1/*
2 * Copyright (c) 1994 SigmaSoft, Th. Lockert <tholo@sigmasoft.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
17 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
18 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
19 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * The split of ipcs.c into ipcs.c and ipc.c to accommodate the
28 * changes in ipcrm.c was done by Edwin Groothuis <edwin@FreeBSD.org>
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/10/usr.bin/ipcs/ipc.c 326818 2017-12-13 06:20:18Z delphij $");
33
34#include <sys/types.h>
35#include <sys/sysctl.h>
36#define _KERNEL
37#include <sys/sem.h>
38#include <sys/shm.h>
39#include <sys/msg.h>
40#undef _KERNEL
41
42#include <assert.h>
43#include <err.h>
44#include <kvm.h>
45#include <nlist.h>
46#include <stddef.h>
47
48#include "ipc.h"
49
50int	use_sysctl = 1;
51struct semid_kernel	*sema;
52struct seminfo		seminfo;
53struct msginfo		msginfo;
54struct msqid_kernel	*msqids;
55struct shminfo		shminfo;
56struct shmid_kernel	*shmsegs;
57void	kget(int idx, void *addr, size_t size);
58
59struct nlist symbols[] = {
60	{"sema"},
61	{"seminfo"},
62	{"msginfo"},
63	{"msqids"},
64	{"shminfo"},
65	{"shmsegs"},
66	{NULL}
67};
68
69#define	SHMINFO_XVEC	X(shmmax, sizeof(u_long))			\
70			X(shmmin, sizeof(u_long))			\
71			X(shmmni, sizeof(u_long))			\
72			X(shmseg, sizeof(u_long))			\
73			X(shmall, sizeof(u_long))
74
75#define	SEMINFO_XVEC	X(semmni, sizeof(int))				\
76			X(semmns, sizeof(int))				\
77			X(semmnu, sizeof(int))				\
78			X(semmsl, sizeof(int))				\
79			X(semopm, sizeof(int))				\
80			X(semume, sizeof(int))				\
81			X(semusz, sizeof(int))				\
82			X(semvmx, sizeof(int))				\
83			X(semaem, sizeof(int))
84
85#define	MSGINFO_XVEC	X(msgmax, sizeof(int))				\
86			X(msgmni, sizeof(int))				\
87			X(msgmnb, sizeof(int))				\
88			X(msgtql, sizeof(int))				\
89			X(msgssz, sizeof(int))				\
90			X(msgseg, sizeof(int))
91
92#define	X(a, b)	{ "kern.ipc." #a, offsetof(TYPEC, a), (b) },
93#define	TYPEC	struct shminfo
94struct scgs_vector shminfo_scgsv[] = { SHMINFO_XVEC { NULL } };
95#undef	TYPEC
96#define	TYPEC	struct seminfo
97struct scgs_vector seminfo_scgsv[] = { SEMINFO_XVEC { NULL } };
98#undef	TYPEC
99#define	TYPEC	struct msginfo
100struct scgs_vector msginfo_scgsv[] = { MSGINFO_XVEC { NULL } };
101#undef	TYPEC
102#undef	X
103
104kvm_t *kd;
105
106void
107sysctlgatherstruct(void *addr, size_t size, struct scgs_vector *vecarr)
108{
109	struct scgs_vector *xp;
110	size_t tsiz;
111	int rv;
112
113	for (xp = vecarr; xp->sysctl != NULL; xp++) {
114		assert(xp->offset <= size);
115		tsiz = xp->size;
116		rv = sysctlbyname(xp->sysctl, (char *)addr + xp->offset,
117		    &tsiz, NULL, 0);
118		if (rv == -1)
119			err(1, "sysctlbyname: %s", xp->sysctl);
120		if (tsiz != xp->size)
121			errx(1, "%s size mismatch (expected %zu, got %zu)",
122			    xp->sysctl, xp->size, tsiz);
123	}
124}
125
126void
127kget(int idx, void *addr, size_t size)
128{
129	const char *symn;		/* symbol name */
130	size_t tsiz;
131	int rv;
132	unsigned long kaddr;
133	const char *sym2sysctl[] = {	/* symbol to sysctl name table */
134		"kern.ipc.sema",
135		"kern.ipc.seminfo",
136		"kern.ipc.msginfo",
137		"kern.ipc.msqids",
138		"kern.ipc.shminfo",
139		"kern.ipc.shmsegs" };
140
141	assert((unsigned)idx <= sizeof(sym2sysctl) / sizeof(*sym2sysctl));
142	if (!use_sysctl) {
143		symn = symbols[idx].n_name;
144		if (*symn == '_')
145			symn++;
146		if (symbols[idx].n_type == 0 || symbols[idx].n_value == 0)
147			errx(1, "symbol %s undefined", symn);
148		/*
149		 * For some symbols, the value we retrieve is
150		 * actually a pointer; since we want the actual value,
151		 * we have to manually dereference it.
152		 */
153		switch (idx) {
154		case X_MSQIDS:
155			tsiz = sizeof(msqids);
156			rv = kvm_read(kd, symbols[idx].n_value,
157			    &msqids, tsiz);
158			kaddr = (u_long)msqids;
159			break;
160		case X_SHMSEGS:
161			tsiz = sizeof(shmsegs);
162			rv = kvm_read(kd, symbols[idx].n_value,
163			    &shmsegs, tsiz);
164			kaddr = (u_long)shmsegs;
165			break;
166		case X_SEMA:
167			tsiz = sizeof(sema);
168			rv = kvm_read(kd, symbols[idx].n_value,
169			    &sema, tsiz);
170			kaddr = (u_long)sema;
171			break;
172		default:
173			rv = tsiz = 0;
174			kaddr = symbols[idx].n_value;
175			break;
176		}
177		if ((unsigned)rv != tsiz)
178			errx(1, "%s: %s", symn, kvm_geterr(kd));
179		if ((unsigned)kvm_read(kd, kaddr, addr, size) != size)
180			errx(1, "%s: %s", symn, kvm_geterr(kd));
181	} else {
182		switch (idx) {
183		case X_SHMINFO:
184			sysctlgatherstruct(addr, size, shminfo_scgsv);
185			break;
186		case X_SEMINFO:
187			sysctlgatherstruct(addr, size, seminfo_scgsv);
188			break;
189		case X_MSGINFO:
190			sysctlgatherstruct(addr, size, msginfo_scgsv);
191			break;
192		default:
193			tsiz = size;
194			rv = sysctlbyname(sym2sysctl[idx], addr, &tsiz,
195			    NULL, 0);
196			if (rv == -1)
197				err(1, "sysctlbyname: %s", sym2sysctl[idx]);
198			if (tsiz != size)
199				errx(1, "%s size mismatch "
200				    "(expected %zu, got %zu)",
201				    sym2sysctl[idx], size, tsiz);
202			break;
203		}
204	}
205}
206