/*- * Copyright (c) 2013-2015 Gleb Smirnoff * Copyright (c) 1998, David Greenman. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_kern_tls.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_SENDFILE, "sendfile", "sendfile dynamic memory"); #define EXT_FLAG_SYNC EXT_FLAG_VENDOR1 #define EXT_FLAG_NOCACHE EXT_FLAG_VENDOR2 #define EXT_FLAG_CACHE_LAST EXT_FLAG_VENDOR3 /* * Structure describing a single sendfile(2) I/O, which may consist of * several underlying pager I/Os. * * The syscall context allocates the structure and initializes 'nios' * to 1. As sendfile_swapin() runs through pages and starts asynchronous * paging operations, it increments 'nios'. * * Every I/O completion calls sendfile_iodone(), which decrements the 'nios', * and the syscall also calls sendfile_iodone() after allocating all mbufs, * linking them and sending to socket. Whoever reaches zero 'nios' is * responsible to * call pru_ready on the socket, to notify it of readyness * of the data. */ struct sf_io { volatile u_int nios; u_int error; int npages; struct socket *so; struct mbuf *m; vm_object_t obj; vm_pindex_t pindex0; #ifdef KERN_TLS struct ktls_session *tls; #endif vm_page_t pa[]; }; /* * Structure used to track requests with SF_SYNC flag. */ struct sendfile_sync { struct mtx mtx; struct cv cv; unsigned count; bool waiting; }; static void sendfile_sync_destroy(struct sendfile_sync *sfs) { KASSERT(sfs->count == 0, ("sendfile sync %p still busy", sfs)); cv_destroy(&sfs->cv); mtx_destroy(&sfs->mtx); free(sfs, M_SENDFILE); } static void sendfile_sync_signal(struct sendfile_sync *sfs) { mtx_lock(&sfs->mtx); KASSERT(sfs->count > 0, ("sendfile sync %p not busy", sfs)); if (--sfs->count == 0) { if (!sfs->waiting) { /* The sendfile() waiter was interrupted by a signal. */ sendfile_sync_destroy(sfs); return; } else { cv_signal(&sfs->cv); } } mtx_unlock(&sfs->mtx); } counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; static void sfstat_init(const void *unused) { COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t), M_WAITOK); } SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL); static int sfstat_sysctl(SYSCTL_HANDLER_ARGS) { struct sfstat s; COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t)); if (req->newptr) COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t)); return (SYSCTL_OUT(req, &s, sizeof(s))); } SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0, sfstat_sysctl, "I", "sendfile statistics"); static void sendfile_free_mext(struct mbuf *m) { struct sf_buf *sf; vm_page_t pg; int flags; KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_SFBUF, ("%s: m %p !M_EXT or !EXT_SFBUF", __func__, m)); sf = m->m_ext.ext_arg1; pg = sf_buf_page(sf); flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; sf_buf_free(sf); vm_page_release(pg, flags); if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { struct sendfile_sync *sfs = m->m_ext.ext_arg2; sendfile_sync_signal(sfs); } } static void sendfile_free_mext_pg(struct mbuf *m) { vm_page_t pg; int flags, i; bool cache_last; M_ASSERTEXTPG(m); cache_last = m->m_ext.ext_flags & EXT_FLAG_CACHE_LAST; flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0; for (i = 0; i < m->m_epg_npgs; i++) { if (cache_last && i == m->m_epg_npgs - 1) flags = 0; pg = PHYS_TO_VM_PAGE(m->m_epg_pa[i]); vm_page_release(pg, flags); } if (m->m_ext.ext_flags & EXT_FLAG_SYNC) { struct sendfile_sync *sfs = m->m_ext.ext_arg1; sendfile_sync_signal(sfs); } } /* * Helper function to calculate how much data to put into page i of n. * Only first and last pages are special. */ static inline off_t xfsize(int i, int n, off_t off, off_t len) { if (i == 0) return (omin(PAGE_SIZE - (off & PAGE_MASK), len)); if (i == n - 1 && ((off + len) & PAGE_MASK) > 0) return ((off + len) & PAGE_MASK); return (PAGE_SIZE); } /* * Helper function to get offset within object for i page. */ static inline vm_ooffset_t vmoff(int i, off_t off) { if (i == 0) return ((vm_ooffset_t)off); return (trunc_page(off + i * PAGE_SIZE)); } /* * Helper function used when allocation of a page or sf_buf failed. * Pretend as if we don't have enough space, subtract xfsize() of * all pages that failed. */ static inline void fixspace(int old, int new, off_t off, int *space) { KASSERT(old > new, ("%s: old %d new %d", __func__, old, new)); /* Subtract last one. */ *space -= xfsize(old - 1, old, off, *space); old--; if (new == old) /* There was only one page. */ return; /* Subtract first one. */ if (new == 0) { *space -= xfsize(0, old, off, *space); new++; } /* Rest of pages are full sized. */ *space -= (old - new) * PAGE_SIZE; KASSERT(*space >= 0, ("%s: space went backwards", __func__)); } /* * Wait for all in-flight ios to complete, we must not unwire pages * under them. */ static void sendfile_iowait(struct sf_io *sfio, const char *wmesg) { while (atomic_load_int(&sfio->nios) != 1) pause(wmesg, 1); } /* * I/O completion callback. */ static void sendfile_iodone(void *arg, vm_page_t *pa, int count, int error) { struct sf_io *sfio = arg; struct socket *so; int i; if (error != 0) sfio->error = error; /* * Restore the valid page pointers. They are already * unbusied, but still wired. * * XXXKIB since pages are only wired, and we do not * own the object lock, other users might have * invalidated them in meantime. Similarly, after we * unbusied the swapped-in pages, they can become * invalid under us. */ MPASS(count == 0 || pa[0] != bogus_page); for (i = 0; i < count; i++) { if (pa[i] == bogus_page) { sfio->pa[(pa[0]->pindex - sfio->pindex0) + i] = pa[i] = vm_page_relookup(sfio->obj, pa[0]->pindex + i); KASSERT(pa[i] != NULL, ("%s: page %p[%d] disappeared", __func__, pa, i)); } else { vm_page_xunbusy_unchecked(pa[i]); } } if (!refcount_release(&sfio->nios)) return; #ifdef INVARIANTS for (i = 1; i < sfio->npages; i++) { if (sfio->pa[i] == NULL) break; KASSERT(vm_page_wired(sfio->pa[i]), ("sfio %p page %d %p not wired", sfio, i, sfio->pa[i])); if (i == 0) continue; KASSERT(sfio->pa[0]->object == sfio->pa[i]->object, ("sfio %p page %d %p wrong owner %p %p", sfio, i, sfio->pa[i], sfio->pa[0]->object, sfio->pa[i]->object)); KASSERT(sfio->pa[0]->pindex + i == sfio->pa[i]->pindex, ("sfio %p page %d %p wrong index %jx %jx", sfio, i, sfio->pa[i], (uintmax_t)sfio->pa[0]->pindex, (uintmax_t)sfio->pa[i]->pindex)); } #endif vm_object_pip_wakeup(sfio->obj); if (sfio->m == NULL) { /* * Either I/O operation failed, or we failed to allocate * buffers, or we bailed out on first busy page, or we * succeeded filling the request without any I/Os. Anyway, * pru_send hadn't been executed - nothing had been sent * to the socket yet. */ MPASS((curthread->td_pflags & TDP_KTHREAD) == 0); free(sfio, M_SENDFILE); return; } #if defined(KERN_TLS) && defined(INVARIANTS) if ((sfio->m->m_flags & M_EXTPG) != 0) KASSERT(sfio->tls == sfio->m->m_epg_tls, ("TLS session mismatch")); else KASSERT(sfio->tls == NULL, ("non-ext_pgs mbuf with TLS session")); #endif so = sfio->so; CURVNET_SET(so->so_vnet); if (__predict_false(sfio->error)) { /* * I/O operation failed. The state of data in the socket * is now inconsistent, and all what we can do is to tear * it down. Protocol abort method would tear down protocol * state, free all ready mbufs and detach not ready ones. * We will free the mbufs corresponding to this I/O manually. * * The socket would be marked with EIO and made available * for read, so that application receives EIO on next * syscall and eventually closes the socket. */ so->so_proto->pr_abort(so); so->so_error = EIO; mb_free_notready(sfio->m, sfio->npages); #ifdef KERN_TLS } else if (sfio->tls != NULL && sfio->tls->mode == TCP_TLS_MODE_SW) { /* * I/O operation is complete, but we still need to * encrypt. We cannot do this in the interrupt thread * of the disk controller, so forward the mbufs to a * different thread. * * Donate the socket reference from sfio to rather * than explicitly invoking soref(). */ ktls_enqueue(sfio->m, so, sfio->npages); goto out_with_ref; #endif } else (void)so->so_proto->pr_ready(so, sfio->m, sfio->npages); sorele(so); #ifdef KERN_TLS out_with_ref: #endif CURVNET_RESTORE(); free(sfio, M_SENDFILE); } /* * Iterate through pages vector and request paging for non-valid pages. */ static int sendfile_swapin(vm_object_t obj, struct sf_io *sfio, int *nios, off_t off, off_t len, int rhpages, int flags) { vm_page_t *pa; int a, count, count1, grabbed, i, j, npages, rv; pa = sfio->pa; npages = sfio->npages; *nios = 0; flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0; sfio->pindex0 = OFF_TO_IDX(off); /* * First grab all the pages and wire them. Note that we grab * only required pages. Readahead pages are dealt with later. */ grabbed = vm_page_grab_pages_unlocked(obj, OFF_TO_IDX(off), VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages); if (grabbed < npages) { for (int i = grabbed; i < npages; i++) pa[i] = NULL; npages = grabbed; rhpages = 0; } for (i = 0; i < npages;) { /* Skip valid pages. */ if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK, xfsize(i, npages, off, len))) { vm_page_xunbusy(pa[i]); SFSTAT_INC(sf_pages_valid); i++; continue; } /* * Next page is invalid. Check if it belongs to pager. It * may not be there, which is a regular situation for shmem * pager. For vnode pager this happens only in case of * a sparse file. * * Important feature of vm_pager_has_page() is the hint * stored in 'a', about how many pages we can pagein after * this page in a single I/O. */ VM_OBJECT_RLOCK(obj); if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL, &a)) { VM_OBJECT_RUNLOCK(obj); pmap_zero_page(pa[i]); vm_page_valid(pa[i]); MPASS(pa[i]->dirty == 0); vm_page_xunbusy(pa[i]); i++; continue; } VM_OBJECT_RUNLOCK(obj); /* * We want to pagein as many pages as possible, limited only * by the 'a' hint and actual request. */ count = min(a + 1, npages - i); /* * We should not pagein into a valid page because * there might be still unfinished write tracked by * e.g. a buffer, thus we substitute any valid pages * with the bogus one. * * We must not leave around xbusy pages which are not * part of the run passed to vm_pager_getpages(), * otherwise pager might deadlock waiting for the busy * status of the page, e.g. if it constitues the * buffer needed to validate other page. * * First trim the end of the run consisting of the * valid pages, then replace the rest of the valid * with bogus. */ count1 = count; for (j = i + count - 1; j > i; j--) { if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, xfsize(j, npages, off, len))) { vm_page_xunbusy(pa[j]); SFSTAT_INC(sf_pages_valid); count--; } else { break; } } /* * The last page in the run pa[i + count - 1] is * guaranteed to be invalid by the trim above, so it * is not replaced with bogus, thus -1 in the loop end * condition. */ MPASS(pa[i + count - 1]->valid != VM_PAGE_BITS_ALL); for (j = i + 1; j < i + count - 1; j++) { if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK, xfsize(j, npages, off, len))) { vm_page_xunbusy(pa[j]); SFSTAT_INC(sf_pages_valid); SFSTAT_INC(sf_pages_bogus); pa[j] = bogus_page; } } refcount_acquire(&sfio->nios); rv = vm_pager_get_pages_async(obj, pa + i, count, NULL, i + count == npages ? &rhpages : NULL, &sendfile_iodone, sfio); if (__predict_false(rv != VM_PAGER_OK)) { sendfile_iowait(sfio, "sferrio"); /* * Do remaining pages recovery before returning EIO. * Pages from 0 to npages are wired. * Pages from (i + count1) to npages are busied. */ for (j = 0; j < npages; j++) { if (j >= i + count1) vm_page_xunbusy(pa[j]); KASSERT(pa[j] != NULL && pa[j] != bogus_page, ("%s: page %p[%d] I/O recovery failure", __func__, pa, j)); vm_page_unwire(pa[j], PQ_INACTIVE); pa[j] = NULL; } return (EIO); } SFSTAT_INC(sf_iocnt); SFSTAT_ADD(sf_pages_read, count); if (i + count == npages) SFSTAT_ADD(sf_rhpages_read, rhpages); i += count1; (*nios)++; } if (*nios == 0 && npages != 0) SFSTAT_INC(sf_noiocnt); return (0); } static int sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res, struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size, int *bsize) { struct vattr va; vm_object_t obj; struct vnode *vp; struct shmfd *shmfd; int error; error = 0; vp = *vp_res = NULL; obj = NULL; shmfd = *shmfd_res = NULL; *bsize = 0; /* * The file descriptor must be a regular file and have a * backing VM object. */ if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; vn_lock(vp, LK_SHARED | LK_RETRY); if (vp->v_type != VREG) { error = EINVAL; goto out; } *bsize = vp->v_mount->mnt_stat.f_iosize; obj = vp->v_object; if (obj == NULL) { error = EINVAL; goto out; } /* * Use the pager size when available to simplify synchronization * with filesystems, which otherwise must atomically update both * the vnode pager size and file size. */ if (obj->type == OBJT_VNODE) { VM_OBJECT_RLOCK(obj); *obj_size = obj->un_pager.vnp.vnp_size; } else { error = VOP_GETATTR(vp, &va, td->td_ucred); if (error != 0) goto out; *obj_size = va.va_size; VM_OBJECT_RLOCK(obj); } } else if (fp->f_type == DTYPE_SHM) { shmfd = fp->f_data; obj = shmfd->shm_object; VM_OBJECT_RLOCK(obj); *obj_size = shmfd->shm_size; } else { error = EINVAL; goto out; } if ((obj->flags & OBJ_DEAD) != 0) { VM_OBJECT_RUNLOCK(obj); error = EBADF; goto out; } /* * Temporarily increase the backing VM object's reference * count so that a forced reclamation of its vnode does not * immediately destroy it. */ vm_object_reference_locked(obj); VM_OBJECT_RUNLOCK(obj); *obj_res = obj; *vp_res = vp; *shmfd_res = shmfd; out: if (vp != NULL) VOP_UNLOCK(vp); return (error); } static int sendfile_getsock(struct thread *td, int s, struct file **sock_fp, struct socket **so) { int error; *sock_fp = NULL; *so = NULL; /* * The socket must be a stream socket and connected. */ error = getsock(td, s, &cap_send_rights, sock_fp); if (error != 0) return (error); *so = (*sock_fp)->f_data; if ((*so)->so_type != SOCK_STREAM) return (EINVAL); /* * SCTP one-to-one style sockets currently don't work with * sendfile(). So indicate EINVAL for now. */ if ((*so)->so_proto->pr_protocol == IPPROTO_SCTP) return (EINVAL); return (0); } int vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { struct file *sock_fp; struct vnode *vp; struct vm_object *obj; vm_page_t pga; struct socket *so; #ifdef KERN_TLS struct ktls_session *tls; #endif struct mbuf *m, *mh, *mhtail; struct sf_buf *sf; struct shmfd *shmfd; struct sendfile_sync *sfs; struct vattr va; off_t off, sbytes, rem, obj_size, nobj_size; int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr; #ifdef KERN_TLS int tls_enq_cnt; #endif bool use_ext_pgs; obj = NULL; so = NULL; m = mh = NULL; sfs = NULL; #ifdef KERN_TLS tls = NULL; #endif hdrlen = sbytes = 0; softerr = 0; use_ext_pgs = false; error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize); if (error != 0) return (error); error = sendfile_getsock(td, sockfd, &sock_fp, &so); if (error != 0) goto out; #ifdef MAC error = mac_socket_check_send(td->td_ucred, so); if (error != 0) goto out; #endif SFSTAT_INC(sf_syscalls); SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags)); if (flags & SF_SYNC) { sfs = malloc(sizeof(*sfs), M_SENDFILE, M_WAITOK | M_ZERO); mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF); cv_init(&sfs->cv, "sendfile"); sfs->waiting = true; } rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset; /* * Protect against multiple writers to the socket. * * XXXRW: Historically this has assumed non-interruptibility, so now * we implement that, but possibly shouldn't. */ error = SOCK_IO_SEND_LOCK(so, SBL_WAIT | SBL_NOINTR); if (error != 0) goto out; #ifdef KERN_TLS tls = ktls_hold(so->so_snd.sb_tls_info); #endif /* * Loop through the pages of the file, starting with the requested * offset. Get a file page (do I/O if necessary), map the file page * into an sf_buf, attach an mbuf header to the sf_buf, and queue * it on the socket. * This is done in two loops. The inner loop turns as many pages * as it can, up to available socket buffer space, without blocking * into mbufs to have it bulk delivered into the socket send buffer. * The outer loop checks the state and available space of the socket * and takes care of the overall progress. */ for (off = offset; rem > 0; ) { struct sf_io *sfio; vm_page_t *pa; struct mbuf *m0, *mtail; int nios, space, npages, rhpages; mtail = NULL; /* * Check the socket state for ongoing connection, * no errors and space in socket buffer. * If space is low allow for the remainder of the * file to be processed if it fits the socket buffer. * Otherwise block in waiting for sufficient space * to proceed, or if the socket is nonblocking, return * to userland with EAGAIN while reporting how far * we've come. * We wait until the socket buffer has significant free * space to do bulk sends. This makes good use of file * system read ahead and allows packet segmentation * offloading hardware to take over lots of work. If * we were not careful here we would send off only one * sfbuf at a time. */ SOCKBUF_LOCK(&so->so_snd); if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2) so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2; retry_space: if (so->so_snd.sb_state & SBS_CANTSENDMORE) { error = EPIPE; SOCKBUF_UNLOCK(&so->so_snd); goto done; } else if (so->so_error) { error = so->so_error; so->so_error = 0; SOCKBUF_UNLOCK(&so->so_snd); goto done; } if ((so->so_state & SS_ISCONNECTED) == 0) { SOCKBUF_UNLOCK(&so->so_snd); error = ENOTCONN; goto done; } space = sbspace(&so->so_snd); if (space < rem && (space <= 0 || space < so->so_snd.sb_lowat)) { if (so->so_state & SS_NBIO) { SOCKBUF_UNLOCK(&so->so_snd); error = EAGAIN; goto done; } /* * sbwait drops the lock while sleeping. * When we loop back to retry_space the * state may have changed and we retest * for it. */ error = sbwait(so, SO_SND); /* * An error from sbwait usually indicates that we've * been interrupted by a signal. If we've sent anything * then return bytes sent, otherwise return the error. */ if (error != 0) { SOCKBUF_UNLOCK(&so->so_snd); goto done; } goto retry_space; } SOCKBUF_UNLOCK(&so->so_snd); /* * At the beginning of the first loop check if any headers * are specified and copy them into mbufs. Reduce space in * the socket buffer by the size of the header mbuf chain. * Clear hdr_uio here and hdrlen at the end of the first loop. */ if (hdr_uio != NULL && hdr_uio->uio_resid > 0) { hdr_uio->uio_td = td; hdr_uio->uio_rw = UIO_WRITE; #ifdef KERN_TLS if (tls != NULL) mh = m_uiotombuf(hdr_uio, M_WAITOK, space, tls->params.max_frame_len, M_EXTPG); else #endif mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 0, 0); hdrlen = m_length(mh, &mhtail); space -= hdrlen; /* * If header consumed all the socket buffer space, * don't waste CPU cycles and jump to the end. */ if (space == 0) { sfio = NULL; nios = 0; goto prepend_header; } hdr_uio = NULL; } if (vp != NULL) { error = vn_lock(vp, LK_SHARED); if (error != 0) goto done; /* * Check to see if the file size has changed. */ if (obj->type == OBJT_VNODE) { VM_OBJECT_RLOCK(obj); nobj_size = obj->un_pager.vnp.vnp_size; VM_OBJECT_RUNLOCK(obj); } else { error = VOP_GETATTR(vp, &va, td->td_ucred); if (error != 0) { VOP_UNLOCK(vp); goto done; } nobj_size = va.va_size; } if (off >= nobj_size) { VOP_UNLOCK(vp); goto done; } if (nobj_size != obj_size) { obj_size = nobj_size; rem = nbytes ? omin(nbytes + offset, obj_size) : obj_size; rem -= off; } } if (space > rem) space = rem; else if (space > PAGE_SIZE) { /* * Use page boundaries when possible for large * requests. */ if (off & PAGE_MASK) space -= (PAGE_SIZE - (off & PAGE_MASK)); space = trunc_page(space); if (off & PAGE_MASK) space += (PAGE_SIZE - (off & PAGE_MASK)); } npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE); /* * Calculate maximum allowed number of pages for readahead * at this iteration. If SF_USER_READAHEAD was set, we don't * do any heuristics and use exactly the value supplied by * application. Otherwise, we allow readahead up to "rem". * If application wants more, let it be, but there is no * reason to go above maxphys. Also check against "obj_size", * since vm_pager_has_page() can hint beyond EOF. */ if (flags & SF_USER_READAHEAD) { rhpages = SF_READAHEAD(flags); } else { rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) - npages; rhpages += SF_READAHEAD(flags); } rhpages = min(howmany(maxphys, PAGE_SIZE), rhpages); rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) - npages, rhpages); sfio = malloc(sizeof(struct sf_io) + npages * sizeof(vm_page_t), M_SENDFILE, M_WAITOK); refcount_init(&sfio->nios, 1); sfio->obj = obj; sfio->error = 0; sfio->m = NULL; sfio->npages = npages; #ifdef KERN_TLS /* * This doesn't use ktls_hold() because sfio->m will * also have a reference on 'tls' that will be valid * for all of sfio's lifetime. */ sfio->tls = tls; #endif vm_object_pip_add(obj, 1); error = sendfile_swapin(obj, sfio, &nios, off, space, rhpages, flags); if (error != 0) { if (vp != NULL) VOP_UNLOCK(vp); sendfile_iodone(sfio, NULL, 0, error); goto done; } /* * Loop and construct maximum sized mbuf chain to be bulk * dumped into socket buffer. */ pa = sfio->pa; /* * Use unmapped mbufs if enabled for TCP. Unmapped * bufs are restricted to TCP as that is what has been * tested. In particular, unmapped mbufs have not * been tested with UNIX-domain sockets. * * TLS frames always require unmapped mbufs. */ if ((mb_use_ext_pgs && so->so_proto->pr_protocol == IPPROTO_TCP) #ifdef KERN_TLS || tls != NULL #endif ) { use_ext_pgs = true; #ifdef KERN_TLS if (tls != NULL) max_pgs = num_pages(tls->params.max_frame_len); else #endif max_pgs = MBUF_PEXT_MAX_PGS; /* Start at last index, to wrap on first use. */ ext_pgs_idx = max_pgs - 1; } for (int i = 0; i < npages; i++) { /* * If a page wasn't grabbed successfully, then * trim the array. Can happen only with SF_NODISKIO. */ if (pa[i] == NULL) { SFSTAT_INC(sf_busy); fixspace(npages, i, off, &space); sfio->npages = i; softerr = EBUSY; break; } pga = pa[i]; if (pga == bogus_page) pga = vm_page_relookup(obj, sfio->pindex0 + i); if (use_ext_pgs) { off_t xfs; ext_pgs_idx++; if (ext_pgs_idx == max_pgs) { m0 = mb_alloc_ext_pgs(M_WAITOK, sendfile_free_mext_pg); if (flags & SF_NOCACHE) { m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; /* * See comment below regarding * ignoring SF_NOCACHE for the * last page. */ if ((npages - i <= max_pgs) && ((off + space) & PAGE_MASK) && (rem > space || rhpages > 0)) m0->m_ext.ext_flags |= EXT_FLAG_CACHE_LAST; } if (sfs != NULL) { m0->m_ext.ext_flags |= EXT_FLAG_SYNC; m0->m_ext.ext_arg1 = sfs; mtx_lock(&sfs->mtx); sfs->count++; mtx_unlock(&sfs->mtx); } ext_pgs_idx = 0; /* Append to mbuf chain. */ if (mtail != NULL) mtail->m_next = m0; else m = m0; mtail = m0; m0->m_epg_1st_off = vmoff(i, off) & PAGE_MASK; } if (nios) { mtail->m_flags |= M_NOTREADY; m0->m_epg_nrdy++; } m0->m_epg_pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pga); m0->m_epg_npgs++; xfs = xfsize(i, npages, off, space); m0->m_epg_last_len = xfs; MBUF_EXT_PGS_ASSERT_SANITY(m0); mtail->m_len += xfs; mtail->m_ext.ext_size += PAGE_SIZE; continue; } /* * Get a sendfile buf. When allocating the * first buffer for mbuf chain, we usually * wait as long as necessary, but this wait * can be interrupted. For consequent * buffers, do not sleep, since several * threads might exhaust the buffers and then * deadlock. */ sf = sf_buf_alloc(pga, m != NULL ? SFB_NOWAIT : SFB_CATCH); if (sf == NULL) { SFSTAT_INC(sf_allocfail); sendfile_iowait(sfio, "sfnosf"); for (int j = i; j < npages; j++) { vm_page_unwire(pa[j], PQ_INACTIVE); pa[j] = NULL; } if (m == NULL) softerr = ENOBUFS; fixspace(npages, i, off, &space); sfio->npages = i; break; } m0 = m_get(M_WAITOK, MT_DATA); m0->m_ext.ext_buf = (char *)sf_buf_kva(sf); m0->m_ext.ext_size = PAGE_SIZE; m0->m_ext.ext_arg1 = sf; m0->m_ext.ext_type = EXT_SFBUF; m0->m_ext.ext_flags = EXT_FLAG_EMBREF; m0->m_ext.ext_free = sendfile_free_mext; /* * SF_NOCACHE sets the page as being freed upon send. * However, we ignore it for the last page in 'space', * if the page is truncated, and we got more data to * send (rem > space), or if we have readahead * configured (rhpages > 0). */ if ((flags & SF_NOCACHE) && (i != npages - 1 || !((off + space) & PAGE_MASK) || !(rem > space || rhpages > 0))) m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE; if (sfs != NULL) { m0->m_ext.ext_flags |= EXT_FLAG_SYNC; m0->m_ext.ext_arg2 = sfs; mtx_lock(&sfs->mtx); sfs->count++; mtx_unlock(&sfs->mtx); } m0->m_ext.ext_count = 1; m0->m_flags |= (M_EXT | M_RDONLY); if (nios) m0->m_flags |= M_NOTREADY; m0->m_data = (char *)sf_buf_kva(sf) + (vmoff(i, off) & PAGE_MASK); m0->m_len = xfsize(i, npages, off, space); /* Append to mbuf chain. */ if (mtail != NULL) mtail->m_next = m0; else m = m0; mtail = m0; } if (vp != NULL) VOP_UNLOCK(vp); /* Keep track of bytes processed. */ off += space; rem -= space; /* * Prepend header, if any. Save pointer to first mbuf * with a page. */ if (hdrlen) { prepend_header: m0 = mhtail->m_next = m; m = mh; mh = NULL; } else m0 = m; if (m == NULL) { KASSERT(softerr, ("%s: m NULL, no error", __func__)); error = softerr; sendfile_iodone(sfio, NULL, 0, 0); goto done; } /* Add the buffer chain to the socket buffer. */ KASSERT(m_length(m, NULL) == space + hdrlen, ("%s: mlen %u space %d hdrlen %d", __func__, m_length(m, NULL), space, hdrlen)); CURVNET_SET(so->so_vnet); #ifdef KERN_TLS if (tls != NULL) ktls_frame(m, tls, &tls_enq_cnt, TLS_RLTYPE_APP); #endif if (nios == 0) { /* * If sendfile_swapin() didn't initiate any I/Os, * which happens if all data is cached in VM, or if * the header consumed all socket buffer space and * sfio is NULL, then we can send data right now * without the PRUS_NOTREADY flag. */ if (sfio != NULL) sendfile_iodone(sfio, NULL, 0, 0); #ifdef KERN_TLS if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) { error = so->so_proto->pr_send(so, PRUS_NOTREADY, m, NULL, NULL, td); if (error != 0) { m_freem(m); } else { soref(so); ktls_enqueue(m, so, tls_enq_cnt); } } else #endif error = so->so_proto->pr_send(so, 0, m, NULL, NULL, td); } else { sfio->so = so; sfio->m = m0; soref(so); error = so->so_proto->pr_send(so, PRUS_NOTREADY, m, NULL, NULL, td); sendfile_iodone(sfio, NULL, 0, error); } CURVNET_RESTORE(); m = NULL; if (error) goto done; sbytes += space + hdrlen; if (hdrlen) hdrlen = 0; if (softerr) { error = softerr; goto done; } } /* * Send trailers. Wimp out and use writev(2). */ if (trl_uio != NULL) { SOCK_IO_SEND_UNLOCK(so); error = kern_writev(td, sockfd, trl_uio); if (error == 0) sbytes += td->td_retval[0]; goto out; } done: SOCK_IO_SEND_UNLOCK(so); out: /* * If there was no error we have to clear td->td_retval[0] * because it may have been set by writev. */ if (error == 0) { td->td_retval[0] = 0; } if (sent != NULL) { (*sent) = sbytes; } if (obj != NULL) vm_object_deallocate(obj); if (so) fdrop(sock_fp, td); if (m) m_freem(m); if (mh) m_freem(mh); if (sfs != NULL) { mtx_lock(&sfs->mtx); if (sfs->count != 0) error = cv_wait_sig(&sfs->cv, &sfs->mtx); if (sfs->count == 0) { sendfile_sync_destroy(sfs); } else { sfs->waiting = false; mtx_unlock(&sfs->mtx); } } #ifdef KERN_TLS if (tls != NULL) ktls_free(tls); #endif if (error == ERESTART) error = EINTR; return (error); } static int sendfile(struct thread *td, struct sendfile_args *uap, int compat) { struct sf_hdtr hdtr; struct uio *hdr_uio, *trl_uio; struct file *fp; off_t sbytes; int error; /* * File offset must be positive. If it goes beyond EOF * we send only the header/trailer and no payload data. */ if (uap->offset < 0) return (EINVAL); sbytes = 0; hdr_uio = trl_uio = NULL; if (uap->hdtr != NULL) { error = copyin(uap->hdtr, &hdtr, sizeof(hdtr)); if (error != 0) goto out; if (hdtr.headers != NULL) { error = copyinuio(hdtr.headers, hdtr.hdr_cnt, &hdr_uio); if (error != 0) goto out; #ifdef COMPAT_FREEBSD4 /* * In FreeBSD < 5.0 the nbytes to send also included * the header. If compat is specified subtract the * header size from nbytes. */ if (compat) { if (uap->nbytes > hdr_uio->uio_resid) uap->nbytes -= hdr_uio->uio_resid; else uap->nbytes = 0; } #endif } if (hdtr.trailers != NULL) { error = copyinuio(hdtr.trailers, hdtr.trl_cnt, &trl_uio); if (error != 0) goto out; } } AUDIT_ARG_FD(uap->fd); /* * sendfile(2) can start at any offset within a file so we require * CAP_READ+CAP_SEEK = CAP_PREAD. */ if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0) goto out; error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset, uap->nbytes, &sbytes, uap->flags, td); fdrop(fp, td); if (uap->sbytes != NULL) copyout(&sbytes, uap->sbytes, sizeof(off_t)); out: free(hdr_uio, M_IOV); free(trl_uio, M_IOV); return (error); } /* * sendfile(2) * * int sendfile(int fd, int s, off_t offset, size_t nbytes, * struct sf_hdtr *hdtr, off_t *sbytes, int flags) * * Send a file specified by 'fd' and starting at 'offset' to a socket * specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes == * 0. Optionally add a header and/or trailer to the socket output. If * specified, write the total number of bytes sent into *sbytes. */ int sys_sendfile(struct thread *td, struct sendfile_args *uap) { return (sendfile(td, uap, 0)); } #ifdef COMPAT_FREEBSD4 int freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap) { struct sendfile_args args; args.fd = uap->fd; args.s = uap->s; args.offset = uap->offset; args.nbytes = uap->nbytes; args.hdtr = uap->hdtr; args.sbytes = uap->sbytes; args.flags = uap->flags; return (sendfile(td, &args, 1)); } #endif /* COMPAT_FREEBSD4 */