1 /*- 2 * Copyright (c) 2013-2015 Gleb Smirnoff <glebius@FreeBSD.org> 3 * Copyright (c) 1998, David Greenman. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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 * 3. 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. 16 * 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 27 * SUCH DAMAGE. 28 */ 29 30 #include "opt_kern_tls.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/capsicum.h> 35 #include <sys/inotify.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/ktls.h> 39 #include <sys/mutex.h> 40 #include <sys/malloc.h> 41 #include <sys/mman.h> 42 #include <sys/mount.h> 43 #include <sys/mbuf.h> 44 #include <sys/proc.h> 45 #include <sys/protosw.h> 46 #include <sys/rwlock.h> 47 #include <sys/sf_buf.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/syscallsubr.h> 51 #include <sys/sysctl.h> 52 #include <sys/sysproto.h> 53 #include <sys/vnode.h> 54 55 #include <net/vnet.h> 56 #include <netinet/in.h> 57 #include <netinet/tcp.h> 58 #include <netinet/in_pcb.h> 59 #include <netinet/tcp_var.h> 60 #include <netinet/tcp_log_buf.h> 61 62 #include <security/audit/audit.h> 63 #include <security/mac/mac_framework.h> 64 65 #include <vm/vm.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_pager.h> 68 69 static MALLOC_DEFINE(M_SENDFILE, "sendfile", "sendfile dynamic memory"); 70 71 #define EXT_FLAG_SYNC EXT_FLAG_VENDOR1 72 #define EXT_FLAG_NOCACHE EXT_FLAG_VENDOR2 73 #define EXT_FLAG_CACHE_LAST EXT_FLAG_VENDOR3 74 75 /* 76 * Structure describing a single sendfile(2) I/O, which may consist of 77 * several underlying pager I/Os. 78 * 79 * The syscall context allocates the structure and initializes 'nios' 80 * to 1. As sendfile_swapin() runs through pages and starts asynchronous 81 * paging operations, it increments 'nios'. 82 * 83 * Every I/O completion calls sendfile_iodone(), which decrements the 'nios', 84 * and the syscall also calls sendfile_iodone() after allocating all mbufs, 85 * linking them and sending to socket. Whoever reaches zero 'nios' is 86 * responsible to call pr_ready() on the socket, to notify it of readyness 87 * of the data. 88 */ 89 struct sf_io { 90 volatile u_int nios; 91 u_int error; 92 int npages; 93 struct socket *so; 94 struct mbuf *m; 95 vm_object_t obj; 96 vm_pindex_t pindex0; 97 #ifdef KERN_TLS 98 struct ktls_session *tls; 99 #endif 100 vm_page_t pa[]; 101 }; 102 103 /* 104 * Structure used to track requests with SF_SYNC flag. 105 */ 106 struct sendfile_sync { 107 struct mtx mtx; 108 struct cv cv; 109 unsigned count; 110 bool waiting; 111 }; 112 113 static void 114 sendfile_sync_destroy(struct sendfile_sync *sfs) 115 { 116 KASSERT(sfs->count == 0, ("sendfile sync %p still busy", sfs)); 117 118 cv_destroy(&sfs->cv); 119 mtx_destroy(&sfs->mtx); 120 free(sfs, M_SENDFILE); 121 } 122 123 static void 124 sendfile_sync_signal(struct sendfile_sync *sfs) 125 { 126 mtx_lock(&sfs->mtx); 127 KASSERT(sfs->count > 0, ("sendfile sync %p not busy", sfs)); 128 if (--sfs->count == 0) { 129 if (!sfs->waiting) { 130 /* The sendfile() waiter was interrupted by a signal. */ 131 sendfile_sync_destroy(sfs); 132 return; 133 } else { 134 cv_signal(&sfs->cv); 135 } 136 } 137 mtx_unlock(&sfs->mtx); 138 } 139 140 counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; 141 142 static void 143 sfstat_init(const void *unused) 144 { 145 146 COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t), 147 M_WAITOK); 148 } 149 SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL); 150 151 static int 152 sfstat_sysctl(SYSCTL_HANDLER_ARGS) 153 { 154 struct sfstat s; 155 156 COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t)); 157 if (req->newptr) 158 COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t)); 159 return (SYSCTL_OUT(req, &s, sizeof(s))); 160 } 161 SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, 162 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0, 163 sfstat_sysctl, "I", 164 "sendfile statistics"); 165 166 static void 167 sendfile_free_mext(struct mbuf *m) 168 { 169 struct sf_buf *sf; 170 vm_page_t pg; 171 int flags; 172 173 KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_SFBUF, 174 ("%s: m %p !M_EXT or !EXT_SFBUF", __func__, m)); 175 176 sf = m->m_ext.ext_arg1; 177 pg = sf_buf_page(sf); 178 flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; 179 180 sf_buf_free(sf); 181 vm_page_release(pg, flags); 182 183 if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { 184 struct sendfile_sync *sfs = m->m_ext.ext_arg2; 185 sendfile_sync_signal(sfs); 186 } 187 } 188 189 static void 190 sendfile_free_mext_pg(struct mbuf *m) 191 { 192 vm_page_t pg; 193 int flags, i; 194 bool cache_last; 195 196 M_ASSERTEXTPG(m); 197 198 cache_last = m->m_ext.ext_flags & EXT_FLAG_CACHE_LAST; 199 flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; 200 201 for (i = 0; i < m->m_epg_npgs; i++) { 202 if (cache_last && i == m->m_epg_npgs - 1) 203 flags = 0; 204 pg = PHYS_TO_VM_PAGE(m->m_epg_pa[i]); 205 vm_page_release(pg, flags); 206 } 207 208 if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { 209 struct sendfile_sync *sfs = m->m_ext.ext_arg1; 210 sendfile_sync_signal(sfs); 211 } 212 } 213 214 /* 215 * Helper function to calculate how much data to put into page i of n. 216 * Only first and last pages are special. 