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 rhpages, int flags) 417 { 418 vm_page_t *pa; 419 int a, count, count1, grabbed, i, j, npages, rv; 420 421 pa = sfio->pa; 422 npages = sfio->npages; 423 *nios = 0; 424 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; 425 sfio->pindex0 = OFF_TO_IDX(off); 426 427 /* 428 * First grab all the pages and wire them. Note that we grab 429 * only required pages. Readahead pages are dealt with later. 430 */ 431 grabbed = vm_page_grab_pages_unlocked(obj, OFF_TO_IDX(off), 432 VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages); 433 if (grabbed < npages) { 434 for (int i = grabbed; i < npages; i++) 435 pa[i] = NULL; 436 npages = grabbed; 437 rhpages = 0; 438 } 439 440 for (i = 0; i < npages;) { 441 /* Skip valid pages. */ 442 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, 443 xfsize(i, npages, off, len))) { 444 vm_page_xunbusy(pa[i]); 445 SFSTAT_INC(sf_pages_valid); 446 i++; 447 continue; 448 } 449 450 /* 451 * Next page is invalid. Check if it belongs to pager. It 452 * may not be there, which is a regular situation for shmem 453 * pager. For vnode pager this happens only in case of 454 * a sparse file. 455 * 456 * Important feature of vm_pager_has_page() is the hint 457 * stored in 'a', about how many pages we can pagein after 458 * this page in a single I/O. 459 */ 460 VM_OBJECT_RLOCK(obj); 461 if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL, 462 &a)) { 463 VM_OBJECT_RUNLOCK(obj); 464 pmap_zero_page(pa[i]); 465 vm_page_valid(pa[i]); 466 MPASS(pa[i]->dirty == 0); 467 vm_page_xunbusy(pa[i]); 468 i++; 469 continue; 470 } 471 VM_OBJECT_RUNLOCK(obj); 472 473 /* 474 * We want to pagein as many pages as possible, limited only 475 * by the 'a' hint and actual request. 476 */ 477 count = min(a + 1, npages - i); 478 479 /* 480 * We should not pagein into a valid page because 481 * there might be still unfinished write tracked by 482 * e.g. a buffer, thus we substitute any valid pages 483 * with the bogus one. 484 * 485 * We must not leave around xbusy pages which are not 486 * part of the run passed to vm_pager_getpages(), 487 * otherwise pager might deadlock waiting for the busy 488 * status of the page, e.g. if it constitues the 489 * buffer needed to validate other page. 490 * 491 * First trim the end of the run consisting of the 492 * valid pages, then replace the rest of the valid 493 * with bogus. 494 */ 495 count1 = count; 496 for (j = i + count - 1; j > i; j--) { 497 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 498 xfsize(j, npages, off, len))) { 499 vm_page_xunbusy(pa[j]); 500 SFSTAT_INC(sf_pages_valid); 501 count--; 502 } else { 503 break; 504 } 505 } 506 507 /* 508 * The last page in the run pa[i + count - 1] is 509 * guaranteed to be invalid by the trim above, so it 510 * is not replaced with bogus, thus -1 in the loop end 511 * condition. 