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 <netinet/in.h> 40 #include <sys/lock.h> 41 #include <sys/ktls.h> 42 #include <sys/mutex.h> 43 #include <sys/sysproto.h> 44 #include <sys/malloc.h> 45 #include <sys/proc.h> 46 #include <sys/mman.h> 47 #include <sys/mount.h> 48 #include <sys/mbuf.h> 49 #include <sys/protosw.h> 50 #include <sys/rwlock.h> 51 #include <sys/sf_buf.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/syscallsubr.h> 55 #include <sys/sysctl.h> 56 #include <sys/vnode.h> 57 58 #include <net/vnet.h> 59 60 #include <security/audit/audit.h> 61 #include <security/mac/mac_framework.h> 62 63 #include <vm/vm.h> 64 #include <vm/vm_object.h> 65 #include <vm/vm_pager.h> 66 67 #define EXT_FLAG_SYNC EXT_FLAG_VENDOR1 68 #define EXT_FLAG_NOCACHE EXT_FLAG_VENDOR2 69 #define EXT_FLAG_CACHE_LAST EXT_FLAG_VENDOR3 70 71 /* 72 * Structure describing a single sendfile(2) I/O, which may consist of 73 * several underlying pager I/Os. 74 * 75 * The syscall context allocates the structure and initializes 'nios' 76 * to 1. As sendfile_swapin() runs through pages and starts asynchronous 77 * paging operations, it increments 'nios'. 78 * 79 * Every I/O completion calls sendfile_iodone(), which decrements the 'nios', 80 * and the syscall also calls sendfile_iodone() after allocating all mbufs, 81 * linking them and sending to socket. Whoever reaches zero 'nios' is 82 * responsible to * call pru_ready on the socket, to notify it of readyness 83 * of the data. 84 */ 85 struct sf_io { 86 volatile u_int nios; 87 u_int error; 88 int npages; 89 struct socket *so; 90 struct mbuf *m; 91 #ifdef KERN_TLS 92 struct ktls_session *tls; 93 #endif 94 vm_page_t pa[]; 95 }; 96 97 /* 98 * Structure used to track requests with SF_SYNC flag. 99 */ 100 struct sendfile_sync { 101 struct mtx mtx; 102 struct cv cv; 103 unsigned count; 104 }; 105 106 counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; 107 108 static void 109 sfstat_init(const void *unused) 110 { 111 112 COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t), 113 M_WAITOK); 114 } 115 SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL); 116 117 static int 118 sfstat_sysctl(SYSCTL_HANDLER_ARGS) 119 { 120 struct sfstat s; 121 122 COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t)); 123 if (req->newptr) 124 COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t)); 125 return (SYSCTL_OUT(req, &s, sizeof(s))); 126 } 127 SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, CTLTYPE_OPAQUE | CTLFLAG_RW, 128 NULL, 0, sfstat_sysctl, "I", "sendfile statistics"); 129 130 static void 131 sendfile_free_mext(struct mbuf *m) 132 { 133 struct sf_buf *sf; 134 vm_page_t pg; 135 int flags; 136 137 KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_SFBUF, 138 ("%s: m %p !M_EXT or !EXT_SFBUF", __func__, m)); 139 140 sf = m->m_ext.ext_arg1; 141 pg = sf_buf_page(sf); 142 flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; 143 144 sf_buf_free(sf); 145 vm_page_release(pg, flags); 146 147 if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { 148 struct sendfile_sync *sfs = m->m_ext.ext_arg2; 149 150 mtx_lock(&sfs->mtx); 151 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0")); 152 if (--sfs->count == 0) 153 cv_signal(&sfs->cv); 154 mtx_unlock(&sfs->mtx); 155 } 156 } 157 158 static void 159 sendfile_free_mext_pg(struct mbuf *m) 160 { 161 struct mbuf_ext_pgs *ext_pgs; 162 vm_page_t pg; 163 int flags, i; 164 bool cache_last; 165 166 KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_PGS, 167 ("%s: m %p !M_EXT or !EXT_PGS", __func__, m)); 168 169 cache_last = m->m_ext.ext_flags & EXT_FLAG_CACHE_LAST; 170 ext_pgs = m->m_ext.ext_pgs; 171 flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; 172 173 for (i = 0; i < ext_pgs->npgs; i++) { 174 if (cache_last && i == ext_pgs->npgs - 1) 175 flags = 0; 176 pg = PHYS_TO_VM_PAGE(ext_pgs->pa[i]); 177 vm_page_release(pg, flags); 178 } 179 180 if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { 181 struct sendfile_sync *sfs = m->m_ext.ext_arg2; 182 183 mtx_lock(&sfs->mtx); 184 KASSERT(sfs->count > 0, ("Sendfile sync botchup count == 0")); 185 if (--sfs->count == 0) 186 cv_signal(&sfs->cv); 187 mtx_unlock(&sfs->mtx); 188 } 189 } 190 191 /* 192 * Helper function to calculate how much data to put into page i of n. 193 * Only first and last pages are special. 