d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
607dba5ff6
freebsd-skq/sys/fs/procfs/procfs_vnops.c
Robert Watson b1fc0ec1a7 o Merge contents of struct pcred into struct ucred. Specifically, add the 
real uid, saved uid, real gid, and saved gid to ucred, as well as the
  pcred->pc_uidinfo, which was associated with the real uid, only rename
  it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
  corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
  original macro that pointed.
  p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
  p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
  cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
  cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
  we figure out locking and optimizations; generally speaking, this
  means moving to a structure like this:
        newcred = crdup(oldcred);
        ...
        p->p_ucred = newcred;
        crfree(oldcred);
  It's not race-free, but better than nothing.  There are also races
  in sys_process.c, all inter-process authorization, fork, exec, and
  exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
  remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
  use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
  pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
  allocation.
o Clean up ktrcanset() to take into account changes, and move to using
  suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
  calls to better document current behavior.  In a couple of places,
  current behavior is a little questionable and we need to check
  POSIX.1 to make sure it's "right".  More commenting work still
  remains to be done.
o Update credential management calls, such as crfree(), to take into
  account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
      change_euid()
      change_egid()
      change_ruid()
      change_rgid()
      change_svuid()
      change_svgid()
  In each case, the call now acts on a credential not a process, and as
  such no longer requires more complicated process locking/etc.  They
  now assume the caller will do any necessary allocation of an
  exclusive credential reference.  Each is commented to document its
  reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
  and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
  questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
  processes and pcreds.  Note that this authorization, as well as
  CANSIGIO(), needs to be updated to use the p_cansignal() and
  p_cansched() centralized authorization routines, as they currently
  do not take into account some desirable restrictions that are handled
  by the centralized routines, as well as being inconsistent with other
  similar authorization instances.
o Update libkvm to take these changes into account.

Obtained from:	TrustedBSD Project
Reviewed by:	green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00

1022 lines
24 KiB
C
Raw Blame History

/*
* Copyright (c) 1993, 1995 Jan-Simon Pendry
* 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. 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
*
* $FreeBSD$
*/
/*
* procfs vnode interface
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/pioctl.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/sx.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <machine/reg.h>
#include <vm/vm_zone.h>
#include <fs/procfs/procfs.h>
static int procfs_access __P((struct vop_access_args *));
static int procfs_badop __P((void));
static int procfs_close __P((struct vop_close_args *));
static int procfs_getattr __P((struct vop_getattr_args *));
static int procfs_ioctl __P((struct vop_ioctl_args *));
static int procfs_lookup __P((struct vop_lookup_args *));
static int procfs_open __P((struct vop_open_args *));
static int procfs_print __P((struct vop_print_args *));
static int procfs_readdir __P((struct vop_readdir_args *));
static int procfs_readlink __P((struct vop_readlink_args *));
static int procfs_reclaim __P((struct vop_reclaim_args *));
static int procfs_setattr __P((struct vop_setattr_args *));
/*
* This is a list of the valid names in the
* process-specific sub-directories. It is
* used in procfs_lookup and procfs_readdir
*/
static struct proc_target {
u_char pt_type;
u_char pt_namlen;
char *pt_name;
pfstype pt_pfstype;
int (*pt_valid) __P((struct proc *p));
} proc_targets[] = {
#define N(s) sizeof(s)-1, s
/* name type validp */
{ DT_DIR, N("."), Pproc, NULL },
{ DT_DIR, N(".."), Proot, NULL },
{ DT_REG, N("mem"), Pmem, NULL },
{ DT_REG, N("regs"), Pregs, procfs_validregs },
{ DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs },
{ DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs },
{ DT_REG, N("ctl"), Pctl, NULL },
{ DT_REG, N("status"), Pstatus, NULL },
{ DT_REG, N("note"), Pnote, NULL },
{ DT_REG, N("notepg"), Pnotepg, NULL },
{ DT_REG, N("map"), Pmap, procfs_validmap },
{ DT_REG, N("etype"), Ptype, procfs_validtype },
{ DT_REG, N("cmdline"), Pcmdline, NULL },
{ DT_REG, N("rlimit"), Prlimit, NULL },
{ DT_LNK, N("file"), Pfile, NULL },
#undef N
};
static const int nproc_targets = sizeof(proc_targets) / sizeof(proc_targets[0]);
static pid_t atopid __P((const char *, u_int));
/*
* 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.
