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NetBSD/sys/miscfs/procfs/procfs_vnops.c

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/* $NetBSD: procfs_vnops.c,v 1.123 2005/05/29 21:55:34 christos Exp $ */
/*
* Copyright (c) 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed 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. 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.
*
* @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95
*/
/*
* Copyright (c) 1993 Jan-Simon Pendry
*
* This code is derived from software contributed 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.
*
* @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95
*/
/*
* procfs vnode interface
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: procfs_vnops.c,v 1.123 2005/05/29 21:55:34 christos Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/dirent.h>
#include <sys/resourcevar.h>
#include <sys/stat.h>
#include <sys/ptrace.h>
#include <uvm/uvm_extern.h> /* for PAGE_SIZE */
#include <machine/reg.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/procfs/procfs.h>
/*
* Vnode Operations.
*
*/
static int procfs_validfile_linux __P((struct proc *, struct mount *));
static int procfs_root_readdir_callback(struct proc *, void *);
/*
* This is a list of the valid names in the
* process-specific sub-directories. It is
* used in procfs_lookup and procfs_readdir
*/
static const struct proc_target {
u_char pt_type;
u_char pt_namlen;
const char *pt_name;
pfstype pt_pfstype;
int (*pt_valid) __P((struct proc *, struct mount *));
} proc_targets[] = {
#define N(s) sizeof(s)-1, s
/* name type validp */
{ DT_DIR, N("."), PFSproc, NULL },
{ DT_DIR, N(".."), PFSroot, NULL },
{ DT_DIR, N("fd"), PFSfd, NULL },
{ DT_REG, N("file"), PFSfile, procfs_validfile },
{ DT_REG, N("mem"), PFSmem, NULL },
{ DT_REG, N("regs"), PFSregs, procfs_validregs },
{ DT_REG, N("fpregs"), PFSfpregs, procfs_validfpregs },
{ DT_REG, N("ctl"), PFSctl, NULL },
{ DT_REG, N("stat"), PFSstat, procfs_validfile_linux },
{ DT_REG, N("status"), PFSstatus, NULL },
{ DT_REG, N("note"), PFSnote, NULL },
{ DT_REG, N("notepg"), PFSnotepg, NULL },
{ DT_REG, N("map"), PFSmap, procfs_validmap },
{ DT_REG, N("maps"), PFSmaps, procfs_validmap },
{ DT_REG, N("cmdline"), PFScmdline, NULL },
{ DT_REG, N("exe"), PFSfile, procfs_validfile_linux },
#ifdef __HAVE_PROCFS_MACHDEP
PROCFS_MACHDEP_NODETYPE_DEFNS
#endif
#undef N
};
static const int nproc_targets = sizeof(proc_targets) / sizeof(proc_targets[0]);
/*
* List of files in the root directory. Note: the validate function will
* be called with p == NULL for these ones.
*/
static const struct proc_target proc_root_targets[] = {
#define N(s) sizeof(s)-1, s
/* name type validp */
{ DT_REG, N("meminfo"), PFSmeminfo, procfs_validfile_linux },
{ DT_REG, N("cpuinfo"), PFScpuinfo, procfs_validfile_linux },
{ DT_REG, N("uptime"), PFSuptime, procfs_validfile_linux },
{ DT_REG, N("mounts"), PFSmounts, procfs_validfile_linux },
#undef N
};
static const int nproc_root_targets =
sizeof(proc_root_targets) / sizeof(proc_root_targets[0]);
int procfs_lookup __P((void *));
#define procfs_create genfs_eopnotsupp
#define procfs_mknod genfs_eopnotsupp
int procfs_open __P((void *));
int procfs_close __P((void *));
int procfs_access __P((void *));
int procfs_getattr __P((void *));
int procfs_setattr __P((void *));
#define procfs_read procfs_rw
#define procfs_write procfs_rw
#define procfs_fcntl genfs_fcntl
#define procfs_ioctl genfs_enoioctl
#define procfs_poll genfs_poll
#define procfs_revoke genfs_revoke
#define procfs_fsync genfs_nullop
#define procfs_seek genfs_nullop
#define procfs_remove genfs_eopnotsupp
int procfs_link __P((void *));
#define procfs_rename genfs_eopnotsupp
#define procfs_mkdir genfs_eopnotsupp
#define procfs_rmdir genfs_eopnotsupp
int procfs_symlink __P((void *));
int procfs_readdir __P((void *));
int procfs_readlink __P((void *));
#define procfs_abortop genfs_abortop
int procfs_inactive __P((void *));
int procfs_reclaim __P((void *));
#define procfs_lock genfs_lock
#define procfs_unlock genfs_unlock
#define procfs_bmap genfs_badop
#define procfs_strategy genfs_badop
int procfs_print __P((void *));
int procfs_pathconf __P((void *));
#define procfs_islocked genfs_islocked
#define procfs_advlock genfs_einval
#define procfs_blkatoff genfs_eopnotsupp
#define procfs_valloc genfs_eopnotsupp
#define procfs_vfree genfs_nullop
#define procfs_truncate genfs_eopnotsupp
#define procfs_update genfs_nullop
#define procfs_bwrite genfs_eopnotsupp
#define procfs_putpages genfs_null_putpages
static int atoi __P((const char *, size_t));
/*
* procfs vnode operations.
