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 * 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. 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 <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_compat.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/capsicum.h> 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/sysproto.h> 42 #include <sys/malloc.h> 43 #include <sys/proc.h> 44 #include <sys/mman.h> 45 #include <sys/mount.h> 46 #include <sys/mbuf.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> 55 56 #include <net/vnet.h> 57 58 #include <security/audit/audit.h> 59 #include <security/mac/mac_framework.h> 60 61 #include <vm/vm.h> 62 #include <vm/vm_object.h> 63 #include <vm/vm_pager.h> 64 65 /* 66 * Structure describing a single sendfile(2) I/O, which may consist of 67 * several underlying pager I/Os. 68 * 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'. 72 * 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 77 * of the data. 78 */ 79 struct sf_io { 80 volatile u_int nios; 81 u_int error; 82 int npages; 83 struct file *sock_fp; 84 struct mbuf *m; 85 vm_page_t pa[]; 86 }; 87 88 /* 89 * Structure used to track requests with SF_SYNC flag. 90 */ 91 struct sendfile_sync { 92 struct mtx mtx; 93 struct cv cv; 94 unsigned count; 95 }; 96 97 counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; 98 99 static void 100 sfstat_init(const void *unused) 101 { 102 103 COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t), 104 M_WAITOK); 105 } 106 SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL); 107 108 static int 109 sfstat_sysctl(SYSCTL_HANDLER_ARGS) 110 { 111 struct sfstat s; 112 113 COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t)); 114 if (req->newptr) 115 COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t)); 116 return (SYSCTL_OUT(req, &s, sizeof(s))); 117 } 118 SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, CTLTYPE_OPAQUE | CTLFLAG_RW, 119 NULL, 0, sfstat_sysctl, "I", "sendfile statistics"); 120 121 /* 122 * Add more references to a vm_page + sf_buf + sendfile_sync. Called 123 * by mbuf(9) code to add extra references to a page. 124 */ 125 void 126 sf_ext_ref(void *arg1, void *arg2) 127 { 128 struct sf_buf *sf = arg1; 129 struct sendfile_sync *sfs = arg2; 130 vm_page_t pg = sf_buf_page(sf); 131 132 sf_buf_ref(sf); 133 134 vm_page_lock(pg); 135 vm_page_wire(pg); 136 vm_page_unlock(pg); 137 138 if (sfs != NULL) { 139 mtx_lock(&sfs->mtx); 140 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0")); 141 sfs->count++; 142 mtx_unlock(&sfs->mtx); 143 } 144 } 145 146 /* 147 * Detach mapped page and release resources back to the system. Called 148 * by mbuf(9) code when last reference to a page is freed. 149 */ 150 void 151 sf_ext_free(void *arg1, void *arg2) 152 { 153 struct sf_buf *sf = arg1; 154 struct sendfile_sync *sfs = arg2; 155 vm_page_t pg = sf_buf_page(sf); 156 157 sf_buf_free(sf); 158 159 vm_page_lock(pg); 160 /* 161 * Check for the object going away on us. This can 162 * happen since we don't hold a reference to it. 163 * If so, we're responsible for freeing the page. 164 */ 165 if (vm_page_unwire(pg, PQ_INACTIVE) && pg->object == NULL) 166 vm_page_free(pg); 167 vm_page_unlock(pg); 168 169 if (sfs != NULL) { 170 mtx_lock(&sfs->mtx); 171 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0")); 172 if (--sfs->count == 0) 173 cv_signal(&sfs->cv); 174 mtx_unlock(&sfs->mtx); 175 } 176 } 177 178 /* 179 * Same as above, but forces the page to be detached from the object 180 * and go into free pool. 181 */ 182 void 183 sf_ext_free_nocache(void *arg1, void *arg2) 184 { 185 struct sf_buf *sf = arg1; 186 struct sendfile_sync *sfs = arg2; 187 vm_page_t pg = sf_buf_page(sf); 188 189 sf_buf_free(sf); 190 191 vm_page_lock(pg); 192 if (vm_page_unwire(pg, PQ_NONE)) { 193 vm_object_t obj; 194 195 /* Try to free the page, but only if it is cheap to. */ 196 if ((obj = pg->object) == NULL) 197 vm_page_free(pg); 198 else if (!vm_page_xbusied(pg) && VM_OBJECT_TRYWLOCK(obj)) { 199 vm_page_free(pg); 200 VM_OBJECT_WUNLOCK(obj); 201 } else 202 vm_page_deactivate(pg); 203 } 204 vm_page_unlock(pg); 205 206 if (sfs != NULL) { 207 mtx_lock(&sfs->mtx); 208 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0")); 209 if (--sfs->count == 0) 210 cv_signal(&sfs->cv); 211 mtx_unlock(&sfs->mtx); 212 } 213 } 214 215 /* 216 * Helper function to calculate how much data to put into page i of n. 217 * Only first and last pages are special. 218 */ 219 static inline off_t 220 xfsize(int i, int n, off_t off, off_t len) 221 { 222 223 if (i == 0) 224 return (omin(PAGE_SIZE - (off & PAGE_MASK), len)); 225 226 if (i == n - 1 && ((off + len) & PAGE_MASK) > 0) 227 return ((off + len) & PAGE_MASK); 228 229 return (PAGE_SIZE); 230 } 231 232 /* 233 * Helper function to get offset within object for i page. 234 */ 235 static inline vm_offset_t 236 vmoff(int i, off_t off) 237 { 238 239 if (i == 0) 240 return ((vm_offset_t)off); 241 242 return (trunc_page(off + i * PAGE_SIZE)); 243 } 244 245 /* 246 * Helper function used when allocation of a page or sf_buf failed. 247 * Pretend as if we don't have enough space, subtract xfsize() of 248 * all pages that failed. 249 */ 250 static inline void 251 fixspace(int old, int new, off_t off, int *space) 252 { 253 254 KASSERT(old > new, ("%s: old %d new %d", __func__, old, new)); 255 256 /* Subtract last one. */ 257 *space -= xfsize(old - 1, old, off, *space); 258 old--; 259 260 if (new == old) 261 /* There was only one page. */ 262 return; 263 264 /* Subtract first one. */ 265 if (new == 0) { 266 *space -= xfsize(0, old, off, *space); 267 new++; 268 } 269 270 /* Rest of pages are full sized. */ 271 *space -= (old - new) * PAGE_SIZE; 272 273 KASSERT(*space >= 0, ("%s: space went backwards", __func__)); 274 } 275 276 /* 277 * I/O completion callback. 278 */ 279 static void 280 sendfile_iodone(void *arg, vm_page_t *pg, int count, int error) 281 { 282 struct sf_io *sfio = arg; 283 struct socket *so; 284 285 for (int i = 0; i < count; i++) 286 vm_page_xunbusy(pg[i]); 287 288 if (error) 289 sfio->error = error; 290 291 if (!refcount_release(&sfio->nios)) 292 return; 293 294 so = sfio->sock_fp->f_data; 295 296 if (sfio->error) { 297 struct mbuf *m; 298 299 /* 300 * I/O operation failed. The state of data in the socket 301 * is now inconsistent, and all what we can do is to tear 302 * it down. Protocol abort method would tear down protocol 303 * state, free all ready mbufs and detach not ready ones. 304 * We will free the mbufs corresponding to this I/O manually. 