1 /* gzwrite.c -- zlib functions for writing gzip files
2  * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013 Mark Adler
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 #include "gzguts.h"
7 
8 /* Local functions */
9 local int gz_init OF((gz_statep));
10 local int gz_comp OF((gz_statep, int));
11 local int gz_zero OF((gz_statep, z_off64_t));
12 
13 /* Initialize state for writing a gzip file.  Mark initialization by setting
14    state->size to non-zero.  Return -1 on failure or 0 on success. */
gz_init(state)15 local int gz_init(state)
16     gz_statep state;
17 {
18     int ret;
19     z_streamp strm = &(state->strm);
20 
21     /* allocate input buffer */
22     state->in = (unsigned char *)malloc(state->want);
23     if (state->in == NULL) {
24         gz_error(state, Z_MEM_ERROR, "out of memory");
25         return -1;
26     }
27 
28     /* only need output buffer and deflate state if compressing */
29     if (!state->direct) {
30         /* allocate output buffer */
31         state->out = (unsigned char *)malloc(state->want);
32         if (state->out == NULL) {
33             free(state->in);
34             gz_error(state, Z_MEM_ERROR, "out of memory");
35             return -1;
36         }
37 
38         /* allocate deflate memory, set up for gzip compression */
39         strm->zalloc = Z_NULL;
40         strm->zfree = Z_NULL;
41         strm->opaque = Z_NULL;
42         ret = deflateInit2(strm, state->level, Z_DEFLATED,
43                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
44         if (ret != Z_OK) {
45             free(state->out);
46             free(state->in);
47             gz_error(state, Z_MEM_ERROR, "out of memory");
48             return -1;
49         }
50     }
51 
52     /* mark state as initialized */
53     state->size = state->want;
54 
55     /* initialize write buffer if compressing */
56     if (!state->direct) {
57         strm->avail_out = state->size;
58         strm->next_out = state->out;
59         state->x.next = strm->next_out;
60     }
61     return 0;
62 }
63 
64 /* Compress whatever is at avail_in and next_in and write to the output file.
65    Return -1 if there is an error writing to the output file, otherwise 0.
66    flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
67    then the deflate() state is reset to start a new gzip stream.  If gz->direct
68    is true, then simply write to the output file without compressing, and
69    ignore flush. */
gz_comp(state,flush)70 local int gz_comp(state, flush)
71     gz_statep state;
72     int flush;
73 {
74     int ret, got;
75     unsigned have;
76     z_streamp strm = &(state->strm);
77 
78     /* allocate memory if this is the first time through */
79     if (state->size == 0 && gz_init(state) == -1)
80         return -1;
81 
82     /* write directly if requested */
83     if (state->direct) {
84         got = write(state->fd, strm->next_in, strm->avail_in);
85         if (got < 0 || (unsigned)got != strm->avail_in) {
86             gz_error(state, Z_ERRNO, zstrerror());
87             return -1;
88         }
89         strm->avail_in = 0;
90         return 0;
91     }
92 
93     /* run deflate() on provided input until it produces no more output */
94     ret = Z_OK;
95     do {
96         /* write out current buffer contents if full, or if flushing, but if
97            doing Z_FINISH then don't write until we get to Z_STREAM_END */
98         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
99             (flush != Z_FINISH || ret == Z_STREAM_END))) {
100             have = (unsigned)(strm->next_out - state->x.next);
101             if (have && ((got = write(state->fd, state->x.next, have)) < 0 ||
102                          (unsigned)got != have)) {
103                 gz_error(state, Z_ERRNO, zstrerror());
104                 return -1;
105             }
106             if (strm->avail_out == 0) {
107                 strm->avail_out = state->size;
108                 strm->next_out = state->out;
109             }
110             state->x.next = strm->next_out;
111         }
112 
113         /* compress */
114         have = strm->avail_out;
115         ret = deflate(strm, flush);
116         if (ret == Z_STREAM_ERROR) {
117             gz_error(state, Z_STREAM_ERROR,
118                       "internal error: deflate stream corrupt");
119             return -1;
120         }
121         have -= strm->avail_out;
122     } while (have);
123 
124     /* if that completed a deflate stream, allow another to start */
125     if (flush == Z_FINISH)
126         deflateReset(strm);
127 
128     /* all done, no errors */