*/
int (**procfs_vnodeop_p) __P((void *));
const struct vnodeopv_entry_desc procfs_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, procfs_lookup }, /* lookup */
{ &vop_create_desc, procfs_create }, /* create */
{ &vop_mknod_desc, procfs_mknod }, /* mknod */
{ &vop_open_desc, procfs_open }, /* open */
{ &vop_close_desc, procfs_close }, /* close */
{ &vop_access_desc, procfs_access }, /* access */
{ &vop_getattr_desc, procfs_getattr }, /* getattr */
{ &vop_setattr_desc, procfs_setattr }, /* setattr */
{ &vop_read_desc, procfs_read }, /* read */
{ &vop_write_desc, procfs_write }, /* write */
{ &vop_fcntl_desc, procfs_fcntl }, /* fcntl */
{ &vop_ioctl_desc, procfs_ioctl }, /* ioctl */
{ &vop_poll_desc, procfs_poll }, /* poll */
{ &vop_revoke_desc, procfs_revoke }, /* revoke */
{ &vop_fsync_desc, procfs_fsync }, /* fsync */
{ &vop_seek_desc, procfs_seek }, /* seek */
{ &vop_remove_desc, procfs_remove }, /* remove */
{ &vop_link_desc, procfs_link }, /* link */
{ &vop_rename_desc, procfs_rename }, /* rename */
{ &vop_mkdir_desc, procfs_mkdir }, /* mkdir */
{ &vop_rmdir_desc, procfs_rmdir }, /* rmdir */
{ &vop_symlink_desc, procfs_symlink }, /* symlink */
{ &vop_readdir_desc, procfs_readdir }, /* readdir */
{ &vop_readlink_desc, procfs_readlink }, /* readlink */
{ &vop_abortop_desc, procfs_abortop }, /* abortop */
{ &vop_inactive_desc, procfs_inactive }, /* inactive */
{ &vop_reclaim_desc, procfs_reclaim }, /* reclaim */
{ &vop_lock_desc, procfs_lock }, /* lock */
{ &vop_unlock_desc, procfs_unlock }, /* unlock */
{ &vop_bmap_desc, procfs_bmap }, /* bmap */
{ &vop_strategy_desc, procfs_strategy }, /* strategy */
{ &vop_print_desc, procfs_print }, /* print */
{ &vop_islocked_desc, procfs_islocked }, /* islocked */
{ &vop_pathconf_desc, procfs_pathconf }, /* pathconf */
{ &vop_advlock_desc, procfs_advlock }, /* advlock */
{ &vop_blkatoff_desc, procfs_blkatoff }, /* blkatoff */
{ &vop_valloc_desc, procfs_valloc }, /* valloc */
{ &vop_vfree_desc, procfs_vfree }, /* vfree */
{ &vop_truncate_desc, procfs_truncate }, /* truncate */
{ &vop_update_desc, procfs_update }, /* update */
{ &vop_putpages_desc, procfs_putpages }, /* putpages */
{ NULL, NULL }
};
const struct vnodeopv_desc procfs_vnodeop_opv_desc =
{ &procfs_vnodeop_p, procfs_vnodeop_entries };
/*
* set things up for doing i/o on
* the pfsnode (vp). (vp) is locked
* on entry, and should be left locked
* on exit.
