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
pad_to(struct archive * a,int fd,int can_lseek,size_t nulls_size,const char * nulls,int64_t target_offset,int64_t actual_offset)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
archive_read_data_into_fd(struct archive * a,int fd)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