194 */ 195 static inline off_t 196 xfsize(int i, int n, off_t off, off_t len) 197 { 198 199 if (i == 0) 200 return (omin(PAGE_SIZE - (off & PAGE_MASK), len)); 201 202 if (i == n - 1 && ((off + len) & PAGE_MASK) > 0) 203 return ((off + len) & PAGE_MASK); 204 205 return (PAGE_SIZE); 206 } 207 208 /* 209 * Helper function to get offset within object for i page. 210 */ 211 static inline vm_ooffset_t 212 vmoff(int i, off_t off) 213 { 214 215 if (i == 0) 216 return ((vm_ooffset_t)off); 217 218 return (trunc_page(off + i * PAGE_SIZE)); 219 } 220 221 /* 222 * Helper function used when allocation of a page or sf_buf failed. 223 * Pretend as if we don't have enough space, subtract xfsize() of 224 * all pages that failed. 225 */ 226 static inline void 227 fixspace(int old, int new, off_t off, int *space) 228 { 229 230 KASSERT(old > new, ("%s: old %d new %d", __func__, old, new)); 231 232 /* Subtract last one. */ 233 *space -= xfsize(old - 1, old, off, *space); 234 old--; 235 236 if (new == old) 237 /* There was only one page. */ 238 return; 239 240 /* Subtract first one. */ 241 if (new == 0) { 242 *space -= xfsize(0, old, off, *space); 243 new++; 244 } 245 246 /* Rest of pages are full sized. */ 247 *space -= (old - new) * PAGE_SIZE; 248 249 KASSERT(*space >= 0, ("%s: space went backwards", __func__)); 250 } 251 252 /* 253 * I/O completion callback. 254 */ 255 static void 256 sendfile_iodone(void *arg, vm_page_t *pg, int count, int error) 257 { 258 struct sf_io *sfio = arg; 259 struct socket *so = sfio->so; 260 261 for (int i = 0; i < count; i++) 262 if (pg[i] != bogus_page) 263 vm_page_xunbusy(pg[i]); 264 265 if (error) 266 sfio->error = error; 267 268 if (!refcount_release(&sfio->nios)) 269 return; 270 271 #if defined(KERN_TLS) && defined(INVARIANTS) 272 if ((sfio->m->m_flags & M_EXT) != 0 && 273 sfio->m->m_ext.ext_type == EXT_PGS) 274 KASSERT(sfio->tls == sfio->m->m_ext.ext_pgs->tls, 275 ("TLS session mismatch")); 276 else 277 KASSERT(sfio->tls == NULL, 278 ("non-ext_pgs mbuf with TLS session")); 279 #endif 280 CURVNET_SET(so->so_vnet); 281 if (sfio->error) { 282 /* 283 * I/O operation failed. The state of data in the socket 284 * is now inconsistent, and all what we can do is to tear 285 * it down. Protocol abort method would tear down protocol 286 * state, free all ready mbufs and detach not ready ones. 287 * We will free the mbufs corresponding to this I/O manually. 288 * 289 * The socket would be marked with EIO and made available 290 * for read, so that application receives EIO on next 291 * syscall and eventually closes the socket. 292 */ 293 so->so_proto->pr_usrreqs->pru_abort(so); 294 so->so_error = EIO; 295 296 mb_free_notready(sfio->m, sfio->npages); 297 #ifdef KERN_TLS 298 } else if (sfio->tls != NULL && sfio->tls->sw_encrypt != NULL) { 299 /* 300 * I/O operation is complete, but we still need to 301 * encrypt. We cannot do this in the interrupt thread 302 * of the disk controller, so forward the mbufs to a 303 * different thread. 304 * 305 * Donate the socket reference from sfio to rather 306 * than explicitly invoking soref(). 307 */ 308 ktls_enqueue(sfio->m, so, sfio->npages); 309 goto out_with_ref; 310 #endif 311 } else 312 (void)(so->so_proto->pr_usrreqs->pru_ready)(so, sfio->m, 313 sfio->npages); 314 315 SOCK_LOCK(so); 316 sorele(so); 317 #ifdef KERN_TLS 318 out_with_ref: 319 #endif 320 CURVNET_RESTORE(); 321 free(sfio, M_TEMP); 322 } 323 324 /* 325 * Iterate through pages vector and request paging for non-valid pages. 