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