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_NEEDGIANT, 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_usrreqs->pru_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_usrreqs->pru_ready)(so, sfio->m, 400 sfio->npages); 401 402 SOCK_LOCK(so); 403 sorele(so); 404 #ifdef KERN_TLS 405 out_with_ref: 406 #endif 407 CURVNET_RESTORE(); 408 free(sfio, M_SENDFILE); 409 } 410 411 /* 412 * Iterate through pages vector and request paging for non-valid pages. 413 */ 414 static int 415 sendfile_swapin(vm_object_t obj, struct sf_io *sfio, int *nios, off_t off, 416 off_t len, int npages, int rhpages, int flags) 417 { 418 vm_page_t *pa; 419 int a, count, count1, grabbed, i, j, rv; 420 421 pa = sfio->pa; 422 *nios = 0; 423 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; 424 sfio->pindex0 = OFF_TO_IDX(off); 425 426 /* 427 * First grab all the pages and wire them. Note that we grab 428 * only required pages. Readahead pages are dealt with later. 429 */ 430 grabbed = vm_page_grab_pages_unlocked(obj, OFF_TO_IDX(off), 431 VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages); 432 if (grabbed < npages) { 433 for (int i = grabbed; i < npages; i++) 434 pa[i] = NULL; 435 npages = grabbed; 436 rhpages = 0; 437 } 438 439 for (i = 0; i < npages;) { 440 /* Skip valid pages. */ 441 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, 442 xfsize(i, npages, off, len))) { 443 vm_page_xunbusy(pa[i]); 444 SFSTAT_INC(sf_pages_valid); 445 i++; 446 continue; 447 } 448 449 /* 450 * Next page is invalid. Check if it belongs to pager. It 451 * may not be there, which is a regular situation for shmem 452 * pager. For vnode pager this happens only in case of 453 * a sparse file. 454 * 455 * Important feature of vm_pager_has_page() is the hint 456 * stored in 'a', about how many pages we can pagein after 457 * this page in a single I/O. 458 */ 459 VM_OBJECT_RLOCK(obj); 460 if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL, 461 &a)) { 462 VM_OBJECT_RUNLOCK(obj); 463 pmap_zero_page(pa[i]); 464 vm_page_valid(pa[i]); 465 MPASS(pa[i]->dirty == 0); 466 vm_page_xunbusy(pa[i]); 467 i++; 468 continue; 469 } 470 VM_OBJECT_RUNLOCK(obj); 471 472 /* 473 * We want to pagein as many pages as possible, limited only 474 * by the 'a' hint and actual request. 475 */ 476 count = min(a + 1, npages - i); 477 478 /* 479 * We should not pagein into a valid page because 480 * there might be still unfinished write tracked by 481 * e.g. a buffer, thus we substitute any valid pages 482 * with the bogus one. 483 * 484 * We must not leave around xbusy pages which are not 485 * part of the run passed to vm_pager_getpages(), 486 * otherwise pager might deadlock waiting for the busy 487 * status of the page, e.g. if it constitues the 488 * buffer needed to validate other page. 489 * 490 * First trim the end of the run consisting of the 491 * valid pages, then replace the rest of the valid 492 * with bogus. 493 */ 494 count1 = count; 495 for (j = i + count - 1; j > i; j--) { 496 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 497 xfsize(j, npages, off, len))) { 498 vm_page_xunbusy(pa[j]); 499 SFSTAT_INC(sf_pages_valid); 500 count--; 501 } else { 502 break; 503 } 504 } 505 506 /* 507 * The last page in the run pa[i + count - 1] is 508 * guaranteed to be invalid by the trim above, so it 509 * is not replaced with bogus, thus -1 in the loop end 510 * condition. 