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-rw-r--r--sys/contrib/lomac/kernel_util.c687
1 files changed, 687 insertions, 0 deletions
diff --git a/sys/contrib/lomac/kernel_util.c b/sys/contrib/lomac/kernel_util.c
new file mode 100644
index 0000000..3a46070
--- /dev/null
+++ b/sys/contrib/lomac/kernel_util.c
@@ -0,0 +1,687 @@
+/*-
+ * Copyright (c) 2001 Networks Associates Technology, Inc.
+ * All rights reserved.
+ * Copyright (c) 1982, 1986, 1989, 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $Id: kernel_util.c,v 1.22 2001/11/15 20:51:13 bfeldman Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/signalvar.h>
+#include <sys/sx.h>
+#include <sys/syscall.h>
+#include <sys/sysent.h>
+#include <sys/sysproto.h>
+#include <sys/systm.h>
+#include <sys/linker.h>
+#include <sys/mount.h>
+#include <sys/mman.h>
+#include <sys/dirent.h>
+#include <sys/namei.h>
+#include <sys/uio.h>
+#include <sys/unistd.h>
+
+#include <vm/vm.h>
+#include <vm/vm_extern.h>
+#include <vm/vm_kern.h>
+
+#include "kernel_interface.h"
+#include "kernel_util.h"
+#include "kernel_mediate.h"
+#include "kernel_monitor.h"
+#include "lomacfs.h"
+
+#include "syscall_gate/syscall_gate.h"
+
+#define AS(name) (sizeof(struct name) / sizeof(register_t))
+
+int
+each_proc(int (*iter)(struct proc *p)) {
+ struct proc *p;
+ int error = 0;
+
+ sx_slock(&allproc_lock);
+ LIST_FOREACH(p, &allproc, p_list) {
+ error = (*iter)(p);
+ if (error)
+ goto out;
+ }
+out:
+ sx_sunlock(&allproc_lock);
+ return (error);
+}
+
+static int
+initialize_proc(struct proc *p) {
+ lattr_t lattr = { LOMAC_HIGHEST_LEVEL, 0 };
+
+ init_subject_lattr(p, &lattr);
+ return (0);
+}
+
+static void
+lomac_at_fork(struct proc *parent, struct proc *p, int flags) {
+
+ if ((flags & RFMEM) == 0) {
+ lattr_t parent_lattr;
+
+ get_subject_lattr(parent, &parent_lattr);
+ init_subject_lattr(p, &parent_lattr);
+ }
+}
+
+static int
+lomac_proc_candebug(struct proc *p1, struct proc *p2) {
+ lattr_t lattr;
+
+ get_subject_lattr(p1, &lattr);
+ if (mediate_subject_level_subject("debug", p1, lattr.level, p2))
+ return (0);
+ else
+ return (EPERM);
+}
+
+static int
+lomac_proc_cansched(struct proc *p1, struct proc *p2) {
+ lattr_t lattr;
+
+ get_subject_lattr(p1, &lattr);
+ if (mediate_subject_level_subject("sched", p1, lattr.level, p2))
+ return (0);
+ else
+ return (EPERM);
+}
+
+static int
+lomac_proc_cansignal(struct proc *p1, struct proc *p2, int signum) {
+ lattr_t lattr;
+
+ get_subject_lattr(p1, &lattr);
+ /*
+ * Always allow signals to init(8) (necessary to shut down).
