diff options
Diffstat (limited to 'sbin/ft')
| -rw-r--r-- | sbin/ft/Makefile | 3 | ||||
| -rw-r--r-- | sbin/ft/ft.8 | 6 | ||||
| -rw-r--r-- | sbin/ft/ft.c | 217 | ||||
| -rw-r--r-- | sbin/ft/ftecc.c | 438 |
4 files changed, 457 insertions, 207 deletions
diff --git a/sbin/ft/Makefile b/sbin/ft/Makefile index 41acb7b37fb9..95e8a96f062f 100644 --- a/sbin/ft/Makefile +++ b/sbin/ft/Makefile @@ -1,7 +1,8 @@ -# $Id: Makefile,v 1.2 1994/02/07 08:40:16 rgrimes Exp $ +# $Id: Makefile,v 1.3 1994/06/22 04:49:02 jkh Exp $ PROG= ft MAN8= ft.8 SRCS= ft.c ftecc.c +COPTS= -O2 -finline-functions -funroll-loops -fexpensive-optimizations .include <bsd.prog.mk> diff --git a/sbin/ft/ft.8 b/sbin/ft/ft.8 index 477f09b36d28..962001ec7bef 100644 --- a/sbin/ft/ft.8 +++ b/sbin/ft/ft.8 @@ -40,7 +40,7 @@ .Sh SYNOPSIS .Nm ft .Op Fl f Ar tape -.Op Fl description +.Op Ar description .Sh DESCRIPTION The .Nm ft @@ -59,8 +59,8 @@ To extract /usr from tape: .Bd -literal -offset indent % ft | tar xvzf - .Ed -.Sh SEE ALSO -.Xr qtar 1 +.\" .Sh SEE ALSO +.\" .Xr qtar 1 .Sh BUGS Formatting/Verifying is in the works. You will need to use your existing backup program to do this for the time being. diff --git a/sbin/ft/ft.c b/sbin/ft/ft.c index 4aa92f81625f..49aadd3331cc 100644 --- a/sbin/ft/ft.c +++ b/sbin/ft/ft.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 1993 Steve Gerakines + * Copyright (c) 1993, 1994 Steve Gerakines * * This is freely redistributable software. You may do anything you * wish with it, so long as the above notice stays intact. @@ -18,6 +18,10 @@ * * ft.c - simple floppy tape filter * + * 06/07/94 v1.0 ++sg + * Added support for tape retension. Added retries for ecc failures. + * Moved to release. + * * 01/28/94 v0.3b (Jim Babb) * Fixed bug when all sectors in a segment are marked bad. * @@ -27,7 +31,7 @@ * 09/02/93 v0.2 pl01 * Initial revision. * - * usage: ftfilt [ -f tape ] [ description ] + * usage: ft [ -f tape ] [ description ] */ #include <stdio.h> @@ -51,6 +55,7 @@ int tvlast; /* TRUE if last volume in set */ long tvsize = 0; /* tape volume size in bytes */ long tvtime = NULL; /* tape change time */ char *tvnote = ""; /* tape note */ +int doretension = 0; /* TRUE if we should retension tape */ /* Lookup the badmap for a given track and segment. */ #define BADMAP(t,s) hptr->qh_badmap[(t)*geo.g_segtrk+(s)] @@ -62,45 +67,22 @@ char *tvnote = ""; /* tape note */ #define equal(s1,s2) (strcmp(s1, s2) == 0) - -/* Entry */ -main(int argc, char *argv[]) +/* + * Print tape usage and then leave. + */ +void +usage(void) { - int r, s; - char *tape, *getenv(); - - if (argc > 2 && (equal(argv[1], "-t") || equal(argv[1], "-f"))) { - argc -= 2; - tape = argv[2]; - argv += 2; - } else - if ((tape = getenv("TAPE")) == NULL) - tape = DEFQIC; - if (argc > 1) { - tvnote = argv[1]; - if (strlen(tvnote) > 18) argv[1][18] = '\0'; - } - - /* Open the tape device */ - if ((tfd = open(tape, 2)) < 0) { - perror(tape); - exit(1); - } - - if (!isatty(0)) - do_write(); - else if (!isatty(1)) - do_read(); - else - do_getname(); - - close(tfd); - exit(0); + fprintf(stderr, "usage: ft [ -r ] [ -f device ] [ \"description\" ]\n"); + exit(1); } -/* Check status of tape drive */ -int check_stat(int fd, int wr) +/* + * Check status of tape drive + */ +int +check_stat(int fd, int wr) { int r, s; int sawit = 0; @@ -138,8 +120,11 @@ int check_stat(int fd, int wr) } - -ULONG qtimeval(time_t t) +/* + * Convert time_t value to QIC time value. + */ +ULONG +qtimeval(time_t t) { struct tm *tp; ULONG r; @@ -154,8 +139,12 @@ ULONG qtimeval(time_t t) return(r); } -/* Return tm struct from QIC date format. */ -struct tm *qtime(UCHAR *qt) + +/* + * Return tm struct from QIC date format. + */ +struct tm * +qtime(UCHAR *qt) { ULONG *vp = (ULONG *)qt; struct tm t; @@ -178,7 +167,10 @@ struct tm *qtime(UCHAR *qt) return(localtime(&tv)); } -/* Return a string, zero terminated */ + +/* + * Return a string, zero terminated. + */ char *qstr(char *str, int nchar) { static char tstr[256]; @@ -187,7 +179,11 @@ char *qstr(char *str, int nchar) return(tstr); } -/* Read header from tape */ + +/* + * Read header from tape + */ +int get_header(int fd) { int r, sn, bytes; @@ -238,6 +234,9 @@ get_header(int fd) } +/* + * Open /dev/tty and ask for next volume. + */ ask_vol(int vn) { FILE *inp; @@ -255,21 +254,26 @@ ask_vol(int vn) } -/* Return the name of the tape only. */ -do_getname() +/* + * Return the name of the tape only. + */ +void +do_getname(void) { if (check_stat(tfd, 0)) exit(1); if (get_header(tfd)) exit(1); fprintf(stderr, "\"%s\" - %s", qstr(hptr->qh_tname,44), asctime(qtime(hptr->qh_chgdate))); - ioctl(tfd, QIOREWIND); } -/* Extract data from tape to stdout */ -do_read() +/* + * Extract data from tape to stdout. + */ +void +do_read(void) { - int sno, vno, sbytes, r; + int sno, vno, sbytes, r, eccfails; long curpos; char *hname; QIC_Segment s; @@ -281,6 +285,13 @@ do_read() ask_vol(vno); continue; } + + if (doretension) { + ioctl(tfd, QIOBOT); + ioctl(tfd, QIOEOT); + ioctl(tfd, QIOBOT); + } + if (get_header(tfd)) { ask_vol(vno); continue; @@ -303,36 +314,50 @@ do_read() /* Process this volume */ curpos = 0; - for (sno = hptr->qh_first; tvsize > 0; sno++) { + eccfails = 0; + sno = hptr->qh_first; + while (tvsize > 0) { s.sg_trk = sno / geo.g_segtrk; s.sg_seg = sno % geo.g_segtrk; s.sg_badmap = BADMAP(s.sg_trk,s.sg_seg); sbytes = sect_bytes(s.sg_badmap) - QCV_ECCSIZE; s.sg_data = (UCHAR *)&buff[0]; + if (sbytes <= 0) { + sno++; + continue; + } + if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD"); - /* skip segments with *all* sectors flagged as bad */ - if (sbytes > 0) { - if (ioctl(tfd, QIOREAD, &s) < 0) perror("QIOREAD"); - r = check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap); - if (r) fprintf(stderr, "** warning: ecc failed at byte %ld\n", - curpos); - if (tvsize < sbytes) sbytes = tvsize; - write(1, s.sg_data, sbytes); - tvsize -= sbytes; - curpos += sbytes; + if (check_parity(s.sg_data, s.sg_badmap, s.sg_crcmap)) { + if (++eccfails <= 5) { + fprintf(stderr, + "ft: retry %d at segment %d byte %ld\n", + eccfails, sno, curpos); + continue; + } else + fprintf(stderr, + "ft: *** ecc failure in segment %d at byte %ld\n", + sno, curpos); } + if (tvsize < sbytes) sbytes = tvsize; + write(1, s.sg_data, sbytes); + tvsize -= sbytes; + curpos += sbytes; + sno++; + eccfails = 0; } if (tvlast) break; ioctl(tfd, QIOREWIND); ask_vol(++vno); } - ioctl(tfd, QIOREWIND); - return(0); } -/* Dump data from stdin to tape */ -do_write() +/* + * Dump data from stdin to tape. + */ +void +do_write(void) { int sno, vno, amt, sbytes; int c, maxseg, r; @@ -348,6 +373,13 @@ do_write() ask_vol(vno); continue; } + + if (doretension) { + ioctl(tfd, QIOBOT); + ioctl(tfd, QIOEOT); + ioctl(tfd, QIOBOT); + } + if (get_header(tfd)) { ask_vol(vno); continue; @@ -376,6 +408,7 @@ do_write() break; } } + /* skip the segment if *all* sectors are flagged as bad */ if (amt) { if (amt < sbytes) @@ -410,7 +443,7 @@ do_write() if (ioctl(tfd, QIOWRITE, &s) < 0) { perror("QIOWRITE"); exit(1); - } + } } if (dhsn >= 0) { s.sg_trk = dhsn / geo.g_segtrk; @@ -428,5 +461,57 @@ do_write() if (tvlast) break; ask_vol(++vno); } - return(0); +} + + +/* + * Entry. + */ +void +main(int argc, char *argv[]) +{ + int r, s, i; + char *tape, *getenv(); + + + /* Get device from environment, command line will override. */ + if ((tape = getenv("TAPE")) == NULL) tape = DEFQIC; + + /* Process args. */ + for (i = 1; i < argc; i++) { + if (argv[i][0] != '-') break; + switch (argv[i][1]) { + case 'f': + case 't': + if (i == (argc - 1)) usage(); + tape = argv[++i]; + break; + case 'r': + doretension = 1; + break; + default: + usage(); + } + } + if (i < (argc - 1)) usage(); + if (i < argc) { + tvnote = argv[i]; + if (strlen(tvnote) > 18) argv[i][18] = '\0'; + } + + /* Open the tape device */ + if ((tfd = open(tape, 2)) < 0) { + perror(tape); + exit(1); + } + + if (!isatty(0)) + do_write(); + else if (!isatty(1)) + do_read(); + else + do_getname(); + + close(tfd); + exit(0); } diff --git a/sbin/ft/ftecc.c b/sbin/ft/ftecc.c index 430f3a8316bb..fbba10f07fa5 100644 --- a/sbin/ft/ftecc.c +++ b/sbin/ft/ftecc.c @@ -1,32 +1,46 @@ /* - * ftecc.c 10/30/93 v0.3 - * Handle error correction for floppy tape drives. + * Copyright (c) 1994 Steve Gerakines * - * File contents are copyrighted by David L. Brown and falls under the - * terms of the GPL version 2 or greater. See his original release for - * the specific terms. + * This is freely redistributable software. You may do anything you + * wish with it, so long as the above notice stays intact. * - * Steve Gerakines - * steve2@genesis.nred.ma.us - * Modified slightly to fit with my tape driver. I'm not at all happy - * with this module and will have it replaced with a more functional one - * in the next release(/RSN). I am close, but progress will continue to - * be slow until I can find a book on the