512 */ 513 MPASS(pa[i + count - 1]->valid != VM_PAGE_BITS_ALL); 514 for (j = i + 1; j < i + count - 1; j++) { 515 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 516 xfsize(j, npages, off, len))) { 517 vm_page_xunbusy(pa[j]); 518 SFSTAT_INC(sf_pages_valid); 519 SFSTAT_INC(sf_pages_bogus); 520 pa[j] = bogus_page; 521 } 522 } 523 524 refcount_acquire(&sfio->nios); 525 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, 526 i + count == npages ? &rhpages : NULL, 527 &sendfile_iodone, sfio); 528 if (__predict_false(rv != VM_PAGER_OK)) { 529 sendfile_iowait(sfio, "sferrio"); 530 531 /* 532 * Do remaining pages recovery before returning EIO. 533 * Pages from 0 to npages are wired. 534 * Pages from (i + count1) to npages are busied. 535 */ 536 for (j = 0; j < npages; j++) { 537 if (j >= i + count1) 538 vm_page_xunbusy(pa[j]); 539 KASSERT(pa[j] != NULL && pa[j] != bogus_page, 540 ("%s: page %p[%d] I/O recovery failure", 541 __func__, pa, j)); 542 vm_page_unwire(pa[j], PQ_INACTIVE); 543 pa[j] = NULL; 544 } 545 return (EIO); 546 } 547 548 SFSTAT_INC(sf_iocnt); 549 SFSTAT_ADD(sf_pages_read, count); 550 if (i + count == npages) 551 SFSTAT_ADD(sf_rhpages_read, rhpages); 552 553 i += count1; 554 (*nios)++; 555 } 556 557 if (*nios == 0 && npages != 0) 558 SFSTAT_INC(sf_noiocnt); 559 560 return (0); 561 } 562 563 static int 564 sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res, 565 struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size, 566 int *bsize) 567 { 568 struct vattr va; 569 vm_object_t obj; 570 struct vnode *vp; 571 struct shmfd *shmfd; 572 int error; 573 574 error = 0; 575 vp = *vp_res = NULL; 576 obj = NULL; 577 shmfd = *shmfd_res = NULL; 578 *bsize = 0; 579 580 /* 581 * The file descriptor must be a regular file and have a 582 * backing VM object. 583 */ 584 if (fp->f_type == DTYPE_VNODE) { 585 vp = fp->f_vnode; 586 vn_lock(vp, LK_SHARED | LK_RETRY); 587 if (vp->v_type != VREG) { 588 error = EINVAL; 589 goto out; 590 } 591 *bsize = vp->v_mount->mnt_stat.f_iosize; 592 obj = vp->v_object; 593 if (obj == NULL) { 594 error = EINVAL; 595 goto out; 596 } 597 598 /* 599 * Use the pager size when available to simplify synchronization 600 * with filesystems, which otherwise must atomically update both 601 * the vnode pager size and file size. 602 */ 603 if (obj->type == OBJT_VNODE) { 604 VM_OBJECT_RLOCK(obj); 605 *obj_size = obj->un_pager.vnp.vnp_size; 606 } else { 607 error = VOP_GETATTR(vp, &va, td->td_ucred); 608 if (error != 0) 609 goto out; 610 *obj_size = va.va_size; 611 VM_OBJECT_RLOCK(obj); 612 } 613 } else if (fp->f_type == DTYPE_SHM) { 614 shmfd = fp->f_data; 615 obj = shmfd->shm_object; 616 VM_OBJECT_RLOCK(obj); 617 *obj_size = shmfd->shm_size; 618 } else { 619 error = EINVAL; 620 goto out; 621 } 622 623 if ((obj->flags & OBJ_DEAD) != 0) { 624 VM_OBJECT_RUNLOCK(obj); 625 error = EBADF; 626 goto out; 627 } 628 629 /* 630 * Temporarily increase the backing VM object's reference 631 * count so that a forced reclamation of its vnode does not 632 * immediately destroy it. 633 */ 634 vm_object_reference_locked(obj); 635 VM_OBJECT_RUNLOCK(obj); 636 *obj_res = obj; 637 *vp_res = vp; 638 *shmfd_res = shmfd; 639 640 out: 641 if (vp != NULL) 642 VOP_UNLOCK(vp); 643 return (error); 644 } 645 646 static int 647 sendfile_getsock(struct thread *td, int s, struct file **sock_fp, 648 struct socket **so) 649 { 650 int error; 651 652 *sock_fp = NULL; 653 *so = NULL; 654 655 /* 656 * The socket must be a stream socket and connected. 