src/mops_tcp.c

   1 /*
   2  * Mausezahn - A fast versatile traffic generator
   3  * Copyright (C) 2008-2010 Herbert Haas
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  12  * details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
  16  *
  17 */
  18
  19
  20 #include "mz.h"
  21 #include "mops.h"
  22 #include "cli.h"
  23
  24 // Calculates the number of TCP transmissions based on SQNR range
  25 u_int32_t mops_tcp_complexity_sqnr (struct mops * mp)
  26 {
  27         u_int32_t a,b,t,result;
  28
  29         a = mp->tcp_seq_start;
  30         b = mp->tcp_seq_stop;
  31         t = mp->tcp_seq_delta;
  32
  33         if (!t) return 1; // delta set to zero means no range
  34
  35         if (a<b) // regular case
  36                 result = ceill ((b-a)/t);
  37         else     // range wraps around
  38                 result = ceill (((0xffffffff-a) + b)/t);
  39
  40         return result;
  41 }
  42
  43
  44 // Calculates the number of TCP transmissions based on SQNR range
  45 u_int32_t mops_tcp_complexity_acknr (struct mops * mp)
  46 {
  47         u_int32_t a,b,t,result;
  48
  49         a = mp->tcp_ack_start;
  50         b = mp->tcp_ack_stop;
  51         t = mp->tcp_ack_delta;
  52
  53         if (!t) return 1; // delta set to zero means no range
  54
  55         if (a<b) // regular case
  56                 result = ceill ((b-a)/t);
  57         else     // range wraps around
  58                 result = ceill (((0xffffffff-a) + b)/t);
  59
  60         return result;
  61 }
  62
  63
  64
  65
  66 // *****TODO: TCP Options ******
  67
  68 // Remove all options
  69 int mops_tcp_option_remove_all (struct mops* mp)
  70 {
  71
  72    return 0;
  73 }
  74
  75
  76 // Prints current flag settings in the provided string 'str'.
  77 // NOTE that str must be at least 32 bytes!
  78 // *** BETTER USE 64 bytes (for future compatibility) ***
  79 //
  80 int mops_tcp_flags2str (struct mops* mp, char *str)
  81 {
  82         if (mp==NULL) {
  83                 sprintf(str, "(no valid mops)\n");
  84                 return 1;
  85         }
  86
  87         sprintf(str, "%s-%s-%s-%s-%s-%s-%s-%s",
  88                 (mp->tcp_ctrl_CWR) ? "CRW" : "---",
  89                 (mp->tcp_ctrl_ECE) ? "ECE" : "---",
  90                 (mp->tcp_ctrl_URG) ? "URG" : "---",
  91                 (mp->tcp_ctrl_ACK) ? "ACK" : "---",
  92                 (mp->tcp_ctrl_PSH) ? "PSH" : "---",
  93                 (mp->tcp_ctrl_RST) ? "RST" : "---",
  94                 (mp->tcp_ctrl_SYN) ? "SYN" : "---",
  95                 (mp->tcp_ctrl_FIN) ? "FIN" : "---");
  96
  97         return 0;
  98 }
  99
 100 // Add TCP options
 101 //
 102 // TODO: currently all params are ignored and a default option combination is added.
 103 //
 104 int mops_tcp_add_option (struct mops* mp,
 105                          int mss,
 106                          int sack,
 107                          int scale,
 108                          u_int32_t tsval,
 109                          u_int32_t tsecr)
 110 {
 111
 112         u_int8_t tcp_default_options[] = {
 113           0x02, 0x04, 0x05, 0xac,                                     // MSS
 114           0x04, 0x02,                                                 // SACK permitted
 115           0x08, 0x0a, 0x19, 0x35, 0x90, 0xc3, 0x00, 0x00, 0x00, 0x00, // Timestamps
 116           0x01,                                                       // NOP
 117           0x03, 0x03, 0x05                                            // Window Scale 5
 118         };
 119
 120
 121        /*   Kind: 8
 122             Length: 10 bytes
 123
 124             +-------+-------+---------------------+---------------------+
 125             |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
 126             +-------+-------+---------------------+---------------------+
 127                1       1              4                     4
 128         *
 129         *  The Timestamps option carries two four-byte timestamp fields. The
 130         *  Timestamp Value field (TSval) contains the current value of the
 131         *  timestamp clock of the TCP sending the option.
 132         *
 133         * The Timestamp Echo Reply field (TSecr) is only valid if the ACK bit
 134         * is set in the TCP header; if it is valid, it echos a times- tamp
 135         * value that was sent by the remote TCP in the TSval field of a
 136         * Timestamps option. When TSecr is not valid, its value must be zero.
 137         * The TSecr value will generally be from the most recent Timestamp
 138         * option that was received; however, there are exceptions that are
 139         * explained below.
 140         *
 141         * A TCP may send the Timestamps option (TSopt) in an initial <SYN>
 142         * segment (i.e., segment containing a SYN bit and no ACK bit), and
 143         * may send a TSopt in other segments only if it re- ceived a TSopt in
 144         * the initial <SYN> segment for the connection.
 145         *
 146         */
 147
 148         memcpy((void*) mp->tcp_option, (void*) tcp_default_options, 20);
 149         mp->tcp_option_s = 20;
 150         mp->tcp_option_used = 1;
 151
 152         return 0;
 153 }
 154