subject where the translator - * understands both the to and from languages. :-( For now it will - * suffice. + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS + * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + * ftecc.c - QIC-40/80 Reed-Solomon error correction + * 05/30/94 v1.0 ++sg + * Did some minor optimization. The multiply by 0xc0 was a dog so it + * was replaced with a table lookup. Fixed a couple of places where + * bad sectors could go unnoticed. Moved to release. + * + * 03/22/94 v0.4 + * Major re-write. It can handle everything required by QIC now. + * + * 09/14/93 v0.2 pl01 + * Modified slightly to fit with my driver. Based entirely upon David + * L. Brown's package. */ #include <sys/ftape.h> -/* - * In order to speed up the correction and adjustment, we can compute - * a matrix of coefficients for the multiplication. - */ +/* Inverse matrix */ struct inv_mat { - UCHAR log_denom; /* The log z of the denominator. */ - UCHAR zs[3][3]; /* The coefficients for the adjustment matrix. */ + UCHAR log_denom; /* Log of the denominator */ + UCHAR zs[3][3]; /* The matrix */ }; -/* This array is a table of powers of x, from 0 to 254. */ + +/* + * Powers of x, modulo 255. + */ static UCHAR alpha_power[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x87, 0x89, 0x95, 0xad, 0xdd, 0x3d, 0x7a, 0xf4, @@ -59,12 +73,12 @@ static UCHAR alpha_power[] = { 0xc8, 0x17, 0x2e, 0x5c, 0xb8, 0xf7, 0x69, 0xd2, 0x23, 0x46, 0x8c, 0x9f, 0xb9, 0xf5, 0x6d, 0xda, 0x33, 0x66, 0xcc, 0x1f, 0x3e, 0x7c, 0xf8, 0x77, - 0xee, 0x5b, 0xb6, 0xeb, 0x51, 0xa2, 0xc3 + 0xee, 0x5b, 0xb6, 0xeb, 0x51, 0xa2, 0xc3, 0x01 }; + /* - * This is the reverse lookup table. There is no log of 0, so the - * first element is not valid. + * Log table, modulo 255 + 1. */ static UCHAR alpha_log[] = { 0xff, 0x00, 0x01, 0x63, 0x02, 0xc6, 0x64, 0x6a, @@ -101,8 +115,51 @@ static UCHAR alpha_log[] = { 0xf6, 0x87, 0xa5, 0x17, 0x3a, 0xa3, 0x3c, 0xb7 }; -/* Return number of sectors available in a segment. */ -int sect_count(ULONG badmap) + +/* + * Multiplication table for 0xc0. + */ +static UCHAR mult_c0[] = { + 0x00, 0xc0, 0x07, 0xc7, 0x0e, 0xce, 0x09, 0xc9, + 0x1c, 0xdc, 0x1b, 0xdb, 0x12, 0xd2, 0x15, 0xd5, + 0x38, 0xf8, 0x3f, 0xff, 0x36, 0xf6, 0x31, 0xf1, + 0x24, 0xe4, 0x23, 0xe3, 0x2a, 0xea, 0x2d, 0xed, + 0x70, 0xb0, 0x77, 0xb7, 0x7e, 0xbe, 0x79, 0xb9, + 0x6c, 0xac, 0x6b, 0xab, 0x62, 0xa2, 0x65, 0xa5, + 0x48, 0x88, 0x4f, 0x8f, 0x46, 0x86, 0x41, 0x81, + 0x54, 0x94, 0x53, 0x93, 0x5a, 0x9a, 0x5d, 0x9d, + 0xe0, 0x20, 0xe7, 0x27, 0xee, 0x2e, 0xe9, 0x29, + 0xfc, 0x3c, 0xfb, 0x3b, 0xf2, 0x32, 0xf5, 0x35, + 0xd8, 0x18, 0xdf, 0x1f, 0xd6, 0x16, 0xd1, 0x11, + 0xc4, 0x04, 0xc3, 0x03, 0xca, 0x0a, 0xcd, 0x0d, + 0x90, 0x50, 0x97, 0x57, 0x9e, 0x5e, 0x99, 0x59, + 0x8c, 0x4c, 0x8b, 0x4b, 0x82, 0x42, 0x85, 0x45, + 0xa8, 0x68, 0xaf, 0x6f, 0xa6, 0x66, 0xa1, 0x61, + 0xb4, 0x74, 0xb3, 0x73, 0xba, 0x7a, 0xbd, 0x7d, + 0x47, 0x87, 0x40, 0x80, 0x49, 0x89, 0x4e, 0x8e, + 0x5b, 0x9b, 