305 * 306 * The socket would be marked with EIO and made available 307 * for read, so that application receives EIO on next 308 * syscall and eventually closes the socket. 309 */ 310 so->so_proto->pr_usrreqs->pru_abort(so); 311 so->so_error = EIO; 312 313 m = sfio->m; 314 for (int i = 0; i < sfio->npages; i++) 315 m = m_free(m); 316 } else { 317 CURVNET_SET(so->so_vnet); 318 (void )(so->so_proto->pr_usrreqs->pru_ready)(so, sfio->m, 319 sfio->npages); 320 CURVNET_RESTORE(); 321 } 322 323 /* XXXGL: curthread */ 324 fdrop(sfio->sock_fp, curthread); 325 free(sfio, M_TEMP); 326 } 327 328 /* 329 * Iterate through pages vector and request paging for non-valid pages. 330 */ 331 static int 332 sendfile_swapin(vm_object_t obj, struct sf_io *sfio, off_t off, off_t len, 333 int npages, int rhpages, int flags) 334 { 335 vm_page_t *pa = sfio->pa; 336 int nios; 337 338 nios = 0; 339 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; 340 341 /* 342 * First grab all the pages and wire them. Note that we grab 343 * only required pages. Readahead pages are dealt with later. 344 */ 345 VM_OBJECT_WLOCK(obj); 346 for (int i = 0; i < npages; i++) { 347 pa[i] = vm_page_grab(obj, OFF_TO_IDX(vmoff(i, off)), 348 VM_ALLOC_WIRED | VM_ALLOC_NORMAL | flags); 349 if (pa[i] == NULL) { 350 npages = i; 351 rhpages = 0; 352 break; 353 } 354 } 355 356 for (int i = 0; i < npages;) { 357 int j, a, count, rv; 358 359 /* Skip valid pages. */ 360 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, 361 xfsize(i, npages, off, len))) { 362 vm_page_xunbusy(pa[i]); 363 SFSTAT_INC(sf_pages_valid); 364 i++; 365 continue; 366 } 367 368 /* 369 * Now 'i' points to first invalid page, iterate further 370 * to make 'j' point at first valid after a bunch of 371 * invalid ones. 372 */ 373 for (j = i + 1; j < npages; j++) 374 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 375 xfsize(j, npages, off, len))) { 376 SFSTAT_INC(sf_pages_valid); 377 break; 378 } 379 380 /* 381 * Now we got region of invalid pages between 'i' and 'j'. 382 * Check that they belong to pager. They may not be there, 383 * which is a regular situation for shmem pager. For vnode 384 * pager this happens only in case of sparse file. 385 * 386 * Important feature of vm_pager_has_page() is the hint 387 * stored in 'a', about how many pages we can pagein after 388 * this page in a single I/O. 389 */ 390 while (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), 391 NULL, &a) && i < j) { 392 pmap_zero_page(pa[i]); 393 pa[i]->valid = VM_PAGE_BITS_ALL; 394 pa[i]->dirty = 0; 395 vm_page_xunbusy(pa[i]); 396 i++; 397 } 398 if (i == j) 399 continue; 400 401 /* 402 * We want to pagein as many pages as possible, limited only 403 * by the 'a' hint and actual request. 404 * 405 * We should not pagein into already valid page, thus if 406 * 'j' didn't reach last page, trim by that page. 407 * 408 * When the pagein fulfils the request, also specify readahead. 