diff options
Diffstat (limited to 'source4/lib/sendfile.c')
| -rw-r--r-- | source4/lib/sendfile.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/source4/lib/sendfile.c b/source4/lib/sendfile.c new file mode 100644 index 0000000000..bcc8cb08ca --- /dev/null +++ b/source4/lib/sendfile.c @@ -0,0 +1,382 @@ +/* + Unix SMB/Netbios implementation. + Version 2.2.x / 3.0.x + sendfile implementations. + Copyright (C) Jeremy Allison 2002. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/* + * This file handles the OS dependent sendfile implementations. + * The API is such that it returns -1 on error, else returns the + * number of bytes written. + */ + +#include "includes.h" + +#if defined(LINUX_SENDFILE_API) + +#include <sys/sendfile.h> + +#ifndef MSG_MORE +#define MSG_MORE 0x8000 +#endif + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + size_t total=0; + ssize_t ret; + size_t hdr_len = 0; + + /* + * Send the header first. + * Use MSG_MORE to cork the TCP output until sendfile is called. + */ + + if (header) { + hdr_len = header->length; + while (total < hdr_len) { + ret = sys_send(tofd, header->data + total,hdr_len - total, MSG_MORE); + if (ret == -1) + return -1; + total += ret; + } + } + + total = count; + while (total) { + ssize_t nwritten; + do { +#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_SENDFILE64) + nwritten = sendfile64(tofd, fromfd, &offset, total); +#else + nwritten = sendfile(tofd, fromfd, &offset, total); +#endif + } while (nwritten == -1 && errno == EINTR); + if (nwritten == -1) + return -1; + if (nwritten == 0) + return -1; /* I think we're at EOF here... */ + total -= nwritten; + } + return count + hdr_len; +} + +#elif defined(LINUX_BROKEN_SENDFILE_API) + +/* + * We must use explicit 32 bit types here. This code path means Linux + * won't do proper 64-bit sendfile. JRA. + */ + +extern int32 sendfile (int out_fd, int in_fd, int32 *offset, uint32 count); + + +#ifndef MSG_MORE +#define MSG_MORE 0x8000 +#endif + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + size_t total=0; + ssize_t ret; + ssize_t hdr_len = 0; + uint32 small_total = 0; + int32 small_offset; + + /* + * Fix for broken Linux 2.4 systems with no working sendfile64(). + * If the offset+count > 2 GB then pretend we don't have the + * system call sendfile at all. The upper layer catches this + * and uses a normal read. JRA. + */ + + if ((sizeof(SMB_OFF_T) >= 8) && (offset + count > (SMB_OFF_T)0x7FFFFFFF)) { + errno = ENOSYS; + return -1; + } + + /* + * Send the header first. + * Use MSG_MORE to cork the TCP output until sendfile is called. + */ + + if (header) { + hdr_len = header->length; + while (total < hdr_len) { + ret = sys_send(tofd, header->data + total,hdr_len - total, MSG_MORE); + if (ret == -1) + return -1; + total += ret; + } + } + + small_total = (uint32)count; + small_offset = (int32)offset; + + while (small_total) { + int32 nwritten; + do { + nwritten = sendfile(tofd, fromfd, &small_offset, small_total); + } while (nwritten == -1 && errno == EINTR); + if (nwritten == -1) + return -1; + if (nwritten == 0) + return -1; /* I think we're at EOF here... */ + small_total -= nwritten; + } + return count + hdr_len; +} + + +#elif defined(SOLARIS_SENDFILE_API) + +/* + * Solaris sendfile code written by Pierre Belanger <belanger@pobox.com>. + */ + +#include <sys/sendfile.h> + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + int sfvcnt; + size_t total, xferred; + struct sendfilevec vec[2]; + ssize_t hdr_len = 0; + + if (header) { + sfvcnt = 2; + + vec[0].sfv_fd = SFV_FD_SELF; + vec[0].sfv_flag = 0; + vec[0].sfv_off = header->data; + vec[0].sfv_len = hdr_len = header->length; + + vec[1].sfv_fd = fromfd; + vec[1].sfv_flag = 0; + vec[1].sfv_off = offset; + vec[1].sfv_len = count; + + } else { + sfvcnt = 1; + + vec[0].sfv_fd = fromfd; + vec[0].sfv_flag = 0; + vec[0].sfv_off = offset; + vec[0].sfv_len = count; + } + + total = count + hdr_len; + + while (total) { + ssize_t nwritten; + + /* + * Although not listed in the API error returns, this is almost certainly + * a slow system call and will be interrupted by a signal with EINTR. JRA. + */ + + xferred = 0; + +#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_SENDFILEV64) + nwritten = sendfilev64(tofd, vec, sfvcnt, &xferred); +#else + nwritten = sendfilev(tofd, vec, sfvcnt, &xferred); +#endif + if (nwritten == -1 && errno == EINTR) { + if (xferred == 0) + continue; /* Nothing written yet. */ + else + nwritten = xferred; + } + + if (nwritten == -1) + return -1; + if (nwritten == 0) + return -1; /* I think we're at EOF here... */ + + /* + * If this was a short (signal interrupted) write we may need + * to subtract it from the header data, or null out the header + * data altogether if we wrote more than vec[0].sfv_len bytes. + * We move vec[1].