326 */ 327 static int 328 sendfile_swapin(vm_object_t obj, struct sf_io *sfio, int *nios, off_t off, 329 off_t len, int npages, int rhpages, int flags) 330 { 331 vm_page_t *pa = sfio->pa; 332 int grabbed; 333 334 *nios = 0; 335 flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; 336 337 /* 338 * First grab all the pages and wire them. Note that we grab 339 * only required pages. Readahead pages are dealt with later. 340 */ 341 VM_OBJECT_WLOCK(obj); 342 343 grabbed = vm_page_grab_pages(obj, OFF_TO_IDX(off), 344 VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages); 345 if (grabbed < npages) { 346 for (int i = grabbed; i < npages; i++) 347 pa[i] = NULL; 348 npages = grabbed; 349 rhpages = 0; 350 } 351 352 for (int i = 0; i < npages;) { 353 int j, a, count, rv; 354 355 /* Skip valid pages. */ 356 if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, 357 xfsize(i, npages, off, len))) { 358 vm_page_xunbusy(pa[i]); 359 SFSTAT_INC(sf_pages_valid); 360 i++; 361 continue; 362 } 363 364 /* 365 * Next page is invalid. Check if it belongs to pager. It 366 * may not be there, which is a regular situation for shmem 367 * pager. For vnode pager this happens only in case of 368 * a sparse file. 369 * 370 * Important feature of vm_pager_has_page() is the hint 371 * stored in 'a', about how many pages we can pagein after 372 * this page in a single I/O. 373 */ 374 if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL, 375 &a)) { 376 pmap_zero_page(pa[i]); 377 pa[i]->valid = VM_PAGE_BITS_ALL; 378 MPASS(pa[i]->dirty == 0); 379 vm_page_xunbusy(pa[i]); 380 i++; 381 continue; 382 } 383 384 /* 385 * We want to pagein as many pages as possible, limited only 386 * by the 'a' hint and actual request. 387 */ 388 count = min(a + 1, npages - i); 389 390 /* 391 * We should not pagein into a valid page, thus we first trim 392 * any valid pages off the end of request, and substitute 393 * to bogus_page those, that are in the middle. 394 */ 395 for (j = i + count - 1; j > i; j--) { 396 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 397 xfsize(j, npages, off, len))) { 398 count--; 399 rhpages = 0; 400 } else 401 break; 402 } 403 for (j = i + 1; j < i + count - 1; j++) 404 if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, 405 xfsize(j, npages, off, len))) { 406 vm_page_xunbusy(pa[j]); 407 SFSTAT_INC(sf_pages_valid); 408 SFSTAT_INC(sf_pages_bogus); 409 pa[j] = bogus_page; 410 } 411 412 refcount_acquire(&sfio->nios); 413 rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, 414 i + count == npages ? &rhpages : NULL, 415 &sendfile_iodone, sfio); 416 if (rv != VM_PAGER_OK) { 417 for (j = i; j < i + count; j++) { 418 if (pa[j] != bogus_page) 419 vm_page_unwire(pa[j], PQ_INACTIVE); 420 } 421 VM_OBJECT_WUNLOCK(obj); 422 return (EIO); 423 } 424 425 SFSTAT_INC(sf_iocnt); 426 SFSTAT_ADD(sf_pages_read, count); 427 if (i + count == npages) 428 SFSTAT_ADD(sf_rhpages_read, rhpages); 429 430 /* 431 * Restore the valid page pointers. They are already 432 * unbusied, but still wired. 433 */ 434 for (j = i; j < i + count; j++) 435 if (pa[j] == bogus_page) { 436 pa[j] = vm_page_lookup(obj, 437 OFF_TO_IDX(vmoff(j, off))); 438 KASSERT(pa[j], ("%s: page %p[%d] disappeared", 439 __func__, pa, j)); 440 441 } 442 i += count; 443 (*nios)++; 444 } 445 446 VM_OBJECT_WUNLOCK(obj); 447 448 if (*nios == 0 && npages != 0) 449 SFSTAT_INC(sf_noiocnt); 450 451 return (0); 452 } 453 454 static int 455 sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res, 456 struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size, 457 int *bsize) 458 { 459 struct vattr va; 460 vm_object_t obj; 461 struct vnode *vp; 462 struct shmfd *shmfd; 463 int error; 464 465 vp = *vp_res = NULL; 466 obj = NULL; 467 shmfd = *shmfd_res = NULL; 468 *bsize = 0; 469 470 /* 471 * The file descriptor must be a regular file and have a 472 * backing VM object. 