657 */ 658 error = getsock_cap(td, s, &cap_send_rights, 659 sock_fp, NULL, NULL); 660 if (error != 0) 661 return (error); 662 *so = (*sock_fp)->f_data; 663 if ((*so)->so_type != SOCK_STREAM) 664 return (EINVAL); 665 /* 666 * SCTP one-to-one style sockets currently don't work with 667 * sendfile(). So indicate EINVAL for now. 668 */ 669 if ((*so)->so_proto->pr_protocol == IPPROTO_SCTP) 670 return (EINVAL); 671 if (SOLISTENING(*so)) 672 return (ENOTCONN); 673 return (0); 674 } 675 676 int 677 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 678 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 679 struct thread *td) 680 { 681 struct file *sock_fp; 682 struct vnode *vp; 683 struct vm_object *obj; 684 vm_page_t pga; 685 struct socket *so; 686 #ifdef KERN_TLS 687 struct ktls_session *tls; 688 #endif 689 struct mbuf *m, *mh, *mhtail; 690 struct sf_buf *sf; 691 struct shmfd *shmfd; 692 struct sendfile_sync *sfs; 693 struct vattr va; 694 off_t off, sbytes, rem, obj_size, nobj_size; 695 int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr; 696 #ifdef KERN_TLS 697 int tls_enq_cnt; 698 #endif 699 bool use_ext_pgs; 700 701 obj = NULL; 702 so = NULL; 703 m = mh = NULL; 704 sfs = NULL; 705 #ifdef KERN_TLS 706 tls = NULL; 707 #endif 708 hdrlen = sbytes = 0; 709 softerr = 0; 710 use_ext_pgs = false; 711 712 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); 713 if (error != 0) 714 return (error); 715 716 error = sendfile_getsock(td, sockfd, &sock_fp, &so); 717 if (error != 0) 718 goto out; 719 720 #ifdef MAC 721 error = mac_socket_check_send(td->td_ucred, so); 722 if (error != 0) 723 goto out; 724 #endif 725 726 SFSTAT_INC(sf_syscalls); 727 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); 728 729 if (flags & SF_SYNC) { 730 sfs = malloc(sizeof(*sfs), M_SENDFILE, M_WAITOK | M_ZERO); 731 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); 732 cv_init(&sfs->cv, "sendfile"); 733 sfs->waiting = true; 734 } 735 736 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; 737 738 /* 739 * Protect against multiple writers to the socket. 740 * 741 * XXXRW: Historically this has assumed non-interruptibility, so now 742 * we implement that, but possibly shouldn't. 743 */ 744 (void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR); 745 #ifdef KERN_TLS 746 tls = ktls_hold(so->so_snd.sb_tls_info); 747 #endif 748 749 /* 750 * Loop through the pages of the file, starting with the requested 751 * offset. Get a file page (do I/O if necessary), map the file page 752 * into an sf_buf, attach an mbuf header to the sf_buf, and queue 753 * it on the socket. 754 * This is done in two loops. The inner loop turns as many pages 755 * as it can, up to available socket buffer space, without blocking 756 * into mbufs to have it bulk delivered into the socket send buffer. 757 * The outer loop checks the state and available space of the socket 758 * and takes care of the overall progress. 759 */ 760 for (off = offset; rem > 0; ) { 761 struct sf_io *sfio; 762 vm_page_t *pa; 763 struct mbuf *m0, *mtail; 764 int nios, space, npages, rhpages; 765 766 mtail = NULL; 767 /* 768 * Check the socket state for ongoing connection, 769 * no errors and space in socket buffer. 