217 */ 218 static inline off_t 219 xfsize(int i, int n, off_t off, off_t len) 220 { 221 222 if (i == 0) 223 return (omin(PAGE_SIZE - (off & PAGE_MASK), len)); 224 225 if (i == n - 1 && ((off + len) & PAGE_MASK) > 0) 226 return ((off + len) & PAGE_MASK); 227 228 return (PAGE_SIZE); 229 } 230 231 /* 232 * Helper function to get offset within object for i page. 233 */ 234 static inline vm_ooffset_t 235 vmoff(int i, off_t off) 236 { 237 238 if (i == 0) 239 return ((vm_ooffset_t)off); 240 241 return (trunc_page(off + i * PAGE_SIZE)); 242 } 243 244 /* 245 * Helper function used when allocation of a page or sf_buf failed. 246 * Pretend as if we don't have enough space, subtract xfsize() of 247 * all pages that failed. 248 */ 249 static inline void 250 fixspace(int old, int new, off_t off, int *space) 251 { 252 253 KASSERT(old > new, ("%s: old %d new %d", __func__, old, new)); 254 255 /* Subtract last one. */ 256 *space -= xfsize(old - 1, old, off, *space); 257 old--; 258 259 if (new == old) 260 /* There was only one page. */ 261 return; 262 263 /* Subtract first one. */ 264 if (new == 0) { 265 *space -= xfsize(0, old, off, *space); 266 new++; 267 } 268 269 /* Rest of pages are full sized. */ 270 *space -= (old - new) * PAGE_SIZE; 271 272 KASSERT(*space >= 0, ("%s: space went backwards", __func__)); 273 } 274 275 /* 276 * Wait for all in-flight ios to complete, we must not unwire pages 277 * under them. 278 */ 279 static void 280 sendfile_iowait(struct sf_io *sfio, const char *wmesg) 281 { 282 while (atomic_load_int(&sfio->nios) != 1) 283 pause(wmesg, 1); 284 } 285 286 /* 287 * I/O completion callback. 288 * 289 * When called via I/O path, the curvnet is not set and should be obtained 290 * from the socket. When called synchronously from vn_sendfile(), usually 291 * to report error or just release the reference (all pages are valid), then 292 * curvnet shall be already set. 293 */ 294 static void 295 sendfile_iodone(void *arg, vm_page_t *pa, int count, int error) 296 { 297 struct sf_io *sfio = arg; 298 struct socket *so; 299 int i; 300 301 if (error != 0) 302 sfio->error = error; 303 304 /* 305 * Restore the valid page pointers. They are already 306 * unbusied, but still wired. 307 * 308 * XXXKIB since pages are only wired, and we do not 309 * own the object lock, other users might have 310 * invalidated them in meantime. Similarly, after we 311 * unbusied the swapped-in pages, they can become 312 * invalid under us. 313 */ 314 MPASS(count == 0 || pa[0] != bogus_page); 315 for (i = 0; i < count; i++) { 316 if (pa[i] == bogus_page) { 317 sfio->pa[(pa[0]->pindex - sfio->pindex0) + i] = 318 pa[i] = vm_page_relookup(sfio->obj, 319 pa[0]->pindex + i); 320 KASSERT(pa[i] != NULL, 321 ("%s: page %p[%d] disappeared", 322 __func__, pa, i)); 323 } else { 324 vm_page_xunbusy_unchecked(pa[i]); 325 } 326 } 327 328 if (!refcount_release(&sfio->nios)) 329 return; 330 331 #ifdef INVARIANTS 332 for (i = 1; i < sfio->npages; i++) { 333 if (sfio->pa[i] == NULL) 334 break; 335 KASSERT(vm_page_wired(sfio->pa[i]), 336 ("sfio %p page %d %p not wired", sfio, i, sfio->pa[i])); 337 if (i == 0) 338 continue; 339 KASSERT(sfio->pa[0]->object == sfio->pa[i]->object, 340 ("sfio %p page %d %p wrong owner %p %p", sfio, i, 341 sfio->pa[i], sfio->pa[0]->object, sfio->pa[i]->object)); 342 KASSERT(sfio->pa[0]->pindex + i == sfio->pa[i]->pindex, 343 ("sfio %p page %d %p wrong index %jx %jx", sfio, i, 344 sfio->pa[i], (uintmax_t)sfio->pa[0]->pindex, 345 (uintmax_t)sfio->pa[i]->pindex)); 346 } 347 #endif 348 349 vm_object_pip_wakeup(sfio->obj); 350 351 if (sfio->m == NULL) { 352 /* 353 * Either I/O operation failed, or we failed to allocate 354 * buffers, or we bailed out on first busy page, or we 355 * succeeded filling the request without any I/Os. Anyway, 356 * pr_send() hadn't been executed - nothing had been sent 357 * to the socket yet. 358 */ 359 MPASS((curthread->td_pflags & TDP_KTHREAD) == 0); 360 free(sfio, M_SENDFILE); 361 return; 362 } 363 364 #if defined(KERN_TLS) && defined(INVARIANTS) 365 if ((sfio->m->m_flags & M_EXTPG) != 0) 366 KASSERT(sfio->tls == sfio->m->m_epg_tls, 367 ("TLS session mismatch")); 368 else 369 KASSERT(sfio->tls == NULL, 370 ("non-ext_pgs mbuf with TLS session")); 371 #endif 372 so = sfio->so; 373 CURVNET_SET_QUIET(so->so_vnet); 374 if (__predict_false(sfio->error)) { 375 /* 376 * I/O operation failed. The state of data in the socket 377 * is now inconsistent, and all what we can do is to tear 378 * it down. Protocol abort method would tear down protocol 379 * state, free all ready mbufs and detach not ready ones. 380 * We will free the mbufs corresponding to this I/O manually. 