*/
static int
procfs_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct proc *p1, *p2;
int error = 0;
p2 = PFIND(pfs->pfs_pid);
if (p2 == NULL)
return (ENOENT);
if (pfs->pfs_pid && p_can(ap->a_p, p2, P_CAN_SEE, NULL)) {
error = ENOENT;
goto out;
}
switch (pfs->pfs_type) {
case Pmem:
if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) ||
((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))) {
error = EBUSY;
goto out;
}
p1 = ap->a_p;
if (p_can(p1, p2, P_CAN_DEBUG, NULL) &&
!procfs_kmemaccess(p1)) {
error = EPERM;
}
if (ap->a_mode & FWRITE)
pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
default:
break;
}
out:
PROC_UNLOCK(p2);
return (error);
}
/*
* 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).
*/
static int
procfs_close(ap)
struct vop_close_args /* {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct proc *p;
switch (pfs->pfs_type) {
case Pmem:
if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL))
pfs->pfs_flags &= ~(FWRITE|O_EXCL);
/*
* If this is the last close, then it checks to see if
* the target process has PF_LINGER set in p_pfsflags,
* if this is *not* the case, then the process' stop flags
* are cleared, and the process is woken up. This is
* to help prevent the case where a process has been
* told to stop on an event, but then the requesting process
* has gone away or forgotten about it.
*/
if ((ap->a_vp->v_usecount < 2) && (p = pfind(pfs->pfs_pid))) {
if (!(p->p_pfsflags & PF_LINGER)) {
p->p_stops = 0;
p->p_step = 0;
wakeup(&p->p_step);
}
PROC_UNLOCK(p);
}
break;
default:
break;
}
return (0);
}
/*
* do an ioctl operation on a pfsnode (vp).
* (vp) is not locked on entry or exit.
*/
static int
procfs_ioctl(ap)
struct vop_ioctl_args *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct proc *procp, *p;
int error;
int signo;
struct procfs_status *psp;
unsigned char flags;
p = ap->a_p;
procp = pfind(pfs->pfs_pid);
if (procp == NULL) {
return ENOTTY;
}
if ((error = p_can(p, procp, P_CAN_DEBUG, NULL))) {
PROC_UNLOCK(procp);
return (error == ESRCH ? ENOENT : error);
}
switch (ap->a_command) {
case PIOCBIS:
procp->p_stops |= *(unsigned int*)ap->a_data;
break;
case PIOCBIC:
procp->p_stops &= ~*(unsigned int*)ap->a_data;
break;
case PIOCSFL:
/*
* NFLAGS is "non-suser_xxx flags" -- currently, only
* PFS_ISUGID ("ignore set u/g id");
*/
#define NFLAGS (PF_ISUGID)
flags = (unsigned char)*(unsigned int*)ap->a_data;
if (flags & NFLAGS && (error = suser(p))) {
PROC_UNLOCK(procp);
return error;
}
procp->p_pfsflags = flags;
break;
case PIOCGFL:
*(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags;
/* FALLTHROUGH */
case PIOCSTATUS:
psp = (struct procfs_status *)ap->a_data;
psp->state = (procp->p_step == 0);
psp->flags = procp->p_pfsflags;
psp->events = procp->p_stops;
if (procp->p_step) {
psp->why = procp->p_stype;
psp->val = procp->p_xstat;
} else {
psp->why = psp->val = 0; /* Not defined values */
}
break;
case PIOCWAIT:
psp = (struct procfs_status *)ap->a_data;
if (procp->p_step == 0) {
error = msleep(&procp->p_stype, &procp->p_mtx, PWAIT | PCATCH,
"piocwait", 0);
if (error) {
PROC_UNLOCK(procp);
return error;
}
}
psp->state = 1; /* It stopped */
psp->flags = procp->p_pfsflags;
psp->events = procp->p_stops;
psp->why = procp->p_stype; /* why it stopped */
psp->val = procp->p_xstat; /* any extra info */
break;
case PIOCCONT: /* Restart a proc */
if (procp->p_step == 0) {
PROC_UNLOCK(procp);
return EINVAL; /* Can only start a stopped process */
}
if ((signo = *(int*)ap->a_data) != 0) {
if (signo >= NSIG || signo <= 0) {
PROC_UNLOCK(procp);
return EINVAL;
}
psignal(procp, signo);
}
procp->p_step = 0;
wakeup(&procp->p_step);
break;
default:
PROC_UNLOCK(procp);
return (ENOTTY);
}
PROC_UNLOCK(procp);
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.