770 * If space is low allow for the remainder of the 771 * file to be processed if it fits the socket buffer. 772 * Otherwise block in waiting for sufficient space 773 * to proceed, or if the socket is nonblocking, return 774 * to userland with EAGAIN while reporting how far 775 * we've come. 776 * We wait until the socket buffer has significant free 777 * space to do bulk sends. This makes good use of file 778 * system read ahead and allows packet segmentation 779 * offloading hardware to take over lots of work. If 780 * we were not careful here we would send off only one 781 * sfbuf at a time. 782 */ 783 SOCKBUF_LOCK(&so->so_snd); 784 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) 785 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; 786 retry_space: 787 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 788 error = EPIPE; 789 SOCKBUF_UNLOCK(&so->so_snd); 790 goto done; 791 } else if (so->so_error) { 792 error = so->so_error; 793 so->so_error = 0; 794 SOCKBUF_UNLOCK(&so->so_snd); 795 goto done; 796 } 797 if ((so->so_state & SS_ISCONNECTED) == 0) { 798 SOCKBUF_UNLOCK(&so->so_snd); 799 error = ENOTCONN; 800 goto done; 801 } 802 803 space = sbspace(&so->so_snd); 804 if (space < rem && 805 (space <= 0 || 806 space < so->so_snd.sb_lowat)) { 807 if (so->so_state & SS_NBIO) { 808 SOCKBUF_UNLOCK(&so->so_snd); 809 error = EAGAIN; 810 goto done; 811 } 812 /* 813 * sbwait drops the lock while sleeping. 814 * When we loop back to retry_space the 815 * state may have changed and we retest 816 * for it. 817 */ 818 error = sbwait(&so->so_snd); 819 /* 820 * An error from sbwait usually indicates that we've 821 * been interrupted by a signal. If we've sent anything 822 * then return bytes sent, otherwise return the error. 823 */ 824 if (error != 0) { 825 SOCKBUF_UNLOCK(&so->so_snd); 826 goto done; 827 } 828 goto retry_space; 829 } 830 SOCKBUF_UNLOCK(&so->so_snd); 831 832 /* 833 * At the beginning of the first loop check if any headers 834 * are specified and copy them into mbufs. Reduce space in 835 * the socket buffer by the size of the header mbuf chain. 836 * Clear hdr_uio here and hdrlen at the end of the first loop. 837 */ 838 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { 839 hdr_uio->uio_td = td; 840 hdr_uio->uio_rw = UIO_WRITE; 841 #ifdef KERN_TLS 842 if (tls != NULL) 843 mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 844 tls->params.max_frame_len, M_EXTPG); 845 else 846 #endif 847 mh = m_uiotombuf(hdr_uio, M_WAITOK, 848 space, 0, 0); 849 hdrlen = m_length(mh, &mhtail); 850 space -= hdrlen; 851 /* 852 * If header consumed all the socket buffer space, 853 * don't waste CPU cycles and jump to the end. 854 */ 855 if (space == 0) { 856 sfio = NULL; 857 nios = 0; 858 goto prepend_header; 859 } 860 hdr_uio = NULL; 861 } 862 863 if (vp != NULL) { 864 error = vn_lock(vp, LK_SHARED); 865 if (error != 0) 866 goto done; 867 868 /* 869 * Check to see if the file size has changed. 