*
* for procfs we don't need to do anything
* in particular for i/o. all that is done
* is to support exclusive open on process
* memory images.
*/
int
procfs_open(v)
void *v;
{
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct proc *p1, *p2;
int error;
p1 = ap->a_p; /* tracer */
p2 = PFIND(pfs->pfs_pid); /* traced */
if (p2 == NULL)
return (ENOENT); /* was ESRCH, jsp */
switch (pfs->pfs_type) {
case PFSmem:
if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) ||
((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE)))
return (EBUSY);
if ((error = process_checkioperm(p1, p2)) != 0)
return (error);
if (ap->a_mode & FWRITE)
pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
return (0);
default:
break;
}
return (0);
}
/*
* close the pfsnode (vp) after doing i/o.
* (vp) is not locked on entry or exit.
*
* nothing to do for procfs other than undo
* any exclusive open flag (see _open above).
*/
int
procfs_close(v)
void *v;
{
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap = v;
struct pfsnode *pfs = VTOPFS(ap->a_vp);
switch (pfs->pfs_type) {
case PFSmem:
if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL))
pfs->pfs_flags &= ~(FWRITE|O_EXCL);
break;
default:
break;
}
return (0);
}
/*
* _inactive is called when the pfsnode
* is vrele'd and the reference count goes
* to zero. (vp) will be on the vnode free
* list, so to get it back vget() must be
* used.
*
* for procfs, check if the process is still
* alive and if it isn't then just throw away
* the vnode by calling vgone(). this may
* be overkill and a waste of time since the
* chances are that the process will still be
* there and PFIND is not free.
*
* (vp) is locked on entry, but must be unlocked on exit.
*/
int
procfs_inactive(v)
void *v;
{
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct pfsnode *pfs = VTOPFS(vp);
VOP_UNLOCK(vp, 0);
if (PFIND(pfs->pfs_pid) == NULL && (vp->v_flag & VXLOCK) == 0)
vgone(vp);
return (0);
}
/*
* _reclaim is called when getnewvnode()
* wants to make use of an entry on the vnode
* free list. at this time the filesystem needs
* to free any private data and remove the node
* from any private lists.
*/
int
procfs_reclaim(v)
void *v;
{
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap = v;
return (procfs_freevp(ap->a_vp));
}
/*
* Return POSIX pathconf information applicable to special devices.
*/
int
procfs_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 is used for debugging.
* just print a readable description
* of (vp).
*/
int
procfs_print(v)
void *v;
{
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct pfsnode *pfs = VTOPFS(ap->a_vp);
printf("tag VT_PROCFS, type %d, pid %d, mode %x, flags %lx\n",
pfs->pfs_type, pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags);
return 0;
}
int
procfs_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
procfs_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);
}
/*
* Invent attributes for pfsnode (vp) and store
* them in (vap).
* Directories lengths are returned as zero since
* any real length would require the genuine size
* to be computed, and nothing cares anyway.
*
* this is relatively minimal for procfs.
*/
int
procfs_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 pfsnode *pfs = VTOPFS(ap->a_vp);
struct vattr *vap = ap->a_vap;
struct proc *procp;
int error;
/* first check the process still exists */
switch (pfs->pfs_type) {
case PFSroot:
case PFScurproc:
case PFSself:
procp = 0;
break;
default:
procp = PFIND(pfs->pfs_pid);
if (procp == NULL)
return (ENOENT);
break;
}
error = 0;
/* start by zeroing out the attributes */
VATTR_NULL(vap);
/* next do all the common fields */
vap->va_type = ap->a_vp->v_type;
vap->va_mode = pfs->pfs_mode;
vap->va_fileid = pfs->pfs_fileno;
vap->va_flags = 0;
vap->va_blocksize = PAGE_SIZE;
/*
* Make all times be current TOD. Avoid microtime(9), it's slow.
