1 /*-
2 * Copyright (c) 2007 Joerg Sonnenberger
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "archive_platform.h"
27 __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_support_compression_program.c 201112 2009-12-28 06:59:35Z kientzle $");
28
29 #ifdef HAVE_SYS_WAIT_H
30 # include <sys/wait.h>
31 #endif
32 #ifdef HAVE_ERRNO_H
33 # include <errno.h>
34 #endif
35 #ifdef HAVE_FCNTL_H
36 # include <fcntl.h>
37 #endif
38 #ifdef HAVE_LIMITS_H
39 # include <limits.h>
40 #endif
41 #ifdef HAVE_SIGNAL_H
42 # include <signal.h>
43 #endif
44 #ifdef HAVE_STDLIB_H
45 # include <stdlib.h>
46 #endif
47 #ifdef HAVE_STRING_H
48 # include <string.h>
49 #endif
50 #ifdef HAVE_UNISTD_H
51 # include <unistd.h>
52 #endif
53
54 #include "archive.h"
55 #include "archive_private.h"
56 #include "archive_read_private.h"
57
58 int
archive_read_support_compression_program(struct archive * a,const char * cmd)59 archive_read_support_compression_program(struct archive *a, const char *cmd)
60 {
61 return (archive_read_support_compression_program_signature(a, cmd, NULL, 0));
62 }
63
64
65 /* This capability is only available on POSIX systems. */
66 #if (!defined(HAVE_PIPE) || !defined(HAVE_FCNTL) || \
67 !(defined(HAVE_FORK) || defined(HAVE_VFORK))) && (!defined(_WIN32) || defined(__CYGWIN__))
68
69 /*
70 * On non-Posix systems, allow the program to build, but choke if
71 * this function is actually invoked.
72 */
73 int
archive_read_support_compression_program_signature(struct archive * _a,const char * cmd,void * signature,size_t signature_len)74 archive_read_support_compression_program_signature(struct archive *_a,
75 const char *cmd, void *signature, size_t signature_len)
76 {
77 (void)_a; /* UNUSED */
78 (void)cmd; /* UNUSED */
79 (void)signature; /* UNUSED */
80 (void)signature_len; /* UNUSED */
81
82 archive_set_error(_a, -1,
83 "External compression programs not supported on this platform");
84 return (ARCHIVE_FATAL);
85 }
86
87 int
__archive_read_program(struct archive_read_filter * self,const char * cmd)88 __archive_read_program(struct archive_read_filter *self, const char *cmd)
89 {
90 (void)self; /* UNUSED */
91 (void)cmd; /* UNUSED */
92
93 archive_set_error(&self->archive->archive, -1,
94 "External compression programs not supported on this platform");
95 return (ARCHIVE_FATAL);
96 }
97
98 #else
99
100 #include "filter_fork.h"
101
102 /*
103 * The bidder object stores the command and the signature to watch for.
104 * The 'inhibit' entry here is used to ensure that unchecked filters never
105 * bid twice in the same pipeline.
106 */
107 struct program_bidder {
108 char *cmd;
109 void *signature;
110 size_t signature_len;
111 int inhibit;
112 };
113
114 static int program_bidder_bid(struct archive_read_filter_bidder *,
115 struct archive_read_filter *upstream);
116 static int program_bidder_init(struct archive_read_filter *);
117 static int program_bidder_free(struct archive_read_filter_bidder *);
118
119 /*
120 * The actual filter needs to track input and output data.
121 */
122 struct program_filter {
123 char *description;
124 pid_t child;
125 int exit_status;
126 int waitpid_return;
127 int child_stdin, child_stdout;
128
129 char *out_buf;
130 size_t out_buf_len;
131 };
132
133 static ssize_t program_filter_read(struct archive_read_filter *,
134 const void **);
135 static int program_filter_close(struct archive_read_filter *);
136
137 int
archive_read_support_compression_program_signature(struct archive * _a,const char * cmd,const void * signature,size_t signature_len)138 archive_read_support_compression_program_signature(struct archive *_a,
139 const char *cmd, const void *signature, size_t signature_len)
140 {
141 struct archive_read *a = (struct archive_read *)_a;
142 struct archive_read_filter_bidder *bidder;
143 struct program_bidder *state;
144
145 /*
146 * Get a bidder object from the read core.
147 */
148 bidder = __archive_read_get_bidder(a);
149 if (bidder == NULL)
150 return (ARCHIVE_FATAL);
151
152 /*
153 * Allocate our private state.
154 */
155 state = (struct program_bidder *)calloc(sizeof (*state), 1);
156 if (state == NULL)
157 return (ARCHIVE_FATAL);
158 state->cmd = strdup(cmd);
159 if (signature != NULL && signature_len > 0) {
160 state->signature_len = signature_len;
161 state->signature = malloc(signature_len);
162 memcpy(state->signature, signature, signature_len);
163 }
164
165 /*
166 * Fill in the bidder object.