870 */ 871 if (obj->type == OBJT_VNODE) { 872 VM_OBJECT_RLOCK(obj); 873 nobj_size = obj->un_pager.vnp.vnp_size; 874 VM_OBJECT_RUNLOCK(obj); 875 } else { 876 error = VOP_GETATTR(vp, &va, td->td_ucred); 877 if (error != 0) { 878 VOP_UNLOCK(vp); 879 goto done; 880 } 881 nobj_size = va.va_size; 882 } 883 if (off >= nobj_size) { 884 VOP_UNLOCK(vp); 885 goto done; 886 } 887 if (nobj_size != obj_size) { 888 obj_size = nobj_size; 889 rem = nbytes ? omin(nbytes + offset, obj_size) : 890 obj_size; 891 rem -= off; 892 } 893 } 894 895 if (space > rem) 896 space = rem; 897 else if (space > PAGE_SIZE) { 898 /* 899 * Use page boundaries when possible for large 900 * requests. 901 */ 902 if (off & PAGE_MASK) 903 space -= (PAGE_SIZE - (off & PAGE_MASK)); 904 space = trunc_page(space); 905 if (off & PAGE_MASK) 906 space += (PAGE_SIZE - (off & PAGE_MASK)); 907 } 908 909 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); 910 911 /* 912 * Calculate maximum allowed number of pages for readahead 913 * at this iteration. If SF_USER_READAHEAD was set, we don't 914 * do any heuristics and use exactly the value supplied by 915 * application. Otherwise, we allow readahead up to "rem". 916 * If application wants more, let it be, but there is no 917 * reason to go above maxphys. Also check against "obj_size", 918 * since vm_pager_has_page() can hint beyond EOF. 919 */ 920 if (flags & SF_USER_READAHEAD) { 921 rhpages = SF_READAHEAD(flags); 922 } else { 923 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - 924 npages; 925 rhpages += SF_READAHEAD(flags); 926 } 927 rhpages = min(howmany(maxphys, PAGE_SIZE), rhpages); 928 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - 929 npages, rhpages); 930 931 sfio = malloc(sizeof(struct sf_io) + 932 npages * sizeof(vm_page_t), M_SENDFILE, M_WAITOK); 933 refcount_init(&sfio->nios, 1); 934 sfio->obj = obj; 935 sfio->error = 0; 936 sfio->m = NULL; 937 sfio->npages = npages; 938 #ifdef KERN_TLS 939 /* 940 * This doesn't use ktls_hold() because sfio->m will 941 * also have a reference on 'tls' that will be valid 942 * for all of sfio's lifetime. 943 */ 944 sfio->tls = tls; 945 #endif 946 vm_object_pip_add(obj, 1); 947 error = sendfile_swapin(obj, sfio, &nios, off, space, rhpages, 948 flags); 949 if (error != 0) { 950 if (vp != NULL) 951 VOP_UNLOCK(vp); 952 sendfile_iodone(sfio, NULL, 0, error); 953 goto done; 954 } 955 956 /* 957 * Loop and construct maximum sized mbuf chain to be bulk 958 * dumped into socket buffer. 959 */ 960 pa = sfio->pa; 961 962 /* 963 * Use unmapped mbufs if enabled for TCP. Unmapped 964 * bufs are restricted to TCP as that is what has been 965 * tested. In particular, unmapped mbufs have not 966 * been tested with UNIX-domain sockets. 967 * 968 * TLS frames always require unmapped mbufs. 969 */ 970 if ((mb_use_ext_pgs && 971 so->so_proto->pr_protocol == IPPROTO_TCP) 972 #ifdef KERN_TLS 973 || tls != NULL 974 #endif 975 ) { 976 use_ext_pgs = true; 977 #ifdef KERN_TLS 978 if (tls != NULL) 979 max_pgs = num_pages(tls->params.max_frame_len); 980 else 981 #endif 982 max_pgs = MBUF_PEXT_MAX_PGS; 983 984 /* Start at last index, to wrap on first use. */ 985 ext_pgs_idx = max_pgs - 1; 986 } 987 988 for (int i = 0; i < npages; i++) { 989 /* 990 * If a page wasn't grabbed successfully, then 991 * trim the array. Can happen only with SF_NODISKIO. 