* We don't guard the read from time(9) with splclock(9) since we
* don't actually need to be THAT sure the access is atomic.
*
* It would be possible to get the process start
* time from the p_stat structure, but there's
* no "file creation" time stamp anyway, and the
* p_stat structure is not addressible if u. gets
* swapped out for that process.
*/
TIMEVAL_TO_TIMESPEC(&time, &vap->va_ctime);
vap->va_atime = vap->va_mtime = vap->va_ctime;
switch (pfs->pfs_type) {
case PFSmem:
case PFSregs:
case PFSfpregs:
#if defined(__HAVE_PROCFS_MACHDEP) && defined(PROCFS_MACHDEP_PROTECT_CASES)
PROCFS_MACHDEP_PROTECT_CASES
#endif
/*
* If the process has exercised some setuid or setgid
* privilege, then rip away read/write permission so
* that only root can gain access.
*/
if (procp->p_flag & P_SUGID)
vap->va_mode &= ~(S_IRUSR|S_IWUSR);
/* FALLTHROUGH */
case PFSctl:
case PFSstatus:
case PFSstat:
case PFSnote:
case PFSnotepg:
case PFSmap:
case PFSmaps:
case PFScmdline:
vap->va_nlink = 1;
vap->va_uid = procp->p_ucred->cr_uid;
vap->va_gid = procp->p_ucred->cr_gid;
break;
case PFSmeminfo:
case PFScpuinfo:
case PFSuptime:
case PFSmounts:
vap->va_nlink = 1;
vap->va_uid = vap->va_gid = 0;
break;
default:
break;
}
/*
* now do the object specific fields
*
* The size could be set from struct reg, but it's hardly
* worth the trouble, and it puts some (potentially) machine
* dependent data into this machine-independent code. If it
* becomes important then this function should break out into
* a per-file stat function in the corresponding .c file.
*/
switch (pfs->pfs_type) {
case PFSroot:
/*
* Set nlink to 1 to tell fts(3) we don't actually know.
*/
vap->va_nlink = 1;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_bytes = vap->va_size = DEV_BSIZE;
break;
case PFScurproc: {
char bf[16]; /* should be enough */
vap->va_nlink = 1;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_bytes = vap->va_size =
snprintf(bf, sizeof(bf), "%ld", (long)curproc->p_pid);
break;
}
case PFSself:
vap->va_nlink = 1;
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_bytes = vap->va_size = sizeof("curproc") - 1;
break;
case PFSfd:
if (pfs->pfs_fd != -1) {
struct file *fp;
struct proc *pown;
if ((error = procfs_getfp(pfs, &pown, &fp)) != 0)
return error;
FILE_USE(fp);
vap->va_nlink = 1;
vap->va_uid = fp->f_cred->cr_uid;
vap->va_gid = fp->f_cred->cr_gid;
switch (fp->f_type) {
case DTYPE_VNODE:
vap->va_bytes = vap->va_size =
((struct vnode *)fp->f_data)->v_size;
break;
default:
vap->va_bytes = vap->va_size = 0;
break;
}
FILE_UNUSE(fp, pown);
break;
}
/*FALLTHROUGH*/
case PFSproc:
vap->va_nlink = 2;
vap->va_uid = procp->p_ucred->cr_uid;
vap->va_gid = procp->p_ucred->cr_gid;
vap->va_bytes = vap->va_size = DEV_BSIZE;
break;
case PFSfile:
error = EOPNOTSUPP;
break;
case PFSmem:
vap->va_bytes = vap->va_size =
ctob(procp->p_vmspace->vm_tsize +
procp->p_vmspace->vm_dsize +
procp->p_vmspace->vm_ssize);
break;
#if defined(PT_GETREGS) || defined(PT_SETREGS)
case PFSregs:
vap->va_bytes = vap->va_size = sizeof(struct reg);
break;
#endif
#if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
case PFSfpregs:
vap->va_bytes = vap->va_size = sizeof(struct fpreg);
break;
#endif
case PFSctl:
case PFSstatus:
case PFSstat:
case PFSnote:
case PFSnotepg:
case PFScmdline:
case PFSmeminfo:
case PFScpuinfo:
case PFSuptime:
case PFSmounts:
vap->va_bytes = vap->va_size = 0;
break;
case PFSmap:
case PFSmaps:
/*
* Advise a larger blocksize for the map files, so that
* they may be read in one pass.
