source: MondoRescue/branches/3.3/mindi-busybox/archival/libarchive/open_transformer.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.
  • Property svn:eol-style set to native
File size: 8.8 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
4 */
5
6#include "libbb.h"
7#include "bb_archive.h"
8
9void FAST_FUNC init_transformer_state(transformer_state_t *xstate)
10{
11 memset(xstate, 0, sizeof(*xstate));
12}
13
14int FAST_FUNC check_signature16(transformer_state_t *xstate, unsigned magic16)
15{
16 if (!xstate->signature_skipped) {
17 uint16_t magic2;
18 if (full_read(xstate->src_fd, &magic2, 2) != 2 || magic2 != magic16) {
19 bb_error_msg("invalid magic");
20 return -1;
21 }
22 xstate->signature_skipped = 2;
23 }
24 return 0;
25}
26
27ssize_t FAST_FUNC transformer_write(transformer_state_t *xstate, const void *buf, size_t bufsize)
28{
29 ssize_t nwrote;
30
31 if (xstate->mem_output_size_max != 0) {
32 size_t pos = xstate->mem_output_size;
33 size_t size;
34
35 size = (xstate->mem_output_size += bufsize);
36 if (size > xstate->mem_output_size_max) {
37 free(xstate->mem_output_buf);
38 xstate->mem_output_buf = NULL;
39 bb_perror_msg("buffer %u too small", (unsigned)xstate->mem_output_size_max);
40 nwrote = -1;
41 goto ret;
42 }
43 xstate->mem_output_buf = xrealloc(xstate->mem_output_buf, size + 1);
44 memcpy(xstate->mem_output_buf + pos, buf, bufsize);
45 xstate->mem_output_buf[size] = '\0';
46 nwrote = bufsize;
47 } else {
48 nwrote = full_write(xstate->dst_fd, buf, bufsize);
49 if (nwrote != (ssize_t)bufsize) {
50 bb_perror_msg("write");
51 nwrote = -1;
52 goto ret;
53 }
54 }
55 ret:
56 return nwrote;
57}
58
59ssize_t FAST_FUNC xtransformer_write(transformer_state_t *xstate, const void *buf, size_t bufsize)
60{
61 ssize_t nwrote = transformer_write(xstate, buf, bufsize);
62 if (nwrote != (ssize_t)bufsize) {
63 xfunc_die();
64 }
65 return nwrote;
66}
67
68void check_errors_in_children(int signo)
69{
70 int status;
71
72 if (!signo) {
73 /* block waiting for any child */
74 if (wait(&status) < 0)
75//FIXME: check EINTR?
76 return; /* probably there are no children */
77 goto check_status;
78 }
79
80 /* Wait for any child without blocking */
81 for (;;) {
82 if (wait_any_nohang(&status) < 0)
83//FIXME: check EINTR?
84 /* wait failed?! I'm confused... */
85 return;
86 check_status:
87 /*if (WIFEXITED(status) && WEXITSTATUS(status) == 0)*/
88 /* On Linux, the above can be checked simply as: */
89 if (status == 0)
90 /* this child exited with 0 */
91 continue;
92 /* Cannot happen:
93 if (!WIFSIGNALED(status) && !WIFEXITED(status)) ???;
94 */
95 bb_got_signal = 1;
96 }
97}
98
99/* transformer(), more than meets the eye */
100#if BB_MMU
101void FAST_FUNC fork_transformer(int fd,
102 int signature_skipped,
103 IF_DESKTOP(long long) int FAST_FUNC (*transformer)(transformer_state_t *xstate)
104)
105#else
106void FAST_FUNC fork_transformer(int fd, const char *transform_prog)
107#endif
108{
109 struct fd_pair fd_pipe;
110 int pid;
111
112 xpiped_pair(fd_pipe);
113 pid = BB_MMU ? xfork() : xvfork();
114 if (pid == 0) {
115 /* Child */
116 close(fd_pipe.rd); /* we don't want to read from the parent */
117 // FIXME: error check?
