/* $NetBSD: kernfs_vnops.c,v 1.67 1999/08/25 14:42:35 sommerfeld Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software donated to Berkeley by * Jan-Simon Pendry. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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. * * @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95 */ /* * Kernel parameter filesystem (/kern) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define KSTRING 256 /* Largest I/O available via this filesystem */ #define UIO_MX 32 #define READ_MODE (S_IRUSR|S_IRGRP|S_IROTH) #define WRITE_MODE (S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH) #define DIR_MODE (S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) struct kern_target kern_targets[] = { /* NOTE: The name must be less than UIO_MX-16 chars in length */ #define N(s) sizeof(s)-1, s /* name data tag type ro/rw */ { DT_DIR, N("."), 0, KTT_NULL, VDIR, DIR_MODE }, { DT_DIR, N(".."), 0, KTT_NULL, VDIR, DIR_MODE }, { DT_REG, N("boottime"), &boottime.tv_sec, KTT_INT, VREG, READ_MODE }, { DT_REG, N("copyright"), copyright, KTT_STRING, VREG, READ_MODE }, { DT_REG, N("hostname"), 0, KTT_HOSTNAME, VREG, WRITE_MODE }, { DT_REG, N("hz"), &hz, KTT_INT, VREG, READ_MODE }, { DT_REG, N("loadavg"), 0, KTT_AVENRUN, VREG, READ_MODE }, { DT_REG, N("msgbuf"), 0, KTT_MSGBUF, VREG, READ_MODE }, { DT_REG, N("pagesize"), &uvmexp.pagesize, KTT_INT, VREG, READ_MODE }, { DT_REG, N("physmem"), &physmem, KTT_INT, VREG, READ_MODE }, #if 0 { DT_DIR, N("root"), 0, KTT_NULL, VDIR, DIR_MODE }, #endif { DT_BLK, N("rootdev"), &rootdev, KTT_DEVICE, VBLK, READ_MODE }, { DT_CHR, N("rrootdev"), &rrootdev, KTT_DEVICE, VCHR, READ_MODE }, { DT_REG, N("time"), 0, KTT_TIME, VREG, READ_MODE }, { DT_REG, N("version"), version, KTT_STRING, VREG, READ_MODE }, #undef N }; static int nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]); int kernfs_lookup __P((void *)); #define kernfs_create genfs_eopnotsupp_rele #define kernfs_mknod genfs_eopnotsupp_rele #define kernfs_open genfs_nullop #define kernfs_close genfs_nullop int kernfs_access __P((void *)); int kernfs_getattr __P((void *)); int kernfs_setattr __P((void *)); int kernfs_read __P((void *)); int kernfs_write __P((void *)); #define kernfs_fcntl genfs_fcntl #define kernfs_ioctl genfs_enoioctl #define kernfs_poll genfs_poll #define kernfs_revoke genfs_revoke #define kernfs_mmap genfs_eopnotsupp #define kernfs_fsync genfs_nullop #define kernfs_seek genfs_nullop #define kernfs_remove genfs_eopnotsupp_rele int kernfs_link __P((void *)); #define kernfs_rename genfs_eopnotsupp_rele #define kernfs_mkdir genfs_eopnotsupp_rele #define kernfs_rmdir genfs_eopnotsupp_rele int kernfs_symlink __P((void *)); int kernfs_readdir __P((void *)); #define kernfs_readlink genfs_eopnotsupp #define kernfs_abortop genfs_abortop int kernfs_inactive __P((void *)); int kernfs_reclaim __P((void *)); #define kernfs_lock genfs_lock #define kernfs_unlock genfs_unlock #define kernfs_bmap genfs_badop #define kernfs_strategy genfs_badop int kernfs_print __P((void *)); #define kernfs_islocked genfs_islocked int kernfs_pathconf __P((void *)); #define kernfs_advlock genfs_einval #define kernfs_blkatoff genfs_eopnotsupp #define kernfs_valloc genfs_eopnotsupp #define kernfs_vfree genfs_nullop #define kernfs_truncate genfs_eopnotsupp #define