409 */ 410 if (j < npages) 411 a = min(a, j - i - 1); 412 count = min(a + 1, npages - i); 413 414 refcount_acquire(&sfio->nios); 415 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, 416 i + count == npages ? &rhpages : NULL, 417 &sendfile_iodone, sfio); 418 KASSERT(rv == VM_PAGER_OK, ("%s: pager fail obj %p page %p", 419 __func__, obj, pa[i])); 420 421 SFSTAT_INC(sf_iocnt); 422 SFSTAT_ADD(sf_pages_read, count); 423 if (i + count == npages) 424 SFSTAT_ADD(sf_rhpages_read, rhpages); 425 426 #ifdef INVARIANTS 427 for (j = i; j < i + count && j < npages; j++) 428 KASSERT(pa[j] == vm_page_lookup(obj, 429 OFF_TO_IDX(vmoff(j, off))), 430 ("pa[j] %p lookup %p\n", pa[j], 431 vm_page_lookup(obj, OFF_TO_IDX(vmoff(j, off))))); 432 #endif 433 i += count; 434 nios++; 435 } 436 437 VM_OBJECT_WUNLOCK(obj); 438 439 if (nios == 0 && npages != 0) 440 SFSTAT_INC(sf_noiocnt); 441 442 return (nios); 443 } 444 445 static int 446 sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res, 447 struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size, 448 int *bsize) 449 { 450 struct vattr va; 451 vm_object_t obj; 452 struct vnode *vp; 453 struct shmfd *shmfd; 454 int error; 455 456 vp = *vp_res = NULL; 457 obj = NULL; 458 shmfd = *shmfd_res = NULL; 459 *bsize = 0; 460 461 /* 462 * The file descriptor must be a regular file and have a 463 * backing VM object. 464 */ 465 if (fp->f_type == DTYPE_VNODE) { 466 vp = fp->f_vnode; 467 vn_lock(vp, LK_SHARED | LK_RETRY); 468 if (vp->v_type != VREG) { 469 error = EINVAL; 470 goto out; 471 } 472 *bsize = vp->v_mount->mnt_stat.f_iosize; 473 error = VOP_GETATTR(vp, &va, td->td_ucred); 474 if (error != 0) 475 goto out; 476 *obj_size = va.va_size; 477 obj = vp->v_object; 478 if (obj == NULL) { 479 error = EINVAL; 480 goto out; 481 } 482 } else if (fp->f_type == DTYPE_SHM) { 483 error = 0; 484 shmfd = fp->f_data; 485 obj = shmfd->shm_object; 486 *obj_size = shmfd->shm_size; 487 } else { 488 error = EINVAL; 489 goto out; 490 } 491 492 VM_OBJECT_WLOCK(obj); 493 if ((obj->flags & OBJ_DEAD) != 0) { 494 VM_OBJECT_WUNLOCK(obj); 495 error = EBADF; 496 goto out; 497 } 498 499 /* 500 * Temporarily increase the backing VM object's reference 501 * count so that a forced reclamation of its vnode does not 502 * immediately destroy it. 503 */ 504 vm_object_reference_locked(obj); 505 VM_OBJECT_WUNLOCK(obj); 506 *obj_res = obj; 507 *vp_res = vp; 508 *shmfd_res = shmfd; 509 510 out: 511 if (vp != NULL) 512 VOP_UNLOCK(vp, 0); 513 return (error); 514 } 515 516 static int 517 sendfile_getsock(struct thread *td, int s, struct file **sock_fp, 518 struct socket **so) 519 { 520 cap_rights_t rights; 521 int error; 522 523 *sock_fp = NULL; 524 *so = NULL; 525 526 /* 527 * The socket must be a stream socket and connected. 528 */ 529 error = getsock_cap(td, s, cap_rights_init(&rights, CAP_SEND), 530 sock_fp, NULL); 531 if (error != 0) 532 return (error); 533 *so = (*sock_fp)->f_data; 534 if ((*so)->so_type != SOCK_STREAM) 535 return (EINVAL); 536 if (((*so)->so_state & SS_ISCONNECTED) == 0) 537 return (ENOTCONN); 538 return (0); 539 } 540 541 int 542 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 543 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 544 int kflags, struct thread *td) 545 { 546 struct file *sock_fp; 547 struct vnode *vp; 548 struct vm_object *obj; 549 struct socket *so; 550 struct mbuf *m, *mh, *mhtail; 551 struct sf_buf *sf; 552 struct shmfd *shmfd; 553 struct sendfile_sync *sfs; 554 struct vattr va; 555 off_t