1303095Ssobomax/* 2303095Ssobomax * Copyright (c) 2016 Maxim Sobolev <sobomax@FreeBSD.org> 3303095Ssobomax * All rights reserved. 4303095Ssobomax * 5303095Ssobomax * Redistribution and use in source and binary forms, with or without 6303095Ssobomax * modification, are permitted provided that the following conditions 7303095Ssobomax * are met: 8303095Ssobomax * 1. Redistributions of source code must retain the above copyright 9303095Ssobomax * notice, this list of conditions and the following disclaimer. 10303095Ssobomax * 2. Redistributions in binary form must reproduce the above copyright 11303095Ssobomax * notice, this list of conditions and the following disclaimer in the 12303095Ssobomax * documentation and/or other materials provided with the distribution. 13303095Ssobomax * 14303095Ssobomax * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15303095Ssobomax * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16303095Ssobomax * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17303095Ssobomax * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18303095Ssobomax * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19303095Ssobomax * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20303095Ssobomax * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21303095Ssobomax * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22303095Ssobomax * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23303095Ssobomax * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24303095Ssobomax * SUCH DAMAGE. 25303095Ssobomax */ 26303095Ssobomax 27303095Ssobomax#include <sys/cdefs.h> 28303095Ssobomax__FBSDID("$FreeBSD$"); 29303095Ssobomax 30303095Ssobomax#include <err.h> 31303095Ssobomax#include <stdio.h> 32303095Ssobomax#include <stdlib.h> 33303095Ssobomax#include <string.h> 34303095Ssobomax#include <unistd.h> 35303095Ssobomax 36303095Ssobomax#if defined(MKUZ_DEBUG) 37303095Ssobomax# include <assert.h> 38303095Ssobomax# include <stdio.h> 39303095Ssobomax#endif 40303095Ssobomax 41303095Ssobomax#include "mkuz_blockcache.h" 42303095Ssobomax#include "mkuz_blk.h" 43303095Ssobomax 44303095Ssobomaxstruct mkuz_blkcache_itm { 45303095Ssobomax struct mkuz_blk_info hit; 46303095Ssobomax struct mkuz_blkcache_itm *next; 47303095Ssobomax}; 48303095Ssobomax 49303095Ssobomaxstatic struct mkuz_blkcache { 50303095Ssobomax struct mkuz_blkcache_itm first[256]; 51303095Ssobomax} blkcache; 52303095Ssobomax 53303095Ssobomaxstatic int 54303095Ssobomaxverify_match(int fd, const struct mkuz_blk *cbp, struct mkuz_blkcache_itm *bcep) 55303095Ssobomax{ 56303095Ssobomax void *vbuf; 57303095Ssobomax ssize_t rlen; 58303095Ssobomax int rval; 59303095Ssobomax 60303095Ssobomax rval = -1; 61303095Ssobomax vbuf = malloc(cbp->info.len); 62303095Ssobomax if (vbuf == NULL) { 63303095Ssobomax goto e0; 64303095Ssobomax } 65303095Ssobomax if (lseek(fd, bcep->hit.offset, SEEK_SET) < 0) { 66303095Ssobomax goto e1; 67303095Ssobomax } 68303095Ssobomax rlen = read(fd, vbuf, cbp->info.len); 69303095Ssobomax if (rlen < 0 || (unsigned)rlen != cbp->info.len) { 70303095Ssobomax goto e2; 71303095Ssobomax } 72303095Ssobomax rval = (memcmp(cbp->data, vbuf, cbp->info.len) == 0) ? 1 : 0; 73303095Ssobomaxe2: 74303095Ssobomax lseek(fd, cbp->info.offset, SEEK_SET); 75303095Ssobomaxe1: 76303095Ssobomax free(vbuf); 77303095Ssobomaxe0: 78303095Ssobomax return (rval); 79303095Ssobomax} 80303095Ssobomax 81303095Ssobomax#define I2J(x) ((intmax_t)(x)) 82303095Ssobomax#define U2J(x) ((uintmax_t)(x)) 83303095Ssobomax 84303095Ssobomaxstatic unsigned char 85303095Ssobomaxdigest_fold(const unsigned char *mdigest) 86303095Ssobomax{ 87303095Ssobomax int i; 88303095Ssobomax unsigned char rval; 89303095Ssobomax 90303095Ssobomax rval = mdigest[0]; 91303095Ssobomax for (i = 1; i < 16; i++) { 92303095Ssobomax rval = rval ^ mdigest[i]; 93303095Ssobomax } 94303095Ssobomax return (rval); 95303095Ssobomax} 96303095Ssobomax 97303095Ssobomaxstruct mkuz_blk_info * 98303095Ssobomaxmkuz_blkcache_regblock(int fd, const struct mkuz_blk *bp) 99303095Ssobomax{ 100303095Ssobomax struct mkuz_blkcache_itm *bcep; 101303095Ssobomax int rval; 102303095Ssobomax unsigned char h; 103303095Ssobomax 104303095Ssobomax#if defined(MKUZ_DEBUG) 105303095Ssobomax assert((unsigned)lseek(fd, 0, SEEK_CUR) == bp->info.offset); 106303095Ssobomax#endif 107303095Ssobomax h = digest_fold(bp->info.digest); 108303095Ssobomax if (blkcache.first[h].hit.len == 0) { 109303095Ssobomax bcep = &blkcache.first[h]; 110303095Ssobomax } else { 111303095Ssobomax for (bcep = &blkcache.first[h]; bcep != NULL; bcep = bcep->next) { 112303095Ssobomax if (bcep->hit.len != bp->info.len) 113303095Ssobomax continue; 114303095Ssobomax if (memcmp(bp->info.digest, bcep->hit.digest, 115303095Ssobomax sizeof(bp->info.digest)) == 0) { 116303095Ssobomax break; 117303095Ssobomax } 118303095Ssobomax } 119303095Ssobomax if (bcep != NULL) { 120303095Ssobomax rval = verify_match(fd, bp, bcep); 121303095Ssobomax if (rval == 1) { 122303095Ssobomax#if defined(MKUZ_DEBUG) 123303095Ssobomax fprintf(stderr, "cache hit %jd, %jd, %jd, %jd\n", 124303095Ssobomax I2J(bcep->hit.blkno), I2J(bcep->hit.offset), 125303095Ssobomax I2J(bp->info.offset), I2J(bp->info.len)); 126303095Ssobomax#endif 127303095Ssobomax return (&bcep->hit); 128303095Ssobomax } 129303095Ssobomax if (rval == 0) { 130303095Ssobomax#if defined(MKUZ_DEBUG) 131303095Ssobomax fprintf(stderr, "block MD5 collision, you should try lottery, " 132303095Ssobomax "man!\n"); 133303095Ssobomax#endif 134303095Ssobomax return (NULL); 135303095Ssobomax } 136303095Ssobomax warn("verify_match"); 137303095Ssobomax return (NULL); 138303095Ssobomax } 139303095Ssobomax bcep = malloc(sizeof(struct mkuz_blkcache_itm)); 140303095Ssobomax if (bcep == NULL) 141303095Ssobomax return (NULL); 142303095Ssobomax memset(bcep, '\0', sizeof(struct mkuz_blkcache_itm)); 143303095Ssobomax bcep->next = blkcache.first[h].next; 144303095Ssobomax blkcache.first[h].next = bcep; 145303095Ssobomax } 146303095Ssobomax bcep->hit = bp->info; 147303095Ssobomax return (NULL); 148303095Ssobomax} 149