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/*
* 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"
// Remove 802.1Q tags from packet mp
//
// k indicates which tag to be removed (1..n)
// k=0 means: remove all tags!
//
// RETURN VALUE: 1 upon failure, 0 upon success
int mops_dot1Q_remove (struct mops *mp, int k)
{
int a,b,n;
if (k==0) {
mp->dot1Q_s=0;
mp->use_dot1Q=0;
return 0;
}
n = mp->dot1Q_s/4; // n = total number of tags
if (k>n) return 1;
if (k==1) { // only delete the single tag
mp->dot1Q_s=0;
mp->use_dot1Q=0;
return 0;
}
// we have more than one tag:
//
if (k==n) { // remove last tag (of several)
mp->dot1Q_s -=4;
return 0;
}
// remove some non-ending tag: 0, 1, 2, 3
a = (k-1)*4; // target
b = k*4; // source (what should be copied)
memcpy(&mp->dot1Q[a], &mp->dot1Q[b], (n-k)*4);
mp->dot1Q_s -=4;
return 0;
}
// Unset CFI in tag k where k=1..n
int mops_dot1Q_nocfi (struct mops *mp, int k)
{
int n;
n = mp->dot1Q_s/4; // n = total number of tags
if (k>n) return 1;
mp->dot1Q[((k-1)*4)+2] &=0xef; // unset CFI (0xef = 1110 1111)
return 0;
}
// Set CFI in tag k where k=1..n
int mops_dot1Q_cfi (struct mops *mp, int k)
{
int n;
n = mp->dot1Q_s/4; // n = total number of tags
if (k>n) return 1;
mp->dot1Q[((k-1)*4)+2] |=0x10; // set CFI (0x10 = 0001 0000)
return 0;
}
// Assign 802.1Q tag with
// v ... VLAN
// c ... CoS
// i ... tag position (starting from zero!)
//
// m ... modification: 1 = dot1Q_s is not changed
//
// NOTE:
// When called from for-loop to add all tags the total size dot1Q_s
// is updated continuously, therefore use m=1.
//
// But when changing a particular tag within an existing 802.1Q stack
// the total number of tags does not change, therefore use m=0.
//
// RETURN VALUE: 0 upon success, 1 upon failure
//
int mops_dot1Q (struct mops *mp, int i, int m, u_int16_t v, u_int16_t c)
{
u_int8_t *ptr, c8;
if (i>=MAX_MOPS_DOT1Q_TAGS) return 1; // max number of tags, see definitions in mops.h
if ((v>4095)||(c>7)) return 1; // greater values do not make sense
// Format: 0x8100 CoS-CFI-VLAN
// where c=CoS, v=VLAN
c8 = (u_int8_t) c;
mp->dot1Q[4*i+0]= 0x81;
mp->dot1Q[4*i+1]= 0x00;
ptr = (u_int8_t*) &v;
mp->dot1Q[4*i+3]=*ptr;
mp->dot1Q[4*i+2]=*(ptr+1);
mp->dot1Q[4*i+2]^= (c8 << 5);
if (m) {
mp->dot1Q_s=4*(1+i); // NOTE: dot1Q_s = current tag position + 1
if (mp->dot1Q_s) mp->use_dot1Q = 1;
}
return 0;
}
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