1 /*
2 protocol_misc.c -- handle the meta-protocol, miscellaneous functions
3 Copyright (C) 1999-2005 Ivo Timmermans,
4 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
5
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.
10
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.
15
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.
19 */
20
21 #include "system.h"
22
23 #include "conf.h"
24 #include "connection.h"
25 #include "logger.h"
26 #include "meta.h"
27 #include "net.h"
28 #include "netutl.h"
29 #include "protocol.h"
30 #include "utils.h"
31
32 int maxoutbufsize = 0;
33
send_ping(connection_t * c)34 bool send_ping(connection_t *c) {
35 c->status.pinged = true;
36 c->last_ping_time = now;
37
38 return send_request(c, "%d", PING);
39 }
40
ping_h(connection_t * c)41 bool ping_h(connection_t *c) {
42 return send_pong(c);
43 }
44
send_pong(connection_t * c)45 bool send_pong(connection_t *c) {
46 return send_request(c, "%d", PONG);
47 }
48
pong_h(connection_t * c)49 bool pong_h(connection_t *c) {
50 c->status.pinged = false;
51
52 /* Successful connection, reset timeout if this is an outgoing connection. */
53
54 if(c->outgoing) {
55 c->outgoing->timeout = 0;
56 c->outgoing->cfg = NULL;
57
58 if(c->outgoing->ai) {
59 freeaddrinfo(c->outgoing->ai);
60 }
61
62 c->outgoing->ai = NULL;
63 c->outgoing->aip = NULL;
64 }
65
66 return true;
67 }
68
69 /* Sending and receiving packets via TCP */
70
send_tcppacket(connection_t * c,const vpn_packet_t * packet)71 bool send_tcppacket(connection_t *c, const vpn_packet_t *packet) {
72 /* If there already is a lot of data in the outbuf buffer, discard this packet.
73 We use a very simple Random Early Drop algorithm. */
74
75 if(2.0 * c->outbuflen / (float)maxoutbufsize - 1 > (float)rand() / (float)RAND_MAX) {
76 return true;
77 }
78
79 if(!send_request(c, "%d %hd", PACKET, packet->len)) {
80 return false;
81 }
82
83 return send_meta(c, (char *)packet->data, packet->len) && flush_meta(c);
84 }
85
tcppacket_h(connection_t * c)86 bool tcppacket_h(connection_t *c) {
87 length_t len;
88
89 if(sscanf(c->buffer, "%*d %hu", &len) != 1) {
90 logger(LOG_ERR, "Got bad %s from %s (%s)", "PACKET", c->name,
91 c->hostname);
92 return false;
93 }
94
95 /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
96
97 c->tcplen = len;
98
99 return true;
100 }
101