473 */ 474 if (fp->f_type == DTYPE_VNODE) { 475 vp = fp->f_vnode; 476 vn_lock(vp, LK_SHARED | LK_RETRY); 477 if (vp->v_type != VREG) { 478 error = EINVAL; 479 goto out; 480 } 481 *bsize = vp->v_mount->mnt_stat.f_iosize; 482 error = VOP_GETATTR(vp, &va, td->td_ucred); 483 if (error != 0) 484 goto out; 485 *obj_size = va.va_size; 486 obj = vp->v_object; 487 if (obj == NULL) { 488 error = EINVAL; 489 goto out; 490 } 491 } else if (fp->f_type == DTYPE_SHM) { 492 error = 0; 493 shmfd = fp->f_data; 494 obj = shmfd->shm_object; 495 *obj_size = shmfd->shm_size; 496 } else { 497 error = EINVAL; 498 goto out; 499 } 500 501 VM_OBJECT_WLOCK(obj); 502 if ((obj->flags & OBJ_DEAD) != 0) { 503 VM_OBJECT_WUNLOCK(obj); 504 error = EBADF; 505 goto out; 506 } 507 508 /* 509 * Temporarily increase the backing VM object's reference 510 * count so that a forced reclamation of its vnode does not 511 * immediately destroy it. 512 */ 513 vm_object_reference_locked(obj); 514 VM_OBJECT_WUNLOCK(obj); 515 *obj_res = obj; 516 *vp_res = vp; 517 *shmfd_res = shmfd; 518 519 out: 520 if (vp != NULL) 521 VOP_UNLOCK(vp, 0); 522 return (error); 523 } 524 525 static int 526 sendfile_getsock(struct thread *td, int s, struct file **sock_fp, 527 struct socket **so) 528 { 529 int error; 530 531 *sock_fp = NULL; 532 *so = NULL; 533 534 /* 535 * The socket must be a stream socket and connected. 536 */ 537 error = getsock_cap(td, s, &cap_send_rights, 538 sock_fp, NULL, NULL); 539 if (error != 0) 540 return (error); 541 *so = (*sock_fp)->f_data; 542 if ((*so)->so_type != SOCK_STREAM) 543 return (EINVAL); 544 if (SOLISTENING(*so)) 545 return (ENOTCONN); 546 return (0); 547 } 548 549 int 550 vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 551 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 552 struct thread *td) 553 { 554 struct file *sock_fp; 555 struct vnode *vp; 556 struct vm_object *obj; 557 struct socket *so; 558 #ifdef KERN_TLS 559 struct ktls_session *tls; 560 #endif 561 struct mbuf_ext_pgs *ext_pgs; 562 struct mbuf *m, *mh, *mhtail; 563 struct sf_buf *sf; 564 struct shmfd *shmfd; 565 struct sendfile_sync *sfs; 566 struct vattr va; 567 off_t off, sbytes, rem, obj_size; 568 int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr; 569 #ifdef KERN_TLS 570 int tls_enq_cnt; 571 #endif 572 bool use_ext_pgs; 573 574 obj = NULL; 575 so = NULL; 576 m = mh = NULL; 577 sfs = NULL; 578 #ifdef KERN_TLS 579 tls = NULL; 580 #endif 581 hdrlen = sbytes = 0; 582 softerr = 0; 583 use_ext_pgs = false; 584 585 error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); 586 if (error != 0) 587 return (error); 588 589 error = sendfile_getsock(td, sockfd, &sock_fp, &so); 590 if (error != 0) 591 goto out; 592 593 #ifdef MAC 594 error = mac_socket_check_send(td->td_ucred, so); 595 if (error != 0) 596 goto out; 597 #endif 598 599 SFSTAT_INC(sf_syscalls); 600 SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); 601 602 if (flags & SF_SYNC) { 603 sfs = malloc(sizeof *sfs, M_TEMP, M_WAITOK | M_ZERO); 604 mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); 605 cv_init(&sfs->cv, "sendfile"); 606 } 607 608 rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; 609 610 /* 611 * Protect against multiple writers to the socket. 612 * 613 * XXXRW: Historically this has assumed non-interruptibility, so now 614 * we implement that, but possibly shouldn't. 615 */ 616 (void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR); 617 #ifdef KERN_TLS 618 tls = ktls_hold(so->so_snd.sb_tls_info); 619 #endif 620 621 /* 622 * Loop through the pages of the file, starting with the requested 623 * offset. Get a file page (do I/O if necessary), map the file page 624 * into an sf_buf, attach an mbuf header to the sf_buf, and queue 625 * it on the socket. 626 * This is done in two loops. The inner loop turns as many pages 627 * as it can, up to available socket buffer space, without blocking 628 * into mbufs to have it bulk delivered into the socket send buffer. 