request(const char *request) {
past_request_t *new, p = {NULL};
2002-09-09 21:25:28 +00:00
p.request = request;
2007-05-18 10:05:26 +00:00
if(splay_search(past_request_tree, &p)) {
logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Already seen request");
2003-07-22 20:55:21 +00:00
return true;
2002-09-09 21:25:28 +00:00
} else {
new = xmalloc(sizeof *new);
2002-09-09 21:25:28 +00:00
new->request = xstrdup(request);
2007-05-18 09:34:06 +00:00
new->firstseen = time(NULL);
2007-05-18 10:05:26 +00:00
splay_insert(past_request_tree, new);
2007-05-17 23:14:42 +00:00
event_add(&past_request_event, &(struct timeval){10, 0});
2003-07-22 20:55:21 +00:00
return false;
2002-09-09 21:25:28 +00:00
}
}
static void age_past_requests(int fd, short events, void *data) {
2007-05-18 10:05:26 +00:00
splay_node_t *node, *next;
2002-09-09 21:25:28 +00:00
past_request_t *p;
int left = 0, deleted = 0;
2007-05-18 09:34:06 +00:00
time_t now = time(NULL);
2002-09-09 21:25:28 +00:00
for(node = past_request_tree->head; node; node = next) {
next = node->next;
2003-08-28 21:05:11 +00:00
p = node->data;
2002-09-09 21:25:28 +00:00
if(p->firstseen + pinginterval <= now)
2007-05-18 10:05:26 +00:00
splay_delete_node(past_request_tree, node), deleted++;
2002-09-09 21:25:28 +00:00
else
left++;
}
if(left || deleted)
logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Aging past requests: deleted %d, left %d",
2002-09-09 21:25:28 +00:00
deleted, left);
2007-05-17 23:14:42 +00:00
if(left)
event_add(&past_request_event, &(struct timeval){10, 0});
}
2007-05-18 10:00:00 +00:00
void init_requests(void) {
2007-05-18 10:05:26 +00:00
past_request_tree = splay_alloc_tree((splay_compare_t) past_request_compare, (splay_action_t) free_past_request);
2007-05-17 23:14:42 +00:00
timeout_set(&past_request_event, age_past_requests, NULL);
}
2007-05-18 10:00:00 +00:00
void exit_requests(void) {
2007-05-18 10:05:26 +00:00
splay_delete_tree(past_request_tree);
2007-05-17 23:14:42 +00:00
if(timeout_initialized(&past_request_event))
event_del(&past_request_event);
}