off, sbytes, rem, obj_size; 556 int error, softerr, bsize, hdrlen; 557 558 obj = NULL; 559 so = NULL; 560 m = mh = NULL; 561 sfs = NULL; 562 sbytes = 0; 563 softerr = 0; 564 565 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); 566 if (error != 0) 567 return (error); 568 569 error = sendfile_getsock(td, sockfd, &sock_fp, &so); 570 if (error != 0) 571 goto out; 572 573 #ifdef MAC 574 error = mac_socket_check_send(td->td_ucred, so); 575 if (error != 0) 576 goto out; 577 #endif 578 579 SFSTAT_INC(sf_syscalls); 580 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); 581 582 if (flags & SF_SYNC) { 583 sfs = malloc(sizeof *sfs, M_TEMP, M_WAITOK | M_ZERO); 584 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); 585 cv_init(&sfs->cv, "sendfile"); 586 } 587 588 /* If headers are specified copy them into mbufs. */ 589 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { 590 hdr_uio->uio_td = td; 591 hdr_uio->uio_rw = UIO_WRITE; 592 /* 593 * In FBSD < 5.0 the nbytes to send also included 594 * the header. If compat is specified subtract the 595 * header size from nbytes. 596 */ 597 if (kflags & SFK_COMPAT) { 598 if (nbytes > hdr_uio->uio_resid) 599 nbytes -= hdr_uio->uio_resid; 600 else 601 nbytes = 0; 602 } 603 mh = m_uiotombuf(hdr_uio, M_WAITOK, 0, 0, 0); 604 hdrlen = m_length(mh, &mhtail); 605 } else 606 hdrlen = 0; 607 608 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; 609 610 /* 611 * Protect against multiple writers to the socket. 612 * 613 * XXXRW: Historically this has assumed non-interruptibility, so now 614 * we implement that, but possibly shouldn't. 615 */ 616 (void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR); 617 618 /* 619 * Loop through the pages of the file, starting with the requested 620 * offset. Get a file page (do I/O if necessary), map the file page 621 * into an sf_buf, attach an mbuf header to the sf_buf, and queue 622 * it on the socket. 623 * This is done in two loops. The inner loop turns as many pages 624 * as it can, up to available socket buffer space, without blocking 625 * into mbufs to have it bulk delivered into the socket send buffer. 626 * The outer loop checks the state and available space of the socket 627 * and takes care of the overall progress. 628 */ 629 for (off = offset; rem > 0; ) { 630 struct sf_io *sfio; 631 vm_page_t *pa; 632 struct mbuf *mtail; 633 int nios, space, npages, rhpages; 634 635 mtail = NULL; 636 /* 637 * Check the socket state for ongoing connection, 638 * no errors and space in socket buffer. 639 * If space is low allow for the remainder of the 640 * file to be processed if it fits the socket buffer. 641 * Otherwise block in waiting for sufficient space 642 * to proceed, or if the socket is nonblocking, return 643 * to userland with EAGAIN while reporting how far 644 * we've come. 645 * We wait until the socket buffer has significant free 646 * space to do bulk sends. This makes good use of file 647 * system read ahead and allows packet segmentation 648 * offloading hardware to take over lots of work. If 649 * we were not careful here we would send off only one 650 * sfbuf at a time. 651 */ 652 SOCKBUF_LOCK(&so->so_snd); 653 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) 654 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; 