511 */ 512 MPASS(pa[i + count - 1]->valid != VM_PAGE_BITS_ALL); 513 for (j = i + 1; j < i + count - 1; j++) { 514 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 515 xfsize(j, npages, off, len))) { 516 vm_page_xunbusy(pa[j]); 517 SFSTAT_INC(sf_pages_valid); 518 SFSTAT_INC(sf_pages_bogus); 519 pa[j] = bogus_page; 520 } 521 } 522 523 refcount_acquire(&sfio->nios); 524 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, 525 i + count == npages ? &rhpages : NULL, 526 &sendfile_iodone, sfio); 527 if (__predict_false(rv != VM_PAGER_OK)) { 528 sendfile_iowait(sfio, "sferrio"); 529 530 /* 531 * Do remaining pages recovery before returning EIO. 532 * Pages from 0 to npages are wired. 533 * Pages from (i + count1) to npages are busied. 534 */ 535 for (j = 0; j < npages; j++) { 536 if (j >= i + count1) 537 vm_page_xunbusy(pa[j]); 538 KASSERT(pa[j] != NULL && pa[j] != bogus_page, 539 ("%s: page %p[%d] I/O recovery failure", 540 __func__, pa, j)); 541 vm_page_unwire(pa[j], PQ_INACTIVE); 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 struct vattr va; 567 vm_object_t obj; 568 struct vnode *vp; 569 struct shmfd *shmfd; 570 int error; 571 572 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 error = VOP_GETATTR(vp, &va, td->td_ucred); 590 if (error != 0) 591 goto out; 592 *obj_size = va.va_size; 593 obj = vp->v_object; 594 if (obj == NULL) { 595 error = EINVAL; 596 goto out; 597 } 598 } else if (fp->f_type == DTYPE_SHM) { 599 error = 0; 600 shmfd = fp->f_data; 601 obj = shmfd->shm_object; 602 *obj_size = shmfd->shm_size; 603 } else { 604 error = EINVAL; 605 goto out; 606 } 607 608 VM_OBJECT_WLOCK(obj); 609 if ((obj->flags & OBJ_DEAD) != 0) { 610 VM_OBJECT_WUNLOCK(obj); 611 error = EBADF; 612 goto out; 613 } 614 615 /* 616 * Temporarily increase the backing VM object's reference 617 * count so that a forced reclamation of its vnode does not 618 * immediately destroy it. 619 */ 620 vm_object_reference_locked(obj); 621 VM_OBJECT_WUNLOCK(obj); 622 *obj_res = obj; 623 *vp_res = vp; 624 *shmfd_res = shmfd; 625 626 out: 627 if (vp != NULL) 628 VOP_UNLOCK(vp); 629 return (error); 630 } 631 632 static int 633 sendfile_getsock(struct thread *td, int s, struct file **sock_fp, 634 struct socket **so) 635 { 636 int error; 637 638 *sock_fp = NULL; 639 *so = NULL; 640 641 /* 642 * The socket must be a stream socket and connected. 643 */ 644 error = getsock_cap(td, s, &cap_send_rights, 645 sock_fp, NULL, NULL); 646 if (error != 0) 647 return (error); 648 *so = (*sock_fp)->f_data; 649 if ((*so)->so_type != SOCK_STREAM) 650 return (EINVAL); 651 /* 652 * SCTP one-to-one style sockets currently don't work with 653 * sendfile(). So indicate EINVAL for now. 654 */ 655 if ((*so)->so_proto->pr_protocol == IPPROTO_SCTP) 656 return (EINVAL); 657 if (SOLISTENING(*so)) 658 return (ENOTCONN); 659 return (0); 660 } 661 662 int 663 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 664 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 665 struct thread *td) 666 { 667 struct file *sock_fp; 668 struct vnode *vp; 669 struct vm_object *obj; 670 vm_page_t pga; 671 struct socket *so; 672 #ifdef KERN_TLS 673 struct ktls_session *tls; 674 #endif 675 struct mbuf *m, *mh, *mhtail; 676 struct sf_buf *sf; 677 struct shmfd *shmfd; 678 struct sendfile_sync *sfs; 679 struct vattr va; 680 off_t off, sbytes, rem, obj_size; 681 int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr; 682 #ifdef KERN_TLS 683 int tls_enq_cnt; 684 #endif 685 bool use_ext_pgs; 686 687 obj = NULL; 688 so = NULL; 689 m = mh = NULL; 690 sfs = NULL; 691 #ifdef KERN_TLS 692 tls = NULL; 693 #endif 694 hdrlen = sbytes = 0; 695 softerr = 0; 696 use_ext_pgs = false; 697 698 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); 699 if (error != 0) 700 return (error); 701 702 error = sendfile_getsock(td, sockfd, &sock_fp, &so); 703 if (error != 0) 704 goto out; 705 706 #ifdef MAC 707 error = mac_socket_check_send(td->td_ucred, so); 708 if (error != 0) 709 goto out; 710 #endif 711 712 SFSTAT_INC(sf_syscalls); 713 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); 714 715 if (flags & SF_SYNC) { 716 sfs = malloc(sizeof(*sfs), M_SENDFILE, M_WAITOK | M_ZERO); 717 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); 718 cv_init(&sfs->cv, "sendfile"); 719 sfs->waiting = true; 720 } 721 722 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; 723 724 /* 725 * Protect against multiple writers to the socket. 726 * 727 * XXXRW: Historically this has assumed non-interruptibility, so now 728 * we implement that, but possibly shouldn't. 729 */ 730 (void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR); 731 #ifdef KERN_TLS 732 tls = ktls_hold(so->so_snd.sb_tls_info); 733 #endif 734 735 /* 736 * Loop through the pages of the file, starting with the requested 737 * offset. Get a file page (do I/O if necessary), map the file page 738 * into an sf_buf, attach an mbuf header to the sf_buf, and queue 739 * it on the socket. 740 * This is done in two loops. The inner loop turns as many pages 741 * as it can, up to available socket buffer space, without blocking 742 * into mbufs to have it bulk delivered into the socket send buffer. 743 * The outer loop checks the state and available space of the socket 744 * and takes care of the overall progress. 745 */ 746 for (off = offset; rem > 0; ) { 747 struct sf_io *sfio; 748 vm_page_t *pa; 749 struct mbuf *m0, *mtail; 750 int nios, space, npages, rhpages; 751 752 mtail = NULL; 753 /* 754 * Check the socket state for ongoing connection, 755 * no errors and space in socket buffer. 756 * If space is low allow for the remainder of the 757 * file to be processed if it fits the socket buffer. 758 * Otherwise block in waiting for sufficient space 759 * to proceed, or if the socket is nonblocking, return 760 * to userland with EAGAIN while reporting how far 761 * we've come. 762 * We wait until the socket buffer has significant free 763 * space to do bulk sends. This makes good use of file 764 * system read ahead and allows packet segmentation 765 * offloading hardware to take over lots of work. If 766 * we were not careful here we would send off only one 767 * sfbuf at a time. 768 */ 769 SOCKBUF_LOCK(&so->so_snd); 770 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) 771 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; 772 retry_space: 773 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 774 error = EPIPE; 775 SOCKBUF_UNLOCK(&so->so_snd); 776 goto done; 777 } else if (so->so_error) { 778 error = so->so_error; 779 so->so_error = 0; 780 SOCKBUF_UNLOCK(&so->so_snd); 781 goto done; 782 } 783 if ((so->so_state & SS_ISCONNECTED) == 0) { 784 SOCKBUF_UNLOCK(&so->so_snd); 785 error = ENOTCONN; 786 goto done; 787 } 788 789 space = sbspace(&so->so_snd); 790 if (space < rem && 791 (space <= 0 || 792 space < so->so_snd.sb_lowat)) { 793 if (so->so_state & SS_NBIO) { 794 SOCKBUF_UNLOCK(&so->so_snd); 795 error = EAGAIN; 796 goto done; 797 } 798 /* 799 * sbwait drops the lock while sleeping. 