contrib/libarchive/libarchive/archive_read_support_compression_program.c

   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: src/lib/libarchive/archive_read_support_compression_program.c,v 1.4 2008/06/15 10:45:57 kientzle Exp $");
  28
  29 /* This capability is only available on POSIX systems. */
  30 #if !defined(HAVE_PIPE) || !defined(HAVE_FCNTL) || \
  31     !(defined(HAVE_FORK) || defined(HAVE_VFORK))
  32
  33 /*
  34  * On non-Posix systems, allow the program to build, but choke if
  35  * this function is actually invoked.
  36  */
  37 int
  38 archive_read_support_compression_program(struct archive *_a, const char *cmd)
  39 {
  40         archive_set_error(_a, -1,
  41             "External compression programs not supported on this platform");
  42         return (ARCHIVE_FATAL);
  43 }
  44
  45 #else
  46
  47 #ifdef HAVE_SYS_WAIT_H
  48 #  include <sys/wait.h>
  49 #endif
  50 #ifdef HAVE_ERRNO_H
  51 #  include <errno.h>
  52 #endif
  53 #ifdef HAVE_FCNTL_H
  54 #  include <fcntl.h>
  55 #endif
  56 #ifdef HAVE_LIMITS_H
  57 #  include <limits.h>
  58 #endif
  59 #ifdef HAVE_STDLIB_H
  60 #  include <stdlib.h>
  61 #endif
  62 #ifdef HAVE_STRING_H
  63 #  include <string.h>
  64 #endif
  65 #ifdef HAVE_UNISTD_H
  66 #  include <unistd.h>
  67 #endif
  68
  69 #include "archive.h"
  70 #include "archive_private.h"
  71 #include "archive_read_private.h"
  72
  73 #include "filter_fork.h"
  74
  75 struct archive_decompress_program {
  76         char            *description;
  77         pid_t            child;
  78         int              child_stdin, child_stdout;
  79
  80         char            *child_out_buf;
  81         char            *child_out_buf_next;
  82         size_t           child_out_buf_len, child_out_buf_avail;
  83
  84         const char      *child_in_buf;
  85         size_t           child_in_buf_avail;
  86 };
  87
  88 static int      archive_decompressor_program_bid(const void *, size_t);
  89 static int      archive_decompressor_program_finish(struct archive_read *);
  90 static int      archive_decompressor_program_init(struct archive_read *,
  91                     const void *, size_t);
  92 static ssize_t  archive_decompressor_program_read_ahead(struct archive_read *,
  93                     const void **, size_t);
  94 static ssize_t  archive_decompressor_program_read_consume(struct archive_read *,
  95                     size_t);
  96
  97 int
  98 archive_read_support_compression_program(struct archive *_a, const char *cmd)
  99 {
 100         struct archive_read *a = (struct archive_read *)_a;
 101         struct decompressor_t *decompressor;
 102
 103         if (cmd == NULL || *cmd == '\0')
 104                 return (ARCHIVE_WARN);
 105
 106         decompressor = __archive_read_register_compression(a,
 107                     archive_decompressor_program_bid,
 108                     archive_decompressor_program_init);
 109         if (decompressor == NULL)
 110                 return (ARCHIVE_WARN);
 111
 112         decompressor->config = strdup(cmd);
 113         return (ARCHIVE_OK);
 114 }
 115
 116 /*
 117  * If the user used us to register, they must really want us to
 118  * handle it, so this module always bids INT_MAX.