167 */
168 bidder->data = state;
169 bidder->bid = program_bidder_bid;
170 bidder->init = program_bidder_init;
171 bidder->options = NULL;
172 bidder->free = program_bidder_free;
173 return (ARCHIVE_OK);
174 }
175
176 static int
program_bidder_free(struct archive_read_filter_bidder * self)177 program_bidder_free(struct archive_read_filter_bidder *self)
178 {
179 struct program_bidder *state = (struct program_bidder *)self->data;
180 free(state->cmd);
181 free(state->signature);
182 free(self->data);
183 return (ARCHIVE_OK);
184 }
185
186 /*
187 * If we do have a signature, bid only if that matches.
188 *
189 * If there's no signature, we bid INT_MAX the first time
190 * we're called, then never bid again.
191 */
192 static int
program_bidder_bid(struct archive_read_filter_bidder * self,struct archive_read_filter * upstream)193 program_bidder_bid(struct archive_read_filter_bidder *self,
194 struct archive_read_filter *upstream)
195 {
196 struct program_bidder *state = self->data;
197 const char *p;
198
199 /* If we have a signature, use that to match. */
200 if (state->signature_len > 0) {
201 p = __archive_read_filter_ahead(upstream,
202 state->signature_len, NULL);
203 if (p == NULL)
204 return (0);
205 /* No match, so don't bid. */
206 if (memcmp(p, state->signature, state->signature_len) != 0)
207 return (0);
208 return ((int)state->signature_len * 8);
209 }
210
211 /* Otherwise, bid once and then never bid again. */
212 if (state->inhibit)
213 return (0);
214 state->inhibit = 1;
215 return (INT_MAX);
216 }
217
218 /*
219 * Shut down the child, return ARCHIVE_OK if it exited normally.
220 *
221 * Note that the return value is sticky; if we're called again,
222 * we won't reap the child again, but we will return the same status
223 * (including error message if the child came to a bad end).
224 */
225 static int
child_stop(struct archive_read_filter * self,struct program_filter * state)226 child_stop(struct archive_read_filter *self, struct program_filter *state)
227 {
228 /* Close our side of the I/O with the child. */
229 if (state->child_stdin != -1) {
230 close(state->child_stdin);
231 state->child_stdin = -1;
232 }
233 if (state->child_stdout != -1) {
234 close(state->child_stdout);
235 state->child_stdout = -1;
236 }
237
238 if (state->child != 0) {
239 /* Reap the child. */
240 do {
241 state->waitpid_return
242 = waitpid(state->child, &state->exit_status, 0);
243 } while (state->waitpid_return == -1 && errno == EINTR);
244 state->child = 0;
245 }
246
247 if (state->waitpid_return < 0) {
248 /* waitpid() failed? This is ugly. */
249 archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC,
250 "Child process exited badly");
251 return (ARCHIVE_WARN);
252 }
253
254 #if !defined(_WIN32) || defined(__CYGWIN__)
255 if (WIFSIGNALED(state->exit_status)) {
256 #ifdef SIGPIPE
257 /* If the child died because we stopped reading before
258 * it was done, that's okay. Some archive formats
259 * have padding at the end that we routinely ignore. */
260 /* The alternative to this would be to add a step
261 * before close(child_stdout) above to read from the
262 * child until the child has no more to write. */
263 if (WTERMSIG(state->exit_status) == SIGPIPE)
264 return (ARCHIVE_OK);
265 #endif
266 archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC,
267 "Child process exited with signal %d",
268 WTERMSIG(state->exit_status));
269 return (ARCHIVE_WARN);
270 }
271 #endif /* !_WIN32 || __CYGWIN__ */
272
273 if (WIFEXITED(state->exit_status)) {
274 if (WEXITSTATUS(state->exit_status) == 0)
275 return (ARCHIVE_OK);
276
277 archive_set_error(&self->archive->archive,
278 ARCHIVE_ERRNO_MISC,
279 "Child process exited with status %d",
280 WEXITSTATUS(state->exit_status));
281 return (ARCHIVE_WARN);
282 }
283
284 return (ARCHIVE_WARN);
285 }
286
287 /*
288 * Use select() to decide whether the child is ready for read or write.
