1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * Decompression module for stand alone file systems. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/sysmacros.h> 34 #include <sys/vnode.h> 35 #include <sys/bootvfs.h> 36 #include <sys/filep.h> 37 #include <zmod/zlib.h> 38 39 #ifdef _BOOT 40 #include "../common/util.h" 41 #else 42 #include <sys/sunddi.h> 43 #endif 44 45 #define MAX_DECOMP_BUFS 8 46 #define GZIP_ID_BYTE_1 0x1f 47 #define GZIP_ID_BYTE_2 0x8b 48 #define GZIP_CM_DEFLATE 0x08 49 #define SEEKBUFSIZE 8192 50 51 #ifdef _BOOT 52 #define dprintf if (cf_debug) printf 53 #else 54 #define dprintf if (cf_debug) printf 55 56 #endif 57 58 extern int bootrd_debug; 59 extern void *bkmem_alloc(size_t); 60 extern void bkmem_free(void *, size_t); 61 62 caddr_t scratch_bufs[MAX_DECOMP_BUFS]; /* array of free scratch mem bufs */ 63 int decomp_bufcnt; /* total no, of allocated decomp bufs */ 64 int free_dcomp_bufs; /* no. of free decomp bufs */ 65 char seek_scrbuf[SEEKBUFSIZE]; /* buffer for seeking */ 66 int cf_debug; /* non-zero enables debug prints */ 67 68 void * 69 cf_alloc(void *opaque, unsigned int items, unsigned int size) 70 { 71 fileid_t *filep; 72 unsigned int nbytes; 73 caddr_t ptr; 74 75 filep = (fileid_t *)opaque; 76 nbytes = roundup(items * size, sizeof (long)); 77 if (nbytes > (DECOMP_BUFSIZE - filep->fi_dcscrused)) { 78 ptr = bkmem_alloc(nbytes); 79 } else { 80 ptr = &filep->fi_dcscrbuf[filep->fi_dcscrused]; 81 filep->fi_dcscrused += nbytes; 82 } 83 bzero(ptr, nbytes); 84 return (ptr); 85 } 86 87 /* 88 * Decompression scratch memory free routine, does nothing since we free 89 * the entire scratch area all at once on file close. 90 */ 91 /* ARGSUSED */ 92 void 93 cf_free(void *opaque, void *addr) 94 { 95 } 96 97 /* 98 * Read the first block of the file described by filep and determine if 99 * the file is gzip-compressed. If so, the compressed flag will be set 100 * in the fileid_t struct pointed to by filep and it will be initialized 101 * for doing decompression on reads to the file. 102 */ 103 int 104 cf_check_compressed(fileid_t *filep) 105 { 106 unsigned char *filebytes; 107 z_stream *zsp; 108 109 /* 110 * If the file is not long enough to check for a decompression header 111 * then return not compressed. 112 */ 113 if (filep->fi_inode->i_size < 3) 114 return (0); 115 filep->fi_offset = 0; 116 if ((filep->fi_getblock)(filep) == -1) 117 return (-1); 118 filep->fi_offset = 0; 119 filep->fi_count = 0; 120 filep->fi_cfoff = 0; 121 filebytes = (unsigned char *)filep->fi_memp; 122 if (filebytes[0] != GZIP_ID_BYTE_1 || filebytes[1] != GZIP_ID_BYTE_2 || 123 filebytes[2] != GZIP_CM_DEFLATE) 124 return (0); /* not compressed */ 125 filep->fi_flags |= FI_COMPRESSED; 126 127 dprintf("file %s is compressed\n", filep->fi_path); 128 129 /* 130 * Allocate decompress scratch buffer 131 */ 132 if (free_dcomp_bufs) { 133 filep->fi_dcscrbuf = scratch_bufs[--free_dcomp_bufs]; 134 } else { 135 filep->fi_dcscrbuf = bkmem_alloc(DECOMP_BUFSIZE); 136 decomp_bufcnt++; 137 } 138 filep->fi_dcscrused = 0; 139 zsp = bkmem_alloc(sizeof (*zsp)); 140 filep->fi_dcstream = zsp; 141 /* 142 * Initialize the decompression stream. Adding 16 to the window size 143 * indicates that zlib should expect a gzip header. 144 */ 145 bzero(zsp, sizeof (*zsp)); 146 zsp->opaque = filep; 147 zsp->zalloc = cf_alloc; 148 zsp->zfree = cf_free; 149 zsp->avail_in = 0; 150 zsp->next_in = NULL; 151 zsp->avail_out = 0; 152 zsp->next_out = NULL; 153 if (inflateInit2(zsp, MAX_WBITS + 16) != Z_OK) { 154 dprintf("inflateInit2() failed\n"); 155 return (-1); 156 } 157 return (0); 158 } 159 160 /* 161 * If the file described by fileid_t struct at *filep is compressed 162 * free any resources associated with the decompression. (decompression 163 * buffer, etc.). 