 119  */
 120 static int
 121 archive_decompressor_program_bid(const void *buff, size_t len)
 122 {
 123         (void)buff; /* UNUSED */
 124         (void)len; /* UNUSED */
 125
 126         return (INT_MAX); /* Default: We'll take it. */
 127 }
 128
 129 static ssize_t
 130 child_read(struct archive_read *a, char *buf, size_t buf_len)
 131 {
 132         struct archive_decompress_program *state = a->decompressor->data;
 133         ssize_t ret, requested;
 134         const void *child_buf;
 135
 136         if (state->child_stdout == -1)
 137                 return (-1);
 138
 139         if (buf_len == 0)
 140                 return (-1);
 141
 142 restart_read:
 143         requested = buf_len > SSIZE_MAX ? SSIZE_MAX : buf_len;
 144
 145         do {
 146                 ret = read(state->child_stdout, buf, requested);
 147         } while (ret == -1 && errno == EINTR);
 148
 149         if (ret > 0)
 150                 return (ret);
 151         if (ret == 0 || (ret == -1 && errno == EPIPE)) {
 152                 close(state->child_stdout);
 153                 state->child_stdout = -1;
 154                 return (0);
 155         }
 156         if (ret == -1 && errno != EAGAIN)
 157                 return (-1);
 158
 159         if (state->child_in_buf_avail == 0) {
 160                 child_buf = state->child_in_buf;
 161                 ret = (a->client_reader)(&a->archive,
 162                     a->client_data,&child_buf);
 163                 state->child_in_buf = (const char *)child_buf;
 164
 165                 if (ret < 0) {
 166                         close(state->child_stdin);
 167                         state->child_stdin = -1;
 168                         fcntl(state->child_stdout, F_SETFL, 0);
 169                         return (-1);
 170                 }
 171                 if (ret == 0) {
 172                         close(state->child_stdin);
 173                         state->child_stdin = -1;
 174                         fcntl(state->child_stdout, F_SETFL, 0);
 175                         goto restart_read;
 176                 }
 177                 state->child_in_buf_avail = ret;
 178         }
 179
 180         if (state->child_stdin == -1) {
 181                 fcntl(state->child_stdout, F_SETFL, 0);
 182                 __archive_check_child(state->child_stdin, state->child_stdout);
 183                 goto restart_read;
 184         }
 185
 186         do {
 187                 ret = write(state->child_stdin, state->child_in_buf,
 188                     state->child_in_buf_avail);
 189         } while (ret == -1 && errno == EINTR);
 190
 191         if (ret > 0) {
 192                 state->child_in_buf += ret;
 193                 state->child_in_buf_avail -= ret;
 194                 goto restart_read;
 195         } else if (ret == -1 && errno == EAGAIN) {
 196                 __archive_check_child(state->child_stdin, state->child_stdout);
 197                 goto restart_read;
 198         } else if (ret == 0 || (ret == -1 && errno == EPIPE)) {
 199                 close(state->child_stdin);
 200                 state->child_stdin = -1;
 201                 fcntl(state->child_stdout, F_SETFL, 0);
 202                 goto restart_read;
 203         } else {
 204                 close(state->child_stdin);
 205                 state->child_stdin = -1;
 206                 fcntl(state->child_stdout, F_SETFL, 0);
 207                 return (-1);
 208         }
 209 }
 210
 211 static int
 212 archive_decompressor_program_init(struct archive_read *a, const void *buff, size_t n)
 213 {
 214         struct archive_decompress_program       *state;
 215         const char *cmd = a->decompressor->config;
 216         const char *prefix = "Program: ";
 217
 218
 219         state = (struct archive_decompress_program *)malloc(sizeof(*state));
 220         if (!state) {
 221                 archive_set_error(&a->archive, ENOMEM,
 222                     "Can't allocate input data");
 223                 return (ARCHIVE_FATAL);
 224         }
 225
 226         a->archive.compression_code = ARCHIVE_COMPRESSION_PROGRAM;
 227         state->description = (char *)malloc(strlen(prefix) + strlen(cmd) + 1);
 228         strcpy(state->description, prefix);
 229         strcat(state->description, cmd);
 230         a->archive.compression_name = state->description;
