/*- * Copyright (c) 1997 Berkeley Software Design, Inc. 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. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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. * * from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp */ #include __FBSDID("$FreeBSD: head/sys/nfsclient/nfs_lock.c 114216 2003-04-29 13:36:06Z kan $"); #include #include #include #include /* for hz */ #include #include #include #include /* for hz */ /* Must come after sys/malloc.h */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * XXX * We have to let the process know if the call succeeded. I'm using an extra * field in the p_nlminfo field in the proc structure, as it is already for * lockd stuff. */ /* * nfs_advlock -- * NFS advisory byte-level locks. */ int nfs_dolock(struct vop_advlock_args *ap) { LOCKD_MSG msg; struct nameidata nd; struct thread *td; struct vnode *vp, *wvp; int error, error1; struct flock *fl; int fmode, ioflg; struct proc *p; td = curthread; p = td->td_proc; vp = ap->a_vp; fl = ap->a_fl; /* * the NLM protocol doesn't allow the server to return an error * on ranges, so we do it. */ if (fl->l_whence != SEEK_END) { if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) || fl->l_start < 0 || (fl->l_len < 0 && (fl->l_start == 0 || fl->l_start + fl->l_len < 0))) return (EINVAL); if (fl->l_len > 0 && (fl->l_len - 1 > OFF_MAX - fl->l_start)) return (EOVERFLOW); } /* * Fill in the information structure. */ msg.lm_version = LOCKD_MSG_VERSION; msg.lm_msg_ident.pid = p->p_pid; /* * if there is no nfsowner table yet, allocate one. */ if (p->p_nlminfo == NULL) { MALLOC(p->p_nlminfo, struct nlminfo *, sizeof(struct nlminfo), M_LOCKF, M_WAITOK | M_ZERO); p->p_nlminfo->pid_start = p->p_stats->p_start; } msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start; msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq); msg.lm_fl = *fl; msg.lm_wait = ap->a_flags & F_WAIT; msg.lm_getlk = ap->a_op == F_GETLK; bcopy(VFSTONFS(vp->v_mount)->nm_nam, &msg.lm_addr, min(sizeof msg.lm_addr, VFSTONFS(vp->v_mount)->nm_nam->sa_len)); msg.lm_fh_len = NFS_ISV3(vp) ? VTONFS(vp)->n_fhsize : NFSX_V2FH; bcopy(VTONFS(vp)->n_fhp, msg.lm_fh, msg.lm_fh_len); msg.lm_nfsv3 = NFS_ISV3(vp); cru2x(td->td_ucred, &msg.lm_cred); /* * Open the lock fifo. If for any reason we don't find the fifo, it * means that the lock daemon isn't running. Translate any missing * file error message for the user, otherwise the application will * complain that the user's file is missing, which isn't the case. * Note that we use proc0's cred, so the fifo is opened as root. * * XXX: Note that this behavior is relative to the root directory * of the current process, and this may result in a variety of * {functional, security} problems in chroot() environments. */ NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, _PATH_LCKFIFO, td); fmode = FFLAGS(O_WRONLY | O_NONBLOCK); error = vn_open_cred(&nd, &fmode, 0, thread0.td_ucred); switch (error) { case ENOENT: case ENXIO: /* * Map a failure to find the fifo or no listener on the * fifo to locking not being supported. */ return (EOPNOTSUPP); case 0: break; default: return (error); } wvp = nd.ni_vp; VOP_UNLOCK(wvp, 0, td); /* vn_open leaves it locked */ ioflg = IO_UNIT | IO_NOMACCHECK; for (;;) { VOP_LEASE(wvp, td, thread0.td_ucred, LEASE_WRITE); error = vn_rdwr(UIO_WRITE, wvp, (caddr_t)&msg, sizeof(msg), 0, UIO_SYSSPACE, ioflg, thread0.td_ucred, NOCRED, NULL, td); if (error && (((ioflg & IO_NDELAY) == 0) || error != EAGAIN)) { break; } /* * If we're locking a file, wait for an answer. Unlocks succeed * immediately. */ if (fl->l_type == F_UNLCK) /* * XXX this isn't exactly correct. The client side * needs to continue sending it's unlock until * it gets a responce back. */ break; /* * retry after 20 seconds if we haven't gotten a responce yet. * This number was picked out of thin air... but is longer * then even a reasonably loaded system should take (at least * on a local network). XXX Probably should use a back-off * scheme. */ error = tsleep(p->p_nlminfo, PCATCH | PUSER, "lockd", 20*hz); if (error != 0) { if (error == EWOULDBLOCK) { /* * We timed out, so we rewrite the request * to the fifo, but only if it isn't already * full. */ ioflg |= IO_NDELAY; continue; } break; } if (msg.lm_getlk && p->p_nlminfo->retcode == 0) { if (p->p_nlminfo->set_getlk_pid) { fl->l_pid = p->p_nlminfo->getlk_pid; } else { fl->l_type = F_UNLCK; } } error = p->p_nlminfo->retcode; break; } error1 = vn_close(wvp, FWRITE, thread0.td_ucred, td); /* prefer any previous 'error' to our vn_close 'error1'. */ return (error != 0 ? error : error1); } /* * nfslockdans -- * NFS advisory byte-level locks answer from the lock daemon. */ int nfslockdans(struct thread *td, struct lockd_ans *ansp) { struct proc *targetp; int error; /* Let root, or someone who once was root (lockd generally * switches to the daemon uid once it is done setting up) make * this call. * * XXX This authorization check is probably not right. */ if ((error = suser(td)) != 0 && td->td_ucred->cr_svuid != 0) return (error); /* the version should match, or we're out of sync */ if (ansp->la_vers != LOCKD_ANS_VERSION) return (EINVAL); /* Find the process, set its return errno and wake it up. */ if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL) return (ESRCH); /* verify the pid hasn't been reused (if we can), and it isn't waiting * for an answer from a more recent request. We return an EPIPE if * the match fails, because we've already used ESRCH above, and this * is sort of like writing on a pipe after the reader has closed it. */ if (targetp->p_nlminfo == NULL || ((ansp->la_msg_ident.msg_seq != -1) && (timevalcmp(&targetp->p_nlminfo->pid_start, &ansp->la_msg_ident.pid_start, !=) || targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) { PROC_UNLOCK(targetp); return (EPIPE); } targetp->p_nlminfo->retcode = ansp->la_errno; targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid; targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid; wakeup(targetp->p_nlminfo); PROC_UNLOCK(targetp); return (0); }