129     return 0;
130 }
131 
132 /* Compress len zeros to output.  Return -1 on error, 0 on success. */
gz_zero(state,len)133 local int gz_zero(state, len)
134     gz_statep state;
135     z_off64_t len;
136 {
137     int first;
138     unsigned n;
139     z_streamp strm = &(state->strm);
140 
141     /* consume whatever's left in the input buffer */
142     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
143         return -1;
144 
145     /* compress len zeros (len guaranteed > 0) */
146     first = 1;
147     while (len) {
148         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
149             (unsigned)len : state->size;
150         if (first) {
151             memset(state->in, 0, n);
152             first = 0;
153         }
154         strm->avail_in = n;
155         strm->next_in = state->in;
156         state->x.pos += n;
157         if (gz_comp(state, Z_NO_FLUSH) == -1)
158             return -1;
159         len -= n;
160     }
161     return 0;
162 }
163 
164 /* -- see zlib.h -- */
gzwrite(file,buf,len)165 int ZEXPORT gzwrite(file, buf, len)
166     gzFile file;
167     voidpc buf;
168     unsigned len;
169 {
170     unsigned put = len;
171     gz_statep state;
172     z_streamp strm;
173 
174     /* get internal structure */
175     if (file == NULL)
176         return 0;
177     state = (gz_statep)file;
178     strm = &(state->strm);
179 
180     /* check that we're writing and that there's no error */
181     if (state->mode != GZ_WRITE || state->err != Z_OK)
182         return 0;
183 
184     /* since an int is returned, make sure len fits in one, otherwise return
185        with an error (this avoids the flaw in the interface) */
186     if ((int)len < 0) {
187         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
188         return 0;
189     }
190 
191     /* if len is zero, avoid unnecessary operations */
192     if (len == 0)
193         return 0;
194 
195     /* allocate memory if this is the first time through */
196     if (state->size == 0 && gz_init(state) == -1)
197         return 0;
198 
199     /* check for seek request */
200     if (state->seek) {
201         state->seek = 0;
202         if (gz_zero(state, state->skip) == -1)
203             return 0;
204     }
205 
206     /* for small len, copy to input buffer, otherwise compress directly */
207     if (len < state->size) {
208         /* copy to input buffer, compress when full */
209         do {
210             unsigned have, copy;
211 
212             if (strm->avail_in == 0)
213                 strm->next_in = state->in;
214             have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
215             copy = state->size - have;
216             if (copy > len)
217                 copy = len;
218             memcpy(state->in + have, buf, copy);
219             strm->avail_in += copy;
220             state->x.pos += copy;
221             buf = (const char *)buf + copy;
222             len -= copy;
223             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
224                 return 0;
225         } while (len);
226     }
227     else {
228         /* consume whatever's left in the input buffer */
229         if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
230             return 0;
231 
232         /* directly compress user buffer to file */
233         strm->avail_in = len;
234         strm->next_in = (z_const Bytef *)buf;
235         state->x.pos += len;
236         if (gz_comp(state, Z_NO_FLUSH) == -1)
237             return 0;
238     }
239 
240     /* input was all buffered or compressed (put will fit in int) */
241     return (int)put;
242 }
243 
244 /* -- see zlib.h -- */
gzputc(file,c)245 int ZEXPORT gzputc(file, c)
246     gzFile file;
247     int c;
248 {
249     unsigned have;
250     unsigned char buf[1];
251     gz_statep state;
252     z_streamp strm;
253 
254     /* get internal structure */
255     if (file == NULL)
256         return -1;
257     state = (gz_statep)file;
258     strm = &(state->strm);
259 
260     /* check that we're writing and that there's no error */
261     if (state->mode != GZ_WRITE || state->err != Z_OK)
262         return -1;
263 
264     /* check for seek request */
265     if (state->seek) {
266         state->seek = 0;
267         if (gz_zero(state, state->skip) == -1)
268             return -1;
269     }
270 
271     /* try writing to input buffer for speed (state->size == 0 if buffer not
272        initialized) */
273     if (state->size) {
274         if (strm->avail_in == 0)
275             strm->next_in = state->in;
276         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