*/
static int
procfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
return (procfs_freevp(ap->a_vp));
}
/*
* _print is used for debugging.
* just print a readable description
* of (vp).
*/
static int
procfs_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
printf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n",
pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags);
return (0);
}
/*
* generic entry point for unsupported operations
*/
static int
procfs_badop()
{
return (EIO);
}
/*
* 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.
*/
static int
procfs_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct vattr *vap = ap->a_vap;
struct proc *procp;
int error;
/*
* First make sure that the process and its credentials
* still exist.
*/
switch (pfs->pfs_type) {
case Proot:
case Pcurproc:
procp = NULL;
break;
default:
procp = PFIND(pfs->pfs_pid);
if (procp == NULL)
return (ENOENT);
if (procp->p_ucred == NULL) {
PROC_UNLOCK(procp);
return (ENOENT);
}
if (p_can(ap->a_p, procp, P_CAN_SEE, NULL)) {
PROC_UNLOCK(procp);
return (ENOENT);
}
PROC_UNLOCK(procp);
}
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;
vap->va_bytes = vap->va_size = 0;
vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
/*
* Make all times be current TOD.
* 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.
*/
nanotime(&vap->va_ctime);
vap->va_atime = vap->va_mtime = vap->va_ctime;
/*
* If the process has exercised some setuid or setgid
* privilege, then rip away read/write permission so
* that only root can gain access.
*/
switch (pfs->pfs_type) {
case Pctl:
case Pregs:
case Pfpregs:
case Pdbregs:
if (procp->p_flag & P_SUGID)
vap->va_mode &= ~((VREAD|VWRITE)|
((VREAD|VWRITE)>>3)|
((VREAD|VWRITE)>>6));
break;
case Pmem:
/* Retain group kmem readablity. */
PROC_LOCK(procp);
if (procp->p_flag & P_SUGID)
vap->va_mode &= ~(VREAD|VWRITE);
PROC_UNLOCK(procp);
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.