629 * The outer loop checks the state and available space of the socket 630 * and takes care of the overall progress. 631 */ 632 for (off = offset; rem > 0; ) { 633 struct sf_io *sfio; 634 vm_page_t *pa; 635 struct mbuf *mtail; 636 int nios, space, npages, rhpages; 637 638 mtail = NULL; 639 /* 640 * Check the socket state for ongoing connection, 641 * no errors and space in socket buffer. 642 * If space is low allow for the remainder of the 643 * file to be processed if it fits the socket buffer. 644 * Otherwise block in waiting for sufficient space 645 * to proceed, or if the socket is nonblocking, return 646 * to userland with EAGAIN while reporting how far 647 * we've come. 648 * We wait until the socket buffer has significant free 649 * space to do bulk sends. This makes good use of file 650 * system read ahead and allows packet segmentation 651 * offloading hardware to take over lots of work. If 652 * we were not careful here we would send off only one 653 * sfbuf at a time. 654 */ 655 SOCKBUF_LOCK(&so->so_snd); 656 if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) 657 so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; 658 retry_space: 659 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 660 error = EPIPE; 661 SOCKBUF_UNLOCK(&so->so_snd); 662 goto done; 663 } else if (so->so_error) { 664 error = so->so_error; 665 so->so_error = 0; 666 SOCKBUF_UNLOCK(&so->so_snd); 667 goto done; 668 } 669 if ((so->so_state & SS_ISCONNECTED) == 0) { 670 SOCKBUF_UNLOCK(&so->so_snd); 671 error = ENOTCONN; 672 goto done; 673 } 674 675 space = sbspace(&so->so_snd); 676 if (space < rem && 677 (space <= 0 || 678 space < so->so_snd.sb_lowat)) { 679 if (so->so_state & SS_NBIO) { 680 SOCKBUF_UNLOCK(&so->so_snd); 681 error = EAGAIN; 682 goto done; 683 } 684 /* 685 * sbwait drops the lock while sleeping. 686 * When we loop back to retry_space the 687 * state may have changed and we retest 688 * for it. 689 */ 690 error = sbwait(&so->so_snd); 691 /* 692 * An error from sbwait usually indicates that we've 693 * been interrupted by a signal. If we've sent anything 694 * then return bytes sent, otherwise return the error. 695 */ 696 if (error != 0) { 697 SOCKBUF_UNLOCK(&so->so_snd); 698 goto done; 699 } 700 goto retry_space; 701 } 702 SOCKBUF_UNLOCK(&so->so_snd); 703 704 /* 705 * At the beginning of the first loop check if any headers 706 * are specified and copy them into mbufs. Reduce space in 707 * the socket buffer by the size of the header mbuf chain. 708 * Clear hdr_uio here and hdrlen at the end of the first loop. 709 */ 710 if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { 711 hdr_uio->uio_td = td; 712 hdr_uio->uio_rw = UIO_WRITE; 713 #ifdef KERN_TLS 714 if (tls != NULL) 715 mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 716 tls->params.max_frame_len, M_NOMAP); 717 else 718 #endif 719 mh = m_uiotombuf(hdr_uio, M_WAITOK, 720 space, 0, 0); 721 hdrlen = m_length(mh, &mhtail); 722 space -= hdrlen; 723 /* 724 * If header consumed all the socket buffer space, 725 * don't waste CPU cycles and jump to the end. 726 */ 727 if (space == 0) { 728 sfio = NULL; 729 nios = 0; 730 goto prepend_header; 731 } 732 hdr_uio = NULL; 733 } 734 735 if (vp != NULL) { 736 error = vn_lock(vp, LK_SHARED); 737 if (error != 0) 738 goto done; 739 error = VOP_GETATTR(vp, &va, td->td_ucred); 740 if (error != 0 || off >= va.va_size) { 741 VOP_UNLOCK(vp, 0); 742 goto done; 743 } 744 if (va.va_size != obj_size) { 745 obj_size = va.va_size; 746 rem = nbytes ? 747 omin(nbytes + offset, obj_size) : obj_size; 748 rem -= off; 749 } 750 } 751 752 if (space > rem) 753 space = rem; 754 else if (space > PAGE_SIZE) { 755 /* 756 * Use page boundaries when possible for large 757 * requests. 