2 * (The copyright below applies to ufs_access())
4 * Copyright (c) 1982, 1986, 1989, 1993, 1995
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
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9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
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13 * modification, are permitted provided that the following conditions
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22 * This product includes software developed by the University of
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40 * @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
41 * $DragonFly: src/sys/kern/vfs_helper.c,v 1.5 2008/05/25 18:34:46 dillon Exp $
44 #include "opt_quota.h"
45 #include "opt_suiddir.h"
47 #include <sys/param.h>
48 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/fcntl.h>
53 #include <sys/mount.h>
54 #include <sys/unistd.h>
55 #include <sys/vnode.h>
56 #include <sys/file.h> /* XXX */
60 #include <sys/sysctl.h>
61 #include <sys/sfbuf.h>
62 #include <vm/vm_extern.h>
63 #include <vm/vm_object.h>
65 #ifdef LWBUF_IS_OPTIMAL
67 static int vm_read_shortcut_enable = 0;
68 static long vm_read_shortcut_count;
69 static long vm_read_shortcut_failed;
70 SYSCTL_INT(_vm, OID_AUTO, read_shortcut_enable, CTLFLAG_RW,
71 &vm_read_shortcut_enable, 0, "Direct vm_object vop_read shortcut");
72 SYSCTL_LONG(_vm, OID_AUTO, read_shortcut_count, CTLFLAG_RW,
73 &vm_read_shortcut_count, 0, "Statistics");
74 SYSCTL_LONG(_vm, OID_AUTO, read_shortcut_failed, CTLFLAG_RW,
75 &vm_read_shortcut_failed, 0, "Statistics");
82 * Provide standard UNIX semanics for VOP_ACCESS, but without the quota
83 * code. This procedure was basically pulled out of UFS.
86 vop_helper_access(struct vop_access_args *ap, uid_t ino_uid, gid_t ino_gid,
87 mode_t ino_mode, u_int32_t ino_flags)
89 struct vnode *vp = ap->a_vp;
90 struct ucred *cred = ap->a_cred;
91 mode_t mask, mode = ap->a_mode;
97 if (ap->a_flags & AT_EACCESS) {
98 proc_uid = cred->cr_uid;
99 proc_gid = cred->cr_gid;
101 proc_uid = cred->cr_ruid;
102 proc_gid = cred->cr_rgid;
106 * Disallow write attempts on read-only filesystems;
107 * unless the file is a socket, fifo, or a block or
108 * character device resident on the filesystem.
111 switch (vp->v_type) {
116 if (vp->v_mount->mnt_flag & MNT_RDONLY)
124 /* If immutable bit set, nobody gets to write it. */
125 if ((mode & VWRITE) && (ino_flags & IMMUTABLE))
128 /* Otherwise, user id 0 always gets access. */
134 /* Otherwise, check the owner. */
135 if (proc_uid == ino_uid) {
142 return ((ino_mode & mask) == mask ? 0 : EACCES);
146 * Otherwise, check the groups.
147 * We must special-case the primary group to, if needed, check against
148 * the real gid and not the effective one.
150 if (proc_gid == ino_gid) {
157 return ((ino_mode & mask) == mask ? 0 : EACCES);
159 for (i = 1, gp = &cred->cr_groups[1]; i < cred->cr_ngroups; i++, gp++)
160 if (ino_gid == *gp) {
167 return ((ino_mode & mask) == mask ? 0 : EACCES);
170 /* Otherwise, check everyone else. */
177 return ((ino_mode & mask) == mask ? 0 : EACCES);
181 vop_helper_setattr_flags(u_int32_t *ino_flags, u_int32_t vaflags,
182 uid_t uid, struct ucred *cred)
187 * If uid doesn't match only a privileged user can change the flags
189 if (cred->cr_uid != uid &&
190 (error = priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0))) {
193 if (cred->cr_uid == 0 &&
194 (!jailed(cred)|| jail_chflags_allowed)) {
195 if ((*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND)) &&
198 *ino_flags = vaflags;
200 if (*ino_flags & (SF_NOUNLINK|SF_IMMUTABLE|SF_APPEND) ||
201 (vaflags & UF_SETTABLE) != vaflags)
203 *ino_flags &= SF_SETTABLE;
204 *ino_flags |= vaflags & UF_SETTABLE;
210 * This helper function may be used by VFSs to implement UNIX initial
211 * ownership semantics when creating new objects inside directories.
