xref: /freebsd/cddl/usr.sbin/dwatch/libexec/vop_symlink (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)

# -*- tab-width: 4 -*- ;; Emacs
# vi: set filetype=sh tabstop=8 shiftwidth=8 noexpandtab :: Vi/ViM
############################################################ IDENT(1)
#
# $Title: dwatch(8) module for VOP_SYMLINK(9) [or similar] entry $
# $Copyright: 2014-2018 Devin Teske. All rights reserved. $
#
############################################################ DESCRIPTION
#
# Print symlink paths being created by VOP_SYMLINK(9) [or similar]
# NB: All paths are shown even if error prevents their creation.
#
############################################################ PROBE

: ${PROBE:=vfs:vop:$PROFILE:entry}

############################################################ ACTIONS

exec 9<<EOF
$PROBE /* probe ID $ID */
{${TRACE:+
	printf("<$ID>");}
	this->vp = (struct vnode *)arg0;
	this->ncp = this->vp != NULL ?
		this->vp->v_cache_dst.tqh_first : 0;
	this->target = args[1] ? args[1]->a_target : "";
	this->fi_name = args[1] ? (
		args[1]->a_cnp != NULL ?
			stringof(args[1]->a_cnp->cn_nameptr) : ""
	) : "";
	this->mount = this->vp != NULL ?
		this->vp->v_mount : NULL; /* ptr to vfs we are in */
	this->fi_fs = this->mount != NULL ?
		stringof(this->mount->mnt_stat.f_fstypename) : "";
	this->fi_mount = this->mount != NULL ?
		stringof(this->mount->mnt_stat.f_mntonname) : "";
	this->d_name = args[0]->v_cache_dd != NULL ?
		stringof(args[0]->v_cache_dd->nc_name) : "";

	$( awk -v MAX_DEPTH=$MAX_DEPTH '
		{ sub(/^\\\t/, "\t") }
		{ buf = buf "\t" $0 "\n" }
		END {
			sub(/\n$/, "", buf)
			$0 = buf
			sub(/^[[:space:]]*/, "")
			for (DEPTH = 1; DEPTH <= MAX_DEPTH + 1; DEPTH++) {
				gsub(/DEPTH/, DEPTH)
				print
				$0 = buf
			}
		}
	' <<-EOFDEPTH
	this->nameDEPTH = "";
	EOFDEPTH
	)
}

$PROBE /this->vp == 0 || this->fi_fs == 0 ||
	this->fi_fs == "devfs" || this->fi_fs == "" ||
	this->fi_name == ""/ /* probe ID $(( $ID + 1 )) */
{${TRACE:+
	printf("<$(( $ID + 1 ))>");}
	this->ncp = 0;
}

/*********************************************************/

$PROBE /this->ncp/ /* probe ID $(( $ID + 2 )) (depth 1) */
{${TRACE:+
	printf("<$(( $ID + 2 ))>");}
	this->dvp = this->ncp->nc_dvp != NULL ?
		this->ncp->nc_dvp->v_cache_dst.tqh_first : 0;
	this->name1 = this->dvp != 0 ? (
		this->dvp->nc_name != 0 ? stringof(this->dvp->nc_name) : ""
	) : "";
}

$PROBE /this->name1 == 0 || this->fi_fs == 0 ||
	this->fi_fs == "devfs" || this->fi_fs == "" ||
	this->name1 == "/" || this->name1 == ""/ /* probe ID $(( $ID + 3 )) */
{${TRACE:+
	printf("<$(( $ID + 3 ))>");}
	this->dvp = 0;
}

/*********************************************************/

/*
 * BEGIN Pathname-depth iterators
 */

$( awk -v ID=$(( $ID + 4 )) -v MAX_DEPTH=$MAX_DEPTH '
	{ buf = buf $0 "\n" }
	END {
		sub(/\n$/, "", buf)
		for (DEPTH = 2; DEPTH <= MAX_DEPTH; DEPTH++) {
			$0 = buf
			gsub(/DEPTH/, DEPTH)
			gsub(/IDNUM/, ID++)
			print
		}
	}
' <<EOFDEPTH
$PROBE /this->dvp/ /* probe ID IDNUM (depth DEPTH) */
{${TRACE:+
	printf("<IDNUM>");}
	this->dvp = this->dvp->nc_dvp != NULL ?
		this->dvp->nc_dvp->v_cache_dst.tqh_first : 0;
	this->nameDEPTH = this->dvp != 0 ? (
		this->dvp->nc_name != 0 ? stringof(this->dvp->nc_name) : ""
	) : "";
}

EOFDEPTH
)

$PROBE /this->dvp/ /* probe ID $(( $ID + $MAX_DEPTH + 3 )) */
{${TRACE:+
	printf("<$(( $ID + $MAX_DEPTH + 3 ))>");}
	this->dvp = this->dvp->nc_dvp != NULL ?
		this->dvp->nc_dvp->v_cache_dst.tqh_first : 0;
	this->name$(( $MAX_DEPTH + 1 )) = this->dvp != 0 ? (
		this->dvp->nc_dvp != NULL ? "..." : ""
	) : "";
}

/*
 * END Pathname-depth iterators
 */

/*********************************************************/

$PROBE /this->fi_mount != 0/ /* probe ID $(( $ID + $MAX_DEPTH + 4 )) */
{${TRACE:+
	printf("<$(( $ID + $MAX_DEPTH + 4 ))>");
}
	/*
	 * Join full path
	 * NB: Up-to but not including the parent directory (joined below)
	 */
	this->path = this->fi_mount;
	this->path = strjoin(this->path, this->fi_mount != 0 ? (
		this->fi_mount == "/" ? "" : "/"
	) : "/");
	$( awk -v MAX_DEPTH=$MAX_DEPTH '
		{ sub(/^\\\t/, "\t") }
		{ buf = buf "\t" $0 "\n" }
		END {
			sub(/\n$/, "", buf)
			$0 = buf
			sub(/^[[:space:]]*/, "")
			for (N = MAX_DEPTH + 1; N > 0; N--) {
				gsub(/N/, N)
				print
				$0 = buf
			}
		}
	' <<-EOFDEPTH
	this->path = strjoin(this->path,
	\	strjoin(this->nameN, this->nameN != "" ? "/" : ""));
	EOFDEPTH
	)

	/* Join the parent directory name */
	this->path = strjoin(this->path, strjoin(this->name =
		(this->d_name != 0 ? this->d_name : ""),
		this->name != "" ? "/" : ""));

	/* Join the entry name */
	this->path = strjoin(this->path,
		this->name = (this->fi_name != 0 ? this->fi_name : ""));
}
EOF
ACTIONS=$( cat <&9 )
ID=$(( $ID + $MAX_DEPTH + 5 ))

############################################################ EVENT ACTION

EVENT_TEST="this->fi_mount != 0"

############################################################ EVENT DETAILS

if [ ! "$CUSTOM_DETAILS" ]; then
exec 9<<EOF
	/*
	 * Print full path and target
	 */
	printf("%s -> %s", this->path, this->target);
EOF
EVENT_DETAILS=$( cat <&9 )
fi

################################################################################
# END
################################################################################