staging: add mausezahn staging directory

After some back and forth, we decided that it is easier to maintain
mausezahn in a staging directory until it is fully reworked and
cleaned up to be ready to be fully integrated. This way, it is better
than having it in a separate branch, and we can also accept patches
from outside more easily. Also, while at it, fix up some function
mismatches with libcli.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 128 insertions, 0 deletions

diff --git a/staging/mops_checksums.c b/staging/mops_checksums.c
new file mode 100644
index 0000000..be20f21
--- /dev/null
+++ b/staging/mops_checksums.c
@@ -0,0 +1,128 @@
+/*
+ * 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;
+}
+