summaryrefslogtreecommitdiff
path: root/nuttx/fs/fs_sendfile.c
blob: 39533a4f2c76b8d3aa4c67ef6bdf10aaf8b19dc3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/************************************************************************
 * fs/fs_sendfile.c
 *
 *   Copyright (C) 2007, 2009, 2011, 2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ************************************************************************/

/************************************************************************
 * Included Files
 ************************************************************************/

#include <nuttx/config.h>

#include <sys/sendfile.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>

#include <nuttx/sched.h>
#include <nuttx/net/net.h>

#if CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_SENDFILE

/************************************************************************
 * Private types
 ************************************************************************/

/************************************************************************
 * Private Variables
 ************************************************************************/

/************************************************************************
 * Public Variables
 ************************************************************************/

/************************************************************************
 * Private Functions
 ************************************************************************/

/************************************************************************
 * Public Functions
 ************************************************************************/

/************************************************************************
 * Name: sendfile
 *
 * Description:
 *   sendfile() copies data between one file descriptor and another.
 *   Used with file descriptors it basically just wraps a sequence of
 *   reads() and writes() to perform a copy.
 *
 *   If the destination descriptor is a socket, it gives a better
 *   performance than simple reds() and writes(). The data is read directly
 *   into the net buffer and the whole tcp window is filled if possible.
 *
 *   NOTE: This interface is *not* specified in POSIX.1-2001, or other
 *   standards.  The implementation here is very similar to the Linux
 *   sendfile interface.  Other UNIX systems implement sendfile() with
 *   different semantics and prototypes.  sendfile() should not be used
 *   in portable programs.
 *
 * Input Parmeters:
 *   infd   - A file (or socket) descriptor opened for reading
 *   outfd  - A descriptor opened for writing.
 *   offset - If 'offset' is not NULL, then it points to a variable
 *            holding the file offset from which sendfile() will start
 *            reading data from 'infd'.  When sendfile() returns, this
 *            variable will be set to the offset of the byte following
 *            the last byte that was read.  If 'offset' is not NULL,
 *            then sendfile() does not modify the current file offset of
 *            'infd'; otherwise the current file offset is adjusted to
 *            reflect the number of bytes read from 'infd.'
 *
 *            If 'offset' is NULL, then data will be read from 'infd'
 *            starting at the current file offset, and the file offset
 *            will be updated by the call.
 *   count -  The number of bytes to copy between the file descriptors.
 *
 * Returned Value:
 *   If the transfer was successful, the number of bytes written to outfd is
 *   returned.  On error, -1 is returned, and errno is set appropriately.
 *   There error values are those returned by read() or write() plus:
 *
 *   EINVAL - Bad input parameters.
 *   ENOMEM - Could not allocated an I/O buffer
 *
 ************************************************************************/

ssize_t sendfile(int outfd, int infd, off_t *offset, size_t count)
{
#if defined(CONFIG_NET_TCP) && CONFIG_NSOCKET_DESCRIPTORS > 0

  /* Check the destination file descriptor:  Is it a (probable) file
   * descriptor?  Check the source file:  Is it a normal file?
   */

  if ((unsigned int)outfd >= CONFIG_NFILE_DESCRIPTORS &&
      (unsigned int)infd < CONFIG_NFILE_DESCRIPTORS)
    {
      FAR struct filelist *list;

      /* This appears to be a file-to-socket transfer.  Get the thread-
       * specific file list.
       */

      list = sched_getfiles();
      DEBUGASSERT(list);

      /* Then let net_sendfile do the work. */

      return net_sendfile(outfd, &list->fl_files[infd], offset, count);
    }
  else
#endif
    {
      /* No... then this is probably a file-to-file transfer.  The generic
       * lib_sendfile() can handle that case.
       */

      return lib_sendfile(outfd, infd, offset, count);
    }
}

#endif /* CONFIG_NFILE_DESCRIPTORS > 0 && CONFIG_NET_SENDFILE */