1 /*- 2 * Copyright (c) 2003-2007 Tim Kientzle 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_data_into_fd.c,v 1.16 2008/05/23 05:01:29 cperciva Exp $"); 28 29 #ifdef HAVE_SYS_TYPES_H 30 #include <sys/types.h> 31 #endif 32 #ifdef HAVE_ERRNO_H 33 #include <errno.h> 34 #endif 35 #ifdef HAVE_UNISTD_H 36 #include <unistd.h> 37 #endif 38 39 #include "archive.h" 40 #include "archive_private.h" 41 42 /* Maximum amount of data to write at one time. */ 43 #define MAX_WRITE (1024 * 1024) 44 45 /* 46 * This implementation minimizes copying of data and is sparse-file aware. 47 */ 48 static int 49 pad_to(struct archive *a, int fd, int can_lseek, 50 size_t nulls_size, const char *nulls, 51 int64_t target_offset, int64_t actual_offset) 52 { 53 size_t to_write; 54 ssize_t bytes_written; 55 56 if (can_lseek) { 57 actual_offset = lseek(fd, 58 target_offset - actual_offset, SEEK_CUR); 59 if (actual_offset != target_offset) { 60 archive_set_error(a, errno, "Seek error"); 61 return (ARCHIVE_FATAL); 62 } 63 return (ARCHIVE_OK); 64 } 65 while (target_offset > actual_offset) { 66 to_write = nulls_size; 67 if (target_offset < actual_offset + (int64_t)nulls_size) 68 to_write = (size_t)(target_offset - actual_offset); 69 bytes_written = write(fd, nulls, to_write); 70 if (bytes_written < 0) { 71 archive_set_error(a, errno, "Write error"); 72 return (ARCHIVE_FATAL); 73 } 74 actual_offset += bytes_written; 75 } 76 return (ARCHIVE_OK); 77 } 78 79 80 int 81 archive_read_data_into_fd(struct archive *a, int fd) 82 { 83 struct stat st; 84 int r, r2; 85 const void *buff; 86 size_t size, bytes_to_write; 87 ssize_t bytes_written; 88 int64_t target_offset; 89 int64_t actual_offset = 0; 90 int can_lseek; 91 char *nulls = NULL; 92 size_t nulls_size = 16384; 93 94 archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA, 95 "archive_read_data_into_fd"); 96 97 can_lseek = (fstat(fd, &st) == 0) && S_ISREG(st.st_mode); 98 if (!can_lseek) 99 nulls = calloc(1, nulls_size); 100 101 while ((r = archive_read_data_block(a, &buff, &size, &target_offset)) == 102 ARCHIVE_OK) { 103 const char *p = buff; 104 if (target_offset > actual_offset) { 105 r = pad_to(a, fd, can_lseek, nulls_size, nulls, 106 target_offset, actual_offset); 107 if (r != ARCHIVE_OK) 108 break; 109 actual_offset = target_offset; 110 } 111 while (size > 0) { 112 bytes_to_write = size; 113 if (bytes_to_write > MAX_WRITE) 114 bytes_to_write = MAX_WRITE; 115 bytes_written = write(fd, p, bytes_to_write); 116 if (bytes_written < 0) { 117 archive_set_error(a, errno, "Write error"); 118 r = ARCHIVE_FATAL; 119 goto cleanup; 120 } 121 actual_offset += bytes_written; 122 p += bytes_written; 123 size -= bytes_written; 124 } 125 } 126 127 if (r == ARCHIVE_EOF && target_offset > actual_offset) { 128 r2 = pad_to(a, fd, can_lseek, nulls_size, nulls, 129 target_offset, actual_offset); 130 if (r2 != ARCHIVE_OK) 131 r = r2; 132 } 133 134 cleanup: 135 free(nulls); 136 if (r != ARCHIVE_EOF) 137 return (r); 138 return (ARCHIVE_OK); 139 } 140