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