1 /*
2 * Unix SMB/CIFS implementation.
3 * Utility functions to transfer files.
4 *
5 * Copyright (C) Jeremy Allison 2001-2002
6 * Copyright (C) Michael Adam 2008
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22
23 #include <includes.h>
24 #include "transfer_file.h"
25 #include "lib/util/sys_rw.h"
26
27 /****************************************************************************
28 Transfer some data between two fd's.
29 ****************************************************************************/
30
31 #ifndef TRANSFER_BUF_SIZE
32 #define TRANSFER_BUF_SIZE 65536
33 #endif
34
35
transfer_file_internal(void * in_file,void * out_file,size_t n,ssize_t (* pread_fn)(void *,void *,size_t,off_t),ssize_t (* pwrite_fn)(void *,const void *,size_t,off_t))36 ssize_t transfer_file_internal(void *in_file,
37 void *out_file,
38 size_t n,
39 ssize_t (*pread_fn)(void *, void *, size_t, off_t),
40 ssize_t (*pwrite_fn)(void *, const void *, size_t, off_t))
41 {
42 char *buf;
43 size_t total = 0;
44 ssize_t read_ret;
45 ssize_t write_ret;
46 size_t num_to_read_thistime;
47 size_t num_written = 0;
48 off_t offset = 0;
49
50 if (n == 0) {
51 return 0;
52 }
53
54 if ((buf = SMB_MALLOC_ARRAY(char, TRANSFER_BUF_SIZE)) == NULL) {
55 return -1;
56 }
57
58 do {
59 num_to_read_thistime = MIN((n - total), TRANSFER_BUF_SIZE);
60
61 read_ret = (*pread_fn)(in_file, buf, num_to_read_thistime, offset);
62 if (read_ret == -1) {
63 DEBUG(0,("transfer_file_internal: read failure. "
64 "Error = %s\n", strerror(errno) ));
65 SAFE_FREE(buf);
66 return -1;
67 }
68 if (read_ret == 0) {
69 break;
70 }
71
72 num_written = 0;
73
74 while (num_written < read_ret) {
75 write_ret = (*pwrite_fn)(out_file, buf + num_written,
76 read_ret - num_written,
77 offset + num_written);
78
79 if (write_ret == -1) {
80 DEBUG(0,("transfer_file_internal: "
81 "write failure. Error = %s\n",
82 strerror(errno) ));
83 SAFE_FREE(buf);
84 return -1;
85 }
86 if (write_ret == 0) {
87 return (ssize_t)total;
88 }
89
90 num_written += (size_t)write_ret;
91 }
92
93 total += (size_t)read_ret;
94 offset += (off_t)read_ret;
95 } while (total < n);
96
97 SAFE_FREE(buf);
98 return (ssize_t)total;
99 }
100
sys_pread_fn(void * file,void * buf,size_t len,off_t offset)101 static ssize_t sys_pread_fn(void *file, void *buf, size_t len, off_t offset)
102 {
103 int *fd = (int *)file;
104
105 return sys_pread(*fd, buf, len, offset);
106 }
107
sys_pwrite_fn(void * file,const void * buf,size_t len,off_t offset)108 static ssize_t sys_pwrite_fn(void *file, const void *buf, size_t len, off_t offset)
109 {
110 int *fd = (int *)file;
111
112 return sys_pwrite(*fd, buf, len, offset);
113 }
114
transfer_file(int infd,int outfd,off_t n)115 off_t transfer_file(int infd, int outfd, off_t n)
116 {
117 return (off_t)transfer_file_internal(&infd, &outfd, (size_t)n,
118 sys_pread_fn, sys_pwrite_fn);
119 }
120