From e4f1faa478abd4673e7f92c3932f9d783e42eb29 Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Wed, 5 Apr 2017 13:31:57 +0200 Subject: [PATCH] Restructure Reed-Solomon code for verity FEC and remove unneeded parts. --- lib/verity/Makefile.am | 9 +- lib/verity/libfec/char.h | 24 -- lib/verity/libfec/encode_rs.h | 58 ----- lib/verity/libfec/encode_rs_char.c | 15 -- lib/verity/libfec/fec.h | 347 ----------------------------- lib/verity/libfec/init_rs.h | 106 --------- lib/verity/libfec/init_rs_char.c | 35 --- lib/verity/libfec/rs-common.h | 26 --- lib/verity/rs.h | 35 +++ lib/verity/rs_encode_char.c | 199 +++++++++++++++++ lib/verity/verity_fec.c | 2 +- 11 files changed, 237 insertions(+), 619 deletions(-) delete mode 100644 lib/verity/libfec/char.h delete mode 100644 lib/verity/libfec/encode_rs.h delete mode 100644 lib/verity/libfec/encode_rs_char.c delete mode 100644 lib/verity/libfec/fec.h delete mode 100644 lib/verity/libfec/init_rs.h delete mode 100644 lib/verity/libfec/init_rs_char.c delete mode 100644 lib/verity/libfec/rs-common.h create mode 100644 lib/verity/rs.h create mode 100644 lib/verity/rs_encode_char.c diff --git a/lib/verity/Makefile.am b/lib/verity/Makefile.am index 15941200..9dce6f95 100644 --- a/lib/verity/Makefile.am +++ b/lib/verity/Makefile.am @@ -9,13 +9,8 @@ libverity_la_SOURCES = \ verity_fec.c \ verity.c \ verity.h \ - libfec/encode_rs_char.c \ - libfec/encode_rs.h \ - libfec/init_rs_char.c \ - libfec/init_rs.h \ - libfec/rs-common.h \ - libfec/char.h \ - libfec/fec.h + rs_encode_char.c \ + rs.h AM_CPPFLAGS = -include config.h \ -I$(top_srcdir)/lib \ diff --git a/lib/verity/libfec/char.h b/lib/verity/libfec/char.h deleted file mode 100644 index 25efd65b..00000000 --- a/lib/verity/libfec/char.h +++ /dev/null @@ -1,24 +0,0 @@ -/* Stuff specific to the 8-bit symbol version of the general purpose RS codecs - * - * Copyright 2003, Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ -typedef unsigned char data_t; - -#define MODNN(x) modnn(rs,x) - -#define MM (rs->mm) -#define NN (rs->nn) -#define ALPHA_TO (rs->alpha_to) -#define INDEX_OF (rs->index_of) -#define GENPOLY (rs->genpoly) -#define NROOTS (rs->nroots) -#define FCR (rs->fcr) -#define PRIM (rs->prim) -#define IPRIM (rs->iprim) -#define PAD (rs->pad) -#define A0 (NN) - - - - diff --git a/lib/verity/libfec/encode_rs.h b/lib/verity/libfec/encode_rs.h deleted file mode 100644 index 2c157f9b..00000000 --- a/lib/verity/libfec/encode_rs.h +++ /dev/null @@ -1,58 +0,0 @@ -/* The guts of the Reed-Solomon encoder, meant to be #included - * into a function body with the following typedefs, macros and variables supplied - * according to the code parameters: - - * data_t - a typedef for the data symbol - * data_t data[] - array of NN-NROOTS-PAD and type data_t to be encoded - * data_t parity[] - an array of NROOTS and type data_t to be written with parity symbols - * NROOTS - the number of roots in the RS code generator polynomial, - * which is the same as the number of parity symbols in a block. - Integer variable or literal. - * - * NN - the total number of symbols in a RS block. Integer variable or literal. - * PAD - the number of pad symbols in a block. Integer variable or literal. - * ALPHA_TO - The address of an array of NN elements to convert Galois field - * elements in index (log) form to polynomial form. Read only. - * INDEX_OF - The address of an array of NN elements to convert Galois field - * elements in polynomial form to index (log) form. Read only. - * MODNN - a function to reduce its argument modulo NN. May be inline or a macro. - * GENPOLY - an array of NROOTS+1 elements containing the generator polynomial in index form - - * The memset() and memmove() functions are used. The appropriate header - * file declaring these