+ */
+ if (p2->p_pid == 1 ||
+ mediate_subject_level_subject("signal", p1, lattr.level, p2))
+ return (0);
+ else
+ return (EPERM);
+}
+
+
+int
+lomac_initialize_procs(void) {
+ int error;
+
+#ifdef P_CAN_HOOKS
+ can_hooks_lock();
+ (void)p_candebug_hook(lomac_proc_candebug);
+ (void)p_cansignal_hook(lomac_proc_cansignal);
+ (void)p_cansched_hook(lomac_proc_cansched);
+ can_hooks_unlock();
+#endif
+ error = at_fork(lomac_at_fork);
+ if (error)
+ return (error);
+ return (each_proc(&initialize_proc));
+}
+
+int
+lomac_uninitialize_procs(void) {
+
+ rm_at_fork(lomac_at_fork);
+ return (0);
+}
+
+extern int (*old_execve)(struct thread *, struct execve_args *);
+
+int
+execve(struct thread *td, struct execve_args *uap) {
+ lattr_t lattr, textattr;
+ struct vmspace *oldvmspace;
+ struct proc *p;
+ int error;
+
+ p = td->td_proc;
+ get_subject_lattr(p, &lattr);
+ oldvmspace = p->p_vmspace;
+ error = old_execve(td, uap);
+ if (error == 0) {
+ lomac_object_t lobj;
+
+ lobj.lo_type = VISLOMAC(p->p_textvp) ? LO_TYPE_LVNODE :
+ LO_TYPE_UVNODE;
+ lobj.lo_object.vnode = p->p_textvp;
+ get_object_lattr(&lobj, &textattr);
+ /*
+ * Install the executable's relevant attributes into the
+ * process.
+ */
+ lattr.flags |= textattr.flags &
+ (LOMAC_ATTR_NODEMOTE | LOMAC_ATTR_NONETDEMOTE);
+ if (p->p_vmspace != oldvmspace)
+ init_subject_lattr(p, &lattr);
+ else
+ set_subject_lattr(p, lattr);
+ mtx_lock(&Giant);
+ (void)monitor_read_object(p, &lobj);
+ mtx_unlock(&Giant);
+ }
+ return (error);
+}
+
+const char *linker_basename(const char* path);
+int linker_load_module(const char *kldname, const char *modname,
+ struct linker_file *parent, struct mod_depend *verinfo,
+ struct linker_file **lfpp);
+
+MALLOC_DECLARE(M_LINKER);
+
+/*
+ * MPSAFE
+ */
+int
+kldload(struct thread* td, struct kldload_args* uap)
+{
+ char *kldname, *modname;
+ char *pathname = NULL;
+ linker_file_t lf;
+ int error = 0;
+
+ td->td_retval[0] = -1;
+
+ if (securelevel > 0) /* redundant, but that's OK */
+ return EPERM;
+
+ mtx_lock(&Giant);
+
+ if ((error = suser_td(td)) != 0)
+ goto out;
+
+ pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
+ if ((error = copyinstr(SCARG(uap, file), pathname, MAXPATHLEN, NULL)) != 0)
+ goto out;
+ if (!mediate_subject_at_level("kldload", td->td_proc,
+ LOMAC_HIGHEST_LEVEL)) {
+ error = EPERM;
+ goto out;
+ }
+
+ /*
+ * If path do not contain qualified name or any dot in it (kldname.ko, or
+ * kldname.ver.ko) treat it as interface name.
+ */
+ if (index(pathname, '/') || index(pathname, '.')) {
+ kldname = pathname;
+ modname = NULL;
+ } else {
+ kldname = NULL;
+ modname = pathname;
+ }
+ error = linker_load_module(kldname, modname, NULL, NULL, &lf);
+ if (error)
+ goto out;
+
+ lf->userrefs++;
+ td->td_retval[0] = lf->id;
+
+out:
+ if (pathname)
+ free(pathname, M_TEMP);
+ mtx_unlock(&Giant);
+ return (error);
+}
+
+
+#ifdef __i386__
+#include <machine/sysarch.h>
+
+extern int (*old_sysarch)(struct thread *, void *);
+
+int
+sysarch(struct thread *td, struct sysarch_args *uap) {
+ switch (uap->op) {
+ case I386_SET_IOPERM:
+ if (!mediate_subject_at_level("ioperm", td->td_proc,
+ LOMAC_HIGHEST_LEVEL))
+ return (EPERM);
+ default:
+ return (old_sysarch(td, uap));
+ }
+}
+#endif
+
+extern int lomac_mmap(struct proc *, struct mmap_args *);
+
+/*
+ * Mount a file system.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct mount_args {
+ char *type;
+ char *path;
+ int flags;
+ caddr_t data;
+};
+#endif
+/* ARGSUSED */
+int
+mount(td, uap)
+ struct thread *td;
+ struct mount_args /* {
+ syscallarg(char *) type;
+ syscallarg(char *) path;
+ syscallarg(int) flags;
+ syscallarg(caddr_t) data;
+ } */ *uap;
+{
+ char *fstype;
+ char *fspath;
+ int error;
+
+ fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK | M_ZERO);
+ fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK | M_ZERO);
+
+ /*
+ * vfs_mount() actually takes a kernel string for `type' and
+ * `path' now, so extract them.