655 retry_space: 656 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 657 error = EPIPE; 658 SOCKBUF_UNLOCK(&so->so_snd); 659 goto done; 660 } else if (so->so_error) { 661 error = so->so_error; 662 so->so_error = 0; 663 SOCKBUF_UNLOCK(&so->so_snd); 664 goto done; 665 } 666 space = sbspace(&so->so_snd); 667 if (space < rem && 668 (space <= 0 || 669 space < so->so_snd.sb_lowat)) { 670 if (so->so_state & SS_NBIO) { 671 SOCKBUF_UNLOCK(&so->so_snd); 672 error = EAGAIN; 673 goto done; 674 } 675 /* 676 * sbwait drops the lock while sleeping. 677 * When we loop back to retry_space the 678 * state may have changed and we retest 679 * for it. 680 */ 681 error = sbwait(&so->so_snd); 682 /* 683 * An error from sbwait usually indicates that we've 684 * been interrupted by a signal. If we've sent anything 685 * then return bytes sent, otherwise return the error. 686 */ 687 if (error != 0) { 688 SOCKBUF_UNLOCK(&so->so_snd); 689 goto done; 690 } 691 goto retry_space; 692 } 693 SOCKBUF_UNLOCK(&so->so_snd); 694 695 /* 696 * Reduce space in the socket buffer by the size of 697 * the header mbuf chain. 698 * hdrlen is set to 0 after the first loop. 699 */ 700 space -= hdrlen; 701 702 if (vp != NULL) { 703 error = vn_lock(vp, LK_SHARED); 704 if (error != 0) 705 goto done; 706 error = VOP_GETATTR(vp, &va, td->td_ucred); 707 if (error != 0 || off >= va.va_size) { 708 VOP_UNLOCK(vp, 0); 709 goto done; 710 } 711 if (va.va_size != obj_size) { 712 if (nbytes == 0) 713 rem += va.va_size - obj_size; 714 else if (offset + nbytes > va.va_size) 715 rem -= (offset + nbytes - va.va_size); 716 obj_size = va.va_size; 717 } 718 } 719 720 if (space > rem) 721 space = rem; 722 723 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); 724 725 /* 726 * Calculate maximum allowed number of pages for readahead 727 * at this iteration. First, we allow readahead up to "rem". 728 * If application wants more, let it be, but there is no 729 * reason to go above MAXPHYS. Also check against "obj_size", 730 * since vm_pager_has_page() can hint beyond EOF. 731 */ 732 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - npages; 733 rhpages += SF_READAHEAD(flags); 734 rhpages = min(howmany(MAXPHYS, PAGE_SIZE), rhpages); 735 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - 736 npages, rhpages); 737 738 sfio = malloc(sizeof(struct sf_io) + 739 npages * sizeof(vm_page_t), M_TEMP, M_WAITOK); 740 refcount_init(&sfio->nios, 1); 741 sfio->error = 0; 742 743 nios = sendfile_swapin(obj, sfio, off, space, npages, rhpages, 744 flags); 745 746 /* 747 * Loop and construct maximum sized mbuf chain to be bulk 748 * dumped into socket buffer. 749 */ 750 pa = sfio->pa; 751 for (int i = 0; i < npages; i++) { 752 struct mbuf *m0; 753 754 /* 755 * If a page wasn't grabbed successfully, then 756 * trim the array. Can happen only with SF_NODISKIO. 757 */ 758 if (pa[i] == NULL) { 759 SFSTAT_INC(sf_busy); 760 fixspace(npages, i, off, &space); 761 npages = i; 762 softerr = EBUSY; 763 break; 764 } 765 766 /* 767 * Get a sendfile buf. When allocating the 768 * first buffer for mbuf chain, we usually 769 * wait as long as necessary, but this wait 770 * can be interrupted. For consequent 771 * buffers, do not sleep, since several 772 * threads might exhaust the buffers and then 773 * deadlock. 