*/
vap->va_blocksize = 4 * PAGE_SIZE;
vap->va_bytes = vap->va_size = 0;
break;
#ifdef __HAVE_PROCFS_MACHDEP
PROCFS_MACHDEP_NODETYPE_CASES
error = procfs_machdep_getattr(ap->a_vp, vap, procp);
break;
#endif
default:
panic("procfs_getattr");
}
return (error);
}
/*ARGSUSED*/
int
procfs_setattr(v)
void *v;
{
/*
* just fake out attribute setting
* it's not good to generate an error
* return, otherwise things like creat()
* will fail when they try to set the
* file length to 0. worse, this means
* that echo $note > /proc/$pid/note will fail.
*/
return (0);
}
/*
* implement access checking.
*
* actually, the check for super-user is slightly
* broken since it will allow read access to write-only
* objects. this doesn't cause any particular trouble
* but does mean that the i/o entry points need to check
* that the operation really does make sense.
*/
int
procfs_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 vattr va;
int error;
if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_p)) != 0)
return (error);
return (vaccess(va.va_type, va.va_mode,
va.va_uid, va.va_gid, ap->a_mode, ap->a_cred));
}
/*
* lookup. this is incredibly complicated in the
* general case, however for most pseudo-filesystems
* very little needs to be done.
*
* Locking isn't hard here, just poorly documented.
*
* If we're looking up ".", just vref the parent & return it.
*
* If we're looking up "..", unlock the parent, and lock "..". If everything
* went ok, and we're on the last component and the caller requested the
* parent locked, try to re-lock the parent. We do this to prevent lock
* races.
*
* For anything else, get the needed node. Then unlock the parent if not
* the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the
* parent in the .. case).
*
* We try to exit with the parent locked in error cases.
*/
int
procfs_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;
const struct proc_target *pt = NULL;
struct vnode *fvp;
pid_t pid;
struct pfsnode *pfs;
struct proc *p = NULL;
int i, error, wantpunlock, iscurproc = 0, isself = 0;
*vpp = NULL;
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);
}
wantpunlock = (~cnp->cn_flags & (LOCKPARENT | ISLASTCN));
pfs = VTOPFS(dvp);
switch (pfs->pfs_type) {
case PFSroot:
/*
* Shouldn't get here with .. in the root node.
*/
if (cnp->cn_flags & ISDOTDOT)
return (EIO);
iscurproc = CNEQ(cnp, "curproc", 7);
isself = CNEQ(cnp, "self", 4);
if (iscurproc || isself) {
error = procfs_allocvp(dvp->v_mount, vpp, 0,
iscurproc ? PFScurproc : PFSself, -1);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
}
for (i = 0; i < nproc_root_targets; i++) {
pt = &proc_root_targets[i];
if (cnp->cn_namelen == pt->pt_namlen &&
memcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 &&
(pt->pt_valid == NULL ||
(*pt->pt_valid)(p, dvp->v_mount)))
break;
}
if (i != nproc_root_targets) {
error = procfs_allocvp(dvp->v_mount, vpp, 0,
pt->pt_pfstype, -1);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
}
pid = (pid_t)atoi(pname, cnp->cn_namelen);
p = PFIND(pid);
if (p == NULL)
break;
error = procfs_allocvp(dvp->v_mount, vpp, pid, PFSproc, -1);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
case PFSproc:
/*
* do the .. dance. We unlock the directory, and then
* get the root dir. That will automatically return ..
* locked. Then if the caller wanted dvp locked, we
* re-lock.