758 */ 759 if (off & PAGE_MASK) 760 space -= (PAGE_SIZE - (off & PAGE_MASK)); 761 space = trunc_page(space); 762 if (off & PAGE_MASK) 763 space += (PAGE_SIZE - (off & PAGE_MASK)); 764 } 765 766 npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); 767 768 /* 769 * Calculate maximum allowed number of pages for readahead 770 * at this iteration. If SF_USER_READAHEAD was set, we don't 771 * do any heuristics and use exactly the value supplied by 772 * application. Otherwise, we allow readahead up to "rem". 773 * If application wants more, let it be, but there is no 774 * reason to go above MAXPHYS. Also check against "obj_size", 775 * since vm_pager_has_page() can hint beyond EOF. 776 */ 777 if (flags & SF_USER_READAHEAD) { 778 rhpages = SF_READAHEAD(flags); 779 } else { 780 rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - 781 npages; 782 rhpages += SF_READAHEAD(flags); 783 } 784 rhpages = min(howmany(MAXPHYS, PAGE_SIZE), rhpages); 785 rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - 786 npages, rhpages); 787 788 sfio = malloc(sizeof(struct sf_io) + 789 npages * sizeof(vm_page_t), M_TEMP, M_WAITOK); 790 refcount_init(&sfio->nios, 1); 791 sfio->so = so; 792 sfio->error = 0; 793 794 #ifdef KERN_TLS 795 /* 796 * This doesn't use ktls_hold() because sfio->m will 797 * also have a reference on 'tls' that will be valid 798 * for all of sfio's lifetime. 799 */ 800 sfio->tls = tls; 801 #endif 802 803 error = sendfile_swapin(obj, sfio, &nios, off, space, npages, 804 rhpages, flags); 805 if (error != 0) { 806 if (vp != NULL) 807 VOP_UNLOCK(vp, 0); 808 free(sfio, M_TEMP); 809 goto done; 810 } 811 812 /* 813 * Loop and construct maximum sized mbuf chain to be bulk 814 * dumped into socket buffer. 815 */ 816 pa = sfio->pa; 817 818 /* 819 * Use unmapped mbufs if enabled for TCP. Unmapped 820 * bufs are restricted to TCP as that is what has been 821 * tested. In particular, unmapped mbufs have not 822 * been tested with UNIX-domain sockets. 823 * 824 * TLS frames always require unmapped mbufs. 825 */ 826 if ((mb_use_ext_pgs && 827 so->so_proto->pr_protocol == IPPROTO_TCP) 828 #ifdef KERN_TLS 829 || tls != NULL 830 #endif 831 ) { 832 use_ext_pgs = true; 833 #ifdef KERN_TLS 834 if (tls != NULL) 835 max_pgs = num_pages(tls->params.max_frame_len); 836 else 837 #endif 838 max_pgs = MBUF_PEXT_MAX_PGS; 839 840 /* Start at last index, to wrap on first use. */ 841 ext_pgs_idx = max_pgs - 1; 842 } 843 844 for (int i = 0; i < npages; i++) { 845 struct mbuf *m0; 846 847 /* 848 * If a page wasn't grabbed successfully, then 849 * trim the array. Can happen only with SF_NODISKIO. 850 */ 851 if (pa[i] == NULL) { 852 SFSTAT_INC(sf_busy); 853 fixspace(npages, i, off, &space); 854 npages = i; 855 softerr = EBUSY; 856 break; 857 } 858 859 if (use_ext_pgs) { 860 off_t xfs; 861 862 ext_pgs_idx++; 863 if (ext_pgs_idx == max_pgs) { 864 m0 = mb_alloc_ext_pgs(M_WAITOK, false, 865 sendfile_free_mext_pg); 866 867 if (flags & SF_NOCACHE) { 868 m0->m_ext.ext_flags |= 869 EXT_FLAG_NOCACHE; 870 871 /* 872 * See comment below regarding 873 * ignoring SF_NOCACHE for the 874 * last page. 875 */ 876 if ((npages - i <= max_pgs) && 877 ((off + space) & PAGE_MASK) && 878 (rem > space || rhpages > 0)) 879 m0->m_ext.ext_flags |= 880 EXT_FLAG_CACHE_LAST; 881 } 882 if (sfs != NULL) { 883 m0->m_ext.ext_flags |= 884 EXT_FLAG_SYNC; 885 m0->m_ext.ext_arg2 = sfs; 886 mtx_lock(&sfs->mtx); 887 sfs->count++; 888 mtx_unlock(&sfs->mtx); 889 } 890 ext_pgs = m0->m_ext.ext_pgs; 891 if (i == 0) 892 sfio->m = m0; 893 ext_pgs_idx = 0; 894 895 /* Append to mbuf chain. */ 896 if (mtail != NULL) 897 mtail->m_next = m0; 898 else 899 m = m0; 900 mtail = m0; 901 ext_pgs->first_pg_off = 902 vmoff(i, off) & PAGE_MASK; 903 } 904 if (nios) { 905 mtail->m_flags |= M_NOTREADY; 906 ext_pgs->nrdy++; 907 } 908 909 ext_pgs->pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pa[i]); 910 ext_pgs->npgs++; 911 xfs = xfsize(i, npages, off, space); 912 ext_pgs->last_pg_len = xfs; 913 MBUF_EXT_PGS_ASSERT_SANITY(ext_pgs); 914 mtail->m_len += xfs; 915 mtail->m_ext.ext_size += PAGE_SIZE; 916 continue; 917 } 918 919 /* 920 * Get a sendfile buf. When allocating the 921 * first buffer for mbuf chain, we usually 922 * wait as long as necessary, but this wait 923 * can be interrupted. For consequent 924 * buffers, do not sleep, since several 925 * threads might exhaust the buffers and then 926 * deadlock. 