- Commit work from libprocstat project. These patches add support for runtime

  file and processes information retrieval from the running kernel via sysctl
  in the form of new library, libprocstat.  The library also supports KVM backend
  for analyzing memory crash dumps.  Both procstat(1) and fstat(1) utilities have
  been modified to take advantage of the library (as the bonus point the fstat(1)
  utility no longer need superuser privileges to operate), and the procstat(1)
  utility is now able to display information from memory dumps as well.

  The newly introduced fuser(1) utility also uses this library and able to operate
  via sysctl and kvm backends.

  The library is by no means complete (e.g. KVM backend is missing vnode name
  resolution routines, and there're no manpages for the library itself) so I
  plan to improve it further.  I'm commiting it so it will get wider exposure
  and review.

  We won't be able to MFC this work as it relies on changes in HEAD, which
  was introduced some time ago, that break kernel ABI.  OTOH we may be able
  to merge the library with KVM backend if we really need it there.

Discussed with:	rwatson

1 files changed, 207 insertions, 0 deletions

diff --git a/lib/libprocstat/common_kvm.c b/lib/libprocstat/common_kvm.c
new file mode 100644
index 0000000..1ff181c
--- /dev/null
+++ b/lib/libprocstat/common_kvm.c
@@ -0,0 +1,207 @@
+/*-
+ * Copyright (c) 2009 Stanislav Sedov <stas@FreeBSD.org>
+ * Copyright (c) 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/user.h>
+#include <sys/stat.h>
+#include <sys/vnode.h>
+#include <sys/conf.h>
+#define	_KERNEL
+#include <sys/pipe.h>
+#include <sys/mount.h>
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/inode.h>
+#include <fs/devfs/devfs.h>
+#include <fs/devfs/devfs_int.h>
+#undef _KERNEL
+#include <nfs/nfsproto.h>
+#include <nfsclient/nfs.h>
+#include <nfsclient/nfsnode.h>
+
+#include <assert.h>
+#include <err.h>
+#include <kvm.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <libprocstat.h>
+#include "common_kvm.h"
+
+int
+kvm_read_all(kvm_t *kd, unsigned long addr, void *buf, size_t nbytes)
+{
+	ssize_t error;
+
+	if (nbytes >= SSIZE_MAX)
+		return (0);
+	error = kvm_read(kd, addr, buf, nbytes);
+	return (error == (ssize_t)(nbytes));
+}
+
+int
+kdevtoname(kvm_t *kd, struct cdev *dev, char *buf)
+{
+	struct cdev si;
+
+	assert(buf);
+	if (!kvm_read_all(kd, (unsigned long)dev, &si, sizeof(si)))
+		return (1);
+	strlcpy(buf, si.__si_namebuf, SPECNAMELEN + 1);
+	return (0);
+}
+
+int
+ufs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
+{
+	struct inode inode;
+
+	if (!kvm_read_all(kd, (unsigned long)VTOI(vp), &inode, sizeof(inode))) {
+		warnx("can't read inode at %p", (void *)VTOI(vp));
+		return (1);
+	}
+	/*
+	 * The st_dev from stat(2) is a dev_t. These kernel structures
+	 * contain cdev pointers. We need to convert to dev_t to make
+	 * comparisons
+	 */
+	vn->vn_fsid = dev2udev(kd, inode.i_dev);
+	vn->vn_fileid = (long)inode.i_number;
+	vn->vn_mode = (mode_t)inode.i_mode;
+	vn->vn_size = (u_long)inode.i_size;
+	return (0);
+}
+
+int
+devfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
+{
+	struct devfs_dirent devfs_dirent;
+	struct mount mount;
+
+	if (!kvm_read_all(kd, (unsigned long)getvnodedata(vp), &devfs_dirent,
+	    sizeof(devfs_dirent))) {
+		warnx("can't read devfs_dirent at %p",
+		    (void *)vp->v_data);
+		return (1);
+	}
+	if (!kvm_read_all(kd, (unsigned long)getvnodemount(vp), &mount,
+	    sizeof(mount))) {
+		warnx("can't read mount at %p",
+		    (void *)getvnodemount(vp));
+		return (1);
+	}
+	vn->vn_fsid = mount.mnt_stat.f_fsid.val[0];
+	vn->vn_fileid = devfs_dirent.de_inode;
+	vn->vn_mode = (devfs_dirent.de_mode & ~S_IFMT) | S_IFCHR;
+	vn->vn_size = 0;
+	return (0);
+}
+
+int
+nfs_filestat(kvm_t *kd, struct vnode *vp, struct vnstat *vn)
+{
+	struct nfsnode nfsnode;
+	mode_t mode;
+
+	if (!kvm_read_all(kd, (unsigned long)VTONFS(vp), &nfsnode,
+	    sizeof(nfsnode))) {
+		warnx("can't read nfsnode at %p",
+		    (void *)VTONFS(vp));
+		return (1);
+	}
+	vn->vn_fsid = nfsnode.n_vattr.va_fsid;
+	vn->vn_fileid = nfsnode.n_vattr.va_fileid;
+	vn->vn_size = nfsnode.n_size;
+	mode = (mode_t)nfsnode.n_vattr.va_mode;
+	switch (vp->v_type) {
+	case VREG:
+		mode |= S_IFREG;
+		break;
+	case VDIR:
+		mode |= S_IFDIR;
+		break;
+	case VBLK:
+		mode |= S_IFBLK;
+		break;
+	case VCHR:
+		mode |= S_IFCHR;
+		break;
+	case VLNK:
+		mode |= S_IFLNK;
+		break;
+	case VSOCK:
+		mode |= S_IFSOCK;
+		break;
+	case VFIFO:
+		mode |= S_IFIFO;
+		break;
+	default:
+		break;
+	};
+	vn->vn_mode = mode;
+	return (0);
+}
+
+/*
+ * Read the cdev structure in the kernel in order to work out the
+ * associated dev_t
+ */
+dev_t
+dev2udev(kvm_t *kd, struct cdev *dev)
+{
+	struct cdev_priv priv;
+
+	assert(kd);
+	if (kvm_read_all(kd, (unsigned long)cdev2priv(dev), &priv,
+	    sizeof(priv))) {
+		return ((dev_t)priv.cdp_inode);
+	} else {
+		warnx("can't convert cdev *%p to a dev_t\n", dev);
+		return (-1);
+	}
+}
+
+void *
+getvnodedata(struct vnode *vp)
+{
+	return (vp->v_data);
+}
+
+struct mount *
+getvnodemount(struct vnode *vp)
+{
+	return (vp->v_mount);
+}