*/
if (cnp->cn_flags & ISDOTDOT) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
error = procfs_root(dvp->v_mount, vpp);
if ((error == 0) && (wantpunlock == 0) &&
((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
cnp->cn_flags &= ~PDIRUNLOCK;
return (error);
}
p = PFIND(pfs->pfs_pid);
if (p == NULL)
break;
for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) {
if (cnp->cn_namelen == pt->pt_namlen &&
memcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 &&
(pt->pt_valid == NULL ||
(*pt->pt_valid)(p, dvp->v_mount)))
goto found;
}
break;
found:
if (pt->pt_pfstype == PFSfile) {
fvp = p->p_textvp;
/* We already checked that it exists. */
VREF(fvp);
vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY);
if (wantpunlock) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
*vpp = fvp;
return (0);
}
error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
pt->pt_pfstype, -1);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
case PFSfd: {
int fd;
struct file *fp;
/*
* do the .. dance. We unlock the directory, and then
* get the proc dir. That will automatically return ..
* locked. Then if the caller wanted dvp locked, we
* re-lock.
*/
if (cnp->cn_flags & ISDOTDOT) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
PFSproc, -1);
if ((error == 0) && (wantpunlock == 0) &&
((error = vn_lock(dvp, LK_EXCLUSIVE)) == 0))
cnp->cn_flags &= ~PDIRUNLOCK;
return (error);
}
fd = atoi(pname, cnp->cn_namelen);
p = PFIND(pfs->pfs_pid);
if (p == NULL || (fp = fd_getfile(p->p_fd, fd)) == NULL)
return ENOENT;
FILE_USE(fp);
switch (fp->f_type) {
case DTYPE_VNODE:
fvp = (struct vnode *)fp->f_data;
/* Don't show directories */
if (fvp->v_type == VDIR)
goto symlink;
VREF(fvp);
FILE_UNUSE(fp, p);
vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY |
(p == curproc ? LK_CANRECURSE : 0));
*vpp = fvp;
error = 0;
break;
default:
symlink:
FILE_UNUSE(fp, p);
error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
PFSfd, fd);
break;
}
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0);
cnp->cn_flags |= PDIRUNLOCK;
}
return error;
}
default:
return (ENOTDIR);
}
return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS);
}
int
procfs_validfile(p, mp)
struct proc *p;
struct mount *mp;
{
return (p->p_textvp != NULL);
}
static int
procfs_validfile_linux(p, mp)
struct proc *p;
struct mount *mp;
{
int flags;
flags = VFSTOPROC(mp)->pmnt_flags;
return ((flags & PROCFSMNT_LINUXCOMPAT) &&
(p == NULL || procfs_validfile(p, mp)));
}
struct procfs_root_readdir_ctx {
struct uio *uiop;
off_t *cookies;
int ncookies;
off_t off;
off_t startoff;
int error;
};
static int
procfs_root_readdir_callback(struct proc *p, void *arg)
{
struct procfs_root_readdir_ctx *ctxp = arg;
struct dirent d;
struct uio *uiop;
int error;
uiop = ctxp->uiop;
if (uiop->uio_resid < UIO_MX)
return -1; /* no space */
if (ctxp->off < ctxp->startoff) {
ctxp->off++;
return 0;
}
memset(&d, 0, UIO_MX);
d.d_reclen = UIO_MX;
d.d_fileno = PROCFS_FILENO(p->p_pid, PFSproc, -1);
d.d_namlen = snprintf(d.d_name,
UIO_MX - offsetof(struct dirent, d_name), "%ld", (long)p->p_pid);
d.d_type = DT_DIR;
proclist_unlock_read();
error = uiomove(&d, UIO_MX, uiop);
proclist_lock_read();
if (error) {
ctxp->error = error;
return -1;
}
ctxp->ncookies++;
if (ctxp->cookies)
*(ctxp->cookies)++ = ctxp->off + 1;
ctxp->off++;
return 0;
}
/*
* readdir returns directory entries from pfsnode (vp).
*
* the strategy here with procfs is to generate a single
* directory entry at a time (struct dirent) and then
* copy that out to userland using uiomove. a more efficent
* though more complex implementation, would try to minimize
* the number of calls to uiomove(). for procfs, this is
* hardly worth the added code complexity.
