2 * Copyright (c) 2013-2015 Gleb Smirnoff <glebius@FreeBSD.org>
3 * Copyright (c) 1998, David Greenman. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include "opt_compat.h"
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/capsicum.h>
38 #include <sys/kernel.h>
40 #include <sys/mutex.h>
41 #include <sys/sysproto.h>
42 #include <sys/malloc.h>
45 #include <sys/mount.h>
47 #include <sys/protosw.h>
48 #include <sys/rwlock.h>
49 #include <sys/sf_buf.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/syscallsubr.h>
53 #include <sys/sysctl.h>
54 #include <sys/vnode.h>
58 #include <security/audit/audit.h>
59 #include <security/mac/mac_framework.h>
62 #include <vm/vm_object.h>
63 #include <vm/vm_pager.h>
66 * Structure describing a single sendfile(2) I/O, which may consist of
67 * several underlying pager I/Os.
69 * The syscall context allocates the structure and initializes 'nios'
70 * to 1. As sendfile_swapin() runs through pages and starts asynchronous
71 * paging operations, it increments 'nios'.
73 * Every I/O completion calls sendfile_iodone(), which decrements the 'nios',
74 * and the syscall also calls sendfile_iodone() after allocating all mbufs,
75 * linking them and sending to socket. Whoever reaches zero 'nios' is
76 * responsible to * call pru_ready on the socket, to notify it of readyness
89 * Structure used to track requests with SF_SYNC flag.
91 struct sendfile_sync {
97 counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)];
100 sfstat_init(const void *unused)
103 COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t),
106 SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL);
109 sfstat_sysctl(SYSCTL_HANDLER_ARGS)
113 COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t));
115 COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t));
116 return (SYSCTL_OUT(req, &s, sizeof(s)));
118 SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, CTLTYPE_OPAQUE | CTLFLAG_RW,
119 NULL, 0, sfstat_sysctl, "I", "sendfile statistics");
122 * Detach mapped page and release resources back to the system. Called
123 * by mbuf(9) code when last reference to a page is freed.
126 sf_ext_free(void *arg1, void *arg2)
128 struct sf_buf *sf = arg1;
129 struct sendfile_sync *sfs = arg2;
130 vm_page_t pg = sf_buf_page(sf);
136 * Check for the object going away on us. This can
137 * happen since we don't hold a reference to it.
138 * If so, we're responsible for freeing the page.
140 if (vm_page_unwire(pg, PQ_INACTIVE) && pg->object == NULL)
146 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0"));
147 if (--sfs->count == 0)
149 mtx_unlock(&sfs->mtx);
154 * Same as above, but forces the page to be detached from the object
155 * and go into free pool.
158 sf_ext_free_nocache(void *arg1, void *arg2)
160 struct sf_buf *sf = arg1;
161 struct sendfile_sync *sfs = arg2;
162 vm_page_t pg = sf_buf_page(sf);
167 if (vm_page_unwire(pg, PQ_NONE)) {
170 /* Try to free the page, but only if it is cheap to. */
171 if ((obj = pg->object) == NULL)
173 else if (!vm_page_xbusied(pg) && VM_OBJECT_TRYWLOCK(obj)) {
175 VM_OBJECT_WUNLOCK(obj);
177 vm_page_deactivate(pg);
183 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0"));
184 if (--sfs->count == 0)
186 mtx_unlock(&sfs->mtx);
191 * Helper function to calculate how much data to put into page i of n.
192 * Only first and last pages are special.
195 xfsize(int i, int n, off_t off, off_t len)
199 return (omin(PAGE_SIZE - (off & PAGE_MASK), len));
201 if (i == n - 1 && ((off + len) & PAGE_MASK) > 0)
202 return ((off + len) & PAGE_MASK);
208 * Helper function to get offset within object for i page.
210 static inline vm_ooffset_t
211 vmoff(int i, off_t off)
215 return ((vm_ooffset_t)off);
217 return (trunc_page(off + i * PAGE_SIZE));
221 * Helper function used when allocation of a page or sf_buf failed.
222 * Pretend as if we don't have enough space, subtract xfsize() of
223 * all pages that failed.