381 * 382 * The socket would be marked with EIO and made available 383 * for read, so that application receives EIO on next 384 * syscall and eventually closes the socket. 385 */ 386 so->so_proto->pr_abort(so); 387 so->so_error = EIO; 388 389 mb_free_notready(sfio->m, sfio->npages); 390 #ifdef KERN_TLS 391 } else if (sfio->tls != NULL && sfio->tls->mode == TCP_TLS_MODE_SW) { 392 /* 393 * I/O operation is complete, but we still need to 394 * encrypt. We cannot do this in the interrupt thread 395 * of the disk controller, so forward the mbufs to a 396 * different thread. 397 * 398 * Donate the socket reference from sfio to rather 399 * than explicitly invoking soref(). 400 */ 401 ktls_enqueue(sfio->m, so, sfio->npages); 402 goto out_with_ref; 403 #endif 404 } else 405 (void)so->so_proto->pr_ready(so, sfio->m, sfio->npages); 406 407 sorele(so); 408 #ifdef KERN_TLS 409 out_with_ref: 410 #endif 411 CURVNET_RESTORE(); 412 free(sfio, M_SENDFILE); 413 } 414 415 /* 416 * Iterate through pages vector and request paging for non-valid pages. 417 */ 418 static int 419 sendfile_swapin(vm_object_t obj, struct sf_io *sfio, int *nios, off_t off, 420 off_t len, int rhpages, int flags) 421 { 422 vm_page_t *pa; 423 int a, count, count1, grabbed, i, j, npages, rv; 424 425 pa = sfio->pa; 426 npages = sfio->npages; 427 *nios = 0; 428 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; 429 sfio->pindex0 = OFF_TO_IDX(off); 430 431 /* 432 * First grab all the pages and wire them. Note that we grab 433 * only required pages. Readahead pages are dealt with later. 434 */ 435 grabbed = vm_page_grab_pages_unlocked(obj, OFF_TO_IDX(off), 436 VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages); 437 if (grabbed < npages) { 438 for (int i = grabbed; i < npages; i++) 439 pa[i] = NULL; 440 npages = grabbed; 441 rhpages = 0; 442 } 443 444 for (i = 0; i < npages;) { 445 /* Skip valid pages. */ 446 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, 447 xfsize(i, npages, off, len))) { 448 vm_page_xunbusy(pa[i]); 449 SFSTAT_INC(sf_pages_valid); 450 i++; 451 continue; 452 } 453 454 /* 455 * Next page is invalid. Check if it belongs to pager. It 456 * may not be there, which is a regular situation for shmem 457 * pager. For vnode pager this happens only in case of 458 * a sparse file. 459 * 460 * Important feature of vm_pager_has_page() is the hint 461 * stored in 'a', about how many pages we can pagein after 462 * this page in a single I/O. 463 */ 464 VM_OBJECT_RLOCK(obj); 465 if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL, 466 &a)) { 467 VM_OBJECT_RUNLOCK(obj); 468 pmap_zero_page(pa[i]); 469 vm_page_valid(pa[i]); 470 MPASS(pa[i]->dirty == 0); 471 vm_page_xunbusy(pa[i]); 472 i++; 473 continue; 474 } 475 VM_OBJECT_RUNLOCK(obj); 476 477 /* 478 * We want to pagein as many pages as possible, limited only 479 * by the 'a' hint and actual request. 480 */ 481 count = min(a + 1, npages - i); 482 483 /* 484 * We should not pagein into a valid page because 485 * there might be still unfinished write tracked by 486 * e.g. a buffer, thus we substitute any valid pages 487 * with the bogus one. 488 * 489 * We must not leave around xbusy pages which are not 490 * part of the run passed to vm_pager_getpages(), 491 * otherwise pager might deadlock waiting for the busy 492 * status of the page, e.g. if it constitues the 493 * buffer needed to validate other page. 494 * 495 * First trim the end of the run consisting of the 496 * valid pages, then replace the rest of the valid 497 * with bogus. 498 */ 499 count1 = count; 500 for (j = i + count - 1; j > i; j--) { 501 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 502 xfsize(j, npages, off, len))) { 503 vm_page_xunbusy(pa[j]); 504 SFSTAT_INC(sf_pages_valid); 505 count--; 506 } else { 507 break; 508 } 509 } 510 511 /* 512 * The last page in the run pa[i + count - 1] is 513 * guaranteed to be invalid by the trim above, so it 514 * is not replaced with bogus, thus -1 in the loop end 515 * condition. 