/*
 * Mausezahn - A fast versatile traffic generator
 * Copyright (C) 2008-2010 Herbert Haas
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 2 as published by the 
 * Free Software Foundation.
 * 
 * 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, see http://www.gnu.org/licenses/gpl-2.0.html
 * 
*/

#include "mz.h"
#include "mops.h"




// -- TOC: --
//
// u_int16_t      mops_sum16                  (u_int16_t len, u_int8_t buff[])
// int            mops_get_transport_sum      (struct mops *mp)


//////////////////////////////////////////////////////////////////////////////////
//
//  See also:
//  
//  RFC1071 - Computing the Internet checksum
//  
//////////////////////////////////////////////////////////////////////////////////



// Generic 16-bit checksum code as required for IP and other headers.
// The checksum is calculated over buff[] which is of length len. 
//
// RETURN VALUE: The checksum! (Validated - correct!!!)
// 
// Example:  t16 = mops_sum16 (20, &mp->frame[fp]);
// 
u_int16_t mops_sum16 (u_int16_t len, u_int8_t buff[])
{
   
   u_int16_t word16;
   u_int32_t sum=0;
   u_int16_t i;
       
   // make 16 bit words out of every two adjacent 8 bit words in the packet and add them up
   for (i=0; i<len; i=i+2)
     {
	word16 =((buff[i]<<8)&0xFF00)+buff[i+1];
	sum = sum + (u_int32_t) word16;
     }
   
   // take only 16 bits out of the 32 bit sum and add up the carries
   while (sum>>16)
     sum = (sum & 0xFFFF)+(sum >> 16);
   
   // one's complement the result
   sum = ~sum;
   
   return ((u_int16_t) sum);
}





// sets UDP or TCP checksum within mp[]->frame
//   TODO: copying the whole segment is ugly and slow;
//         make it more efficient and realize it in-place.
//         
int mops_get_transport_sum(struct mops *mp)
{
   u_int8_t buf[MAX_PAYLOAD_SIZE];
   u_int16_t len;
   int udp_used;
   
   u_int16_t sum;
   
   udp_used = mp->use_UDP; // 0 or 1, 0 means TCP
   
   // IP Pseudoheader (12 Bytes)
   mops_hton4(&mp->ip_src, &buf[0]);
   mops_hton4(&mp->ip_dst, &buf[4]);
   buf[9]=0x00;

   
   // Copy segment
   if (udp_used) 
     {
	buf[10]=0x11; // proto UDP (17 dec)
	len = mp->udp_len;
	mops_hton2(&len, &buf[11]);
	memcpy(&buf[13], &mp->frame[mp->begin_UDP], len);
	// reset checksum to zero
	buf[19] = 0x00;
	buf[20] = 0x00;
	sum = mops_sum16(len+12, buf); 
	// insert checksum in UDP header (in frame)
	mops_hton2 (&sum, &mp->frame[(mp->begin_UDP)+7]);

     }
   else
     {
	buf[10]=0x06; // proto TCP
	len = mp->ip_len - mp->ip_IHL;
	mops_hton2((u_int16_t*)&len, &buf[11]);
	memcpy(&buf[13], &mp->frame[mp->begin_TCP], len);
	// reset checksum to zero
	buf[29] = 0x00;
	buf[30] = 0x00;
	sum = mops_sum16(len+12, buf);
	// insert checksum in TCP header (in frame)
	mops_hton2 (&sum, &mp->frame[(mp->begin_TCP)+17]);
     }
   
   
   return 0;
}

tion><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;</td><td class='right'>2016-10-29 16:38:43 -0400</td></tr>
<tr><th>committer</th><td>Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;</td><td class='right'>2016-11-10 16:55:46 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=c1eac0d034d36cfa0da3e35f2add6d6de1e696e5'>c1eac0d034d36cfa0da3e35f2add6d6de1e696e5</a> (<a href='/cgit.cgi/linux/net-next.git/patch/?id=c1eac0d034d36cfa0da3e35f2add6d6de1e696e5'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=c1eac0d034d36cfa0da3e35f2add6d6de1e696e5'>df6d68171a0668148a14afb682907f9421354f6d</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=2d4d3b5d45f2885ec7e7ecd149ce7b975f4964dd'>2d4d3b5d45f2885ec7e7ecd149ce7b975f4964dd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?id=c1eac0d034d36cfa0da3e35f2add6d6de1e696e5&amp;id2=2d4d3b5d45f2885ec7e7ecd149ce7b975f4964dd'>diff</a>)</td></tr></table>
<div class='commit-subject'>s390: char: make slp_ctl explicitly non-modular</div><div class='commit-msg'>The Makefile currently controlling compilation of this code is obj-y,
meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular usage, so that when reading
the driver there is no doubt it is builtin-only.

Since module_misc_device translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
Cc: Michael Holzheu &lt;holzheu@linux.vnet.ibm.com&gt;
Cc: linux-s390@vger.kernel.org
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
Acked-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=c1eac0d034d36cfa0da3e35f2add6d6de1e696e5'>Diffstat</a></div><table summary='diffstat' class='diffstat'>