226 fixspace(int old, int new, off_t off, int *space)
229 KASSERT(old > new, ("%s: old %d new %d", __func__, old, new));
231 /* Subtract last one. */
232 *space -= xfsize(old - 1, old, off, *space);
236 /* There was only one page. */
239 /* Subtract first one. */
241 *space -= xfsize(0, old, off, *space);
245 /* Rest of pages are full sized. */
246 *space -= (old - new) * PAGE_SIZE;
248 KASSERT(*space >= 0, ("%s: space went backwards", __func__));
252 * I/O completion callback.
255 sendfile_iodone(void *arg, vm_page_t *pg, int count, int error)
257 struct sf_io *sfio = arg;
260 for (int i = 0; i < count; i++)
261 vm_page_xunbusy(pg[i]);
266 if (!refcount_release(&sfio->nios))
269 so = sfio->sock_fp->f_data;
275 * I/O operation failed. The state of data in the socket
276 * is now inconsistent, and all what we can do is to tear
277 * it down. Protocol abort method would tear down protocol
278 * state, free all ready mbufs and detach not ready ones.
279 * We will free the mbufs corresponding to this I/O manually.
281 * The socket would be marked with EIO and made available
282 * for read, so that application receives EIO on next
283 * syscall and eventually closes the socket.
285 so->so_proto->pr_usrreqs->pru_abort(so);
289 for (int i = 0; i < sfio->npages; i++)
292 CURVNET_SET(so->so_vnet);
293 (void )(so->so_proto->pr_usrreqs->pru_ready)(so, sfio->m,
298 /* XXXGL: curthread */
299 fdrop(sfio->sock_fp, curthread);
304 * Iterate through pages vector and request paging for non-valid pages.
307 sendfile_swapin(vm_object_t obj, struct sf_io *sfio, off_t off, off_t len,
308 int npages, int rhpages, int flags)
310 vm_page_t *pa = sfio->pa;
314 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0;
317 * First grab all the pages and wire them. Note that we grab
318 * only required pages. Readahead pages are dealt with later.
320 VM_OBJECT_WLOCK(obj);
322 grabbed = vm_page_grab_pages(obj, OFF_TO_IDX(off),
323 VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages);
324 if (grabbed < npages) {
325 for (int i = grabbed; i < npages; i++)
331 for (int i = 0; i < npages;) {
334 /* Skip valid pages. */
335 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK,
336 xfsize(i, npages, off, len))) {
337 vm_page_xunbusy(pa[i]);
338 SFSTAT_INC(sf_pages_valid);
344 * Now 'i' points to first invalid page, iterate further
345 * to make 'j' point at first valid after a bunch of
348 for (j = i + 1; j < npages; j++)
349 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK,
350 xfsize(j, npages, off, len))) {
351 SFSTAT_INC(sf_pages_valid);
356 * Now we got region of invalid pages between 'i' and 'j'.
357 * Check that they belong to pager. They may not be there,
358 * which is a regular situation for shmem pager. For vnode
359 * pager this happens only in case of sparse file.
361 * Important feature of vm_pager_has_page() is the hint
362 * stored in 'a', about how many pages we can pagein after
363 * this page in a single I/O.
365 while (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)),
366 NULL, &a) && i < j) {
367 pmap_zero_page(pa[i]);
368 pa[i]->valid = VM_PAGE_BITS_ALL;
369 MPASS(pa[i]->dirty == 0);
370 vm_page_xunbusy(pa[i]);
377 * We want to pagein as many pages as possible, limited only
378 * by the 'a' hint and actual request.
380 * We should not pagein into already valid page, thus if
381 * 'j' didn't reach last page, trim by that page.
383 * When the pagein fulfils the request, also specify readahead.