800 * When we loop back to retry_space the 801 * state may have changed and we retest 802 * for it. 803 */ 804 error = sbwait(&so->so_snd); 805 /* 806 * An error from sbwait usually indicates that we've 807 * been interrupted by a signal. If we've sent anything 808 * then return bytes sent, otherwise return the error. 809 */ 810 if (error != 0) { 811 SOCKBUF_UNLOCK(&so->so_snd); 812 goto done; 813 } 814 goto retry_space; 815 } 816 SOCKBUF_UNLOCK(&so->so_snd); 817 818 /* 819 * At the beginning of the first loop check if any headers 820 * are specified and copy them into mbufs. Reduce space in 821 * the socket buffer by the size of the header mbuf chain. 822 * Clear hdr_uio here and hdrlen at the end of the first loop. 823 */ 824 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { 825 hdr_uio->uio_td = td; 826 hdr_uio->uio_rw = UIO_WRITE; 827 #ifdef KERN_TLS 828 if (tls != NULL) 829 mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 830 tls->params.max_frame_len, M_EXTPG); 831 else 832 #endif 833 mh = m_uiotombuf(hdr_uio, M_WAITOK, 834 space, 0, 0); 835 hdrlen = m_length(mh, &mhtail); 836 space -= hdrlen; 837 /* 838 * If header consumed all the socket buffer space, 839 * don't waste CPU cycles and jump to the end. 840 */ 841 if (space == 0) { 842 sfio = NULL; 843 nios = 0; 844 goto prepend_header; 845 } 846 hdr_uio = NULL; 847 } 848 849 if (vp != NULL) { 850 error = vn_lock(vp, LK_SHARED); 851 if (error != 0) 852 goto done; 853 error = VOP_GETATTR(vp, &va, td->td_ucred); 854 if (error != 0 || off >= va.va_size) { 855 VOP_UNLOCK(vp); 856 goto done; 857 } 858 if (va.va_size != obj_size) { 859 obj_size = va.va_size; 860 rem = nbytes ? 861 omin(nbytes + offset, obj_size) : obj_size; 862 rem -= off; 863 } 864 } 865 866 if (space > rem) 867 space = rem; 868 else if (space > PAGE_SIZE) { 869 /* 870 * Use page boundaries when possible for large 871 * requests. 872 */ 873 if (off & PAGE_MASK) 874 space -= (PAGE_SIZE - (off & PAGE_MASK)); 875 space = trunc_page(space); 876 if (off & PAGE_MASK) 877 space += (PAGE_SIZE - (off & PAGE_MASK)); 878 } 879 880 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); 881 882 /* 883 * Calculate maximum allowed number of pages for readahead 884 * at this iteration. If SF_USER_READAHEAD was set, we don't 885 * do any heuristics and use exactly the value supplied by 886 * application. Otherwise, we allow readahead up to "rem". 887 * If application wants more, let it be, but there is no 888 * reason to go above MAXPHYS. Also check against "obj_size", 889 * since vm_pager_has_page() can hint beyond EOF. 890 */ 891 if (flags & SF_USER_READAHEAD) { 892 rhpages = SF_READAHEAD(flags); 893 } else { 894 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - 895 npages; 896 rhpages += SF_READAHEAD(flags); 897 } 898 rhpages = min(howmany(MAXPHYS, PAGE_SIZE), rhpages); 899 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - 900 npages, rhpages); 901 902 sfio = malloc(sizeof(struct sf_io) + 903 npages * sizeof(vm_page_t), M_SENDFILE, M_WAITOK); 904 refcount_init(&sfio->nios, 1); 905 sfio->obj = obj; 906 sfio->error = 0; 907 sfio->m = NULL; 908 #ifdef KERN_TLS 909 /* 910 * This doesn't use ktls_hold() because sfio->m will 911 * also have a reference on 'tls' that will be valid 912 * for all of sfio's lifetime. 913 */ 914 sfio->tls = tls; 915 #endif 916 vm_object_pip_add(obj, 1); 917 error = sendfile_swapin(obj, sfio, &nios, off, space, npages, 918 rhpages, flags); 919 if (error != 0) { 920 if (vp != NULL) 921 VOP_UNLOCK(vp); 922 sendfile_iodone(sfio, NULL, 0, error); 923 goto done; 924 } 925 926 /* 927 * Loop and construct maximum sized mbuf chain to be bulk 928 * dumped into socket buffer. 