*/
vap->va_nlink = 1;
if (procp) {
PROC_LOCK(procp);
vap->va_uid = procp->p_ucred->cr_uid;
vap->va_gid = procp->p_ucred->cr_gid;
PROC_UNLOCK(procp);
}
switch (pfs->pfs_type) {
case Proot:
/*
* 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_size = vap->va_bytes = DEV_BSIZE;
break;
case Pcurproc: {
char buf[16]; /* should be enough */
vap->va_uid = 0;
vap->va_gid = 0;
vap->va_size = vap->va_bytes =
snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid);
break;
}
case Pproc:
vap->va_nlink = nproc_targets;
vap->va_size = vap->va_bytes = DEV_BSIZE;
break;
case Pfile: {
char *fullpath, *freepath;
error = textvp_fullpath(procp, &fullpath, &freepath);
if (error == 0) {
vap->va_size = strlen(fullpath);
free(freepath, M_TEMP);
} else {
vap->va_size = sizeof("unknown") - 1;
error = 0;
}
vap->va_bytes = vap->va_size;
break;
}
case Pmem:
/*
* If we denied owner access earlier, then we have to
* change the owner to root - otherwise 'ps' and friends
* will break even though they are setgid kmem. *SIGH*
*/
PROC_LOCK(procp);
if (procp->p_flag & P_SUGID)
vap->va_uid = 0;
else
vap->va_uid = procp->p_ucred->cr_uid;
PROC_UNLOCK(procp);
vap->va_gid = KMEM_GROUP;
break;
case Pregs:
vap->va_bytes = vap->va_size = sizeof(struct reg);
break;
case Pfpregs:
vap->va_bytes = vap->va_size = sizeof(struct fpreg);
break;
case Pdbregs:
vap->va_bytes = vap->va_size = sizeof(struct dbreg);
break;
case Ptype:
case Pmap:
case Pctl:
case Pstatus:
case Pnote:
case Pnotepg:
case Pcmdline:
case Prlimit:
break;
default:
panic("procfs_getattr");
}
return (error);
}
static int
procfs_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
if (ap->a_vap->va_flags != VNOVAL)
return (EOPNOTSUPP);
/*
* 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.
*/
static int
procfs_access(ap)
struct vop_access_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct pfsnode *pfs = VTOPFS(ap->a_vp);
struct vnode *vp = ap->a_vp;
struct proc *procp;
struct vattr *vap;
struct vattr vattr;
int error;
switch (pfs->pfs_type) {
case Proot:
case Pcurproc:
break;
default:
procp = PFIND(pfs->pfs_pid);
if (procp == NULL)
return (ENOENT);
if (p_can(ap->a_p, procp, P_CAN_SEE, NULL)) {
PROC_UNLOCK(procp);
return (ENOENT);
}
PROC_UNLOCK(procp);
}
vap = &vattr;
error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
if (error)
return (error);
return (vaccess(vp->v_type, vap->va_mode, vap->va_uid, vap->va_gid,
ap->a_mode, ap->a_cred, NULL));
}
/*
* lookup. this is incredibly complicated in the
* general case, however for most pseudo-filesystems
* very little needs to be done.
*
* unless you want to get a migraine, just make sure your
* filesystem doesn't do any locking of its own. otherwise
* read and inwardly digest ufs_lookup().
*/
static int
procfs_lookup(ap)
struct vop_lookup_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap;
{
struct componentname *cnp = ap->a_cnp;
struct vnode **vpp = ap->a_vpp;
struct vnode *dvp = ap->a_dvp;
char *pname = cnp->cn_nameptr;
struct proc *curp = cnp->cn_proc;
struct proc_target *pt;
pid_t pid;
struct pfsnode *pfs;
struct proc *p;
int i;
*vpp = NULL;
if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME ||
cnp->cn_nameiop == CREATE)
return (EROFS);
if (cnp->cn_namelen == 1 && *pname == '.') {
*vpp = dvp;
VREF(dvp);
/* vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, curp); */
return (0);
}
pfs = VTOPFS(dvp);
switch (pfs->pfs_type) {
case Proot:
if (cnp->cn_flags & ISDOTDOT)
return (EIO);
if (CNEQ(cnp, "curproc", 7))
return (procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc));
pid = atopid(pname, cnp->cn_namelen);
if (pid == NO_PID)
break;
p = PFIND(pid);
if (p == NULL)
break;
if (p_can(curp, p, P_CAN_SEE, NULL)) {
PROC_UNLOCK(p);
break;
}
PROC_UNLOCK(p);
return (procfs_allocvp(dvp->v_mount, vpp, pid, Pproc));
case Pproc:
if (cnp->cn_flags & ISDOTDOT)
return (procfs_root(dvp->v_mount, vpp));
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 &&
bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 &&
(pt->pt_valid == NULL || (*pt->pt_valid)(p)))
goto found;
}
PROC_UNLOCK(p);
break;
found:
PROC_UNLOCK(p);
return (procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
pt->pt_pfstype));
default:
return (ENOTDIR);
}
return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS);
}
/*
* Does this process have a text file?
