2 utcp.h -- Userspace TCP
3 Copyright (C) 2014 Guus Sliepen <guus@tinc-vpn.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #define PREP(l) char pkt[(l) + sizeof struct hdr]; struct hdr *hdr = &pkt;
37 #define AUX_TIMESTAMP 4
39 #define MAX_UNRELIABLE_SIZE 16777215
40 #define DEFAULT_MTU 1000
42 #define USEC_PER_SEC 1000000L
43 #define NSEC_PER_SEC 1000000000L
44 #define DEFAULT_USER_TIMEOUT 60
45 #define START_RTO (1 * USEC_PER_SEC)
46 #define MAX_RTO (3 * USEC_PER_SEC)
49 uint16_t src; // Source port
50 uint16_t dst; // Destination port
51 uint32_t seq; // Sequence number
52 uint32_t ack; // Acknowledgement number
53 uint32_t wnd; // Window size
54 uint16_t ctl; // Flags (SYN, ACK, FIN, RST)
55 uint16_t aux; // other stuff
72 static const char *strstate[] __attribute__((unused)) = {
75 [SYN_SENT] = "SYN_SENT",
76 [SYN_RECEIVED] = "SYN_RECEIVED",
77 [ESTABLISHED] = "ESTABLISHED",
78 [FIN_WAIT_1] = "FIN_WAIT_1",
79 [FIN_WAIT_2] = "FIN_WAIT_2",
80 [CLOSE_WAIT] = "CLOSE_WAIT",
81 [CLOSING] = "CLOSING",
82 [LAST_ACK] = "LAST_ACK",
83 [TIME_WAIT] = "TIME_WAIT"
86 struct utcp_connection {
123 struct timespec conn_timeout;
124 struct timespec rtrx_timeout;
125 struct timespec rtt_start;
130 uint32_t srtt; // usec
131 uint32_t rttvar; // usec
132 uint32_t rto; // usec
134 // Per-socket options
140 // Congestion avoidance state
142 struct timespec tlast;
151 utcp_accept_t accept;
152 utcp_listen_t listen;
159 // Global socket options
161 uint16_t mtu; // The maximum size of a UTCP packet, including headers.
162 uint16_t mss; // The maximum size of the payload of a UTCP packet.
165 // Connection management
167 struct utcp_connection **connections;