kernfs_update genfs_nullop #define kernfs_bwrite genfs_eopnotsupp int kernfs_xread __P((struct kern_target *, int, char **, int)); int kernfs_xwrite __P((struct kern_target *, char *, int)); int (**kernfs_vnodeop_p) __P((void *)); struct vnodeopv_entry_desc kernfs_vnodeop_entries[] = { { &vop_default_desc, vn_default_error }, { &vop_lookup_desc, kernfs_lookup }, /* lookup */ { &vop_create_desc, kernfs_create }, /* create */ { &vop_mknod_desc, kernfs_mknod }, /* mknod */ { &vop_open_desc, kernfs_open }, /* open */ { &vop_close_desc, kernfs_close }, /* close */ { &vop_access_desc, kernfs_access }, /* access */ { &vop_getattr_desc, kernfs_getattr }, /* getattr */ { &vop_setattr_desc, kernfs_setattr }, /* setattr */ { &vop_read_desc, kernfs_read }, /* read */ { &vop_write_desc, kernfs_write }, /* write */ { &vop_fcntl_desc, kernfs_fcntl }, /* fcntl */ { &vop_ioctl_desc, kernfs_ioctl }, /* ioctl */ { &vop_poll_desc, kernfs_poll }, /* poll */ { &vop_revoke_desc, kernfs_revoke }, /* revoke */ { &vop_mmap_desc, kernfs_mmap }, /* mmap */ { &vop_fsync_desc, kernfs_fsync }, /* fsync */ { &vop_seek_desc, kernfs_seek }, /* seek */ { &vop_remove_desc, kernfs_remove }, /* remove */ { &vop_link_desc, kernfs_link }, /* link */ { &vop_rename_desc, kernfs_rename }, /* rename */ { &vop_mkdir_desc, kernfs_mkdir }, /* mkdir */ { &vop_rmdir_desc, kernfs_rmdir }, /* rmdir */ { &vop_symlink_desc, kernfs_symlink }, /* symlink */ { &vop_readdir_desc, kernfs_readdir }, /* readdir */ { &vop_readlink_desc, kernfs_readlink }, /* readlink */ { &vop_abortop_desc, kernfs_abortop }, /* abortop */ { &vop_inactive_desc, kernfs_inactive }, /* inactive */ { &vop_reclaim_desc, kernfs_reclaim }, /* reclaim */ { &vop_lock_desc, kernfs_lock }, /* lock */ { &vop_unlock_desc, kernfs_unlock }, /* unlock */ { &vop_bmap_desc, kernfs_bmap }, /* bmap */ { &vop_strategy_desc, kernfs_strategy }, /* strategy */ { &vop_print_desc, kernfs_print }, /* print */ { &vop_islocked_desc, kernfs_islocked }, /* islocked */ { &vop_pathconf_desc, kernfs_pathconf }, /* pathconf */ { &vop_advlock_desc, kernfs_advlock }, /* advlock */ { &vop_blkatoff_desc, kernfs_blkatoff }, /* blkatoff */ { &vop_valloc_desc, kernfs_valloc }, /* valloc */ { &vop_vfree_desc, kernfs_vfree }, /* vfree */ { &vop_truncate_desc, kernfs_truncate }, /* truncate */ { &vop_update_desc, kernfs_update }, /* update */ { &vop_bwrite_desc, kernfs_bwrite }, /* bwrite */ { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } }; struct vnodeopv_desc kernfs_vnodeop_opv_desc = { &kernfs_vnodeop_p, kernfs_vnodeop_entries }; int kernfs_xread(kt, off, bufp, len) struct kern_target *kt; int off; char **bufp; int len; { switch (kt->kt_tag) { case KTT_TIME: { struct timeval tv; microtime(&tv); sprintf(*bufp, "%ld %ld\n", tv.tv_sec, tv.tv_usec); break; } case KTT_INT: { int *ip = kt->kt_data; sprintf(*bufp, "%d\n", *ip); break; } case KTT_STRING: { char *cp = kt->kt_data; *bufp = cp; break; } case KTT_MSGBUF: { long n; /* * deal with cases where the message buffer has * become corrupted. */ if (!msgbufenabled || msgbufp->msg_magic != MSG_MAGIC) { msgbufenabled = 0; return (ENXIO); } /* * Note that reads of /kern/msgbuf won't necessarily yield * consistent results, if the message buffer is modified * while the read is in progress. The worst that can happen * is that incorrect