516 */ 517 MPASS(pa[i + count - 1]->valid != VM_PAGE_BITS_ALL); 518 for (j = i + 1; j < i + count - 1; j++) { 519 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 520 xfsize(j, npages, off, len))) { 521 vm_page_xunbusy(pa[j]); 522 SFSTAT_INC(sf_pages_valid); 523 SFSTAT_INC(sf_pages_bogus); 524 pa[j] = bogus_page; 525 } 526 } 527 528 refcount_acquire(&sfio->nios); 529 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, 530 i + count == npages ? &rhpages : NULL, 531 &sendfile_iodone, sfio); 532 if (__predict_false(rv != VM_PAGER_OK)) { 533 sendfile_iowait(sfio, "sferrio"); 534 535 /* 536 * Do remaining pages recovery before returning EIO. 537 * Pages from 0 to npages are wired. 538 * Pages from (i + count1) to npages are busied. 539 */ 540 for (j = 0; j < npages; j++) { 541 if (j >= i + count1) 542 vm_page_xunbusy(pa[j]); 543 KASSERT(pa[j] != NULL && pa[j] != bogus_page, 544 ("%s: page %p[%d] I/O recovery failure", 545 __func__, pa, j)); 546 vm_page_unwire(pa[j], PQ_INACTIVE); 547 pa[j] = NULL; 548 } 549 return (EIO); 550 } 551 552 SFSTAT_INC(sf_iocnt); 553 SFSTAT_ADD(sf_pages_read, count); 554 if (i + count == npages) 555 SFSTAT_ADD(sf_rhpages_read, rhpages); 556 557 i += count1; 558 (*nios)++; 559 } 560 561 if (*nios == 0 && npages != 0) 562 SFSTAT_INC(sf_noiocnt); 563 564 return (0); 565 } 566 567 static int 568 sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res, 569 struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size, 570 int *bsize) 571 { 572 vm_object_t obj; 573 struct vnode *vp; 574 struct shmfd *shmfd; 575 int error; 576 577 error = 0; 578 vp = *vp_res = NULL; 579 obj = NULL; 580 shmfd = *shmfd_res = NULL; 581 *bsize = 0; 582 583 /* 584 * The file descriptor must be a regular file and have a 585 * backing VM object. 586 */ 587 if (fp->f_type == DTYPE_VNODE) { 588 vp = fp->f_vnode; 589 vn_lock(vp, LK_SHARED | LK_RETRY); 590 if (vp->v_type != VREG) { 591 error = EINVAL; 592 goto out; 593 } 594 *bsize = vp->v_mount->mnt_stat.f_iosize; 595 obj = vp->v_object; 596 if (obj == NULL) { 597 error = EINVAL; 598 goto out; 599 } 600 601 /* 602 * Use the pager size when available to simplify synchronization 603 * with filesystems, which otherwise must atomically update both 604 * the vnode pager size and file size. 605 */ 606 if (obj->type == OBJT_VNODE) { 607 VM_OBJECT_RLOCK(obj); 608 *obj_size = obj->un_pager.vnp.vnp_size; 609 } else { 610 error = vn_getsize_locked(vp, obj_size, td->td_ucred); 611 if (error != 0) 612 goto out; 613 VM_OBJECT_RLOCK(obj); 614 } 615 } else if (fp->f_type == DTYPE_SHM) { 616 shmfd = fp->f_data; 617 obj = shmfd->shm_object; 618 VM_OBJECT_RLOCK(obj); 619 *obj_size = shmfd->shm_size; 620 } else { 621 error = EINVAL; 622 goto out; 623 } 624 625 if ((obj->flags & OBJ_DEAD) != 0) { 626 VM_OBJECT_RUNLOCK(obj); 627 error = EBADF; 628 goto out; 629 } 630 631 /* 632 * Temporarily increase the backing VM object's reference 633 * count so that a forced reclamation of its vnode does not 634 * immediately destroy it. 635 */ 636 vm_object_reference_locked(obj); 637 VM_OBJECT_RUNLOCK(obj); 638 *obj_res = obj; 639 *vp_res = vp; 640 *shmfd_res = shmfd; 641 642 out: 643 if (vp != NULL) 644 VOP_UNLOCK(vp); 645 return (error); 646 } 647 648 static int 649 sendfile_getsock(struct thread *td, int s, struct file **sock_fp, 650 struct socket **so) 651 { 652 int error; 653 654 *sock_fp = NULL; 655 *so = NULL; 656 657 /* 658 * The socket must be a stream socket and connected. 659 */ 660 error = getsock(td, s, &cap_send_rights, sock_fp); 661 if (error != 0) 662 return (error); 663 *so = (*sock_fp)->f_data; 664 if ((*so)->so_type != SOCK_STREAM) 665 return (EINVAL); 666 /* 667 * SCTP one-to-one style sockets currently don't work with 668 * sendfile(). So indicate EINVAL for now. 669 */ 670 if ((*so)->so_proto->pr_protocol == IPPROTO_SCTP) 671 return (EINVAL); 672 return (0); 673 } 674 675 /* 676 * Check socket state and wait (or EAGAIN) for needed amount of space. 677 */ 678 int 679 sendfile_wait_generic(struct socket *so, off_t need, int *space) 680 { 681 int error; 682 683 MPASS(need > 0); 684 MPASS(space != NULL); 685 686 /* 687 * XXXGL: the hack with sb_lowat originates from d99b0dd2c5297. To 688 * achieve high performance sending with sendfile(2) a non-blocking 689 * socket needs a fairly high low watermark. Otherwise, the socket 690 * will be reported as writable too early, and sendfile(2) will send 691 * just a few bytes each time. It is important to understand that 692 * we are changing sb_lowat not for the current invocation of the 693 * syscall, but for the *next* syscall. So there is no way to 694 * workaround the problem, e.g. provide a special version of sbspace(). 