Annotation of src/usr.bin/compress/gzopen.c, Revision 1.14
1.14 ! mickey 1: /* $OpenBSD: gzopen.c,v 1.13 2003/07/17 20:06:01 millert Exp $ */
1.1 mickey 2:
3: /*
4: * Copyright (c) 1997 Michael Shalayeff
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
1.5 mickey 16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1.1 mickey 18: * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26: * SUCH DAMAGE.
27: *
28: */
29: /* this is partially derived from the zlib's gzio.c file, so the notice: */
30: /*
31: zlib.h -- interface of the 'zlib' general purpose compression library
32: version 1.0.4, Jul 24th, 1996.
33:
34: Copyright (C) 1995-1996 Jean-loup Gailly and Mark Adler
35:
36: This software is provided 'as-is', without any express or implied
37: warranty. In no event will the authors be held liable for any damages
38: arising from the use of this software.
39:
40: Permission is granted to anyone to use this software for any purpose,
41: including commercial applications, and to alter it and redistribute it
42: freely, subject to the following restrictions:
43:
44: 1. The origin of this software must not be misrepresented; you must not
45: claim that you wrote the original software. If you use this software
46: in a product, an acknowledgment in the product documentation would be
47: appreciated but is not required.
48: 2. Altered source versions must be plainly marked as such, and must not be
49: misrepresented as being the original software.
50: 3. This notice may not be removed or altered from any source distribution.
51:
52: Jean-loup Gailly Mark Adler
53: gzip@prep.ai.mit.edu madler@alumni.caltech.edu
54:
55:
56: The data format used by the zlib library is described by RFCs (Request for
57: Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
58: (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
59: */
60:
1.5 mickey 61: const char gz_rcsid[] =
1.14 ! mickey 62: "$OpenBSD: gzopen.c,v 1.13 2003/07/17 20:06:01 millert Exp $";
1.5 mickey 63:
1.13 millert 64: #include <sys/param.h>
1.1 mickey 65: #include <sys/stat.h>
1.13 millert 66: #include <sys/uio.h>
1.1 mickey 67: #include <stdio.h>
68: #include <stdlib.h>
1.11 david 69: #include <string.h>
1.1 mickey 70: #include <errno.h>
71: #include <unistd.h>
72: #include <zlib.h>
73: #include "compress.h"
74:
75: /* gzip flag byte */
76: #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
77: #define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
78: #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
79: #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
80: #define COMMENT 0x10 /* bit 4 set: file comment present */
81: #define RESERVED 0xE0 /* bits 5..7: reserved */
82:
83: #define DEF_MEM_LEVEL 8
84: #define OS_CODE 0x03 /* unix */
85:
86: typedef
87: struct gz_stream {
88: int z_fd; /* .gz file */
89: z_stream z_stream; /* libz stream */
90: int z_eof; /* set if end of input file */
91: u_char z_buf[Z_BUFSIZE]; /* i/o buffer */
1.13 millert 92: u_int32_t z_time; /* timestamp (mtime) */
93: u_int32_t z_hlen; /* length of the gz header */
1.1 mickey 94: u_int32_t z_crc; /* crc32 of uncompressed data */
95: char z_mode; /* 'w' or 'r' */
96:
97: } gz_stream;
98:
1.5 mickey 99: static const u_char gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
1.1 mickey 100:
1.3 millert 101: static int put_int32(gz_stream *, u_int32_t);
