1 /*- 2 * Copyright (c) 2012 Michihiro NAKAJIMA 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 28 #ifdef HAVE_ERRNO_H 29 #include <errno.h> 30 #endif 31 #ifdef HAVE_STDLIB_H 32 #include <stdlib.h> 33 #endif 34 #ifdef HAVE_STRING_H 35 #include <string.h> 36 #endif 37 #ifdef HAVE_UNISTD_H 38 #include <unistd.h> 39 #endif 40 41 #include "archive.h" 42 #include "archive_private.h" 43 #include "archive_read_private.h" 44 45 static const unsigned char grzip_magic[] = { 46 0x47, 0x52, 0x5a, 0x69, 0x70, 0x49, 0x49, 0x00, 47 0x02, 0x04, 0x3a, 0x29 }; 48 49 static int grzip_bidder_bid(struct archive_read_filter_bidder *, 50 struct archive_read_filter *); 51 static int grzip_bidder_init(struct archive_read_filter *); 52 53 54 static const struct archive_read_filter_bidder_vtable 55 grzip_bidder_vtable = { 56 .bid = grzip_bidder_bid, 57 .init = grzip_bidder_init, 58 }; 59 60 int 61 archive_read_support_filter_grzip(struct archive *_a) 62 { 63 struct archive_read *a = (struct archive_read *)_a; 64 65 if (__archive_read_register_bidder(a, NULL, NULL, 66 &grzip_bidder_vtable) != ARCHIVE_OK) 67 return (ARCHIVE_FATAL); 68 69 /* This filter always uses an external program. */ 70 archive_set_error(_a, ARCHIVE_ERRNO_MISC, 71 "Using external grzip program for grzip decompression"); 72 return (ARCHIVE_WARN); 73 } 74 75 /* 76 * Bidder just verifies the header and returns the number of verified bits. 77 */ 78 static int 79 grzip_bidder_bid(struct archive_read_filter_bidder *self, 80 struct archive_read_filter *filter) 81 { 82 const unsigned char *p; 83 ssize_t avail; 84 85 (void)self; /* UNUSED */ 86 87 p = __archive_read_filter_ahead(filter, sizeof(grzip_magic), &avail); 88 if (p == NULL || avail == 0) 89 return (0); 90 91 if (memcmp(p, grzip_magic, sizeof(grzip_magic))) 92 return (0); 93 94 return (sizeof(grzip_magic) * 8); 95 } 96 97 static int 98 grzip_bidder_init(struct archive_read_filter *self) 99 { 100 int r; 101 102 r = __archive_read_program(self, "grzip -d"); 103 /* Note: We set the format here even if __archive_read_program() 104 * above fails. We do, after all, know what the format is 105 * even if we weren't able to read it. */ 106 self->code = ARCHIVE_FILTER_GRZIP; 107 self->name = "grzip"; 108 return (r); 109 } 110