*/
int
procfs_validfile(p)
struct proc *p;
{
return (procfs_findtextvp(p) != NULLVP);
}
/*
* readdir() returns directory entries from pfsnode (vp).
*
* We generate just one directory entry at a time, as it would probably
* not pay off to buffer several entries locally to save uiomove calls.
*/
static int
procfs_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *a_ncookies;
u_long **a_cookies;
} */ *ap;
{
struct uio *uio = ap->a_uio;
struct dirent d;
struct dirent *dp = &d;
struct pfsnode *pfs;
int count, error, i, off;
static u_int delen;
if (!delen) {
d.d_namlen = PROCFS_NAMELEN;
delen = GENERIC_DIRSIZ(&d);
}
pfs = VTOPFS(ap->a_vp);
off = (int)uio->uio_offset;
if (off != uio->uio_offset || off < 0 ||
off % delen != 0 || uio->uio_resid < delen)
return (EINVAL);
error = 0;
count = 0;
i = off / delen;
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 Pproc: {
struct proc *p;
struct proc_target *pt;
p = PFIND(pfs->pfs_pid);
if (p == NULL)
break;
if (p_can(curproc, p, P_CAN_SEE, NULL)) {
PROC_UNLOCK(p);
break;
}
for (pt = &proc_targets[i];
uio->uio_resid >= delen && i < nproc_targets; pt++, i++) {
if (pt->pt_valid && (*pt->pt_valid)(p) == 0)
continue;
dp->d_reclen = delen;
dp->d_fileno = PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype);
dp->d_namlen = pt->pt_namlen;
bcopy(pt->pt_name, dp->d_name, pt->pt_namlen + 1);
dp->d_type = pt->pt_type;
if ((error = uiomove((caddr_t)dp, delen, uio)) != 0)
break;
}
PROC_UNLOCK(p);
break;
}
/*
* this is for the root of the procfs filesystem
* what is needed is a special entry for "curproc"
* followed by an entry for each process on allproc
#ifdef PROCFS_ZOMBIE
* and zombproc.
#endif
*/
case Proot: {
#ifdef PROCFS_ZOMBIE
int doingzomb = 0;
#endif
int pcnt = 0;
struct proc *p;
sx_slock(&allproc_lock);
p = LIST_FIRST(&allproc);
for (; p && uio->uio_resid >= delen; i++, pcnt++) {
bzero((char *) dp, delen);
dp->d_reclen = delen;
switch (i) {
case 0: /* `.' */
case 1: /* `..' */
dp->d_fileno = PROCFS_FILENO(0, Proot);
dp->d_namlen = i + 1;
bcopy("..", dp->d_name, dp->d_namlen);
dp->d_name[i + 1] = '\0';
dp->d_type = DT_DIR;
break;
case 2:
dp->d_fileno = PROCFS_FILENO(0, Pcurproc);
dp->d_namlen = 7;
bcopy("curproc", dp->d_name, 8);
dp->d_type = DT_LNK;
break;
default:
while (pcnt < i) {
p = LIST_NEXT(p, p_list);
if (p == NULL)
goto done;
if (p_can(curproc, p, P_CAN_SEE, NULL))
continue;
pcnt++;
}
while (p_can(curproc, p, P_CAN_SEE, NULL)) {
p = LIST_NEXT(p, p_list);
if (p == NULL)
goto done;
}
dp->d_fileno = PROCFS_FILENO(p->p_pid, Pproc);
dp->d_namlen = sprintf(dp->d_name, "%ld",
(long)p->p_pid);
dp->d_type = DT_DIR;
p = LIST_NEXT(p, p_list);
break;
}
if ((error = uiomove((caddr_t)dp, delen, uio)) != 0)
break;
}
done:
#ifdef PROCFS_ZOMBIE
if (p == NULL && doingzomb == 0) {
doingzomb = 1;
p = LIST_FIRST(&zombproc);
goto again;
}
#endif
sx_sunlock(&allproc_lock);
break;
}
default:
error = ENOTDIR;
break;
}
uio->uio_offset = i * delen;
return (error);
}
/*
* readlink reads the link of `curproc' or `file'
*/
static int
procfs_readlink(ap)
struct vop_readlink_args *ap;
{
char buf[16]; /* should be enough */
struct proc *procp;
struct vnode *vp = ap->a_vp;
struct pfsnode *pfs = VTOPFS(vp);
char *fullpath, *freepath;
int error, len;
switch (pfs->pfs_type) {
case Pcurproc:
if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc))
return (EINVAL);
len = snprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid);
return (uiomove(buf, len, ap->a_uio));
/*
* There _should_ be no way for an entire process to disappear
* from under us...