695 * Since this hack has been in the kernel for a long time, we 696 * anticipate that there is a lot of software that will suffer if we 697 * remove it. See also b21104487324. 698 */ 699 error = 0; 700 SOCK_SENDBUF_LOCK(so); 701 if (so->so_snd.sb_flags & SB_AUTOLOWAT) { 702 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) 703 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; 704 if (so->so_snd.sb_lowat < PAGE_SIZE && 705 so->so_snd.sb_hiwat >= PAGE_SIZE) 706 so->so_snd.sb_lowat = PAGE_SIZE; 707 } 708 retry_space: 709 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 710 error = EPIPE; 711 goto done; 712 } else if (so->so_error) { 713 error = so->so_error; 714 so->so_error = 0; 715 goto done; 716 } 717 if ((so->so_state & SS_ISCONNECTED) == 0) { 718 error = ENOTCONN; 719 goto done; 720 } 721 722 *space = sbspace(&so->so_snd); 723 if (*space < need && (*space <= 0 || *space < so->so_snd.sb_lowat)) { 724 if (so->so_state & SS_NBIO) { 725 error = EAGAIN; 726 goto done; 727 } 728 /* 729 * sbwait() drops the lock while sleeping. When we loop back 730 * to retry_space the state may have changed and we retest 731 * for it. 732 */ 733 error = sbwait(so, SO_SND); 734 /* 735 * An error from sbwait() usually indicates that we've been 736 * interrupted by a signal. If we've sent anything then return 737 * bytes sent, otherwise return the error. 738 */ 739 if (error != 0) 740 goto done; 741 goto retry_space; 742 } 743 done: 744 SOCK_SENDBUF_UNLOCK(so); 745 746 return (error); 747 } 748 749 int 750 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 751 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 752 struct thread *td) 753 { 754 struct file *sock_fp; 755 struct vnode *vp; 756 struct vm_object *obj; 757 vm_page_t pga; 758 struct socket *so; 759 const struct protosw *pr; 760 #ifdef KERN_TLS 761 struct ktls_session *tls; 762 #endif 763 struct mbuf *m, *mh, *mhtail; 764 struct sf_buf *sf; 765 struct shmfd *shmfd; 766 struct sendfile_sync *sfs; 767 struct vattr va; 768 off_t off, sbytes, rem, obj_size, nobj_size; 769 int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr; 770 #ifdef KERN_TLS 771 int tls_enq_cnt; 772 #endif 773 bool use_ext_pgs; 774 775 obj = NULL; 776 so = NULL; 777 m = mh = NULL; 778 sfs = NULL; 779 #ifdef KERN_TLS 780 tls = NULL; 781 #endif 782 hdrlen = sbytes = 0; 783 softerr = 0; 784 use_ext_pgs = false; 785 786 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); 787 if (error != 0) 788 return (error); 789 790 error = sendfile_getsock(td, sockfd, &sock_fp, &so); 791 if (error != 0) 792 goto out; 793 pr = so->so_proto; 794 795 #ifdef MAC 796 error = mac_socket_check_send(td->td_ucred, so); 797 if (error != 0) 798 goto out; 799 #endif 800 801 SFSTAT_INC(sf_syscalls); 802 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); 803 804 if (__predict_false(flags & SF_SYNC)) { 805 gone_in(16, "Warning! %s[%u] uses SF_SYNC sendfile(2) flag. " 806 "Please follow up to https://bugs.freebsd.org/" 807 "bugzilla/show_bug.cgi?id=287348. ", 808 td->td_proc->p_comm, td->td_proc->p_pid); 809 sfs = malloc(sizeof(*sfs), M_SENDFILE, M_WAITOK | M_ZERO); 810 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); 811 cv_init(&sfs->cv, "sendfile"); 812 sfs->waiting = true; 813 } 814 815 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; 816 817 /* 818 * Protect against multiple writers to the socket. 819 * 820 * XXXRW: Historically this has assumed non-interruptibility, so now 821 * we implement that, but possibly shouldn't. 822 */ 823 error = SOCK_IO_SEND_LOCK(so, SBL_WAIT | SBL_NOINTR); 824 if (error != 0) 825 goto out; 826 CURVNET_SET(so->so_vnet); 827 #ifdef KERN_TLS 828 tls = ktls_hold(so->so_snd.sb_tls_info); 829 #endif 830 831 /* 832 * Loop through the pages of the file, starting with the requested 833 * offset. Get a file page (do I/O if necessary), map the file page 834 * into an sf_buf, attach an mbuf header to the sf_buf, and queue 835 * it on the socket. 836 * This is done in two loops. The inner loop turns as many pages 837 * as it can, up to available socket buffer space, without blocking 838 * into mbufs to have it bulk delivered into the socket send buffer. 839 * The outer loop checks the state and available space of the socket 840 * and takes care of the overall progress. 841 */ 842 for (off = offset; rem > 0; ) { 843 struct sf_io *sfio; 844 vm_page_t *pa; 845 struct mbuf *m0, *mtail; 846 int nios, space, npages, rhpages; 847 848 mtail = NULL; 849 if ((error = pr->pr_sendfile_wait(so, rem, &space)) != 0) 850 goto done; 851 /* 852 * At the beginning of the first loop check if any headers 853 * are specified and copy them into mbufs. Reduce space in 854 * the socket buffer by the size of the header mbuf chain. 