774 */ 775 sf = sf_buf_alloc(pa[i], 776 m != NULL ? SFB_NOWAIT : SFB_CATCH); 777 if (sf == NULL) { 778 SFSTAT_INC(sf_allocfail); 779 for (int j = i; j < npages; j++) { 780 vm_page_lock(pa[j]); 781 vm_page_unwire(pa[j], PQ_INACTIVE); 782 vm_page_unlock(pa[j]); 783 } 784 if (m == NULL) 785 softerr = ENOBUFS; 786 fixspace(npages, i, off, &space); 787 npages = i; 788 break; 789 } 790 791 m0 = m_get(M_WAITOK, MT_DATA); 792 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); 793 m0->m_ext.ext_size = PAGE_SIZE; 794 m0->m_ext.ext_arg1 = sf; 795 m0->m_ext.ext_arg2 = sfs; 796 /* 797 * SF_NOCACHE sets the page as being freed upon send. 798 * However, we ignore it for the last page in 'space', 799 * if the page is truncated, and we got more data to 800 * send (rem > space), or if we have readahead 801 * configured (rhpages > 0). 802 */ 803 if ((flags & SF_NOCACHE) == 0 || 804 (i == npages - 1 && 805 ((off + space) & PAGE_MASK) && 806 (rem > space || rhpages > 0))) 807 m0->m_ext.ext_type = EXT_SFBUF; 808 else 809 m0->m_ext.ext_type = EXT_SFBUF_NOCACHE; 810 m0->m_ext.ext_flags = 0; 811 m0->m_flags |= (M_EXT | M_RDONLY); 812 if (nios) 813 m0->m_flags |= M_NOTREADY; 814 m0->m_data = (char *)sf_buf_kva(sf) + 815 (vmoff(i, off) & PAGE_MASK); 816 m0->m_len = xfsize(i, npages, off, space); 817 818 if (i == 0) 819 sfio->m = m0; 820 821 /* Append to mbuf chain. */ 822 if (mtail != NULL) 823 mtail->m_next = m0; 824 else 825 m = m0; 826 mtail = m0; 827 828 if (sfs != NULL) { 829 mtx_lock(&sfs->mtx); 830 sfs->count++; 831 mtx_unlock(&sfs->mtx); 832 } 833 } 834 835 if (vp != NULL) 836 VOP_UNLOCK(vp, 0); 837 838 /* Keep track of bytes processed. */ 839 off += space; 840 rem -= space; 841 842 /* Prepend header, if any. */ 843 if (hdrlen) { 844 mhtail->m_next = m; 845 m = mh; 846 mh = NULL; 847 } 848 849 if (m == NULL) { 850 KASSERT(softerr, ("%s: m NULL, no error", __func__)); 851 error = softerr; 852 free(sfio, M_TEMP); 853 goto done; 854 } 855 856 /* Add the buffer chain to the socket buffer. */ 857 KASSERT(m_length(m, NULL) == space + hdrlen, 858 ("%s: mlen %u space %d hdrlen %d", 859 __func__, m_length(m, NULL), space, hdrlen)); 860 861 CURVNET_SET(so->so_vnet); 862 if (nios == 0) { 863 /* 864 * If sendfile_swapin() didn't initiate any I/Os, 865 * which happens if all data is cached in VM, then 866 * we can send data right now without the 867 * PRUS_NOTREADY flag. 868 */ 869 free(sfio, M_TEMP); 870 error = (*so->so_proto->pr_usrreqs->pru_send) 871 (so, 0, m, NULL, NULL, td); 872 } else { 873 sfio->sock_fp = sock_fp; 874 sfio->npages = npages; 875 fhold(sock_fp); 876 error = (*so->so_proto->pr_usrreqs->pru_send) 877 (so, PRUS_NOTREADY, m, NULL, NULL, td); 878 sendfile_iodone(sfio, NULL, 0, 0); 879 } 880 CURVNET_RESTORE(); 881 882 m = NULL; /* pru_send always consumes */ 883 if (error) 884 goto done; 885 sbytes += space + hdrlen; 886 if (hdrlen) 887 hdrlen = 0; 888 if (softerr) { 889 error = softerr; 890 goto done; 891 } 892 } 893 894 /* 895 * Send trailers. Wimp out and use writev(2). 