+ */
+ error = copyinstr(SCARG(uap, type), fstype, MFSNAMELEN, NULL);
+ if (error)
+ goto finish;
+ error = copyinstr(SCARG(uap, path), fspath, MNAMELEN, NULL);
+ if (error)
+ goto finish;
+ if (!mediate_subject_at_level("mount", td->td_proc,
+ LOMAC_HIGHEST_LEVEL)) {
+ error = EPERM;
+ goto finish;
+ }
+ error = vfs_mount(td, fstype, fspath, SCARG(uap, flags),
+ SCARG(uap, data));
+finish:
+ free(fstype, M_TEMP);
+ free(fspath, M_TEMP);
+ return (error);
+}
+
+/*
+ * Unmount a file system.
+ *
+ * Note: unmount takes a path to the vnode mounted on as argument,
+ * not special file (as before).
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct unmount_args {
+ char *path;
+ int flags;
+};
+#endif
+/* ARGSUSED */
+int
+unmount(td, uap)
+ struct thread *td;
+ register struct unmount_args /* {
+ syscallarg(char *) path;
+ syscallarg(int) flags;
+ } */ *uap;
+{
+ register struct vnode *vp;
+ struct mount *mp;
+ int error;
+ struct nameidata nd;
+
+ NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
+ SCARG(uap, path), td);
+ if ((error = namei(&nd)) != 0)
+ return (error);
+ vp = nd.ni_vp;
+ NDFREE(&nd, NDF_ONLY_PNBUF);
+ mp = vp->v_mount;
+
+ /*
+ * Only root, or the user that did the original mount is
+ * permitted to unmount this filesystem.
+ */
+ if (!mediate_subject_at_level("unmount", td->td_proc,
+ LOMAC_HIGHEST_LEVEL) ||
+ ((mp->mnt_stat.f_owner != td->td_proc->p_ucred->cr_uid) &&
+ (error = suser_td(td)))) {
+ vput(vp);
+ return (error);
+ }
+
+ /*
+ * Don't allow unmounting the root file system.
+ */
+ if (mp->mnt_flag & MNT_ROOTFS) {
+ vput(vp);
+ return (EINVAL);
+ }
+
+ /*
+ * Must be the root of the filesystem
+ */
+ if ((vp->v_flag & VROOT) == 0) {
+ vput(vp);
+ return (EINVAL);
+ }
+ vput(vp);
+ return (dounmount(mp, SCARG(uap, flags), td));
+}
+
+static struct syscall_override {
+ int offset;
+ sy_call_t *call;
+ int narg;
+ int mpsafe;
+} syscall_overrides[] = {
+ { SYS_mmap, (sy_call_t *)mmap, AS(mmap_args), 1 },
+ { SYS_execve, (sy_call_t *)execve, AS(execve_args), 1 },
+ { SYS_kldload, (sy_call_t *)kldload, AS(kldload_args), 1 },
+ { SYS_mount, (sy_call_t *)mount, AS(mount_args), 0 },
+ { SYS_unmount, (sy_call_t *)unmount, AS(unmount_args), 0 },
+#ifdef __i386__
+ { SYS_sysarch, (sy_call_t *)sysarch, AS(sysarch_args), 1 }
+#endif
+};
+
+int
+lomac_initialize_syscalls(void) {
+ int error, i;
+
+ for (i = 0;
+ i < sizeof(syscall_overrides) / sizeof(syscall_overrides[0]); i++) {
+ struct syscall_override *so = &syscall_overrides[i];
+
+ error = syscall_gate_register(so->offset, so->call, so->narg,
+ so->mpsafe);
+ if (error) {