927 */ 928 sf = sf_buf_alloc(pa[i], 929 m != NULL ? SFB_NOWAIT : SFB_CATCH); 930 if (sf == NULL) { 931 SFSTAT_INC(sf_allocfail); 932 for (int j = i; j < npages; j++) 933 vm_page_unwire(pa[j], PQ_INACTIVE); 934 if (m == NULL) 935 softerr = ENOBUFS; 936 fixspace(npages, i, off, &space); 937 npages = i; 938 break; 939 } 940 941 m0 = m_get(M_WAITOK, MT_DATA); 942 m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); 943 m0->m_ext.ext_size = PAGE_SIZE; 944 m0->m_ext.ext_arg1 = sf; 945 m0->m_ext.ext_type = EXT_SFBUF; 946 m0->m_ext.ext_flags = EXT_FLAG_EMBREF; 947 m0->m_ext.ext_free = sendfile_free_mext; 948 /* 949 * SF_NOCACHE sets the page as being freed upon send. 950 * However, we ignore it for the last page in 'space', 951 * if the page is truncated, and we got more data to 952 * send (rem > space), or if we have readahead 953 * configured (rhpages > 0). 954 */ 955 if ((flags & SF_NOCACHE) && 956 (i != npages - 1 || 957 !((off + space) & PAGE_MASK) || 958 !(rem > space || rhpages > 0))) 959 m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; 960 if (sfs != NULL) { 961 m0->m_ext.ext_flags |= EXT_FLAG_SYNC; 962 m0->m_ext.ext_arg2 = sfs; 963 mtx_lock(&sfs->mtx); 964 sfs->count++; 965 mtx_unlock(&sfs->mtx); 966 } 967 m0->m_ext.ext_count = 1; 968 m0->m_flags |= (M_EXT | M_RDONLY); 969 if (nios) 970 m0->m_flags |= M_NOTREADY; 971 m0->m_data = (char *)sf_buf_kva(sf) + 972 (vmoff(i, off) & PAGE_MASK); 973 m0->m_len = xfsize(i, npages, off, space); 974 975 if (i == 0) 976 sfio->m = m0; 977 978 /* Append to mbuf chain. */ 979 if (mtail != NULL) 980 mtail->m_next = m0; 981 else 982 m = m0; 983 mtail = m0; 984 } 985 986 if (vp != NULL) 987 VOP_UNLOCK(vp, 0); 988 989 /* Keep track of bytes processed. */ 990 off += space; 991 rem -= space; 992 993 /* Prepend header, if any. */ 994 if (hdrlen) { 995 prepend_header: 996 mhtail->m_next = m; 997 m = mh; 998 mh = NULL; 999 } 1000 1001 if (m == NULL) { 1002 KASSERT(softerr, ("%s: m NULL, no error", __func__)); 1003 error = softerr; 1004 free(sfio, M_TEMP); 1005 goto done; 1006 } 1007 1008 /* Add the buffer chain to the socket buffer. */ 1009 KASSERT(m_length(m, NULL) == space + hdrlen, 1010 ("%s: mlen %u space %d hdrlen %d", 1011 __func__, m_length(m, NULL), space, hdrlen)); 1012 1013 CURVNET_SET(so->so_vnet); 1014 #ifdef KERN_TLS 1015 if (tls != NULL) { 1016 error = ktls_frame(m, tls, &tls_enq_cnt, 1017 TLS_RLTYPE_APP); 1018 if (error != 0) 1019 goto done; 1020 } 1021 #endif 1022 if (nios == 0) { 1023 /* 1024 * If sendfile_swapin() didn't initiate any I/Os, 1025 * which happens if all data is cached in VM, then 1026 * we can send data right now without the 1027 * PRUS_NOTREADY flag. 1028 */ 1029 free(sfio, M_TEMP); 1030 #ifdef KERN_TLS 1031 if (tls != NULL && tls->sw_encrypt != NULL) { 1032 error = (*so->so_proto->pr_usrreqs->pru_send) 1033 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1034 soref(so); 1035 ktls_enqueue(m, so, tls_enq_cnt); 1036 } else 1037 #endif 1038 error = (*so->so_proto->pr_usrreqs->pru_send) 1039 (so, 0, m, NULL, NULL, td); 1040 } else { 1041 sfio->npages = npages; 1042 soref(so); 1043 error = (*so->so_proto->pr_usrreqs->pru_send) 1044 (so, PRUS_NOTREADY, m, NULL, NULL, td); 1045 sendfile_iodone(sfio, NULL, 0, 0); 1046 } 1047 CURVNET_RESTORE(); 1048 1049 m = NULL; /* pru_send always consumes */ 1050 if (error) 1051 goto done; 1052 sbytes += space + hdrlen; 1053 if (hdrlen) 1054 hdrlen = 0; 1055 if (softerr) { 1056 error = softerr; 1057 goto done; 1058 } 1059 } 1060 1061 /* 1062 * Send trailers. Wimp out and use writev(2). 