0x5c, 0x9c, 0x55, 0x95, 0x52, 0x92, + 0x7f, 0xbf, 0x78, 0xb8, 0x71, 0xb1, 0x76, 0xb6, + 0x63, 0xa3, 0x64, 0xa4, 0x6d, 0xad, 0x6a, 0xaa, + 0x37, 0xf7, 0x30, 0xf0, 0x39, 0xf9, 0x3e, 0xfe, + 0x2b, 0xeb, 0x2c, 0xec, 0x25, 0xe5, 0x22, 0xe2, + 0x0f, 0xcf, 0x08, 0xc8, 0x01, 0xc1, 0x06, 0xc6, + 0x13, 0xd3, 0x14, 0xd4, 0x1d, 0xdd, 0x1a, 0xda, + 0xa7, 0x67, 0xa0, 0x60, 0xa9, 0x69, 0xae, 0x6e, + 0xbb, 0x7b, 0xbc, 0x7c, 0xb5, 0x75, 0xb2, 0x72, + 0x9f, 0x5f, 0x98, 0x58, 0x91, 0x51, 0x96, 0x56, + 0x83, 0x43, 0x84, 0x44, 0x8d, 0x4d, 0x8a, 0x4a, + 0xd7, 0x17, 0xd0, 0x10, 0xd9, 0x19, 0xde, 0x1e, + 0xcb, 0x0b, 0xcc, 0x0c, 0xc5, 0x05, 0xc2, 0x02, + 0xef, 0x2f, 0xe8, 0x28, 0xe1, 0x21, 0xe6, 0x26, + 0xf3, 0x33, 0xf4, 0x34, 0xfd, 0x3d, 0xfa, 0x3a +}; + + +/* + * Return number of sectors available in a segment. + */ +int +sect_count(ULONG badmap) { int i, amt; @@ -111,8 +168,12 @@ int sect_count(ULONG badmap) return(amt); } -/* Return number of bytes available in a segment. */ -int sect_bytes(ULONG badmap) + +/* + * Return number of bytes available in a segment. + */ +int +sect_bytes(ULONG badmap) { int i, amt; @@ -121,146 +182,215 @@ int sect_bytes(ULONG badmap) return(amt); } -/* Multiply two numbers in the field. */ -static UCHAR multiply(UCHAR a, UCHAR b) + +/* + * Multiply two numbers in the field. + */ +static inline UCHAR +multiply(UCHAR a, UCHAR b) { int tmp; - if (a == 0 || b == 0) return(0); - tmp = (alpha_log[a] + alpha_log[b]); + if (!a || !b) return(0); + tmp = alpha_log[a] + alpha_log[b]; if (tmp > 254) tmp -= 255; - return (alpha_power[tmp]); + return(alpha_power[tmp]); } -static UCHAR divide(UCHAR a, UCHAR b) + +/* + * Multiply by an exponent. + */ +static inline UCHAR +multiply_out(UCHAR a, int b) { int tmp; - if (a == 0 || b == 0) return(0); - tmp = (alpha_log[a] - alpha_log[b]); + if (!a) return(0); + tmp = alpha_log[a] + b; + if (tmp > 254) tmp -= 255; + return(alpha_power[tmp]); +} + + +/* + * Divide two numbers. + */ +static inline UCHAR +divide(UCHAR a, UCHAR b) +{ + int tmp; + + if (!a || !b) return(0); + tmp = alpha_log[a] - alpha_log[b]; if (tmp < 0) tmp += 255; return (alpha_power[tmp]); } + /* - * This is just like divide, except we have already looked up the log - * of the second number. + * Divide using exponent. */ -static UCHAR divide_out(UCHAR a, UCHAR b) +static inline UCHAR +divide_out(UCHAR a, UCHAR b) { int tmp; - if (a == 0) return 0; + if (!a) return 0; tmp = alpha_log[a] - b; if (tmp < 0) tmp += 255; return (alpha_power[tmp]); } -/* This returns the value z^{a-b}. */ -static UCHAR z_of_ab(UCHAR a, UCHAR b) + +/* + * This returns the value z^{a-b}. + */ +static inline UCHAR +z_of_ab(UCHAR a, UCHAR b) { - int tmp = (int)a - (int)b; + int tmp = a - b; - if (tmp < 0) - tmp += 255; - else if (tmp >= 255) - tmp -= 255; + if (tmp < 0) tmp += 255; return(alpha_power[tmp]); } -/* Calculate the inverse matrix. Returns 1 if the matrix is valid, or - * zero if there is no inverse. The i's are the indices