*
* this should just be done through read()
*/
int
procfs_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 pfsnode *pfs;
off_t i;
int error;
off_t *cookies = NULL;
int ncookies;
struct vnode *vp;
const struct proc_target *pt;
struct procfs_root_readdir_ctx ctx;
vp = ap->a_vp;
pfs = VTOPFS(vp);
if (uio->uio_resid < UIO_MX)
return (EINVAL);
if (uio->uio_offset < 0)
return (EINVAL);
error = 0;
i = uio->uio_offset;
memset(&d, 0, UIO_MX);
d.d_reclen = UIO_MX;
ncookies = uio->uio_resid / UIO_MX;
switch (pfs->pfs_type) {
/*
* this is for the process-specific sub-directories.
* all that is needed to is copy out all the entries
* from the procent[] table (top of this file).
*/
case PFSproc: {
struct proc *p;
if (i >= nproc_targets)
return 0;
p = PFIND(pfs->pfs_pid);
if (p == NULL)
break;
if (ap->a_ncookies) {
ncookies = min(ncookies, (nproc_targets - i));
cookies = malloc(ncookies * sizeof (off_t),
M_TEMP, M_WAITOK);
*ap->a_cookies = cookies;
}
for (pt = &proc_targets[i];
uio->uio_resid >= UIO_MX && i < nproc_targets; pt++, i++) {
if (pt->pt_valid &&
(*pt->pt_valid)(p, vp->v_mount) == 0)
continue;
d.d_fileno = PROCFS_FILENO(pfs->pfs_pid,
pt->pt_pfstype, -1);
d.d_namlen = pt->pt_namlen;
memcpy(d.d_name, pt->pt_name, pt->pt_namlen + 1);
d.d_type = pt->pt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
}
break;
}
case PFSfd: {
struct proc *p;
struct filedesc *fdp;
struct file *fp;
int lim, nc = 0;
p = PFIND(pfs->pfs_pid);
if (p == NULL)
return ESRCH;
fdp = p->p_fd;
lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
if (i >= lim)
return 0;
if (ap->a_ncookies) {
ncookies = min(ncookies, (fdp->fd_nfiles + 2 - i));
cookies = malloc(ncookies * sizeof (off_t),
M_TEMP, M_WAITOK);
*ap->a_cookies = cookies;
}
for (; i < 2 && uio->uio_resid >= UIO_MX; i++) {
pt = &proc_targets[i];
d.d_namlen = pt->pt_namlen;
d.d_fileno = PROCFS_FILENO(pfs->pfs_pid,
pt->pt_pfstype, -1);
(void)memcpy(d.d_name, pt->pt_name, pt->pt_namlen + 1);
d.d_type = pt->pt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
nc++;
}
if (error) {
ncookies = nc;
break;
}
for (; uio->uio_resid >= UIO_MX && i < fdp->fd_nfiles; i++) {
/* check the descriptor exists */
if ((fp = fd_getfile(fdp, i - 2)) == NULL)
continue;
simple_unlock(&fp->f_slock);
d.d_fileno = PROCFS_FILENO(pfs->pfs_pid, PFSfd, i - 2);
d.d_namlen = snprintf(d.d_name, sizeof(d.d_name),
"%lld", (long long)(i - 2));
d.d_type = VREG;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
if (cookies)
*cookies++ = i + 1;
nc++;
}
ncookies = nc;
break;
}
/*
* this is for the root of the procfs filesystem
* what is needed are special entries for "curproc"
* and "self" followed by an entry for each process
* on allproc.
*/
case PFSroot: {
int nc = 0;
if (ap->a_ncookies) {
/*
* XXX Potentially allocating too much space here,
* but I'm lazy. This loop needs some work.