functions (usually ) must be included by the calling - * program. - - * Copyright 2004, Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ - - -#undef A0 -#define A0 (NN) /* Special reserved value encoding zero in index form */ - -{ - int i, j; - data_t feedback; - - memset(parity,0,NROOTS*sizeof(data_t)); - - for(i=0;i - -#include "char.h" -#include "rs-common.h" - -void encode_rs_char(void *p,data_t *data, data_t *parity){ - struct rs *rs = (struct rs *)p; - -#include "encode_rs.h" - -} diff --git a/lib/verity/libfec/fec.h b/lib/verity/libfec/fec.h deleted file mode 100644 index 08e8454e..00000000 --- a/lib/verity/libfec/fec.h +++ /dev/null @@ -1,347 +0,0 @@ -/* User include file for libfec - * Copyright 2004, Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ - -#ifndef _FEC_H_ -#define _FEC_H_ - -/* r=1/2 k=7 convolutional encoder polynomials - * The NASA-DSN convention is to use V27POLYA inverted, then V27POLYB - * The CCSDS/NASA-GSFC convention is to use V27POLYB, then V27POLYA inverted - */ -#define V27POLYA 0x6d -#define V27POLYB 0x4f - -void *create_viterbi27(int len); -void set_viterbi27_polynomial(int polys[2]); -int init_viterbi27(void *vp,int starting_state); -int update_viterbi27_blk(void *vp,unsigned char sym[],int npairs); -int chainback_viterbi27(void *vp, unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27(void *vp); - -#ifdef __VEC__ -void *create_viterbi27_av(int len); -void set_viterbi27_polynomial_av(int polys[2]); -int init_viterbi27_av(void *p,int starting_state); -int chainback_viterbi27_av(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27_av(void *p); -int update_viterbi27_blk_av(void *p,unsigned char *syms,int nbits); -#endif - -#ifdef __i386__ -void *create_viterbi27_mmx(int len); -void set_viterbi27_polynomial_mmx(int polys[2]); -int init_viterbi27_mmx(void *p,int starting_state); -int chainback_viterbi27_mmx(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27_mmx(void *p); -int update_viterbi27_blk_mmx(void *p,unsigned char *syms,int nbits); - -void *create_viterbi27_sse(int len); -void set_viterbi27_polynomial_sse(int polys[2]); -int init_viterbi27_sse(void *p,int starting_state); -int chainback_viterbi27_sse(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27_sse(void *p); -int update_viterbi27_blk_sse(void *p,unsigned char *syms,int nbits); - -void *create_viterbi27_sse2(int len); -void set_viterbi27_polynomial_sse2(int polys[2]); -int init_viterbi27_sse2(void *p,int starting_state); -int chainback_viterbi27_sse2(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27_sse2(void *p); -int update_viterbi27_blk_sse2(void *p,unsigned char *syms,int nbits); -#endif - -void *create_viterbi27_port(int len); -void set_viterbi27_polynomial_port(int polys[2]); -int init_viterbi27_port(void *p,int starting_state); -int chainback_viterbi27_port(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi27_port(void *p); -int update_viterbi27_blk_port(void *p,unsigned char *syms,int nbits); - -/* r=1/2 k=9 convolutional encoder polynomials */ -#define V29POLYA 0x1af -#define V29POLYB 0x11d - -void *create_viterbi29(int len); -void set_viterbi29_polynomial(int polys[2]); -int init_viterbi29(void *vp,int starting_state); -int update_viterbi29_blk(void *vp,unsigned char syms[],int nbits); -int chainback_viterbi29(void *vp, unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29(void *vp); - -#ifdef __VEC__ -void *create_viterbi29_av(int len); -void set_viterbi29_polynomial_av(int polys[2]); -int init_viterbi29_av(void *p,int starting_state); -int chainback_viterbi29_av(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29_av(void *p); -int update_viterbi29_blk_av(void *p,unsigned char *syms,int nbits); -#endif - -#ifdef __i386__ -void *create_viterbi29_mmx(int