+ while (--i >= 0)
+ syscall_gate_deregister(
+ syscall_overrides[i].offset);
+ return (error);
+ }
+ }
+ return (0);
+}
+
+int
+lomac_uninitialize_syscalls(void) {
+ int i;
+
+ for (i = 0;
+ i < sizeof(syscall_overrides) / sizeof(syscall_overrides[0]); i++)
+ syscall_gate_deregister(syscall_overrides[i].offset);
+ return (0);
+}
+
+/* This memory is shared by all lomac_do_recwd() calls, in sequence. */
+static char *pathmem;
+#define DIRENTMEM_SIZE (64 << 10) /* 64KB is good, I guess! */
+static char *direntmem;
+
+static int
+lomac_dirents_searchbyid(struct vnode *dvp, struct dirent *dp,
+ struct dirent *enddp, const struct vattr *vap, struct dirent **retdp)
+{
+ struct vattr pvattr;
+ struct componentname cnp;
+ struct thread *td = curthread;
+ struct ucred *ucred = td->td_ucred;
+ struct vnode *vp;
+ int error;
+
+ *retdp = NULL;
+ for (; dp != enddp; dp = (struct dirent *)((char *)dp + dp->d_reclen)) {
+ cnp.cn_nameiop = LOOKUP;
+ cnp.cn_flags = LOCKPARENT | ISLASTCN | NOFOLLOW;
+ cnp.cn_thread = td;
+ cnp.cn_cred = ucred;
+ cnp.cn_nameptr = dp->d_name;
+ cnp.cn_namelen = dp->d_namlen;
+
+ error = VOP_LOOKUP(dvp, &vp, &cnp);
+ if (error)
+ return (error);
+ error = VOP_GETATTR(vp, &pvattr, ucred, td);
+ if (vp != dvp)
+ (void)vput(vp);
+ else
+ vrele(vp); /* if looking up "." */
+ if (error)
+ return (error);
+ if (pvattr.va_fsid == vap->va_fsid &&
+ pvattr.va_fileid == vap->va_fileid) {
+ *retdp = dp;
+ break;
+ }
+ }
+ return (0);
+}
+
+static int
+lomac_getcwd(
+ struct thread *td,
+ char *buf,
+ size_t buflen,
+ char **bufret
+) {
+ struct vattr cvattr;
+ char *bp;
+ int error, i, slash_prefixed;
+ struct filedesc *fdp;
+ struct vnode *vp, *startvp, *dvp;
+
+ if (buflen < 2)
+ return (EINVAL);
+ if (buflen > MAXPATHLEN)
+ buflen = MAXPATHLEN;
+ bp = buf;
+ bp += buflen - 1;
+ *bp = '\0';
+ fdp = td->td_proc->p_fd;
+ slash_prefixed = 0;
+#if defined(LOMAC_DEBUG_RECWD)
+ printf("lomac_getcwd for %d:\n", td->td_proc->p_pid);
+#endif
+ startvp = fdp->fd_cdir;
+ vref(startvp);
+ for (vp = startvp; vp != rootvnode; vp = dvp) {
+ struct iovec diov = {
+ direntmem,
+ DIRENTMEM_SIZE
+ };
+ struct uio duio = {
+ &diov,
+ 1,
+ 0,
+ DIRENTMEM_SIZE,
+ UIO_SYSSPACE,
+ UIO_READ,
+ curthread
+ };
+ struct dirent *dp;
+ int direof;
+
+ if (vp->v_flag & VROOT) {
+ if (vp->v_mount == NULL) /* forced unmount */
+ return (EBADF);
+ dvp = vp->v_mount->mnt_vnodecovered;
+ continue;
+ }
+ dvp = vp->v_dd;
+ if (vp == dvp)
+ break;
+ /*
+ * Utilize POSIX requirement of files having same
+ * st_dev and st_ino to be the same file, in our
+ * case with vattr.va_fsid and vattr.va_fileid.