118#if BB_MMU
119 {
120 IF_DESKTOP(long long) int r;
121 transformer_state_t xstate;
122 init_transformer_state(&xstate);
123 xstate.signature_skipped = signature_skipped;
124 xstate.src_fd = fd;
125 xstate.dst_fd = fd_pipe.wr;
126 r = transformer(&xstate);
127 if (ENABLE_FEATURE_CLEAN_UP) {
128 close(fd_pipe.wr); /* send EOF */
129 close(fd);
130 }
131 /* must be _exit! bug was actually seen here */
132 _exit(/*error if:*/ r < 0);
133 }
134#else
135 {
136 char *argv[4];
137 xmove_fd(fd, 0);
138 xmove_fd(fd_pipe.wr, 1);
139 argv[0] = (char*)transform_prog;
140 argv[1] = (char*)"-cf";
141 argv[2] = (char*)"-";
142 argv[3] = NULL;
143 BB_EXECVP(transform_prog, argv);
144 bb_perror_msg_and_die("can't execute '%s'", transform_prog);
145 }
146#endif
147 /* notreached */
148 }
149
150 /* parent process */
151 close(fd_pipe.wr); /* don't want to write to the child */
152 xmove_fd(fd_pipe.rd, fd);
153}
154
155
156#if SEAMLESS_COMPRESSION
157
158/* Used by e.g. rpm which gives us a fd without filename,
159 * thus we can't guess the format from filename's extension.
160 */
161static transformer_state_t *setup_transformer_on_fd(int fd, int fail_if_not_compressed)
162{
163 union {
164 uint8_t b[4];
165 uint16_t b16[2];
166 uint32_t b32[1];
167 } magic;
168 transformer_state_t *xstate;
169
170 xstate = xzalloc(sizeof(*xstate));
171 xstate->src_fd = fd;
172 xstate->signature_skipped = 2;
173
174 /* .gz and .bz2 both have 2-byte signature, and their
175 * unpack_XXX_stream wants this header skipped. */
176 xread(fd, magic.b16, sizeof(magic.b16[0]));
177 if (ENABLE_FEATURE_SEAMLESS_GZ
178 && magic.b16[0] == GZIP_MAGIC
179 ) {
180 xstate->xformer = unpack_gz_stream;
181 USE_FOR_NOMMU(xstate->xformer_prog = "gunzip";)
182 goto found_magic;
183 }
184 if (ENABLE_FEATURE_SEAMLESS_Z
185 && magic.b16[0] == COMPRESS_MAGIC
186 ) {
187 xstate->xformer = unpack_Z_stream;
188 USE_FOR_NOMMU(xstate->xformer_prog = "uncompress";)
189 goto found_magic;
190 }
191 if (ENABLE_FEATURE_SEAMLESS_BZ2
192 && magic.b16[0] == BZIP2_MAGIC
193 ) {
194 xstate->xformer = unpack_bz2_stream;
195 USE_FOR_NOMMU(xstate->xformer_prog = "bunzip2";)
196 goto found_magic;
197 }
198 if (ENABLE_FEATURE_SEAMLESS_XZ
199 && magic.b16[0] == XZ_MAGIC1
200 ) {
201 xstate->signature_skipped = 6;
202 xread(fd, magic.b32, sizeof(magic.b32[0]));
203 if (magic.b32[0] == XZ_MAGIC2) {
204 xstate->xformer = unpack_xz_stream;
205 USE_FOR_NOMMU(xstate->xformer_prog = "unxz";)
206 goto found_magic;
207 }
208 }
209
210 /* No known magic seen */
211 if (fail_if_not_compressed)
212 bb_error_msg_and_die("no gzip"
213 IF_FEATURE_SEAMLESS_BZ2("/bzip2")
214 IF_FEATURE_SEAMLESS_XZ("/xz")
215 " magic");
216
217 /* Some callers expect this function to "consume" fd
218 * even if data is not compressed. In this case,
219 * we return a state with trivial transformer.
220 */
221// USE_FOR_MMU(xstate->xformer = copy_stream;)
222// USE_FOR_NOMMU(xstate->xformer_prog = "cat";)
223
224 found_magic:
225 return xstate;
226}
227
228/* Used by e.g. rpm which gives us a fd without filename,
229 * thus we can't guess the format from filename's extension.