len); -void set_viterbi29_polynomial_mmx(int polys[2]); -int init_viterbi29_mmx(void *p,int starting_state); -int chainback_viterbi29_mmx(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29_mmx(void *p); -int update_viterbi29_blk_mmx(void *p,unsigned char *syms,int nbits); - -void *create_viterbi29_sse(int len); -void set_viterbi29_polynomial_sse(int polys[2]); -int init_viterbi29_sse(void *p,int starting_state); -int chainback_viterbi29_sse(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29_sse(void *p); -int update_viterbi29_blk_sse(void *p,unsigned char *syms,int nbits); - -void *create_viterbi29_sse2(int len); -void set_viterbi29_polynomial_sse2(int polys[2]); -int init_viterbi29_sse2(void *p,int starting_state); -int chainback_viterbi29_sse2(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29_sse2(void *p); -int update_viterbi29_blk_sse2(void *p,unsigned char *syms,int nbits); -#endif - -void *create_viterbi29_port(int len); -void set_viterbi29_polynomial_port(int polys[2]); -int init_viterbi29_port(void *p,int starting_state); -int chainback_viterbi29_port(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi29_port(void *p); -int update_viterbi29_blk_port(void *p,unsigned char *syms,int nbits); - -/* r=1/3 k=9 convolutional encoder polynomials */ -#define V39POLYA 0x1ed -#define V39POLYB 0x19b -#define V39POLYC 0x127 - -void *create_viterbi39(int len); -void set_viterbi39_polynomial(int polys[3]); -int init_viterbi39(void *vp,int starting_state); -int update_viterbi39_blk(void *vp,unsigned char syms[],int nbits); -int chainback_viterbi39(void *vp, unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39(void *vp); - -#ifdef __VEC__ -void *create_viterbi39_av(int len); -void set_viterbi39_polynomial_av(int polys[3]); -int init_viterbi39_av(void *p,int starting_state); -int chainback_viterbi39_av(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39_av(void *p); -int update_viterbi39_blk_av(void *p,unsigned char *syms,int nbits); -#endif - -#ifdef __i386__ -void *create_viterbi39_mmx(int len); -void set_viterbi39_polynomial_mmx(int polys[3]); -int init_viterbi39_mmx(void *p,int starting_state); -int chainback_viterbi39_mmx(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39_mmx(void *p); -int update_viterbi39_blk_mmx(void *p,unsigned char *syms,int nbits); - -void *create_viterbi39_sse(int len); -void set_viterbi39_polynomial_sse(int polys[3]); -int init_viterbi39_sse(void *p,int starting_state); -int chainback_viterbi39_sse(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39_sse(void *p); -int update_viterbi39_blk_sse(void *p,unsigned char *syms,int nbits); - -void *create_viterbi39_sse2(int len); -void set_viterbi39_polynomial_sse2(int polys[3]); -int init_viterbi39_sse2(void *p,int starting_state); -int chainback_viterbi39_sse2(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39_sse2(void *p); -int update_viterbi39_blk_sse2(void *p,unsigned char *syms,int nbits); -#endif - -void *create_viterbi39_port(int len); -void set_viterbi39_polynomial_port(int polys[3]); -int init_viterbi39_port(void *p,int starting_state); -int chainback_viterbi39_port(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi39_port(void *p); -int update_viterbi39_blk_port(void *p,unsigned char *syms,int nbits); - - -/* r=1/6 k=15 Cassini convolutional encoder polynomials without symbol inversion - * dfree = 56 - * These bits may be left-right flipped from some textbook representations; - * here I have the bits entering the shift register from the right (low) end - * - * Some other spacecraft use the same code, but with the polynomials in a different order. - * E.g., Mars Pathfinder and STEREO swap POLYC and POLYD. All use alternate symbol inversion, - * so use set_viterbi615_polynomial() as