289 */
290 static ssize_t
child_read(struct archive_read_filter * self,char * buf,size_t buf_len)291 child_read(struct archive_read_filter *self, char *buf, size_t buf_len)
292 {
293 struct program_filter *state = self->data;
294 ssize_t ret, requested, avail;
295 const char *p;
296
297 requested = buf_len > SSIZE_MAX ? SSIZE_MAX : buf_len;
298
299 for (;;) {
300 do {
301 ret = read(state->child_stdout, buf, requested);
302 } while (ret == -1 && errno == EINTR);
303
304 if (ret > 0)
305 return (ret);
306 if (ret == 0 || (ret == -1 && errno == EPIPE))
307 /* Child has closed its output; reap the child
308 * and return the status. */
309 return (child_stop(self, state));
310 if (ret == -1 && errno != EAGAIN)
311 return (-1);
312
313 if (state->child_stdin == -1) {
314 /* Block until child has some I/O ready. */
315 __archive_check_child(state->child_stdin,
316 state->child_stdout);
317 continue;
318 }
319
320 /* Get some more data from upstream. */
321 p = __archive_read_filter_ahead(self->upstream, 1, &avail);
322 if (p == NULL) {
323 close(state->child_stdin);
324 state->child_stdin = -1;
325 fcntl(state->child_stdout, F_SETFL, 0);
326 if (avail < 0)
327 return (avail);
328 continue;
329 }
330
331 do {
332 ret = write(state->child_stdin, p, avail);
333 } while (ret == -1 && errno == EINTR);
334
335 if (ret > 0) {
336 /* Consume whatever we managed to write. */
337 __archive_read_filter_consume(self->upstream, ret);
338 } else if (ret == -1 && errno == EAGAIN) {
339 /* Block until child has some I/O ready. */
340 __archive_check_child(state->child_stdin,
341 state->child_stdout);
342 } else {
343 /* Write failed. */
344 close(state->child_stdin);
345 state->child_stdin = -1;
346 fcntl(state->child_stdout, F_SETFL, 0);
347 /* If it was a bad error, we're done; otherwise
348 * it was EPIPE or EOF, and we can still read
349 * from the child. */
350 if (ret == -1 && errno != EPIPE)
351 return (-1);
352 }
353 }
354 }
355
356 int
__archive_read_program(struct archive_read_filter * self,const char * cmd)357 __archive_read_program(struct archive_read_filter *self, const char *cmd)
358 {
359 struct program_filter *state;
360 static const size_t out_buf_len = 65536;
361 char *out_buf;
362 char *description;
363 const char *prefix = "Program: ";
364
365 state = (struct program_filter *)calloc(1, sizeof(*state));
366 out_buf = (char *)malloc(out_buf_len);
367 description = (char *)malloc(strlen(prefix) + strlen(cmd) + 1);
368 if (state == NULL || out_buf == NULL || description == NULL) {
369 archive_set_error(&self->archive->archive, ENOMEM,
370 "Can't allocate input data");
371 free(state);
372 free(out_buf);
373 free(description);
374 return (ARCHIVE_FATAL);
375 }
376
377 self->code = ARCHIVE_COMPRESSION_PROGRAM;
378 state->description = description;
379 strcpy(state->description, prefix);
380 strcat(state->description, cmd);
381 self->name = state->description;
382
383 state->out_buf = out_buf;
384 state->out_buf_len = out_buf_len;
385
386 if ((state->child = __archive_create_child(cmd,
387 &state->child_stdin, &state->child_stdout)) == -1) {
388 free(state->out_buf);
389 free(state);
390 archive_set_error(&self->archive->archive, EINVAL,
391 "Can't initialise filter");
392 return (ARCHIVE_FATAL);
393 }
394
395 self->data = state;
396 self->read = program_filter_read;
397 self->skip = NULL;
398 self->close = program_filter_close;
399
400 /* XXX Check that we can read at least one byte? */
401 return (ARCHIVE_OK);
402 }
403
404 static int
program_bidder_init(struct archive_read_filter * self)405 program_bidder_init(struct archive_read_filter *self)
406 {
407 struct program_bidder *bidder_state;
408
409 bidder_state = (struct program_bidder *)self->bidder->data;
410 return (__archive_read_program(self, bidder_state->cmd));
411 }
412
413 static ssize_t
program_filter_read(struct archive_read_filter * self,const void ** buff)414 program_filter_read(struct archive_read_filter *self, const void **buff)
415 {
416 struct program_filter *state;
417 ssize_t bytes;
418 size_t total;
419 char *p;
420
421 state = (struct program_filter *)self->data;
422
423 total = 0;
424 p = state->out_buf;
425 while (state->child_stdout != -1 && total < state->out_buf_len) {
426 bytes = child_read(self, p, state->out_buf_len - total);
427 if (bytes < 0)
428 /* No recovery is possible if we can no longer
429 * read from the child. */
430 return (ARCHIVE_FATAL);
431 if (bytes == 0)
432 /* We got EOF from the child. */
433 break;
434 total += bytes;
435 p += bytes;
436 }
437
438 *buff = state->out_buf;
439 return (total);
440 }
441
442 static int
program_filter_close(struct archive_read_filter * self)443 program_filter_close(struct archive_read_filter *self)
444 {
445 struct program_filter *state;
446 int e;
447
448 state = (struct program_filter *)self->data;
449 e = child_stop(self, state);
450
451 /* Release our private data. */
452 free(state->out_buf);
453 free(state->description);
454 free(state);
455
456 return (e);
457 }
458
459 #endif /* !defined(HAVE_PIPE) || !defined(HAVE_VFORK) || !defined(HAVE_FCNTL) */
460