* to vec[0].* and set sfvcnt to 1 + */ + + if (sfvcnt == 2 && nwritten >= vec[0].sfv_len) { + vec[1].sfv_off += nwritten - vec[0].sfv_len; + vec[1].sfv_len -= nwritten - vec[0].sfv_len; + + /* Move vec[1].* to vec[0].* and set sfvcnt to 1 */ + vec[0] = vec[1]; + sfvcnt = 1; + } else { + vec[0].sfv_off += nwritten; + vec[0].sfv_len -= nwritten; + } + total -= nwritten; + } + return count + hdr_len; +} + +#elif defined(HPUX_SENDFILE_API) + +#include <sys/socket.h> +#include <sys/uio.h> + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + size_t total=0; + struct iovec hdtrl[2]; + size_t hdr_len = 0; + + if (header) { + /* Set up the header/trailer iovec. */ + hdtrl[0].iov_base = header->data; + hdtrl[0].iov_len = hdr_len = header->length; + } else { + hdtrl[0].iov_base = NULL; + hdtrl[0].iov_len = hdr_len = 0; + } + hdtrl[1].iov_base = NULL; + hdtrl[1].iov_base = 0; + + total = count; + while (total + hdtrl[0].iov_len) { + ssize_t nwritten; + + /* + * HPUX guarantees that if any data was written before + * a signal interrupt then sendfile returns the number of + * bytes written (which may be less than requested) not -1. + * nwritten includes the header data sent. + */ + + do { +#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_SENDFILE64) + nwritten = sendfile64(tofd, fromfd, offset, total, &hdtrl[0], 0); +#else + nwritten = sendfile(tofd, fromfd, offset, total, &hdtrl[0], 0); +#endif + } while (nwritten == -1 && errno == EINTR); + if (nwritten == -1) + return -1; + if (nwritten == 0) + return -1; /* I think we're at EOF here... */ + + /* + * If this was a short (signal interrupted) write we may need + * to subtract it from the header data, or null out the header + * data altogether if we wrote more than hdtrl[0].iov_len bytes. + * We change nwritten to be the number of file bytes written. + */ + + if (hdtrl[0].iov_base && hdtrl[0].iov_len) { + if (nwritten >= hdtrl[0].iov_len) { + nwritten -= hdtrl[0].iov_len; + hdtrl[0].iov_base = NULL; + hdtrl[0].iov_len = 0; + } else { + /* iov_base is defined as a void *... */ + hdtrl[0].iov_base = ((char *)hdtrl[0].iov_base) + nwritten; + hdtrl[0].iov_len -= nwritten; + nwritten = 0; + } + } + total -= nwritten; + offset += nwritten; + } + return count + hdr_len; +} + +#elif defined(FREEBSD_SENDFILE_API) + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/uio.h> + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + size_t total=0; + struct sf_hdtr hdr; + struct iovec hdtrl; + size_t hdr_len = 0; + + hdr.headers = &hdtrl; + hdr.hdr_cnt = 1; + hdr.trailers = NULL; + hdr.trl_cnt = 0; + + /* Set up the header iovec. */ + if (header) { + hdtrl.iov_base = header->data; + hdtrl.iov_len = hdr_len = header->length; + } else { + hdtrl.iov_base = NULL; + hdtrl.iov_len = 0; + } + + total = count; + while (total + hdtrl.iov_len) { + SMB_OFF_T nwritten; + int ret; + + /* + * FreeBSD sendfile returns 0 on success, -1 on error. + * Remember, the tofd and fromfd are reversed..... :-). + * nwritten includes the header data sent. + */ + + do { + ret = sendfile(fromfd, tofd, offset, total, &hdr, &nwritten, 0); + } while (ret == -1 && errno == EINTR); + if (ret == -1) + return -1; + + if (nwritten == 0) + return -1; /* I think we're at EOF here... */ + + /* + * If this was a short (signal interrupted) write we may need + * to subtract it from the header data, or null out the header + * data altogether if we wrote more than hdtrl.iov_len bytes. + * We change nwritten to be the number of file bytes written. + */ + + if (hdtrl.iov_base && hdtrl.iov_len) { + if (nwritten >= hdtrl.iov_len) { + nwritten -= hdtrl.iov_len; + hdtrl.iov_base = NULL; + hdtrl.iov_len = 0; + } else { + hdtrl.iov_base += nwritten; + hdtrl.iov_len -= nwritten; + nwritten = 0; + } + } + total -= nwritten; + offset += nwritten; + } + return count + hdr_len; +} + +#else /* No sendfile implementation. Return error. */ + +ssize_t sys_sendfile(int tofd, int fromfd, const DATA_BLOB *header, SMB_OFF_T offset, size_t count) +{ + /* No sendfile syscall. */ + errno = ENOSYS; + return -1; +} +#endif |