/*
* 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().
*/
int
procfs_lookup(void *v)
{
struct vop_lookup_args *ap = v;
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 = curproc;
const struct proc_target *pt;
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 Proot:
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 ? Pcurproc : Pself);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0, curp);
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);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0, curp);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
}
pid = atopid(pname, cnp->cn_namelen);
if (pid == NO_PID)
break;
p = pfind(pid);
if (p == 0)
break;
error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc);
if ((error == 0) && wantpunlock) {
VOP_UNLOCK(dvp, 0, curp);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
case Pproc:
/*
* 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, p);
cnp->cn_flags |= PDIRUNLOCK;
error = procfs_root(dvp->v_mount, vpp);
if ((error == 0) && (wantpunlock == 0) &&
((error = vn_lock(dvp, LK_EXCLUSIVE, curp)) == 0))
cnp->cn_flags &= ~PDIRUNLOCK;
return (error);
}
p = pfind(pfs->pfs_pid);
if (p == 0)
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, dvp->v_mount)))
goto found;
}
break;
found:
if (pt->pt_pfstype == Pfile) {
fvp = p->p_textvp;
/* We already checked that it exists. */
VREF(fvp);
vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY, curp);
if (wantpunlock) {
VOP_UNLOCK(dvp, 0, curp);
cnp->cn_flags |= PDIRUNLOCK;
}
*vpp = fvp;
return (0);
}
error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
pt->pt_pfstype);
if ((error == 0) && (wantpunlock)) {
VOP_UNLOCK(dvp, 0, curp);
cnp->cn_flags |= PDIRUNLOCK;
}
return (error);
default:
return (ENOTDIR);
}
return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS);
}
/*
* lookup. this is incredibly complicated in the general case, however
* for most pseudo-filesystems very little needs to be done.
*
* procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
* struct componentname *a_cnp)
*/
static int
procfs_lookup(struct vop_old_lookup_args *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;
struct lwp *lp;
int i;
int error;
*vpp = NULL;
if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME)
return (EROFS);
p = NULL;
error = 0;
if (cnp->cn_namelen == 1 && *pname == '.') {
*vpp = dvp;
vref(*vpp);
goto out;
}
pfs = VTOPFS(dvp);
switch (pfs->pfs_type) {
case Proot:
if (cnp->cn_flags & CNP_ISDOTDOT)
return (EIO);
if (CNEQ(cnp, "curproc", 7)) {
error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc);
goto out;
}
pid = atopid(pname, cnp->cn_namelen);
if (pid == NO_PID)
break;
p = pfs_pfind(pid);
if (p == NULL)
break;
if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred))
break;
if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 &&
ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid)
break;
error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc);
goto out;
case Pproc:
if (cnp->cn_flags & CNP_ISDOTDOT) {
error = procfs_root(dvp->v_mount, vpp);
goto out;
}
p = pfs_pfind(pfs->pfs_pid);
if (p == NULL)
break;
/* XXX lwp */
lp = FIRST_LWP_IN_PROC(p);
if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred))
break;
if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 &&
ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid)
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)(lp)))
goto found;
}
break;
found:
error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid,
pt->pt_pfstype);
goto out;
default:
error = ENOTDIR;
goto out;
}
if (cnp->cn_nameiop == NAMEI_LOOKUP)
error = ENOENT;
else
error = EROFS;
/*
* If no error occured *vpp will hold a referenced locked vnode.
* dvp was passed to us locked and *vpp must be returned locked.
* If *vpp != dvp then we should unlock dvp if (1) this is not the
* last component or (2) CNP_LOCKPARENT is not set.
*/
out:
if (error == 0 && *vpp != dvp) {
if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) {
cnp->cn_flags |= CNP_PDIRUNLOCK;
vn_unlock(dvp);
}
}
if (p)
PRELE(p);
return (error);
}