diff options
Diffstat (limited to 'staging/mops_mpls.c')
| -rw-r--r-- | staging/mops_mpls.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/staging/mops_mpls.c b/staging/mops_mpls.c new file mode 100644 index 0000000..5a03a0a --- /dev/null +++ b/staging/mops_mpls.c @@ -0,0 +1,149 @@ +/* + * 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" + +// Assigns MPLS tag at position i (starting at zero!) with values: +// +// m ... total number of tags (important to set BoS in last tag) +// Label ... label value +// Exp ... EXP field (typically CoS) +// TTL ... Time To Live +// +// NOTE: Two usage possibilities! +// +// 1.) When called from for-loop to add all tags the total size mpls_s +// is updated continuously and the BoS is set in the last tag. +// Therefore set m = total number of tags! +// +// 2.) But when changing a particular tag within an existing MPLS stack +// the total number of tags does not change, therefore use m=0. +// +// RETURN VALUE: 0 upon success, 1 upon failure +// +int mops_mpls(struct mops *mp, int i, int m, u_int32_t Label, u_int8_t Exp, u_int8_t TTL) +{ + u_int8_t *ptr; + + if ((m) && (i>=m)) return 1; // label index greater than number of labels! + if (Label > 1048575) return 1; + if (Exp > 7) return 1; + + // Create binary tag: Label(20) EXP(3) BoS(1) TTL(8) + Label <<= 4; + ptr = (u_int8_t *) &Label; + mp->mpls[4*i+0] = *(ptr+2); + mp->mpls[4*i+1] = *(ptr+1); + mp->mpls[4*i+2] = *(ptr+0); + Exp <<= 1; + mp->mpls[4*i+2] |= Exp; + mp->mpls[4*i+3] = TTL; + + if ((m) && (i==(m-1))) // reached last tag! + { + mp->mpls[4*i+2] |= 0x01; // set BoS in last tag + mp->mpls_s =4*m; + mp->use_MPLS = 1; + if ( (mp->eth_type != 0x8847) && (mp->eth_type != 0x8848) ) + { + mp->eth_type_backup = mp->eth_type; + } + mp->eth_type = 0x8847; + } + return 0; +} + + +// Remove MPLS tags from packet mp +// +// j indicates which tag to be removed (1..n) +// j=0 means: remove all tags! +// +// RETURN VALUE: 1 upon failure, 0 upon success +int mops_mpls_remove (struct mops *mp, int j) +{ + int a, b, k; + + + if (j==0) // remove all tags + { + if (mp->use_MPLS) + { + mp->mpls_s=0; + mp->use_MPLS=0; + mp->eth_type = mp->eth_type_backup; // restore original ethertype + return 0; + } + else + return 1; + } + + k = mp->mpls_s/4; + if (j>k) return 1; // The packet only consists of k tag(s) + + if (k==1) // only delete the single tag + { + mp->mpls_s=0; + mp->use_MPLS=0; + mp->eth_type = mp->eth_type_backup; // restore original ethertype + return 0; + } + + // if we got here we have more than one tag: + + if (j==k) // remove last tag (of several) + { + mp->mpls_s -=4; + return 0; + } + + // remove some non-ending tag: 0, 1, 2, 3 + a = (j-1)*4; // target + b = j*4; // source (what should be copied) + memcpy(&mp->mpls[a], &mp->mpls[b], (k-j)*4); + mp->mpls_s -=4; + return 0; +} + + +// Set BOS in tag k where k=1..n +int mops_mpls_bos (struct mops *mp, int k) +{ + int n; + + n = mp->mpls_s/4; // n = total number of tags + if (k>n) return 1; + + mp->mpls[(k-1)*4+2] |= 0x01; + return 0; +} + + +// Unset BOS in tag k where k=1..n +int mops_mpls_nobos (struct mops *mp, int k) +{ + int n; + + n = mp->mpls_s/4; // n = total number of tags + if (k>n) return 1; + + mp->mpls[(k-1)*4+2] &= 0xfe; + return 0; +} |