appropriate. - */ -#define V615POLYA 042631 -#define V615POLYB 047245 -#define V615POLYC 056507 -#define V615POLYD 073363 -#define V615POLYE 077267 -#define V615POLYF 064537 - -void *create_viterbi615(int len); -void set_viterbi615_polynomial(int polys[6]); -int init_viterbi615(void *vp,int starting_state); -int update_viterbi615_blk(void *vp,unsigned char *syms,int nbits); -int chainback_viterbi615(void *vp, unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615(void *vp); - -#ifdef __VEC__ -void *create_viterbi615_av(int len); -void set_viterbi615_polynomial_av(int polys[6]); -int init_viterbi615_av(void *p,int starting_state); -int chainback_viterbi615_av(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615_av(void *p); -int update_viterbi615_blk_av(void *p,unsigned char *syms,int nbits); -#endif - -#ifdef __i386__ -void *create_viterbi615_mmx(int len); -void set_viterbi615_polynomial_mmx(int polys[6]); -int init_viterbi615_mmx(void *p,int starting_state); -int chainback_viterbi615_mmx(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615_mmx(void *p); -int update_viterbi615_blk_mmx(void *p,unsigned char *syms,int nbits); - -void *create_viterbi615_sse(int len); -void set_viterbi615_polynomial_sse(int polys[6]); -int init_viterbi615_sse(void *p,int starting_state); -int chainback_viterbi615_sse(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615_sse(void *p); -int update_viterbi615_blk_sse(void *p,unsigned char *syms,int nbits); - -void *create_viterbi615_sse2(int len); -void set_viterbi615_polynomial_sse2(int polys[6]); -int init_viterbi615_sse2(void *p,int starting_state); -int chainback_viterbi615_sse2(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615_sse2(void *p); -int update_viterbi615_blk_sse2(void *p,unsigned char *syms,int nbits); - -#endif - -void *create_viterbi615_port(int len); -void set_viterbi615_polynomial_port(int polys[6]); -int init_viterbi615_port(void *p,int starting_state); -int chainback_viterbi615_port(void *p,unsigned char *data,unsigned int nbits,unsigned int endstate); -void delete_viterbi615_port(void *p); -int update_viterbi615_blk_port(void *p,unsigned char *syms,int nbits); - - -/* General purpose RS codec, 8-bit symbols */ -void encode_rs_char(void *rs,unsigned char *data,unsigned char *parity); -int decode_rs_char(void *rs,unsigned char *data,int *eras_pos, - int no_eras); -void *init_rs_char(int symsize,int gfpoly, - int fcr,int prim,int nroots, - int pad); -void free_rs_char(void *rs); - -/* General purpose RS codec, integer symbols */ -void encode_rs_int(void *rs,int *data,int *parity); -int decode_rs_int(void *rs,int *data,int *eras_pos,int no_eras); -void *init_rs_int(int symsize,int gfpoly,int fcr, - int prim,int nroots,int pad); -void free_rs_int(void *rs); - -/* CCSDS standard (255,223) RS codec with conventional (*not* dual-basis) - * symbol representation - */ -void encode_rs_8(unsigned char *data,unsigned char *parity,int pad); -int decode_rs_8(unsigned char *data,int *eras_pos,int no_eras,int pad); - -/* CCSDS standard (255,223) RS codec with dual-basis symbol representation */ -void encode_rs_ccsds(unsigned char *data,unsigned char *parity,int pad); -int decode_rs_ccsds(unsigned char *data,int *eras_pos,int no_eras,int pad); - -/* Tables to map from conventional->dual (Taltab) and - * dual->conventional (Tal1tab) bases - */ -extern unsigned char Taltab[],Tal1tab[]; - - -/* CPU SIMD instruction set available */ -extern enum cpu_mode {UNKNOWN=0,PORT,MMX,SSE,SSE2,ALTIVEC} Cpu_mode; -void find_cpu_mode(void); /* Call this once at startup to set Cpu_mode */ - -/* Determine parity of argument: 1 = odd, 0 = even */ -#ifdef __i386__ -static inline int parityb(unsigned char x){ - __asm__ __volatile__ ("test %1,%1;setpo %0" : "=g"(x) : "r" (x)); - return