277         if (have < state->size) {
278             state->in[have] = c;
279             strm->avail_in++;
280             state->x.pos++;
281             return c & 0xff;
282         }
283     }
284 
285     /* no room in buffer or not initialized, use gz_write() */
286     buf[0] = c;
287     if (gzwrite(file, buf, 1) != 1)
288         return -1;
289     return c & 0xff;
290 }
291 
292 /* -- see zlib.h -- */
gzputs(file,str)293 int ZEXPORT gzputs(file, str)
294     gzFile file;
295     const char *str;
296 {
297     int ret;
298     unsigned len;
299 
300     /* write string */
301     len = (unsigned)strlen(str);
302     ret = gzwrite(file, str, len);
303     return ret == 0 && len != 0 ? -1 : ret;
304 }
305 
306 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
307 #include <stdarg.h>
308 
309 /* -- see zlib.h -- */
gzvprintf(gzFile file,const char * format,va_list va)310 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
311 {
312     int size, len;
313     gz_statep state;
314     z_streamp strm;
315 
316     /* get internal structure */
317     if (file == NULL)
318         return -1;
319     state = (gz_statep)file;
320     strm = &(state->strm);
321 
322     /* check that we're writing and that there's no error */
323     if (state->mode != GZ_WRITE || state->err != Z_OK)
324         return 0;
325 
326     /* make sure we have some buffer space */
327     if (state->size == 0 && gz_init(state) == -1)
328         return 0;
329 
330     /* check for seek request */
331     if (state->seek) {
332         state->seek = 0;
333         if (gz_zero(state, state->skip) == -1)
334             return 0;
335     }
336 
337     /* consume whatever's left in the input buffer */
338     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
339         return 0;
340 
341     /* do the printf() into the input buffer, put length in len */
342     size = (int)(state->size);
343     state->in[size - 1] = 0;
344 #ifdef NO_vsnprintf
345 #  ifdef HAS_vsprintf_void
346     (void)vsprintf((char *)(state->in), format, va);
347     for (len = 0; len < size; len++)
348         if (state->in[len] == 0) break;
349 #  else
350     len = vsprintf((char *)(state->in), format, va);
351 #  endif
352 #else
353 #  ifdef HAS_vsnprintf_void
354     (void)vsnprintf((char *)(state->in), size, format, va);
355     len = strlen((char *)(state->in));
356 #  else
357     len = vsnprintf((char *)(state->in), size, format, va);
358 #  endif
359 #endif
360 
361     /* check that printf() results fit in buffer */
362     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
363         return 0;
364 
365     /* update buffer and position, defer compression until needed */
366     strm->avail_in = (unsigned)len;
367     strm->next_in = state->in;
368     state->x.pos += len;
369     return len;
370 }
371 
gzprintf(gzFile file,const char * format,...)372 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
373 {
374     va_list va;
375     int ret;
376 
377     va_start(va, format);
378     ret = gzvprintf(file, format, va);
379     va_end(va);
380     return ret;
381 }
382 
383 #else /* !STDC && !Z_HAVE_STDARG_H */
384 
385 /* -- see zlib.h -- */
gzprintf(file,format,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12,a13,a14,a15,a16,a17,a18,a19,a20)386 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
387                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
388     gzFile file;
389     const char *format;
390     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
391         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
392 {
393     int size, len;
394     gz_statep state;
395     z_streamp strm;
396 
397     /* get internal structure */
398     if (file == NULL)
399         return -1;
400     state = (gz_statep)file;
401     strm = &(state->strm);
402 
403     /* check that can really pass pointer in ints */
404     if (sizeof(int) != sizeof(void *))
405         return 0;
406 
407     /* check that we're writing and that there's no error */
408     if (state->mode != GZ_WRITE || state->err != Z_OK)
409         return 0;
410 
411     /* make sure we have some buffer space */
412     if (state->size == 0 && gz_init(state) == -1)
413         return 0;
414 
415     /* check for seek request */
416     if (state->seek) {
417         state->seek = 0;
418         if (gz_zero(state, state->skip) == -1)
419             return 0;
420     }
421 
422     /* consume whatever's left in the input buffer */
423     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
424         return 0;
425 
426     /* do the printf() into the input buffer, put length in len */