 231
 232         state->child_out_buf_next = state->child_out_buf = malloc(65536);
 233         if (!state->child_out_buf) {
 234                 free(state);
 235                 archive_set_error(&a->archive, ENOMEM,
 236                     "Can't allocate filter buffer");
 237                 return (ARCHIVE_FATAL);
 238         }
 239         state->child_out_buf_len = 65536;
 240         state->child_out_buf_avail = 0;
 241
 242         state->child_in_buf = buff;
 243         state->child_in_buf_avail = n;
 244
 245         if ((state->child = __archive_create_child(cmd,
 246                  &state->child_stdin, &state->child_stdout)) == -1) {
 247                 free(state->child_out_buf);
 248                 free(state);
 249                 archive_set_error(&a->archive, EINVAL,
 250                     "Can't initialise filter");
 251                 return (ARCHIVE_FATAL);
 252         }
 253
 254         a->decompressor->data = state;
 255         a->decompressor->read_ahead = archive_decompressor_program_read_ahead;
 256         a->decompressor->consume = archive_decompressor_program_read_consume;
 257         a->decompressor->skip = NULL;
 258         a->decompressor->finish = archive_decompressor_program_finish;
 259
 260         /* XXX Check that we can read at least one byte? */
 261         return (ARCHIVE_OK);
 262 }
 263
 264 static ssize_t
 265 archive_decompressor_program_read_ahead(struct archive_read *a, const void **buff,
 266     size_t min)
 267 {
 268         struct archive_decompress_program *state;
 269         ssize_t bytes_read;
 270
 271         state = (struct archive_decompress_program *)a->decompressor->data;
 272
 273         if (min > state->child_out_buf_len)
 274                 min = state->child_out_buf_len;
 275
 276         while (state->child_stdout != -1 && min > state->child_out_buf_avail) {
 277                 if (state->child_out_buf != state->child_out_buf_next) {
 278                         memmove(state->child_out_buf, state->child_out_buf_next,
 279                             state->child_out_buf_avail);
 280                         state->child_out_buf_next = state->child_out_buf;
 281                 }
 282
 283                 bytes_read = child_read(a,
 284                     state->child_out_buf + state->child_out_buf_avail,
 285                     state->child_out_buf_len - state->child_out_buf_avail);
 286                 if (bytes_read == -1)
 287                         return (-1);
 288                 if (bytes_read == 0)
 289                         break;
 290                 state->child_out_buf_avail += bytes_read;
 291                 a->archive.raw_position += bytes_read;
 292         }
 293
 294         *buff = state->child_out_buf_next;
 295         return (state->child_out_buf_avail);
 296 }
 297
 298 static ssize_t
 299 archive_decompressor_program_read_consume(struct archive_read *a, size_t request)
 300 {
 301         struct archive_decompress_program *state;
 302
 303         state = (struct archive_decompress_program *)a->decompressor->data;
 304
 305         state->child_out_buf_next += request;
 306         state->child_out_buf_avail -= request;
 307
 308         a->archive.file_position += request;
 309         return (request);
 310 }
 311
 312 static int
 313 archive_decompressor_program_finish(struct archive_read *a)
 314 {
 315         struct archive_decompress_program       *state;
 316         int status;
 317
 318         state = (struct archive_decompress_program *)a->decompressor->data;
 319
 320         /* Release our configuration data. */
 321         free(a->decompressor->config);
 322         a->decompressor->config = NULL;
 323
 324         /* Shut down the child. */
 325         if (state->child_stdin != -1)
 326                 close(state->child_stdin);
 327         if (state->child_stdout != -1)
 328                 close(state->child_stdout);
 329         while (waitpid(state->child, &status, 0) == -1 && errno == EINTR)
 330                 continue;
 331
 332         /* Release our private data. */
 333         free(state->child_out_buf);
 334         free(state->description);
 335         free(state);
 336         a->decompressor->data = NULL;
 337
 338         return (ARCHIVE_OK);
 339 }
 340
 341 #endif /* !defined(HAVE_PIPE) || !defined(HAVE_VFORK) || !defined(HAVE_FCNTL) */