x; -} -#else -void partab_init(); - -static inline int parityb(unsigned char x){ - extern unsigned char Partab[256]; - extern int P_init; - if(!P_init){ - partab_init(); - } - return Partab[x]; -} -#endif - - -static inline int parity(int x){ - /* Fold down to one byte */ - x ^= (x >> 16); - x ^= (x >> 8); - return parityb(x); -} - -/* Useful utilities for simulation */ -double normal_rand(double mean, double std_dev); -unsigned char addnoise(int sym,double amp,double gain,double offset,int clip); - -extern int Bitcnt[]; - -/* Dot product functions */ -void *initdp(signed short coeffs[],int len); -void freedp(void *dp); -long dotprod(void *dp,signed short a[]); - -void *initdp_port(signed short coeffs[],int len); -void freedp_port(void *dp); -long dotprod_port(void *dp,signed short a[]); - -#ifdef __i386__ -void *initdp_mmx(signed short coeffs[],int len); -void freedp_mmx(void *dp); -long dotprod_mmx(void *dp,signed short a[]); - -void *initdp_sse(signed short coeffs[],int len); -void freedp_sse(void *dp); -long dotprod_sse(void *dp,signed short a[]); - -void *initdp_sse2(signed short coeffs[],int len); -void freedp_sse2(void *dp); -long dotprod_sse2(void *dp,signed short a[]); -#endif - -#ifdef __VEC__ -void *initdp_av(signed short coeffs[],int len); -void freedp_av(void *dp); -long dotprod_av(void *dp,signed short a[]); -#endif - -/* Sum of squares - accepts signed shorts, produces unsigned long long */ -unsigned long long sumsq(signed short *in,int cnt); -unsigned long long sumsq_port(signed short *in,int cnt); - -#ifdef __i386__ -unsigned long long sumsq_mmx(signed short *in,int cnt); -unsigned long long sumsq_sse(signed short *in,int cnt); -unsigned long long sumsq_sse2(signed short *in,int cnt); -#endif -#ifdef __VEC__ -unsigned long long sumsq_av(signed short *in,int cnt); -#endif - - -/* Low-level data structures and routines */ - -int cpu_features(void); - -#endif /* _FEC_H_ */ - - - diff --git a/lib/verity/libfec/init_rs.h b/lib/verity/libfec/init_rs.h deleted file mode 100644 index cbb5fab2..00000000 --- a/lib/verity/libfec/init_rs.h +++ /dev/null @@ -1,106 +0,0 @@ -/* Common code for intializing a Reed-Solomon control block (char or int symbols) - * Copyright 2004 Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ -#undef NULL -#define NULL ((void *)0) - -{ - int i, j, sr,root,iprim; - - rs = NULL; - /* Check parameter ranges */ - if(symsize < 0 || symsize > 8*(int)sizeof(data_t)){ - goto done; - } - - if(fcr < 0 || fcr >= (1<= (1<= (1<= ((1<mm = symsize; - rs->nn = (1<pad = pad; - - rs->alpha_to = (data_t *)malloc(sizeof(data_t)*(rs->nn+1)); - if(rs->alpha_to == NULL){ - free(rs); - rs = NULL; - goto done; - } - rs->index_of = (data_t *)malloc(sizeof(data_t)*(rs->nn+1)); - if(rs->index_of == NULL){ - free(rs->alpha_to); - free(rs); - rs = NULL; - goto done; - } - - /* Generate Galois field lookup tables */ - rs->index_of[0] = A0; /* log(zero) = -inf */ - rs->alpha_to[A0] = 0; /* alpha**-inf = 0 */ - sr = 1; - for(i=0;inn;i++){ - rs->index_of[sr] = i; - rs->alpha_to[i] = sr; - sr <<= 1; - if(sr & (1<nn; - } - if(sr != 1){ - /* field generator polynomial is not primitive! */ - free(rs->alpha_to); - free(rs->index_of); - free(rs); - rs = NULL; - goto done; - } - - /* Form RS code generator polynomial from its roots */ - rs->genpoly = (data_t *)malloc(sizeof(data_t)*(nroots+1)); - if(rs->genpoly == NULL){ - free(rs->alpha_to); - free(rs->index_of); - free(rs); - rs = NULL; - goto done; - } - rs->fcr = fcr; - rs->prim = prim; - rs->nroots = nroots; - - /* Find prim-th root of 1, used in decoding */ - for(iprim=1;(iprim % prim) != 0;iprim += rs->nn) - ; - rs->iprim = iprim / prim; - - rs->genpoly[0] = 1; - for (i = 0,root=fcr*prim; i < nroots; i++,root += prim) { - rs->genpoly[i+1] = 