1063 */ 1064 if (trl_uio != NULL) { 1065 sbunlock(&so->so_snd); 1066 error = kern_writev(td, sockfd, trl_uio); 1067 if (error == 0) 1068 sbytes += td->td_retval[0]; 1069 goto out; 1070 } 1071 1072 done: 1073 sbunlock(&so->so_snd); 1074 out: 1075 /* 1076 * If there was no error we have to clear td->td_retval[0] 1077 * because it may have been set by writev. 1078 */ 1079 if (error == 0) { 1080 td->td_retval[0] = 0; 1081 } 1082 if (sent != NULL) { 1083 (*sent) = sbytes; 1084 } 1085 if (obj != NULL) 1086 vm_object_deallocate(obj); 1087 if (so) 1088 fdrop(sock_fp, td); 1089 if (m) 1090 m_freem(m); 1091 if (mh) 1092 m_freem(mh); 1093 1094 if (sfs != NULL) { 1095 mtx_lock(&sfs->mtx); 1096 if (sfs->count != 0) 1097 cv_wait(&sfs->cv, &sfs->mtx); 1098 KASSERT(sfs->count == 0, ("sendfile sync still busy")); 1099 cv_destroy(&sfs->cv); 1100 mtx_destroy(&sfs->mtx); 1101 free(sfs, M_TEMP); 1102 } 1103 #ifdef KERN_TLS 1104 if (tls != NULL) 1105 ktls_free(tls); 1106 #endif 1107 1108 if (error == ERESTART) 1109 error = EINTR; 1110 1111 return (error); 1112 } 1113 1114 static int 1115 sendfile(struct thread *td, struct sendfile_args *uap, int compat) 1116 { 1117 struct sf_hdtr hdtr; 1118 struct uio *hdr_uio, *trl_uio; 1119 struct file *fp; 1120 off_t sbytes; 1121 int error; 1122 1123 /* 1124 * File offset must be positive. If it goes beyond EOF 1125 * we send only the header/trailer and no payload data. 1126 */ 1127 if (uap->offset < 0) 1128 return (EINVAL); 1129 1130 sbytes = 0; 1131 hdr_uio = trl_uio = NULL; 1132 1133 if (uap->hdtr != NULL) { 1134 error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); 1135 if (error != 0) 1136 goto out; 1137 if (hdtr.headers != NULL) { 1138 error = copyinuio(hdtr.headers, hdtr.hdr_cnt, 1139 &hdr_uio); 1140 if (error != 0) 1141 goto out; 1142 #ifdef COMPAT_FREEBSD4 1143 /* 1144 * In FreeBSD < 5.0 the nbytes to send also included 1145 * the header. If compat is specified subtract the 1146 * header size from nbytes. 1147 */ 1148 if (compat) { 1149 if (uap->nbytes > hdr_uio->uio_resid) 1150 uap->nbytes -= hdr_uio->uio_resid; 1151 else 1152 uap->nbytes = 0; 1153 } 1154 #endif 1155 } 1156 if (hdtr.trailers != NULL) { 1157 error = copyinuio(hdtr.trailers, hdtr.trl_cnt, 1158 &trl_uio); 1159 if (error != 0) 1160 goto out; 1161 } 1162 } 1163 1164 AUDIT_ARG_FD(uap->fd); 1165 1166 /* 1167 * sendfile(2) can start at any offset within a file so we require 1168 * CAP_READ+CAP_SEEK = CAP_PREAD. 1169 */ 1170 if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0) 1171 goto out; 1172 1173 error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, 1174 uap->nbytes, &sbytes, uap->flags, td); 1175 fdrop(fp, td); 1176 1177 if (uap->sbytes != NULL) 1178 copyout(&sbytes, uap->sbytes, sizeof(off_t)); 1179 1180 out: 1181 free(hdr_uio, M_IOV); 1182 free(trl_uio, M_IOV); 1183 return (error); 1184 } 1185 1186 /* 1187 * sendfile(2) 1188 * 1189 * int sendfile(int fd, int s, off_t offset, size_t nbytes, 1190 * struct sf_hdtr *hdtr, off_t *sbytes, int flags) 1191 * 1192 * Send a file specified by 'fd' and starting at 'offset' to a socket 1193 * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == 1194 * 0. Optionally add a header and/or trailer to the socket output. If 1195 * specified, write the total number of bytes sent into *sbytes. 1196 */ 1197 int 1198 sys_sendfile(struct thread *td, struct sendfile_args *uap) 1199 { 1200 1201 return (sendfile(td, uap, 0)); 1202 } 1203 1204 #ifdef COMPAT_FREEBSD4 1205 int 1206 freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) 1207 { 1208 struct sendfile_args args; 1209 1210 args.fd = uap->fd; 1211 args.s = uap->s; 1212 args.offset = uap->offset; 1213 args.nbytes = uap->nbytes; 1214 args.hdtr = uap->hdtr; 1215 args.sbytes = uap->sbytes; 1216 args.flags = uap->flags; 1217 1218 return (sendfile(td, &args, 1)); 1219 } 1220 #endif /* COMPAT_FREEBSD4 */ 1221