855 * Clear hdr_uio here and hdrlen at the end of the first loop. 856 */ 857 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { 858 hdr_uio->uio_td = td; 859 hdr_uio->uio_rw = UIO_WRITE; 860 #ifdef KERN_TLS 861 if (tls != NULL) 862 mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 863 tls->params.max_frame_len, M_EXTPG); 864 else 865 #endif 866 mh = m_uiotombuf(hdr_uio, M_WAITOK, 867 space, 0, 0); 868 hdrlen = m_length(mh, &mhtail); 869 space -= hdrlen; 870 /* 871 * If header consumed all the socket buffer space, 872 * don't waste CPU cycles and jump to the end. 873 */ 874 if (space == 0) { 875 sfio = NULL; 876 nios = 0; 877 goto prepend_header; 878 } 879 hdr_uio = NULL; 880 } 881 882 if (vp != NULL) { 883 error = vn_lock(vp, LK_SHARED); 884 if (error != 0) 885 goto done; 886 887 /* 888 * Check to see if the file size has changed. 889 */ 890 if (obj->type == OBJT_VNODE) { 891 VM_OBJECT_RLOCK(obj); 892 nobj_size = obj->un_pager.vnp.vnp_size; 893 VM_OBJECT_RUNLOCK(obj); 894 } else { 895 error = VOP_GETATTR(vp, &va, td->td_ucred); 896 if (error != 0) { 897 VOP_UNLOCK(vp); 898 goto done; 899 } 900 nobj_size = va.va_size; 901 } 902 if (off >= nobj_size) { 903 VOP_UNLOCK(vp); 904 goto done; 905 } 906 if (nobj_size != obj_size) { 907 obj_size = nobj_size; 908 rem = nbytes ? omin(nbytes + offset, obj_size) : 909 obj_size; 910 rem -= off; 911 } 912 } 913 914 if (space > rem) 915 space = rem; 916 else if (space > PAGE_SIZE) { 917 /* 918 * Use page boundaries when possible for large 919 * requests. 920 */ 921 if (off & PAGE_MASK) 922 space -= (PAGE_SIZE - (off & PAGE_MASK)); 923 space = trunc_page(space); 924 if (off & PAGE_MASK) 925 space += (PAGE_SIZE - (off & PAGE_MASK)); 926 } 927 928 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); 929 930 /* 931 * Calculate maximum allowed number of pages for readahead 932 * at this iteration. If SF_USER_READAHEAD was set, we don't 933 * do any heuristics and use exactly the value supplied by 934 * application. Otherwise, we allow readahead up to "rem". 935 * If application wants more, let it be, but there is no 936 * reason to go above maxphys. Also check against "obj_size", 937 * since vm_pager_has_page() can hint beyond EOF. 938 */ 939 if (flags & SF_USER_READAHEAD) { 940 rhpages = SF_READAHEAD(flags); 941 } else { 942 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - 943 npages; 944 rhpages += SF_READAHEAD(flags); 945 } 946 rhpages = min(howmany(maxphys, PAGE_SIZE), rhpages); 947 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - 948 npages, rhpages); 949 950 sfio = malloc(sizeof(struct sf_io) + 951 npages * sizeof(vm_page_t), M_SENDFILE, M_WAITOK); 952 refcount_init(&sfio->nios, 1); 953 sfio->obj = obj; 954 sfio->error = 0; 955 sfio->m = NULL; 956 sfio->npages = npages; 957 #ifdef KERN_TLS 958 /* 959 * This doesn't use ktls_hold() because sfio->m will 960 * also have a reference on 'tls' that will be valid 961 * for all of sfio's lifetime. 962 */ 963 sfio->tls = tls; 964 #endif 965 vm_object_pip_add(obj, 1); 966 error = sendfile_swapin(obj, sfio, &nios, off, space, rhpages, 967 flags); 968 if (error != 0) { 969 if (vp != NULL) 970 VOP_UNLOCK(vp); 971 sendfile_iodone(sfio, NULL, 0, error); 972 goto done; 973 } 974 975 /* 976 * Loop and construct maximum sized mbuf chain to be bulk 977 * dumped into socket buffer. 978 */ 979 pa = sfio->pa; 980 981 /* 982 * Use unmapped mbufs if enabled for TCP. Unmapped 983 * bufs are restricted to TCP as that is what has been 984 * tested. In particular, unmapped mbufs have not 985 * been tested with UNIX-domain sockets. 986 * 987 * TLS frames always require unmapped mbufs. 988 */ 989 if ((mb_use_ext_pgs && pr->pr_protocol == IPPROTO_TCP) 990 #ifdef KERN_TLS 991 || tls != NULL 992 #endif 993 ) { 994 use_ext_pgs = true; 995 #ifdef KERN_TLS 996 if (tls != NULL) 997 max_pgs = num_pages(tls->params.max_frame_len); 998 else 999 #endif 1000 max_pgs = MBUF_PEXT_MAX_PGS; 1001 1002 /* Start at last index, to wrap on first use. */ 1003 ext_pgs_idx = max_pgs - 1; 1004 } 1005 1006 for (int i = 0; i < npages; i++) { 1007 /* 1008 * If a page wasn't grabbed successfully, then 1009 * trim the array. Can happen only with SF_NODISKIO. 