386 a = min(a, j - i - 1);
387 count = min(a + 1, npages - i);
389 refcount_acquire(&sfio->nios);
390 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL,
391 i + count == npages ? &rhpages : NULL,
392 &sendfile_iodone, sfio);
393 KASSERT(rv == VM_PAGER_OK, ("%s: pager fail obj %p page %p",
394 __func__, obj, pa[i]));
396 SFSTAT_INC(sf_iocnt);
397 SFSTAT_ADD(sf_pages_read, count);
398 if (i + count == npages)
399 SFSTAT_ADD(sf_rhpages_read, rhpages);
402 for (j = i; j < i + count && j < npages; j++)
403 KASSERT(pa[j] == vm_page_lookup(obj,
404 OFF_TO_IDX(vmoff(j, off))),
405 ("pa[j] %p lookup %p\n", pa[j],
406 vm_page_lookup(obj, OFF_TO_IDX(vmoff(j, off)))));
412 VM_OBJECT_WUNLOCK(obj);
414 if (nios == 0 && npages != 0)
415 SFSTAT_INC(sf_noiocnt);
421 sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res,
422 struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size,
433 shmfd = *shmfd_res = NULL;
437 * The file descriptor must be a regular file and have a
440 if (fp->f_type == DTYPE_VNODE) {
442 vn_lock(vp, LK_SHARED | LK_RETRY);
443 if (vp->v_type != VREG) {
447 *bsize = vp->v_mount->mnt_stat.f_iosize;
448 error = VOP_GETATTR(vp, &va, td->td_ucred);
451 *obj_size = va.va_size;
457 } else if (fp->f_type == DTYPE_SHM) {
460 obj = shmfd->shm_object;
461 *obj_size = shmfd->shm_size;
467 VM_OBJECT_WLOCK(obj);
468 if ((obj->flags & OBJ_DEAD) != 0) {
469 VM_OBJECT_WUNLOCK(obj);
475 * Temporarily increase the backing VM object's reference
476 * count so that a forced reclamation of its vnode does not
477 * immediately destroy it.
479 vm_object_reference_locked(obj);
480 VM_OBJECT_WUNLOCK(obj);
492 sendfile_getsock(struct thread *td, int s, struct file **sock_fp,
502 * The socket must be a stream socket and connected.
504 error = getsock_cap(td, s, cap_rights_init(&rights, CAP_SEND),
505 sock_fp, NULL, NULL);
508 *so = (*sock_fp)->f_data;
509 if ((*so)->so_type != SOCK_STREAM)
511 if (((*so)->so_state & SS_ISCONNECTED) == 0)
517 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
518 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
521 struct file *sock_fp;
523 struct vm_object *obj;
525 struct mbuf *m, *mh, *mhtail;
528 struct sendfile_sync *sfs;
530 off_t off, sbytes, rem, obj_size;
531 int error, softerr, bsize, hdrlen;
540 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize);
544 error = sendfile_getsock(td, sockfd, &sock_fp, &so);
549 error = mac_socket_check_send(td->td_ucred, so);
554 SFSTAT_INC(sf_syscalls);
555 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags));
557 if (flags & SF_SYNC) {
558 sfs = malloc(sizeof *sfs, M_TEMP, M_WAITOK | M_ZERO);
559 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF);
560 cv_init(&sfs->cv, "sendfile");
563 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset;
566 * Protect against multiple writers to the socket.
568 * XXXRW: Historically this has assumed non-interruptibility, so now
569 * we implement that, but possibly shouldn't.
571 (void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR);
574 * Loop through the pages of the file, starting with the requested
575 * offset. Get a file page (do I/O if necessary), map the file page
576 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
578 * This is done in two loops. The inner loop turns as many pages
579 * as it can, up to available socket buffer space, without blocking
580 * into mbufs to have it bulk delivered into the socket send buffer.
581 * The outer loop checks the state and available space of the socket
582 * and takes care of the overall progress.
584 for (off = offset; rem > 0; ) {
588 int nios, space, npages, rhpages;
592 * Check the socket state for ongoing connection,
593 * no errors and space in socket buffer.
594 * If space is low allow for the remainder of the
595 * file to be processed if it fits the socket buffer.
596 * Otherwise block in waiting for sufficient space
597 * to proceed, or if the socket is nonblocking, return
598 * to userland with EAGAIN while reporting how far
600 * We wait until the socket buffer has significant free
601 * space to do bulk sends. This makes good use of file
602 * system read ahead and allows packet segmentation
603 * offloading hardware to take over lots of work. If
604 * we were not careful here we would send off only one
607 SOCKBUF_LOCK(&so->so_snd);
608 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2)
609 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2;
611 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
613 SOCKBUF_UNLOCK(&so->so_snd);
615 } else if (so->so_error) {
616 error = so->so_error;
618 SOCKBUF_UNLOCK(&so->so_snd);
621 space = sbspace(&so->so_snd);
624 space < so->so_snd.sb_lowat)) {
625 if (so->so_state & SS_NBIO) {
626 SOCKBUF_UNLOCK(&so->so_snd);
631 * sbwait drops the lock while sleeping.