1; - - /* Multiply rs->genpoly[] by @**(root + x) */ - for (j = i; j > 0; j--){ - if (rs->genpoly[j] != 0) - rs->genpoly[j] = rs->genpoly[j-1] ^ rs->alpha_to[modnn(rs,rs->index_of[rs->genpoly[j]] + root)]; - else - rs->genpoly[j] = rs->genpoly[j-1]; - } - /* rs->genpoly[0] can never be zero */ - rs->genpoly[0] = rs->alpha_to[modnn(rs,rs->index_of[rs->genpoly[0]] + root)]; - } - /* convert rs->genpoly[] to index form for quicker encoding */ - for (i = 0; i <= nroots; i++) - rs->genpoly[i] = rs->index_of[rs->genpoly[i]]; - done:; - -} diff --git a/lib/verity/libfec/init_rs_char.c b/lib/verity/libfec/init_rs_char.c deleted file mode 100644 index a51099a3..00000000 --- a/lib/verity/libfec/init_rs_char.c +++ /dev/null @@ -1,35 +0,0 @@ -/* Initialize a RS codec - * - * Copyright 2002 Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ -#include - -#include "char.h" -#include "rs-common.h" - -void free_rs_char(void *p){ - struct rs *rs = (struct rs *)p; - - free(rs->alpha_to); - free(rs->index_of); - free(rs->genpoly); - free(rs); -} - -/* Initialize a Reed-Solomon codec - * symsize = symbol size, bits - * gfpoly = Field generator polynomial coefficients - * fcr = first root of RS code generator polynomial, index form - * prim = primitive element to generate polynomial roots - * nroots = RS code generator polynomial degree (number of roots) - * pad = padding bytes at front of shortened block - */ -void *init_rs_char(int symsize,int gfpoly,int fcr,int prim, - int nroots,int pad){ - struct rs *rs; - -#include "init_rs.h" - - return rs; -} diff --git a/lib/verity/libfec/rs-common.h b/lib/verity/libfec/rs-common.h deleted file mode 100644 index e64eb39c..00000000 --- a/lib/verity/libfec/rs-common.h +++ /dev/null @@ -1,26 +0,0 @@ -/* Stuff common to all the general-purpose Reed-Solomon codecs - * Copyright 2004 Phil Karn, KA9Q - * May be used under the terms of the GNU Lesser General Public License (LGPL) - */ - -/* Reed-Solomon codec control block */ -struct rs { - int mm; /* Bits per symbol */ - int nn; /* Symbols per block (= (1<= rs->nn) { - x -= rs->nn; - x = (x >> rs->mm) + (x & rs->nn); - } - return x; -} diff --git a/lib/verity/rs.h b/lib/verity/rs.h new file mode 100644 index 00000000..5faa81a4 --- /dev/null +++ b/lib/verity/rs.h @@ -0,0 +1,35 @@ +/* + * Reed-Solomon codecs, based on libfec + * + * Copyright (C) 2004 Phil Karn, KA9Q + * libcryptsetup modifications + * Copyright (C) 2017, Red Hat, Inc. All rights reserved. + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This file 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef _LIBFEC_RS_H +#define _LIBFEC_RS_H + +typedef unsigned char data_t; +struct rs; + +struct rs *init_rs_char(int symsize, int gfpoly, int fcr, int prim, int nroots, int pad); +void free_rs_char(struct rs *rs); + +/* General purpose RS codec, 8-bit symbols */ +void encode_rs_char(struct rs *rs, data_t *data, data_t *parity); + +#endif diff --git a/lib/verity/rs_encode_char.c b/lib/verity/rs_encode_char.c new file mode 100644 index 00000000..f3cbd4c3 --- /dev/null +++ b/lib/verity/rs_encode_char.c @@ -0,0 +1,199 @@ +/* + * Reed-Solomon encoder, based on libfec + * + * Copyright (C) 2002, Phil Karn, KA9Q + * libcryptsetup modifications + * Copyright (C) 2017, Red Hat, Inc. All rights reserved. + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This file 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include + +#include "rs.h" + +/* Special reserved value encoding zero in index form. */ +#define A0 (rs->nn) + +/* Reed-Solomon codec control block */ +struct rs { + int mm; /* Bits per symbol */ + int nn; /* Symbols per block (= (1<= rs->nn) { + x -= rs->nn; + x = (x >> rs->mm) + (x & rs->nn); + } + return x; +} + +/* Initialize a Reed-Solomon codec + * symsize = symbol