xref: /netbsd-src/sys/kern/kern_ktrace_vfs.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: kern_ktrace_vfs.c,v 1.2 2014/09/05 09:20:59 matt Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1989, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)kern_ktrace.c	8.5 (Berkeley) 5/14/95
61  */
62 
63 #include <sys/cdefs.h>
64 __KERNEL_RCSID(0, "$NetBSD: kern_ktrace_vfs.c,v 1.2 2014/09/05 09:20:59 matt Exp $");
65 
66 #include <sys/param.h>
67 #include <sys/systm.h>
68 #include <sys/file.h>
69 #include <sys/filedesc.h>
70 #include <sys/namei.h>
71 #include <sys/vnode.h>
72 #include <sys/kernel.h>
73 #include <sys/ktrace.h>
74 #include <sys/kauth.h>
75 
76 #include <sys/mount.h>
77 #include <sys/syscallargs.h>
78 
79 /*
80  * ktrace system call, the part of the ktrace framework that
81  * explicitly interacts with VFS
82  */
83 /* ARGSUSED */
84 int
85 sys_ktrace(struct lwp *l, const struct sys_ktrace_args *uap, register_t *retval)
86 {
87 	/* {
88 		syscallarg(const char *) fname;
89 		syscallarg(int) ops;
90 		syscallarg(int) facs;
91 		syscallarg(int) pid;
92 	} */
93 	struct vnode *vp = NULL;
94 	file_t *fp = NULL;
95 	struct pathbuf *pb;
96 	struct nameidata nd;
97 	int error = 0;
98 	int fd;
99 
100 	if (ktrenter(l))
101 		return EAGAIN;
102 
103 	if (KTROP(SCARG(uap, ops)) != KTROP_CLEAR) {
104 		/*
105 		 * an operation which requires a file argument.
106 		 */
107 		error = pathbuf_copyin(SCARG(uap, fname), &pb);
108 		if (error) {
109 			ktrexit(l);
110 			return (error);
111 		}
112 		NDINIT(&nd, LOOKUP, FOLLOW, pb);
113 		if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0) {
114 			pathbuf_destroy(pb);
115 			ktrexit(l);
116 			return (error);
117 		}
118 		vp = nd.ni_vp;
119 		pathbuf_destroy(pb);
120 		VOP_UNLOCK(vp);
121 		if (vp->v_type != VREG) {
122 			vn_close(vp, FREAD|FWRITE, l->l_cred);
123 			ktrexit(l);
124 			return (EACCES);
125 		}
126 		/*
127 		 * This uses up a file descriptor slot in the
128 		 * tracing process for the duration of this syscall.
129 		 * This is not expected to be a problem.
130 		 */
131 		if ((error = fd_allocfile(&fp, &fd)) != 0) {
132 			vn_close(vp, FWRITE, l->l_cred);
133 			ktrexit(l);
134 			return error;
135 		}
136 		fp->f_flag = FWRITE;
137 		fp->f_type = DTYPE_VNODE;
138 		fp->f_ops = &vnops;
139 		fp->f_vnode = vp;
140 		vp = NULL;
141 	}
142 	error = ktrace_common(l, SCARG(uap, ops), SCARG(uap, facs),
143 	    SCARG(uap, pid), &fp);
144 	if (KTROP(SCARG(uap, ops)) != KTROP_CLEAR)
145 		fd_abort(curproc, fp, fd);
146 	return (error);
147 }
148