632 * When we loop back to retry_space the
633 * state may have changed and we retest
636 error = sbwait(&so->so_snd);
638 * An error from sbwait usually indicates that we've
639 * been interrupted by a signal. If we've sent anything
640 * then return bytes sent, otherwise return the error.
643 SOCKBUF_UNLOCK(&so->so_snd);
648 SOCKBUF_UNLOCK(&so->so_snd);
651 * At the beginning of the first loop check if any headers
652 * are specified and copy them into mbufs. Reduce space in
653 * the socket buffer by the size of the header mbuf chain.
654 * Clear hdr_uio here and hdrlen at the end of the first loop.
656 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) {
657 hdr_uio->uio_td = td;
658 hdr_uio->uio_rw = UIO_WRITE;
659 mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 0, 0);
660 hdrlen = m_length(mh, &mhtail);
663 * If header consumed all the socket buffer space,
664 * don't waste CPU cycles and jump to the end.
675 error = vn_lock(vp, LK_SHARED);
678 error = VOP_GETATTR(vp, &va, td->td_ucred);
679 if (error != 0 || off >= va.va_size) {
683 if (va.va_size != obj_size) {
684 obj_size = va.va_size;
686 omin(nbytes + offset, obj_size) : obj_size;
694 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE);
697 * Calculate maximum allowed number of pages for readahead
698 * at this iteration. First, we allow readahead up to "rem".
699 * If application wants more, let it be, but there is no
700 * reason to go above MAXPHYS. Also check against "obj_size",
701 * since vm_pager_has_page() can hint beyond EOF.
703 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - npages;
704 rhpages += SF_READAHEAD(flags);
705 rhpages = min(howmany(MAXPHYS, PAGE_SIZE), rhpages);
706 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) -
709 sfio = malloc(sizeof(struct sf_io) +
710 npages * sizeof(vm_page_t), M_TEMP, M_WAITOK);
711 refcount_init(&sfio->nios, 1);
714 nios = sendfile_swapin(obj, sfio, off, space, npages, rhpages,
718 * Loop and construct maximum sized mbuf chain to be bulk
719 * dumped into socket buffer.
722 for (int i = 0; i < npages; i++) {
726 * If a page wasn't grabbed successfully, then
727 * trim the array. Can happen only with SF_NODISKIO.
731 fixspace(npages, i, off, &space);
738 * Get a sendfile buf. When allocating the
739 * first buffer for mbuf chain, we usually
740 * wait as long as necessary, but this wait
741 * can be interrupted. For consequent
742 * buffers, do not sleep, since several
743 * threads might exhaust the buffers and then
746 sf = sf_buf_alloc(pa[i],
747 m != NULL ? SFB_NOWAIT : SFB_CATCH);
749 SFSTAT_INC(sf_allocfail);
750 for (int j = i; j < npages; j++) {
752 vm_page_unwire(pa[j], PQ_INACTIVE);
753 vm_page_unlock(pa[j]);
757 fixspace(npages, i, off, &space);
762 m0 = m_get(M_WAITOK, MT_DATA);
763 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf);
764 m0->m_ext.ext_size = PAGE_SIZE;
765 m0->m_ext.ext_arg1 = sf;
766 m0->m_ext.ext_arg2 = sfs;
768 * SF_NOCACHE sets the page as being freed upon send.
769 * However, we ignore it for the last page in 'space',
770 * if the page is truncated, and we got more data to
771 * send (rem > space), or if we have readahead
772 * configured (rhpages > 0).
774 if ((flags & SF_NOCACHE) == 0 ||
776 ((off + space) & PAGE_MASK) &&
777 (rem > space || rhpages > 0)))
778 m0->m_ext.ext_type = EXT_SFBUF;
780 m0->m_ext.ext_type = EXT_SFBUF_NOCACHE;
781 m0->m_ext.ext_flags = EXT_FLAG_EMBREF;
782 m0->m_ext.ext_count = 1;
783 m0->m_flags |= (M_EXT | M_RDONLY);
785 m0->m_flags |= M_NOTREADY;
786 m0->m_data = (char *)sf_buf_kva(sf) +
787 (vmoff(i, off) & PAGE_MASK);
788 m0->m_len = xfsize(i, npages, off, space);
793 /* Append to mbuf chain. */
803 mtx_unlock(&sfs->mtx);
810 /* Keep track of bytes processed. */
814 /* Prepend header, if any. */
823 KASSERT(softerr, ("%s: m NULL, no error", __func__));
829 /* Add the buffer chain to the socket buffer. */
830 KASSERT(m_length(m, NULL) == space + hdrlen,
831 ("%s: mlen %u space %d hdrlen %d",
832 __func__, m_length(m, NULL), space, hdrlen));
834 CURVNET_SET(so->so_vnet);
837 * If sendfile_swapin() didn't initiate any I/Os,
838 * which happens if all data is cached in VM, then
839 * we can send data right now without the
840 * PRUS_NOTREADY flag.