data will be read. There's no way * that this can crash the system unless the values in the * message buffer header are corrupted, but that'll cause * the system to die anyway. */ if (off >= msgbufp->msg_bufs) return (0); n = msgbufp->msg_bufx + off; if (n >= msgbufp->msg_bufs) n -= msgbufp->msg_bufs; len = min(msgbufp->msg_bufs - n, msgbufp->msg_bufs - off); *bufp = msgbufp->msg_bufc + n; return (len); } case KTT_HOSTNAME: { char *cp = hostname; int xlen = hostnamelen; if (xlen >= (len-2)) return (EINVAL); memcpy(*bufp, cp, xlen); (*bufp)[xlen] = '\n'; (*bufp)[xlen+1] = '\0'; break; } case KTT_AVENRUN: averunnable.fscale = FSCALE; sprintf(*bufp, "%d %d %d %ld\n", averunnable.ldavg[0], averunnable.ldavg[1], averunnable.ldavg[2], averunnable.fscale); break; default: return (0); } len = strlen(*bufp); if (len <= off) return (0); *bufp += off; return (len - off); } int kernfs_xwrite(kt, buf, len) struct kern_target *kt; char *buf; int len; { switch (kt->kt_tag) { case KTT_HOSTNAME: if (buf[len-1] == '\n') --len; memcpy(hostname, buf, len); hostname[len] = '\0'; hostnamelen = len; return (0); default: return (EIO); } } /* * vp is the current namei directory * ndp is the name to locate in that directory... */ int kernfs_lookup(v) void *v; { struct vop_lookup_args /* { struct vnode * a_dvp; struct vnode ** a_vpp; struct componentname * a_cnp; } */ *ap = v; struct componentname *cnp = ap->a_cnp; struct vnode **vpp = ap->a_vpp; struct vnode *dvp = ap->a_dvp; const char *pname = cnp->cn_nameptr; struct kern_target *kt; struct vnode *fvp; int error, i, wantpunlock; #ifdef KERNFS_DIAGNOSTIC printf("kernfs_lookup(%p)\n", ap); printf("kernfs_lookup(dp = %p, vpp = %p, cnp = %p)\n", dvp, vpp, ap->a_cnp); printf("kernfs_lookup(%s)\n", pname); #endif *vpp = NULLVP; cnp->cn_flags &= ~PDIRUNLOCK; if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) return (EROFS); if (cnp->cn_namelen == 1 && *pname == '.') { *vpp = dvp; VREF(dvp); return (0); } /* * This code only supports a flat directory, so we don't * need to worry about .. */ #if 0 if (cnp->cn_namelen == 4 && memcmp(pname, "root", 4) == 0) { *vpp = rootdir; VREF(rootdir); vn_lock(rootdir, LK_SHARED | LK_RETRY); return (0); } #endif wantpunlock = (~cnp->cn_flags & (LOCKPARENT | ISLASTCN)); for (kt = kern_targets, i = 0; i < nkern_targets; kt++, i++) { if (cnp->cn_namelen == kt->kt_namlen && memcmp(kt->kt_name, pname, cnp->cn_namelen) == 0) goto found; } #ifdef KERNFS_DIAGNOSTIC printf("kernfs_lookup: i = %d, failed", i); #endif return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS); found: if (kt->kt_tag == KTT_DEVICE) { dev_t *dp = kt->kt_data; loop: if (*dp == NODEV || !vfinddev(*dp, kt->kt_vtype, &fvp)) { return (ENOENT); } *vpp = fvp; if (vget(fvp, LK_EXCLUSIVE)) goto loop; if (wantpunlock) { VOP_UNLOCK(dvp, 0); cnp->cn_flags |= PDIRUNLOCK; } return (0); } #ifdef KERNFS_DIAGNOSTIC printf("kernfs_lookup: allocate new vnode\n"); #endif error = getnewvnode(VT_KERNFS, dvp->v_mount, kernfs_vnodeop_p, &fvp); if (error) { return (error); } MALLOC(fvp->v_data, void *, sizeof(struct kernfs_node), M_TEMP, M_WAITOK); VTOKERN(fvp)->kf_kt = kt; fvp->v_type = kt->kt_vtype; vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY); *vpp = fvp; #ifdef KERNFS_DIAGNOSTIC printf("kernfs_lookup: newvp = %p\n", fvp); #endif if (wantpunlock) { VOP_UNLOCK(dvp, 0); cnp->cn_flags |= PDIRUNLOCK; } return (0); } int kernfs_access(v) void *v; { struct vop_access_args /* { struct vnode *a_vp; int a_mode; struct ucred *a_cred; struct proc *a_p; } */ *ap = v; struct vnode *vp = ap->a_vp; mode_t mode; if (vp->v_flag & VROOT) { mode = DIR_MODE; } else { struct kern_target *kt = VTOKERN(vp)->kf_kt; mode = kt->kt_mode; } return (vaccess(vp->v_type, mode, (uid_t)0, (gid_t)0, ap->a_mode, ap->a_cred)); } int kernfs_getattr(v) void *v; { struct vop_getattr_args /* { struct vnode *a_vp; struct vattr *a_vap; struct ucred *a_cred; struct proc *a_p; } */ *ap = v; struct vnode *vp = ap->a_vp; struct vattr *vap = ap->a_vap; struct timeval tv; int error = 0; char strbuf[KSTRING], *buf; memset((caddr_t) vap, 0, sizeof(*vap)); vattr_null(vap); vap->va_uid = 0; vap->va_gid = 0; vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0]; vap->va_size = 0; vap->va_blocksize = DEV_BSIZE; microtime(&tv); TIMEVAL_TO_TIMESPEC(&tv, &vap->va_atime); vap->va_mtime = vap->va_atime; vap->va_ctime = vap->va_ctime; vap->va_gen = 0; vap->va_flags = 0; vap->va_rdev = 0; vap->va_bytes = 0; if (vp->v_flag & VROOT) { #ifdef KERNFS_DIAGNOSTIC printf("kernfs_getattr: stat rootdir\n"); #endif vap->va_type = VDIR; vap->va_mode = DIR_MODE; vap->va_nlink = 2; vap->va_fileid = 2; vap->va_size = DEV_BSIZE; } else { struct kern_target *kt = VTOKERN(vp)->kf_kt; int nbytes, total; #ifdef KERNFS_DIAGNOSTIC printf("kernfs_getattr: stat target %s\n", kt->kt_name); #endif vap->va_type = kt->kt_vtype; vap->va_mode = kt->kt_mode; vap->va_nlink = 1; vap->va_fileid = 1 + (kt - kern_targets); total = 0; while (buf = strbuf, nbytes = kernfs_xread(kt, total, &buf, sizeof(strbuf))) total += nbytes; vap->va_size = total; } #ifdef KERNFS_DIAGNOSTIC printf("kernfs_getattr: return error %d\n", error); #endif return (error); } /*ARGSUSED*/ int kernfs_setattr(v) void *v; { /* * Silently ignore attribute changes. * This allows for open with truncate to have no * effect until some data is written. I want to * do it this way because all writes are atomic. */ return (0); } int kernfs_read(v) void *v; { struct vop_read_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap = v; struct vnode *vp = ap->a_vp; struct uio *uio = ap->a_uio; struct kern_target *kt; char strbuf[KSTRING], *buf; int off, len; int error; if (vp->v_type == VDIR) return (EOPNOTSUPP); kt = VTOKERN(vp)->kf_kt; #ifdef KERNFS_DIAGNOSTIC printf("kern_read %s\n", kt->kt_name); #endif off = uio->uio_offset; #if 0 while (buf = strbuf, #else if (buf = strbuf, #endif len = kernfs_xread(kt, off, &buf, sizeof(strbuf))) { if ((error = uiomove(buf, len, uio)) != 0) return (error); off += len; } return (0); } int kernfs_write(v) void *v; { struct vop_write_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap = v; struct vnode *vp = ap->a_vp; struct uio *uio = ap->a_uio; struct kern_target *kt; int error, xlen; char strbuf[KSTRING]; if (vp->v_type == VDIR) return (EOPNOTSUPP); kt = VTOKERN(vp)->kf_kt; if (uio->uio_offset != 0) return (EINVAL); xlen = min(uio->uio_resid, KSTRING-1); if ((error = uiomove(strbuf, xlen, uio)) != 0) return (error); if (uio->uio_resid != 0) return (EIO); strbuf[xlen] = '\0'; xlen = strlen(strbuf); return (kernfs_xwrite(kt, strbuf, xlen)); } int kernfs_readdir(v) void *v; { struct vop_readdir_args /* { struct vnode *a_vp; struct uio *a_uio; struct ucred *a_cred; int *a_eofflag; off_t **a_cookies; int a_*ncookies; } */ *ap = v; struct uio *uio = ap->a_uio; struct dirent d; struct kern_target *kt; off_t i; int error; off_t *cookies = NULL; int ncookies = 0, nc = 0; if (ap->a_vp->v_type != VDIR) return (ENOTDIR); if (uio->uio_resid < UIO_MX) return (EINVAL); if (uio->uio_offset < 0) return (EINVAL); error = 0; i = uio->uio_offset; if (i >= nkern_targets) return 0; memset((caddr_t)&d, 0, UIO_MX); d.d_reclen = UIO_MX; if (ap->a_ncookies) { nc = uio->uio_resid / UIO_MX; nc = min(nc, (nkern_targets - i)); MALLOC(cookies, off_t *, nc * sizeof(off_t), M_TEMP, M_WAITOK); *ap->a_cookies = cookies; } for (kt = &kern_targets[i]; uio->uio_resid >= UIO_MX && i < nkern_targets; kt++, i++) { #ifdef KERNFS_DIAGNOSTIC printf("kernfs_readdir: i = %d\n", i); #endif if (kt->kt_tag == KTT_DEVICE) { dev_t *dp = kt->kt_data; struct vnode *fvp; if (*dp == NODEV || !vfinddev(*dp, kt->kt_vtype, &fvp)) continue; } d.d_fileno = i + 3; d.d_namlen = kt->kt_namlen; memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1); d.d_type = kt->kt_type; if ((error = uiomove((caddr_t)&d, UIO_MX, uio)) != 0) break; if (cookies) { *cookies++ = i + 1; ncookies++; } } if (ap->a_ncookies) { if (error) { FREE(*ap->a_cookies, M_TEMP); *ap->a_ncookies = 0; *ap->a_cookies = NULL; } else *ap->a_ncookies = ncookies; } uio->uio_offset = i; return (error); } int kernfs_inactive(v) void *v; { struct vop_inactive_args /* { struct vnode *a_vp; struct proc *a_p; } */ *ap = v; struct vnode *vp = ap->a_vp; #ifdef KERNFS_DIAGNOSTIC printf("kernfs_inactive(%p)\n", vp); #endif /* * Clear out the v_type field to avoid * nasty things happening in vgone(). */ VOP_UNLOCK(vp, 0); vp->v_type = VNON; return (0); } int kernfs_reclaim(v) void *v; { struct vop_reclaim_args /* { struct vnode *a_vp; } */ *ap = v; struct vnode *vp = ap->a_vp; #ifdef KERNFS_DIAGNOSTIC printf("kernfs_reclaim(%p)\n", vp); #endif if (vp->v_data) { FREE(vp->v_data, M_TEMP); vp->v_data = 0; } return (0); } /* * Return POSIX pathconf information applicable to special devices. */ int kernfs_pathconf(v) void *v; { struct vop_pathconf_args /* { struct vnode *a_vp; int a_name; register_t *a_retval; } */ *ap = v; switch (ap->a_name) { case _PC_LINK_MAX: *ap->a_retval = LINK_MAX; return (0); case _PC_MAX_CANON: *ap->a_retval = MAX_CANON; return (0); case _PC_MAX_INPUT: *ap->a_retval = MAX_INPUT; return (0); case _PC_PIPE_BUF: *ap->a_retval = PIPE_BUF; return (0); case _PC_CHOWN_RESTRICTED: *ap->a_retval = 1; return (0); case _PC_VDISABLE: *ap->a_retval = _POSIX_VDISABLE; return (0); case _PC_SYNC_IO: *ap->a_retval = 1; return (0); default: return (EINVAL); } /* NOTREACHED */ } /* * Print out the contents of a /dev/fd vnode. */ /* ARGSUSED */ int kernfs_print(v) void *v; { printf("tag VT_KERNFS, kernfs vnode\n"); return (0); } int kernfs_link(v) void *v; { struct vop_link_args /* { struct vnode *a_dvp; struct vnode *a_vp; struct componentname *a_cnp; } */ *ap = v; VOP_ABORTOP(ap->a_dvp, ap->a_cnp); vput(ap->a_dvp); return (EROFS); } int kernfs_symlink(v) void *v; { struct vop_symlink_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; struct vattr *a_vap; char *a_target; } */ *ap = v; VOP_ABORTOP(ap->a_dvp, ap->a_cnp); vput(ap->a_dvp); return (EROFS); }