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 28 #ifdef HAVE_SYS_TYPES_H 29 #include <sys/types.h> 30 #endif 31 #ifdef HAVE_ERRNO_H 32 #include <errno.h> 33 #endif 34 #ifdef HAVE_UNISTD_H 35 #include <unistd.h> 36 #endif 37 38 #include "archive.h" 39 #include "archive_private.h" 40 41 /* Maximum amount of data to write at one time. */ 42 #define MAX_WRITE (1024 * 1024) 43 44 /* 45 * This implementation minimizes copying of data and is sparse-file aware. 46 */ 47 static int 48 pad_to(struct archive *a, int fd, int can_lseek, 49 size_t nulls_size, const char *nulls, 50 int64_t target_offset, int64_t actual_offset) 51 { 52 size_t to_write; 53 ssize_t bytes_written; 54 55 if (can_lseek) { 56 actual_offset = lseek(fd, 57 target_offset - actual_offset, SEEK_CUR); 58 if (actual_offset != target_offset) { 59 archive_set_error(a, errno, "Seek error"); 60 return (ARCHIVE_FATAL); 61 } 62 return (ARCHIVE_OK); 63 } 64 while (target_offset > actual_offset) { 65 to_write = nulls_size; 66 if (target_offset < actual_offset + (int64_t)nulls_size) 67 to_write = (size_t)(target_offset - actual_offset); 68 bytes_written = write(fd, nulls, to_write); 69 if (bytes_written < 0) { 70 archive_set_error(a, errno, "Write error"); 71 return (ARCHIVE_FATAL); 72 } 73 actual_offset += bytes_written; 74 } 75 return (ARCHIVE_OK); 76 } 77 78 79 int 80 archive_read_data_into_fd(struct archive *a, int fd) 81 { 82 struct stat st; 83 int r, r2; 84 const void *buff; 85 size_t size, bytes_to_write; 86 ssize_t bytes_written; 87 int64_t target_offset; 88 int64_t actual_offset = 0; 89 int can_lseek; 90 char *nulls = NULL; 91 size_t nulls_size = 16384; 92 93 archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA, 94 "archive_read_data_into_fd"); 95 96 can_lseek = (fstat(fd, &st) == 0) && S_ISREG(st.st_mode); 97 if (!can_lseek) { 98 nulls = calloc(1, nulls_size); 99 if (!nulls) { 100 r = ARCHIVE_FATAL; 101 goto cleanup; 102 } 103 } 104 105 while ((r = archive_read_data_block(a, &buff, &size, &target_offset)) == 106 ARCHIVE_OK) { 107 const char *p = buff; 108 if (target_offset > actual_offset) { 109 r = pad_to(a, fd, can_lseek, nulls_size, nulls, 110 target_offset, actual_offset); 111 if (r != ARCHIVE_OK) 112 break; 113 actual_offset = target_offset; 114 } 115 while (size > 0) { 116 bytes_to_write = size; 117 if (bytes_to_write > MAX_WRITE) 118 bytes_to_write = MAX_WRITE; 119 bytes_written = write(fd, p, bytes_to_write); 120 if (bytes_written < 0) { 121 archive_set_error(a, errno, "Write error"); 122 r = ARCHIVE_FATAL; 123 goto cleanup; 124 } 125 actual_offset += bytes_written; 126 p += bytes_written; 127 size -= bytes_written; 128 } 129 } 130 131 if (r == ARCHIVE_EOF && target_offset > actual_offset) { 132 r2 = pad_to(a, fd, can_lseek, nulls_size, nulls, 133 target_offset, actual_offset); 134 if (r2 != ARCHIVE_OK) 135 r = r2; 136 } 137 138 cleanup: 139 free(nulls); 140 if (r != ARCHIVE_EOF) 141 return (r); 142 return (ARCHIVE_OK); 143 } 144