992 */ 993 if (pa[i] == NULL) { 994 SFSTAT_INC(sf_busy); 995 fixspace(npages, i, off, &space); 996 sfio->npages = i; 997 softerr = EBUSY; 998 break; 999 } 1000 pga = pa[i]; 1001 if (pga == bogus_page) 1002 pga = vm_page_relookup(obj, sfio->pindex0 + i); 1003 1004 if (use_ext_pgs) { 1005 off_t xfs; 1006 1007 ext_pgs_idx++; 1008 if (ext_pgs_idx == max_pgs) { 1009 m0 = mb_alloc_ext_pgs(M_WAITOK, 1010 sendfile_free_mext_pg); 1011 1012 if (flags & SF_NOCACHE) { 1013 m0->m_ext.ext_flags |= 1014 EXT_FLAG_NOCACHE; 1015 1016 /* 1017 * See comment below regarding 1018 * ignoring SF_NOCACHE for the 1019 * last page. 1020 */ 1021 if ((npages - i <= max_pgs) && 1022 ((off + space) & PAGE_MASK) && 1023 (rem > space || rhpages > 0)) 1024 m0->m_ext.ext_flags |= 1025 EXT_FLAG_CACHE_LAST; 1026 } 1027 if (sfs != NULL) { 1028 m0->m_ext.ext_flags |= 1029 EXT_FLAG_SYNC; 1030 m0->m_ext.ext_arg1 = sfs; 1031 mtx_lock(&sfs->mtx); 1032 sfs->count++; 1033 mtx_unlock(&sfs->mtx); 1034 } 1035 ext_pgs_idx = 0; 1036 1037 /* Append to mbuf chain. */ 1038 if (mtail != NULL) 1039 mtail->m_next = m0; 1040 else 1041 m = m0; 1042 mtail = m0; 1043 m0->m_epg_1st_off = 1044 vmoff(i, off) & PAGE_MASK; 1045 } 1046 if (nios) { 1047 mtail->m_flags |= M_NOTREADY; 1048 m0->m_epg_nrdy++; 1049 } 1050 1051 m0->m_epg_pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pga); 1052 m0->m_epg_npgs++; 1053 xfs = xfsize(i, npages, off, space); 1054 m0->m_epg_last_len = xfs; 1055 MBUF_EXT_PGS_ASSERT_SANITY(m0); 1056 mtail->m_len += xfs; 1057 mtail->m_ext.ext_size += PAGE_SIZE; 1058 continue; 1059 } 1060 1061 /* 1062 * Get a sendfile buf. When allocating the 1063 * first buffer for mbuf chain, we usually 1064 * wait as long as necessary, but this wait 1065 * can be interrupted. For consequent 1066 * buffers, do not sleep, since several 1067 * threads might exhaust the buffers and then 1068 * deadlock. 1069 */ 1070 sf = sf_buf_alloc(pga, 1071 m != NULL ? SFB_NOWAIT : SFB_CATCH); 1072 if (sf == NULL) { 1073 SFSTAT_INC(sf_allocfail); 1074 sendfile_iowait(sfio, "sfnosf"); 1075 for (int j = i; j < npages; j++) { 1076 vm_page_unwire(pa[j], PQ_INACTIVE); 1077 pa[j] = NULL; 1078 } 1079 if (m == NULL) 1080 softerr = ENOBUFS; 1081 fixspace(npages, i, off, &space); 1082 sfio->npages = i; 1083 break; 1084 } 1085 1086 m0 = m_get(M_WAITOK, MT_DATA); 1087 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); 1088 m0->m_ext.ext_size = PAGE_SIZE; 1089 m0->m_ext.ext_arg1 = sf; 1090 m0->m_ext.ext_type = EXT_SFBUF; 1091 m0->m_ext.ext_flags = EXT_FLAG_EMBREF; 1092 m0->m_ext.ext_free = sendfile_free_mext; 1093 /* 1094 * SF_NOCACHE sets the page as being freed upon send. 1095 * However, we ignore it for the last page in 'space', 1096 * if the page is truncated, and we got more data to 1097 * send (rem > space), or if we have readahead 1098 * configured (rhpages > 0). 1099 */ 1100 if ((flags & SF_NOCACHE) && 1101 (i != npages - 1 || 1102 !((off + space) & PAGE_MASK) || 1103 !