230 */
231int FAST_FUNC setup_unzip_on_fd(int fd, int fail_if_not_compressed)
232{
233 transformer_state_t *xstate = setup_transformer_on_fd(fd, fail_if_not_compressed);
234
235 if (!xstate || !xstate->xformer) {
236 free(xstate);
237 return 1;
238 }
239
240# if BB_MMU
241 fork_transformer_with_no_sig(xstate->src_fd, xstate->xformer);
242# else
243 /* NOMMU version of fork_transformer execs
244 * an external unzipper that wants
245 * file position at the start of the file.
246 */
247 xlseek(fd, - xstate->signature_skipped, SEEK_CUR);
248 xstate->signature_skipped = 0;
249 fork_transformer_with_sig(xstate->src_fd, xstate->xformer, xstate->xformer_prog);
250# endif
251 free(xstate);
252 return 0;
253}
254
255static transformer_state_t *open_transformer(const char *fname, int fail_if_not_compressed)
256{
257 transformer_state_t *xstate;
258 int fd;
259
260 fd = open(fname, O_RDONLY);
261 if (fd < 0)
262 return NULL;
263
264 if (ENABLE_FEATURE_SEAMLESS_LZMA) {
265 /* .lzma has no header/signature, can only detect it by extension */
266 char *sfx = strrchr(fname, '.');
267 if (sfx && strcmp(sfx+1, "lzma") == 0) {
268 xstate = xzalloc(sizeof(*xstate));
269 xstate->src_fd = fd;
270 xstate->xformer = unpack_lzma_stream;
271 USE_FOR_NOMMU(xstate->xformer_prog = "unlzma";)
272 return xstate;
273 }
274 }
275
276 xstate = setup_transformer_on_fd(fd, fail_if_not_compressed);
277
278 return xstate;
279}
280
281int FAST_FUNC open_zipped(const char *fname, int fail_if_not_compressed)
282{
283 int fd;
284 transformer_state_t *xstate;
285
286 xstate = open_transformer(fname, fail_if_not_compressed);
287 if (!xstate)
288 return -1;
289
290 fd = xstate->src_fd;
291# if BB_MMU
292 if (xstate->xformer) {
293 fork_transformer_with_no_sig(fd, xstate->xformer);
294 } else {
295 /* the file is not compressed */
296 xlseek(fd, - xstate->signature_skipped, SEEK_CUR);
297 xstate->signature_skipped = 0;
298 }
299# else
300 /* NOMMU can't avoid the seek :( */
301 xlseek(fd, - xstate->signature_skipped, SEEK_CUR);
302 xstate->signature_skipped = 0;
303 if (xstate->xformer) {
304 fork_transformer_with_sig(fd, xstate->xformer, xstate->xformer_prog);
305 } /* else: the file is not compressed */
306# endif
307
308 free(xstate);
309 return fd;
310}
311
312void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p)
313{
314# if 1
315 transformer_state_t *xstate;
316 char *image;
317
318 xstate = open_transformer(fname, /*fail_if_not_compressed:*/ 0);
319 if (!xstate) /* file open error */
320 return NULL;
321
322 image = NULL;
323 if (xstate->xformer) {
324 /* In-memory decompression */
325 xstate->mem_output_size_max = maxsz_p ? *maxsz_p : (size_t)(INT_MAX - 4095);
326 xstate->xformer(xstate);
327 if (xstate->mem_output_buf) {
328 image = xstate->mem_output_buf;
329 if (maxsz_p)
330 *maxsz_p = xstate->mem_output_size;
331 }
332 } else {
333 /* File is not compressed */
334//FIXME: avoid seek
335 xlseek(xstate->src_fd, - xstate->signature_skipped, SEEK_CUR);
336 xstate->signature_skipped = 0;
337 image = xmalloc_read(xstate->src_fd, maxsz_p);
338 }
339
340 if (!image)
341 bb_perror_msg("read error from '%s'", fname);
342 close(xstate->src_fd);
343 free(xstate);
344 return image;
345# else
346 /* This version forks a subprocess - much more expensive */
347 int fd;
348 char *image;
349
350 fd = open_zipped(fname, /*fail_if_not_compressed:*/ 0);
351 if (fd < 0)
352 return NULL;
353
354 image = xmalloc_read(fd, maxsz_p);
355 if (!image)
356 bb_perror_msg("read error from '%s'", fname);
357 close(fd);
358 return image;
359# endif
360}
361
362#endif /* SEAMLESS_COMPRESSION */
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