*/
case Pfile:
procp = PFIND(pfs->pfs_pid);
if (procp == NULL || procp->p_ucred == NULL) {
if (procp != NULL)
PROC_UNLOCK(procp);
printf("procfs_readlink: pid %d disappeared\n",
pfs->pfs_pid);
return (uiomove("unknown", sizeof("unknown") - 1,
ap->a_uio));
}
PROC_UNLOCK(procp);
error = textvp_fullpath(procp, &fullpath, &freepath);
if (error != 0)
return (uiomove("unknown", sizeof("unknown") - 1,
ap->a_uio));
error = uiomove(fullpath, strlen(fullpath), ap->a_uio);
free(freepath, M_TEMP);
return (error);
default:
return (EINVAL);
}
}
/*
* convert decimal ascii to pid_t
*/
static pid_t
atopid(b, len)
const char *b;
u_int len;
{
pid_t p = 0;
while (len--) {
char c = *b++;
if (c < '0' || c > '9')
return (NO_PID);
p = 10 * p + (c - '0');
if (p > PID_MAX)
return (NO_PID);
}
return (p);
}
/*
* procfs vnode operations.
*/
vop_t **procfs_vnodeop_p;
static struct vnodeopv_entry_desc procfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_access_desc, (vop_t *) procfs_access },
{ &vop_advlock_desc, (vop_t *) procfs_badop },
{ &vop_close_desc, (vop_t *) procfs_close },
{ &vop_create_desc, (vop_t *) procfs_badop },
{ &vop_getattr_desc, (vop_t *) procfs_getattr },
{ &vop_link_desc, (vop_t *) procfs_badop },
{ &vop_lookup_desc, (vop_t *) procfs_lookup },
{ &vop_mkdir_desc, (vop_t *) procfs_badop },
{ &vop_mknod_desc, (vop_t *) procfs_badop },
{ &vop_open_desc, (vop_t *) procfs_open },
{ &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
{ &vop_print_desc, (vop_t *) procfs_print },
{ &vop_read_desc, (vop_t *) procfs_rw },
{ &vop_readdir_desc, (vop_t *) procfs_readdir },
{ &vop_readlink_desc, (vop_t *) procfs_readlink },
{ &vop_reclaim_desc, (vop_t *) procfs_reclaim },
{ &vop_remove_desc, (vop_t *) procfs_badop },
{ &vop_rename_desc, (vop_t *) procfs_badop },
{ &vop_rmdir_desc, (vop_t *) procfs_badop },
{ &vop_setattr_desc, (vop_t *) procfs_setattr },
{ &vop_symlink_desc, (vop_t *) procfs_badop },
{ &vop_write_desc, (vop_t *) procfs_rw },
{ &vop_ioctl_desc, (vop_t *) procfs_ioctl },
{ NULL, NULL }
};
static struct vnodeopv_desc procfs_vnodeop_opv_desc =
{ &procfs_vnodeop_p, procfs_vnodeop_entries };
VNODEOP_SET(procfs_vnodeop_opv_desc);
Reference in New Issue View Git Blame Copy Permalink