2 protocol.c -- handle the meta-protocol, basic functions
3 Copyright (C) 1999-2005 Ivo Timmermans,
4 2000-2009 Guus Sliepen <guus@tinc-vpn.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 #include "connection.h"
31 bool tunnelserver = false;
33 /* Jumptable for the request handlers */
35 static bool (*request_handlers[])(connection_t *) = {
36 id_h, metakey_h, challenge_h, chal_reply_h, ack_h,
37 status_h, error_h, termreq_h,
39 add_subnet_h, del_subnet_h,
40 add_edge_h, del_edge_h,
41 key_changed_h, req_key_h, ans_key_h, tcppacket_h,
46 static char (*request_name[]) = {
47 "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK",
48 "STATUS", "ERROR", "TERMREQ",
50 "ADD_SUBNET", "DEL_SUBNET",
51 "ADD_EDGE", "DEL_EDGE", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", "PACKET",
54 static avl_tree_t *past_request_tree;
56 bool check_id(const char *id) {
58 if(!isalnum(*id) && *id != '_')
64 /* Generic request routines - takes care of logging and error
67 bool send_request(connection_t *c, const char *format, ...) {
69 char buffer[MAXBUFSIZE];
72 /* Use vsnprintf instead of vxasprintf: faster, no memory
73 fragmentation, cleanup is automatic, and there is a limit on the
74 input buffer anyway */
76 va_start(args, format);
77 len = vsnprintf(buffer, MAXBUFSIZE, format, args);
80 if(len < 0 || len > MAXBUFSIZE - 1) {
81 logger(LOG_ERR, "Output buffer overflow while sending request to %s (%s)",
82 c->name, c->hostname);
87 sscanf(buffer, "%d", &request);
89 logger(LOG_DEBUG, "Sending %s to %s (%s): %s",
90 request_name[request], c->name, c->hostname, buffer);
92 logger(LOG_DEBUG, "Sending %s to %s (%s)", request_name[request],
93 c->name, c->hostname);
99 broadcast_meta(NULL, buffer, len);
102 return send_meta(c, buffer, len);
105 void forward_request(connection_t *from) {
109 sscanf(from->buffer, "%d", &request);
111 logger(LOG_DEBUG, "Forwarding %s from %s (%s): %s",
112 request_name[request], from->name, from->hostname,
115 logger(LOG_DEBUG, "Forwarding %s from %s (%s)",
116 request_name[request], from->name, from->hostname);
119 from->buffer[from->reqlen - 1] = '\n';
121 broadcast_meta(from, from->buffer, from->reqlen);
124 bool receive_request(connection_t *c) {
127 if(sscanf(c->buffer, "%d", &request) == 1) {
128 if((request < 0) || (request >= LAST) || !request_handlers[request]) {
130 logger(LOG_DEBUG, "Unknown request from %s (%s): %s",
131 c->name, c->hostname, c->buffer);
133 logger(LOG_ERR, "Unknown request from %s (%s)",
134 c->name, c->hostname);
140 logger(LOG_DEBUG, "Got %s from %s (%s): %s",
141 request_name[request], c->name, c->hostname,
144 logger(LOG_DEBUG, "Got %s from %s (%s)",
145 request_name[request], c->name, c->hostname);
149 if((c->allow_request != ALL) && (c->allow_request != request)) {
150 logger(LOG_ERR, "Unauthorized request from %s (%s)", c->name,
155 if(!request_handlers[request](c)) {
156 /* Something went wrong. Probably scriptkiddies. Terminate. */
158 logger(LOG_ERR, "Error while processing %s from %s (%s)",
159 request_name[request], c->name, c->hostname);
163 logger(LOG_ERR, "Bogus data received from %s (%s)",
164 c->name, c->hostname);
171 static int past_request_compare(const past_request_t *a, const past_request_t *b) {
172 return strcmp(a->request, b->request);
175 static void free_past_request(past_request_t *r) {
182 void init_requests(void) {
183 past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request);
186 void exit_requests(void) {
187 avl_delete_tree(past_request_tree);
190 bool seen_request(char *request) {
191 past_request_t *new, p = {0};
195 if(avl_search(past_request_tree, &p)) {
196 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Already seen request");
199 new = xmalloc(sizeof(*new));
200 new->request = xstrdup(request);
201 new->firstseen = now;
202 avl_insert(past_request_tree, new);
207 void age_past_requests(void) {
208 avl_node_t *node, *next;
210 int left = 0, deleted = 0;
212 for(node = past_request_tree->head; node; node = next) {
216 if(p->firstseen + pinginterval < now)
217 avl_delete_node(past_request_tree, node), deleted++;
223 ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Aging past requests: deleted %d, left %d",