| /* sendfile -- copy data directly from one file descriptor to another |
| Copyright (C) 2002-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sys/sendfile.h> |
| #include <hurd.h> |
| #include <hurd/fd.h> |
| #include <sys/mman.h> |
| |
| /* Send COUNT bytes from file associated with IN_FD starting at OFFSET to |
| descriptor OUT_FD. */ |
| ssize_t |
| sendfile64 (int out_fd, int in_fd, off64_t *offset, size_t count) |
| { |
| /* We just do a vanilla io_read followed by a vanilla io_write here. |
| In theory the IN_FD filesystem can return us out-of-line data that |
| we then send out-of-line to the OUT_FD filesystem and no copying |
| takes place until those pages need to be flushed or packaged by |
| that filesystem (e.g. packetized by a network socket). However, |
| we momentarily consume COUNT bytes of our local address space, |
| which might blow if it's huge or address space is real tight. */ |
| |
| char *data = 0; |
| size_t datalen = 0; |
| error_t err = HURD_DPORT_USE (in_fd, |
| __io_read (port, &data, &datalen, |
| offset ? *offset : (off_t) -1, |
| count)); |
| if (err == 0) |
| { |
| size_t nwrote; |
| if (datalen == 0) |
| return 0; |
| err = HURD_DPORT_USE (out_fd, __io_write (port, data, datalen, |
| (off_t) -1, &nwrote)); |
| munmap (data, datalen); |
| if (err == 0) |
| { |
| if (offset) |
| *offset += datalen; |
| return nwrote; |
| } |
| } |
| return __hurd_fail (err); |
| } |