of the bytes - * to be corrected. + +/* + * Calculate the inverse matrix for two or three errors. Returns 0 + * if there is no inverse or 1 if successful. */ -static int calculate_inverse (int *pblk, struct inv_mat *inv) +static inline int +calculate_inverse(int nerrs, int *pblk, struct inv_mat *inv) { /* First some variables to remember some of the results. */ UCHAR z20, z10, z21, z12, z01, z02; UCHAR i0, i1, i2; + UCHAR iv0, iv1, iv2; - i0 = pblk[0]; i1 = pblk[1]; i2 = pblk[2]; - - z20 = z_of_ab (i2, i0); z10 = z_of_ab (i1, i0); - z21 = z_of_ab (i2, i1); z12 = z_of_ab (i1, i2); - z01 = z_of_ab (i0, i1); z02 = z_of_ab (i0, i2); - inv->log_denom = (z20 ^ z10 ^ z21 ^ z12 ^ z01 ^ z02); - if (inv->log_denom == 0) return 0; - inv->log_denom = alpha_log[inv->log_denom]; + if (nerrs < 2) return(1); + if (nerrs > 3) return(0); - /* Calculate all of the coefficients on the top. */ - inv->zs[0][0] = alpha_power[i1] ^ alpha_power[i2]; - inv->zs[0][1] = z21 ^ z12; - inv->zs[0][2] = alpha_power[255-i1] ^ alpha_power[255-i2]; + i0 = pblk[0]; i1 = pblk[1]; i2 = pblk[2]; + if (nerrs == 2) { + /* 2 errs */ + z01 = alpha_power[255 - i0]; + z02 = alpha_power[255 - i1]; + inv->log_denom = (z01 ^ z02); + if (!inv->log_denom) return(0); + inv->log_denom = 255 - alpha_log[inv->log_denom]; - inv->zs[1][0] = alpha_power[i0] ^ alpha_power[i2]; - inv->zs[1][1] = z20 ^ z02; - inv->zs[1][2] = alpha_power[255-i0] ^ alpha_power[255-i2]; + inv->zs[0][0] = multiply_out( 1, inv->log_denom); + inv->zs[0][1] = multiply_out(z02, inv->log_denom); + inv->zs[1][0] = multiply_out( 1, inv->log_denom); + inv->zs[1][1] = multiply_out(z01, inv->log_denom); + } else { + /* 3 errs */ + z20 = z_of_ab (i2, i0); + z10 = z_of_ab (i1, i0); + z21 = z_of_ab (i2, i1); + z12 = z_of_ab (i1, i2); + z01 = z_of_ab (i0, i1); + z02 = z_of_ab (i0, i2); + inv->log_denom = (z20 ^ z10 ^ z21 ^ z12 ^ z01 ^ z02); + if (!inv->log_denom) return(0); + inv->log_denom = 255 - alpha_log[inv->log_denom]; - inv->zs[2][0] = alpha_power[i0] ^ alpha_power[i1]; - inv->zs[2][1] = z10 ^ z01; - inv->zs[2][2] = alpha_power[255-i0] ^ alpha_power[255-i1]; + iv0 = alpha_power[255 - i0]; + iv1 = alpha_power[255 - i1]; + iv2 = alpha_power[255 - i2]; + i0 = alpha_power[i0]; + i1 = alpha_power[i1]; + i2 = alpha_power[i2]; + inv->zs[0][0] = multiply_out(i1 ^ i2, inv->log_denom); + inv->zs[0][1] = multiply_out(z21 ^ z12, inv->log_denom); + inv->zs[0][2] = multiply_out(iv1 ^ iv2, inv->log_denom); + inv->zs[1][0] = multiply_out(i0 ^ i2, inv->log_denom); + inv->zs[1][1] = multiply_out(z20 ^ z02, inv->log_denom); + inv->zs[1][2] = multiply_out(iv0 ^ iv2, inv->log_denom); + inv->zs[2][0] = multiply_out(i0 ^ i1, inv->log_denom); + inv->zs[2][1] = multiply_out(z10 ^ z01, inv->log_denom); + inv->zs[2][2] = multiply_out(iv0 ^ iv1, inv->log_denom); + } return(1); } + /* - * Determine the error values for a given inverse matrix and syndromes. + * Determine the error magnitudes for a given matrix and syndromes. */ -static void determine3(struct inv_mat *inv, UCHAR *es, UCHAR *ss) +static inline void +determine(int nerrs, struct inv_mat *inv, UCHAR *ss, UCHAR *es) { UCHAR tmp; int i, j; - for (i = 0; i < 3; i++) { - tmp = 0; - for (j = 0; j < 3; j++) tmp ^= multiply (ss[j], inv->zs[i][j]); - es[i] = divide_out(tmp, inv->log_denom); + for (i = 0; i < nerrs; i++) { + es[i] = 0; + for (j = 0; j < nerrs; j++) + es[i] ^= multiply(ss[j], inv->zs[i][j]); } } /* - * Compute the 3 syndrome values. The data pointer should point to - * the offset within the first block of the column to calculate. The - * count of blocks is in blocks. The three bytes will be placed in - * ss[0], ss[1], and ss[2]. + * Compute the 3 syndrome values. */ -static void compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss) +static inline int +compute_syndromes(UCHAR *data, int nblks, int col, UCHAR *ss) { - int i; - UCHAR v; + UCHAR r0, r1, r2, t1, t2; + UCHAR *rptr; - ss[0] = 0; ss[1] = 0; ss[2] = 0; - for (i = (nblks-1)*QCV_BLKSIZE; i >= 0; i -= QCV_BLKSIZE) { - v = data[i+col]; - if (ss[0] & 0x01) { ss[0] >>= 1; ss[0] ^= 0xc3; } else ss[0] >>= 1; - ss[0] ^= v; - ss[1] ^= v; - if (ss[2] & 0x80) { ss[2] <<= 1; ss[2] ^= 0x87; } else ss[2] <<= 1; - ss[2] ^= v; + rptr = data + col; + data += nblks << 10; + r0 = r1 = r2 = 0; + while (rptr < data) { + t1 = *rptr ^ r0; + t2 = mult_c0[t1]; + r0 = t2 ^ r1; + r1 = t2 ^ r2; + r2 = t1; + rptr += QCV_BLKSIZE; + } + if (r0 || r1 || r2) { + ss[0] = divide_out(r0 ^ divide_out(r1 ^ divide_out(r2, 1), 1), nblks); + ss[1] = r0 ^ r1 ^ r2; + ss[2] = multiply_out(r0 ^ multiply_out(r1 ^ multiply_out(r2, 1), 1), nblks); + return(0); } + return(1); } + /* - * Calculate the parity bytes for a segment. Returns 0 on success. + * Calculate the parity bytes for a segment, returns 0 on success (always). */ -int set_parity (UCHAR *data, ULONG badmap) +int +set_parity (UCHAR *data, ULONG badmap) { - int col; - struct inv_mat inv; - UCHAR ss[3], es[3]; - int nblks, pblk[3]; + UCHAR r0, r1, r2, t1, t2; + UCHAR *rptr; + int max, row, col; - nblks = sect_count(badmap); - pblk[0] = nblks-3; pblk[1] = nblks-2; pblk[2] = nblks-1; - if (!calculate_inverse(pblk, &inv)) return(1); - - pblk[0] *= QCV_BLKSIZE; pblk[1] *= QCV_BLKSIZE; pblk[2] *= QCV_BLKSIZE; - for (col = 0; col < QCV_BLKSIZE; col++) { - compute_syndromes (data, nblks-3, col, ss); - determine3(&inv, es, ss); - data[pblk[0]+col] = es[0]; - data[pblk[1]+col] = es[1]; - data[pblk[2]+col] = es[2]; + max = sect_count(badmap) - 3; + col = QCV_BLKSIZE; + while (col--) { + rptr = data; + r0 = r1 = r2 = 0; + row = max; + while (row--) { + t1 = *rptr ^ r0; + t2 = mult_c0[t1]; + r0 = t2 ^ r1; + r1 = t2 ^ r2; + r2 = t1; + rptr += QCV_BLKSIZE; + } + *rptr = r0; rptr += QCV_BLKSIZE; + *rptr = r1; rptr += QCV_BLKSIZE; + *rptr = r2; + data++; } return(0); } @@ -270,47 +400,81 @@ int set_parity (UCHAR *data, ULONG badmap) * Check and correct errors in a block. Returns 0 on success, * 1 if