843 error = (*so->so_proto->pr_usrreqs->pru_send)
844 (so, 0, m, NULL, NULL, td);
846 sfio->sock_fp = sock_fp;
847 sfio->npages = npages;
849 error = (*so->so_proto->pr_usrreqs->pru_send)
850 (so, PRUS_NOTREADY, m, NULL, NULL, td);
851 sendfile_iodone(sfio, NULL, 0, 0);
855 m = NULL; /* pru_send always consumes */
858 sbytes += space + hdrlen;
868 * Send trailers. Wimp out and use writev(2).
870 if (trl_uio != NULL) {
871 sbunlock(&so->so_snd);
872 error = kern_writev(td, sockfd, trl_uio);
874 sbytes += td->td_retval[0];
879 sbunlock(&so->so_snd);
882 * If there was no error we have to clear td->td_retval[0]
883 * because it may have been set by writev.
886 td->td_retval[0] = 0;
892 vm_object_deallocate(obj);
903 cv_wait(&sfs->cv, &sfs->mtx);
904 KASSERT(sfs->count == 0, ("sendfile sync still busy"));
905 cv_destroy(&sfs->cv);
906 mtx_destroy(&sfs->mtx);
910 if (error == ERESTART)
917 sendfile(struct thread *td, struct sendfile_args *uap, int compat)
920 struct uio *hdr_uio, *trl_uio;
927 * File offset must be positive. If it goes beyond EOF
928 * we send only the header/trailer and no payload data.
934 hdr_uio = trl_uio = NULL;
936 if (uap->hdtr != NULL) {
937 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
940 if (hdtr.headers != NULL) {
941 error = copyinuio(hdtr.headers, hdtr.hdr_cnt,
945 #ifdef COMPAT_FREEBSD4
947 * In FreeBSD < 5.0 the nbytes to send also included
948 * the header. If compat is specified subtract the
949 * header size from nbytes.
952 if (uap->nbytes > hdr_uio->uio_resid)
953 uap->nbytes -= hdr_uio->uio_resid;
959 if (hdtr.trailers != NULL) {
960 error = copyinuio(hdtr.trailers, hdtr.trl_cnt,
967 AUDIT_ARG_FD(uap->fd);
970 * sendfile(2) can start at any offset within a file so we require
971 * CAP_READ+CAP_SEEK = CAP_PREAD.
973 if ((error = fget_read(td, uap->fd,
974 cap_rights_init(&rights, CAP_PREAD), &fp)) != 0) {
978 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset,
979 uap->nbytes, &sbytes, uap->flags, td);
982 if (uap->sbytes != NULL)
983 copyout(&sbytes, uap->sbytes, sizeof(off_t));
986 free(hdr_uio, M_IOV);
987 free(trl_uio, M_IOV);
994 * int sendfile(int fd, int s, off_t offset, size_t nbytes,
995 * struct sf_hdtr *hdtr, off_t *sbytes, int flags)
997 * Send a file specified by 'fd' and starting at 'offset' to a socket
998 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes ==
999 * 0. Optionally add a header and/or trailer to the socket output. If
1000 * specified, write the total number of bytes sent into *sbytes.
1003 sys_sendfile(struct thread *td, struct sendfile_args *uap)
1006 return (sendfile(td, uap, 0));
1009 #ifdef COMPAT_FREEBSD4
1011 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap)
1013 struct sendfile_args args;
1017 args.offset = uap->offset;
1018 args.nbytes = uap->nbytes;
1019 args.hdtr = uap->hdtr;
1020 args.sbytes = uap->sbytes;
1021 args.flags = uap->flags;
1023 return (sendfile(td, &args, 1));
1025 #endif /* COMPAT_FREEBSD4 */