ipc.c revision 208986 
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 accomodate the
28 * changes in ipcrm.c was done by Edwin Groothuis <edwin@FreeBSD.org>
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/usr.bin/ipcs/ipc.c 208986 2010-06-10 14:19:51Z bz $");
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#include <stdio.h>
48
49#include "ipc.h"
50
51int	use_sysctl = 1;
52struct semid_kernel	*sema;
53struct seminfo		seminfo;
54struct msginfo		msginfo;
55struct msqid_kernel	*msqids;
56struct shminfo		shminfo;
57struct shmid_kernel	*shmsegs;
58void	kget(int idx, void *addr, size_t size);
59
60struct nlist symbols[] = {
61	{"sema"},
62	{"seminfo"},
63	{"msginfo"},
64	{"msqids"},
65	{"shminfo"},
66	{"shmsegs"},
67	{NULL}
68};
69
70#define	SHMINFO_XVEC	X(shmmax, sizeof(u_long))			\
71			X(shmmin, sizeof(u_long))			\
72			X(shmmni, sizeof(u_long))			\
73			X(shmseg, sizeof(u_long))			\
74			X(shmall, sizeof(u_long))
75
76#define	SEMINFO_XVEC	X(semmap, sizeof(int))				\
77			X(semmni, sizeof(int))				\
78			X(semmns, sizeof(int))				\
79			X(semmnu, sizeof(int))				\
80			X(semmsl, sizeof(int))				\
81			X(semopm, sizeof(int))				\
82			X(semume, sizeof(int))				\
83			X(semusz, sizeof(int))				\
84			X(semvmx, sizeof(int))				\
85			X(semaem, sizeof(int))
86
87#define	MSGINFO_XVEC	X(msgmax, sizeof(int))				\
88			X(msgmni, sizeof(int))				\
89			X(msgmnb, sizeof(int))				\
90			X(msgtql, sizeof(int))				\
91			X(msgssz, sizeof(int))				\
92			X(msgseg, sizeof(int))
93
94#define	X(a, b)	{ "kern.ipc." #a, offsetof(TYPEC, a), (b) },
95#define	TYPEC	struct shminfo
96struct scgs_vector shminfo_scgsv[] = { SHMINFO_XVEC { NULL } };
97#undef	TYPEC
98#define	TYPEC	struct seminfo
99struct scgs_vector seminfo_scgsv[] = { SEMINFO_XVEC { NULL } };
100#undef	TYPEC
101#define	TYPEC	struct msginfo
102struct scgs_vector msginfo_scgsv[] = { MSGINFO_XVEC { NULL } };
103#undef	TYPEC
104#undef	X
105
106kvm_t *kd;
107
108void
109sysctlgatherstruct(void *addr, size_t size, struct scgs_vector *vecarr)
110{
111	struct scgs_vector *xp;
112	size_t tsiz;
113	int rv;
114
115	for (xp = vecarr; xp->sysctl != NULL; xp++) {
116		assert(xp->offset <= size);
117		tsiz = xp->size;
118		rv = sysctlbyname(xp->sysctl, (char *)addr + xp->offset,
119		    &tsiz, NULL, 0);
120		if (rv == -1)
121			err(1, "sysctlbyname: %s", xp->sysctl);
122		if (tsiz != xp->size)
123			errx(1, "%s size mismatch (expected %d, got %d)",
124			    xp->sysctl, xp->size, tsiz);
125	}
126}
127
128void
129kget(int idx, void *addr, size_t size)
130{
131	const char *symn;		/* symbol name */
132	size_t tsiz;
133	int rv;
134	unsigned long kaddr;
135	const char *sym2sysctl[] = {	/* symbol to sysctl name table */
136		"kern.ipc.sema",
137		"kern.ipc.seminfo",
138		"kern.ipc.msginfo",
139		"kern.ipc.msqids",
140		"kern.ipc.shminfo",
141		"kern.ipc.shmsegs" };
142
143	assert((unsigned)idx <= sizeof(sym2sysctl) / sizeof(*sym2sysctl));
144	if (!use_sysctl) {
145		symn = symbols[idx].n_name;
146		if (*symn == '_')
147			symn++;
148		if (symbols[idx].n_type == 0 || symbols[idx].n_value == 0)
149			errx(1, "symbol %s undefined", symn);
150		/*
151		 * For some symbols, the value we retrieve is
152		 * actually a pointer; since we want the actual value,
153		 * we have to manually dereference it.
154		 */
155		switch (idx) {
156		case X_MSQIDS:
157			tsiz = sizeof(msqids);
158			rv = kvm_read(kd, symbols[idx].n_value,
159			    &msqids, tsiz);
160			kaddr = (u_long)msqids;
161			break;
162		case X_SHMSEGS:
163			tsiz = sizeof(shmsegs);
164			rv = kvm_read(kd, symbols[idx].n_value,
165			    &shmsegs, tsiz);
166			kaddr = (u_long)shmsegs;
167			break;
168		case X_SEMA:
169			tsiz = sizeof(sema);
170			rv = kvm_read(kd, symbols[idx].n_value,
171			    &sema, tsiz);
172			kaddr = (u_long)sema;
173			break;
174		default:
175			rv = tsiz = 0;
176			kaddr = symbols[idx].n_value;
177			break;
178		}
179		if ((unsigned)rv != tsiz)
180			errx(1, "%s: %s", symn, kvm_geterr(kd));
181		if ((unsigned)kvm_read(kd, kaddr, addr, size) != size)
182			errx(1, "%s: %s", symn, kvm_geterr(kd));
183	} else {
184		switch (idx) {
185		case X_SHMINFO:
186			sysctlgatherstruct(addr, size, shminfo_scgsv);
187			break;
188		case X_SEMINFO:
189			sysctlgatherstruct(addr, size, seminfo_scgsv);
190			break;
191		case X_MSGINFO:
192			sysctlgatherstruct(addr, size, msginfo_scgsv);
193			break;
194		default:
195			tsiz = size;
196			rv = sysctlbyname(sym2sysctl[idx], addr, &tsiz,
197			    NULL, 0);
198			if (rv == -1)
199				err(1, "sysctlbyname: %s", sym2sysctl[idx]);
200			if (tsiz != size)
201				errx(1, "%s size mismatch "
202				    "(expected %d, got %d)",
203				    sym2sysctl[idx], size, tsiz);
204			break;
205		}
206	}
207}
208