xref: /netbsd-src/sys/miscfs/procfs/procfs_limit.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: procfs_limit.c,v 1.4 2020/05/23 23:42:43 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2019 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
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 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: procfs_limit.c,v 1.4 2020/05/23 23:42:43 ad Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/proc.h>
38 #include <sys/malloc.h>
39 #include <sys/resource.h>
40 #include <miscfs/procfs/procfs.h>
41 
42 #define MAXBUFFERSIZE (256 * 1024)
43 
44 static size_t
45 prl(char *buf, size_t len, intmax_t lim, char sep)
46 {
47 	if (lim == RLIM_INFINITY)
48 		return snprintf(buf, len, "%#20jx%c", lim, sep);
49 	else
50 		return snprintf(buf, len, "%20jd%c", lim, sep);
51 }
52 
53 int
54 procfs_dolimit(struct lwp *curl, struct proc *p, struct pfsnode *pfs,
55      struct uio *uio)
56 {
57 	static const char *label[] = RLIM_STRINGS;
58 	int error;
59 	char *buffer;
60 	size_t bufsize, pos, i;
61 	struct rlimit rl[RLIM_NLIMITS];
62 
63 	if (uio->uio_rw != UIO_READ)
64 		return EOPNOTSUPP;
65 
66 	mutex_enter(&proc_lock);
67 	mutex_enter(p->p_lock);
68 	memcpy(rl, p->p_rlimit, sizeof(rl));
69 	mutex_exit(p->p_lock);
70 	mutex_exit(&proc_lock);
71 
72 	error = 0;
73 
74 	bufsize = (64 * 3) * __arraycount(rl);
75 	buffer = malloc(bufsize, M_TEMP, M_WAITOK);
76 	pos = 0;
77 	for (i = 0; i < __arraycount(rl); i++) {
78 		pos += snprintf(buffer + pos, bufsize - pos, "%20.20s ",
79 		    label[i]);
80 		pos += prl(buffer + pos, bufsize - pos, rl[i].rlim_cur, ' ');
81 		pos += prl(buffer + pos, bufsize - pos, rl[i].rlim_max, '\n');
82 	}
83 
84 	if ((uintmax_t)uio->uio_offset < pos)
85 		error = uiomove(buffer + uio->uio_offset,
86 		    pos - uio->uio_offset, uio);
87 	else
88 		error = 0;
89 
90 	if (buffer != NULL)
91 		free(buffer, M_TEMP);
92 
93 	return error;
94 }
95