896 */ 897 if (trl_uio != NULL) { 898 sbunlock(&so->so_snd); 899 error = kern_writev(td, sockfd, trl_uio); 900 if (error == 0) 901 sbytes += td->td_retval[0]; 902 goto out; 903 } 904 905 done: 906 sbunlock(&so->so_snd); 907 out: 908 /* 909 * If there was no error we have to clear td->td_retval[0] 910 * because it may have been set by writev. 911 */ 912 if (error == 0) { 913 td->td_retval[0] = 0; 914 } 915 if (sent != NULL) { 916 (*sent) = sbytes; 917 } 918 if (obj != NULL) 919 vm_object_deallocate(obj); 920 if (so) 921 fdrop(sock_fp, td); 922 if (m) 923 m_freem(m); 924 if (mh) 925 m_freem(mh); 926 927 if (sfs != NULL) { 928 mtx_lock(&sfs->mtx); 929 if (sfs->count != 0) 930 cv_wait(&sfs->cv, &sfs->mtx); 931 KASSERT(sfs->count == 0, ("sendfile sync still busy")); 932 cv_destroy(&sfs->cv); 933 mtx_destroy(&sfs->mtx); 934 free(sfs, M_TEMP); 935 } 936 937 if (error == ERESTART) 938 error = EINTR; 939 940 return (error); 941 } 942 943 static int 944 sendfile(struct thread *td, struct sendfile_args *uap, int compat) 945 { 946 struct sf_hdtr hdtr; 947 struct uio *hdr_uio, *trl_uio; 948 struct file *fp; 949 cap_rights_t rights; 950 off_t sbytes; 951 int error; 952 953 /* 954 * File offset must be positive. If it goes beyond EOF 955 * we send only the header/trailer and no payload data. 956 */ 957 if (uap->offset < 0) 958 return (EINVAL); 959 960 hdr_uio = trl_uio = NULL; 961 962 if (uap->hdtr != NULL) { 963 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); 964 if (error != 0) 965 goto out; 966 if (hdtr.headers != NULL) { 967 error = copyinuio(hdtr.headers, hdtr.hdr_cnt, 968 &hdr_uio); 969 if (error != 0) 970 goto out; 971 } 972 if (hdtr.trailers != NULL) { 973 error = copyinuio(hdtr.trailers, hdtr.trl_cnt, 974 &trl_uio); 975 if (error != 0) 976 goto out; 977 } 978 } 979 980 AUDIT_ARG_FD(uap->fd); 981 982 /* 983 * sendfile(2) can start at any offset within a file so we require 984 * CAP_READ+CAP_SEEK = CAP_PREAD. 985 */ 986 if ((error = fget_read(td, uap->fd, 987 cap_rights_init(&rights, CAP_PREAD), &fp)) != 0) { 988 goto out; 989 } 990 991 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, 992 uap->nbytes, &sbytes, uap->flags, compat ? SFK_COMPAT : 0, td); 993 fdrop(fp, td); 994 995 if (uap->sbytes != NULL) 996 copyout(&sbytes, uap->sbytes, sizeof(off_t)); 997 998 out: 999 free(hdr_uio, M_IOV); 1000 free(trl_uio, M_IOV); 1001 return (error); 1002 } 1003 1004 /* 1005 * sendfile(2) 1006 * 1007 * int sendfile(int fd, int s, off_t offset, size_t nbytes, 1008 * struct sf_hdtr *hdtr, off_t *sbytes, int flags) 1009 * 1010 * Send a file specified by 'fd' and starting at 'offset' to a socket 1011 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == 1012 * 0. Optionally add a header and/or trailer to the socket output. If 1013 * specified, write the total number of bytes sent into *sbytes. 1014 */ 1015 int 1016 sys_sendfile(struct thread *td, struct sendfile_args *uap) 1017 { 1018 1019 return (sendfile(td, uap, 0)); 1020 } 1021 1022 #ifdef COMPAT_FREEBSD4 1023 int 1024 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) 1025 { 1026 struct sendfile_args args; 1027 1028 args.fd = uap->fd; 1029 args.s = uap->s; 1030 args.offset = uap->offset; 1031 args.nbytes = uap->nbytes; 1032 args.hdtr = uap->hdtr; 1033 args.sbytes = uap->sbytes; 1034 args.flags = uap->flags; 1035 1036 return (sendfile(td, &args, 1)); 1037 } 1038 #endif /* COMPAT_FREEBSD4 */ 1039