(rem > space || rhpages > 0))) 1104 m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; 1105 if (sfs != NULL) { 1106 m0->m_ext.ext_flags |= EXT_FLAG_SYNC; 1107 m0->m_ext.ext_arg2 = sfs; 1108 mtx_lock(&sfs->mtx); 1109 sfs->count++; 1110 mtx_unlock(&sfs->mtx); 1111 } 1112 m0->m_ext.ext_count = 1; 1113 m0->m_flags |= (M_EXT | M_RDONLY); 1114 if (nios) 1115 m0->m_flags |= M_NOTREADY; 1116 m0->m_data = (char *)sf_buf_kva(sf) + 1117 (vmoff(i, off) & PAGE_MASK); 1118 m0->m_len = xfsize(i, npages, off, space); 1119 1120 /* Append to mbuf chain. */ 1121 if (mtail != NULL) 1122 mtail->m_next = m0; 1123 else 1124 m = m0; 1125 mtail = m0; 1126 } 1127 1128 if (vp != NULL) 1129 VOP_UNLOCK(vp); 1130 1131 /* Keep track of bytes processed. */ 1132 off += space; 1133 rem -= space; 1134 1135 /* 1136 * Prepend header, if any. Save pointer to first mbuf 1137 * with a page. 1138 */ 1139 if (hdrlen) { 1140 prepend_header: 1141 m0 = mhtail->m_next = m; 1142 m = mh; 1143 mh = NULL; 1144 } else 1145 m0 = m; 1146 1147 if (m == NULL) { 1148 KASSERT(softerr, ("%s: m NULL, no error", __func__)); 1149 error = softerr; 1150 sendfile_iodone(sfio, NULL, 0, 0); 1151 goto done; 1152 } 1153 1154 /* Add the buffer chain to the socket buffer. */ 1155 KASSERT(m_length(m, NULL) == space + hdrlen, 1156 ("%s: mlen %u space %d hdrlen %d", 1157 __func__, m_length(m, NULL), space, hdrlen)); 1158 1159 CURVNET_SET(so->so_vnet); 1160 #ifdef KERN_TLS 1161 if (tls != NULL) 1162 ktls_frame(m, tls, &tls_enq_cnt, TLS_RLTYPE_APP); 1163 #endif 1164 if (nios == 0) { 1165 /* 1166 * If sendfile_swapin() didn't initiate any I/Os, 1167 * which happens if all data is cached in VM, or if 1168 * the header consumed all socket buffer space and 1169 * sfio is NULL, then we can send data right now 1170 * without the PRUS_NOTREADY flag. 1171 */ 1172 if (sfio != NULL) 1173 sendfile_iodone(sfio, NULL, 0, 0); 1174 #ifdef KERN_TLS 1175 if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) { 1176 error = (*so->so_proto->pr_usrreqs->pru_send) 1177 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1178 if (error != 0) { 1179 m_freem(m); 1180 } else { 1181 soref(so); 1182 ktls_enqueue(m, so, tls_enq_cnt); 1183 } 1184 } else 1185 #endif 1186 error = (*so->so_proto->pr_usrreqs->pru_send) 1187 (so, 0, m, NULL, NULL, td); 1188 } else { 1189 sfio->so = so; 1190 sfio->m = m0; 1191 soref(so); 1192 error = (*so->so_proto->pr_usrreqs->pru_send) 1193 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1194 sendfile_iodone(sfio, NULL, 0, error); 1195 } 1196 CURVNET_RESTORE(); 1197 1198 m = NULL; 1199 if (error) 1200 goto done; 1201 sbytes += space + hdrlen; 1202 if (hdrlen) 1203 hdrlen = 0; 1204 if (softerr) { 1205 error = softerr; 1206 goto done; 1207 } 1208 } 1209 1210 /* 1211 * Send trailers. Wimp out and use writev(2). 1212 */ 1213 if (trl_uio != NULL) { 1214 sbunlock(&so->so_snd); 1215 error = kern_writev(td, sockfd, trl_uio); 1216 if (error == 0) 1217 sbytes += td->td_retval[0]; 1218 goto out; 1219 } 1220 1221 done: 1222 sbunlock(&so->so_snd); 1223 out: 1224 /* 1225 * If there was no error we have to clear td->td_retval[0] 1226 * because it may have been set by writev. 