102: static u_int32_t get_int32(gz_stream *);
1.13 millert 103: static int get_header(gz_stream *, char *, int);
104: static int put_header(gz_stream *, char *, u_int32_t);
1.3 millert 105: static int get_byte(gz_stream *);
1.1 mickey 106:
107: void *
1.13 millert 108: gz_open(int fd, const char *mode, char *name, int bits,
109: u_int32_t mtime, int gotmagic)
1.1 mickey 110: {
111: gz_stream *s;
112:
113: if (fd < 0 || !mode)
114: return NULL;
115:
116: if ((mode[0] != 'r' && mode[0] != 'w') || mode[1] != '\0' ||
117: bits < 0 || bits > Z_BEST_COMPRESSION) {
118: errno = EINVAL;
119: return NULL;
120: }
1.4 aaron 121: if ((s = (gz_stream *)calloc(1, sizeof(gz_stream))) == NULL)
1.1 mickey 122: return NULL;
123:
124: s->z_stream.zalloc = (alloc_func)0;
125: s->z_stream.zfree = (free_func)0;
126: s->z_stream.opaque = (voidpf)0;
127: s->z_stream.next_in = Z_NULL;
128: s->z_stream.next_out = Z_NULL;
129: s->z_stream.avail_in = s->z_stream.avail_out = 0;
130: s->z_fd = 0;
131: s->z_eof = 0;
1.13 millert 132: s->z_time = 0;
133: s->z_hlen = 0;
1.1 mickey 134: s->z_crc = crc32(0L, Z_NULL, 0);
135: s->z_mode = mode[0];
136:
137: if (s->z_mode == 'w') {
138: /* windowBits is passed < 0 to suppress zlib header */
139: if (deflateInit2(&(s->z_stream), bits, Z_DEFLATED,
140: -MAX_WBITS, DEF_MEM_LEVEL, 0) != Z_OK) {
141: free (s);
142: return NULL;
143: }
144: s->z_stream.next_out = s->z_buf;
145: } else {
146: if (inflateInit2(&(s->z_stream), -MAX_WBITS) != Z_OK) {
147: free (s);
148: return NULL;
149: }
150: s->z_stream.next_in = s->z_buf;
151: }
152: s->z_stream.avail_out = Z_BUFSIZE;
153:
154: errno = 0;
155: s->z_fd = fd;
156:
157: if (s->z_mode == 'w') {
1.13 millert 158: /* write the .gz header */
159: if (put_header(s, name, mtime) != 0) {
160: gz_close(s, NULL);
1.1 mickey 161: s = NULL;
162: }
163: } else {
1.13 millert 164: /* read the .gz header */
165: if (get_header(s, name, gotmagic) != 0) {
166: gz_close(s, NULL);
1.1 mickey 167: s = NULL;
168: }
169: }
170:
171: return s;
172: }
173:
174: int
1.13 millert 175: gz_close(void *cookie, struct z_info *info)
1.1 mickey 176: {
1.2 mpech 177: gz_stream *s = (gz_stream*)cookie;
1.1 mickey 178: int err = 0;
179:
180: if (s == NULL)
181: return -1;
182:
183: if (s->z_mode == 'w' && (err = gz_flush (s, Z_FINISH)) == Z_OK) {
1.13 millert 184: if ((err = put_int32 (s, s->z_crc)) == Z_OK) {
185: s->z_hlen += sizeof(int32_t);
186: if ((err = put_int32 (s, s->z_stream.total_in)) == Z_OK)
187: s->z_hlen += sizeof(int32_t);
188: }
1.1 mickey 189: }
190:
191: if (!err && s->z_stream.state != NULL) {
192: if (s->z_mode == 'w')
193: err = deflateEnd(&s->z_stream);
194: else if (s->z_mode == 'r')
195: err = inflateEnd(&s->z_stream);
196: }
1.10 mickey 197:
1.13 millert 198: if (info != NULL) {
199: info->mtime = s->z_time;
200: info->crc = s->z_crc;
201: info->hlen = s->z_hlen;
202: info->total_in = (off_t)s->z_stream.total_in;
203: info->total_out = (off_t)s->z_stream.total_out;
204: }
205:
1.10 mickey 206: if (!err)
207: err = close(s->z_fd);
208: else
209: (void)close(s->z_fd);
1.1 mickey 210:
211: free(s);
212:
213: return err;
214: }
215:
216: int
1.7 deraadt 217: gz_flush(void *cookie, int flush)
1.1 mickey 218: {
1.2 mpech 219: gz_stream *s = (gz_stream*)cookie;
1.1 mickey 220: size_t len;
221: int done = 0;
222: int err;
223:
224: if (s == NULL || s->z_mode != 'w') {
225: errno = EBADF;
226: return Z_ERRNO;
227: }
228:
229: s->z_stream.avail_in = 0; /* should be zero already anyway */
230:
231: for (;;) {
232: len = Z_BUFSIZE - s->z_stream.avail_out;
233:
234: if (len != 0) {
235: if (write(s->z_fd, s->z_buf, len) != len)
236: return Z_ERRNO;
237: s->z_stream.next_out = s->z_buf;
238: s->z_stream.avail_out = Z_BUFSIZE;
239: }
240: if (done)
241: break;
242: if ((err = deflate(&(s->z_stream), flush)) != Z_OK &&
243: err != Z_STREAM_END)
244: return err;
245:
246: /* deflate has finished flushing only when it hasn't
247: * used up all the available space in the output buffer
248: */
249: done = (s->z_stream.avail_out != 0 || err == Z_STREAM_END);
250: }
251: return 0;
252: }
253:
254: static int
1.7 deraadt 255: put_int32(gz_stream *s, u_int32_t x)
1.1 mickey 256: {
1.8 millert 257: u_int32_t y = htole32(x);
258:
259: if (write(s->z_fd, &y, sizeof(y)) != sizeof(y))
1.1 mickey 260: return Z_ERRNO;
261: return 0;
262: }
263:
264: static int
1.7 deraadt 265: get_byte(gz_stream *s)
1.1 mickey 266: {
267: if (s->z_eof)
268: return EOF;
1.5 mickey 269:
1.1 mickey 270: if (s->z_stream.avail_in == 0) {
271: errno = 0;
272: s->z_stream.avail_in = read(s->z_fd, s->z_buf, Z_BUFSIZE);
273: if (s->z_stream.avail_in <= 0) {
274: s->z_eof = 1;
275: return EOF;
276: }
277: s->z_stream.next_in = s->z_buf;
278: }
279: s->z_stream.avail_in--;
280: return *s->z_stream.next_in++;
281: }
282:
1.5 mickey 283: static u_int32_t
1.7 deraadt 284: get_int32(gz_stream *s)
1.1 mickey 285: {
1.2 mpech 286: u_int32_t x;
1.1 mickey 287:
288: x = ((u_int32_t)(get_byte(s) & 0xff));
289: x |= ((u_int32_t)(get_byte(s) & 0xff))<<8;
290: x |= ((u_int32_t)(get_byte(s) & 0xff))<<16;
291: x |= ((u_int32_t)(get_byte(s) & 0xff))<<24;
292: return x;
293: }
294:
295: static int
1.13 millert 296: get_header(gz_stream *s, char *name, int gotmagic)
1.1 mickey 297: {
298: int method; /* method byte */
299: int flags; /* flags byte */
1.13 millert 300: char *ep;
1.1 mickey 301: uInt len;
302: int c;
303:
304: /* Check the gzip magic header */
1.12 millert 305: if (!gotmagic) {
306: for (len = 0; len < 2; len++) {
307: c = get_byte(s);
308: if (c != gz_magic[len]) {
309: errno = EFTYPE;
310: return -1;
311: }
1.1 mickey 312: }
313: }
314:
315: method = get_byte(s);
316: flags = get_byte(s);
317: if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
318: errno = EFTYPE;
319: return -1;
320: }
321:
1.13 millert 322: /* Stash timestamp (mtime) */
323: s->z_time = get_int32(s);
324:
325: /* Discard xflags and OS code */
326: (void)get_byte(s);
327: (void)get_byte(s);
1.1 mickey 328:
1.13 millert 329: s->z_hlen = 10; /* magic, method, flags, time, xflags, OS code */
1.1 mickey 330: if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
331: len = (uInt)get_byte(s);
332: len += ((uInt)get_byte(s))<<8;
1.13 millert 333: s->z_hlen += 2;
1.1 mickey 334: /* len is garbage if EOF but the loop below will quit anyway */
335: while (len-- != 0 && get_byte(s) != EOF)
1.13 millert 336: s->z_hlen++;
1.1 mickey 337: }
338:
1.13 millert 339: if ((flags & ORIG_NAME) != 0) { /* read/save the original file name */
340: if ((ep = name) != NULL)
341: ep += MAXPATHLEN - 1;
342: while ((c = get_byte(s)) != EOF) {
343: s->z_hlen++;
344: if (c == '\0')
345: break;
346: if (name < ep)
347: *name++ = c;