failed. */ -int check_parity(UCHAR *data, ULONG badmap, ULONG crcmap) +int +check_parity(UCHAR *data, ULONG badmap, ULONG crcmap) { - int i, j, col, crcerrs, r, tries, nblks; - struct inv_mat inv; + int crcerrs, eblk[3]; + int col, row; + int i, j, nblks; UCHAR ss[3], es[3]; - int i1, i2, eblk[3]; + int i1, i2, saverrs; + struct inv_mat inv; nblks = sect_count(badmap); - crcerrs = 0; - for (i = 0; crcerrs < 3 && i < nblks; i++) - if (crcmap & (1 << i)) eblk[crcerrs++] = i; - for (i = 1, j = crcerrs; j < 3 && i < nblks; i++) - if ((crcmap & (1 << i)) == 0) eblk[j++] = i; + /* Count the number of CRC errors and note their locations. */ + crcerrs = 0; + if (crcmap) { + for (i = 0; i < nblks; i++) { + if (crcmap & (1 << i)) { + if (crcerrs == 3) return(1); + eblk[crcerrs++] = i; + } + } + } - if (!calculate_inverse (eblk, &inv)) return(1); + /* Calculate the inverse matrix */ + if (!calculate_inverse(crcerrs, eblk, &inv)) return(1); - eblk[0] *= QCV_BLKSIZE; eblk[1] *= QCV_BLKSIZE; eblk[2] *= QCV_BLKSIZE; - r = 0; + /* Scan each column for problems and attempt to correct. */ for (col = 0; col < QCV_BLKSIZE; col++) { - compute_syndromes (data, nblks, col, ss); + if (compute_syndromes(data, nblks, col, ss)) continue; + es[0] = es[1] = es[2] = 0; + + /* Analyze the error situation. */ + switch (crcerrs) { + case 0: /* 0 errors >0 failures */ + if (!ss[0]) return(1); + eblk[crcerrs] = alpha_log[divide(ss[1], ss[0])]; + if (eblk[crcerrs] >= nblks) return(1); + es[0] = ss[1]; + if (++crcerrs > 3) return(1); + break; - if (!ss[0] && !ss[1] && !ss[2]) continue; - if (crcerrs) { - determine3 (&inv, es, ss); - for (j = 0; j < crcerrs; j++) - data[eblk[j] + col] ^= es[j]; - compute_syndromes (data, nblks, col, ss); - if (!ss[0] && !ss[1] && !ss[2]) { - r = 1; - continue; + case 1: /* 1 error (+ possible failures) */ + i1 = ss[2] ^ multiply_out(ss[1], eblk[0]); + i2 = ss[1] ^ multiply_out(ss[0], eblk[0]); + if (!i1 && !i2) { /* only 1 error */ + inv.zs[0][0] = alpha_power[eblk[0]]; + inv.log_denom = 0; + } else if (!i1 || !i2) { /* too many errors */ + return(1); + } else { /* add failure */ + eblk[crcerrs] = alpha_log[divide(i1, i2)]; + if (eblk[crcerrs] >= nblks) return(1); + if (++crcerrs > 3) return(1); + if (!calculate_inverse(crcerrs, eblk, &inv)) return(1); } + determine(crcerrs, &inv, ss, es); + break; + + case 2: /* 2 errors */ + case 3: /* 3 errors */ + determine(crcerrs, &inv, ss, es); + break; + + default: + return(1); } - determine3 (&inv, es, ss); - i1 = alpha_log[divide(ss[2], ss[1])]; - i2 = alpha_log[divide(ss[1], ss[0])]; - if (i1 != i2 || ((QCV_BLKSIZE * i1) + col) > QCV_SEGSIZE) - r = 1; - else - data[QCV_BLKSIZE * i1 + col] ^= ss[1]; - } - return(r); + /* Make corrections. */ + for (i = 0; i < crcerrs; i++) { + data[(eblk[i] << 10) | col] ^= es[i]; + ss[0] ^= divide_out(es[i], eblk[i]); + ss[1] ^= es[i]; + ss[2] ^= multiply_out(es[i], eblk[i]); + } + if (ss[0] || ss[1] || ss[2]) return(1); + } + return(0); } |