1227 */ 1228 if (error == 0) { 1229 td->td_retval[0] = 0; 1230 } 1231 if (sent != NULL) { 1232 (*sent) = sbytes; 1233 } 1234 if (obj != NULL) 1235 vm_object_deallocate(obj); 1236 if (so) 1237 fdrop(sock_fp, td); 1238 if (m) 1239 m_freem(m); 1240 if (mh) 1241 m_freem(mh); 1242 1243 if (sfs != NULL) { 1244 mtx_lock(&sfs->mtx); 1245 if (sfs->count != 0) 1246 error = cv_wait_sig(&sfs->cv, &sfs->mtx); 1247 if (sfs->count == 0) { 1248 sendfile_sync_destroy(sfs); 1249 } else { 1250 sfs->waiting = false; 1251 mtx_unlock(&sfs->mtx); 1252 } 1253 } 1254 #ifdef KERN_TLS 1255 if (tls != NULL) 1256 ktls_free(tls); 1257 #endif 1258 1259 if (error == ERESTART) 1260 error = EINTR; 1261 1262 return (error); 1263 } 1264 1265 static int 1266 sendfile(struct thread *td, struct sendfile_args *uap, int compat) 1267 { 1268 struct sf_hdtr hdtr; 1269 struct uio *hdr_uio, *trl_uio; 1270 struct file *fp; 1271 off_t sbytes; 1272 int error; 1273 1274 /* 1275 * File offset must be positive. If it goes beyond EOF 1276 * we send only the header/trailer and no payload data. 1277 */ 1278 if (uap->offset < 0) 1279 return (EINVAL); 1280 1281 sbytes = 0; 1282 hdr_uio = trl_uio = NULL; 1283 1284 if (uap->hdtr != NULL) { 1285 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); 1286 if (error != 0) 1287 goto out; 1288 if (hdtr.headers != NULL) { 1289 error = copyinuio(hdtr.headers, hdtr.hdr_cnt, 1290 &hdr_uio); 1291 if (error != 0) 1292 goto out; 1293 #ifdef COMPAT_FREEBSD4 1294 /* 1295 * In FreeBSD < 5.0 the nbytes to send also included 1296 * the header. If compat is specified subtract the 1297 * header size from nbytes. 1298 */ 1299 if (compat) { 1300 if (uap->nbytes > hdr_uio->uio_resid) 1301 uap->nbytes -= hdr_uio->uio_resid; 1302 else 1303 uap->nbytes = 0; 1304 } 1305 #endif 1306 } 1307 if (hdtr.trailers != NULL) { 1308 error = copyinuio(hdtr.trailers, hdtr.trl_cnt, 1309 &trl_uio); 1310 if (error != 0) 1311 goto out; 1312 } 1313 } 1314 1315 AUDIT_ARG_FD(uap->fd); 1316 1317 /* 1318 * sendfile(2) can start at any offset within a file so we require 1319 * CAP_READ+CAP_SEEK = CAP_PREAD. 1320 */ 1321 if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0) 1322 goto out; 1323 1324 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, 1325 uap->nbytes, &sbytes, uap->flags, td); 1326 fdrop(fp, td); 1327 1328 if (uap->sbytes != NULL) 1329 copyout(&sbytes, uap->sbytes, sizeof(off_t)); 1330 1331 out: 1332 free(hdr_uio, M_IOV); 1333 free(trl_uio, M_IOV); 1334 return (error); 1335 } 1336 1337 /* 1338 * sendfile(2) 1339 * 1340 * int sendfile(int fd, int s, off_t offset, size_t nbytes, 1341 * struct sf_hdtr *hdtr, off_t *sbytes, int flags) 1342 * 1343 * Send a file specified by 'fd' and starting at 'offset' to a socket 1344 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == 1345 * 0. Optionally add a header and/or trailer to the socket output. If 1346 * specified, write the total number of bytes sent into *sbytes. 1347 */ 1348 int 1349 sys_sendfile(struct thread *td, struct sendfile_args *uap) 1350 { 1351 1352 return (sendfile(td, uap, 0)); 1353 } 1354 1355 #ifdef COMPAT_FREEBSD4 1356 int 1357 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) 1358 { 1359 struct sendfile_args args; 1360 1361 args.fd = uap->fd; 1362 args.s = uap->s; 1363 args.offset = uap->offset; 1364 args.nbytes = uap->nbytes; 1365 args.hdtr = uap->hdtr; 1366 args.sbytes = uap->sbytes; 1367 args.flags = uap->flags; 1368 1369 return (sendfile(td, &args, 1)); 1370 } 1371 #endif /* COMPAT_FREEBSD4 */ 1372