427     size = (int)(state->size);
428     state->in[size - 1] = 0;
429 #ifdef NO_snprintf
430 #  ifdef HAS_sprintf_void
431     sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
432             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
433     for (len = 0; len < size; len++)
434         if (state->in[len] == 0) break;
435 #  else
436     len = sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
437                   a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
438 #  endif
439 #else
440 #  ifdef HAS_snprintf_void
441     snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6, a7, a8,
442              a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
443     len = strlen((char *)(state->in));
444 #  else
445     len = snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6,
446                    a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18,
447                    a19, a20);
448 #  endif
449 #endif
450 
451     /* check that printf() results fit in buffer */
452     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
453         return 0;
454 
455     /* update buffer and position, defer compression until needed */
456     strm->avail_in = (unsigned)len;
457     strm->next_in = state->in;
458     state->x.pos += len;
459     return len;
460 }
461 
462 #endif
463 
464 /* -- see zlib.h -- */
gzflush(file,flush)465 int ZEXPORT gzflush(file, flush)
466     gzFile file;
467     int flush;
468 {
469     gz_statep state;
470 
471     /* get internal structure */
472     if (file == NULL)
473         return -1;
474     state = (gz_statep)file;
475 
476     /* check that we're writing and that there's no error */
477     if (state->mode != GZ_WRITE || state->err != Z_OK)
478         return Z_STREAM_ERROR;
479 
480     /* check flush parameter */
481     if (flush < 0 || flush > Z_FINISH)
482         return Z_STREAM_ERROR;
483 
484     /* check for seek request */
485     if (state->seek) {
486         state->seek = 0;
487         if (gz_zero(state, state->skip) == -1)
488             return -1;
489     }
490 
491     /* compress remaining data with requested flush */
492     gz_comp(state, flush);
493     return state->err;
494 }
495 
496 /* -- see zlib.h -- */
gzsetparams(file,level,strategy)497 int ZEXPORT gzsetparams(file, level, strategy)
498     gzFile file;
499     int level;
500     int strategy;
501 {
502     gz_statep state;
503     z_streamp strm;
504 
505     /* get internal structure */
506     if (file == NULL)
507         return Z_STREAM_ERROR;
508     state = (gz_statep)file;
509     strm = &(state->strm);
510 
511     /* check that we're writing and that there's no error */
512     if (state->mode != GZ_WRITE || state->err != Z_OK)
513         return Z_STREAM_ERROR;
514 
515     /* if no change is requested, then do nothing */
516     if (level == state->level && strategy == state->strategy)
517         return Z_OK;
518 
519     /* check for seek request */
520     if (state->seek) {
521         state->seek = 0;
522         if (gz_zero(state, state->skip) == -1)
523             return -1;
524     }
525 
526     /* change compression parameters for subsequent input */
527     if (state->size) {
528         /* flush previous input with previous parameters before changing */
529         if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
530             return state->err;
531         deflateParams(strm, level, strategy);
532     }
533     state->level = level;
534     state->strategy = strategy;
535     return Z_OK;
536 }
537 
538 /* -- see zlib.h -- */
gzclose_w(file)539 int ZEXPORT gzclose_w(file)
540     gzFile file;
541 {
542     int ret = Z_OK;
543     gz_statep state;
544 
545     /* get internal structure */
546     if (file == NULL)
547         return Z_STREAM_ERROR;
548     state = (gz_statep)file;
549 
550     /* check that we're writing */
551     if (state->mode != GZ_WRITE)
552         return Z_STREAM_ERROR;
553 
554     /* check for seek request */
555     if (state->seek) {
556         state->seek = 0;
557         if (gz_zero(state, state->skip) == -1)
558             ret = state->err;
559     }
560 
561     /* flush, free memory, and close file */
562     if (gz_comp(state, Z_FINISH) == -1)
563         ret = state->err;
564     if (state->size) {
565         if (!state->direct) {
566             (void)deflateEnd(&(state->strm));
567             free(state->out);
568         }
569         free(state->in);
570     }
571     gz_error(state, Z_OK, NULL);
572     free(state->path);
573     if (close(state->fd) == -1)
574         ret = Z_ERRNO;
575     free(state);
576     return ret;
577 }
578