*/
cookies = malloc(ncookies * sizeof (off_t),
M_TEMP, M_WAITOK);
*ap->a_cookies = cookies;
}
error = 0;
/* 0 ... 3 are static entries. */
for (; i <= 3 && uio->uio_resid >= UIO_MX; i++) {
switch (i) {
case 0: /* `.' */
case 1: /* `..' */
d.d_fileno = PROCFS_FILENO(0, PFSroot, -1);
d.d_namlen = i + 1;
memcpy(d.d_name, "..", d.d_namlen);
d.d_name[i + 1] = '\0';
d.d_type = DT_DIR;
break;
case 2:
d.d_fileno = PROCFS_FILENO(0, PFScurproc, -1);
d.d_namlen = sizeof("curproc") - 1;
memcpy(d.d_name, "curproc", sizeof("curproc"));
d.d_type = DT_LNK;
break;
case 3:
d.d_fileno = PROCFS_FILENO(0, PFSself, -1);
d.d_namlen = sizeof("self") - 1;
memcpy(d.d_name, "self", sizeof("self"));
d.d_type = DT_LNK;
break;
}
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
nc++;
if (cookies)
*cookies++ = i + 1;
}
/* 4 ... are process entries. */
ctx.uiop = uio;
ctx.error = 0;
ctx.off = 4;
ctx.startoff = i;
ctx.cookies = cookies;
ctx.ncookies = nc;
proclist_foreach_call(&allproc,
procfs_root_readdir_callback, &ctx);
cookies = ctx.cookies;
nc = ctx.ncookies;
error = ctx.error;
if (error)
break;
/* misc entries. */
if (i < ctx.off)
i = ctx.off;
if (i >= ctx.off + nproc_root_targets)
break;
for (pt = &proc_root_targets[i - ctx.off];
uio->uio_resid >= UIO_MX &&
pt < &proc_root_targets[nproc_root_targets];
pt++, i++) {
if (pt->pt_valid &&
(*pt->pt_valid)(NULL, vp->v_mount) == 0)
continue;
d.d_fileno = PROCFS_FILENO(0, pt->pt_pfstype, -1);
d.d_namlen = pt->pt_namlen;
memcpy(d.d_name, pt->pt_name, pt->pt_namlen + 1);
d.d_type = pt->pt_type;
if ((error = uiomove(&d, UIO_MX, uio)) != 0)
break;
nc++;
if (cookies)
*cookies++ = i + 1;
}
ncookies = nc;
break;
}
default:
error = ENOTDIR;
break;
}
if (ap->a_ncookies) {
if (error) {
if (cookies)
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);
}
/*
* readlink reads the link of `curproc'
*/
int
procfs_readlink(v)
void *v;
{
struct vop_readlink_args *ap = v;
char bf[16]; /* should be enough */
char *bp = bf;
char *path = NULL;
int len;
int error = 0;
struct pfsnode *pfs = VTOPFS(ap->a_vp);
if (pfs->pfs_fileno == PROCFS_FILENO(0, PFScurproc, -1))
len = snprintf(bf, sizeof(bf), "%ld", (long)curproc->p_pid);
else if (pfs->pfs_fileno == PROCFS_FILENO(0, PFSself, -1))
len = snprintf(bf, sizeof(bf), "%s", "curproc");
else {
struct file *fp;
struct proc *pown;
struct vnode *vxp, *vp;
if ((error = procfs_getfp(pfs, &pown, &fp)) != 0)
return error;
FILE_USE(fp);
switch (fp->f_type) {
case DTYPE_VNODE:
vxp = (struct vnode *)fp->f_data;
if (vxp->v_type != VDIR) {
FILE_UNUSE(fp, pown);
return EINVAL;
}
if ((path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK))
== NULL) {
FILE_UNUSE(fp, pown);
return ENOMEM;
}
bp = path + MAXPATHLEN;
*--bp = '\0';
vp = curproc->p_cwdi->cwdi_rdir;
if (vp == NULL)
vp = rootvnode;
error = getcwd_common(vxp, vp, &bp, path,
MAXPATHLEN / 2, 0, curproc);
FILE_UNUSE(fp, pown);
if (error) {
free(path, M_TEMP);
return error;
}
len = strlen(bp);
break;
case DTYPE_MISC:
len = snprintf(bf, sizeof(bf), "%s", "[misc]");
break;
case DTYPE_KQUEUE:
len = snprintf(bf, sizeof(bf), "%s", "[kqueue]");
break;
default:
return EINVAL;
}
}
error = uiomove(bp, len, ap->a_uio);
if (path)
free(path, M_TEMP);
return error;
}
/*
* convert decimal ascii to int
*/
static int
atoi(b, len)
const char *b;
size_t len;
{
int p = 0;
while (len--) {
char c = *b++;
if (c < '0' || c > '9')
return -1;
p = 10 * p + (c - '0');
}
return p;
}
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