164 */ 165 void 166 cf_close(fileid_t *filep) 167 { 168 if ((filep->fi_flags & FI_COMPRESSED) == 0) 169 return; 170 dprintf("cf_close: %s\n", filep->fi_path); 171 (void) inflateEnd(filep->fi_dcstream); 172 bkmem_free(filep->fi_dcstream, sizeof (z_stream)); 173 if (free_dcomp_bufs == MAX_DECOMP_BUFS) { 174 bkmem_free(filep->fi_dcscrbuf, DECOMP_BUFSIZE); 175 } else { 176 scratch_bufs[free_dcomp_bufs++] = filep->fi_dcscrbuf; 177 } 178 } 179 180 void 181 cf_rewind(fileid_t *filep) 182 { 183 z_stream *zsp; 184 185 dprintf("cf_rewind: %s\n", filep->fi_path); 186 zsp = filep->fi_dcstream; 187 zsp->avail_in = 0; 188 zsp->next_in = NULL; 189 (void) inflateReset(zsp); 190 filep->fi_cfoff = 0; 191 } 192 193 #define FLG_FHCRC 0x02 /* crc field present */ 194 #define FLG_FEXTRA 0x04 /* "extra" field present */ 195 #define FLG_FNAME 0x08 /* file name field present */ 196 #define FLG_FCOMMENT 0x10 /* comment field present */ 197 198 /* 199 * Read at the current uncompressed offset from the compressed file described 200 * by *filep. Will return decompressed data. 201 */ 202 int 203 cf_read(fileid_t *filep, caddr_t buf, size_t count) 204 { 205 z_stream *zsp; 206 struct inode *ip; 207 int err = Z_OK; 208 int infbytes; 209 off_t soff; 210 caddr_t smemp; 211 212 dprintf("cf_read: %s ", filep->fi_path); 213 dprintf("%lx bytes\n", count); 214 zsp = filep->fi_dcstream; 215 ip = filep->fi_inode; 216 dprintf(" reading at offset %lx\n", zsp->total_out); 217 zsp->next_out = (unsigned char *)buf; 218 zsp->avail_out = count; 219 while (zsp->avail_out != 0) { 220 if (zsp->avail_in == 0 && filep->fi_cfoff < ip->i_size) { 221 /* 222 * read a block of the file to inflate 223 */ 224 soff = filep->fi_offset; 225 smemp = filep->fi_memp; 226 filep->fi_memp = NULL; 227 filep->fi_offset = filep->fi_cfoff; 228 filep->fi_count = 0; 229 if ((*filep->fi_getblock)(filep) == -1) 230 return (-1); 231 filep->fi_offset = soff; 232 zsp->next_in = (unsigned char *)filep->fi_memp; 233 zsp->avail_in = filep->fi_count; 234 filep->fi_memp = smemp; 235 filep->fi_cfoff += filep->fi_count; 236 } 237 infbytes = zsp->avail_out; 238 dprintf("attempting inflate of %x bytes to buf at: %lx\n", 239 zsp->avail_out, (unsigned long)zsp->next_out); 240 err = inflate(zsp, Z_NO_FLUSH); 241 infbytes -= zsp->avail_out; 242 dprintf("inflated %x bytes, errcode=%d\n", infbytes, err); 243 /* 244 * break out if we hit end of the compressed file 245 * or the end of the compressed byte stream 246 */ 247 if (filep->fi_cfoff >= ip->i_size || err == Z_STREAM_END) 248 break; 249 } 250 dprintf("cf_read: returned %lx bytes\n", count - zsp->avail_out); 251 return (count - zsp->avail_out); 252 } 253 254 /* 255 * Seek to the location specified by addr 256 */ 257 void 258 cf_seek(fileid_t *filep, off_t addr, int whence) 259 { 260 z_stream *zsp; 261 int readsz; 262 263 dprintf("cf_seek: %s ", filep->fi_path); 264 dprintf("to %lx\n", addr); 265 zsp = filep->fi_dcstream; 266 if (whence == SEEK_CUR) 267 addr += zsp->total_out; 268 /* 269 * To seek backwards, must rewind and seek forwards 270 */ 271 if (addr < zsp->total_out) { 272 cf_rewind(filep); 273 filep->fi_offset = 0; 274 } else { 275 addr -= zsp->total_out; 276 } 277 while (addr > 0) { 278 readsz = MIN(addr, SEEKBUFSIZE); 279 (void) cf_read(filep, seek_scrbuf, readsz); 280 addr -= readsz; 281 } 282 } 283