929 */ 930 pa = sfio->pa; 931 932 /* 933 * Use unmapped mbufs if enabled for TCP. Unmapped 934 * bufs are restricted to TCP as that is what has been 935 * tested. In particular, unmapped mbufs have not 936 * been tested with UNIX-domain sockets. 937 * 938 * TLS frames always require unmapped mbufs. 939 */ 940 if ((mb_use_ext_pgs && 941 so->so_proto->pr_protocol == IPPROTO_TCP) 942 #ifdef KERN_TLS 943 || tls != NULL 944 #endif 945 ) { 946 use_ext_pgs = true; 947 #ifdef KERN_TLS 948 if (tls != NULL) 949 max_pgs = num_pages(tls->params.max_frame_len); 950 else 951 #endif 952 max_pgs = MBUF_PEXT_MAX_PGS; 953 954 /* Start at last index, to wrap on first use. */ 955 ext_pgs_idx = max_pgs - 1; 956 } 957 958 for (int i = 0; i < npages; i++) { 959 /* 960 * If a page wasn't grabbed successfully, then 961 * trim the array. Can happen only with SF_NODISKIO. 962 */ 963 if (pa[i] == NULL) { 964 SFSTAT_INC(sf_busy); 965 fixspace(npages, i, off, &space); 966 npages = i; 967 softerr = EBUSY; 968 break; 969 } 970 pga = pa[i]; 971 if (pga == bogus_page) 972 pga = vm_page_relookup(obj, sfio->pindex0 + i); 973 974 if (use_ext_pgs) { 975 off_t xfs; 976 977 ext_pgs_idx++; 978 if (ext_pgs_idx == max_pgs) { 979 m0 = mb_alloc_ext_pgs(M_WAITOK, 980 sendfile_free_mext_pg); 981 982 if (flags & SF_NOCACHE) { 983 m0->m_ext.ext_flags |= 984 EXT_FLAG_NOCACHE; 985 986 /* 987 * See comment below regarding 988 * ignoring SF_NOCACHE for the 989 * last page. 990 */ 991 if ((npages - i <= max_pgs) && 992 ((off + space) & PAGE_MASK) && 993 (rem > space || rhpages > 0)) 994 m0->m_ext.ext_flags |= 995 EXT_FLAG_CACHE_LAST; 996 } 997 if (sfs != NULL) { 998 m0->m_ext.ext_flags |= 999 EXT_FLAG_SYNC; 1000 m0->m_ext.ext_arg1 = sfs; 1001 mtx_lock(&sfs->mtx); 1002 sfs->count++; 1003 mtx_unlock(&sfs->mtx); 1004 } 1005 ext_pgs_idx = 0; 1006 1007 /* Append to mbuf chain. */ 1008 if (mtail != NULL) 1009 mtail->m_next = m0; 1010 else 1011 m = m0; 1012 mtail = m0; 1013 m0->m_epg_1st_off = 1014 vmoff(i, off) & PAGE_MASK; 1015 } 1016 if (nios) { 1017 mtail->m_flags |= M_NOTREADY; 1018 m0->m_epg_nrdy++; 1019 } 1020 1021 m0->m_epg_pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pga); 1022 m0->m_epg_npgs++; 1023 xfs = xfsize(i, npages, off, space); 1024 m0->m_epg_last_len = xfs; 1025 MBUF_EXT_PGS_ASSERT_SANITY(m0); 1026 mtail->m_len += xfs; 1027 mtail->m_ext.ext_size += PAGE_SIZE; 1028 continue; 1029 } 1030 1031 /* 1032 * Get a sendfile buf. When allocating the 1033 * first buffer for mbuf chain, we usually 1034 * wait as long as necessary, but this wait 1035 * can be interrupted. For consequent 1036 * buffers, do not sleep, since several 1037 * threads might exhaust the buffers and then 1038 * deadlock. 1039 */ 1040 sf = sf_buf_alloc(pga, 1041 m != NULL ? SFB_NOWAIT : SFB_CATCH); 1042 if (sf == NULL) { 1043 SFSTAT_INC(sf_allocfail); 1044 sendfile_iowait(sfio, "sfnosf"); 1045 for (int j = i; j < npages; j++) 1046 vm_page_unwire(pa[j], PQ_INACTIVE); 1047 if (m == NULL) 1048 softerr = ENOBUFS; 1049 fixspace(npages, i, off, &space); 1050 npages = i; 1051 break; 1052 } 1053 1054 m0 = m_get(M_WAITOK, MT_DATA); 1055 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); 1056 m0->m_ext.ext_size = PAGE_SIZE; 1057 m0->m_ext.ext_arg1 = sf; 1058 m0->m_ext.ext_type = EXT_SFBUF; 1059 m0->m_ext.ext_flags = EXT_FLAG_EMBREF; 1060 m0->m_ext.ext_free = sendfile_free_mext; 1061 /* 1062 * SF_NOCACHE sets the page as being freed upon send. 1063 * However, we ignore it for the last page in 'space', 1064 * if the page is truncated, and we got more data to 1065 * send (rem > space), or if we have readahead 1066 * configured (rhpages > 0). 