+ */
+ error = vget(vp, LK_EXCLUSIVE, curthread);
+ if (error)
+ goto out2;
+ error = VOP_GETATTR(vp, &cvattr, curthread->td_ucred,
+ curthread);
+ if (error)
+ goto out2;
+ (void)vput(vp);
+ error = vget(dvp, LK_EXCLUSIVE, curthread);
+ if (error)
+ goto out2;
+ for (direof = 0; !direof;) {
+ error = VOP_READDIR(dvp, &duio,
+ curthread->td_ucred, &direof, NULL, NULL);
+ if (error)
+ break;
+ error = lomac_dirents_searchbyid(dvp,
+ (struct dirent *)direntmem,
+ (struct dirent *)(direntmem +
+ DIRENTMEM_SIZE - duio.uio_resid),
+ &cvattr,
+ &dp);
+ if (error)
+ break;
+ if (dp != NULL) {
+ (void)vput(dvp);
+#if defined(LOMAC_DEBUG_RECWD)
+ printf("\tdirent component: \"%.*s\"\n",
+ dp->d_namlen, dp->d_name);
+#endif
+ for (i = dp->d_namlen - 1; i >= 0; i--)
+ if (bp == buf)
+ return (ENOMEM);
+ else
+ *--bp = dp->d_name[i];
+ goto nextcomp;
+ }
+ diov.iov_base = direntmem;
+ diov.iov_len = DIRENTMEM_SIZE;
+ duio.uio_resid = DIRENTMEM_SIZE;
+ }
+ if (direof)
+ error = ENOENT;
+ (void)vput(dvp);
+ out2:
+#if defined(LOMAC_DEBUG_RECWD)
+ printf("backup dirent lookup problem: %d\n", error);
+#endif
+ goto out;
+ nextcomp:
+ if (bp == buf)
+ return (ENOMEM);
+ *--bp = '/';
+ slash_prefixed = 1;
+ }
+ if (!slash_prefixed) {
+ if (bp == buf)
+ return (ENOMEM);
+ *--bp = '/';
+ }
+ error = 0;
+ *bufret = bp;
+out:
+ vrele(startvp);
+ return (error);
+}
+
+static int
+lomac_do_recwd(struct proc *p) {
+ struct nameidata nd;
+ struct filedesc *fdp = curthread->td_proc->p_fd;
+ struct thread *td = &p->p_thread;
+ char *nbuf;
+ struct vnode *cdir, *rdir, *vp;
+ int error;
+
+ if (p == curthread->td_proc)
+ return (0);
+ PROC_LOCK(p);
+ if (p->p_flag & P_SYSTEM) {
+ PROC_UNLOCK(p);
+ return (0);
+ }
+ PROC_UNLOCK(p);
+ error = lomac_getcwd(td, pathmem, MAXPATHLEN, &nbuf);
+ if (error) {
+#if defined(LOMAC_DEBUG_RECWD)
+ printf("lomac: recwd() failure, lomac_getcwd() == %d\n",
+ error);
+#endif
+ return (0);
+ }
+ rdir = fdp->fd_rdir;
+ fdp->fd_rdir = rootvnode;
+ vref(fdp->fd_rdir);
+ NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
+ nbuf, curthread);
+ error = namei(&nd);
+ vrele(fdp->fd_rdir);
+ fdp->fd_rdir = rdir;
+ if (error == 0) {
+ vp = nd.ni_vp;
+ if (vp->v_type != VDIR)
+ error = ENOTDIR;
+ else
+ error = VOP_ACCESS(vp, VEXEC, td->td_proc->p_ucred,
+ curthread);
+ if (error)
+ vput(vp);
+ else {
+ NDFREE(&nd, NDF_ONLY_PNBUF);
+ fdp = p->p_fd;
+ cdir = fdp->fd_cdir;
+ fdp->fd_cdir = vp;
+ vrele(cdir);
+ VOP_UNLOCK(vp, 0, curthread);
+ }
+ }
+#if defined(LOMAC_DEBUG_RECWD)
+ printf("\trecwd() to \"%.*s\" == %d\n",
+ MAXPATHLEN, nbuf, error);
+#endif
+ return (0);
+}
+
+int
+lomac_initialize_cwds(void) {
+ int error;
+
+ pathmem = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
+ direntmem = malloc(DIRENTMEM_SIZE, M_TEMP, M_WAITOK);
+ mtx_lock(&Giant);
+ error = each_proc(lomac_do_recwd);
+ mtx_unlock(&Giant);
+ free(pathmem, M_TEMP);
+ free(direntmem, M_TEMP);
+ return (error);
+}
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