1010 */ 1011 if (pa[i] == NULL) { 1012 SFSTAT_INC(sf_busy); 1013 fixspace(npages, i, off, &space); 1014 sfio->npages = i; 1015 softerr = EBUSY; 1016 break; 1017 } 1018 pga = pa[i]; 1019 if (pga == bogus_page) 1020 pga = vm_page_relookup(obj, sfio->pindex0 + i); 1021 1022 if (use_ext_pgs) { 1023 off_t xfs; 1024 1025 ext_pgs_idx++; 1026 if (ext_pgs_idx == max_pgs) { 1027 m0 = mb_alloc_ext_pgs(M_WAITOK, 1028 sendfile_free_mext_pg, M_RDONLY); 1029 1030 if (flags & SF_NOCACHE) { 1031 m0->m_ext.ext_flags |= 1032 EXT_FLAG_NOCACHE; 1033 1034 /* 1035 * See comment below regarding 1036 * ignoring SF_NOCACHE for the 1037 * last page. 1038 */ 1039 if ((npages - i <= max_pgs) && 1040 ((off + space) & PAGE_MASK) && 1041 (rem > space || rhpages > 0)) 1042 m0->m_ext.ext_flags |= 1043 EXT_FLAG_CACHE_LAST; 1044 } 1045 if (sfs != NULL) { 1046 m0->m_ext.ext_flags |= 1047 EXT_FLAG_SYNC; 1048 m0->m_ext.ext_arg1 = sfs; 1049 mtx_lock(&sfs->mtx); 1050 sfs->count++; 1051 mtx_unlock(&sfs->mtx); 1052 } 1053 ext_pgs_idx = 0; 1054 1055 /* Append to mbuf chain. */ 1056 if (mtail != NULL) 1057 mtail->m_next = m0; 1058 else 1059 m = m0; 1060 mtail = m0; 1061 m0->m_epg_1st_off = 1062 vmoff(i, off) & PAGE_MASK; 1063 } 1064 if (nios) { 1065 mtail->m_flags |= M_NOTREADY; 1066 m0->m_epg_nrdy++; 1067 } 1068 1069 m0->m_epg_pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pga); 1070 m0->m_epg_npgs++; 1071 xfs = xfsize(i, npages, off, space); 1072 m0->m_epg_last_len = xfs; 1073 MBUF_EXT_PGS_ASSERT_SANITY(m0); 1074 mtail->m_len += xfs; 1075 mtail->m_ext.ext_size += PAGE_SIZE; 1076 continue; 1077 } 1078 1079 /* 1080 * Get a sendfile buf. When allocating the 1081 * first buffer for mbuf chain, we usually 1082 * wait as long as necessary, but this wait 1083 * can be interrupted. For consequent 1084 * buffers, do not sleep, since several 1085 * threads might exhaust the buffers and then 1086 * deadlock. 1087 */ 1088 sf = sf_buf_alloc(pga, 1089 m != NULL ? SFB_NOWAIT : SFB_CATCH); 1090 if (sf == NULL) { 1091 SFSTAT_INC(sf_allocfail); 1092 sendfile_iowait(sfio, "sfnosf"); 1093 for (int j = i; j < npages; j++) { 1094 vm_page_unwire(pa[j], PQ_INACTIVE); 1095 pa[j] = NULL; 1096 } 1097 if (m == NULL) 1098 softerr = ENOBUFS; 1099 fixspace(npages, i, off, &space); 1100 sfio->npages = i; 1101 break; 1102 } 1103 1104 m0 = m_get(M_WAITOK, MT_DATA); 1105 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); 1106 m0->m_ext.ext_size = PAGE_SIZE; 1107 m0->m_ext.ext_arg1 = sf; 1108 m0->m_ext.ext_type = EXT_SFBUF; 1109 m0->m_ext.ext_flags = EXT_FLAG_EMBREF; 1110 m0->m_ext.ext_free = sendfile_free_mext; 1111 /* 1112 * SF_NOCACHE sets the page as being freed upon send. 1113 * However, we ignore it for the last page in 'space', 1114 * if the page is truncated, and we got more data to 1115 * send (rem > space), or if we have readahead 1116 * configured (rhpages > 0). 1117 */ 1118 if ((flags & SF_NOCACHE) && 1119 (i != npages - 1 || 1120 !((off + space) & PAGE_MASK) || 1121 !(rem > space || rhpages > 0))) 1122 m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; 1123 if (sfs != NULL) { 1124 m0->m_ext.ext_flags |= EXT_FLAG_SYNC; 1125 m0->m_ext.ext_arg2 = sfs; 1126 mtx_lock(&sfs->mtx); 1127 sfs->count++; 1128 mtx_unlock(&sfs->mtx); 1129 } 1130 m0->m_ext.ext_count = 1; 1131 m0->m_flags |= (M_EXT | M_RDONLY); 1132 if (nios) 1133 m0->m_flags |= M_NOTREADY; 1134 m0->m_data = (char *)sf_buf_kva(sf) + 1135 (vmoff(i, off) & PAGE_MASK); 1136 m0->m_len = xfsize(i, npages, off, space); 1137 1138 /* Append to mbuf chain. */ 1139 if (mtail != NULL) 1140 mtail->m_next = m0; 1141 else 1142 m = m0; 1143 mtail = m0; 1144 } 1145 1146 if (vp != NULL) 1147 VOP_UNLOCK(vp); 1148 1149 /* Keep track of bytes processed. */ 1150 off += space; 1151 rem -= space; 1152 1153 /* 1154 * Prepend header, if any. Save pointer to first mbuf 1155 * with a page. 1156 */ 1157 if (hdrlen) { 1158 prepend_header: 1159 m0 = mhtail->m_next = m; 1160 m = mh; 1161 mh = NULL; 1162 } else 1163 m0 = m; 1164 1165 if (m == NULL) { 1166 KASSERT(softerr, ("%s: m NULL, no error", __func__)); 1167 error = softerr; 1168 sendfile_iodone(sfio, NULL, 0, 0); 1169 goto done; 1170 } 1171 1172 /* Add the buffer chain to the socket buffer. */ 1173 KASSERT(m_length(m, NULL) == space + hdrlen, 1174 ("%s: mlen %u space %d hdrlen %d", 1175 __func__, m_length(m, NULL), space, hdrlen)); 1176 1177 #ifdef KERN_TLS 1178 if (tls != NULL) 1179 ktls_frame(m, tls, &tls_enq_cnt, TLS_RLTYPE_APP); 1180 #endif 1181 if (nios == 0) { 1182 /* 1183 * If sendfile_swapin() didn't initiate any I/Os, 1184 * which happens if all data is cached in VM, or if 1185 * the header consumed all socket buffer space and 1186 * sfio is NULL, then we can send data right now 1187 * without the PRUS_NOTREADY flag. 1188 */ 1189 if (sfio != NULL) 1190 sendfile_iodone(sfio, NULL, 0, 0); 1191 #ifdef KERN_TLS 1192 if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) { 1193 error = pr->pr_send(so, PRUS_NOTREADY, m, NULL, 1194 NULL, td); 1195 if (error != 0) { 1196 m_freem(m); 1197 } else { 1198 soref(so); 1199 ktls_enqueue(m, so, tls_enq_cnt); 1200 } 1201 } else 1202 #endif 1203 error = pr->pr_send(so, 0, m, NULL, NULL, td); 1204 } else { 1205 sfio->so = so; 1206 sfio->m = m0; 1207 soref(so); 1208 error = pr->pr_send(so, PRUS_NOTREADY, m, NULL, NULL, 1209 td); 1210 sendfile_iodone(sfio, NULL, 0, error); 1211 } 1212 #ifdef TCP_REQUEST_TRK 1213 if (so->so_proto->pr_protocol == IPPROTO_TCP) { 1214 /* log the sendfile call to the TCP log, if enabled */ 1215 tcp_log_sendfile(so, offset, nbytes, flags); 1216 } 1217 #endif 1218 m = NULL; 1219 if (error) 1220 goto done; 1221 sbytes += space + hdrlen; 1222 if (hdrlen) 1223 hdrlen = 0; 1224 if (softerr) { 1225 error = softerr; 1226 goto done; 1227 } 1228 } 1229 1230 /* 1231 * Send trailers. Wimp out and use writev(2). 