214 vop_helper_create_uid(struct mount *mp, mode_t dmode, uid_t duid,
215 struct ucred *cred, mode_t *modep)
218 if ((mp->mnt_flag & MNT_SUIDDIR) && (dmode & S_ISUID) &&
219 duid != cred->cr_uid && duid) {
224 return(cred->cr_uid);
228 * This helper may be used by VFSs to implement unix chmod semantics.
231 vop_helper_chmod(struct vnode *vp, mode_t new_mode, struct ucred *cred,
232 uid_t cur_uid, gid_t cur_gid, mode_t *cur_modep)
236 if (cred->cr_uid != cur_uid) {
237 error = priv_check_cred(cred, PRIV_VFS_CHMOD, 0);
242 if (vp->v_type != VDIR && (*cur_modep & S_ISTXT))
244 if (!groupmember(cur_gid, cred) && (*cur_modep & S_ISGID))
247 *cur_modep &= ~ALLPERMS;
248 *cur_modep |= new_mode & ALLPERMS;
253 * This helper may be used by VFSs to implement unix chown semantics.
256 vop_helper_chown(struct vnode *vp, uid_t new_uid, gid_t new_gid,
258 uid_t *cur_uidp, gid_t *cur_gidp, mode_t *cur_modep)
264 if (new_uid == (uid_t)VNOVAL)
266 if (new_gid == (gid_t)VNOVAL)
270 * If we don't own the file, are trying to change the owner
271 * of the file, or are not a member of the target group,
272 * the caller must be privileged or the call fails.
274 if ((cred->cr_uid != *cur_uidp || new_uid != *cur_uidp ||
275 (new_gid != *cur_gidp && !(cred->cr_gid == new_gid ||
276 groupmember(new_gid, cred)))) &&
277 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) {
288 * DragonFly clears both SUID and SGID if either the owner or
289 * group is changed and root isn't doing it. If root is doing
290 * it we do not clear SUID/SGID.
292 if (cred->cr_uid != 0 && (ouid != new_uid || ogid != new_gid))
293 *cur_modep &= ~(S_ISUID | S_ISGID);
297 #ifdef LWBUF_IS_OPTIMAL
300 * A VFS can call this function to try to dispose of a read request
301 * directly from the VM system, pretty much bypassing almost all VFS
302 * overhead except for atime updates.
304 * If 0 is returned some or all of the uio was handled. The caller must
305 * check the uio and handle the remainder.
307 * The caller must fail on a non-zero error.
310 vop_helper_read_shortcut(struct vop_read_args *ap)
315 struct lwbuf lwb_cache;
326 * We can't short-cut if there is no VM object or this is a special
327 * UIO_NOCOPY read (typically from VOP_STRATEGY()). We also can't
328 * do this if we cannot extract the filesize from the vnode.
330 if (vm_read_shortcut_enable == 0)
332 if (vp->v_object == NULL || uio->uio_segflg == UIO_NOCOPY)
334 if (vp->v_filesize == NOOFFSET)
336 if (uio->uio_resid == 0)
340 * Iterate the uio on a page-by-page basis
342 * XXX can we leave the object held shared during the uiomove()?
344 ++vm_read_shortcut_count;
346 vm_object_hold_shared(obj);
349 while (uio->uio_resid && error == 0) {
350 offset = (int)uio->uio_offset & PAGE_MASK;
351 n = PAGE_SIZE - offset;
352 if (n > uio->uio_resid)
354 if (vp->v_filesize < uio->uio_offset)
356 if (uio->uio_offset + n > vp->v_filesize)
357 n = vp->v_filesize - uio->uio_offset;
361 m = vm_page_lookup(obj, OFF_TO_IDX(uio->uio_offset));
363 ++vm_read_shortcut_failed;
367 if (m->flags & PG_BUSY) {
368 ++vm_read_shortcut_failed;
372 if ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
373 ++vm_read_shortcut_failed;
377 lwb = lwbuf_alloc(m, &lwb_cache);
378 error = uiomove((char *)lwbuf_kva(lwb) + offset, n, uio);
379 vm_page_flag_set(m, PG_REFERENCED);
391 * If lwbuf's aren't optimal then it's best to just use the buffer
395 vop_helper_read_shortcut(struct vop_read_args *ap)