348: }
349: if (name != NULL)
350: *name = '\0';
1.1 mickey 351: }
352:
353: if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
1.13 millert 354: while ((c = get_byte(s)) != EOF) {
355: s->z_hlen++;
356: if (c == '\0')
357: break;
358: }
1.1 mickey 359: }
360:
361: if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
1.14 ! mickey 362: (void)get_byte(s);
! 363: (void)get_byte(s);
1.13 millert 364: s->z_hlen += 2;
1.1 mickey 365: }
366:
367: if (s->z_eof) {
368: errno = EFTYPE;
369: return -1;
370: }
371:
372: return 0;
373: }
374:
1.13 millert 375: static int
376: put_header(gz_stream *s, char *name, u_int32_t mtime)
377: {
378: struct iovec iov[2];
379: u_char buf[10];
380:
381: buf[0] = gz_magic[0];
382: buf[1] = gz_magic[1];
383: buf[2] = Z_DEFLATED;
384: buf[3] = name ? ORIG_NAME : 0;
385: buf[4] = mtime & 0xff;
386: buf[5] = (mtime >> 8) & 0xff;
387: buf[6] = (mtime >> 16) & 0xff;
388: buf[7] = (mtime >> 24) & 0xff;
389: buf[8] = 0 /* xflags */;
390: buf[9] = OS_CODE;
391: iov[0].iov_base = buf;
392: iov[0].iov_len = sizeof(buf);
393: s->z_hlen = sizeof(buf);
394:
395: if (name != NULL) {
396: iov[1].iov_base = name;
397: iov[1].iov_len = strlen(name) + 1;
398: s->z_hlen += iov[1].iov_len;
399: }
400: if (writev(s->z_fd, iov, name ? 2 : 1) == -1)
401: return (-1);
402: return (0);
403: }
404:
1.1 mickey 405: int
1.7 deraadt 406: gz_read(void *cookie, char *buf, int len)
1.1 mickey 407: {
1.2 mpech 408: gz_stream *s = (gz_stream*)cookie;
1.1 mickey 409: u_char *start = buf; /* starting point for crc computation */
410:
411: s->z_stream.next_out = buf;
412: s->z_stream.avail_out = len;
413:
414: while (s->z_stream.avail_out != 0 && !s->z_eof) {
415:
416: if (s->z_stream.avail_in == 0) {
417:
418: errno = 0;
419: if ((s->z_stream.avail_in =
1.7 deraadt 420: read(s->z_fd, s->z_buf, Z_BUFSIZE)) == 0)
1.1 mickey 421: s->z_eof = 1;
422: s->z_stream.next_in = s->z_buf;
423: }
424:
425: if (inflate(&(s->z_stream), Z_NO_FLUSH) == Z_STREAM_END) {
426: /* Check CRC and original size */
427: s->z_crc = crc32(s->z_crc, start,
1.7 deraadt 428: (uInt)(s->z_stream.next_out - start));
1.1 mickey 429: start = s->z_stream.next_out;
430:
1.9 millert 431: if (get_int32(s) != s->z_crc) {
432: errno = EINVAL;
433: return -1;
434: }
435: if (get_int32(s) != s->z_stream.total_out) {
1.7 deraadt 436: errno = EIO;
1.1 mickey 437: return -1;
438: }
1.13 millert 439: s->z_hlen += 2 * sizeof(int32_t);
1.1 mickey 440: s->z_eof = 1;
441: break;
442: }
443: }
444: s->z_crc = crc32(s->z_crc, start,
1.7 deraadt 445: (uInt)(s->z_stream.next_out - start));
1.1 mickey 446:
447: return (int)(len - s->z_stream.avail_out);
448: }
449:
450: int
1.7 deraadt 451: gz_write(void *cookie, const char *buf, int len)
1.1 mickey 452: {
1.2 mpech 453: gz_stream *s = (gz_stream*)cookie;
1.1 mickey 454:
455: s->z_stream.next_in = (char *)buf;
456: s->z_stream.avail_in = len;
457:
458: while (s->z_stream.avail_in != 0) {
459: if (s->z_stream.avail_out == 0) {
460: if (write(s->z_fd, s->z_buf, Z_BUFSIZE) != Z_BUFSIZE)
461: break;
462: s->z_stream.next_out = s->z_buf;
463: s->z_stream.avail_out = Z_BUFSIZE;
464: }
465: if (deflate(&(s->z_stream), Z_NO_FLUSH) != Z_OK)
466: break;
467: }
468: s->z_crc = crc32(s->z_crc, buf, len);
469:
470: return (int)(len - s->z_stream.avail_in);
471: }
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