1232 */ 1233 if (trl_uio != NULL) { 1234 SOCK_IO_SEND_UNLOCK(so); 1235 CURVNET_RESTORE(); 1236 error = kern_writev(td, sockfd, trl_uio); 1237 if (error == 0) 1238 sbytes += td->td_retval[0]; 1239 goto out; 1240 } 1241 1242 done: 1243 SOCK_IO_SEND_UNLOCK(so); 1244 CURVNET_RESTORE(); 1245 out: 1246 /* 1247 * If there was no error we have to clear td->td_retval[0] 1248 * because it may have been set by writev. 1249 */ 1250 if (error == 0) { 1251 td->td_retval[0] = 0; 1252 if (sbytes > 0 && vp != NULL) 1253 INOTIFY(vp, IN_ACCESS); 1254 } 1255 if (sent != NULL) { 1256 (*sent) = sbytes; 1257 } 1258 if (obj != NULL) 1259 vm_object_deallocate(obj); 1260 if (so) 1261 fdrop(sock_fp, td); 1262 if (m) 1263 m_freem(m); 1264 if (mh) 1265 m_freem(mh); 1266 1267 if (sfs != NULL) { 1268 mtx_lock(&sfs->mtx); 1269 if (sfs->count != 0) 1270 error = cv_wait_sig(&sfs->cv, &sfs->mtx); 1271 if (sfs->count == 0) { 1272 sendfile_sync_destroy(sfs); 1273 } else { 1274 sfs->waiting = false; 1275 mtx_unlock(&sfs->mtx); 1276 } 1277 } 1278 #ifdef KERN_TLS 1279 if (tls != NULL) 1280 ktls_free(tls); 1281 #endif 1282 if (error == ERESTART) 1283 error = EINTR; 1284 1285 return (error); 1286 } 1287 1288 static int 1289 sendfile(struct thread *td, struct sendfile_args *uap, int compat) 1290 { 1291 struct sf_hdtr hdtr; 1292 struct uio *hdr_uio, *trl_uio; 1293 struct file *fp; 1294 off_t sbytes; 1295 int error; 1296 1297 /* 1298 * File offset must be positive. If it goes beyond EOF 1299 * we send only the header/trailer and no payload data. 1300 */ 1301 if (uap->offset < 0) 1302 return (EINVAL); 1303 1304 sbytes = 0; 1305 hdr_uio = trl_uio = NULL; 1306 1307 if (uap->hdtr != NULL) { 1308 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); 1309 if (error != 0) 1310 goto out; 1311 if (hdtr.headers != NULL) { 1312 error = copyinuio(hdtr.headers, hdtr.hdr_cnt, 1313 &hdr_uio); 1314 if (error != 0) 1315 goto out; 1316 #ifdef COMPAT_FREEBSD4 1317 /* 1318 * In FreeBSD < 5.0 the nbytes to send also included 1319 * the header. If compat is specified subtract the 1320 * header size from nbytes. 1321 */ 1322 if (compat) { 1323 if (uap->nbytes > hdr_uio->uio_resid) 1324 uap->nbytes -= hdr_uio->uio_resid; 1325 else 1326 uap->nbytes = 0; 1327 } 1328 #endif 1329 } 1330 if (hdtr.trailers != NULL) { 1331 error = copyinuio(hdtr.trailers, hdtr.trl_cnt, 1332 &trl_uio); 1333 if (error != 0) 1334 goto out; 1335 } 1336 } 1337 1338 AUDIT_ARG_FD(uap->fd); 1339 1340 /* 1341 * sendfile(2) can start at any offset within a file so we require 1342 * CAP_READ+CAP_SEEK = CAP_PREAD. 1343 */ 1344 if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0) 1345 goto out; 1346 1347 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, 1348 uap->nbytes, &sbytes, uap->flags, td); 1349 fdrop(fp, td); 1350 1351 if (uap->sbytes != NULL) 1352 (void)copyout(&sbytes, uap->sbytes, sizeof(off_t)); 1353 1354 out: 1355 freeuio(hdr_uio); 1356 freeuio(trl_uio); 1357 return (error); 1358 } 1359 1360 /* 1361 * sendfile(2) 1362 * 1363 * int sendfile(int fd, int s, off_t offset, size_t nbytes, 1364 * struct sf_hdtr *hdtr, off_t *sbytes, int flags) 1365 * 1366 * Send a file specified by 'fd' and starting at 'offset' to a socket 1367 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == 1368 * 0. Optionally add a header and/or trailer to the socket output. If 1369 * specified, write the total number of bytes sent into *sbytes. 1370 */ 1371 int 1372 sys_sendfile(struct thread *td, struct sendfile_args *uap) 1373 { 1374 1375 return (sendfile(td, uap, 0)); 1376 } 1377 1378 #ifdef COMPAT_FREEBSD4 1379 int 1380 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) 1381 { 1382 struct sendfile_args args; 1383 1384 args.fd = uap->fd; 1385 args.s = uap->s; 1386 args.offset = uap->offset; 1387 args.nbytes = uap->nbytes; 1388 args.hdtr = uap->hdtr; 1389 args.sbytes = uap->sbytes; 1390 args.flags = uap->flags; 1391 1392 return (sendfile(td, &args, 1)); 1393 } 1394 #endif /* COMPAT_FREEBSD4 */ 1395