size, bits + * gfpoly = Field generator polynomial coefficients + * fcr = first root of RS code generator polynomial, index form + * prim = primitive element to generate polynomial roots + * nroots = RS code generator polynomial degree (number of roots) + * pad = padding bytes at front of shortened block + */ +struct rs *init_rs_char(int symsize, int gfpoly, int fcr, int prim, int nroots, int pad) +{ + struct rs *rs; + int i, j, sr, root, iprim; + + /* Check parameter ranges */ + if (symsize < 0 || symsize > 8 * (int)sizeof(data_t)) + return NULL; + if (fcr < 0 || fcr >= (1<= (1<= (1<= ((1<mm = symsize; + rs->nn = (1<pad = pad; + + rs->alpha_to = malloc(sizeof(data_t) * (rs->nn + 1)); + if (rs->alpha_to == NULL) { + free(rs); + return NULL; + } + rs->index_of = malloc(sizeof(data_t) * (rs->nn + 1)); + if (rs->index_of == NULL) { + free(rs->alpha_to); + free(rs); + return NULL; + } + memset(rs->index_of, 0, sizeof(data_t) * (rs->nn + 1)); + + /* Generate Galois field lookup tables */ + rs->index_of[0] = A0; /* log(zero) = -inf */ + rs->alpha_to[A0] = 0; /* alpha**-inf = 0 */ + sr = 1; + for (i = 0; i < rs->nn; i++) { + rs->index_of[sr] = i; + rs->alpha_to[i] = sr; + sr <<= 1; + if(sr & (1<nn; + } + if (sr != 1) { + /* field generator polynomial is not primitive! */ + free(rs->alpha_to); + free(rs->index_of); + free(rs); + return NULL; + } + + /* Form RS code generator polynomial from its roots */ + rs->genpoly = malloc(sizeof(data_t) * (nroots + 1)); + if (rs->genpoly == NULL) { + free(rs->alpha_to); + free(rs->index_of); + free(rs); + return NULL; + } + + rs->fcr = fcr; + rs->prim = prim; + rs->nroots = nroots; + + /* Find prim-th root of 1, used in decoding */ + for (iprim = 1; (iprim % prim) != 0; iprim += rs->nn) + ; + rs->iprim = iprim / prim; + + rs->genpoly[0] = 1; + for (i = 0, root = fcr * prim; i < nroots; i++, root += prim) { + rs->genpoly[i + 1] = 1; + + /* Multiply rs->genpoly[] by @**(root + x) */ + for (j = i; j > 0; j--){ + if (rs->genpoly[j] != 0) + rs->genpoly[j] = rs->genpoly[j - 1] ^ rs->alpha_to[modnn(rs, rs->index_of[rs->genpoly[j]] + root)]; + else + rs->genpoly[j] = rs->genpoly[j - 1]; + } + /* rs->genpoly[0] can never be zero */ + rs->genpoly[0] = rs->alpha_to[modnn(rs, rs->index_of[rs->genpoly[0]] + root)]; + } + /* convert rs->genpoly[] to index form for quicker encoding */ + for (i = 0; i <= nroots; i++) + rs->genpoly[i] = rs->index_of[rs->genpoly[i]]; + + return rs; +} + +void free_rs_char(struct rs *rs) +{ + if (!rs) + return; + + free(rs->alpha_to); + free(rs->index_of); + free(rs->genpoly); + free(rs); +} + +void encode_rs_char(struct rs *rs, data_t *data, data_t *parity) +{ + int i, j; + data_t feedback; + + memset(parity, 0, rs->nroots * sizeof(data_t)); + + for (i = 0; i < rs->nroots - rs->pad; i++) { + feedback = rs->index_of[data[i] ^ parity[0]]; + if (feedback != A0) { + /* feedback term is non-zero */ +#ifdef UNNORMALIZED + /* This line is unnecessary when GENPOLY[NROOTS] is unity, as it must + * always be for the polynomials constructed by init_rs() */ + feedback = modnn(rs, rs->nn - rs->genpoly[rs->nroots] + feedback); +#endif + for(j = 1; j < rs->nroots; j++) + parity[j] ^= rs->alpha_to[modnn(rs, feedback + rs->genpoly[rs->nroots - j])]; + } + + /* Shift */ + memmove(&parity[0], &parity[1], sizeof(data_t) * (rs->nroots - 1)); + + if (feedback != A0) + parity[rs->nroots - 1] = rs->alpha_to[modnn(rs, feedback + rs->genpoly[0])]; + else + parity[rs->nroots - 1] = 0; + } +} diff --git a/lib/verity/verity_fec.c b/lib/verity/verity_fec.c index 7f459886..43f078e0 100644 --- a/lib/verity/verity_fec.c +++ b/lib/verity/verity_fec.c @@ -25,7 +25,7 @@ #include "verity.h" #include "internal.h" -#include "libfec/fec.h" +#include "rs.h" /* ecc parameters */ #define FEC_RSM 255