/*
 * 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;
}

ion><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><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>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-05-24 12:55:26 -0700</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-05-24 12:55:26 -0700</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=0e01df100b6bf22a1de61b66657502a6454153c5'>0e01df100b6bf22a1de61b66657502a6454153c5</a> (<a href='/cgit.cgi/linux/net-next.git/patch/?id=0e01df100b6bf22a1de61b66657502a6454153c5'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=0e01df100b6bf22a1de61b66657502a6454153c5'>aae8f9787efc3014696b3e5ae854c1cf9e472bdd</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=a56f489502e28caac56c8a0735549740f0ae0711'>a56f489502e28caac56c8a0735549740f0ae0711</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=0e01df100b6bf22a1de61b66657502a6454153c5&amp;id2=a56f489502e28caac56c8a0735549740f0ae0711'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=12735f881952c32b31bc4e433768f18489f79ec9'>12735f881952c32b31bc4e433768f18489f79ec9</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=0e01df100b6bf22a1de61b66657502a6454153c5&amp;id2=12735f881952c32b31bc4e433768f18489f79ec9'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4</div><div class='commit-msg'>Pull ext4 updates from Ted Ts'o:
 "Fix a number of bugs, most notably a potential stale data exposure
  after a crash and a potential BUG_ON crash if a file has the data
  journalling flag enabled while it has dirty delayed allocation blocks
  that haven't been written yet.  Also fix a potential crash in the new
  project quota code and a maliciously corrupted file system.

  In addition, fix some DAX-specific bugs, including when there is a
  transient ENOSPC situation and races between writes via direct I/O and
  an mmap'ed segment that could lead to lost I/O.

  Finally the usual set of miscellaneous cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (23 commits)
  ext4: pre-zero allocated blocks for DAX IO
  ext4: refactor direct IO code
  ext4: fix race in transient ENOSPC detection
  ext4: handle transient ENOSPC properly for DAX
  dax: call get_blocks() with create == 1 for write faults to unwritten extents
  ext4: remove unmeetable inconsisteny check from ext4_find_extent()
  jbd2: remove excess descriptions for handle_s
  ext4: remove unnecessary bio get/put
  ext4: silence UBSAN in ext4_mb_init()
  ext4: address UBSAN warning in mb_find_order_for_block()
  ext4: fix oops on corrupted filesystem
  ext4: fix check of dqget() return value in ext4_ioctl_setproject()
  ext4: clean up error handling when orphan list is corrupted
  ext4: fix hang when processing corrupted orphaned inode list
  ext4: remove trailing \n from ext4_warning/ext4_error calls
  ext4: fix races between changing inode journal mode and ext4_writepages
  ext4: handle unwritten or delalloc buffers before enabling data journaling
  ext4: fix jbd2 handle extension in ext4_ext_truncate_extend_restart()
  ext4: do not ask jbd2 to write data for delalloc buffers
  jbd2: add support for avoiding data writes during transaction commits
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=0e01df100b6bf22a1de61b66657502a6454153c5'>Diffstat</a></div><table summary='diffstat' class='diffstat'>