1067 */ 1068 if ((flags & SF_NOCACHE) && 1069 (i != npages - 1 || 1070 !((off + space) & PAGE_MASK) || 1071 !(rem > space || rhpages > 0))) 1072 m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; 1073 if (sfs != NULL) { 1074 m0->m_ext.ext_flags |= EXT_FLAG_SYNC; 1075 m0->m_ext.ext_arg2 = sfs; 1076 mtx_lock(&sfs->mtx); 1077 sfs->count++; 1078 mtx_unlock(&sfs->mtx); 1079 } 1080 m0->m_ext.ext_count = 1; 1081 m0->m_flags |= (M_EXT | M_RDONLY); 1082 if (nios) 1083 m0->m_flags |= M_NOTREADY; 1084 m0->m_data = (char *)sf_buf_kva(sf) + 1085 (vmoff(i, off) & PAGE_MASK); 1086 m0->m_len = xfsize(i, npages, off, space); 1087 1088 /* Append to mbuf chain. */ 1089 if (mtail != NULL) 1090 mtail->m_next = m0; 1091 else 1092 m = m0; 1093 mtail = m0; 1094 } 1095 1096 if (vp != NULL) 1097 VOP_UNLOCK(vp); 1098 1099 /* Keep track of bytes processed. */ 1100 off += space; 1101 rem -= space; 1102 1103 /* 1104 * Prepend header, if any. Save pointer to first mbuf 1105 * with a page. 1106 */ 1107 if (hdrlen) { 1108 prepend_header: 1109 m0 = mhtail->m_next = m; 1110 m = mh; 1111 mh = NULL; 1112 } else 1113 m0 = m; 1114 1115 if (m == NULL) { 1116 KASSERT(softerr, ("%s: m NULL, no error", __func__)); 1117 error = softerr; 1118 sendfile_iodone(sfio, NULL, 0, 0); 1119 goto done; 1120 } 1121 1122 /* Add the buffer chain to the socket buffer. */ 1123 KASSERT(m_length(m, NULL) == space + hdrlen, 1124 ("%s: mlen %u space %d hdrlen %d", 1125 __func__, m_length(m, NULL), space, hdrlen)); 1126 1127 CURVNET_SET(so->so_vnet); 1128 #ifdef KERN_TLS 1129 if (tls != NULL) 1130 ktls_frame(m, tls, &tls_enq_cnt, TLS_RLTYPE_APP); 1131 #endif 1132 if (nios == 0) { 1133 /* 1134 * If sendfile_swapin() didn't initiate any I/Os, 1135 * which happens if all data is cached in VM, or if 1136 * the header consumed all socket buffer space and 1137 * sfio is NULL, then we can send data right now 1138 * without the PRUS_NOTREADY flag. 1139 */ 1140 if (sfio != NULL) 1141 sendfile_iodone(sfio, NULL, 0, 0); 1142 #ifdef KERN_TLS 1143 if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) { 1144 error = (*so->so_proto->pr_usrreqs->pru_send) 1145 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1146 soref(so); 1147 ktls_enqueue(m, so, tls_enq_cnt); 1148 } else 1149 #endif 1150 error = (*so->so_proto->pr_usrreqs->pru_send) 1151 (so, 0, m, NULL, NULL, td); 1152 } else { 1153 sfio->so = so; 1154 sfio->m = m0; 1155 sfio->npages = npages; 1156 soref(so); 1157 error = (*so->so_proto->pr_usrreqs->pru_send) 1158 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1159 sendfile_iodone(sfio, NULL, 0, 0); 1160 } 1161 CURVNET_RESTORE(); 1162 1163 m = NULL; /* pru_send always consumes */ 1164 if (error) 1165 goto done; 1166 sbytes += space + hdrlen; 1167 if (hdrlen) 1168 hdrlen = 0; 1169 if (softerr) { 1170 error = softerr; 1171 goto done; 1172 } 1173 } 1174 1175 /* 1176 * Send trailers. Wimp out and use writev(2). 1177 */ 1178 if (trl_uio != NULL) { 1179 sbunlock(&so->so_snd); 1180 error = kern_writev(td, sockfd, trl_uio); 1181 if (error == 0) 1182 sbytes += td->td_retval[0]; 1183 goto out; 1184 } 1185 1186 done: 1187 sbunlock(&so->so_snd); 1188 out: 1189 /* 1190 * If there was no error we have to clear td->td_retval[0] 1191 * because it may have been set by writev. 1192 */ 1193 if (error == 0) { 1194 td->td_retval[0] = 0; 1195 } 1196 if (sent != NULL) { 1197 (*sent) = sbytes; 1198 } 1199 if (obj != NULL) 1200 vm_object_deallocate(obj); 1201 if (so) 1202 fdrop(sock_fp, td); 1203 if (m) 1204 m_freem(m); 1205 if (mh) 1206 m_freem(mh); 1207 1208 if (sfs != NULL) { 1209 mtx_lock(&sfs->mtx); 1210 if (sfs->count != 0) 1211 error = cv_wait_sig(&sfs->cv, &sfs->mtx); 1212 if (sfs->count == 0) { 1213 sendfile_sync_destroy(sfs); 1214 } else { 1215 sfs->waiting = false; 1216 mtx_unlock(&sfs->mtx); 1217 } 1218 } 1219 #ifdef KERN_TLS 1220 if (tls != NULL) 1221 ktls_free(tls); 1222 #endif 1223 1224 if (error == ERESTART) 1225 error = EINTR; 1226 1227 return (error); 1228 } 1229 1230 static int 1231 sendfile(struct thread *td, struct sendfile_args *uap, int compat) 1232 { 1233 struct sf_hdtr hdtr; 1234 struct uio *hdr_uio, *trl_uio; 1235 struct file *fp; 1236 off_t sbytes; 1237 int error; 1238 1239 /* 1240 * File offset must be positive. If it goes beyond EOF 1241 * we send only the header/trailer and no payload data. 1242 */ 1243 if (uap->offset < 0) 1244 return (EINVAL); 1245 1246 sbytes = 0; 1247 hdr_uio = trl_uio = NULL; 1248 1249 if (uap->hdtr != NULL) { 1250 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); 1251 if (error != 0) 1252 goto out; 1253 if (hdtr.headers != NULL) { 1254 error = copyinuio(hdtr.headers, hdtr.hdr_cnt, 1255 &hdr_uio); 1256 if (error != 0) 1257 goto out; 1258 #ifdef COMPAT_FREEBSD4 1259 /* 1260 * In FreeBSD < 5.0 the nbytes to send also included 1261 * the header. If compat is specified subtract the 1262 * header size from nbytes. 1263 */ 1264 if (compat) { 1265 if (uap->nbytes > hdr_uio->uio_resid) 1266 uap->nbytes -= hdr_uio->uio_resid; 1267 else 1268 uap->nbytes = 0; 1269 } 1270 #endif 1271 } 1272 if (hdtr.trailers != NULL) { 1273 error = copyinuio(hdtr.trailers, hdtr.trl_cnt, 1274 &trl_uio); 1275 if (error != 0) 1276 goto out; 1277 } 1278 } 1279 1280 AUDIT_ARG_FD(uap->fd); 1281 1282 /* 1283 * sendfile(2) can start at any offset within a file so we require 1284 * CAP_READ+CAP_SEEK = CAP_PREAD. 1285 */ 1286 if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0) 1287 goto out; 1288 1289 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, 1290 uap->nbytes, &sbytes, uap->flags, td); 1291 fdrop(fp, td); 1292 1293 if (uap->sbytes != NULL) 1294 copyout(&sbytes, uap->sbytes, sizeof(off_t)); 1295 1296 out: 1297 free(hdr_uio, M_IOV); 1298 free(trl_uio, M_IOV); 1299 return (error); 1300 } 1301 1302 /* 1303 * sendfile(2) 1304 * 1305 * int sendfile(int fd, int s, off_t offset, size_t nbytes, 1306 * struct sf_hdtr *hdtr, off_t *sbytes, int flags) 1307 * 1308 * Send a file specified by 'fd' and starting at 'offset' to a socket 1309 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == 1310 * 0. Optionally add a header and/or trailer to the socket output. If 1311 * specified, write the total number of bytes sent into *sbytes. 1312 */ 1313 int 1314 sys_sendfile(struct thread *td, struct sendfile_args *uap) 1315 { 1316 1317 return (sendfile(td, uap, 0)); 1318 } 1319 1320 #ifdef COMPAT_FREEBSD4 1321 int 1322 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) 1323 { 1324 struct sendfile_args args; 1325 1326 args.fd = uap->fd; 1327 args.s = uap->s; 1328 args.offset = uap->offset; 1329 args.nbytes = uap->nbytes; 1330 args.hdtr = uap->hdtr; 1331 args.sbytes = uap->sbytes; 1332 args.flags = uap->flags; 1333 1334 return (sendfile(td, &args, 1)); 1335 } 1336 #endif /* COMPAT_FREEBSD4 */ 1337